Hu Siqi, Zhang Qiao, Luo Xiaoguang, Zhang Xutao, Wang Tao, Cheng Yingchun, Jie Wanqi, Zhao Jianlin, Mei Ting, Gan Xuetao
MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions, and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710129, China.
Shannxi Institute of Flexible Electronics, Northwestern Polytechnical University, Xi'an 710129, China.
Nanoscale. 2020 Feb 14;12(6):4094-4100. doi: 10.1039/c9nr08791e. Epub 2020 Feb 5.
The Schottky junction, composed of a rectifying metal-semiconductor interface, is an essential component for microelectronic and optoelectronic devices. However, due to the considerable reverse tunneling current, typical Schottky junctions cannot be widely applied in devices requiring high signal-to-noise ratios, such as photodetectors with high detectivity. Here, a van der Waals (vdW) Schottky junction is constructed by mechanically stacking a gold (Au) electrode onto a multilayer indium selenide (InSe) nanosheet, which shows an ultralow reverse current in sub-picoamperes and an excellent rectification ratio exceeding 10 at room temperature. The reverse current, which corresponds to the thermionic emission transport model, is independent of the applied reverse bias. As a result, the Au-InSe vdW Schottky junction device can function as an ultrasensitive photodetector with a photodetectivity over 2.4 × 10 Jones, corresponding to a photoresponsivity of 853 A W and a light on/off ratio exceeding 1 × 10. The work offers an idea for investigating electronic and optoelectronic devices with high signal-to-noise ratios based on vdW Schottky junctions.
肖特基结由整流金属 - 半导体界面组成，是微电子和光电器件的重要组成部分。然而，由于存在可观的反向隧穿电流，典型的肖特基结无法广泛应用于需要高信噪比的器件中，例如具有高探测率的光电探测器。在此，通过将金（Au）电极机械堆叠在多层硒化铟（InSe）纳米片上构建了范德华（vdW）肖特基结，该结在室温下显示出亚皮安级的超低反向电流和超过10的优异整流比。对应于热电子发射传输模型的反向电流与施加的反向偏压无关。因此，Au - InSe vdW肖特基结器件可以用作超灵敏光电探测器，其探测率超过2.4×10琼斯，对应于853 A/W的光响应度和超过1×10的光开/关比。这项工作为研究基于vdW肖特基结的高信噪比电子和光电器件提供了思路。
