Enhanced power efficiency of single-layer white triplet polymer light-emitting diodes by blending with polymer oxides

Abstract

In this study, we have demonstrated enhanced performance of blue, red and white phosphorescent polymer light-emitting diodes (PLEDs) by blending poly(ethylene glycol) (PEG) into the active layer of the devices. By introducing PEG into the PLEDs, the turn-on voltages of these devices became lower than those of the conventional devices. In addition, the luminance efficiency and the external quantum efficiency of the blue and while phosphorescent PLEDs were both improved. Most important of all, because of the lower operating voltage, the higher power efficiency (7.3 lm/W, 1.5 lm/W, 4.61m1W) of the blue, red and white phosphorescent PLEDs than those of the control devices (2.9 lm/W, 1. 1 lm/W, 1. 9 lM/W) have been achieved, respectively. Finally, the improvement mechanism will be discussed.