Applied Surface Science, Vol.360, 731-737, 2016
Structural and gas sensing properties of ex-situ oxidized Sn grown by thermal evaporation
SnO2 thin films were obtained by ex-situ oxidation of Sn metal film deposited by thermal evaporation. The oxidation of the Sn film was carried out at 600, 700 and 900 degrees C for 2 h in a controlled oxygen atmosphere. GIXRD confirmed the tetragonal rutile phase of SnO2 which was further confirmed by Raman spectroscopy. The RBS measurements provided the thickness and chemical information of the film. Thickness of the film was in the range of 6-12 nm and the presence of Sn and oxygen in the films are shown. Scanning electron microscopy revealed spherical particles of different sizes for films annealed at different temperatures. The SnO2 thin film oxidized at 900 degrees C was tested for methane gas sensing. A sensing response of 78.46% for 100 ppm of methane at an operating temperature of 100 degrees C which is one of lowest reported was obtained. (C) 2015 Elsevier B.V. All rights reserved.