Efficient Spin-Flip between Charge-Transfer States for High-Performance Electroluminescence, without an Intermediate Locally Excited State  

作　　者：Donghai Zhang Shanshan Jiang Xiaodong Tao Fulin Lin Lingyi Meng Xu-Lin Chen Can-Zhong Lu 

机构地区：[1]State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou,Fujian 350002,China [2]Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China,Fuzhou,Fujian 350108,China [3]Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials,Xiamen Institute of Rare Earth Materials,Haixi Institutes,Chinese Academy of Sciences,Xiamen,Fujian 361021,China [4]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Research》2024年第1期339-349,共11页研究（英文）

基　　金：the National Natural Science Foundation of China(Grant Nos.52073286 and 21805281);the Natural Science Foundation of Fujian Province(Grant No.2006L2005);the Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China(Grant Nos.2021ZR132 and 2021ZZ115);the Youth Innovation Foundation of Xiamen City(Grant Nos.3502Z20206082 and 3502Z20206083).

摘　　要：Thermally activated delayed fluorescence(TADF)materials with both high photoluminescence quantum yield(PLQY)and fast reverse intersystem crossing(RISC)are strongly desired to realize efficient and stable organic light-emitting diodes(OLEDs).Control of excited-state dynamics via molecular design plays a central role in optimizing the PLQY and RISC rate of TADF materials but remains challenging.Here,3 TADF emitters possessing similar molecular structures,similar high PLQYs(89.5%to 96.3%),and approximate energy levels of the lowest excited singlet states(S_(1)),but significantly different spin-flipping RISC rates(0.03×10^(6) s^(−1) vs.2.26×10^(6) s^(−1))and exciton lifetime(297.1 to 332.8μs vs.6.0μs)were systematically synthesized to deeply investigate the feasibility of spin-flip between charge-transfer excited states(^(3)CT–^(1)CT)transition.

关 键 词：transition LIFETIME DESIRED 

分 类 号：TN312[电子电信—物理电子学]