Extreme In-Plane Thermal Conductivity Anisotropy in Titanium Trisulfide Caused by Heat-Carrying Optical Phonons

Huili Liu, Xiaoxia Yu, Kedi Wu, Yang Gao, Sefaattin Tongay, Ali Javey, Lidong Chen, Jiawang Hong, Junqiao Wu

Research output: Contribution to journalArticle

Abstract

High in-plane anisotropies arise in layered materials with large structural difference along different in-plane directions. We report an extreme case in layered TiS3, which features tightly bonded atomic chains along the b-axis direction, held together by weaker, interchain bonding along the a-axis direction. Experiments show thermal conductivity along the chain twice as high as between the chain, an in-plane anisotropy higher than any other layered materials measured to date. We found that in contrast to most other materials, optical phonons in TiS3 conduct an unusually high portion of heat (up to 66% along the b-axis direction). The large dispersiveness of optical phonons along the chains, contrasted to many fewer dispersive optical phonons perpendicular to the chains, is the primary reason for the observed high anisotropy in thermal conductivity. The finding discovers materials with unusual thermal conduction mechanism, as well as provides new material platforms for potential heat-routing or heat-managing devices.

Original languageEnglish (US)
Pages (from-to)5221-5227
Number of pages7
JournalNano Letters
Volume20
Issue number7
DOIs
StatePublished - Jul 8 2020

Keywords

  • Titanium trisulfide
  • in-plane anisotropy
  • optical phonons
  • thermal conductivity

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Extreme In-Plane Thermal Conductivity Anisotropy in Titanium Trisulfide Caused by Heat-Carrying Optical Phonons'. Together they form a unique fingerprint.

Cite this