Molecular Tuning for a High EL Durable OLED

From the practical viewpoint, one of the most significant performances of OLEDs is device stability under continuous operation. Here, we summarize previous reports on durability. 

the reduction of a carrier injection barrier between organic/electrode interfaces was reported to enhance device duration.55,61 Although joule heat at the interfaces is supposed to induce microcrystallization of organic molecules and successive destruction of balanced hole and electron injection and transport, the precise degradation mechanism is still unclear. 

Another significant report is the development of the molecular structures of the HTM. Using (a-naphthyl-substituted TPD, a-NPD,55 a long duration of over 4000 h (half-decay of initial luminance) was revealed without doping. The reversible behavior of the radical cation was pointed out as the main reason for 

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