Swedish solar energy expert Midsummer slashes CIGS layer thickness by half for reduced manufacturing cost

[Stockholm, Sweden, November 25, 2014.] Midsummera leading supplier of production lines for cost effective manufacturing of flexible thin film CIGS solar cells, announces that its CIGS layer thickness has been reduced to 800nm, less than half of what other suppliers can offer, “This puts the foundation for low manufacturing cost, which further strengthens the business case and attractiveness for Midsummer’s thin film CIGS solar cells”, said Sven Lindström, CEO at Midsummer.

Midsummer has managed to halve the thickness of the CIGS layer while maintaining performance.

Earlier this year, Midsummer announced that the company has managed to increase the efficiency of the whole solar cell to 16.2 per cent aperture area of the full 156×156 mm cell.Since then, Midsummer has raised the efficiency from 16.2% to 16.7% on 156x156mm aperture area. With the help of a new aggressive grading of the CIGS layer, they have also been able to thin it out to 800 nanometres (nm); normally the thickness of the CIGS layer is 2000 nm or 2 microns.Most of the light is absorbed in the first 800 nm, so for productivity reasons the absorber layer can be kept thin.A thinner CIGS layer has a number of advantages. CIGS is the most expensive layer in the solar cell; so reducing the thickness has major cost advantages. Also, if the CIGS layer is reduced, the production time is reduced which increases productivity. A thinner CIGS layer also means that it takes less energy to coat the layer. It also reduces the time during which the substrate needs to be kept warm.“Considering that the solar cell is made on stainless steel substrates, contains no cadmium buffer layer and that the production process is an all-dry, all vacuum process where all layers (including the buffer layer) are deposited by sputtering, this achievement by our engineers is truly impressive. By halving the thickness of the CIGS thin film solar cell the manufacturing cost will be significantly reduced, which further strengthens the business case”, said Sven Lindström, CEO Midsummer.Midsummer’s scientists see the opportunity to reduce the thickness even further with a reflective back contact, i.e. any photons that have passed through the CIGS layer would be reflected and have the chance to do work on the way back.“Our scientists are constantly working on reducing the thickness and they will now start to work on this opportunity. As soon as we are done we will report it. We are always aiming to increase the productivity in our machines while many of our competitors are chasing records, which means their CIGS-layers turn out to be thicker than ours”, Sven Lindström concluded.

For photos of thin film CIGS solar cells and the Midsummer manufacturing equipment, please go to the media gallery or contact Mr. Lindström.For additional information please contact:

CEO, Midsummer
Sven Lindström
Email: 
Phone: +46-8-525 09 610

About Midsummer
Midsummer is a leading supplier of equipment for cost effective manufacturing of CIGS thin film flexible solar cells. Midsummer’s turnkey manufacturing lines have a small footprint, are perfectly scalable and allow for small-scale production of solar cells and modules.

Midsummer’s customers are thin film solar cell manufacturers all over the world. CIGS flexible solar modules are growing in popularity thanks to their low weight, flexibility and durability. Applications are e.g. floating modules, vehicles, landfills, portable power generation and membrane roofs on factories, offices and other structures that are not strong enough for traditional glass modules.

Founded in 2004 by people with a background from the optical disc manufacturing equipment and the photo mask industry, Midsummer has its head office in Stockholm, Sweden. Midsummer was the fastest growing greentech company in EMEA (Europe, Middle East and Africa) in 2007-2011 (according to Deloitte).

About CIGS thin film solar cells
CIGS stands for copper-indium-gallium-selenium, a metal alloy that converts the energy of light directly into electricity by the photovoltaic effect (PV). The CIGS absorber is deposited on a stainless steel substrate, along with electrodes on the front to collect current. The cells are then connected in series and covered by a protective layer of plastic to form a flexible solar module.

Since a stainless steel substrate is used, the modules can be made without glass. The CIGS solar modules are therefore much lighter, flexible and can be made frameless, to suit applications where traditional silicon solar cells cannot be used, e.g. on structures that are uneven, moving or weak.

CIGS solar cells are manufactured by sputtering the material onto 156x156 mm stainless steel substrates. The solar cells from Midsummer are free of cadmium, a toxic material usually used in CIGS and other thin film solar cells. Flexible CIGS solar modules are gaining market share thanks to its high efficiency, low weight, flexibility and durability.

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