Computational Modeling of the Photophysics of Conjugated Polymers

Carnegie Mellon University, Pittsburgh PA

Investigators

Abstract

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.