Abstract: Methods of fabricating solar cell emitter regions with differentiated P-type and N-type architectures and incorporating dotted diffusion, and resulting solar cells, are described. In an example, a solar cell includes a substrate having a light-receiving surface and a back surface. A first polycrystalline silicon emitter region of a first conductivity type is disposed on a first thin dielectric layer disposed on the back surface of the substrate. A second polycrystalline silicon emitter region of a second, different, conductivity type is disposed on a second thin dielectric layer disposed in a plurality of non-continuous trenches in the back surface of the substrate.

Abstract: Foil trim approaches for the foil-based metallization of solar cells and the resulting solar cells are described. For example, a method involves attaching a metal foil sheet to a metallized surface of an underlying supported wafer to provide a unified pairing of the metal foil sheet and the wafer. Subsequent to attaching the metal foil sheet, a portion of the metal foil sheet is laser scribed from above to form a groove in the metal foil sheet. Subsequent to laser scribing the metal foil sheet, the unified pairing of the metal foil sheet and the wafer is rotated to provide the metal sheet below the wafer. Subsequent to the rotating, the unified pairing of the metal foil sheet and the wafer is placed on a chuck with the metal sheet below the wafer. The metal foil sheet is torn at least along the groove to trim the metal foil sheet.

Abstract: 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.

Abstract: A solar cell can include a substrate and a semiconductor region disposed in or above the substrate. The solar cell can also include a contact finger coupled to the semiconductor region via a plurality of weld regions with at least one of the weld regions being a partial weld.

Abstract: A system and method of patterning dopants of opposite polarity to form a solar cell is described. Two dopant films are deposited on a substrate. A laser is used to pattern the N-type dopant, by mixing the two dopant films into a single film with an exposure to the laser and/or drive the N-type dopant into the substrate to form an N-type emitter. A thermal process drives the P-type dopant from the P-type dopant film to form P-type emitters and further drives the N-type dopant from the single film to either form or further drive the N-type emitter.

Abstract: Solar cells having a plurality of sub-cells coupled by metallization structures, and singulation approaches to forming solar cells having a plurality of sub-cells coupled by metallization structures, are described. In an example, a solar cell, includes a plurality of sub-cells, each of the sub-cells having a singulated and physically separated semiconductor substrate portion. Adjacent ones of the singulated and physically separated semiconductor substrate portions have a groove there between. The solar cell also includes a monolithic metallization structure. A portion of the monolithic metallization structure couples ones of the plurality of sub-cells. The groove between adjacent ones of the singulated and physically separated semiconductor substrate portions exposes a portion of the monolithic metallization structure.

Abstract: One embodiment relates to a method of fabricating a solar cell. A silicon lamina is cleaved from the silicon substrate. The backside of the silicon lamina includes the P-type and N-type doped regions. A metal foil is attached to the backside of the silicon lamina. The metal foil may be used advantageously as a built-in carrier for handling the silicon lamina during processing of a frontside of the silicon lamina. Another embodiment relates to a solar cell that includes a silicon lamina having P-type and N-type doped regions on the backside. A metal foil is adhered to the backside of the lamina, and there are contacts formed between the metal foil and the doped regions. Other embodiments, aspects and features are also disclosed.

Abstract: Methods of fabricating a solar cell including metallization techniques and resulting solar cells, are described. In an example, a semiconductor region can be formed in or above a substrate. A first metal layer can be formed over the semiconductor region. A laser can be applied over a first region of the metal layer to form a first metal weld between the metal layer and the semiconductor region, where applying a laser over the first region comprises applying the laser at a first scanning speed. Subsequent to applying the laser over the first region, the laser can be applied over a second region of the metal layer where applying the laser over the second region includes applying a laser at a second scanning speed. Subsequent to applying the laser over the second region, the laser can be applied over a third region of the metal layer to form a second metal weld, where applying the laser over the third region comprises applying the laser at a third scanning speed.

Abstract: A solar cell can include a conductive foil having a first portion with a first yield strength coupled to a semiconductor region of the solar cell. The solar cell can be interconnected with another solar cell via an interconnect structure that includes a second portion of the conductive foil, with the interconnect structure having a second yield strength greater than the first yield strength.

Abstract: Methods of fabricating a solar cell including metallization techniques and resulting solar cells, are described. In an example, a semiconductor region can be formed in or above a substrate. A first metal layer can be formed over the semiconductor region. A laser can be applied over a first region of the metal layer to form a first metal weld between the metal layer and the semiconductor region, where applying a laser over the first region comprises applying the laser at a first scanning speed. Subsequent to applying the laser over the first region, the laser can be applied over a second region of the metal layer where applying the laser over the second region includes applying a laser at a second scanning speed. Subsequent to applying the laser over the second region, the laser can be applied over a third region of the metal layer to form a second metal weld, where applying the laser over the third region comprises applying the laser at a third scanning speed.

