The three main types of thin film technologies use cadmium-telluride, copper-indium-gallium-selenide and amorphous-silicon to convert sunlight into electricity.
Nanosolar is one of several Silicon Valley startups that have attracted billions of dollars in venture capital to develop a thin-film technology called copper indium gallium selenide, or CIGS. Such solar cells use little expensive silicon, the main ingredient of conventional photovoltaic cells.
IBM's approach is based on a process developed by IBM Research to crank out so-called thin-film solar cells based on copper, indium, gallium and selenide.