Properties of self-oxidized single crystalline perovskite N : BaTiO$_3$ oxynitride epitaxial thin films

International audienceEpitaxial perovskite self-oxidized oxynitride N : BaTiO$_3$thin films, deposited on 1% Nb-doped SrTiO$_3$(001) single crystals, were obtained by atomic nitrogen assisted molecular beam epitaxy without supplying additional oxygen gas. Their growth, crystalline and electronic structures as well as photo-electrochemical and optical properties were investigated and compared to those of pure BaTiO$_3$ films grown with atomic oxygen on the same substrate. More tetragonal perovskite crystalline structures, profound electronic structure modifications, improved photo-electrochemical properties and an enhanced (almost 10%) optical window for light absorption are demonstrated. This new class of compounds shows promise for a large panel of new applications based on visible light absorption