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Highly Efficient Ultralong Organic Phosphorescence through Intramolecular-Space Heavy-Atom Effect
journal contribution
posted on 2019-01-23, 00:00 authored by Huifang Shi, Lulu Song, Huili Ma, Chen Sun, Kaiwei Huang, Anqi Lv, Wenpeng Ye, He Wang, Suzhi Cai, Wei Yao, Yujian Zhang, Ruilin Zheng, Zhongfu An, Wei HuangMetal-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.