Abstract: A photovoltaic device is provided which includes a plurality of junction layers. Each junction layer includes a plurality of photovoltaic cells electrically connected to one another. At least one of the junction layers is at least in part optically transmissive. The junction layers are arranged in a stack on top of each other.

Abstract: A multi-junction photovoltaic cell includes at least two P-N junctions electrically connected to each other in series. Each P-N junction includes a P-type absorber layer and a N-type emitter layer, each P-type absorber layer including a plurality of alternating thin film layers of zinc telluride and lead telluride, wherein zinc telluride and lead telluride have respective bandgaps when in bulk thickness and the effective bandgap of each P-type absorber layer is between the respective bandgaps. The effective bandgap of at least one P-type absorber layer is different from that of at least one other P-type absorber layer.

Abstract: The present invention describes a method of producing a p-type light-absorbing semiconductor copper zinc tin selenide/sulfide (Cu2(ZnxSn2-x)(SySe1-y)4) (abbreviated CZTS) with electrochemical deposition. It can be used in the production of solar cell when combined with an n-type inorganic or an organic semiconductor layer. The present method comprises a one-step or a sequence of depositions using electroplating to fabricate a low-cost and large-area CZTS solar cell, without using expensive and complicated deposition techniques or highly toxic and flammable chemicals in the production process. The present method significantly reduces the cost and energy requirement for production of solar cell.

Abstract: An integrated photovoltaic cell and battery device, a method of manufacturing the same and a photovoltaic power system incorporating the integrated photovoltaic cell and battery device. The integrated photovoltaic cell and battery device includes a photovoltaic cell, a battery, and interconnects providing three-dimensional integration of the photovoltaic cell and the battery into an integrated device for capturing and storing solar energy. Also provided is a design structure readable by a machine to simulate, design, or manufacture the above integrated photovoltaic cell and battery device.

Abstract: A photovoltaic cell structure is disclosed that includes a buffer/passivation layer at a CdTe/Back contact interface. The buffer/passivation layer is formed from the same material that forms the n-type semiconductor active layer. In one embodiment, the buffer layer and the n-type semiconductor active layer are formed from cadmium sulfide (CdS). A method of forming a photovoltaic cell includes the step of forming the semiconductor active layers and the buffer/passivation layer within the same deposition chamber and using the same material source.

Abstract: Processes for making a solar cell by depositing various layers of components on a substrate and converting the components into a thin film photovoltaic absorber material. Processes of this disclosure can be used to control the stoichiometry of metal atoms in making a solar cell for targeting a particular concentration and providing a gradient of metal atom concentration. A selenium layer can be used in annealing a thin film photovoltaic absorber material.

Abstract: A process for the preparation of a thin film having at least one layer of a predetermined thickness not exceeding 5 microns is provided such that the integrity of the thin film is preserved. The process for the preparation of such a thin film comprises the step of rolling at least one sheet. The step of rolling is preceded by a step of stacking at least one sheet on a substrate having a predetermined thickness. The process of stacking preferably includes the step of bonding at least one sheet to a substrate. The sheet is a metal, alloy or a combination thereof, the metal and the alloy being of metals selected from the groups IB, IIB, IIIA, IVA, IVB, VB and VIB.

Abstract: A method of manufacturing an order vacancy compound (OVC) is provided. The method includes the following steps. A trivalent ion, a hexavalent ion and one of a univalent ion and a bivalent ion for an electrodeposition process are provided to form a solar energy absorbing film. The OVC is formed by performing an electrochemical etching process on the solar energy absorbing film.

Abstract: A photovoltaic module may include a transparent conductive layer on a substrate a first submodule including a first plurality of photovoltaic cells connected in series and a second submodule including a second plurality of photovoltaic cells connected in series.

Abstract: An improved efficiency thin film solar cell is disclosed. Nanoscale indentations or protrusions are formed on the cross sectional surface of a carrier layer, onto which a thin metal film is deposited. Additional layers, including semiconductor absorber and collector layers and a window layer, are disposed on the metal film, thereby completing the solar cell. The nanostructure underlying the metal film serves to reduce the work function of the metal and thereby assists in the absorption of holes created by solar photons. This leads to more efficient electricity generation in the solar cell. In a further embodiment of the present invention the cross sectional surface of the semiconductor absorber layer is also modified by nanoscale indentations or protrusions. These indentations or protrusions have the effect of altering the size of the semiconductor band gap, thereby optimizing the radiation absorption properties of the solar cell.

