Building a Better Solar Cell

Why isn’t solar energy more widely used? After all, sunlight is a free and essentially infinite resource.

Adrienne Stiff-Roberts is on a mission to build the solar cell of the future.

And she’s doing it by experimenting with new materials that have the potential to solve many of the challenges of current solar energy.

“Efficiency is the challenge with solar energy,” says Stiff-Roberts, Ph.D., the Jeffrey N. Vinik Professor of Electrical and Computer Engineering. “If solar cells are more efficient, then the technology is less expensive and you’re talking about renewable energy being a replacement for carbon-based energy sources.”

Traditional solar cells are made from silicon and distribute only a quarter of the energy they take in from the sun. Stiff-Roberts and her team are working on incorporating new materials in the cells to capture significantly more energy.

By combining inorganic and organic compounds into one solar cell, Stiff-Roberts says, a solar panel can benefit from “the best of both worlds.”

To do this, Stiff-Roberts had to create a novel way for the the hybrid materials to be transformed into a semiconductor film, something that is found in cell phones, computers, and televisions, for example. And, she was awarded $1 million from the National Science Foundation to investigate the feasibility of scaling up her thin-film technique to make it commercially viable.

Understanding the materials and their capabilities is the first step, she says.

“There’s a lot about these materials we don’t understand,” Stiff-Roberts says, “and if you don’t understand the material, you can’t improve it or control it to make better devices.”

But, Stiff-Roberts says she is thrilled by the possibilities. At Duke, climate-related research like Stiff-Roberts is leading is conducted at the Pratt School of Engineering, where she can collaborate with other Duke faculty across disciplines. Duke’s collaborative, team-based culture also allows the Stiff-Roberts to collaborate not just with science and engineering faculty, but faculty representing diverse areas from policy to economics.

“If you want to solve renewable energy problems, it’s all related” she says, “And Duke has expertise in all these broader aspects. That’s where Duke has something unique to offer.”