A simple route to controllable growth of ZnO nanorod arrays on conducting substrates

Aligned ZnO nanorod arrays are grown on Zn foil using a simple and low cost solution chemistry approach. We have studied the effects of various growth parameters, including the temperature, solution composition and the concentration of individual components on the morphology, structural quality, and properties of the ZnO nanorods. The average diameter of the nanorods in the array can be tuned from similar to 20 nm to similar to 150 nm by systematically changing the growth conditions. We found that nanorods with larger diameters are of better structural quality as compared to the smaller diameter ones, as suggested by the cathodoluminescence measurement of these nanorods. Electrical measurements performed on individual ZnO nanorod-on-Zn substrate reveal ohmic contact between them. By pre-depositing a Zn layer (with controlled thickness) on other conducting substrates, such as Cu, ZnO nanorod arrays can be grown on a number of different substrates using a similar method.