摘要:

In this work, we have provided a new possible explanation for the micromechanism of electroplex. The time-resolved electroluminescent spectra of light-emitting diodes based on the blend of TAPC and TpPyPB were measured. They show that when a high bias voltage is applied on the devices, the electroplex emission gradually increases over time. After the devices worked at a high bias voltage, a strong electroplex emission can be maintained at low bias voltage, but the peaks related to the electroplex are still insignificant in photoluminescence. These results may suggest that the electroplex is a charge-transfer complex with changed conformation caused by polaron-induced molecular aggregation under electric field in essence, though further investigation is needed. Using materials with morphology stability under an electric field, electroplex was greatly reduced, which may enlarge the consideration in designing exciplex-based organic light-emitting diodes (ExOLEDs). (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim