Article
Physics, Applied
B. Jiang, N. P. Opondo, S. A. Bhave
Summary: Silicon carbide (SiC) is known for its exceptional mechanical properties and has been widely used in microelectromechanical systems. Recent advancements in mechanical tuning of color centers in 4H-SiC have enhanced its application in quantum spintronics. This work demonstrates a lateral overtone mechanical resonator fabricated from a semi-insulating bulk 4H-SiC wafer, showcasing its potential for manipulating quantum states.
APPLIED PHYSICS LETTERS
(2021)
Article
Materials Science, Multidisciplinary
K. Kamalakkannan, R. Rajaraman, B. Sundaravel, G. Amarendra, K. Sivaji
Summary: Depth-resolved Raman spectroscopy was used to study the changes in sem-insulating 6H-Silicon Carbide (SI:6H-SiC) after Al+ ion implantation and annealing at 800 degrees C. Results showed deformations related to bond breakages and defect recovery, which were observed through the analysis of Raman first-order acoustical and second-order optical phonon modes. Annealing led to symmetrical Raman peaks and the recovery of active Raman modes. The Raman Z-scan studies revealed amorphous features near the surface and partial recovery in the deep region, indicating defect agglomeration and recrystallization.
Article
Physics, Applied
Meng-meng Gao, Liu-yan Fan, Xiao-ye Gong, Jing-lin You, Zhi-zhan Chen
Summary: The photoexcited carrier dynamics of high-purity (HPSI) and vanadium-doped semi-insulating (VDSI) 4H-SiC irradiated by lasers with different wavelengths and powers were investigated. It was found that the longitudinal optical (LO) peaks of HPSI and VDSI did not shift with laser power variations when a 532-nm laser was used, due to a low concentration of photoexcited carriers. However, when a 355-nm laser was adapted, the relationship between the photoexcited carrier concentrations and the laser power was found to be nonlinear because of the dominance of trap-assisted Auger (TAA) recombination.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Applied
Kazutoshi Kojima, Shin-ichiro Sato, Takeshi Ohshima, Shin-Ichiro Kuroki
Summary: 4H-SiC epitaxial layers with ultrahigh resistivity of over 10(10) omega cm were grown using a hot wall chemical vapor deposition system with vanadium doping, and the resistivity was found to be dependent on the type of dopant impurities.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Materials Science, Coatings & Films
Hsueh- Chen, Kun-An Chiu, Jing-Feng Lin, Kuan-Yu Lin, Wei-Chia Chen, Ping-Hsun Wu, Cheng-Jung Ko, Li Chang, Chun-Hua Chen
Summary: Epitaxial TiN film has been successfully grown on a semi-insulating single crystal SiC substrate. The effects of growth temperature and nitrogen flow ratio on film quality and growth rate were investigated, revealing that increasing the nitrogen flow ratio improves film quality but decreases growth rate.
SURFACE & COATINGS TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Pyeung Hwi Choi, Yong Pyo Kim, Min-Seong Kim, Jiheon Ryu, Sung-Hyun Baek, Sung-Min Hong, Sungbae Lee, Jae-Hyung Jang
Summary: High purity semi-insulating 4H-silicon carbide was utilized to fabricate lateral and vertical photoconductive semiconductor switches. Among them, the vertical PCSS demonstrated superior performance in terms of minimum ON-state resistance and output pulse amplitude.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Physics, Applied
Hongyue Wang, Po-Chun (Brent) Hsu, Ming Zhao, Eddy Simoen, Stefan De Gendt, Arturo Sibaja-Hernandez, Jinyan Wang
Summary: The study investigates electrically active defects in carbon-doped GaN layers using a metal/carbon-doped GaN/Si-doped GaN MIS structure, revealing trap states associated with different carbon doping concentrations. This provides further insights into the impact of these defects on the electrical characteristics of GaN power devices.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Thermodynamics
Thorsten Summ, Mathias Ehrenwirth, Christoph Trinkl, Wilfried Zoerner, Kaj Pischow, Richard Greenough, Muyiwa Oyinlola
Summary: Insulating glass flat-plate collectors can be produced quickly and automatically in insulated glass production facilities, and filling them with argon can reduce heat loss. However, the influence of argon concentration on collector efficiency is not well understood. This study conducted theoretical calculations and experimental measurements to analyze this effect. The results show that the influence of argon concentration on convective losses and thermal efficiency is nonlinear, and an argon leakage threshold is proposed to maintain efficiency over time.
