First-principles phonon thermal transport in graphene: Effects of exchange-correlation and type of pseudopotential

Abstract

First-principles calculations of the thermal conductivity of two-dimensional materials have recently attracted a great deal of attention. The choice of the exchange-correlation (XC) and pseudopotential (PP) is a crucial step towards an accurate first-principles calculation using density functional theory (DFT). This work investigates the sensitivity of the intrinsic thermal conductivity and phonon properties of graphene to the choice of XC and PP in the temperature range of 300–550 K, using first-principles DFT simulations and an iterative solution of the Boltzmann transport equation. We consider six XC-PP combinations (LDA-NC, LDA-US, PBEsol-US, LDA-PAW, PBE-PAW, and PBEsol-PAW). Our results showed that the choice of XC-PP combination results in significant discrepancies, in the range of 5442–8677 W m−1 K−1, among predicted thermal conductivities at room temperature. The LDA-NC and PBE-PAW combinations predicted the thermal conductivities in best agreement with available experimental data. The phonon properties revealed that these discrepancies are mainly due to variations in the prediction of phonon lifetimes and Grüneisen parameters from different XC-PP combinations.