Bimetallic Superlattice Enhances Efficiency and Stability of Top-Emitting Perovskite Light-Emitting Diodes

Although perovskite emitters exhibit high electroluminescence quantum efficiency, the external quantum efficiency (EQE) of perovskite light-emitting diodes (PeLEDs) remains constrained by the refractive index contrast. This limitation is particularly pronounced in TE-PeLEDs, where severe optical losses arise from surface plasmon polarization (SPP) at the interfaces of the two metal electrodes. Here, we introduce a plasmonic scheme that leverages a bimetallic bottom electrode with a superlattice pattern to simultaneously enhance SPP outcoupling and introduce plasmon-enhanced fluorescence. The interplay of reduced optical loss and boosted spontaneous emission yields an EQE of 14.7%, which is the highest reported value for blue top-emitting PeLED. Furthermore, the reduction in energy loss leads to a decrease in device working temperature, thereby producing a 0.57-fold enhancement in operational lifetime. This approach represents a significant step toward bridging the gap between research innovations and industrial applications in display technology.