HIGH-FREQUENCY RESPONSE OF POLYMERIC LIGHT-EMITTING-DIODES

The frequency dependence of alternating-current polymeric light-emitti ng diodes has been studied. Langmuir-Blodgett (LB) films of poly(3-hex ylthiophene) have been used as the active emitting material sandwiched between LB films of emeraldine base polyaniline to form the device. W e have shown that by reducing the thickness of the emitting layer usin g the LB deposition technique, one can increase the high-frequency ope rating limit of the device. From the -3 dB frequency, we have calculat ed the carrier mobility in the emitting polymer layer, and compared it with the Poole-Frenkel model. The electroluminescence and photolumine scence spectra have been studied. (C) 1997 American Institute of Physi cs.