Solution-Processed SnSe2–RGO-Based Bulk Heterojunction for Self-Powered and Broadband Photodetection

Metal dichalcogenide semiconductors have shown tremendous performance in various optoelectronic applications due to their excellent properties. However, low carrier mobility associated with the photoactive materials restricts its applications in highly responsive and ultrafast photodetectors. Here, to improve the device performance, SnSe2 has been incorporated with reduced graphene oxide (RGO) to form a SnSe2–RGO bulk heterojunction. SnSe2–RGO solution has been drop cast on a pulsed laser deposited MoS2 film to fabricate SnSe2–RGO/MoS2 hybrid structure. The built-in electric potential generated at the SnSe2–RGO/MoS2 interface facilitates the self-powered photodetection. Under IR illumination, the device exhibits excellent photoresponse with a responsivity of 13.75 A W–1 and a detectivity of 5.08 × 1012 Jones at 0 V. The excellent performance of the device is attributed to high charge carrier mobility of RGO and a robust built-in electric field at the interface. Also, the device shows excellent photoresponse under visible light illumination.