High performance photodetector based on few-layer MoTe2/CdS0.42Se0.58 flake heterojunction
Ran Ma, Qiuhong Tan, Peizhi Yang, Yingkai Liu, Qianjin Wang
Abstract
Two-dimensional (2D) transition metal dichalcogenides have been extensively studied due to their fascinating physical properties for constructing high-performance photodetectors. However, their relatively low responsivities, current on/off ratios and response speeds have hindered their widespread application. Herein, we fabricated a high-performance photodetector based on few-layer MoTe2 and CdS0.42Se0.58 flake heterojunctions. The photodetector exhibited a high responsivity of 7221 A/W, a large current on/off ratio of 1.73×104, a fast response speed of 90/120 µs, external quantum efficiency (EQE) reaching up to 1.52×106 % and detectivity (D*) reaching up to 1.67×1015 Jones. The excellent performance of the heterojunction photodetector was analyzed by a photocurrent mapping test and first-principle calculations. Notably, the visible light imaging function was successfully attained on the MoTe2/CdS0.42Se0.58 photodetectors, indicating that the device had practical imaging application prospects. Our findings provide a reference for the design of ultrahigh-performance MoTe2-based photodetectors.