Abstract: An aqueous acidic etching solution suitable for texturing the surface of single crystal and polycrystal silicon substrates and containing, based on the complete weight of the solution, 3 to 10% by weight of hydrofluoric acid; 10 to 35% by weight of nitric acid; 5 to 40% by weight of sulfuric acid; and 55 to 82% by weight of water; a method for texturing the surface of single crystal and polycrystal silicon substrates comprising the step of (1) contacting at least one major surface of a substrate with the said aqueous acidic etching solution; (2) etching the at least one major surface of the substrate for a time and at a temperature sufficient to obtain a surface texture consisting of recesses and protrusions; and (3) removing the at least one major surface of the substrate from the contact with the aqueous acidic etching solution; and a method for manufacturing photovoltaic cells and solar cells using the said solution and the said texturing method.

Abstract: A product is obtained by mixing at least one polyethylene glycol with a base, allowing the mixture to rest in ambient air and at a temperature of approximately 25 degrees Celsius to form two phases, and separating the less dense phase representing the product. The product is used as an additive to etching solutions.

Abstract: Method for producing solar cells with a two-stage doping (9, 11) comprising the method steps of heavy doping (50) of at least a part of the solar cell substrate (1), of at least temporarily protecting doped areas (8), in which heavily doped areas (9) of the two-stage doping (9, 11) should be formed, from an etching medium and etching back (54; 62, 64; 72, 74) unprotected doped areas (17) of the solar cell substrate (1) by means of the etching medium, whereby, for the purpose of protecting the doped areas, sacrificial structures (7) are applied (52) on the areas (8) to be protected, which are at least partly etched (54; 62, 64; 72, 74) during etching back (54; 62, 64; 72, 74) of the unprotected doped areas.

Abstract: An etching solution contains water, nitric acid, hydrofluoric acid, and sulphuric acid. More specifically it contains 15 to 40% by weight of nitric acid, 10 to 41% by weight of sulphuric acid and 0.8 to 2.0% by weight of hydrofluoric acid. The etching solution is used for etching silicon and to etching methods for silicon wafers.

Abstract: A contact-making method for a semiconductor material contains the method steps of forming a diffusion barrier which promotes electrical contact and adhesion on at least one portion of a surface of a semiconductor and forming a metallization on the diffusion barrier. The diffusion barrier being formed by applying a metalliforous paste to at least one portion of the semiconductor surface or to at least one portion of a layer covering the semiconductor surface, and a semiconductor component with a diffusion barrier which is arranged in the surface of the semiconductor and which promotes electrical contact between the semiconductor material and a metallization. The metallization is applied to the diffusion barrier. The diffusion barrier is formed by a sintered metalliforous paste applied to at least one portion of the semiconductor surface.

Abstract: A method for producing a semiconductor component, in particular a solar cell, having regions which are doped to different extents. A layer is formed which inhibits the diffusion of a dopant and can be penetrated by a dopant, on at least one part of the surface of a semiconductor component material. The diffusion-inhibiting layer is at least partially removed in at least one high-doping region. A dopant source is formed on the diffusion-inhibiting layer and in the at least one high-doping region. Then the dopant is diffused from the dopant source into the semiconductor component material. The semiconductor component is suitable for use in integrated circuits, electronic circuits, solar cell modules, and to produce solar cells having a selective emitter structure.