Highly processable and stable PMMA-grafted CsPbBr3-SiO2 nanoparticles for down-conversion photoluminescence

The recent trend in display fabrication using well-controlled composites containing phosphor requires achieving the desired property of their nanocomposites in accordance with the optoelectronic properties and morphological details of the constituent materials. While several approaches lead to good photostability of CsPbX3 (X = Cl, Br, I) via proper encapsulation, practical deposition and patterning techniques require a complicated post-process to avoid the formation of considerable aggregates, cracks, and non-uniform packing during their drying process. Here, we report a new strategy to synthesize PMMA-grafted mesoporous SiO2 nanoparticles (NPs) with infiltrated CsPbX3 nanocrystals (NCs) by a solid-state reaction at high temperatures (300-800 degrees C) and subsequent surface-initiated atom transfer radical polymerization. The CsPbX3 NCs embedded in the mesoporous SiO2 NPs exhibited excellent photostability (photoluminescence intensity similar to 100%) for more than 5 months under various polar solvents. In particular, PMMA brushes on the surface of CsPbX3-SiO2 NPs provided improved wettability, leading to high polymeric processability and mechanical properties (elastic modulus = 3.99 GPa, hardness = 0.21 GPa) of PMMA-grafted CsPbX3-SiO2 films. The combination of photostability and polymeric processability based on PMMA-grafted CsPbX3-SiO2 NPs provides novel opportunities for low-cost and simple solution-processable multifunctional fluorescence materials in optoelectronics and biological imaging without severely compromising the auxiliary characteristics.

Automated summary

A new strategy was developed to synthesize PMMA-grafted mesoporous SiO2 nanoparticles (NPs) infiltrated with CsPbX3 nanocrystals (NCs) with excellent photostability. The PMMA brushes on the surface of CsPbX3-SiO2 NPs improved wettability and processing properties, providing novel opportunities for low-cost and simple solution-processable multifunctional fluorescence materials.