Other

Colorado State University Research Foundation

Abound Solar, Inc.

Kurt L Barth

Walajabad S Sampath

Robert A Enzenroth

An apparatus and method for manufacturing thin-film CdS/CdTe photovoltaic modules in a vacuum environment. The apparatus deposits CdS and CdTe layers onto a substrate using heated pocket deposition, a form of physical vapor deposition (PVD) in which a material thermally sublimes from a thermal sublimation source block and is deposited onto a substrate. The thermal sublimation source block includes a pocket having a lower surface into which an array of holes is formed to house plugs of deposition material. Upon heating, deposition material sublimes from a surface of each plug of deposition material, and the surface of each plug regresses into its corresponding hole while maintaining a constant surface area. The sublimation surface area of deposition material across the pocket remains substantially constant during an extended deposition process, and the deposition material is substantially free of undesired thermal radiation from the substrate. As such, the thermal sublimation source block provides a temporally- and spatially-uniform thin film deposition rate across the lower surface of the substrate.

Apparatus and method for fabricating photovoltaic modules using heated pocket deposition in a vacuum

The present invention is directed to an apparatus and method for rapid cooling of a large substrate in a vacuum environment. A first cooled plate is brought into close proximity with one surface of a flat substrate. The spatial volume between the first cooling plate and the substrate is sealed and brought to a higher pressure than the surrounding vacuum level to increase the cooling efficiency. A second cooled plate is brought into close proximity with the opposite surface of the flat substrate. A second spatial volume between the second cooling plate and the substrate is sealed and the gas pressure is equalized to the gas pressure in the first spatial volume. The equalization of the gas pressure on both sides of the flat substrate eliminates deflection of the substrate and bending stress in the substrate.

Apparatus and method for rapid cooling of large area substrates in vacuum

An apparatus and processes for large scale inline manufacturing of CdTe photovoltaic modules in which all steps, including rapid substrate heating, deposition of CdS, deposition of CdTe, CdCltreatment, and ohmic contact formation, are performed within a single vacuum boundary at modest vacuum pressures. A p+ ohmic contact region is formed by subliming a metal salt onto the CdTe layer. A back electrode is formed by way of a low cost spray process, and module scribing is performed by means of abrasive blasting or mechanical brushing through a mask. The vacuum process apparatus facilitates selective heating of substrates and films, exposure of substrates and films to vapor with minimal vapor leakage, deposition of thin films onto a substrate, and stripping thin films from a substrate. A substrate transport apparatus permits the movement of substrates into and out of vacuum during the thin film deposition processes, while preventing the collection of coatings on the substrate transport apparatus itself.

Apparatus and processes for the mass production of photovoltaic modules

An apparatus and processes for large scale inline manufacturing of CdTe photovoltaic modules in which all steps, including rapid substrate heating, deposition of CdS, deposition of CdTe, CdCl treatment, and ohmic contact formation, are performed within a single vacuum boundary at modest vacuum pressures. A p&plus; ohmic contact region is formed by subliming a metal salt onto the CdTe layer. A back electrode is formed by way of a low cost spray process, and module scribing is performed by means of abrasive blasting or mechanical brushing through a mask. The vacuum process apparatus facilitates selective heating of substrates and films, exposure of substrates and films to vapor with minimal vapor leakage, deposition of thin films onto a substrate, and stripping thin films from a substrate. A substrate transport apparatus permits the movement of substrates into and out of vacuum during the thin film deposition processes, while preventing the collection of coatings on the substrate transport apparatus itself.

Growing community of inventors

Fort Collins, CO, United States of America

Kurt L Barth