High-Performance Self-Driven SnSe/Si Heterojunction Photovoltaic Photodetector

Tin monoselenide (SnSe), which belongs to group IV-VI monochalcogenides, has obtained significant attention in the field of photodetection owing to its ultrahigh carrier mobilities. However, the great challenges of preparing high-quality films and high-performance devices still need to be conquered. Herein, high-density continuous SnSe films were deposited on a Si substrate using magnetron sputtering technology, and a self-driven photovoltaic-type broadband photodetector from the visible light range (VIS) to the near-infrared (NIR) range based on SnSe/Si heterojunction was constructed. Owing to its high carrier mobility, narrow band gap structure, and strong internal electric field, the SnSe/Si heterojunction device exhibits an ultrafast response and high responsivity (R), which achieves a wide spectral response of 405-980 nm. Under zero bias voltage, the greatest R and detectivity (D*) of the heterojunction were 704.6 mA/W and 3.36 X 10(11) Jones at 405 nm. Furthermore, the device had a fast response time (rise time) of 20.4 mu s at 980 nm of illumination. This work provides a new strategy for the fabrication of high-performance, low-cost, and self-driven photodetectors.