Transient photoconductivity in a film of ladder-type poly-phenylene: failure of the Onsager approach

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.