Room temperature low level formaldehyde sensor using spray deposited cerium oxide thin film

Abstract

Deposition of nanostructured CeO2 thin film was done at 250 °C on glass substrates by homemade SP technique and the film was annealed at 350 °C in the sounding of air for 2 hrs. The structural properties of the samples were investigated by XRD to confirm the crystal structure as cubic. Optical property of annealed film was studied using UV–Visible Spectrometer to calculate the band gap. The sensing performances of the film formed with annealing (350 °C) of different formaldehyde concentrations in dry air at 32 °C were investigated. The sensing response of 0.033% is obtained for 0.5 ppm of HCHO with a quick response time of (46 s) and fast recovery time of (16 s). Sensing operation at low concentration level, detection at room temperature, stability, repeatability, fast response and recovery characteristics of the film within the cost effective formation supports the appropriate developing formaldehyde sensor.