Structure, microstructure and optical properties of Sn-doped ZnO thin films

N. Chahmat, T. Souier, A. Mokri, M. Bououdina, M. S. Aida, M. Ghers

Research output: Contribution to journalArticle

46 Citations (Scopus)

Abstract

Transparent and conductive Sn-ZnO films were successfully doped up to higher concentration of 10 wt% by spray pyrolysis on glass substrates. Structural, microstructural, and optical characterizations were carried out. All the films crystallise within the würtzite hexagonal structure, confirming successful Sn doping, but with different preferred orientation depending on Sn concentration. Despite these differences, the thin films show enhanced crystalline properties up to 8% of Sn, in agreement with SEM images that reveal grains with regular shape and sharp edges. In disagreements with reported data, the increase in Sn concentration improves the crystalline properties and increases the grain size, i.e. 20-200 nm. It is important to note that only at high doping level of 10%, the crystalline properties are slightly degraded. In line with this observation, the Urbach tail energy of 10% film reaches a value of 145 meV which is attributed to a disorder in the film structural and crystalline properties. Finally, the optical band gap was found to increase with increasing Sn up to 6% followed with a slight decrease at higher Sn concentration. The shift in the bad gap energy with Sn doping is discussed in terms of widening due to Burstein-Moss effect and narrowing due to many-body effect. It is found that 4% seems to be the optimal doping concentration for Sn-doped ZnO films, with enhanced crystalline and structural properties, and with a transmittance similar or even higher than un-doped ZnO film.

Original languageEnglish
Pages (from-to)148-153
Number of pages6
JournalJournal of Alloys and Compounds
Volume593
DOIs
Publication statusPublished - Apr 25 2014

Fingerprint

Optical properties
Thin films
Microstructure
Crystalline materials
Doping (additives)
Spray pyrolysis
Optical band gaps
Structural properties
Energy gap
Glass
Scanning electron microscopy
Substrates

Keywords

  • Optical band gap
  • Sn-doping
  • Spray pyrolysis
  • Transparent conductive oxide
  • ZnO thin films

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

Cite this

Structure, microstructure and optical properties of Sn-doped ZnO thin films. / Chahmat, N.; Souier, T.; Mokri, A.; Bououdina, M.; Aida, M. S.; Ghers, M.

In: Journal of Alloys and Compounds, Vol. 593, 25.04.2014, p. 148-153.

Research output: Contribution to journalArticle

Chahmat, N. ; Souier, T. ; Mokri, A. ; Bououdina, M. ; Aida, M. S. ; Ghers, M. / Structure, microstructure and optical properties of Sn-doped ZnO thin films. In: Journal of Alloys and Compounds. 2014 ; Vol. 593. pp. 148-153.
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