Basal plane-oriented gallium nitride films on fused silica via acetate dip coating

c-axis-oriented gallium nitride (wurtzite GaN) thin films were fabricated by nitridation of acetate derived precursor films deposited on fused silica substrates without any buffer layer on the top of the substrate. The acetate derived precursors were obtained by (i) preparing a gallium-acetate sol by reacting Ga metal with acetic acid, (ii) coating cleared fused silica substrate with the sol and (iii) after drying the coated films at 100 °C, annealing them in air at 300°, 500° and 900 °C. Only films showing crystallization of α-GaO(OH) (300 °C) and (α + β)-Ga2