MICROSTRUCTURE AND MORPHOLOGY OF TIN DIOXIDE MULTILAYER THIN-FILM GASSENSORS

Structural, morphological, and electrical measurements have been carri ed out on SnO2 multilayer thin film grown by the rheotaxial growth and thermal oxidation method on Al2O3 substrates. The analysis of X-ray a nd electron diffraction patterns shows that, in addition to the SnO2 c assiterite phase, a contribution from another SnO2 phase is present, w hich can be related to cassiterite by introducing microtwinning effect s. The electrical measurements show that these thin films have a highe r sensitivity towards CO with respect to the conventional single layer SnO2 sensors. (C) 1997 Elsevier Science S.A.