Simple fabrication of ZnO nanosheets/p-GaN heterostructure and ultraviolet detection

A simple two-step solvothermal method was employed to grow ZnO nanostructres on p-GaN/sapphire at low temperature. The obtained ZnO nanostructres were uniformly distributed on the surface of p-GaN/sapphire substrates and showed the sheet-like morphology. The ultraviolet(UV) photodetector based on ZnO nanosheet/p-GaN heterostructure was also fabricated by simple method. The characteristics of the photodetector such as current-voltage, repeatability, rise and fall time were investigated. The device exhibited excellent UV photoresponse. It can be attributed the large numbers of high surface-to-volume ratio of ZnO nanosheets increased the surface area and hence higher absorption in the UV region. Furthermore, The two dimensional sheet-like structures could obtain high charge mobility, which contributed to the response speed. The research work will provide a facile route for large area growth ZnO/GaN heterostructure at low temperature.