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Title: Atomic and electronic structures of lattice mismatched Cu{sub 2}O/TiO{sub 2} interfaces

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.
Authors:
 [1] ; ;  [2] ; ;  [3] ; ;  [1] ;  [4]
  1. Materials Sciences Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Mail Stop 66, Berkeley, California 94720 (United States)
  2. Department of Materials Science and Engineering, University of California at Berkeley, Berkeley, California 94720 (United States)
  3. Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)
  4. (United States)
Publication Date:
OSTI Identifier:
22300113
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 21; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COPPER OXIDES; DENSITY; DISLOCATIONS; DISTRIBUTION; ELECTRONIC STRUCTURE; EPITAXY; HETEROJUNCTIONS; INTERFACES; METALS; RANDOMNESS; THIN FILMS; TITANIUM OXIDES