Nowadays, the semiconductor nanowires (NWs) typically used in hydrogen gas sensors. Gallium nitride (GaN) with a wide band gap of 3.4 eV, is one of the best semiconductors for this function. NWs surface roughness have important role in gas sensors performance. In this research, GaN NWs have been synthesized on Si substrate by plasma-assisted vapor phase deposition at different deposition time, without using any catalyst. The precursors were gallium (Ga) metal and nitrogen (N) plasma. The GaN NWs were characterized by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy )FE-SEM(, photoluminescence (PL) and Raman Spectroscopy. The results indicate the serrated morphology for hexagonal structure of GaN NWs. The band gap energy of GaN NWs was obtained about 3.41 eV. The Raman results show two Raman active optical phonons at 563 cm-1 and 720 cm-1 due to E2(high) and A1(LO), respectively and indicates a good crystallinity of the NWs with the presence of defects in the crystal lattice.
Development of β-Ga2O3 layers growth on sapphire substrates employing modeling of precursors ratio in halide vapor phase epitaxy reactor