有机光伏非富勒烯受体的分子堆积结构和电子传输性能的理论研究

Recently, the power conversion efficiencies have achieved significant improvements for organic solar cells based on the non-fullerene molecular electron acceptors, which are approaching and even higher than those for the fullerene-based devices. However, compared with fullerenes, the non-fullerene acceptors displays much lower electron mobilities; moreover, their molecular packing structures are unclear yet and difficult to be measured experimentally. In this project, we are going to reveal the accurate molecular packing structures for the non-fullerene molecular acceptors by means of molecular dynamics simulations and elucidate the related intermolecular interactions. Furthermore, we will reliably estimate their charge carrier mobilities through combining the charge-transfer theories with kinetic Monte-Carlo simulations, and investigate the influence of different molecular structures and experimental conditions. This will be very helpful for rational molecular design and device optimization to increase the electron mobilities for non-fullerene acceptors and thus further improve their photovoltaic performances.

最近基于非富勒烯分子受体的有机太阳能电池的能量转换效率取得重要进展，逼近甚至超过基于富勒烯的器件。但是，相比于富勒烯，非富勒烯受体的电子迁移率普遍更低，而且分子堆积结构尚不清楚，实验上也难以测量。本项目拟发展和运用分子动力学方法精确模拟非富勒烯受体的分子堆积结构，阐明分子间的相互作用方式；进一步结合电荷转移理论与动态蒙特-卡罗模拟可靠计算非富勒烯受体的载流子迁移率，揭示不同分子结构和实验条件的影响，从而指导帮助实验分子设计和优化器件提高非富勒烯受体的电子迁移率而进一步改善光伏性能。

得益于非富勒烯受体的发展，有机光伏电池的能量转换效率得到迅猛的提高。然而，非富勒烯受体的电子迁移率还比较低，成为进一步提升有机光伏效率的瓶颈。本项目结合分子动力学方法和电荷转移理论，系统研究了A-D-A型稠环电子受体、苝二酰亚胺二聚体、以及π桥连接的小分子聚合化受体的分子堆积结构和电子传输性质，揭示不同分子结构和加工过程的影响，强调了分子内和分子间协同优化对改善分子堆积和电子迁移率的重要性，为进一步优化分子设计提供了有益的理论依据。