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: Approaches for foil-based metallization of solar cells and the resulting solar cells are described. For example, a method of fabricating a solar cell involves locating a metal foil above a plurality of alternating N-type and P-type semiconductor regions disposed in or above a substrate. The method also involves laser welding the metal foil to the alternating N-type and P-type semiconductor regions. The method also involves patterning the metal foil by laser ablating through at least a portion of the metal foil at regions in alignment with locations between the alternating N-type and P-type semiconductor regions. The laser welding and the patterning are performed at the same time.

Abstract: Methods of fabricating solar cell emitter regions with differentiated P-type and N-type region architectures, and resulting solar cells, are described. In an example a solar cell includes a first emitter region of a first conductivity type disposed on a first dielectric region, the first dielectric region disposed on a surface of a substrate. A second dielectric region is disposed laterally adjacent to the first and second emitter region. The second emitter region of a second, different, conductivity type is disposed on a third dielectric region, the third dielectric region disposed on the surface of the substrate, over the second dielectric region, and partially over the first emitter region. A first metal foil is disposed over the first emitter region. A second metal foil is disposed over the second emitter region.

Abstract: 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.

Abstract: 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.

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: 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: 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 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: Approaches for fabricating foil-based metallization of solar cells based on a leave-in etch mask, and the resulting solar cells, are described. In an example, a solar cell includes a substrate having a back surface and an opposing light-receiving surface. A plurality of alternating N-type and P-type semiconductor regions is disposed in or above the back surface of the substrate. A conductive contact structure is disposed on the plurality of alternating N-type and P-type semiconductor regions. The conductive contact structure includes metal foil portions in alignment with corresponding ones of the alternating N-type and P-type semiconductor regions. A patterned wet etchant-resistant polymer layer is disposed on the conductive contact structure. Portions of the patterned wet etchant-resistant polymer layer are disposed on and in alignment with the metal foil portions.

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: 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: 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: A solar cell can include a built-in bypass diode. In one embodiment, the solar cell can include an active region disposed in or above a first portion of a substrate and a bypass diode disposed in or above a second portion of the substrate. The first and second portions of the substrate can be physically separated with a groove. A metallization structure can couple the active region to the bypass diode.

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: 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: Approaches for the metallization of solar cells and the resulting solar cells are described. In an example, a method of fabricating a solar cell involves forming a plurality of alternating N-type and P-type regions in or above a substrate. The method also involves forming a metal seed layer on the plurality of alternating N-type and P-type regions. The method also involves patterning at least a portion of the metal seed layer at regions in alignment with locations between the alternating N-type and P-type regions. The method also involves, subsequent to the patterning, etching to form trenches at the locations between the alternating N-type and P-type regions, isolating the alternating N-type and P-type regions from one another.

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 built-in bypass diode. In one embodiment, the solar cell can include an active region disposed in or above a first portion of a substrate and a bypass diode disposed in or above a second portion of the substrate. The first and second portions of the substrate can be physically separated with a groove. A metallization structure can couple the active region to the bypass diode.

Abstract: Approaches for fabricating one-dimensional metallization for solar cells, and the resulting solar cells, are described. In an example, a solar cell includes a substrate having a back surface and an opposing light-receiving surface. A plurality of alternating N-type and P-type semiconductor regions is disposed in or above the back surface of the substrate and parallel along a first direction to form a one-dimensional layout of emitter regions for the solar cell. A conductive contact structure is disposed on the plurality of alternating N-type and P-type semiconductor regions. The conductive contact structure includes a plurality of metal lines corresponding to the plurality of alternating N-type and P-type semiconductor regions. The plurality of metal lines is parallel along the first direction to form a one-dimensional layout of a metallization layer for the solar cell.