Photoluminescence of confined excitons in nanoscale C60 clusters

Formation of C-60 aggregates has been found in toluene, benzene and carbon disulfide (CS,) solutions by means of photoluminescence spectroscopy. From the detailed investigation of the temperature dependence of luminescence, it has been confirmed that the C-60 aggregates are formed at freezing temperature of these solvents in the cooling process. The 0-0 transition energy of their luminescence spectrum has been found to be blue-shifted in comparison with that of C-60 crystal. It has been also found that the irradiation of ultraviolet light upon the C-60 aggregates in benzene at 265 K transforms them to stable substances under atmosphere, which look like round-shaped nanoscale particles in the high-resolution TEM images. (C) 1998 Elsevier Science B.V. All rights reserved.