Abstract: A method for improving contact resistance of a multi-junction solar cell having a front and a back and multiple subcells, including: a) delivering the solar cell with front and back contacts in grid, strip or transparent form; b) contact-connecting one region of the back contact to a contact device connected to one pole of a voltage source, and the front contact or another region of the back contact, which is electrically insulated from the region, to another contact device, which is connected to the other pole of the voltage source; c) applying a voltage against the forward direction of the solar cell to the contacts, the voltage smaller than a solar cell breakdown voltage; d) guiding a point light source over the solar cell, a subregion of the front or back being illuminated, inducing current in the subregion, and illuminating the subregion with light beams of different wavelengths.

Abstract: A method for repairing and/or optimizing a solar module having a sun-facing front and a sun-averted back, a multiplicity of solar cells being encapsulated between the front and the sun-averted back, the method having the following steps: a) providing a solar module, b) applying a voltage to the provided solar module in the reverse direction, c) locally illuminating and scanning the front of the solar module to which the voltage is applied with a point light source, with the result that a flow of current flows through the solar cells encapsulated in the solar module.

Abstract: A device for improving ohmic contact between a front contact and a doped layer of a wafer solar cell having a front, a back, the front contact, the doped layer and a back contact. The front and back contacts are strip-shaped or grid-shaped. The device having: two contacting apparatuses for electrically contacting the front and back contacts; a voltage source having a pole for electrical connection to one contacting apparatus and a pole for connection to the other contacting apparatus; and two point light sources to illuminate the front and the back.

Abstract: A method for improving contact resistance of a multi-junction solar cell having a front and a back and multiple subcells, including: a) delivering the solar cell with front and back contacts in grid, strip or transparent form; b) contact-connecting one region of the back contact to a contact device connected to one pole of a voltage source, and the front contact or another region of the back contact, which is electrically insulated from the region, to another contact device, which is connected to the other pole of the voltage source; c) applying a voltage against the forward direction of the solar cell to the contacts, the voltage smaller than a solar cell breakdown voltage; d) guiding a point light source over the solar cell, a subregion of the front or back being illuminated, inducing current in the subregion, and illuminating the subregion with light beams of different wavelengths.

Abstract: A device for improving the ohmic contact between a front side contact and a doped layer of a wafer solar cell that includes a front side, a rear side and a rear side contact. The front side and/or the rear side contact are strips or grids. The device includes: a contacting unit for contacting the front or rear side contact; a further contacting unit for contacting the other contact; a voltage source having one pole for connection to the contact unit and another pole for connection to the further contacting unit; and a point light source to illuminate the front or rear side. The further contacting unit includes: an optically transparent material, coated using an optically transparent, electrically conductive layer; or an optically transparent material having microscopically-thin wires; or an optically transparent, electrically conductive material having microscopically-thin wires; or a mesh or a network made up of microscopically-thin wires.

Abstract: A method for improving the ohmic contact between a front contact grid and a doped layer of a wafer solar cell, including: providing the wafer solar cell; electrically contacting the front contact grid with a contacting device electrically connected to a pole of a voltage source; electrically contacting another contacting device electrically connected to the other pole of the voltage source with a back contact grid of the cell; applying a voltage directed against the forward direction of the cell to the front contact grid and the back contact grid with the voltage source, wherein the voltage is smaller than a breakdown voltage of cell; guiding a point light source over the sun-averted back side of the cell while the voltage is applied, wherein a partial region of the sun-averted back side is illuminated such that a current flow is induced in, and acts on, the partial region.

Abstract: A solar cell comprising: a semiconductor substrate; a metallization paste on a surface of the semiconductor substrate; and a tunneling layer between the substrate surface and the metallization paste.

Abstract: A solar cell comprising: a semiconductor substrate; a metallization paste on a surface of the semiconductor substrate; and a tunneling layer between the substrate surface and the metallization paste.

Abstract: A wafer solar cell comprising a semiconductor layer, a back-side emitter layer, a passivation layer arranged on the emitter layer, openings being formed in said passivation layer, and a metallization layer arranged on the passivation layer, wherein the emitter layer, the passivation layer and/or the metallization layer substantially completely covers a solar cell back side, and wherein adjacent to each opening a doping region is formed which extends into the emitter layer and/or into the semiconductor layer and is doped by means of a metal from the metallization layer and/or from the passivation layer. Furthermore, the invention relates to a solar cell production method for producing such a wafer solar cell.