Three-terminal photodetectors based on chemical vapor deposition-grown triangular MoSe₂ flakes

Two-dimensional (2D) transition metal dichalcogenides (TMDs) materials play a significant role in the fabrication of nano-scale devices. To construct high-performance devices with rich functions for adaptation to specific applications, a strategy for engineering 2D nanostructures must be developed. In addition, multi-channel devices with superior optoelectronic characteristics have attracted great interest because they can be used in nano-chip systems. Herein, we synthesized high-quality and homogenous MoSe₂ flakes with the assistance of sodium hydroxide (NaOH) powder by the chemical vapor deposition (CVD) method. Three-terminal photodetectors were fabricated based on the triangular MoSe₂ flakes. A high photoresponse can be achieved from the photodetectors with a photoresponsivity of 1.79 mA·W⁻¹ and a specific detectivity of 13.55 × 10⁹ Jones at a bias voltage of 3 V. The key benefits of this type of multi-terminal photodetectors on regular 2D flakes include their usefulness in detecting high-precision light at different locations on a single-chip device. Therefore, this work provides a facile way to fabricate position detection photodetectors on various 2D materials.