A number of grand challenges have emerged in the semiconductor industry as it moves toward the miniaturization of the active components. Similarly, there is a need to develop polymers with well-defined architectures, heterogeneity, and control of properties through molecular design. To bridge the gap between polymer chemistry and nanostructured semiconductors, this CAREER project at Columbia University is focused on the development of photoactive heterogeneous side-chain block copolymers (HSBCPs) bearing electron donor and acceptor molecules. The purpose is to control heterogeneous hierarchical structures and understand their photophysics. Fulfilling three objectives will test the central hypothesis, which is founded on the concept that HSBCPs can be engineered to yield nanostructured donor-acceptor junctions capable of undergoing efficient electron transfer. First, a family of new electron acceptor mesogens with finely tuned lowest unoccupied molecular orbital (LUMO) levels will be developed. Second, the ability to control the microphase segregation of heterogeneous HSBCPs containing novel electron acceptors and other donors will be characterized by several X-ray scattering and imaging techniques in thin films and in the bulk. Third, the overall control of polymer structure, morphology, and positioning of heterogeneous molecular components are the key features of the materials in this project, which will be evaluated by pump-probe techniques to characterize the photophysics of the materials. The success of this project could impact renewable energy, and provide a fundamental understanding of artificial photosynthesis.
NON-TECHNICAL SUMMARY:
Elucidating the function of organic materials in artificial photosynthesis and solar-energy generation is a challenge encompassing multiple length scales, from molecules to nanostructures to large-scale devices. The use of polymers can provide the means to control heterogeneous molecular assemblies to mimic nature's photosynthetic nanoscale machinery. With this in mind, the PI will design and synthesize new materials with unique molecular architectures and study their resulting optical and electronic properties. This project on new polymeric materials will expose students to various disciplines spanning fields across chemistry, physics, and engineering. Additionally, the students will get first-hand research experience in National Labs and other institutions through established collaborations. The outreach component will focus on middle-school students from The Bronx, as well as aspiring undergraduates interested in research careers. Visiting middle-school students will get personal exposure to the college atmosphere and running experiments in a lab setting. Outreach to predominantly minority-serving undergraduate institutions will be the main focus, spending time with students to provide them with advice and guidance to become competitive applicants for graduate school. A key outcome of this CAREER project is aimed at strengthening the materials curricula at the graduate and undergraduate levels at Columbia University. These components will impact multiple levels of education through outreach and classroom activities, with the hope of instilling interest in students to pursue higher education in the science or engineering fields.
