Penta-graphene (PG), as a novel carbon allotrope, has attracted considerable attention because of its unique atomic structure and outstanding intrinsic properties. Here, we systematically investigate the effect of layer numbers on the lattice thermal conductivity of the stacked PG structures by solving exactly the linearized phonon Boltzmann transport equation combined with first-principles calculations. We find that the lattice thermal conductivity of the stacked PG is insensitive to the number of layers, which is in sharp contrast to that of graphene. Such a layer-independent thermal conductivity is attributed to the buckled structure of PG which breaks the two-dimensional selection rule of three-phonon scattering and the weak van der Waals interlayer interactions that hardly have any effect on the lattice thermal conductivity. This mechanism can be generalized to other van der Waals layered materials with buckled or puckled structures, which may also show the layer-independent lattice thermal conductivity.

中文翻译：

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晶格热导率对五石墨烯堆叠厚度的弱层间依赖性

五石墨烯（PG）作为一种新型的碳同素异形体，由于其独特的原子结构和出色的内在性质而引起了广泛的关注。在这里，我们通过精确求解线性化声子玻尔兹曼输运方程结合第一性原理计算，系统地研究了层数对堆叠 PG 结构晶格热导率的影响。我们发现堆叠 PG 的晶格热导率对层数不敏感，这与石墨烯的晶格热导率形成鲜明对比。这种与层无关的热导率归因于 PG 的屈曲结构，它打破了三声子散射的二维选择规则和对晶格热导率几乎没有任何影响的弱范德华层间相互作用。