Unified model for singlet fission within a non-conjugated covalent pentacene dimer.
Unified model for singlet fission within a non-conjugated covalent pentacene dimer.
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DOI：
10.1038/ncomms15171
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发表时间：
2017-05-18
影响因子：
16.6
通讯作者：
Guldi DM
中科院分区：
文献类型：
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作者：
Basel BS;Zirzlmeier J;Hetzer C;Phelan BT;Krzyaniak MD;Reddy SR;Coto PB;Horwitz NE;Young RM;White FJ;Hampel F;Clark T;Thoss M;Tykwinski RR;Wasielewski MR;Guldi DM
当分子二聚体、晶体膜或分子聚集体吸收光子产生单线态激子时，允许自旋的单线态裂变可能产生两个三重态激子，可用于产生两个电子-空穴对，从而使太阳能电池的最大性能提高约50%。单线态裂变的机理还没有被很好地理解。在这里，我们报告了使用时间分辨光学和电子顺磁共振波谱来探测由非共轭间隔剂连接的并五烯二聚体的单线态裂变。我们观察了单线态裂变过程中的关键中间体，包括五重态的形成和衰变，五重态的形成先于五重态激子的形成。利用这些综合数据，我们开发了一个单一的动力学模型，描述了在室温和低温下超过七个时间数量级的数据。单线态裂变是太阳能电池中的一个重要过程，但其机理尚不清楚。在这里，作者揭示了非共轭并五苯二聚体单线态裂变过程中的中间体，并建立了一个单一的动力学模型来描述室温和低温下七个时间数量级的数据。
When molecular dimers, crystalline films or molecular aggregates absorb a photon to produce a singlet exciton, spin-allowed singlet fission may produce two triplet excitons that can be used to generate two electron–hole pairs, leading to a predicted ∼50% enhancement in maximum solar cell performance. The singlet fission mechanism is still not well understood. Here we report on the use of time-resolved optical and electron paramagnetic resonance spectroscopy to probe singlet fission in a pentacene dimer linked by a non-conjugated spacer. We observe the key intermediates in the singlet fission process, including the formation and decay of a quintet state that precedes formation of the pentacene triplet excitons. Using these combined data, we develop a single kinetic model that describes the data over seven temporal orders of magnitude both at room and cryogenic temperatures. Singlet fission is an important process occurring in solar cells, however the mechanism is not well understood. Here the authors reveal intermediates during singlet fission of a non-conjugated pentacene dimer, developing a single kinetic model to describe the data over seven temporal orders of magnitude at room and cryogenic temperatures.