Thin films of SnO2–CeO2 binary oxides obtained by pulsed laser deposition for sensing application

Binary tin oxide–cerium oxide thin films with ceria concentrations in the range 10–30% have been obtained by pulsed laser deposition technique, with or without additional oxygen RF plasma beam assistance. A good preservation of the Ce/Sn atomic concentration and Ce3+ content on the film surface of about 30% was obtained for almost all the investigated conditions of substrate temperature and RF powers. The sharp decrease of the electrical resistance in hydrogen environment at temperatures above 300 °C indicates a direct interaction between hydrogen and metal oxides surfaces leading to OH groups formation, as evidenced by XPS measurements. The highest sensitivity (∼40) was attained for the sample with 10% ceria and RF assistance, while the lowest operating temperature (∼250–320 °C) was encountered for that with 30% ceria deposited in the presence of RF discharge.