The effect of the gaseous medium composition on the electrically conductive properties of In2O3-Ga2O3 films obtained by chloride vapor phase epitaxy has been studied. In the temperature range of 100-550ºC the In2O3 -Ga2O3 films exhibit high sensitivity to H2, NH3 and CO possessing high-speed performance and low-base-resistance. A qualitative mechanism for the sensitivity of In2O3-Ga2O3 films to gases is proposed.

The effect of H2, NH3, CO and O2 on the electrically conductive properties of In2O3 films grown by halide vapor phase epitaxy has been studied. In the temperature range of 200−550°C, In2O3 films demonstrate gas sensitivity to all considered gases, a relatively high operation speed and repeatability of cycles. The greatest response to NH3 was obtained, which exceeded 33 arb.units at a temperature of 400°C and a gas concentration of 1000 ppm. A qualitative mechanism of gas sensitivity of In2O3 films is proposed. The obtained gas-sensitive characteristics are compared with known NH3 sensors based on various materials. It is shown that the method of halide vapor phase epitaxy makes it possible to obtain indium oxide films with high gas sensitivity

The effect of ambient humidity on the electrical conductive properties of α-Ga2O3 and α-Ga2O3/ε-Ga2O3 structures has been studied. Polymorphic Ga2O3 epitaxial layers were deposited by chloride vapor phase epitaxy on sapphire substrates. Pt and Pt/Ti were used as contacts. It was found that the Pt/α-Ga2O3/Pt and Pt/Ti/α-Ga2O3/ε-Ga2O3/Ti/Pt structures exhibit a high sensitivity of the current – voltage characteristics (I–V characteristics) to atmospheric humidity in the temperature range 25–100 °C. It was found that the effect of water vapor on the I–V characteristics of the structures is reversible and the most significant changes in the current in the samples are observed at a relative humidity RH ≥ 60%. With increasing temperature the effect of atmospheric humidity on the I–V characteristics decreases and disappears at T > 100 °C. The experimental results obtained are explained in terms of the Grottguss mechanism.