Electric Field Induced Luminescence Quenching in C₆₀Films: Evidence of Intermolecular Charge Transfer Excitation

S. Kazaoui, R. Ross, and N. Minami
[Physics and Chemistry of Fullerenes and Derivatives, pp.242-245, 1995]

Excitation relaxation and photocarrier generation processes in C₆₀film are investigated by means of luminescence (emission, excitation) and photoconductivity (T=77K). The electric field induced luminescence quenching increases with increasing the excitation energy in the range 2.3-3.75eV whereas no quenching is observed in the range 1.77-2.3eV. The concomitant drop of the luminescence yield as well as the sharp increase of the photocarrier generation efficiency occurring above the same energy range (hv>2.3eV), are interpretated in terms of branching either in the excitation or relaxation processes involving intermolecular charge transfer excited states.