Self-powered photodetector with high performance based on PtSe2/MoSe2 van der Waals heterojunction

Due to the increasing demand for miniaturization and portability, the development of self-powered photodetectors that can work without external power supply has aroused great interest among researchers. As a group-10 layered transitional metal dichalcogenides, PtSe2 exhibits potential applications in photoelectric detection because of the unique properties such as high carrier mobility, tunable bandgap, and stability. However, its inherent large dark current hinders the further improvement of the performance of the PtSe2 photodetectors. In this paper, we fabricated a vertically aligned Two-dimensional (2D) van der Waals (vdWs) heterojunction composed of PtSe2 and MoSe2, which exhibits high sensitivity photoelectric detection performance in a wide band from visible light (405 nm) to near-infrared (1550 nm) without external bias. As a result, working in self-driving mode at room temperature, the responsivity and detectivity can reach 22.95 A W-1 and 9.27×1011 Jones with a fast response speed of 180/48 μs. This work is expected to provide a new idea for broadband, energy-efficient and high-performance miniaturized detectors.