Using density functional theory and the Boltzmann transport equation for phonons, we demonstrate that the thermal conductivity is massively reduced in monolayer CN as compared to isostructural graphene. We show that larger phase space for three-phonon scattering processes is available in monolayer CN, which results in much shorter phonon life-times. Although both materials are characterized by sp hybridisation, anharmonicity effects are found to be enhanced for the C-N and C-C bonds in monolayer CN, reflected by a Grüneisen parameter of -8.5 as compared to -2.2 in graphene. The combination of these properties with the fact that monolayer CN is organic, non-toxic, and built of earth abundant elements gives rise to great potential in thermoelectric applications.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: The research reported in this publication was supported by funding from the King Abdullah University of Science and Technology (KAUST). For computer time, this research used the resources of the Supercomputing Laboratory at the KAUST.