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 CsPbX 3 (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 SiO 2 nanoparticles (NPs) with infiltrated CsPbX 3 nanocrystals (NCs) by a solid-state reaction at high temperatures (300–800 °C) and subsequent surface-initiated atom transfer radical polymerization . The CsPbX 3 NCs embedded in the mesoporous SiO 2 NPs exhibited excellent photostability (photoluminescence intensity ∼100%) for more than 5 months under various polar solvents . In particular, PMMA brushes on the surface of CsPbX 3 -SiO 2 NPs provided improved wettability , leading to high polymeric processability and mechanical properties (elastic modulus = 3.99 GPa, hardness = 0.21 GPa) of PMMA-grafted CsPbX 3 -SiO 2 films. The combination of photostability and polymeric processability based on PMMA-grafted CsPbX 3 -SiO 2 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. PMMA-grafted CsPbBr 3 –SiO 2 nanoparticles provide not only distinct enhancement of the photostability in various chemical environments but also excellent processability and surface wettability in the process of film formation, which is a prerequisite for their practical application.