Phonon heat transport in two-dimensional phagraphene-graphene superlattice

In this study, we perform non-equilibrium molecular dynamics simulations to investigate phonon heat transport in a two-dimensional superlattice with equal-sized domains of graphene and phagraphene. Effects on conductivity are examined in relation to modifications of domain sizes, the length of employed nanoribbons and temperature differences between the thermal baths used with the superlattices. We have determined that effective thermal conductivity reaches a minimum value of 155W/mK for ribbons with a superlattice period of 12.85nm. This minimum thermal conductivity of graphene-phagraphene superlattices at infinite length is approximately 5%, of pure graphene thermal conductivity, and ≈50% of phagraphene thermal conductivity. Minimum thermal conductivity occurs at the transition from coherent to incoherent phonon transport, where the superlattice period is comparable to the phonon coherence length.