Method for manufacturing a photovoltaic cell with a locally diffused rear side

US9306087B2 · kind B2 · utility

Assignee

• E.I. DU PONT DE NEMOURS AND COMPANY · US

Inventors

• Giuseppe Scardera · Sunnyvale, US
• Maxim Kelman · Mountain View, US
• Elena Rogojina · San Jose, US
• Dmitry Poplavskyy · San Jose, US
• Elizabeth Tai · Cupertino, US
• Gonghou Wang · Foster City, US

Key dates

• Filing date: Sep 4, 2012
• Grant date: Apr 5, 2016
• Expiry date: Oct 17, 2033

Classification

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

Abstract

A method for manufacturing a photovoltaic cell with a locally diffused rear side, comprising steps of: (a) providing a doped silicon substrate, the substrate comprising a front, sunward facing, surface and a rear surface; (b) forming a silicon dioxide layer on the front surface and the rear surface; (c) depositing a boron-containing doping paste on the rear surface in a pattern, the boron-containing paste comprising a boron compound and a solvent; (d) depositing a phosphorus-containing doping paste on the rear surface in a pattern, the phosphorus-containing doping paste comprising a phosphorus compound and a solvent; (e) heating the silicon substrate in an ambient to a first temperature and for a first time period in order to locally diffuse boron and phosphorus into the rear surface of the silicon substrate.