Theoretical study of heat transfer across biphenylene/h-BN superlattice nanoribbons

Controlling thermal conductivity of nanostructures is a key element in manufacturing tailor-made nanodevices for thermoelectric applications. Moreover, superlattice nanostructures have been demonstrated to be useful in achieving minimal thermal conductivity for the employed nanomaterials. In this work, we model two-dimensional biphenylene, a recently-synthesized sp²-hybridized allotrope of carbon atoms, for the implementation of a biphenylene/hexagonal Boron-Nitride (biphenylene/h-BN) superlattice nanoribbons. The effects of the length of ribbon and its superlattice period (l_p) on the thermal conductivity are explored using molecular dynamics simulations. We calculated the length-independent intrinsic thermal conductivity (K_α) of the superlattice nanostructure, which was approximately 68% and 55% lower than the thermal conductivity of pristine h-BN and biphenylene nanosheets, respectively. The superlattice period largely determines the minimum thermal conductivity, which was at 64.1 W m⁻¹k⁻¹ for a period value of l_p = 2.51 nm. This work opens a new window to tune and/or minimize thermal conductivity in nanoribbons when designing thermoelectric and thermal insulation materials for favorable applications.