Surface-modified ZnO nanowire arrays ultraviolet photodetector with Cu nanoparticles for enhanced detection performance

The state-of-the-art ultraviolet photodetectors (UV PDs) have been extensively used in environmental monitoring, security checks, and optical communication. The conventional ZnO UV PDs often exhibit low sensitivity and slow response/decay speed. In this study, Cu nanoparticles (NPs) were first used to modify the surface of ZnO nanowire array (ZNWA) UV PDs. The results showed that after Cu NP modification, the dark current (Id) of the device at 5 V bias was reduced by more than one order of magnitude, while its responsivity and detectivity were about twice those of the ZNWA UV PD. The response and decay times reduced by 2.8 and 27.4 s, respectively. The present simple scheme offers a new strategy to suppress the Id in ZnO UV PDs for ultrasensitive photodetection applications.