Nanoparticle-based etching of silicon surfaces

US8075792B1 · kind B1 · utility

Assignee

• Alliance for Sustainable Energy, LLC · US

Inventors

• Howard M. Branz · Boulder, US
• Anna Duda · Denver, US
• David S. Ginley · Evergreen, US
• Vernon Yost · Littleton, US
• Daniel L. Meier · Pittsburgh, US
• James Ward · Ashburn, US

Key dates

• Filing date: Mar 21, 2008
• Grant date: Dec 13, 2011
• Expiry date: Oct 9, 2030

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/24917

Abstract

A method (300) of texturing silicon surfaces (116) such to reduce reflectivity of a silicon wafer (110) for use in solar cells. The method (300) includes filling (330, 340) a vessel (122) with a volume of an etching solution (124) so as to cover the silicon surface 116) of a wafer or substrate (112). The etching solution (124) is made up of a catalytic nanomaterial (140) and an oxidant-etchant solution (146). The catalytic nanomaterial (140) may include gold or silver nanoparticles or noble metal nanoparticles, each of which may be a colloidal solution. The oxidant-etchant solution (146) includes an etching agent (142), such as hydrofluoric acid, and an oxidizing agent (144), such as hydrogen peroxide. Etching (350) is performed for a period of time including agitating or stirring the etching solution (124). The etch time may be selected such that the etched silicon surface (116) has a reflectivity of less than about 15 percent such as 1 to 10 percent in a 350 to 1000 nanometer wavelength range.