文献类型：期刊文献

英文题名：Sulfur Lone Pairs Open Avenues for π* → n Orange-to-Red TADF and OLEDs

作者：Sun, Hao[1,3];Li, Xuping[4];Hsu, Chao-Hsien[2];Hung, Chieh-Ming[2];Wu, Bin[1];Su, Zhe-Hong[2];Baryshnikov, Glib V.[5];Li, Chenzi[1];Agren, Hans[6];Zhang, Zhiyun[7];Huang, Wei[3];Wu, Dayu[3];Chou, Pi-Tai[2];Zhu, Liangliang[1]

机构：[1]Fudan Univ, Dept Macromol Sci, State Key Lab Mol Engn Polymers, Shanghai 200438, Peoples R China;[2]Natl Taiwan Univ, Dept Chem, Taipei 106319, Taiwan;[3]Changzhou Univ, Adv Catalysis & Green Mfg Collaborat Innovat Ctr, Sch Petrochem Engn, Jiangsu Key Lab Adv Catalyt Mat & Technol, Changzhou 213164, Jiangsu, Peoples R China;[4]Inner Mongolia Univ, Coll Energy Mat & Chem, Hohhot 010021, Peoples R China;[5]Linkoping Univ, Dept Sci & Technol, Lab Organ Elect, S-60174 Norrkoping, Sweden;[6]Uppsala Univ, Dept Phys & Astron, S-75120 Uppsala, Sweden;[7]East China Univ Sci & Technol, Key Lab Adv Mat & Feringa Nobel Prize Scientist Jo, Frontiers Sci Ctr Materiobiol & Dynam Chem, Sch Chem & Mol Engn, Shanghai 200237, Peoples R China

年份：2025

卷号：147

期号：6

起止页码：5432

外文期刊名：JOURNAL OF THE AMERICAN CHEMICAL SOCIETY

收录：;EI(收录号：20250617809044);WOS:【SCI-EXPANDED(收录号:WOS:001411200500001)】；

基金：This work was supported by the National Natural Science Foundation of China (NSFC, Grant Nos. 22405053, 22275038, and 22304089). P.-T.C. thanks the National Science and Technology Council, R.O.C (grant no. NSTC-113-2639-M-002-001-ASP) for gracious support. This research was also supported by United Microelectronics Corporation (UMC) Fellowship. G.V.B. acknowledges the financial support from the Swedish Research Council (grant no. 2024-05286), Swedish Government Strategic Research Area in Materials Science on Advanced Functional Materials at Linkoping University (Faculty grant SFO-Mat-LiU no. 2009-00971), and European Union (ERC, LUMOR, 101077649).

语种：英文

外文关键词：Organic light emitting diodes (OLED) - Photoluminescence - Quantum yield - Spin orbit coupling

摘要：It is always important and fascinating to explore new organic emitters that exploit unconventional pathways to unveil their emission with unique properties, such as thermally activated delayed fluorescence (TADF). In this study, we report that the rarely explored sulfur lone pair (n) is a promising alternative, where the correlated pi* -> n emission can be used to attain strong TADF and thus practical OLEDs. The designed strategy incorporates several key concepts (Figure 1a), in which the persulfide aromatic spirocycle enhances spin-orbit coupling, thereby increasing the intersystem crossing rate. Next, molecules with a twisted donor-acceptor configuration bridged by spiro[4.4]nonane as well as spatially orthogonal sulfur lone pairs and pi* features significantly reduce the singlet-triplet gap. Finally, the rigid spirocyclic backbone inhibits nonradiative transitions. The proof-of-concept is given by compound 1, which achieves n pi* thermally activated delayed fluorescence (TADF) maximized at 635 nm with photoluminescence quantum yields as high as 52% in CH2Cl2. Wet-processed OLEDs containing 1 achieved a maximum external quantum efficiency of 6.4% at a brightness of 189 cd m-2 (similar to 600 nm), opening an alternative 1n pi* route for practical pi* -> n TADF OLEDs.