Transduction in Semiconducting Metal Oxide Based Gas Sensors - Implications of the Conduction Mechanism

For chemoresistive sensors based on semiconducting metal oxides the conduction mechanism in the sensing layer has a very large impact on the magnitude and even on the direction of the sensor signal. That means that for very similar surface reactivity (reception function) the translation of the surface charge transfer processes into sensor resistance changes (transduction function) can be very different. This idea is illustrated with the example of the different sensor signals for different conduction types, n and p and with the example of the change of sensor signal direction determined by the change of the conduction type under various ambient atmospheres.