The strategies for preparing blue perovskite light-emitting diodes

Abstract

Abstract Metal halide perovskites have attracted tremendous interest due to their excellent optical and electrical properties, and they find many promising applications in the optoelectronic fields of solar cells, light-emitting diodes, and photodetectors. Thanks to the contributions of international researchers, significant progress has been made for perovskite light-emitting diodes (Pero-LEDs). The external quantum efficiencies (EQEs) of Pero-LEDs with emission of green, red, and near-infrared have all exceeded 20%. However, the blue Pero-LEDs still lag due to the poor film quality and deficient device structure. Herein, we summarize the strategies for preparing blue-emitting perovskites and categorize them into two: compositional engineering and size controlling of the emitting units. The advantages and disadvantages of both strategies are discussed, and a perspective of preparing high-performance blue-emitting perovskite is proposed. The challenges and future directions of blue Pero-LEDs fabrication are also discussed.