Effects of Surface Modification on the Recovery Time and Stability of Nanostructured Tin Oxide Thick Films Gas Sensors

Along with high sensitivity in detecting gas, the response and recovery times of semiconductor gas sensors are of considerable importance for real life applications. In most cases, the recovery time is more than the response time. At the same time, water vapor present in the ambient, is chemisorbed on the tin oxide, SnO2 surface and the water molecules dissociate into hydroxyl species, which act as electron donors. In this research , we find that if the interference of absorbed moisture can be reduced by surface treatment with thiourea diluted solution, the recovery time and stability of tin oxide sensors improves, which makes them suitable in real life applications.