Photoinduced light absorption by C60 films in the 0.08–4.0-eV spectral range

Spectra of photoinduced light absorption in C₆₀ films at high and low excitations in the temperature range between 15 and 300 K have been measured. In addition to the well-known explanation of photoinduced absorption in terms of optical transitions in the system of photogenerated singlet excitons, triplet excitons, and polarons, changes in the absorption spectrum of the fullerite ground state must be considered. We suggest taking into account the effect of crystal field in explaining the features of the photoinduced absorption spectrum. A feature similar to the inverted luminescence spectrum and ascribed to optical excitation of singlet excitons, which is partially allowed owing to intermolecular interaction, has been detected in spectrum of photoinduced absorption. Zh. éksp. Teor. Fiz. 112, 246–256 (July 1997)