The Role of Local Heterogeneity in Organic Semiconductor Performance

技术支持：这项建议的目标是研究如何使用电子扫描探针显微镜局部纳米异质性影响有机半导体的性能。通过带来新的实验能力，直接测量模型有机半导体薄膜的电子特性的纳米级变化，并在微观水平上研究处理参数变化引起的异质性如何导致性能变化。本项目将致力于解决独特的新挑战，包括：1）研究有机半导体中局部电流分布的演变作为加工诱导的电荷输运无序的函数; 2）获得关于垂直膜结构的局部信息，以使用局部扫描探针构建光伏共混物中的3D形态的图片。3）使用时间分辨静电力显微镜来研究在亚100微秒上的捕获、解捕获和光化学降解动力学，这些目标对有机半导体领域具有基本的科学重要性，并解决了这些系统中传输过程的基本描述：如果1D模型不足，什么是3D模型包括+必要的空间无序的最物理但有效的方法？理论上的无序参数是如何与实验处理条件和可观测量联系起来的？虽然有机物中的形态/性能关系被广泛认为是影响从理论到合成再到制造领域的核心挑战，但表征形态的大多数方法仅允许平均性能与平均局部结构的相关性，从而忽视了局部异质性的重要作用。非技术性：该项目旨在解决材料科学领域的基础研究问题，并有望为跨学科领域的研究生和本科生培训提供独特的机会。通过培训这一研究领域的科学家，通过出版物广泛传播这一研究成果，这一研究项目预计也将产生更广泛的影响。拟议的研究计划将在化学，物理和材料科学的交叉点进行，并在光电子学，节能显示器和照明领域具有技术应用。 该提案将支持既定的教育计划，包括正在进行的招募代表性不足的群体进入科学事业，向K- 12学生进行公众宣传，以及与当地社区进行更广泛的互动。该项目将创建新的本科研究项目，国际合作，以及新的工业教育经验和伙伴关系。

Technical: The goal of this proposal is to study how local nanoscale heterogeneity affects the performance of organic semiconductors using electrical scanning-probe microscopy. By bringing novel experimental capabilities to directly measure nanoscale variations in the electronic properties of model organic semiconductor films and study at the microscopic level how heterogeneity arising from variations in processing parameters leads to variations in performance. This project will address unique new challenges including:1) Studying the evolution of local current distributions as a function of processing-induced disorder in charge transport in organic semiconductors;2) Obtaining local information about vertical film structure to construct a picture of 3D morphology in photovoltaic blends using local scanning probes.3) Using time-resolved electrostatic force microscopy to study trapping, de-trapping, and photochemical degradation kinetics on sub-100 microsecond, and sub-100 nm scales to probe correlations between nanoscale film structures and trapping in organic semiconductor films.These objectives are of fundamental scientific importance to the field of organic semiconductors and address basic description of transport processes in these systems: if 1D models are insufficient, what is the most physical yet efficient way for 3D models to include +the requisite spatial disorder? How are the disorder parameters in theory linked to experimental processing conditions and observables? While the morphology/performance relationship in organics is widely recognized as a central challenge that affects the field from theory to synthesis to manufacturing, most methods of characterizing morphology permit only a correlation of average performance with average local structure and thus overlook the important role of local heterogeneity. This proposal will help transform the understanding and use of organic semiconductors.Non-technical: The project addresses basic research issues in a topical area of materials science with technological relevance, and is expected to provide unique opportunities for graduate and undergraduate training in an interdisciplinary field. This research project is also expected to have broader impacts through the training of scientists in this research field, through the wide dissemination of the findings of this research through publications. The proposed research program will take place at the intersection of chemistry, physics, and materials science, and has technological applications in the areas of photovoltaics, energy efficient displays, and lighting. This proposal will support established educational programs including ongoing recruitment of under-represented groups into scientific careers, public outreach to K- 12 students, and broader interactions with the local community. The project will create new undergraduate research projects, international collaborations, and new industrial educational experiences and partnerships.