Taouali Walid, Alimi Kamel
Laboratoire de Recherche: Synthèse asymétrique et ingénierie moléculaires des matériaux nouveaux pour l'électroniques Organiques (LR18ES19), Faculté des Sciences de Monastir, Université de Monastir-Tunisie, Monastir, Tunisia.
J Mol Model. 2024 Sep 19;30(10):342. doi: 10.1007/s00894-024-06120-x.
Looking for novel outstanding performance materials suitable for organic solar cells, we constructed a range of non-fullerene acceptors (NFAs) evolved from the recently synthesized acceptor molecule identified as DICTIF, structured around fluorene core where 2-(2,3-dihydro-3-oxo-1H-inden-1-ylidene) propanedinitrile presented the terminals end-groups. Employing density functional theory (DFT) and time dependent-DFT (TD-DFT) simulations, we have simulated the impact of altering the end groups of DICTIF molecule by five assorted acceptors molecules, for the purpose of exploring their opto-electronic properties and their performance in organic solar cell (OSC) applications. We proved that the designed non-fullerene acceptors provide enhanced efficiency compared to the synthesized molecule, such as planar geometries and narrower energy gap ranging from 1.51 to 1.95 eV. A red shift in absorption was observed for all tailored molecules (λ = 583.5-711.4 nm) as compared to the reference molecule (λ = 578 nm).Various decisive factors such as frontier molecular orbitals (FMOs), exciton binding energy (EB), absorption maximum (λ), open circuit voltage (V), reorganization energies (RE), transition density matrix (TDM), reduced density gradient (RDG), and electron-hole overlap have also been computed for analyzing the performance of NFAs. Low reorganizational energy values facilitate charge mobility which improves the conductivity of all the designed molecules. This study showed that our novel tailored molecules might be suitable candidates for the fabrication of highly efficient photovoltaic materials.
After testing various hybrid functionals, optimized geometries were assigned using DFT HSEH1PBE/6-31G(d) level of theory. Electronic excitations and absorption spectra were investigated using the TD-DFT MPW1PW91/6-31G(d) level of theory. We ascertained that HSEH1PBE/6-31G(d) level of theory yield the closest calculated highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of the DICTIF to the corresponding experimental ones and that TD-MPW1PW91//6-31G(d) was the most suitable level of theory for exploring electronic excitations and finding the maximum of absorption (λ).
为寻找适用于有机太阳能电池的新型优异性能材料，我们构建了一系列从最近合成的名为DICTIF的受体分子衍生而来的非富勒烯受体（NFA），其结构以芴为核心，其中2-(2,3-二氢-3-氧代-1H-茚-1-亚基)丙二腈作为端基。利用密度泛函理论（DFT）和含时密度泛函理论（TD-DFT）模拟，我们模拟了用五种不同的受体分子改变DICTIF分子端基的影响，目的是探索它们的光电性质及其在有机太阳能电池（OSC）应用中的性能。我们证明，与合成分子相比，设计的非富勒烯受体具有更高的效率，例如平面几何结构和1.51至1.95 eV的较窄能隙。与参考分子（λ = 578 nm）相比，所有定制分子（λ = 583.5 - 711.4 nm）均观察到吸收峰红移。还计算了各种决定性因素，如前沿分子轨道（FMO）、激子结合能（EB）、最大吸收波长（λ）、开路电压（V）、重组能（RE）、跃迁密度矩阵（TDM）、约化密度梯度（RDG）和电子 - 空穴重叠，以分析NFA的性能。低重组能值有利于电荷迁移，从而提高所有设计分子的电导率。这项研究表明，我们新定制的分子可能是制造高效光伏材料的合适候选物。
在测试了各种杂化泛函后，使用DFT HSEH1PBE/6 - 31G(d)理论水平指定优化的几何结构。使用TD-DFT MPW1PW91/6 - 31G(d)理论水平研究电子激发和吸收光谱。我们确定HSEH1PBE/6 - 31G(d)理论水平得出的DICTIF的计算最高占据分子轨道（HOMO）和最低未占据分子轨道（LUMO）能级与相应的实验值最接近，并且TD-MPW1PW91//6 - 31G(d)是探索电子激发和找到吸收最大值（λ）最合适的理论水平。
