Nucleation and growth behavior of well-aligned ZnO nanorods on organic substrates in aqueous solutions

Abstract

A low-temperature synthetic route was used to prepare well-aligned arrays of oriented ZnO nanorods on organic substrates coated with polystyrene beads (PS) in an aqueous solution. The corresponding growth behavior and photoluminescence properties of ZnO nanorods were analyzed. It was found that the ZnO nanorods are initially nucleated from the ZnO monolayer under the concave regions of the PS layers and preferentially grown along [0 0 0 1] direction. High-resolution transmission electron microscopy (HRTEM) observation reveals that the ZnO nanorods tend to coalesce together with other adjacent nanorods to form a larger ZnO crystal in the later growth stage. The room-temperature photoluminescence spectra demonstrate that a stronger ultraviolet (UV) emission with a broad yellow emission around 575 nm was observed for the ZnO nanorods grown on the organic substrates and the relative intensity ratio of ultraviolet emission to yellow emission depends on the growth periods of time. This simple approach demonstrates great potential for optoelectronic devices because it can produce large-scale highly well-aligned ZnO nanorods on the flexible organic substrates at lower temperatures. (c) 2005 Elsevier B.V. All rights reserved.