NSF Award
2203595
With the support of the Macromolecular, Supramolecular and Nanochemistry program in the Division of Chemistry, Professor Genevieve Sauve of Case Western Reserve University is employing innovative chemical design to create low-cost solution-processable semiconductors with high electron affinity, excellent charge transport and low optical gap. These features are critical for a variety of organic electronic and solar energy conversion applications. Organic aromatic molecules that contain pi-conjugation will be developed with the ability to manipulate the molecular geometry by chelation with a variety of metals. As a result of pi-conjugation, these materials will become conductive when one applies a voltage (like in transistors) or shine light on them (like in photovoltaic cells). The purpose of metals in these materials is not only to control the molecular geometry, but also to tune optoelectronic properties, crystallinity and solution processable properties. The ability to solution-process these organic semiconductors will impact the printable electronic industry, providing portable devices and alternatives ways to convert solar energy to high value electricity. This project, if successful, will provide access to much needed high-performance optoelectronic materials that are low-cost and use sustainable chemistries and earth abundant elements. The research team will broaden participation of women in science through the Flora Stone Mather Center for Women Mentoring Program at Case Western University. This program pairs upper-level undergraduate students or advanced doctoral students with professionals to foster a sense of community and provide professional role models. Mentors are matched with mentees based on career interests, educational focus, and mentoring relationship expectations. To broaden participation of minority students in STEM, local high school students will be recruited through the American Chemical Society project SEED program. This outreach activity will place economically disadvantaged students into research laboratories during the summer. <br/><br/>This proposal will focus on the development of novel azadipyrromethene (ADP)-based complexes that have the rare combination of solution processability, excellent charge transport, absorption in the visible to NIR spectrum, and low synthetic complexity. In the first objective, difluorinated naphthyls and trifluoromethyl functionalization of non-planar zinc(II) complexes of ADP will be explored to further the understanding of how the dipole moment strength and direction effects self-assembly. This will also establish generalized guidelines to improve charge transport in non-planar systems. Organic photovoltaic efficiency will be increased by optimizing the polymer donor. Planar aza-BODIPY ligands as well as N2O2-type ADP ligands coordinated with group IV elements will also be researched. The second objective will focus on the synthesis and studies of novel NIR semiconductors based on aza-BODIPY ligands by extending pi-conjugation using noncovalent conformational locks. This research will provide fundamental structure-property relationships that have the potential to transform the field of pi-conjugated molecules and polymers, dyes with visible NIR absorption, ADP chemistry, and organic electronics. The findings could also impact applications including NIR photodetectors and sensors, bioimaging, solar energy conversion and photocatalysis.<br/><br/>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.
