Enhanced photocurrent performance of partially decorated Au nanoparticles on ZnO nanorods based UV photodetector

Abstract

The surface modification is essentially required to develop a variety of hybrid zinc oxide (ZnO) nanostructures for fabricating optoelectronic devices. A facile solution method was proposed to prepare the relatively low and high aspect ratio ZnO nanorods (NRs) and subsequently decorated with gold nanoparticles (Au NPs) partially on the surface of ZnO NRs. The Au-ZnO NRs exhibited an enhanced band-edge emission due to the surface plasmon resonance quenching of deep level defect emission, as compared to bare ZnO NRs. The UV photodetector with the relatively low aspect ratio Au-ZnO NRs showed a lower photocurrent in dark. However, after UV light illumination, a remarkable enhancement in photocurrent owing to the Au modification was observed, which leads a strong absorption and an improved interfacial charge separation process. Hence, the relatively low aspect ratio Au-ZnO NRs provides a channel for fabricating a high performance UV photodetector, in the near future.