Low temperature wet chemical synthesis of good optical quality vertically aligned crystalline ZnO nanorods

The growth of ZnO nanorods on Au-coated ITO substrates using a low temperature wet chemical process is presented. Electron microscopy and x-ray diffraction observations reveal that the crystalline ZnO nanorods are preferentially oriented along the c axis. Room temperature photoluminescence (PL) measurements reveal a strong band edge emission at 382 nm, a signature of good crystallinity, with a weak and broad orange-red emission, which is typically attributed to the oxygen interstitials, in the range between 520 and 720 nm. Other than the second order feature of the band edge emission at 760 nm, no red or near-infrared bands are observed. The effect of precursor concentration on the morphological, structural and PL properties are studied, and the results are discussed.