Multilayered PdSe₂/Perovskite Schottky Junction for Fast, Self‐Powered, Polarization‐Sensitive, Broadband Photodetectors, and Image Sensor Application

Abstract

Group-10 transition metal dichalcogenides (TMDs) with distinct optical and tunable electrical properties have exhibited great potential for various optoelectronic applications. Herein, a self-powered photodetector is developed with broadband response ranging from deep ultraviolet to near-infrared by combining FA_1- <i>_x</i> Cs <i>_x</i> PbI₃ perovskite with PdSe₂ layer, a newly discovered TMDs material. Optoelectronic characterization reveals that the as-assembled PdSe₂/perovskite Schottky junction is sensitive to light illumination ranging from 200 to 1550 nm, with the highest sensitivity centered at ≈800 nm. The device also shows a large on/off ratio of ≈10⁴, a high responsivity (<i>R</i>) of 313 mA W^-1, a decent specific detectivity (<i>D</i>*) of ≈10¹³ Jones, and a rapid response speed of 3.5/4 µs. These figures of merit are comparable with or much better than most of the previously reported perovskite detectors. In addition, the PdSe₂/perovskite device exhibits obvious sensitivity to polarized light, with a polarization sensitivity of 6.04. Finally, the PdSe₂/perovskite detector can readily record five "P," "O," "L," "Y," and "U" images sequentially produced by 808 nm. These results suggest that the present PdSe₂/perovskite Schottky junction photodetectors may be useful for assembly of optoelectronic system applications in near future.