Light Emitting Diodes Based on Inorganic Composite Halide Perovskites

Abstract

Abstract CsPbBr 3 is a promising type of light‐emitting halide perovskite with inorganic composition and desirable thermal stability. The luminescence efficiency of pristine CsPbBr 3 thin films, however, appears to be limited. In this work, light emitting diodes based on CsPbBr 3 |Cs 4 PbBr 6 composites are demonstrated. Both quantum efficiency and emission brightness are improved significantly compared with similar devices constructed using pure CsPbBr 3 . The high brightness can be attributed to the enhanced radiative recombination from CsPbBr 3 crystallites confined in the Cs 4 PbBr 6 host matrix. The unfavorable charge transport property of Cs 4 PbBr 6 can be circumvented by optimizing the ratio between the host and the guest components and the total thickness of the composite thin films. The inorganic composition of the emitting layer also leads to improved device stability under the condition of continuous operation.