A solar cell apparatus according to the embodiment includes a support substrate including a plurality of patterns; a back electrode layer on the support substrate; a light absorbing layer on the back electrode layer; a buffer layer on the light absorbing layer; and a front electrode layer on the buffer layer, wherein the patterns are formed in an undercut structure including a first inner side surface, a second inner side surface and a bottom surface.

A method and apparatus for forming a crystalline cadmium stannate layer of a photovoltaic device by heating an amorphous layer in the presence of hydrogen gas.

A compositional range of high strain point and/or intermediate expansion coefficient alkali metal free aluminosilicate and boroaluminosilicate glasses are described herein. The glasses can be used as substrates or superstrates for photovoltaic devices, for example, thin film photovoltaic devices such as CdTe or CIGS photovoltaic devices or crystalline silicon wafer devices. These glasses can be characterized as having strain points 600 C., thermal expansion coefficient of from 35 to 5010.sup.7/ C.

A method is provided for fabricating a thin-film semiconductor device. The method includes providing a plurality of raw semiconductor materials. The raw semiconductor materials undergo a pre-reacting process to form a homogeneous compound semiconductor material. This pre-reaction typically includes processing above the liquidus temperature of the compound semiconductor. The compound semiconductor material is reduced to a particulate form and deposited onto a substrate to form a thin-film having a composition and atomic structure substantially the same as a composition and atomic structure of the compound semiconductor material.

Sodium-containing aluminosilicate and boroaluminosilicate glasses are described herein. The glasses can be used as substrates for photovoltaic devices, for example, thin film photovoltaic devices such as CIGS photovoltaic devices. These glasses can be characterized as having strain points 540 C., thermal expansion coefficient of from 6.5 to 9.5 ppm/ C., as well as liquidus viscosities in excess of 50,000 poise. As such they are ideally suited for being formed into sheet by the fusion process.

The present invention concerns a method for the manufacture of the first layer of a back contact layer for thin-layer solar cells in superstrate configuration. In the prior art, this layer is deposited as a compound, for example as a layer of Sb.sub.2Te.sub.3. In accordance with the invention, however, a tellurium-rich surface layer of the cadmium telluride layer is produced, on which a first material is deposited which is capable of forming an electrically conductive second material with tellurium and of producing the second material by reaction of the first material and tellurium in the surface layer. The second material forms the first layer of the back contact layer.

A method for manufacturing a solar cell includes the following steps: a step in which a first electrode layer is formed on top of a substrate; a step in which a selenium-containing p-type CZTS light-absorbing layer is formed on top of the first electrode layer; a step in which the surface of the CZTS light-absorbing layer is brought into contact with an aqueous solution containing an organic sulfur compound, increasing the concentration of sulfur on the surface of the CZTS light-absorbing layer, and an n-type buffer layer is formed on top of CZTS light-absorbing layer; and a step in which a second electrode layer is formed on top of said buffer layer.

A method for forming a back contact on an absorber layer in a photovoltaic device includes forming a two dimensional material on a first substrate. An absorber layer including CuZnSnS(Se) (CZTSSe) is grown over the first substrate on the two dimensional material. A buffer layer is grown on the absorber layer on a side opposite the two dimensional material. The absorber layer is exfoliated from the two dimensional material to remove the first substrate from a backside of the absorber layer opposite the buffer layer. A back contact is deposited on the absorber layer.

Described herein is a method of using the buffer layer of a transparent conductive substrate as a dopant source for the n-type window layer of a photovoltaic device. The dopant source of the buffer layer distributes to the window layer of the photovoltaic device during semiconductor processing. Described herein are also methods of manufacturing embodiments of the substrate structure and photovoltaic device. Disclosed embodiments also describe a photovoltaic module and a photovoltaic structure with a plurality of photovoltaic devices having an embodiment of the substrate structure.

A method for forming a back contact on an absorber layer in a photovoltaic device includes forming a two dimensional material on a first substrate. An absorber layer including CuZnSnS(Se) (CZTSSe) is grown over the first substrate on the two dimensional material. A buffer layer is grown on the absorber layer on a side opposite the two dimensional material. The absorber layer is exfoliated from the two dimensional material to remove the first substrate from a backside of the absorber layer opposite the buffer layer. A back contact is deposited on the absorber layer.