Enhancing the stability of CsPbX3 (X = Br, I) through combination with Y-zeolites for WLED application

Abstract

The stability of perovskite quantum dots (PQDs) plays a vital role in practical devices. Besides silica coating, embedding PQDs in zeolites is another strategy to improve their stability significantly. Although the zeolite rigid framework has been reported to protect PQDs, there are few reports on the in situ synthesis of PQDs in zeolites. In this work, cubic phase CsPbX₃ (X = Br, I) nanocrystals were successfully prepared by the ion exchange method combined with a non-polar organic trigger. Dropping a certain amount of ZnM₂ (M = Br, I) solution into the intermediate product Cs₄PbCl₆ nanocrystals resulted in the formation of the final CsPbX₃ nanocrystals. The ZnM₂ solutions were prepared in non-polar solvents (hexane, octane, or chloroform). The highest photoluminescence quantum yield (PLQY) of the synthesized CsPbX₃@zeolite composites can reach 83%, with a lifetime of 1.37 μs. The stability of the CsPbX₃@zeolite composites thin film against damage from air and light is significantly improved. We fabricated white light-emitting diodes (WLEDs) using CsPbBr₃@zeolite as the green light source and CsPbI₃@zeolite as the red light source to further emphasize the practical application effect of the CsPbX₃@zeolite composites. This work not only provides a new method for the synthesis of CsPbX₃ nanocrystals but also involves the in situ synthesis of high stability CsPbX₃@zeolite composites within the zeolite.