Gas Sensitivity of IBSD Deposited TiO2 Thin Films

TiO2 films of 130 nm and 463 nm in thickness were deposited by ion beam sputter deposition (IBSD), followed by annealing at temperatures of 800 degrees C and 1000 degrees C. The effect of H-2, CO, CO2, NO2, NO, CH4 and O-2 on the electrically conductive properties of annealed TiO2 thin films in the operating temperature range of 200-750 degrees C were studied. The prospects of IBSD deposited TiO2 thin films in the development of high operating temperature and high stability O-2 sensors were investigated. TiO2 films with a thickness of 130 nm and annealed at 800 degrees C demonstrated the highest response to O-2, of 7.5 arb.un. when exposed to 40 vol. %. An increase in the annealing temperature of up to 1000 degrees C at the same film thickness made it possible to reduce the response and recovery by 2 times, due to changes in the microstructure of the film surface. The films demonstrated high sensitivity to H-2 and nitrogen oxides at an operating temperature of 600 degrees C. The possibility of controlling the responses to different gases by varying the conditions of their annealing and thicknesses was shown. A feasible mechanism for the sensory effect in the IBSD TiO2 thin films was proposed and discussed.

Automated summary

This study investigates the electrical conductivity and gas response of TiO2 films deposited using IBSD at high temperatures. It is found that annealing temperature affects the response and recovery of the films, and the response to different gases can be controlled by varying the annealing conditions and film thickness.