A team of scientists at the Leibniz Institute for New Materials (INM) has developed a glass-like barrier layer that separates the metal carrier from the absorber film. The new material is said to increase the efficiency of metal-based CIGS thin-film solar cells by as much as 13%.
The diffusion barrier–which is transparent, flexible, and only a few microns thick–is applied on the metal carrier by means of a sol-gel process, according to the INM group. The scientists said they have produced DIN A3 size foils using a combination of dip coating and slot coating. By employing a traditional roll-to-roll printing process, continuously layered foils could be produced at lengths up to 50m and widths of about half a meter.
The newly developed layer “works as iron diffusion barrier and thus prevents corrosion and oxidation of the carrier,” explained Peter William de Oliveira, head of the program division. “At the same time, the barrier works as insulating layer and reduces unintentional electrical currents from the absorber to the carrier.”
INM will be showing the new CIGS barrier film and other technologies at its booth at the upcoming Nano Tech 2011 show in Tokyo next week.