Synthetic polymers are being widely developed as replacements for natural materials. While these new polymers cannot precisely duplicate the properties of naturally occurring materials, they can be modified at the atomic level to afford materials with different and potentially improved properties. For electronic applications, semiconducting polymers that rival inorganic-based materials are readily prepared. Furthermore, it is possible to alter their properties through chemical synthesis, prepare a large amount of material under moderate conditions, and fabricate large-area films using solution-processing techniques such as inkjet printing. All of these can significantly reduce the cost of polymer-based solar cells. This award will (i) support research intended to increase basic knowledge for designing and producing conducting polymers with optimized properties for use in "plastic" solar cells; (ii) provide interdisciplinary research experiences for both undergraduate and graduate students, and (iii) foster interest in polymer science through a creative outreach effort targeting female and underrepresented minority students at all educational levels.
Due to their unique combination of semiconducting and polymer processing properties, conjugated polymers are being explored both academically and commercially for use in organic electronic applications. Two important benefits of these materials are the opportunity to optimize their optical and electronic properties for specific applications through synthesis and the chance to reduce the cost of electronic device manufacturing through the use of solution processing techniques. Although a number of different conjugated polymers have been synthesized, only a few have exhibited high efficiencies in organic photovoltaic cells. Furthermore, many of these are based on complex combinations of heterocycles that are difficult to synthesize. The vision and goals of this project are to develop new polymers based on benzodichalocogenophenes, a class of heterocycles that includes benzo[1,2-b:4,5-b']dithiophene, which has been used in copolymers for high performing organic photovoltaic cells. Furthermore, these building blocks can be easily synthesized in a few high yielding steps from low-cost starting materials and are readily customized. This project will (i) evaluate the impact of atomic engineering on the materials properties; (ii) investigate the physical, optical, and electronic properties of the materials through spectroscopic measurements and performance in organic photovoltaic cells; (iii) provide interdisciplinary research experiences for both undergraduate and graduate students, and (iv) foster interest in polymer science through a creative outreach effort targeting female and underrepresented minority students at all educational levels.
