Local Structure Studies of As-Made Cu2ZnSnS4 Nanoparticles

Local Structure Studies of As-Made Cu2ZnSnS4 Nanoparticles Though Cu2ZnSnS4 (CZTS) is a promising material for thin-film solar cells, a significant challenge remains in understanding the structures being formed, particularly in nonstoichiometric materials. We use the extended x-ray absorption fine-structure technique to study the local structure and stoichiometry of as-made, Cu-deficient CZTS nanoparticles and present K-edge data and fits for each of the cations (Cu, Zn, and Sn). The data show that all of the metal-S (M-S) pairs have the bond lengths of the kesterite structure within 0.02 Å, and the pair distribution function is very narrow (σ∼0.07  Å). These results preclude significant fractions of other phases with different M-S bond lengths. The data also reveal some Sn second neighbors around Sn, whereas there are none in the stoichiometric kesterite (or stannite) structure. Consequently, Sn antisite defects must be present on Cu or Zn sites; this is not surprising since there is some excess of Sn. More importantly, the second-neighbor Sn-Sn distance is significantly longer than other M-M distances, and the antisite Sn defects must therefore introduce significant disorder within the Cu and Zn sublattices. The largest distortions are found around Cu and are modeled using a strongly broadened (or split) peak distribution for the Cu-Cu/Zn pairs. We also find that excess Zn does not occupy Cu sites but instead, goes onto Sn sites. The samples are best described as a kesterite structure with significant antisite disorder. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Physical Review Applied American Physical Society (APS)

Local Structure Studies of As-Made Cu2ZnSnS4 Nanoparticles

Preview Only

Local Structure Studies of As-Made Cu2ZnSnS4 Nanoparticles

Abstract

Though Cu2ZnSnS4 (CZTS) is a promising material for thin-film solar cells, a significant challenge remains in understanding the structures being formed, particularly in nonstoichiometric materials. We use the extended x-ray absorption fine-structure technique to study the local structure and stoichiometry of as-made, Cu-deficient CZTS nanoparticles and present K-edge data and fits for each of the cations (Cu, Zn, and Sn). The data show that all of the metal-S (M-S) pairs have the bond lengths of the kesterite structure within 0.02 Å, and the pair distribution function is very narrow (σ∼0.07  Å). These results preclude significant fractions of other phases with different M-S bond lengths. The data also reveal some Sn second neighbors around Sn, whereas there are none in the stoichiometric kesterite (or stannite) structure. Consequently, Sn antisite defects must be present on Cu or Zn sites; this is not surprising since there is some excess of Sn. More importantly, the second-neighbor Sn-Sn distance is significantly longer than other M-M distances, and the antisite Sn defects must therefore introduce significant disorder within the Cu and Zn sublattices. The largest distortions are found around Cu and are modeled using a strongly broadened (or split) peak distribution for the Cu-Cu/Zn pairs. We also find that excess Zn does not occupy Cu sites but instead, goes onto Sn sites. The samples are best described as a kesterite structure with significant antisite disorder.
Loading next page...
 
/lp/aps_physical/local-structure-studies-of-as-made-cu2znsns4-nanoparticles-eHJgeNNSAF
Publisher
The American Physical Society
Copyright
Copyright © © 2017 American Physical Society
eISSN
2331-7019
D.O.I.
10.1103/PhysRevApplied.7.064026
Publisher site
See Article on Publisher Site

Abstract

Though Cu2ZnSnS4 (CZTS) is a promising material for thin-film solar cells, a significant challenge remains in understanding the structures being formed, particularly in nonstoichiometric materials. We use the extended x-ray absorption fine-structure technique to study the local structure and stoichiometry of as-made, Cu-deficient CZTS nanoparticles and present K-edge data and fits for each of the cations (Cu, Zn, and Sn). The data show that all of the metal-S (M-S) pairs have the bond lengths of the kesterite structure within 0.02 Å, and the pair distribution function is very narrow (σ∼0.07  Å). These results preclude significant fractions of other phases with different M-S bond lengths. The data also reveal some Sn second neighbors around Sn, whereas there are none in the stoichiometric kesterite (or stannite) structure. Consequently, Sn antisite defects must be present on Cu or Zn sites; this is not surprising since there is some excess of Sn. More importantly, the second-neighbor Sn-Sn distance is significantly longer than other M-M distances, and the antisite Sn defects must therefore introduce significant disorder within the Cu and Zn sublattices. The largest distortions are found around Cu and are modeled using a strongly broadened (or split) peak distribution for the Cu-Cu/Zn pairs. We also find that excess Zn does not occupy Cu sites but instead, goes onto Sn sites. The samples are best described as a kesterite structure with significant antisite disorder.

Journal

Physical Review AppliedAmerican Physical Society (APS)

Published: Jun 1, 2017

There are no references for this article.

Sorry, we don’t have permission to share this article on DeepDyve,
but here are related articles that you can start reading right now:

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches

$49/month

Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.

$588

$360/year

billed annually
Start Free Trial

14-day Free Trial