Hybrid spacer for high-efficiency white organic light-emitting diodes

High-efficient white organic light-emitting diodes (WOLEDs) were fabricated by using the following three different emitting materials: 4 ''-(2,2-diphenylvinyl)-]-[4-(N,N-diphenylamino)styryl]-terphenyl for blue emission, fac-tris(2-phenypyridine) iridium(III) for green emission, and bis(5-benzoyl-2-phenylpyridinato-C, N)iridium (III) (acetylacetonate) for red emission. For higher efficiency, a hybrid spacer (HS) was inserted between each emissive layer (blue-red, red-green, and green-blue emissive layers). It was found that the WOLEDs using HS showed maximum power efficiency of 28.69 lm/W, maximum external quantum efficiency of 13.1%, and Commission Internationale de I'Eclairage coordinates (CIEx,y) of (x=0.37,y=0.37). (C) 2008 American Institute of Physics.