| AVS 55th International Symposium & Exhibition | |
| Energy Science and Technology Focus Topic | Tuesday Sessions |
| Session EN-TuP |
| Session: | Energy Focus Topic Poster Session |
| Presenter: | S. Gupta, Portland State University |
| Authors: | S. Gupta, Portland State University S.V.N.T. Kuchibhata, Pacific Northwest National Laboratory M.H. Engelhard, Pacific Northwest National Laboratory P. Nachimuthu, Pacific Northwest National Laboratory V. Shutthanandan, Pacific Northwest National Laboratory L.V. Saraf, Pacific Northwest National Laboratory S. Thevuthasan, Pacific Northwest National Laboratory S. Prasad, Portland State University |
| Correspondent: | Click to Email |
Oxygen sensors have come into wide use in automotive and industrial applications as leak detectors, industrial process flow evaluators, as well as in life science industry in diagnostic applications such as respiratory vital signs monitoring, and metabolic rate monitoring. All these applications require the fast monitoring of the oxygen gas. Hence we have explored the possibilities to develop an oxygen sensor operating on the chemiresistive principle at aggressive environments with a reduced response time. Ceria is known for its unique ability to lose or gain oxygen based on the ambient environment. The doping of trivalent elements including Y, Sm and Gd in ceria is expected to create oxygen vacancies and eventually influence virtually all types of transport properties like ionic and electronic properties. The overarching objective of this project is to study the effects of changes in surrounding conditions such as temperature, pressure, dopant concentration on the transport properties of doped ceria films. High quality, epitaxial, pure and doped ceria thin films were grown on sapphire (0001) substrates using oxygen plasma assisted molecular beam epitaxy (OPA-MBE) and characterized them using several bulk and surface sensitive techniques. Conductivity in these films was measured as a function of temperature (room temperature to 700C) under various oxygen partial pressure (1 torr to 100 torr) and vacuum conditions. Preliminary results show that response of the doped ceria film is much faster than the pure ceria films under the same conditions of temperature and pressure. Moreover response time of these films is few milliseconds with the change in the oxygen partial pressure. It was observed that the samarium concentration of approximately 4-6 atom% is the optimum doping content.