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.