Sean Roberts, an assistant professor in the Department of Chemistry at The University of Texas at Austin, has received the Faculty Early Career Development (CAREER) Award from the National Science Foundation to pursue his research on the electrical properties of the surfaces of thin materials, which has long-range potential to inspire more energy efficient solar cells, lighting and electronic displays. The award will also support an outreach program designed to give community college students hands-on experience with research.
The CAREER award is a prestigious grant given to promising junior faculty who do a masterful job of combining education and research. The award funds five years of innovative science.
"This is a great honor," says Roberts, "because it focuses not just on research, but also on education. As a faculty member, these are the things that I value and enjoy doing on a day-to-day basis."
Roberts joined the UT Austin faculty in 2014. He received his Ph.D. in physical chemistry from the Massachusetts Institute of Technology and carried out postdoctoral research at the University of Southern California.
The chemical and electrical properties of a material can be very different at its surface than deep within. And, when thin layers of different materials are sandwiched together—as they are in solar cells, light-emitting diodes and electronic displays—the surface properties of one material can change depending on what other material is next to it. All of this means that it can be hard to predict, say, how efficiently a photon of light will be converted to electricity in a solar photovoltaic cell.
To solve this problem, and gain insights into how to make these devices more efficient, Roberts is developing an imaging technique known as Electronic Sum Frequency Generation. The technique uses two light sources that combine at the surface of a material or interface between thin layers of different materials. The way the photons combine and reflect from a surface reveal the chemical and electrical properties at the surface of the material. The basic concept has been around for a few decades, but Roberts is pushing it forward by using light sources that flicker rapidly like a strobe to allow real-time imaging of kinetic processes, such as the migration of individual electrons.
Roberts' CAREER award will also support a new educational outreach initiative called Green Energy at Texas (GREAT), which will bring students from Austin Community College into labs on the Forty Acres to work on research projects under the guidance of faculty in chemistry and chemical engineering. The first cohort of seven research interns will spend eight weeks this summer at UT Austin.