Effects of gas flow rate on structural features of ZnO nanowire arrays fabricated on silicon substrate

Abstract

Arrays of single-crystal zinc oxide (ZnO) nanowires have been synthesized on silicon substrates by vapor–liquid–solid growth techniques. The effect of growth conditions including the substrate temperature and Ar gas flow rate on the growth properties of ZnO nanowire arrays were studied. Structural and optical characteristics were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD), and photoluminescence (PL) spectroscopy. The XRD measurements showed that the single-crystal nanowires exhibited growth in the (002) direction. SEM images of the ZnO nanowire arrays grown at various Ar gas flow rates indicated that the alignment and structural features of the ZnO nanowires were affected by the gas flow rate. The PL of the ZnO nanowire arrays exhibited strong UV emission at 380 nm and weak green emission at approximately 510 nm. A blue shift and broadening of the UV emission were observed with increasing Ar gas flow rate.