Light-absorbing layer and layer system containing the layer, process for producing the layer system and sputter target suitable therefor

Light-absorbing layer systems are used for various applications, such as for solar-thermal applications or so-called ''black matrix'' layers in conjunction with liquid crystal displays. The layer or layers should accordingly exhibit a high absorption and low reflection in the visible spectral range and they should be able to be etched without the formation of toxic substances and without particle residues while using simple dilute acids. In order to ensure this, it is proposed according to the invention that the absorber layer has an oxidic matrix, based on a base component K1 made of zinc oxide, tin oxide and/or indium oxide, and on an added component K3 which can replace the base component K1 up to a fraction of 75% by weight and which consists of niobium oxide, hafnium oxide, titanium oxide, tantalum oxide, vanadium oxide, yttrium oxide, zirconium oxide, aluminium oxide and mixtures thereof, where a blackening component K2 made of molybdenum, tungsten and alloys and mixtures thereof is distributed in the matrix and is present either as metal or as substoichiometric-oxidic compound of the metal in such a way that the layer material has a degree of reduction which is defined by an oxygen content of at most 65% of the stoichiometrically maximum oxygen content, and where the fraction ''x'' of the blackening component K2-calculated from the weight of its elemental fraction based on the weight of the layer material- is in the range between 20 and 50% by weight.