Berlin 2015 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 17: Postersession I

MM 17.22: Poster

Monday, March 16, 2015, 18:00–20:00, Poster E

Gas sensors based on metal oxides deposited on AAO for the detection of carbon monoxide — •Jonas Lübke, Stefan Ostendorp, Nina Winkler, and Gerhard Wilde — Institute of Materials Physics, WWU Münster, Germany

Carbon monoxide is a colourless, odourless, flavourless and non-irritant gas produced from partial oxidation of carbon-containing compounds. If inhaled, it connects to the central iron atom of haemoglobin and therefore prohibits oxygen transport in blood, which leads to death by choking. Therefore sensitive and reliable detection is of great interest. Carbon monoxide acts reductive on most oxidized semi-conductors (SC's), leading to increased or decreased resistance, depending on whether they are n- or p-type SC's. Former work has shown successful detection of CO with metal oxide semi-conductors (MO-SC) on glass substrates. To increase the detecting surface and the inspected volume, use of "Anodic Aluminum Oxide" (AAO)-membranes as substrate seems to be promising. To this end, metal oxides were deposited on AAO via atomic layer deposition (ALD). The gas sensor set-up is brought into a temperature-controlled vacuum chamber to provide the required activation energy for chemisorption of CO in a defined gas environment. A well-defined amount of air is introduced to the chamber and then a well-defined amount of CO. The current through the sample/gas sensor is measured via a four probe measurement. The effect of modifications of the membranes and oxide films concerning the resultant gas sensing properties was examined.