Abstract: Laser foil trim approaches for foil-based metallization of solar cells, and the resulting solar cells, are described. For example, a method of fabricating a solar cell includes attaching a metal foil sheet to a surface of a wafer to provide a unified pairing of the metal foil sheet and the wafer, wherein the wafer has a perimeter and the metal foil sheet has a portion overhanging the perimeter. The method also includes laser scribing the metal foil sheet along the perimeter of the wafer using a laser beam that overlaps the metal foil sheet outside of the perimeter of the wafer and at the same time overlaps a portion of the unified pairing of the metal foil sheet and the wafer inside the perimeter of the wafer to remove the portion of the metal foil sheet overhanging the perimeter and to provide a metal foil piece coupled to the surface of the wafer.

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: 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 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 structure includes a semiconductor region disposed in or above a substrate. A damage buffer can be disposed above the semiconductor region. First and second conductive layers can be bonded together at a location above the damage buffer.

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: 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: 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 foil-based metallization of solar cells are described. For example, a method of fabricating a solar cell involves placing a metal foil over a metalized surface of a wafer of the solar cell. The method further involves placing a protection layer over the metal foil. The method further involves locating the metal foil with the metalized surface of the wafer. The protection layer preserves an optically consistent surface of the metal foil during the locating. The method also involves, subsequent to the locating, electrically contacting the metal foil to the metalized surface of the wafer.

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: A solar cell can include a semiconductor region disposed in or above a substrate. The solar cell can also include a contact finger formed over the semiconductor region, where a first weld region couples the contact finger to the semiconductor region. The contact finger can include a first relief structure.

Abstract: A method and apparatus for single-sided etching is disclosed. The etcher includes a vacuum chamber; a perforated belt positioned against the vacuum chamber; and an etch chamber positioned on an opposing side of the perforated belt relative to the vacuum chamber. The etch chamber has an opening through which an etchant is released. The vacuum chamber is configured to create a pressure differential which protects the back side of the wafer from the etchant. In use, a back side of a wafer is disposed against the perforated belt. The front side of the wafer is exposed to the released etchant. The pressure differential secures the back side of the wafer to the belt and/or extracts through a perforation of the belt etchant not deposited on the front side of the wafer.