Method for fabricating crystalline photovoltaic cells

Abstract

A method is provided for fabricating a crystalline semiconductor photovoltaic cell, wherein the method comprises depositing a dielectric layer at first predetermined locations on a surface of a semiconductor substrate and growing a doped epitaxial layer at second predetermined locations on a surface of the semiconductor substrate, the second predetermined locations being different from and non-overlapping with the first predetermined locations. The dielectric layer is maintained as a surface passivation layer in the photovoltaic cell. The doped epitaxial layer forms an emitter region, a back surface field region or a front surface field region of the photovoltaic cell.

Description

technical field [0001] The present invention relates to methods for manufacturing crystalline photovoltaic cells, such as crystalline silicon photovoltaic cells. Background technique [0002] Epitaxial growth of highly doped regions is a promising technique for constructing the emitter, back surface field (BSF) and / or front surface field (FSF) regions of silicon photovoltaic cells. High throughput for epitaxial growth can be achieved by using eg LPCVD (low pressure chemical vapor deposition) systems, where silicon substrates or wafers are loaded into batch type substrate boats. In this high-throughput system, all substrate surfaces are exposed to the precursors used in the epitaxial growth process. Epitaxial growth is performed on all silicon surfaces exposed to the precursor. Thus, a masking step before epitaxy or a patterning step after epitaxy is required if localized epitaxial layer patterning is required or if the epitaxial layer is only to be provided on a single sub...

AI Technical Summary

Problems solved by technology

Classical thermal oxidation (dry or wet) yields high-quality surface passivation but requires a high thermal budget and oxidizes all exposed surfaces including the epitaxial layer surface

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