In-plane thermal transport in black phosphorene/graphene layered heterostructures: a molecular dynamics study

Heterostructures, which stack two different two-dimensional (2D) materials vertically together, have recently attracted tremendous attention. However, as one of their members, the in-plane thermal conductivity of black phosphorene/graphene (BP/GE) heterostructures, which plays a key role in determining their functional properties, is still unknown. In this work, we use non-equilibrium molecular dynamics (NEMD) simulations to study the in-plane thermal conductivities of BP/GE heterostructures and BP in BP/GE heterostructures. The effect on in-plane thermal conductivity with respect to the size effect (sample length), coupling strength, and hydrogen coverage is systematically examined. It is found that the in-plane thermal conductivity of infinite-size BP/GE bilayer heterostructures exhibits strong anisotropy, which is calculated to be 206.61 ± 6.35 (along the zigzag direction) and 51.02 ± 3.72 W m-1 K-1 (along the armchair direction). In addition, we found that the enhancement of the coupling strength increases the in-plane thermal conductivity of BP/GE heterostructures and BP in BP/GE heterostructures, which may be due to an increase in phonon group velocities in BP and a stronger phonon coupling between BP and GE. In our research, hydrogenation has also been found to enhance the thermal conductivity of BP in heterostructures. The present study is expected to provide guidance for the study of the in-plane thermal transport properties in other 2D heterostructures, and it is of significance for understanding the thermal transport behavior of BP/GE heterostructures and BP in heterostructures and promoting their future applications in thermal management and thermoelectric devices.