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 P-type solar cell comprises a layer stack with: a back electrode, a p-type semiconductor absorber layer disposed on the back electrode, a crystalline cadmium sulfide (CdS) layer disposed on the absorber layer, and a front electrode disposed on the side of the layer stack opposite of the back electrode. The CdS layer has Cu-doping and a layer thickness between 50 and 300 . A method for producing a p-type solar cell comprises: providing a p-type photoactive semiconductor absorber layer, etching the surface of the absorber layer such that crystallographic unevenness and pinholes are reduced, depositing a CdS layer on the absorber layer, with a layer thickness between 50 and 200 , heating at least the CdS layer to recrystallize the CdS layer, and optionally placing on the absorber layer a Cu-containing layer different from the CdS layer, either after etching or after the application of the CdS layer.

A P-type solar cell comprises a layer stack with: a back electrode, a p-type semiconductor absorber layer disposed on the back electrode, a crystalline cadmium sulfide (CdS) layer disposed on the absorber layer, and a front electrode disposed on the side of the layer stack opposite the back electrode. The CdS layer has Cu-doping and a layer thickness between 50 and 300 . A method for producing a p-type solar cell comprises: providing a p-type photoactive semiconductor absorber layer, etching the surface of the absorber layer such that crystallographic unevenness and pinholes are reduced, depositing a CdS layer on the absorber layer, with a layer thickness between 50 and 200 , applying heat to at least the CdS layer to recrystallize the CdS layer, and optionally placing on the absorber layer a Cu-containing layer different from the CdS layer, either after etching or after the application of the CdS layer.

A multi-junction photovoltaic cell includes a substrate and a back contact layer formed on the substrate. A low bandgap Group IB-IIIB-VIB.sub.2 material solar absorber layer is formed on the back contact layer. A heterojunction partner layer is formed on the low bandgap solar absorber layer, to help form the bottom cell junction, and the heterojunction partner layer includes at least one layer of a high resistivity material having a resistivity of at least 100 ohms-centimeter. The high resistivity material has the formula (Zn and/or Mg)(S, Se, O, and/or OH). A conductive interconnect layer is formed above the heterojunction partner layer, and at least one additional single-junction photovoltaic cell is formed on the conductive interconnect layer, as a top cell. The top cell may have an amorphous Silicon or p-type Cadmium Selenide solar absorber layer. Cadmium Selenide may be converted from n-type to p-type with a chloride doping process.

A method of manufacturing a photovoltaic device may include concurrently transforming a transparent conductive oxide layer from a substantially amorphous state to a substantially crystalline state and forming one or more semiconductor layers.

Methods for doping an absorbent layer of a p-n heterojunction in a thin film photovoltaic device are provided. The method can include depositing a window layer on a transparent substrate, where the window layer includes at least one dopant (e.g,. copper). A p-n heterojunction can be formed on the window layer, with the p-n heterojunction including a photovoltaic material (e.g., cadmium telluride) in an absorber layer. The dopant can then be diffused from the window layer into the absorber layer (e.g., via annealing).

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 manufacturing a photovoltaic device includes a step of depositing one of an amorphous layer of ZnTe and a multilayer stack of Zn and Te adjacent a semiconductor layer. The one of the amorphous layer and the multilayer stack is then subjected to an energy impulse at a temperature equal to or greater than its critical temperature. The energy impulse results in an explosive crystallization to form a polycrystalline layer of ZnTe from the one of the amorphous layer and the multilayer stack.

In one aspect of the present invention, a photovoltaic device is provided. The photovoltaic device includes a window layer and an absorber layer disposed on the window layer, wherein the absorber layer includes a first region and a second region, the first region disposed adjacent to the window layer. The absorber layer further includes a first additive and a second additive, wherein a concentration of the first additive in the first region is greater than a concentration of the first additive in the second region, and wherein a concentration of the second additive in the second region is greater than a concentration of the second additive in the first region. Method of making a photovoltaic device is also provided.

A photovoltaic cell can include a dopant in contact with a semiconductor layer.