Abstract: The invention relates to a method and device for characterizing wafers during the production of solar cells. Characterizing wafers includes 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 a lifetime of charge carriers in the wafer; c) irradiating the wafer with light for creating the 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).

Abstract: A method for doping a semiconductor substrate includes heating the semiconductor substrate by irradiation with laser radiation and at the same time diffusing dopant from a dopant source into the semiconductor substrate in heated regions. The semiconductor substrate is heated by the irradiation with laser radiation. A surface portion of the semiconductor substrate that is less than 10% of the total surface of all irradiated regions is melted and recrystallized. There is also provided a solar cell.