SrTiO3/Si(001) epitaxial interface:: A density functional theory study -: art. no. 165319

The Sr and SrO monolayers on Si(001) and the SrTiO3/Si(001) interface have been simulated by means of total energy minimization within the density functional theory formalism and the generalized gradient approximation form of exchange-correlation potential. It has been found that the first SrO layer restores a 1x1 structure of the substrate thus providing a template for subsequent epitaxy of the SrTiO3 layers. The calculated densities of states are in good agreement with recent x-ray and ultraviolet photoemission valence band spectra. The role of the buffer layer in forming the electronic structure is discussed and illustrated with an example of SrO monolayer at the SrTiO3/Si(001) interface.