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Title: Tuning the electronic structure of SrTiO{sub 3}/SrFeO{sub 3−x} superlattices via composition and vacancy control

Using density functional theory-based calculations, we explore the effects of oxygen vacancies and epitaxial layering on the atomic, magnetic, and electronic structure of (SrTiO{sub 3}){sub n}(SrFeO{sub 3−x}){sub 1} superlattices. While structures without oxygen vacancies (x = 0) possess small or non-existent band gaps and ferromagnetic ordering in their iron layers, those with large vacancy concentrations (x = 0.5) have much larger gaps and antiferromagnetic ordering. Though the computed gaps depend numerically on the delicate energetic balance of vacancy ordering and on the value of Hubbard U{sub eff} used in the calculations, we demonstrate that changes in layering can tune the band gaps of these superlattices below that of SrTiO{sub 3} (3.2 eV) by raising their valence band maxima. This suggests the possibility that these superlattices could absorb in the solar spectrum, and could serve as water-splitting photocatalysts.
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [2]
  1. Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
22269599
Resource Type:
Journal Article
Resource Relation:
Journal Name: APL Materials; Journal Volume: 2; Journal Issue: 4; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ANTIFERROMAGNETISM; CONTROL; DENSITY FUNCTIONAL METHOD; ELECTRONIC STRUCTURE; EPITAXY; FERRITES; LAYERS; OXYGEN; SPECTRA; STRONTIUM TITANATES; SUPERLATTICES; VACANCIES