The investigations of lattice thermal conductivity of few layer black phosphorus show the onset of anisotropic thermal conductivity cross-over between zigzag and armchair direction in the low temperature regime ($~25K-40K)$. For the first time, we address anisotropic-isotropic-low anisotropic transition regimes of thermal conductivity in black phosphorus and discuss the influence of phonon-boundary, phonon-phonon and phonon-impurity scattering on transition regimes. Single set of phonon scattering coefficients for black phosphorus obtained are used to describe the thermal conductivity cross-over of zigzag and armchair black phosphorus. We analyze the thermal conductivity cross-over data and found to show the best fit to the recent experimental thermal conductivity reports in the wide temperature range $(10K–600K)$. The importance of the phonon frequency and angle of phonon incidence dependent speculation reflections is discussed.

对少量黑磷晶格热导率的研究表明，在低温条件下，曲折形和扶手椅方向之间各向异性热导率的转变开始（$〜25ķ-40ķ）$。首次，我们讨论了黑磷中热导率的各向异性-各向异性-低各向异性跃迁形式，并讨论了声子边界，声子-声子和声子-杂质扩散对跃迁形式的影响。所获得的用于黑磷的单组声子散射系数用于描述之字形和扶手椅黑磷的热导率穿越。我们分析了热导率交叉数据，发现在宽温度范围内显示出最适合最新的实验热导率报告$（10ķ–600ķ）$。讨论了声子频率和声子入射依赖的反射反射角的重要性。