By comparing the field dependent evolution of the transient absorption of geminate pairs generated of singlet excitons in a film of ladder-type poly-phenylene and the field dependent transient photocurrent it is argued that the rate limiting step for photoionization is the initial field assisted dissociation into geminately bounded electron-hole pairs rather than its ultimate escape from the coulombic well. (C) 2003 Elsevier B.V. All rights reserved.