Abstract
C60 films have been investigated by means of optical absorption, luminescence, and electric-field-induced luminescence quenching, as well as with steady-state photoconductivity spectroscopies. The drop of the luminescence yield, the increase of the electric-field-induced luminescence-quenching efficiency, and the sharp increase of the photocarrier-generation efficiency above 2.3 eV, are interpreted in terms of branching either in the excitation or relaxation processes involving intermolecular charge-transfer excited states.