CSE grad students win Dow sustainability competition with energy-collecting windows

$10,000 first prize recognizes and rewards students for innovation and research

MINNEAPOLIS / ST. PAUL (12/08/2017) — What if the windows that bring natural light into our buildings could also be working to convert that sunlight into energy?

A project by University of Minnesota College of Science and Engineering graduate students to advance this world-changing goal won the 2017 Dow Sustainability Innovation Student Challenge Award (SISCA), an annual University-wide, solutions-driven competition for graduate and professional students hosted by the Institute on the Environment.

Mechanical engineering Ph.D. student Samantha Hill and materials science Ph.D. student Ryan Connell won the sustainability competition, which includes a $10,000 grand prize, for their low-cost solar concentrating windows. Their invention uses novel materials and light-management techniques, to harvest solar energy on the entirety of a building’s exterior without sacrificing its aesthetics or functionality.

Hill and Connell point out that traditional photovoltaics, such as solar panels, don’t lend themselves to applications when it is important that the building look a certain way. “As a result, most of the building surfaces in our cities that could be used for solar energy harvesting, such as windows, remain unused,” the students said in their presentation.

Luminescent solar concentrators (LSCs) are a potential solution. Made of transparent plastic sheets doped, or intentionally contaminated, with photoluminescent material, LSCs concentrate sunlight and convert it into energy. But thus far, inefficient design and a lack of suitable photoluminescent materials have prevented commercialization of the technology.

Employing silicon nanocrystals, Connell and Hill developed an efficient, non-toxic, large-area and semi-transparent LSC. Silicon, they note, is the second most abundant element on Earth. It’s both low-cost and environmentally friendly. In their work, the partners were able to demonstrate the feasibility of dispersing the silicon nanocrystals in polymers, for ease of fabrication, and predict a five-times concentration of light onto solar cells.

“We’re grateful for the opportunity the Institute on the Environment provided to share our work to create solar energy harvesting building materials and the support to bring it into a commercial space,” said Connell and Hill. They also expressed gratitude to their mentors and advisors, chemical engineering and materials science assistant professor Vivian Ferry, mechanical engineering professor Uwe Kortshagen, and chemistry professor Marc Hillmyer, as well as their respective groups for their feedback and guidance.

Runners-up also CSE students

Dow sustainability competition runners-up standing by their posterThe competition runners-up, materials science Ph.D. students Bryan Voigt and Jeff Walter, also presented work to advance solar energy and received a $2,500 prize. They are working to resolve challenges impeding the use of low-cost, Earth-abundant pyrite FeS2 as a solar cell material.

The research partners solved a long-standing doping puzzle in FeS2, as well as developed a model to describe its diverse surface properties, among other advances. Their research paves the way for large-scale, sustainable FeS2 solar cells.

CSE chemical engineering and materials science Professors Chris Leighton and Eray Aydil served as advisors.

“We’re very proud of all of these students,” Aydil said. “They gave terrific presentations on first-rate scientific work while looking like seasoned entrepreneurs.”

The Dow SISCA competition is made possible by a collaboration between the Institute on the Environment and the Dow Chemical Company.

The nine finalist projects were judged based on excellence in research; innovation of idea; sustainability (including alignment with Dow’s 2025 sustainability goals); scale and importance of the problem addressed; and viability of moving the research into practice, whether that’s in the marketplace or the world at large. Read more about the Dow SISCA finalists.

If you'd like to support University of Minnesota College of Science and Engineering graduate student research, visit our CSE Giving website.