Atomic structure analysis of heavily hole doped LaCuOSe:Mg/MgO epitaxial thin film

Abstract

We have made cross-sectional TEM observations of p-type wide gap semiconductor LaCuOSe:Mg thin film grown by the reactive solid phase epitaxy method on magnesium oxide substrate. We confirmed epitaxial relationship between the film and the substrate from the electron diffraction. Layered structure of the compound, which is composed of alternate stacking of La-O and Cu-Se layers, was directly observed by HAADF-STEM images. At the film/substrate interface, a peculiar atomic structure which is different from the bulk compound was observed.