Patent application number | Description | Published |
20080299297 | Array of small contacts for solar cell fabrication - Fabrication of a solar cell using a printed contact mask. The contact mask may include dots formed by inkjet printing. The dots may be formed in openings between dielectric layers (e.g., polyimide). Intersections of overlapping dots may form gaps that define contact regions. The spacing of the gaps may be dictated by the alignment of nozzles that dispense the dots. Using the dots as a contact mask, an underlying dielectric layer may be etched to form the contact regions through the underlying dielectric layer. Metal contact fingers may be formed over the wafer to form electrical connections to corresponding diffusion regions through the contact regions. | 12-04-2008 |
20090205712 | Front contact solar cell with formed emitter - A bipolar solar cell includes a backside junction formed by an N-type silicon substrate and a P-type polysilicon emitter formed on the backside of the solar cell. An antireflection layer may be formed on a textured front surface of the silicon substrate. A negative polarity metal contact on the front side of the solar cell makes an electrical connection to the substrate, while a positive polarity metal contact on the backside of the solar cell makes an electrical connection to the polysilicon emitter. An external electrical circuit may be connected to the negative and positive metal contacts to be powered by the solar cell. The positive polarity metal contact may form an infrared reflecting layer with an underlying dielectric layer for increased solar radiation collection. | 08-20-2009 |
20090308438 | Trench Process and Structure for Backside Contact Solar Cells with Polysilicon Doped Regions - A solar cell includes polysilicon P-type and N-type doped regions on a backside of a substrate, such as a silicon wafer. An interrupted trench structure separates the P-type doped region from the N-type doped region in some locations but allows the P-type doped region and the N-type doped region to touch in other locations. Each of the P-type and N-type doped regions may be formed over a thin dielectric layer. Among other advantages, the resulting solar cell structure allows for increased efficiency while having a relatively low reverse breakdown voltage. | 12-17-2009 |
20100000597 | Front Contact Solar Cell With Formed Electrically Conducting Layers On the Front Side And Backside - A bipolar solar cell includes a backside junction formed by a silicon substrate and a first doped layer of a first dopant type on the backside of the solar cell. A second doped layer of a second dopant type makes an electrical connection to the substrate from the front side of the solar cell. A first metal contact of a first electrical polarity electrically connects to the first doped layer on the backside of the solar cell, and a second metal contact of a second electrical polarity electrically connects to the second doped layer on the front side of the solar cell. An external electrical circuit may be electrically connected to the first and second metal contacts to be powered by the solar cell. | 01-07-2010 |
20100075234 | Generation Of Contact Masks For Inkjet Printing On Solar Cell Substrates - A contact mask for inkjet printing on a solar cell substrate may be generated by creating a printing bitmap of contacts to be printed on the solar cell substrate. The contacts may be located on the solar cell substrate by mapping coordinates of the printing bitmap to coordinates of the solar cell substrate as positioned in the inkjet printer. The location of the contacts on the solar cell substrate may be defined relative to a location on the solar cell substrate, such as relative to center of mass. The contact mask may be printed by the inkjet printer using the printing bitmap and location information of the contacts. | 03-25-2010 |
20100139745 | Back Contact Sliver Cells - A solar cell uses a sliver of a silicon wafer as a substrate. The sliver has a front side that faces the sun during normal operation. The front side of the sliver includes a surface from along a thickness of the wafer, allowing for more efficient use of silicon. Metal contacts are formed on the back side of the sliver. The metal contacts electrically connect to the emitter and base of the solar cell, which may be formed within the sliver or be made of polysilicon. The emitter of the solar cell may be a P-type doped region and the base of the solar cell may be an N-type doped region, for example. The solar cell may include an anti-reflective coating formed on the front side of the sliver. The anti-reflective coating may be over a textured surface on the front side of the sliver. | 06-10-2010 |
20100218800 | Methods and Apparatus for Metallization of Solar Cells - A superstrate, such as a sheet of polymer film, is used as a transport during metallization of solar cells. The back sides of the solar cells are attached to the sheet of polymer film. Contact holes are formed through the sheet of polymer film to expose doped regions of the solar cells. Metals are formed in the contact holes to electrically connect to the exposed doped regions of the solar cells. The metals are electroplated to form metal contacts of the solar cell. Subsequently, the solar cells are separated from other solar cells that were metallized while supported by the same sheet of polymer film to form strings of solar cells or individual solar cells. | 09-02-2010 |
