Disordered ZnO nanowires composited with photochemically reduced graphene oxide for enhancement in UV photoresponse

摘要

This article presents a high-performance ultraviolet (UV) photodetector based on one-dimensional (1D) disordered zinc oxide nanowires (ZNWs) composited with reduced graphene oxide (RGO) for improving the photon absorption and suppressing high recombination rate of electron-hole pairs (EHPs) in ZNWs. The RGO/ZNWs composites have been successfully synthetized through UV-assisted photoch. The material characterizations in morphology and Raman scattering verified the formation of graphene sheets attached in ZNWs network and the enhancement of UV absorption due to the introduction of graphene. In comparison with photodetectors based on pure ZNWs, the photodetectors based on RGO/ZNWs composite exhibit stable response to frequency-modulated UV irraddiation and enhanced photoresponse with photocurrent density of 5.87 mA.cm~2, on/off current ratio of 3.01xl0~4, and responsivity of 1.83 A.W~(-1) when a UV irradiation of 3.26 mW.cm~2 and 1.0 V bias were used. Theory analysis is also presented to get insight into the inherent mechanisms of separation and transportation of photo-excited carriers in RGO/ZNWs composite.