Influence of chemical composition and structural factors of Fe2O3/In2O3 sensors on their selectivity and sensitivity to ethanol

The influence of structure, phase composition, system dispersity and particle morphology of Fe2O3- and In2O3-based thin film layers on the electrical parameters of the corresponding gas sensors was studied in this paper. High selectivity and sensitivity of heterostructural gamma-Fe2O3/In2O3 thin film sensors in the detection of alcohols has been here established. As it was found, the above mentioned sensors are almost insensitive to NO2, O-3, CO and CH4 at the operating temperature which is optimal for alcohol detection (300 degreesC). The peculiarities of sensor behaviour are discussed taking into account the activity of Fe2O3 layers in the reductive-oxidative and acid-base processes accompanying the adsorption of CH3OH and C2H5OH molecules at the oxide surface. (C) 2003 Elsevier B.V. All rights reserved.