Growth mechanism of seed/catalyst-free zinc oxide nanowire balls using intermittently pumped carrier gas: Synthesis, characterization and applications

Abstract

We report the growth mechanism of ZnO nanowire balls by thermal evaporation under intermittently pumped carrier gas as a new and simple nucleation method. The structural, morphological, and optical properties of the nanowires were analyzed by field emission scanning electron microscopy, X-ray diffraction, UV–vis spectroscopy, and photoluminescence spectroscopy. Results showed that the proposed method facilitates epitaxial nucleation and growth of high density vertically aligned ZnO nanowires with length of several micrometers and that have a smaller diameter compared to that of ZnO nanowires fabricated by traditional continuous pumping described in the literature under the same growth condition. These findings suggest that the use of intermittently pumped carrier gas is one of effective control parameters that promote the nucleation and growth of nanomaterials using thermal evaporation method.