GAINESVILLE, Fla., July 28 -- University of Florida engineers are working to develop a method of producing thinner and cheaper solar cells. The thin-film solar cells are 100 times thinner and potentially lighter than current silicon cells, and also require less semiconductor material. The material cost is very minimal, said Sheng Li, a professor of electrical and computer engineering at the University and part of a four-member faculty team working on the process. This is a very promising technology for solar cells. The Florida team, part of the Thin Film Partnership program, is focusing on a technology that uses a compound semiconductor called copper indium diselenide (CIS). Li explained that the method involves depositing a layer of CIS two to three microns thick on a specially prepared material such as glass. Researchers elsewhere have demonstrated that CIS cells can convert as much as 18 percent of sunlight to electricity -- about the same efficiency as the most efficient traditional silicon cells, according to the National Renewable Energy Laboratory. The engineers point out that there remain major challenges to overcome in manufacturing the cells. They have a more complicated structure and require more complicated processing, said Tim Anderson, chairman of the University's chemical engineering department and a member of the CIS team. Our role is to better understand the processing and transfer the technology to industry.