Han Lixiang, Yang Mengmeng, Wen Peiting, Gao Wei, Huo Nengjie, Li Jingbo
School of Materials and Energy, Guangdong University of Technology Guangzhou 510006 China.
Institute of Semiconductors, South China Normal University Guangzhou 510631 P.R. China
Nanoscale Adv. 2021 Mar 15;3(9):2657-2665. doi: 10.1039/d1na00073j. eCollection 2021 May 4.
One-dimensional (1D)-two-dimensional (2D) van der Waals (vdWs) mixed-dimensional heterostructures with advantages of an atomically sharp interface, high quality and good compatibility have attracted tremendous attention in recent years. Herein, a mixed-dimensional vertical heterostructure is constructed by transferring mechanically exfoliated 2D WS nanosheets on epitaxially grown 1D tellurium (Te) microwires. According to the theoretical type-II band alignment, the device exhibits a photovoltaic effect and serves as an excellent self-powered photodetector with a maximum open-circuit voltage ( ) up to ∼0.2 V. Upon 635 nm light illumination, the photoresponsivity, external quantum efficiency and detectivity of the self-powered photodetector (SPPD) are calculated to be 471 mA W, 91% and 1.24 × 10 Jones, respectively. Moreover, the dark current of the SPPD is highly suppressed to the sub-pA level due to the large lateral built-in electric field, which leads to a high / ratio of 10 with a rise time of 25 ms and decay time of 14.7 ms. The abovementioned properties can be further enhanced under a negative bias of -2 V. In brief, the 1D Te-2D WS mixed-dimensional heterostructures have great application potential in high performance photodetectors and photovoltaics.
具有原子级清晰界面、高质量和良好兼容性等优点的一维（1D）-二维（2D）范德华（vdWs）混合维异质结构近年来引起了极大关注。在此，通过将机械剥离的二维WS纳米片转移到外延生长的一维碲（Te）微线上，构建了一种混合维垂直异质结构。根据理论II型能带排列，该器件表现出光伏效应，并作为一种优异的自供电光电探测器，最大开路电压（ ）高达约0.2V。在635nm光照下，自供电光电探测器（SPPD）的光响应度、外量子效率和探测率分别计算为471mA/W、91%和1.24×10琼斯。此外，由于大的横向内建电场，SPPD的暗电流被高度抑制到亚皮安水平，导致高达10的高 / 比，上升时间为25ms，衰减时间为14.7ms。在-2V的负偏压下，上述性能可以进一步提高。简而言之，一维Te-二维WS混合维异质结构在高性能光电探测器和光伏领域具有巨大的应用潜力。
