Centrifugal-Coated Quasi-Two-Dimensional Perovskite CsPb2Br5 Films for Efficient and Stable Light-Emitting Diodes

The optical, structural, and electroluminescent (EL) characteristics of pure quasi-2D CsPb2Br5 were reported. We fabricated continuous, compact, well-crystallized CsPb2Br5 films by centrifugal coating from a colloidal solution containing CsPb2Br5 nanoparticles. The centrifugal-coated CsPb2Br5 films have a photoluminescence quantum yield (PLQY) of similar to 35% because of its low-dimensional structure. Taking advantage of the high PLQY, we fabricated perovskite light-emitting diodes (PeLEDs) with a centrifugal coated CsPb2Br5 emitting layer exhibiting bright green EL, a maximum luminance of 7317 cd m(-2), an and external quantum efficiency of 1.1%. Additionally, the EL color could be changed easily from green to red using a halogen exchange method. The half lifetime of our CsPb2Br5 PeLEDs reached around 6 h under continuous operation at 10 mA cm(-2).