One step toward a new generation of C-MOS compatible oxide p-n junctions: Structure of the LSMO/ZnO interface elucidated by an experimental and theoretical synergic work

Heterostructures formed by La0.7Sr0.3MnO3/ZnO (LSMO/ZnO) interfaces exhibit extremely interesting electronic properties making them promising candidatea for novel oxide p-n junctions with multifunctional features. In this work, the structure of the interface is studied through a combined experimental/theoretical approach, . Hetero-structures were grown epitaxially and homogeneously on 4" silicon wafers, characterized by advanced electron microscopy imaging and spectroscopy, and simulated by ab-initio DFT calculations. The simulation resultsuggest that the most stable interface configuration is composed by of the (001) face of LSMO, with LaO planes exposed, in contact with the (11-20) face of ZnO. The ab-initio predictions agree welly with experimental High Angle Annular Dark Field Scanning Transmission Electron Microscopy (HAADF-STEM) images and confirm the validity of the suggested structural model. Electron energy loss spectroscopy confirms the the atomic sharpness of the interface. From statistical parameter estimation theory, it has been found that the distances between interfacial planes are displaced from the respective ones of the bulk material. This can be ascribed to the strain induced by the mismatch between the lattices of the two materials employed.