TY - CONF A1 - Fischer, Daniel A1 - Hertwig, Andreas A1 - Beck, Uwe A1 - Kormunda, M. A1 - Esser, N. T1 - Ellipsometric characterization of metal doped SnOx thin films for SPREE-based gas sensors N2 - Gas sensors are an important tool in various areas for example in industrial process control as well as Gas sensors are an important tool in various areas for example in industrial process control as well as safety applications or in research. A useful gas detector should be selective, precise, stable and cost-effective. In the present research a surface based gas detection technique is investigated using the SPR effect with ellipsometric readout. This technique is called surface plasmon resonance enhanced ellipsometry (SPREE). The sensor consists of a gold layer (40 nm) top-coated with a doped metal-oxide (M:SnOₓ, 5 nm). The coating is added by magnetron sputtering with doped targets with different doping concentrations. It could be shown that, without the top-coating, these type of sensors can detect various gases, e.g. CO, H2, O2, O3, He, N2, with sensitivities down to the ppm range (in air). The goal of the present study is to characterize the additional coating materials in dependence of the coating conditions. With the help of the doped-metal oxide, the sensitivity increases dramatically by a factor of 100. Additionally, a selectivity for specific gases is observed which depends on the doping conditions of the coating. Changing the properties of the plasma coating process and the doping metal gives access to a variety of different layers and enables us to find the best conditions. T2 - Leibniz Institut für Analytische Wissenschaften ISAS e.V. - Kolloqium CY - Berlin, Germany DA - 05.05.2016 KW - Ellipsometry KW - SPR effect KW - SnOx KW - Gas sensors PY - 2016 AN - OPUS4-37034 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -