Abstract: In one embodiment of the present invention, silicon spheres are fabricated by applying a slurry of metallurgical grade silicon, or other suitable material, on the surface of a substrate capable of maintaining integrity beyond the melting point of silicon. The layer of metallurgical grade silicon is then patterned to provide regions of metallurgical grade silicon of uniform size. The substrate and metallurgical grade silicon are then heated beyond the melting point of silicon. The metallurgical grade silicon then beads to the surface as relatively pure silicon and forms silicon spheres due to the high cohesion of silicon. The structure is then cooled below the melting point of silicon and the silicon spheres then crystallize. The silicon spheres are then removed from the surface of the substrate and are further processed using techniques disclosed in copending U.S. patent application Ser. Nos. 647,551 and 647,578 to further purify the crystalline silicon spheres.

Abstract: The disclosure relates to a method of sealing the surface of an aluminum member, such as an aluminum foil, from the environment by first placing the foil in an H.sub.2 SO.sub.4 bath to form an oxide which normally will not provide a total seal of the aluminum from the environment and then placing the aluminum member with oxide thereon in an H.sub.3 PO.sub.4 bath to close the pores in the oxide layer and provide sealing of the aluminum from the environment. This process also passivates the silicon.

Abstract: The disclosure relates to a method of etching semiconductor material wherein the material is secured in an oxide coated aluminum foil which acts as an etchant mask. The portion of the material extending from one side of the foil can then be etched with a semiconductor material etchant with the remainder of the material being masked from the etchant by the foil.

Abstract: Semiconductor spheres are arranged within a plastic sheet and laminated between two metal foil layers to make electrical contacts. A portion of each sphere is exposed on one side to allow light entry. The back ohmic contact has a spreading resistance which protects large array configurations from short circuits. Series interconnections of cells, for higher voltage, can be made in the same processing sequence, and are coplanar with the array. All manufacturing steps are completed at temperatures less than 400.degree. C.

Abstract: A method and device are disclosed which allows an ohmic electrical contact with P-type semiconductor material using metallic foil at low temperature without significant diffusion of the metal into the semiconductor. The contact exhibits opposition to physical separation and has a predetermined electrical resistance.

Abstract: Polycrystalline semiconductor material is treated to form a skin of a thermally stable substance and melted with the molten material retained by the film. Upon cooling, the material solidifies as single crystal and the skin is removed.

Abstract: Polycrystalline semiconductor material is treated to form a skin of a thermally stable substance and melted with the molten material retained by the film. Upon cooling, the material solidifies as single crystal and the skin is removed.

Abstract: Semiconductor spheres are arranged within a plastic sheet, and laminated between two metal foil layers to make electrical contacts. A portion of each sphere is exposed on one side to allow light entry. The back ohmic contact has a spreading resistance which protects large array configurations from short circuits. Series interconnections of cells, for higher voltage, can be made in the same processing sequence, and are coplanar with the array. All manufacturing steps are completed at temperatures less than 400.degree. C.