Realization of a reduced graphene oxide/ZnO nanorod photodetector, suitable for self-powered applications

In this report, we propose a reduced graphene oxide (rGO) /ZnO nanorod hybrid structure, which benefits from high photosensitivity and piezoelectric properties of ZnO nanorods, beside excellent carrier mobility, high optical transparency and mechanical flexibility of the reduced graphene oxide sheets. Comparing with the pristine ZnO nanorod based structure; it is shown that the proposed hybrid photodetector exhibits improved output sensitivity to UV-illumination (ΔI/I=424). Also, by taking advantage of the coupled semiconducting/piezoelectric properties of ZnO nanorods, we demonstrate the application of the proposed hybrid rGO/ZnO nanorod structure as a photosensitive piezoelectric nanogenerator. In this regard, we have achieved enhanced open circuit voltage (1.5 V) and open circuit sensitivity (ΔVoc/Voc=-0.66 %), beside a faster photoresponse, for the realized rGO/ZnO hybrid structure in comparison with ZnO nanorod based counterpart. The observed enhancements are attributed to the presence of underlying reduced graphene oxide sheet, as an efficient carrier transport layer in the proposed hybrid structure.