Reverse saturable optical absorption of C60, soluble methanofullerenes, and fullerodendrimers in sol-gel mesoporous silica host matrices

Porous sol-gel glasses with various pore size distributions are prepared and either impregnated with pure C-60 or soaked with methanofullerenes or fullerodendrimers derivative solution. Induced absorption or "reverse saturable absorption" (RSA) has been studied in both types of solid materials. The samples impregnated by pure C-60 mainly contain well-dispersed fullerene molecules. Unlike crystalline films of C-60, their absorption dynamics can be well described by a 5-level model, developed for non-interacting C-60-molecules in solutions. Methanofullerene samples, on the other hand, show signs of micellar aggregation and therefore RSA dynamics, which are influenced by solid state effects. Fullerodendrimers derivatives lead to the highest quantum yield.