Astropower, Inc.

Christopher L Kendall

Allen M Barnett

Robert B Hall

James A Rand

David H Ford

Joseph C Checchi

Sandra R Collins

Chad Byron Moore

Jacob E Brown

William P Mulligan

Todd R Ruffins

Steven M Lampo

The invention relates to a silicon sheet having columnar grains extending axially through the sheet from one free surface of the sheet to the other free surface. The sheet has an electrical resistivity in the range of 0.1 to 10 ohm-cm.

Columnar-grained polycrystalline solar cell substrate

The invention relates to improved techniques for manufacturing columnar-grained polycrystalline sheets which have particular utility as substrates or wafers for solar cells. The sheet is made from silicon on a setter material which supports the silicon material. The setter material and silicon are subjected to a thermal profile all of which promote columnar growth. The thermal profile sequentially creates a melt region where a thin-film capping layer grows at the top of the silicon, a nucleation region where preferential nucleation occurs at the capping-layer/molten-silicon interface, and then a growth region where both liquid and a growing polycrystalline sheet layer coexist. An annealing region is created where the temperature of the grown polycrystalline silicon sheet layer is controllably reduced to effect stress relief.

Columnar-grained polycrystalline solar cell substrate and improved

The invention relates to techniques for manufacturing columnar-grained polycrystalline sheets which have particular utility as substrates or wafers for solar cells. The sheet is made by applying granular silicon to a setter material which supports the granular material. The setter material and granular silicon are subjected to a thermal profile all of which promote columnar growth by melting the silicon from the top downwardly. The thermal profile sequentially creates a melt region at the top of the granular silicon and then a growth region where both liquid and a growing polycrystalline sheet layer coexist. An annealing region is created where the temperature of the grown polycrystalline silicon sheet layer is controllably reduced to effect stress relief.

Columnar-grained polycrystalline solar cell and process of manufacture

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Hockessin, DE, United States of America

Christopher L Kendall