(b) International Conferences

339. S. F. Chichibu, K. Ohnishi, H. Watanabe, S. Nitta, Y. Honda, H. Amano, A. Uedono, S. Ishibashi, and K. Shima:

"Room-temperature photoluminescence lifetimes of Mg-doped p-type GaN layers grown by halide vapor phase epitaxy",
12th International Workshop on Nitride Semiconductors (IWN2024), Hawaii, USA, Nov.3-8 (2024), Session Characterization: Optical Properties, No.241 (oral).

338. S. F. Chichibu, K. Shima, A. Uedono, S. Ishibashi, H. Iguchi, T. Narita, K. Kataoka, R. Tanaka, S. Takashima, K. Ueno, M. Edo, H. Watanabe, A. Tanaka, Y. Honda, J. Suda, H. Amano, T. Kachi, T. Nabatame, Y. Irokawa, and Y. Koide:

"Minority carrier capture coefficients of major midgap recombination centers in the state-of-the-art GaN substrates, epilayers, and Mg-implanted layers",
12th International Workshop on Nitride Semiconductors (IWN2024), Hawaii, USA, Nov.3-8 (2024), Session Characterization: Carrier Dynamics II, No.229 (oral).

337. K. Shima, W. Lu, T. Takeuchi, S. Kamiyama, and S. F. Chichibu:

"Spatio-time-resolved cathodoluminescence study of InGaN/GaN multiquantum shells",
12th International Workshop on Nitride Semiconductors (IWN2024), Hawaii, USA, Nov.3-8 (2024), Session Characterization: InGaN, No.60 (oral).

336. S. Schimmel, D. Tomida, T. Ishiguro, Y. Honda, S. F. Chichibu, and H. Amano:

"Transition from etch-back to growth conditions during ammonothermal growth of GaN - a transient numerical model for convective flow and temperature distribution in a retrograde solubility configuration",
GaN Marathon 2024, Verona, Italy, June 10-12 (2024), (poster).

335. S. F. Chichibu, K. Hara, T. S. Cheng, C. J. Mellor, P. H. Beton, P. Valvin, B. Gil, G. Cassabois, S. V. Novikov, and K. Shima:

"Cathodoluminescence studies of hexagonal BN polytypes and monolayer BN",
European Materials Research Society, 2024 Fall Meeting, Symposium P: Boron Nitride: from advanced growth approaches to advanced applications, Warsaw University of Technology, Warsaw, Poland, Sep.16-19 (2024), No. P05 (Invited-oral).

334. K. Shima, T. S. Cheng, C. J. Mellor, P. H. Beton, C. Elias, P. Valvin, B. Gil, G. Cassabois, S. V. Novikov, and S. F. Chichibu:

"Cathodoluminescence spectroscopy of monolayer hexagonal boron nitride grown on a highly oriented pyrolytic graphite substrate",
The 7th International Workshop on UV Materials and Devices (IWUMD-VII), Taipei, Taiwan, Jun.2-5 (2024), No.TB1-3 (oral).

333. Y. Saito, A. Miyazaki, S. Boyama, K. Okuno, M. Oya, K. Kataoka, T. Narita, K. Horibuchi, M. Kushimoto, Y. Honda, H. Amano, H. Ishiguro, T. Takeuchi, K. Shima, and S. F. Chichibu:

"Developments in highly efficient and long-life AlGaN-based UVC LEDs",
The 7th International Workshop on UV Materials and Devices (IWUMD-VII), Taipei, Taiwan, Jun.2-5 (2024), No.TA2-1 (Invited-oral).

332. S. F. Chichibu, K. Kikuchi, B. Moody, S. Mita, R. Collazo, Z. Sitar, Y. Kumagai, S. Ishibashi, A. Uedono, and K. Shima:

"Roles of vacancy complexes on the luminescence spectra of Si-doped AlN layers grown by HVPE on (0001) AlN substrates prepared by PVT",
The 7th International Workshop on UV Materials and Devices (IWUMD-VII), Taipei, Taiwan, Jun.2-5 (2024), No.MA3-5 (oral).

331. Y. Saito, A. Miyazaki, S. Boyama, K. Okuno, M. Oya, K. Kataoka, T. Narita, K. Horibuchi, M. Kushimoto, Y. Honda, H. Amano, H. Ishiguro, T. Takeuchi, K. Shima, and S. F. Chichibu:

"Technology development for long life and high efficiency DUV LEDs",
The 10th International Conference on Light-Emitting Devices and Their Industrial Applications (LEDIA 2024), Yokohama, Japan, Apr.24-25 (2024), No.LEDIA1-03 (Invited-oral).

330. S. F. Chichibu, K. Okuno, M. Oya, Y. Saito, H. Ishiguro, T. Takeuchi, and K. Shima:

"Short-term degradation mechanisms of 275-nm-band AlGaN quantum well deep-ultraviolet light emitting diodes fabricated on a sapphire substrate",
The 10th International Conference on Light-Emitting Devices and Their Industrial Applications (LEDIA 2024), Yokohama, Japan, Apr.24-25 (2024), No.LEDIA1-02 (Invited-oral).

329. S. F. Chichibu, K. Okuno, M. Oya, Y. Saito, H. Ishiguro, T. Takeuchi, and K. Shima:

"Operation-induced short-term degradation mechanisms of 275-nm-band AlGaN-based deep-ultraviolet light-emitting diodes on a sapphire substrate",
The Society of Photo-Optical Instrumentation Engineers (SPIE) Photonics West 2024, OPTO, Light-Emitting Devices, Materials, and Applications XXVIII (OE603), San Francisco, USA, Jan.27-Feb.1, (2024), No.12906-25 (Invited-oral).

328. S. F. Chichibu, K. Kurimoto, Q. Bao, Y. Mikawa, M. Saito, D. Tomida, T. Ishiguro, and K. Shima:

"Low-pressure acidic ammonothermal (LPAAT) growth of large diameter nearly bowing-free GaN crystals",
The Society of Photo-Optical Instrumentation Engineers (SPIE) Photonics West 2024, OPTO, Gallium Nitride Materials and Devices XIX (OE107), San Francisco, USA, Jan.27-Feb.1, (2024), No.12886-1 (Invited-oral).

327. S. F. Chichibu, K. Okuno, M. Oya, Y. Saito, H. Ishiguro, T. Takeuchi, and K. Shima:

"Operation-induced short-term degradation mechanisms of 275-nm-band AlGaN-based deep-ultraviolet light-emitting diodes fabricated on a sapphire substrate",
49th Conference on the Physics and Chemistry of Semiconductor Interfaces (PCSI-49), Santa Fe, New Mexico, USA, Jan.14-18 (2024), Session PCSI-ThM1 Wide Bandgap Materials, No.PCSI-ThM1-9 (Invited-oral&poster).

326. S. F. Chichibu, K. Nagata, K. Okuno, M. Oya, Y. Saito, H. Ishiguro, T. Takeuchi, and K. Shima:

"Short-term degradation mechanisms of 275-nm-band AlGaN-based deep-ultraviolet light emitting diodes on a sapphire substrate",
The 14th International Conference on Nitride Semiconductors (ICNS-14), Fukuoka, Japan, Nov.12-17 (2023), No.OD13-3 (oral).

325. Y. Saito, K. Nagata, A. Miyazaki, S. Boyama, K. Okuno, M. Oya, K. Kataoka, T. Narita, K. Horibuchi, M. Kushimoto, Y. Honda, H. Amano, H. Ishiguro, T. Takeuchi, K. Shima, and S. F. Chichibu:

"Recent developments for high efficiency for deep UV LEDs",
The 14th International Conference on Nitride Semiconductors (ICNS-14), Fukuoka, Japan, Nov.12-17 (2023), No.OD13-1 (Invited-oral).

324. R. Ozeki, D. Nakamura, R. Kudo, T. Ito, K. Shima, S. F. Chichibu, and T. Nakano:

"Optical characteristics of BGaN films using oblique polishing",
The 14th International Conference on Nitride Semiconductors (ICNS-14), Fukuoka, Japan, Nov.12-17 (2023), No.ThP-GR-16 (poster).

323. S. F. Chichibu, N. Umehara, K. Hara, and K. Shima:

"Spatially resolved cathodoluminescence studies of graphitic BN segments formed in hexagonal BN epilayers grown on a (0001) sapphire by CVD",
The 14th International Conference on Nitride Semiconductors (ICNS-14), Fukuoka, Japan, Nov.12-17 (2023), No.CH12-3 (oral).

322. R. Akaike, K. Uesugi, K. Shima, S. F. Chichibu, A. Uedono, and H. Miyake:

"Effect on QWs qualities of thickness of homoepitaxial AlN on AlN/sapphire prepared by sputtering and high-temperature annealing",
The 14th International Conference on Nitride Semiconductors (ICNS-14), Fukuoka, Japan, Nov.12-17 (2023), No.CH9-2 (oral).

321. K. Shima, T. Narita, K. Kataoka, S. Ishibashi, A. Uedono, M. Bockowski, J. Suda, T. Kachi, and S. F. Chichibu:

"Luminescence studies of Mg-implanted and undoped GaN-on-GaN structures processed by ultra-high-pressure annealing",
The 14th International Conference on Nitride Semiconductors (ICNS-14), Fukuoka, Japan, Nov.12-17 (2023), No.CH6-3 (oral).

320. S. F. Chichibu, A. Uedono, H. Iguchi, T. Narita, K. Kataoka, M. Bockowski, J. Suda, T. Kachi, S. Takashima, R. Tanaka, K. Ueno, M. Edo, S. Ishibashi, and K. Shima:

"Impacts of vacancy clusters on the luminescence dynamics in Mg-implanted GaN on GaN structures",
The 14th International Conference on Nitride Semiconductors (ICNS-14), Fukuoka, Japan, Nov.12-17 (2023), No.CH6-1 (Invited-oral).

319. K. Shima and S. F. Chichibu:

"Wafer-scale characterization of mosaics and the impact on point defects in GaN studied using 2D birefringence and photoluminescence measurements",
The 14th International Conference on Nitride Semiconductors (ICNS-14), Fukuoka, Japan, Nov.12-17 (2023), No.CH5-4 (oral).

318. S. F. Chichibu, K. Shima, T. Kasuya, K. Nagata, K. Okuno, M. Oya, Y. Saito, H. Ishiguro, and T. Takeuchi:

"Short-term degradation mechanisms of 275-nm-band AlGaN-based deep-ultraviolet light emitting diodes fabricated on a sapphire substrate",
65th Electronic Materials Conference (EMC-65), University of California, Santa Barbara, California, USA, Jun.28-30 (2023), Session Group III-Nitrides Optical Emitters, No.M01 (oral).

317. T. Kasuya, K. Shima, K. Hara, and S. F. Chichibu:

"Ultraviolet luminescence dynamics of hexagonal BN epilayers grown by chemical vapor deposition using carbon-free precursors",
65th Electronic Materials Conference (EMC-65), University of California, Santa Barbara, California, USA, Jun.28-30 (2023), Session 2D Materials Synthesis and Characterizations, No.P07 (oral).

316. K. Shima, K. Kurimoto, Q. Bao, Y. Mikawa, T. Ishiguro, and S. F. Chichibu:

"Luminescence studies of bulk GaN crystals grown by the low-pressure acidic ammonothermal method",
65th Electronic Materials Conference (EMC-65), University of California, Santa Barbara, California, USA, Jun.28-30 (2023), Session Group III-Nitrides Growth and Characterization No.X06 (oral).

315. K. Shima, R. Tanaka, S. Takashima, K. Ueno, M. Edo, A. Uedono, S. Ishibashi, and S. F. Chichibu:

"Temporary and spatially resolved luminescence studies of p-GaN segments fabricated by vacancy-guided redistribution of Mg using sequential ion implantation of Mg and N",
21st International Workshop on Junction Technology (IWJT2023), Kyoto University (Yoshida Campus), Kyoto, Japan, and Online (Hybrid) June 8,9 (2023) No.S3-1 (oral). Proceedings of IWJT2023, IEEE Xplore Digital Library (2023) (pdf)

314. Y. Yoshida, K. Kojima, M. Shiraiwa, A. Kanno, A. Hirano, Y. Nagasawa, M. Ippommatsu, N. Yamamoto, S. F. Chichibu, and Y. Awaji:

"Gbps-Class Solar-Blind WDM Optical Wireless Communication By (264, 274, 282)-nm Deep-UV LEDs and CsTe Photomultiplier Tube",
Optical Fiber Communication Conference and Exposition (OFC2023), San Diego Convention Center, San Diego, CA, USA, Mar.5-9 (2023), Session Satellite Communications and UV, LWIR Free Space Optical Communications, No.Th1H.2 (oral).

313. A. Uedono, H. Sakurai, J. Uzuhashi, T. Narita, K. Sierakowski, S. Ishibashi, S. F. Chichibu, M. Bockowski, J. Suda, T. Ohkubo, N. Ikarashi, K. Hono, and T. Kachi:

"Annealing properties of vacancy-type defects in ion implanted GaN during ultra-high-pressure annealing studied by using a monoenergetic positron beam",
The Society of Photo-Optical Instrumentation Engineers (SPIE) Photonics West 2023, OPTO, Gallium Nitride Materials and Devices XVIII (OE107), San Francisco, USA, Jan.30-Feb.2, (2023), No.12421-25 (Invited-oral). Proceedings of SPIE (pdf)

312. S. F. Chichibu, K. Shima, H. Iguchi, T. Narita, K. Kataoka, H. Sakurai, M. Bockowski, J. Suda, T. Kachi, S. Takashima, R. Tanaka, K. Ueno, M. Edo, S. Ishibashi, and A. Uedono:

"Impacts of vacancy clusters on the recombination dynamics in Mg-implanted GaN on GaN structures",
The Society of Photo-Optical Instrumentation Engineers (SPIE) Photonics West 2023, OPTO, Gallium Nitride Materials and Devices XVIII (OE107), San Francisco, USA, Jan.30-Feb.2, (2023), No.12421-26 (Invited-oral).

311. K. Kojima, Y. Yoshida, M. Shiraiwa, Y. Awaji, A. Kanno, N. Yamamoto, A. Hirano, Y. Nagasawa, M. Ippommatsu, and S. F. Chichibu:

"High-speed solar-blind optical wireless communications based on AlGaN deep-ultraviolet light-emitting diodes grown on AlN/sapphire templates with dense macro-steps",
The Society of Photo-Optical Instrumentation Engineers (SPIE) Photonics West 2023, OPTO, Gallium Nitride Materials and Devices XVIII (OE107), San Francisco, USA, Jan.30-Feb.2, (2023), No.12421-56 (Invited-oral).

310. S. F. Chichibu, K. Shima, N. Umehara, K. Takiguchi, Y. Ishitani, and K. Hara:

"Emission dynamics of indirect excitons in hexagonal BN epilayers containing polytypic segments grown by chemical vapor deposition using carbon-free precursors",
11th International Workshop on Nitride Semiconductors (IWN2022), Berlin, Germany, Oct. 9-14 (2022), Session Novel Materials and Nanostructures, Excitons in hexagonal and cubic GaN, No. IT26 (Invited-oral).

309. K. Shima, R. Tanaka, S. Takashima, K. Ueno, M. Edo, K. Kojima, A. Uedono, S. Ishibashi, and S. F. Chichibu:

"Improved minority carrier lifetime in p-type GaN segments prepared by vacancy-guided redistribution of Mg",
11th International Workshop on Nitride Semiconductors (IWN2022), Berlin, Germany, Oct. 9-14 (2022), Session Electronic devices, Ion implantation and annealing, No. AT049 (oral).

308. S. F. Chichibu, K. Shima, K. Kojima, and Y. Kangawa:

"Self-formed compositional superlattices in m-plane Al_0.7In_0.3N alloys on a GaN substrate triggered by atomic ordering of In and Al along the c-axis",
11th International Workshop on Nitride Semiconductors (IWN2022), Berlin, Germany, Oct. 9-14 (2022), Session Novel Materials and Nanostructures, No. PP170 (poster).

307. S. Schimmel, D. Tomida, T. Ishiguro, Y. Honda, S. F. Chichibu, and H. Amano:

"Temperature field and fluid flow in ammonothermal growth of GaN during etch-back and crystal growth for a retrograde solubility configuration",
11th International Workshop on Nitride Semiconductors (IWN2022), Berlin, Germany, Oct. 9-14 (2022), Session Growth, No. PP272 (poster).

306. K. Kurimoto, Q. Bao, Y. Mikawa, K. Shima, T. Ishiguro, and S. F. Chichibu:

"Low-pressure acidic ammonothermal (LPAAT) growth of 2-inch-diameter bulk GaN crystals",
11th International Workshop on Nitride Semiconductors (IWN2022), Berlin, Germany, Oct. 9-14 (2022), Session Growth, GaN Bulk Growth, No. AT167 (oral).

305. T. Nakano, Y. Ota, A. Miyazawa, H. Nakagawa, S. Kawasaki, Y. Ando, Y. Honda, H. Amano, K. Shima, S. F. Chichibu, Y. Inoue, and T. Aoki:

"Fabrication of BGaN neutron detectors and evaluation of the radiation detection characteristics",
11th International Workshop on Nitride Semiconductors (IWN2022), Berlin, Germany, Oct. 9-14 (2022), Session Novel Materials and Nanostructures, Processing of hBN No. AT231 (oral).

304. K. Shima, C. Elias, T. S. Cheng, C. J. Mellor, P. H. Beton, S. V. Novikov, B. Gil, G. Cassabois, and S. F. Chichibu:

"Near-band-edge recombination in monolayer hBN epitaxial films studied using cathodoluminescence spectroscopy",
11th International Workshop on Nitride Semiconductors (IWN2022), Berlin, Germany, Oct. 9-14 (2022), Session Novel Materials and Nanostructures, Processing of hBN No. AT232 (oral).

303. S. Schimmel, M. Salamon, D. Tomida, I. Kobelt, L. Heinlein, A.-C. L. Kimmel, T. G. Steigerwald, T. Ishiguro, Y. Honda, S. F. Chichibu, H. Amano, E. Schluecker, and P. Wellmann:

"In situ monitoring technologies as prospective validation tools for numerical simulations of ammonothermal crystal growth",
7th European Conference on Crystal Growth (ECCG-7), Paris, France, Jul.25 -27 (2022), Session 5-A: Semiconductors No.5 (poster).

302. Akira Hirano, Yosuke Nagasawa, Kazunobu Kojima, Masamichi Ippommatsu, Hideki Sako, Ai Hashimoto, Ryuichi Sugie, Yoshio Honda, Hiroshi Amano, and Shigefusa F. Chichibu:

"Mechanism underlying high internal quantum efficiency of AlGaN-based LEDs fabricated on AlN with dense macrosteps",
The 20th International Conference on Metal Organic Vapor Phase Epitaxy (ICMOVPE-20), Fellbach, Germany, July 10-15 (2022), No.Tu A3.4; LN375 (oral).

301. S. Schimmel, M. Salamon, D. Tomida, M. Saito, Q. Bao, T. Ishiguro, Y. Honda, S. F. Chichibu, and H. Amano:

"High energy computed tomography as a tool for validation of numerical simulations of ammonothermal crystal growth of GaN",
8th International Workshop on Crystal Growth Technology (IWCGT-8), Berlin, Germany, May 29 -Jun.2 (2022). No.P13 (poster).

