An algorithm developed by an undergraduate student in the Whiting School of Engineering’s Department of Electrical and Computer Engineering (ECE) could lead to the creation of more efficient solar cells.

Ekin Gunes-Ozaktas

Fourth-year student Ekin Gunes Ozaktas’ approach improves on an algorithm that researchers use to model the properties of materials with complex geometries, so-called “metamaterials”. He applies this method to facilitate the design and optimization of solar cells with complex nanoscale geometries.

“I took this algorithm that looks at the metamaterial like a black box that light goes in and out of, improved it, and applied it to solar cells,” Ozaktas said. “Using conventional methods to study and optimize the optical behavior of a solar cell under various conditions takes a long time. We figured out how to use this algorithm to make the process faster, allowing optimization over more design parameters in a shorter amount of time.”

Ozaktas is working on the project in the NanoEnergy Laboratory with ECE Professor Susanna Thon, principal investigator and a core member of the Ralph O’Connor Sustainable Energy Institute (ROSEI). Their results appear in Optical Materials Express, and have also been presented at the IEEE Photovoltaic Specialists Conference.

Thon’s group works with solar cells featuring complex nanoscale geometries that are more efficient than ordinary solar cells because their complex nanoscale geometries enable them to selectively absorb specific wavelengths of light.

Ozaktas’ method involves treating complex-structured regions of the solar cell as uniform slabs of a “fictional” material, that does not appear in nature and bears novel optical properties differing from those of the constituent materials.  Surprisingly, he found that such treatment didn’t affect the accuracy with which the behavior of the cell could be studied.

“What I am trying to do is simplify how we deal with complex nanopatterned geometry in solar cells,” he said. “We found that you can do it without getting into the individual nanoscale geometry, by treating the entire structure as a whole. Ultimately, this approach could help with optimizing the design of spectrally selective solar cells, as well as offer insights into the properties of these “metamaterials” in a broader range of contexts.”