Realization of a high-Responsivity ultraviolet sensor base on ZnO nanowires modified by Au nanoparticles

In this paper, an ultraviolet photodetector based on ZnO nanowires modified by Au nanoparticles. Due to the high specific surface area of the nanowires and the nano-plasmonic enhancement induced by the adsorbed Au nanoparticles, the measurements reveal a higher photocurrent compared with pure ZnO photodetectors. The dark current was reduced cause of the Schottky junction between metal and semiconductor. By calculation, the maximum responsivity in ultraviolet band of obtained device is up to 9.4A/W at operating bias. Another role of Au NPs adsorbed on the surface of NWs is the scattering effect, which may contribute to more photo absorption. The results indicated that nano-plasmonic enhancement effect could be efficient for UV region and the demonstration of the as-fabricated device provides a feasible and cost-effective method to potential application for UV optoelectronic device.