Construction of Ag-Sb2Se2Te/SnSe2 heterojunction for self-powered photoelectrochemical photodetector

Sb 2 Se 2 Te is a novel ternary V–VIA topological insulator, which shows significant potential as a material for optoelectronic devices. In this work, the Ag-Sb 2 Se 2 Te/SnSe 2 heterojunction-based PEC photodetector was fabricated using a two-step drop-coating method. The obtained photodetector has a responsivity of 71.94 μA W −1 at 0 V bias under 400 nm illumination, which is about 30 times higher than that of the Sb 2 Se 2 Te photodetector. Furthermore, the photodetectors exhibited an increased responsivity of 283.49 μA W −1 at a bias voltage of −0.2 V. The performance enhancement is attributed to the Ag modification and formation of a Z-scheme heterojunction, which facilitates the light absorption and efficient charge separation and transfer. This study provides a potential strategy for designing high-performance ternary V-VIA semiconductor-based photodetectors. Graphical In this study, the Ag-Sb 2 Se 2 Te/SnSe 2 heterojunction-based PEC photodetector was fabricated using a two-step drop-coating method. The Ag-Sb 2 Se 2 Te/SnSe 2 heterostructure achieves a photocurrent density and responsivity of 1.11 μA cm −2 and 71.94 μA W −1 at 0 V bias under 400 nm illumination, which shows ~ 28 times and ~ 34 times increase compared to the Sb 2 Se 2 Te based photodetectors, respectively. This study provides a potential strategy for designing high-performance ternary V-VIA semiconductor-based photodetectors.