Multiscale modeling of polycrystalline graphene: A comparison of structure and defect energies of realistic samples from phase field crystal models

TL;DR

This paper extends the phase field crystal (PFC) model to accurately simulate polycrystalline graphene, enabling large-scale realistic sample generation and detailed analysis of defect and structure energies aligned with quantum-mechanical calculations.

Contribution

The study introduces a PFC modeling framework fitted to DFT data for realistic polycrystalline graphene, allowing multiscale analysis of defect structures and energies.

Findings

PFC predicts formation energies consistent with DFT and MD.

Large realistic polycrystalline samples can be constructed using PFC.

PFC-based samples show realistic defect and structure energies.

Abstract

We extend the phase field crystal (PFC) framework to quantitative modeling of polycrystalline graphene. PFC modeling is a powerful multiscale method for finding the ground state configurations of large realistic samples that can be further used to study their mechanical, thermal or electronic properties. By fitting to quantum-mechanical density functional theory (DFT) calculations, we show that the PFC approach is able to predict realistic formation energies and defect structures of grain boundaries. We provide an in-depth comparison of the formation energies between PFC, DFT and molecular dynamics (MD) calculations. The DFT and MD calculations are initialized using atomic configurations extracted from PFC ground states. Finally, we use the PFC approach to explicitly construct large realistic polycrystalline samples and characterize their properties using MD relaxation to demonstrate their quality.