Article
Physics, Applied
Gunnar Kusch, Martin Frentrup, Nan Hu, Hiroshi Amano, Rachel A. Oliver, Markus Pristovsek
Summary: This study combines scanning electron microscopy with structural characterization and optical characterization to analyze the defects in a (10 (1) over bar3)-oriented GaN layer. The results show that the samples grown along (10 (1) over bar3) orientation have a lower defect density and higher radiative efficiency potential compared to other orientations.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Jun Chen, Wei Yi, Shun Ito, Takashi Sekiguchi
Summary: The extended defects in m-plane seed-grown GaN substrate, specifically the presence of basal-plane stacking faults (BSFs), have been studied using cathodoluminescence (CL) and transmission electron microscopy (TEM). The luminescence characteristics and emission peaks of I-1 and I-2 BSFs have been identified through high-resolution CL and spatially resolved spectral analysis. Additionally, the movement of dislocations under electron beam irradiation and its correlation with stacking faults have been discussed.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Ronghuo Yuan, Qingyuan Luo, Zenghui Zhang, Yufan Zheng, Dengtang Feng, Defa Wang, Yan-Ling Hu
Summary: InxGa1-xN nanowires were grown on an n-type Si substrate via Ni-catalyzed CVD, with growth direction controlled by the position of metallic sources. NWs grown at higher temperatures were straight and coarse, while NWs grown at lower temperatures were curved and fine, exhibiting different photocatalytic performances.
Article
Engineering, Electrical & Electronic
Amel Lachichi, Philip Mawby
Summary: This article investigates the bipolar degradation issue of 4H-SiC power MOSFET devices and presents simulation and experimental results showing an increase in voltage consistent with the experimental findings. Additionally, a novel method using electroluminescence to detect the presence of SFs within power devices is proposed.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Optics
Poulami Ghosh, Dapeng Yu, Gaomin Li, Mingyuan Huang, Yingkai Liu
Summary: Through various optical measurements, it was found that the decrease in diameter of gallium nitride microrods results in a blueshift in the band gap energy due to the formation of whispering gallery mode polaritons. Raman spectra confirmed that the band gap energy changes were not due to stress/strain or different doping concentrations. Photoluminescence experiments revealed that the exciton photon coupling strength depends on the microrod diameter and decreases as the diameter decreases.
Article
Physics, Applied
Petr Vacek, Martin Frentrup, Lok Yi Lee, Fabien C. P. Massabuau, Menno J. Kappers, David J. Wallis, Roman Groeger, Rachel A. Oliver
Summary: The defect structure of zincblende GaN nucleation layers grown on 3C-SiC/Si (001) was investigated, which includes perfect dislocations, partial dislocations, and stacking faults. These defects, especially perfect and partial dislocations, help relieve the compressive lattice mismatch strain in GaN layers. The stacking faults in the layers are mainly bounded by 30 degrees Shockley partial dislocations and occasionally by Lomer-Cottrell partial dislocations, originating from the dissociation of perfect dislocations or direct nucleation of partial dislocations loops from the surface.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
A. Mendoza, G. Guzman, I. Rivero, S. Camacho-Lopez, M. Herrera-Zaldivar
Summary: The study reveals that oxygen impurities incorporate at lower concentrations in decorative GaN nanoparticles grown on GaN:O nanorods, reducing the formation of point defects in GaN. Decorative GaN nanoparticles exhibit strong band-edge emission and weak emission.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Review
Physics, Applied
D. J. Binks, P. Dawson, R. A. Oliver, D. J. Wallis
Summary: LEDs based on hexagonal InGaN/GaN quantum wells are widely used for lighting applications, but their performance is limited for green and amber emission and at high drive currents. Growing quantum wells in the cubic phase is a promising alternative due to its reduced bandgap and absence of strong polarization fields. The major structural defects in cubic GaN are stacking faults, which affect the optical properties and can propagate into active layers.