300. S. F. Chichibu, K. Shima, K. Kojima, S. Takashima, R. Tanaka, K. Ueno, M. Edo, H. Iguchi, T. Narita, K. Kataoka, S. Ishibashi, and A. Uedono:

"Impacts of vacancy clusters on the recombination dynamics in Mg-implanted GaN on GaN structures for power devices",
Compound Semiconductor Week (CSW) 2022, University of Michigan, Ann Arbor, MI, USA, June 1-3 (2022), Session: Power Elecronics I, No.5:00-5:30PM (Invited-oral).

299. K. Kojima, S. Ichikawa, O. Maida, K. Shima, and S. F. Chichibu:

"Characterization of semiconductor crystals based on omnidirectional photoluminescence (ODPL) spectroscopy",
241st Meeting of ECS, The Electrochemical Society, Vancouver Convention Center, Vancouver, BC, Canada, May 29-Jun.2 (2022), No. H01-13-1 (Invited-oral).

298. L. Li, K. Shima, M. Yamanaka, T. Egawa, T. Takeuchi, M. Miyoshi, and S. F. Chichibu:

"Luminescence studies of nearly lattice-matched c-plane AlInN/GaN heterostructures",
5th International Workshop on UV Materials and Devices (IWUMD-V), Jeju, Korea, May 23-26 (2022). No.ThB4-2, Hybrid Conference (oral).

297. S. F. Chichibu, K, Shima, S. Ishibashi, and A. Uedono:

"Vacancy complexes acting as midgap recombination centers in (Al,Ga)N semiconductors",
Advances in III-Nitride Materials & Photonic Devices (IIIN-MPD), Org. by T. Wernicke, A. Haglund, M. Weyers, S. Einfeldt, and M. Kneissl, Technical University of Berlin, Germany, Mar.9 (2022), Online webinar series (Invited lecturer).

296. S. F. Chichibu, K. Shima, K. Kojima, S. Ishibashi, and A. Uedono:

"Vacancy complexes acting as midgap recombination centers in (Al,Ga)N semiconductors",
20th International Workshop on Junction Technology (IWJT2021), June 10-11 (2021), No.KN-4, On-line Conference (Plenary). Proceedings of IWJT2021, IEEE Xplore Digital Library (2021) (pdf)

295. K. Kojima, Y. Yoshida, M. Shiraiwa, Y. Awaji, A. Kanno, N. Yamamoto, A. Hirano, Y. Nagasawa, Y. Honda, H. Amano, and S. F. Chichibu:

"Characterization of AlGaN deep-ultraviolet light-emitting diodes grown on AlN/sapphire templates with dense macro-steps and application of high-speed solar-blind optical wireless communications",
2nd International Conference on UV LED Technologies & Applications (ICULTA2020), Apr.18-21 (2021), No.Mo-A3-1, On-line Conference (Invited-oral).

294. A. Uedono, H. Sakurai, T. Narita, K. Sierakowski, M. Bockowski, J. Suda, S. Ishibashi, S. F. Chichibu, and T. Kachi:

"Behaviors of vacancy-type defects in Mg-implanted GaN during ultra-high- pressure annealing studied by using a monoenergetic positron beam",
The Society of Photo-Optical Instrumentation Engineers (SPIE) Photonics West 2021, OPTO, Gallium Nitride Materials and Devices XV (OE107), San Francisco, USA, Mar.6-11, (2021), No.11686-48, On-line Conference (Invited-oral).

293. K. Kojima, K. Ikemura, and S. F. Chichibu:

"Current progress of omnidirectional photoluminescence spectroscopy for the quantification of quantum efficiency of radiation in GaN crystals",
The Society of Photo-Optical Instrumentation Engineers (SPIE) Photonics West 2021, OPTO, Gallium Nitride Materials and Devices XV (OE107), San Francisco, USA, Mar.6-11, (2021), No.11686-50, On-line Conference (Invited-oral).

292. K. Shima, T. Kasuya, K. Shojiki, K. Uesugi, K. Kojima, A. Uedono, H. Miyake, and S. F. Chichibu:

"Cathodoluminescence studies of AlN epilayers grown by MOVPE on sputtered AlN templates annealed at high temperature",
The 8th Asian Conference on Crystal Growth and Crystal Technology (CGCT-8), Japan, Mar.1-3 (2021), Category 10. Singularity Project, No.C10-10-57 On-line Conference (oral).

291. L. Y. Li, K. Shima, M. Yamanaka, K. Kojima, T. Egawa, T. Takeuchi, M. Miyoshi, and S. F. Chichibu:

"Macroscopically homogeneous cathodoluminescence mapping images of c-plane nearly lattice-matched Al_1-xIn_xN films on a GaN substrate",
The 8th Asian Conference on Crystal Growth and Crystal Technology (CGCT-8), Japan, Mar.1-3 (2021), Category 10. Singularity Project, No.C10-10-56 On-line Conference (oral).

290. A. Uedono, K. Shojiki, K. Uesugi, S. F. Chichibu, S. Ishibash, M. Dickmann, W. Egger, C. Hugenschmidt, and H. Miyake:

"Vacancies in AlN deposited by radio-frequency sputtering and MOVPE studied by positron annihilation spectroscopy",
The 8th Asian Conference on Crystal Growth and Crystal Technology (CGCT-8), Japan, Mar.1-3 (2021), Category 10. Singularity Project, No.C10-03-13 On-line Conference (oral).

289. S. F. Chichibu, K. Shima, K. Kojima, and Y. Kangawa:

"Striped and fin-shaped cation orderings and self-formed compositional superlattices in an m-plane Al_0.7In_0.3N on GaN heterostructure",
The 8th Asian Conference on Crystal Growth and Crystal Technology (CGCT-8), Japan, Mar.1-3 (2021), Category 10. Singularity Project, No.C10-02-07 On-line Conference (oral).

288. S. Schimmel, D. Tomida, M. Saito, Q. Bao, T. Ishiguro, Y. Honda, S. F. Chichibu, and H. Amano:

"Evaluation of realistic boundary conditions for simulations of ammonothermal GaN crystal growth",
The 8th Asian Conference on Crystal Growth and Crystal Technology (CGCT-8), Japan, Mar.1-3 (2021), Category 7. Crystal Growth Fundamentals and Simulation, No.C07-02-08 On-line Conference (oral).

287. S. F. Chichibu, K, Shima, K. Kojima, and Y. Kangawa:

"Self-formed compositional superlattices triggered by cation orderings in m-plane Al_1-xIn_xN on GaN",
Virtual Workshop on Materials Science and Advanced Electronics Created by Singularity, Feb.1-3 (2021), No. Feb.3 9:00-9:20 JST, On-line Conference (oral).

286. K. Kojima and S. F. Chichibu:

"Omnidirectional photoluminescence (ODPL) spectroscopy for the quantification of quantum efficiency of radiation in GaN crystals",
Virtual Workshop on Materials Science and Advanced Electronics Created by Singularity, Feb.1-3 (2021), No. Feb.2 15:20-15:35 JST, On-line Conference (oral).

285. K. Kojima, Y. Yoshida, M. Shiraiwa, Y. Awaji, A. Kanno, N. Yamamoto, A. Hirano, Y. Nagasawa, M. Ippommatsu, and S. F. Chichibu:

"Characterization of a self-organized deep-ultraviolet micro-light-emitting diode structure for high-speed solar-blind optical wireless communications",
Conference on Lasers and Electro-Optics (CLEO) 2020, Laser Science to Photonic Applications, Session Free-Space & Underwater Communication, USA, May 10-15, (2020), Session Wide Bandgap Devices, No.SM4R.6 On-line Virtual Conference (oral).

284. A. Uedono, M. Dickmann, W. Egger, C. Hugenschmidt, S. Ishibashi, and S. F. Chichibu:

"Control of vacancy-type defects in Mg implanted GaN studied by positron annihilation spectroscopy",
The Society of Photo-Optical Instrumentation Engineers (SPIE) Photonics West 2020, OPTO, Gallium Nitride Materials and Devices XV (OE107), San Francisco, USA, Feb.1-Feb.6, (2020), No.11280-11 (Invited-oral).Proceedings of SPIE (pdf)

283. S. F. Chichibu, K. Shima, K. Kojima, S. Ishibashi, and A. Uedono:

"Origin and dynamic properties of major intrinsic nonradiative recombination centers in wide bandgap nitride semiconductors",
The Society of Photo-Optical Instrumentation Engineers (SPIE) Photonics West 2020, OPTO, Gallium Nitride Materials and Devices XV (OE107), San Francisco, USA, Feb.1-Feb.6, (2020), No.11280-10 (Invited-oral).Proceedings of SPIE (pdf)

282. T. Nakano, Y. Takahashi, Y. Ohta, N. Yamada, H. Nakagawa, Y. Honda, H. Amano, K. Shima, K. Kojima, S. F. Chichibu, Y. Inoue, and T. Aoki:

"Improvement of neutron detection efficiency for BGaN semiconductor detectors",
2019 IEEE Nuclear Science Symposium and Medical Imaging Conference, and Workshop on Room-Temperature Semiconductor X-Ray and Gamma-Ray Detectors (NSS/MIC/RTSD), the Manchester Convention Centre, Manchester, UK, Oct.26-Nov.2 (2019), No.R-04-450 (poster).

281. Y. Takahashi, T. Maruyama, N. Yamada, K. Ebara, Y. Ohta, H. Nakagawa, S. Usami, Y. Honda, H. Amano, K. Kojima, S. F. Chichibu, Y. Inoue, T. Aoki, and T. Nakano:

"Evaluation of BGaN growth temperature dependence and fabrication of neutron semiconductor detectors",
9th Asia-Pacific Workshop on Widegap Semiconductors (APWS2019), Okinawa Institute of Science and Technology, Okinawa, Japan, Nov.10-15, (2019), No.MoP-GR-12 (poster).

280. S. F. Chichibu, H. Miyake, and A. Uedono:

"Role of Al-vacancy complexes in AlN and high AlN mole fraction AlGaN alloys",
4th International Workshop on UV Materials and Devices (IWUMD-IV), St. Petersburg, Russia, Sep.8-13 (2019). No.Th-3i (Invited-oral).

279. H. Asai, K. Kojima, S. F. Chichibu, and K. Fukuda:

"Theoretical Analysis of Photo-Recycling Effect on External Quantum Efficiency Considering Spatial Carrier Dynamics",
2019 International Conference on Solid State Devices and Materials, Nagoya, Aichi, Japan, Sep.2-5, 2019, F-1-04, (oral) Extended Abstracts of SSDM2019 pp.F-1-04 (2019).

278. S. F. Chichibu, K. Shima, K. Kojima, S. Ishibashi, and A. Uedono:

"Impact of vacancy complexes on the nonradiative recombination processes in III-N devices",
The 13th International Conference on Nitride Semiconductors (ICNS-13), Bellevue, Washington, USA, July 12 (2019), No.PL02.02 (Plenary).

277. Y. Nagasawa, R. Sugie, K. Kojima, A. Hirano, M. Ipponmatsu, Y. Honda, H. Amano, I. Akasaki, and S. F. Chichibu:

"Microscopic nonuniformities in AlGaN-based 260 and 285 nm light-emitting multiple quantum wells grown on AlN templates with dense macrosteps analyzed by cathodoluminescence spectroscopy",
The 13th International Conference on Nitride Semiconductors (ICNS-13), Bellevue, Washington, USA, July 8 (2019), No.A01.06 (oral).

276. D. Tomida, Q. Bao, M. Saito, K. Kurimoto, M. Ito, T. Ishiguro, and S. F. Chichibu:

"Effects of an extra Al metal added during the acidic ammonothermal growth of GaN crystals",
The 13th International Conference on Nitride Semiconductors (ICNS-13), Bellevue, Washington, USA, July 8 (2019), No.F01.02 (oral).

275. S. Takashima, R. Tanaka, K. Ueno, H. Matsuyama, Y. Fukushima, M. Edo, K. Shima, K. Kojima, S. F. Chichibu, and A. Uedono:

"Evaluation of Subsequent Implantation Effect into Mg Implanted Region in GaN",
The 13th International Conference on Nitride Semiconductors (ICNS-13), Bellevue, Washington, USA, July 7-12 (2019), No.BP01.30 (poster). Selected as Best Poster Award of ICNS13

274. H. Asai, K. Kojima, S. F. Chichibu, and K. Fukuda:

"Analytical formula for quantum efficiency of radiation considering self-absorption process",
The 13th International Conference on Nitride Semiconductors (ICNS-13), Bellevue, Washington, USA, July 7-12 (2019), No.JP02.03 (poster).

273. K. Shima, H. Iguchi, T. Narita, K. Kataoka, K. Kojima, A. Uedono, and S. F. Chichibu:

"Photoluminescence studies of sequentially Mg and H ion-implanted GaN with various implantation depths and crystallographic planes",
The 13th International Conference on Nitride Semiconductors (ICNS-13), Bellevue, Washington, USA, July 10 (2019), No.E01.04 (oral).

272. K. Kojima, F. Horikiri, Y. Narita, T. Yoshida, and S. F. Chichibu:

"Dependences of external quantum efficiency of radiation and photoluminescence lifetime on the carbon concentration in GaN on GaN structures",
The 13th International Conference on Nitride Semiconductors (ICNS-13), Bellevue, Washington, USA, July 10 (2019), No.G08.06 (oral).

271. S. F. Chichibu, N. Umehara, K. Takiguchi, K. Shima, K. Kojima, Y. Ishitani, and K. Hara:

"Time-resolved luminescence studies of indirect excitons in h-BN epitaxial films grown by chemical vapor deposition using carbon-free precursors",
The 13th International Conference on Nitride Semiconductors (ICNS-13), Bellevue, Washington, USA, July 10 (2019), No.A10.06 (oral).

270. K. Hara, N. Umehara, K. Shima, K. Kojima, and S. F. Chichibu:

"Improvement in the luminescence property of hexagonal boron nitride grown by CVD on a c-plane sapphire substrate",
The 4th International Conference on Physics of 2D Crystals (ICP2C4), Hangzhou, China, Jun.10-15 (2019), No. Technology of Thin Crystals 11:30 (Invited-oral).

269. K. Kojima, K. Watanabe, T. Taniguchi, and S. F. Chichibu:

"Quantification of external quantum efficiency for near-band-edge emission of freestanding h-BN crystals under photo-excitation",
Compound Semiconductor Week 2019 (CSW 2019), Spectroscopy & growth of h-BN II, Kasugano International Forum, Nara, Japan, May 19-23 (2019), No.TuE3-3 (oral).

268. K. Shima, K. Kojima, A. Uedono, and S. F. Chichibu:

"Photoluminescence Studies of Sequentially Mg and H Ion-implanted GaN with Various Implantation Depths and Crystallographic Planes",
19th International Workshop on Junction Technology (IWJT2019), Kyoto University (Uji Campus), Kyoto, Japan, June 6,7 (2019) No.S5-2 (oral). Proceedings of IWJT2019, IEEE Xplore Digital Library (2019) (pdf)
Selected as Best Paper Award of IWJT2019

267. Y. Yoshida, K. Kojima, M. Shiraiwa, Y. Awaji, A. Kanno, N. Yamamoto, S. Chichibu, A. Hirano, and M. Ippommatsu:

"An outdoor evaluation of 1-Gbps optical wireless communication using AlGaN-based LED in 280-nm Band",
Conference on Lasers and Electro-Optics (CLEO) 2019, Laser Science to Photonic Applications, Session Free-Space & Underwater Communication, San Jose, California, USA, May 05-10, (2019), (oral).

266. S. F. Chichibu, M. Saito, Q. Bao, D. Tomida, K. Kurimoto, K. Shima, K. Kojima,and T. Ishiguro:

"Recent progress in acidic ammonothermal growth of GaN crystals",
11th International Symposium on Advanced Plasma Science and its Applications for Nitrides and Nanomaterials (ISPLasma2019), Nagoya Institute of Technology, Nagoya, Japan, March 17-21 (2019), No.18pF04I (Invited-oral).

265. Y. Nagasawa, K. Kojima, R. Sugie, A. Hirano, M. Ippommatsu, H. Amano, I. Akasaki, and S. F. Chichibu:

"Different nonradiative recombination between on the terraces and macrosteps of uneven QW for 285 nm-LED grown on AlN template with dense macrosteps",
The International Workshop on UV Materials and Devices, Kunming, China, Dec.9-12 (2018). No.LEO-6 (oral).

264. S. F. Chichibu, N. Umehara, K. Shima, K. Kojima, and K. Hara:

"Luminescence dynamics of indirect excitons in h-BN epitaxial films grown by BCl₃-NH₃ chemical vapor deposition on a c-plane sappire substrate",
Materials Research Society, 2018 Fall Meeting, Symposium EP08:Ultra-Wide-Bandgap Materials and Devices, Boston, MA, USA, Nov.25-30 (2018). No.EP08.09.07 (oral).

263. M. Saito, Q. Bao, K. Shima, D. Tomida, K. Kojima, T. Ishiguro, and S. F. Chichibu:

"Recent progress of large size bulk GaN crystal growth by acidic ammonothermal method",
International Workshop on Nitride Semiconductors 2018 (IWN2018), Kanazawa, Japan, Nov.11-16, (2018), Session Liquid Growth, No.GR4-1 (Invited-oral).

262. S. Sakai, K. Kojima, S. F. Chichibu, and A. A. Yamaguchi:

"Determination of Deformation Potentials in InGaN-Alloy Material for Theoretical Prediction of Optical Gain Characteristics in Semipolar and Nonpolar InGaN Quantum Wells Laser Diodes",
IEEE 26th International Semiconductor Laser Conference (ISLC2018), Santa Fe, New Mexico, USA, Sep.16-19, (2018), No.TuP11 (poster).

261. K. Kojima, Y. Yoshida, M. Shiraiwa, Y. Awaji, A. Kanno, N. Yamamoto, and S. Chichibu:

"1.6-Gbps LED-based ultraviolet communication at 280 nm in direct sunlight",
44th European Conference on Optical Communication (ECOC 2018), Roma, Italy, Sep.23-27, (2018), (oral).

260. N. Yamada, K. Mochizuki, T. Maruyama, K. Ebara, Y. Takahashi, H. Nakagawa, S. Usami, Y. Honda, H. Amano, K. Kojima, S. F. Chichibu, Y. Inoue, T. Aoki, and T. Nakano:

"Radiation detection characteristic of BGaN semiconductor detectors",
2018 IEEE Nuclear Science Symposium and Medical Imaging Conference and Workshop on Room-Temperature Semiconductor X-Ray and Gamma-Ray Detectors (NSS/MIC/RTSD), International Convention Centre Sydney, Sydney, Australia, Nov.10-17, (2018), Session R-05 RTSD (Poster)

259. K. Kojima, Y. Nagasawa, A. Hirano, M. Ipponmatsu, Y. Honda, H. Amano, I. Akasaki, and S. F. Chichibu:

"Current localization structure observed in AlGaN-based deep-ultraviolet light-emitting diodes grown on AlN templates with macrosteps",
International Workshop on Nitride Semiconductors 2018 (IWN2018), Kanazawa, Japan, Nov.11-16, (2018), Session Monday Poster, No.MoP-OD-4 (poster).

258. S. F. Chichibu, K. Shima, K. Kojima, S. Takashima, K. Ueno, M. Edo, H. Iguchi, T. Narita, K. Kataoka, S. Ishibashi, and A. Uedono:

"Room-temperature photoluminescence lifetime for the near-band-edge emission of epitaxial and ion-implanted Mg-doped GaN on GaN structures",
International Workshop on Nitride Semiconductors 2018 (IWN2018), Kanazawa, Japan, Nov.11-16, (2018), Session Carrier and Phonon Dynamics in GaN, No.CR6-6 (oral).

