A study on thin film gas sensor based on SnO2 prepared by pulsed laser deposition method

SnO2 thin films were fabricated by pulsed laser deposition (PLD) technique using Sn metallic target under ambient O2 gas. X-ray diffraction (XRD) and atomic force microscopy (AFM) were used to investigate the morphology and structure of the films. From a study of the gas sensing characteristics of SnO2 films, it was evident that if the shorter wavelength of the laser beam was used for film deposition, the better sample was obtained. The sample, heated to 375°C during ablation and post-annealed at 500°C for 4 h, showed higher sensitivity compared to sample which was not heated. It can be explained, that the substrate heating is needed to compensate the kinetic energy of particles in laser plasma decreased due to loose-focusing.