Computational Modeling of the Photophysics of Conjugated Polymers

卡内基梅隆大学的David J. Yaron在理论与计算化学和材料理论的共同支持下，在共轭聚合物的光物理计算建模领域进行理论研究。这项工作涉及发展半经验方法，由更高水平的量子力学处理提供信息，这些处理能够使用粒子-空穴激励的局部表示来处理聚合物中的激子现象。这类系统的模拟由于需要相关处理、单位细胞大小和紊乱的存在而变得复杂。此外，考虑与极化粒子-空穴激发态集合相关的介电屏蔽效应是准确描述由一组局域正交基函数构成的单一组态相互作用基中的光激发所需的关键因素。共轭聚合物在平板显示器、柔性显示器、有机晶体管和光电池等电子和光物理领域具有巨大的应用潜力。这种设备是目前用于电子、信息显示和光源的技术的高度便携、环保的替代品。这里开发的程序允许人们使用量子化学方法来探索这些材料的结构-性质关系。这种类型的理论研究可以提供最可靠的手段来理解结构无序和长期静电因素如何影响这些系统的光学性质。

David J. Yaron, of Carnegie Mellon University, is co supported by Theoretical and Computational Chemistry and Materials Theory to perform theoretical research in the area of computational modeling of the photophysics of conjugated polymers. This work deals with developing semi empirical methodologies, informed by higher-level quantum mechanical treatments that are capable of treating excitonic phenomena in polymers using a localized representation for the particle-hole excitations. Simulation of such systems is complicated by the need for correlated treatments, the unit cell size, and the presence of disorder. In addition, including the effects of dielectric screening associated with a collection of polarizable particle-hole excited states is a key ingredient that is needed to accurately describe the optical excitations within a single configuration interaction basis constructed from a set of localized orthogonal basis functions.Conjugated polymers have great potential for electronic and photo-physical applications such as flat-panel displays, flexible displays, organic transistors and photocells. Such devices represent highly portable environmentally friendly alternatives to the technologies in current use for electronics, information display and light sources. The programs developed here allow one to use quantum-chemical methods for exploration of structure-property relationships for these materials. Theoretical investigations of this type may provide the most reliable means for understanding how structural disorder and long-range electrostatic considerations affect the optical properties of these systems.