Electrical and Optical Properties of Green Polymer Light Emitting Diodes with Various Structures of Au Nanoparticles

The green polymer light emitting diodes (PLEDs) were fabricated using the solution precursor synthesis method. To improve the device's electrical and optical properties, gold (Au) nanoparticles (NPs) were added to the hole injection layer (HIL) with poly(3,4-ethylenedioxythiophene):poly(styrenesulfolnate) (PEDOT: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 20430 cd/m(2) and 7.49%, respectively.