First principles calculations of the band offset at SrTiO3-TiO2 interfaces

We report on first principles calculations of the properties of the epitaxial SrTiO3 - TiO2 (anatase) heterojunction, with an emphasis on the electronic band profile and lineup at the interface. The valence and conduction band offsets are calculated as a function of the number of anatase layers deposited onto the SrTiO3, as well as of the position of an oxygen vacancy with respect to the interface. It is shown that the presence of oxygen vacancies in the SrTiO3 is a way to effectively lower the barrier heights at the interface. Our results are in agreement with recent experiments reporting nearly zero band offset. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4757281]