Quinolinoacridine as High Efficiency Building Unit in Single‐Layer Phosphorescent Organic Light‐Emitting Diodes

Abstract

AbstractThe performances of simplified single‐layer phosphorescent organic light‐emitting diodes (SL‐PhOLEDs) have significantly increased and they now appear to be a promising alternative to multi‐layer PhOLEDs. The blue and white emissions, far more challenging than all the other colours, are still particularly desired. Herein, a high efficiency host material for blue emitting SL‐PhOLED using the blue emitter FIr6 is reported, which is particularly interesting as it displays an emission at shorter wavelengths than the well‐known FIrpic emitter, almost exclusively reported in the SL‐PhOLEDs literature. The host material investigated herein is constructed on the electron‐rich quinolinoacridine and displays when incorporated in FIr6‐based SL‐PhOLEDs, an external quantum efficiency (EQE)⟩10% and a low Von of 3.1 V. This is the first work passing an EQE of 10% with FIr6 as an emitter. This host also reaches a very high EQE of 19% when used with the green emitter Ir(ppy)2acac, this performance being among the highest recorded for green SL‐PhOLEDs. Finally, as white SL‐PhOLEDs involve blue emitting SL‐PhOLEDs, this host is also used with a combination of blue and yellow emitters. An extremely high EQE of 24% is reached with CIE coordinates of (0.40;0.48). These findings show the real potential of the quinolinoacridine fragment to reach high performance multi‐colour SL‐PhOLEDs.