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.

Approaches for foil-based metallization of solar cells and the resulting solar cells are described. For example, a method of fabricating a solar cell involves locating a metal foil above a plurality of alternating N-type and P-type semiconductor regions disposed in or above a substrate. The method also involves laser welding the metal foil to the alternating N-type and P-type semiconductor regions. The method also involves patterning the metal foil by laser ablating through at least a portion of the metal foil at regions in alignment with locations between the alternating N-type and P-type semiconductor regions. The laser welding and the patterning are performed at the same time.

A solar cell assembly includes a plurality of solar cells and an inter-cell region provided between adjacent ones of the solar cells included in the plurality of solar cells. Each of the solar cells and the inter-cell region includes: a semiconductor substrate having a first conductivity type and having a first main surface and a second main surface that face away from each other; a first amorphous semiconductor layer having a second conductivity type and being provided on a first main surface side of the semiconductor substrate; an insulating layer provided on part of the first amorphous semiconductor layer; and a first transparent conductive film provided on the first amorphous semiconductor layer so as to cover the insulating layer. In a plan view of the solar cell assembly, the insulating layer is provided along the inter-cell region and partially overlapping the inter-cell region.

An APD includes a photoconverter and at least one avalanche amplifier of the photocurrent, the amplifier having two layers—a contact layer and a multiplication layer, wherein the multiplication layer is formed on top of the entire conductive wafer, while the contact layer of at least one avalanche amplifier is formed on top of a certain area of the multiplication layer. Meanwhile, outside the contact layer, the multiplication layer functions as a photoconverter. This makes it possible for photocarriers to get into the avalanche amplifier effectively and unimpeded. In order to mitigate the influence of parasite near-surface charge carriers on the avalanche amplifier, its multiplication region is deepened in relation to the upper surface of the photoconverter region. The proposed APD embodiment with less dark current seeping from peripheral areas of the instrument provides higher threshold sensitivity that allows it be on par with state of the art.

Method for manufacturing avalanche photodetector, including forming multiplication layer on wafer; etching closed groove on surface of the multiplication layer, so that depth of the closed groove is greater than or equal to thickness of the multiplication layer, but less than total thickness of the wafer and multiplication layer combined; filling the groove with highly-doped polycrystalline silicon of same conductivity type as multiplication layer; forming, on upper surface of multiplication layer, inside groove, avalanche amplifier as mesa structure, by forming contact layer on multiplication layer, while simultaneously forming photoconverter outside contact layer, and etching away portion of multiplication layer in the photoconverter to depth less than thickness of the multiplication layer; forming dielectric layer on multiplication layer where etching took place, its thickness equal to the depth of multiplication layer that was etched away; forming first electrode of transparent material on surfaces of contact and dielectric layers; forming second electrode.

A solar cell, and methods of fabricating said solar cell, are disclosed. The solar cell can include a substrate having a light-receiving surface and a back surface. The solar cell can include a first semiconductor region of a first conductivity type disposed on a first dielectric layer, wherein the first dielectric layer is disposed on the substrate. The solar cell can also include a second semiconductor region of a second, different, conductivity type disposed on a second dielectric layer, where a portion of the second thin dielectric layer is disposed between the first and second semiconductor regions. The solar cell can include a third dielectric layer disposed on the second semiconductor region. The solar cell can include a first conductive contact disposed over the first semiconductor region but not the third dielectric layer. The solar cell can include a second conductive contact disposed over the second semiconductor region, where the second conductive contact is disposed over the third dielectric layer and second semiconductor region. In an embodiment, the third dielectric layer can be a dopant layer.

A method for treating a stack, the stack including a substrate of crystalline silicon, a first passivation layer of hydrogenated amorphous silicon, disposed on a first face of the substrate; and a first layer of n-doped amorphous silicon, disposed on the first passivation layer; the method including a step of exposing the stack to electromagnetic radiation emitted by an electromagnetic radiation source, the first face of the substrate pointing to the electromagnetic radiation source, the electromagnetic radiation having at least one first wavelength of between 300 nm and 550 nm and at least one second wavelength of between 550 nm and 1100 nm.

Method and structural embodiments are described which provide an integrated structure using polysilicon material having different optical properties in different regions of the structure.

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.

The present invention is directed to a method as well as to a machine for producing a starting material for a silicon solar cell with passivated contacts.