Elucidating Physical and Electronic Interactions in Ternary Blend Organic Solar Cells

太阳能是最具吸引力的可再生能源之一，它为基础研究提供了动力，使低成本技术能够适应各种应用。其中，薄膜有机光伏电池（基于小有机分子和聚合物）是一个潜在的合适选择。这项技术为将可再生电力生产能力整合到建筑基础设施中提供了一个轻量级、灵活的平台。在正在研究的有机太阳能电池中，三元混合电池已经展示了最先进效率的潜力。此外，该技术将自身修正为简单的设备制造方法，与现有的连续卷对卷加工制造方法兼容。该项目将对控制材料活性层（聚合物混合物）的机制进行基础研究，以提高最终设备的效率。该项目将重点关注三元聚合物混合物中复杂的物理和电子相互作用，这决定了电池的太阳能转换效率。该项目的研究计划与一个有凝聚力的教育计划相结合，使社区大学生以及南加州大学（USC）的本科生和研究生受益。每年夏天，来自喜瑞都学院（Norwalk， CA）的社区大学生将被邀请参加这个研究项目。这些学生大多来自STEM中代表性不足的群体，许多是第一代大学生。该项目还涉及与德国和丹麦实验室的合作。本科生和研究生（来自喜瑞都和南加州大学）也将与国际合作者密切合作，包括研究生交换，以获得更广泛的国际研究经验。最后，该项目还包括在南加州大学本科有机化学课程中开发“写着学”教学法的努力，目的是促进学习和学生保留率。基础研究项目的重点是扩大对三元共混有机太阳能电池中协同成分混溶作用的理解，特别是那些基于两个给体聚合物和一个分子受体的有机太阳能电池。具体的兴趣集中在物理关系如何影响开路电压和对组件之间有利的电子相互作用的更全面的图景的发展。该项目的目标是：阐明协同组件之间的基本物理和电子相互作用，并阐明其运作机制；建立协同供体组分之间有效电子关系的极限，特别关注最大有效最高占位分子轨道偏移；并制定合理的协同部件设计规则。这项工作将通过聚合物合成、基本电子和结构表征、器件表征和理论的结合来完成。为实现上述目标，应加强对三元共混平台的基本了解，并为新的供体和受体组分制定明确的设计原则。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Solar energy is among the most attractive renewable energy sources, providing motivation for fundamental research to enable low-cost technologies that are adaptable for a variety of applications. Among these, thin film organic photovoltaic cells (based on small organic molecules and polymers) are a potentially suitable option. This technology provides a path towards a lightweight, flexible platform for integration of renewable electricity production capacity into building infrastructure. Of the organic solar cells under study, ternary blend cells have demonstrated the potential for state-of-the-art efficiency. In addition, the technology amends itself to simple device fabrication methods that are compatible with existing continuous roll-to-roll processing manufacturing methods. This project will address fundamental research into the mechanisms that govern the active layer of material, the polymer blend, in order to increase efficiency of the resulting device. The project will focus on the complex physical and electronic interactions in the ternary polymer blend mixture that determines the cell's solar conversion efficiency. The research plan of the project is coupled with a cohesive educational plan that benefits community college students as well as University of Southern California (USC) undergraduates and graduate students. Community college students from Cerritos College (Norwalk, CA) will be hosted each summer to participate in the research project. These students are largely from under-represented groups in STEM and many are first generation college students. The project also involves collaborations with laboratories in Germany and Denmark. Undergraduate and graduate students (from Cerritos and USC) will also work closely with the international collaborators, including graduate student exchange for an extended international research experience. Finally, the project includes efforts toward developing write-to-learn pedagogies are being pursued in undergraduate organic chemistry courses at USC with the goal of facilitating learning and student retention. The focus of the fundamental research project is to expand the understanding of the role of miscibility of synergistic components in ternary blend organic solar cells, specifically those based on two donor polymers and one molecular acceptor. Specific interests are centered on how physical relationships influence the open circuit voltage and on the development of a more global picture of favorable electronic interactions between components. The objectives of the project are: to elucidate the fundamental physical and electronic interactions between synergistic components and clarify the mechanism of operation; to establish the limits of effective electronic relationships between synergistic donor components, specifically focusing on the maximum effective highest occupied molecular orbital offset; and to develop rational design rules for synergistic components. This work will be executed through a combination of polymer synthesis, basic electronic and structural characterization, device characterization and theory. Achievement of the stated objectives should lead to an enhanced fundamental understanding of the ternary blend platform and the path to clear design principles for new donor and acceptor components.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.