The SrTiO3/BiFeO3 (001) interface: commutativity of energy band discontinuities

The interface formation between the perovskite oxides SrTiO _3 and BiFeO _3 was studied using in situ photoelectron spectroscopy by depositing BiFeO _3 on SrTiO _3 and vice versa via pulsed laser deposition. For the interfaces characterized, a type II band alignment with a valence band offset of 0.9–1.0 eV and a conduction band offset of 0.5–0.6 eV was observed. Within the margin of error the commutativity was fulfilled for the SrTiO _3 /BiFeO _3 interface, meaning that the band alignment does not depend on the deposition sequence.