Two pulse femtosecond photocurrent experiments are performed on a conjugate
d polymer photodiode. With a photon energy of 3.1eV a first laser pulse exc
ites singlet excitons. Photons absorbed from a time-delayed second pulse wi
th a photon energy of 1.26eV lead to the excitation of higher lying states.
The high dissociation rate for these states leads to an efficient two step