Emerging Design Principles for Enhanced Solar Energy Utilization with Singlet Fission
Emerging Design Principles for Enhanced Solar Energy Utilization with Singlet Fission
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DOI：
10.1021/acs.jpcc.8b10876
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发表时间：
2019-02-21
影响因子：
3.7
通讯作者：
Johnson, Justin C.
中科院分区：
文献类型：
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作者：
Gish, Melissa K.;Pace, Natalie A.;Johnson, Justin C.
单重态裂变（SF），即每吸收一个光子产生两个三重态激子，是一种很有前途的策略，用于将太阳能电池的效率提高到超过34%的理论Shockley-Queisser极限。当SF分子吸收光子时，最初产生的单重激发态（S-1）与相邻的发色团相互作用，并首先转化为三重态对（TT），其随后可以分离成独立的三重态激子（2 T（1））。这些独立的三重态激子可以通过三重态电荷提取或三重态能量转移到受体来收获。对SF系统的研究已经揭示了三重态形成和三重态对去相关的速率和效率，其强烈依赖于发色团间偶联，这由分子结构和共价键中采用的发色团的所得几何排列（例如，二聚体）和非共价的（例如，薄膜和晶体）系统。将SF材料结合到现实的器件架构中引入了许多新的挑战，需要考虑关于通过SF生成的三重峰的有效提取。在这篇专题文章中，我们回顾了我们的工作，这些工作在一定程度上理解和控制了太阳能收集架构中的分子间和分子内SF速率，包括染料敏化太阳能电池，共轭聚合物薄膜和配体交换量子点。我们强调的重要性，理解和操纵SF分子之间的相互作用，并与跨界面的电荷或能量收集器，以达到动力学平衡，导致有效利用三重态激子。
Singlet fission (SF), the generation of two triplet excitons per the absorption of one photon, is a promising strategy for increasing the efficiency of solar cells beyond the theoretical Shockley-Queisser limit of 34%. Upon photon absorption by a SF molecule, the initially created singlet excited state (S-1) interacts with a neighboring chromophore and is first transformed into a triplet pair (TT), which can be subsequently separated into independent triplet excitons (2T(1)). These independent triplet excitons can be harvested through triplet charge extraction or triplet energy transfer to an acceptor. Research on SF systems has revealed rates and efficiencies of triplet formation and triplet pair decorrelation that are strongly dependent on interchromophore coupling, which is dictated by molecular structure and the resulting geometrical arrangement of chromophores adopted in covalent (e.g., dimers) and noncovalent (e.g., films and crystals) systems. Incorporation of SF materials into realistic device architectures introduces a host of new challenges to consider regarding the efficient extraction of triplets generated through SF. In this Feature Article, we review our work that has led to some degree of understanding and control of inter- and intramolecular SF rates placed in the context of solar energy harvesting architectures, including dye-sensitized solar cells, conjugated polymer films, and ligand-exchanged quantum dots. We emphasize the importance of understanding and manipulating interactions between SF molecules with each other and with the charge or energy collectors across an interface in order to strike a kinetic balance that leads to efficient utilization of triplet excitons.