Enhanced Photodetection Performance of Photodetectors Based on Indium-Doped Tin Disulfide Few Layers.

Two dimensional (2D) tin disulfide (SnS2) has attracted growing interest as a promising high performance photodetector with superior performance such as fast response time, high responsivity, and good stability. However, SnS2-based photodetectors still face great challenges, and the photodetection performance needs to be improved for practical applications. Herein, indium-doped SnS2 (In-SnS2) few layers were exfoliated from CVT-grown single crystals, which were synthesized by chemical vapor transport. Photodetectors based on In-SnS2 few layers were fabricated and detected. Compared with photodetectors based on pristine SnS2, photodetectors based on In-SnS2 few layers exhibited better photodetection performances, including higher responsivities, higher external quantum efficiencies, and greater normalized detectivities. The responsivity (R), external quantum efficiency (EQE), and normalized detectivity (D*) were increased by up to 2 orders of magnitude after In doping. Considering responsivity and response time, the photodetector based on 1.4 at. % In-SnS2 few layers exhibited an optimal photodetection performance with a high R of 153.8 A/W, a high EQE of 4.72 × 104 %, a great D* of 5.81 × 1012 Jones, and a short response time of 13 ms. Our work provides an efficient path to enhance photodetection performances of photodetectors based on SnS2 for future high-performance optoelectronic applications.