Precipitation of cesium lead halide perovskite nanocrystals in glasses based on liquid phase separation

Incorporation of cesium lead halide perovskite nanocrystals (CsPbX3 PNCs, X = Cl, Br, I) into glasses can significantly improve their stabilities and extend their application areas. Precipitation of CsPbX3 PNCs in glasses is mainly based on thermal treatment; however, the formation of mechanism is not clarified. Here, several in situ methods are employed to illustrate the precipitation mechanism of CsPbX3 PNCs. It is found that precipitation of CsPbX3 PNCs in glasses is based on the liquid phase separation in solid amorphous matrix, followed by crystallization in the supercooled state. Liquid phase separation process determines the composition of CsPbX3 PNCs, and cooling process has strong effect on the crystallinity and quality of CsPbX3 PNCs. These results clarify the precipitation mechanism of CsPbX3 PNCs in glasses and provide important guideline for the development of CsPbX3 PNCs embedded glasses for opto-electronic applications.