Effect of Iodine addition on the structural and optical properties of ZnO microrods grown via Hydrothermal method
Introducing defects or impurities to ZnO is a great method in enhancing its optical and structural characteristics. In most researches, metallic elements, which are also cations, are being doped into ZnO incorporating into the zinc site. In this paper, the effects of the addition of an anion, specifically iodine, to the structural and optical properties of ZnO microrods fabricated using hydrothermal method were investigated. SEM images showed that iodine-added ZnO (ZnO+I) microrods decreased in length when iodine concentration was increased. Using PL spectroscopy, a broadening of the visible emission was also observed for increasing iodine concentrations. These results were attributed to the increase in the number of defects which might be due to oxygen interstitials and vacancies in the ZnO crystal structure which interacted with iodine during the growth process. However, XRD patterns showed no significant change in peak shifts and lattice parameters for varying concentrations of iodine. With the enhanced optical properties of ZnO due to the addition of iodine, an increase in the efficiency of optoelectronic devices such as LEDs is expected.