Stable Perovskite Quantum Dots Coated with Superhydrophobic Organosilica Shells for White Light-Emitting Diodes.

Metalammonium lead perovskite (MAPbX , MA=CH NH ; X=Cl, Br, I) quantum dots (QDs) have attracted tremendous attention due to their outstanding optical properties. However, they usually suffer from poor stability towards water or moisture, which seriously limits their practical applications. Here, we report a simple and effective approach to improve the stability of MAPbBr QDs by encapsulating them with superhydrophobic fluorinated organosilica (FSiO ) shells. The water-resistant stability of the superhydrophobic MAPbBr QDs/FSiO is significantly enhanced and they display strong fluorescence even after immersion in water for 12 hours. This method is readily extended to prepare superhydrophobic MAPbBr Cl QDs/FSiO and MAPbI QDs/FSiO powders. These superhydrophobic MAPbX QDs/FSiO can be further used to fabricate white light-emitting diodes (LEDs) with comparable color to pure white emission.