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: Thin film photovoltaic devices including a transparent substrate defining a front surface area; a photovoltaic thin film stack on the transparent substrate; and, a back panel defining a rear surface area are provided. The photovoltaic thin film stack is positioned between the transparent substrate and the back panel. The front surface area can be less than the rear surface area (e.g., about 90% to about 99.9% of the rear surface area). As such, the back panel can extend farther than the transparent substrate along at least one edge of the device. An encapsulant layer defining an encapsulant surface area can be positioned between the photovoltaic thin film stack and the back panel. The encapsulant surface area can be greater than or equal to the front surface area or can be less than or equal to the rear surface area.

Abstract: An apparatus and a method for detecting defects within a photovoltaic module are provided. To detect defects within the photovoltaic module, light from a light source is directed towards the photovoltaic module. The light generates a voltage within each solar cell of the photovoltaic module. The generated voltages are measured and compared in order to detect defects within the solar cells of the photovoltaic module.

Abstract: Methods are generally provided for forming a conductive oxide layer on a substrate by sputtering a target to deposit a transparent conductive oxide layer (e.g., comprising comprises cadmium, tin, and oxygen) on the substrate; positioning an anneal surface in close proximity to the transparent conductive oxide layer (e.g., about 3 cm or less); and, annealing the transparent conductive oxide layer while the anneal surface is in close proximity to the transparent conductive oxide layer (e.g., at an anneal temperature of about 500° C. to about 700° C.) to create a localized cadmium vapor between the transparent conductive oxide layer and the anneal surface. The anneal surface can include a material reactive with oxygen at the anneal temperature. Apparatus is also provided for annealing a thin film layer on a substrate.

Abstract: Thin film photovoltaic devices are provided. The device includes a transparent substrate; a transparent conductive oxide layer on the transparent substrate; an n-type window layer on the transparent conductive oxide layer, an absorber layer on the n-type window layer, and a back contact layer on the absorber layer. The n-type window layer includes a plurality of nanoparticles spatially distributed within a medium, with the nanoparticles comprising cadmium sulfide. In one embodiment, the medium has an optical bandgap that is greater than about 3.0 eV (e.g., includes a material other than cadmium sulfide). Methods are also provided for such thin film photovoltaic devices.

Abstract: Cylindrical sputtering targets are provided. The cylindrical sputtering target can include a tubular member having a length in a longitudinal direction and defining a tube surface. A source material is positioned about the tube surface of the tubular member and forms a sputtering surface about the tubular member. The source material generally includes a plurality of first areas and a plurality of second areas, each first area comprising a first compound and each second area comprising a second compound that is different than the first compound.

Abstract: A conveyor assembly for conveying substrates through a vapor deposition system is disclosed. The conveyor assembly may generally include a first carriage rail disposed on a drive side of the conveyor assembly and a second carriage rail disposed on an opposite side of the conveyor assembly. Each of the carriage rails may define a plurality of roller positions, with a plurality of the roller positions on the first carriage rail being configured as drive positions. The conveyor assembly may also include a drive pulley positioned at each drive position. Each drive pulley may be configured to rotationally drive a drive device. In addition, the conveyor assembly may include a plurality of rollers extending between the carriage rails at the roller positions. The rollers disposed at the drive positions may be configured to engage the drive devices.

Abstract: Cylindrical sputtering targets, along with methods of their manufacture and use, are provided. The cylindrical sputtering target includes a tubular member having a length in a longitudinal direction and defining a tube surface, and a source material positioned about the tube surface of the tubular member and forming a sputtering surface about the tubular member. The source material generally defines an inner surface opposite of the sputtering surface and non-bonded to the tube surface of the tubular member. The inner surface of the source material is mechanically engaged to the tube surface of the tubular member, and/or the source material can include a first cylindrical ring directly stacked onto a second cylindrical ring with the first cylindrical ring being mechanically engaged to the second cylindrical ring.

Abstract: Methods for forming a thin film layer on a substrate are provided. The method can include: rotating a cylindrical target about a center axis; ejecting atoms from the sputtering surface with a plasma; transporting a substrate across the plasma at a substantially consistent speed; and depositing the atoms ejected from the sputtering surface onto the substrate to form a thin film layer. The cylindrical target generally includes a source material forming a sputtering surface about the cylindrical target, with the source material having a plurality of first areas and a plurality of second areas. Each first area includes a first compound, and each second area includes a second compound, while the first compound is different than the second compound.

