Datensatz

Zusammenfassung

The low-temperature Raman spectrum of 2a₀-fcc single crystal C₆₀ recorded using low-irradiance 514 nm excitation shows only a single peak in the region of the 1468 cm⁻¹ out-of-phase ring mode. For higher irradiances a new broad peak appears in the spectrum at a somewhat lower frequency. Simultaneously, an increase of the luminescence is observed. As the irradiance increases the new peak gains intensity and shifts to lower frequencies, whereas the orginal peak slowly disappears. It is argued that this peak originates from electronically excited C₆₀. A simple electronic four-level model is proposed to explain the observed effects.