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.

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.

A bifacial photovoltaic module with at least one bifacial solar cell is provided. The at least one bifacial solar cell includes a substrate with a front-side and a rear-side. The front-side is the light incident side and the rear-side has rear-side contact structure. The rear-side contact structure includes a plurality of electrically conductive contact fingers, which have a first metal, a plurality of solder pads electrically connected to the contact fingers. The solder pads have a top. The solder pads have a second metal, which is different from the first metal. The rear-side contact structure further includes several cell connectors electrically connected to the solder pads. The top of the solder pads is free from the contact fingers in an area along one direction. The cell connectors are disposed planar on or above this area.

A solar cell structure for wireless charging includes a substrate and at least one thin film solar cell disposed on a surface of the substrate, wherein the thin film solar cell has a winding coil structure. Accordingly, in the thin film solar cell, the electrode which is the winding coil structure may be used as electromagnetic induction coil or millimeter-wave radio wave receiving radiator.

A method including providing a substrate comprising a device layer on which a plurality of device cells are defined; depositing a first dielectric layer on the device layer and metal interconnect such that the deposited interconnect is electrically connected to at least two of the device cells; depositing a second dielectric layer over the interconnect; and exposing at least one contact point on the interconnect through the second dielectric layer. An apparatus including a substrate having defined thereon a device layer including a plurality of device cells; a first dielectric layer disposed directly on the device layer; a plurality of metal interconnects, each of which is electrically connected to at least two of the device cells; and a second dielectric layer disposed over the first dielectric layer and over the interconnects, wherein the second dielectric layer is patterned in a positive or negative planar spring pattern.

A preparation method for a solar cell includes: providing a silicon wafer having a first surface and a second surface opposite to the first surface; forming an ultrathin silicon oxide layer on the first surface of the silicon wafer, and sequentially forming a phosphorus-doped amorphous silicon layer and a silicon oxide mask layer on the ultrathin silicon oxide layer; and annealing the silicon wafer to densify the silicon oxide mask layer and convert the phosphorus-doped amorphous silicon layer into a phosphorus-doped polycrystalline silicon layer.

A welding method for a welding strip of a back-contact solar cell chip includes the following steps: firstly, welding small chip assemblies of a back-contact solar cell to be interconnected to form a small cell string through an interconnected bar; then, punching the small cell string into small cell assemblies separated from each other through a cutting or punching process; subsequently, flexibly welding the small cell assemblies by a bus bar to reach a required length of a finished assembly product; and finally, breaking the bus bar through a post cutting or punching process to form cell assemblies with positive and negative electrodes connected in series or in parallel. The method makes the welding surfaces of the solar cell chips be on the same surface through using the back-contact solar cell chips, so that the interconnected bar of the solar cell chips can be welded rapidly and continuously.

The present disclosure provides a method of reducing the thermomechanical stress in the silicon solar cells induced in the interconnection process. The front and rear metal electrodes of the solar cell are provided in such a way that the outermost bonding point between the front metal electrodes and the front interconnects (ribbons or wires) is aligned to the outermost bonding point between the rear metal electrodes and the rear interconnects. The method is applicable to busbar-based interconnection using stringing/tabbing process and wire-based interconnection such as Multi-Busbar and smart wire connection technology. The method can be applied to both mono-facial and bifacial solar cells. The reduced-area busbar end in the busbar-based interconnection increases the tolerance of misalignment of the outermost bonding points introduced by the manufacturing processes.

A solar cell, and methods of fabricating said solar cell, are disclosed. The solar cell can include a first emitter region over a substrate, the first emitter region having a perimeter around a portion of the substrate. A first conductive contact is electrically coupled to the first emitter region at a location outside of the perimeter of the first emitter region.