Enhanced sensitivity and response speed of graphene oxide/ZnO nanorods photodetector fabricated by introducing graphene oxide in seed layer

Graphene/ZnO nanocomposites photodetectors hold great potential for UV detection because of the combination of photosensitive ZnO and high electron-mobility graphene. In this paper, graphene oxide (GO)/ZnO nanorods photoconductive photodetector with seed layer of GO and ZnO nanocrystals (NCs) hybrids is fabricated via a low-cost solution process. Uniform and oriented GO/ZnO nanorods have been obtained due to the positive role of GO in the growth process of ZnO nanorods, which gives rise to less light scattering and thereby stronger absorption and enhanced photocurrent. When the growth time is 1 h, the optimum photocurrent of GO/ZnO nanorods is about 9.4 times than pure ZnO nanorods, meanwhile, the corresponding detectivity reaches 7.17 x 10(11) cm Hz(1/2) W-1. In addition, owing to the high carrier mobility of graphene, the response time t (90) of GO/ZnO photodetector beneficially decreases to similar to 1 s, which is much faster than many other GO/ZnO hybrid photodetectors.