A marking method for applying a unique identification to each individual solar cell stack of a semiconductor wafer, at least comprising the steps: Providing a semiconductor wafer having an upper side and an underside, which comprises a Ge substrate forming the underside; and generating an identification with a unique topography by means of laser ablation, using a first laser, on a surface area of the underside of each solar cell stack of the semiconductor wafer, the surface area being formed in each case by the Ge substrate or by an insulating layer covering the Ge substrate.