A Highly Sensitive and Fast-Responding SnO2 Sensor Fabricated by Combustion Chemical Vapor Deposition

Highly porous and nanostructured SnO2 thin-film gas sensors with Pt interdigitated electrodes have been fabricated via a combustion chemical vapor deposition process. The SnO2 films were less than 1 μm thick and consisted of nanocrystallines smaller than 30 nm. At 300 °C, the as-prepared SnO2 gas sensor showed a sensitivity of 1075 to 500 ppm ethanol vapor, and the corresponding response time and recovery time were 31 and 8 s, respectively. The extrapolated low detection limit appears to be below 1 ppm. Consequently, the as-fabricated sensor demonstrated significant improvements over those reported in the literature. These highly sensitive, fast-responding, and low-cost SnO2 sensors could have many practical applications.