Hi All,
This talk by Michael McGehee at MIT on March 8 might interest folks who are
interested in OPVs, solar cells, etc.
See below for details.
Tamar
From: energy_colloquium-bounces(a)MIT.EDU [mailto:
energy_colloquium-bounces(a)MIT.EDU] On Behalf Of MIT Energy Initiative
Sent: Tuesday, March 01, 2011 11:21 AM
To: energy colloquium
Subject: [Energy_colloquium] March 8 - Organic and Dye Sensitized Solar
Cells - Michael McGehee
[
cid:~WRD000.jpg]<http://web.mit.edu/mitei/news/seminars/<https://webm…
Organic and Dye Sensitized Solar Cells
Michael McGehee
Associate Professor of Materials Science and Engineering and Director of the
Center for Advanced Molecular Photovoltaics, Stanford University
Tuesday, March 8
4:15 PM
Room 66-110
<http://whereis.mit.edu/?go=66<https://webmail.mit.edu/horde/services/go.php?url=http%3A%2F%2Fwhereis.mit.edu%2F%3Fgo%3D66
[cid:image001.jpg@01CBD808.06E6AD30]
Abstract
Organic solar cells and dye sensitized solar cells are very promising
because they can be deposited rapidly in roll-to-roll coating machines
without expensive vacuum chambers or high temperature processing. Since they
can be lightweight and flexible, it may soon be possible to roll them onto
rooftops at a cost several times lower than is now possible with silicon or
cadmium telluride solar cells. Since organic semiconductors do not contain
any rare or toxic elements, such as indium, cadmium or tellurium, organic
solar cells could be used to provide the world with a significant fraction
of its electricity.
My research group has used synchrotron x-ray diffraction and other
characterization techniques to reveal in detail how semiconducting polymer
chains and fullerene molecules pack in solar cells and shown how this
packing influences the electronic processes that determine how well solar
cells work. We have also measured the lifetime of polymer solar cells and
found it to be as high as 7 years.
We have also pioneered the use of long range Forster energy transfer to
improve light absorption in solar cells. We believe that the incorporation
of energy relay dyes into dye sensitized solar cells (DSCs) is going to make
it possible to raise their efficiency from 11 to 15% in the next few years
by extending the region of the spectrum that the cells can absorb farther
out into the infrared, where almost half of the sun's energy is located.
One of the great challenges to making highly efficient solar cells with
solution deposited films that have high defect densities is keeping the
films thin so the charge carriers can be collected before recombination
occurs while at the same time absorbing all of the light. We have recently
demonstrated that absorption and power conversion efficiency can be
increased by as much as 20% simply by nanoimprinting an array of domes into
the active layer before depositing a silver electrode so that incoming light
can be coupled into plasmonic modes that travel in the plane of the solar
cell.
About the speaker
Michael D. McGehee is an Associate Professor in the Materials Science and
Engineering Department and Director of the Center for Advanced Molecular
Photovoltaics at Stanford University. His research interests are patterning
materials at the nanometer length scale, semiconducting polymers, large area
electronics and renewable energy. He has taught courses on nanotechnology,
organic semiconductors, polymer science and solar cells. He received his
undergraduate degree in physics from Princeton University and his PhD degree
in Materials Science from the University of California at Santa Barbara,
where he did research on polymer lasers in the lab of Nobel Laureate Alan
Heeger. He did postdoctoral research with Galen Stucky and Brad Chmelka at
the University of California at Santa Barbara on the self-assembly of
organic-inorganic mesostructures. He has won the 2007 Materials Research
Society Outstanding Young Investigator Award and the Mohr Davidow Innovators
Award.
The Seminar Series is made possible with the generous support of IHS-CERA
[cid:image002.jpg@01CBD808.06E6AD30]