n-Type and Ambipolar Polymer Semiconductors

技术概述：目前所有的聚合物半导体器件，如薄膜晶体管、光伏电池、发光晶体管、发光二极管和光电探测器，其性能主要受到电流材料载流子迁移率的限制。因此，提高所有这些器件的性能并将其推向实际系统应用的根本挑战是实现更高的载流子迁移率。此外，对n型和双极性聚合物半导体的研究远远落后于p型聚合物半导体。在这个项目中，寻求对控制聚合物半导体中高迁移率电子和双极电荷传输的结构因素的基本见解。新型有机溶剂可溶的n型聚合物半导体将被合成和研究，包括聚(蒽唑啉)S、聚(吡嗪并喹恶啉)S和梯形聚(吡嗪并喹恶啉)S，而聚(双吲哚喹啉)S和其他给体-受体共聚物将被探索为双极性半导体。利用电子显微镜和X射线衍射仪对聚合物半导体薄膜和纳米线中的固体形态和分子堆积进行了表征。用场效应晶体管作为测量平台，测量聚合物半导体薄膜和纳米线的载流子迁移率。最有希望的材料将被用于高性能场效应管、互补逆变器和光伏电池。将空气稳定性与高电子迁移率或双极传输与高载流子迁移率相结合的聚合物半导体将有助于开发用于逻辑和存储功能的全塑料互补集成电路，并有助于提高塑料太阳能电池的效率。事实上，具有高载流子迁移率的双极性聚合物的实现可能会彻底改变有机太阳能电池、发光晶体管以及所有有机电子设备和系统的设计。非技术概述：基于有机和聚合物半导体的电子设备，称为塑料电子，开始发现许多应用，如手机、数码相机和汽车仪表盘的显示器。塑料电子也在接受测试，应用范围从电脑和电视屏幕的平板显示器、固态照明、化学和生物传感器，到低成本太阳能电池。该项目将为提高聚合物半导体的性能提供基础知识。该项目的成果将导致塑料电子产品的新材料和制造技术，以及信息技术和可再生能源的相关应用。该项目为培训科学家和工程师提供了极好的机会，包括妇女和少数民族，在塑料电子这一新兴的跨学科领域，这需要化学、物理、材料科学和工程学的知识。首席研究员S实验室与希腊、韩国、台湾、瑞士和日本的科学家在塑料电子的一般领域进行了几次研究合作；它接待了来自其中一些国家的资深科学家和学生访问。该项目将加强这些国际合作。

TECHNICAL SUMMARY: The performance of all current polymer semiconductor devices, such as thin film transistors, photovoltaic cells, light-emitting transistors, light-emitting diodes, and photodetectors, is limited primarily by the charge carrier mobilities of current materials. A fundamental challenge to improving the performance of all these devices and moving them towards practical systems applications is thus to achieve higher charge carrier mobilities. Furthermore, investigation of n-type and ambipolar polymer semiconductors has lagged far behind p-type polymer semiconductors. In this project, fundamental insights into the structural factors that govern high-mobility electron and ambipolar charge transport in polymer semiconductors are sought. Novel organic solvent-soluble n-type polymer semiconductors will be synthesized and studied, including poly(anthrazoline)s, poly(pyrazinoquinoxalines)s, and ladder poly(pyrazinoquinoxaline)s whereas poly(bisindoloquinoline)s and other donor-acceptor copolymers will be explored as ambipolar semiconductors. The solid state morphology and molecular packing in thin films and nanowires of polymer semiconductors will be characterized by electron microscopy and X-ray diffraction techniques. Charge carrier mobilities of polymer semiconductor thin films and nanowires will be measured by using the field-effect transistor as a platform. The most promising materials will be explored in high-performance field-effect transistors, complementary inverters, and photovoltaic cells. Polymer semiconductors that combine air-stability with high electron mobility or ambipolar transport with high carrier mobilities will be useful for developing all-plastic complementary integrated circuits for logic and memory functions and for improving the efficiency of plastic solar cells. Indeed, the realization of ambipolar polymers with high carrier mobilities could revolutionize the design of organic solar cells, light-emitting transistors, and all organic electronic devices and systems. NON-TECHNICAL SUMMARY:Electronic devices based on organic and polymer semiconductors, termed plastic electronics, are beginning to find many applications such as displays in cell phones, digital cameras, and car dashboards. Plastic electronics are also being tested for uses in applications ranging from flat-panel displays for computer and television screens, solid-state lighting, chemical- and bio-sensors, to low cost solar cells. This project will develop the basic knowledge for improving the performance of polymer semiconductors. Results from the project will lead to new materials and manufacturing technologies for plastic electronics and related applications in information technologies and renewable power sources. The project provides excellent opportunities for the training of scientists and engineers, including women and minorities, in the emerging interdisciplinary field of plastic electronics, which requires knowledge of chemistry, physics, materials science, and engineering. The principal investigator?s laboratory has several research collaborations with scientists in Greece, South Korea, Taiwan, Switzerland, and Japan in the general area of plastic electronics; it has hosted visits by senior scientists and students from some of these countries. This project will strengthen those international collaborations.