The origins and properties of intrinsic nonradiative recombination centers in wide bandgap GaN and AlGaN SF Chichibu, A Uedono, K Kojima, H Ikeda, K Fujito, S Takashima, M Edo, ...
Journal of applied physics 123 (16), 2018
157 2018 Epitaxial growth and optical properties of semipolar (112¯ 2) GaN and InGaN∕ GaN quantum wells on GaN bulk substrates M Ueda, K Kojima, M Funato, Y Kawakami, Y Narukawa, T Mukai
Applied Physics Letters 89 (21), 2006
137 2006 Polarization switching phenomena in semipolar quantum well active layers M Ueda, M Funato, K Kojima, Y Kawakami, Y Narukawa, T Mukai
Physical Review B—Condensed Matter and Materials Physics 78 (23), 233303, 2008
101 2008 Optical gain spectra for near UV to aquamarine (Al, In) GaN laser diodes K Kojima, UT Schwarz, M Funato, Y Kawakami, S Nagahama, T Mukai
Optics Express 15 (12), 7730-7736, 2007
94 2007 Nitrogen vacancies as a common element of the green luminescence and nonradiative recombination centers in Mg-implanted GaN layers formed on a GaN substrate K Kojima, S Takashima, M Edo, K Ueno, M Shimizu, T Takahashi, ...
Applied Physics Express 10 (6), 061002, 2017
87 2017 Accurate alignment of a photonic crystal nanocavity with an embedded quantum dot based on optical microscopic photoluminescence imaging T Kojima, K Kojima, T Asano, S Noda
Applied Physics Letters 102 (1), 2013
76 2013 Interplay of built-in potential and piezoelectric field on carrier recombination in green light emitting InGaN quantum wells UT Schwarz, H Braun, K Kojima, Y Kawakami, S Nagahama, T Mukai
Applied Physics Letters 91 (12), 2007
70 2007 Carrier Trapping by Vacancy‐Type Defects in Mg‐Implanted GaN Studied Using Monoenergetic Positron Beams A Uedono, S Takashima, M Edo, K Ueno, H Matsuyama, W Egger, ...
physica status solidi (b) 255 (4), 1700521, 2018
67 2018 Large electron capture-cross-section of the major nonradiative recombination centers in Mg-doped GaN epilayers grown on a GaN substrate SF Chichibu, K Shima, K Kojima, S Takashima, M Edo, K Ueno, ...
Applied Physics Letters 112 (21), 2018
64 2018 Gain suppression phenomena observed in InxGa1− xN quantum well laser diodes emitting at 470nm K Kojima, M Funato, Y Kawakami, S Nagahama, T Mukai, H Braun, ...
Applied physics letters 89 (24), 2006
59 2006 Carrier localization structure combined with current micropaths in AlGaN quantum wells grown on an AlN template with macrosteps K Kojima, Y Nagasawa, A Hirano, M Ippommatsu, Y Honda, H Amano, ...
Applied Physics Letters 114 (1), 2019
50 2019 Stimulated emission at 474nm from an InGaN laser diode structure grown on a (112¯ 2) GaN substrate K Kojima, M Funato, Y Kawakami, S Masui, S Nagahama, T Mukai
Applied Physics Letters 91 (25), 2007
50 2007 Theoretical investigations on anisotropic optical properties in semipolar and nonpolar InGaN quantum wells K Kojima, H Kamon, M Funato, Y Kawakami
physica status solidi c 5 (9), 3038-3041, 2008
48 2008 Defect-Resistant Radiative Performance of m-Plane Immiscible Al1−xInxN Epitaxial Nanostructures for Deep-Ultraviolet and Visible Polarized Light Emitters AUYS Shigefusa F. Chichibu, Kazunobu Kojima
Advanced materials, 2016
46 * 2016 Room-temperature photoluminescence lifetime for the near-band-edge emission of (0001¯) p-type GaN fabricated by sequential ion-implantation of Mg and H K Shima, H Iguchi, T Narita, K Kataoka, K Kojima, A Uedono, SF Chichibu
Applied Physics Letters 113 (19), 2018
41 2018 Determination of absolute value of quantum efficiency of radiation in high quality GaN single crystals using an integrating sphere K Kojima, T Ohtomo, K Ikemura, Y Yamazaki, M Saito, H Ikeda, K Fujito, ...
Journal of Applied Physics 120 (1), 2016
40 2016 Quantum electrodynamics of a nanocavity coupled with exciton complexes in a quantum dot M Yamaguchi, T Asano, K Kojima, S Noda
Physical Review B—Condensed Matter and Materials Physics 80 (15), 155326, 2009
40 2009 Annealing behavior of vacancy‐type defects in Mg‐and H‐implanted GaN studied using monoenergetic positron beams A Uedono, H Iguchi, T Narita, K Kataoka, W Egger, T Koschine, ...
physica status solidi (b) 256 (10), 1900104, 2019
33 2019 1.6-Gbps LED-based ultraviolet communication at 280 nm in direct sunlight K Kojima, Y Yoshida, M Shiraiwa, Y Awaji, A Kanno, N Yamamoto, ...
2018 European Conference on Optical Communication (ECOC), 1-3, 2018
33 2018 Low-resistivity m-plane freestanding GaN substrate with very low point-defect concentrations grown by hydride vapor phase epitaxy on a GaN seed crystal synthesized by the … K Kojima, Y Tsukada, E Furukawa, M Saito, Y Mikawa, S Kubo, H Ikeda, ...
Applied Physics Express 8 (9), 095501, 2015
33 2015