Charge transfer in solid fractal systems. Low concentration of acceptors

Abstract

Known charge-transfer kinetics theory for infinite regular space has been extended to include irregular fractal systems. The probability P ct( t) of finding a donor cation state in regular infinite space is larger than in fractal space. The back charge transfer effect increases with decreasing fractal dimension. The fractal structure of the reaction space slows down the charge separation. Two theoretical models considered are: the method of conditional concentration of molecules and the model of nearest neighbors. Both models give nearly the same results at low acceptor concentrations. The long-time branch of probability P ct( t) falls down if back charge transfer takes place. The results are good in the limit of low concentrations of acceptors.