Team Develops New Method to Map Phosphorene, 2-Dimensional Materials

Photo by Amy Schlesing

From left, Salvador Barraza-Lopez, Edmund Harriss and Mehrshad Mehboudi. At right, a non-planar phosphorene segment with red balls representing phosphorus atoms connected by covalent bonds.

FAYETTEVILLE, Ark. – A team of University of Arkansas researchers has identified a way to more accurately model two-dimensional atomistic structures through geometry, allowing them to link the effect of shape on their properties.

The research team was led by Salvador Barraza-Lopez, a U of A assistant professor of physics; Edmund Harriss, clinical assistant professor of mathematics; Mehrshad Mehboudi, doctoral student in microelectronics and photonics; Kainen Utt, mathematics and physics undergraduate, and collaborators Humberto Terrones of Rensselaer Polytechnic Institute in New York and Alejandro Pacheco San Juan of Universidad del Norte in Colombia. The national journal, Proceedings of the National Academy of Sciences, published their results last week.

Interest in phosphorene — an atom-thick layer of phosphorus — grew over the last year.

The researchers used discrete differential geometry to map phosphorene using the positions of individual atoms and studied how shape variations affect its properties.

“This is the first study of its kind using discrete differential geometry to study two-dimensional material,” Barraza-Lopez said.

The team used discrete differential geometry to map the atomistic shape of the material and to associate this shape with changes in its optical properties — the color at which it absorbs and emits light. Discrete differential geometry is used in computer animation, and as shown by the team, is well-poised for use within the context of two-dimensional materials.

“We can use this framework across other materials,” Harriss said. “One of the goals of the research is to provide fundamental tools to model these materials.”

“There is great excitement in exploring a wealth of two-dimensional atomic structures right now, especially when their shape is not ideal and planar” Barraza-Lopez said. “We remain certain that the research community will realize the potential of a discrete geometry in understanding shape/properties relations in those materials. There is a sense of joy in reexamining our basic understanding of geometry, using an intriguing two-dimensional material that is being extensively studied at the present moment for this purpose.”

About the University of Arkansas: The University of Arkansas provides an internationally competitive education for undergraduate and graduate students in more than 200 academic programs. The university contributes new knowledge, economic development, basic and applied research, and creative activity while also providing service to academic and professional disciplines. The Carnegie Foundation classifies the University of Arkansas among only 2 percent of universities in America that have the highest level of research activity. U.S. News & World Report ranks the University of Arkansas among its top American public research universities. Founded in 1871, the University of Arkansas comprises 10 colleges and schools and maintains a low student-to-faculty ratio that promotes personal attention and close mentoring.