Zahoor Amna, Hadia N M A, Akram Sahar Javaid, Mehmood Rana Farhat, Sadiq Sonia, Shawky Ahmed M, Alatawi Naifa S, Ahmed Asma, Iqbal Javed, Khera Rasheed Ahmad
Department of Chemistry, University of Agriculture Faisalabad 38000 Pakistan
Physics Department, College of Science, Jouf University P.O. Box 2014 Sakaka Al-Jouf Saudi Arabia
RSC Adv. 2023 Feb 24;13(10):6530-6547. doi: 10.1039/d2ra08091e. eCollection 2023 Feb 21.
Modifying the central core is a very efficient strategy to boost the performance of non-fullerene acceptors. Herein five non-fullerene acceptors (M1-M5) of A-D-D'-D-A type were designed by substituting the central acceptor core of the reference (A-D-A'-D-A type) with different strongly conjugated and electron donating cores (D') to enhance the photovoltaic attributes of OSCs. All the newly designed molecules were analyzed through quantum mechanical simulations to compute their optoelectronic, geometrical, and photovoltaic parameters and compare them to the reference. Theoretical simulations of all the structures were carried out through different functionals with a carefully selected 6-31G(d,p) basis set. Absorption spectra, charge mobility, dynamics of excitons, distribution pattern of electron density, reorganization energies, transition density matrices, natural transition orbitals and frontier molecular orbitals, respectively of the studied molecules were evaluated at this functional. Among the designed structures in various functionals, M5 showed the most improved optoelectronic properties, such as the lowest band gap (2.18 e V), highest maximum absorption (720 nm), and lowest binding energy (0.46 eV) in chloroform solvent. Although the highest photovoltaic aptitude as acceptors at the interface was perceived to be of M1, its highest band gap and lowest absorption maxima lowered its candidature as the best molecule. Thus, M5 with its lowest electron reorganization energy, highest light harvesting efficiency, and promising open-circuit voltage (better than the reference), amongst other favorable features, outperformed the others. Conclusively, each evaluated property commends the aptness of designed structures to augment the power conversion efficiency (PCE) in the field of optoelectronics in one way or another, which reveals that a central un-fused core having an electron-donating capability with terminal groups being significantly electron withdrawing, is an effective configuration for the attainment of promising optoelectronic parameters, and thus the proposed molecules could be utilized in future NFAs.
修饰中心核是提高非富勒烯受体性能的一种非常有效的策略。在此，通过用不同的强共轭给电子核（D'）取代参考物（A-D-A'-D-A型）的中心受体核，设计了五种A-D-D'-D-A型非富勒烯受体（M1-M5），以增强有机太阳能电池（OSC）的光伏特性。通过量子力学模拟分析了所有新设计的分子，以计算它们的光电、几何和光伏参数，并与参考物进行比较。所有结构的理论模拟均通过不同的泛函和精心选择的6-31G(d,p)基组进行。在该泛函下分别评估了所研究分子的吸收光谱、电荷迁移率、激子动力学、电子密度分布模式、重组能、跃迁密度矩阵、自然跃迁轨道和前线分子轨道。在各种泛函设计的结构中，M5表现出最优异的光电性能，如在氯仿溶剂中具有最低的带隙（2.18 eV）、最高的最大吸收（720 nm）和最低的结合能（0.46 eV）。尽管M1在界面处作为受体被认为具有最高的光伏能力，但其最高的带隙和最低的吸收最大值降低了其作为最佳分子的候选资格。因此，M5具有最低的电子重组能、最高的光捕获效率和有前景的开路电压（优于参考物）以及其他有利特性，表现优于其他分子。总之，每个评估的性质都表明设计的结构在某种程度上适合提高光电子领域的功率转换效率（PCE），这表明具有给电子能力的中心未稠合核与末端基团显著吸电子的结构是获得有前景的光电参数的有效构型，因此所提出的分子可用于未来的非富勒烯受体。
