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\begin{document}$_2$\end{document}/GaAs heterojunction, which was made by transferring a multilayered PdSe\begin{document}$_2$\end{document} film onto a planar GaAs. The as-fabricated PdSe\begin{document}$_2$\end{document}/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\begin{document}$\times$\end{document}10\begin{document}$^5$\end{document} 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\begin{document}$\times$\end{document}10\begin{document}$^{11}$\end{document} 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\begin{document}$_2$\end{document}. Finally, the PdSe\begin{document}$_2$\end{document}/GaAs-based heterojunction device can also function as a near-infrared light sensor.