Limiting dynamics of C-60 in solid matrices

We study the limiting dynamics of C-60-doped porous sol-gel glasses by sing le- and double-pulse pump-probe experiments. We find that, contrary to crys talline films of C-60, reverse saturable absorption (RSA) of these solid sa mples can be described by a B-level model developed for C-60-solutions. We observe an ultrafast rise time, a large transmission-decrease at high fluen ce, a shortened singlet-state lifetime as compared to solutions, but nevert heless an important triplet yield. We explain differences with respect to s olutions by the absence of stabilizing aromatic solvents and by the interac tion of the amorphous environment with the molecules, broadening considerab ly the spectral features of RSA.