Photoluminescence of C60 aggregates in solvent mixtures

Temperature dependence of the photoluminescence of C-60 in CS2, as a typical example of the formation of C-60 aggregates by the liquid-solid transition of solution, and the photoluminescence of C-60 in room-temperature benzene-ethanol mixtures of different compositions are presented. By comparing the photoluminescence spectra of C-60 in benzene-ethanol mixtures with those of C-60 in solution (toluene, benzene and CS2) and C-60 single-crystal, it has been found that the drastic spectral change in photoluminescence spectrum of C-60 in benzene-ethanol mixture. of different compositions are strongly ascribed to the formation of C-60 aggregates. Moreover, it has been found that the energy of maximum intensity and the spectral shape in the room-temperature photoluminescence of C-60 aggregates in benzene-ethanol mixtures are not sensitive to the ethanol fraction.