Self-powered infrared photodetectors based on PdSe2/graphene heterojunctions

A PdSe₂/graphene van der Waals heterojunction-based high-performance near-infrared photodetector is shown. Electrical measurements showed excellent rectification and a distinct Schottky behaviour with an ideality value approaching 1. Under 915 nm infrared illumination, the heterojunction exhibits a strong photoresponse even at zero bias, achieving a peak responsivity of 47.40 mA/W, and the peak specific detectivity of 1.28×10¹³ Jones. The photocurrent shows a powerdependent behavior following, indicating efficient photocarrier separation. Moreover, by applying a gate voltage to modulate the Fermi level of graphene, the Schottky barrier can be reversibly tuned between n-type and p-type. Benefiting from the narrow bandgap of PdSe2, the device also demonstrates broadband detection capability spanning from visible to near-infrared. These results highlight the potential of PdSe₂/graphene heterostructures for self-powered infrared photodetection applications.