Defect Manipulation in Pi-Conjugated Semiconducting Polymers and their Effect on Microstructure and Transport Properties

技术概述：聚酰亚胺共轭半导体聚合物正在紧锣密鼓地开发中，用于有机发光二极管、薄膜晶体管和太阳能电池。然而，由于很难建立结构-性质关系的详细关联，对它们在许多应用中的性能的了解是有限的。这反过来需要对这些材料的结构发展和形成有更深入的了解，目前合成化学家无法精确控制pi共轭半导体聚合物中的缺陷。这项建议的目标是开发具有精确可控缺陷的模型PI共轭聚合物，以便能够更完整地描述其微观结构，从而阐明微结构如何影响光电性能。模型聚合物将是聚(3-己基噻吩基)(P3HT)，随着项目的进展，其他聚合物系统将被研究。为了简化模型，将用聚合物纳米线代替半结晶薄膜来表征聚合物纳米线，以便于对晶区进行广泛的研究。随着工作的进行，薄膜中的无序度将被系统地增加，以探索晶区和非晶区之间的相互作用，以及无序在pi共轭半导体聚合物的光电性能中的作用。非技术摘要：这一提议旨在加深对一类日益重要的材料的理解，即pi共轭半导体聚合物。这些聚合物在柔性电子领域引起了人们的极大兴趣，目的是以更具成本效益和能源效率的方式开发便携式电子设备。这些聚合物越来越多地被用于商业应用，例如在有机发光二极管(OLED)中。此外，它们正在积极开发用于可再生能源，作为太阳能电池的光吸收材料。尽管它们被广泛使用，但关于缺陷(例如，聚合物链中的扭结)如何影响聚合物的性能，仍有许多未知之处。在这项建议中，聚合物中的缺陷将被系统地改变，以便对这些材料有更详细的了解。将通过太平洋科学中心、科学咖啡馆开展社区外联活动，以及为代表不足的少数群体(URM)和妇女开展辅导活动，从而加强拟议的研究。该项目还包括针对本科生和高中生的教育活动。

TECHNICAL SUMMARY: Pi-conjugated semiconducting polymers are under intense development for use in organic light-emitting diodes, thin-film transistors, and solar cells. However, the understanding of their performance in many applications is limited because of the difficulty in establishing a detailed correlation of structure-property relationships. This in turn requires deeper understanding of structure development and formation of these classes of materials, which is currently hampered by the synthetic chemists' inability to precisely control defects in pi-conjugated semiconducting polymers. The goal of this proposal is to develop model pi-conjugated polymers with precisely controlled defects, so that a more complete description of their microstructure can be developed and therefore elucidate how the microstructure affects optoelectronic properties. The model polymer will be poly(3-hextylthiophene) (P3HT) to begin with, and as the project moves on other polymer systems will be investigated. To simplify the model, polymer nanowires will be characterized rather than the semi-crystalline thin film so that the crystalline domains can be studied extensively. As the work progresses, the degree of disorder in the films will be systematically increased in order to explore the interplay between the crystalline and amorphous domains, and the role of disorder in optoelectronic properties of pi-conjugated semiconducting polymers.NON-TECHNICAL SUMMARY: This proposal aims to further the understanding of an increasingly important class of materials, namely pi-conjugated semiconducting polymers. These polymers have been attracting a lot of interest in the general area of flexible electronics, where the aim is to develop portable electronic devices in a more cost-effective and energy-efficient manner. These polymers are increasingly being used in commercial applications, for example in organic light-emitting diodes (OLEDs). Furthermore, they are actively being developed for use in renewable energy as the light absorber material in solar cells. Despite their widespread usage, there is much that remains unknown about how defects (for example, kinks in the polymer chain) affect the polymers' properties. In this proposal, the defects in the polymers will be systematically altered so that a more detailed understanding of these materials can be developed. The proposed research will be enhanced by community outreach activities through the Pacific Science Center, the Science Cafe, and through mentoring activities for underrepresented minorities (URMs) and for women. The project also includes educational activities for undergraduate and high-school students.