XRD, XPS, SEM, PL and Raman scattering analysis of synthesised GaN powder

Gallium nitride (GaN) has been synthesised by reacting metal gallium (Ga) with ammonia (NH3) using a horizontal quartz reactor. The optimised synthesis conditions of GaN such as experimental temperature and reaction period are 950 °C and 8 h, respectively. X-ray diffraction (XRD) reveals that the GaN powder is of single-phase wurtzite structure and X-ray photo-electron spectroscopy (XPS) confirms the formation of bonding between Ga and N. Room temperature photoluminescence (PL) exhibits the band-to-band emission of GaN at 363 nm. Raman scattering indicates a shift in A1(TO), E1(TO) and E2 vibrational modes of wurtzite GaN due to its polycrystalline nature.