SnS₂/h-BN/SnSe Tri-Layer Heterojunctions for High Responsivity and Low Dark Current Self-Powered Near-Violet Detector

Near-violet(NV)detectors based on two-dimensional materials have attracted much attention due to their atomic-scale thickness and various band gaps. Among them, tin disulfide (SnS2) has demonstrated significant potential for high-performance NV detectors due to its unique photoelectric properties. However, SnS2-based NV detector still have drawbacks such as low responsivity and high dark current. In this work a tri-layer van der Waals heterojunction of tin disulfide/h-boron nitride/tin selenide (SnS2/h-BN/SnSe) is proposed. The detector based on such tri-layer heterojunction exhibits an excellent self-powered detection performance to 405-nm NV illumination with a responsivity of 1.5 AW-1, a low dark current of 2.6 pA, and a high fill factor of 51.8%, superior to detectors based on SnS2/SnSe bi-layer heterojunctions and most other two-dimensional materials. This study provides an efficient optimizing strategy for SnS2-based self-powered detector, thereby offering an opportunity for implementing innovation in NV detectors.