Chun-Yan Wu, Wei Peng, Ting Fang, Bin Wang, Chao Xie, * Li Wang, Wen-Hua Yang, Lin-Bao Luo*

Abstract:With combined enormous features of one-dimensional geometry and hybrid perovskite materials, perovskite micro/nanowires have recently attracted particular attentions for a variety of optoelectronic device applications. Herein, by taking advantage of the strong built-in potential induced by asymmetric contact with varied work functions, we report highly sensitive visible photodetectors based on CH3NH3PbI3 microwires array, which display pronounced photovoltaic activities affording the capability of working without external power supply. A representative detector with Au/Ag electrodes achieves a decent responsivity of 161.1 mAW-1 with a fast response speed of 13.8/16.1 μs under 520 nm illumination, at zero bias. In addition, such a device is also characterized by an ultralow dark current of tens of picoamps enabling a high specific detectivity of 1.3×10¹² Jones. Furthermore, a flexible photodetector is successfully prepared, which shows comparable photoresponse performance and outstanding flexibility and bending durability. Given the good device performance and simple device geometry, the present self-driven photodetectors hold great promise for future highly sensitive and low energy consumption photodetection systems.