Sensing properties of gold contact in diode type gas sensors

S. Rahbarpour

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URL :   http://research.shahed.ac.ir/WSR/WebPages/Report/PaperView.aspx?PaperID=85488
Date :  2017/12/01
Publish in :     Journal of Physics: Conference Series
DOI :  https://doi.org/10.1088/1742-6596/939/1/012033
Link :  http://dx.doi.org/10.1088/1742-6596/939/1/012033
Keywords :Sensing, sensors

Abstract :

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Gold nanoparticles have been increasingly used as catalytic material since 1997, when their chemical activity was discovered. Here, chemical activity of gold contacts in Au-TiO2-Ti structures is reported and verified experimentally. Diode type Au-TiO2-Ti structures was fabricated by Au deposition on thermally oxidized titanium film. The samples demonstrated I-V characteristics of a typical Schottky diode at operated temperatures up to 400°C, the highest examined temperature. The Schottky barrier height (SBH) of different fabricated Au-TiO2 junctions was measured. It was shown that the measured SBHs depended strongly on the temperature and particle size of utilized gold contacts and could vary in the range of 1 to 1.8 eV. The hydrogen sensing properties of the samples were also investigated. The samples demonstrated high sensitivity to hydrogen; 1 Vol% of hydrogen in air could increase the reverse current of the diodes ~1000 times. The results are described based on the reactions taking place at the Au/TiO2 interface.