Highly efficient white organic light-emitting diodes using two emitting materials for three primary colors (red, green, and blue)

The authors have demonstrated highly efficient white organic light-emitting diodes (WOLEDs) by using two emissive materials as a dopant, 1,4-bis[2-(7-N-diphenyamino-2-(9,9-diethyl-9H-fluoren-2-yl)) vinyl] benzene (DAF-ph) and iridium(III) bis(5-acetyl-2-phenylpyridinato-N,C2′) acetylacetonate ((acppy)2Ir(acac)). It was found that the OLED fabricated in this study emitted a white color consisting of three primary colors (red, green, and blue). The luminance-voltage (L-V) characteristics of the WOLEDs showed the maximum luminance of 30500cd∕m2 at 14V and the maximum luminous efficiency of 38.0cd∕A, respectively. The CIEx,y coordinates of the WOLED also showed (x=0.33, y=0.40) at 10V.