Masashi Ishii, Atsushi Koizumi, Yoshikazu Takeda, and Yasufumi Fujiwara: "Discrimination between energy transfer and back transfer processes for GaAs host and Er luminescent dopants using electric response analysis"
Journal of Applied Physics 115 (2014) pp. 133510/1-5. http://dx.doi.org/10.1063/1.4870808
Yasufumi Fujiwara and Volkmar Dierolf: "Present understanding of Eu luminescent centers in Eu-doped GaN grown by organometallic vapor phase epitaxy"
Japanese Journal of Applied Physics 53 (2014) pp. 05FA13/1-8. http://dx.doi.org/10.7567/JJAP.53.05FA13
H. Taguchi, A. Kitahara, S. Miyake, A. Nakae, and Y. Fujiwara: "Analysis of crystalline in GaN epitaxial layer after the wafer dicing process"
Proceedings of MRS, Vol. 1593 (2013). http://dx.doi.org/10.1557/opl.2013.1203
F. Elmasry, S. Okubo, H. Ohta, and Y. Fujiwara: "ESR study of Er-concentration effect in GaAs;Er,O containing charge carriers"
Journal of Applied Physics 115 (2014) pp. 193904/1-7. http://dx.doi.org/10.1063/1.4876487
D. Lee, B. Mitchell, Y. Fujiwara, and V. Dierolf: "Thermodynamics and kinetics of three Mg-H-VN complexes in Mg:GaN - A combined First-Principle and experimental study"
Physical Review Letters 112 (2014) pp. 205501/1-5. http://dx.doi.org/10.1103/PhysRevLett.112.205501
B. Mitchell, J. Poplawsky, D. Lee, Koizumi, Y. Fujiwara, and V. Dierolf: "The role of donor-acceptor pairs in the excitation of Eu-ions in GaN:Eu epitaxial layers"
Journal of Applied Physics 115 (2014) pp. 204501/1-7. http://dx.doi.org/10.1063/1.4879253
W. D. Boer, C. McConigle, T. Gregorkiewicz, Y. Fujiwara, S. Tanabe, and P. Stallinga: "Optical activity and external photoluminescence quantum efficiency of Eu3+ in GaN"
Scientific Reports 4 (2014) pp. 5235/1-5. http://dx.doi.10.1038/srep05235
R. Okada, W. Miao, Y. Terai, T. Tsuji, and Y. Fujiwara: "Sputtering-assisted metal-organic chemical vapor deposition of Yb-doped ZnO for photonic conversion in Si solar cells"
Physica Status Solidi C 11 (2014) pp. 1292-1295. http://dx.doi.10.1002/pssc.201300614
R. Wakamatsu, D. Timmerman, D. Lee, A. Koizumi, and Y. Fujiwara: "Afterglow of Eu-related emission in Eu-doped gallium nitride grown by organometallic vapor phase epitaxy"
Journal of Applied Physics 116 (2014) pp. 043515/1-6. http://dx.doi.org/10.1063/1.4891232
Masashi Ishii, Atsushi Koizumi, and Yasufumi Fujiwara: "Enhancement in light efficiency of a GaN:Eu red light-emitting diode by pulse-controlled injected charges"
Applied Physics Letters 105 (2014) 171903/1-4. http://dx.doi.org/10.1063/1.4900840
Y. Kashiwagi, A. Koizumi, Y. Takemura, S. Furuta, M. Yamamoto, M. Saitoh, M. Takahashi, T. Ohno, Y. Fujiwara, K. Murahashi, K. Ohtsuka, and M. Nakamoto: "Direct transparent electrode patterning on layered GaN substrate by screen printing of indium tin oxide nanoparticle ink for Eu-doped GaN red light-emitting diode"
Applied Physics Letters 105 (2014) 223509/1-4. http://dx.doi.org/10.1063/1.4903234
F. Elmasry, W. Zhang, Y. Fukuoka, S. Okubo, H. Ohta, and Y. Fujiwara: "ESR study of Er-concentration effect in GaAs;Er,O containing charge carrier"
1st Kansai Nanoscience and Nanotechnology International Symposium, P20, February 3-4 (2014).