257. K. Kojima, Y. Yoshida, M. Shiraiwa, Y. Awaji, A. Kanno, N. Yamamoto, and S. F. Chichibu:

"Multi-gigabit-class deep ultraviolet wireless communication at 280 nm based on an AlGaN light emitting diode",
International Workshop on Nitride Semiconductors 2018 (IWN2018), Kanazawa, Japan, Nov.11-16, (2018), Session New Optical Devices I, No.OD7-3 (oral).

256. T. Maruyama, Y. Takahashi, N. Yamada, K. Ebara, H. Nakagawa, S. Usami, Y. Honda, H. Amano, K. Kojima, S. F. Chichibu, Y. Inoue, T. Aoki, and T. Nakano:

"Fabrication and evaluation of thick BGaN neutron detection diodes",
International Workshop on Nitride Semiconductors 2018 (IWN2018), Kanazawa, Japan, Nov.11-16, (2018), Session Epitaxial Growth II, No.GR10-4 (oral).

255. K. Ebara, K. Mochizuki, Y. Inoue, T. Aoki, K. Kojima, S. F. Chichibu, and T. Nakano:

"Kinetics analysis of desorption process in BGaN MOVPE",
International Workshop on Nitride Semiconductors 2018 (IWN2018), Kanazawa, Japan, Nov.11-16, (2018), Session Epitaxial Growth II, No.GR10-5 (oral).

254. S. F. Chichibu, N. Umehara, K. Shima, K. Kojima, and K. Hara:

"Luminescence dynamics of indirect excitons in h-BN epitaxial films grown by BCl₃-NH₃ chemical vapor deposition on a c-plane sapphire substrate",
International Workshop on Nitride Semiconductors 2018 (IWN2018), Kanazawa, Japan, Nov.11-16, (2018), Session BN, No.J6-3 (oral).

253. Y. Nagasawa, K. Kojima, A. Hirano, M. Ipponmatsu, Y. Honda, H. Amano, I. Akasaki, and S. F. Chichibu:

"Microscopic structure of boosting IQE for AlGaN-based UV-B (285 nm) LED grown on macrosteps",
International Workshop on Nitride Semiconductors 2018 (IWN2018), Kanazawa, Japan, Nov.11-16, (2018), Session DUV LED I, No.OD14-2 (oral).

252. S. F. Chichibu, M. Saito, Q. Bao, D. Tomida, K. Kurimoto, K. Shima, K. Kojima, and T. Ishiguro:

"Recent progress in acidic ammonothermal growth of GaN crystals",
The 7th International Symposium of Growth of III-Nitrides (ISGN-7), Warsaw, Poland, Aug. 5-10 (2018), No.Tu1.1 (Invited-oral).

251. K. Ebara, K. Mochizuki, Y. Inoue, T. Aoki, K. Kojima, S. F. Chichibu, and T. Nakano:

"Evaluation of cubic phase formation in wurtzite type BGaN by MOVPE",
The 19th International Conference on Metal Organic Vapor Phase Epitaxy (ICMOVPE-19), Nara, Japan, June 3-8, (2018), No.P2-8 (poster).

250. T. Tanikawa, T. Fujita, K. Kojima, S. F. Chichibu, and T. Matsuoka:

"Influence of Self Absorption in Two-Photon-Excitation Photoluminescence of GaN",
The 19th International Conference on Metal Organic Vapor Phase Epitaxy (ICMOVPE-19), Nara, Japan, June 3-8, (2018), No.7C-3.5 (oral).

249. S. F. Chichibu, N. Umehara, K. Shima, K. Kojima, and K. Hara:

"Luminescence spectra of hexagonal BN thin films grown by chemical vapor deposition on a c-plane sapphire substrate",
The 3rd International Conference on Physics of 2D Crystals (ICP2C3), La Valletta, Malta, May 29-Jun.2 (2018), No. Characterization 11:30 (Invited-oral).

248. A. Uedono, S. Takashima, M. Edo, K. Ueno, H. Matsuyama, W. Egger, T. Koschine, C. Hugenschmidt, M. Dickmann, K. Kojima, S. F. Chichibu, and S. Ishibashi:

"Carrier trapping properties of defects in Mg-implanted GaN probed by monoenergetic positron beams",
The 45th International Symposium on Compound Semiconductors (ISCS 2018), Massachusetts Institute of Technology, Cambridge, MA, USA, May 29-June 1 (2018), No.We5PP‐WBG.3 (poster).

247. Y. Inatomi, A. Kusaba, Y. Kangawa, K. Kojima, and S. F. Chichibu:

"Formation mechanism of singular structure in AlInN layer grown on m-GaN substrate by MOVPE",
The 6th International Conference on Light-Emitting Devices and Their Industrial Applications (LEDIA'18), Yokohama, Japan, Apr.23-27 (2018), No.LEDIA6-1 (Upgraded Invited-oral).

246. T. Narita, K. Kataoka, H. Iguchi, K. Shima, K. Kojima, S. F. Chichibu, M. Kanechika, T. Uesugi, and T. Kachi:

"P-type Conduction of Mg-ion Implanted N-polar GaN and the Optical Investigation",
The 6th International Conference on Light-Emitting Devices and Their Industrial Applications (LEDIA'18), Yokohama, Japan, Apr.23-27 (2018), No.LEDIA7-5 (Invited-oral).

245. K. Kojima and S. F. Chichibu:

"Quantum efficiency of radiation in wide bandgap semiconductors",
19th International Conference on Physics of Light-Matter Coupling in Nanostructures (PLMCN19), Chengdu, China, May 15-19 (2018), No.INVITED-SESSION1 (Invited-oral).

244. T. Nakano, K. Mochizuki, T. Maruyama, N. Yamada, H. Nakagawa, S. Usami, Y. Honda, H. Amano, S. F. Chichibi, Y. Inoue, and T. Aoki:

"Fabrication of BGaN solid state detector for neutron imaging",
International Workshop on Position Sensitive Neutron Detectors (PSND 2018 workshop), Julich, Germany, May 15-17 (2018), No.PT-13 (poster).

243. M. Winkler, M. Feneberg, S. F. Chichibu, R. Collazo, Z. Sitar, M. D. Neumann, N. Esser, and R. Goldhahn:

"Parametric model for the anisotropic dielectric function of m-plane AlGaN up to 20 eV",
German Physical Society (DPG) Spring Meeting, Session HL 27, Nitrides: Preparation and Characterization II, Berlin, Germany, Mar.11-26 (2018), No. HL27.10 (oral).

242. K. Kojima, H. Ikeda, K. Fujito, and S. F. Chichibu:

"Determination of absolute quantum efficiency of radiation in nitride semiconductors using an integrating sphere",
The Society of Photo-Optical Instrumentation Engineers (SPIE) Photonics West 2018, Gallium Nitride Materials and Devices XIII (OE107), San Francisco, USA, Jan.27-Feb.1, (2018), No.10532-61 (Invited-oral).

241. S. F. Chichibu, Y. Ishikawa, H. Kominami, and K. Hara:

"Spatio-time-resolved cathodoluminescence of h-BN microcrystals",
The Society of Photo-Optical Instrumentation Engineers (SPIE) Photonics West 2018, Gallium Nitride Materials and Devices XIII (OE107), San Francisco, USA, Jan.27-Feb.1, (2018), No.10532-18 (Invited-oral).

240. W. Zehua, H. Nakai, M. Sugiyama, and S. F. Chichibu:

"UV light absorbing and emitting diodes consisting of a p-type NiO film deposited on an n-type GaN homoepitaxial epilayer",
Materials Research Society, 2017 Fall Meeting, Symposium EM4: Wide- and Ultra-Wide-Bandgap Materials and Devices, Boston, MA, USA, Nov.26-Dec.1 (2017) No.EM04.06.07 (oral).

239. S. F. Chichibu, K. Kojima, K. Shima, A. Uedono, and S. Ishibashi:

"Consideration of Shockley-Read-Hall nonradiative recombination centers in wide bandgap (Al,Ga)N and ZnO",
Materials Research Society, 2017 Fall Meeting, Symposium EM4: Wide- and Ultra-Wide-Bandgap Materials and Devices, Boston, MA, USA, Nov.26-Dec.1 (2017) No.EM04.04.06 (Invited-oral).

238. N. Umehara, T. Kouno, H. Kominami, K. Kojima, S. F. Chichibu, and K. Hara:

"Cathodoluminescence characterization of the hexagonal boron nitride thin films grown on c-plane sapphire substrates",
International Workshop on UV Materials and Devices (IWUMD) 2017, Fukuoka, Japan, Nov.14-18 (2017). No.Th-P31 (poster).

237. S. F. Chichibu, Y. Ishikawa, H. Kominami, and K. Hara:

"Spatio-time-resolved cathodoluminescence studies of hexagonal BN microcrystals",
International Workshop on UV Materials and Devices (IWUMD) 2017, Fukuoka, Japan, Nov.14-18 (2017). No.Th-P23 (poster).

236. T. Nakano, K. Mochizuki, T. Nakamura, T. Aoki, Y. Inoue, K. Kojima, and S. F. Chichibu:

"Study of Boron metal organic sources for BGaN growth using MOVPE",
International Workshop on UV Materials and Devices (IWUMD) 2017, Fukuoka, Japan, Nov.14-18 (2017). No.Th-P15 (poster).

235. Y. Inatomi, Y. Kangawa, S. F. Chichibu, and K. Kakimoto:

"Theoretical study of composition pulling effect in AlGaN and AlInN MOVPE",
International Workshop on UV Materials and Devices (IWUMD) 2017, Fukuoka, Japan, Nov.14-18 (2017). No.Th-P8 (poster).

234. K. Kojima, Y. Hayashi, K. Hiramatsu, H. Miyake, and S. F. Chichibu:

"Compositional modulation for high AlN mole fraction Al_xGa_1-xN multiple quantum wells to enhance overlap integral of carrier wavefunctions",
International Workshop on UV Materials and Devices (IWUMD) 2017, Fukuoka, Japan, Nov.14-18 (2017). No.We-P41 (poster).

233. T. Nakano, T. Arikawa, K. Mochizuki, H. Nakagawa, S. Usami, M. Kushimoto, Y. Honda, H. Amano, K. Kojima, S. F. Chichibu, H. Mimura, Y. Inoue, and T. Aoki:

"Fabrication and evaluation of vertical type BGaN neutron detection diodes",
2017 IEEE Nuclear Science Symposium and Medical Imaging Conference, Workshop on Room-Temperature Semiconductor X-Ray and Gamma-Ray Detectors (NSS/MIC/RTSD), Hyatt Regency, Atlanta, Georgia, USA, Oct.21-28 (2017). No.R-17-4 (oral).

232. S. F. Chichibu, K. Kojima, A. Uedono, and Y. Sato:

"Vacuum-fluorescent-display devices emitting polarized deep-ultraviolet and visible lights using m-plane Al_1-xIn_xN epitaxial nanostructures",
11th International Symposium on Semiconductor Light Emitting Devices (ISSLED 2017), Session: Th-3 - Novel Devices and Structures 1, Banff, Canada, Oct.8-12 (2017), No.Th3.1 (Invited-oral).

231. S. Usami, Y. Honda, K. Kojima, M. Kushimoto, M. Deki, S. Nitta, S. F. Chichibu, and H. Amano:

"Internal quantum efficiency evaluation of LED by photocurrent measurement",
11th International Symposium on Semiconductor Light Emitting Devices (ISSLED 2017), Session: W-5 - UV materials and characterization, Banff, Canada, Oct.8-12 (2017), No.W5.4 (Late News oral).

230. S. F. Chichibu, K. Kojima, and A. Uedono:

"Optical and defect characteristics of m-plane Al_1-xIn_xN epitaxial nanostructures",
8th Asia-Pacific Workshop on Widegap Semiconductors (APWS-2017), Qingdao, China, Sep 24-27 (2017) No.MOCRI1 (Invited-oral).

229. S. F. Chichibu and K. Kojima:

"Periodic compositional undulation in the m-plane Al_1-xIn_xN epilayers grown by metalorganic vapor phase epitaxy on a GaN substrate",
European Materials Research Society, 2017 Fall Meeting, Session P: Group III-Nitrides: fundamental research, optoelectronic devices and sensors, Warsaw University of Technology, Warsaw, Poland, Sep.18-21 (2017), No. P.10.2 (Invited-oral).

228. M. Saito, Q. Bao, K. Kurimoto, D. Tomida, K. Kojima, Y. Kagamitani, R. Kayano, T. Ishiguro, and S. F. Chichibu:

"Recent progress of acidic ammonothermal growth of GaN",
10th International Workshop on Bulk Nitride Semiconductors (IWBNS-X), Nuuksio Natinoal Park, Espoo, Finland, Sept.18.-22 (2017), No.11:00 (Invited-oral).

227. S. F. Chichibu, K. Kojima, H. Ikeda, K. Fujito, S. Takashima, M. Edo, K. Ueno, M. Shimizu, T. Takahashi, S. Ishibashi, and A. Uedono:

"Origin and properties of intrinsic Shockley-Read-Hall nonradiative recombination centers in GaN",
29th International Conference on Defects in Semiconductors (ICDS2017), Matsue, Japan, July 31-Aug. 4 (2017), No.TuB3-1 (Invited-oral).

226. S. F. Chichibu, K. Kojima, K. Furusawa, Y. Yamazaki, K. Hiramatsu, and H. Miyake:

"A way to achieve more than 90% of the overlap integral of electron and hole wavefunctions in high AlN mole fraction AlGaN MQWs",
The 12th International Conference on Nitride Semiconductors (ICNS-12), Strasbourg, France, July 24-28 (2017), No.B.8.2 (oral).

225. S. Sakai, T. Minami, K. Kojima, S. F. Chichibu, and A. A. Yamaguchi:

"Quantum-Wire-Like Density of States in c-plane AlGaN Quantum Wells in Polarization-Crossover Composition Regionn",
The 12th International Conference on Nitride Semiconductors (ICNS-12), Strasbourg, France, July 24-28 (2017), No.E.1.6 (poster).

224. K. Mochizuki, T. Nakamura, T. Arikawa, Y. Inoue, S. Usami, M. Kushimoto, Y. Honda, H. Amano, K. Kojima, S. F. Chichibu, H. Mimura, T. Aoki, and T. Nakano:

"Fabrication and evaluation of vertical type BGaN diodes by MOVPE using trimethylboron",
The 12th International Conference on Nitride Semiconductors (ICNS-12), Strasbourg, France, July 24-28 (2017), No.D.1.12 (poster).

223. S. F. Chichibu, Y. Ishikawa, Y. Kominami, and K. Hara:

"Spatio-Time-Resolved Cathodoluminescence studies of h-BN microcrystals",
The 12th International Conference on Nitride Semiconductors (ICNS-12), Strasbourg, France, July 24-28 (2017), No.A.1.24 (poster).

222. S. F. Chichibu, K. Kojima, S. Takashima, M. Edo, K. Ueno, M. Shimizu, T. Takahashi, S. Ishibashi, and A. Uedono:

"Role of point defects on the luminescent properties of epitaxial and ion-implanted Mg-doped GaN fabricated on a GaN substrate",
The 12th International Conference on Nitride Semiconductors (ICNS-12), Strasbourg, France, July 24-28 (2017), No.A.1.23 (poster).

221. K. Kojima, H. Ikeda, K. Fujito, and S. F. Chichibu:

"A high internal quantum efficiency of the emission in GaN single crystals observed by omnidirectional photoluminescence (ODPL)",
The 12th International Conference on Nitride Semiconductors (ICNS-12), Strasbourg, France, July 24-28 (2017), No.E.1.6 (oral).

220. K. Kojima, Y. Nagasawa, A. Hirano, M. Ipponmatsu, Y. Honda, H. Amano, I. Akasaki, and S. F. Chichibu:

"Optical characteristics of c-plane AlGaN multiple-quantum-well light-emitting diode structures with macro-size steps",
The 12th International Conference on Nitride Semiconductors (ICNS-12), Strasbourg, France, July 24-28 (2017), No.B.2.1 (oral).

219. M. Saito, Q. Bao, K. Kurimoto, D. Tomida, K. Kojima, Y. Kagamitani, R. Kayano, T. Ishiguro, and S. F. Chichibu:

"High Quality Bulk GaN Crystal Grown by Acidic Ammonothermal Method",
The 12th International Conference on Nitride Semiconductors (ICNS-12), Strasbourg, France, July 24-28 (2017), No.A2.2 (oral).

218. K. Kojima, K. Furusawa, Y. Yamazaki, H. Miyake, K. Hiramatsu, and S. F. Chichibu:

"A theoretical proposal for achieving more than 90% of the overlap integral of electron and hole wavefunctions in high AlN mole fraction AlxGa1-xN multiple quantum wells",
The 18th International Conference on Physics of Light-Matter Coupling in Nanostructures (PLMCN18), Wuerzburg, Germany, Jul.9-14 (2017), No.P3-008 (poster).

217. S. F. Chichibu, Y. Ishikawa, Y. Kominami, and K. Hara:

"Spatio-time-resolved cathodoluminescence studies on hexagonal BN microcrystals",
The 2nd International Conference on Physics of 2D Crystals (ICP2C2), Ha Long, Vietnam, Apr.25-30 (2017), No.2-16h45 (Invited-oral).

216. K. Kojima, H. Ikeda, K. Fujito, and S. F. Chichibu:

"IQE Quantification of Nitride Semiconductors - Omnidirectional photoluminescence (ODPL) measurement utilizing an integrating sphere - Recent progress of ammonothermal growth of GaN using acidic mineralizers",
The 5th International Conference on Light-Emitting Devices and Their Industrial Applications (LEDIA'17), Yokohama, Japan, Apr.18-21 (2017), No.LED-LDC1-1 (Invited-oral).

215. M. Winkler, S. F. Chichibu, R. Collazo, Z. Sitar, M. D. Neumann, N. Esser, R. Goldhahn, and M. Feneberg:

"Anisotropic dielectric function of nonpolar AlGaN up to 20eV",
German Physical Society (DPG) Spring Meeting, Dresden, Germany,Session HL 50: Nitrides: Preparation and Characterization, Mar.19-24 (2017), No. HL 50.10 (oral).

214. S. F. Chichibu, M. Saito, Q. Bao, K. Kurimoto, D. Tomida, K. Kojima, Y. Kagamitani, R. Kayano, and T. Ishiguro:

"Recent progress of ammonothermal growth of GaN using acidic mineralizers",
Workshop on Frontier Photonic and Electronic Materials and Devices - 2017 German-Japanese-Spanish Joint Workshop, Hotel Punta Rotja, Mallorca, Spain, Mar.5-8 (2017) No. Mo-7 (Invited-oral).

213. S. F. Chichibu, K. Kojima, and A. Uedono:

"Origin of Shockley-Read-Hall nonradiative recombination centers in (Al,Ga)N",
The Society of Photo-Optical Instrumentation Engineers (SPIE) Photonics West 2017, OE127 Light-Emitting Diodes: Materials, Devices, and Applications for Solid State Lighting XXI, San Francisco, USA, Jan.28-Feb.2, (2017), No.10124-20 (Invited-oral).

212. S. F. Chichibu, K. Kojima, S. Takashima, M. Edo, K. Ueno, M. Shimizu, T. Takahashi, S. Ishibashi, and A. Uedono:

"Photoluminescence characterization of ion-implanted and epitaxial Mg-doped GaN prepared on freestanding GaN substrates",
Materials Research Society, 2016 Fall Meeting, Symposium EM11: Wide-Bandgap Materials for Energy Efficiency-Power Electronics and Solid-State Lighting, Boston, MA, USA, Nov.27-Dec.2 (2016) No.EM11.2.03 (oral).

