NSF Award
2305112
With support from the Macromolecular, Supramolecular and Nanochemistry program in the Division of Chemistry, Professor Tianquan Lian and a team of Emory graduate and undergraduate students are developing two novel ways to control photoinduced electron transfer (ET) from quantum confined semiconductor nanocrystals (NCs), one of the most important processes in photocatalysis and quantum information science. Quantum confined semiconductor NCs are promising novel materials with potential applications in energy conversion and quantum information science. In this project, the first aim is focused on using polaritons formed by coupling NCs with optical cavity modes as a new way to control photoinduced ET. The second aim is focused on NC Donor-chiral Bridge-Acceptor (D-B-A) complexes for selective transfer of light generated spins using chiral-induced spin selectivity (CISS) effects. The goals of the research are: 1) to advance the understanding of the formation and decay dynamics of polariton states; 2) to directly measure polariton mediated ET in NC-molecular acceptor complexes in cavity and test theoretical models; 3) to develop design principles for NCs with both slow electron spin relaxation and fast ET rates; and 4) to advance the understanding CISS effect in photoinduced ET in NC-chiral bridge-acceptor complexes.<br/><br/>Molecular polaritons, formed by coupling the molecular electronic or vibrational transition to a photonic cavity mode have received intense interest in chemistry since the reports that they can provide a novel approach for controlling chemical reactions. The proposed effort is focused on polariton mediated electron transfer because of its potential roles in polariton enabled chemical reactions. The proposed study will provide much needed experimental data to test current models of polariton state dynamics and polariton mediated ET, as well as important insights on how to use cavities to control ET rates for many potential applications. Controlling electron spin states is essential for spintronics and quantum information. Although electron spins can be selectively transferred during transport through chiral materials, this process is not understood at the quantitative level. The proposed NC donor-chiral bridge-acceptor platform represents a new approach to combine photonics with spintronics for potential applications in quantum information processing. The proposed study will lead to the development of design principles for NCs with both slow electron spin relaxation and fast ET rates and advance the understanding of the CISS effect in photoinduced ET in NC-chiral bridge-acceptor complexes. The proposed research program also offers unique opportunities for training graduate and undergraduate students and for integrating research with teaching and outreach activities.<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.
