Hydrothermal selective growth of low aspect ratio isolated ZnO nanorods

Abstract

We have grown patterned, low-aspect-ratio, well-separated single ZnO nanorods using a hydrothermal method on two different substrates with dissimilar crystal orientations. ZnO nuclei have been used as a seed layer to compensate the crystal mismatch between the substrates and nanorods. Based on XRD results, in order to have highly oriented nanorods, the seed layer must be annealed over 300°C. Micro-Raman spectra show that our patterned nanorods have a wurtzite crystal structure, with most nanorods presenting vertical orientation relative to the substrate. Room-temperature micro-photoluminescence (PL) spectra from the nanorods show sharp band edge emission at 385nm and a common broadband defect emission in the visible range. Our method is a significant step towards an economical controlled synthesis of 1D ZnO for application in mass-production advanced devices.