A bipolar solar cell includes a backside junction formed by an N-type silicon substrate and a P-type polysilicon emitter formed on the backside of the solar cell. An antireflection layer may be formed on a textured front surface of the silicon substrate. A negative polarity metal contact on the front side of the solar cell makes an electrical connection to the substrate, while a positive polarity metal contact on the backside of the solar cell makes an electrical connection to the polysilicon emitter. An external electrical circuit may be connected to the negative and positive metal contacts to be powered by the solar cell. The positive polarity metal contact may form an infrared reflecting layer with an underlying dielectric layer for increased solar radiation collection.

A layered structure is provided for a solar cell having tunnel-oxide-passivated contacts. The layered structure includes at least one tunnel oxide layer and a c-SiCx layer, wherein x0.5. A solar cell having tunnel-oxide-passivated contacts is also provided. The solar cell includes at least one crystalline n-doped or p-doped silicon layer, and the layered structure having the tunnel-oxide passivated contacts. A method for producing a layered structure for a solar cell having tunnel-oxide-passivated contacts is additionally provided. The method includes providing a substrate layer comprising a silicon layer, depositing a tunnel oxide layer on the substrate layer, and depositing a u c-SiCx:H layer, which is n-doped or p-doped, on the tunnel oxide layer.

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.

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.

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.

One embodiment of the invention can provide a system for fabricating a photovoltaic structure. During fabrication, the system can form a sacrificial layer on a first side of a Si substrate; load the Si substrate into a chemical vapor deposition tool, with the sacrificial layer in contact with a wafer carrier; and form a first doped Si layer on a second side of the Si substrate. The system subsequently can remove the sacrificial layer; load the Si substrate into a chemical vapor deposition tool, with the first doped Si layer facing a wafer carrier; and form a second doped Si layer on the first side of the Si substrate.

Die-cutting approaches for foil-based metallization of solar cells, and the resulting solar cells are disclosed herein. Die-cutting approaches for foil-based metallization of solar cells include forming a plurality of semiconductor regions in or above a substrate and forming a patterned damage buffer in alignment with locations between the plurality of semiconductor regions. Additionally, a metal layer comprising a metal seed layer and/or metal foil is formed over the patterned damage buffer. The metal layer is cut by a cutting die at locations between the plurality of semiconductor regions by applying a mechanical force to the cutting die.

A laser processing system can be utilized to produce high-performance interdigitated back contact (IBC) solar cells. The laser processing system can be utilized to ablate, transfer material, and/or laser-dope or laser fire contacts. Laser ablation can be utilized to remove and pattern openings in a passivated or emitter layer. Laser transferring may then be utilized to transfer dopant and/or contact materials to the patterned openings, thereby forming an interdigitated finger pattern. The laser processing system may also be utilized to plate a conductive material on top of the transferred dopant or contact materials.

A solar cell includes polysilicon P-type and N-type doped regions on a backside of a substrate, such as a silicon wafer. A trench structure separates the P-type doped region from the N-type doped region. Each of the P-type and N-type doped regions may be formed over a thin dielectric layer. The trench structure may include a textured surface for increased solar radiation collection. Among other advantages, the resulting structure increases efficiency by providing isolation between adjacent P-type and N-type doped regions, thereby preventing recombination in a space charge region where the doped regions would have touched.

Solar cells of varying composition are disclosed, generally including a central substrate, conductive layer(s), antireflection layers(s), passivation layer(s) and/or electrode(s). Multifunctional layers provide combined functions of passivation, transparency, sufficient conductivity for vertical carrier flow, the junction, and/or varying degrees of anti-reflectivity. Improved manufacturing methods including single-side CVD deposition processes and thermal treatment for layer formation and/or conversion are also disclosed.