Nakadai Yuki, Tsuchiya Shuta, Uehara Masumi, Umezawa Sena, Motoki Reina, Umezawa Hibiki, Ikoma Tadaaki, Yui Tatsuto
Department of Materials Science and Technology, Faculty of Engineering, Niigata University, 8050 Ikarashi-2, Niigata950-2181, Japan.
Graduate School of Science and Technology, Niigata University, 8050 Ikarashi-2, Niigata950-2181, Japan.
J Phys Chem B. 2022 Oct 20;126(41):8245-8250. doi: 10.1021/acs.jpcb.2c04109. Epub 2022 Oct 10.
A triplet-triplet annihilation-based photon upconversion (TTA-UC) system with a low threshold excitation intensity () in plain water was developed. Water-soluble anionic porphyrin (PdTPPS) and diphenylanthracene (DCDPA) derivatives were used as light absorbers and emitter molecules, respectively, and no additives such as surfactants were required. The phosphorescence emission from PdTPPS under an excitation wavelength of 528 nm was quenched by DCDPA, resulting in triplet energy transfer, whereas fluorescence from DCDPA was observed in a short wavelength region (400-500 nm). Three independent emission studies utilizing different excitation light sources validated the TTA-UC process in a simple aqueous solution. TTA occurred after the triplet energy transfer, according to the time profiles of phosphorescence and fluorescence detected following pulse laser excitation. The for TTA-UC was estimated to be lower than 6 mW cm, although it could not be exactly determined due to the sensitivity limit of the experimental setup. The upper limit of for the aqueous solution of DCDPA and PdTPPS is the smallest value obtained to date for aqueous systems and comparable to that of high-performance TTA-UC systems in organic solutions.
开发了一种基于三重态-三重态湮灭的光子上转换（TTA-UC）系统，其在纯水中具有低阈值激发强度（）。水溶性阴离子卟啉（PdTPPS）和二苯基蒽（DCDPA）衍生物分别用作光吸收剂和发射体分子，并且不需要诸如表面活性剂之类的添加剂。在528 nm激发波长下，PdTPPS的磷光发射被DCDPA淬灭，导致三重态能量转移，而在短波长区域（400 - 500 nm）观察到DCDPA的荧光。利用不同激发光源进行的三项独立发射研究验证了在简单水溶液中的TTA-UC过程。根据脉冲激光激发后检测到的磷光和荧光的时间分布，三重态能量转移后发生了TTA。尽管由于实验装置的灵敏度限制无法精确确定，但TTA-UC的估计值低于6 mW cm。DCDPA和PdTPPS水溶液的上限是迄今为止在水性体系中获得的最小值，并且与有机溶液中的高性能TTA-UC系统相当。
