Ion-exchange controlled precipitation of CsPbX3 nanocrystals in glasses

Embedding CsPbX3 (X--Cl, Br, I) perovskite nanocrystals (PNCs) into glasses can significantly improve the chemical and thermal properties, and show promising applications in photonic fields. Spatially controlled pre-cipitation of PNCs in glasses is necessary for the fabrication of structured devices. Here, we report that spatially controlled precipitation of CsPbX3 PNCs in the surface layer of glasses through ion-exchange in molten cesium nitrate salt. Spatial distribution and average diameter of CsPbX3 PNCs are mainly determined by the distribution of Cs+ and halide ions, and composition of CsPbX3 PNCs is mainly determined by the composition of host glass. Through ion-exchange, CsPbCl3_xBrx and CsPbBr3_xIx PNCs with tunable compositions are precipitated in the surface layer of glasses, and efficient photoluminescence spanning from blue to cyan, green, yellow, orange, and red is realized. Our results demonstrate that ion-exchange is promising to fabricate planar and linear waveguides and various microstructures based on CsPbX3 PNCs embedded glasses.