Polymeric electrophosphorescent devices with low turn-on voltages and high power conversion efficiency by blending with poly(ethylene glycol)

Abstract

Phosphorescent polymer light-emitting diodes (PLEDs) with low turn-on and operating voltages and high power efficiency have been achieved by blending poly(ethylene glycol) (PEG) into the active layer. The luminance efficiency of the device with Al as the cathode achieves to 16cd/A. In addition, the device performance of this kind device with the Ca/Al and LiF/Ca/Al cathode architecture after blending of 10 wt.% PEG was also investigated. It is found that the driving voltages of the devicse were lower than those of the conventional devices, while the luminance efficiencies remind high. Consequently. a higher power conversion efficiency (14 lm/W) than that of the control device (9 lm/w) has been achieved.