A photovoltaic device including a single junction solar cell provided by an absorption layer of a type IV semiconductor material having a first conductivity, and an emitter layer of a type III-V semiconductor material having a second conductivity, wherein the type III-V semiconductor material has a thickness that is no greater than 50 nm.

A photovoltaic device and method include forming a plurality of pillar structures in a substrate, forming a first electrode layer on the pillar structures and forming a continuous photovoltaic stack including an N-type layer, a P-type layer and an intrinsic layer on the first electrode. A second electrode layer is deposited over the photovoltaic stack such that gaps or fissures occur in the second electrode layer between the pillar structures. The second electrode layer is wet etched to open up the gaps or fissures and reduce the second electrode layer to form a three-dimensional electrode of substantially uniform thickness over the photovoltaic stack.

A semiconductor structure includes a silicon substrate, a protection layer, an electrical pad, an isolation layer, a redistribution layer, a conductive layer, a passivation layer, and a conductive structure. The silicon substrate has a concave region, a step structure, a tooth structure, a first surface, and a second surface opposite to the first surface. The step structure and the tooth structure surround the concave region. The step structure has a first oblique surface, a third surface, and a second oblique surface facing the concave region and connected in sequence. The protection layer is located on the first surface of the silicon substrate. The electrical pad is located in the protection layer and exposed through the concave region. The isolation layer is located on the first and second oblique surfaces, the second and third surfaces of the step structure, and the tooth structure.

A process is provided for contacting a nanostructured surface. The process may include (a) providing a substrate having a nanostructured material on a surface, (b) passivating the surface on which the nanostructured material is located, (c) screen printing onto the nanostructured surface and (d) firing the screen printing ink at a high temperature. In some embodiments, the nanostructured material compromises silicon. In some embodiments, the nanostructured material includes silicon nanowires. In some embodiments, the nanowires are around 150 nm, 250 nm, or 400 nm in length. In some embodiments, the nanowires have a diameter range between about 30 nm and about 200 nm. In some embodiments, the nanowires are tapered such that the base is larger than the tip. In some embodiments, the nanowires are tapered at an angle of about 1 degree, about 3 degrees, or about 10 degrees. In some embodiments, a high temperature can be approximately 700 C, 750 C, 800 C, or 850 C.

A bifacial solar cell includes a substrate; an emitter portion formed on a first surface of the substrate; a first insulating layer formed on the emitter portion; a plurality of first electrodes contacting the emitter portion through the first insulating layer and extended in a first direction; a plurality of first current collectors extended in a second direction crossing the first direction, wherein the plurality of first current collectors are electrically and physically connected to the plurality of first electrodes; a second insulating layer formed on a second surface of the substrate; a back surface field formed on the second surface of the substrate, and having an impurity concentration that is higher than an impurity concentration of the substrate; a plurality of second electrodes contacting the back surface field through the second insulating layer and extended in the first direction; and a plurality of second current collectors extended in the second direction.

A method for use in forming a photovoltaic device includes forming a doped semiconductor layer on a surface of a semiconductor substrate and forming a metal film on the doped semiconductor layer. A patterned etched resist is formed on the metal film and a dielectric layer is formed on the doped semiconductor layer and the etched resist. A laser having a wavelength absorbable by the patterned etch resist is applied through the dielectric layer to the patterned etch resist to remove the patterned etch resist.

In accordance with embodiments disclosed herein, there are provided methods and systems for implementing damage-and-resist-free laser patterning of dielectric films on textured silicon. For example, in one embodiment, such means include means for depositing a Silicon nitride (SiNx) or SiOx (silicon oxide) layer onto a crystalline silicon (c-Si) substrate by a Plasma Enhanced Chemical Vapor Deposition (PECVD) processing; depositing an amorphous silicon (a-Si) film on top of the SiNx or SiOx layer; patterning the a-Si film to define an etch mask for the SiNx or SiOx layer; removing the SiNx or SiOx layer via a Buffered Oxide Etch (BOE) chemical etch to expose the c-Si surface; removing the a-Si mask with a hydrogen plasma etch in a PECVD tool to prevent current loss from the mask; and plating the exposed c-Si surface with metal contacts. Other related embodiments are disclosed.

Methods of fabricating solar cell emitter regions with differentiated P-type and N-type regions architectures, and resulting solar cells, are described. In an example, a back contact 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 on the back surface of the substrate. A third thin dielectric layer is disposed laterally directly between the first and second polycrystalline silicon emitter regions. A first conductive contact structure is disposed on the first polycrystalline silicon emitter region. A second conductive contact structure is disposed on the second polycrystalline silicon emitter region.

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.

Disclosed is a solar cell. The solar cell includes a semiconductor substrate, conductivity-type regions located in or on the semiconductor substrate, electrodes conductively connected to the conductivity-type regions, and insulating films located on at least one of opposite surfaces of the semiconductor substrate, and including a first film and a second film located on the first film, the second film has a higher carbon content than that of the first film, a refractive index of the second film is equal to or less than a refractive index of the first film, and an extinction coefficient of the second film is equal to or greater than an extinction coefficient of the first film.