CsPbBr3/CH3NH3PbCl3 Double Layer Enhances Efficiency and Lifetime of Perovskite Light-Emitting Diodes

At present, perovskite light-emitting diodes are mostly based on various forms of nanostructures exploiting their exciton confinement property. However, the few reports utilizing bulk or polycrystalline perovskites have been limited in application because of the difficulties of forming high-quality films, especially on the existing organic charge transport layers. When these charge transport organics are exchanged with thicker CH3NH3PbCl3, the emitting CsPbBr3 thick polycrystalline films containing CH3NH3Br are conformally deposited with improved luminescence quality without driving voltage increase. Enhanced crystallinity and prolonged photoluminescence are observed by exploiting interfacial defect passivation and the strain-induced effect in the hetero-structures. This approach could lead to high-performance light-emitting diodes and may also be extended to other perovskite devices.