Fabrication of GaN nanowires on porous GaN substrate by thermal evaporation

In this research, we used an inexpensive method to fabricate highly crystalline gallium nitride (GaN) nanowires (NWs) on porous GaN (PGaN) on a Si (1 1 1) wafer by thermal evaporation using commercial GaN powder using a combination of argon and nitrogen gas atmosphere without any catalyst. Microstructural studies using scanning electron microscopy and transmission electron microscope measurements revealed the role of porosity in the nucleation and alignment of the GaN NWs. The GaN NWs have diameters of 30–45 nm and lengths of around 1 μm. Further structural and optical characterizations were performed using high resolution X-ray diffraction, energy-dispersive X-ray spectroscopy, and photoluminescence spectroscopy. Results indicate that the NWs are of a single-crystal hexagonal GaN and have the growth direction of [0 0 0 1].