Highly Efficient Sky-Blue Perovskite Light-Emitting Diode Via Suppressing Nonradiative Energy Loss

Metal halide perovskites show significant promise for light-emitting diodes (LEDs) because of superior optoelectronic properties, such as direct band gap, excellent mobilities, and high color purity. Blue perovskite LEDs (PeLEDs), however, still suffer from inferior performance compared with green and near-infrared counterparts. Here, we report a highly efficient sky-blue PeLED operating with an external quantum efficiency of 13.8% based on a quasi-two-dimensional structure. The outstanding efficiency arises from simultaneously suppressing both triplet and trap-assisted nonradiative energy loss via using a ligand with high-triplet-energy and dual-functional passivation groups. Our work proposes a universal strategy to improve the efficiency of sky-blue PeLEDs.