Ultrafine ZnO nanowires grown on patternable Pd catalyst and their source-energy dependent photoluminescence

Abstract

Patterned arrays of ZnO nanostructures have been obtained from a solution based method using Pd nanoparticles as catalyst. The catalyst nanoparticles were patterned using a direct-write e-beam lithography process. Within 10 minutes in an aqueous solution of zinc nitrate and triethyamine borane at 80°C, fine nanowires of ZnO with diameter around 10 nm were produced on patterned Pd nanoparticles. Longer duration in the precursor solution led to formation of ZnO fibril-like structures. Photoluminescence measurements revealed that the nanostructures exhibited a blue shift for the emission peak at 390 nm, when the excitation energy was increased, unlike bulk ZnO. This is attributed to the discrete defect states present in confined nanostructures.