Multimodal Luminescent Low-Dimension Cs 2 ZrCl 6 : x Sb 3+ Crystals for White Light-Emitting Diodes and Information Encryption

Low-dimension perovskite materials have attracted wide attention due to their excellent optical properties and stability. Herein, Sb -doped Cs ZrCl crystals are synthesized by a coprecipitation method in which Sb ions partially replace Zr ions. The Cs ZrCl : Sb powder shows blue and orange-red emissions under a 254 and 365 nm light, respectively, due to the [ZrCl ] octahedron and [SbCl ] octahedron. The photoluminescence quantum yield (PLQY) of Cs ZrCl : Sb ( = 0.1) crystals is up to 52.5%. According to experimental and computational results, the emission mechanism of the Cs ZrCl : Sb crystals is proposed. On the one hand, a wide blue emission with a large Stokes shift is caused by the self-trapping excitons of [ZrCl ] octahedra under a 260 nm excitation. On the other hand, the luminescence mechanism of [SbCl ] octahedron is divided into two parts: P → S (490 nm) and P → S (625 nm). The broad-band emission, high PLQY, and excellent stability endow the Cs ZrCl : Sb powders with the potential for the fabrication of white light-emitting diodes (WLEDs). A WLED device is fabricated using a commercial 310 nm NUV chip, which shows a high color rendering index of 89.7 and a correlated color temperature of 5333 K. In addition, the synthesized Cs ZrCl : Sb crystals can be also successfully used for information encryption. Our work will provide a deep understanding of the photophysical properties of Sb -doped perovskites and facilitate the development of Cs ZrCl : Sb crystals in encrypting multilevel optical codes and WLEDs.