Catalyst-free growth of high-optical quality GaN nanowires by metal-organic vapor phase epitaxy

摘要

Catalyst-free GaN wires with 100-200 run diameters are grown on bare c-sapphire substrates by a metal-organic vapor phase epitaxy approach using both low Ⅴ/Ⅲ ratio and Ⅴ-Ⅲ precursor flows that favor a reaction-limited growth regime. The polarity control of the initial seeds allows obtaining pencil-shape wires with very sharp pyramids at their top (~5nm diameter). These defect-free nanowires evidence excellent structural and optical properties as shown by a sharp photoluminescence linewidth (1-3 meV at 5 K).