P-type GaN powders obtained by nitridation of Ga-Mg liquid metallic solution.

Abstract Magnesium doped GaN powders were obtained by nitridation of a Ga-Mg liquid metallic solution in a chemical vapor deposition system during two hours at 1000 °C. Photoluminescence spectrum, obtained at room temperature of the Mg doped GaN powders, showed an emission band with a maximum energy of 2.9 eV (427.5 nm), which is characteristic of Mg doped GaN. Raman spectra agree with the incorporation of Mg as dopant in the GaN powders, showing a shoulder at 669.98 cm−1 and a slight shift to low frequency of the vibration mode A 1 (TO) with respect to undoped GaN powders. X-ray diffraction patterns suggested that the crystalline structure of the GaN powders was not affected by the incorporation of Mg into the lattice. Finally, scanning electronic microscope images showed that the surface morphology of the Mg doped GaN powders was composed of hexagonal platelets, which could be due to the magnesium diffusion in the gallium before the nitridation process takes place. Highlights • Mg doped GaN powders were obtained by nitridation of a Ga-Mg liquid metallic. • PL spectrum showed an emission band with a maximum energy of 2.9 eV (427.5 nm). • Raman spectrum agrees with the incorporation of Mg as dopant in the GaN powders. • Crystalline structure of GaN powders was not affected by the incorporation of Mg. • The surface morphology of Mg doped GaN powders is formed by hexagonal platelets. [ABSTRACT FROM AUTHOR]