Highly crystalline α-phase gallium oxide (Ga₂O₃) thin films were grown by fine-channel mist chemical vapor deposition on c-sapphire substrates at 400 °C at a deposition rate of more than 20 nm/min. The thin films were doped with Sn(IV) atoms, which were obtained from Sn(II) chloride by the reaction SnCl₂+ H₂O₂+ 2HCl→SnCl₄+ 2H₂O. Conductive α-phase Ga₂O₃ thin films were successfully grown from source solutions containing less than 10 at. % Sn(IV). The source solution containing 4 at. % Sn(IV) resulted in obtaining a thin film with an n-type conductivity as high as 0.28 S cm^-1, a mobility of 0.23 cm² V^-1 s^-1, a carrier concentration of 7×10¹⁸ cm^-3, and a full width at half maximum (FWHM) of the (0006) reflection X-ray rocking curve as low as 64 arcsec.

Oxide semiconductors have been investigated as channel layers for thin film transistors (TFTs) which enable next-generation devices such as high-resolution liquid crystal displays (LCDs), organic light emitting diode (OLED) displays, flexible electronics, and innovative devices. Here, high-performance and stable Ga-Sn-O (GTO) TFTs were demonstrated for the first time without the use of rare metals such as In. The GTO thin films were deposited using radiofrequency (RF) magnetron sputtering. A high field effect mobility of 25.6 cm²/Vs was achieved, because the orbital structure of Sn was similar to that of In. The stability of the GTO TFTs was examined under bias, temperature, and light illumination conditions. The electrical behaviour of the GTO TFTs was more stable than that of In-Ga-Zn-O (IGZO) TFTs, which was attributed to the elimination of weak Zn-O bonds.