Fast response thin film SnO2 gas sensors operating at room temperature

SnO2 thin film gas sensors operating at room temperature were prepared with SnCl4 as the starting material. The gas sensing characteristics of the sensors towards methyl alcohol vapor were investigated. The sensors exhibit ultra-fast and reversible electrical response (t90% ∼5 s for response and ∼1 s for recovery) at room temperature. In addition, the electrical responses are reproducible during cycling tests. The particle size of the hydrolyzed SnCl4 affects the sensitivity of the sensors, but does not have much effect on their response time. The sensors show different electrical response in the detection of the vapors of methyl, ethyl, isopropyl and butyl alcohol at room temperature, which is proposed to be related to the variation in the reducing ability of the alcohols with a different number of methyl groups.