Performance evaluation of an oxygen sensor as a function of the Samaria doped ceria film thickness

Rahul P. Sanghavi, M. Nandasiri, S. Kuchibhatla, P. Nachimuthu, M. H. Engelhard, V. Shutthanandan, W. Jiang, S. Thevuthasan, A. Kayani, S. Prasad

    Research output: Chapter in Book/Report/Conference proceedingConference contribution


    The current demand in the automobile industry is in the control of air-fuel mixture in the combustion engine of automobiles. Oxygen partial pressure can be used as an input parameter for regulating or controlling systems in order to optimize the combustion process. Our goal is to identify and optimize the material system that would potentially function as the active sensing material for such a device that monitors oxygen partial pressure in these systems. We have used thin film Samaria doped ceria (SDC) as the sensing material for the sensor operation, exploiting the fact that at high temperatures, oxygen vacancies generated due to samarium doping act as conducting medium for oxygen ions which hop through the vacancies from one side to the other contributing to an electrical signal. We have recently established that 6 atom % Sm doping in ceria films has optimum conductivity. Based on this observation, we have studied the variation in the overall conductivity of 6 atom % Samaria doped ceria thin films as a function of thickness in the range of 50 nm to 300 nm at a fixed bias voltage of 2 volts. A direct proportionality in the increase in the overall conductivity is observed with the increase in sensing film thickness. For a range of oxygen pressure values from 0.001 Torr to 100 Torr, a tolerable hysteresis error, good dynamic response and a response time of less than 10 seconds was observed.

    Original languageEnglish
    Title of host publicationBusiness and Safety Issues in the Commercialization of Nanotechnology
    Number of pages6
    Publication statusPublished - 1 Jul 2010
    Event2009 MRS Fall Meeting - Boston, MA, United States
    Duration: 29 Nov 20092 Dec 2009

    Publication series

    NameMaterials Research Society Symposium Proceedings
    ISSN (Print)0272-9172


    Conference2009 MRS Fall Meeting
    CountryUnited States
    CityBoston, MA


    ASJC Scopus subject areas

    • Materials Science(all)
    • Condensed Matter Physics
    • Mechanics of Materials
    • Mechanical Engineering

    Cite this

    Sanghavi, R. P., Nandasiri, M., Kuchibhatla, S., Nachimuthu, P., Engelhard, M. H., Shutthanandan, V., Jiang, W., Thevuthasan, S., Kayani, A., & Prasad, S. (2010). Performance evaluation of an oxygen sensor as a function of the Samaria doped ceria film thickness. In Business and Safety Issues in the Commercialization of Nanotechnology (pp. 107-112). (Materials Research Society Symposium Proceedings; Vol. 1209).