ZnO Nanorod LEDs and Silicon Nanowire Integration

This article reports on the growth and integration of ZnO and Si nanowires sponsored under this grant. The first part was carried out by Xinyu Wang and is completed. It reports ZnO growth for the formation of nanorod LED arrays on Mg-doped p-GaN films. The electroluminescence spectra under forward and reverse bias were found to be distinctly different. Forward bias showed two peaks centered around 390 nm and 585 nm, while reverse bias showed a single peak at 510 nm. Forward bias transport and luminescence were attributed to hole injection from the GaN into the ZnO and recombination at defect states inside the ZnO yielding distinct color variations between individual wires. The color variations, defect emission, and quality of the ZnO has been improved in a separate study [see progress report for #0621137 and [1, 2]]. The second part carried out by Chris Smith reports on post processing of VLS grown silicon nanowires to gain control over location, density, diameter and orientation. Preliminary results on the proposed nanorotation and nanotransfer are presented which require further improvement.