Ab initio study of the effect of vacancies on the thermal conductivity of boron arsenide

Using a first principles theoretical approach, we show that vacancies give anomalously strong suppression of the lattice thermal conductivity. of cubic Boron arsenide (BAs), which has recently been predicted to have an exceptionally high.. This effect is tied to the unusually large phonon lifetimes in BAs and results in a stronger reduction in the BAs. than occurs in diamond. The large changes in bonding around vacancies cannot be accurately captured using standard perturbative methods and are instead treated here using an ab initio Green function approach. As and B vacancies are found to have similar effects on.. In contrast, we show that commonly used mass disorder models for vacancies fail for large mass ratio compounds such as BAs, incorrectly predicting much stronger (weaker) phonon scattering when the vacancy is on the heavy (light) atom site. The quantitative treatment given here contributes to fundamental understanding of the effect of point defects on thermal transport in solids and provides guidance to synthesis efforts to grow high quality BAs.