| TWIN CREEKS TECHNOLOGIES, INC. Patent applications |
| Patent application number | Title | Published |
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| 20120104273 | Ion Source and a Method of Generating an Ion Beam Using an Ion Source - Multiple control electrodes are provided asymmetrically within the plasma chamber of an ion source at respective positions along the length of the plasma chamber. Biasing the control electrodes selectively can selectively enhance the ion extraction current at adjacent positions along the length of the extraction slit. A method of generating an ion beam is disclosed in which the strengths of the transverse electric fields at different locations along the length of the plasma chamber are controlled to modify the ion beam linear current density profile along the length of the slit. The method is used for controlling the uniformity of a ribbon beam. | 05-03-2012 |
| 20120080083 | SEMICONDUCTOR ASSEMBLY WITH A METAL OXIDE LAYER HAVING INTERMEDIATE REFRACTIVE INDEX - A semiconductor assembly is described with a thin metal oxide layer interposed between a transparent conductive oxide and an amorphous silicon layer, along with methods for making this structure. The metal oxide layer has a refractive index or range of refractive indices intermediate between that of the transparent conductive oxide and the amorphous silicon layer, and thus tends to reduce reflection at the interface. Such a layer can be used at the light-facing surface of a light-sensitive device such as a photovoltaic cell to maximize the amount of incident light entering the cell. Titanium oxide is a suitable metal oxide, and has a refractive index between those of silicon and of both indium tin oxide and aluminum-doped zinc oxide, two common transparent conductive oxides. | 04-05-2012 |
| 20120003775 | Formed Ceramic Receiver Element Adhered to a Semiconductor Lamina - A method is described to create a thin semiconductor lamina adhered to a ceramic body. The method includes defining a cleave plane in a semiconductor donor body, applying a ceramic mixture to a first face of the semiconductor body, the ceramic mixture including ceramic powder and a binder, curing the ceramic mixture to form a ceramic body, and cleaving a lamina from the semiconductor donor body at the cleave plane, the lamina remaining adhered to the ceramic body. Forming the ceramic body this way allows outgassing of volatiles during the curing step. Devices can be formed in the lamina, including photovoltaic devices. The ceramic body and lamina can withstand high processing temperatures. In some embodiments, the ceramic body may be conductive. | 01-05-2012 |
| 20110237013 | Creation of Low-Relief Texture for a Photovoltaic Cell - A novel method is described to create low-relief texture at a light-facing surface or a back surface of a photovoltaic cell. The peak-to-valley height and average peak-to-peak distance of the textured surface is less than about 1 microns, for example less than about 0.8 micron, for example about 0.5 microns or less. In a completed photovoltaic device, average reflectance for light having wavelength between 375 and 1010 nm at a light-facing surface with this texture is 6 percent or less, for example about 5 percent or less, in some instances about 3.5 percent. This texture is produced by forming an optional oxide layer at the surface, lightly buffing the surface, and etching with a crystallographically selective etch. Excellent texture may be produced by etching for as little as twelve minutes or less. Very little silicon, for example about 0.3 mg/cm | 09-29-2011 |
| 20110162688 | ASSYMETRIC SURFACE TEXTURING FOR USE IN A PHOTOVOLTAIC CELL AND METHOD OF MAKING - A novel surface texturing provides improved light-trapping characteristics for photovoltaic cells. The surface is asymmetric and includes shallow slopes at between about 5 and about 30 degrees from horizontal as well as steeper slopes at about 70 degrees or more from horizontal. It is advantageously used as either the front or back surface of a thin semiconductor lamina, for example between about 1 and about 20 microns thick, which comprises at least the base or emitter of a photovoltaic cell. In embodiments of the present invention, the shallow slopes are formed using imprint photolithography. | 07-07-2011 |
