Highly efficient orange and white phosphorescent organic light-emitting devices with simplified structure

We successfully developed efficient orange and white phosphorescent organic light-emitting devices based on simplified structure. The maximum power efficiency and current efficiency of the orange device with only 5 nm emission layer are 34.1 lm/W and 38.0 cd/A. Performances of the simplified orange devices can be greatly improved to 62.6 lm/W (79.7 cd/A) by introducing one blue phosphorescent dye iridium(III)[bis(4,6-difluorophenyl)-pyridina-to-N, C2'] picolinate into the orange emission layer. The emission mechanism of the above orange devices was also discussed. White light emission with Commission International de L'Eclairage coordinates of (0.36, 0.45) and efficiency of 40.6 lm/W (38.7 cd/A) was obtained by exactly adjusting the doping concentration of orange phosphorescent dye. (C) 2015 Elsevier B.V. All rights reserved.