Photoelectrochemical-type sunlight photodetector based on MoS 2 /graphene heterostructure

We have fabricated a novel sunlight photo-detector based on a MoS2/graphene heterostructure. The MoS2/graphene heterostructure was prepared by a facile hydrothermal method along with a subsequent annealing process followed by a substrate-induced high selective nucleation and growth mechanism. The microstructures and morphologies of the two-dimensional MoS2/graphene heterostructure can be experimentally confirmed by x-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and a UV–vis absorption spectrometer. Photoresponse investigations performed by a photoelectrochemical (PEC) measurement system indicate that the synthesized MoS2/graphene heterostructure shows superior photoresponse activities under the illumination of sunlight in contrast with bare MoS2 and graphene. The improved photoresponsivity can be attributed to the enhanced light absorption, strong light–matter interaction and the extremely efficient charge separation of the heterostructure. The structure and performances of the MoS2/graphene heterostructure suggest promising applications in the field of photonics and optoelectronics.