Enhancing the Stability of CH₃NH₃PbBr₃ Nanoparticles Using Double Hydrophobic Shells of SiO₂ and Poly(vinylidene fluoride)

The instability of lead halide perovskites (LHPs) has tremendously hindered their practical applications. Although some examples on encapsulating LHPs into a SiO2 shell have been reported, these SiO2-coated LHPs still suffer from limited stability. Herein, MAPbBr3 (MA = CH3NH3+) nanoparticles encapsulated in double hydrophobic shells of organic functionalized SiO2 and poly(vinylidene fluoride) (MAPbBr3@SiO2/PVDF) are successfully synthesized by infiltrating the MAPbBr3 precursor solution into hollow siliceous nanospheres and followed by PVDF capping. With the dual protection of SiO2 and PVDF, the MAPbBr3@SiO2/PVDF nanoparticles exhibit drastically improved stability against water and UV-light illumination. A white light-emitting diode with luminous efficiency up to 147.5 lm W–1 and a color gamut encompassing 120% of National Television System Committee in Commission Internationale de L’Eclairage 1931 color space has been demonstrated using the MAPbBr3@SiO2/PVDF nanoparticles as the green light source. This study enlightens new insights into the synthesis of highly stable LHPs-based core–shell–shell architectures toward their practical applications.