Charge Transfer at High Excitation Power of Solids

Electron transfer between excited donor molecules followed by the back reaction is treated theoretically for a solid solution at high excitation power. An expression for the average donor cation probability P⁺(t) is derived. Calculations of the time dependence for P⁺(t) are presented. The results indicate that the maximum value of P⁺(t) in the nonlinear quenching process is less than the corresponding values of P⁺(t) for the linear quenching at a low excitation power due to the depletion of the acceptors with time t. The restriction of the reaction volume slows down the charge separation if the back charge transfer takes place.