High Photoresponsivity and Response Speed of Visible-Light Photodetectors Based on Tin Disulfide/Indium-Doped Tin Disulfide Homostructures

Tin disulfide (SnS2) is an emerging 2D-layered metal dichalcogenide with promising application potential for highly sensitive and fast-response-speed photodetectors. However, SnS2-based photodetectors still have drawbacks that limit their practical and commercial applications. Herein, an effective route is proposed for constructing SnS2/indium-doped SnS2 homostructures to improve photodetector performance. Vertical SnS2/Sn0.991In0.009S2 homostructures and photodetectors based on these homostructures were fabricated via a polydimethylsiloxane-assisted dry-transfer method. The photodetectors exhibit excellent performance, including a high photoresponsivity of up to 271.7 A W-1, high normalized detectivity of up to 2.13 x 10(12) cm Hz(1/2) W-1, and fast response time of approximate to 10 ms. The pseudo-built-in electrical field of the SnS2/Sn0.991In0.009S2 homostructure results in the superior performance of the photodetectors based on this material compared to that based on individual SnS2 and Sn0.991In0.009S2 thin layers, most 2D materials, and commercial photodetectors (e.g., THORLABS FD11A Si, and FGA01 InGaAs). This study provides a facile and effective approach to enhance the performance of SnS2-based photodetectors and paves the way for future applications of photodetectors based on SnS2 and other 2D materials.