Magnetic Field Effects on Temporal and Spatial Dynamics of Functional Nanostructures
Abstract
Motivated by a novel phenomenon, giant magnetoresistance (GMR), strenuous efforts have been made to investigate magnetic field effects (MFE) in organic materials. In contrast to GMR, which is applicable to inorganic materials in the limit of high magnetic field over several tesla, it has recently been demonstrated that electric properties of organic counterparts, such as resistance, conductance, and electroluminescence, are readily varied under a lower magnetic field (~100 mT). By the virtue of MFE manifestation under low magnetic field, MFE research in organic materials has attracted much attention for their distinctiveness and potential for real-world applications.So far, progress has been made in development of magnetic-field-active organic materials and electric measurements characterizing only macroscopic traits of the systems. As MFE emerges from quantum coupling between external magnetic field and spin magnetic moments of multiple charge carriers, exploiting MFE for high performance organic photovoltaic materials requires precise understanding of charge carrier dynamics and their spin-state mixing in complex chemical nanostructures. In this proposal, we aim to accomplish the goal by introducing novel spectroscopic techniques, which utilize ultrashort pulses for generation of charge carriers and tracking down their dynamics, and systematic bottom-up development of donor-acceptor nanocomposites from the simplest single donor-acceptor pair to higher-dimensional nanostructures. This proposed research will be proceeded by three-year phases in a stepwise manner. In the first year, MFEs on temporal dynamics from fs to ?s in the simplest donor/acceptor system will be investigated introducing various timeresolved spectroscopic methodologies covering a whole temporal regime. In the second year, MFEs on spatial dynamics of organic nanomaterials will be studied based on high-resolution space-resolved spectroscopic tools.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 11, 2017
- Source ID
- FA23861714086
Entities
People
- Dongho Kim
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- Yonsei University