Highly sensitive ethanol sensors based on {100}-bounded In2O3 nanocrystals due to face contact

The authors report the fabrication and characterization of ethanol sensors with extremely high sensitivity using In2O3 nanocrystals bounded by {100} facets as the sensing materials. The sensitivity of the sensors is about 10to1ppm ethanol, and increases nearly linearly up to about 200 as the ethanol concentration is raised to 100ppm. In the sensing film, the nanocrystals contact each other mainly through face contacts, most of which contribute to the gas sensing. This is the basis for the highly sensitive ethanol sensing.