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Title: Thermal Conductivity and Large Isotope Effect in GaN from First Principles

Abstract

We present atomistic first principles results for the lattice thermal conductivity of GaN and compare them to those for GaP, GaAs, and GaSb. In GaN we find a large increase to the thermal conductivity with isotopic enrichment, ~65% at room temperature. We show that both the high thermal conductivity and its enhancement with isotopic enrichment in GaN arise from the weak coupling of heat-carrying acoustic phonons with optic phonons. This weak scattering results from stiff atomic bonds and the large Ga to N mass ratio, which give phonons high frequencies and also a pronounced energy gap between acoustic and optic phonons compared to other materials. Rigorous understanding of these features in GaN gives important insights into the interplay between intrinsic phonon-phonon scattering and isotopic scattering in a range of materials.

Authors:
 [1];  [2];  [1]
  1. Naval Research Lab. (NRL), Washington, DC (United States)
  2. Boston College, Chestnut Hill, MA (United States)
Publication Date:
Research Org.:
Energy Frontier Research Centers (EFRC); Solid-State Solar-Thermal Energy Conversion Center (S3TEC)
Sponsoring Org.:
USDOE
OSTI Identifier:
1081204
DOE Contract Number:  
SC0001299; FG02-09ER46577
Resource Type:
Journal Article
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 109; Journal Issue: 9; Related Information: S3TEC partners with Massachusetts Institute of Technology (lead); Boston College; Oak Ridge National Laboratory; Rensselaer Polytechnic Institute; Journal ID: ISSN 0031-9007: PRLTAO
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; solar (photovoltaic), solar (thermal), solid state lighting, phonons, thermal conductivity, thermoelectric, defects, mechanical behavior, charge transport, spin dynamics, materials and chemistry by design, optics, synthesis (novel materials), synthesis (self-assembly), synthesis (scalable processing)

Citation Formats

Lindsay, L., Broido, D. A., and Reinecke, T. L. Thermal Conductivity and Large Isotope Effect in GaN from First Principles. United States: N. p., 2012. Web. doi:10.1103/PhysRevLett.109.095901.
Lindsay, L., Broido, D. A., & Reinecke, T. L. Thermal Conductivity and Large Isotope Effect in GaN from First Principles. United States. https://doi.org/10.1103/PhysRevLett.109.095901
Lindsay, L., Broido, D. A., and Reinecke, T. L. Tue . "Thermal Conductivity and Large Isotope Effect in GaN from First Principles". United States. https://doi.org/10.1103/PhysRevLett.109.095901.
@article{osti_1081204,
title = {Thermal Conductivity and Large Isotope Effect in GaN from First Principles},
author = {Lindsay, L. and Broido, D. A. and Reinecke, T. L.},
abstractNote = {We present atomistic first principles results for the lattice thermal conductivity of GaN and compare them to those for GaP, GaAs, and GaSb. In GaN we find a large increase to the thermal conductivity with isotopic enrichment, ~65% at room temperature. We show that both the high thermal conductivity and its enhancement with isotopic enrichment in GaN arise from the weak coupling of heat-carrying acoustic phonons with optic phonons. This weak scattering results from stiff atomic bonds and the large Ga to N mass ratio, which give phonons high frequencies and also a pronounced energy gap between acoustic and optic phonons compared to other materials. Rigorous understanding of these features in GaN gives important insights into the interplay between intrinsic phonon-phonon scattering and isotopic scattering in a range of materials.},
doi = {10.1103/PhysRevLett.109.095901},
url = {https://www.osti.gov/biblio/1081204}, journal = {Physical Review Letters},
issn = {0031-9007: PRLTAO},
number = 9,
volume = 109,
place = {United States},
year = {2012},
month = {8}
}