Abstract: Methods of fabricating solar cell emitter regions with differentiated P-type and N-type architectures and incorporating dotted diffusion, and resulting solar cells, are described. In an example, a solar cell includes a substrate having a light-receiving surface and a back surface. A first polycrystalline silicon emitter region of a first conductivity type is disposed on a first thin dielectric layer disposed on the back surface of the substrate. A second polycrystalline silicon emitter region of a second, different, conductivity type is disposed on a second thin dielectric layer disposed in a plurality of non-continuous trenches in the back surface of the substrate.

Abstract: Foil trim approaches for the foil-based metallization of solar cells and the resulting solar cells are described. For example, a method involves attaching a metal foil sheet to a metallized surface of an underlying supported wafer to provide a unified pairing of the metal foil sheet and the wafer. Subsequent to attaching the metal foil sheet, a portion of the metal foil sheet is laser scribed from above to form a groove in the metal foil sheet. Subsequent to laser scribing the metal foil sheet, the unified pairing of the metal foil sheet and the wafer is rotated to provide the metal sheet below the wafer. Subsequent to the rotating, the unified pairing of the metal foil sheet and the wafer is placed on a chuck with the metal sheet below the wafer. The metal foil sheet is torn at least along the groove to trim the metal foil sheet.

Abstract: 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.

Abstract: One embodiment relates to a method of fabricating a solar cell. A silicon lamina is cleaved from the silicon substrate. The backside of the silicon lamina includes the P-type and N-type doped regions. A metal foil is attached to the backside of the silicon lamina. The metal foil may be used advantageously as a built-in carrier for handling the silicon lamina during processing of a frontside of the silicon lamina. Another embodiment relates to a solar cell that includes a silicon lamina having P-type and N-type doped regions on the backside. A metal foil is adhered to the backside of the lamina, and there are contacts formed between the metal foil and the doped regions. Other embodiments, aspects and features are also disclosed.

Abstract: Thermocompression bonding approaches for foil-based metallization of non-metal surfaces of solar cells, and the resulting solar cells, are described. For example, a solar cell includes a substrate and a plurality of alternating N-type and P-type semiconductor regions disposed in or above the substrate. A plurality of conductive contact structures is electrically connected to the plurality of alternating N-type and P-type semiconductor regions. Each conductive contact structure includes a metal foil portion disposed in direct contact with a corresponding one of the alternating N-type and P-type semiconductor regions.

Abstract: A photovoltaic laminate is disclosed. Embodiments include placing a first encapsulant on a substantially transparent layer that includes a front side of a photovoltaic laminate. Embodiments also include placing a first solar cell on the first encapsulant. Embodiments include placing a metal foil on the first solar cell, where the metal foil uniformly contacts a back side of the first solar cell. Embodiments include forming a metal bond that couples the metal foil to the first solar cell. In some embodiments, forming the metal bond includes forming a metal contact region using a laser source, wherein the formed metal contact region electrically couples the metal foil to the first solar cell. Embodiments can also include placing a backing material on the metal foil. Embodiments can further include forming a back layer on the backing material layer and curing the substantially transparent layer, first encapsulant, first solar cell, metal foil, backing material and back layer to form a photovoltaic laminate.

Abstract: A method of fabricating a solar cell is disclosed. The method can include forming a dielectric region on a surface of a solar cell structure and forming a metal layer on the dielectric layer. The method can also include configuring a laser beam with a particular shape and directing the laser beam with the particular shape on the metal layer, where the particular shape allows a contact to be formed between the metal layer and the solar cell structure.

Abstract: Methods of fabricating solar cells using a metal-containing thermal and diffusion barrier layer in foil-based metallization approaches, and the resulting solar cells, are described. For example, a method of fabricating a solar cell includes forming a plurality of semiconductor regions in or above a substrate. The method also includes forming a metal-containing thermal and diffusion barrier layer above the plurality of semiconductor regions. The method also includes forming a metal seed layer on the metal-containing thermal and diffusion barrier layer. The method also includes forming a metal conductor layer on the metal seed layer. The method also includes laser welding the metal conductor layer to the metal seed layer. The metal-containing thermal and diffusion barrier layer protects the plurality of semiconductor regions during the laser welding.

Abstract: Approaches for the foil-based metallization of solar cells and the resulting solar cells are described. In an example, a solar cell includes a substrate. A plurality of alternating N-type and P-type semiconductor regions is disposed in or above the substrate. A conductive contact structure is disposed above the plurality of alternating N-type and P-type semiconductor regions. The conductive contact structure includes a plurality of metal seed material regions providing a metal seed material region disposed on each of the alternating N-type and P-type semiconductor regions. A metal foil is disposed on the plurality of metal seed material regions, the metal foil having anodized portions isolating metal regions of the metal foil corresponding to the alternating N-type and P-type semiconductor regions.

Abstract: Solar cells having a plurality of sub-cells coupled by metallization structures having a metal bridge, and singulation approaches to forming solar cells having a plurality of sub-cells coupled by metallization structures, are described. In an example, the metal bridge can provide structural support and provide for an electrical connection between a first contact pad and a first busbar. Adjacent ones of the singulated and physically separated semiconductor substrate portions have a groove there between and where the metal bridge can be perpendicular to the groove. The solar cell can include a first contact pad adjacent to a second contact pad.