Enhancing the Light Output‐Coupling of Inverted Top‐Emitting Organic Light‐Emitting Diodes by Using the Localized Surface Plasmon Resonance of Ag Nanoparticles

Abstract In this study, a light out‐coupling layer (LOCL) composed of Ag nanoparticles (NPs) and MoO x is introduced on top of the inverted top‐emitting organic light‐emitting diode (OLED). The full width at half maximum (FWHM) is narrowed to 50 nm due to the micro‐cavity effect of the top‐emitting structure and the turn‐on voltage is as low as 2.6 V. The AgNPs in the LOCL significantly improves the light output‐coupling of the OLED owing to the localized surface plasmon resonance, and the MoO x in the LOCL effectively protects the water‐ and oxygen‐sensitive electron injection material. As a result, the performance of the OLED with the LOCL is significantly enhanced. The maximum current efficiency and external quantum efficiency of the device are increased by 53% and 30% to 28.27 cd A −1 and 13.09%. The enhanced electroluminescent performance of the OLED, together with the narrowed FWHM and the low turn‐on voltage, provides a new way to realize ultra‐high‐definition display and micro‐display.