Ab initio study of C60-silicon clusters

We report on the energetics of C-60-Si clusters. By means of ab initio calculations based on the local density approximation to the density functional theory, we have investigated stable and metastable structures of C-60-Si, C-60-Si-C-60, and (C-60-Si)(2) clusters. In each case, we show that silicon preferentially binds to C-60 over a carbon-carbon double bond, in accordance with calculations on the interaction of C-60 with silicon surfaces. This bonding is characterized by a partial charge transfer from silicon to C-60. We show that the interaction between C-60 and silicon is local and not perturbed by the addition of more C-60-Si clusters or C-60 molecules. The binding energy for stable and metastable (C-60-Si)(nless than or equal to2) systems is high enough (several eV) to open the prospect of synthesizing nanostructured films from the C-60-Si unit. Furthermore, in all three cases, the silicon position on a fivefold symmetry axis is found to be a metastable position. The nature and structure of nanostructured films resulting from the deposition of these clusters is qualitatively discussed. (C) 2002 American Institute of Physics.