Interlayer surface modification modulating thermal transport at Si/Gr/HEA heterostructure interfaces

We investigate the effect of nanoslot modification and defects on the interfacial thermal resistance (ITR) of silicon/graphene/FeNiCrCoCu vdW heterostructures (Si/Gr/HEA) by using molecular dynamics (MD). The results show the triangular and rectangular nanoslots have opposite trends for changing on ITR. When the number of nanoslots in the system increases to seven, the ITR of the triangular nanoslots decreases by 41.47 %. It shows that ITR strongly depends on the type and concentration of all three defects. By analyzing the phonon density of states (PDOS), phonon coupling coefficient (S), phonon participation rate (PPR), and phonon coupling spectral decomposition (PCSD), the results show that the construction of triangular nanoslots induced strong local pressure in Gr layer, resulting in enhanced interface phonon coupling and decreased ITR. The decrease of ITR caused by single vacancy defect (SV) is mainly due to the increase of PPR in 10–15 THz and 22–30 THz frequencies in the Gr layer, and the increase of non-localized phonon mode. This means that it is possible to improve the heat conduction of Si/Gr/HEA vdW heterogeneous devices.