5 years ago

Possible Mechanism for Hole Conductivity in Cu–As–Te Thermoelectric Glasses: A XANES and EXAFS Study

Possible Mechanism for Hole Conductivity in Cu–As–Te Thermoelectric Glasses: A XANES and EXAFS Study
Soraya Ababou-Girard, Bruno Bureau, Alain Gellé, Angela Trapananti, Catherine Boussard-Pledel, Shuo Cui, Sergio Di Matteo, Carmelo Prestipino, Bhuvanesh Srinivasan
Recently synthesized thermoelectric Cu–As–Te glasses have been analyzed by X-ray absorption spectroscopy, both near-edge (XANES) and in the extended region (EXAFS), in order to shed light on the mechanism at the basis of the huge increase of conductivity, up to 5 orders of magnitude, that was found with Cu doping. Experimental data have been modeled by means of multiple-scattering calculations. Our model suggests that the experimental results can be interpreted in terms of a small charge-transfer from Te to Cu, leading to an unexpected positive valence for Te. Interestingly, on the basis of these findings, a global picture explaining the enhancement of electrical conductivity with Cu doping can be proposed: electrical conductivity is determined by the holes created in nonbonding Te 5p orbitals (lone pair) by Cu acceptors. The critical parameter to increase electrical conductivity is the number of Cu–Te bonds that are formed and not simply the number of Cu atoms.

Publisher URL: http://dx.doi.org/10.1021/acs.jpcc.7b04555

DOI: 10.1021/acs.jpcc.7b04555

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.