Methods for wet chemistry polishing for improved low viscosity printing in solar cell fabrication

US9437757B2 · kind B2 · utility

Assignee

• SUNPOWER CORPORATION · US

Inventors

• Genevieve A. Solomon · Palo Alto, US
• Scott Harrington · San Jose, US
• Kahn Wu · San Francisco, US
• Paul Loscutoff · Castro Valley, US
• Junbo Wu · Palo Alto, US
• Steven Molesa · San Jose, US

Key dates

• Filing date: Jun 19, 2015
• Grant date: Sep 6, 2016
• Expiry date: Jun 19, 2035

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P70/50

Abstract

A method of fabricating a solar cell is disclosed. The method includes forming a polished surface on a silicon substrate and forming a first flowable matrix in an interdigitated pattern on the polished surface, where the polished surface allows the first flowable matrix to form an interdigitated pattern comprising features of uniform thickness and width. In an embodiment, the method includes forming the silicon substrate using a method such as, but not limited to, of diamond wire or slurry wafering processes. In another embodiment, the method includes forming the polished surface on the silicon substrate using a chemical etchant such as, but not limited to, sulfuric acid (H2SO4), acetic acid (CH3COOH), nitric acid (HNO3), hydrofluoric acid (HF) or phosphoric acid (H3PO4). In still another embodiment, the etchant is an isotropic etchant. In yet another embodiment, the method includes providing a surface of the silicon substrate with at most 500 nanometer peak-to-valley roughness.