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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.

PSS) organic material. The green PLED devices with a structure of glass/ITO/PEDOT:PSS+Au NPs/PVK:Ir(ppy)3/TPBi/LiF/Al were prepared by conventional spin-coating and thermal evaporation methods. Various concentrations of Au NPs were doped to the HILs to optimize the device's light emitting characteristic. The effects of Au NPs concentrations on the properties of PLEDs were investigated. The doping concentrations of Au NPs were changed ranging from 0.0 to 1.0 vol%. At the optimized Au NPs concentration of 0.5 vol%, we also studied the effects of various film layers with and without Au NPs on the properties of PLEDs. The maximum luminance and external quantum efficiency of the devices were found to be 20,430 cd/m2 and 7.49%, respectively.