非富勒烯小分子受体的官能团取代效应

Functional Group Substitution Effect of Non-Fullerene Small-Molecule Acceptors

为进一步促进有机太阳能电池的发展,以最近合成的A-D-A′-D-A型非富勒烯小分子受体IDTP-4F(IDTP-R)为参考分子,通过用-CN/-COOCH_(3)官能团取代其末端受体单元中的氟原子设计了IDTP-R1~IDTP-R3三种受体。利用密度泛函理论和含时密度泛函理论对这些分子的基态和激发态进行了理论模拟,研究结果表明,设计分子具有比IDTP-R更窄的能隙、更高的电子亲和势、更低的化学硬度、更强的电子接受能力、显著红移的吸收光谱、更小的激发能和结合能,尤其是IDTP-R2,其在大多关键参数方面都优于其他设计分子,将表现出更好的光伏性能。

To further promote the development of organic solar cells,three types of acceptors,IDTP-R1~IDTP-R3,were designed using the recently synthesized A-D-A′-D-A type non-fullerene small-molecule acceptor IDTP-4F(IDTP-R)as a reference molecule by replacing the fluorine atoms in its terminal acceptor unit with-CN/-COOCH3 functional groups.The ground and excited states of these molecules were theoretically simulated and calculated using DFT and TD-DFT.The results showed that the designed molecules have narrower energy gaps,higher electron affinity,lower chemical hardness,stronger electron accepting ability,significantly red-shifted absorption spectra,smaller excitation and binding energies than IDTP-R.In particular,the IDTP-R2 outperformed the other designed molecules in most key parameters,and is expected to exhibit better photovoltaic performance.