Tomohiro Inaba, Dong-gun Lee, Ryuta Wakamatsu, Takanori Kojima, Atsushi Koizumi, and Yasufumi Fujiwara: "Improvement of Eu transition probability in Eu,O-codoped GaN by microcavity"
1st Kansai Nanoscience and Nanotechnology International Symposium, P50, February 3-4 (2014).
Atsushi Koizumi, Souichirou Kuwata, and Yasufumi Fujiwara: "Eu-related traps in Eu,Si-codoped GaN studied by deep level transient spectroscopy"
1st Kansai Nanoscience and Nanotechnology International Symposium, P65, February 3-4 (2014).
R. Wakamatsu, D. Timmerman, K. Tanaka, T. Kojima, A. Koizumi, and Y. Fujiwara: "Energy transfer between Eu luminescent sites in Eu-doped GaN under resonant excitation"
1st Kansai Nanoscience and Nanotechnology International Symposium, P66, February 3-4 (2014).
Y. Kashiwagi, A. Koizumi, Y. Takemura, S. Furuta, M. Yamamoto, M. Saitoh, M. Takahashi, T. Ohno, Y. Fujiwara, K. Murahashi, K. Ohtsuka, and M. Nakamoto: "Direct transparent electrode patterning by screen printing with indium tin oxide nanoparticle ink for Eu-doped GaN red-light-emitting diode"
1st Kansai Nanoscience and Nanotechnology International Symposium, P77, February 3-4 (2014).
T. Inaba, D. Lee, R. Wakamatsu, T. Kojima, A. Koizumi, and Y. Fujiwara: "Enhancement of photoluminescence intensity in Eu,O-codoped GaN by microcavity"
41st International Symposium on Compound Semiconducotrs (ISCS2014), We-C2-2, Montpellier, France, May 11-15 (2014).
Y. Fujiwara, D. Lee, A. Koizumi, B. Mitchell, and V. Dierolf: [Invited Talk] "Effects of impurity codoping on luminescence properties in Eu-doped GaN"
5th International Workshop on Photoluminescence Rare Earths (PRE¡Ç14): Photonic Materials and Devices, I-2, San Sebastian, Spain, May 14-16 (2014).
T. Kojima, S. Takano, R. Hasegawa, D. Timmerman, A. Koizumi, M. Funato, Y. Kawakami, and Y. Fujiwara: "Fabrication of InGaN/GaN multiple quantum wells on semipolar {1-101} and {2-201} facets formed using selective-area growth of Eu-doped GaN"
5th International Conference on White LEDs and Solid State Lighting (WLED-5), MB2-4, Jeju, Korea, June 1-5 (2014).
Y. Fujiwara: [Invited Talk] "Rare-earth-doped Semiconductors and their application to photonic devices"
Collaborative Conference on 3D & Materials Research (CC3DMR) 2014, Incheon, Korea, June 22-28 (2014).
Y. Fujiwara, R. Wakamatsu, and A. Koizumi: [Invited Talk] "Strain-dependent energy transfer from GaN host to Eu ions in Eu-doped GaN"
16th International Conference on High Pressure in Semiconductor Physics, Inv-8, Mexico City, Mexico, August 6-8 (2014).
A. Koizumi, S. Kuwata, and Y. Fujiwara: [Invited Talk] "Optical and electrical properties of Eu,Si-codoped GaN grown by organometallic vapor-phase epitaxy"
Energy Materials Nanotechnology Open Access Week (2014 EMN Open), A31, Chengdu, China, September 22-25 (2014).
Y. Fujiwara, D. Timmerman, T. Kojima, and A. Koizumi: [Invited Talk] "Eu-doped GaN and its application to environmentally-friendly red light-emitting diodes"
The second International Conference on Advanced Materials and Nanotechnology (ICAMN2014), IN04, Hanoi, Vietnam, October 29-November 1 (2014).
