Li Tianyu, Xue Lin, Ma Lishuang, Wang Xianyuan, Fan Xiaonan, Cui Boce, Tang Linglong, Yao Wen, Zhang Teng, Shen Li, Liu Heyuan
College of Chemistry and Chemical Engineering, School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao, 266580, China.
Jinan Ecology and Environment Monitoring Center of Shandong Province, Jinan 250101, China.
Phys Chem Chem Phys. 2024 Oct 17;26(40):25848-25860. doi: 10.1039/d4cp02048k.
Singlet fission (SF) is considered as a promising strategy to overcome the Shockley-Queisser limit of single-junction solar cells. However, only a handful of chromophores were observed to undergo SF to date. To broaden the number of SF chromophores, we designed a series of phosphorus-doped perylenes based on the diradical character strategy and examined their SF feasibility using theoretical calculations. By analysis of frontier orbitals, diradical character and aromaticity, SF-capable candidates were prescreened. These analyses reveal that the diradical character of perylene is effectively enhanced by P-doping at - and -positions of perylene, making SF more thermodynamically feasible. However, the diradical character remains nearly unchanged when P atoms are doped at -positions because the spin center cannot be stabilized, leading to a more endothermic SF. This study shows how SF-related energies and diradical character of SF chromophores are altered by P doping, and extends the SF-capable molecular library.
单线态裂变（SF）被认为是克服单结太阳能电池的肖克利-奎塞尔极限的一种有前景的策略。然而，迄今为止，仅观察到少数发色团会发生单线态裂变。为了增加能够发生单线态裂变的发色团数量，我们基于双自由基特性策略设计了一系列磷掺杂苝，并使用理论计算研究了它们发生单线态裂变的可行性。通过对前线轨道、双自由基特性和芳香性的分析，对有能力发生单线态裂变的候选物进行了预筛选。这些分析表明，在苝的α-位和β-位进行磷掺杂可有效增强苝的双自由基特性，使单线态裂变在热力学上更可行。然而，当磷原子掺杂在γ-位时，双自由基特性几乎保持不变，因为自旋中心无法被稳定，导致单线态裂变的吸热性更强。这项研究展示了磷掺杂如何改变与单线态裂变相关的能量和单线态裂变发色团的双自由基特性，并扩展了能够发生单线态裂变的分子库。
