近日，香港城市大学的Feng Wang及其研究小组与西北大学的郭崇峰等人合作并取得一项新进展。经过不懈努力，他们实现双钙钛矿单晶中多激子态的激发模式选择性发射。相关研究成果已于2025年1月2日在国际知名学术期刊《光：科学与应用》上发表。

该研究团队报道了一类掺锑的钪基双钙钛矿晶体，该类晶体能在紫外、蓝色和黄色光谱区域产生多激子发射。由于晶体格子的零维特性最大限度地减少了能量串扰，因此可以通过紫外线、X射线辐照和机械作用选择性激发晶体中的不同激子态，从而通过调节激发模式实现对稳态/瞬态光谱特征的动态控制。

值得注意的是，这种透明晶体展现出高效的白色光致发光（量子产率>97%）、具有长余辉（持续时间>9小时）的X射线激发蓝色发射，以及高亮度的自重现蓝紫色机械发光。这些发现揭示了低维钙钛矿晶体在集成各种激子发光方面的卓越能力，为多级数据加密和一体化认证技术提供了令人兴奋的新机遇。

据悉，低维无铅金属卤化物钙钛矿材料对前沿光电子应用具有极高的吸引力。

附：英文原文

Title: Excitation-mode-selective emission through multiexcitonic states in a double perovskite single crystal

Author: Suo, Hao, Wang, Nan, Zhang, Yu, Zhang, Xin, Xiang, Jinmeng, Wang, Xiaojia, Xing, Guansheng, Guo, Dongxu, Chang, Jiwen, Wang, Yu, Li, Panlai, Wang, Zhijun, Zhang, Yuhai, Chen, Bing, Li, Shuzhou, Guo, Chongfeng, Wang, Feng

Issue&Volume: 2025-01-02

Abstract: Low-dimensional lead-free metal halide perovskites are highly attractive for cutting-edge optoelectronic applications. Herein, we report a class of scandium-based double perovskite crystals comprising antimony dopants that can generate multiexcitonic emissions in the ultraviolet, blue, and yellow spectral regions. Owing to the zero-dimensional nature of the crystal lattice that minimizes energy crosstalk, different excitonic states in the crystals can be selectively excited by ultraviolet light, X-ray irradiation, and mechanical action, enabling dynamic control of steady/transient-state spectral features by modulating the excitation modes. Remarkably, the transparent crystal exhibits highly efficient white photoluminescence (quantum yield >97%), X-ray excited blue emission with long afterglow (duration >9h), and high-brightness self-reproducible violet-blue mechanoluminescence. These findings reveal the exceptional capability of low-dimensional perovskite crystals for integrating various excitonic luminescence, offering exciting opportunities for multi-level data encryption and all-in-one authentication technologies.

DOI: 10.1038/s41377-024-01689-7

Source: https://www.nature.com/articles/s41377-024-01689-7