Department Lecture Series
Thursday November 1, 9:45 am, Smith 331

Small Molecule Design for Organic Electronics

ABSTRACT: To fulfill the promise of low-cost large-area electronics (displays, solar cells and solid-state lighting), materials for organic electronic applications must be easily prepared, stable, and amenable to solution deposition methods. The latter requirement typically thwarts most efforts to develop new materials - approaches to solubilize large aromatic chromophores typically do so by disrupting the strong intermolecular interactions necessary for electronic device performance. Our group has taken a holistic approach to improving both solubility and stability while simultaneously engineering the solid-state organization of linear aromatic compounds to induce strong π-stacking interactions. Separating the "waxy" solubilizing substituent from the rigid aromatic core by a flexible alkyne spacer allows the aromatic moieties to interact strongly, while the solubilizing substituents segregate into domains of insulating hydrocarbon. The ethyne substituent also increases the oxidation potential of the aromatic chromophore, significantly enhancing material stability. This approach to chromophore functionalization has yielded high-performance materials for thin film transistors, light emitting diodes and flexible solar cells. Furthermore, the stabilization afforded by properly selected substituents has allowed us to explore heretofore poorly studied materials such as hexacene and heptacene. This talk will focus on materials optimization for a variety of electronic applications, and the relationship between functionalization, crystal packing, thin-film morphology and electronic device performance.