Atomic and electronic structures of lattice mismatched Cu{sub 2}O/TiO{sub 2} interfaces
- Materials Sciences Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Mail Stop 66, Berkeley, California 94720 (United States)
- Department of Materials Science and Engineering, University of California at Berkeley, Berkeley, California 94720 (United States)
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)
Heterojunction interfaces between metal oxides are often highly lattice mismatched. The atomic and electronic structures of such interfaces, however, are not well understood. We have synthesized Cu{sub 2}O/TiO{sub 2} heterojunction thin films with 13% lattice mismatch and studied the interface via experimental methods and large-scale density function theory calculations of supercells containing ∼1300 atoms. We find that an interface of epitaxial quality is formed via a coincidence site lattice of 8 Cu{sub 2}O unit cells matching 9 TiO{sub 2} unit cells. Calculations reveal the existence of a dislocation core of the O sublattices at the interface and a random arrangement of one layer of interfacial Cu atoms. The interfacial electronic structure is found to be mostly determined by the interfacial Cu distribution, rather than by the O dislocation core. The conduction band minimum and valence band maximum states are spatially separated, and there is no strongly localized state near the core.
- OSTI ID:
- 22300113
- Journal Information:
- Applied Physics Letters, Vol. 104, Issue 21; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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