Connecting Junction Molecular Orientation to Excited State Structure and Dynamics in Organic Devices

基于柔性有机材料的可打印电子设备有可能彻底改变我们可再生地获取和储存能源的方式。塑料分子在各层之间的界面上的排列情况可以决定设备的性能是否良好。然而，目前对这种安排如何管理设备性能的了解有限。在这个项目中，研究了塑料油墨印刷的太阳能电池和发光体。这些设备有重要的接口，在那里发电和发光。这个项目涉及改变分子在这些界面上的排列，通过强大的X射线技术进行监测。相应地，电能和光的产生过程被测量，并与分子的排列有关。其结果将是一种新的能力，即定制界面上的分子排列，以最大限度地提高设备性能。这种能力将使灵活和可打印的技术能够显著降低能源成本。参与该项目的学生将参加科学大使计划，为高中生开发一个塑料太阳能电池实验室。这项活动将展示这些技术的基础科学和潜力。该项目的跨学科和协作性质将为学生提供专业知识，以交流下一代科学家所需的不同观点。可打印有机设备中的光电特性可以通过设计界面结构的简单加工技术为革命性的应用量身定做，但实现这一目标的知识缺口。这一差距是由于难以定量解析埋藏的有机界面纳米结构并将其与基本器件工艺直接关联而造成的。在这项拟议的工作中，一套最近开发的共振X射线纳米探测器将用于量化分子取向、聚集和局部到埋藏的有机界面的混合。这些测量将与在完全相同的设备上对激发态结构和动力学的高级研究相结合-消除与样品变化性相关的不确定性。其目的是定义掩埋的有机结上的分子有序如何控制与性能相关的激发态动力学的定量关系。它将通过系统地研究平面结中的所有结构情况并将这一信息扩展到打印的3D异质结来实现。我们的目标不仅是建立一般概念，而且定义这些关系的功能形式，以实现高性能有机设备中的设计属性。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Printable electronic devices based on flexible organic-based materials have the potential to revolutionize how we renewably harvest and store energy. The arrangement of plastic molecules at interfaces between layers can determine whether the device performs well. However, there is currently limited knowledge of how such arrangements govern device performance. In this project, solar cells and light emitters printed from plastic inks are studied. These devices have important interfaces where power is generated and light is emitted. This project involves varying the arrangement of the molecules at these interfaces, monitored by powerful X-ray techniques. Correspondingly, power- and light-generating processes are measured and related to the arrangement of the molecules. The result will be a new capability to tailor molecule arrangements at interfaces to maximize device performance. Such a capability will enable flexible and printable technologies to dramatically reduce the cost of energy. Students involved in this project will take part in the Science Ambassadors Program by developing a plastic solar cell lab for high school students. This activity will demonstrate both the fundamental science and the potential of these technologies. The interdisciplinary and collaborative nature of the project will provide the students with expertise to communicate diverse viewpoints that will be required of the next generation of scientists.Optoelectronic properties in printable organic devices could be tailored for revolutionary applications through simple processing techniques that engineer interfacial structures, but there is a gap in knowledge to realize this goal. This gap is due to the difficulty in quantitatively resolving buried organic interfacial nanostructure and directly correlating this to fundamental device processes. In the proposed work, a suite of recently developed resonant X-ray nanoprobes will be used to quantify molecular orientation, aggregation, and mixing local to buried organic interfaces. These measurements will be combined with advanced studies of excited state structure and dynamics on the exact same device - eliminating uncertainties related to sample variability. The objective is to define quantitative relationships on how molecular ordering at buried organic junctions controls excited state dynamics connected to performance. It will be accomplished by systematically investigating all structural cases in planar junctions and extending this information to printed 3D heterojunctions. Our aim is not only to establish the general concepts, but to define the functional form of these relationships to enable designed properties in high-performing organic devices.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.