Select your localized edition:

Close ×

More Ways to Connect

Discover one of our 28 local entrepreneurial communities »

Be the first to know as we launch in new countries and markets around the globe.

Interested in bringing MIT Technology Review to your local market?

MIT Technology ReviewMIT Technology Review - logo


Unsupported browser: Your browser does not meet modern web standards. See how it scores »

{ action.text }

Inside the polymer, electrons go from a low to a high energy level when bombarded by photons. The smaller the difference (or bandgap) between these levels, the more light a cell absorbs, and the higher its efficiency. One way to decrease the bandgap is to bring down the higher energy level. University of Chicago chemistry professor Yu is using this technique to design new types of narrow-bandgap polymers. “The beauty of organic solar cells is that we’re able to engineer new materials that can tailor those energy levels,” Yang says.

The researchers are also trying to improve the interface between the polymer and the carbon nanostructure so that electrons can move faster to the external circuit without getting trapped in the material. And they are developing better electrode materials and improved ways of fabricating the electrodes. Yang says these advances will eventually make it possible to boost the efficiency of individual cells and of stacked cells.

Even if Solarmer reaches its target of 10 percent efficiency, Wu says, it may take as long as three years before the company can print commercial-grade rooftop panels with those ratings. Right now, the company plans to have devices on laptop bags and cell phone back panels in early 2011, followed by awnings and sunshades.

Yang says organic solar cells need not only higher efficiencies but also more stability. “What’s commercialized is not the highest efficiency but most reproducible technology,” he says. Indeed, plastic solar startup Konarka, based in Lowell, MA, is producing flexible panels on a large scale despite just a 3 to 5 percent efficiency.

Adam Moulé, a chemical engineering and materials science professor at the University of California, Davis, says that increasing the lifetime of organic solar cells is now the biggest challenge. Solarmer’s panels have a lifetime of up to three years.

“The 7.9 percent reported efficiency record is really amazing,” Moulé says. “If organic photovoltaic units of more than 5 percent power efficiency could be made that have a guaranteed lifetime of over five years, then I think that they will be competitive with CIGS and silicon because of reduced panel cost.”

9 comments. Share your thoughts »

Credit: Solarmer Energy

Tagged: Energy, Materials, renewable energy, solar, plastic solar cells, silicon solar cells

Reprints and Permissions | Send feedback to the editor

From the Archives


Introducing MIT Technology Review Insider.

Already a Magazine subscriber?

You're automatically an Insider. It's easy to activate or upgrade your account.

Activate Your Account

Become an Insider

It's the new way to subscribe. Get even more of the tech news, research, and discoveries you crave.

Sign Up

Learn More

Find out why MIT Technology Review Insider is for you and explore your options.

Show Me