| 20110143521 | APPARATUS AND METHOD FOR SIMULTANEOUS TREATMENT OF MULTIPLE WORKPIECES - A system for simultaneously treating multiple workpieces is configured with treatment sites, configured to hold respective workpieces, fixed on a rotatable base. Treatment stations are equipped with respective active components operable simultaneously to treat respective workpieces identically on respective aligned treatment sites. For loading and unloading the treatment sites are rotated through distinct loading and unloading stations of the treatment stations which allow loading of a second batch while a first batch is being unloaded. | 06-16-2011 |
| 20110143520 | TWO-CHAMBER SYSTEM AND METHOD FOR SERIAL BONDING AND EXFOLIATION OF MULTIPLE WORKPIECES - A system for treating distinct batches of workpieces to serial procedures comprises first and second multi-site structures. In each multi-site structure the sites are rotatable for alignment in turn with loading and unloading stations together constituting treatment or process stations. Workpieces of a batch are loaded onto all of the treatment sites and then simultaneously and identically treated by operation of treatment stations with which the process sites are aligned. After treatment in the first structure, workpieces of a batch are transferred from the unloading stations of the first structure to the loading stations of the second structure for further processing. | 06-16-2011 |
| 20110143480 | MICROWAVE ANNEAL OF A THIN LAMINA FOR USE IN A PHOTOVOLTAIC CELL - A cleave plane is defined in a semiconductor donor body by implanting ions into the wafer. A lamina is cleaved from the donor body, and a photovoltaic cell is formed which comprises the lamina. The implant may cause some damage to the crystal structure of the lamina. This damage can be repaired by annealing the lamina using microwave energy. If the lamina is bonded to a receiver element, the receiver element may be either transparent to microwaves, or may reflect microwaves, while the semiconductor material absorbs the microwaves. In this way the lamina can be annealed at high temperature while the receiver element remains cooler. | 06-16-2011 |
| 20110140334 | APPARATUS AND METHOD FOR SIMULTANEOUS TREATMENT OF MULTIPLE WORKPIECES - A system for simultaneously treating multiple workpieces is configured with sites, configured to hold respective workpieces, affixed on a rotatable base. Each site has a shelf accommodating an interior space and may be positioned by base rotation in alignment with a station of fixed location. Each station is equipped with an active component. The active components are movable simultaneously within respective stations into the respective interior spaces of respective aligned sites. | 06-16-2011 |
| 20110114851 | METHOD AND APPARATUS FOR MODIFYING A RIBBON-SHAPED ION BEAM - A ribbon-shaped ion beam having an elongate cross-section normal to a beam direction is modified by generating, at a predetermined position along the ribbon-shaped beam, a magnetic field extending in an x-direction along an x-axis. The x-direction magnetic field has a non-uniform intensity which is a desired function of x. | 05-19-2011 |
| 20110114850 | METHOD AND APPARATUS FOR MODIFYING A RIBBON-SHAPED ION BEAM - A ribbon-shaped ion beam is modified using multiple coil structures on a pair of opposed ferromagnetic bars. The coil structures comprise continuous windings which have predetermined variations along the length of the bar of turns per unit length. In an example, one coil structure may have uniform turns per unit length along the bar, so that energizing the coil structures forms a magnetic field component extending across the gap between the bars with a quadrupole intensity distribution. A second coil structure may have turns per unit length varying to produce a hexapole magnetic field intensity distribution. Further coil structures may be provided to produce octopole and decapole magnetic field distributions. The coil structures may be energized to produce magnetic fields parallel to the bars which vary along the length of the bars, to twist or flatten the ribbon-shaped beam. | 05-19-2011 |
