Ali Amjad, Farid Tanveer, Rafiq Muhammad Imran, Zhou Baojing, Tang Weihua
Institute of Flexible electronics (IFE, Future Technologies), Xiamen University, Xiamen 361005, P. R. China.
School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, P. R. China.
Phys Chem Chem Phys. 2022 Sep 14;24(35):21270-21282. doi: 10.1039/d2cp02228a.
The acceptor-donor-acceptor structured fused-ring electron acceptors (FREAs) have piqued interest for organic solar cells. We herein employ time-dependent density functional theory to evaluate the effect of Hartree-Fock exact exchange (HFX) on the performance of 16 global hybrid functionals for computing the maximum absorption wavelengths () and the vertical excitation energies () of 34 molecules. We customize the HFX ratio in the functionals used to perform an in-depth analysis of its impact on the values. The computed values strictly follow an inverse proportionality to the HFX percentage. The performance of the methods with the same ratio of HFX is almost identical, such as B3LYP, B3PW91, and mPW3PBE containing 20% HFX. The performance enhances with a relatively higher HFX ratio of 21% in X3LYP, B971, B972, and 22% in B98 giving smaller deviations. APF and APFD containing 23% HFX provide the smallest deviations for all compounds, with a mean signed error limited to 0.02 eV and a mean absolute error (MAE) of 0.06 eV. The performance drops using M06 and M05 with comparatively higher HFX ratios providing MAE values of 0.07 eV and 0.1 eV, respectively. M06-2X with 54% HFX provides the largest MAE value of 0.35 eV. The lowest obtained MAE is 0.06 eV at 23 to 25% HFX in most of the functionals considered in this study, suggesting that these are the optimal values for the prediction of excitation energies of FREAs. It has also been found that global hybrids seem to be more efficient for larger-sized molecules with a smaller bandgap.
受体-供体-受体结构的稠环电子受体（FREAs）已引起有机太阳能电池领域的关注。在此，我们采用含时密度泛函理论来评估哈特里-福克精确交换（HFX）对16种全局杂化泛函性能的影响，这些泛函用于计算34种分子的最大吸收波长（ ）和垂直激发能（ ）。我们在所用泛函中定制HFX比例，以深入分析其对 值的影响。计算得到的 值与HFX百分比严格成反比。具有相同HFX比例的方法性能几乎相同，例如含有20% HFX的B3LYP、B3PW91和mPW3PBE。在X3LYP中HFX比例相对较高为21%、B972中为22%时性能有所提高，偏差较小。含有23% HFX的APF和APFD对所有化合物的偏差最小，平均符号误差限制在0.02 eV，平均绝对误差（MAE）为0.06 eV。使用HFX比例相对较高的M06和M05时性能下降，其MAE值分别为0.07 eV和0.1 eV。含有54% HFX的M06-2X的MAE值最大，为0.35 eV。在本研究中考虑的大多数泛函中，HFX比例在23%至25%时获得的最低MAE为0.06 eV，这表明这些是预测FREAs激发能的最佳值。还发现全局杂化泛函对于带隙较小的较大分子似乎更有效。
