Naveed Ayesha, Akram Sahar Javaid, Ans Muhammad, Iqbal Javed, Batool Ifrah, Mehmood Rana Farhat, Khera Rasheed Ahmad
Department of Chemistry, University of Agriculture, Faisalabad, 38000, Pakistan.
University of Education, Lahore, D.G. Khan Campus, Kangan Road, Dera Ghazi Khan, Pakistan.
J Mol Model. 2022 Jul 12;28(8):218. doi: 10.1007/s00894-022-05217-5.
With the aim of utilizing structural modeling techniques to design efficient organic solar cells, a quantum chemical density functional theory (DFT) and its time-dependent DFT (TD-DFT) study have been carried out for the examination of the photovoltaic properties of four BT-ClC-based novel non-fullerene acceptor (NFA) molecules. The designed entities (BT1-BT4) have an A-π-D-π-A configuration with seven fused ring-based BDT central core and newly substituted peripheral acceptor moieties. The optical parameters (absorption maxima, light-harvesting efficiency, first excitation energies, and dipole moments), electronic properties (frontier molecular orbitals, density of states, and molecular electrostatic potential), and charge transfer characteristics (open-circuit voltage, transition density matrix, and fill factor) of the investigated molecules were evaluated using the selected B3LYP/6-31G (d,p) level of theory. The systematic computational analysis reveals that under the influence of terminal acceptor groups, there is an augmentation in the absorption range, and reduction in the band gap values. The electron withdrawing effect of acceptor moieties is evident from the electronic density distribution on the HOMO-LUMO orbitals, along with the density of state (DOS) graphs. Transition density matrix (TDM) analyses reveal consistent charge transfer in the newly devised entities. Reorganization energies computed for electron and hole are significantly lower than the reference, making the transfer of charge carriers efficient. Open-circuit voltage (V) of reported acceptor entities, theoretically computed with PTB7-Th donor, revealed maximum output. Furthermore, the estimated fill factor (FF) of the investigated molecules predicted an increase in power conversion efficiencies. Consequently, all the computed parameters favor the applicability of our designed molecules in the field of organic photovoltaics by virtue of their excellent charge mobilities, increased absorption maximum values, and reduced band gaps.
为了利用结构建模技术设计高效有机太阳能电池，开展了量子化学密度泛函理论（DFT）及其含时密度泛函理论（TD-DFT）研究，以考察四种基于BT-ClC的新型非富勒烯受体（NFA）分子的光伏特性。所设计的实体（BT1-BT4）具有A-π-D-π-A构型，带有基于七个稠环的BDT中心核和新取代的外围受体部分。使用选定的B3LYP/6-31G（d,p）理论水平评估了所研究分子的光学参数（最大吸收波长、光捕获效率、第一激发能和偶极矩）、电子性质（前沿分子轨道、态密度和分子静电势）以及电荷转移特性（开路电压、跃迁密度矩阵和填充因子）。系统的计算分析表明，在末端受体基团的影响下，吸收范围增大，带隙值减小。受体部分的吸电子效应从HOMO-LUMO轨道上的电子密度分布以及态密度（DOS）图中明显可见。跃迁密度矩阵（TDM）分析表明新设计的实体中存在一致的电荷转移。计算得到的电子和空穴的重组能显著低于参考值，使得电荷载流子的转移效率很高。用PTB7-Th供体理论计算报道的受体实体的开路电压（V）显示出最大输出。此外，所研究分子的估计填充因子（FF）预示着功率转换效率的提高。因此，所有计算参数都有利于我们设计的分子凭借其优异的电荷迁移率、增大的最大吸收值和减小的带隙而应用于有机光伏领域。
