A conductive paste is provided which can form electrodes in crystalline silicon solar cells at low cost while ensuring that the electrodes exhibit low contact resistance with respect to both p-type and n-type impurity diffusion layers. The conductive paste for forming a solar cell electrode includes a silver powder, a glass frit, an additive particle and an organic vehicle, the glass frit having a glass transition point of 150 to 440 C., the additive particle including an alloy material containing 20 to 98 mass % aluminum, the conductive paste including the additive particle in an amount of 2 to 30 parts by weight with respect to 100 parts by weight of the silver powder.

Methods of fabricating solar cell emitter regions using self-aligned implant and cap, and the resulting solar cells, are described. In an example, a method of fabricating an emitter region of a solar cell involves forming a silicon layer above a substrate. The method also involves implanting, through a stencil mask, dopant impurity atoms in the silicon layer to form implanted regions of the silicon layer with adjacent non-implanted regions. The method also involves forming, through the stencil mask, a capping layer on and substantially in alignment with the implanted regions of the silicon layer. The method also involves removing the non-implanted regions of the silicon layer, wherein the capping layer protects the implanted regions of the silicon layer during the removing. The method also involves annealing the implanted regions of the silicon layer to form doped polycrystalline silicon emitter regions.

A method for 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 first metal layer on the dielectric region. The method can also include forming a second metal layer on the first metal layer and locally heating a particular region of the second metal layer, where heating includes forming a metal bond between the first and second metal layer and forming a contact between the first metal layer and the solar cell structure. The method can include forming an adhesive layer on the first metal layer and forming a second metal layer on the adhesive layer, where the adhesive layer mechanically couples the second metal layer to the first metal layer and allows for an electrical connection between the second metal layer to the first metal layer.

Embodiments relate to a thin film solar cell backside contact. A planar substrate is provided and an associated backside of the substrate is modified to form one or more pedestals. The modified substrate is layered with multiple layers of material, including a conducting layer, a reflective layer, and a passivation layer. The layered backside substrate is polished to expose portions of the conducting layer at discrete locations on the backside of the substrate. The exposed portions of the conducting layer maintain direct electrical communication between an absorber layer deposited on the layered backside substrate and the conducting layer.

Methods of fabricating solar cell emitter regions using ion implantation, and resulting solar cells, are described. In an example, a back contact solar cell includes a crystalline silicon substrate having a light-receiving surface and a back surface. A first polycrystalline silicon emitter region is disposed above the crystalline silicon substrate. The first polycrystalline silicon emitter region is doped with dopant impurity species of a first conductivity type and further includes ancillary impurity species different from the dopant impurity species of the first conductivity type. A second polycrystalline silicon emitter region is disposed above the crystalline silicon substrate and is adjacent to but separated from the first polycrystalline silicon emitter region. The second polycrystalline silicon emitter region is doped with dopant impurity species of a second, opposite, conductivity type. First and second conductive contact structures are electrically connected to the first and second polycrystalline silicon emitter regions, respectively.

A photovoltaic device and method include a doped germanium-containing substrate, an emitter contact coupled to the substrate on a first side and a back contact coupled to the substrate on a side opposite the first side. The emitter includes at least one doped layer of an opposite conductivity type as that of the substrate and the back contact includes at least one doped layer of the same conductivity type as that of the substrate. The at least one doped layer of the emitter contact or the at least one doped layer of the back contact is in direct contact with the substrate, and the at least one doped layer of the emitter contact or the back contact includes an n-type material having an electron affinity smaller than that of the substrate, or a p-type material having a hole affinity larger than that of the substrate.

A solar cell includes: a semiconductor substrate having a light receiving surface and a back surface; a first semiconductor layer of the first conductivity type on the back surface; a second semiconductor layer of the second conductivity type on the back surface; a first electrode electrically connected to the first semiconductor layer; and an insulating layer for electrically insulating the first semiconductor layer and the second semiconductor layer from each other in a region in which an edge of the first semiconductor layer and an edge of second semiconductor layer overlap. The first electrode includes a first transparent electrode layer and a first collection electrode layer on the first transparent electrode layer. The first transparent electrode layer is separated into a primary electrode layer that is on the first semiconductor layer and a separated electrode layer that is on the second semiconductor layer in the region.

A solar cell can include a substrate and a semiconductor region disposed in or above the substrate. The solar cell can also include a conductive contact disposed on the semiconductor region with the conductive contact including a paste, a first metal, and a first conductive portion that includes a conductive alloy formed from the first metal at an interface of the substrate and the semiconductor region.

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.

The present invention discloses in detail a semiconductor device and a patterning method for the plated electrode thereof. By using the laser ablation method according to the prior art, the semiconductor substrate below the ARC is damaged by direct destructive burning. According to the present invention, an additional protection layer is inserted between the ARC and the semiconductor substrate. Then a laser is used for heating and liquefying the protection layer below the ARC, and thus separating the ARC from the liquefied protection layer underneath and forming pattered openings. Afterwards, by a plating process, nickel and copper can plated.