Extending the pi-Conjugation Length of Soluble Semiconducting Polymers to Effect Efficient Charge Transport

具有明确尺寸和功能的聚合物结构的实现是当前有机半导体材料领域的研究挑战之一。满足必要的性能目标并将显著降低整体工艺复杂性的材料至关重要。该提案集中于设计、合成和表征具有以下特征的聚酰亚胺共轭聚合物：低禁带、低HOMO能级和有效的聚异氰酸酯相互作用。其目的是确定一种有效延长具有电光特性的聚合物的共轭长度的策略。具体来说，PI将(1)研究乙烯键延长目标聚合物共轭长度的有效性，(2)研究替代烷基侧链及其在普通有机溶剂中溶解目标聚合物的能力，允许溶液处理，(3)合成替代D-A结构，(4)对目标材料进行必要的物理表征，(5)构造场效应晶体管和光伏器件以评估所述方法的影响。通过以上定义的研究，预计关键的、可合成的结构特征的识别将提供具有必要特征的半导体聚合物的圆周率共轭长度的延长，这将允许有利于电荷传输的取向和排列。这些研究将确定实现能级和带隙的方法，这些方法不仅可以提供所需的电光性能，还可以支持坚固可靠的器件。非技术摘要共轭聚合物材料，特别是聚合物半导体，由于其可能的广泛应用而引起广泛的兴趣，包括有机发光二极管(OLED)、有机场效应晶体管(OFET)、光伏器件(PV)、电光快门、印刷天线、基于塑料的致动器和信号开关。此外，聚合物提供了与高产量、低成本的加工技术的兼容性。拟议的研究计划将为开发和部署具有重大社会影响的电光器件应用的先进聚合物材料提供必要的洞察力，上面描述了这些应用的例子。参与这项工作的学生将获得在多学科项目中工作的宝贵经验。这种方法将使他们能够经历广泛的教育，并获得聚合物科学和工程领域的坚实知识基础，同时欣赏其他学科的贡献。该研究计划将与本科生和研究生团队合作，以促进提案的目标。此外，还将为高中生寻找参加这些团队的机会。外展活动将针对当地非常多样化的社区，国际和平协会和学生都将参与。通过这些活动，将增进公众对STEM的了解，从而对不同的未来一代学生进入STEM领域产生积极影响。

TECHNICAL ABSTRACTRealization of polymer architectures with well-defined dimensions and functions is one of the current research challenges in the field of organic semiconducting materials. Materials that meet requisite performance targets and will markedly reduce overall process complexity are essential. The proposal focusses on the design, synthesis and characterization of pi-conjugated polymers having the following characteristics: a low bandgap, a low HOMO level, and effective pi-pi interactions. The aim is to define a strategy for the effective extension of the conjugation length of polymers having electro-optic characteristics. The materials are expected to exhibit enhanced field-effect induced charge transport and photovoltaic properties, features that an imperative for the successful introduction of robust and reliable polymer based devices.Specifically, the PI will (1) investigate the effectiveness of the vinylene linkage to extend the conjugation length of targeted polymers, (2) investigate alternative alkyl side chains and their ability to solubilize targeted polymers in common organic solvents, allowing for solution processing, (3) synthesize alternative D-A architectures, (4) perform requisite physical characterization of the targeted materials, (5) fabricate field effect transistor and photovoltaic devices to evaluate the impact of the approach. Through the studies defined above, it is anticipated that identification of key, synthetically accessible structural features will provide for an extension of the pi-conjugation length of semiconducting polymers with requisite characteristics that will allow for orientation and alignment that are favorable for charge transport. These studies will identify means to achieve energy levels and bandgaps that not only afford desired electro-optic performance, but also support robust and reliable devices.NON-TECHNICAL ABSTRACTConjugated polymeric materials in general, and polymer semiconductors in particular, are of broad interest because of the wide range of possible applications including organic light-emitting diodes (OLED), organic field effect transistors (OFET), photovoltaic devices (PV), electro-optic shutters, printed antennas, plastic-based actuators, and signal switches. Further, polymers offer compatibility with high through-put, low cost processing techniques. The proposed research program will provide essential insight needed for the development and deployment of advanced polymer materials for electro-optic device applications having significant societal impact, examples of which are described above. Students participating in this effort will gain invaluable experience working in a multidisciplinary program. This approach will allow them to experience a broad education and to acquire a sound knowledge base in the area of polymer science and engineering coupled with an appreciation of the contributions of other disciplines. The research program will be integrated with undergraduate and graduate students working in teams to further the objectives of the proposal. Additionally, opportunities will be sought for high school students to participate in these teams. Outreach activities will target the local very diverse community, and both the PI and students will participate. Through these activities, public understanding of STEM will be enhanced, thereby positively influencing a diverse future generation of students to enter STEM fields.