APPLIED PHYSICS REVIEWS
(2022)
Article
Physics, Applied
S. A. Church, M. Quinn, K. Cooley-Greene, B. Ding, A. Gundimeda, M. J. Kappers, M. Frentrup, D. J. Wallis, R. A. Oliver, D. J. Binks
Summary: Research indicates that growing InGaN/GaN quantum wells in the zincblende crystal phase has the potential to improve efficiency, with increasing the number and width of the quantum wells significantly enhancing emission efficiency.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Bangyao Mao, Shu'an Xing, Guijuan Zhao, Lianshan Wang, Ning Zhang, Hailong Du, Guipeng Liu
Summary: We have successfully grown high-quality semi-polar (11-22) GaN with a smooth surface on patterned Si (113) substrate by delicately tuning the V/III ratio in a three-step approach. The smoothest surface was achieved when the V/III ratio for each step was 700/1500/1500. X-ray diffraction analysis confirmed the orientation of GaN, and rocking curve analysis indicated the presence of strain in the samples. Raman and photoluminescence spectra further confirmed the strain in the samples and showed a low density of basal plane stacking faults.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2023)
Article
Materials Science, Ceramics
Ting-Ting Zhao, Hui Gu, Xian-Hao Wang, Juan-Juan Xing, Zhi-Jun Zhang, Wen-Liang Zhu
Summary: Understanding the dopant distribution and microstructure properties of silicon carbide (SiC) ceramics is crucial in studying their sintering behavior. Various core rim structures and stacking faults were observed in SiC ceramics sintered with rare-earth oxides, affecting the luminescence properties and phase transformation. Systematic correlation between microstructure development, defect luminescence, and phase transformation provides insights into the performance of SiC ceramics and electronic materials.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2021)
Article
Physics, Applied
Huixin Xiu, Simon M. Fairclough, Abhiram Gundimeda, Menno J. Kappers, David J. Wallis, Rachel A. Oliver, Martin Frentrup
Summary: Aberration-corrected scanning transmission electron microscopy techniques were used to investigate the bonding configuration of GaN in metalorganic vapor-phase epitaxy-grown cubic zincblende structure on vicinal (001) 3C-SiC/Si. The study identified the orientation and bond polarity of planar defects and found that the substrate miscut direction correlated with the crystallographic in-plane direction. The presence of hexagonal wurtzite phase on Ga-polar {111} planes and their absence on N-polar {111} planes can be tentatively explained by the preferential growth of wurtzite GaN in the Ga-polar direction.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Florian Pantle, Fabian Becker, Max Kraut, Simon Worle, Theresa Hoffmann, Sabrina Artmeier, Martin Stutzmann
Summary: GaN-on-diamond is a promising approach for high-power transistor devices, offering outstanding performance and improved heat management compared to GaN-on-SiC. The selective area growth of GaN nanostructures on cost-efficient diamond substrates by plasma-assisted molecular beam epitaxy shows high selectivity and controllable dimensions, enabling applications in high-power/high-frequency devices.
NANOSCALE ADVANCES
(2021)
Article
Materials Science, Multidisciplinary
Aixing Li, Yufeng Li, Haifeng Yang, Minyan Zhang, Zhenhuan Tian, Qiang Li, Feng Yun
Summary: In this study, the excitation-dependent luminescence properties of InGaN/GaN light-emitting diodes with air-cavity arrays were investigated using scanning near-field optical microscopy. The effect of the air-cavity structure on the spatial distributions of light-extraction efficiency, internal quantum efficiency, and external quantum efficiency were quantified through experiments and numerical simulations. The results showed that the air-cavity areas exhibited higher light-extraction efficiency and reduced stress compared to flat areas.
