Fabrication of InGaN Nanowires on Tantalum Substrates by Vapor-Liquid-Solid Chemical Vapor Deposition.

InGaN nanowires (NWs) have drawn great attentions for their applications in optoelectronic and energy conversion devices. Compared to conventional substrates, metal substrates can offer InGaN NW devices with better thermal conductivity, electric conductivity, and mechanic flexibility. In this article, InGaN NWs were successfully grown on the surface of a tantalum (Ta) substrate via vapor-liquid-solid chemical vapor deposition (VLS-CVD), as characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), scanning and transmission electron microscope (STEM), and photoluminescence spectroscopy (PL). It was found that the surface pretreatment of Ta and the composition of metallic catalysts played important roles in the formation of NWs. A dimpled nitrided Ta surface combined with a catalyst of nickle is suitable for VLS-CVD growth of the NWs. The obtained InGaN NWs grew along the [1100] direction with the presence of basal stacking faults and an enriched indium composition of ~3 at.%. The successful VLS-CVD preparation of InGaN nanowires on Ta substrates could pave the way for the large-scale manufacture of optoelectronic devices in a more cost-effective way.