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 }

IBM researchers worked with Japanese thin-film solar company Solar Frontier to get higher solar efficiencies for solar cells made from more abundant materials than current thin-film cells. Credit: IBM Research

IBM says it has made technical progress on a solar technology that researchers hope will yield efficient thin-film solar cells made from abundant materials.

IBM photovoltaic scientists Teodor Todorov and David Mitzi on Friday detailed the findings of a paper that showed the highest efficiency to date for solar cells made from a combination of copper, zinc, tin, and selenium (CZTS). Published in Advanced Energy Materials, the technical paper described a CZTS solar cell able to convert 11.1 percent of solar energy to electricity.

 That level of efficiency is a significant jump from the 10.1 percent efficiency Mitzi and colleagues showed last year. (See, Efficiency Solar Cells from Cheaper Materials). The paper also argues that CZTS solar cells could achieve efficiencies high enough to make them commercially viable.

The benchmark CZTS the IBM-led research group is pursuing is CIGS, solar cells made from copper, indium, gallium, and selenium. In commercial products, the efficiency of these cells is about 12 percent in solar panels and 20 percent in labs. If CZTS could get to 15 percent efficiency, it could start to displace CIGS, says Mitzi.

“There’s no fundamental reason that we know of why we cannot get up to the same efficiencies with CZTS as we do with CIGS,” he says. “It’s one of the key goals for the field for the next year or two.”

Developing an alternative to CIGS is driven not so much by cost as availability of the raw material to make cells, Mitzi explained. Gallium and indium, which is used in flat-panel production, could become constrained as solar volumes increased. Much of the production of those elements is centered in China, he added.

Replacing those elements with more abundant copper and tin in CZTS cells has the potential to supply 500 gigawatts of solar power, many times more than CIGS, according to the paper. The researchers have sought to replace selenium with more abundant sulfur as well to address material availability.

Having CZTS match CIGS on efficiency within five years is a reasonable time horizon, Mitzi said. IBM is working solar companies in the research, including Japan-based Solar Frontier, which installed 577 megawatts worth of CIGS panels last year, according to GTM Research.

Solar manufacturers have developed thin-film solar panels because they promise to be cheaper. But the costs of the incumbent silicon solar processes have dropped precipitously over the past three years. (See, The Dog Days of Solar).

That has made thin-film’s cost advantage dwindle. But there are a number of research groups working with CZTS with an eye towards the long term. “We’re building an understanding of what we need to fix and address to get the higher performance,” says Mitzi.

9 comments. Share your thoughts »

Tagged: Energy, solar, solar cells, CZTS

Reprints and Permissions | Send feedback to the editor

From the Archives

Close

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