20100269904 | Solar Cell Having Doped Semiconductor Heterojunction Contacts - A silicon solar cell has doped amorphous silicon contacts formed on a tunnel silicon oxide layer on a surface of a silicon substrate. High temperature processing is unnecessary in fabricating the solar cell. | 10-28-2010 |
20110000540 | Back Side Contact Solar Cell Structures And Fabrication Processes - In one embodiment, active diffusion junctions of a solar cell are formed by diffusing dopants from dopant sources selectively deposited on the back side of a wafer. The dopant sources may be selectively deposited using a printing method, for example. Multiple dopant sources may be employed to form active diffusion regions of varying doping levels. For example, three or four active diffusion regions may be fabricated to optimize the silicon/dielectric, silicon/metal, or both interfaces of a solar cell. The front side of the wafer may be textured prior to forming the dopant sources using a texturing process that minimizes removal of wafer material. Openings to allow metal gridlines to be connected to the active diffusion junctions may be formed using a self-aligned contact opening etch process to minimize the effects of misalignments. | 01-06-2011 |
20110003424 | Back Side Contact Solar Cell Structures And Fabrication Processes - In one embodiment, active diffusion junctions of a solar cell are formed by diffusing dopants from dopant sources selectively deposited on the back side of a wafer. The dopant sources may be selectively deposited using a printing method, for example. Multiple dopant sources may be employed to form active diffusion regions of varying doping levels. For example, three or four active diffusion regions may be fabricated to optimize the silicon/dielectric, silicon/metal, or both interfaces of a solar cell. The front side of the wafer may be textured prior to forming the dopant sources using a texturing process that minimizes removal of wafer material. Openings to allow metal gridlines to be connected to the active diffusion junctions may be formed using a self-aligned contact opening etch process to minimize the effects of misalignments. | 01-06-2011 |
20110059571 | Trench Process and Structure for Backside Contact Solar Cells with Polysilicon Doped Regions - A solar cell includes polysilicon P-type and N-type doped regions on a backside of a substrate, such as a silicon wafer. An interrupted trench structure separates the P-type doped region from the N-type doped region in some locations but allows the P-type doped region and the N-type doped region to touch in other locations. Each of the P-type and N-type doped regions may be formed over a thin dielectric layer. Among other advantages, the resulting solar cell structure allows for increased efficiency while having a relatively low reverse breakdown voltage. | 03-10-2011 |
20110061731 | Array Of Small Contacts For Solar Cell Fabrication - Fabrication of a solar cell using a printed contact mask. The contact mask may include dots formed by inkjet printing. The dots may be formed in openings between dielectric layers (e.g., polyimide). Intersections of overlapping dots may form gaps that define contact regions. The spacing of the gaps may be dictated by the alignment of nozzles that dispense the dots. Using the dots as a contact mask, an underlying dielectric layer may be etched to form the contact regions through the underlying dielectric layer. Metal contact fingers may be formed over the wafer to form electrical connections to corresponding diffusion regions through the contact regions. | 03-17-2011 |
20110272016 | SOLAR CELL WITH REDUCED BASE DIFFUSION AREA - In one embodiment, a solar cell has base and emitter diffusion regions formed on the back side. The emitter diffusion region is configured to collect minority charge carriers in the solar cell, while the base diffusion region is configured to collect majority charge carriers. The emitter diffusion region may be a continuous region separating the base diffusion regions. Each of the base diffusion regions may have a reduced area to decrease minority charge carrier recombination losses without substantially increasing series resistance losses due to lateral flow of majority charge carriers. Each of the base diffusion regions may have a dot shape, for example. | 11-10-2011 |
20110300665 | Ablation Of Film Stacks In Solar Cell Fabrication Processes - A dielectric film stack of a solar cell is ablated using a laser. The dielectric film stack includes a layer that is absorptive in a wavelength of operation of the laser source. The laser source, which fires laser pulses at a pulse repetition rate, is configured to ablate the film stack to expose an underlying layer of material. The laser source may be configured to fire a burst of two laser pulses or a single temporally asymmetric laser pulse within a single pulse repetition to achieve complete ablation in a single step. | 12-08-2011 |
