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 degrees C indicates a direct interaction between hydrogen and metal oxides surfaces leading to OH groups formation, as evidenced by XPS measurements. The highest sensitivity (similar to 40) was attained for the sample with 10% ceria and RF assistance, while the lowest operating temperature (similar to 250-320 degrees C) was encountered for that with 30% ceria deposited in the presence of RF discharge. (C) 2012 Elsevier B.V. All rights reserved.