Smoothed doped layer for solar cell

US11075317B2 · kind B2 · utility

Assignees

• IMEC VZW · BE
• Katholieke Universiteit Leuven · BE

Inventors

• Yuandong Li · Leuven, BE
• Filip Duerinckx · Kessel-Lo, BE
• Maria Jesus Recaman Payo · Attenrode, BE
• Jef Poortmans · Kessel-Lo, BE

Key dates

• Filing date: Dec 13, 2019
• Grant date: Jul 27, 2021
• Expiry date: Dec 13, 2039

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P70/50
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

The disclosed technology generally relates to silicon solar cells and more particularly to a doped layer formed on a textured surface of a silicon solar cell, and methods of fabricating the same. In one aspect, a method of creating a doped layer at a rear side of a crystalline silicon bifacial solar cell is disclosed. The method can include texturing at least a rear side of a silicon substrate of the solar cell to create a pattern of pyramids, thereby creating a pyramidal topology of the rear side. The method can also include forming a doped layer at the rear side by, using epitaxial growth, growing at least one doped silicon epitaxial layer on the pyramids. Simultaneously with forming the doped layer and by using facet evolution, the pyramidal topology of the rear side can be smoothed by the growth of the at least one epitaxial layer. The epitaxial growth can be continued until, on upper parts of a majority of the pyramids, an angle between a surface of the at least one epitaxial layer and the substrate is between 5 to 35°. A crystalline silicon bifacial solar cell is also disclosed.