Ab initiothermal transport in compound semiconductors

Abstract

We use a recently developed ab initio approach to calculate the lattice thermal conductivities of compound semiconductors. An exact numerical solution of the phonon Boltzmann transport equation is implemented, which uses harmonic and anharmonic interatomic force constants determined from density functional theory as inputs. We discuss the method for calculating the anharmonic interatomic force constants in some detail, and we describe their role in providing accurate thermal conductivities in a range of systems. This first-principles approach obtains good agreement with experimental results for well-characterized systems (Si, Ge, and GaAs).We determine the intrinsic upper bound to the thermal conductivities of cubic aluminum-V, gallium-V, and indium-V compounds as limited by anharmonic phonon scattering. The effects of phonon-isotope scattering on the thermal conductivities are examined in these materials and compared to available experimental data. We also obtain the lattice thermal conductivities of other technologically important materials, AlN and SiC. For most materials, good agreement with the experimental lattice thermal conductivities for naturally occurring isotopic compositions is found. We show that the overall frequency scale of the acoustic phonons and the size of the gap between acoustic and optic phonons play important roles in determining the lattice thermal 2 conductivity of each system. The first-principles approach used here can provide quantitative predictions of thermal transport in a wide range of systems. 63.20.kg,

Resonant bonding leads to low lattice thermal conductivity

“…It is interesting to directly compare SnTe and InSb as these materials are close to each other in the periodic table, and therefore they have a similar Debye temperature and mass ratio. The thermal conductivity calculation of InSb using first-principles was recently reported 36 . The calculated and experimental thermal conductivity values in Fig.…”

On the tuning of electrical and thermal transport in thermoelectrics: an integrated theory–experiment perspective

“…86,96 In addition, as revealed by the recent ab initio third-order interatomic force constant (IFC) calculations, a large scattering channel, analogue to the electronic DOS in the carrier scatterings (equation (7)), can serve as another approach to obtain a strong PPI. 97 Binary chalcogenide compounds have served as a target of many theoretical studies aimed at the understanding of their low κ L s. 24,98-102 An et al 98 and Zhang et al 100 revealed that the very soft transverse optic phonon at Γ point in PbTe, responsible for the low κ L of the compound, is caused by the near ferroelectricity and the partially covalent character of Pb-Te bond. The covalent character was further highlighted by Lee et al 102 who found strong resonant bonding in IV-VI rock-salt chalcogenides.…”

Rethinking phonons: The issue of disorder

“…1a). However, with the ab initio approach developed by Broido and coworkers 16,19,25 as well as Esfarjani and coworkers, 14,19 one can now evaluate the two scattering mechanisms (e.g., phonon-phonon anharmonic scattering and phonon impurity scattering-often termed mass disorder scattering) without fitting to any experimental data. As a result, the VCA still represents the most advanced theoretical understanding of phonon transport in alloys, and this has largely been justified by the instances in the literature, where good agreement between the VCA and experiments has been observed.…”

“…[1][2][3]5,8,10 The validity of this assumption has been in many ways validated 5,[11][12][13][14][15][16][17][18][19][20] and consequently, the PGM has been used almost ubiquitously to understand phonon transport in all classes of solids. 13,18,19,[21][22][23][24][25] However, here we will examine more deeply the behaviors in a random alloy as a representative example, because its compositional disorder reveals a rather fundamental issue with the way phonons have been conceptualized, namely considering them to be plane waves/quasi-particles that travel and scatter.…”