Fabrication of High-Gain Photodetector With Graphene–PbSe Heterostructure

In this letter, a novel photodetector based on graphene-PbSe van der Waals heterostructure for near-infrared detection is demonstrated. Generation and transportation of photocarriers are conducted in the PbSe photosensitive layer and graphene channel, respectively. The proposed structure is benefiting from the premium photoactivity of PbSe and high mobility of graphene with fast response time. Remarkable photoresponse was thus achieved. Photoresponse of the device can be controlled through the modulation on bias state of grapheme-PbSe Schottky heterojunction. The peak gain, responsivity, and detectivity are 7824, 6613 A/W, and 1.16 × 10
¹²
Jones, respectively. With a response time at millisecond level, fast response speed is also achieved in this structure.