Center for Excitonics
Seminar Series Announcement
The Center for Excitonics is sponsoring 2009 series of energy-related
lectures from scholars and colleagues
in the private sector who are working in the field. We invite you to join
us and to forward this information on to others who
might be interested in attending this and other seminars.
Title: Electronic Structure and Excited State
Dynamics in Biological and Nanoscale Systems
Presenter: Professor Gregory D. Scholes
Organization: University of Toronto
Department of Chemistry
Lash-Miller Chemical Laboratories
Institute for Optical Sciences and Centre for
Quantum Information and Quantum Control
Date: February 25, 2009
Time: 3:00 - 4:00pm
Place: 36-428
Refreshments: Yes
Seminar URL:
http://www.rle.mit.edu/excitonics/scholes-022509.html
Center URL:
http://www.rle.mit.edu/excitonics/
Abstract
After photoexcitation, energy absorbed by a molecule can be transferred
efficiently over a distance of up to several tens of Ångstrom to another
molecule by the process of resonance energy transfer, RET (also commonly
known as electronic energy transfer, EET). Examples of where RET is
observed include natural and artificial antennae for the capture and
energy conversion of light in photosynthesis, amplification of
fluorescence-based sensors, optimization of organic light-emitting diodes,
and the measurement of structure in biological systems (FRET). Recent
experimental work in our laboratory suggests that RET in conjugated
polymers may involve surprising electronic coherence. This, in turn,
contributes to enhancing the semiconductor-like optical properties of
these systems. I will describe an ultrafast polarization experiment
specifically designed to observe quantum coherent dynamics in this regime.
Our results suggest that quantum transport effects occur at room
temperature when chemical bonds connecting donor and acceptor help to
correlate dephasing perturbations. A fascinating topic in quantum
chemistry is the elucidation and quantification of models for electron
correlation, which is crucial for the correct description of electronic
excited states. In the second part of this talk I will discuss experiments
that we have used to probe electron correlation in molecules and nanoscale
systems, such as nanocrystals and carbon nanotubes.
Bio
Dr. Scholes obtained both his B.Sc. (Hons) and Ph.D. (1994) from the
University of Melbourne. He undertook postdoctoral studies at Imperial
College in London from 1995–1997 as a Ramsay Memorial Research Fellow.
During the period 1997–2000 he pursued further postdoctoral studies at the
University of California, Berkeley (with Prof Graham Fleming, presently
Deputy Director of Lawrence Berkeley National Lab). He subsequently took a
faculty position at the University of Toronto, in the Department of
Chemistry (2000) and was promoted to Associate Professor in 2005. Dr.
Scholes took research and study leave during 2006–2007, and spent
productive and enoyable time at the National Renewable Energy Laboratory
(Colorado, USA) and Università di Pisa (Toscana, Italia). Recent awards
honoring his research achievements include the 2007 Royal Society of
Canada Rutherford Medal in Chemistry, a 2007 NSERC Steacie Fellowship, the
2006 Canadian Society of Chemistry Keith Laidler Award, and an Alfred P.
Sloan Fellowship (2005–2006).