CNT Sensors for Detecting Gases with Low Adsorption Energy by Ionization

In case of typical chemical gas sensors reacted by gas adsorption on surface of an active layer, it is difficult to detect some gases which have low chemical adsorption energy like inert gases. In this paper, we report a gas sensor using carbon nanotube(CNT) array as electron emitters for the purpose of detecting these gases. Specifically, sensors were fabricated with applications of glass patterning by a sand-blast process and of anodic bonding between glass and silicon to improve the compactness of the structure and the reliability in process. The proposed sensor, based on an electrical discharge theory known as Paschen's law, worked by figuring the changes of dark discharge current and initial breakdown voltage depending on the concentration and the identity of gases. In this work, air and Ar gases were examined and discussed.