Anisotropic and high thermal conductivity in monolayer quasi-hexagonal fullerene: A comparative study against bulk phase fullerene

Recently a novel two-dimensional (2D) C60 based crystal called quasi-hexagonal-phase fullerene (QHPF) has been fabricated and demonstrated to be promising candidate for 2D electronic devices [Hou et al. Nature 606, 507–510 (2022)]. We construct an accurate transferable machine-learned potential study heat transport related properties of this material, with comparison the face-centered-cubic bulk-phase (BPF). Using homogeneous nonequilibrium molecular dynamics spectral decomposition methods, we show that thermal conductivity in QHPF is anisotropic, which 137(7) W/mK at 300 K direction parallel cycloaddition bonds 102(3) perpendicular in-plane direction. By contrast, BPF isotropic only 0.45(5) W/mK. inter-molecular covalent bonding plays crucial role enhancing as compared BPF. The characterized work will useful application devices.