초록 |
Metal halide perovskites is a promising emitting material in light-emitting diodes (PeLEDs) due to many advantages such as high color purity. Here, we present high-efficiency PeLEDs where the perovskite layers are in forms of (1) 3D polycrystalline films, (2) quasi-2D polycrystalline films, (3) nanoparticles (NPs). First, we introduced a self-organized buffer hole injection layer to reduce the hole injection barrier and prevent luminescence quenching at the interface. We also decreased grain size, improved film uniformity, controlled the stoichiometry in methylammonium lead bromide layers and developed high efficiency PeLEDs (current efficiency = 42.9 cd/A). Second, we developed efficient quasi-2D PeLEDs that incorporate perovskite emission layers with Ruddlesden-Popper phase. Third, we synthesized colloidal ligand-engineered perovskite NPs and fabricated efficient PeLEDs. |