Cooperative Electrical and Optical Behavior in Quantum Dot Arrays
ECE 595 Department Seminar Series
November 12, 2021
11:00 AM - 12:15 PM
Cooperative Electrical and Optical Behavior in Quantum Dot Arrays
Presenter: Elliott R. Brown, Wright State University, and Terapico, LLC, Dayton, OH
Abstract: Quantum dots (QDs) have been a paradigm of nanoscience since their advent in the 1980s, with the three common types formed by colloidal chemistry in liquids, self assembly in solids, or nanoscale electrostatics. Being essentially giant atoms, they individually display very strong interaction with light so are commonly used to enhance aqueous photochemical reactions in biology and medicine, increase the quantum efficiency in photodetectors such as solar cells, and offer the ability to resolve single electrons in semiconductor devices. But there is another possible realm of QD behavior when they become dense, defined roughly by an inter-QD separation less than or equal to the QD exciton radius (Brus condition), wherein they can display cooperative behavior. This talk will summarize some research on dense arrays of ErAs self-assembled QDs embedded in GaAs and grown by MBE. A photonic effect (superradiance) has been observed and explained using the Dicke model of quantum optics, and has a promising application as a pulsed THz source. An electronic effect (metal-to-insulator transition) has also been observed and explained using Mott electron transport in disordered conductors, and offers promising applications in sensors such as magnetometers and microbolometers. And remarkably, all of these effects occur at room temperature.
This is joint work with W-D. Zhang. The MBE was carried out by our collaborator, Richard Mirin, NIST, Boulder, CO.
Speaker bio: Elliott R. Brown received his PhD degree in applied physics from the California Institute of Technology in 1985, followed by a postdoc appointment at MIT Lincoln Laboratory. His research interest is in quantum-effect devices and sensors, mm-wave-to-THz technology of all sorts, resonant tunneling light emitters, and biomedical sensing and imaging. He has published 220 peer-reviewed journal articles and book chapters, and 170 archival conference proceedings. He also holds 19 U.S. patents. He is a Fellow of IEEE, APS, and OSA. He has received multiple awards, including one for Outstanding Achievement from the Office of the Secretary of Defense for service at the Defense Advanced Research Projects Agency (DARPA) from 1995 to 1998.
Faculty Host: Michael Stroscio (stroscio@uic.edu)
This lecture will not be recorded. Please contact the department for login information.
Date posted
Nov 11, 2021
Date updated
Nov 11, 2021