Application of a semiconductor sol-gel sensor array to the discrimination of pollutants in air

Pure and Pd, Pt and Os activated tin oxide thin films have been prepared by the sol-gel process. The physical properties have been investigated by var ious techniques such as Fourier transform infrared (FTIR), X-ray diffractio n (XRD) and scanning electron microscopy (SEM) to obtain information on che mical, structural and morphological composition of the layers. In particula r microstructure and morphology has been shown to be dependent on the prese nce of the doping element. Integrated gas micro-sensors were obtained that showed the different sensing characteristics depending also on doping eleme nts. PCA analysis was performed on an array consisting of the prepared sens ors and the results have shown the capability to discriminate different air pollutants. (C) 2001 Elsevier Science B.V. All rights reserved.