Abstract: A deposition method and a system are provided to deposit a CdS buffer layer on a surface of a solar cell absorber layer of a flexible workpiece from a process solution including all chemical components of the CdS buffer layer material. CdS is deposited from the deposition solution while the flexible workpiece is heated and elastically shaped by a heated shaping plate to retain the process solution on the solar cell absorber layer. The flexible workpiece is elastically shaped by pulling a back surface of the flexible workpiece into a cavity area in the heated shaping plate using an attractive force.

Abstract: The present invention relates to methods and apparatus for providing composition control to thin compound semiconductor films for radiation detector and photovoltaic applications. In one aspect of the invention, there is provided a method in which the molar ratio of the elements in a plurality of layers are detected so that tuning of the multi-element layer can occur to obtain the multi-element layer that has a predetermined molar ratio range. In another aspect of the invention, there is provided a method in which the thickness of a sub-layer and layers thereover of Cu, In and/or Ga are detected and tuned in order to provide tuned thicknesses that are substantially the same as pre-determined thicknesses.

Abstract: Described is an electrodeposition solution for deposition of a Group IB-IIIA thin film on a conductive surface. In a preferred embodiment, the electrodeposition solution comprises a solvent; a Group IB material source that dissolves in the solvent and provides a Group IB material; a Group IIIA material source that dissolves in the solvent and provides a Group IIIA material; and a blend of at least two complexing agents, one of the at least two complexing agent forming a complex with the Group IB material and the other one of the at least two complexing agent forming a complex with the Group IIIA material; wherein the pH of the solution is at least 7.

Abstract: In one embodiment, a continuous electroless deposition method and a system to form a solar cell buffer layer with a varying composition through its thickness are provided. The composition of the buffer layer is varied by varying the composition of a chemical bath deposition solution applied onto an absorber surface on which the buffer layer with varying composition is formed. In one example, the buffer layer with varying composition includes a first section containing CdS, a second section containing CdZnS formed on top of the already deposited CdS, and a third section containing ZnS is formed on the second section All the process steps are applied in a roll-to-roll fashion. In another embodiment, a transparent conductive layer including a first transparent conductive film such as aluminum doped zinc oxide and a second transparent conductive film such as indium tin oxide is deposited over the buffer layer with the varying composition.

Abstract: The present invention relates to method and apparatus for preparing thin films of semiconductor films for radiation detector and photovoltaic applications. In one aspect, the present invention includes a series of chambers between the inlet and the outlet, with each chamber having a gap that allows a substrate to pass therethrough, and which is temperature controlled, thereby allowing each chamber to maintain a different temperature, and the substrate to be annealed based upon a predetermined temperature profile by efficiently moving through the series of chambers. In another aspect, each of the chambers opens and closes, and creates a seal when in the closed position during which time annealing takes place within the gap of the chamber. In a further aspect, the present invention provides a method of forming a Group IBIIIAVIA compound layer on a surface of a flexible roll.

Abstract: A method of forming a Group IBIIIAVIA absorber layer on a base for manufacturing a solar cell is provided. The method, in one embodiment, includes forming a precursor stack by electroplating a first metallic layer on the base. The first metallic layer includes at least one of copper, indium and gallium. A first selenium layer is deposited on the first metallic layer, and an interlayer is electrodeposited on the selenium layer. The interlayer includes one of gold and silver. A second metallic layer is electrodeposited on the interlayer, the second metallic layer comprising at least one of copper indium and gallium. The interlayer inhibits dissolution of selenium during the electrodeposition of the second metallic layer. Such prepared precursor stack is reacted at a temperature range of 300-600° C. to form the Group IBIIIAVIA absorber layer.

Abstract: A method of forming a doped Group IBIIIAVIA absorber layer for solar cells by reacting a partially reacted precursor layer with a dopant structure. The precursor layer including Group IB, Group IIIA and Group VIA materials such as Cu, Ga, In and Se are deposited on a base and partially reacted. After the dopant structure is formed on the partially reacted precursor layer, the dopant structure and partially reacted precursor layer is fully reacted. The dopant structure includes a dopant material such as Na.

Abstract: A method of manufacturing partially light transparent thin film solar cells generally includes forming a solar cell structure stack and forming multiple openings through the solar cell structure stack. The solar cell structure stack includes a flexible foil substrate, a contact layer formed over the flexible foil substrate, a Group IBIIIAVIA absorber layer formed over the contact layer and a transparent conductive layer formed over the Group IBIIIAVIA absorber layer. A terminal structure including at least one busbar and a plurality of conductive finger patterns is deposited onto a top surface of the transparent conductive layer forming a semi-transparent solar cell.

Abstract: The present invention relates to method and apparatus for preparing thin films of semiconductor films for radiation detector and photovoltaic applications. In one aspect, the present invention is directed to a method of forming a Cu(In,Ga)(S,Se)2 layer with substantially uniform Ga distribution. In a particular aspect, the method includes depositing a precursor film on the base, the precursor film including Cu, In and Ga, sulfurizing the precursor film thus forming a sulfurized precursor layer with a substantially uniform Ga distribution, and selenizing the sulfurized precursor layer to reduce the sulfur concentration therein and obtain the Cu(In,Ga)(S,Se)2 layer with substantially uniform Ga distribution. In a further aspect, the method also includes the step of selenizing the precursor film.

