关键词: 分子动力学, C₂₀, Si表面

Abstract: The interaction between a low energy C₂₀ molecule and a reconstructed silicon (100)-(2×1) surface is simulated with a hybrid potential, which is a combination of the Tersoff potential and the repulsive KrC potential. After impacting of the silicon substrate, the C₂₀ cluster is found to move along 〈110〉 direction as a rigid sphere. The collective motion of the C₂₀ molecule can be explained by the anisotropic force field between the dimerized silicon surface and the C₂₀ molecule. Different impact energies lead to different closet interaction distances between the C₂₀ molecule and the silicon surface, which generate different distributions of the lateral force field. Changes in the force field lead to different kinetic behavior of the C₂₀ along the 〈110〉 direction. Finally, the C₂₀ comes to rest on the surface when its kinetic energy is consumed up. In the trough or on the top of a dimer are the two energy favored adsorption sites of the C₂₀ on the silicon surface. The formation of C-Si bonds is an indication that strong bindings between the C₂₀ and the silicon surface exist. These results are consistent with experimental findings of C₂₀ molecules adsorbed on a reconstructed silicon surface.

Key words: molecular dynamics simulations, C₂₀, silicon