Fabrication of PdSe₂/GaAs Heterojunction for Sensitive Near-Infrared Photovoltaic Detector and Image Sensor Application

In this study, we have developed a high-sensitivity, near-infrared photodetector based on PdSe_2/GaAs heterojunction, which was made by transferring a multilayered PdSe_2 film onto a planar GaAs. The as-fabricated PdSe_2/GaAs heterojunction device exhibited obvious photovoltaic behavior to 808 nm illumination, indicating that the near-infrared photodetector can be used as a self-driven device without external power supply. Further device analysis showed that the hybrid heterojunction exhibited a high on/off ratio of 1.16\times10^5 measured at 808 nm under zero bias voltage. The responsivity and specific detectivity of photodetector were estimated to be 171.34 mA/W and 2.36\times10^11 Jones, respectively. Moreover, the device showed excellent stability and reliable repeatability. After 2 months, the photoelectric characteristics of the near-infrared photodetector hardly degrade in air, attributable to the good stability of the PdSe_2. Finally, the PdSe_2/GaAs-based heterojunction device can also function as a near-infrared light sensor.