For thin-film panels, a special procedure is applied to deposit the semiconductor materials needed to convert the energy in extremely thin layers onto a carrier material (substrate) made of glass, plastic or metal foil. Most common today are thin-film panels made of amorphous silicon.

Thin-film panels have some advantages over crystalline or poly-crystalline silicon solar panels: As the material thickness of the cells is about 100 times thinner, the amount of energy and material required is much lower. Thin-film panels are therefore particularly suitable for mass production and offer an enormous cost reduction potential.

At the moment, the level of efficiency of thin-film solar cells is lower than those of mono-crystalline and poly-crystalline solar cells; however because it is a relatively new technology, it is safe to assume that the technological possibilities have not yet nearly reached their end. In laboratory tests, high conversion efficiencies have been measured for CIS or CIGS thin-film cells that almost reach or even exceed those of poly-crystalline silicon.

One particular strength of thin-film panels is that it is better able to make use of diffuse sunrays and weak light – for example when the sky is overcast – than crystalline panels. Thin-layer panels are much more tolerant to shadowing. A further advantage is that thin-film-panels are quite insensitive to high temperatures.

In contrast to crystalline and poly-crystalline silicon panels, thin-film panels do not depend on rigid carrier materials. For example, they can be applied to flexible metal foils to form light and bendable panels that can also be made weather- or waterresistant by attaching a synthetic lamination on the outside. Using these compound panels, fully new application fields can be opened up that depend on a low weight and resistance to mechanical load, for example in the outdoor field.