Fabrication of UV-VIS photodetector based on the ZnO/MoS₂and ZnO/WS₂heterostructures

Two-dimensional layers of the transition metal dichalcogenides (2D TMDs) such as molybdenum disulfide (MoS2) and tungsten disulfide (WS2) attract much attention due to their potential applications in optoelectronic devices. MoS2 and WS2 with tunable bandgap are promising materials to enhance the light absorption range on ZnO-based photodetector. In this work, we report that the exfoliated MoS2 and WS2 were deposited on the surface ZnO nanorods for UV-vis photodetector application. The photoelectrical response of photodetector was observed using electrometer under 325, 505, and 625 nm laser diodes as UV and visible light sources. This study shows that the addition of MoS2 and WS2 could improve the performance of the ZnO photodetector due to higher photocurrent. The increase in both dark current and photocurrent is not yet clearly understood, but it may be that the edge sites of MoS2 and WS2 play a vital role to reduce the natural defects of ZnO; hence the mobility of charge carriers was improved.