P2GS.21 - Bulk Gold/Bulk Rutile/Bulk Gold Sturdy Structure Resistive Gas Sensor for Exhaust Monitoring
- 17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
- P-2 - Gas Sensors
- N. Dehghani, E. Yousefiazari, S. Aghili - Electronic Materials Laboratory, Electrical Engineering Department, K. N. Toosi University of Technology, Tehran (Iran)
- 807 - 808
A miniature, but sturdy, gas sensor capable of operation at temperatures as high as 600 ºC is presented. The device comprises two back-to-back connected gold/rutile Schottky diodes, which are fabricated on the opposite bases of a self-standing pellet of polycrystalline rutile. The rutile layer is formed by the direct oxidation of titanium metal in air at 900 ºC, and the Au/rutile contacts are formed by the diffusion bonding of the gold wire segments to the pellet bases. The current vs. voltage diagrams of the Au/rutile/Au structured device are recorded at different operating frequencies. The device current depends on the concentration of the oxygen vacancy at the Au/rutile interface and, hence, on the composition of the surrounding atmosphere. The current increases 15 times in response to the presence of 1000 ppm of ethanol vapor in air. Consisting only of bulk gold and bulk rutile, the device is resilient to harsh environments and elevated temperatures; a suitable gas sensor for in-exhaust installation.