High-efficiency solution-processed WOLEDs with very high color rendering index based on a macrospirocyclic oligomer matrix host

Phosphorescent white organic light-emitting diodes (WOLEDs) with high efficiency and color rendering index (CR1) are demonstrated based on a macrospirocyclic oligomer matrix (TPA-PO)(3), which exhibits good solution processability, stable film morphology, and excellent compatibility with phosphorescent emitters. High-efficiency blue. green, orange, and red OLEDs were demonstrated with maximum current efficiencies of 21.7. 21.9, 13.1, and 6.4 cd A(-1), maximum brightness of 22475, 67757, 21232, and 8046 cd m(-2), respectively. Furthermore, by simultaneously incorporating blue, green, orange, and red emitters into a single emitting layer, a quaternary doping WOLED with a maximum current efficiency of 18.9 cd A(-1) (at 280 cd m(-2)) was realized. featuring a "warm-white" light emission with correlated color temperatures ranging from 2841 to 3514 K. Importantly, color rendering index values over 90 were obtained at practical brightness of 100 similar to 1000 cd m(-2). Even at a high brightness of similar to 5000 cd m(-2), the CRI was still above 88, which is among the highest CRI values achieved for solution-processed phosphorescent WOLEDs. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement