High performance Photodetector Based on PdSe2/MoS2 heterojunction

Abstract Photodetectors are devices that instantaneously convert optical signals into electrical signals. With the advancement of science and technology, they are being widely used in various fields. Two-dimensional materials possess many unique and important properties, such as tunable band gap, etc., and have been widely used in photodetectors, and have been widely used in photodetectors in terms of responsivity (R), detectability (D*) and external quantum efficiency (EQE) Shows excellent performance. By building heterojunctions, 2D materials can serve as excellent photodetector components. Herein, We prepared two-dimensional multilayer PdSe 2 thin films by a simple one-step direct selenization method and a high performance photodetector was fabricated based on vertically stacked MoS 2 /PdSe 2 heterojunctions via a Van der Waals force mechanical transfer method. The fabricated device displays current rectification characteristics in darkness (on/off ratio > 10 2 ) and superior photovoltaic behavious under illumination. In addition, the MoS 2 /PdSe 2 heterojunctions exhibits a remarkable responsivity of 2.7A·W -1 and a fast response time at 193/96 μs under 532nm laser irradiation. These results provide new opportunities for developing highly responsive and high-speed photodetectors to address integrated applications.