High-speed hydrogen sensor fabricated using a platinum/titanium oxide nanocontact

Titanium dioxide (TiO2) thin films have been extensively studied for use in solid-state hydrogen (H2) gas sensors. In this work, TiOx/platinum (Pt) nanocontacts which constitute a Schottky-diode sensor were developed using shadow evaporation. Large resistance changes and short reaction times were achieved through measurement of the resistance of the contacts. The sensing was quite depended on the thickness of the TiOx layer. The results indicate that the large sensor response over 105 was achieved just neighboring outermost surfaces of TiOx layer. As this sensor can be fabricated at temperatures less than 400 K, it is expected to be applicable to on-tip sensors.