Universal binary theory of photochemical charge separation and distribution

Using integral formalism we developed the encounter theory of reversible photoionization followed by charge recombination. This is a problem that can not be approached with conventional !differential! formalism, unless ionization is highly exothermic and thus irreversible. in this limit, the integral theory supplemented by the recipe for calculating the ion distribution may be successfully reduced to the differential theory used in our previous work. However, there is no alternative to integral theory when ionization is quasiresonant and the back electron transfer to the excited state should be accounted for. Using the contact approximation we calculated the free-energy dependence of the Stern-Volmer constant of reversible photoionization accompanied by charge recombination. (C) 1997 American Institute of Physics.