Sol-gel materials embedding fullerene derivatives for optical limiting

Fullerene derivatives with high solubilities in polar solvents and able to covalently link to a silica matrix, have been prepared. Optical limiting (OL) properties of these molecules in solution have been measured and the comparison with the behavior of C-60 shows that their performance is better in the near-infrared region. This behavior can be understood on the basis of the reverse saturable absorption mechanism which determines the OL properties of these molecules. The sol-gel method is used to include the fullerene derivatives in a silica matrix and allows one to obtain films and bulk materials. The OL properties of the latter are also reported.