APPLIED THERMAL ENGINEERING
(2023)
Article
Materials Science, Multidisciplinary
Shuang Wu, Qian Liu, Zhonggang Wang, Zhenhua Zhang, Zhihong Lu, Rui Xiong, Jinlei Yao, Dengjing Wang
Summary: In this paper, H+ is used to bombard N-type undoped GaAs substrates to impart semiconductor-like electrical properties. The shape and structure of the sample were measured using atomic force microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy, while the electrical properties were tested using the Physical Property Measurement System. The treated GaAs substrate surface showed hole-type conductivity at 84 K and electron-type conductivity at room temperature. This method not only preserves the lattice structure but also transforms the surface properties of GaAs, providing a new idea for the future development of GaAs-based heterojunction devices.
Article
Chemistry, Physical
Fumihiko Maeda, Makoto Takamura, Hiroki Hibino
Summary: By using core-level photoelectron spectroscopy, the surface of SiC(0001)-6 root 3 x 6 root 3R30 degrees (buffer layer surface) formed on n-type and semi-insulating substrates was studied. The adsorption of hydrocarbons and chemical bonding of oxygen atoms to the carbon atoms in the buffer layer were observed when the surface was exposed to air after buffer layer formation. However, annealing in ultra-high vacuum and an ethylene ambient resulted in the removal of these impurities and a clean buffer layer surface was obtained. The band bending of the buffer layer on the n-type and semi-insulating substrates was estimated through the peak position of Si 2p.
Article
Engineering, Electrical & Electronic
Yuxin Zhao, Qilin Wu, Tao Xun, Langning Wang, Hanwu Yang
Summary: 6H-SiC photoconductive semiconductor switches (PCSS) offer a new alternative for high power microwave or RF generators, with potential for compactness, tunable frequency, and pulse width. This study establishes a major physics framework based on the expressions of influencing factors, and constructs a scalable PCSS model in PSpice, validated through experiments. The correspondence between measured and simulated results confirms the applicability of the model.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS
(2021)
Article
Computer Science, Information Systems
Shenglei Zhao, Jincheng Zhang, Yachao Zhang, Lansheng Feng, Shuang Liu, Xiufeng Song, Yixin Yao, Jun Luo, Zhihong Liu, Shengrui Xu, Yue Hao
Summary: This study presents a 1.7 kV normally-off p-GaN gate high-electron-mobility transistor (HEMT) on SiC substrates. The fabricated p-GaN HEMT showed a threshold voltage of 1.10V, a maximum drain current of 235 mA/mm, an ON/OFF ratio of 10^8, and a breakdown voltage of 440V with L-GD = 5 μm. With L-GD = 23 μm, the p-GaN HEMT achieved a remarkably high breakdown voltage of 1740V with substrate grounded. The results demonstrate the significant potential of p-GaN gate HEMTs on SiC substrates for high-voltage power applications.
SCIENCE CHINA-INFORMATION SCIENCES
(2023)
Article
Construction & Building Technology
Ning Li, Qinglin Meng, Lihua Zhao, Hao Li, Junsong Wang, Nan Zhang, Pin Wang, Sumei Lu
Summary: With the development of global economy, the proportion of energy consumption in buildings is increasing. In this paper, polycarbonate films with high transparency are used as the interval layers of double glazing to improve thermal insulation and sunlight transmittance. The results show that the developed glazing system has better energy consumption performance compared to traditional double silver Low-E pane.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Computer Science, Information Systems
Pyeung Hwi Choi, Yong Pyo Kim, Min-Seong Kim, Jiheon Ryu, Sung-Hyun Baek, Sung-Min Hong, Sungbae Lee, Jae-Hyung Jang
Summary: The performance of a photoconductive semiconductor switch (PCSS) under two different load conditions, 50-Omega and 0.05-Omega, was investigated using a 532-nm pulsed laser. The PCSS exhibited significantly different output characteristics for the two different loads.
Article
Physics, Multidisciplinary
Martin Rejhon, Mykola Brynza, Roman Grill, Eduard Belas, Jan Kunc
Summary: Researchers measured spectral-resolved photocurrent, current-voltage characteristics, and mid to near-infrared transmittance spectra on a semi-insulating 4H-SiC wafer at room temperature. They identified four deep levels, their energies, and localization radii, and their model considered defects' wavefunction as a linear combination of s- and p-states, leading to a mixture of dipole allowed and forbidden transitions which affected the width of photocurrent peaks.
