High Quality GaAs Nanowires Grown on Glass Substrates

We report for the first time the growth of GaAs nanowires directly on low-cost glass substrates using atmospheric pressure metal organic vapor phase epitaxy via a vapor liquid solid mechanism with gold as catalyst. Substrates used in this work were of float glass type typically seen in household window glasses. Growth of GaAs nanowires on glass were investigated for growth temperatures between 410 and 580 degrees C. Perfectly cylindrical nontapered nanowires with a growth rate of similar to 33 nm/s were observed at growth temperatures of 450 and 470 degrees C, whereas highly tapered pillar-like wires were observed at 580 degrees C. Nanowires grew horizontally on the glass surface at 410 degrees C with a tendency to grow in vertically from the substrate as the growth temperature was increased. X-ray diffraction and transmission electron microscopy revealed that the nanowires have a perfect zinc blende structure with no planar structural defects or stacking faults. Strong photoluminescence emission was observed both at low temperature and room temperature indicating a high optical quality of GaAs nanowires. Growth comparison on impurity free fused silica substrate suggests unintentional doping of the nanowires from the glass substrate.