Optical and structural characterization of solution processed zinc oxide nanorods via hydrothermal method

Solution processing of zinc oxide (ZnO) is an effective and low-cost method for large surface area fabrication. This paper reports on the fabrication and properties of ZnO nanorods synthesized via a low-temperature hydrothermal process on the FTO (F-doped SnO2) substrate covered with a ZnO seed layer. These nanorods were characterized using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), photoluminescence (PL) measurements, and UV vis spectroscopy (UV vis). The resulting nanorods exhibited vertical orientation and uniform distribution on the substrate with a hexagonal crystal structure. Morphological changes of these nanorods and their aspect ratios were systematically investigated as a function of the deposition time and precursor concentration. Both XRD and HRTEM results indicated that the ZnO nanorods preferentially grow along the (002) direction. The synthesized ZnO nanorods possessed a UV emission peak at approximately 387 nm and a relatively strong orange-red emission peak at around 625-675 nm. The optical transmission showed a high transparency of 85% and 70% for the seed layer and nanorods respectively. (C) 2014 Published by Elsevier Ltd and Techna Group S.r.l.