TIME-RESOLVED PHOTOLUMINESCENCE MEASUREMENTS OF C-60 AND C-60-TOLUENESOLUTIONS

The photoluminescence lifetimes and spectra at room temperature of C-6 0 and C-70 toluene solutions are investigated. The photoluminescence s pectra of C-60 solutions were found to be independent of solution conc entration, laser excitation wavelength and excitation fluence. The pho toluminescence spectra of C-70 toluenes solution change as excitation fluence changes; indicating competing decay pathways of the fluorescen ce relaxation of the upper excited singlet states. The near linear rel ationship between the photoluminescence intensity and the excitation f luence indicates that photoluminescence is most likely from excitonic recombination.