Gallium nitride nanowires with a metal initiated metal-organic chemical vapor deposition (MOCVD) approach

We have studied structural and electrical properties of one dimensionally grown single crystalline gallium nitride (GaN) nanowires (NWs) for nanoscale devices using a metal-initiated metal-organic chemical vapor deposition (MOCVD). GaN nanowires were formed via the vapor-liquid-solid (VLS) mechanism with gold, iron, or nickel as growth initiators and were found to have triangular cross-sections with widths of 15 ∼ 200 nm and lengths of 5 ∼ 20 μm. TEM confirmed that the nanowires were single crystalline and were well oriented along the [210] or [110] direction on substrate depending on the metal initiators. For electrical transport properties of un-doped GaN nanowires, the back-gated field effect transistors (FET) were also fabricated by standard e-beam lithography. In our electrical measurement, the carrier concentration and mobility were ≈2 ∼ 4 × 10¹⁸ cm^-3 and 60 ∼ 70 cm²/V s, respectively.