Phase-controlled synthesis of SnS2 and SnS flakes and photodetection properties

Abstract

Abstract Two-dimensional (2D) layered tin sulfide compounds including SnS2 and SnS have attracted increasing attention due to their great potential application in the fields of optoelectronics and energy storage. However, device development has been delayed by the lack of capabilities to synthesize large-scale and high-quality 2D tin sulfide. Here, a phase-controlled synthesis of SnS2 and SnS flakes with lateral size over 100 μm was successfully realized via a facile chemical vapor deposition method. The lateral size of flakes and phase transformation of SnS2 to SnS can be tuned via changing the synthesis temperature. Compared to the formation of the SnS2 phase at relative low temperature (<750 °C), the SnS phase is favorable at higher temperature. The phototransistor based on the as-prepared SnS2 and SnS exhibits excellent photoresponse to 405 nm laser, including a high responsivity (1.7 × 106 mA W−1), fast response rates (rise/decay time of 13/51 ms), an outstanding external quantum efficiency (5.3 × 105%), and a remarkable detectivity (6.24 × 1012 Jones) for SnS2-based phototransistor, and these values are superior to the most reported SnS2 based photodetectors. Although the responsivity (3390 mA W−1) and detectivity (1.1 × 1010 Jones) of SnS-based device is lower than that of the SnS2 phototransistor, it has a faster rise/decay time of 3.10/1.59 ms. This work provides a means of tuning the size and phase of 2D layered tin sulfide, and promotes the application of SnS2 in high-performance optoelectronic devices.