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 C60 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.