Effect of hydrophobic silica aerogels in-situ on encapsulation the stability of CsPbBr3 quantum dots for white light-emitting diodes

Abstract

Despite the outstanding optical features of lead halide perovskite quantum dots (QDs), they are troubled by stability issues that hinder their prospects in practical applications. Herein, the CsPbBr3 QDs generated here were grown in situ in hydrophobic silica aerogels (SiO2 AGs). More importantly, the photoinitiated cross-linking reaction of the capping ligands, conjugated linoleic acids (CLA), forms hydrophobic polymer shells from CsPbBr3 QDs@SiO2 AGs-poly. And these polymer shells further improve the water stability of QDs. The composite retains 83 % photoluminescence (PL) intensity after being dispersed in water for five days. And SiO2 AGs also act as confined templates owing to their unique porous structure to avoid aggregation and regrowth of QDs in the polymerization process of CLA. With the combined effects of SiO2 AGs and polymer shells, the composite shows remarkable optical performance with a high absolute quantum yield (QY) (89.08 %). And this green-emitting composite was applied as a luminescent material in a white light-emitting diode (WLED), which exhibited excellent luminescence with the color coordinates of (0.3344, 0.3253) and light efficiency of 28.8 lm/W at 20 mA, and light stability under large current.