Abstract: A process and apparatus for the manufacture of silicon blocks having a columnar structure comprising monocrystalline crystal zones having a crystallographic preferred orientation. In a casting process, each mold filled with molten silicon is transferred, before the silicon has solidified completely, to a separate crystallization station where the silicon can then crystallize completely. During this process, the exposed surface of the silicon is maintained in a molten state until the end of the solidification process has almost been reached. The process allows the various, necessary steps to be carried out simultaneously and yields high-quality solar cell base material.

Abstract: Crystalline rods or blocks can be sawed into thin wafers by sawing the rod or block into a plurality of wafers that are connected to each other. The wafers can be connected by introducing a connecting agent after each sawing step, into the resulting cutting gaps. The wafers are separated only after the whole rod has been sawed with a two-blade internal-hole saw.

Abstract: Crystalline rods or blocks can be sawed into thin wafers by sawing the rod r block into a plurality of wafers that are connected to each other. The wafers can be connected by introducing a connecting agent after each sawing step, into the resulting cutting gaps. The wafers are separated only after the whole rod has been sawed. The method makes possible the use of multiple-blade internal-hole saws, and preferably two-blade internal-hole saws.

Abstract: The invention relates to a process and apparatus for manufacturing silicon astings or moldings, having a columnar structure of single-crystal regions of crystal with a preferential crystallographic orientation, and which can be manufactured cheaply and in large numbers in a semi-continuous mode of production. Liquid silicon is cast in a casting station, under an inert gas and preferably under reduced pressure, preferably in graphite molds which are exposed to a temperature gradient of 200.degree. to 1,000.degree. C. After cooling, the silicon is withdrawn automatically via a transport chamber connected to the casting station into special cooling stations, while the casting station is reloaded with an empty mold for repeating the process. The silicon blocks which have preferably been produced by this procedure are use as basic material for inexpensive solar cells having efficiencies of more than 10%, after they have been sawn into individual small wafers and have been doped and lead-bonded.

Abstract: A process for the crucible-free zone pulling of a polycrystalline rod held ertically, together with a seed crystal fixed at its lower end, in which a melting zone is produced by means of an induction heating coil surrounding the rod, which zone, by means of relative movement of the coil and rod, traverses the entire length of the rod starting from the seed crystal, characterized in that after attaching the seed crystal to the rod, a support member is moved, below the induction heating coil, towards the rod, which support member rests gently against the rod and after being positioned, solidifies to form a firm support for the rod. A device for carrying out the process is also included.

Abstract: Device for supporting a crystalline rod during crucible-free zone melting ich comprises a zone-drawing apparatus, a rotating shaft in said apparatus, means for fastening the shaft in the apparatus, a screw bolt mounted for rotation with the shaft, the top end of the screw bolt having a bore for receiving a seed crystal, two or more swivel arms mounted adjacent to the bore and capable of being opened and closed, a ring coaxially surrounding the bolt and means for vertically moving the ring.