Experimental and Computational Study of Structure and Dynamics of Bulk Conjugated Polymer Systems

Abstract

Conjugated polymers are a highly relevant class of materials due to their low processing cost and applicability in flexible electronic devices. A significant challenge in the field remains to relate the chemical structure of these materials with their morphology and dynamics, which in turn affect their charge transport characteristics. There are several experimental and computational methods that are commonly used when characterizing conjugated polymers. In this work, we attempt to synergistically apply these techniques so as to obtain a clear understanding of the properties that affect the structure and dynamics of conjugated polymers. A large experimental data set is used to validate molecular dynamics (MD) simulations of poly(3-hexylthiophene), a model conjugated polymer system. A sensitivity analysis of system and simulation parameters is performed, and the key factors affecting the conjugated polymer dynamics and configuration are found to be molecular weight, crystallinity, equilibration method, and force field parameters. Specifically, the atomistic partial charges are found to have the greatest influence on both properties. The identification of these key parameters will inform further studies of more complex conjugated polymer systems, elucidating the relationship between conjugated polymer chemistry and performance.