Method for producing plate-, tape- or film-shaped Si crystal bodies for solar cells

Claim 1

In a method of producing plate-, tape- or film-shaped Si crystal bodies having crystalline pillar structures therein, which are substantially equivalent to crystalline columnar structures, without melting of the base material which forms such Si bodies and which bodies are useful for further processing into large-surface solar cells, which include the steps of: (a) forming a slurry from an admixture of a Si powder having an average particle size in the range of less than about 1 μm, optional additives and a compatible liquid binder; (b) extruding such slurry with an extrusion means onto a first inert support member as a relatively thin slurry layer, which is dried into a self-supporting layer and removing the support member; and (c) sintering the self-supporting layer on a temperature-stable second inert support member in a protective gas atmosphere at a sintering temperature below about 1430° C. in such a manner that a layer of Si crystal particles is generated, each particle having an average particle diameter substantially corresponding to the thickness of the self-supporting layer; the improvement comprising: coating said self-supporting Si slurry layer, prior to sintering, with a substantially uniform layer of germanium powder and subjecting the resultant layer structure to sintering in accordance with step (c).