Controlled growth of single-crystalline 2D p-type semiconductor α-MnSe for broadband photodetector

As a wide band-gap p-type semiconductor, α-MnSe has been expected to make up for the scarcity of two-dimensional (2D) semiconductor materials, which is crucial for the construction of multifunctional and miniaturized p-n junctions. Herein, we report the synthesis of single crystalline α-MnSe with its domain size, thickness and coverage controlled by hydrogen modulated CVD. The back-gate FET device was fabricated to study the electrical properties of α-MnSe. Moreover, the α-MnSe-based photodetector exhibits a broadband photo-response ranging from 532 nm to 980 nm with response times as low as ∼ 20 ms, comparable to most 2D materials.