Abstract: CIGS absorber layers fabricated using coated semiconducting nanoparticles and/or quantum dots are disclosed. Core nanoparticles and/or quantum dots containing one or more elements from group 13 and/or IIIA and/or VIA may be coated with one or more layers containing elements group IB, IIIA or VIA. Using nanoparticles with a defined surface area, a layer thickness could be tuned to give the proper stoichiometric ratio, and/or crystal phase, and/or size, and/or shape. The coated nanoparticles could then be placed in a dispersant for use as an ink, paste, or paint. By appropriate coating of the core nanoparticles, the resulting coated nanoparticles can have the desired elements intermixed within the size scale of the nanoparticle, while the phase can be controlled by tuning the stoichiometry, and the stoichiometry of the coated nanoparticle may be tuned by controlling the thickness of the coating(s).

Abstract: A back contact configuration for a CIGS-type photovoltaic device is provided. The back contact configuration includes an interfacial seed layer, made up of one or more layers/sublayers, disposed between a Mo based rear contact/electrode and a CIGS inclusive semiconductor absorber. The interfacial seed layer may be of or include one or more element(s) that make up, or help make up, the CIGS inclusive semiconductor absorber. Various methods and compositions of the interfacial seed layer are disclosed, including a seed layer comprising metallic and/or substantially metallic Cu—In—Ga, CIGS, and/or a stack of alternating layers of or including Cu, In and Ga. Methods for making the back contact configuration, including an interfacial seed layer, are also provided.

Abstract: Provided are a co-polymer of formula (I) of 2,7-carbazole and dithienyl thiazolothiazole, a method for preparing same, and a solar battery containing same. The structural formula of the co-polymer of 2,7-carbazole and dithienyl thiazolothiazole is as shown by formula (I), wherein both R1 and R2 are C1-C20 alkyl groups, and n is an integer of 10-100. The co-polymer of the present invention has a novel structure, a good dissolving property, an excellent film-forming property, and a high power conversion efficiency, and can be used as the material for a solar battery. Also provided are the method for preparing the co-polymer and the solar battery containing same. The preparation method uses raw materials widely available and has a simple synthesis route.

Abstract: Techniques for improving energy conversion efficiency in photovoltaic devices are provided. In one aspect, an antimony (Sb)-doped film represented by the formula, Cu1-yIn1-xGaxSbzSe2-wSw, provided, wherein: 0?x?1, and ranges therebetween; 0?y?0.2, and ranges therebetween; 0.001?z?0.02, and ranges therebetween; and 0?w?2, and ranges therebetween. A photovoltaic device incorporating the Sb-doped CIGS film and a method for fabrication thereof are also provided.

Abstract: A solar cell includes a p-n junction formed by joining a p-type semiconductor and an n-type semiconductor. The p-type semiconductor is a chalcopyrite compound semiconductor with a band gap of 1.5 eV or more within which an intermediate level exists with a half bandwidth of 0.05 eV or more. The intermediate level is different from an impurity level. The chalcopyrite compound semiconductor includes a first element having first electronegativity of 1.9 or more in Pauling units, the first element occupying a lattice site of the semiconductor. A portion of the first element is substituted with a second element having second electronegativity different from the first electronegativity, the second element being a congeneric element of the first element. The intermediate level is created by substituting the first element with the second element.

Abstract: Metal chalcogenides, and methods of making and using metal chalcogenides, are disclosed herein. Metal chalcogenides can be prepared by heating suitable copper, zinc, and/or tin compounds selected from the group consisting of chalcogenocarbamates, dichalcogenocarbamates, mercaptides, thiiocarbonates, trithiocarbonates, and combinations thereof (e.g., copper, zinc, and/or tin dichalcogenocarbamates) under conditions effective to form metal can be used, for example, to prepare solar cells.

Abstract: A method for producing a nanoparticle for forming a CZTS compound semiconductor thin film is provided which includes the step of reacting a solution including a metal salt or a metal complex with a solution including a chalcogenide salt to produce a CZTS compound nanoparticle. A CZTS compound semiconductor thin film is formed by coating or printing the nanoparticle for forming the CZTS compound semiconductor thin film, and subjecting it to a heat treatment. A solar cell including the CZTS compound semiconductor thin film as the light-absorbing layer is provided.

Abstract: A light absorbing material may have an energy bandgap of greater than or equal to about 0.8 eV and an absorption coefficient of greater than about 2.1×105 cm?1 at about 0.8 eV.

