Charge transport in highly aligned conjugated polymers (Presentation Recording)

Abstract

Charge transport in conjugated polymers has a complex dependence on film morphology. Aligning the polymer chains in the plane of the film simplifies the morphology of the system allowing for insight into the morphological dependence of charge transport. Highly aligned conjugated polymers have also been shown to lead to among the highest reported field effect mobilities in these materials to date. In this talk, a comparison will be made between aligned polymer films processed using two primary methods, nanostructured substrate assisted growth and mechanical strain. A number of polymer systems including P3HT, pBTTT, N2200, and PCDTPT are considered, and the processed films are analyzed in detail with optical spectroscopy, AFM, TEM, and X-ray scattering providing insight into the molecular features that allow for effective alignment. By contrasting the morphology of these films, several insights into underlying charge transport limitations can be made. A number of key morphological features that lead to high field effect mobility and charge transport anisotropy in these films will be discussed. In addition, several unique features of organic thin film transistor device behavior in these systems will be examined including the commonly observed gate voltage dependence of saturated field effect mobility.