Photovoltaic cells, methods for fabricating surface mount multijunction photovoltaic cells, methods for assembling solar panels, and solar panels comprising photovoltaic cells are disclosed. The surface mount multijunction photovoltaic cells include through-wafer-vias for interconnecting the front surface epitaxial layer to a contact pad on the back surface. The through-wafer-vias are formed using a wet etch process that removes semiconductor materials non-selectively without major differences in etch rates between heteroepitaxial III-V semiconductor layers.

Photovoltaic devices are formed by laser drilling vias through silicon substrates and, following surface preparation of the via sidewalls, plating a continuous, electrically conductive layer on the via sidewalls to electrically connect the emitter side of the cell with the back side of the cell. The electrically conductive layer can be formed on portions of a base emitter within the vias and on the back side of the substrate. Alternatively, the electrically conductive layer can be formed on a passivation layer on the via sidewalls and back side of the cell.

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.

This disclosure relates to semiconductor devices and methods for fabricating semiconductor devices. Particularly, the disclosure relates to back-contact-only multijunction solar cells and the process flows for making such solar cells, including a wet etch process that removes semiconductor materials non-selectively without major differences in etch rates between heteroepitaxial III-V semiconductor layers.

Photovoltaic devices are formed by laser drilling vias through silicon substrates and, following surface preparation of the via sidewalls, plating a continuous, electrically conductive layer on the via sidewalls to electrically connect the emitter side of the cell with the back side of the cell. The electrically conductive layer can be formed on portions of a base emitter within the vias and on the back side of the substrate. Alternatively, the electrically conductive layer can be formed on a passivation layer on the via sidewalls and back side of the cell.

A photovoltaic module comprises a back substrate having a plurality of conductive interconnects on top thereof. A conductive interconnect includes a first contact region and a second contact region. The photovoltaic module further comprises a plurality of photovoltaic cells comprising front electrodes disposed on a front surface of a photovoltaic layer on top of back electrodes on top of a support substrate. A plurality of back vias extending through the support substrate of a first cell form an electrical contact between the back electrodes and the second contact region, and a plurality of front vias extending through the support substrate, the back electrodes and the photovoltaic layer of a second cell form an electrical contact between the front electrodes and the first contact region, and is insulated from an electrical contact with the back electrodes and a P side of the photovoltaic layer.

Back side connection layer for a photo-voltaic module with a plurality of PV-cells (1, 2). The PV-cells (1, 2) are of a type having a plurality of back side contacts (11, 12). A by-pass diode connection path (6) is formed in the back side connection layer (3) along an edge direction of two adjacent cells (1, 2) with a straight or meandering pattern around outer contacts (4, 5) of the plurality of back side contacts (11, 12) of the two adjacent cells (1, 2).

A solar cell and a solar cell module including a plurality of solar cells are discussed. The solar cell according to an embodiment includes a substrate of a first conductive type, an emitter layer of a second conductive type opposite the first conductive type disposed on the substrate, a plurality of first electrodes electrically connected to the emitter layer, a second electrode electrically connected to the substrate, a first current collector electrically connected to the plurality of first electrodes, and a second current collector electrically connected to the second electrode. The second current collector includes a plurality of second electrode current collectors electrically connected to the second electrode, and a current collector connector for connecting the plurality of second electrode current collectors to one another.

Photovoltaic cells, methods for fabricating surface mount multijunction photovoltaic cells, methods for assembling solar panels, and solar panels comprising photovoltaic cells are disclosed. The surface mount multijunction photovoltaic cells include through-wafer-vias for interconnecting the front surface epitaxial layer to a contact pad on the back surface. The through-wafer-vias are formed using a wet etch process that removes semiconductor materials non-selectively without major differences in etch rates between heteroepitaxial III-V semiconductor layers.

A solar module and a method for fabricating a solar module comprising a plurality of rear contact solar cells are described. Rear contact solar cells (1) are provided with a large size of e.g. 156156 mm.sup.2. Soldering pad arrangements (13, 15) applied on emitter contacts (5) and base contacts (7) are provided with one or more soldering pads (9, 11) arranged linearly. The soldering pad arrangements (13, 15) are arranged asymmetrically with respect to a longitudinal axis (17). Each solar cell (1) is then separated into first and second cell portions (19, 21) along a line (23) perpendicular to the longitudinal axis (17). Due to such cell separation and the asymmetrical design of the soldering pad arrangements (13, 15), the first and second cell portions (19, 21) may then be arranged alternately along a line with each second cell portion (21) arranged in a 180-orientation with respect to the first cell portions (19) and such that emitter soldering pad arrangements (13) of a first cell portion (19) are aligned with base soldering pad arrangements (15) of neighboring second cell portions (21), and vice versa. Simple linear ribbon-type connector strips (25) may be used for interconnecting the cell portions (19, 21) by soldering onto the underlying aligned emitter and base soldering pad arrangements (13, 15). The interconnection approach enables using standard ribbon-type connector strips (25) while reducing any bow as well as reducing series resistance losses.