ABSTRACT
Highly ecient large-area light sources call for the development of white organic light-emitting diodes (WOLEDs) (Zhi-lin et al. 2001). WOLEDs having eciencies reaching 90 lm/W at 1000 cd/m2 are practicable, promising to be increased to 124 lm/W by improving the light outcoupling e- ciency (Reineke et al. 2009). Indeed, the most gorgeous emitting color in LED industry is the white color because it oers numerous benets in lighting technology such as energy saving in architectural lighting, ashlights, backlighting of liquid crystal displays, and full color displays of larger areas by union with color lters (Cho et al. 2010, Oner et al. 2011).
