Growth of aligned ZnO nanorod arrays from an aqueous solution: effect of additives and substrates

We report a simple, versatile, low cost fabrication technique for synthesizing nanorod arrays whose architecture is suited for many applications spanning the nanometer to micrometer range. Specifically, we have covered the range of nanorod diameter from 50 to 1200 nm. From a detailed study of the growth parameters involved in the synthesis of the ZnO nanorod arrays from an aqueous solution, we report, in particular, the effects of varying the capping agent, substrate and substrate-seeding. We find that seeding the substrate and selecting the appropriate capping agent play the most crucial roles in the alignment of nanorod arrays. Our study on the use of different precursor materials and varied substrates for the growth of ZnO nanorod arrays should lead to an enhanced understanding of the controllable growth of ZnO crystals and nanostructures.