Photoluminescence studies of organic light-emitting devices based on 9,10-bis (2-naphthyl)-2-t-butylanthracene (TBADN)

摘要

We studied changes in photoluminescence yield of 9,10-bis (2-naphthyl)-2-t-butylanthracene (TBADN), a commonly used blue emitter in organic light emitting devices (OLEDs). Our studies show that, unlike in case of tris(8-hydroxyquinoline) aluminum (AlQ_3), current flow does not bring about a significant change in TBADN photoluminescence yield under 400nm excitation. We attribute the different behavior of TBADN to its bipolar carrier transport nature, which, in comparison to AlQ_3, does not facilitate the build-up of significant space charges. Excitation at 360nm, however, leads to a rapid decrease in photoluminescence yield, even in the absence of electrical stressing, revealing that higher excited states of TBADN are less stable, and suggesting they could be playing a role in OLED electroluminescence degradation.