Semiconducting materials with high thermal conductivity are valuable for thermal management in highly integrated systems, in which heat must be dissipated efficiently. Cubic boron arsenide (BAs) is recently attracting numerous research attention due to its comparable thermal conductivity with diamond. However, thermal conductivity of monolayer honeycomb BAs is much lower than the bulk counterpart. Herein, based on Boltzmann transport equation and non-equilibrium Green’s function calculation, we suggest a new unexplored covalently bonded bi-layer BAs to exhibit high thermal conductivity, which is about two times of that of bulk silicon. Unlike the remarkable reduction in thermal conductivity from monolayer graphene to bi-layer graphene, thermal conductivity of bi-layer BAs is about 70% higher than its monolayer counterpart. Central to this novel behavior was the largely suppressed phonon scattering phase space and anharmonicity. The anomalously high thermal conductivity of the covalently bonded bi-layer BAs and the emergent underlying mechanism discussed here open up space for further manipulation of thermal properties of 2D materials, and facilitate their applications to important problems in nanoscale electronic and optoelectronic devices.

具有高导热率的半导体材料对于高度集成系统中的热管理非常重要，在这些系统中，必须高效散热。立方砷化硼（BAs）由于具有与金刚石相当的导热性，最近引起了众多研究关注。但是，单层蜂窝状BA的热导率远低于块状BA。在此，基于玻尔兹曼输运方程和非平衡格林函数计算，我们建议一种新的未探索的共价键合的双层BA表现出高的热导率，约为本体硅的两倍。与从单层石墨烯到双层石墨烯的热导率显着降低不同，双层BA的热导率比其单层石墨烯高约70％。这种新颖行为的中心是很大程度上抑制了声子散射的相空间和非谐性。共价键结合的双层BA的异常高的热导率和此处讨论的新兴潜在机理为进一步处理2D材料的热性能开辟了空间，并促进了它们在纳米级电子和光电设备中的重要问题中的应用。