Enhanced conductivity of ZnO nanorods/rGO composites for photo induced current collection in optoelectronic devices

M. Jeyavelan, A. Ramesh, T. Sonia, K. Rugunandhiri, M. Sterlin Leo Hudson
Central University of Tamil Nadu,
India

Keywords: Graphene oxide, conductive oxides, electrical conductivity, bandgap

Summary:

Nanostructured zinc oxide (ZnO) has received enthusiastic attention in the recent years as a functional material due to its unique and tunable electrical and optical properties. The very high electron mobility (between 100-200 cm2V-1s-1¬¬) and wide direct bandgap (3.37 eV) of ZnO nanostructures are attractive for photo induced electron collection in optoelectronic devices such as photodiodes, phototransistors, photovoltaic cells etc. However, the poor conductivity of ZnO, especially in its nanoform is the most challenging issue for its applications in optoelectronic devices. In this work, we report the improvement in conductivity of hydrothermally derived ZnO nanorods by making a composite mixture with reduced graphene oxide (rGO). We have carried out systematic analysis on the improvement in electrical properties of ZnO nanorods/rGO composites with variation in concentration of rGO. We have observed that the addition of 1 wt.% rGO on ZnO nanorods, exponentially increases its conductivity from 2.44 х 10-9 S/cm to 0.1681 S/cm. Structural, microstructural and optical characterization of the samples were carried out using XRD, SEM, TEM, UV-Vis and FTIR techniques and the results will be discussed.