Synthesis of ultra-stable perovskite composite quantum dots for light-emitting diodes

CsPbX3 (X = Cl, Br, and I), as a potential luminescent material with excellent optical characteristics, has attracted researchers for several years but it is difficult to use it commercially due to its low stability. Herein, a simple green process was successfully optimized without using any solvents for synthesizing an ultra-stable CsPbBr3@SiO2 composite. The phase transformation process in obtaining the CsPbBr3@SiO2 composite was resolved according to in situ X-ray diffraction measurements. Based on the results, the best sintering condition for the CsPbBr3@SiO2 composite was obtained, realizing the highest photoluminescence quantum yield of 15.5%. The obtained CsPbBr3@SiO2 exhibited a narrowband green emission and achieved ultra-high stability with an intensity of 100% being maintained after the 196 h test under double-85 conditions. Moreover, it maintained the emission intensity and color coordinate during the 1000 h irradiation test in the light-emitting diode package. This excellent performance revealed the great potential of the CsPbBr3@SiO2 composite for commercialization in backlight applications.