211. M. Saito, Q. Bao, K. Kurimoto, D. Tomida, K. Kojima, Y. Kagamitani, R. Kayano, T. Ishiguro, and S. F. Chichibu:

"High Quality Bulk GaN Crystal Grown by Acidic Ammonothermal Method",
International Workshop on Nitride Semiconductors 2016 (IWN2016), Orland, Florida, USA, Oct. 2-7 (2016), Session A1.1: Bulk Growth I: Bulk Crystal Growth, No.A1.1.07 (Invited-oral).

210. S. F. Chichibu, K. Kojima, A. Uedono, and Y. Sato:

"Defect-resistant emission properties of nonpolar m-plane Al_1-xIn_xN epilayers for deep-ultraviolet to visible polarized-light-emitting vacuum fluorescent display devices",
International Workshop on Nitride Semiconductors 2016 (IWN2016), Orland, Florida, USA, Oct. 2-7 (2016), Session B2.1: UV Devices I: UV Emitters, No.B2.1.06 (oral).

209. K. Kojima, T. Ohtomo, M. Saito, H. Ikeda, K. Fujito, and S. F. Chichibu:

"Quantifying absolute value of quantum efficiency of radiation in high quality GaN single crystals",
International Workshop on Nitride Semiconductors 2016 (IWN2016), Orland, Florida, USA, Oct. 2-7 (2016), Session D1.5: Materials Characterization V: Characterization of GaN and InN, No.D1.5.01 (oral).

208. S. F. Chichibu, K. Kojima, A. Uedono, and Y. Sato:

"Defect-resistant luminescent probability of m-plane AlInN alloy films for deep ultraviolet and visible polarized light-emitters",
European Materials Research Society, 2016 Fall Meeting, Session F: AlN and AlGaN materials and devices, Warsaw University of Technology, Warsaw, Poland, Sep.19-22 (2016), No. F.08.1 (Invited-oral).

207. A. A. Yamaguchi, T. Minami, S. Sakai, K. Kojima, and S. F. Chichibu:

"Alloy-Compositional-Fluctuation Effects on Optical Gain Characteristics in AlGaN and InGaN Quantum-Well Laser Diodes",
The 25th International Semiconductor Laser Conference (ISLC2016), Kobe, Japan, Sep.12-15, (2016), No.WE60 (poster).

206. S. F. Chichibu, K. Kojima, Y. Yamazaki, and K. Furusawa:

"Metalorganic vapor phase epitaxy of pseudomorphic m-plane Al1-xInxN alloy films on a low defect density m-plane GaN substrate",
The 18th International Conference on Crystal Growth and Epitaxy (ICCGE-18), Nagoya Congress Center, Nagoya, Japan, Aug. 7-12 (2016), No.Tu2-T09-5 (oral).

205. M. Saito, Q. Bao, K. Kurimoto, D. Tomida, K. Kojima, Y. Kagamitani, R. Kayano, T. Ishiguro, and S. F. Chichibu:

"High Quality Bulk GaN Crystal Grown by Acidic Ammonothermal Method",
The 18th International Conference on Crystal Growth and Epitaxy (ICCGE-18), Nagoya Congress Center, Nagoya, Japan, Aug. 7-12 (2016), No.Th1-T01-6 (oral).

204. S. M. Islam, V. Protasenko, H. (Grace) Xing, Debdeep Jena, K. Kojima, and S. F. Chichibu:

"Cathodoluminescence Spectroscopy of GaN/AlN Quantum Structures for sub-280 nm emission",
The International Workshop on UV Materials and Devices (IWUMD-2016), Peking, China, July 27-31 (2016), No.P-42 (poster).

203. M. Saito, Q. Bao, K. Kurimoto, D. Tomida, K. Kojima, Y. Kagamitani, R. Kayano, T. Ishiguro, and S. F. Chichibu:

"High Quality Bulk GaN Crystal Grown by Acidic Ammonothermal Method",
9th International Conference on High Temperature Ceramic Matrix Composites (HTCMC-9) and Global Forum on Advanced Materials and Technologies for Sustainable Development (GFMAT 2016), G5: Advanced materials, technologies, and devices for electro-optical and medical applications, Tronto, Canada, Jun.26-30, (2016), No.G5-002-2016 (Invited-oral).

202. S. F. Chichibu, Y. Ishikawa, K. Furusawa, A. Uedono, H. Miyake, and K. Hiramatsu:

"Spatio-time-resolved cathodoluminescence study on high AlN mole fraction Al_xGa_1-xN structures grown by metalorganic vapor phase epitaxy on GaN and AlGaN structures",
The 43rd International Symposium on Compound Semiconductors (ISCS 2016), Toyama International Conference Center, Toyama, Japan, June 26-30 (2016), No.TuB2-1 (Invited-oral).

201. Q. Bao, M. Saito, K. Kurimoto, D. Tomida, K. Kojima, Y. Kagamitani, R. Kayano, T. Ishiguro, and S. F. Chichibu:

"High Quality Bulk GaN Crystal Grown by Acidic Ammonothermal Method",
The 43rd International Symposium on Compound Semiconductors (ISCS 2016), Toyama International Conference Center, Toyama, Japan, Jun. 26-30 (2016), No.ThD2-3 (oral).

200. K. Kojima, H. Ikeda, K. Fujito, and S. F. Chichibu:

"Recombination dynamics of hot carriers excited in a highly-doped m-plane GaN single crystal",
17th International Conference on Physics of Light-Matter Coupling in Nanostructures (PLMCN17), Nara, Japan, Mar. 28-31 (2016), No. TuP34 (poster).

199. M. Saito, Q. Bao, K. Kurimoto, D. Tomida, K. Kojima, Y. Kagamitani, R. Kayano, T. Ishiguro, and S. F. Chichibu:

"High Quality Bulk GaN Crystal Grown by Acidic Ammonothermal Method",
The Society of Photo-Optical Instrumentation Engineers (SPIE) Photonics West 2016, OPTO, Gallium Nitride Materials and Devices XI, San Francisco, USA, Feb.13 -18, (2016), No.9748-9 (Invited-oral).

198. K. Shimada, D. Ito, K. Iwasaki, and S. F. Chichibu:

"First-principles calculations of structural, elastic, and piezoelectric properties in wurtzite In_xAl_1-xN",
The Sixth International Symposium on Growth of III-Nitrides (ISGN-6), Act City Hamamatsu, Hamamatsu, Japan, Nov.8-13 (2015), No.We-B43 (oral+poster).

197. S. F. Chichibu, K. Kojima, Y. Yamazaki, K. Furusawa, H. Ikeda, and K. Fujito:

"Metalorganic vapor phase epitaxy and time-resolved luminescence studies of pseudomorphic m-plane Al_1-xIn_xN epitaxial films on a low defect density m-plane GaN substrate",
The Sixth International Symposium on Growth of III-Nitrides (ISGN-6), Act City Hamamatsu, Hamamatsu, Japan, Nov.8-13 (2015), No.We-A43 (oral+poster).

196. M. Saito, Q. Bao, K. Kurimoto, D. Tomida, K. Kojima, Y. Kagamitani, R. Kayano, T. Ishiguro, and S. F. Chichibu:

"High Quality Bulk GaN Crystal Grown by Acidic Ammonothermal Method",
The Sixth International Symposium on Growth of III-Nitrides (ISGN-6), Act City Hamamatsu, Hamamatsu, Japan, Nov.8-13 (2015), No.Tu-A28 (oral+poster).

195. K. Kojima, D. Kagaya, Y. Yamazaki, H, Ikeda, K. Fujito, and S. F. Chichibu:

"Spectroscopic ellipsometry studies on the m-plane Al_1-xIn_xN epilayers grown by metalorganic vapor phase epitaxy on a freestanding GaN substrate",
The Sixth International Symposium on Growth of III-Nitrides (ISGN-6), Act City Hamamatsu, Hamamatsu, Japan, Nov.8-13 (2015), No.Tu-B19 (oral+poster).

194. K. Kojima, K. Furusawa, E. Furukawa, M. Saito, Y. Tsukada, Y. Mikawa, S. Kubo, H. Ikeda, K. Fujito, A. Uedono, and S. F. Chichibu:

"Low resistivity m-plane freestanding GaN substrate with very low point defect concentration grown by hydride vapor phase epitaxy on an ammonothermal GaN seed crystal",
The Sixth International Symposium on Growth of III-Nitrides (ISGN-6), Act City Hamamatsu, Hamamatsu, Japan, Nov.8-13 (2015), No.I-We-B2 (Upgraded Invited-oral).

193. M. Matsuo, T. Murayama, K. Koike, S. Sasa, M. Yano, S. Gonda, R. Ishigami, K. Kume, A. Uedono, T. Ohtomo, E. Furukawa, Y. Yamazaki, K. Kojima, and S. Chichibu:

"Polarity Dependent Radiation Hardness of GaN",
The 2015 International Meeting for Future of Electron Devices, Kansai, Ryukoku University Avanti Kyoto Hall, Kyoto, Japan, June 4-5 (2015) No.PA-09 (poster). Proceedings of IEEE IMFEDK2015, pp.50-51: IEEE Xplore Digital Library (2015) (pdf)

192. M. Saito, Q. Bao, K. Kurimoto, D. Tomida, K. Kojima, Y. Yamazaki, Y. Kagamitani, R. Kayano, T. Ishiguro, and S. F. Chichibu:

"High Quality Bulk GaN Crystal Grown by Acidic Ammonothermal Method",
The 11th International Conference on Nitride Semiconductors (ICNS-11), Beijing, China, Aug.30-Sep.4 (2015), No.TuGO10 (oral).

191. S. F. Chichibu, K. Kojima, Y. Yamazaki, K. Furusawa, H. Ikeda, and K. Fujito:

"Time-resolved and spatially-resolved luminescence studies on ultraviolet to green luminescence peaks of m-plane Al_1-xIn_xN epilayers grown on a low defect density m-plane GaN substrate",
The 11th International Conference on Nitride Semiconductors (ICNS-11), Beijing, China, Aug.30-Sep.4 (2015), No.TuBO5 (oral).

190. S. F. Chichibu, M. Saito, Q. Bao, K. Kurimoto, D. Tomida, K. Kojima, Y. Yamazaki, Y. Kagamitani, R. Kayano, and T. Ishiguro:

"High-Quality Bulk Crystal Growth of GaN by the Ammonothermal Method in a Supercritical NH₃ Using Acidic Mineralizers",
Workshop on Frontier Photonic and Electronic Materials and Devices - 2015 German -Japanese-Spanish Joint Workshop, Shiran Kaikan, Kyoto University, Kyoto, Japan, July 11-14 (2015), No. Mo-14 (Invited-oral).

189. S. F. Chichibu:

"Wide bandgap III-nitride semiconductors for short wavelength light emitters",
UK Semiconductors 2015, Sheffield Hallam University, Sheffield, United Kingdom, July 1-2 (2015), Plenary Talk.

188. S. F. Chichibu, Y. Ishikawa, K. Furusawa, H. Miyake, and K. Hiramatsu:

"Spatio-time-resolved cathodoluminescence studies on the Si-doping effects in high AlN mole fraction Al_xGa_1-xN multiple quantum wells grown on an AlN template by metalorganic vapor phase epitaxy",
15th International Workshop on Junction Technology (IWJT2015), Kyoto University (Uji Campus), Kyoto, Japan, June 11-12 (2015) No.S3-1 (Invited-oral). Proceedings of IWJT2015, IEEE Xplore Digital Library (2015) (pdf)

187. S. F. Chichibu, Y. Ishikawa, S. Mita, J. Xie, R. Collazo, and Z. Sitar:

"Spatio-time-resolved cathodoluminescence studies on AlN epitaxial films",
Materials Research Society, 2014 Fall Meeting, Symposium AA: Synthesis, Processing and Mechanical Properties of Functional Hexagonal Materials for Energy Applications, Boston, MA, USA, Nov.30-Dec.5 (2014), No. AA10.01/T9.01 (Invited-oral).

186. Y. Yamazaki, K. Furusawa, K. Kojima, K. Nakahama, H. Miyake, K. Hiramatsu, and S.F. Chichibu:

"A strategy to improve the emission efficiency of Si-doped AlGaN multiple quantum wells by out-of-plane compositional modulations",
Materials Research Society, 2014 Fall Meeting, Symposium T: Wide-Bandgap Materials for Solid-State Lighting and Power Electronics, Boston, MA, USA, Nov.30-Dec.5 (2014), No. T3.07 (oral).

185. S. F. Chichibu, Y. Ishikawa, T. Ohtomo, K. Furusawa, H. Miyake, and K. Hiramatsu:

"Spatio-time-resolved cathodoluminescence studies on the Si-doping effects in high AlN mole fraction Al_xGa_1-xN multiple quantum wells grown on an AlN template",
Materials Research Society, 2014 Fall Meeting, Symposium T: Wide-Bandgap Materials for Solid-State Lighting and Power Electronics, Boston, MA, USA, Nov.30-Dec.5 (2014), No. T3.08 (oral).

184. K. Kojima, H. Ikeda, K. Fujito, and S. F. Chichibu:

"Optical polarization properties of Al_1-xIn_xN epilayers grown on m-plane freestanding GaN substrates",
Materials Research Society, 2014 Fall Meeting, Symposium AA: Synthesis, Processing and Mechanical Properties of Functional Hexagonal Materials for Energy Applications, Boston, MA, USA, Nov.30-Dec.5 (2014), No. AA10.03/T9.03 (oral).

183. M. Saito, Q. Bao, K. Kurimoto, D. Tomida, K. Kojima, Y. Yamazaki, Y. Kagamitani, R. Kayano, K. Qiao, T. Ishiguro, C. Yokoyama, and S. F. Chichibu:

"High Quality Bulk GaN Crystal Growth by Acidic Ammonothermal Method",
Materials Research Society, 2014 Fall Meeting, Symposium AA: Synthesis, Processing and Mechanical Properties of Functional Hexagonal Materials for Energy Applications, Boston, MA, USA, Nov.30-Dec.5 (2014), No. AA11.05/T10.05 (oral).

182. S. F. Chichibu, K. Furusawa, K. Hazu, Y. Ishikawa, T. Onuma, T. Ohtomo, Y. Yamazaki, K. Kojima, H. Ikeda, and K. Fujito:

"Epitaxial growth of thick m-plane Al_1-xIn_xN epilayers exhibiting a dominant ultraviolet to green near-band-edge luminescence peak on a low defect density m-plane GaN substrate",
International Workshop on Nitride Semiconductors 2014 (IWN2014), Wrockaw, Poland, Aug. 24-29 (2014), Session Growth, No. WeGI21 (Invited-oral).

181. S. F. Chichibu, Y. Ishikawa, T. Ohtomo, K. Furusawa, A. Uedono, H. Miyake, K. Hiramatsu, S. Mita, J. Xie, R. Collazo, and Z. Sitar:

"Spatio-time-resolved cathodoluminescence studies on AlN and high AlN mole fraction Al_xGa_1-xN alloys",
International Workshop on Nitride Semiconductors 2014 (IWN2014), Wrockaw, Poland, Aug. 24-29 (2014), Session Growth, No. WeBI13 (Invited-oral).

180. H. Sumiyoshi, Y. Kangawa, S. F. Chichibu, M. Knetzger, E. Meissner, Y. Iwasaki, and K. Kakimoto:

"Cathodoluminescence studies of AlN/AlN(0001) grown by solid source solution growth method",
International Workshop on Nitride Semiconductors 2014 (IWN2014), Wrockaw, Poland, Aug. 24-29 (2014), Session Growth, No. TuGP57 (poster).

179. M. Saito, Q. Bao, D. Tomida, K. Furusawa, Y. Kagamitani, R. Kayano, K. Qiao, T. Ishiguro, C. Yokoyama, and S. F. Chichibu:

"High Quality Bulk GaN Crystal Growth by Acidic Ammonothermal Method",
International Workshop on Nitride Semiconductors 2014 (IWN2014), Wrockaw, Poland, Aug. 24-29 (2014), Session Growth, No. MoG04 (oral).

178. S. F. Chichibu, Y. Ishikawa, and K. Furusawa:

"Spatio-time-resolved cathodoluminescence studies on wide bandgap wurtzite AlN and GaN",
International Conference on Metamaterials and Nanophysics (METANANO2014) , Varadero, Cuba, Apr.22-May.1 (2014), No. Thu 24.04.2014 10:00 (Invited-oral).

177. S. F. Chichibu, H. Miyake, K. Hazu, Y. Ishikawa, M. Tashiro, T. Ohtomo, K. Furusawa, K. Hiramatsu, and A. Uedono:

"Effects of Si-doping on the near-band- edge emission dynamics of Al_0.6Ga_0.4N epilayers grown on AlN templates by metalorganic vapor phase epitaxy",
The IUMRS International Conference in Asia 2013 (IUMRS-ICA-2013), Indian Isntitute of Science, Bangalore, India, Dec. 16-20 (2013), No. Invited Talk (4) (Invited-oral).

176. S. F. Chichibu, Y. Ishikawa, M. Tashiro, K. Hazu, and K. Furusawa:

"Spatio-time-resolved cathodoluminescence studies on group-III-nitride semiconductors",
The 2nd International Conference on Advanced Electromaterials (ICAE2013), ICC Jeju, Jeju, Korea, Nov. 12-15 (2013), Symposium 4: Advanced LED and Lighting Technology, No. LT-3356 (Invited-oral).

175. K. Furusawa, Y. Ishikawa, M. Tashiro, K. Hazu, S. Nagao, H. Ikeda, K. Fujito, and S. F. Chichibu:

"Local carrier dynamics in and around the sub-surface stacking faults in GaN studied using spatio-time-resolved cathodoluminescence equipped with a front-excitation configuration femtosecond pulsed photoelectron gun",
2013 Japan Society of Applied Physics - Materials Research Society Joint Symposia, Doshisha University, Kyoto, Japan, Sep.16-20 (2013), Symposium J, No.18p-M6-12 (oral).

174. S. F. Chichibu and A. Uedono:

"Influences of point defects on the emission dynamics of wide bandgap nitride and oxide semiconductors",
2013 Japan Society of Applied Physics - Materials Research Society Joint Symposia, Doshisha University, Kyoto, Japan, Sep.17 (2013), Symposium H: Smart Materials Design for Ultimate Functional Materials: Functional Core Concept, No.17p-M4-5 (Invited-oral).

173. D. Tomida, Q. Bao, M. Saito, Y. Kagamitani, K. Hazu, K. Qiao, T. Ishiguro, S. F. Chichibu, and C. Yokoyama:

"Effect of mineralizer species on the crystal growth of gallium nitride by the acidic ammonothermal method",
2013 Japan Society of Applied Physics - Materials Research Society Joint Symposia, Doshisha University, Kyoto, Japan, Sep. 16-20 (2013), Symposium J, No.17a-M6-3 (Invited-oral).

172. T. Miyanaga, T. Azuhata, K. Nakajima, H. Nagoya, K. Hazu, and S. F. Chichibu:

"Polarized XAFS study of Al K-edge for m-plane AlGaN films",
Light and Particle Beams in Materials Science 2013 (LPBMS2013), Ibaraki, Japan, Aug.29-31 (2013), No.P023 (Poster).

