Incorporating Tailored Hydrogen Bonding Interactions in Organic Optoelectronic Thin Films - Pursuing Universality of Form and Function

碳基（有机）材料在日常应用中具有巨大的潜力，包括显示器，照明，太阳能电池，晶体管和传感器。 在这些情况下，通常是薄（10- 1，000纳米）膜中分子的三维（3-D）排列最终影响效率，稳定性和整体效用。这项研究借用了自然界使用的一种称为自组装的方法，以鼓励有机材料在薄膜中采用有利可图的安排，而这在很大程度上与它们的大小和形状无关。 自组装的通用方法的核心是氢键相互作用，它也负责将水分子或DNA碱基“粘”在一起。 从最广泛的意义上说，该研究有助于从根本上了解如何在纳米/介观尺度上控制有机物的三维结构，以加速下一代有机基电子材料的开发。 教育和培训方面的更广泛影响来自研究生和本科生接触多学科科学，包括合成和物理有机化学，光谱学，计算和材料加工/表征。 教授Castellano和薛利用佛罗里达（UF）桥博士奖学金计划，在UF研究生院和佛罗里达州-格鲁吉亚路易斯·斯托克斯少数民族参与联盟（FGLSAMP）之间的合作大学，以帮助招募女性和少数民族学生有助于研究和接受指导，以鼓励完成学位。通过该团队参与U-FUTURES，物理科学内容被交付给佛罗里达科学教师（4年级？8).薄膜中π-共轭有机分子之间的普遍相互作用在竞争的固态堆积排列之间不产生大的能量差，导致动力学驱动的空间结构对分子结构和加工的微小变化敏感。 本研究中的结构-性质研究揭示了氢键（H-键）引导的薄膜组装的热力学和动力学驱动器，以允许通过合理的设计和合成来独立地解决电荷迁移率和光学特性。 本项目通过改变程序化的分子间相互作用和沉积条件，具体研究了成膜过程中动力学和热力学的相互作用。 该研究还引入了一种生物启发的结构扫描，将H-键合构型与光电性质联系起来，并研究了涉及π-框架内重新定位H-键合单元的替代分子设计，以改善π-框架中的组装取向控制。该奖项反映了NSF的法定使命，并被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准。

Carbon-based (organic) materials hold enormous potential for use in everyday applications including displays, lighting, solar cells, transistors, and sensors. In these contexts, it is often the three-dimensional (3-D) arrangement of the molecules in thin (10-1,000 nanometer) films that ultimately affects efficiency, stability, and overall utility. This research borrows an approach used by nature, called self-assembly, to encourage organic materials to adopt profitable arrangements in thin films largely independent of their size and shape. Central to the universal approach of self-assembly are hydrogen bonding interactions that are also responsible for "sticking" water molecules or the DNA bases together. In the broadest sense, the research contributes to a fundamental understanding of how to control the 3-dimensional structure of organic matter at the nano-/mesoscale to accelerate development of next-generation organic-based electronic materials. Broader impacts with respect to education and training come from graduate and undergraduate students being exposed to multidisciplinary science that includes synthetic and physical organic chemistry, spectroscopy, computation, and materials processing/characterization. Professors Castellano and Xue take advantage of the University of Florida (UF) Bridge to Doctorate Fellowship program, a collaboration between the Graduate School at UF and the Florida-Georgia Louis Stokes Alliance for Minority Participation (FGLSAMP), to help recruit female and minority students contribute to research and receive mentorship to encourage degree completion. Through the team's participation in U-FUTuRES, physical science content is delivered to Florida science teachers (grades 4?8).The prevailing interactions between pi-conjugated organic molecules in thin films do not yield large energy differences among competing solid-state packing arrangements, leading to kinetically-driven spatial structures that are susceptible to minor changes to molecular structure and processing. The structure-property studies in this research expose the thermodynamic and kinetic drivers of hydrogen bond (H-bond) guided thin film assembly to allow the charge mobility and optical characteristics to be independently addressed through rational design and synthesis. This project specifically examines the interplay of kinetics and thermodynamics in film formation through variation of programmed intermolecular interactions and deposition conditions. The research also introduces a bioinspired structural scan to relate H-bonding configuration to optoelectronic properties and examines alternative molecular designs involving repositioned H-bonding units within the pi-framework to improve assembly orientational control in the pi-stacking direction and with respect to the substrate.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.