Charge carrier escape rate from electrode–liquid interface

Carrier photoinjection after excitation of low dielectric constant medium has been described in terms of forced diffusion of ions away from image forces at the electrode. The rate of this detachment process is expected to have a characteristic dependence on the strength of applied electric field at the electrode. We describe an extrinsic photoconductivity experiment using a thin layer cell where space charge modification by dark current of the local field due to injection or blocking effects can be made negligible. At high applied fields we find quantitative agreement of photocharge yield with the predicted characteristic behavior. This agreement strongly supports the correctness of the ion detachment model in such systems.