Highlights
May 15, 2009
Northwestern University
X-ray Characterization of Self-Assembled Nanoscale Dielectrics
Jonathan D. Emery, Young-Geun Ha, Antonio Facchetti, Tobin J. Marks, Michael J. Bedzyk Northwestern University Materials Science and Engineering, NSF DMR-0520513; Dennis Keane, Qing Ma Argonne National Laboratory
Self-Assembled Nanoscale Dielectric (SAND) thin films are emerging as leading contenders in applications for organic and hybrid thin film transistors, allowing for low operating voltages and ideal device characteristics in next-generation flexible electronics.Â’ Dielectric properties are highly dependent on the behavior of the counter-anions within the film, specifically their position and motion under applied electric fields.Â’ Through utilization of advanced x-ray techniques, including long-period X-ray Standing Wave and X-ray Reflectivity, it is possible to locate and moni
May 15, 2009
Northwestern University
Correlating the Structure, Optical Spectra, and Electrodynamics of Single Silver Nanocubes
Jeffrey M. McMahon, Yingmin Wang, Leif J. Sherry, Richard P. Van Duyne, Laurence D. Marks, Stephen K. Gray, and George C. Schatz Northwestern University Materials Research Science & Engineering Center, DMR-0520513
The plasmonic properties of noble metal nanoparticles have potential uses in a wide variety of technologies based on their optical response.Â’ Recent collaborative efforts of the NU-MRSEC demonstrate that correlated localized surface plasmon resonance (LSPR) spectroscopy and high-resolution transmission electron microscopy (HRTEM) measurements can be used to obtain the optical response and detailed structural information for a single nanoparticle.Â’ By carefully incorporating the HRTEM structural details into finite-difference time-domain (FDTD) electrodynamics calculations,
May 14, 2009
Princeton University
Chemical Doping of Organic Molecular Films for Photovoltaic Applications
Calvin Chan, Wei Zhao, and Antoine Kahn (Princeton) Stephen Barlow and Seth Marder (Georgia Tech)
To advance the application of organic molecular films in solar cells, PCCM researchers have improved their conductivity and carrier injection by n-doping the acceptor layer in a donor-acceptor cell. The acceptor was a fullerene layer, C60, while the dopant was the low-ionization-energy molecule decamethylcobaltocene (CoCp2*).
May 14, 2009
Princeton University
3D Topological Dirac Insulator with a Quantum Spin Hall Phase
David Hsieh, Dong Qian, Lewis Wray, YuQi Xia, Yew San Hor, Bob Cava, and Zahid Hasan
An insulator is usually described as a material with completely filled electronic bands that do not contribute to any interesting transport behavior. However, recent theories have shown that in a particular class of band insulators called "topological insulators", the quantum motion of these electronically inert bulk electrons are entangled in non-trivial ways, giving rise to highly unusual conducting states at the surface of the material.
May 14, 2009
Princeton University
MRSEC Education Directors Network Meeting Hosted by PCCM
The MRSEC Education Directors conducted a workshop at Princeton (September 14-17, 2008), chaired by PCCM's Dr. Dan Steinberg. The group collectively produced one logic model for each of the 6 E/O concentration areas.The MRSEC Education Directors conducted a workshop at Princeton (September 14-17, 2008), chaired by PCCM's Dr.
May 12, 2009
University of California, Santa Barbara
Materials Research Facilities Network
The Materials Research Facilities Network (MRFN) has recently been established and is currently in operation at ca. 50% of MRSEC sites. The goal of the MRFN is to maximize the usage of MRSEC facilities and is directed towards the efficient and strategic development of materials characterization within the United States.
May 12, 2009
University of California, Santa Barbara
Micro-tensiometry
Surfactants are everywhere in nature and everyday life: animals rely on lung surfactants to breathe, and mayonnaise would separate into oil and water without them. To develop advanced multiphase polymeric materials, the efficacy of synthetic surfactants must be determined and optimized.
Apr 30, 2009
Crack Interaction With Grain Boundaries in Zinc Bicrystals
D. Catoor, K.S. Kumar, A.F. Bower, Y. Wei and W.M. Curtin
Grain boundaries are inherent defects in most materials of technological
relevance. Understanding how a growing crack interacts with them will enable design of microstructures to enhance the material toughness, a
Apr 30, 2009
Kinetic model of whisker growth in Sn films
E. Buchovecky, A.F. Bower, E. Chason, S. Kumar Division of Engineering, Brown University
The spontaneous growth of whiskers from Pb-free Sn solder films on Cu
substrates poses a serious threat to the reliability of electronic circuits.
Researchers at Brown are using experiments and computer simulations
to understand the mechanisms for the formation of Sn whiskers. As part
Apr 30, 2009
BrownOut: Engineering Educational Outreach
J. Blume, Division of Engineering
Classroom Visits Program
J. Blume, Division of Engineering
Brown undergraduates and faculty visit local science/math classes or youth programs to present engineering topics to students in Grades K-12. Presentations are developed by students and faculty based on current research or topics covered in the Brown
curriculum.
Student groups, such as the National Society of Black Engineers Student Chapter, Engineers without Borders, and th FSAE Care Team participate.
Example Presentations
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