OPTICAL MATERIALS EXPRESS
(2022)
Article
Physics, Applied
D. Dyer, S. A. Church, M. Jain, M. J. Kappers, M. Frentrup, D. J. Wallis, R. A. Oliver, D. J. Binks
Summary: The effects of thermal annealing on the optical properties of Mg-doped cubic zincblende GaN epilayers grown by metalorganic chemical vapor deposition on 3C-SiC/Si (001) substrates were investigated. The results showed an increase in the intensity of the blue luminescence band by a factor of 5 after annealing in a N-2 atmosphere, along with an increase in the recombination lifetime. Time decay measurements confirmed the reduction in non-radiative defects concentration after annealing.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Physics, Applied
Yosuke Nagasawa, Kazunobu Kojima, Akira Hirano, Masamichi Ipponmatsu, Yoshio Honda, Hiroshi Amano, Isamu Akasaki, Shigefusa F. Chichibu
APPLIED PHYSICS EXPRESS
(2019)
Article
Physics, Applied
Kazunobu Kojima, Kenichiro Ikemura, Shigefusa F. Chichibu
APPLIED PHYSICS EXPRESS
(2019)
Article
Physics, Applied
Kazushi Ebara, Ken Mochizuki, Yoku Inoue, Toru Aoki, Kazunobu Kojima, Shigefusa F. Chichibu, Takayuki Nakano
JAPANESE JOURNAL OF APPLIED PHYSICS
(2019)
Article
Physics, Applied
Shigefusa F. Chichibu, Kohei Shima, Kazunobu Kojima, Shin-ya Takashima, Katsunori Ueno, Masaharu Edo, Hiroko Iguchi, Tetsuo Narita, Keita Kataoka, Shoji Ishibashi, Akira Uedono
JAPANESE JOURNAL OF APPLIED PHYSICS
(2019)
Article
Physics, Condensed Matter
Akira Uedono, Hiroko Iguchi, Tetsuo Narita, Keita Kataoka, Werner Egger, Toenjes Koschine, Christoph Hugenschmidt, Marcel Dickmann, Kohei Shima, Kazunobu Kojima, Shigefusa F. Chichibu, Shoji Ishibashi
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2019)
Article
Physics, Applied
Hidehiro Asai, Kazunobu Kojima, Shigefusa F. Chichibu, Koichi Fukuda
PHYSICAL REVIEW APPLIED
(2019)
Article
Nanoscience & Nanotechnology
K. Kojima, K. Ikemura, K. Matsumori, Y. Yamada, Y. Kanemitsu, S. F. Chichibu
Article
Physics, Applied
S. F. Chichibu, K. Kojima, K. Hazu, Y. Ishikawa, K. Furusawa, S. Mita, R. Collazo, Z. Sitar, A. Uedono
APPLIED PHYSICS LETTERS
(2019)
Review
Physics, Applied
Shigefusa F. Chichibu, Yoichi Ishikawa, Kouji Hazu, Kentaro Furusawa
JAPANESE JOURNAL OF APPLIED PHYSICS
(2020)
Article
Physics, Applied
Yosuke Nagasawa, Ryuichi Sugie, Kazunobu Kojima, Akira Hirano, Masamichi Ippommatsu, Yoshio Honda, Hiroshi Amano, Isamu Akasaki, Shigefusa F. Chichibu
JOURNAL OF APPLIED PHYSICS
(2019)
Article
Physics, Condensed Matter
Masahiro Takahashi, Atsushi Tanaka, Yuto Ando, Hirotaka Watanabe, Manato Deki, Maki Kushimoto, Shugo Nitta, Yoshio Honda, Kohei Shima, Kazunobu Kojima, Shigefusa F. Chichibu, Kevin J. Chen, Hiroshi Amano
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2020)
Article
Physics, Applied
K. Shima, K. Furusawa, S. F. Chichibu
APPLIED PHYSICS LETTERS
(2020)
Article
Crystallography
Saskia Schimmel, Daisuke Tomida, Makoto Saito, Quanxi Bao, Toru Ishiguro, Yoshio Honda, Shigefusa Chichibu, Hiroshi Amano
Summary: The thermal boundary conditions for numerical simulations of ammonothermal GaN crystal growth were investigated in this study, with a global heat transfer model presented to analyze fluid flow and thermal field. Machine learning was applied to efficiently determine power boundary conditions for set temperatures at specified locations.
Review
Crystallography
Saskia Schimmel, Daisuke Tomida, Tohru Ishiguro, Yoshio Honda, Shigefusa Chichibu, Hiroshi Amano
Summary: Numerical simulations play a crucial role in the design and optimization of crystal growth processes, especially for ammonothermal growth of bulk GaN where technical limitations in experimental investigations and accessing internal parameters exist. Factors such as fluid flow, thermal boundary conditions, and uncertainty in fluid properties under specific conditions are key considerations for developing accurate numerical models. A closer integration of numerical modeling, physical modeling, and measurements under ammonothermal process conditions is necessary to improve the accuracy of simulations.
Article
Chemistry, Physical
Saskia Schimmel, Michael Salamon, Daisuke Tomida, Steffen Neumeier, Tohru Ishiguro, Yoshio Honda, Shigefusa F. Chichibu, Hiroshi Amano
Summary: An in situ monitoring technique for tracking mass transport of the nitride in the ammonothermal method was evaluated using high-energy computed tomography. Suitable transparency in the autoclave volume can be achieved in a lab-scale setup for GaN crystal growth. For ammonoacidic growth, shorter scan durations or lower acceleration voltages are feasible.
