Interface modification of MoS2/ZnO heterojunction for controllable electron flow and fabrication of high-performance UV photodetectors with fast response/recovery speed

Abstract

Hetero-structured thin films, MoS2/ZnO thin films, were fabricated by adding MoS2 films under the ZnO thin films via sol-gel spin-coating method; ZnO nanoparticles were observed on the surface of sol-gel spin-coated ZnO thin films. Although ZnO nanoparticles were observed on the surface of hetero-structured thin films, the surface area of the hetero-structured thin films was higher than ZnO thin films owing to the high surface roughness of the MoS2 films. Three diffraction peaks were observed in the hetero-structured thin films at 31.74°, 34.38°, and 36.22°, which indicates heterostructure was polycrystalline, and the heterostructure was formed successfully. When the UV photodetector was fabricated by using hetero-structured thin films, the enhanced values of photocurrent, photoresponsivity and photosensitivity were observed. In addition, the hetero-structured thin films exhibited a faster response/recovery speed because the move of electrons and holes during UV illumination. Thus, it was concluded that the interface modification of the MoS2/ZnO heterojunction is an effective solution for overcoming the drawbacks of ZnO-based UV photodetectors. This approach can be considered a novel method for high-performance optoelectronics with fast response speed applicable to various fields.