Low-temperature-operated sensitive NO2 gas sensors based on p-type SnO thin-film and thin-film transistors

초록

We demonstrated a p-type MOS-based thin-film transistor (TNT) nitrogen dioxide (NO2) gas sensor that uses tin monoxide (SnO) for both the channel and sensing layers. The fabricated SnO TFT showed a maximum response value of 19.4-10 ppm NO2 at mom temperature (RT) when operated in the subthreshold region, which was significantly higher than the maximum response value of 2.8-10 ppm NO2 obtained with a SnO thin-film chemiresistor at RT. In addition, the SnO TFT gas sensor showed significantly higher sensitivity to NO2 gas than to other target gases such as NH3, H2S, CO2 , and CO at RT. To our knowledge, this is the first report on a p-type MOS-based field-effect transistor-type gas sensor. Our experimental results demonstrate that the p-type SnO TFT is a promising gas sensor that can operate at RT with high sensitivity and selectivity to NO2 gas.

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