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120 results on '"Cheng, Junji"'

2. A novel field plate with arcuate end for improving GaN HEMTs.

Author

Cheng, Junji, Liu, Jiaping, Luo, Yuanjie, He, Gongtao, Meng, Fanxin, He, Zhaofeng, Yi, Bo, Huang, Haimeng, Yang, Hongqiang, and Wang, Zhiming

Subjects
*MODULATION-doped field-effect transistors, *POWER semiconductors, *BREAKDOWN voltage, *ELECTRONIC circuits, *GALLIUM nitride, *POWER electronics, *ELECTRIC fields
Abstract

A new field plate (FP) is proposed for gallium nitride high‐electron‐mobility transistors (HEMTs). It features an innovative arcuate end (AE), which allows the induced charges that originally gathered at the FP end to diffuse over a wider area. Hence, not only is the electric field in the channel at the gate edge alleviated due to the induced charges, but also that concentrated at the FP end is reduced by means of AE. The simulation results indicate that by upgrading a source FP with AE, HEMT gains a 99% increase in breakdown voltage while remaining unaltered in specific on‐resistance. It also gets a 43.41% decrease in power loss during one cycle while maintaining the same breakdown voltage, which greatly contributes to enhance the efficiency of power electronic circuits. [ABSTRACT FROM AUTHOR]

Published
2024
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16. Use of carrier injection engineering to increase the light intensity of a polycrystalline silicon avalanche mode light-emitting device.

Author

Wu, Kejun, Chen, Yanxu, Cheng, Junji, and Xu, Kaikai

Subjects
LIGHT intensity, POLYCRYSTALLINE silicon, AVALANCHES, VISIBLE spectra
Abstract

This paper demonstrates a polycrystalline silicon avalanche mode light-emitting device. The unique N+PN+PN+ cascade structure is designed to enhance light intensity via carrier injection engineering, in which the minority carriers are injected from the forward-biased junction to the light emission junction. Visible light can be observed at the reverse-biased PN junctions when the device operating voltage exceeds 20 V. In particular, the phonon-assisted indirect interband recombination of carriers with excess energy may be the main mechanism of photon emission. A specific junction model is proposed to explain that the light intensity peaks are generated primarily via carrier injection. Comparing the spectral measurements of a single polysilicon N+P junction device and the proposed cascade device shows that the strategy of improving the luminous intensity via carrier injection engineering is feasible and effective. [ABSTRACT FROM AUTHOR]

Published
2020
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22. Investigation of a Novel Enhancement-Mode Al0.25Ga0.75N/AlN/AlXGa(1-X)N/GaN MIS-HEMT for High Vth and Low Ron,sp

Author

Yi, Bo, Xu, Yi, Cheng, Junji, Huang, Haimeng, Kong, Moufu, and Yang, Hongqiang

Abstract

In this article, we proposed a composite-barrier-metal–insulator–semiconductor-high electron mobility transistor (CB-MIS-HEMT), in which a thick AlxGa $_{({1}-{x}{)}}\text{N}$ with small Al mol fraction is implemented in the gate region to achieve both high threshold voltage ( ${V}_{\text {th}}{)}$ and high electron mobility. A Al $_{{0}.{25}}$ Ga $_{{0}.{75}}\text{N}$ /AlN, working as a second barrier, is set on the AlxGa $_{({1}-{x}{)}}\text{N}$ -layer to maintain high 2DEG density in the access region. The thick AlxGa $_{({1}-{x}{)}}\text{N}$ in the gate region reduces the mobility degradation effects caused by the interface charges, acoustic phonon scattering, and surface roughness scattering. Combined with small Almol fraction design, both low specific ON-resistance (Ron,sp)and high ${V}_{\text {th}}$ can be obtained simultaneously. An analytical model for the electron density in both the lower and upper channels as well as ${V}_{\text {th}}$ is presented, which matches very well with the experimentally calibrated TCAD simulation. For a 600-V design, it shows that the electron mobility in the lower channel can be improved to 1255 cm2/ $\text{V}\cdot \text{s}$ , and at ${V}_{\text {th}}$ around 2.5 V, Ron,sp of the CB-MIS-HEMT can be reduced by 33.6% compared to a conventional recess-gate MIS-HEMT.

Published
2023
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36. Design and Realization of a Novel Poly-Silicon Light-Emitting Device Based on Standard CMOS Technology

Author

刘志伟 Liu Zhiwei, 黄磊 Huang Lei, 刘钟远 Liu Zhongyuan, 艾康 Ai Kang, 吴克军 Wu Kejun, 赵建明 Zhao Jianming, 程骏骥 Cheng Junji, 朱坤峰 Zhu Kunfeng, and 徐开凯 Xu Kaikai

Subjects
Materials science, CMOS, Silicon, chemistry, business.industry, Optoelectronics, chemistry.chemical_element, Electrical and Electronic Engineering, business, Realization (systems), Atomic and Molecular Physics, and Optics, Light emitting device, Electronic, Optical and Magnetic Materials
Published
2020

48. A Novel IGBT With High-k Dielectric Modulation Achieving Ultralow Turn-Off Loss.

Author

Chen, Weizhen, Cheng, Junji, and Chen, Xing Bi

Subjects
*INSULATED gate bipolar transistors, *DIELECTRICS, *BIPOLAR transistors, *TRANSISTORS, *ELECTRIC fields
Abstract

A novel insulated gate bipolar transistor modulated by a high-k dielectric (HK-IGBT) is presented. By laterally alternating the HK-pillar and N-drift, HK-IGBT can offer a quick and complete depletion to the drift region during the turn-off transient. This merit greatly reduces the current varying time of an HK-IGBT. Moreover, HK-IGBT can obtain a better electric field distribution, which enables the carrier stored layer (CSL) to have a higher doping dose when compared to a typical carrier stored trench gate bipolar transistor (CSTBT). These advantages improve the relationship between the static and transient power losses. According to the simulation results, HK-IGBT obtains a 66% lower turn-off loss than that of a field stop (FS) IGBT with the same ON-state voltage. Moreover, by using a CSL, the performance of an HK-IGBT can be comparable with that of a super-junction IGBT (SJ-IGBT). [ABSTRACT FROM AUTHOR]

Published
2020
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