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:
The present disclosure provides thin film solar cell structures that can achieve dramatically improved power conversion efficiencies in relation to other thin film solar cell structures. The application of tandem solar cells composed of poly-crystalline Group II- VI (e.g., CdTe-based alloy) solar cells under low temperature deposition can achieve practical efficiencies above 25% in a low cost, high through-put, large area production environment. A poly- crystalline Group II- VI (e.g., CdTe-based alloy) solar cell can be deposited in tandem with a crystalline or multi-crystalline silicon p-type substrate with embedded n-type emitter on the deposition side of the substrate. This low temperature poly-crystalline/crystalline approach can allow for the development of a substantially efficient tandem solar cell produced in a relatively low cost, high through-put, large area production environment.
Abstract:
Thin film photovoltaic devices that include a transparent substrate; a transparent conductive oxide layer on the transparent substrate; a n-type window layer on the transparent conductive oxide layer; a p-type absorber layer on the n-type window layer; and, a back contact on the p-type absorber layer are provided. The p-type absorber layer comprises cadmium telluride, and forms a photovoltaic junction with the n-type window layer. Generally, the p-type absorber layer defines a plurality of finger structures protruding from the p-type absorber layer into the back contact. The finger structures can have an aspect ratio of about 1 or greater and/or can have a height that is about 20% to about 200% of the thickness of the p-type absorber layer. Methods of forming such finger structures protruding from a back surface of the p-type absorber layer are also provided.
Abstract:
A photovoltaic device (100) including a protective layer (114) between a window layer (112) and an absorber layer (116), the protective layer inhibiting dissolving/intermixing of the window layer into the absorber layer during a device activation step, and methods of forming such photovoltaic devices.
Abstract:
A photovoltaic device includes a substrate structure and a p-type semiconductor absorber layer, the substrate structure including a CdSSe layer. A photovoltaic device may alternatively include a CdSeTe layer. A process for manufacturing a photovoltaic device includes forming a CdSSe layer over a substrate by at least one of sputtering, evaporation deposition, CVD, chemical bath deposition process, and vapor transport deposition process. The process includes forming a p- type absorber layer above the CdSSe layer.
Abstract:
A method to improve CdTe-based photovoltaic device efficiency is disclosed, the method including steps for removing surface contaminants from a semiconductor absorber layer prior to the deposition or formation of a back contact layer on the semiconductor absorber layer, the surface contaminants removed using at least one of a dry etching process and a wet etching process.
Abstract:
An article, such as a photovoltaic device, and methods for making such articles, are provided. For example, one embodiment is an article comprising a plurality of layers comprising an absorber layer and a window stack. The window stack comprises antimony.
Abstract:
A photovoltaic device is presented. The photovoltaic device includes a first semiconductor layer, a second semiconductor layer, and an interlayer disposed between the first semiconductor layer and the second semiconductor layer, wherein the interlayer includes gadolinium. Methods of making 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.