Abstract: Photovoltaic module modules are provided, along with method of their construction. The photovoltaic module includes a window substrate; a photovoltaic material; and an encapsulation substrate laminated to the window substrate with the photovoltaic material positioned therebetween. A support structure is mounted onto a back surface of the encapsulation substrate to inhibit bowing of the encapsulation substrate. The support structure can be indirectly mounted onto the back surface with an intermediate material (e.g., an adhesive strip) positioned therebetween. The support structure can include ridges that define peaks and valleys that are configured to inhibit bowing of the support structure.

Abstract: Racking systems for supporting a photovoltaic module are provided. The racking system includes a support lip; a lower retaining wall substantially oriented in a retaining plane and extending from the lower retaining wall; a lower support wall substantially oriented in a support plane and positioned on an opposite side of the lower retaining wall than the support lip; and an upper support wall substantially oriented in the support plane. The lower retaining wall and the lower support wall are joined together by a resting rail to define a retaining groove therebetween. Methods are also provided for mounting a photovoltaic module onto a racking system.

Abstract: Thin film photovoltaic devices that include a direct connection to at least one lead bar extending through a connection aperture defined in the encapsulation substrate to electrically connect to an underlying conductive ribbon are provided. The photovoltaic device can include: a transparent substrate; a plurality of photovoltaic cells; a conductive ribbon electrically connected to a photovoltaic cell; an encapsulation substrate laminated to the transparent substrate such that the plurality of photovoltaic cells and the conductive ribbon are positioned between the transparent substrate and the encapsulation substrate; and a lead bar extending through a connection aperture defined in the encapsulation substrate and electrically connected to the conductive ribbon. The lead bar can define a lead tab that establishes a mechanical connection having a biasing force between the lead bar and the conductive ribbon.

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: Thin film photovoltaic devices that include at least one lead bar extending through a connection aperture defined in the encapsulation substrate are provided. The photovoltaic device can include: a transparent substrate; a plurality of photovoltaic cells on the transparent substrate; a first conductive ribbon electrically connected to a first photovoltaic cell; an encapsulation substrate laminated to the transparent substrate such that the plurality of photovoltaic cells and the conductive ribbon are positioned between the transparent substrate and the encapsulation substrate; and, a first lead bar extending through a first connection aperture defined in the encapsulation substrate. The first lead bar is electrically connected to the first conductive ribbon. For example, a meltable conductive material can be connected to the first lead bar and to the first conductive ribbon to establish an electrical connection therebetween.

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 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.

Abstract: Apparatus and method for vapor deposition of a sublimated source material are generally provided. The apparatus includes a deposition head with a first sublimation compartment and a second sublimation compartment, each configured for receipt and sublimation of a source material. A first distribution plate can be positioned at a first defined distance above a horizontal conveyance plane of an upper surface of substrates conveyed through a first deposition area of the apparatus, and a second distribution plate can be positioned at a second defined distance above a horizontal conveyance plane of an upper surface of substrates conveyed through a second deposition area of said apparatus. The first sublimation compartment and the second sublimation compartment can be isolated from each other such that the sublimated first source material is substantially prevented from mixing with the sublimated second source material, at least during sublimation.

Abstract: A system for vapor deposition of a thin film layer on a photovoltaic module substrate is provided. The system includes a vacuum chamber having a pre-heat section, a vapor deposition apparatus, and a cool-down section; and a conveyor system operably disposed within said vacuum chamber and configured for conveying the substrates in a serial arrangement from said pre-heat section and through said vapor deposition apparatus at a controlled constant linear speed. The vapor deposition apparatus is configured for depositing a thin film of a sublimed source material onto an upper surface of the substrates as the substrates are continuously conveyed by said conveyor system through said vapor deposition apparatus.

Abstract: A method for controlling a plurality of heaters of a heating system is disclosed. The method may generally include generating control commands for turning on the plurality of heaters during a time period, determining which electrical phase is powering each heater of the plurality of heaters and staggering execution of the control commands across the time period for two or more of the heaters powered by the same electrical phase.