FLUORESCENCE SPECTROSCOPY OF C-60 AT ROOM-TEMPERATURE

Fluorescence spectra of a C60 polycrystalline film at room temperature , obtained under excitation at 514.5 and 337.1 nm, are presented. The spectra were measured with subnanosecond laser excitation in a 5-ns ga te that is synchronous with the excitation. For both excitation wavele ngths, the emission spectra show the same band, peaking at 1.68 eV, an d containing well resolved structures, in the range 1.4 to 1.8 eV. An intense band at energies greater than 1.8 eV emerges for 514.5-nm exci tation, while no emission above 1.8 eV could be detected for excitatio n at 337.1 nm. These spectral features are compared with those of C60 dissolved in n-hexane at room temperature.