Effect of poly ethylene glycol addition on the microstructure and sensor characteristics of SnO2 thin films prepared by sol–gel method

Effects of poly ethylene glycol (PEG) addition on the microstructure and CO sensing characteristics of SnO2 thin films prepared by sol–gel method were investigated. Microstructure of SnO2 thin film was drastically developed by the addition of PEG, indicating that the addition of PEG was effective to prevent the agglomeration of SnO2 particles. CO sensitivity of SnO2 thin films increased as PEG content increased, and drastically improved to 565 at operating temperature of 773 K. This result shows about 12 times larger than that of PEG-free SnO2 thin film (48). It is considered that the enhancement of the sensitivity was caused by high surface area of nano-sized SnO2 particles.