High-performances ultraviolet photodetector based on vertical van der Waals heterostructures

High-performance ultraviolet (UV) photodetectors play a very important role in many fields, especially in the military, biomedical and other fields. [1]In recent years, many studies have realized ultraviolet photodetectors of 2D layered materials, overcome the problems of traditional ultraviolet detectors that are large and use high voltages. [1]Up to now, most of these works use atomically thin layers and simple p-n van der Waals (vdW) heterostructures, which have difficulty meeting the conditions of high sensitivity and ultrafast response at the same time. we report the double p-n van der Waals (vdW) heterostructure built on a large electrode. The two p-n junctions connected in parallel were proven to be able to effectively separate photo-generated carriers and suitable for ultraviolet light. This new type of photodetector exhibits competitive performance, including high R up to 254.8 A/W under UV light, and fast photoresponse τr = 7.9 μs and τd = 3.9 μs. These results provide an ideal platform for realizing highly sensitive UV photodetectors.