Solution for increasing wafer sheet resistance and/or photovoltaic cell power density level

• Main Authors: OOSTERHOLT JOHANNES A. E, RITMEIJER SABRINA, GROENEWOUD LUCAS M. H, HOOGBOOM JOANNES T. V
• Format: Patent
• Language: English
• Published: 05.02.2013
• Subjects: APPARATUS THEREFOR; CHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUSENAMELS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DECORATIVE ARTS; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; GLASS; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; JOINING GLASS TO GLASS OR OTHER MATERIALS; METALLURGY; MINERAL OR SLAG WOOL; MOSAICS; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLICMATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASSC23 AND AT LEAST ONEPROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25; NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; PAPERHANGING; PERFORMING OPERATIONS; PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROMOBJECTS; PRODUCING DECORATIVE EFFECTS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS,MINERALS OR SLAGS; SURFACE TREATMENT OF GLASS; TARSIA WORK; TRANSMISSION; TRANSPORTING

Treating thin film amorphous or mono- or multi-crystalline silicon wafer substrate for use in a photovoltaic cell, the wafer substrate having at least one of a pn- or np junction and a partial phosphosilicate or borosilicate glass layer on a top surface of the wafer substrate, to increase at least one of (a) the sheet resistance in the wafer and (b) the power density level of the photovoltaic cell made from said wafer. The treatment solution being an acidic treatment solution of a buffered oxide etch (BOE) solution of at least one tetraalkylammonium hydroxide, acetic acid, at least one non-ionic surfactant, at least one metal chelating agent, a metal free source of ammonia, a metal free source, of fluoride ions, and water, mixed with an oxidizer solution and optionally water.