Ultrasensitive and broad-spectrum photodetectors based on InSe/MoTe2 heterostructure

The photogating effect based on the vertical structure of a two-dimensional material allows high-sensitivity and broad-spectrum photodetector. A high-sensitivity photodetector based on the vertical heterostructure of indium selenide (InSe)/molybdenum ditelluride (MoTe2) is reported, which exhibits excellent broad-spectrum detection capability from 365 to 965 nm. The top layer of InSe was used as the grating layer to regulate the channel current, and MoTe2 was used as the transmission layer. By combining the advantages of the two materials, the photodetector has a fast response time of 21. 6 ms and achieves a maximum detectivity of 1.05 x 1013 Jones under 365 nm laser irradiation. Under the illumination of 965 nm, the detectivity still achieves the order of 109 Jones. In addition, the InSe/MoTe2 heterostructure exhibits an external quantum efficiency of 1. 03 x 105%, demonstrating strong photoelectric conversion capability.