Mixed-potential sensors modeling

Garzon, R., Mukundan, R. and Brosha, E.L. (2001) Modeling the response of mixed potential electrochemical sensors. Proceedings of the Electrochemical Society, 2000-32 Solid-State Ionic Devices II Ceramic Sensors, The Electrochemical Society, Pennington, New Jersey, pp. 305-13. 

Taking into account the results obtained by the different research groups, it can be concluded that the sensing mechanism of the solid electrolyte NO sensor with the oxide-SE is based on the mixed-potential model under the coexistence of NO,j and O2. This mechanism is rather complex, and the NO2 sensitivity can be indirectly determined by the following factors [50] ... 

A mixed ion conductor, BaSnO, has also been tested as a contact layer on a Schottky sensor [90]. The BaSnOj/SiC sensor showed a response to oxygen and this was most pronounced at 400°C. The sensor was tested from 200°C to 700°C. Operated at 700°C, the sensor showed a negative resistance peak at a bias of 2V (Figure 2.8). This peak was accounted for by the tunneling or Esaki effect [91]. Up to an operation temperature of 400°C, thermionic emission was proposed to explain its behavior. At higher temperatures, a resistance connected in series with a Schottky diode can model the device [5, 73]. At temperatures of 500-600°C, the BaSn03 shows a mixed behavior of electronic and ion conduction, and the Nernst potential [92] can be added to the model. The complete proposed model is given in (2.9). 

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