The team was recently awarded a $750,000 Sunshot grant from the U.S. Department of Energy.
Rakesh Agrawal, Purdue’s Winthrop E. Stone Distinguished Professor in the school of chemical engineering, said he arrived at the project by looking to the future.
“You have to try to see what the future looks like and work back from there,” he said.
He was able to see that affordable power would be needed in the future and then began looking at options that exist today and how he might be able to achieve a more palatable future.
Solar thin-film is a popular lower-cost option for solar right now. But the Copper Indium Gallium Selenide (CIGS) solar cells use expensive and rare Earth materials that might not make the product sustainable.
“So we looked for materials that were abundant and absorbent,” he said.
That’s how Agrawal and his team came to be the first to begin developing Copper Zink Tin Sulfide (CZTS) ink.
The Purdue team was the first to begin working with the combination and has had a lot of success.
Agrawal said the idea behind turning the compound into an ink is that it can be quickly printed, roll-to-roll, on film, cutting down the production cost and making the product more competitive against traditional power production equipment.
While there have been some breakthroughs since the team began working, now it’s time to improve on that success, Agrawal said.
“Right now we’re getting about 8 or 8-and-a-half percent efficiency,” he said. “We want that to be closer to 15 percent.”
That’s what his team is using the DOE money to try to accomplish.
Agrawal said they are working on centering the solar cells better on the film. They’re studying the materials they use at the molecular level to find ways of improving them, and they’re looking for more efficient processes.
“We’re looking for constant improvement,” he said. “I believe 15 percent is definitely achievable.”
Pictured: Rakesh Agrawal holding a bit of the solar ink. Image courtesy of Purdue University.