Synthesis of High Quality ZnO Nanorods by Low Temperature Wet Chemical Process

The authors synthesized high quality ZnO nanorods on Au-and ZnO-coated ITO substrates using a low temperature wet chemical process. Scanning electron microscopy and X-ray diffraction showed that ZnO nanorods were vertically aligned on both type of substrates. Room temperature photoluminescence (PL) measurements showed a strong band-edge emission at ~380 nm for ZnO nanorods on both type of substrates, but substrate-dependent difference was observed in weak and broad visible emissions. Through the careful and systematic analysis of PL spectra, the authors confirmed that the apparent peak at ~760 nm were nothing but the second-order feature of the band-edge emission. Finally, the authors took advantage the selectivity of ZnO-nanorod growth on particular surfaces to demonstrate the possibility for pattered growth.