▎ 摘　　要

A high-performance heterojunction photodetector is formed by combining an n-type Si substrate with p-type monolayer WSe2 obtained using physical vapor deposition. The high quality of the WSe2/Si heterojunction is demonstrated by the suppressed dark current of 1 nA and the extremely high rectification ratio of 10(7). Under illumination, the heterojunction exhibits a wide photoresponse range from ultraviolet to near-infrared radiation. The introduction of graphene quantum dots (GQDs) greatly elevates the photodetective capabilities of the heterojunction with strong light absorption and long carrier lifetimes. The GQDs/WSe2/Si heterojunction exhibits a high responsivity of 707 mA center dot W-1, short response time of 0.2 ms, and good specific detectivity of 4.51 x 10(9) Jones. These properties suggest that the GQDs/WSe2/Si heterojunction holds great potential for application in future high-performance photodetectors.