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

Abstract The photoluminescence quantum yield (PLQY) of CsPbBr 3 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 CsPbBr 3 NCs impedes their applications. Here, a facile method is reported to synthesize CsPbBr 3 @ZrO 2 NCs at room temperature in air. Owing to using ZrO 2 coated CsPbBr 3 NCs, the prepared CsPbBr 3 @ZrO 2 NCs not only present a PLQY of 80% but also exhibit an enhanced stability to heat and moisture. Furthermore, WLEDs are fabricated with CsPbBr 3 @ZrO 2 NCs and commercial red phosphors (CaAlSiN 3 :Eu 2+ ) 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 CsPbBr 3 @ZrO 2 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.