10.11.2009
Innovative development of thin-film solar cells on steel sheets
Baden-Württemberg’s Centre for Solar Power and Hydrogen Research (ZSW) has announced that it has successfully manufactured the world’s first fully-functional flexible thin-film solar cell on extremely thin steel sheeting. Steel sheeting is between two and three times cheaper than the conventional steel or plastic support panels used for flexible thin film photovoltaic to date. Construction steel may open up entirely new fields for the flexible use of solar modules, such as off-the-roll roof sheeting or on cars and ships.
A large 50 square centimetre steel module with CIGS solar cells was shown by one test agency to have an efficiency of 8.6 per cent. CIGS thin-film solar cells are made of a copper indium gallium selenide compound and have been developed to production maturity by ZSW in collaboration with Würth-Solar using other support materials (mainly glass to date). The 150 experts working at the ZSW research institute in Stuttgart and Ulm are worldwide leaders in this field.
The newly developed steel sheeting enables an extremely thin but highly effective insulation and diffusion barrier to be developed between the steel and the CIGS cells which is capable of withstanding the high temperatures which arise during the industrial manufacturing process. CIGS thin-film cells can be seamlessly connected to form single modules. No additional metallic connections of the type needed for conventional crystalline silicon solar cells are required for this purpose. However, a number of hurdles still need to be overcome before the new steel sheet design will be ready for market. The ZSW researchers are now looking for suitable materials which will ensure the CIGS cells remain watertight on the steel sheeting over a period of many years. The researchers also aim to boost the effectiveness of the modules.
