Abstract: A charcopyrite-based thin film solar cell device and a method of fabricating the same is described. The solar cell includes a stacked absorber film over a substrate. The stacked absorber film includes at least two sets of absorber materials and each set includes at least three layers. At least one of the three layers includes elemental selenium and at least one of the layers includes a metal selected from the group consisting of copper, indium or gallium. The at least one selenium layer is in contact with the at least one metal layer. The at least two sets form an absorber film including multi-layer embedded selenium.

Abstract: A solar cell includes an absorber layer formed of a CIGAS, copper, indium, gallium, aluminum, and selenium. A method for forming the absorber layer provides for using an indium-aluminum target and depositing an aluminum-indium film as a metal precursor layer using sputter deposition. Additional metal precursor layers such as a CuGa layer are also provided and a thermal processing operation causes the selenization of the metal precursor layers. The thermal processing operation/selenization operation converts the metal precursor layers to an absorber layer. In some embodiments, the absorber layer includes a double graded chalcopyrite-based bandgap.

Abstract: A multi-step scribing operation is provided for forming scribe lines in solar panels to form multiple interconnected cells on a solar panel substrate. The multi-step scribing operation includes at least one step utilizing a nanosecond laser cutting operation. The nanosecond laser cutting operation is followed by a mechanical cutting operation or a subsequent nanosecond laser cutting operation. In some embodiments, the multi-step scribing operation produces a two-tiered scribe line profile and the method prevents local shunting and minimizes active area loss on the solar panel.

Abstract: A solar cell comprises a back contact layer, an absorber layer on the back contact layer, a buffer layer on the absorber layer, and a front contact layer above the buffer layer. The front contact layer has a first portion and a second portion. The first and second portions of the front contact layer differ from each other in thickness or dopant concentration.

Abstract: A method is disclosed for manufacturing an absorber layer, such as a CIS-based absorber layer, in a thin film solar cell, such as a CIS-based thin film solar cell. One method includes a selenization step, an annealing step, and a sulfuration step. Another method includes an annealing step and a sulfuration step. Additionally, a disclosed CIS-based absorber layer has a surface-to-bottom ratio of gallium which is greater than that for a conventional absorber layer and the ratio of sulfur to sulfur-plus-selenium is less than that for a conventional absorber layer. Also provided is a process for producing an absorber layer, such as a CIS-based absorber layer, over a large area where the layer is capable of achieving both a high open circuit voltage and a high fill factor by preferable depth composition profile through controllable gallium-diffusion/sulfur-incorporation and the enlarged grain size.

Abstract: A solar cell with a transparent conductive layer having improved transmittance is described. The solar cell can include a solar cell substructure comprising an absorber layer disposed over a substrate; and a transparent conductive oxide (TCO) layer disposed over the substructure. The TCO layer can include a TCO film with a plurality of spaced-apart, high-transmittance structures therein. The TCO layer can have a higher transmittance of absorbable radiation than a comparable, homogeneous TCO film. The high-transmittance structures can be selected from the group consisting of perforations, high-transmittance particles, and combinations thereof. Methods of making solar cell with a transparent conductive layer having improved transmittance are also described.

Abstract: A photovoltaic device includes a substrate; a back contact layer disposed above the substrate; an absorber layer for photon absorption disposed above the back contact layer; a buffer layer disposed above the absorber layer; a conductive coating disposed above the buffer layer; and a transparent conductive layer disposed over the conductive coating. The conductive coating includes at least one type of nanomaterial, which has at least one dimension in the range of from 0.5 nm to 1000 nm.

Abstract: A method of fabricating a buffer layer of a photovoltaic device comprises: providing a substrate having a back contact layer disposed above the substrate and an absorber layer disposed above the back contact layer; depositing a metal layer on the absorber layer; and performing a thermal treatment on the deposited metal layer in an atmosphere comprising sulfur, selenium or oxygen, to form a buffer layer.

Abstract: A solar cell includes an absorber layer formed of a CIGAS, copper, indium, gallium, aluminum, and selenium. A method for forming the absorber layer provides for using an indium-aluminum target and depositing an aluminum-indium film as a metal precursor layer using sputter deposition. Additional metal precursor layers such as a CuGa layer are also provided and a thermal processing operation causes the selenization of the metal precursor layers. The thermal processing operation/selenization operation converts the metal precursor layers to an absorber layer. In some embodiments, the absorber layer includes a double graded chalcopyrite-based bandgap.

Abstract: A method and apparatus for forming a solar cell. The apparatus includes a housing defining a vacuum chamber and a rotatable substrate apparatus configured to hold a plurality of substrates on a plurality of surfaces wherein each of the plurality of surfaces are disposed facing an interior surface of the vacuum chamber. A first sputtering source is configured to deposit a plurality of absorber layer atoms of a first type over at least a portion of a surface of each one of the plurality of substrates. An evaporation source is disposed in a first subchamber of the vacuum chamber and configured to deposit a plurality of absorber layer atoms of a second type over at least a portion of the surface of each one of the plurality of substrates. A first isolation source is configured to isolate the evaporation source from the first sputtering source.

