PNNL

Abstract

The Sr and SrO monolayers on Si(001) and the SrTiO3/Si(001) interface have been simulated by means of total energy minimization within DFT (Density Functional Theory) formalism and GGA (Generalized Gradient Approximation) form of exchange-correlation potential. It has been found that the first SrO layer restores a 1´1 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 XPS and UPS valence band spectra. The role of the “buffer layer” in forming electronic structure is discussed and illustrated with an example of SrO monolayer at the SrTiO3 – Si(001) interface.