Enhanced H2S sensing characteristics of Au modified Fe2O3 thin films

H2S sensing characteristics of pure and Au modified Fe2O3 thin films have been investigated. Fe2O3 thin films were realized in two steps; first pure Fe films were deposited using electron-beam evaporation method and subsequently subjected to oxidation at 800 degrees C in O-2 environment. Surface modification with Au was achieved by employing RF sputtering. Both pure and Au modified Fe2O3 samples exhibited an n-type conductivity pattern. Modification with 2.33 at% of Au resulted in an enhanced response of 538% towards 10 ppm of H2S at 250 degrees C, with response and recovery times of 1.65 and 27 min, respectively. The enhanced response has been attributed mainly to the dual role of Au i.e., forming nano-Schottky barriers with the host Fe2O3 matrix and as a promoter for the spillover effect. (C) 2015 Elsevier B.V. All rights reserved.