Seed/Catalyst Free Growth and Self-Powered Photoresponse of Vertically Aligned ZnO Nanorods on Reduced Graphene Oxide Nanosheets

The seed/catalyst-free and selective-growth process is developed for in situ grown single-crystalline and vertically aligned ZnO nanorods on the reduced graphene oxide (rGO) nanosheets. In this process, the position of ZnO nanorod arrays correlates well with the size and position of rGO nanosheets, which is strongly depended on both dangling bonds such as oxygen containing groups on rGO surface and the step edges in rGO boundaries. To our best knowledge, it is the first time to report that in situ ZnO/rGO nanohybrids perform self-powered and fast (the response time of 0.1 s and the recovery time of 0.2 s) photoresponse to ultraviolet light. The fast and self-powered photocurrent generation can be attributed to the Schottky contact at the rGO/ZnO interface. These results demonstrate an effective way to promote the wide applications in light energy harvesting devices based on semiconductor/graphene hybrids including solar cells, photodetectors, sensors and photocatalysis.