Impact Of Cr2o3 Additives On The Gas-Sensitive Properties Of Beta-Ga2o3 Thin Films To Oxygen, Hydrogen, Carbon Monoxide, And Toluene Vapors

High-temperature beta -Ga2O3:Cr2O3-based sensors sensitive to oxygen- and hydrogen-containing gases have been developed and studied. Magnetron cosputtering is the method of choice for the thin film synthesis as an industry-compatible technique. The composition-structure-properties relationship has been revealed. An introduction of 0.04-0.14wt.% Cr leads to a significant increase in the response of the O-2 sensors over the temperature range 250-400 degrees C. The highest response in the above-mentioned temperature range has been achieved for a Cr addition of 0.14wt.%. An increase in the Cr content from 0.04 to 0.22wt.% leads to a decrease in the beta -Ga2O3-based sensors' response time, especially for low O-2 concentrations (<= 10vol.%). Reliable control of the beta -Ga2O3:Cr2O3-based sensors' selectivity to industry-relevant reducing gases-hydrogen, carbon monoxide, and toluene-is demonstrated. beta -Ga2O3 films with a Cr incorporation content of 0.04 and 0.06wt.% have a high response to toluene at operating temperatures 300-500 degrees C, while the films with 0.14 and 0.22wt.% Cr have a high response to H-2 in the range 400-500 degrees C. Regardless of the Cr content in beta -Ga2O3 thin films, all sensors considered demonstrate a weak response to CO within the operating temperature range 250-500 degrees C. The results attained are of certain technological importance, i.e., in terms of the development of cost-effective methods for the synthesis of materials and systems for monitoring and control of industry-relevant gases for an environmentally friendly and sustainable growth.