Strain-induced electronic phase transition and strong enhancement of thermopower of TiS2

Atanu Samanta, Tribhuwan Pandey, Abhishek K. Singh

Research output: Contribution to journalArticlepeer-review

31 Scopus citations

Abstract

Using first-principles density functional theory calculations, we show a semimetal to semiconducting electronic phase transition for bulk TiS2 by applying uniform biaxial tensile strain. This electronic phase transition is triggered by charge transfer from Ti to S, which eventually reduces the overlap between Ti-(d) and S-(p) orbitals. The electronic transport calculations show a large anisotropy in electrical conductivity and thermopower, which is due to the difference in the effective masses along the in-plane and out-of-plane directions. Strain-induced opening of band gap together with changes in dispersion of bands lead to threefold enhancement in thermopower for both p- and n-type TiS2. We further demonstrate that the uniform tensile strain, which enhances the thermoelectric performance, can be achieved by doping TiS2 with larger iso-electronic elements such as Zr or Hf at Ti sites.

Original languageEnglish
Article number174301
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume90
Issue number17
DOIs
StatePublished - 3 Nov 2014
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2014 American Physical Society.

Fingerprint

Dive into the research topics of 'Strain-induced electronic phase transition and strong enhancement of thermopower of TiS2'. Together they form a unique fingerprint.

Cite this