Collaborative Research: Controlling Photoinduced Spin Processes through Polymer Design

Nontechnical Description This collaborative project will explore how polymers can be designed to leverage electron spin properties using light. This quantum phenomenon offers potential to transform emerging applications in information science and imaging. One promising but unproven way of generating useful spins involves a special class of organic molecules that, when properly designed, can efficiently use light to generate desirable quantum states. In this project the research team will develop a new approach to assemble light harvesting polymers that contain stable radicals to study the flow of energy to the spin center. The discoveries that ensue from these studies will lead to transformative technologies for spintronics, magnetic imaging, and quantum information science. The collaborative approach also focuses on mentorship, collaboration, and inclusion to foster a sense of belonging while expanding access to science. The researchers will promote recruitment and long-term success through initiatives that create pipelines from K-12 to professional careers. Technical Description This project will explore the unique spin characteristics of triplet pairs generated through singlet fission (SF) in macromolecular systems. The research team will develop macromolecular architectures that enable control over exciton dynamics and spin interactions in radical-containing polymers. The research will focus on designing novel multifunctional systems that can harness high spin polarization of the triplet pair multiexciton state to achieve enhanced energy conversion, spin polarization transfer, and optoelectronic applications. The project is structured around two primary objectives: (1) designing and characterizing multiexciton dynamics in radical-containing polymers, and (2) determining the spin and population dynamics to demonstrate the efficacy of spin polarization transfer in these systems. These activities will address significant hurdles hindering substantial progress in applications of SF that span from the lack of fundamental guidelines of multichromophore design in macromolecules to the orchestration of spin polarization transfer pathways to stable radicals. Traditional studies have focused on generating multiple excitons from a single photon, but this project differentiates itself by emphasizing the control and utilization of spin dynamics for energy conversion and quantum information processes. The project’s success will lead to a deeper understanding of the fundamental interactions between triplet pairs and radical spin centers, establishing new paradigms in multiexciton chemistry and molecular spintronics. This will significantly impact emerging technologies such as spintronics, magnetic imaging, and quantum information science by providing foundational knowledge for designing systems with enhanced spin polarization and stability at non-cryogenic temperatures. 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.