Geminate pair recombination in molecular systems with correlated disorder

Influence of the correlation of the disorder on the geminate charge pair recombination is theoretically analyzed. Charge dynamics is considered in one- and three-dimensional systems by means of Monte Carlo simulations. It is demonstrated that the correlation radius of the disorder is the limiting distance factor by discriminating the effect of the disorder in the mobile charge movement. Because of that the concept of the local disorder, which expresses itself in the geminate recombination kinetics, is introduced. The correlation effects express themselves in the intermediate times and are lost in the large-scale movement of the charges. It is demonstrated that the discrepancies between disorder values obtained by the geminate pair recombination kinetics and those from the charge drift studies can be attributed to the correlative effects of the disorder. The radius of the correlation is estimated to reach 17 to 28 lattice constants for the organic semiconductors.