INFLUENCE OF DOPANTS ON THE RESPONSE-TIME AND THE SIGNALS OF LAMBDA SENSORS BASED ON THIN-FILMS OF STRONTIUM-TITANATE

New sensors produced on the basis of oxygen-sensitive thin films of strontium titanate appear to allow cylinder-selective monitoring of the combustion of an Otto engine. Selective incorporation of dopants into the basic material permits the properties to be optimized with respect to special application effects. The incorporation of acceptors (e.g. Fe or Ga) into the sensitive material leads to a reduction of the sensor response time. If the basic material is doped with donors, the measurement sensitivity increases with respect to the lambda value.