In this work, the lattice thermal conductivity of two-dimensional honeycomb structures of BN, AlN, and GaN studied using first-principles density functional theory and solving the linearized Boltzmann transport equation by relaxation time approximation. Investigation of the influence of the phonon modes on the thermal conductivity revealed that ZA, and LA + TA + ZO modes have the most and TO + LO have the least contribution to the thermal conductivity of BN whereas in AlN, the contribution of ZA decreases while the effect of TO + LO increases. In GaN, the TO + LO branches Play the major role on the thermal conductivity. The observed differences in the lattice thermal conductivity of these monolayers were explained by considering the variations of their frequency-dependent phonon lifetimes, group velocities, and heat capacities. In BN monolayer, the group velocity and phonon lifetime of the acoustic phonons found to be higher whereas the heat capacity of it's LO and TO branches was lower than the monolayers of AlN and GaN and therefore, the contribution of the acoustical phonon branches to thermal conductivity has become more important. However in GaN, the LO and TO phonons revealed the highest phonon lifetime and specific heat resulting the dominance of the contribution of these phonon modes to the total thermal conductivity.

在这项工作中，BN、AlN 和 GaN 的二维蜂窝结构的晶格热导率使用第一性原理密度泛函理论并通过弛豫时间近似求解线性化的 Boltzmann 输运方程进行了研究。声子模式对热导率影响的研究表明，ZA 和 LA + TA + ZO 模式对 BN 的热导率的贡献最大，TO + LO 模式对 BN 的热导率的贡献最小，而在 AlN 中，ZA 的贡献减少，而TO + LO 的效果增加。在 GaN 中，TO + LO 分支对热导率起主要作用。观察到的这些单层晶格热导率的差异是通过考虑它们与频率相关的声子寿命、群速度和热容的变化来解释的。在 BN 单层中，发现声学声子的群速度和声子寿命更高，而其 LO 和 TO 分支的热容低于 AlN 和 GaN 单层，因此声子分支对热导率的贡献变得更加重要. 然而，在 GaN 中，LO 和 TO 声子显示出最高的声子寿命和比热，导致这些声子模式对总热导率的贡献占主导地位。