High sensitivity of halide vapor phase epitaxy grown indium oxide films to ammonia

Abstract

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 200-550oC, 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 400oC and a gas concentration of 1000 ppm-1. A qualitative mechanism of gas sensitivity of In2O3 films is proposed. The obtained gas-sensitive characteristics are compared with known In2O3 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. Keywords: In2O3 films, halide vapor phase epitaxy, gas-sensitive properties, response.