▎ 摘　　要

The conventional quantum dot infrared photodetector (QDIP) has a weak ability to capture light, which limits the further improvement of absorptivity. In this paper, the graphene surface is combined with a conventional quantum dot infrared photodetector, and the principle of surface plasmon is used to enhance the interaction between graphene and light improving the absorption rate of QDIP. The results show that the highest absorptivity of QDIP by introducing graphene structure is 1.29 times higher than that of conventional QDIP, and the highest absorptivity can reach 98.41%. At the same time, the designed graphene concentric ring structure significantly expands the absorption bandwidth of the QDIP by utilizing the plasmonic hybridization between them.