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

Metalammonium lead perovskite (MAPbX3 , MA=CH3 NH3 + ; 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 MAPbBr3 QDs by encapsulating them with superhydrophobic fluorinated organosilica (FSiO2 ) shells. The water-resistant stability of the superhydrophobic MAPbBr3 QDs/FSiO2 is significantly enhanced and they display strong fluorescence even after immersion in water for 12 hours. This method is readily extended to prepare superhydrophobic MAPbBr2.4 Cl0.6 QDs/FSiO2 and MAPbI3 QDs/FSiO2 powders. These superhydrophobic MAPbX3 QDs/FSiO2 can be further used to fabricate white light-emitting diodes (LEDs) with comparable color to pure white emission.