Abstract
Crystalline semiconductors exhibiting innate low lattice thermal conductivity (κl) are technologically very important for the development of thermal barrier coatings, thermal data-storage devices, and high-performance thermoelectrics. Here, using first-principles calculations based on density functional theory and anharmonic lattice dynamics, we predict intrinsically low κl (<1 W/m K along the stacking direction for T ≥ 400 K) in many known layered semiconductors, AMM′Q3 (A = Na, K, Cs, Tl; M = Cu; M′ = Zr, Hf; Q = S, Se), that possess chemical bonding heterogeneity. We show that low κl in this class of materials arises from (a) the rattling vibrations of the weakly bonded A atoms, characterized by low-frequency localized phonon branches with very small dispersion that give rise to numerous additional scattering channels and (b) strong lattice anharmonicity which is manifested in the large-mode Gruneisen parameters that increase the phonon scattering rates. Our work uncovers inherent low κl in this previously unexplored class of metal chalcogenides which should open up opportunities for applications of these compounds in various thermal energy management devices.
Original language | English (US) |
---|---|
Journal | Chemistry of Materials |
DOIs | |
State | Accepted/In press - 2019 |
Funding
K.P. (DFT, thermal conductivity calculations and analysis) and C.W. (overall leadership of the project) acknowledge support from the U.S. Department of Energy under contract no. DE-SC0015106. Y.X. (analysis of thermal transport properties) acknowledges support from the Toyota Research Institute through the Accelerated Materials Design and Discovery program. J.H. acknowledges support from the Center for Hierarchical Materials Design (CHiMaD) and from the U.S. Department of Commerce, National Institute of Standards and Technology under award no. 70NANB14H012. All authors discussed the results and commented on the manuscript. We acknowledge the computing resources provided by the (a) National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility operated under contract no. DE-AC02-05CH11231, (b) Quest high-performance computing facility at Northwestern University which is jointly supported by the Office of the Provost, the Office for Research, and Northwestern University Information Technology, and (c) the Extreme Science and Engineering Discovery Environment (National Science Foundation Contract ACI-1548562).
ASJC Scopus subject areas
- General Chemistry
- General Chemical Engineering
- Materials Chemistry