Computational studies for the interpretation of gas response of SnO2(110) surface

Tin dioxide is a widely used material in gas sensing applications. This is partly due to its stable surface structure and high sensitivity to many gases. The interaction of different gas components with an oxide surface may lead to changes in the lattice oxygen content at the surface in addition to changes in the amount of adsorbed species. The electronic and atomic structures of the surface change with the changes in the lattice oxygen content. This leads to surface relaxation and changes in the surface dipole layer of the ionic surface in addition to changes in the Schottky barrier which is a result of the charge accumulation onto the surface from the bulk of the semiconducting oxide. Changes in both the dipole layer and the Schottky barrier change the work function of the semiconductor and may reflect in its electrical conductivity. Here we have used first-principles calculations based on LDA-SCF to study changes in the electronic and atomic structures of the SnO2(110) surface as a result of oxygen exchange between the lattice and the ambient gas. The transducer function relating the changes at the surface to the changes in the conductivity of a ceramic microstructure is also described by an example. (C) 2000 Elsevier Science B.V. All rights reserved.