Enhanced ultraviolet photoresponse in Au/ZnO nanorods

•Au NPs capped ZnO NRs have been synthesized by a chemical method.•The photocurrent and UV photoresponse have been enhanced in Au/ZnO NRs.•The UV PL intensity is decreased after Au capping on ZnO NRs.•Enhanced UV response is due to pronounced electron-hole separation by the formation of localized Schottky junctions.

ZnO nanorods (NRs) have been decorated by Au nanoparticles (NPs) by a chemical method. The ultraviolet (UV) photoresponse of Au/ZnO NRs has been investigated. As the loading of Au NPs increases, the photocurrent as well as the photo-to-dark current ratio (gain) increases attaining a maximum gain value which is ∼15 times higher than that of the pristine ZnO NRs. Photoresponse enhancement is probably due to efficient separation of photo-generated electron-holes by an enhanced electric field and hot carrier injection over the Au localized Schottky junctions.

Graphical abstractZnO NRs have been decorated by Au NPs by a chemical method. The photocurrent as well as the photo-to-dark current ratio (gain) increases in Au/ZnO NRs as compared to pristine ZnO NRs. Maximum UV photoresponse in Au-ZnO has become ∼15 times larger than bare ZnO. This enhanced UV photoresponse is due to very efficient separation of the photo-generated electron-holes by the enhanced electric field caused by the Au localized Schottky junctions. These studies are very useful showing a way to design UV photodetector based on ZnO nanostructures.Download high-res image (208KB)Download full-size image