Origins of low lattice thermal conductivity in 2D carbon allotropes

Ultrahigh Electron Thermal Conductivity in T‐Graphene, Biphenylene, and Net‐Graphene

“…Specifically, we show ph 3+4ph κ adopting the solution of Boltzmann transport equation (BTE) with the optimized Tersoff potential [58] for graphene, [35] ph 3ph κ calculated from density functional theory (DFT) for T-graphene, [28] κ ph calculated from the DFT with only 3ph scatterings [29] and the equilibrium molecular dynamics [30] (EMD) for biphenylene, and κ ph by nonequilibrium EMD (NEMD) for net-graphene. [31] Overall, our calculations agree with the literature data, indicating the reliability of our implementations, and further allow for the following insights: i) The 4ph scattering effects induce a suppression (…”

“…In (a), the left inset is the κ ph attributed to different scattering events and the right inset is the scattering rates due to 3ph, 4ph, and pe interaction processes at T = 300 K. The most recently available literature data are provided for validation as marked in the left inset of (a) with: ph 3+4ph κ for graphene, [35] ph 3ph κ for T-graphene, [28] κ ph calculated by only 3ph scatterings [29] and EMD [30] for biphenylene, and κ ph by NEMD for net-graphene. [31] In (b), the TA, LA, ZA, and one transverse optical (ZO) phonon modes are labeled and the Brillouin zone are shown. In (c), the zero of energy is set to the Fermi level.…”

“…Our results and the insights uncovered here for T-graphene, biphenylene, and net-graphene could also be shared with other theoretically predicted 2D carbon allotropes displaying metallic character, such as penta-graphene, a-graphene, g-graphene, Ψ-graphene, and pop-graphene. [3,31,64]…”

“…In strained bonds, anharmonicity effects [26,27] can decrease significantly the phonon thermal conductivity (κ ph ). [28][29][30][31] In this work, we conduct a comprehensive ab initio calculation to consistently compare the phonon-and electron-based conduction of pristine graphene with that of the T-graphene, biphenylene, and net-graphene carbon allotropes. There is an established notion that thermal energy transport in 2D carbon materials is largely phonon-based [32] and that the negligible electron-based conduction can become important only under n-doping.…”

Optical and Thermoelectric Behavior of Phagraphene with Site‐Specific B‐N Co‐Doping

“…Most of the 2D carbon-based structures related to graphene exhibit significant value of lattice-induced thermal conductivity at low temperatures. [17,84] That is why it is recommended to predict ZT e values at some higher temperatures (>500 K). Around 500 K, phagraphene possesses a maximum ZT e value of 0.37.…”