Developing in operando structure-property-function guidelines for small molecule organic electron acceptors and its implication on device performance and charge carrier mobility

有机光伏（OPV）技术具有独特的特点，如灵活性，重量轻，能源回收期短（即生产所需的能源所需的时间），因此有可能产生重大的经济影响。为了实现更大的商业应用，OPV需要克服效率，稳定性，耐用性以及安全和可持续生产方面的技术挑战。 该项目将调查在操作条件下导致OPV的有限寿命和效率的过程。这些研究将使用一套内部和同步加速器衍射和光谱工具与设备制造相结合进行。该项目小组将通过涉及高中教师的创新教育和推广工作，使湖城社区参与能源和有机电子主题。此外，项目团队还将通过Young WISE为硅谷经济困难的年轻女学生提供STEM方面的专业指导和短期研究活动&。（科学和工程领域的妇女）外联工作。合理设计和研究良好控制的非富勒烯电子受体的物理和化学性质对于实现高效率、灵活、和可溶液处理的有机光致变色剂（OPV）。尽管对于在常规本体异质结架构中包含p型供体聚合物和n型小分子受体的OPV，功率转换效率接近15%，但仍然存在主要的基础知识差距（即，形态变化、适当的供体-受体偶联、能级错配），这阻碍了它们的加速开发和商业化。此外，有很少或没有基本知识的形态，施主-受主界面，能级对准，和设备特性如何在operando条件和偏置应力的影响下演变。在这个基础研究项目中，研究小组将1）设计一个基于硫化扭曲的四元苝二酰亚胺螺旋桨作为有效电子受体的模型系统; 2）开发衍射和光谱表征方法，以阐明电子受体在操作条件下与其他分子界面时的能级排列，分子取向和形态;以及3）研究激子相互作用和自旋过程，以提高功率转换效率。该奖项反映了NSF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。

Organic photovoltaic (OPV) technology has the potential for significant economic impact due to unique features such as flexibility, low weight, and short energy payback time (i.e. the time needed to produce the energy that was required for its production). To achieve greater commercial application, OPVs need to overcome technology challenges in efficiency, stability, durability, and safe and sustainable production. This project will investigate the processes responsible for the limited lifetime and efficiency of OPVs under operating conditions. These studies will be carried out using a suite of in-house and synchrotron diffraction and spectroscopy tools coupled with device fabrication. The project team will engage the Salt Lake City community in energy and organic electronic topics through an innovative education and outreach effort involving high school teachers. Also, the project team will provide professional mentoring and short research activities in STEM to economically disadvantaged young female students in the Valley through the Young & WISE (Women in Science and Engineering) outreach effort.The rational design and investigation of the physical and chemical properties of well-controlled non-fullerene electron acceptors are critical for enabling high efficiency, flexible, and solution processable organic photovoltaics (OPVs). Although, power conversion efficiencies are approaching 15% for OPVs comprising a p-type donor polymer and an n-type small molecule acceptor in a conventional bulk-heterojunction architecture, there are still major fundamental knowledge gaps (i.e., morphology changes, appropriate donor-acceptor coupling, energy level mismatches) that impede their accelerated development and commercialization. Furthermore, there is little to no fundamental knowledge on how morphology, donor-acceptor interfaces, energy level alignments, and device characteristics evolve under operando conditions and bias stress effects. In this fundamental research project, the research team will 1) design a model system based on thionated contorted quaternary perylene diimide propellers as efficient electron acceptors; 2) develop diffraction and spectroscopy characterization approaches to elucidate energy level alignment, molecular orientation, and morphology of electron acceptors when interfaced with other molecules under operating conditions; and 3) investigate exciton interactions and spin processes that could enhance power conversion efficiencies.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.