Increased efficiency for CIGS solar cells

(Nanowerk News) Scientists at INM — Leibniz Institute for New Materials developed a barrier layer that separates the metal carrier from the absorber film and thus increases the efficiency of metal-based CIGS solar cells. For the first time, the INM program division "Optical Materials" presents this development in the German Pavilion at the international trade fair "nano tech 2011" and also nationwide at the Hannover Messe 2011.
Corrosion and poor isolation between substrate and carrier material cause a lower efficiency for CIGS solar cells apart from other influences. Solar cells consist of copper (C), indium (I), gallium (G), and sulphur (S). Glass as carrier material and the low efficiency prevent the flexible application of these future solar cells in the automotive industry, for example.
The developed layer 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", says Oliveira. Both functions increase the efficiency of metal-based CIGS solar cells by up to 13 percent.
The glass-like diffusion barrier is applied on the metal carrier by means of the sol-gel process. It is transparent and flexible and has a thickness of only a few micrometers. The INM scientists developed both the layer and up-scaled process. By means of dip coating and slot coating they 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 50 meters and a width of about half a meter.
These and other applications are exhibited by INM at the international trade fair "nano tech 2011". Included are coatings with special properties, as for example transparent conductivity, antiadhesive, scratch-proof, antireflective or self-cleaning function, or layers for friction reduction or corrosion protection. Multifunctional coatings, which combine several of these properties, also belong to the INM research portfolio. The INM – Leibniz Institute for New Materials presents itself in the German Pavilion (Booth E-18-24) at the nano tech 2011 in Tokyo from 16th to 18th February 2011.
At the Hannover Messe, too, INM will present its skills and competencies at the Booth A-50 in Hall 2 – the Leading Trade Fair for Research and Technology and the International Leading Trade Fair for Research, Development and Technology Transfer.
The INM — Leibniz Institute for New Materials, situated in Saarbrücken (Germany), engages in fundamental and applied materials research – from molecules to pilot production. In interdisciplinary cooperation, the work of INM includes the fields of chemical nanotechnology, interface materials and materials in biology. Its focal research fields are chemical synthesis, physical analysis of surfaces, coatings and interfacial materials.
Source: INM - Leibniz Institute for New Materials