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

Abstract

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.