Electronic and optical properties of TaO1-xN1+x-based alloys

Nabil Al-Aqtash, Florin Apostol, Wai Ning Mei, Renat F. Sabirianov

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

TaON is considered as a potential candidate as a visible-light responsive photocatalyst. We report the results of ab initio studies of electronic structure of TaON-based alloys. Specifically, we show that the position of conduction and valence band can be modified by varying the oxygen and nitrogen concentrations in TaO1-xN1+x. We find that the band gap decreases monotonically with the increase of N/O ratio. The band gap energy is decreased in monoclinic TaON from near 2.3 eV to just over 1.7 eV (i.e., by 35%) when N/O ratio is increased from 3/5 to 5/3. Our calculations show that the band gap reduces in a series of experimentally fabricated alloys ZrTa 3O5N3→TaON→YTa7O 7N8. The band gap reduction is mostly associated with the change in the position of the valence band due to the hybridization of N 2p states, while the conduction band consisting mostly of Ta 5d-states is not sensitive to N content. The calculated optical absorption spectra show reduction in the optical band gap with increasing N/O ratio.

Original languageEnglish (US)
Pages (from-to)337-343
Number of pages7
JournalJournal of Solid State Chemistry
Volume198
DOIs
StatePublished - Feb 1 2013

Fingerprint

Electronic properties
Energy gap
Optical properties
optical properties
Valence bands
Conduction bands
electronics
Optical band gaps
Photocatalysts
conduction bands
Light absorption
Electronic structure
Absorption spectra
Nitrogen
valence
Oxygen
optical spectrum
optical absorption
electronic structure
absorption spectra

Keywords

  • First-principles calculations on the electronic and optical properties
  • TaON-based alloys
  • Visible-light responsive photocatalyst

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

Cite this

Electronic and optical properties of TaO1-xN1+x-based alloys. / Al-Aqtash, Nabil; Apostol, Florin; Mei, Wai Ning; Sabirianov, Renat F.

In: Journal of Solid State Chemistry, Vol. 198, 01.02.2013, p. 337-343.

Research output: Contribution to journalArticle

Al-Aqtash, Nabil ; Apostol, Florin ; Mei, Wai Ning ; Sabirianov, Renat F. / Electronic and optical properties of TaO1-xN1+x-based alloys. In: Journal of Solid State Chemistry. 2013 ; Vol. 198. pp. 337-343.
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