On the fluorescence of crystalline C60 at 1.2 K

Abstract Well-resolved fluorescence spectra are reported for single crystals of C 60 at 1.2 K. The fluorescence is found to be composed of two contributions. Fluorescence-microwave double-resonance experiments indicate that the dominant component originates from deep X-traps that consists of pairs of C 60 molecules. The minor component most likely derives from shallow monomolecular C 60 X-traps.