The bonding sites and structure of C-60 on the Si(100) surface

The possible structures of C60 on the Si(1 0 0) surface have been investigated using ab initio total energy minimisations. The results show that fullerenes bond to the silicon surface by breaking carbon–carbon double bonds. One electron from the broken bond is contributed to the carbon–silicon bond. The second electron is generally involved in forming a new π-bond within the fullerene cage, or, for the less energetically favourable structures, is delocalised over the surrounding bonds. The carbon–silicon bond formed is primarily covalent with some charge transfer.