Highly responsive photodetectors based on NiPS3/WS2 van der Waals type-II heterostructures

A heterostructure photodetector composed of few-layer NiPS3/WS2 is made by using mechanical exfoliation and micro-nano fabrication techniques. The photodetector exhibits a broad-band response wavelengths of ranging of 405 nm and 800 nm. Under the light illumination of 405-nm wavelength and a bias voltage of -2 V, the photoresponsivity is 62.6 mA/W and the specific detectivity is 8.59 x 10(10) Jones. In addition, the device demonstrates a relatively fast response with rise and fall times of 70 ms and 120 ms. Theoretical calculation suggest that this excellent performance can be ascribed to the type-II band alignment at the NiPS3/WS2 heterostructure interface.