Lower-Cost Solar Cells to Be Printed Like Newspaper, Painted on Rooftops

Aug. 24, 2009

AUSTIN, Texas — Solar cells could soon be produced more cheaply using nanoparticle "inks" that allow them to be printed like newspaper or painted onto the sides of buildings or rooftops to absorb electricity-producing sunlight.

Brian Korgel applies the nanoparticle 'inks' as a spray on the solar cells
Researchers apply the nanoparticle "inks" as a spray on the solar cells.

Brian Korgel, a University of Texas at Austin chemical engineer, is hoping to cut costs to one-tenth of their current price by replacing the standard manufacturing process for solar cells—gas-phase deposition in a vacuum chamber, which requires high temperatures and is relatively expensive.

"That's essentially what's needed to make solar-cell technology and photovoltaics widely adopted," Korgel said. "The sun provides a nearly unlimited energy resource, but existing solar energy harvesting technologies are prohibitively expensive and cannot compete with fossil fuels."

For the past two years, Korgel and his team have been working on this low-cost, nanomaterials solution to photovoltaics—or solar cell—manufacturing. Korgel is collaborating with professors Al Bard and Paul Barbara, both of the Department of Chemistry and Biochemistry, and Professor Ananth Dodabalapur of the Electrical and Computer Engineering Department. They recently showed proof-of-concept in the Journal of the American Chemical Society.

The inks could be printed on a roll-to-roll printing process on a plastic substrate or stainless steel. And the prospect of being able to paint the "inks" onto a rooftop or building is not far-fetched.

"You'd have to paint the light-absorbing material and a few other layers as well," Korgel said. "This is one step in the direction towards paintable solar cells."

Korgel uses the light-absorbing nanomaterials, which are 10,000 times thinner than a strand of hair, because their microscopic size allows for new physical properties that can help enable higher-efficiency devices.

In 2002, he co-founded a company called Innovalight, based in California, which is producing inks using silicon as the basis. This time, Korgel and his team are using copper indium gallium selenide or CIGS, which is both cheaper and benign in terms of environmental impact.

"CIGS has some potential advantages over silicon," Korgel said. "It's a direct band gap semiconductor, which means that you need much less material to make a solar cell, and that's one of the biggest potential advantages."

His team has developed solar-cell prototypes with efficiencies at one percent; however, they need to be about 10 percent.

"If we get to 10 percent, then there's real potential for commercialization," Korgel said. "If it works, I think you could see it being used in three to five years."

He also said that the inks, which are semi-transparent, could help realize the prospect of having windows that double as solar cells. Korgel said his work has attracted the interest of industrial partners.

Funding for the research comes from the National Science Foundation, the Welch Foundation and the Air Force Research Laboratory.

Download high-resolution photos of Korgel and the solar cells.

Learn more about Korgel's work.

For more information, contact: Daniel Vargas;  Brian Korgel, Department of Chemical Engineering, Cockrell School of Engineering College of Engineering, 512-471-5633.

3 Comments to "Lower-Cost Solar Cells to Be Printed Like Newspaper, Painted on Rooftops"

1.  Colin Miller said on Sept. 16, 2009

The potential for nanomaterials CIGS solar PV technology seems tremendous, especially if it could be painted or sprayed onto other surfaces. I am wondering about how much "more benign in terms of environmental impact" CIGS PV cells are than silicon, and what sources I could find to learn more about the overall environmental impact of CIGS PV technology? Could you please refer me to further research on this issue? I am conducting research on the solar industry for the Greenlining Institute, a non-profit. Thank you very much!

2.  Preetom said on Sept. 18, 2009

It seems to me that we are going to overcome the deficiency of power especially for poor countries like mine (Bangladesh). But one question arises in my mind: Does it work in the rainy season also? If yes, is there any possible danger for people in houses?

3.  Jakob said on Nov. 22, 2009

Thank you for a great post! I'm in research mode right now as I'm about to install solar panels in my own home. But I'm a bit confused.

I've just read an article about thin solar panel film. According to that article thin-film solar panels is state of the art technology.

Could you please explain the difference between thin-film panels and nanoparticle "inks"? Are they two completely different technologies?