Researchers from Xiamen University and China Jiliang University have reported ultrahigh-efficiency green PeLEDs with quantum efficiencies surpassing a milestone of 30% by regulating the charge carrier transport and near-field light distribution to reduce electron leakage and achieve a high light outcoupling efficiency of 41.82%.
The scientists applies Ni0.9Mg0.1Ox films with a high refractive index and increased hole carrier mobility as the hole injection layer to balance the charge carrier injection and insert the polyethylene glycol layer between the hole transport layer and the perovskite emissive layer to block the electron leakage and reduce the photon loss.
With the modified structure, the resulting green PeLEDs reportedly achieved a world-record external quantum efficiency of 30.84% (average = 29.05 ± 0.77%) at a luminance of 6514 cd/m2.
This work provides an interesting idea to construct super high-efficiency PeLEDs by balancing the electron-hole recombination and enhancing the light outcoupling.
