Processing Mechanically Reliable Flexible Organic Electronic Films

加工机械可靠的柔性有机电子薄膜用有机（碳基）半导体材料制成的印刷电子产品的发展导致了几种有前途的技术，包括用于显示器的有机发光二极管、固态照明和有机光伏。与无机半导体材料相比，有机电子材料的优点是成本低、可用性好。然而，一般来说，有机电子产品中使用的活性层和电极在使用过程中容易与水蒸气和/或氧气发生化学反应，从而降低其使用寿命、效率和整体性能。考虑到封装在有机电子产品可靠性中的作用以及对这些产品不断增长的需求，迫切需要开发先进的渗透屏障来组装这些设备。当使用过程中施加较大的应变时，这些屏障膜还必须具有机械坚固性（抗开裂）。该奖项支持基础研究，为用原子层沉积技术加工机械可靠的超薄聚合物屏障膜提供知识。此外，还计划为高中生提供夏季丰富课程，以鼓励他们在STEM领域追求教育和职业的兴趣。所提出的研究的总体目标是为应用于柔性印刷电子产品的原子层沉积制成的超屏障薄膜的机械可靠性提供一个基本的理解。实验方案将探索加工条件、开始失效应变和材料成分/结构失效之间的关系，以阐明影响柔性电子中使用的原子层沉积屏障可靠性的因素。这些薄膜与大多数原子层沉积薄膜的不同之处在于，它们在低于100°C的温度下加工，以与低成本衬底和/或敏感的有机电子器件兼容。因此，这些原子层状沉积薄膜的化学计量学可能与那些在较高温度下处理的薄膜大不相同，从而导致无法完全表征或理解的特性。本研究将提供系统的科学研究，以了解、预测和减少低温涂层的开裂，并特别关注加工条件（温度、聚合物基材的化学功能化）对其阻隔性能和机械性能的影响。这将通过将最先进的机械测试与表面科学和多尺度建模研究相结合来实现，这些研究将提供原子层沉积涂层的化学计量学、氢含量和分析的机械行为之间的联系。

Processing Mechanically Reliable Flexible Organic Electronic FilmsThe development of printed electronics made with organic (carbon-based) semiconductor materials has resulted in several promising technologies including organic light emitting diodes for displays, solid state lighting, and organic photovoltaics. The advantages of organic electronic materials are their relatively low cost and availability compared with inorganic semiconductor materials. However, in general, the active layers and electrodes used in organic electronics can be susceptible to chemical reactions with water vapor and/or oxygen during use, thereby reducing their lifetime, efficiency, and overall performance. There is a critical need to develop advanced permeation barriers for assembling these devices given the role the packaging has in the reliability of the organic electronics and the ever-increasing demand for these products. These barrier films must also be mechanically robust (resist cracking) when large applied strains are imposed during use. This award supports fundamental research to provide knowledge for the processing of mechanically reliable, ultrathin polymer barrier films processed with the atomic layer deposition technique. Additionally, summer enrichment programs are planned for high school students to encourage their interest in pursuing education and careers in STEM fields. The overarching goal of the proposed research is to provide a fundamental understanding of mechanical reliability of ultra-barrier films made by atomic layer deposition for application to flexible printed electronics. The experimental protocol will explore the relationship between processing conditions, onset failure strain, and material composition/structure failures to elucidate the factors that impact the reliability of atomic-layered-deposited barriers used in flexible electronics. These films differ from most atomic-layered-deposited film in that they are processed at temperatures below 100°C for compatibility with low cost substrates and/or sensitive organic electronic devices. Thus, the stoichiometry of these atomic-layered-deposited films can be quite different than those processed at higher temperatures, resulting in properties that are not fully characterized or understood. This research will provide a systematic scientific study to understand, predict and minimize cracking of low-temperature coatings, with a specific focus on the effects of processing conditions (temperature, chemical functionalization of the polymer substrates) on their barrier performance and mechanical properties. This will be enabled by coupling state-of-the-art mechanical testing with surface science and multi-scale modeling studies that will provide the link between the stoichiometry of the atomic-layered-deposited coatings, their hydrogen content, and the analyzed mechanical behavior.