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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.