Ultrafast visible-infrared photodetector based on the SnSe₂/Bi₂Se₃ heterostructure

Abstract

Using the inherent properties of a heterostructure, ultrafast photodetectors with high sensitivity can be progressively developed that have the potential to carve a niche among the optoelectronic devices. In this Letter, a heterojunction photodetector based on SnSe 2 /Bi 2 Se 3 is constructed, and a visible–infrared photoresponse with good sensitivity at room temperature is obtained. The SnSe 2 /Bi 2 Se 3 photodetector demonstrates a high I ph / I d ratio of 1.2 × 10 4 at 0 V. Moreover, the high responsivity of 2.3 A/W, detectivity of 1.6 × 10 11 Jones, and fast response time of 40 µs are simultaneously achieved. The presented results offer an alternative route for ultrafast photodetectors with high sensitivity.