The aim of this work is to provide an in-depth study of the optical, electronic, and charge transfer properties for substituent effects on the dimeric perylene diimide (PPDI). The ground state geometry and relevant electronic properties of investigated molecules for photovoltaic applications were evaluated by the CAM-B3LYP/6–31G (d,p) method. The absorption spectra simulated at the TD-B3LYP/6–31 + G (d,p) level. The results reveal that different positions and amount of substituents significantly affect on the distributions of frontier molecular orbitals for PPDI. The different positions of the same substituent group affect the frontier molecular orbital energy and energy gap of PPDI slightly. The different positions and amount of substituents affect the absorption spectra of PPDI slightly. The calculated reorganization energies of electrons and holes for PPDI and its derivatives implied that their charge transfer rates are higher than that of the typical electron and hole transport materials, respectively. Moreover, we have also predicted the mobility of designed molecules with better performances.

这项工作的目的是深入研究取代基对二聚per二酰亚胺（PPDI）的光学，电子和电荷转移性质。通过CAM-B3LYP / 6–31G（d，p）方法评估了用于光伏应用的被研究分子的基态几何形状和相关的电子性质。在TD-B3LYP / 6–31 + G（d，p）水平模拟的吸收光谱。结果表明，不同取代基的位置和数量对PPDI前沿分子轨道的分布有显着影响。同一取代基的不同位置会影响PPDI的前沿分子轨道能和能隙轻微地。取代基的不同位置和数量会对PPDI的吸收光谱产生轻微影响。计算得出的PPDI及其衍生物的电子和空穴的重组能表明它们的电荷传输速率分别高于典型的电子和空穴传输材料。此外，我们还预测了性能更好的设计分子的迁移性。