Semiconducting Polymer Spherulites-From Fundamentals to Polymer Electronics

Abstract

The control of the morphology of semiconducting semicrystalline polymers is crucial to the performance of various electronic devices. Among other superstructures in semicrystalline polymers, spherulites stand out for various reasons. They are highly ordered, relatively easy to grow, and their underlying molecular structure provides anisotropic optical and electronic properties of the resulting polymeric material. In this feature article, a short overview of classical crystallization theory is given as well as a brief introduction to spherulites as supermolecular structures. The article then focuses on semicrystalline polymers with semiconducting properties. From classical melt crystallization toward solvent vapor annealing, different strategies of growing spherulites of these types of polymers are presented and examples of the corresponding polymers and their resulting morphology are given. Eventually, the potential application of spherulitic thin films in organic electronics such as field-effect transistors is demonstrated. Conductivity and mobility measurements are shown, particularly focusing on the anisotropy of the latter.

Keywords: conducting polymers; crystallization; electronic properties; optical properties; spherulites.