| 20110076796 | INTERMETAL STACK FOR USE IN A PHOTOVOLTAIC CELL - A donor silicon wafer may be bonded to a substrate and a lamina cleaved from the donor wafer. A photovoltaic cell may be formed from the lamina bonded to the substrate. An intermetal stack is described that is optimized for use in such a cell. The intermetal stack may include a transparent conductive oxide layer serving as a quarter-wave plate, a low resistance layer, an adhesion layer to help adhesion to the receiver element, and may also include a barrier layer to prevent or impede unwanted diffusion within the stack. | 03-31-2011 |
| 20110073781 | ION IMPLANTATION APPARATUS - An ion implanter has an implant wheel with a plurality of wafer carriers distributed about a periphery of the wheel. Each wafer carrier has a heat sink for removing heat from a wafer on the carrier during the implant process by thermal contact between the wafer and the heat sink. The wafer carriers have wafer retaining fences formed as cylindrical rollers with axes in the respective wafer support planes of the wafer carriers. The cylindrical surfaces of the rollers provide wafer abutment surfaces which can move transversely to the wafer support surfaces so that no transverse loading is applied by the fences to wafer edges as the wafer is pushed against the heat sink by centrifugal force. The wafer support surfaces comprise layers of elastomeric material and the movable abutment surfaces of the fences allow even thermal coupling with the heat sink over the whole area of the wafer. | 03-31-2011 |
| 20110073779 | ION IMPLANTATION APPARATUS - An ion implanter has an implant wheel with a plurality of wafer carriers distributed about a periphery of the wheel. Each wafer carrier has a heat sink for removing heat from a wafer on the carrier during the implant process by thermal contact between the wafer and the heat sink. A respective wafer lift structure on each carrier is moveable between first and second positions, with the wafer supported spaced away from the heat sink and in thermal contact with the heat sink respectively. The lift structure is operated to move between the first and second positions wheel the implant is rotating. This allows control of wafer temperature during the implant process by adjusting the thermal contact between wafers and heat sinks. | 03-31-2011 |
| 20110073175 | PHOTOVOLTAIC CELL COMPRISING A THIN LAMINA HAVING EMITTER FORMED AT LIGHT-FACING AND BACK SURFACES - A photovoltaic cell is described having emitter portions formed at both a light-facing surface and a back surface of the cell. In some embodiments, heavily doped emitter regions extend between the front and back emitter regions, connecting them electrically. Use of this structure is particularly well-adapted to a cell formed by implanting a semiconductor donor body with hydrogen and/or helium ions, affixing the donor body to a receiver element, cleaving a lamina from the donor body, and completing fabrication of a photovoltaic cell comprising the lamina. The emitter portion formed at the unbonded surface may comprise amorphous silicon. The lamina may be thin, for example 10 microns thick or less. | 03-31-2011 |
| 20110032736 | MIRROR-IMAGE VOLTAGE SUPPLY - A voltage supply incorporates two voltage supplies connected in a mirror-image series arrangement to generate a DC voltage between the respective common terminals of the voltage supplies. | 02-10-2011 |
| 20100330731 | METHOD TO FORM A THIN SEMICONDUCTOR LAMINA ADHERED TO A FLEXIBLE SUBSTRATE - A semiconductor donor body such as a wafer is implanted with ions to form a cleave plane. The donor wafer is affixed to a polyimide receiver element, for example by applying polyimide in liquid form to the donor wafer, then curing, or by affixing the donor wafer to a preformed polyimide sheet. Annealing causes a lamina to cleave from the donor wafer at the cleave plane. The resulting adhered lamina and polyimide body are not adhered to another rigid substrate and can be jointly flexed. | 12-30-2010 |
| 20100327190 | ION IMPLANTATION APPARATUS AND A METHOD - A hydrogen ion implanter for the exfoliation of silicon from silicon wafers uses a large scan wheel carrying 50+ wafers around its periphery and rotating about an axis. In one embodiment, the axis of rotation of the wheel is fixed and a ribbon beam of hydrogen ions is directed down on a peripheral edge of the wheel. The ribbon beam extends over the full radial width of wafers on the wheel. The beam is generated by an ion source providing an extracted ribbon beam having at least 100 mm major cross-sectional diameter. The ribbon beam may be passed through a 90° bending magnet which bends the beam in the plane of the ribbon. The magnet provides intensity correction across the ribbon to compensate for the dependency on the radial distance from the wheel axis of the speed at which parts of the wafers pass through the ribbon beam. | 12-30-2010 |
