Enhanced crystalline size of undoped GaN powders obtained by nitridation of metallic gallium

Optical and structural study of undoped GaN powders obtained by nitridation of metallic gallium and pyrolysis of Ga(NO3)3-CH6N4O polymer were made. A high synthesis efficiency for the nitridation of metallic gallium was observed, while the pyrolysis synthesis of the Ga(NO3)3-CH6N4O polymer was very low. The XRD patterns showed an intense peak in the orientation (101) of the hexagonal GaN in both cases. The photoluminescence spectrum for nitridation technique of metallic gallium at room temperature, shown how the point defects generated during the preparation of GaN powders allow the adequate incorporation of nitrogen and favor the crystal growth (sizes up to 3.6 μm length and 3 μm wide). The visible separation in the micro-Raman spectrum of the E1 and E2 modes in the samples obtained by nitridation of metallic gallium was an indicative of the contribution of interstitial gallium in the lattice vibration, an aspect not reported yet. On the other hand, SEM studies confirmed the higher crystalline size of the material obtained by nitridation of metallic gallium compared with the synthesized by pyrolysis of the Ga(NO3)3-CH6N4O metalorganic complex polymer.