CAS: Photoinduced Interfacial Charge Transfers with Organic Sensitizers using Low Energy Photons and Fundamental Physical Organic Design Concepts

University Of Mississippi, University MS

Investigators

Abstract

In this project, funded by the Chemical Structure, Dynamics & Mechanisms B Program of the Chemistry Division, Professors Jared Delcamp and Nathan Hammer of the Department of Chemistry and Biochemistry at the University of Mississippi are developing new classes of organic dye molecules that exhibit interesting light-matter interactions. The goal of this research is to design organic dyes that absorb low-energy light to enable the design of higher-performing electronic devices such as night vision technologies, infrared cameras, secure display technologies, solar cells including transparent ones integrable with buildings, solar batteries, and artificial photosynthetic systems. This project relies on interdisciplinary research utilizing organic, inorganic, materials, and physical chemistry. To encourage STEM involvement, outreach activities to the general public and student groups with large populations of underrepresented minorities are planned. A yearly summer research program brings STEM students onto campus to conduct independent research related to this award. Near-infrared absorbing organic dyes capable of undergoing interfacial charge separation at metal oxide interfaces are needed to advance a number of emerging technologies. Metal oxide bound organic dyes that absorb low energy photons (>800 nm) and subsequently undergo charge separation in high quantum yields are rare. Systems in these regions are often limited in utility by excited-state and charge separated state lifetimes. The study of fundamental physical organic chemistry is needed to enable the rational design of systems using low energy photons. In this project, four types of systems are studied at interfaces: (1) dyes with delocalized charge states after electron transfer to metal oxides, (2) dyes with excited-state aromaticity for prolonging excited states to promote higher quantum yields of interfacial photoinduced charge separation, (3) double cross-conjugated dyes for lower energy photon absorptions, and (4) Near-infrared absorbing chromophores incorporating proaromatic functionality. 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.