171. M. Saito, Q. Bao, D. Tomida, K. Hazu, K. Furusawa, Y. Kagamitani, K. Qiao, T. Ishiguro, C. Yokoyama, and S. F. Chichibu:

"Effect of mineralizer species on the crystal growth of GaN in supercritical acidic ammonia",
The 10th International Conference on Nitride Semiconductors (ICNS-10), Washington, DC, USA, Aug.28 (2013), No.A6.09 (oral).

170. S. F. Chichibu, K. Hazu, T. Ohtomo, Y. Ishikawa, K. Furusawa, and T. Nakayama:

"Transport and emission properties of Nb-doped n++-type (001) anatase-TiO2 / Mg-doped p-type (0001) GaN heteroepitaxial structures",
The 10th International Conference on Nitride Semiconductors (ICNS-10), Washington, DC, USA, Aug.27 (2013), No.BP2.15 (poster).

169. K. Furusawa, Y. Ishikawa, M. Tashiro, K. Hazu, S. Nagao, H. Ikeda, K. Fujito, and S. F. Chichibu:

"Local emission dynamics in and around the sub-surface basal-plane stacking faults in GaN studied by the spatio-time-resolved cathodoluminescence method using a front-excitation photoelectron gun",
The 10th International Conference on Nitride Semiconductors (ICNS-10), Washington, DC, USA, Aug.27 (2013), No.AP2.36 (poster).

168. S. F. Chichibu, Y. Ishikawa, M. Tashiro, K. Furusawa, K. Hazu, S. Mita, J. Xie, R. Collazo, and Z. Sitar:

"Spatio-time-resolved cathodoluminescence studies on AlN epitaxial films grown on low dislocation density bulk AlN substrates prepared by the physical vapor transport method",
The 10th International Conference on Nitride Semiconductors (ICNS-10), Washington, DC, USA, Aug.27 (2013), No.C4.02 (oral).

167. S. F. Chichibu, H. Miyake, Y. Ishikawa, M. Tashiro, T. Ohtomo, K. Hazu, K. Furusawa, K. Hiramatsu, and A. Uedono:

"Effects of Si-doping on the recombination dynamics of excitons in AlGaN alloys studied by time-resolved cathodoluminescence",
European Materials Research Society, 2013 Spring Meeting, Session L: Group III nitrides, Congress Center, Strasbourg, France, May 29 (2013), No. L-91 (Invited-oral).

166. K. Furusawa, Y. Ishikawa, M. Tashiro, K. Hazu, S. Nagao, H. Ikeda, K. Fujito, and S. F. Chichibu:

"Spatio-time-resolved cathodoluminescence studies on local exciton dynamics of a freestanding GaN substrate grown by hydride vapor phase epitaxy",
The 40th International Symposium on Compound Semiconductors (ISCS 2013), Kobe, Japan, May 19-23 (2013), No. TuA1-4 (oral).

165. K. Furusawa, Y. Ishikawa, M. Tashiro, K. Hazu, S. Nagao, K. Fujito, A. Uedono, and S. F. Chichibu:

"Local carrier dynamics in freestanding GaN substrates grown by hydride vapor phase epitaxy studied using the spatio-time-resolved cathodoluminescence technique",
International Workshop on Nitride Semiconductors 2012 (IWN2012), Sapporo, Japan, Oct.14-19 (2012), No. MoP-GR-54 (poster).

164. C. Yokoyama, Q. Bao, H. Sawayama, T. Hashimoto, F. Sato, K. Hazu, Y. Kagamitani, T. Ishinabe, M. Saito, R. Kayano, D. Tomida, K. Qiao, S. F. Chichibu, and T. Ishiguro:

"Powder synthesis and ammonothermal crystal growth of GaN using Ga metal as a starting material",
International Workshop on Nitride Semiconductors 2012 (IWN2012), Sapporo, Japan Oct.14-19 (2012), Session GR1 (Bulk I), No. GR1-4 (oral).

163. K. Shimada, S. F. Chichibu, M. Hata, H. Sazawa, T. Takada, and T. Sota:

"Electronic structure and spontaneous polarization in Sc_xAl_yGa_1-x-yN alloys lattice-matched to GaN: A first-principles study",
International Workshop on Nitride Semiconductors 2012 (IWN2012), Sapporo, Japan Oct.14-19 (2012), No. TuP-PR-41 (poster).

162. K. Hazu, T. Ohtomo, T. Nakayama, A. Tanaka, and S. F. Chichibu:

"Band alignments and lateral transport properties of Nb-doped (100) rutile- and (001) anatase-TiO₂ / (0001) GaN heteroepitaxial structures",
International Workshop on Nitride Semiconductors 2012 (IWN2012), Sapporo, Japan Oct.14-19 (2012), Session OD4 (UV-LED II / Physics), No. OD4-3 (oral).

161. S. F. Chichibu, K. Hazu, Y. Ishikawa, M. Tashiro, H. Miyake, K. Hiramatsu, and A. Uedono:

"Impacts of point defects on the photoluminescence lifetime of Si-doped Al_0.6Ga_0.4N epilayers grown on an AlN template",
International Workshop on Nitride Semiconductors 2012 (IWN2012), Sapporo, Japan Oct.14-19 (2012), Session PR6 (Defects), No. PR6-2 (oral).

160. S. F. Chichibu, Y. Ishikawa, K. Hazu, M. Tashiro, K. Furusawa, H. Namita, S. Nagao, K. Fujito, and A. Uedono:

"Spatio-time-resolved cathodoluminescence studies on freestanding GaN substrates grown by hydride vapor phase epitaxy",
Pacific Rim Meeting on Electrochemical and Solid-State Science (PRiME 2012), Joint international meeting: 222nd Meeting of ECS, The Electrochemical Society and 2012 Fall Meeting of The Electrochemical Society of Japan, Session J3: Materials for Solid State Lighting, Hawaii Convention Center and the Hilton Hawaiian Village, Honolulu, Hawaii, USA, Oct. 7-12 (2012), No.J3-3956 (Invited-oral).

159. S. F. Chichibu, Y. Ishikawa, M. Tashiro, K. Hazu, K. Furusawa, S. Nagao, K. Fujito, and A. Uedono:

"Spatio-time-resolved cathodoluminescence study using a femtosecond focused electron beam on freestanding GaN substrates grown by hydride vapor phase epitaxy",
The 39th International Symposium on Compound Semiconductors (ISCS 2012), Santa Barbara, CA, USA, Aug.27-30 (2012), No. We-2B.2 (oral).

158. S. F. Chichibu and A. Uedono:

"Time-resolved luminescence studies on AlN and high AlN mole fraction AlGaN alloys",
The Fourth International Symposium on Growth of III-Nitrides (ISGN-4), St. Petersburg, Russia, Jul.16-19 (2012), No. Th-1i (Invited-oral).

157. K. Hazu, Y. Ishikawa, M. Tashiro, H. Namita, S. Nagao, K. Fujito, A. Uedono, and S. F. Chichibu:

"Time-resolved photoluminescence studies on HVPE freestanding GaN substrates exhibiting record-long positron diffusion length",
The Fourth International Symposium on Growth of III-Nitrides (ISGN-4), St. Petersburg, Russia, Jul.16-19 (2012), No. Mo-51p (poster).

156. C. Yokoyama, Q. Bao, S. F. Chichibu, T. Ishiguro, and K. Qiao:

"Powder synthesis of GaN using Ga metal as a starting material",
The Fourth International Symposium on Growth of III-Nitrides (ISGN-4), St. Petersburg, Russia, Jul.16-19 (2012), No. Mo-17p (poster).

154. K. Hazu, A. N. Fouda, M. Haemori, T. Nakayama, A. Tanaka, and S. F. Chichibu:

"Crystal phase-selective epitaxy of rutile and anatase Nb-doped TiO₂ films on a GaN template by the helicon-wave-excited-plasma sputtering epitaxy",
The 9th International Conference on Nitride Semiconductors (ICNS-9), Glasgow, UK, Jul.10-15 (2011), No. B9.4 (oral).

153. S. F. Chichibu, T. Onuma, K. Hazu, T. Sota, and A. Uedono:

"Time-resolved photoluminescence and time-resolved cathodoluminescence studies on AlN and high AlN mole fraction AlGaN alloys",
The 9th International Conference on Nitride Semiconductors (ICNS-9), Glasgow, UK, Jul.10-15 (2011), No. E3.4 (oral).

152. H. Matsumoto, K. Suzaki, K. Fujito, S. Nagao, M. Shigeiwa, Y. Ishikawa, K. Hazu, and S. F. Chichibu:

"Annealing effects of thick-GaN crystals",
The 9th International Conference on Nitride Semiconductors (ICNS-9), Glasgow, UK, Jul.10-15 (2011), No. PA1.11 (poster).

151. S. F. Chichibu, K. Hazu, Y. Kagamitani, T. Onuma, D. Ehrentraut, T. Fukuda, and T. Ishiguro:

"Ammonothermal growth of low oxygen concentration GaN using a dry acidic mineralizer and fabrication of an Al_0.2Ga_0.8N/GaN heterostructure",
The 9th International Conference on Nitride Semiconductors (ICNS-9), Glasgow, UK, Jul.10-15 (2011), No. A3.2 (oral).

150. Y. Ishikawa, K. Hazu, H. Matsumoto, K. Suzaki, K. Fujito, S. Nagao, M. Shigeiwa, and S. F. Chichibu:

"Spatio-time-resolved cathodoluminescence study on a freestanding GaN substrate grown by halide vapor phase epitaxy",
The 9th International Conference on Nitride Semiconductors (ICNS-9), Glasgow, UK, Jul.10-15 (2011), No. A2.5 (oral).

149. Y. Kagamitani, Q. Bao, S. F. Chichibu, K. Sugiyama, T. Fukuda, T. Ishiguro, and C. Yokoyama:

"GaN Growth by the Ammonothermal Method Using an Acidic Mineralizer",
The 5th Asian Conference on Crystal Growth and Crystal Technology (CGCT-5) - International Conference on Materials for Advanced Technologies (ICMAT-2011), International Convention and Exhibition Centre, Singapore, Jun.26 - Jul.1 (2011), No. EE5-9 (oral).

148. S. F. Chichibu, K. Hazu, Y. Kagamitani, T. Onuma, D. Ehrentraut, T. Fukuda, and T. Ishiguro:

"Optical properties of GaN films and an AlGaN/GaN heterostructure fabricated on GaN substrates grown by the ammonothermal method using gas-phase synthesized NH₄Cl mineralizer",
5th Asia-Pacific Workshop on Widegap Semiconductors (APWS-2011), Ise-Shima National Park, Toba, Mie, Japan, May 22-26 (2011) No. We-B4 (oral).

147. S. F. Chichibu, K. Hazu, T. Onuma, T. Sota, and A. Uedono:

"Time-resolved photoluminescence and time-resolved cathodoluminescence studies on AlN and high AlN mole fraction AlGaN alloys",
European Materials Research Society 2011 Spring Meeting (E-MRS2011), Nice, France, May9-13 (2011), No.F53 (Invited-oral).

146. K. Hazu, Y. Kagamitani, T. Onuma, D. Ehrentraut, T. Fukuda, T. Ishiguro, and S. F. Chichibu:

"Time-resolved photoluminescence of a two-dimensional electron gas in an Al_0.2Ga_0.8N/GaN heterostructure fabricated on GaN substrates grown by the ammonothermal method using acidic mineralizers",
European Materials Research Society 2011 Spring Meeting (E-MRS2011), Nice, France, May9-13 (2011), No.F24 (Oral).

145. A. Uedono, S. Ishibashi, S. F. Chichibu, and K. Akimoto:

"Point defects in GaN and related group-III nitrides studied by means of positron annihilation",
The Society of Photo-Optical Instrumentation Engineers (SPIE) Photonics West 2011, OPTO, Gallium Nitride Materials and Devices VI, San Francisco, USA, Jan.22-27, (2011), No.7939-31 (Invited-oral); Proceedings of the Society of Photo-Optical Instrumentation Engineers (SPIE), Gallium Nitride Materials and Devices VI, Edited by J.-I. Chyi, Y. Nanishi, H. Morkoc, J. Piprek, and E. Yoon, Vol. 7939, pp. 79390I 1-10 DOI: 10.1117/12.871611 (2011).

144. S. F. Chichibu, K. Hazu, T. Onuma, T. Sota, and A. Uedono:

"Identification of extremely radiative nature of AlN by timeresolved photoluminescence and time-resolved cathodoluminescence measurements",
The Society of Photo-Optical Instrumentation Engineers (SPIE) Photonics West 2011, OPTO, Gallium Nitride Materials and Devices VI, San Francisco, USA, Jan.22-27, (2011), No.7937-34 (Invited-oral).

143. S. F. Chichibu, K. Hazu, T. Onuma, T. Sota, and A. Uedono:

"Time-resolved Photoluminescence and Time-resolved Cathodoluminescence Studies on AlN Epilayers Grown by Low-pressure Metalorganic Vapor Phase Epitaxy",
International Workshop on Nitride Semiconductors 2010 (IWN2010), Tampa, Florida, USA, Sep.19-24 (2010), No.C4.2 (oral).

142. M. Kagaya, P. Corfdir, J. -D. Ganièl, B. Deveaud-Plédran, N. Garndjean, and S. F. Chichibu:

"Spatio-Time-Resolved Cathodoluminescence Studies on the m-plane In_0.05Ga_0.95N Epilayer Grown on a Freestanding GaN Substrate by Metalorganic Vapor Phase Epitaxy",
International Workshop on Nitride Semiconductors 2010 (IWN2010), Tampa, Florida, USA, Sep.19-24 (2010), No.A2.9 (oral).

141. K. Hazu, Y. Kagamitani, T. Onuma, T. Ishiguro, T. Fukuda, and S. F. Chichibu:

"Optical Properties of GaN Crystals Grown by Ammonothermal Method Using Acidic Mineralizers and Homoepitaxial Films Grown by Metalorganic Vapor Phase Epitaxy",
International Workshop on Nitride Semiconductors 2010 (IWN2010), Tampa, Florida, USA, Sep.19-24 (2010), No.B1.10 (oral).

139. K. Hazu, M. Kagaya, T. Hoshi, T. Onuma, and S. F. Chichibu:

"Identification of cathodoluminescence peaks in m-plane Al_xGa1_-xN epilayers grown on freestanding GaN substrates prepared by halide vapor phase epitaxy",
The Third International Symposium on Growth of III-Nitrides (ISGN-3), Montpellier, France, Jul. 4-7 (2010), No.TU2-5 (oral).

138. S. F. Chichibu, Y. Kagamitani, K. Hazu, T. Onuma, T. Ishiguro, and T. Fukuda:

"Ammonothermal growth of GaN using a gas-phase synthesized acidic mineralizer and homoepitaxy by metalorganic vapor phase epitaxy",
The Third International Symposium on Growth of III-Nitrides (ISGN-3), Montpellier, France, Jul. 4-7 (2010), No.MO2-4 (oral).

137. S. F. Chichibu, A. Uedono, T. Onuma, S. P. DenBaars, U. K. Mishra, J. S. Speck, and S. Nakamura:

"Impacts of point defects on the luminescence properties of (Al,Ga)N",
The Society of Photo-Optical Instrumentation Engineers (SPIE) Photonics West 2010, OPTO, Gallium Nitride Materials and Devices V, San Francisco, USA, Jan.25-28, (2010), No.7620-7 (Invited-oral).

136. 尾沼猛儀, 羽豆耕治, 宗田孝之, 上殿明良, 秩父重英

「AlNエピタキシャル薄膜における励起子発光機構」
電子情報通信学会 レーザ・量子エレクトロニクス研究会/電子デバイス研究会/電子部品・材料研究会2009年11月19-20日 No.(7)

135. T. Onuma, T. Yamada, H. Yamane, and S. F. Chichibu:

"Capability of the bulk GaN single crystals spontaneously nucleated by the Na-flux method as an homoepitaxial substrate",
The 8th International Conference on Nitride Semiconductors (ICNS-8), Jeju, Korea, Oct.18-23 (2009), No.B4 (oral).

134. K. Hazu, T. Hoshi, M. Kagaya, T. Onuma, and S. F. Chichibu:

"Polarization properties of m-plane Al_xGa_1-xN films suffering from in-plane anisotropic stress",
The 8th International Conference on Nitride Semiconductors (ICNS-8), Jeju, Korea, Oct.18-23 (2009), No.Z6 (oral).

133. T. Onuma, K. Hazu, T. Shibata, K. Kosaka, K. Asai, S. Sumiya, M. Tanaka, T. Sota, and S. F. Chichibu:

"Time-resolved photoluminescence study of AlN epilayers grown by low-pressure metalorganic vapor phase epitaxy",
The 8th International Conference on Nitride Semiconductors (ICNS-8), Jeju, Korea, Oct.18-23 (2009), No.JJ3 (oral).

132. S. F. Chichibu, K. Hazu, T. Hoshi, M. Kagaya, and T. Onuma:

"Spatially-resolved cathodoluminescence study on m-plane Al_xGa_1-xN films grown on m-plane free-standing GaN substrates",
The 8th International Conference on Nitride Semiconductors (ICNS-8), Jeju, Korea, Oct.18-23 (2009), No.ThP41 (poster).

131. Y. Kagamitani, S. F. Chichibu, T. Onuma, K. Hazu, T. Fukuda, and T. Ishiguro:

"High purity GaN growth by the ammonothermal method using an acidic mineralizer",
The 36th International Symposium on Compound Semiconductors (ISCS 2009), Santa Barbara, CA, USA, Aug.30-Sep.2 (2009), No.12.2 (oral).

130. T. Onuma, K. Hazu, T. Shibata, K. Kosaka, K. Asai, S. Sumiya, M. Tanaka, T. Sota, and S. F. Chichibu:

"Time-resolved photoluminescence studies of excitons in AlN epilayers grown by metalorganic vapor phase epitaxy",
The 36th International Symposium on Compound Semiconductors (ISCS 2009), Santa Barbara, CA, USA, Aug.30-Sep.2 (2009), No.19.7 (oral).

129. T. Onuma, H. Yamaguchi, L. Zhao, M. Kubota, K. Okamoto, H. Ohta, and S. F. Chichibu:

"Optical Properties of m-plane (In,Ga)N Films Grown by Metalorganic Vapor Phase Epitaxy",
International Symposium of post-silicon materials and devices research alliance project, Osaka, Japan, Sep. 5-6 (2009), No.P-03 (poster).

128. K. Hazu, T. Hoshi, M. Kagaya, T. Onuma, K. Fujito, H. Namita, and S. F. Chichibu:

"Polarization properties of m-plane AlxGa1-xN films suffering from in-plane anisotropic stress",
9th International Conference on Physics of Light-Matter Coupling in Nanostructures (PLMCN9), Lecce, Italy, Apr. 16-20 (2009), No. MoA1-1 (oral).

127. S. F. Chichibu:

"Growth issues and optical properties of nonpolar (Al,In,Ga)N films and quantum wells",
The 3rd Japan-Germany Joint Workshop on Nanoelectronics 2009, Kyoto, Japan, Jan.21-23 (2009), Session 1-1 (Invited-oral).

126. K. Hazu, T. Hoshi, K. Oshita, M. Kagaya, K. Fujito, H. Namita, T. Onuma, and S. F. Chichibu:

"Polarized and spatially-resolved cathodoluminescence studies of m-plane Al_xGa_1-xN films grown on low defect density free-standing GaN substrates",
International Workshop on Nitride Semiconductors 2008 (IWN2008), Montreux, Switzerland, Oct.6-10 (2008), No. We5-B1: Opto 1: Materials and physics (Invited-oral).