D. Timmerman and Y. Fujiwara: [Invited Talk] "Energy transfer processes in Eu-doped GaN"
The second International Conference on Advanced Materials and Nanotechnology (ICAMN2014), IN19, Hanoi, Vietnam, October 29-November 1 (2014).
Y. Fujiwara, D. Timmerman, T. Kojima, and A. Koizumi: [Invited Talk] "Europium-doped gallium nitride and its application to environmentally-friendly red light-emitters"
1st International Symposium on Interactive Materials Science Cadet Program, IL7, Hotel Hankyu Expo Park, Osaka, November 16-19 (2014).
J. Takatsu, M. Matsuda, T. Kojima, A. Koizumi, and Y. Fujiwara: "Effects of oxygen codoping on Eu luminescence properties in Eu-doped GaN"
1st International Symposium on Interactive Materials Science Cadet Program, PP-17, Hotel Hankyu Expo Park, Osaka, November 16-19 (2014).
W. Zhu, D. Timmerman, B. Mitchell, A. Koizumi, and Y. Fujiwara: "Formation of efficient Eu luminescent centers in Eu-doped GaN by low-temperature organometallic vapor phase epitaxy"
1st International Symposium on Interactive Materials Science Cadet Program, PP-19, Hotel Hankyu Expo Park, Osaka, November 16-19 (2014).
Y. Fujiwara, R. Wakamatsu, D. Lee, B. Mitchell, A. Koizumi, and V. Dierolf: [Invited Talk] "Eu site-dependent energy transfer in red light emitter of Eu-doped GaN"
2014 MRS Fall Meeting, Symposium T: Wide-Bandgap Materials for Solid-State Lighting and Power Electronics, T4.05, Boston, USA, November 30-December 5 (2014).
W. Zhu, D. Timmerman, B. Mitchell, A. Koizumi, and Y. Fujiwara: "Low-temperature growth of Eu-doped GaN by organometallic vapor phase epitaxy"
2014 MRS Fall Meeting, Symposium T: Wide-Bandgap Materials for Solid-State Lighting and Power Electronics, T4.06, Boston, USA, November 30-December 5 (2014).
A. Morikawa, K. Mizuguchi, and Y. Fujiwara: "High-power SHG green lasers using periodically poled Mg-doped stoichiometric LiTaO3 and fiber lasers"
18th SANKEN International, The 13th SANKEN Nanotechnology Symposium, 2nd KANSAI Nanoscience and Nanotechnology, 10th Handai Nanoscience and Nanotechnology International Symposium, PB-31, The Congres Convention Center, Osaka, Japan, December 10-11 (2014).
A. Koizumi, K. Okada, T. Shigemune, T. Kojima, and Y. Fujiwara: "Temperature dependence of photoconductivity in Eu-doped GaN"
18th SANKEN International, The 13th SANKEN Nanotechnology Symposium, 2nd KANSAI Nanoscience and Nanotechnology, 10th Handai Nanoscience and Nanotechnology International Symposium, PB-47, The Congres Convention Center, Osaka, Japan, December 10-11 (2014).
T. Inaba, D. Lee, R. Wakamatsu, T. Kojima, A. Koizumi, and Y. Fujiwara: "Enhancement of photoluminescence intensity in Eu-doped GaN by improvement of directionality"
18th SANKEN International, The 13th SANKEN Nanotechnology Symposium, 2nd KANSAI Nanoscience and Nanotechnology, 10th Handai Nanoscience and Nanotechnology International Symposium, PB-48, The Congres Convention Center, Osaka, Japan, December 10-11 (2014).
T. Inaba, T. Kojima, A. Koizumi, and Y. Fujiwara: "Improvement of Eu internal quantum efficiency in Eu-doped GaN by surface plasmon resonance"
10th International Symposium on Semiconductor Light Emitting Devices (ISSLED2014), Tu-O32, Kaohsiung, Taiwan, December 14-19 (2014).
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¥ì¡¼¥¶¡¼¸¦µæ 42(3) (2014) pp. 211-215.
Y. Fujiwara: "First demonstration of environmentally friendly nitride-based red light-emitting diodes"
Osaka University Prospectus 2014 (2014) pp. 12-13.