| 20100327189 | ION IMPLANTATION APPARATUS AND A METHOD FOR FLUID COOLING - A hydrogen ion implanter for the exfoliation of silicon from silicon wafers uses a large scan wheel carrying 50+ wafers around its periphery and rotating about an axis. In one embodiment, the axis of rotation of the wheel is fixed and the wheel is formed with tensioned spokes supporting a rim carrying the wafer supports. The spokes may be used for carrying cooling fluid to and from the wafer supports. Detachable connections in the cooling fluid conduits in the vacuum chamber may comprise tandem seals with an intermediate chamber between them which can be vented outside the vacuum chamber, or independently vacuum pumped. In one embodiment, a ribbon beam of hydrogen ions is directed down on a peripheral edge of the wheel. The ribbon beam extends over the full radial width of wafers on the wheel. | 12-30-2010 |
| 20100327181 | ION IMPLANTATION APPARATUS - A hydrogen ion implanter for the exfoliation of silicon from silicon wafers uses a large scan wheel carrying 50+ wafers around its periphery and rotating about an axis. In one embodiment, the axis of rotation of the wheel is fixed and the wheel is formed with tensioned spokes supporting a rim carrying the wafer supports. The spokes may be used for carrying cooling fluid to and from the wafer supports. In one embodiment, a ribbon beam of hydrogen ions is directed down on a peripheral edge of the wheel. The ribbon beam extends over the full radial width of wafers on the wheel. | 12-30-2010 |
| 20100327178 | ION SOURCE ASSEMBLY FOR ION IMPLANTATION APPARATUS AND A METHOD OF GENERATING IONS THEREIN - A hydrogen ion implanter for the exfoliation of silicon from silicon wafers uses a large scan wheel carrying 50+ wafers around its periphery and rotating about an axis. In one embodiment, the axis of rotation of the wheel is fixed and a ribbon beam of hydrogen ions is directed down on a peripheral edge of the wheel. The ribbon beam extends over the full radial width of wafers on the wheel. The beam is generated by an ion source providing an extracted ribbon beam having at least 100 mm major cross-sectional diameter. The ion source may use core-less saddle type coils to provide a uniform field confining the plasma in the ion source. The ribbon beam may be passed through a 90° bending magnet which bends the beam in the plane of the ribbon. | 12-30-2010 |
| 20100326510 | THIN SEMICONDUCTOR LAMINA ADHERED TO A FLEXIBLE SUBSTRATE - A semiconductor donor body such as a wafer is implanted with ions to form a cleave plane. The donor wafer is affixed to a polyimide receiver element, for example by applying polyimide in liquid form to the donor wafer, then curing, or by affixing the donor wafer to a preformed polyimide sheet. Annealing causes a lamina to cleave from the donor wafer at the cleave plane. The resulting adhered lamina and polyimide body are not adhered to another rigid substrate and can be jointly flexed. | 12-30-2010 |
| 20100317145 | SELECTIVE ETCH FOR DAMAGE AT EXFFOLIATED SURFACE - Ions are implanted into a silicon donor body, defining a cleave plane. A first surface of the donor body is affixed to a receiver element, and a lamina is exfoliated at the cleave plane, creating a second surface of the lamina. There is damaged silicon at the second surface, which will compromise the efficiency of a photovoltaic cell formed from the lamina. A selective etchant, having an etch rate which is positively correlated with the concentration of structural defects in silicon, is used to remove the damaged silicon at the second surface, while removing very little of the relatively undamaged lamina. | 12-16-2010 |
