Computational Modeling of the Photophysics of Conjugated Polymers

该奖项由化学部特别项目办公室和材料研究部联合颁发，以支持David Yaron博士的计算研究。半经验量子化学模型将被发展并应用于共轭聚合物的光物理。将根据齐聚物和聚合物以及不同聚合体系的实验数据开发同时拟合，以提供对操作筛选机制的研究。通过为聚乙炔、聚二乙炔和聚对苯乙炔开发一种统一的方法，将开发出可应用于其他聚合物的参数。激发态电子和空穴之间的库仑屏蔽将包括通过显式计算周围聚合物链中诱导的极化，以及通过显式计算链上的扫描机制。为非线性光学发展的运动方程形式将被用来计算激发态，提供了一种尺寸一致和计算上可行的方法来计算长高聚物链的激发态。与无机材料相比，共轭聚合物在光学和电子应用方面的主要优势是能够通过合成在分子水平上控制结构，并通过自组装在大分子水平上控制结构。半经验模型的发展将允许预测重要类别材料的结构-性能关系，并为新材料的设计提供基础。

This award is made jointly by the Office of Special Projects in the Chemistry Division and by the Division of Materials Research in support of the computational studies of Dr. David Yaron. Semi-empirical quantum chemistry models will be developed and applied to the photophysics of conjugated polymers. Simultaneous fits will be developed based on experimental data on oligomers and polymers and on different polymeric systems to provide for the investigation of the operative screening mechanisms. By developing a single consistent approach for polyacetylenes, polydiacetylenes and poly(paraphenylenevinylene), parameters will be developed that can be applied to other polymers. Coulomb screening between electrons and holes in excited states will be included through explicit calculations of the polarization induced in surrounding polymer chains, and through explicit calculations of on-chain screning mechanisms. Equation-of-motion formalisms developed for nonlinear optics will be used to calculate excited states, providing a size-consistent and computationally feasible approach to the excited states of long polymer chains. The major advantage of conjugated polymers over inorganic materials in optical and electronic applications is the ability to control structure at the molecular level by synthesis, and at the macromolecular level by self-assembly. The development of semi-empirical models will allow for the prediction of structure-property relationships in important classes of materials and provide a basis for the design of new materials.