The phonon transport properties in cubic graphene with entirely sp2 hybridization state

Abstract

Cubic graphene is an intrinsic semiconductor with hollow geometric structure and entirely sp2 hybridization state. In this paper, using first principles calculations, we investigate the phonon transport properties of this novel carbon allotrope. The calculations show that at room temperature the thermal conductivity of cubic graphene is approximately 266.17 W/mK, which is obviously lower than that of diamond with fully sp3 hybridization state (2033 W/mK). Such low thermal conductivity mainly originated from the distorted sp2 bond and complex structure which give rise to the flatted and mixed phonon branches as well as strong phonon anharmonicity. Meanwhile, to provide detectable structure fingerprints for experiment, the Raman spectrum and vibrational features of Raman-active phonon modes are also calculated in this work. These results elucidate the intrinsic phonon transport properties of cubic graphene as compared with the case of diamond, and could underpin its potential applications in the field of thermal management.