Collaborative Research: Charge Transport Pathways in Semiconducting Polymer Films

技术总结本课程将研究半导体聚合物薄膜中电荷传输和分子有序性之间的联系。在大多数电子设备中，半导体聚合物链并不跨越电极之间的距离，由此产生的电学性质是沿链和链到链的电荷传输的结果。通过UCSB和NCSU的科学家的合作，将通过以下方式研究半导体聚合物中的电荷传输路径：1)使用物理和电学表征方法相结合的方法测量半导体聚合物主链的面内体积和界面相关长度；2)研究具有不同能量结构的模型嵌段共聚体系中的输运，以揭示正负载流子在复杂体系中的输运方式。这项工作将使用一种新的偏振软X射线散射方法来探测主干关联长度，这将使我们能够更好地理解形态和电输运之间的联系。这项工作中开发的散射技术将对半导体和传统聚合物的表征产生影响。非技术概述共轭聚合物作为简单电路中的晶体管、发光二极管和太阳能电池，在廉价、灵活、轻质设备中具有巨大的潜力。我们对导电聚合物性能控制的改进将使新型电子设备能够用于能源转换和生物医学诊断。这项工作将集中在确定共轭聚合物中的电荷传输路径。聚合物电子学的研究是高度多学科的，将为研究生提供材料科学、化学和微电子学方面的培训。PIs和研究生还将为来自代表性不足群体的有前途的本科生提供实验室空间和培训，以推动他们未来在科学和工程领域的职业生涯。将通过研究生研究人员在当地科学之夜展示灵活的电子设备，向儿童推广当地学区的科学教育。

TECHNICAL SUMMARYThe connection between charge transport and molecular order on intermediate length scales in films of semiconducting polymers will be examined. In most electrical devices, semiconducting polymer chains do not span the distance between the electrodes and the resulting electrical properties are the result of charge transport both along the chains and from chain-to-chain. Through a collaborative effort between scientists at UCSB and NCSU the charge transport pathways in semiconducting polymers will be studied by: 1) measuring the in-plane bulk and interface correlation length of the backbone of semiconducting polymers using a combination of physical and electrical characterization methods and 2) investigating transport in model block co-polymer systems with varying energetic structure to uncover how both positive and negative carriers are transported in complex systems. This work will use a novel polarized soft X-ray scattering method to probe the backbone correlation length that will enable a greater understanding of the connection between morphology and electrical transport. The scattering techniques developed in this work will have impact on characterization of both semiconducting and conventional polymers. NON-TECHNICAL SUMMARY Conjugated polymers have tremendous potential for use in cheap, flexible, light-weight devices as transistors in simple circuits, light emitting diodes, and solar cells. Improvement of our control of the properties of electrically conducting polymers will enable new types of electronic devices for use in energy conversion and biomedical diagnostics. This work will focus on the determination of the pathways of charge transport in conjugated polymers. Research in polymer electronics is highly multidisciplinary and will provide training for graduate students in materials science, chemistry, and microelectronics. The PIs and graduate students will also provide lab space and training for promising undergraduate students from underrepresented groups to advance their future careers in science and engineering. Outreach to children to promote science education in the local school districts will be done through demonstrations of flexible electronics devices by graduate student researchers at local science nights.