Enhancing Photoresponsivity of Self-Aligned MoS2 Field-Effect Transistors by Piezo-Phototronic Effect from GaN Nanowires

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• 作者：Xingqiang Liu ; Xiaonian Yang ; Guoyun Gao ; Zhenyu Yang ; Haitao Liu ; Qiang Li ; Zheng Lou ; Guozhen Shen ; Lei Liao ; Caofeng Pan ; Zhong Lin Wang
• 刊名：ACS Nano
• 出版年：2016
• 出版时间：August 23, 2016
• 年：2016
• 卷：10
• 期：8
• 页码：7451-7457
• 全文大小：434K
• 年卷期：0
• ISSN：1936-086X

文摘

We report high-performance self-aligned MoS₂ field-effect transistors (FETs) with enhanced photoresponsivity by the piezo-phototronic effect. The FETs are fabricated based on monolayer MoS₂ with a piezoelectric GaN nanowire (NW) as the local gate, and a self-aligned process is employed to define the source/drain electrodes. The fabrication method allows the preservation of the intrinsic property of MoS₂ and suppresses the scattering center density in the MoS₂/GaN interface, which results in high electrical and photoelectric performances. MoS₂ FETs with channel lengths of ∼200 nm have been fabricated with a small subthreshold slope of 64 mV/dec. The photoresponsivity is 443.3 A·W^–1, with a fast response and recovery time of ∼5 ms under 550 nm light illumination. When strain is introduced into the GaN NW, the photoresponsivity is further enhanced to 734.5 A·W^–1 and maintains consistent response and recovery time, which is comparable with that of the mechanical exfoliation of MoS₂ transistors. The approach presented here opens an avenue to high-performance top-gated piezo-enhanced MoS₂ photodetectors.