Columnar-grained polycrystalline solar cell and process of manufacture
USRE36156E · kind E · reissue
Assignee
Inventors
Key dates
| Filing date | Jan 24, 1997 |
| Grant date | Mar 23, 1999 |
| Priority date | — |
| Expiry date | Jan 24, 2017 |
Classification
- Technology area (CPC —)General
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.