Search

Your search keyword '"Zheng, Zheyang"' showing total 10 results
Start Over Author "Zheng, Zheyang" Journal applied physics letters
10 results on '"Zheng, Zheyang"'

7. Observation and characterization of impact ionization-induced OFF-state breakdown in Schottky-type p-GaN gate HEMTs.

Author

Cheng, Yan, Wang, Yuru, Feng, Sirui, Zheng, Zheyang, Chen, Tao, Lyu, Gang, Ng, Yat Hon, and Chen, Kevin J.

Subjects
TWO-dimensional electron gas, IMPACT ionization, MODULATION-doped field-effect transistors, HOT carriers, BUFFER layers, THRESHOLD voltage
Abstract

In this work, the impact ionization-induced OFF-state breakdown is revealed and systematically investigated in 100 V Schottky-type p-GaN gate high-electron-mobility transistors. Impact ionization is found to occur in the peak electric-field region at the source-terminated field-plate edge and is initiated by electrons injected from the source-side two-dimensional electron gas channel through the buffer layer. Hot electrons generated from impact ionization, when being captured by surface traps, could lead to redistribution and peak value reduction of electric-field. Consequently, the sudden rise in the OFF-state leakage current by impact ionization could be self-clamped temporally to avoid catastrophic rupture of the device. The impact ionization is further verified by the increase in dynamic OFF-state leakage current and a negative shift in threshold voltage, both of which result from positively charged holes (generated from impact ionization) drifting toward the gated channel. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

10. Enhanced monolayer MoS2/InP heterostructure solar cells by graphene quantum dots

Author

Wenli Xu, Sen Xu, Zhiqian Wu, Peng Wang, Guqiao Ding, Xiaoqiang Li, Zhijuan Xu, Shengjiao Zhang, Zheng Zheyang, Yanghua Lu, and Shisheng Lin

Subjects
Materials science, Photoluminescence, Physics and Astronomy (miscellaneous), Graphene, business.industry, Heterojunction, 02 engineering and technology, Photovoltaic effect, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, law.invention, chemistry.chemical_compound, chemistry, law, Quantum dot, Monolayer, Indium phosphide, Optoelectronics, 0210 nano-technology, business, Molybdenum disulfide
Abstract

We demonstrate significantly improved photovoltaic response of monolayer molybdenum disulfide (MoS2)/indium phosphide (InP) van der Waals heterostructure induced by graphene quantum dots (GQDs). Raman and photoluminescence measurements indicate that effective charge transfer takes place between GQDs and MoS2, which results in n-type doping of MoS2. The doping effect increases the barrier height at the MoS2/InP heterojunction, thus the averaged power conversion efficiency of MoS2/InP solar cells is improved from 2.1% to 4.1%. The light induced doping by GQD provides a feasible way for developing more efficient MoS2 based heterostructure solar cells.

Published
2016

Catalog

Books, media, physical & digital resources
See catalog results