Abstract: An apparatus for forming a solar cell includes a housing defining a vacuum chamber, a rotatable substrate support, at least one inner heater and at least one outer heater. The substrate support is inside the vacuum chamber configured to hold a substrate. The at least one inner heater is between a center of the vacuum chamber and the substrate support, and is configured to heat a back surface of a substrate on the substrate support. The at least one outer heater is between an outer surface of the vacuum chamber and the substrate support, and is configured to heat a front surface of a substrate on the substrate support.

Abstract: A removable cover system for protecting solar cells from exposure to moisture during fabrication processes. The cover system includes a cover having a configuration that complements the configuration of a solar cell substrate to be processed in an apparatus where moisture is present. A resiliently deformable seal member attached to the cover is positionable with the cover to engage and seal the top surface of the substrate. In one embodiment, the cover is dimensioned and arranged so that the seal member engages the peripheral angled edges and corners of the substrate for preventing the ingress of moisture beneath the cover. An apparatus for fabricating a solar cell using the cover and associated method are also disclosed.

Abstract: A method and system provide for depositing a TCO, transparent conductive oxide, film in one chamber of a manufacturing tool then irradiating the TCO film with light energy in another chamber of the same tool. The TCO film is used in a solar cell and formed on a solar cell substrate in some embodiments. The method includes irradiating the TCO film for a time and energy to reduce resistance of the TCO film without reducing transmittance. One or multiple light sources are used in the light irradiation chamber. Light in the infrared range, visible light range and ultraviolet light range are used either individually or in combination.

Abstract: A method and apparatus for measuring thickness of a film in a solar cell provides for directing light emitted at multiple emission wavelengths, to a surface of the solar cell. Each emission results in the generation of a responsive photo current. The photo currents are read by a current meter having one contact coupled to a surface of the solar cell and another contact coupled to another surface. The currents associated with each of the different light emissions are identified and the thickness of a film in the solar cell is calculated based on the two currents or associated quantum efficiencies, and associated absorption coefficients. In one embodiment, the film thickness is the thickness of a CdS or other buffer film in a thin film solar cell.

Abstract: A method for manufacturing a thin film solar cell device includes forming a back contact layer on a substrate, forming an CIGS absorber layer on the back contact layer, treating the CIGS absorber layer with a metal-based alkaline solution, and forming a buffer layer on the CIGS absorber layer where the treatment of the CIGS absorber layer improves the adhesion between the CIGS absorber layer and the buffer layer and also improves the quality of the p-n junction at the CIGS absorber layer/buffer layer interface.

Abstract: A sputtering apparatus comprises a chamber configured to contain at least one sputter target and at least one substrate to be coated. The chamber has at least one adjustable shielding member defining an adjustable aperture. The member is positioned between the at least one sputter target and the at least one substrate. The aperture is adjustable in at least one of the group consisting of area and shape.

Abstract: A method for manufacturing a thin film solar cell device includes forming a back contact layer on a substrate, forming an CIGS absorber layer on the back contact layer, treating the CIGS absorber layer with a metal-based alkaline solution, and forming a buffer layer on the CIGS absorber layer where the treatment of the CIGS absorber layer improves the adhesion between the CIGS absorber layer and the buffer layer and also improves the quality of the p-n junction at the CIGS absorber layer/buffer layer interface.

Abstract: A solar cell with a molybdenum back electrode layer and a molybdenum selenide ohmic contact layer over the molybdenum back electrode, is provided. The molybdenum selenide layer includes an accurately controlled thickness. A distinct interface exists between the molybdenum back electrode layer and the molybdenum silicide layer. The molybdenum silicide layer is produced by forming a molybdenum layer or a molybdenum nitride layer or a molybdenum oxide layer over an initially formed molybdenum layer such that an interface exists between the two layers. A selenization and sulfurization process is carried out to selectively convert the molybdenum-containing layer to molybdenum selenide but not the original molybdenum back electrode layer which remains as a molybdenum layer.

Abstract: Apparatuses for forming material films on a solar cell substrate of substantially uniform thickness and processes for forming the same are disclosed. The process performed in the apparatuses is physical vapor deposition (PVD) in some embodiments. In one embodiment, an apparatus includes a specially configured flow aperture. In another embodiment, an apparatus includes moveable shutters which open and close in synchronization with a rotating drum on which substrates are mounted for processing. In other embodiments, the apparatus includes a variable power supply or drum speed control which automatically vary the power supply to the apparatus or drum speed respectively in synchronization with the rotating drum.

Abstract: Apparatus for forming a solar cell comprises a housing defining a chamber including a substrate support. A sputtering source is configured to deposit particles of a first type over at least a portion of a surface of a substrate on the substrate support. An evaporation source is configured to deposit a plurality of particles of a second type over the portion of the surface of the substrate. A cooling unit is provided between the sputtering source and the evaporation source. A control system is provided for controlling the evaporation source based on a rate of mass flux emitted by the evaporation source.