Highly Luminescent and Ultrastable CsPbBr Perovskite Quantum Dots Incorporated into a Silica/Alumina Monolith.

We successfully prepared QDs incorporated into a silica/alumina monolith (QDs-SAM) by a simple sol-gel reaction of an Al-Si single precursor with CsPbBr QDs blended in toluene solution, without adding water and catalyst. The resultant transparent monolith exhibits high photoluminescence quantum yields (PLQY) up to 90 %, and good photostability under strong illumination of blue light for 300 h. We show that the preliminary ligand exchange of didodecyl dimethyl ammonium bromide (DDAB) was very important to protect CsPbBr QDs from surface damages during the sol-gel reaction, which not only allowed us to maintain the original optical properties of CsPbBr QDs but also prevented the aggregation of QDs and made the monolith transparent. The CsPbBr QDs-SAM in powder form was easily mixed into the resins and applied as color-converting layer with curing on blue light-emitting diodes (LED). The material showed a high luminous efficacy of 80 lm W and a narrow emission with a full width at half maximum (FWHM) of 25 nm.