Build-up of thin-film modules

Thin-film solar cells consist of a front electrode, an absorber and a back electrode. These three components are several hundred nanometers to a few micrometer thick layers of conductive and semi-conductive materials on a carrier – typically glass. This construction forms a large-scale photodiode. The incidence of light produces free charge carriers inside the absorber which are separated in the photodiode’s electrical field of the p-n junctionand can be collected as electricity via the two electrodes.

The individual material layers are successively deposited as a continuous layer. After each coating step the new layer is divided into strips to form a so-called monolithic serial interconnection in the finished thin-film module. Structuring it into individual about 5 to 10 mm wide cells connected in series ensures viable division of current and voltage values. The more accurate they are scribed the more efficient the solar module will be.