Heterojunction based on layered metal dichalcogenides (LMDs) has attracted considerable attention for emerging photodetectors owing to their band gap tunability and high carrier mobility. In this work, we report the realization of a type II \({SnS}_{2}/{MoS}_{2}\) n–n heterojunction thin-film photodetector and demonstrate its excellent self-powered photodetection characteristics. The device exhibits broadband photoresponse extending from the ultraviolet to the near-infrared region (300–1100 nm), achieving maximum responsivity of 3.106 A/W at 912 nm, under a low light intensity of 0.05 mw/cm2. Notably, the photodetector shows ultrafast temporal response with rise and recovery times of \(16 \mu s\) and \(22 \mu s\) , respectively, underscoring its potential for high-speed photodetection. These results represent one of the most competitive performances reported for \({SnS}_{2}/{MoS}_{2}\) thin-film heterojunction-based photodetectors to date. This study not only advances the fundamental understanding of LMD-based heterojunction photodetectors but also paves the way for their integration into nanoscale electronics and optoelectronics where high efficiency, fast operation and self-powered capability are essential.
