Preparation and Nanometer-scale Characterization of p-conjugated Organic Thin Film Materials

广泛共轭p电子系统的纳米级生长、结构和形貌将被研究。本研究的重点是共轭p电子系统，如硫代噻吩、聚吡咯和其他固体材料，这些材料是有机导电体和/或由于其共轭p系统而具有新的光学特性。提出的研究重点是制备和表征共轭体系的策略，其中由于分子在表面的局部取向而具有高度各向异性的性质。将研究几种实现分子定向的方案，包括在表面使用定向键和使用具有高阶密度的邻近表面。各种各样的结构、化学、电学和光学探针将被用来将分子结构和键与所产生的电学和光学性质联系起来。扫描隧道显微镜将用于研究薄膜的结构顺序和取向，而近场扫描光学显微镜（NSOM）将用于探测局部光学响应。反射-差分各向异性光谱学将作为一种非接触的评价分子取向程度的方法。拟议中的研究将在几个方面对社会有益。第一，通过培养未来的科学家。拟议的研究在范围上是跨学科的，弥合了合成化学，物理/分析化学和物理学之间的差距。在这项资助下接受培训的学生和博士后将获得成功的科学事业所需的跨学科培训。其次，拟议的研究本身将以新的方式造福社会。人们普遍认识到，过去25年来微电子技术的进步导致了“计算机革命”，不能用传统方法无限期地继续下去；使用分子作为基本构建模块代表了微电子学的新范式，如果成功，可能会使新型设备比现有设备小几个数量级。例如，有机发光二极管原则上比现有的灯泡效率高得多，并有望大大节省能源成本；这种结构的成功制造需要对有机薄膜的电导率和光学特性进行大量的研究。该项目由化学司和多学科事务办公室共同资助。

9901293 Hamers The nanometer-scale growth, structure, and morphology of extensively conjugated p-electron systems will be investigated. This research is focused on conjugated p-electron systems such as sexithiophene, polypyrrole, and other solid materials that are organic conductors of electricity and/or have novel optical properties as a consequence of their conjugated p systems. The proposed research focuses on strategies for preparing and for characterizing conjugated systems in which the properties are highly anisotropic due to the local orientations of the molecules on the surface. Several schemes for achieving molecular orientation will be investigated, including the use of oriented bonds at the surface and the use of vicinal surfaces with high step densities. A wide variety of structural, chemical, electrical, and optical probes will be utilized to link the molecular structure and bonding with the resulting electrical and optical properties. Scanning tunneling microscopy will be used to investigate the structural order and the orientation of the films, while near-field scanning optical microscopy (NSOM) will be used to probe the local optical response. Reflectance-difference anisotropy spectroscopy will be used as a non-contact method for evaluating the degree of molecular orientation. %%% The proposed research will benefit society in several ways. First, through training of future scientists. The proposed research is quite interdisciplinary in scope, bridging gaps between synthetic chemistry, physical/analytical chemistry, and physics. Students and postdocs trained under this grant will receive the kind of interdiscplinary training that is needed for successful scientific careers. Secondly, the proposed research itself would benefit society in new ways. It is generally recognized that the advances in microelectronics technology over the last 25 years that have lead to the "computer revolution" cannot continue indefinitely using conventional approaches; the use of molecules as fundamental building blocks represents a new paradigm for microelectronics that, if successful, might enable new types of devices orders of magnitude smaller than those existing today. Organic light emitting diodes, for example, can in principle have efficiencies much higher than existing light bulbs, with the promise of great savings in energy costs; successful fabrication of such structures requires a significant research effort into the electrical conductivity and optical properties of organic then films. This project is co-funded with the Chemistry Division and the Office of Multidisciplinary Affairs.