| 20100273329 | METHOD FOR PREPARING A DONOR SURFACE FOR REUSE - A donor wafer, for example of silicon, has an irregular surface following cleaving of a lamina from the surface, for example by exfoliation following implant of hydrogen and/or helium ions to define a cleave plane. Pinholes in the lamina leave column asperities at the exfoliated surface of the donor wafer, and the beveled edge may leave an edge asperity which fails to exfoliate. To prepare the surface of the donor wafer for reuse, mechanical grinding removes the column and edge asperities, and minimal additional thickness. Following cleaning, growth and removal of an oxide layer at the surface rounds remaining peaks. The smoothed surface is well adapted to bonding to a receiver element and exfoliation of a new lamina. A variety of devices may be fabricated from the lamina, for example a photovoltaic cell. | 10-28-2010 |
| 20100264303 | ION IMPLANTER FOR PHOTOVOLTAIC CELL FABRICATION - Ion implanters are especially suited to meet process dose and energy demands associated with fabricating photovoltaic devices by ion implantation followed by cleaving. | 10-21-2010 |
| 20100243912 | ISOLATION CIRCUIT FOR TRANSMITTING AC POWER TO A HIGH-VOLTAGE REGION - A sequence of series-connected transformers for transmitting power to high voltages incorporates an applied voltage distribution to maintain each transformer in the sequence below its withstanding voltage. | 09-30-2010 |
| 20100229928 | BACK-CONTACT PHOTOVOLTAIC CELL COMPRISING A THIN LAMINA HAVING A SUPERSTRATE RECEIVER ELEMENT - A photovoltaic assembly comprises a thin semiconductor lamina and a receiver element, where the receiver element serves as a superstrate in the completed device. The photovoltaic assembly includes a photovoltaic cell. The photovoltaic cell is a back-contact cell; photocurrent passes into and out of the back surface of the cell, but does not pass through the light-facing surface. The lamina is typically substantially crystalline and has a thickness less than about 100 microns, in some embodiments 10 microns or less. | 09-16-2010 |
| 20100224238 | PHOTOVOLTAIC CELL COMPRISING AN MIS-TYPE TUNNEL DIODE - A photovoltaic cell comprising a thin semiconductor lamina is described; the lamina is formed by cleaving from a donor wafer while the wafer is bonded to a receiver element which provides mechanical support. Thus fabrication steps performed following cleaving are advantageously performed at temperatures that will not damage the receiver element. By fabricating a cell comprising an MIS-type tunnel diode, rather than a conventional p-n diode, a high-temperature doping step may be avoided. | 09-09-2010 |
| 20100184248 | Creation and Translation of Low-Relieff Texture for a Photovoltaic Cell - Low-relief texture can be created by applying and firing frit paste on a silicon surface. Where frit contacts the surface at high temperature, it etches silicon, dissolving silicon in the softened glass frit. The result is a series of small, randomly located pits, which produce a near-Lambertian surface, suitable for use in a photovoltaic cell. This texturing method consumes little silicon, and is advantageously used in a photovoltaic cell in which a thin silicon lamina comprises the base region of the cell. When the lamina is formed by implanting ions in a donor wafer to form a cleave plane and cleaving the lamina from the donor wafer at the cleave plane, the ion implantation step will serve to translate texture formed at a first surface to the cleave plane, and thus to the second, opposing surface following cleaving. Low-relief texture formed by other methods can be translated from the first surface to the second surface in this way as well. | 07-22-2010 |
| 20100167454 | DOUBLE-SIDED DONOR FOR PREPARING A PAIR OF THIN LAMINAE - A method for forming a photovoltaic cell is disclosed which comprises the steps of providing a semiconductor donor body having a first surface and a second surface opposite the first surface, cleaving a first portion from the first surface of the semiconductor donor body to form a first lamina of semiconductor material, wherein the first lamina of semiconductor material has a first lamina thickness, and cleaving a second portion from the second surface of the semiconductor donor body to form a second lamina of semiconductor material, wherein the second lamina of semiconductor material has a second lamina thickness. | 07-01-2010 |
