Highlights

MRSEC scientists and collaborators have shown [1] that the localized buckling of a compressed thin sheet, important for molecular interfaces, [2] has the same mathematical origin as the localization of kinetic energy in a line of swinging pendulums.  It is a form of soliton. 

Luping Yu, Dmitri Talapin and collaborators from the University of Chicago MRSEC are working to develop highly efficient bulk heterojunction organic solar cells.  They have recently created composite polymer solar cells from a combination of the semiconducting polymer, PTB7, PC71BM, and doped multiwall carbon nanotubes (MCNT--these MCNT are doped with N (nitrogen), 

Highly-symmetrized MnAu nanoalloys may possess high magnetic moments for potential application. The magnetic properties of MnAu nanoclusters exhibit strong dependence on the cluster sizes and morphologies.

The detection of noxious gases or bio-agents is important for various environmental and security needs. High sensitivity, sufficient selectivity and molecular recognition are key characteristics for such sensing. Nebraska MRSEC researchers have developed a scheme for molecular sensing using magnetic tracer particles and a microcantilever torsional magnetometer. An example of using this system with a detection process is illustrated in the Figure below.

To change the magnetization of a ferromagnet usually requires a magnetic field.  So, for example, if we put a compass needle into the high field of an MRI machine, we can no longer trust it to swivel to the North.  Similarly, the magnetic stripes on credit cards and key cards can be destroyed in high magnetic fields.  Electric fields don’t have the same effect on magnetic materials, which is just as well for everyday applications.

Photovoltaics is a method of converting solar radiation into electricity.  Some semiconducting materials exhibit a property known as the photoelectric effect that causes them to absorb light and release electrons. In addition to the semiconductors, ferroelectric materials have been employed to create ferroelectric-photovoltaic devices. In these devices, a ferroelectric thin film is used as a light absorbing layer and the electric field created by ferroelectric polarization is the driving force for the photocurrent.

The Nebraska MRSEC Professor/Student Pairs Program brings in professor/student pairs from non-research intensive four-year institutions to conduct research with Nebraska MRSEC scientists.  The goal is to provide a research experience which benefits both the participants and the MRSEC projects.  For the professor, this program provides an opportunity to conduct new research, access to facilities typically unavailable at their home institution, and make strong and lasting connections with MRSEC researchers.  For the student, this program provides an opportunity to conduct world-class research

High conductivity and efficient charge injection into organic layers could lead to the design of more efficient organic solar cells and molecular electronics, especially light emitting diodes. Most organic materials are however insulators and only few exhibit high conducting properties. Nebraska MRSEC researchers in collaboration with their colleagues at University of Puerto Rico have discovered that zwitterion molecules of the p-benzoquinonemonoimine type are different from being a standard insulator.

Ferroelectric materials are characterized by a spontaneous polarization that can be switched by external electric field. This property is important for various technological applications such ferroelectric random access memories. However, when ferroelectric film thickness is reduced down to a nanoscale the ferroelectric polarization may become unstable due to strong depolarization fields and interface effects.