Method large-area silicon bodies
AssigneeSiemens Aktiengesellschaft
InventorsRichard Falckenberg, Christa Grabmaier, Josef Grabmaier
Life of this patent
Estimating the term…
Abstract
A method and an apparatus is provided for the manufacture of large-area silicon crystal bodies useful for solar cells. A carrier member consisting of a net-like graphite fabric or quartz fabric is moved horizontally through a heater arrangement carrying silicon plates on its surface which are matched to the dimensions of the carrier member. The silicon body is caused to melt and the molten silicon fills in the meshes of the net after which crystallization is induced. Meshes having dimensions up to about 10 mm.times.10 mm are thus filled with silicon. The technique involves low production costs and high product crystal quality and serves for the continuous manufacture of silicon ribbons for solar cells.
Claims18
A method for manufacture of polycrystalline, large-area silicon bodies adapted for further processing into solar cells, said method comprising the sequented steps of:
- (a) depositing on surface portions of a horizontally oriented net-like structure preformed silicon in a plate-like form, said net-like structure being
- (a) resistant to molten silicon, and
- (b) wettable by molten silicon,
- (b) heating the resulting assembly of said net-like structure and said preformed silicon to a temperature sufficient to melt said silicon, and
- (c) crystallizing the resulting melted silicon in said net-like structure.
A continuous process for making polycrystalline large-area silicon bodies adapted for processing into solar cells comprising:
- (a) continuously moving a ribbon having a net-like structure wherein individual mesh sizes range up to about 100 mm.sup.2 each and which is comprised of a material selected from the group consisting of graphite thread and graphitized silica glass thread, said ribbon being horizontally oriented, said moving extending successively through each of:
- (1) a silicon loading zone,
- (2) a silicon heating zone, and
- (3) a silicon cooling zone,
- (b) in said loading zone, successively depositing along and upon said ribbon individual preformed plate-like forms of silicon in predetermined locations,
- (c) in said heating zone, successively preheating said silicon forms from above and then heating the assembly of said silicon forms and said ribbon to a temperature sufficient to melt said silicon, and
- (d) in said cooling zone, crystallizing said molten silicon in mesh portions of said ribbon while simultaneously heating from below and cooling from above.
Apparatus for continuously making polycrystalline large-area silicon bodies adapted for further processing into solar cells comprising:
- (a) conveying means for moving continuously a net-like carrier ribbon along a horizontal path,
- (b) feeder means for holding, positioning and depositing in a sequented manner a plurality of plate-like silicon bodies upon the upper surface of said carrier ribbon with individual said silicon bodies being in longitudinally predetermined adjacent relationship to one another,
- (c) heater means located along said horizontal path and downstream of said feeder means relative to the direction of movement of said carrier ribbon, for melting said plate-like bodies, and
- (d) silicon crystallization means located along said horizontal path and downstream of said heater means relative to said direction of movement including heating means for selectively applying heat to lower surface portions of the resulting combination of said melted silicon and said carrier ribbon and further including cooling means for simultaneously applying cold to upper surface portions of said resulting combination.
Dependencies are inferred from the claim text.