| 20100159630 | METHOD FOR MAKING A PHOTOVOLTAIC CELL COMPRISING CONTACT REGIONS DOPED THROUGH A LAMINA - In aspects of the present invention, a method is disclosed to form a lamina having opposing first and second surfaces. Heavily doped contact regions extend from the first surface to the second surface. Generally the lamina is formed by affixing a semiconductor donor body to a receiver element, then cleaving the lamina from the semiconductor donor body wherein the lamina remains affixed to the receiver element. In the present invention, the heavily doped contact regions are formed by doping the semiconductor donor body before cleaving of the lamina. A photovoltaic cell comprising the lamina is then fabricated. By forming the heavily doped contact regions before bonding to the receiver element and cleaving, post-bonding high-temperature steps can be avoided, which may be advantageous. | 06-24-2010 |
| 20100159629 | METHOD TO TEXTURE A LAMINA SURFACE WITHIN A PHOTOVOLTAIC CELL - It is advantageous to create texture at the surface of a photovoltaic cell to reduce reflection and increase travel length of light within the cell. A method is disclosed to create texture at the surface of a silicon body by reacting a silicide-forming metal at the surface, where the silicide-silicon interface is non-planar, then stripping the silicide, leaving behind a textured surface. Depending on the metal and the conditions of silicide formation, the resulting surface may be faceted. The peak-to-valley height of this texturing will generally be between about 300 and about 5000 angstroms, which is well-suited for use in photovoltaic cells comprising a thin silicon lamina. | 06-24-2010 |
| 20100154873 | PHOTOVOLTAIC CELL COMPRISING CCONTACT REGIONS DOPED THROUGH LAMINA - In aspects of the present invention, a lamina is formed having opposing first and second surfaces. Heavily doped contact regions extend from the first surface to the second surface. Generally the lamina is formed by affixing a semiconductor donor body to a receiver element, then cleaving the lamina from the semiconductor donor body wherein the lamina remains affixed to the receiver element. In the present invention, the heavily doped contact regions are formed by doping the semiconductor donor body before cleaving of the lamina. A photovoltaic cell comprising the lamina is then fabricated. By forming the heavily doped contact regions before bonding to the receiver element and cleaving, post-bonding high-temperature steps can be avoided, which may be advantageous. | 06-24-2010 |
| 20100147448 | METHODS OF TRANSFERRING A LAMINA TO A RECEIVER ELEMENT - Methods for bonding a donor wafer to a receiver element and transferring a lamina from the donor wafer to the receiver element are disclosed herein. The donor wafer may be, for example, a monocrystalline silicon wafer with a thickness of from about 300 microns to about 1000 microns, and the lamina may be may be less than 100 microns thick. The receiver element may be composed of, for example, metal or glass, and the receiver element may have dissimilar thermal expansion properties from the lamina. Although the lamina and the receiver element may have dissimilar thermal expansion properties, the methods disclosed herein maintain the integrity of the bond between the lamina and the receiver element. | 06-17-2010 |
| 20100139755 | FRONT CONNECTED PHOTOVOLTAIC ASSEMBLY AND ASSOCIATED METHODS - A photovoltaic device is disclosed herein that, in various aspects, includes a conductive layer, and a substantially crystalline lamina with a first surface oriented toward the conductive layer and a second surface oriented away from the conductive layer. The lamina thickness is within the range between about 0.2 microns and about 50 microns. An aperture passes through the lamina from the first surface to the second surface. A connector in electrical communication with the conductive layer is disposed through the aperture. Methods of manufacture of the photovoltaic devise are also disclosed. | 06-10-2010 |
| 20100072401 | HYDROGEN ION IMPLANTER USING A BROAD BEAM SOURCE - Ion implanters incorporating multibeam ion sources are used to meet process dose and energy demands associated with fabricating a thin lamina for use in photovoltaic devices. The thin lamina are formed by ion implantation followed by cleaving. | 03-25-2010 |
