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

Abstract 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/Sn_0.991In_0.009S₂ 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 × 10¹² cm Hz^1/2 W⁻¹, and fast response time of ≈10 ms. The pseudo‐built‐in electrical field of the SnS₂/Sn_0.991In_0.009S₂ homostructure results in the superior performance of the photodetectors based on this material compared to that based on individual SnS₂ and Sn_0.991In_0.009S₂ 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.