Abstract: The present invention advantageously provides for, in different embodiments, low-cost deposition techniques to form high-quality, dense, well-adhering Group IBIIIAVIA compound thin films with macro-scale as well as micro-scale compositional uniformities. It also provides methods to monolithically integrate solar cells made on such compound thin films to form modules. In one embodiment, there is provided a method of growing a Group IBIIIAVIA semiconductor layer on a base, and includes the steps of depositing on the base a nucleation and/or a seed layer and electroplating over the nucleation and/or the seed layer a precursor film comprising a Group IB material and at least one Group IIIA material, and reacting the electroplated precursor film with a Group VIA material. Other embodiments are also described.

Abstract: The present invention relates to methods and apparatus for providing composition control to thin compound semiconductor films for radiation detector and photovoltaic applications. In one aspect of the invention, there is provided a method in which the molar ratio of the elements in a plurality of layers are detected so that tuning of the multi-element layer can occur to obtain the multi-element layer that has a predetermined molar ratio range. In another aspect of the invention, there is provided a method in which the thickness of a sub-layer and layers thereover of Cu, In and/or Ga are detected and tuned in order to provide tuned thicknesses that are substantially the same as pre-determined thicknesses.

Abstract: A deposition method and a system are provided to deposit a CdS buffer layer on a surface of a solar cell absorber layer of a flexible workpiece from a process solution including all chemical components of the CdS buffer layer material. CdS is deposited from the deposition solution while the flexible workpiece is elastically shaped by a series of shaping rollers to retain the process solution on the solar cell absorber layer and while the flexible workpiece is heated by contacting to a heated liquid that the shaping rollers are fully or partially immersed. The flexible workpiece is elastically shaped by pulling a back surface of the flexible workpiece into surface cavity of the shaping rollers using magnetic force.

Abstract: The present invention provides a method of making a Cu—In—Ga sputtering target by melting Cu, In and Ga, Cu and In or Cu and Ga to form a uniform melt with a pre-determined stoichiometry, which melt is sprayed to cause sprayed uniform melt particles to solidify into Cu—In—Ga particles with the pre-determined stoichiometry. The sputtering target is then made using the Cu—In—Ga particles.

Abstract: The present invention relates to thin film solar cell structures and methods of manufacturing them. In particular and in one aspect the present invention is related to apparatus and methods for forming a solar cell structure in which an insulator film is disposed over a region of a conductive contact layer, which is either adjacent or below the absorber layer.

Abstract: A method of forming a Group IBIIIAVIA solar cell absorber which includes an active portion and an electrically resistive portion. The absorber is interposed between a base layer and a transparent conductive layer. The electrically resistive portion increases resistance between the base layer and a connector layer that is formed on the transparent conductive layer. The connector layer comprises the busbar and the fingers of the solar cell. The busbar is preferably placed over the electrically resistive portion while the fingers extend over the active portion of the absorber layer.

Abstract: A thin film solar cell including a Group IBIIIAVIA absorber layer on a defect free base including a stainless steel substrate is provided. The stainless steel substrate of the base is surface treated to remove the surface roughness such as protrusions that cause shunts. Before removing the protrusions, a thin protective ruthenium film is first deposited on the recessed surface portions of the substrate to protect these portions during the following protrusion removal. The protrusions on the surface receives very little or no ruthenium during the deposition. After the ruthenium film is formed, the protrusions are etched and removed by an etchant which only attacks the stainless steel but neutral to the ruthenium film. A contact layer is formed over the ruthenium layer and the exposed portions of the substrate to complete the base.

Abstract: The present inventions provide structures and methods for manufacturing high electrical conductivity grid patterns having minimum shadowing effect on the illuminated side of the solar cells. In a particular aspect, a width of an effective channel region is greater than a spacing that exists between conductive elements in adjacent grid patterns that exist along a lengthwise direction of a continuous workpiece.

Abstract: A method of manufacturing partially light transparent thin film solar cells generally includes forming a solar cell structure stack and forming multiple openings through the solar cell structure stack. The solar cell structure stack includes a flexible foil substrate, a contact layer formed over the flexible foil substrate, a Group IBIIIAVIA absorber layer formed over the contact layer and a transparent conductive layer formed over the Group IBIIIAVIA absorber layer. A terminal structure including at least one busbar and a plurality of conductive finger patterns is deposited onto a top surface of the transparent conductive layer forming a semi-transparent solar cell.

Abstract: A method of manufacturing partially light transparent thin film solar cells generally includes forming a solar cell structure stack and forming multiple openings through the solar cell structure stack. The solar cell structure stack includes a flexible foil substrate, a contact layer formed over the flexible foil substrate, a Group IBIIIAVIA absorber layer formed over the contact layer and a transparent conductive layer formed over the Group IBIIIAVIA absorber layer. A terminal structure including at least one busbar and a plurality of conductive finger patterns is deposited onto a top surface of the transparent conductive layer forming a semi-transparent solar cell.

Abstract: Described are roll-to-roll or reel-to-reel thermal or rapid thermal processing tools (reactors) are used to react a precursor layer on a continuous flexible workpiece. Variants of the reactors are described, including a reactor having multiple exhaust outlets connected to a process gap of the reactor between an entrance opening and an exit opening of the process gap; a reactor including multiple gas inlets and exhaust outlets connected to a process gap of the reactor between an entrance opening and an exit opening of the process gap; a reactor including multiple gas inlets and exhaust outlets connected to a process gap of the reactor between an entrance opening and an exit opening of the process gap; and a reactor including multiple gas inlets and exhaust outlets connected to a process gap of the reactor between an entrance opening and an exit opening of the process gap.