Immensely enhanced color-adjustable upconversion fluorescence in electron donor-acceptor exciplex chromophores doped with fluorescent emitters  

作　　者：ZHEN CHEN QIAN ZHOU HUITIAN DU YUAN YU CHUANG ZHANG SHENGHAO HAN ZHIYONG PANG 

机构地区：[1]School of Microelectronics,State Key Laboratory of Crystal Materials,Shandong University,Jinan 250100,China [2]Institute of Chemistry,Chinese Academy of Sciences,Beijing 100190,China

出　　处：《Photonics Research》2021年第5期865-872,共8页光子学研究（英文版）

基　　金：National Natural Science Foundation of China(11874237);Natural Science Foundation of Shandong Province(ZR2018MF030);Major Program of Shandong Province Natural Science Foundation(ZR2019ZD43)。

摘　　要：Two-photon excited fluorescence materials usually suffer from inefficient two-photon absorption(TPA) and nonradiative excited states. Here, upconversion fluorescence in an electron donor-acceptor(DA) exciplex doped with fluorescent emitters are systematically investigated. It has been found that the undoped DA exciplex exhibits enhancements of ~129% and ~365% in upconversion fluorescence compared to donor-and acceptor-only systems, respectively. Interestingly, photoluminescence quantum yields(PLQYs) up to ~98.65% were measured and immensely enhanced upconversion fluorescence was observed after doping various fluorescent emitters into the DA exciplex. Our results reveal the existence of two-photon excited energy harvesting in a thermally activated delayed fluorescence(TADF) DA exciplex doped with fluorescent emitters, via reverse intersystem crossing followed by rapid F?rster resonance energy transfer. Moreover, the additional gain mechanism related to intermolecular CT interaction that occurs at the TPA stage is found in the TADF DA exciplex system.

关 键 词：DONOR ACCEPTOR excited 

分 类 号：O43[机械工程—光学工程]