Polychromatic ZnO/CdxZn_1-xO composite nanorods prepared by simple chemical methods: nanoscale optical characteristics

Abstract

We report the fabrication and nanoscale optical characteristics of polychromatic ZnO/CdxZn1-xO composite nanorods prepared by simple hydrothermal and sol-gel chemical methods. Hydrothermally grown ~300 nm diameter and ~3.5 µm long ZnO nanorods were coated, using the sol-gel method, with a thin CdxZn1-xO layer having a spatially varying Cd mole fraction, where x ranged from x = 0 to 1. Full control of the emission color, including white emission, was achieved by simply varying the local Cd mole fraction along the single ZnO/CdxZn1-xO nanorod. The continuous variation of the optical band gap energy along the single nanorod was visualized using nanoscale confocal absorption spectral imaging.