| abstract |
Treatment of an amorphous or mono- or multi-crystalline thin-film silicone sheet substrate for use in a photovoltaic cell, the sheet substrate has at least one of a pn- or np coupling and a phosphosilicate or borosilicate glass layer partial on an upper surface of the sheet substrate, to increase one of (a) the resistance of the sheet and (b) the level of energy density of the photovoltaic cell made of such sheet. The treatment solution is an acid treatment solution of a pH-regulated oxide etching solution (BOE) of at least one tetraalkylammonium hydroxide, acetic acid, at least one anionic surfactant, at least one metal chelating agent, and one ammonium source without metal, a source of fluoride ions without metal, and water, mixed with an oxidizing solution and optionally water. |