Coupling of Phase Transition and Self-Powered Photodetection of a NbSe2/VO2 Heterojunction

An endeavor to design a self-powered photodetector that can work in a broad temperature range is required for everyday applications. Herein, we present a self-powered NbSe2/VO2 bilayer photodetector with boosted performance stimulated by the phase transition of VO2 after heating. The NbSe2/VO2 heterojunction can be converted into a Schottky junction from a staggered heterojunction thanks to the semiconductor-to-metal phase transition (SMT) of VO2, resulting in a controlled built-in electric field at the bilayer junction. Its origin comes from a sharp increase in carrier transport, which results in a boosted photoresponse in the bilayer. Our photovoltaic detector has shown a fast response time of 122 mu s at the VO2 metallic phase for a visible wavelength (405 nm), featuring a self-powered, high-speed, and energy-efficient device.