| 20100032010 | METHOD TO MITIGATE SHUNT FORMATION IN A PHOTOVOLTAIC CELL COMPRISING A THIN LAMINA - A photovoltaic cell can be formed from a thin semiconductor lamina cleaved from a substantially crystalline wafer. Shunts may inadvertently be formed through such a lamina, compromising device performance. By physically severing the lamina into a plurality of segments, the segments of the lamina preferably electrically connected in series, loss of efficiency due to shunt formation may be substantially reduced. In some embodiments, adjacent laminae are connected in series into strings, and the strings are connected in parallel to compensate for the reduction in current caused by severing the lamina into segments. | 02-11-2010 |
| 20100032007 | PHOTOVOLTAIC CELL COMPRISING A THIN LAMINA HAVING A REAR JUNCTION AND METHOD OF MAKING - Fabrication of a photovoltaic cell comprising a thin semiconductor lamina may require additional processing after the semiconductor lamina is bonded to a receiver. To minimize high-temperature steps after bonding, the p−n junction is formed at the back of the cell, at the bonded surface. In some embodiments, the front surface of the semiconductor lamina is not doped or is locally doped using low-temperature methods. The base resistivity of the photovoltaic cell may be reduced, allowing a front surface field to be reduced or omitted. | 02-11-2010 |
| 20100031995 | PHOTOVOLTAIC MODULE COMPRISING THIN LAMINAE CONFIGURED TO MITIGATE EFFICIENCY LOSS DUE TO SHUNT FORMATION - A photovoltaic cell can be formed from a thin semiconductor lamina cleaved from a substantially crystalline wafer. Shunts may inadvertently be formed through such a lamina, compromising device performance. By physically severing the lamina into a plurality of segments, the segments of the lamina preferably electrically connected in series, loss of efficiency due to shunt formation may be substantially reduced. In some embodiments, adjacent laminae are connected in series into strings, and the strings are connected in parallel to compensate for the reduction in current caused by severing the lamina into segments. | 02-11-2010 |
| 20100009488 | METHOD TO FORM A PHOTOVOLTAIC CELL COMPRISING A THIN LAMINA - A very thin photovoltaic cell is formed by implanting gas ions below the surface of a donor body such as a semiconductor wafer. Ion implantation defines a cleave plane, and a subsequent step exfoliates a thin lamina from the wafer at the cleave plane. A photovoltaic cell, or all or a portion of the base or emitter of a photovoltaic cell, is formed within the lamina. In preferred embodiments, the wafer is affixed to a receiver before the cleaving step. Electrical contact can be formed to both surfaces of the lamina, or to one surface only. | 01-14-2010 |
| 20090293931 | ASYMMETRIC SURFACE TEXTURING FOR USE IN A PHOTOVOLTAIC CELL AND METHOD OF MAKING - A novel surface texturing provides improved light-trapping characteristics for photovoltaic cells. The surface is asymmetric and includes shallow slopes at between about 5 and about 30 degrees from horizontal as well as steeper slopes at about 70 degrees or more from horizontal. It is advantageously used as either the front or back surface of a thin semiconductor lamina, for example between about 1 and about 20 microns thick, which comprises at least the base or emitter of a photovoltaic cell. In embodiments of the present invention, the shallow slopes are formed using imprint photolithography. | 12-03-2009 |
| 20090242031 | Photovoltaic Assembly Including a Conductive Layer Between a Semiconductor Lamina and a Receiver Element - A semiconductor donor body is affixed to a receiver element, and a thin semiconductor lamina is cleaved from the donor body, remaining affixed to the receiver element. A photovoltaic assembly is fabricated which includes the lamina and the receiver element, wherein a photovoltaic cell comprises the lamina. The bond between the semiconductor donor body and the receiver element must survive processing to complete the cell, as well as eventual assembly, transport, and operation in a finished photovoltaic module. It has been found that inclusion of a conductive layer such as titanium or aluminum aids bonding between the semiconductor donor body and the receiver element. In some embodiments, the conductive layer may also serve as an electrical contact and/or as a reflective layer. | 10-01-2009 |