125. S. F. Chichibu, H. Yamaguchi, Lu Zhao, M. Kubota, T. Onuma, K. Okamoto, and H. Ohta:

"Optical properties of nearly stacking-fault-free m-plane GaN and InGaN films grown by metalorganic vapor phase epitaxy on low defect density free-standing substrates",
International Workshop on Nitride Semiconductors 2008 (IWN2008), Montreux, Switzerland, Oct.6-10 (2008), No. Plenary Mo-III3 (oral).

124. S. F. Chichibu, T. Onuma, T. Hashimoto, K. Fujito, F. Wu, J. S. Speck, and S. Nakamura:

"Impacts of dislocation bending and growth polar direction on the local cathodoluminescence spectra of GaN prepared by seeded ammonothermal growth",
International Workshop on Nitride Semiconductors 2008 (IWN2008), Montreux, Switzerland, Oct.6-10 (2008), No. Mo1-P13: Substrates for nitride epitaxy (poster).

123. T. Onuma, K. Okamoto, H. Ohta, and S. F. Chichibu:

"Optical gain in low dislocation density nonpolar m-plane InGaN/GaN MQW LD wafers lased at 400 nm and 426 nm",
International Workshop on Nitride Semiconductors 2008 (IWN2008), Montreux, Switzerland, Oct.6-10 (2008), No. We6-A5: Opto 2: Technology and devices (oral).

122. T. Hoshi, K. Oshita, M. Kagaya, K. Fujito, H. Namita, K. Hazu, T. Onuma, and S. F. Chichibu:

"Ammonia source molecular beam epitaxy of m-plane Al_xGa_1-xN films exhibiting negligible deep emission bands on low defect density free-standing GaN substrates",
International Workshop on Nitride Semiconductors 2008 (IWN2008), Montreux, Switzerland,Oct.6-10 (2008), No. We2b-6: Challenging materials issues: AlN and high Al content alloys (oral).

121. T. Ishiguro, Y. Toda, S. Adachi, and S. F. Chichibu:

"Study on dephasing dynamics of exciton fine structures in GaN",
International Workshop on Nitride Semiconductors 2008 (IWN2008), Montreux, Switzerland, Oct.6-10 (2008), No. Th5-E4 : Opto 1: Materials and physics (oral).

120. S. F. Chichibu, T. Onuma, T. Hashimoto, K. Fujito, F. Wu, J. S. Speck, and S. Nakamura:

"Effects of dislocation bending and impurity incorporation on the local cathodoluminescence spectra of GaN prepared by seeded ammonothermal growth"
The Second International Symposium on Growth of III-Nitrides (ISGN-2), Shuzenji, Izu, Japan, Jul. 6-9 (2008), No.Tu-55 (oral+poster).

119. S. F. Chichibu, H. Yamaguchi, L. Zhao, M. Kubota, T. Onuma, K. Okamoto, and H. Ohta:

"Optical properties of nearly stacking-fault-free m-plane (In,Ga)N films grown by metalorganic vapor phase epitaxy on low defect density free-standing substrates"
The Second International Symposium on Growth of III-Nitrides (ISGN-2), Shuzenji, Izu, Japan, Jul. 6-9 (2008), No.Tu-9 (oral+poster).

118. T. Onuma, K. Okamoto, H. Ohta, and S. F. Chichibu:

"Optical gain in low dislocation density nonpolar m-plane InGaN/GaN MQW LD wafers"
50th Electronic Materials Conference (EMC-50), University of California, Santa Barbara, California, USA, Jun.25-27 (2007), No.BB2 (oral).

117. S. F. Chichibu, H. Yamaguchi, L. Zhao, M. Kubota, T. Onuma, K. Okamoto, and H. Ohta:

"Optical properties of nearly stacking-fault-free m-plane (In,Ga)N films grown by metalorganic vapor phase epitaxy on low defect density free-standing substrates"
50th Electronic Materials Conference (EMC-50), University of California, Santa Barbara, California, USA, Jun.25-27 (2008), No.AA1 (oral).

116. S. F. Chichibu, T. Onuma, T. Hashimoto, K. Fujito, F. Wu, J. S. Speck, and S. Nakamura:

"Effects of dislocation bending and impurity incorporation on the local cathodoluminescence spectra of GaN prepared by seeded ammonothermal growth
50th Electronic Materials Conference (EMC-50), University of California, Santa Barbara, California, USA, Jun.25-27 (2008), No.H4 (oral).

115. S. F. Chichibu, T. Onuma, and A. Uedono:

"Impacts of point defects on the recombination dynamics and emission efficiency of (Al,Ga)N"
The Fourth Asian Conference on Crystal Growth and Crystal Technology (CGCT-4), Sendai, Japan, May 21-24 (2008), No. A-23PM1-I-1-BB-1K (Keynote-oral).

114. T. Onuma, K. Kosaka, K. Asai, S. Sumiya, T. Shibata, M. Tanaka, T. Sota, A. Uedono, and S. F. Chichibu:

"Exciton fine structures in AlN epilayers grown by metalorganic vapor phase epitaxy",
7th International Symposium on Semiconductor Light Emitting Devices (ISSLED 2008), Phoenix, Arizona, USA, Apr. 27-May 2 (2008), No.L1 (Invited-oral).

113. T. Onuma, H. Amaike, M. Kubota, K. Okamoto, H. Ohta, J. Ichihara, H. Takasu, and S. F. Chichibu:

"Built-in and external bias-induced quantum-confined Stark effects in a nonpolar m-plane In_0.15Ga_0.85N/GaN multiple quantum well light-emitting diode",
7th International Symposium on Semiconductor Light Emitting Devices (ISSLED 2008), Phoenix, Arizona, USA, Apr. 27-May 2 (2008), No.G1 (Invited-oral).

112. K. Okamoto, T. Tanaka, M. Kubota, S. F. Chichibu, and H. Ohta:

"Present status of LEDs and LDs based on m-plane Gallium Nitride",
The 34th International Symposium on Compound Semiconductors (ISCS 2007), Kyoto, Japan, Oct.15-18 (2007), CATEGORY 8. GaN optical devices No. ThA II-1 (Invited-oral).

111. S. F. Chichibu, T. Koyama, M. Sugawara, T. Hoshi, J. F. Kaeding, R. Sharma, S. Nakamura, and A. Uedono:

"Correlation between the violet luminescence intensity and defect density in AlN epilayers grown by NH₃ source molecular beam epitaxy",
The 34th International Symposium on Compound Semiconductors (ISCS 2007), Kyoto, Japan, Oct.15-18 (2007), CATEGORY 7. GaN and related semiconductors No. WeA I-3 (oral).

110. S. F. Chichibu:

"Origin of defect-insensitive emission probability in (Al,In,Ga)N alloy films containing In",
The 7th International Conference on Nitride Semiconductors (ICNS-7), Las Vegas, Nevada, USA, Sep.16-21 (2007), No.GG1 (Invited-oral).

109. J. Han, S. Chichibu, and H. Tang:

"III-Nitride Nanowires and Networks: Growth, Heterostructures, Epitaxial Alignment, and Applications",
The 7th International Conference on Nitride Semiconductors (ICNS-7), Las Vegas, Nevada, USA, Sep.16-21 (2007), No.FF1 (Invited-oral).

108. K. Okamoto, H. Ohta, S. F. Chichibu, T. Tanaka, T. Tanabe, and H. Takasu:

"Progress of nonpolar m-plane InGaN/GaN laser diodes",
The 7th International Conference on Nitride Semiconductors (ICNS-7), Las Vegas, Nevada, USA, Sep.16-21 (2007), No.CC1 (Invited-oral).

107. S. F. Chichibu, M. Kubota, H. Yamaguchi, L. Zhao, K. Okamoto, and H. Ohta:

"Homoepitaxial growth of nearly stacking-fault-free m-plane (In,Ga)N films by metalorganic vapor phase using low defect density free-standing substrates",
The 7th International Conference on Nitride Semiconductors (ICNS-7), Las Vegas, Nevada, USA, Sep.16-21 (2007), No.W1 (oral).

106. T. Onuma, H. Amaike, M. Kubota, K. Okamoto, H. Ohta, J. Ichihara, H. Takasu, and S. F. Chichibu:

"Quantum-confined Stark effects in nonpolar m-plane In_xGa_1-xN/GaN multiple quantum well light-emitting diodes fabricated on low defect density free-standing substrates",
The 7th International Conference on Nitride Semiconductors (ICNS-7), Las Vegas, Nevada, USA, Sep.16-21 (2007), No.U1 (oral).

105. T. Koyama, M. Sugawara, T. Hoshi, J. F. Kaeding, R. Sharma, S. Nakamura, A. Uedono, and S. F. Chichibu:

"Correlation between the violet luminescence intensity and defect density in AlN epilayers grown by NH₃ source molecular beam epitaxy",
The 7th International Conference on Nitride Semiconductors (ICNS-7), Las Vegas, Nevada, USA, Sep.16-21 (2007), (poster).

104. T. Onuma, T. Koyama, K. Kosaka, K. Asai, S. Sumiya, T. Shibata, M. Tanaka, T. Sota, A. Uedono, and S. F. Chichibu:

"Observation of well-resolved bound, free, and higher order excitons in AlN epilayers grown by metalorganic vapor phase epitaxy",
The 7th International Conference on Nitride Semiconductors (ICNS-7), Las Vegas, Nevada, USA, Sep.16-21 (2007), No.I4 (oral).

103. Q. Sun, S. -Y. Kwon, Z. Ren, J. Han, T. Onuma, and S. F. Chichibu:

"Microstructural Evolution in the Initial Growth Stage of m-Plane GaN on m-Plane SiC with a High-Temperature Grown AlN Buffer",
49th Electronic Materials Conference (EMC-49), University of Notre Dame, Indiana, USA, Jun.20-22 (2007), No.FF3 (oral).

102. S. F. Chichibu, A. Uedono, T. Onuma, B. A. Haskell, A. Chakraborty, T. Koyama, P. T. Fini, S. Keller, S. P. DenBaars, J. S. Speck, U. K. Mishra, S. Nakamura, S. Yamaguchi, S. Kamiyama, H. Amano, I. Akasaki, J. Han, and T. Sota:

"Raditive and nonradiative processes in (Al,In,Ga)N alloy films",
14th Semiconducting and Insulating Materials Conference (SIMC-XIV), Fayetteville, Arkansas, USA, May.15-20, (2007), No.W1222042 (Invited-oral).

101. J. Han, Z. Ren, T. Henry, Q. Sun, S. -Y. Kwon, Y. K. Song, A. V. Nurmikko, T. Onuma, S. F. Chichibu, and H. Tang:

"III-Nitride Nanowires: Growth, Heterostructures, Epitaxial Alignment, and Applications",
34th Conference on the Physics and Chemistry of Semiconductor Interfaces (PCSI-34), Salt Lake City, Utah, USA, Jan.14-18, (2007) No.We1330 (Invited-oral & poster).

100. T. Onuma, A. Chakraborty, M. McLaurin, B. A. Haskell, T. Koyama, P. T. Fini, S. Keller, S. P. DenBaars, J. S. Speck, S. Nakamura, U. K. Mishra, T. Sota, and S. F. Chichibu:

"Impacts of morphological features of GaN templates on the In-incorporation efficiency in nonpolar m-plane In_xGa_1-xN / GaN multiple quantum wells",
34th Conference on the Physics and Chemistry of Semiconductor Interfaces (PCSI-34), Salt Lake City, Utah, USA, Jan.14-18, (2007) No.Tu1115 (oral & poster).

99. S. F. Chichibu, A. Uedono, T. Onuma, B. A. Haskell, A. Chakraborty, T. Koyama, P. T. Fini, S. Keller, S. P. DenBaars, J. S. Speck, U. K. Mishra, S. Nakamura, S. Yamaguchi, S. Kamiyama, H. Amano, I. Akasaki, J. Han, and T. Sota:

"Defect-insensitive emission probability universally seen in In-containing group-III nitride alloys",
34th Conference on the Physics and Chemistry of Semiconductor Interfaces (PCSI-34), Salt Lake City, Utah, USA, Jan.14-18, (2007) No.Tu1030 (Invited-oral & poster).

98. T. Koyama, M. Sugawara, T. Hoshi, P. Cantu, J. F. Kaeding, R. Sharma, T. Onuma, S. Keller, U. K. Mishra, S. P. DenBaars, S. Nakamura,T. Sota, A. Uedono, and S. F. Chichibu:

"Relation between the near-band-edge emission intensity and structural defects in AlN epilayers",
34th Conference on the Physics and Chemistry of Semiconductor Interfaces (PCSI-34), Salt Lake City, Utah, USA, Jan.14-18, (2007) No.Mo1125 (oral & poster).

97. S. F. Chichibu, T. Koyama, T. Onuma, H. Masui, A. Chakraborty, B. A. Haskell, S. Keller, T. Sota, U. K. Mishra, J. S. Speck, S. Nakamura, and S. P. DenBaars:

"Recombination dynamics and in-plane polarization of the emission in an m-plane In_xGa_1-xN/GaN blue light-emitting-diode fabricated on the free-standing GaN substrate",
International Workshop on Nitride Semiconductors 2006 (IWN2006), Kyoto, Japan, Oct.22-27 (2006), No.WeOD3-2 (oral).

96. T. Ishiguro, Y. Toda, S. Adachi, K. Hazu, T. Sota, and S. F. Chichibu:

"Coherent manipulation of A and B excitons in GaN",
International Workshop on Nitride Semiconductors 2006 (IWN2006), Kyoto, Japan, Oct.22-27 (2006), No.TuP2-10 (poster).

95. S. F. Chichibu, A. Uedono, T. Onuma, B. A. Haskell, A. Chakraborty, T. Koyama, P. T. Fini, S. Keller, S. P. DenBaars, J. S. Speck, U. K. Mishra, S. Nakamura, S. Yamaguchi, S. Kamiyama, H. Amano, I. Akasaki, J. Han, and T. Sota:

"Point defects and their influence on the luminescence efficiency in AlInGaN materials",
The IUMRS International Conference in Asia 2006 (IUMRS-ICA-2006), Hotel Shilla, Jeju, Korea, Sep. 10-14, (2006) No. 2-I-1 (Invited-oral).

94. S. F. Chichibu, A. Uedono, T. Onuma, B. A. Haskell, A. Chakraborty, T. Koyama, P. T. Fini, S. Keller, S. P. DenBaars, J. S. Speck, U. K. Mishra, S. Nakamura, S. Yamaguchi, S. Kamiyama, H. Amano, I. Akasaki, J. Han, and T. Sota:

"Defect-insensitive emission probability in group-III nitride alloys containing In",
International Symposium on Compound Semiconductors 2006 (ISCS 2006), Vancouver, Canada, Aug.13-17 (2006) No. T7 (Invited-oral).

93. M. Kubota, A. Uedono, Y. Ishihara, T. Onuma, A. Usui, and S. F. Chichibu:

"Thermally stable semi-insulating properties of Fe-doped GaN grown by hydride vapor phase epitaxy characterized by photoluminescence and positron annihilation techniques",
The 13th International Conference on Metal Organic Vapor Phase Epitaxy (ICMOVPE-13), Miyazaki, Japan, May 22-25, (2006), No.Fr-B1.5 (oral).

92. T. Onuma, H. Yamaguchi, T. Suzuki, T. Nozaka, and S. F. Chichibu:

"Cross-sectional spatially-resolved cathodoluminescence study of cubic GaN grown by metalorganic vapor phase epitaxy on free-standing (001) 3C-SiC and GaAs substrates",
The 13th International Conference on Metal Organic Vapor Phase Epitaxy (ICMOVPE-13), Miyazaki, Japan, May 22-25, (2006), No.We-A1.1 (oral).

91. M. Sugawara, T. Koyama, J. F. Kaeding, R. Sharma, Y. Uchinuma, T. Araya, T. Onuma, S. Nakamura, and S. F. Chichibu:

"Observation of a 208 nm emission at room temperature from AlN epilayers grown at high temperature by NH₃-source molecular-beam epitaxy on GaN templates using low-temperature interlayers",
The 6th International Symposium on Blue Laser and Light Emitting Diodes (ISBLLED 2006), Montpellier, France, May.15-19, (2006), No.D3.03 (oral).

90. T. Onuma, S. Keller, S. P. DenBaars, J. S. Speck, S. Nakamura, U. K. Mishra, T. Sota, and S. F. Chichibu:

"Recombination dynamics of a 268 nm emission peak in strained Al_0.53In_0.11Ga_0.36N multiple quantum wells grown on AlGaN templates on (0001) Al₂O₃",
The 6th International Symposium on Blue Laser and Light Emitting Diodes (ISBLLED 2006), Montpellier, France, May.15-19, (2006), No.P1.33 (poster).

89. T. Koyama, T. Onuma, H. Masui, A. Chakraborty, B. A. Haskell, U. K. Mishra, J. S. Speck, S. Nakamura, S. P. DenBaars, T. Sota, and S. F. Chichibu:

"Prospective emission efficiency and in-plane light polarization of nonpolar (1-100) In_xGa_1-xN / GaN blue light-emitting-diodes fabricated on free-standing GaN substrates",
The 6th International Symposium on Blue Laser and Light Emitting Diodes (ISBLLED 2006), Montpellier, France, May.15-19, (2006), No.B1.05 (oral)

88. S. F. Chichibu, A. Uedono, T. Onuma, A. Chakraborty, B. A. Haskell, P. T. Fini, S. Keller, T. Sota, S. P. DenBaars, U. K. Mishra, J. S. Speck, and S. Nakamura:

"Relation between the point defect density and quantum efficiency in (Al,In,Ga)N studied by time-resolved photoluminescence and slow positron annihilation techniques: defect-resistant emission of localized excitons in InGaN",
The 6th International Conference on Nitride Semiconductors (ICNS-6), Bremen, Germany, Aug.28-Sept.2 (2005), No. Tu-OP2-4 (oral).

87. T. Onuma, A. Chakraborty, B. A. Haskell, S. Keller, T. Sota, U. K. Mishra, S. P. DenBaars, J. S. Speck, S. Nakamura, and S. F. Chichibu:

"Exciton dynamics in nonpolar (11-20) InGaN/GaN multiple quantum wells grown on GaN templates prepared by lateral epitaxial overgrowth",
The 6th International Conference on Nitride Semiconductors (ICNS-6), Bremen, Germany, Aug.28-Sept.2 (2005), No. Tu-P-103 (poster).

86. T. Koyama, M. Sugawara, Y. Uchinuma, J. F. Keading,　R. Sharma, T. Onuma, S. Nakamura, and S. FChichibu:

"Strain-relaxation in NH₃-source molecular beam epitaxy of AlN epilayers on GaN epitaxial templates",
The 6th International Conference on Nitride Semiconductors (ICNS-6), Bremen, Germany, Aug.28-Sept.2 (2005), No. Mo-P-033 (poster).

85. T. Onuma, A. Chakraborty, B. A. Haskell, S. Keller, T. Sota, S. P. DenBaars, J. S. Speck, S. Nakamura, U. K. Mishra, and S. F. Chichibu:

"Recombination dynamics in nonpolar (11-20) In_xGa_1-xN multiple quantum wells grown on GaN templates prepared by lateral epitaxial overgrowth",
47th Electronic Materials Conference (EMC-47), Santa Barbara, California, USA, Jun.22-24 (2005), No. LL3 (oral).

