Applied Physics Seminar
Abstract: Optical nanomaterials offer the ability to bend, twist, guide, and confine light in nanoscale dimensions, leading to new applications in photovoltaics, sensing, light emission control, and other optoelectronic devices. The first part of this talk will discuss strategies for capturing and managing incident sunlight effectively for solar energy conversion. I will discuss complementary strategies for managing incident sunlight before it interacts with the solar panel, including luminescent solar concentrators that down shift and concentrate sunlight using a combination of luminescent nanocrystals and nanostructured surfaces, and structures that integrate with photovoltaic modules for thermal management.
The second part of the talk will discuss the development of chiral nanomaterials that interact selectively with right and left handed circularly polarized light. Chiral molecules typically have small dissymmetry factors, due to the mismatch in size between the helical pitch of circularly polarized light and the size of the molecule. Chiral nanomaterials, in contrast, exhibit orders of magnitude stronger dissymmetry factors but have only been realized in a limited set of materials systems. I will discuss two different approaches to make tunable nanoscale chiral materials. In the first, we make tunable chiral metamaterials that incorporate both metal and dielectric components, where the sign and magnitude of the circular dichroism response depends on the refractive index of the dielectric component. In the second, we synthesize chiral semiconductor nanocrystals by tethering chiral ligands to the surface of nanocrystals, and show that the ligand-surface interaction tunes the chiral optical properties.
More about the Speaker: Vivian Ferry is an assistant professor at the University of Minnesota in the Department of Chemical Engineering and Materials Science. She received her S. B. in Chemistry from the University of Chicago in 2006, and her Ph.D. in Chemistry from the California Institute of Technology in 2011, working with Prof. Harry Atwater. She was a postdoctoral fellow with Prof. Paul Alivisatos in the Materials Science Division at Lawrence Berkeley National Laboratory from 2011 to 2014. Her research focuses on light-matter interactions in nanoscale materials, and her specific research interests include light management in solar energy conversion, switchable metamaterials, and nanoscale chirality. She is the recipient of an NSF CAREER award, an Air Force Office of Scientific Research Young Investigator Award, was named as one of Technology Review's 35 Innovators under 35 in 2016, and holds a McKnight Land-Grant Professorship at the University of Minnesota.
**Refreshments will be provided at 3:45pm in the Watson Lobby.