Multimodal Luminescent Low-Dimension Cs<sub>2</sub>ZrCl<sub>6</sub>:<i>x</i>Sb<sup>3+</sup> Crystals for White Light-Emitting Diodes and Information Encryption
Zhilin Li, Qiaoqiao Li, Mengyan Cao, Zhihui Rao, Xinyu Shi, Liujiang Zhou, Xiujian Zhao, Xiao Gong
Abstract
Low-dimension perovskite materials have attracted wide attention due to their excellent optical properties and stability. Herein, Sb 3+ -doped Cs 2 ZrCl 6 crystals are synthesized by a coprecipitation method in which Sb 3+ ions partially replace Zr 4+ ions. The Cs 2 ZrCl 6: x Sb 3+ powder shows blue and orange–red emissions under a 254 and 365 nm light, respectively, due to the [ZrCl 6 ] 2– octahedron and [SbCl 6 ] 3– octahedron. The photoluminescence quantum yield (PLQY) of Cs 2 ZrCl 6: x Sb 3+ ( x = 0.1) crystals is up to 52.5%. According to experimental and computational results, the emission mechanism of the Cs 2 ZrCl 6: x Sb 3+ 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 6 ] 2– octahedra under a 260 nm excitation. On the other hand, the luminescence mechanism of [SbCl 6 ] 3– octahedron is divided into two parts: 1 P 1 → 1 S 0 (490 nm) and 3 P 1 → 1 S 0 (625 nm). The broad-band emission, high PLQY, and excellent stability endow the Cs 2 ZrCl 6: x Sb 3+ 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 2 ZrCl 6: x Sb 3+ crystals can be also successfully used for information encryption. Our work will provide a deep understanding of the photophysical properties of Sb 3+ -doped perovskites and facilitate the development of Cs 2 ZrCl 6: x Sb 3+ crystals in encrypting multilevel optical codes and WLEDs.