Self-driven photodetectors based on flexible silicon nanowires array surface-passivated with Tin-based perovskites

Self-driven photodetectors based on flexible silicon nanowires (Si-NWs) array have attracted widespread research interests since they can continuously operate without external bias. However, their practical performances are limited due to the high density of intrinsic defects introduced by the chemical etching procedure for the Si-NWs. To address this issue, firstly ultra-thin silicon wafers are etched with metal-assisted chemical etching method, and then flexible Si-NWs are obtained, and finally a high-performance self-driven photodetector Si/[Si-NWs/FASnBr ₃ ]/MoO ₃ /Au, in which Si-NWs were surface-passivated with FASnBr ₃ nanocrystals, is presented. As a result, the responsivity and specific detectivity of the self-driven photodetector reaches to 0.694 A/W and 2.9×10 ¹³ Jones, respectively, under 0.8 μW/cm ² 980 nm illumination at zero bias, with a rising time of 58.552 ms and a falling time of 43.729 ms. The enhanced device performance is mainly due to the improved surface-passivating effect on the silicon nanowire surfaces by FASnBr ₃ nanocrystals. Thus, it provides an efficient method to passivate the surfaces of silicon nanowires, and it is a promising method to enhance the performances of self-driven Si-NWs based photodetectors.