Massive band gap variation in layered oxides through cation ordering

Prasanna V. Balachandran, James M. Rondinelli*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

20 Scopus citations

Abstract

The electronic band gap is a fundamental material parameter requiring control for light harvesting, conversion and transport technologies, including photovoltaics, lasers and sensors. Although traditional methods to tune band gaps rely on chemical alloying, quantum size effects, lattice mismatch or superlattice formation, the spectral variation is often limited to <1eV, unless marked changes to composition or structure occur. Here we report large band gap changes of up to 200% or ∼2eV without modifying chemical composition or use of epitaxial strain in the LaSrAlO4 Ruddlesden-Popper oxide. First-principles calculations show that ordering electrically charged [LaO]1+ and neutral [SrO]0 monoxide planes imposes internal electric fields in the layered oxides. These fields drive local atomic displacements and bond distortions that control the energy levels at the valence and conduction band edges, providing a path towards electronic structure engineering in complex oxides.

Original languageEnglish (US)
Article number6191
JournalNature communications
Volume6
DOIs
StatePublished - Jan 30 2015

ASJC Scopus subject areas

  • Chemistry(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Physics and Astronomy(all)

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