Article
Optics
Sida Wei, Xiaodong Gao, Xiaodan Wang, Yangye Pan, Xionghui Zeng, Jiafan Chen, Shunan Zheng, Ke Xu
Summary: Time-resolved photoluminescence measurements were used to study the minority carrier recombination mechanism of p-GaN films grown on different GaN substrates. The slow decay lifetime of the m-plane Mg-doped GaN reached a record value of 493.7 ps. The decrease in non-radiative recombination centers resulted in a longer slow decay lifetime for the m-plane sample.
JOURNAL OF LUMINESCENCE
(2023)
Article
Materials Science, Multidisciplinary
Z. Benzarti, A. Khalfallah, Z. Bougrioua, M. Evaristo, A. Cavaleiro
Summary: This study investigates the impact of Mg doping concentration in GaN thin films on their physical and mechanical properties, specifically on their conductivity transition, luminescence, hardness, Young's modulus, and creep behavior. The results demonstrate that an increase in the Mg concentration leads to a conductivity transition from n-type to p-type, with the highest hole concentration and blue luminescence attained at a specific Mg concentration. Moreover, the hardness, Young's modulus, and the intensity of compressive stress increase with the Mg flow rate.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Chemistry, Physical
Lei Liu, Jian Tian, Feifei Lu
Summary: Based on first principles, this study discussed the electronic properties and atomic structure of Mg-doped multilayer g-GaN. It was found that doping position and concentration both have an impact on the electronic properties. Achieving high concentration doping in bilayer g-GaN is difficult, and when all layers are doped with Mg atoms, the multilayer structure shows lower band gap and work function.
APPLIED SURFACE SCIENCE
(2021)
Article
Nanoscience & Nanotechnology
Kwang Jae Lee, Yusuke Nakazato, Jaeyi Chun, Xinyi Wen, Chuanzhe Meng, Rohith Soman, Maliha Noshin, Srabanti Chowdhury
Summary: This study presents experimental evidence for the use of nanoporous GaN (NP GaN) as a compensation layer to prevent the diffusion of magnesium (Mg) from p-type gallium nitride (p-GaN). Additionally, the study reveals the significant impact of NP GaN on the electron concentration of AlGaN/GaN structures.
Article
Materials Science, Multidisciplinary
Sida Wei, Jing Wang, Xiaodan Wang, Xiaodong Gao, Jiafan Chen, Hongmin Mao, Xionghui Zeng, Ke Xu
Summary: This study investigates the influence of free-standing GaN substrates with different polarities on the surface morphologies and physical properties of epitaxial Mg-doped GaN films grown by MOCVD. The films grown on polar, semipolar, and nonpolar FS-GaN substrates show varying surface morphologies due to different surface states and growth modes. Despite the differences, all films exhibit high crystalline quality and are mostly stress-free.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Minghao Chen, Qian Zhang, Chunlei Fang, Zhijie Shen, Yong Lu, Ting Liu, Shuxin Tan, Jicai Zhang
Summary: In this study, the influence of m-miscut angle of sapphire substrates on the morphology, crystal quality, and residual stress of BN films was investigated. It was found that with the increase of miscut angle, the h-BN (002) diffraction peak broadened and the E-2g vibration mode of h-BN exhibited a blueshift. When the miscut angle was 0.1°, the crystal quality of BN film was optimized, with the h-BN content reaching 45.93% and the residual stress minimized.
Article
Optics
A. El Hamidi, E. El Mahboub, K. Meziane, A. El Hichou, A. Almaggoussi
Summary: Mg-doped ZnO thin films were studied for improved solar cell performance, with XRD showing optimal performance at 2% Mg concentration. This was attributed to electronegativity differences and grain size variations.
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
Engineering, Electrical & Electronic
Ruidong Li, Jinxiang Deng, Le Kong, Junhua Meng, Juxin Luo, Qing Zhang, Hongli Gao, Qianqian Yang, Guisheng Wang, Xiaolei Wang
Summary: In this study, Nb-doped beta-Ga2O3 films were successfully deposited at different substrate temperatures using radio frequency magnetron sputtering technology. The films exhibited a flat surface and good crystal structure at a substrate temperature of 523 K. Furthermore, the films showed high transmittance and a decrease in optical band gap with increasing substrate temperature.
JOURNAL OF ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Suraya Ahmad Kamil, Gin Jose
Summary: The influence of substrate temperature on the morphological, structural, and optical properties of ultrafast laser plasma doped substrates was studied. It was found that temperatures below 400 degrees C were insufficient for the plasma plume to modify the silica bonds, while higher temperatures caused deeper diffusion of Er-doped tellurite glass into silica.
Article
Chemistry, Multidisciplinary
Zhiwei Li, Yugang Zeng, Yue Song, Jianwei Zhang, Yinli Zhou, Yongqiang Ning, Li Qin, Lijun Wang
Summary: This study investigated the effect of substrate misorientation on the crystal quality, structural properties, and optical properties of InGaAs/GaAsP single quantum wells. Results revealed that different misorientation angles led to variations in lattice relaxation and optical properties of the quantum wells. The experimental findings proposed a mechanism explaining the impact of substrate miscuts on the structural and optical properties of quantum wells.
