Synthesis of vertically oriented GaN nanowires on a LiAlO2 substrate via chemical vapor deposition

Abstract

Vertically oriented nanowires (NWs) of single-crystalline wurtzite GaN have been fabricated on a γ-LiAlO2 (100) substrate coated with a Au layer, via a chemical vapor deposition process at 1000 °C using gallium and ammonia as source materials. The GaN NWs grow along the nonpolar [1010] direction with steeply tapering tips, and have triangular cross-sections with widths of 50–100 nm and lengths of up to several microns. The GaN NWs are formed by a vapor-liquid-solid growth mechanism and the tapering tips are attributed to the temperature decrease in the final stage of the synthesis process. The aligned GaN NWs show blue-yellow emission originating from defect levels, residual impurities or surface states of the GaN NWs, and have potential applications in nanotechnology.