A review of low-dimensional metal halide perovskites for blue light emitting diodes

Low-dimensional metal halide perovskites (LMHPs) hold promising potential for light emitting diodes due to high color purity, strong exciton binding energy, and facile film fabrication of the emitting layer. However, in contrast with red and green counterparts, blue light emitting diodes (LEDs) still encounter some tough problems in efficiency, luminance, and operational stability. In recent years, dramatically increasing investigations have been devoted to the synthesis method of LMHPs for blue LEDs. Herein, we describe the recent advances on blue low-dimensional perovskites involving zero-dimensional quantum dots (0D QDs), two-dimensional nanoplatelets (2D NPLs), and quasi-two-dimensional perovskites (quasi-2D perovskites) as well as the related devices. Further, we provide a new perspective for the development of blue-emissive perovskite LEDs in industrialization, including the strategies for improving performance and solutions for major challenges regarding deep-blue perovskite LEDs.