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

Abstract

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 μA 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.