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Title: First principles study of thermal conductivity cross-over in nanostructured zinc-chalcogenides

Systematic first principles studies of zinc-chalcogenides have been performed to understand their thermal transport behaviour. We have applied the Boltzmann transport equation in the relaxation time approximation to calculate the thermal conductivity of ZnS, ZnSe, and ZnTe. We find a thermal conductivity cross-over between ZnS and ZnSe at nanostructure sizes around 0.1–0.2 μm and explain this in terms of the different contributions of phonon modes in these materials. We study the effect of nanostructuring using both the diffusive boundary scattering and confined mean free path limit and discuss the variations in the results. Furthermore, we show the strong influence of isotope scattering on the thermal conductivity. The calculated thermal conductivity is found to be strongly dependent on the volume and we explain the observed differences between local density and generalized gradient approximation calculations. We compare further calculated thermal properties, such as the thermal expansion coefficient, to experiment to validate our approach.
Authors:
;  [1] ; ;  [2]
  1. ICAMS, Ruhr-Universität Bochum, 44801 Bochum (Germany)
  2. ESISM, Kyoto University, Sakyo, Kyoto 606-8501 (Japan)
Publication Date:
OSTI Identifier:
22413009
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; APPROXIMATIONS; BOLTZMANN EQUATION; COMPARATIVE EVALUATIONS; MEAN FREE PATH; NANOSTRUCTURES; PHONONS; RELAXATION TIME; THERMAL CONDUCTIVITY; THERMAL EXPANSION; ZINC SELENIDES; ZINC SULFIDES; ZINC TELLURIDES