A method is provided for fabricating a thin-film semiconductor substrate by forming a porous semiconductor layer conformally on a reusable semiconductor template and then forming a thin-film semiconductor substrate conformally on the porous semiconductor layer. An inner trench having a depth less than the thickness of the thin-film semiconductor substrate is formed on the thin-film semiconductor substrate. An outer trench providing access to the porous semiconductor layer is formed on the thin-film semiconductor substrate and is positioned between the inner trench and the edge of the thin-film semiconductor substrate. The thin-film semiconductor substrate is then released from the reusable semiconductor template.

A method for preparing silicon substrate having average crystallite size greater than or equal to 20 μm, including at least the steps of: (i) providing polycrystalline silicon substrate of which average grain size is less than or equal to 10 μm; (ii) subjecting substrate to overall homogeneous plastic deformation, at temperature of at least 1000° C.; (iii) subjecting substrate to localized plastic deformation in plurality of areas of substrate, called external stress areas, spacing between two consecutive areas being at least 20 μm, local deformation of substrate being strictly greater than overall deformation carried out in step (ii); step (iii) being able to be carried out subsequent to or simultaneous to step (ii); and (iv) subjecting substrate obtained in step (iii) to recrystallization heat treatment in solid phase, at temperature strictly greater than temperature used in step (ii), in order to obtain desired substrate.

The present invention relates to a method for producing highly doped polycrystalline semiconductor layers on a semiconductor substrate, wherein a first Si precursor composition comprising at least one first dopant is applied to one or more regions of the surface of the semiconductor substrate; optionally a second Si precursor composition comprising at least one second dopant is applied to one or more other regions of the surface of the semiconductor substrate, where the first dopant is an n-type dopant and the second dopant is a p-type dopant or vice versa; and the coated regions of the surface of the semiconductor substrate are each converted, so as to form polycrystalline silicon from the Si precursor. The invention further relates to the semiconductor obtainable by the method and to the use thereof, especially in the production of solar cells.

Solar cells having emitter regions composed of wide bandgap semiconductor material are described. In an example, a method includes forming, in a process tool having a controlled atmosphere, a thin dielectric layer on a surface of a semiconductor substrate of the solar cell. The semiconductor substrate has a bandgap. Without removing the semiconductor substrate from the controlled atmosphere of the process tool, a semiconductor layer is formed on the thin dielectric layer. The semiconductor layer has a bandgap at least approximately 0.2 electron Volts (eV) above the bandgap of the semiconductor substrate.

Photovoltaic structures are provided with field-effect inversion/accumulation layers as emitter layers induced by work-function differences between gate conductor layers and substrates thereof. Localized contact regions are in electrical communication with the gate conductors of such structures for repelling minority carriers. Such localized contact regions may include doped crystalline or polycrystalline silicon regions between the gate conductor and silicon absorption layers. Fabrication of the structures can be conducted without alignment between metal contacts and the localized contact regions or high temperature processing.

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.

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.

Disclosed herein are approaches to fabricating solar cells, solar cell strings and solar modules using roll-to-roll foil-based metallization approaches. Methods disclosed herein can comprise the steps of providing at least one solar cell wafer on a first roll unit and conveying a metal foil to the first roll unit. The metal foil can be coupled to the solar cell wafer on the first roll unit to produce a unified pairing of the metal foil and the solar cell wafer. We disclose solar energy collection devices and manufacturing methods thereof enabling reduction of manufacturing costs due to simplification of the manufacturing process by a high throughput foil metallization process.

The present invention relates to a method for manufacturing a photovoltaic device comprising: —forming a porous first conducting layer on one side of a porous insulating substrate, —coating the first conducting layer with a layer of grains of a doped semiconducting material to form a structure, —performing a first heat treatment of the structure to bond the grains to the first conducting layer, —forming electrically insulating layers on surfaces of the first conducting layer, —forming a second conducting layer on an opposite side of the porous insulating substrate, —applying a charge conducting material onto the surfaces of the grains, inside pores of the first conducting layer, and inside pores of the insulating substrate, and—electrically connecting the charge conducting material to the second conducting layer.

The present invention relates to an alkaline etching agent for treating a surface of a semiconductor substrate for solar cells, containing at least one hydroxystyrene polymer represented by the general formula (1) and an alkaline agent. According to the present invention, some effects are exhibited that the texture formation is made possible to a semiconductor substrate for solar cells at relatively lower temperatures with a shorter amount of time, thereby having excellent productivity.