Abstract: The invention relates to a method for characterizing wafers during the production of solar cells, comprising the steps: a) providing a wafer and carrying out a production process with the wafer for producing a solar cell or a plurality of solar cells; b) carrying out a wet chemical step with the wafer during the production process, wherein the wet chemical step decreases an influence of the wafer surface on the lifetime of charge carriers in the wafer; c) irradiating the wafer with light for creating charge carriers in the wafer during the wet chemical step or after the wet chemical step; d) determining the lifetime of the charge carriers created in step c); and e) characterizing the wafer by means of the lifetime determined in step d). In a second aspect, the invention relates to a device for characterizing wafers during the production of solar cells.