Highly efficient excimer-based white phosphorescent devices with improved power efficiency and color rendering index

Power efficiency, Commission Internationale d'Enclairage (CIE) coordinates, and color rendering index (CRI) of white phosphorescent excimer devices were improved by utilizing two platinum complexes as emissive dopants and exploring different device structures. Compared with devices containing two emissive layers each having a different dopant, devices having two dopants incorporated in a single host layer showed better color stability with the change in operating voltage. White phosphorescent excimer devices having the double-doped emissive layer showed an external quantum efficiency and a power efficiency of 14.5% and 17 lm/W, respectively, at 500 cd/m(2). The CIE coordinates and CRI of the devices were (0.382, 0.401) and 81, which were almost independent of the drive voltage.