Gold nanoparticles modified ITO anode for enhanced PLEDs brightness and efficiency

We reported a facile and controllable electrostatic adsorption of gold nanoparticles (Au NPs) on an indium tin oxide (ITO) anode, for applications in polymer light-emitting diodes (PLEDs). Au NPs (size 20 nm) were found to be well dispersed on a pre-treated ITO anode, and the density of Au NPs was well controlled from 0 to 60 mu m super(-2) depending on the adsorption time. By using the Au NPs modified ITO as the anode, the optimized PLEDs showed a 60% enhancement in brightness and 40% enhancement in luminous efficiency. Our results showed that the enhancement of devices performance mainly originated from enhanced photoluminescence, the maximum of luminous efficiency appeared when the distance of Au NPs and light emission profile was about 40-80 nm, which indicated that the origin of enhanced luminescence is due to the "far-field" effect of the Au NPs layer rather than a classical localized surface plasma resonance.