Department of Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, 600 S. Mathews Avenue, Urbana, Illinois 61801, United States.
Department of Chemistry, University of Illinois Urbana-Champaign, 505 S. Mathews Avenue, Urbana, Illinois 61801, United States.
Chem Rev. 2023 Jul 12;123(13):8395-8487. doi: 10.1021/acs.chemrev.2c00905. Epub 2023 Jun 5.
The assembly of conjugated organic molecules from solution to solid-state plays a critical role in determining the thin film morphology and optoelectronic properties of solution-processed organic electronics and photovoltaics. During evaporative solution processing, π-conjugated systems can assemble via various forms of intermolecular interactions, forming distinct aggregate structures that can drastically tune the charge transport landscape in the solid-state. In blend systems composed of donor polymer and acceptor molecules, assembly of neat materials couples with phase separation and crystallization processes, leading to complex phase transition pathways which govern the blend film morphology. In this review, we provide an in-depth review of molecular assembly processes in neat conjugated polymers and nonfullerene small molecule acceptors and discuss their impact on the thin film morphology and optoelectronic properties. We then shift our focus to blend systems relevant to organic solar cells and discuss the fundamentals of phase transition and highlight how the assembly of neat materials and processing conditions can affect blend morphology and device performance.
共轭有机分子从溶液到固态的组装在决定溶液处理有机电子学和光电子学的薄膜形态和光电性能方面起着关键作用。在蒸发溶液处理过程中，π 共轭体系可以通过各种形式的分子间相互作用进行组装，形成不同的聚集结构，从而在固态中急剧调整电荷输运景观。在由给体聚合物和受体分子组成的共混体系中，纯材料的组装与相分离和结晶过程耦合，导致复杂的相转变途径，从而控制共混膜形态。在这篇综述中，我们深入回顾了纯共轭聚合物和非富勒烯小分子受体中的分子组装过程，并讨论了它们对薄膜形态和光电性能的影响。然后，我们将重点转移到与有机太阳能电池相关的共混体系上，并讨论相转变的基本原理，强调纯材料的组装和处理条件如何影响共混形态和器件性能。
