Dr. Vivian Ferry will present Optical nanomaterials: chirality and nanopatterned quantum dot solids
- Friday, April 12, 2019 from 4:10pm to 5:00pm
- Barnard Hall, 103 - view map
Friday, April 12, 2019
4:10 – 5:00 PM
Barnard Hall (EPS) 103
Optical nanomaterials: chirality and nanopatterned quantum dot solids
Professor Vivian Ferry
University of Minnesota
Chemical Engineering & Material Science
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.
First, I 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 show two different examples of nanoscale chiral systems that are tunable and potentially switchable. In the first, binding a series of different chiral carboxylic acid ligands to the surface of a semiconductor nanocrystal results in a 30x change in dissymmetry factors. In the second example, I will show 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.
The second part of the talk will discuss quantum dot solids for applications in nanophotonics. We have recently prepared patterned nanocrystal solids with lateral feature sizes as small as 30 nm, and heights in excess of 100 nm, without degradation of the photoluminescence. We show that by nanostructuring the nanocrystal solid at this length scale and controlling connectivity between the nanocrystals, we can enhance absorption and tailor the refractive index for applications in nanophotonics and as light-emitting components of metamaterials.
Host: Nick Borys
- Department of Physics