Multivalley Band Structure and Phonon-Glass Behavior of TlAgTe

Aamir Shafique, Sitansh Sharma, Muhammad Sajjad, Udo Schwingenschlögl

Research output: Journal PublicationArticlepeer-review

5 Citations (Scopus)


We show that the extraordinary crystal structure of TlAgTe results in a phonon-glass electron-crystal behavior. The material's electronic transport properties are evaluated by first-principles calculations and Boltzmann transport theory. We find a multivalley conduction band (n-doping) and low dispersion at the valence band edge (p-doping), which results in a high power factor. Since the mean free path of a large number of phonon modes is found to fall below the Ioffe-Regel limit, semiclassical Boltzmann transport theory cannot describe the phonon transport, but a two-channel model must be applied. The lattice thermal conductivity turns out to be as low as 0.43 W m-1 K-1 because of strong lattice anharmonicity (originating from Tl 6s2 lone pairs) and low group velocities (originating from loose bonding of the Tl atoms), which renders TlAgTe to be a highly promising thermoelectric material.

Original languageEnglish
Pages (from-to)2174-2180
Number of pages7
JournalACS Applied Energy Materials
Issue number3
Publication statusPublished - 22 Mar 2021
Externally publishedYes


  • Boltzmann
  • electron-crystal
  • first-principles
  • phonon-glass
  • thermoelectricity

ASJC Scopus subject areas

  • Chemical Engineering (miscellaneous)
  • Energy Engineering and Power Technology
  • Electrochemistry
  • Electrical and Electronic Engineering
  • Materials Chemistry


Dive into the research topics of 'Multivalley Band Structure and Phonon-Glass Behavior of TlAgTe'. Together they form a unique fingerprint.

Cite this