Polarization-Sensitive and Self-Driven Photodetector Based on 2D PdSe2/InSe Asymmetric van der Waals Heterojunction with Vertical Transportation Channel.

Polarized photodetectors are promising in civil and military fields. Limited response range and low integration level are critical challenges which can be solved by the introduction of a 2D asymmetric vertical heterojunction. Vertical structure design has the advantages of higher integration level and shorter channel length. In this work, a PdSe2/InSe vertical heterojunction is constructed with an asymmetric structure and a short vertical transportation channel for polarization-sensitive and self-driven photodetection. The device exhibits excellent photoresponse characteristics, including a wide spectral range spanning from 405 to 980 nm, a high responsivity of 296 mA/W, and a specific detectivity of 1.97 × 1011 Jones. It also demonstrates excellent photovoltaic performance with a notable open-circuit voltage reaching 480.6 mV and exhibits remarkable polarization sensitivity. Finally, the device is integrated into a polarized light imaging system successfully. This finding underscores the critical role of the PdSe2/InSe heterojunction in advancing compact, high-performance, broadband, and self-driven polarized photodetectors.