Enhanced photodetection performance of Schottky Pt/SnS2/Al and Au/SnS2/Al photodetectors

As an emerging two-dimensional material, tin disulfide (SnS2) has attracted growing interest due to its superior performance in high-speed and high-sensitive photodetectors. However, low responsivity, large dark current, and slow response speed severely hinder its further practical application. Herein, the enhanced photodetection performance of Schottky photodetectors based on SnS2 nanosheets and Schottky contact effects on the photodetection performance were investigated. High-quality SnS2 nanosheets were synthesized via a facile hydrothermal method. Then Schottky photodetectors with Pt/SnS2/Al and Au/SnS2/Al structures were fabricated and detected. Compared to the Ohmic Al/SnS2/Al photodetector, the Schottky Pt/SnS2/Al and Au/SnS2/Al photodetectors exhibited better photodetection performances, including tenfold higher responsivities, tenfold lower dark currents, and slightly shorter response times. In particular, the Schottky Pt/SnS2/Al photodetector obtained a low dark current of 5.2 nA, a high responsivity of 952 mu A W-1, and a response time of 0.13 s. The enhancement in the photodetection performance of the Schottky photodetectors is due to the reverse bias and built-in electric field caused by Schottky contacts. Our finding provides an effective approach to enhance the photodetection performance of SnS2-based photodetectors for high-performance optoelectronic applications.