Abstract
The rate of generation of a free electron and a trapped hole due to the Coulomb interaction between charge carriers of two Frenkel excitons (one free and one trapped) is derived for molecular crystals by time dependent perturbation theory. Electron-lattice and spin-orbit interactions are neglected. The theory is finally applied to benzophenone single crystals where a transition rate approximately 109 cm-3 s-1 is obtained.