The spatial distribution of electron-cation pairs formed in polymer films through two-photon ionization of aromatic dopants was evaluated from the decay of charge recombination luminescence at 20 K according to Hama's theory. The distribution was also examined directly using a layer-structure of ultrathin polymer films where the separation distance between donor and acceptor moiety was controlled on a nanometer scale. The results in both systems show that electrons ejected by two-photon ionization are distributed over 30 Angstrom away from the parent cations. (C) 2001 Elsevier Science Ltd. All rights reserved.