OSU ChEs Create a New Inkjet-Printed CIGS Solar Device

It looks like the humble inkjet printer might be the next great solar-tech manufacturing platform. Several confident Oregon State University ChemEs are touting an amazing accomplishment: the world's first inkjet-printed CIGS solar device, which can reduce raw material waste by 90 percent. They've glimpsed a solar holy grail: high performing, rapidly produced, ultra-low-cost, thin-film solar electronics.

The dramatic reduction of waste material

Of course, this technology is still in the early stages of development, but part of the excitement is the hazy future. With findings recently published in Solar

Energy Materials

, the researchers have also applied for a patent, but commercialization is still years and multiple iterations away. "This could be an important new technology to add to the solar energy field," said Chih-hung Chang, an OSU professor in the School of Chemical Engineering. The real advantage of this approach, he said, is a dramatic reduction in waste material. Instead of depositing chemical compounds on a substrate with a more expensive vapor phase deposition--wasting most of the material in the process--inkjet technology creates precise patterning with very low waste.

"Some of the materials we want to work with, such as indium, are relatively expensive," Chang said. "If that's what you're using you can't really afford to waste." One of the most promising compounds and the focus of the current study is called chalcopyrite, or "CIGS." CIGS has extraordinary solar efficiency--a layer of chalcopyrite one or two microns thick has the ability to capture the energy from photons about as efficiently as a 50-micron-thick layer made with silicon.

Potential for new industries

SEM Cross section showing a new inkjet Chalcopyrite solar cell

In new findings, researchers report that they were able to create an ink that could print chalcopyrite onto substrates with a power conversion efficiency of about 5 percent. The OSU researchers say that they should be able to achieve an efficiency of about 12 percent, which would make a commercially viable solar cell.

If costs can be reduced enough and other hurdles breached, it might even be possible to create solar cells that could be built directly into roofing materials, opening a huge new potential for solar energy, new jobs, and industries.

Just for context, here is a short video interview of Caltech Professor Harry Atwater who is pursuing the same goal, talking about his startup, Alta Devices.

What other competitive waste reduction processes currently exist?

Photo: Solar cell--Sun, istockphoto.com
Photo: conventional solar cell, istockphoto.com
Photo: cross section solar cell, Oregon State University, flickr