84. T. Hashimoto, K. Fujito, F. Wu, B. A. Haskell, T. Onuma, S. F. Chichibu, J. S. Speck, and S. Nakamura:

"Characterization of GaN films grown on free-standing GaN seeds by ammonothermal growth",
47th Electronic Materials Conference (EMC-47), Santa Barbara, California, USA, Jun.22-24 (2005), No. CC1 (oral).

83. J. Su, M. Gherasimova, G. Cui, J. Han, C. Broadbridge, A. Lehman, T. Onuma, S. F. Chichibu, Y. He, and A. V. Nurmikko:

"Epitaxially aligned GaN nanowires and nanobridges by MOCVD",
47th Electronic Materials Conference (EMC-47), Santa Barbara, California, USA, Jun.22-24 (2005), No. Q7 (oral).

82. Y. Uchinuma, M. Sugawara, T. Koyama, J. F. Keading, R. Sharma, T. Onuma, S. Nakamura, and S. F. Chichibu:

"Atomically-flat AlN epitaxial layers grown on MOVPE GaN templates by NH₃-source molecular-beam epitaxy"
32nd Conference on the Physics and Chemistry of Semiconductor Interfaces (PCSI-32), Bozeman, Montana, USA, Jan.23-27, SESSION: Wide Bandgap Semiconductors (2005) No.We1505 (oral & poster).

81. T. Onuma, A. Chakraborty, B. A. Haskell, S. Keller, T. Sota, U. K. Mishra, S. P. DenBaars, J. S. Speck, S. Nakamura, and S. F. Chichibu:

"Emission mechanisms in nonpolar (11-20) InGaN/GaN multiple quantum wells grown on GaN templates prepared by lateral epitaxial overgrowth"
32nd Conference on the Physics and Chemistry of Semiconductor Interfaces (PCSI-32), Bozeman, Montana, USA, Jan.23-27, SESSION: Wide Bandgap Semiconductors (2005) No.We1455 (oral & poster).

80. S. F. Chichibu, A. Uedono, T. Onuma, T. Koida, M. Sugiyama, B. A. Haskell, M. Sumiya, H. Okumura, T. Sota, J. S. Speck, S. P. DenBaars, and S. Nakamura:

"Direct comparison of defect density and photoluminescence lifetime in polar and nonpolar wurtzite and zincblende GaN studied by time-resolved photoluminescence and slow positron annihilation techniques"
International Workshop on Nitride Semiconductors 2004 (IWN2004), Pittsburg, USA, Jul.19-23, (2004), No.A10.3 (Oral).

79. T. Koida, S. F. Chichibu, T. Sota, M. D. Craven, B. A. Haskell, J. S. Speck, S. P. DenBaars, and S. Nakamura:

"Reduction of bound-state and nonradiative defect densities in nonpolar (11-20) AlGaN/GaN quantum wells by the use of lateral epitaxial overgrowth technique"
International Workshop on Nitride Semiconductors 2004 (IWN2004), Pittsburg, USA, Jul.19-23, (2004), No.A10.5 (Oral).

78. T. Nosaka, M. Sugiyama, T. Suzuki, T. Koida, K. Nakajima, T. Aoyama, M. Sumiya, T. Chikyow, A. Uedono, and S. F. Chichibu:

"Reduction of point defect in cubic GaN epilayers on (001) GaAs substrates using Al_xGa_1-xN/GaN superlattice underlayers"
The 12th International Conference on Metal Organic Vapor Phase Epitaxy (ICMOVPE-12), Lahaina, Maui, Hawai, May 30-June 4, (2004), Wide Gap Nitrides No.31 (poster).

77. T. Koida, S. F. Chichibu, Y. Uchinuma, J. Kikuchi, K. R. Wang, M. Terazaki, T. Onuma, J. F. Keading, R. Sharma, and S. Nakamura:

"Reduction of surface crevice density in GaN homoepitaxial layers grown by NH₃-source molecular beam epitaxy"
31th Conference on the Physics and Chemistry of Semiconductor Interfaces (PCSI-31), Kailua-Kona, Hawaii, USA, Jan.18-22, SESSION: NITRIDE GROWTH AND INTERFACES (2004) No.We0920 (oral & poster).

76. SF. Chichibu, T. Onuma, T. Koida, T. Kitamura, K. Nakajima, P. Ahmet, T. Aoyama, T. Chikyow, Y. Ishida, T. Sota, S. P. DenBaars, S. Nakamura, and H. Okumura:

"Recombination dynamics of localized excitons in cubic InxGa1-xN / GaN multiple quantum wells on 3C-SiC (001) substrates grown by rf-MBE"

combined with

SF. Chichibu, T. Onuma, T. Sota, S. Yamaguchi, S. Kamiyama, H. Amano, and I. Akasaki:

"Recombination dynamics of localized excitons in Al1-xInxN epitaxial films grown by metalorganic vapor phase epitaxy",
International Conference on Materials for Advanced Technologies (ICMAT-2003), Singapore, Dec. 7-12, (2003), No. H-4-1-I (Invited-oral).

75. T. Shibata, M. Tanaka, K. Asai, S. Sumiya, M. Sakai, H. Katsukawa, O. Oda, H. Miake, K. Hiramatsu, H. Ishikawa, T. Egawa, T. Jimbo, and S. Chichibu:

"High-Quality AlN Epitaxial Films Grown using MOVPE and Their Applications",
Materials Research Society, 2003 Fall Meeting, Session Y: GaN and Related Alloys, Boston, MA, USA, Dec.1-5, (2003), No.Y3.6 (Invited-oral).

74. T. Nagata, P. Ahmet, T. Onuma, T. Koida, S. F. Chichibu, and T. Chikyow:

"Position Controlled GaN Nano-Structures Fabricated by Low Energy Focused Ion Beam System",
Materials Research Society, 2003 Fall Meeting, Session R: Radiation Effects and Ion Beam Processing of Materials, Boston, MA, USA, Dec.1-5, (2003) No.R9.39 (poster).

73. S. P. Lepkowski, T. Suski, H. Teisseyre, P. Perlin, T. Kitamura, Y. Ishida, H. Okumura, T.Onuma, T.Koida, and SF.Chichibu:

"Nonlinear elastic properties of cubic InGaN",
The 5th International Conference on Nitride Semiconductors (ICNS-5), Nara, Japan, May 25-30 (2003), No.Th-B9.2 (oral).

72. T. Onuma, SF. Chichibu, Y. Uchinuma, T. Sota, S. Yamaguchi, S. Kamiyama, H. Amano, and I. Akasaki:

"Bandgap bowing and emission mechanisms in AI_1-xIn_xN epitaxial films grown by metalorganic vapor phase epitaxy",
The 5th International Conference on Nitride Semiconductors (ICNS-5), Nara, Japan, May 25-30 (2003), No.We-A6.6 (oral).

71. T. Onuma, T. Koida, P. Cantu, J. F. Keading, S. Keller, T. Sota, S. P. DenBaars, U. K. Mishra, S. Nakamura, and S. F. Chichibu:

"Emission mechanisms in AI_xGa_1-xN films grown on sapphire (0001) substrates by low-pressure metalorganic vapor phase epitaxy",
The 5th International Conference on Nitride Semiconductors (ICNS-5), Nara, Japan, May 25-30 (2003), No.Tu-P2.039 (poster).

70. A. Uedono, SF. Chichibu, M. Sumiya, R. Suzuki, T. Ohdaira, T. Mikado, and T. Mukai:

"Vacancy-type defects in GaN grown along different polar directions by MOVPE probed using monoenergetic positron beams",
The 5th International Conference on Nitride Semiconductors (ICNS-5), Nara, Japan, May 25-30 (2003), No.Mo-P1.089 (poster).

69. T. Onuma, SF. Chichibu, T. Kitamura, K. Nakajima, P. Ahmet, T. Aoyama, T. Chikyow, Y. Ishida, T. Sota, S. P. DenBaars, S. Nakamura, and H. Okumura:

"Recombination dynamics of localized excitons in cubic In_xGa_1-xN/GaN quantum wells grown on 3C-SiC (001) substrates by rf-MBE",
The 5th International Conference on Nitride Semiconductors (ICNS-5), Nara, Japan, May 25-30 (2003), No.Mo-P1.067 (poster).

68. T. Onuma, Y. Uchinuma, E. -K. Suh, H. J. Lee, T. Sota, and SF. Chichibu:

"Carrier dynamics in InGaN/GaN quantum wells with composition-graded walls"
The 5th International Conference on Nitride Semiconductors (ICNS-5), Nara, Japan, May 25-30 (2003), No.Mo-P1.066 (poster).

67. S. Adachi, K. Hazu, T. Sota, S. F. Chichibu, S. Muto, K. Suzuki, and T. Mukai:

"Exciton-exciton correlation effects on FWM in GaN",
The 5th International Conference on Nitride Semiconductors (ICNS-5), Nara, Japan, May 25-30 (2003), No.Mo-P1.053 (poster).

66. M. Sugiyama, T. Nosaka, K. Nakajima, P. Ahmet, T. Aoyama, T. Chikyow, and SF. Chichibu:

"Effects of deposition parameters of low-temperature GaN buffer layer on the structural and optical properties of cubic GaN epilayers on GaAs (001) substrates grown by MOVPE"
The 5th International Conference on Nitride Semiconductors (ICNS-5), Nara, Japan, May 25-30 (2003), No.Tu-P2.016 (poster).

65. S. F. Chichibu, A. Uedono, T. Onuma, T. Sota, P. Cantu, T. M. Katona, J. F. Keading, S. Keller, U. K. Mishra, S. Nakamura, and S. P. DenBaars:

"Recombination Dynamics in Strain-free Al_xGa_1-xN Alloys Studied by Time-Resolved Photoluminescence and Slow Positron Annihilation Techniques"
Materials Research Society, 2003 Fall Meeting, Session Y: GaN and Related Alloys, Boston, MA, USA, Dec.1-5, (2003), No.Y6.9 (oral).

64. SF. Chichibu, T. Onuma, T. Kitamura, Y. Ishida, T. Sota, S. P. DenBaars, S. Nakamura, and H. Okumura:

"Recombination dynamics of localized excitons in cubic In_xGa_1-xN/GaN multiple quantum wells grown by rf-MBE on 3C-SiC substrate"
30th Conference on the Physics and Chemistry of Semiconductor Interfaces (PCSI-30), Salt Lake City, Utah, USA, Jan.19-23, SESSION: III-NITRIDES (2003) No.Mo1415 (oral & poster).

63. T. Suski, H. Teisseyre, S. P. Lepkowski, P. Perlin, T. Kitamura, Y. Ishida, H. Okumura, and S. F. Chichibu:

"Pressure Coefficients of the Light Emission in Cubic InGaN Epilayers and Cubic InGaN/GaN Quantum Wells",
International Workshop on Nitride Semiconductors 2002 (IWN2002), Aachen, Germany, Jul.22-25, (2002), No.P3-354(poster). Physica Status Solidi (b) 234 (3), pp.759-763 (2002).

62. T. Suski, H. Teisseyre, S. P. Lepkowski, P. Perlin, H. Mariette, T. Kitamura, Y. Ishida, H. Okumura, and SF. Chichibu:

"Light Emission Versus Energy Gap in Group-III Nitrides. Hydrostatic Pressure Studies",
10th International Conference on High Pressure in Semiconductor Physics, Surrey, August, 5-8, (2002). (Invited-Oral); Physica Status Solidi (b) 235 (2), pp.225-231 (2003).

61. S. F. Chichibu, T. Onuma, T. Kitamura, T. Sota, S. P. DenBaars, S. Nakamura, and H. Okumura:

"Recombination dynamics of localized excitons in cubic phase In_xGa_1-xN/GaN multiple quantum wells on 3C-SiC/Si (001)",
International Workshop on Nitride Semiconductors 2002 (IWN2002), Aachen, Germany, Jul.22-25, (2002), No.A06-046(oral).

60. T. Suski, P. Perlin, S. P. Lepkowski, H. Teisseyre, I. Gorczyca, P. Prystawko, M. Leszczynski, N. Grandjean, J. Massies, T. Kitamura, Y. Ishida, S. F. Chichibu, and H. Okumura:

"Piezoelectric Field and its influence on the Pressure Behavior of the Light Emission from InGaN/GaN and GaN/AlGaN Quantum Wells",
Materials Research Society, 2001 Fall Meeting, Session I: GaN and Related Alloys, Boston, MA, USA, Nov.26-Nov.30, (2001) No. (Oral); Materials Research Society Symposium Proceedings Series Vol.693, pp.487-499 (2002).

59. T. Onuma, S. F. Chichibu, T. Sota, K. Asai, S. Sumiya, T. Shibata, and M. Tanaka:

"Exciton Spectra of AlN Epitaxial Films",
Materials Research Society, 2001 Fall Meeting, Session I: GaN and Related Alloys, Boston, MA, USA, Nov.26-Nov.30, (2001) No.I8.6 (Oral); Materials Research Society Symposium Proceedings Series Vol.693, pp.515-520 (2002).

58. S. F. Chichibu, M. Sugiyama, T. Onuma, T. Kuroda, A. Tackeuchi, T. Sota, T. Kitamura, H. Nakanishi, Y. Ishida, H. Okumura, S. Keller, S. P. DenBaars, U. K. Mishra, and S. Nakamura:

"Similarities in the Optical Properties of hexagonal and cubic InGaN Quantum Wells",
Materials Research Society, 2001 Fall Meeting, Session I: GaN and Related Alloys, Boston, MA, USA, Nov.26-Nov.30, (2001) No.I7.5 (Oral); Materials Research Society Symposium Proceedings Series Vol.693, pp.481-486 (2002).

57. S. F. Chichibu, M. Sugiyama, T. Azuhata, T. Kuroda, A. Tackeuchi, T. Sota, T. Kitamura, Y. Ishida, H. Okumura, H. Nakanishi, T. Mukai, S. P. DenBaars, and S. Nakamura,

"OPTICAL AND STRUCTURAL STUDIES IN WURTZITE AND ZINCBLENDE InGaN QUANTUM WELL STRUCTURES",
The 4th International Conference on Nitride Semiconductors (ICNS-4), Denver, Colorado, USA, Jul.16-20 (2001), No. A13.5 (oral).

56. T. Kitamura, Y. Suzuki, Y. Ishida, X. -Q. Shen, H. Nakanishi, S. F. Chichibu, M. Shimizu, and H. Okumura,

"Optical properties of cubic InGaN/GaN multiple quantum wells on 3C-SiC substrates by radio-frequency plasma-assisted molecular beam epitaxy",
The 4th International Conference on Nitride Semiconductors (ICNS-4), Denver, Colorado, USA, Jul.16-20 (2001), No. P4.31 (poster). Physica Status Solidi (2001) (submitted).

55. T. Kitamura, Y. Ishida, X. -Q. Shen, H. Nakanishi, S. F. Chichibu, M. Shimizu, and H. Okumura,

"Achievement of two-dimensional electron gas at cubic GaN/AlN heterointerface grown by radio-frequency plasma-assisted molecular beam epitaxy",
The 4th International Conference on Nitride Semiconductors (ICNS-4), Denver, Colorado, USA, Jul.16-20 (2001), No. A2.2 (oral). Physica Status Solidi (2001) (submitted).

54. S. F. Chichibu, T. Azuhata, H. Okumura, A. Tackeuchi, T. Sota and T. Mukai:

"Localized exciton dynamics in InGaN quantum well structures",
8th International Conference on the Formation of Semiconductor Interfaces (ICFSI-8), Sapporo, Hokkaido, Japan, Jun. 10-15 (2001), No. Fr2-2 (Invited-oral). Applied Surface Science (in press).

53. S. F. Chichibu, T. Azuhata, M. Sugiyama, T. Kitamura, Y. Ishida, H. Okumura, H. Nakanishi, T. Sota, T. Mukai, and S. Nakamura:

"Optical and structural studies in InGaN quantum well structure laser diodes",
28th Conference on the Physics and Chemistry of Semiconductor Interfaces (PCSI-28), Orlando, Florida, USA, Jan. 7-11 (2001), No.Mo0905 (Invited).

52. M. Sumiya, K. Mizuno, M. Furuwasa, M. Yoshimoto, S. Chichibu, and S. Nakamura:

"STRUCTURAL ANALYSIS IN REAL SPACE OF INxGAxN SINGLE QUANTUM WELLS BY COAXIAL IMPACT IONIZATION SCATTERING SPECTROSCOPY",
Materials Research Society, 2000 Fall Meeting, Session G: GaN and Related Alloys, Boston, MA, USA, Nov.27-Dec.1, (2000) No.G11.43 (Poster).

51. A. Setoguchi, K. Yoshimura, M. Sumiya, A. Uedono, and S. F. Chichibu :

"IMPACT OF THE GROWTH POLAR DIRECTION ON THE EMISSION MECHANISMS OF GaN GROWN BY METALORGANIC VAPOR PHASE EPITAXY",
Materials Research Society, 2000 Fall Meeting, Session G: GaN and Related Alloys, Boston, MA, USA, Nov.27-Dec.1, (2000) No.G11.6 (Poster); Materials Research Society Symposium Proceedings Series Vol.639, pp.G.11.6.1-6 (2001).

50. S. F. Chichibu, T. Sota, and S. Nakamura:

"ROLE OF LOCALIZED QUANTUM WELL EXCITONS IN InGaN QUANTUM WELL STRUCTURE CORRELATED WITH MICROSTRUCTURAL ANALYSIS",
Materials Research Society, 2000 Fall Meeting, Session G: GaN and Related Alloys, Boston, MA, USA, Nov.27-Dec.1, (2000) No.G9.3 (Oral); Materials Research Society Symposium Proceedings Series Vol.639, pp.G.9.3.1-6 (2001).

49. Y. Ito, T. Mita, N. Yamamoto, S. F. Chichibu, and S. P. DenBaars:

"Cathodoluminescence characterization of defects in GaN using a transmission electron microscope"
Proceedings of 6th International Workshop on Beam Injection Assessment of Microstructures in Semiconductors, (Fukuoka, Japan) p.10 (2000).

48. T. Kitamura, S. H. Cho, Y. Ishida, T.I de, X. Q. Shen, H. Nakanishi, S. F. Chichibu, and H. Okumura:

"Growth and characterization of cubic InGaN/GaN multiquantum wells on 3C-SiC by RF MBE"
International Workshop on Nitride Semiconductors 2000 (IWN2000), Nagoya, Japan, Sep.24-27, 2000, WA-1-6 (oral). Institute of Pure and Applied Physics Conference Series Vol.1, pp. 93-96 (2000).

47. M. Sumiya, S. F. Chichibu, K. Mizuno, M. Furusawa, M. Yoshimoto, and S. Nakamura:

"Correlation between Electroluminescence and Disordering of Indium in In_xGa_1-xN Single Quantum Wells Analyzed by Coaxial Impact Collision Ion Scattering Spectroscopy",
International Workshop on Nitride Semiconductors 2000 (IWN2000), Nagoya, Japan, Sep.24-27, 2000, TA-2-6(oral). Institute of Pure and Applied Physics Conference Series Vol.1, pp.575-578 (2000).

46. K. Torii, S. F. Chichibu, T. Deguchi, H. Nakanishi, T. Sota, and S. Nakamura:

"Photoreflectance spectra of excitonic polaritons in wurtzite GaN",
International Workshop on Nitride Semiconductors 2000 (IWN2000), Nagoya, Japan, Sep.24-27, 2000, TA-1-4 (oral). Institute of Pure and Applied Physics Conference Series Vol.1, pp.548-551 (2000).

