Enhanced OLED Efficiency via Gold Nanoparticle Doped PEDOT: PSS as a Hole Injection Layer

Abstract

In this work, organic light-emitting diodes (OLEDs) were fabricated with a modified hole injection layer (HIL) by incorporating gold nanoparticles (AuNPs) into poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT: PSS). AuNPs with an average size of ~30 nm was introduced at different volume ratio to investigate their influence on charge injection and electroluminescence performance. The optimized device with a 1:4 AuNPs/PEDOT:PSS ratio achieved a reduced turn-on voltage of 2.2 V and significantly enhanced luminance compared to the pristine device. These improvements are attributed to localized surface plasmon resonance (LSPR), which promotes charge balance, exciton generation, and radiative recombination. Electroluminescence spectra showed broadened emission over 300–800 nm with tunable correlated color temperatures (2000–3500 K), This study demonstrates that embedding AuNPs into PEDOT: PSS offers a simple and scalable strategy for improving OLED efficiency and advancing next-generation optoelectronic devices.