Room Temperature Synthesis of Stable Zirconia-Coated CsPbBr3 Nanocrystals for White Light-Emitting Diodes and Visible Light Communication

The photoluminescence quantum yield (PLQY) of CsPbBr3 perovskite nanocrystals (NCs) prepared by the hot-injection method can exceed 90%, which have attracted intensive attention for white light-emitting diodes (WLEDs). However, the whole hot-injection experiment requires air isolation and relatively high temperature. In addition, the poor stability of CsPbBr3 NCs impedes their applications. Here, a facile method is reported to synthesize CsPbBr3@ZrO2 NCs at room temperature in air. Owing to using ZrO2 coated CsPbBr3 NCs, the prepared CsPbBr3@ZrO2 NCs not only present a PLQY of 80% but also exhibit an enhanced stability to heat and moisture. Furthermore, WLEDs are fabricated with CsPbBr3@ZrO2 NCs and commercial red phosphors (CaAlSiN3:Eu2+) on blue LEDs chips. The fabricated WLEDs exhibit a correlated color temperature (CCT) of 4743 K and luminous efficacy as high as 64.0 Lm W-1. In addition, visible light communication with a high data rate of 33.5 Mbps is achieved using the WLEDs. This work provides a room temperature strategy to coat zirconia for CsPbBr3@ZrO2 NCs, benefiting to enhance the optical performance and stability, as well as the promotion of the great potentials in solid-state illuminating and visible light communication applications.