Beijing Institute of Nanoenergy and Nanosystems, National Center for Nanoscience and Technology (NCNST), Chinese Academy of Sciences , Beijing 100083, China.
Department of Physics and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University , Wuhan 430072, China.
ACS Nano. 2016 Aug 23;10(8):7451-7. doi: 10.1021/acsnano.6b01839. Epub 2016 Aug 1.
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.
我们通过压电 - 光电效应报告了高性能自对准 MoS2 场效应晶体管 (FET)，其光响应率得到了增强。该 FET 基于单层 MoS2 制造，具有作为局部栅极的压电 GaN 纳米线 (NW)，并采用自对准工艺来定义源/漏电极。这种制造方法允许保留 MoS2 的固有特性，并抑制 MoS2/GaN 界面中的散射中心密度，从而实现了高的电学和光电性能。已经制造了具有约 200nm 沟道长度的 MoS2 FET，其亚阈值斜率为 64mV/dec。在 550nm 光照射下，光响应率为 443.3A·W-1，响应和恢复时间快，约为 5ms。当应变引入 GaN NW 时，光响应率进一步增强至 734.5A·W-1，并且保持一致的响应和恢复时间，这与机械剥离的 MoS2 晶体管相当。这里提出的方法为高性能顶栅压增强 MoS2 光电探测器开辟了一条途径。
