Interfacial Thermal Conductance of a Silicene/Graphene Bilayer Heterostructure and the Effect of Hydrogenation

Abstract

van der Waals heterostructures, obtained by stacking layers of isolated two-dimensional atomic crystals like graphene (GE) and silicene (SE), are one of emerging nanomaterials for the development of future multifunctional devices. Thermal transport behaviors at the interface of these heterostructures play a pivotal role in determining their thermal properties and functional performance. Using molecular dynamics simulations, the interfacial thermal conductance G of an SE/GE bilayer heterostructure is studied. Simulations show that G of a pristine SE/GE bilayer at room temperature is 11.74 MW/m(2)K when heat transfers from GE to SE, and is 9.52 MW/m(2)K for a reverse heat transfer, showing apparent thermal rectification effects. In addition, G increases monotonically with both the temperature and the interface coupling strength. Furthermore, hydrogenation of GE is efficient in enhancing G if an optimum hydrogenation pattern is adopted. By changing the hydrogen coverage f, G can be controllably manipulated and maximized up to five times larger than that of pristine SE/GE. This study is helpful for understanding the interface thermal transport behaviors of novel van der Waals heterostructures and provides guidance for the design and control of their thermal properties.

Thermal transport across graphene and single layer hexagonal boron nitride

“…relaxation time, and C v is the effective constant volume heat capacity of the hybrid system. Liu et al 11 proved that the specific heat of graphene varies by no more than 7% within the temperature range of 300-500 K. Most of the previous studies regarded specific heat as a constant for interfacial thermal conductance calculations at different temperatures. [35][36][37] Thus, it is reasonable to treat R as a constant and use it in Eq.…”

“…The calculated thermal resistance ranges from 10 À9 to 10 À7 KÁm 2 /W depending on the system geometry and temperature. 10,11 Using nonequilibrium MD (NEMD) simulation, Wei et al 12 calculated the interfacial thermal resistance between two neighboring graphene layers at $ 4 Â 10 À9 KÁm 2 /W. Stacked 2D materials have attracted much attention with the emerging demand for high performance thermal interface materials (TIMs).…”

Thermionic Energy Conversion Based on Graphene van der Waals Heterostructures

“…The thermal conductance (or Kapitza conductance) for these two interfaces is about G  =  J /Δ T  = 16.56 and 14.59 MW/m 2 /K, respectively. Note that the difference of G at the upper and the lower interface can be attributed to the temperature dependence of G 4748. These two values are larger than the cross-plane thermal conductance of a few-layer MoSe 2 by one to two orders of magnitude using the experiment data39.…”

Investigating thermal conductivities of functionalized graphene and graphene/epoxy nanocomposites

“…In addition, direct characterization of the ITC of the graphene/matrix interface is essential for understanding the mechanism of interfacial thermal transport and the enhancement of nanocomposite thermal conductivity. Therefore, the influences of functional groups on the ITC have been investigated using molecular dynamics (MD) simulation [9][10][11][12][13]. Wang et al [9] examined the ITC in graphene/polyethylene (PE) nanocomposites and indicated that grafting PE chains to the graphene surface can effectively improve the ITC as well as the vibrational coupling between the graphene and polymer.…”

“…Shen et al [12] evaluated the vibrational power spectrum of functionalized graphene (FG) and epoxy and demonstrated that the extent of vibrational coupling between the graphene and epoxy can be improved by the functional groups. Liu et al [13] studied the effects of the hydrogenation of a graphene surface and the interfacial bonding strength on the ITC in a silicene/graphene bilayer structure. When the hydrogen coverage on the graphene surface attained 50%, the ITC reached a peak value.…”