Science at the Edge
Engineering Seminar
February 21st,
2014
11:30 a.m.
Room1400 Biomedical and Physical
Sciences Building
Refreshments served at 11:15 a.m.
Enrique Gomez
Chemical Engineering
The Pennsylvania State University
From molecules to devices: self-assembled organic
photovoltaics
Abstract
Organic
electronic materials have the potential to impact almost every
aspect of modern
life including how we access information, light our homes, and
power personal
electronics. Unfortunately,
weak
intermolecular interactions and disorder at junctions of
different organic
materials limit the performance and stability of organic
interfaces and hence
the applicability of organic semiconductors to electronic
devices. Our approach
has focused on utilizing block
copolymer architectures –where critical interfaces are
controlled and
stabilized by covalent bonds– to demonstrate that
self-assembled soft materials
can provide the hierarchical structure needed for
high-performance organic
electronics. For
example, we have
demonstrated control of donor-acceptor heterojunctions through
microphase-separated
conjugated block copolymers to achieve 3% power conversion
efficiencies in non-fullerene
photovoltaics. Characterization
through
X-ray scattering and electron microscopy reveals that the
efficient performance
of block copolymer solar cells is due to self-assembly into
mesoscale lamellar
morphologies with primarily face-on crystallite orientations.
Although inferior
in performance to inorganic and champion polymer/fullerene
solar cells, the
significant photovoltaic response of block copolymer devices
provides the
initial results needed to accelerate the design of
next-generation materials. Control
of interfacial morphologies afforded
by the block copolymer architecture facilitates theory
efforts, such that we
can utilize the combination of Density Functional Theory,
Molecular Dynamics
simulations and polymer theory to predict donor-acceptor block
copolymers with
control of charge transfer processes.
Bio
Enrique D.
Gomez received
his B.S. in Chemical Engineering from the University of
Florida in 2002 and his
Ph.D. in Chemical Engineering from the University of
California, Berkeley in
2007. After a year and a half as a postdoctoral research
associate at Princeton
University, he joined the faculty at the Chemical Engineering
Department of the
Pennsylvania State University in August of 2009. Enrique’s
research focus is on
understanding how structure at various length scales affects
macroscopic
properties of soft condensed matter. In
particular, the current emphasis of his research group is on
the relationship
between microstructure and electrical properties in the active
layers of
organic thin film transistors and photovoltaics. Enrique has been awarded
multiple awards,
including a Visiting Scientist Fellowship from the National
Center for Electron
Microscopy, the Ralph E. Powe Junior Faculty Award by the Oak
Ridge Associated
Universities, and the NSF CAREER Award.
For further
information
please contact Prof. Christina Chan, Department of Chemical
Engineering and
Materials Science at [log in to unmask]
Persons with disabilities have the right
to request and
receive reasonable accommodation. Please call the Department of
Chemical
Engineering and Materials Science at 355-5135 at least one day
prior to the
seminar; requests received after this date will be met when
possible.