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: Approaches for fabricating spot-welded and adhesive bonded interconnects 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. A conductive contact structure is disposed on the plurality of alternating N-type and P-type semiconductor regions. An interconnect structure is electrically connected to the conductive contact structure. The interconnect structure includes a plurality of protrusions in contact with the conductive contact structure. Each of the plurality of protrusions is spot-welded to the conductive contact structure and is surrounded by an adhesive material.

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: 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 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: 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: 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: An adhesive may be applied to a surface of a reusable carrier. Metal foil may be attached to the adhesive to couple the metal foil to the surface of the reusable carrier. The metal foil may be patterned without damaging the reusable carrier. A semiconductor structure (e.g., a solar cell) may be attached to the patterned metal foil. The reusable carrier may then be removed. In some embodiments, the semiconductor structure may be encapsulated using an encapsulant, with the adhesive being compatible with the encapsulant.

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: 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: Approaches for the foil-based metallization of solar cells and the resulting solar cells are described. A method involves patterning a first surface of a metal foil to provide a plurality of alternating grooves and ridges in the metal foil. Non-conductive material regions are formed in the grooves in the metal foil. The metal foil is located above a plurality of alternating N-type and P-type semiconductor regions disposed in or above a substrate to provide the non-conductive material regions in alignment with locations between the alternating N-type and P-type semiconductor regions and to provide the ridges in alignment with the alternating N-type and P-type semiconductor regions. The ridges of the metal foil are adhered to the alternating N-type and P-type semiconductor regions. The metal foil is patterned through the metal foil from a second surface of the metal foil at regions in alignment with the non-conductive material regions.

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: 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: 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.

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: 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.

Abstract: An adhesive may be applied to a surface of a reusable carrier. Metal foil may be attached to the adhesive to couple the metal foil to the surface of the reusable carrier. The metal foil may be patterned without damaging the reusable carrier. A semiconductor structure (e.g., a solar cell) may be attached to the patterned metal foil. The reusable carrier may then be removed. In some embodiments, the semiconductor structure may be encapsulated using an encapsulant, with the adhesive being compatible with the encapsulant.

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.