Research Reveals Insights Into Optical Properties of Plasmonic Nanostructures

From left: Pijush K. Ghosh, Desalegn T. Debu and David A. French.
Photos by Whit Pruitt, University Relations

From left: Pijush K. Ghosh, Desalegn T. Debu and David A. French.

FAYETTEVILLE, Ark. – University of Arkansas researchers have helped define the optical properties of plasmonic nanostructures, work that could lead to improved sensors in security and biomedical devices, and have applications in solar cells. The research team in the Department of Physics recently published its findings in the journal PLOS ONE.

Plasmons are waves of electrons on the surface of a metal. The frequency of these electronic waves can be altered to couple with light by changing the particle size, shape, material and surrounding environment. The plasmons can increase light intensity and focus the light down to nanoscale volumes, which can be useful for a variety of nanoscience applications.

The core of the work is the subject of graduate student Pijush K. Ghosh’s master thesis in physics. Ghosh collaborated with fellow graduate students Desalegn T. Debu and David A. French for the journal article, titled “Calculated thickness dependent plasmonic properties of gold nanobars in the visible to near-infrared light regime.” The students are part of a physics research group led by assistant professor Joseph Herzog.

This work explores the optical properties of rectangular-shaped gold nanoparticles, in particular how they scatter light and the strength of the scattered light near the nanoparticle. The researchers determined how variations in the structures’ geometry affected how they coupled with light, making it easier to work with structures that aren’t perfectly square. The findings could enable plasmonic devices, such as sensors, to be more accurately tuned for a specific application.

“Making nanostructures with perfectly square corners is difficult using common nanofabrication techniques,” Ghosh said. “In our work, we investigated realistic structures with rounded corners. The work determined the difference in resonance wavelength of round-corner and sharp-corner nanobars. We also found how the spectrum precisely shifts as you make thicker nanobars. This reveals insight into another dimension of the structures that allows for more control and tunability of these plasmonic nanostructures.”

Ghosh is pursuing his doctorate in electrical engineering. He is working on a thin-film capacitor project with funding from the U of A’s Center for Power Optimization of Electro-Thermal System, a National Science Foundation-sponsored center.

Contacts

Joseph Herzog, assistant professor
Department of Physics
479-575-4217, jbherzog@uark.edu

Bob Whitby, feature writer
University Relations
479-575-4737, whitby@uark.edu

Headlines

School of Art Launches Master of Arts in Art History Graduate Program

The art history M.A. degree is an accredited two-year program in partnership with Crystal Bridges Museum and specializes in studying the arts of the Americas.  

Graduate School Awards Outstanding Faculty Mentor, Master's Thesis Awards

Kaleb Turner was honored for his master's thesis, which looked at resilience during the pandemic, and Mike Richardson was honored for their success in mentoring graduate students.

Research Technologist Named Engineering Employee of the Quarter

Jason Crawley, a scientific research technologist with the Department of Computer Science and Computer Engineering, has been selected Employee of the First Quarter for the College of Engineering.

UAPD's SafeZone Mobile App Adds CAPS Services and SEAR Resources to Promote Well-Being

The UAPD's SafeZone Mobile Safety App launched its "Wellbeing" function on Monday, bringing the services and resources of the Counseling and Pschological Services program closer to you.

U of A Speech and Debate Succeeds in Last Tournament of Semester

The students Daisy Rehbock, Luke Hubbard, Megan Dial, Hadley Adkison, Jaci Sabatini, Luke Thurmon, Jacob Hurbanek and Max Green all succeeded in winning at least one round.

News Daily