Comparative study of thermal transport properties in hexagonal boron nitride with different stacking orders

Recent studies have extensively explored the phonon heat transport properties of bulk hexagonal boron nitride ( h -BN); however, the influence of stacking order on its thermal conductivity ( κ ) has received rare attention. In this work, we employ first-principles calculations to predict the thermal conductivity of h -BN with wurtize ( w ), AB, and ABC stacking. Our calculations show that w -BN possesses the highest thermal conductivity , with in-plane and out-of-plane values of 611 W/mK and 521 W/mK at room temperature (RT), respectively. In contrast, AB and ABC stacking exhibit comparable thermal conductivities, with RT in-plane (out-of-plane) values of 338 (5.8) and 357 (7.2) W/mK, respectively. Notably, four-phonon scattering is found to reduce the κ of ABC and AB stacking by 9% and 13% at RT, while exerting non-negligible suppression on the κ of w -BN only at high temperature. Through detailed mode-level analysis, we uncover that the lower thermal conductivity of AB and ABC stacking, compared to w-BN, stems from their stronger phonon anharmonicity , driven by weak interlayer van der Waals interactions . Furthermore, the calculated modal κ reveals that the stacking sequence has opposite effects on the out-of-plane flexural acoustic phonons and other modes, and their competing effect noticeably weakens the difference in κ between AB and ABC stacking phases. This work provides a fundamental understanding of the phonon thermal transport properties of bulk h -BN with different stacking orders and elucidates the roles of stacking order and higher-order anharmonicity in determining the thermal conductivity of van der Waals layered materials. • Both AB and ABC-stacked h-BN exhibit markedly lower thermal conductivity than w-BN, resulting from the weak van der Waals interlayer interactions. • Fourth-phonon scattering play a more significant role in lowering thermal conductivity of AB and ABC-stacked h-BN than w-BN. • The stacking sequence exhibits opposing effects on the contributions of out-of-plane flexural acoustic phonons and in-plane modes to thermal conductivity.