Abstract: In order to efficiently recycle a silicon scrap obtained by cutting a silicon chunk as a raw material silicon for solar batteries, a silicon recycling method of the present invention, according to one aspect, includes the steps of melting a silicon scrap by heating, and immersing a crystallization substrate in molten silicon and depositing silicon on a surface of the crystallization substrate. The step of separating silicon on the surface of the crystallization substrate from the crystallization substrate is preferably included. In addition, a silicon ingot obtained by melting the silicon raw material for solar batteries in a mold and solidifying the same is suitable as the silicon chunk.

Abstract: A silicon semiconductor material is charged in a double-structured crucible of an outer crucible and an inner crucible. The crucible is heated from the upper side thereof by the heat radiated from a heating member energized by an induction heating coil, so that the silicon raw semiconductor material is melted. The bottom of the crucible is mounted on a supporting bed cooled by cooling water supplied from a cooling medium tank. The silicon semiconductor material is melted in the inner crucible and starts solidifying from the bottom portion thereof. The silicon semiconductor material expands in volume at the time of solidification. Since a gap is formed between the inner crucible and the outer crucible, however, the outward extension of the inner crucible with the silicon semiconductor material alleviates a strain generated at the time of solidification, thereby producing an excellent polycrystalline semiconductor ingot.

Abstract: A process and apparatus for producing a high-quality polycrystalline semiconductor ingot with excellent crystallographic properties are disclosed. The interior of an airtight vessel is kept in an inert atmosphere for semiconductors. A raw semiconductor material is charged in a crucible, and the raw semiconductor material is heated by an induction heating coil so as to be melted. Then the bottom of the crucible is deprived of heat for causing the raw semiconductor material to solidify, thereby producing a polycrystalline semiconductor. The semiconductor crystal grows in one direction from the bottom to the top of the crucible while the heat emission is changed in accordance with a predetermined relationship for keeping the solidification rate of the raw semiconductor material constant.

Abstract: A process and an apparatus for producing a polycrystalline semiconductor including charging a raw semiconductor material into a crucible, heating to melt the raw semiconductor material in the crucible by heating means, solidifying the melted material while depriving the bottom of the crucible of heat, and then cooling the crucible to cool the solidified semiconductor, in an atmosphere inert to the semiconductor throughout, characterized by alternately subjecting the semiconductor crystal to growth and annealing in the solidification step while periodically varying the amount of heat liberated from the raw semiconductor material.

Abstract: For the highly repeatable growth of high-quality semiconductor polycrystals with excellent crystallographic properties, at a low cost, there are provided a process for producing a polycrystalline semiconductor including charging a raw semiconductor material into a crucible with semiconductor seed crystals placed on its bottom in an atmosphere inert to the semiconductor, heating to melt the raw semiconductor material in the crucible by heating means while depriving the bottom of the crucible of heat to maintain the underside temperature T1 of the bottom below the melting point of the raw semiconductor material, and then cooling the crucible to solidify the melted material, wherein the underside temperature T1 of the bottom of the crucible under heating is measured, and the heating by the heating means is suspended when the rate .DELTA.

Abstract: A photovoltaic device comprises a p-type amorphous layer, an intrinsic amorphous layer, and an n-type amorphous layer formed on a conductive or insulative substrate. The intrinsic amorphous layer is formed by glow discharge decomposition in the atmosphere of silicon tetrafluoride with discharge source frequency in the range between 10 kHz and 100 kHz.