High Thermal Conductivity of Wurtzite Boron Arsenide Predicted by Including Four-Phonon Scattering with Machine Learning Potential

Materials
with high thermal conductivity are of great importance
to the thermal management of modern electronic devices. Recently,
it was found that cubic boron arsenide (c-BAs) is a high thermal conductivity
(κ) material with a value of ∼1300 W/(m·K) at room
temperature (RT), where four-phonon scattering plays a crucial role
in limiting the κ. In this work, with four-phonon scattering
included, we find that the κ of wurtzite BAs (w-BAs) reaches
as high as 1036 W/(m·K) along the a–b plane at RT, decreasing by 43% compared to the calculation without
considering four-phonon scattering. The similar phonon transport properties
between c-BAs and w-BAs can be understood in terms of similar projected
density of states and scattering rates, which have the origin in crystal
structural resemblance. To accelerate the calculation, the moment
tensor potential derived from machine learning is adopted and proven
to be a reliable and efficient method to obtain high-order interatomic
force constants.