Fig. 1. XRD results of Ga₂O₃ films annealed in different atmospheres. (a) XRD pattern; (b) crystal size

Fig. 2. Annealed SEM images for different gas. (a)(c)(e) Surface topographies of Ga₂O₃ films; (b)(d)(f) cross-section images of Ga₂O₃ films

Fig. 3. UV-Vis results of different samples. (a) Transmission spectrum of quartz sheet; (b) transmission spectra of Ga₂O₃ films; (c) reflection spectra of Ga₂O₃ films; (d) relationship between (αhv)² and hv

Fig. 4. Room temperature photoluminescence spectra of Ga₂O₃ films prepared under different annealing conditions

Fig. 5. Schematic diagram of carrier transition luminescence of sample annealed in nitrogen atmosphere

Fig. 6. I-V results of annealed samples in different atmosphere. (a) I-V characteristic diagram; (b) variation of average resistance