Abstract: A method of purifying silicon, comprising feeding a sparging gas into a liquid melt [10] containing molten silicon and at least one impurity, in which the sparging gas is used to react with or move one or more impurity contained within the silicon. The products of such reaction or movement may be removed, e.g., by liquid-gas extraction, by liquid-liquid extraction or by liquid-solid extraction.

Abstract: A polycrystalline film of silicon including silicon grains having an aspect ratio, d/t, of more than 1:1, wherein “d” is the grain diameter and “t” is the grain thickness. The polycrystalline film of silicon can be used to form an electronic device, such as a monolithically integrated solar cell having ohmic contacts formed on opposed surfaces or on the same surface of the film. A plurality of solar cells can be monolithically integrated to provide a solar cell module that includes an electrically insulating substrate and at least two solar cells disposed on the substrate in physical isolation from one another. Methods for manufacturing the film, solar cell and solar cell module are also disclosed. The simplified structure and method allow for substantial cost reduction on a mass-production scale, at least in part due to the high aspect ratio silicon grains in the film.

Abstract: A polycrystalline film of silicon including silicon grains having an aspect ratio, d/t, of more than 1:1, wherein “d” is the grain diameter and “t” is the grain thickness. The polycrystalline film of silicon can be used to form an electronic device, such as a monolithically integrated solar cell having ohmic contacts formed on opposed surfaces or on the same surface of the film. A plurality of solar cells can be monolithically integrated to provide a solar cell module that includes an electrically insulating substrate and at least two solar cells disposed on the substrate in physical isolation from one another. Methods for manufacturing the film, solar cell and solar cell module are also disclosed. The simplified structure and method allow for substantial cost reduction on a mass-production scale, at least in part due to the high aspect ratio silicon grains in the film.

Abstract: A method of purifying silicon, comprising feeding a sparging gas into a liquid melt [10] containing molten silicon and at least one impurity, in which the sparging gas is used to react with or move one or more impurity contained within the silicon. The products of such reaction or movement may be removed, e.g., by liquid-gas extraction, by liquid-liquid extraction or by liquid-solid extraction.

Abstract: A polycrystalline film of silicon including silicon grains having an aspect ratio, d/t, of more than 1:1, wherein “d” is the grain diameter and “t” is the grain thickness. The polycrystalline film of silicon can be used to form an electronic device, such as a monolithically integrated solar cell having ohmic contacts formed on opposed surfaces or on the same surface of the film. A plurality of solar cells can be monolithically integrated to provide a solar cell module that includes an electrically insulating substrate and at least two solar cells disposed on the substrate in physical isolation from one another. Methods for manufacturing the film, solar cell and solar cell module are also disclosed. The simplified structure and method allow for substantial cost reduction on a mass-production scale, at least in part due to the high aspect ratio silicon grains in the film.

Abstract: A polycrystalline film of silicon including silicon grains having an aspect ratio, d/t, of more than 1:1, wherein “d” is the grain diameter and “t” is the grain thickness. The polycrystalline film of silicon can be used to form an electronic device, such as a monolithically integrated solar cell having ohmic contacts formed on opposed surfaces or on the same surface of the film. A plurality of solar cells can be monolithically integrated to provide a solar cell module that includes an electrically insulating substrate and at least two solar cells disposed on the substrate in physical isolation from one another. Methods for manufacturing the film, solar cell and solar cell module are also disclosed. The simplified structure and method allow for substantial cost reduction on a mass-production scale, at least in part due to the high aspect ratio silicon grains in the film.

Abstract: A polycrystalline film of silicon including silicon grains having an aspect ratio, d/t, of more than 1:1, wherein “d” is the grain diameter and “t” is the grain thickness. The polycrystalline film of silicon can be used to form an electronic device, such as a monolithically integrated solar cell having ohmic contacts formed on opposed surfaces or on the same surface of the film. A plurality of solar cells can be monolithically integrated to provide a solar cell module that includes an electrically insulating substrate and at least two solar cells disposed on the substrate in physical isolation from one another. Methods for manufacturing the film, solar cell and solar cell module are also disclosed. The simplified structure and method allow for substantial cost reduction on a mass-production scale, at least in part due to the high aspect ratio silicon grains in the film.

Abstract: The invention relates to a silicon sheet having columnar grains extending axially through the sheet from one free surface of the sheet to the other free surface. The sheet has an electrical resistivity in the range of 0.1 to 10 ohm-cm.

Abstract: The invention relates to improved techniques for manufacturing columnar-grained polycrystalline sheets which have particular utility as substrates or wafers for solar cells. The sheet is made from silicon on a setter material which supports the silicon material. The setter material and silicon are subjected to a thermal profile all of which promote columnar growth. The thermal profile sequentially creates a melt region where a thin-film capping layer grows at the top of the silicon, a nucleation region where preferential nucleation occurs at the capping-layer/molten-silicon interface, and then a growth region where both liquid and a growing polycrystalline sheet layer coexist. An annealing region is created where the temperature of the grown polycrystalline silicon sheet layer is controllably reduced to effect stress relief.

