Highly Efficient Ultralong Organic Phosphorescence through Intramolecular-Space Heavy-Atom Effect

• Published in: The journal of physical chemistry letters Vol. 10; no. 3; pp. 595 - 600
• Main Authors: Shi, Huifang, Song, Lulu, Ma, Huili, Sun, Chen, Huang, Kaiwei, Lv, Anqi, Ye, Wenpeng, Wang, He, Cai, Suzhi, Yao, Wei, Zhang, Yujian, Zheng, Ruilin, An, Zhongfu, Huang, Wei
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 07-02-2019
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.8b03712

Metal-free organic phosphorescent materials have attracted considerable attention in the fields of organic electronics and bioelectronics. However, it remains a great challenge to achieve organic phosphors with high quantum efficiency in a single-component system. We designed and synthesized two organic phosphors (PDCz and PDBCz) with an ultralong organic phosphorescence (UOP) feature. Both molecules showed ultralong emission lifetime of >200 ms. For PDBCz crystal, it was found that the absolute phosphorescence quantum efficiency reaches up to 38.1%. Combining the experimental and theoretical studies, the highly efficient UOP was mainly attributed to the intramolecular space heavy-metal effect, which facilitates the spin–orbit coupling between singlet and triplet excited states to effectively promote the intersystem crossing. This study will provide a new platform to rationally design highly efficient UOP materials and show its potential in the field of flexible electronics.