Abstract: Disclosed herein are the use of materials that have high affinity for oxygen, “oxygen getters” (e.g. Al), in conjunction with group V dopants (e.g. As) in II-VI materials (e.g. CdTe, Cd(Se)Te), that enable p-type doping by reducing group V oxides found in as-grown II-VI materials, thereby freeing up the anionic form of the Group V element.

Abstract: Methods for growing and using large-grain templates are provided. According to an aspect of the invention, a method includes depositing a small-grain layer of a semiconductor material; treating the small-grain layer such that the small-grain layer becomes a large-grain layer; and growing an epitaxial layer of the semiconductor material on the large-grain layer. A ratio of an average grain size of the small-grain layer to a thickness of the small-grain layer is less than 1.0, and a ratio of an average grain size of the large-grain layer to a thickness of the large-grain layer is greater than 1.5.

Abstract: Methods for growing and using large-grain templates are provided. According to an aspect of the invention, a method includes depositing a small-grain layer of a semiconductor material; treating the small-grain layer such that the small-grain layer becomes a large-grain layer; and growing an epitaxial layer of the semiconductor material on the large-grain layer. A ratio of an average grain size of the small-grain layer to a thickness of the small-grain layer is less than 1.0, and a ratio of an average grain size of the large-grain layer to a thickness of the large-grain layer is greater than 1.5.

Abstract: Methods for treating a semiconductor layer including a semiconductor material are presented. A method includes contacting at least a portion of the semiconductor material with a passivating agent. The method further includes forming a first region in the semiconductor layer by introducing a dopant into the semiconductor material; and forming a chalcogen-rich region. The method further includes forming a second region in the semiconductor layer, the second region including a dopant, wherein an average atomic concentration of the dopant in the second region is greater than an average atomic concentration of the dopant in the first region. Photovoltaic devices are also presented.

Abstract: Methods for treating a semiconductor layer including a semiconductor material are presented. A method includes contacting at least a portion of the semiconductor material with a passivating agent. The method further includes forming a first region in the semiconductor layer by introducing a dopant into the semiconductor material; and forming a chalcogen-rich region. The method further includes forming a second region in the semiconductor layer, the second region including a dopant, wherein an average atomic concentration of the dopant in the second region is greater than an average atomic concentration of the dopant in the first region. Photovoltaic devices are also presented.

Abstract: Photovoltaic devices are presented. A photovoltaic device includes a window layer and a semiconductor layer including a semiconductor material disposed on window layer. The semiconductor layer includes a first region and a second region, the first region disposed proximate to the window layer, and the second region including a chalcogen-rich region, wherein the first region and the second region include a dopant, and an average atomic concentration of the dopant in the second region is greater than an average atomic concentration of the dopant in the first region.

Abstract: Methods for preparing an exposed surface of a p-type absorber layer of a p-n junction for coupling to a back contact in the manufacture of a thin film photovoltaic device are provided. The method can include: applying a treatment solution onto the exposed surface defined by the p-type absorber layer of cadmium telluride; and annealing the device with the p-type absorber layer in contact with the treatment solution to form a tellurium-enriched region in the p-type absorber layer at the exposed surface. The treatment solution comprises a chlorinated compound component that is substantially free from copper, a copper-containing metal salt, and a solvent.

Abstract: Photovoltaic devices are presented. A photovoltaic device includes a window layer and a semiconductor layer including a semiconductor material disposed on window layer. The semiconductor layer includes a first region and a second region, the first region disposed proximate to the window layer, and the second region including a chalcogen-rich region, wherein the first region and the second region include a dopant, and an average atomic concentration of the dopant in the second region is greater than an average atomic concentration of the dopant in the first region.

Abstract: Methods for treating a semiconductor layer including a semiconductor material are presented. A method includes contacting at least a portion of the semiconductor material with a passivating agent. The method further includes forming a first region in the semiconductor layer by introducing a dopant into the semiconductor material; and forming a chalcogen-rich region. The method further includes forming a second region in the semiconductor layer, the second region including a dopant, wherein an average atomic concentration of the dopant in the second region is greater than an average atomic concentration of the dopant in the first region. Photovoltaic devices are also presented.

Abstract: Photovoltaic devices are provided that include a transparent superstrate; a transparent conductive oxide on the transparent superstrate; an n-type window layer on the transparent superstrate; a p-type absorber layer on the n-type window layer; and an inert conductive paste layer on the back surface of the p-type absorber layer. The p-type absorber layer includes cadmium telluride, and defines a back surface positioned opposite from the n-type window layer that is tellurium enriched. The inert conductive paste layer is substantially free from an acid or acid generator. Methods are also generally provided of forming such a back contact.

Abstract: Methods for preparing an exposed surface of a p-type absorber layer of a p-n junction for coupling to a back contact in the manufacture of a thin film photovoltaic device are provided. The method can include: applying a treatment solution onto the exposed surface defined by the p-type absorber layer of cadmium telluride; and annealing the device with the p-type absorber layer in contact with the treatment solution to form a tellurium-enriched region in the p-type absorber layer at the exposed surface. The treatment solution comprises a chlorinated compound component that is substantially free from copper, a copper-containing metal salt, and a solvent.

Abstract: Methods for forming a back contact on a thin film photovoltaic device are provided. The method can include: applying a conductive paste onto a surface defined by a p-type absorber layer (of cadmium telluride) of a p-n junction; and, curing the conductive paste to form a conductive coating on the surface such that during curing an acid from the conductive paste reacts to enrich the surface with tellurium but is substantially consumed during curing. The conductive paste can comprises a conductive material, an optional solvent system, and a binder. Thin film photovoltaic devices are also provided, such as those that have a conductive coating that is substantially free from an acid.

Abstract: A photovoltaic device is provided. The device comprises a transparent conducting layer. A p-type semiconductor window layer is disposed over the n-type transparent conducting layer. An n-type semiconductor layer is disposed over the p-type semiconductor window layer. An n-type cadmium telluride absorber layer is disposed between the p-type semiconductor window layer and the n-type semiconductor layer.