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

Tin disulfide (SnS 2 ) is an emerging 2D-layered metal dichalcogenide with promising application potential for highly sensitive and fast-response-speed photodetectors. However, SnS 2 -based photodetectors still have drawbacks that limit their practical and commercial applications. Herein, an effective route is proposed for constructing SnS 2 /indium-doped SnS 2 homostructures to improve photodetector performance. Vertical SnS 2 /Sn 0.991 In 0.009 S 2 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 × 10 12 cm Hz 1/2 W −1 , and fast response time of ≈10 ms. The pseudo-built-in electrical field of the SnS 2 /Sn 0.991 In 0.009 S 2 homostructure results in the superior performance of the photodetectors based on this material compared to that based on individual SnS 2 and Sn 0.991 In 0.009 S 2 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 SnS 2 -based photodetectors and paves the way for future applications of photodetectors based on SnS 2 and other 2D materials.