Leiden Institute of Chemistry, Leiden University, PO Box 9502, 2300 RA, Leiden, Netherlands.
Van't Hoff Institute for Molecular Sciences, University of Amsterdam, 1098XH, Amsterdam, Netherlands.
ChemSusChem. 2022 Aug 5;15(15):e202200594. doi: 10.1002/cssc.202200594. Epub 2022 Jun 22.
Dye-sensitized photoelectrochemical cells are promising devices in solar energy conversion. However, several limitations still have to be addressed, such as the major loss pathway through charge recombination at the dye-semiconductor interface. Charge separating dyes constructed as push-pull systems can increase the spatial separation of electron and hole, decreasing the recombination rate. Here, a family of dyes, consisting of polyphenylamine donors, fluorene bridges, and perylene monoimide acceptors, was investigated in silico using a combination of semi-empirical nuclear dynamics and a quantum propagation of photoexcited electron and hole. To optimize the charge separation, several molecular design strategies were investigated, including modifying the donor molecule, increasing the π-bridge length, and decoupling the molecular components through steric effects. The combination of a triphenylamine donor, using an extended 2-fluorene π-bridge, and decoupling the different components by steric hindrance from side groups resulted in a dye with significantly improved charge separation properties in comparison to the original supramolecular complex.
染料敏化光电化学电池在太阳能转换中是很有前途的器件。然而，仍有一些局限性需要解决，例如通过染料-半导体界面的电荷复合的主要损失途径。构建为推拉系统的电荷分离染料可以增加电子和空穴的空间分离，从而降低复合速率。在此，使用半经验核动力学和光激发电子和空穴的量子传播相结合的方法，对由聚苯胺给体、芴桥和苝单酰亚胺受体组成的染料家族进行了计算机模拟研究。为了优化电荷分离，研究了几种分子设计策略，包括修饰给体分子、增加π-桥的长度以及通过空间位阻使分子组件解耦。用扩展的 2-芴桥的三苯胺给体和通过侧基的空间位阻使不同组件解耦的组合得到了与原始超分子复合物相比具有显著改进的电荷分离性质的染料。
