Tang Yuxiang, Hao Hao, Kang Yan, Liu Qirui, Sui Yizhen, Wei Ke, Cheng Xiang'ai, Jiang Tian
College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, P. R. China.
State Key Laboratory of High Performance Computing, College of Computer, National University of Defense Technology, Changsha 410073, P. R. China.
ACS Appl Mater Interfaces. 2020 Nov 25;12(47):53475-53483. doi: 10.1021/acsami.0c14886. Epub 2020 Nov 12.
Van der Waals (vdWs) heterostructures based on in-plane isotropic/anisotropic 2D-layered semiconducting materials have recently received wide attention because of their unique interlayer coupling properties and hold a bright future as building blocks for advanced photodetectors. However, a fundamental understanding of charge behavior inside this kind of heterostructure in the photoexcited state remains elusive. In this work, we carry out a systematic investigation into the photoinduced interfacial charge behavior in type-II WS/ReS vertical heterostructures via polarization-dependent pump-probe microscopy. Benefiting from the distinctive (ultrafast and anisotropic) charge-transfer mechanisms, the photodetector based on the WS/ReS heterojunction displays more superior optoelectronic properties compared to its constituents with diverse functionalities including moderate photoresponsivity, polarization sensitivity, and fast photoresponse speed. Additionally, this device can function as a self-driven photodetector without the external bias. These results of our work tangibly corroborate the intriguing interlayer interaction in in-plane isotropic/anisotropic heterostructures and are expected to shed light on designing balanced-performance multifunctional optoelectrical devices.
基于面内各向同性/各向异性二维层状半导体材料的范德华（vdWs）异质结构，因其独特的层间耦合特性，近来受到广泛关注，并有望成为先进光探测器的基础材料，前景光明。然而，对于这种处于光激发态的异质结构内部电荷行为的基本认识仍不明确。在这项工作中，我们通过偏振相关泵浦 - 探测显微镜，对II型WS/ReS垂直异质结构中的光致界面电荷行为进行了系统研究。受益于独特的（超快且各向异性的）电荷转移机制，基于WS/ReS异质结的光探测器相较于其具有多种功能的组分，展现出更优异的光电性能，包括适度的光响应性、偏振敏感性和快速的光响应速度。此外，该器件无需外部偏置即可作为自驱动光探测器工作。我们工作的这些结果切实证实了面内各向同性/各向异性异质结构中有趣的层间相互作用，并有望为设计具有平衡性能的多功能光电器件提供启示。
