Photoresponse of wafer-scale palladium diselenide films prepared by selenization method

Palladium diselenide (PdSe₂) films exhibit a high charge carrier mobility and sensitivity in photodetection. In this work, wafer-scale PdSe₂ thin films with controllable thickness have been synthesized by the selenization of Pd films. A PdSe₂-based photodetector can detect a broad wavelength ranging from 420 nm to 1200 nm. The responsivity and detectivity can reach 1.96 × 10³ A W^-1 and 1.72 × 10¹⁰ W Hz^-1/2 at V _SD = 3 V, respectively. The figure of merit of the photodetection are comparable to the mechanically exfoliated PdSe₂ based photodetector. This work demonstrated that selenization is a facile method to synthesize PdSe₂ films in large scale and the films are promising for broadband photodetection.