Abstract: This invention relates to a high efficiency solar cell with a novel architecture. In one embodiment, the solar cell is comprised of a high energy gap cell stack and a dichroic mirror. The high energy gap cell stack is exposed to solar light before there is any splitting of the solar light into spectral components. Each cell in the high energy gap cell stack absorbs the light with photons of energy greater than or equal to its energy gap, i.e., the blue-green to ultraviolet portion of the solar light. Each cell in the high energy gap cell stack is transparent to and transmits light with photons of energy less than its energy gap. Spectral splitting is then performed by means of the dichroic mirror on the remaining light, i.e., the light transmitted by the high energy gap cell stack.

Abstract: This invention relates to an improved high efficiency solar cell with a “HEGC stack-dichroic mirror-MEGC stack” architecture or a “HEGC stack-dichroic mirror-MEGC stack-LEGC stack” architecture. The improvement comprises the addition of a silicon cell to act as a scavenger cell to absorb light that would otherwise not be absorbed and to convert that energy to electricity. The silicon cell is positioned adjacent to the cell with the smallest energy gap of the cells in the MEGC stack.

Abstract: This invention relates to an improved high efficiency solar cell. The improvement comprises the addition of one or more silicon cells to surround at least a portion of the active region of the solar cell. Preferably, the silicon cells completely surround the active region of the solar cell. The silicon cells act as scavenger cells to absorb light that would otherwise not be absorbed by other components of the solar cell and to convert that energy to electricity.

Abstract: This invention relates to a high efficiency hybrid solar cell preferably comprised of a static concentrator, a dichroic mirror, a first cell stack comprising two cells, the first cell being a GaInP cell and the second cell being a GaAs cell and a second cell stack comprising three cells, the first cell being a Si cell, the second cell being a GaInAsP cell and the third cell being a GaInAs cell. The dichroic mirror provides a separation of the solar light into two spectral components, one component of light with photons of energy?Eg that impinges upon the first cell stack and one component of light with photons of energy<Eg that impinges upon the second cell stack.

Abstract: A front-surface-illuminated photovoltaic device, having a first semiconductor layer (180) with a back surface, a second semiconductor layer (130) with a front surface, the second layer (130) having the opposite doping type to the first layer (180) and deposited on the first layer (180); and at least one ohmic contact (160, 230) to each of the first (180) and second (130) semiconductor layers; and a process for making the photovoltaic device. The device may also have a barrier layer (190) for reducing diffusion of impurities from the first semiconductor layer (180) into the second semiconductor layer (130), a blocking layer (120), and a reflector layer (200). The device may have an array of first regions (115) in which the second layer (130) is of opposite doping type to that of the first layer (180) and forms p-n junctions (240) in these first regions (115), and second regions (300), each second region (300) containing the barrier layer (190) and the reflector layer (200).

Abstract: This invention relates to an improved high efficiency solar cell with a “HEGC stack-dichroic mirror-MEGC stack” architecture or a “HEGC stack-dichroic mirror-MEGC stack-LEGC stack” architecture. The improvement comprises the addition of a silicon cell to act as a scavenger cell to absorb light that would otherwise not be absorbed and to convert that energy to electricity. The silicon cell is positioned adjacent to the cell with the smallest energy gap of the cells in the MEGC stack.

Abstract: This invention relates to a high efficiency solar cell with a novel architecture. In one embodiment, the solar cell is comprised of a high energy gap cell stack and a dichroic mirror. The high energy gap cell stack is exposed to solar light before there is any splitting of the solar light into spectral components. Each cell in the high energy gap cell stack absorbs the light with photons of energy greater than or equal to its energy gap, i.e., the blue-green to ultraviolet portion of the solar light. Each cell in the high energy gap cell stack is transparent to and transmits light with photons of energy less than its energy gap. Spectral splitting is then performed by means of the dichroic mirror on the remaining light, i.e., the light transmitted by the high energy gap cell stack.

Abstract: A photovoltaic device having a front and back orientation and comprising: a crystalline substrate having a resistivity greater than about 0.01 ohm-cm; and an epitaxy thin-film layer in front of said substrate, said thin-film layer contacting said substrate in at least one region to define a p-n junction.

Abstract: A photovoltaic device having a front and back orientation and comprising: a crystalline substrate having a resistivity greater than about 0.01 ohm-cm; and an epitaxy thin-film layer in front of said substrate, said thin-film layer contacting said substrate in at least one region to define a p-n junction.

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.