Density functional theory driven phononic thermal conductivity prediction of biphenylene: A comparison with graphene

TL;DR

This study uses density functional theory and Boltzmann transport equations to predict the anisotropic thermal conductivity of biphenylene, revealing significantly lower values than graphene due to increased anharmonicity from reduced symmetry.

Contribution

It provides the first theoretical prediction of biphenylene's thermal transport properties using DFT and BTE, highlighting the role of anharmonicity and symmetry.

Findings

Biphenylene exhibits anisotropic thermal conductivity.

Thermal conductivity of biphenylene is over ten times lower than graphene.

Reduced symmetry enhances anharmonicity, lowering thermal conductivity.

Abstract

The thermal transport properties of biphenylene network (BPN), a novel sp2 -hybridized two-dimensional allotrope of carbon atoms recently realized in experiments [Fan et al., Science, 372 852-856 (2021)], are studied using the density functional theory-driven solution of the Boltzmann transport equation. The thermal transport in BPN is anisotropic and the obtained thermal conductivities are more than an order of magnitude lower than that in graphene, despite similar sp2-hybridized planar-structure of both allotropes. The lower thermal conductivity in BPN is found to originate from enhanced anharmonicity which in turn is a result of reduced crystal symmetry of BPN.