Their new copper indium gallium diselenide (CIGS) cell hit 19.9% efficiency, which is a world’s record for this type of solar cell. Most thin-film cells are currently in the high single digit or low double digit efficiency range.
NREL Senior Scientist Miguel Contreras said that the NREL researchers were able to hit 19.9% because of improvements that have been made in the quality of the material applied during the manufacturing process. CIGS cells use very thin layers of semiconducting material that are applied to a low cost backing such as flexible metal foils, glass, plastic, or stainless steel. Thin-film cells need less energy to produce and can be made several different ways. Some possible future uses for CIGS cells include roof shingles, windows, siding, along with portable solar chargers.
Companies such as First Solar, Nanosolar, and Solyndra – some of the current makers of thin film solar cells, are at the 10-14% efficiency range with their products.