Enhancing the thermal boundary conductance of Cu/Diamond interface via diamond surface amorphization by molecular dynamics simulation

Abstract

Based on the non-equilibrium molecular dynamics simulation, a Cu/amorphous diamond/crystalline diamond sandwich model was established to investigate the effects of the amorphous degree diamond surface and the thickness of the amorphous layer on the thermal boundary conductance of Cu/crystalline diamond. The simulation results show that the thermal boundary conductance can be enhanced by diamond surface amorphization, and increases with the increase of the amorphous degree. For the fully amorphous layer, the thermal boundary conductance increases gradually with the increase of the thickness of the amorphous layer and can be enhanced up to 4 times. The analysis of the vibrational density of states, overlap energy and phonon participation ratio shows that the diamond surface amorphization promotes the vibrational coupling between diamond and Cu atoms at low frequencies, as well as the occurrence of phonon inelastic scattering, and thus improves the thermal transport capacity of interface.