Enhanced performance and self-driven optoelectronic device based on the MoS2/GaTe van der Waals heterojunction

Abstract

van der Waals (vdW) heterojunctions hold significant promise for optoelectronic applications due to their high-quality interfaces and exceptional fabrication flexibility. In this study, lateral MoS2/GaTe vdW heterojunctions were fabricated, and their electronic and optoelectronic properties were thoroughly investigated. The devices, however, exhibited poor rectification behavior. Additionally, the electron-dominated conductivity indicates that electrons play a key role in the performance of the MoS2/GaTe vdW heterojunction device. To enhance device performance, the suppression of electron recombination was achieved by eliminating the non-heterojunction regions on the GaTe side, optimizing the device structure. Notably, a rectification ratio of 1 × 103 and an ideality factor of 1.58 were observed. The device also demonstrated self-driven photodetection performance under 532 nm laser irradiation, with a responsivity of 409.2 mA/W, a high-speed response/recovery time of 43.1/72.4 μs, and a high on/off ratio of 1.3 × 103. The results provide an effective strategy for optimizing and enhancing the performance of optoelectronic devices based on the vdW heterojunctions.