Chih-hung Chang, an associate professor of chemical engineering at Oregon State University, is developing a new approach to solar energy which he believes may dramatically lower their cost while reducing waste and environmental impacts.

Currently, thin-film solar cells are made using methods such as sputtering, evaporation and electrodeposition. Those processes can be time-consuming, or require expensive vacuum systems or exotic chemicals that raise production costs.

An alternative approch is to use chemical bath deposition. This is a low-cost deposition technique that was developed more than a century ago. The problem is that changes in the growth solution over time make it difficult to control thickness. The depletion of reactants also limits the achievable thickness.

The technology developed at Oregon State University to deposit "nanostructure films" on various surfaces in a continuous flow microreactor makes the use of this process more commercially practical.

"We’ve now demonstrated that this system can produce thin-film solar absorbers on a glass substrate in a short time, and that’s quite significant," said Chih-hung Chang. "That’s the first time this has been done with this new technique."

Thin-film solar cells produced by applications such as this could ultimately be used in the creation of solar energy roofing systems. "If we could produce roofing products that cost-effectively produced solar energy at the same time, that would be a game changer," Chang said. "Thin film solar cells are one way that might work. All solar applications are ultimately a function of efficiency, cost and environmental safety, and these products might offer all of that."