Yang Yubo, Su Wenli, Wang Hang, Bao Xiaotian, Liu Xinfeng, Bo Zhishan, Zhang Wenkai
School of Physics and Astronomy, Applied Optics Beijing Area Major Laboratory, Center for Advanced Quantum Studies, Beijing Normal University, Beijing 100875, China.
College of Textiles & Clothing, State Key Laboratory of Bio-Fibers and Eco-Textiles, Qingdao University, Qingdao 266071, China.
J Phys Chem B. 2024 Jul 25;128(29):7219-7226. doi: 10.1021/acs.jpcb.4c01744. Epub 2024 Jul 15.
Singlet fission (SF) is a triplet generation mechanism capable of turning a singlet exciton into two triplet excitons. It has the potential to enhance the power conversion efficiency of single-junction solar cells. Perylene diimides (PDIs) are a class of dye molecules with photovoltaic properties and are beginning to receive more and more attention due to their potential for SF. Here, we report a selenium-substituted PDI dimer, Se-PDI-II, and we studied its SF mechanism by using steady-state, transient absorption, and time-resolved photoluminescence spectroscopy. Compared with the unsubstituted dimer PDI-II, we found that the introduction of selenium atoms can suppress excimer emission during the SF process, showing much higher SF efficiency and triplet yield.
单线态裂变（SF）是一种能将单重态激子转化为两个三重态激子的三重态产生机制。它具有提高单结太阳能电池功率转换效率的潜力。苝二亚胺（PDIs）是一类具有光伏特性的染料分子，由于其单线态裂变潜力而开始受到越来越多的关注。在此，我们报道了一种硒取代的苝二亚胺二聚体Se-PDI-II，并通过稳态、瞬态吸收和时间分辨光致发光光谱研究了其单线态裂变机制。与未取代的二聚体PDI-II相比，我们发现硒原子的引入可以抑制单线态裂变过程中的激基缔合物发射，表现出更高的单线态裂变效率和三重态产率。