20120000522 | Fabrication Of Solar Cells With Counter Doping Prevention - A solar cell fabrication process includes printing of dopant sources over a polysilicon layer over backside of a solar cell substrate. The dopant sources are cured to diffuse dopants from the dopant sources into the polysilicon layer to form diffusion regions, and to crosslink the dopant sources to make them resistant to a subsequently performed texturing process. To prevent counter doping, dopants from one of the dopant sources are prevented from outgassing and diffusing into the other dopant source. For example, phosphorus from an N-type dopant source is prevented from diffusing to a P-type dopant source comprising boron. | 01-05-2012 |
20120003788 | High Throughput Solar Cell Ablation System - A solar cell is formed using a solar cell ablation system. The ablation system includes a single laser source and several laser scanners. The laser scanners include a master laser scanner, with the rest of the laser scanners being slaved to the master laser scanner. A laser beam from the laser source is split into several laser beams, with the laser beams being scanned onto corresponding wafers using the laser scanners in accordance with one or more patterns. The laser beams may be scanned on the wafers using the same or different power levels of the laser source. | 01-05-2012 |
20120204926 | PROCESS AND STRUCTURES FOR FABRICATION OF SOLAR CELLS - Contact holes of solar cells are formed by laser ablation to accommodate various solar cell designs. Use of a laser to form the contact holes is facilitated by replacing films formed on the diffusion regions with a film that has substantially uniform thickness. Contact holes may be formed to deep diffusion regions to increase the laser ablation process margins. The laser configuration may be tailored to form contact holes through dielectric films of varying thicknesses. | 08-16-2012 |
20120312791 | HIGH THROUGHPUT SOLAR CELL ABLATION SYSTEM - A solar cell is formed using a solar cell ablation system. The ablation system includes a single laser source and several laser scanners. The laser scanners include a master laser scanner, with the rest of the laser scanners being slaved to the master laser scanner. A laser beam from the laser source is split into several laser beams, with the laser beams being scanned onto corresponding wafers using the laser scanners in accordance with one or more patterns. The laser beams may be scanned on the wafers using the same or different power levels of the laser source. | 12-13-2012 |
20130065357 | SOLAR CELL CONTACT FORMATION USING LASER ABLATION - The formation of solar cell contacts using a laser is described. A method of fabricating a back-contact solar cell includes forming a poly-crystalline material layer above a single-crystalline substrate. The method also includes forming a dielectric material stack above the poly-crystalline material layer. The method also includes forming, by laser ablation, a plurality of contacts holes in the dielectric material stack, each of the contact holes exposing a portion of the poly-crystalline material layer; and forming conductive contacts in the plurality of contact holes. | 03-14-2013 |
20130237007 | TRENCH PROCESS AND STRUCTURE FOR BACKSIDE CONTACT SOLAR CELLS WITH POLYSILICON DOPED REGIONS - A solar cell includes polysilicon P-type and N-type doped regions on a backside of a substrate, such as a silicon wafer. An interrupted trench structure separates the P-type doped region from the N-type doped region in some locations but allows the P-type doped region and the N-type doped region to touch in other locations. Each of the P-type and N-type doped regions may be formed over a thin dielectric layer. Among other advantages, the resulting solar cell structure allows for increased efficiency while having a relatively low reverse breakdown voltage. | 09-12-2013 |
20140034107 | METHODS AND APPARATUS FOR METALLIZATION OF SOLAR CELLS - A superstrate, such as a sheet of polymer film, is used as a transport during metallization of solar cells. The back sides of the solar cells are attached to the sheet of polymer film. Contact holes are formed through the sheet of polymer film to expose doped regions of the solar cells. Metals are formed in the contact holes to electrically connect to the exposed doped regions of the solar cells. The metals are electroplated to form metal contacts of the solar cell. Subsequently, the solar cells are separated from other solar cells that were metallized while supported by the same sheet of polymer film to form strings of solar cells or individual solar cells. | 02-06-2014 |
