In this project funded by the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Dr. Genevieve Sauve of the Department of Chemistry at Case Western Reserve University is developing new synthetic approaches for making semiconducting organic materials by incorporating metals. Organic semiconductors are solids whose building blocks mainly consist of carbon and hydrogen atoms, and at times nitrogen, sulfur and oxygen. Each carbon atom in these materials is bonded to other carbons not only through single bonds, but also with special bonds called pi-bonds. The alternating pi-bonds enables the molecules (polymers) to conduct electrons. Just like traditional semiconductors made with silicon, these materials can become conductive when one applies a voltage (like in transistors) or shines light on them (like in photovoltaic cells). The big advantage of organic semiconductors is that they can be printed, just like ink, enabling inexpensive and scalable production of electronic devices. In addition, organic semiconductors are plastic-like, producing flexible and lightweight devices that could be used where rigid and heavy silicon-based devices cannot. However, devices based on organic semiconductors tend to have lower performance than devices based on traditional semiconductors. In this research, highly innovative and creative chemical reactions are used to improve the performance of organic semiconductors by using metals. The purpose of adding metals to these materials is to provide additional control over not only electrical conductivity, but also crystallinity and solution processing properties. Materials prepared in this project are expected to impact the printable electronic industry, providing portable devices and alternative ways to convert solar energy to high value electricity. Students associated with this project are exposed to interdisciplinary research and are prepared to be next generation of scientists. Education and outreach activities posted on YouTube target high school students and underrepresented groups as the videos demonstration the real-life applications of pi-conjugated materials.
Solution-processable organic semiconductors are poised to revolutionize the electronic and printing industries, but to achieve the most desirable properties, new creative approaches and synthetic strategies are required. Conventional approaches to organic semiconductor design typically rely on purely planar pi-conjugated systems whose opto-electronic properties are tuned with the nature of the chemical backbone, functional groups and side-chains. To access new functionalities, this project turns to hybrid organic/inorganic coordination compounds, where coordination with main group or transition metals provides an additional tool to tune the properties of pi-conjugated systems, such as molecular shape, crystallinity and opto-electronic properties. This research exploits azadipyrromethene complexes as a versatile platform for development of the next generation of solution-processable hybrid semiconductors. The research has the potential to impact the field of pi-conjugated systems, dyes with visible NIR absorption and organic electronics.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
