In2O3 films deposited by spray pyrolysis as a material for ozone gas sensors

The correlation between technological modes of In2O3 film deposition by spray pyrolysis and gas response to ozone is discussed in this report. In2O3 films were deposited from InCl3-water solution (T-pyr = 300-550 degreesC). It is shown that grain size, porosity, and film stoichiometry are the main factors controlling gas sensing characteristics of In2O3 films. Porous films with minimal grain sizes and maximal deviation from stoichiometry have both maximal gas response to ozone, and minimal response time. For films with optimal structure, the gas response to ozone (Rozone/Rair) reaches a value of similar to10(3) to 10(4). Recommendations are made for optimizing the method of In2O3 film deposition to achieve optimal gas response to ozone. (C) 2003 Elsevier B.V. All rights reserved.