GaN ceramics obtained by fusing of nanocrystalline GaN powder at high pressures and temperatures as substrate for growth of GaN epilayers

In this paper, we have grown GaN films by metalorganic chemical vapor-phase epitaxy (MOVPE) on GaN ceramics obtained from nanocrystalline powder of different initial grain sizes. The samples have been investigated by X-ray diffraction (XRD) and photoluminescence (PL). XRD reveals that the MOVPE GaN films are of single-phase wurtzite structure. Also, it has been observed that the PL spectrum is different for the GaN films compared to that for the GaN powder and also depends on the initial grain sizes.