摘要:
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.
摘要:
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.
摘要:
Described is 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 example, 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.
摘要:
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.
摘要:
A roll to roll system for depositing a material on a workpiece is provided. In one embodiment, the system includes a drum, which rotates about an axis that is transverse to a process direction, and a number of PVD deposition units. The drum further includes a peripheral surface that includes a groove having a recessed workpiece contact surface that is parallel to the axis and disposed between a first side wall and a second side wall. A portion of the recessed workpiece contact surface supports a section of the workpiece and the first and second side walls maintain the section of the workpiece on the portion of the recessed workpiece contact surface as the workpiece is moved along the process direction. The PVD deposition units are disposed across from some of the portion of the peripheral surface and continuously deposit the material across a width of some of the section of the workpiece.
摘要:
A system and method of forming a thin film solar cell with a metallic foil substrate are provided. After forming a semiconductor absorber film over the front surface of the metallic foil substrate a back surface of the metallic foil substrate is treated using a material removal process to form a treated back surface in a process chamber. In one embodiment, the material removal process is performed while depositing a transparent conductive layer over the semiconductor absorber film in the process chamber.
摘要:
Methods of forming thin film solar cells with a metallic substrate are described, as well as solar cells and solar cells strings. The front surface of the metallic substrate is polished to form a polished front surface so that the average roughness of the polished front surface is less than 50 nm. The back surface of the metallic substrate is roughened to form a rough back surface so that the average roughness of the conditioned back surface is more than 500 nm. A Group IBIIIAVIA compound absorber layer is formed over the polished front surface.
摘要:
An evaporation tool for forming a dopant structure on a front surface of a continuous workpiece, wherein the front surface includes a precursor layer to form Group IBIIIAVIA absorbers for solar cells and the dopant structure is used to introduce dopants into the precursor layer. The tool includes at least a first vapor source station to deposit a Group VIA material, such as Se, and a second vapor station to deposit a dopant material, such as Na, onto the continuous workpiece. A moving assembly of the tool holds and moves the continuous workpiece within the tool by feeding the continuous workpiece from a first end and taking up from a second end of the tool. A support assembly of the tool contacts a back surface of the continuous workpiece to remove the heat from and apply tension to the continuous workpiece during the process.
摘要:
An evaporation tool for forming a dopant structure on a front surface of a continuous workpiece, wherein the front surface includes a precursor layer to form Group IBIIIAVIA absorbers for solar cells and the dopant structure is used to introduce dopants into the precursor layer. The tool includes at least a first vapor source station to deposit a Group VIA material, such as Se, and a second vapor station to deposit a dopant material, such as Na, onto the continuous workpiece. A moving assembly of the tool holds and moves the continuous workpiece within the tool by feeding the continuous workpiece from a first end and taking up from a second end of the tool. A support assembly of the tool contacts a back surface of the continuous workpiece to remove the heat from and apply tension to the continuous workpiece during the process.
摘要:
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. Also described is an exhaust system that separates the Group VIA material vapors from other gaseous species for re-cycling or easy disposal and techniques and apparatus for efficient removal of moisture from the workpiece before processing precursor layer in the RTP tool.