Graphene-ZnO NWs hybrid film for large-area UV photodetector

One of the major barriers in the way of developing high-performance graphene-based photodetector is the low and wavelength-independent light absorption by graphene. In this regard, the schemes that adopt a heterogeneous integration of graphene and light sensitive materials are considered to hold the promise. However, to realize large-area heterogenous integration itself is not easy as some of the micro/nanofabrication steps are known to degrade the quality of graphene. This work demonstrates the successful integration of graphene-ZnO nanowires (NWs) over 4 cm2 with a facile and cost-effective method. The as-fabricated graphene-ZnO hybrid film can function as an ultraviolet (UV) photodetector (PD) with a high performance and good uniformity over large-area. The huge sensitivity of ZnO NWs to UV light, combined with the high carrier mobility of graphene, enable the UV PD with a photoresponse up to 2100 A/W, and fast response times down to millisecond.