ELECTRIC-FIELD-INDUCED QUENCHING OF EXCIPLEX FLUORESCENCE AND PHOTOCURRENT GENERATION IN A MIXTURE OF ETHYLCARBAZOLE AND DIMETHYL TEREPHTHALATE DOPED IN A PMMA POLYMER FILM

Exciplex fluorescence in a mixture of N-ethylcarbazole (ECZ) and dimet hyl terephthalate (DMTP) doped in a PMMA polymer film, which appears a s a result of photoinduced electron transfer from ECZ to DMTP, is quen ched by an electric field as the concentration of the electron donor, i.e., ECZ, is increased. Even when the DMTP concentration is increased , the exciplex fluorescence is not quenched by an external electric fi eld as long as the ECZ concentration is low. These concentration depen dences indicate that a hole transport occurs very efficiently and that an electron transport does not occur in this photoinduced electron-tr ansfer system. In fact, a photocurrent could be detected in a mixture of ECZ and DMTP in PMMA films only when the concentration of ECZ was h igh.