| 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 | 138 | 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 | 131 | 2006 |
| Polarization switching phenomena in semipolar In x Ga 1− x N/GaN quantum well active layers M Ueda, M Funato, K Kojima, Y Kawakami, Y Narukawa, T Mukai Physical Review B 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 | 82 | 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 | 69 | 2013 |
| 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 |
| 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 | 66 | 2007 |
| 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 | 58 | 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 | 57 | 2006 |
| 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 | 49 | 2008 |
| 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 | 49 | 2007 |
| 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 | 44 | 2019 |
| 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 | 44* | 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 | 39 | 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 80 (15), 155326, 2009 | 38 | 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 |
| 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 | 31 | 2015 |
| Internal quantum efficiency of radiation in a bulk CH3NH3PbBr3 perovskite crystal quantified by using the omnidirectional photoluminescence spectroscopy K Kojima, K Ikemura, K Matsumori, Y Yamada, Y Kanemitsu, SF Chichibu APL Materials 7 (7), doi.org/10.1063/1.5110652, 2019 | 28 | 2019 |
