MoSe2/NbSe2 Van der Waals heterostructure with efficiently gate-tunable optoelectronic properties

NbSe₂, serving as a 2D metal electrode, has been proven to form a Schottky heterojunction with MoSe₂ to realize a highperformance broadband photodetector. Here, we further investigated the effect of gate voltage on the optoelectronic characteristics of the device. The results revealed that NbSe₂ exhibits a weak electrostatic screening effect similar to graphene, and due to the high-quality contact between the 2D metal and semiconductor, the rectification ratio of the device can be significantly modulated from 0.32 to 5.5×10⁴. Regarding the photovoltaic response characteristics of the device, the gate voltage similarly achieves significant modulation of the short-circuit current (20 nA-1.6 μA), open-circuit voltage (0-0.32 V), maximum electrical power (0-210 nW). Furthermore, the response speed of the device is also influenced by the gate voltage. This work demonstrates that Schottky heterojunctions constructed based on 2D metals can achieve effective control of optoelectronic properties, and has encouraging prospects in the fields of optical communications, optical sensing, and imaging.