7 February 2011

INM’s glass-like diffusion barrier layer boosts CIGS PV efficiency by 13%

Researchers at INM — Leibniz Institute for New Materials in Saarbrücken, Germany have developed a barrier layer that separates the metal carrier from the absorber film and thus increases the solar energy conversion efficiency of metal-based CIGS (copper indium gallium sulphur/selenium) thin-film photovoltaic cells.

The INM’s ‘Optical Materials’ program division will present the development for the first time in the German Pavilion at the ‘nano tech 2011’ international trade fair in Tokyo, Japan (16–18 February) as well as at Hannover Messe 2011 in Germany (4–8 April).

Using glass as carrier material can prevent the flexible application of CIGS solar cells in the automotive industry, for example. However, corrosion and poor isolation between a metal carrier material and the substrate can reduce efficiency for CIGS solar cells.

The barrier layer that has been developed is glass-like. “It works as iron diffusion barrier and thus prevents corrosion and oxidation of the carrier,” explains 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,” he adds. Both functions increase the efficiency of metal-based CIGS solar cells by up to 13%.

The glass-like diffusion barrier is applied on the metal carrier via a sol-gel process. It is transparent and flexible and has a thickness of just a few microns. INM has developed both the layer and the up-scaled process. By means of dip coating and slot coating they have produced foils in a DIN A3 size. The traditional roll-to-roll printing process allows the production of continuous layered foils up to a length of 50m and a width of about 0.5m.

Tags: CIGS

Visit: www.inm-gmbh.de/en

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