Hybrid Plasmon Mode Enhancing the Lifetime and Forward‐Directional Emission for Solution‐Processed OLEDs

AbstractOngoing research is dedicated to tackling the trade‐off between out‐coupling efficiency, transparency, and conductivity for transparent conductive electrodes (TCEs), owing to their continuously increasing application in smartphones/watches, augmented/virtual reality, and naked eye 3D projection. Herein, an aluminum substrate‐mediated hybrid plasmon mode is deliberately embedded in solution‐processed organic light‐emitting diode (SOLED). The created TCE with a 6‐nm‐Al film‐mediated indium tin oxide (ITO) displays an average transmittance of 88.3%, an average ultra‐low haze of 0.2%, and a sheet resistance of 9.5 Ω sq−1, surpassing commercial ITO substrates. By precisely controlling the geometry of this aluminium film/dielectric spacer/silver nanoparticle (Al film‐TAPC‐Ag NP) coupled system, a hybrid dipolar, and quadrupolar mode is required, providing further enhanced scattering strength and plasmon coupling effect in the resultant OLED. These Al film‐TAPC‐Ag NP system mediated SOLEDs display improved decay rate of triplet excitons, elevated electroluminescence out‐coupling efficiency, and suppressed waveguide confinement. Consequently, enhanced stability by 10% after 580 h storage without encapsulation, forward‐directed emission with a ± 70° light‐emitting angle, and a 22% current efficiency enhancement are simultaneously realized, compared with conventional SOLEDs. This work presents new opportunities for LED design and for the implementation of solution‐processed LEDs in large‐area high‐performance displays.