Mehboob Muhammad Yasir, Hussain Riaz, Khan Muhammad Usman, Adnan Muhammad, Alvi Muhammad Usman, Yaqoob Junaid, Khalid Muhammad
Department of Chemistry, University of Okara, Okara, 56300, Pakistan.
Graduate School of Energy Science and Technology, Chungnam National University, 34134, Daejeon, Republic of Korea.
J Mol Model. 2022 Apr 22;28(5):125. doi: 10.1007/s00894-022-05116-9.
One key strategy to further improve the power conversion efficiency (PCE) of organic solar cells (OSCs) is to incorporate various complementary functional groups in a molecule. Such strategies proved attractive for tuning the photovoltaic performances of the materials and can show a much higher absorption phenomenon with narrower band gaps. Despite the outstanding benefits, materials selection and their efficient modeling is also an extremely challenging job for the development of OSCs materials. In this manuscript, we proficiently developed an efficient series of small molecule-based non-fullerene acceptors (SM-NFAs) SN1-SN9 for OSCs and characterized by density functional theory (DFT) and time-dependent DFT (TD-DFT). The characteristics required to estimate electron and hole mobility, and open-circuit voltage (V) were investigated by optimizing the geometrical parameters, absorption spectra, exciton binding energy, frontier molecular orbitals (FMOs), electronic structures, and charge transfer rates. The outcomes of these materials showed that all newly constructed small-molecule-based non-fullerene acceptors exhibit broader and better absorption efficiency (λ = 761 to 778 nm) and exciton dissociation, while much lower LUMO energy levels which may help to enhance the reorganizational energies. Further, a narrow bandgap also offers better photovoltaic properties. Hence, the designed molecules exhibited narrow bandgap values (E = 2.82 to 2.98 eV) which are lower than that of the reference molecule (3.05 eV). High V and photocurrent density values with lower excitation and binding energies eventually increase the PCEs of the OSC devices. The obtained results have shown that designed molecules could be effective aspirants for high-performance OSCs.
进一步提高有机太阳能电池（OSC）功率转换效率（PCE）的一个关键策略是在分子中引入各种互补官能团。事实证明，此类策略对于调节材料的光伏性能具有吸引力，并且可以在带隙更窄的情况下表现出更高的吸收现象。尽管有这些显著优点，但对于OSC材料的开发而言，材料选择及其有效建模也是一项极具挑战性的工作。在本论文中，我们成功开发了一系列用于OSC的基于小分子的高效非富勒烯受体（SM-NFA）SN1-SN9，并通过密度泛函理论（DFT）和含时DFT（TD-DFT）进行了表征。通过优化几何参数、吸收光谱、激子结合能、前线分子轨道（FMO）、电子结构和电荷转移速率，研究了估算电子和空穴迁移率以及开路电压（V）所需的特性。这些材料的结果表明，所有新构建的基于小分子的非富勒烯受体均表现出更宽且更好的吸收效率（λ = 761至778 nm）和激子解离，同时其最低未占分子轨道（LUMO）能级低得多，这可能有助于提高重组能。此外，窄带隙还具有更好的光伏性能。因此，所设计的分子表现出窄带隙值（E = 2.82至2.98 eV），低于参考分子（3.05 eV）。具有较低激发能和结合能的高V值和光电流密度值最终提高了OSC器件的PCE。所得结果表明，所设计的分子可能是高性能OSC的有效候选材料。
