Highly efficient sky-blue perovskite light-emitting diodes based on buried interface modification

In this work, KCl was used as the modification layer between the hole injection layer (HIL) and the perovskite film. KCl particles at the surface of HIL served as seeds, which improved the morphology and modulated the n phases distribution of perovskite film. K+ + entered the perovskite lattice by replacing Cs+ + at A site. The interaction between Cl-- and PEA+ + in perovskite film were studied. The EQE of PeLED increased from 4.85 % to 8.70 % with a sky-blue emission at 488 nm. This work provided a facial and effective method to modulate the n phase distribution of perovskite film and enhance the performance of PeLED.