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O: Fachverband Oberflächenphysik

O 41: Poster Session I (Semiconductor Substrates: Epitaxy and growth; Semiconductor Substrates: Adsorbtion; Semiconductor Substrates: Solid-liquid interfaces; Semiconductor Substrates: Clean surfaces; Oxides and insulators: Epitaxy and growth; Oxides and insulators: Adsorption; Oxides and insulators: Clean surfaces; Organic, polymeric and biomolecular films - also with adsorbates; Organic electronics and photovoltaics, Surface chemical reactions; Heterogeneous catalysis; Phase transitions; Particles and clusters; Surface dynamics; Surface or interface magnetism; Electron and spin dynamics; Spin-Orbit Interaction at Surfaces; Electronic structure; Nanotribology; Solid/liquid interfaces; Graphene; Others)

O 41.113: Poster

Dienstag, 23. März 2010, 18:30–21:00, Poster B1

Graphite and multigraphene based Gas sensor — •Ana Ballestar, Jose Barzola-Quiquia, and Pablo Esquinazi — Division of Superconductivity and Magnetism, Universität Leipzig, 04103 Leipzig

The research and development of solid state gas sensors have widely advanced in recent years. Sensing gas molecules is critical to environmental monitoring, control of chemical processes, space missions and medical applications. In order to judge whether or not a sensor is likely to be commercially successful, the sensitivity, selectivity, stability, speed of response and low cost manufacturing are the parameters to be taken into account. Graphite, considered a semi-metal or zero-gap semiconductor, is a good electrical conductor at 300K. The operational system proposed here is based on the changes of the electrical resistivity produced in mm- and µm-sized samples of graphite and multigraphene while being exposed to different gas molecules. By means of low noise measurements and high sensitivity concerning the variations in the resistivity of graphite samples, we are able to detect the adsorption and desorption of the gas molecules on graphite surface. Depending on the gas molecules we get different variations in the signal, so we have selectivity in the device as well.