Efficient open-air synthesis of Mg-doped CsPbI nanocrystals for high-performance red LEDs.

Inorganic CsPbI perovskite nanocrystals (NCs) exhibit remarkable optoelectronic properties for illumination. However, their poor stability has hindered the development of light-emitting diodes (LEDs) based on these materials. In this study, we propose a facile method to synthesize Mg-doped CsPbI NCs with enhanced stability and high photoluminescence (PL) intensity under ambient air conditions. Theoretical calculations confirm that doped NCs possess stronger formation energy compared to undoped NCs. The undoped CsPbI NCs emit red light at approximately 653 nm. We optimize the doping ratio to 1/30, which significantly enhances the photoluminescence of single-particle CsPbI NCs. Subsequently, we fabricate a red LED by combining the CsPbI NCs with a blue chip. The resulting LED, based on the doped CsPbI NCs, exhibits excellent performance with a high luminance of 4902.22 cd m and stable color coordinates of (0.7, 0.27). This work not only presents a simple process for synthesizing perovskite NCs but also provides a design strategy for developing novel red LEDs for various applications.