A photovoltaic cell can include a substrate having a copper-doped semiconductor layer. The doping can be mediated with a salt.

A technique is described depositing a new formula of indium and tin salt solutions as a precursor to form a solid transparent indium tin oxide (ITO) film on non-conductive solid substrates. The utilization of this new composition of matter prompted the discovery of a method for preparing the first top-to-bottom completely solution processed solar cell. The specific patterning of the liquid-processed ITO precursor solution and the subsequent layers of a solar cell outlined here also demonstrate a unique way to connect solution processed (as opposed to deposited using vacuum techniques) solar cells in series and in parallel. Also disclosed are related methods for zinc tin oxide (ZTO), indium oxide (IO), indium zinc oxide (IZO), cadmium tin oxide (CTO), aluminum zinc oxide (AZO), and zinc oxide (ZO).

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.

Disclosed herein are compositions and methods for making polycrystalline thin films having very large grains sizes and exhibiting improved properties over existing thin films.

A method for producing, apparatus for producing and photovoltaic device including semiconductor layers with halide heat treated surfaces that increase grain growth within at least one of the semiconductor layers and improve the interface between the semiconductor layers. The halide heat treatment includes applying and heating multiple coatings of a halide compound on surfaces adjacent to or part of the semiconductor layers.

The present invention refers to a method for producing CdTe thin-film solar cells, respectively a semi-finished CdTe thin-film solar cell, where in an additional temperature step is carried out after applying the CdTe layer on to a substrate. In particular, the temperature step is performed after activating the CdTe layer using a suitable activation agent and removing the residual activation agent from the CdTe layer. The temperature treatment is performed under vacuum or in a heating chamber filled with either air or inert gas, during which treatment the substrate is exposed to a temperature between 180 C. and 380 C. for a time between 5 minutes and 60 minutes. Due to the inventive additional temperature step, the number and extension of crystal defects in the CdTe layer is reduced and the electric efficiency of the solar cell is further improved.

According to the embodiments provided herein, a photovoltaic device can include a buffer layer adjacent to an absorber layer doped p-type with a group V dopant. The buffer layer can have a plurality of layers compatible with group V dopants.

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.

Methods and systems for forming a scribe line in a thin film stack on an inner surface of a thin film photovoltaic superstrate are provided via the use of a cleaning laser beam and a scribing laser beam. The cleaning laser beam is focused directly onto the exposed surface of the superstrate such that the cleaning laser beam removes debris from the exposed surface of the superstrate, and the scribing laser beam is focused through the exposed surface of the superstrate and onto the thin film stack such that the scribing laser beam passes through the superstrate to form a scribe within the thin film stack on the inner surface of the superstrate. The method and system can further utilize a conveyor to transport the superstrate in a machine direction to move the superstrate past the cleaning laser source and the scribing laser source.