Nature of Gas Sensitivity in Nanocrystalline Metal Oxides

Problems associated with developing gas-sensitive inorganic materials are discussed. The principle of operation of a semiconductor gas sensor of resistive type is considered, and main band structure parameters sensitive to the gas phase composition are determined. Ways to solve the problem of selectivity of semiconducting oxides are discussed. The influence of microstructure, dopants, and analysis temperature is looked into on the basis of experimental results obtained in studying nanocrystalline tin dioxide and zinc oxide. Prospects for use of systems based on two or more nanocrystalline oxides (nanocomposites) are considered.