Solid State Gas Sensor Research in Germany – a Status Report

Sensors

Ralf Moos⁴  Kathy Sahner⁴  Maximilian Fleischer¹  Ulrich Guth³  Nicolae Barsan² 

[1]Siemens AG, Corporate Technology, CT PS 6, 81730 München, Germany

[2]Institute of Physical Chemistry, University of Tübingen, 72076 Tübingen, Germany

[3]Kurt-Schwabe Research Institute Meinsberg, 04720 Ziegra-Knobelsdorf, Germany

[4]Functional Materials Laboratory, University of Bayreuth, 95440 Bayreuth, Germany

关键词: impedance spectroscopy;    mixed potential;    SnO₂;    Ga₂O₃;    Kelvin probe;    operando;   

DOI  :  10.3390/s90604323

来源: mdpi

【 摘 要 】

This status report overviews activities of the German gas sensor research community. It highlights recent progress in the field of potentiometric, amperometric, conductometric, impedimetric, and field effect-based gas sensors. It is shown that besides step-by-step improvements of conventional principles, e.g. by the application of novel materials, novel principles turned out to enable new markets. In the field of mixed potential gas sensors, novel materials allow for selective detection of combustion exhaust components. The same goal can be reached by using zeolites for impedimetric gas sensors. Operando spectroscopy is a powerful tool to learn about the mechanisms in n-type and in p-type conductometric sensors and to design knowledge-based improved sensor devices. Novel deposition methods are applied to gain direct access to the material morphology as well as to obtain dense thick metal oxide films without high temperature steps. Since conductometric and impedimetric sensors have the disadvantage that a current has to pass the gas sensitive film, film morphology, electrode materials, and geometrical issues affect the sensor signal. Therefore, one tries to measure directly the Fermi level position either by measuring the gas-dependent Seebeck coefficient at high temperatures or at room temperature by applying a modified miniaturized Kelvin probe method, where surface adsorption-based work function changes drive the drain-source current of a field effect transistor.

【 授权许可】

CC BY   
© 2009 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.