Fig. 1. (Color online) Schematic of a vertical hot-wall mist-CVD.

Fig. 2. Cross-sectional SEM images of the Ga₂O₃ films on a sapphire epitaxy at 520 °C with different substrate positions.

Fig. 3. Growth rates of the Ga₂O₃ films at different substrate positions.

Fig. 4. (Color online) XRD patterns of Ga₂O₃ film grown at 500–580 °C.

Fig. 5. (Color online) The crystal phases distributions of Ga₂O₃ films at (a) T = 560 °C and z = 50 mm, (b) T = 540 °C and z = 50 mm.

Fig. 6. (Color online) SEM images of Ga₂O₃ films grown at (a) 500 °C, (b) 520 °C, (c) 540 °C, (d) 560 °C, (e) 580 °C, and (f) photograph of 2-inch α-Ga₂O₃ films prepared at 540 °C.

Fig. 7. (Color online) (a) Optical transmittance spectra of α-Ga₂O₃ films grown at 500 to 580°C. The inset is the partial optical transmittance spectra at the range of wavelength between 200 and 300 nm. (b) The optical bandgaps of α-Ga₂O₃ films grown at 500 to 580 °C.

Fig. 8. (Color online) (a) XRD ω scan of samples grown at 500−560 °C for α-Ga₂O₃ (0006) planes. (b) The locations of P1-5 on 2-inch α-Ga₂O₃ film grown at 540 °C. (c) The rocking curves of α-Ga₂O₃ (0006) planes recorded from five different points (P1–P5). (d) The rocking curves of α-Ga₂O₃ (0006) and (10-14) planes, corresponds to the point of P1.