Enhanced optical absorption due to symmetry breaking in TiO 2(1-x)S2x alloys

André Schleife, Patrick Rinke, Friedhelm Bechstedt, Chris G. Van De Walle

Research output: Contribution to journalArticlepeer-review

Abstract

Titania (TiO2) is frequently used in photovoltaic and photocatalytic applications, despite the fact that its main optical absorption occurs only at ∼4 eV. Absorption across the band gap of 3 eV is dipole-forbidden in rutile TiO2. By means of first-principles theoretical spectroscopy calculations, we demonstrate that alloying with TiS2 introduces an absorption band into the fundamental gap of TiO2. In addition, band-edge transitions contribute to optical absorption because the S incorporation breaks the symmetry of the TiO 2 lattice. Both effects lead to pronounced absorption of visible light for S concentrations as low as 1.5%.

Original languageEnglish (US)
Pages (from-to)4189-4193
Number of pages5
JournalJournal of Physical Chemistry C
Volume117
Issue number8
DOIs
StatePublished - Feb 28 2013
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Energy(all)
  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films

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