45. S. F. Chichibu, T. Azuhata, T. Sota, T. Mukai, and S. Nakamura:

"Spectroscopic Studies in InGaN Single-Quantum-Well Amber Light-Emitting Diodes",
International Workshop on Nitride Semiconductors 2000 (IWN2000), Nagoya, Japan, Sep.24-27, 2000, TM-2-5 (oral); Institute of Pure and Applied Physics Conference Series Vol.1, pp.528-531 (2000).

44. T. Kitamura, S. H. Cho, Y. Ishida, T. Ide, X. Q. Shen, H. Nakanishi, S. Chichibu, and H. Okumura:

"Growth and characterization of cubic InGaN epilayers on 3C-SiC by RF MBE",
Eleventh International Conference on Molecular Beam Epitaxy, Beijing, China, Sept.10-15 (2000).

43. S. F. Chichibu, T. Sota, K. Wada, O. Brandt, K. H. Ploog, S. P. DenBaars, and S. Nakamura:

"Impacts of internal electric field and localization of quantum well excitons in AlGaN/GaN/InGaN light emitting diodes",
International workshop on Physics of light-Matter Coupling in Nitrides, Saint-Nectaire, Clearmont-Ferrand, France, Oct.8-12, (2000) No.W-5 (Invited-oral).

42. S. F. Chichibu, A. Setoguchi, T. Azuhata, T. Deguchi, T. Sota, and S. Nakamura:

"Efficient emission against the internal piezoelectric field of InGaN/GaN/AlGaN single-quantum-well amber light-emitting diodes",
42th Electronic Materials Conference (EMC-42), Session C, Polarization and Piezoelectric Effects in Nitrides, Denver, Colorado, USA, Jun.21-Jun.23, 2000, No.C5 (oral).

41. S. F. Chichibu, A. Setoguchi, T. Azuhata, J. Mullhauser, M. Sugiyama, T. Mizutani, T. Deguchi, H. Nakanishi, T. Sota, O. Brandt, K. H. Ploog, T. Mukai, and S. Nakamura:

"Effective localization of quantum well excitons in InGaN quantum well structures with high InN mole fraction",
International Symposium on Blue Laser and Light Emitting Diodes (ISBLLED 2000), Berlin, Germany, Mar.6-10, 2000, No.ThC1 (oral).

40. S. Chichibu, T. Deguchi, A. Setoguchi, M. Sugiyama, H. Nakanishi, T. Sota, T. Mukai and S. Nakamura:

"Comparison of Optical Properties in GaN/AlGaN and InGaN/AlGaN Single Quantum Wells",
International Conference on Solid State Devices and Materials, Tokyo, Japan, Sep.21-24, 1999, C-4-1, (oral) Extended Abstracts of SSDM'99 pp.198-199 (1999).

39. S. F. Chichibu, A. Shikanai, T. Deguchi, A. Setoguchi, R. Nakai, K. Wada, S. P. DenBaars, T. Sota, T. Mukai, and S. Nakamura:

"Comparison of optical properties in GaN and InGaN quantum well structures",
International Symposium on Photonics and Applications (ISPA'99), Design, Fabrication, and Characterization of Photonic Devices, Singapore, sponsered by SPIE, Nov.29-Dec.3, 1999, (oral) ; Proceedings of the Society of Photo-Optical Instrumentation Engineers (SPIE), Vol. 3896, pp. 98-106,(1999).

38. H. Marchand, J. P. Ibbetson, P. T. Fini, S. Chichibu, S. J. Rosner, S. Keller, S. P. DenBaars. J. S. Speck, and U. K. Mishra:

"Structural and optical properties of low-dislocation-density GaN laterally overgrown by metalorganic chemical vapor deposition",
The 25th International Symposium on Compound Semiconductors, Nara, Japan, Oct.12-16, 1998 (poster). Proceedings of the 25th International Symposium on Compound Semiconductors, edited by H.Hirayama (IOP Publishing Co., Toyko, 1999); Institute of Physics Conference Series No.162, Chapter 12 pp.681-686

37. T. Deguchi, K. Sekiguchi, A. Nakamura, T. Sota, R. Matsuo, S. Chichibu, and S. Nakamura:

"Quantum-Confined Stark Effect in an AlGaN/GaN Single Quantum Well Structure",
The 3rd International Conference on Nitride Semiconductors (ICNS3), Montpellier, France, Jul.5-9, 1999, No. Tu_P081 (poster).

36. H. Okumura, T. Koizumi, Y. Ishida, H. Yaguchi, S. Yoshida, and S. Chichibu:

"Optical Characterization of Cubic AlGaN Epilayers by Cathodoluminescence and Spectroscopic Ellipsometry",
The 3rd International Conference on Nitride Semiconductors (ICNS3), Montpellier, France, Jul.5-9, 1999, No. Tu_P048 (poster).

35. S. F. Chichibu, T. Deguchi, T. Sota, S. P. DenBaars, and S. Nakamura:

"Properties of Quantum Well Excitons in GaN/AlGaN and InGaN/GaN/AlGaN UV, Blue, Green, and Amber Light Emitting Diode Structures",
The 3rd International Conference on Nitride Semiconductors (ICNS3), Montpellier, France, Jul.5-9,1999, No. Tu_14 (oral).

34. S. Keller, S. B. Fleischer, S. F. Chichibu, J. E. Bowers, U. K. Mishra, and S. P. DenBaars:

"Effect of the Confinement Layer Design on the Luminescence of InGaN/GaN Single Quantum Wells",
The 3rd International Conference on Nitride Semiconductors (ICNS3), Montpellier, France, Jul.5-9,1999, No. Mo_04 (oral).

33. S. F. Chichibu, T. Deguchi, T. Sota, S. P. DenBaars, and S. Nakamura:

"Behavior of quantum well excitons under internal fields of GaN/AlGaN and InGaN/GaN/AlGaN quantum well structures",
41th Electronic Materials Conference (EMC-41), Session R (Wide-band-gap III-V Materials (GaN, AlN, AlGaN): Growth, Processing, Characterization, Theory, and Devices), Santa Barbara, USA, Jun.30-Jul.2, 1999 (oral).

32. S. Keller, S. F. Chichibu, M. Minski, E. Hu, U. Mishra, and S. DenBaars:

"Effect of the growth rate and the barrier doping on the morphology and the properties of InGaN/GaN quantum wells",
The 9th International Conference on Metal Organic Vapor Phase Epitaxy (ICMOVPE IX), La Jolla, California, USA, May 30-Jun.4, 1998 (oral).

31. S. Chichibu, T. Sota, K. Wada, S. P. DenBaars, and S. Nakamura:

"Spectroscopic studies in InGaN quantum wells",
Materials Research Society, 1998 Fall Meeting, Session G: GaN and Related Alloys, Boston, MA, USA, Nov.30-Dec.4, 1998, No. G2.7 (Invited).

30. Marchand, J. P. Ibbetson, P. T. Fini, S. Chichibu, S. J. Rosner, S. Keller, S. P. DenBaars. J. S. Speck, and U. K. Mishra:

"Structural and optical properties of low-dislocation-density GaN laterally overgrown by metalorganic chemical vapor deposition",
The 25th International Symposium on Compound Semiconductors, Nara, Japan, Oct.12-16, 1998 (poster).

29. S. Chichibu, L. Sugiura, J. Nishio, A. Setoguchi, H. Nakanishi, and K. Itaya:

"Effective Bandgap Separation in InGaN Epilayers Grown by Metalorganic Chemical Vapor Deposition",
The 2nd International Symposium on Blue Laser and Light Emitting Diodes, Chiba, Japan, Sep.29-Oct.2,1998, Th-P45 (poster): Proceedings of the 2nd International Symposium on Blue Laser and Light Emitting Diodes (Ohmsha Ltd., Tokyo, 1998) pp.616-619.

28. S. Chichibu, H. Marchand, S. Keller, P. Fini, J. Ibbetson, M. Minsky, S. Fleischer, J. Speck, J. Bowers, E. Hu, U. Mishra, S. DenBaars, T. Deguchi, T. Sota, and S. Nakamura:

"Exciton Localization in InGaN Quantum Wells Grown on Lateral Epitaxially Overgrown (LEO) GaN",
The 2nd International Symposium on Blue Laser and Light Emitting Diodes, Chiba, Japan, Sep.29-Oct.2,1998, Th-P42 (poster): Proceedings of the 2nd International Symposium on Blue Laser and Light Emitting Diodes (Ohmsha Ltd., Tokyo,1998) pp.604-607.

27. S. Chichibu, D. Cohen, M. Mack, A. Abare, P. Kozodoy, M. Minsky, S. Fleischer, S. Keller, J. Bowers, U. Mishra, L. Coldren, D. Clarke, and S. DenBaars:

"Improved Properties of InGaN Multiple Quantum Well Purplish-Blue Laser Diodes by Si-Doping in the InGaN Barriers",
The 2nd International Symposium on Blue Laser and Light Emitting Diodes, Chiba, Japan, Sep.29-Oct.2,1998, Th-03 (oral): Proceedings of the 2nd International Symposium on Blue Laser and Light Emitting Diodes (Ohmsha Ltd., Tokyo, 1998) pp.381-384.

26. S. Chichibu, A. Abare, M. Mack, M. Minsky, T. Deguchi, D. Cohen, P. Kozodoy, S. Fleischer, S. Keller, J. Speck, J. E. Bowers, E. Hu, U. K. Mishra, L. A. Coldren, S. P. DenBaars, K. Wada, T. Sota, and S. Nakamura:

"Optical properties of InGaN quantum wells"
European Materials Research Society, 1998 Spring Meeting, Session L: III-V Nitrides, Strasbourg, France, Jun.16-19, 1998, No. L-IV.1 (Invited-oral).

25. S. Chichibu, T. Deguchi, T. Sota, K. Wada, and S. Nakamura:

"Exciton localization in InGaN quantum well devices",
25th Conference on the Physics and Chemistry of Semiconductor Interfaces (PCSI-25), Salt Lake City, Utah, USA, Jan.18-22, 1998, SESSION: III-NITRIDES No.Mo1030 (Invited-oral & poster).

24. S. Chichibu, T. Deguchi, T. Sota, K. Wada, and S. Nakamura:

"LOCALIZED EXCITONS IN InGaN",
Materials Research Society, 1997 Fall Meeting, Session N: ‡V-‡X Nitrides, Boston, MA, USA, Dec.1-5, 1997, No. D12.1 (Invited-oral). Materials Research Society Symposium Proceedings Series Vol.482,p.613-624.

23. T. Deguchi, A. Shikanai, T. Sota, S. Chichibu, and S. Nakamura:

"Gain Spectroscopy of Continuous Wave InGaN Multi-Quantum Well Laser Diodes with Different Degree of Compositional Fluctuation",
The 2nd International Conference on Nitride Semiconductors (ICNS'97), Tokushima, Japan, Oct.27-31, 1997, S-8(oral).

22. M. Arita, S. Chichibu, H. Nakanishi, T. Deguchi, T. Azuhata, T. Sota, and S. Nakamura:

"Exciton-Phonon Interaction in Wurtzite GaN Epilayers",
The 2nd International Conference on Nitride Semiconductors (ICNS'97), Tokushima, Japan, Oct.27-31, 1997, Th1-6(oral).

21. H. Hamaguchi, G. Feuillet, H. Okumura, Y. Ishida, S. Chichibu, H. Nakanishi, and S. Yoshida:

"Surface Reconstructions of Cubic GaN on 3C-SiC and GaAs",
The 2nd International Conference on Nitride Semiconductors (ICNS'97), Tokushima, Japan, Oct.27-31, 1997, P2-55(poster).

20. M. Sugiyama, S. Chichibu, A. Shikanai, T. Azuhata, T. Sota, H. Amano, and I. Akasaki:

"Photoreflectance and Photoluminescence Spectra of Tensile-Strained Wurtzite GaN Epilayers",
The 2nd International Conference on Nitride Semiconductors (ICNS'97), Tokushima, Japan, Oct.27-31, 1997, P2-33(poster).

19. T. Deguchi, T. Azuhata, T. Sota, S. Chichibu, and S. Nakamura:

"Optical Absorption Coefficient in Wurtzite GaN",
The 2nd International Conference on Nitride Semiconductors (ICNS'97), Tokushima, Japan, Oct.27-31, 1997, P2-32(poster).

18. S. Chichibu, T. Azuhata, T. Sota, and S. Nakamura:

"Bright Emissions due to Recombination of Localized Excitons in InGaN Bulk and Quantum Well Devices",
The 2nd International Conference on Nitride Semiconductors (ICNS'97), Tokushima, Japan, Oct.27-31, 1997, Tu3-2(oral).

17. H. Okumura, H. Hamaguchi, T. Koizumi, K. Balakrishnan, Y. Ishida, M. Arita, S. Chichibu, H. Nakanishi, T. Nagamoto, and S. Yoshida:

"Growth of Cubic III-nitrides by Gas Source MBE Using Atomic Nitrogen Plasma : GaN, AlGaN and AlN",
The 2nd International Conference on Nitride Semiconductors (ICNS'97), Tokushima, Japan, Oct.27-31, 1997, Tu1-3(oral) .

16. K. Iwata, H. Asahi, K. Asami, A. Ishida, R. Kuroiwa, H. Tampo, S. Gonda, and S. Chichibu:

"Promising characteristics of GaN layers grown on amorphous silica substrates by gas source MBE",
The 2nd International Conference on Nitride Semiconductors (ICNS'97), Tokushima, Japan, Oct.27-31, 1997, Tu1-2(oral).

15. S. Chichibu, K. Wada, M. Arita, T. Sota, and S. Nakamura:

"Monochromated Cathodeluminescence Mapping of InGaN Single Quantum Wells",
The 2nd International Conference on Nitride Semiconductors (ICNS'97), Tokushima, Japan, Oct.27-31, 1997, P1-LN-11(late news-poster).

14. H. Okumura, K. Balakrishnan, H. Hamaguchi, T. Koizumi, S. Chichibu, H. Nakanishi, T. Nagamoto, and S. Yoshida:

"Analysis of MBE Growth Mode for GaN Epilayers by RHEED",
The 2nd International Conference on Nitride Semiconductors (ICNS'97), Tokushima, Japan, Oct.27-31, 1997, P1-50(poster).

13. S. Yoshida, H. Okumura, Y. Ishida, K. Balakrishnan, H. Hamaguchi, S. Chichibu, and H. Nakanishi:

"MBE GROWTH MONITORING OF CUBIC AND HEXAGONAL GaN BY SURFACE RECONSTRUCTION",
The 4th IUMRS International Conference in Asia, Makuhari, Japan, Sept.16-18, 1997.

12. S. Chichibu, T. Azuhata, T. Sota, and S. Nakamura:

"Localized Excitons in InGaN Quantum Wells",
16th Electronic Materials Symposium, Minou, Japan, Jul.9-11 (1997). Session H10, pp.219-222.

11. S. Chichibu, A. Shikanai, T. Azuhata, T. Sota, A. Kuramata, K. Horino, and S. Nakamura:

"Biaxial Strain Effect on the Exciton Resonance Energies of h-GaN Heteroepitaxial Layers Grown by MOVPE",
15th Electronic Materials Symposium, Izu-Nagaoka, Japan, Jul.10-12 (1996). Session C20, pp.77-80.

10. H. Okumura, H. Hamaguchi, K. Ohta, G. Feuillet, K. Barakrishnan, Y. Ishida, S. Chichibu, H. Nakanishi, T. Nagamoto, and S. Yoshida:

"Surface Reconstruction and As Surfactant Effects on MBE-Grown GaN Epilayers",
International Conference on Silicon Carbide, III - Nitrides and Related Materials 1997.

9. T. Deguchi, T. Azuhata, T. Sota, S. Chichibu, and S. Nakamura:

"GAIN SPECTRA IN CW InGaN/GaN LASER DIODES",
European Materials Research Society, 1997 Spring Meeting, Session L: ‡V-‡X Nitrides, Strasbourg, France, Jun.16-20, 1997, No. L-XIII-3 (Invited).

8. T. Deguchi, T. Azuhata, T. Sota, S. Chichibu, N. Sarukura, H. Ohtake, T. Yamanaka, and S. Nakamura:

"NANOSECOND PUMP-AND-PROBE STUDY OF WURTZITE GaN"
European Materials Research Society, 1997 Spring Meeting, Session L: III-V Nitrides, Strasbourg, France, Jun.16-20, 1997, No. L-V-2 (Invited).

7. T. Azuhata, T. Sota, S. Chichibu, A. Kuramata, K. Horino, M. Yamaguchi, T. Yagi, and S. Nakamura:

"VALENCE BAND PHYSICS IN WURTZITE GaN",
Materials Research Society, 1997 Spring Meeting, Session D: Gallium Nitride and Related Materials, San Francisco, CA, USA, Mar.31-Apr.3, 1997, No. D5.3 (Invited). Materials Research Society Symposium Proceedings Series

6. H. Okumura, K. Balakrishnan, G. Feuillet, Y. Ishida, S. Yoshida, K. Ohta, H. Hamaguchi, and S. Chichibu:

"STRUCTURAL AND OPTICAL CHARACTERIZATION OF HIGH-QUALITY CUBIC GaN EPILAYERS GROWN ON GaAs AND 3C-SiC SUBSTRATES BY GAS SOURCE MBE USING RHEED IN-SITU MONITORING",
Materials Research Society, 1996 Fall Meeting, Session N: ‡V-‡X Nitrides, Boston, MA, USA, Dec.2-6, 1996, No. N3.31. Materials Research Society Symposium Proceedings Series Vol.449,p.435-440.

5. S. Chichibu, T. Azuhata, T. Sota, and S. Nakamura

"RECOMBINATION OF LOCALIZED EXCITONS IN InGaN SINGLE- AND MULTI-QUANTUM WELL STRUCTURES",
Materials Research Society, 1996 Fall Meeting, Session N: ‡V-‡X Nitrides, Boston, MA, USA, Dec.2-6, 1996, No. N1.7. Materials Research Society Symposium Proceedings Series Vol.449,p.653-658.

4. S. Chichibu, H. Okumura, G. Feuillet, S. Nakamura, and S. Yoshida:

"Exciton Spectra of Cubic and Hexagonal GaN Epitaxial Films",
International Conference on Solid State Devices and Materials, Yokohama, Japan, Aug.26-29, 1996, C-2-3, Extended Abstract pp.227-229.

3. S. Chichibu, T. Azuhata, T. Sota, and S. Nakamura:

"Localized excitons in InGaN single- and multi-quantum well structures",
38th Electronic Materials Conference (EMC-38), Session W (Optical and Electrical Characterization of III-V nitrides), Late News W10, Santa Barbara, USA, Jun.26-28,1996.

2. S. Chichibu, A. Shikanai, T. Azuhata, T. Sota, A. Kuramata, K. Horino, and S. Nakamura:

"Exciton Structures in h-GaN Heteroepitaxial Layers Grown on Sapphire Substrates by MOCVD",
38th Electronic Materials Conference (EMC-38), Session W (Optical and Electrical Characterization of III-V nitrides), W2, Santa Barbara, USA, Jun.26-28,1996.

1. S. Chichibu, T. Azuhata, T. Sota, and S. Nakamura:

"Contribution of Excitons in the Photoluminescence Spectra of h-GaN Epitaxial Layers Grown on Sapphire Substrates by TF-MOCVD",
International Symposium on Blue Laser and Light Emitting Diodes, Chiba, Japan, Mar. 5-7,1996. We-19: Proceedings of the International Symposium on Blue Laser and Light Emitting Diodes (Ohmsha Ltd, Tokyo, 1996) pp.202-205.