作者： | Rajat Walia1,2#, Xin Xiong1,2#, Xiao-Chun Fan1,2#, Ting-Feng Chen1, Hui Wang1, Kai Wang1,3*,Yi-Zhong Shi4, Xun Tang5,Jean-Luc Bredas6, Chihaya Adachi5*,Xian-Kai Chen1,3* & Xiao-Hong Zhang1,7* |
单位： | 1Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China 2Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, P. R. China 3State Key Laboratory of Bioinspired interfacial Materials Science, Soochow University, Suzhou, P. R. China 4School of Materials Science and Engineering, Suzhou University of Science and Technology, Suzhou, P. R. China 5Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Fukuoka, Japan 6Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ, USA 7Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou, P. R. China |
摘要： | In polycyclic heteroaromatic (PHA) emitters, which possess great potential for application in ultrahigh-definition displays, the origin of a small singlet–triplet energy gap (ΔES1T1) and its relationship with the molecular structure still remain poorly established. Here we derive an effective expression for ΔES1T1, in which ΔES1T1 positively depends on 2KHL (where KHL is the exchange energy between the highest occupied molecular orbital and the lowest unoccupied molecular orbital (LUMO)) and on the energy gap between LUMO and LUMO+1 (ΔELUMO–LUMO+1). This expression for ΔES1T1 is validated over a series of 100 reported PHA emitters. It allows us to easily identify various molecular design approaches for managing ΔES1T1 by synergistically regulating 2KHL and ΔELUMO–LUMO+1. The proof-of-concept PHA molecules were synthesized and characterized to further confirm the validity of this expression for ΔES1T1. Overall, our work provides a physical picture to not only modulate ΔES1T1 in emerging PHA emitters but also design and screen such materials with small ΔES1T1. |
