CAREER: Smart Molecular Design for One-Dimensional n-Type Nanostructures: Controlling Electronic Properties and Morphologies

技术概述：明确定义的有机半导体纳米结构不仅对未来的纳米电子学很重要，而且对改善当前有机光电器件的性能也很重要。在现代有机光电子学中存在两个关键问题：有用的n型半导体的稀缺性和溶液处理薄膜中的电荷输运性差。这一建议提出了一种新的方法来解决这两个关键问题，使用一个分子设计程序。通过分子间的轨道重叠来创建一维（1D）纳米结构是实现增强电荷迁移率的一种很有前途的方法。从PI那里得到的指导方针？根据以往用某些不对称取代缺电子双苯那嗪制备一维纳米结构的实验，本文提出了三种新型的一维n型纳米材料：i)利用外围取代基具有可控电子性质和自组装形态的t形杂芳构建单元，ii)通过“ð-偶联”连接的t构建单元的二聚体和三聚体，以及iii)与吸电子伙伴连接的t构建单元的二聚体和三聚体。本研究的主要目标是在电子缺乏的可调性方面对结构-性能关系有一个基本的理解，并增强新型n型材料衍生的一维纳米结构形态的可控性。有机光伏器件将使用n型纳米材料作为异质结的组成部分，为激子解离和通过纳米结构创建的途径增强电荷传输提供一个大的供体/受体界面区域。提议的工作涵盖了基本方面和器件应用。设备性能的反馈将指导未来材料的升级？设计。非技术总结：利用大量的太阳能资源来克服未来的能源挑战是必要的。有机太阳能电池可以提供重量轻、灵活、价格便宜的设备。然而，提高器件性能的一个障碍是缺乏关键组件之一（n型半导体）。该项目的目的是开发用于有机太阳能电池（和其他电子设备）的新型有机纳米材料，通过新颖的分子设计来克服这一障碍，从而帮助有机太阳能电池在未来的能源组合中发挥重要作用。这个项目包括一个与当地一所高中有关的教育推广的绝佳机会。PI处于一个独特的位置，利用他的研究来激励年轻学生在他们的早期教育与引人注目的可视化和真实的研究经验。在整个项目期间，PI将与克拉克县学区的当地高中建立伙伴关系，开展暑期高中生实习和高中教师暑期研究项目。此外，合成化学、分子组装、纳米科学、有机材料和光电子器件应用的结合将为研究生和本科生学习界面化学提供一个极好的智力舞台，界面化学作为一门当代科学越来越重要。

TECHNICAL SUMMARY: Well-defined nanostructures of organic semiconductors are important not only for future nanoelectronics, but also for improving the performance of current organic optoelectronic devices. There are two critical issues in modern organic optoelectronics: the scarcity of useful n-type semiconductors and poor charge transport in solution-processed films. This proposal presents a novel approach for addressing these two critical issues using one molecular design procedure.Creating one-dimensional (1D) nanostructures via intermolecular ð-orbital overlap is a promising approach for achieving enhanced charge mobility. With the guidelines obtained from the PI?s previous experiments in generating 1D nanostructures from certain asymmetrically substituted electron-deficient bisphenazines, three types of novel 1D n-type nanomaterials are proposed: i) T-shaped heteroaromatic building blocks with controllable electronic properties and self-assembly morphologies using peripheral substituents, ii) dimers and trimers of the T-building blocks connected through ð-conjugation, and iii) dimers and trimers of the T-building blocks connected with electron-withdrawing partners. The main objectives of this research are to develop a fundamental understanding of the structure-property relationship in terms of the tunability of the electron-deficiency, and to enhance the controllability of the 1D nanostructure morphologies derived from the new n-type materials.Organic photovoltaic devices will be fabricated using the n-type nanomaterials as a constituent of the heterojunction, providing a large donor/acceptor interface area for exciton dissociation and enhanced charge transport through the pathway created by the nanostructures. The proposed work covers both fundamental aspects as well as device applications. The feedback from device performance will guide future upgrades in the materials? design.NON-TECHNICAL SUMMARY: It is necessary to utilize vast solar sources to overcome energy challenges of tomorrow. Organic solar cells can provide light-weight, flexible, and cheaper devices. However, an obstacle to improve device performance is lack of one of the crucial components (n-type semiconductors). The purpose of this project is to develop novel organic nanomaterials for organic solar cells (and other electronic devices) to overcome this obstacle through novel molecular designs, and thus help making organic solar cells play a significant role in the future energy portfolio.This project includes an outstanding opportunity for educational outreach involving a local high school. The PI is in a unique position to utilize his research for motivating young students in their early education with eye-catching visualization and real research experiences. Throughout the project period, the PI will initiate a partnership with local high schools in the Clark County School District, launching a summer high school student internship and a high school teacher summer research program. In addition, the combination of synthetic chemistry, molecular assembly, nanoscience, organic materials, and optoelectronic device application will provide an excellent intellectual stage for graduate and undergraduate students to learn about interfacial chemistry which has growing importance as a contemporary science.