| 20090242010 | Method to Form a Photovoltaic Cell Comprising a Thin Lamina Bonded to a Discrete Receiver Element - A donor semiconductor wafer is processed to define a cleave plane, then affixed to a discrete receiver element, which may be glass, metal or a metal compound, plastic, or semiconductor. A semiconductor lamina is cleaved from the donor wafer at the cleave plane. A photovoltaic assembly is fabricated comprising the semiconductor lamina and the receiver element. The photovoltaic assembly comprises a photovoltaic cell. After fabrication, the photovoltaic assembly can be inspected for defects and tested for performance, and select photovoltaic assemblies can be assembled into a completed photovoltaic module. | 10-01-2009 |
| 20090197368 | METHOD TO FORM A PHOTOVOLTAIC CELL COMPRISING A THIN LAMINA - A very thin photovoltaic cell is formed by implanting gas ions below the surface of a donor body such as a semiconductor wafer. Ion implantation defines a cleave plane, and a subsequent step exfoliates a thin lamina from the wafer at the cleave plane. A photovoltaic cell, or all or a portion of the base or emitter of a photovoltaic cell, is formed within the lamina. In preferred embodiments, the wafer is affixed to a receiver before the cleaving step. Electrical contact can be formed to both surfaces of the lamina, or to one surface only. | 08-06-2009 |
| 20090197367 | METHOD TO FORM A PHOTOVOLTAIC CELL COMPRISING A THIN LAMINA - A very thin photovoltaic cell is formed by implanting gas ions below the surface of a donor body such as a semiconductor wafer. Ion implantation defines a cleave plane, and a subsequent step exfoliates a thin lamina from the wafer at the cleave plane. A photovoltaic cell, or all or a portion of the base or emitter of a photovoltaic cell, is formed within the lamina. In preferred embodiments, the wafer is affixed to a receiver before the cleaving step. Electrical contact can be formed to both surfaces of the lamina, or to one surface only. | 08-06-2009 |
| 20090194164 | METHOD TO FORM A PHOTOVOLTAIC CELL COMPRISING A THIN LAMINA - A very thin photovoltaic cell is formed by implanting gas ions below the surface of a donor body such as a semiconductor wafer. Ion implantation defines a cleave plane, and a subsequent step exfoliates a thin lamina from the wafer at the cleave plane. A photovoltaic cell, or all or a portion of the base or emitter of a photovoltaic cell, is formed within the lamina. In preferred embodiments, the wafer is affixed to a receiver before the cleaving step. Electrical contact can be formed to both surfaces of the lamina, or to one surface only. | 08-06-2009 |
| 20090194163 | METHOD TO FORM A PHOTOVOLTAIC CELL COMPRISING A THIN LAMINA - A very thin photovoltaic cell is formed by implanting gas ions below the surface of a donor body such as a semiconductor wafer. Ion implantation defines a cleave plane, and a subsequent step exfoliates a thin lamina from the wafer at the cleave plane. A photovoltaic cell, or all or a portion of the base or emitter of a photovoltaic cell, is formed within the lamina. In preferred embodiments, the wafer is affixed to a receiver before the cleaving step. Electrical contact can be formed to both surfaces of the lamina, or to one surface only. | 08-06-2009 |
| 20090194162 | METHOD TO FORM A PHOTOVOLTAIC CELL COMPRISING A THIN LAMINA - A very thin photovoltaic cell is formed by implanting gas ions below the surface of a donor body such as a semiconductor wafer. Ion implantation defines a cleave plane, and a subsequent step exfoliates a thin lamina from the wafer at the cleave plane. A photovoltaic cell, or all or a portion of the base or emitter of a photovoltaic cell, is formed within the lamina. In preferred embodiments, the wafer is affixed to a receiver before the cleaving step. Electrical contact can be formed to both surfaces of the lamina, or to one surface only. | 08-06-2009 |
| 20090194153 | PHOTOVOLTAIC CELL COMPRISING A THIN LAMINA HAVING LOW BASE RESISTIVITY AND METHOD OF MAKING - Fabrication of a photovoltaic cell comprising a thin semiconductor lamina may require additional processing after the semiconductor lamina is bonded to a receiver. To minimize high-temperature steps after bonding, the p-n junction is formed at the back of the cell, at the bonded surface. In some embodiments, the front surface of the semiconductor lamina is not doped or is locally doped using low-temperature methods. The base resistivity of the photovoltaic cell may be reduced, allowing a front surface field to be reduced or omitted. | 08-06-2009 |
