Fabrication and Characterization of White Phosphorescent Polymer Light Emitting Diodes Using PVK:FCNIrpic:Ir(mppy)₃:Ir(piq)₃

Abstract

White phosphorescent polymer light emitting diodes (WPhPLEDs) with a glass/ITO/ PEDOT:PSS/PVK:FCNIrpic:Ir(mppy) 3 :Ir(piq) 3 /TPBI/LiF/Al structure were fabricated to investigate the effects of the doping concentration of Ir(piq) 3 emission materials. The PVK, FCNIrpic, Ir(mppy) 3 and Ir(piq) 3 organic materials as the host and guest emission materials were spin coated at various concentrations of Ir(piq) 3 ranging from 0.1 to 0.4 wt%. With increasing the concentration of Ir(piq) 3 from 0.1 to 0.3 wt%, the luminance was increased clearly. However, the luminance was decreased by 6400 cd/m 2 when the Ir(piq) 3 doping concentration reached 0.4 wt%. The drop in luminance is caused by the quenching effect at a high doping concentration. The maximum luminance and current efficiency were 9486 cd/m 2 and 2.23 cd/A, respectively for WPhPLED with 0.3 wt% of Ir(piq) 3 . The average CIE color coordinates for the WPhPLED with 0.2 wt% of Ir(piq) 3 were about (x=0.32, y=0.33) at 12V, showing a good white emission color.