Browsing by Author "Liu, W. J."

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Control of optical loss in GaN-based planar cavities
(2015-12-01)
Ying, L. Y.
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Hu, X. L.
;
Liu, W. J.
;
Zhang, J. Y.
;
Zhang, B. P.
Optical losses in GaN-based resonant planar cavity are discussed and experimentally examined in respects of indium tin oxide (ITO) inner-cavity current spreading layer, the defect-rich GaN layer, and multi-quantum well (MQW) active region. Devices with different structures are adopted to study the optical loss. It is demonstrated that a thin ITO layer and a coupled MQW active region are essential to achieve a low loss and high Q-value cavity. The results show that low-loss MQW design is particularly important in fabricating high-Q value GaN-based planar cavities. (C) 2015 Elsevier Ltd. All rights reserved.
Investigation of Traps at MoS2/Al2O3 Interface in nMOSFETs by Low-Frequency Noise
(2016-04)
Yuan, Hui-Wen
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Shen, Hui
;
Li, Jun-Jie
;
Shao, Jinhai
;
Huang, Daming
A new method is proposed to distinguish the contributions of the low-frequency noise (LFN) from the channel and the source/drain Schottky contacts in MOS devices. The method is applied to back-gated nMOSFETs with MoS2 channel and Al2O3 gate dielectric. To avoid a possible noise signal contamination from the top MoS2 surface by oxygen or water molecules absorption, the nMOSFETs with multilayer MoS2 are fabricated, and the measurements are carried out in the vacuum. The trap density Not at the MoS2/Al2O3 interface is derived for the first time using the proposed method. It is found that the Not responsible to LFN depends strongly on the surface potential, ranging from 4 x 10(10) cm(-2) in the weak over-drive region to 5 x 10(11) cm(-2) in the strong over-drive region.