Zhang Yongfeng, Gao Liang, Zheng Xian, Wang Zhonghao, Yang Chaolong, Tang Hailong, Qu Lunjun, Li Youbing, Zhao Yanli
School of Materials Science and Engineering, Chongqing University of Technology, Chongqing, China.
Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore.
Nat Commun. 2021 Apr 16;12(1):2297. doi: 10.1038/s41467-021-22609-y.
Room temperature phosphorescence (RTP) has drawn extensive attention in recent years. Efficient stimulus-responsive phosphorescent organic materials are attractive, but are extremely rare because of unclear design principles and intrinsically spin-forbidden intersystem crossing. Herein, we present a feasible and facile strategy to achieve ultraviolet irradiation-responsive ultralong RTP (IRRTP) of some simple organic phosphors by doping into amorphous poly(vinyl alcohol) matrix. In addition to the observed green and yellow afterglow emission with distinct irradiation-enhanced phosphorescence, the phosphorescence lifetime can be tuned by varying the irradiation period of 254 nm light. Significantly, the dynamic phosphorescence lifetime could be increased 14.3 folds from 58.03 ms to 828.81 ms in one of the obtained hybrid films after irradiation for 45 min under ambient conditions. As such, the application in polychromatic screen printing and multilevel information encryption is demonstrated. The extraordinary IRRTP in the amorphous state endows these systems with a highly promising potential for smart flexible luminescent materials and sensors with dynamically controlled phosphorescence.
室温磷光（RTP）近年来受到广泛关注。高效的刺激响应性磷光有机材料很有吸引力，但由于设计原理不明确以及本质上自旋禁阻的系间窜越，这类材料极为罕见。在此，我们提出一种可行且简便的策略，通过将一些简单有机磷光体掺杂到非晶态聚乙烯醇基质中，实现对紫外线照射响应的超长RTP（IRRTP）。除了观察到具有明显辐照增强磷光的绿色和黄色余辉发射外，磷光寿命可以通过改变254nm光的辐照时间来调节。值得注意的是，在环境条件下照射45分钟后，在其中一种获得的混合薄膜中，动态磷光寿命可从58.03毫秒增加14.3倍至828.81毫秒。因此，展示了其在多色丝网印刷和多级信息加密中的应用。非晶态下的非凡IRRTP赋予这些体系在具有动态可控磷光的智能柔性发光材料和传感器方面极具潜力。
