With support from the Organic and Macromolecular Chemistry Program at the National Science Foundation, Professor John Anthony of the Department of Chemistry at the University of Kentucky will work with linearly-fused hydrocarbons (acenes) that are benchmark components of low-cost displays and plastic solar cells. However, materials only up to the pentamer (pentacene) are well-characterized. This project will significantly enhance understanding of these important molecules by expanding the acene series through a functionalization strategy that retards common decomposition pathways, improving stability and solubility. By developing stabilized hexamers and heptamers, new materials for use in display technologies and energy generation are envisioned. Applying these stabilization methods to even larger systems (octamers, nonamers) will develop a better understanding of the evolution of aromaticity with increased oligomer length, which will improve chemists' ability to engineer the electronic properties of this class of molecules.
With this award Professor Anthony's research program will adopt a comprehensive approach to the development of new materials for organic electronics, including the development of new synthetic methodologies, the design of novel functionalization strategies, and the application of designed molecules to thin-film electronics. This approach will lead to materials suited for several emerging technologies, and train students in both the synthesis and application of self-assembled organic materials.
Progress in electronics, in particular personal and power electronics, will depend on the development of new materials that allow the creation of lighter, flexible, lower-cost devices (such as displays and solar cells) that have the potential to be recycled or are bio-degradable. In pursuit of these technologically and economically critical goals, many researchers have begun investigating organic carbon-based (rather than inorganic silicon-based) semiconductors. The scope of this project aimed to develop new organic semiconductors based on extended versions of materials commonly used for this purpose. Extending the length of the organic molecule has been predicted to yield improved performance in electronics, but to-date no research group has been able to make extended materials that were stable enough or processable enough for device studies. In the end, we succeeded in creating these extended materials, and some of them are indeed among the highest-performing semiconductors ever reported (e.g. 1, and the associated device). Furthermore, we also prepared and characterized the most extended aromatic reported to-date, a compound known as nonacene (2). This highly collaborative project provided new materials to researchers at 8 different Universities or Institutions, providing new avenues for the research programs of a dozen graduate students at those locations. Further, the information on molecule design gained from this project will direct the development of high-stability carbon-based semiconductors for commercial applications in flexible displays and solar cells.
