Dual Mechanism of Indium Incorporation into TiO2 (Rutile)

This work considers the effect of indium on defect disorder and semiconducting properties of TiO2 (rutile). It is shown that the electrical conductivity and thermoelectric power data of indium-doped TiO2 can be best described by a dual mechanism of indium incorporation into the TiO2 lattice, including both the titanium sites, leading to the formation of acceptors and interstitial sites, leading to the formation of donors. The concentration ratio of these defects depends on the distance from the surface. The proposed defect disorder model of In-doped TiO2 is considered in terms of the surface layer enriched predominantly in indium located in interstitial sites and the bulk phase involving mainly indium located in the titanium sublattice.