InN growth on BaTiO3 (111) substrates: A first-principles study

The surface stability of the polar (111) BaTiO3 surfaces is systematically studied by first-principle calculations. Surface energy and atomic relaxation have been calculated for BaO3 and Ti polar terminations in perovskite BaTiO3 ceramics. The specific adsorption sites at the initial growth stage and the atomic structure of InN on the BaTiO3 (111) substrate have been systematically investigated. The In adsorption atoms are more favorable than the N atoms for the BaTiO3 (111) surface. The energetically favorable In/BaO3 interface is pointed out among the atomic arrangements of the InN/BaTiO3 (111) interfaces. Oxygen vacancies in the first layer of the BaO3-terminated BaTiO3 substrate induce the occupied defect states of In 5s5p character at the energetically favorable In/BaO3 interface.