CHARGE-TRANSFER INDUCED LOCAL EXCITON-STATES AT HIGH DOPANT CONCENTRATION

The model attributing the occurrence of local Frenkel exciton levels i n doped naphthalene crystals to charge transfer effects is investigate d for dopant concentrations high enough to enable a host molecule to i nteract with multiple impurities. The predictions are compared with th ose of the conventional model where the local levels are explained in terms of a substantial perturbation of the diagonal exciton energy, an d found to differ for some deep local states. In view of existing ambi guities in the experimental data, new experiments are suggested to est ablish the mechanism of local state creation.