Durability characteristics of aminopyrene dimer molecules as an emitter in organic multilayered electroluminescent diodes

We report the structure design of emitter molecules using aminopyrene dimers for obtaining durable organic electroluminescent (EL) diodes. Using eighteen kinds of emitter molecules having a variety of substituents and linking groups, we investigated the durability of the cell structure of the anode/hole transport layer/emitter layer/electron transport layer 2/electron transport layer 1/cathode. We observed that the chemical structures of the emitter molecules strongly influenced the durability of the EL devices under continuous DC operation. Mie observed no direct relationships between melting point (T-m); glass transition temperature (T-g), ionization potential (I-p), electron affinity (E(a)) of emitter layers and EL device durabilities. The effect of the substituent groups of emitter molecules on EL device durability suggests that the chemical stability of the emitter molecules largely influences EL device durability.