Thermal conductivity properties of the graphene-carbon nanotube hybrid / Al2O3 interface

A pressing task of modern materials science is the creation of interfaces based on carbon nanostructures and metal oxides for subsequent use in nanoelectronic and spintronic devices. One of the central problems in the operation of nanoelectronic devices is the problem of heat removal, which imposes serious requirements on the thermal conductivity of carbon / metal oxide interfaces. This paper investigates the thermal conductivity properties of the graphene-nanotube hybrid / metal oxide interface. A quasi-2D nanomaterial in the form of a seamless junction of graphene and vertically oriented single-walled carbon nanotubes (SWCNTs) with chirality indices (16, 0) is considered as a graphene-nanotube hybrid. Thin films (2D) and nanoparticles (0D) of aluminum oxide Al2O3 are considered as a metal oxide. The self-consistent-charge density-functional tight-binding method (SCC-DFTB) is used to identify the equilibrium configurations of the supercells of the graphene-nanotube hybrid / 2D-Al2O3 and graphene-nanotube hybrid / 0D-Al2O3 interfaces, characterized by a minimum value of the total energy. Using the molecular dynamics (MD) method with the empirical force field ReaxFF, we established the patterns of the influence of Al2O3 on the thermal conductivity properties of the graphene-SWCNT (16, 0) hybrid nanomaterial. It is shown that the thermal conductivity of the graphene-SWCNT (16,0) / 2D-Al2O3 and SWCNT (16, 0) / 0D-Al2O3 interfaces at a temperature of 300 K exceeds the thermal conductivity of the graphene-SWCNT (16, 0) hybrid by several orders of magnitude. The thermal conductivity coefficient of both graphene-nanotube hybrid / Al2O3 interfaces decreases by ≈6 times with an increase in temperature from 100 to 600 K. At the same time, it remains an order of magnitude higher compared to the carbon material graphene-SWCNT (16, 0). The results obtained open up broad prospects for the use of graphene-SWCNT / Al2O3 nanomaterials as thermal interfaces in nanoelectronic devices.