Aqueous acidic etching solution and method for texturing the surface of single crystal and polycrystal silicon substrates

US8969276B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Simon Braun · Mannheim, DE
• Julian Proelss · Allschwil, CH
• Ihor Melnyk · Horlivka, UA
• Michael Michel · Dallas, US
• Stefan Mathijssen · Konstanz, DE

Key dates

• Filing date: Sep 9, 2010
• Grant date: Mar 3, 2015
• Expiry date: Jul 12, 2031

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02E10/50
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

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.