Distribution of phonon lifetime in Brillouin zone

TL;DR

This study analyzes phonon lifetime distributions in zincblende and wurtzite compounds, revealing complex wave vector dependencies and highlighting the importance of anharmonic interactions for accurate thermal conductivity predictions.

Contribution

It provides detailed phonon linewidth distributions and emphasizes the critical role of phonon-phonon interactions and selection rules in determining phonon lifetimes.

Findings

Phonon linewidths vary non-smoothly with wave vector.

Phonon lifetime prediction requires anharmonic force constants.

Weighted joint density of states can screen lattice thermal conductivity.

Abstract

Lattice thermal conductivities of zincblende- and wurtzite-type compounds with 33 combinations of elements are calculated with the single-mode relaxation-time approximation and linearized phonon Boltzmann equation from first-principles anharmonic lattice dynamics calculations. In 9 zincblende-type compounds, distributions of phonon linewidths (inverse phonon lifetimes) are discussed in detail. The phonon linewidths vary non-smoothly with respect to wave vector, which is explained from the imaginary parts of the self energies. It is presented that detailed combination of phonon-phonon interaction strength and three phonon selection rule is critically important to determine phonon lifetime for these compounds. This indicates difficulty to predict phonon lifetime quantitatively without anharmonic force constants. However it is shown that joint density of states weighted by phonon numbers, which is calculated only from harmonic force constants, can be potentially used for a screening of the lattice thermal conductivity of materials.