Atomic-Level Engineering Anisotropy of Thermal Transport in Two-Dimensional Penta-XPN (X = Ni, Pd, Pt)

Anisotropic heat conduction is critical for device cooling, enabling efficient heat dissipation via optimized pathways. Two-dimensional (2D) pentagonal materials (e.g., penta-graphene) exhibit superior properties to traditional 2D materials. However, systematic research on the anisotropic thermal transport remains scarce, particularly regarding its intrinsic mechanisms and tunability via atomic-level design. This knowledge gap hinders the rational development of such materials for targeted thermal management applications. Herein, via first-principles calculations, we engineer the anisotropy on atomic-level of thermal transport in 2D penta-XPN (X = Ni, Pd, Pt). Our results reveal moderate thermal conductivity anisotropy of 1.04, 0.96, and 1.28, while the lattice thermal conductivity increases with the atomic mass from Ni to Pt, which contradicts the simple mass-variance analysis. This behavior stems from the directional dependence of phonon group velocities, with heavy atom incorporation on bonding properties enhancing electron wave function localization, which suppresses phonon scattering and consequently prolongs phonon lifetimes. These findings highlight penta-XPN’s potential for nanoelectronics thermal management and offer guidance for designing advanced thermal functional materials.