20140034122 | FRONT CONTACT SOLAR CELL WITH FORMED ELECTRICALLY CONDUCTING LAYERS ON THE FRONT SIDE AND BACKSIDE - A bipolar solar cell includes a backside junction formed by a silicon substrate and a first doped layer of a first dopant type on the backside of the solar cell. A second doped layer of a second dopant type makes an electrical connection to the substrate from the front side of the solar cell. A first metal contact of a first electrical polarity electrically connects to the first doped layer on the backside of the solar cell, and a second metal contact of a second electrical polarity electrically connects to the second doped layer on the front side of the solar cell. An external electrical circuit may be electrically connected to the first and second metal contacts to be powered by the solar cell. | 02-06-2014 |
20140038338 | FRONT CONTACT SOLAR CELL WITH FORMED EMITTER - A bipolar solar cell includes a backside junction formed by an N-type silicon substrate and a P-type polysilicon emitter formed on the backside of the solar cell. An antireflection layer may be formed on a textured front surface of the silicon substrate. A negative polarity metal contact on the front side of the solar cell makes an electrical connection to the substrate, while a positive polarity metal contact on the backside of the solar cell makes an electrical connection to the polysilicon emitter. An external electrical circuit may be connected to the negative and positive metal contacts to be powered by the solar cell. The positive polarity metal contact may form an infrared reflecting layer with an underlying dielectric layer for increased solar radiation collection. | 02-06-2014 |
20140096824 | PROCESS AND STRUCTURES FOR FABRICATION OF SOLAR CELLS - Contact holes of solar cells are formed by laser ablation to accommodate various solar cell designs. Use of a laser to form the contact holes is facilitated by replacing films formed on the diffusion regions with a film that has substantially uniform thickness. Contact holes may be formed to deep diffusion regions to increase the laser ablation process margins. The laser configuration may be tailored to form contact holes through dielectric films of varying thicknesses. | 04-10-2014 |
20140134787 | SOLAR CELL CONTACT FORMATION USING LASER ABLATION - The formation of solar cell contacts using a laser is described. A method of fabricating a back-contact solar cell includes forming a poly-crystalline material layer above a single-crystalline substrate. The method also includes forming a dielectric material stack above the poly-crystalline material layer. The method also includes forming, by laser ablation, a plurality of contacts holes in the dielectric material stack, each of the contact holes exposing a portion of the poly-crystalline material layer; and forming conductive contacts in the plurality of contact holes. | 05-15-2014 |
20140190561 | SOLAR CELL WITH REDUCED BASE DIFFUSION AREA - In one embodiment, a solar cell has base and emitter diffusion regions formed on the back side. The emitter diffusion region is configured to collect minority charge carriers in the solar cell, while the base diffusion region is configured to collect majority charge carriers. The emitter diffusion region may be a continuous region separating the base diffusion regions. Each of the base diffusion regions may have a reduced area to decrease minority charge carrier recombination losses without substantially increasing series resistance losses due to lateral flow of majority charge carriers. Each of the base diffusion regions may have a dot shape, for example. | 07-10-2014 |
20140326308 | SOLAR CELL CONTACT FORMATION USING LASER ABLATION - The formation of solar cell contacts using a laser is described. A method of fabricating a back-contact solar cell includes forming a poly-crystalline material layer above a single-crystalline substrate. The method also includes forming a dielectric material stack above the poly-crystalline material layer. The method also includes forming, by laser ablation, a plurality of contacts holes in the dielectric material stack, each of the contact holes exposing a portion of the poly-crystalline material layer; and forming conductive contacts in the plurality of contact holes. | 11-06-2014 |
20140345688 | SOLAR CELL HAVING DOPED SEMICONDUCTOR HETEROJUNCTION CONTACTS - A silicon solar cell has doped amorphous silicon contacts formed on a tunnel silicon oxide layer on a surface of a silicon substrate. High temperature processing is unnecessary in fabricating the solar cell. | 11-27-2014 |
20150083215 | FRONT CONTACT SOLAR CELL WITH FORMED EMITTER - A bipolar solar cell includes a backside junction formed by an N-type silicon substrate and a P-type polysilicon emitter formed on the backside of the solar cell. An antireflection layer may be formed on a textured front surface of the silicon substrate. A negative polarity metal contact on the front side of the solar cell makes an electrical connection to the substrate, while a positive polarity metal contact on the backside of the solar cell makes an electrical connection to the polysilicon emitter. An external electrical circuit may be connected to the negative and positive metal contacts to be powered by the solar cell. The positive polarity metal contact may form an infrared reflecting layer with an underlying dielectric layer for increased solar radiation collection. | 03-26-2015 |