A design strategy for intramolecular singlet fission mediated by charge-transfer states in donor-acceptor organic materials
A design strategy for intramolecular singlet fission mediated by charge-transfer states in donor-acceptor organic materials
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DOI：
10.1038/nmat4175
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发表时间：
2015-04-01
期刊：
影响因子：
41.2
通讯作者：
Sfeir, Matthew Y.
中科院分区：
文献类型：
--
作者：
Busby, Erik;Xia, Jianlong;Sfeir, Matthew Y.
提高我们对有机材料中多激子产生(MEG)的理解的能力一直受到能够进行单重态裂变的材料数量的限制。一个特别的挑战是开发能够进行有效的分子内裂变的材料，这样局部有序和强烈的最近邻耦合不再是设计的限制。在这里，我们通过证明强大的链内供体-受体相互作用是能够进行分子内单重态裂变的有机材料的关键设计特征来解决这些挑战。通过共轭强受体和强施主构筑块，合成了具有电荷转移态的小分子和聚合物，它们介导了单态激子和三态激子之间的布居转移。利用瞬变光学技术，我们证明了可以产生高达170%的三重态布居。这些准则广泛适用于类似的聚合物和小分子家族，并可导致开发具有可调电子结构的新的裂变材料，以及加深对MEG的基本理解。
The ability to advance our understanding of multiple exciton generation (MEG) in organic materials has been restricted by the limited number of materials capable of singlet fission. A particular challenge is the development of materials that undergo efficient intramolecular fission, such that local order and strong nearest-neighbour coupling is no longer a design constraint. Here we address these challenges by demonstrating that strong intrachain donor-acceptor interactions are a key design feature for organic materials capable of intramolecular singlet fission. By conjugating strong-acceptor and strong-donor building blocks, small molecules and polymers with charge-transfer states that mediate population transfer between singlet excitons and triplet excitons are synthesized. Using transient optical techniques, we show that triplet populations can be generated with yields up to 170%. These guidelines are widely applicable to similar families of polymers and small molecules, and can lead to the development of new fission-capable materials with tunable electronic structure, as well as a deeper fundamental understanding of MEG.