Wang Qungui, Li Yuanzuo, Song Peng, Su Runzhou, Ma Fengcai, Yang Yanhui
College of Science, Northeast Forestry University, Harbin 150040, China.
Department of Physics, Liaoning University, Shenyang 110036, China.
Polymers (Basel). 2017 Dec 8;9(12):692. doi: 10.3390/polym9120692.
The development of non-fullerene small molecule as electron acceptors is critical for overcoming the shortcomings of fullerene and its derivatives (such as limited absorption of light, poor morphological stability and high cost). We investigated the electronic and optical properties of the two selected promising non-fullerene acceptors (NFAs), IDIC and IDTBR, and five conjugated donor polymers using quantum-chemical method (QM). Based on the optimized structures of the studied NFAs and the polymers, the ten donor/acceptor (D/A) interfaces were constructed and investigated using QM and Marcus semi-classical model. Firstly, for the two NFAs, IDTBR displays better electron transport capability, better optical absorption ability, and much greater electron mobility than IDIC. Secondly, the configurations of D/A yield the more bathochromic-shifted and broader sunlight absorption spectra than the single moiety. Surprisingly, although IDTBR has better optical properties than IDIC, the IDIC-based interfaces possess better electron injection abilities, optical absorption properties, smaller exciton binding energies and more effective electronic separation than the IDTBR-based interfaces. Finally, all the polymer/IDIC interfaces exhibit large charge separation rate () (up to 10⁻10 s) and low charge recombination rate () (<10⁶ s), which are more likely to result in high power conversion efficiencies (PCEs). From above analysis, it was found that the polymer/IDIC interfaces should display better performance in the utility of bulk-heterojunction solar cells (BHJ OSC) than polymer/IDTBR interfaces.
开发非富勒烯小分子作为电子受体对于克服富勒烯及其衍生物的缺点（如光吸收有限、形态稳定性差和成本高）至关重要。我们使用量子化学方法（QM）研究了两种选定的有前景的非富勒烯受体（NFA），即IDIC和IDTBR，以及五种共轭供体聚合物的电子和光学性质。基于所研究的NFA和聚合物的优化结构，构建了十个供体/受体（D/A）界面，并使用QM和马库斯半经典模型进行了研究。首先，对于这两种NFA，IDTBR显示出比IDIC更好的电子传输能力、更好的光吸收能力和更大的电子迁移率。其次，D/A的构型比单一部分产生更多的红移和更宽的太阳光吸收光谱。令人惊讶的是，尽管IDTBR比IDIC具有更好的光学性质，但基于IDIC的界面比基于IDTBR的界面具有更好的电子注入能力、光吸收性质、更小的激子结合能和更有效的电子分离。最后，所有聚合物/IDIC界面都表现出大的电荷分离率（高达10⁻¹⁰ s）和低的电荷复合率（<10⁶ s），这更有可能导致高功率转换效率（PCE）。从上述分析中发现，聚合物/IDIC界面在体异质结太阳能电池（BHJ OSC）的应用中应比聚合物/IDTBR界面表现出更好的性能。
