Room temperature conductometric gas sensors based on metal oxide nanowires and nanocrystals

The conductometric response of metal oxide nanowires and nanocrystals to oxidizing molecules at room temperature and under UV illumination is studied. We demonstrate that UV illumination induces an electron-hole pair generation as well as a surface oxygen´s desorption leading to a reduced surface that is highly reactive to oxidizing species. Based on these mechanisms, we present room temperature conductometric sensors based on nanoparticles and nanowires. The electrical response of these devices under different illumination conditions is theoretically modeled and predicted. The interfering effect of other gases, such as humidity, is also analyzed.