LAYER SYSTEM FOR THIN-FILM SOLAR CELLS

The present invention relates to a layer system (1) for thin-film solar cells (100) and solar modules, comprising an absorber layer (4), which includes a chalcogenide compound semiconductor, and a buffer layer (5), which is arranged on the absorber layer (4) and includes halogen-enriched ZnxIn1-xSy with 0.01≦x≦0.9 and 1≦y≦2, wherein the buffer layer (5) consists of a first layer region (5.1) adjoining the absorber layer (4) with a halogen mole fraction A1 and a second layer region (5.2) adjoining the first layer region (5.1) with a halogen mole fraction A2 and the ratio A1/A2 is ≧2 and the layer thickness (d1) of the first layer region (5.1) is ≦50% of the layer thickness (d) of the buffer layer (5).