Abstract: The invention relates to techniques for manufacturing columnar-grained polycrystalline sheets which have particular utility as substrates or wafers for solar cells. The sheet is made by applying granular silicon to a setter material which supports the granular material. The setter material and granular silicon are subjected to a thermal profile all of which promote columnar growth by melting the silicon from the top downwardly. The thermal profile sequentially creates a melt region at the top of the granular silicon and then a growth region where both liquid and a growing polycrystalline sheet layer coexist. An annealing region is created where the temperature of the grown polycrystalline silicon sheet layer is controllably reduced to effect stress relief.

Abstract: The invention relates to techniques for manufacturing columnar-grained polycrystalline sheets which have particular utility as substrates or wafers for solar cells. The sheet is made by applying granular silicon to a setter material which supports the granular material. The setter material and granular silicon are subjected to a thermal profile all of which promote columnar growth by melting the silicon from the top downwardly. The thermal profile sequentially creates a melt region at the top of the granular silicon and then a growth region where both liquid and a growing polycrystalline sheet layer coexist. An annealing region is created where the temperature of the grown polycrystalline silicon sheet layer is controllably reduced to effect stress relief.

Abstract: A plurality of thin polycrystalline silicon solar cells formed on a ceramic substrate and which are electrically series connected to form a monolithically interconnected submodule. Adjacent solar cells are electrically separated by a vertical trench and electrically connected by interconnects located below the light receiving surface of each solar cell. The submodules are provided with external electrical contacts for electrically connecting into a photovoltaic module assembly.

Abstract: A thin-film photovoltaic solar cell features a thin polycrystalline silicon active semiconductor formed over a conductive ceramic substrate. Between the substrate and the adjacent active semiconductor layer is a barrier layer which provides for reflection of light, minimizes back surface recombination and prevents contamination of the active semiconductor.

Abstract: A thin-film solar cell is made up of semiconductor layers formed on an aluminum silicon eutectic alloy substrate. The substrate includes an aluminum oxide insulator containing electrically conducting silicon nucleation sites which is interposed between the electrical contact of the substrate and the adjacent semiconductor. Grain boundaries and voids terminate on the insulator. The solar cell is fabricated by oxidizing the aluminum-silicon substrate to form a layer of aluminum oxide with unactivated silicon site material dispersed therein and activating the silicon nucleation sites during growth of the semiconductor layers.

Abstract: A thin-film solar cell on a substrate is fabricated by selectively introducing nucleation sites into the insulator layer which is formed on the substrate material, and activating the nucleation sites during growth of the semiconductor layers. The solar cell is made up of semiconductor layers formed on a substrate. The substrate includes an insulator containing electrically conducting nucleation sites which is interposed between the electrical contact of the substrate and the adjacent semiconductor. The insulator can also be optically transparent. Grain boundaries and voids terminate on the insulator.

Abstract: A thin-film solar cell is made up of semiconductor layers formed on a substrate. The substrate includes an insulator containing electrically conducting nucleation sites which is interposed between the electrical contact of the substrate and the adjacent semiconductor. The insulator can also be optically transparent. Grain boundaries and voids terminate on the insulator. The solar cell is fabricated by selectively introducing nucleation sites into the insulator layer which is formed on the substrate material, and activating the nucleation sites during growth of the semiconductor layers.

Abstract: The invention relates to a process and apparatus for formation and deposition of thin films on a substrate, in a vacuum, by evaporation of the elements to form a Zn.sub.x Cd.sub.1-x S compound having a preselected fixed ratio of cadmium to zinc, characterized by the evaporation of cadmium and zinc at a rate the ratio of which is proportional to the stoichiometric ratio of those elements in the intended compound and evaporation of sulfur at a rate at least twice the combined rates of cadmium and zinc, and at least twice that required by the stoichiometry of the intended compound.

Abstract: A photovoltaic cell having a zinc phosphide absorber. The zinc phosphide can be a single or multiple crystal slice or a thin polycrystalline film. The cell can be a Schottky barrier, heterojunction or homojunction device. Methods for synthesizing and crystallizing zinc phosphide are disclosed as well as a method for forming thin films.

Abstract: A solar cell having a copper-bearing absorber is provided with a composite transparent encapsulating layer specifically designed to prevent oxidation of the copper sulfide. In a preferred embodiment, the absorber is a layer of copper sulfide and the composite layer comprises a thin layer of copper oxide formed on the copper sulfide and a layer of encapsulating glass formed on the oxide. It is anticipated that such devices, when exposed to normal operating conditions of various terrestrial applications, can be maintained at energy conversion efficiencies greater than one-half the original conversion efficiency for periods as long as thirty years.

Abstract: The invention relates to techniques for manufacturing columnar-grained polycrystalline sheets which have particular utility as substrates or wafers for solar cells. The sheet is made by applying granular silicon to a setter material which supports the granular material. The setter material and granular silicon are subjected to a thermal profile all of which promote columnar growth by melting the silicon from the top downwardly. The thermal profile sequentially creates a melt region at the top of the granular silicon and then a growth region where both liquid and a growing polycrystalline sheet layer coexist. An annealing region is created where the temperature of the grown polycrystalline silicon sheet layer is controllably reduced to effect stress relief.