APPLIED SCIENCES-BASEL
(2021)
Article
Materials Science, Multidisciplinary
M. Osiac, V. Satulu, M. Jigau, I. Tirca, I. R. Tudorascu
Summary: The crystalline structure and optical properties of pure tungsten oxide WO3 and Fe-doped WO3 thin films deposited on sapphire substrates were investigated. The X-ray diffraction analysis showed that the thin films exhibited different crystal phases depending on the substrate temperature. The presence of Fe in the deposited layer influenced the film structure and reduced the optical bandgap of the 4% Fe-doped WO3 thin film.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2023)
Article
Materials Science, Ceramics
Julia Ramirez-Gonzalez, Anthony R. West
Summary: Impedance measurements on Mg-doped alumina ceramics showed a combination of oxide ion conductivity and p-type electronic conductivity depending on temperature and oxygen partial pressure. Co-doping with Mg and Si resulted in a reduction in oxide ion conductivity and p-type conductivity due to direct replacement of Al3+by Mg2+ and Si4+ ions.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2021)
Article
Nanoscience & Nanotechnology
Suman Bhandari, John L. Lyons, Darshana Wickramaratne, M. E. Zvanut
Summary: This work investigates the optical transitions of Mg-doped gallium oxide using photoinduced electron paramagnetic resonance spectroscopy. The data analysis reveals that the observed transition involves electron transition from the valence band to the defect and the energy level of Mg-Ga(-/0) is located 1.2 eV above the valence band maximum.
Article
Physics, Condensed Matter
Pengfei Shen, Enling Li, Lin Zhang, Hongyuan Zhao, Zhen Cui, Deming Ma
Summary: Doping in g-GaN materials has been studied using first-principles calculations, showing that C-Ga and S-N systems achieve n-type doping, while Mg-Ga and C-N systems achieve p-type doping. The substitution of C for Ga is easier and more stable, leading to blue-shift or red-shift in UV absorption spectra and sharp peaks in the visible range for doped g-GaN systems.
SUPERLATTICES AND MICROSTRUCTURES
(2021)
Article
Engineering, Electrical & Electronic
Houqiang Fu, Jossue Montes, Xuguang Deng, Xin Qi, Stephen M. Goodnick, Fernando A. Ponce, Yuji Zhao, Kai Fu, Shanthan R. Alugubelli, Chi-Yin Cheng, Xuanqi Huang, Hong Chen, Tsung-Han Yang, Chen Yang, Jingan Zhou
IEEE ELECTRON DEVICE LETTERS
(2020)
Article
Physics, Applied
Abhinav Chikhalkar, Abhinandan Gangopadhyay, Hanxiao Liu, Chaomin Zhang, Fernando A. Ponce, David J. Smith, Christiana Honsberg, Richard R. King
JOURNAL OF APPLIED PHYSICS
(2020)
Article
Physics, Applied
Chen Yang, Houqiang Fu, Po-Yi Su, Hanxiao Liu, Kai Fu, Xuanqi Huang, Tsung-Han Yang, Hong Chen, Jingan Zhou, Xuguang Deng, Jossue Montes, Xin Qi, Fernando A. Ponce, Yuji Zhao
APPLIED PHYSICS LETTERS
(2020)
Article
Physics, Applied
Po-Yi Su, Hanxiao Liu, Shuo Wang, Zhihao Wu, Rong Liu, Fernando A. Ponce
JOURNAL OF APPLIED PHYSICS
(2020)
Article
Physics, Applied
Po-Yi Su, Hanxiao Liu, Chen Yang, Kai Fu, Houqiang Fu, Yuji Zhao, Fernando A. Ponce
APPLIED PHYSICS LETTERS
(2020)
Article
Engineering, Electrical & Electronic
Chen Yang, Houqiang Fu, Viswanathan Naveen Kumar, Kai Fu, Hanxiao Liu, Xuanqi Huang, Tsung-Han Yang, Hong Chen, Jingan Zhou, Xuguang Deng, Jossue Montes, Fernando A. Ponce, Dragica Vasileska, Yuji Zhao
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2020)
Article
Engineering, Electrical & Electronic
Kai Fu, Xin Qi, Houqiang Fu, Po-Yi Su, Hanxiao Liu, Tsung-Han Yang, Chen Yang, Jossue Montes, Jingan Zhou, Fernando A. Ponce, Yuji Zhao
Summary: The roughness of re-grown p-type GaN layers increases linearly with growth rate, while screw dislocation density increases significantly above a certain growth rate. High magnesium doping concentrations result in visible Mg precipitates in high-doping p-GaN layers. Different growth rates lead to variations in electroluminescence spectra, with transitions related to defect levels appearing with increasing growth rate.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2021)
Article
Physics, Applied
Kai Fu, Houqiang Fu, Xuguang Deng, Po-Yi Su, Hanxiao Liu, Kevin Hatch, Chi-Yin Cheng, Daniel Messina, Reza Vatan Meidanshahi, Prudhvi Peri, Chen Yang, Tsung-Han Yang, Jossue Montes, Jingan Zhou, Xin Qi, Stephen M. Goodnick, Fernando A. Ponce, David J. Smith, Robert Nemanich, Yuji Zhao
Summary: The paper investigates the silicon (Si) contamination issue in gallium nitride (GaN) power devices and presents an approach to reduce its impact on device performance. Through optimized etching methods and chemical treatment, the silicon concentration levels at the regrowth interface can be effectively lowered, leading to improved performance in vertical GaN-based p-n diodes.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Applied
Frank Mehnke, Alec M. Fischer, Zhiyu Xu, Henri Bouchard, Theeradetch Detchprohm, Shyh-Chiang Shen, Fernando A. Ponce, Russell D. Dupuis
Summary: This study presents a non-planar growth approach for crack-free deposition of high-Al-mole-fraction AlxGa1-xN on GaN/sapphire templates and bulk GaN substrates. By controlling the dimensions and etch depth of the mesas, the Al alloy composition and layer thickness can be increased, leading to a higher critical layer thickness for the heterostructures.
JOURNAL OF APPLIED PHYSICS
(2022)