Abstract: A method, in certain embodiments, includes providing a metal alloy, annealing the metal alloy, and contacting the metal alloy with vapors of selenium, or sulfur, or a combination thereof. The metal alloy having a uniform first bulk composition and a first surface composition on annealing provides an annealed metal alloy having a non uniform second bulk composition and a second surface composition which on being contacted vapors of selenium, or sulfur, or a combination thereof, produces a selenized or a sulfurized metal alloy. Further the metal alloy may have a layer formed in situ from a low melting point metal within the alloy via diffusion rather than sequential deposition and co-evaporation.

Abstract: Disclosed are a solar cell apparatus and a method for manufacturing the same. The solar cell apparatus includes a substrate; a back electrode layer on the substrate; a light absorbing layer on the back electrode layer; and a front electrode layer on the light absorbing layer, wherein an outer peripheral side of the back electrode layer is aligned on a plane different from a plane of an outer peripheral side of the light absorbing layer.

Abstract: The disclosure relates to apparatus and methods of photovoltaic or solar module design and fabrication. A photovoltaic (PV) module includes one or more photovoltaic cells mounted to a support, a first terminal connected to at least one of the one or more PV cells, a second terminal connected to at least one of the one or more PV cells, and a bypass line mounted to the support for bypassing the one or more PV cells. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: A photovoltaic device can include a doped contact layer adjacent to a semiconductor absorber layer, where the doped contact layer includes a metal base material and a dopant.

Abstract: A structure for a single junction solar cell. The structure includes a substrate member having a surface region. The structure includes a first electrode structure overlying the surface region of the substrate member. A P absorber layer is formed overlying the first electrode structure. In a specific embodiment, the P absorber layer has a P? type impurity characteristics and a first optical absorption coefficient greater than 104 cm?1 in a wavelength range comprising 400 nm to 800 nm. An N+ layer is provided overlying the P absorber layer and an interface region formed within a vicinity of the P layer and the N+ layer. The structure also includes a high resistivity buffer layer overlying the N+ layer and a second electrode structure overlying the buffer layer.

Abstract: Methods for improving the efficiency of solar cells are disclosed. A solar cell consistent with the present disclosure includes a back contact metal layer disposed on a substrate. The solar cell also includes an electron reflector material(s) layer formed on the back contact metal layer and an absorber material(s) layer disposed on the electron reflector material(s) layer. In addition, the solar cell includes a buffer material(s) layer formed on the absorber material(s) layer wherein the electron reflector material(s) layer, absorber material(s) layer, and buffer material(s) layer form a pn junction within the solar cell. Furthermore, a TCO material(s) layer is formed on the buffer material(s) layer. In addition, the front contact layer is formed on the TCO material(s) layer.

Abstract: New photovoltaic device configurations utilize combinations of n-copper indium selenide (n-CIS) absorber and p-type semiconducting organic/polymeric or inorganic materials to maximize the efficiency of solar energy conversion into electric power. Fabrication methods to produce various device configurations, based on n-CIS thin films, nanoparticles, organic or polymeric materials deposited on flexible or rigid substrates are described, that simplify process steps and hence the costs for high volume solar cell manufacturing.

Abstract: A photoelectric conversion element of an embodiment includes: a p-type light absorbing layer having a chalcopyrite structure; an n-type semiconductor layer on the p-type light absorbing layer; an oxide layer on the n-type semiconductor layer; and a transparent electrode on the oxide layer.

Abstract: A solar cell includes a substrate, a rear electrode layer on the substrate, a light-absorption layer on the rear electrode layer, the light-absorption layer including Se and S, and a buffer layer on the light-absorption layer; the light-absorption layer including a depletion region extending from a surface of the light-absorption layer adjacent to the buffer layer, the depletion region having an average S/(Se+S) mole ratio in a range of about 0.10 to about 0.30.

Abstract: An ink composition, a thin film solar cell and method for forming the thin film solar cell are disclosed. The ink composition includes a solvent system, a source of Cu, a source of Zn, a source of Sn, a source of S and/or Se, and a source of group III element, wherein the ink composition is adapted in forming a I-II-IV-VI thin film solar cell to increase a fill factor of the I-II-IV-VI thin film solar cell.

Abstract: A method of fabrication of thin films for photovoltaic or electronic applications is provided. The method includes fabricating a nanocrystal precursor layer and selenizing the nanocrystal precursor layer in a selenium containing atmosphere. The nanocrystal precursor layer includes one of CuInS2, CuIn(Sy,Se1-y)2, CuGaS2, CuGa(Sy, Se1-y)2, Cu(InxGa1-x)S2, and Cu(InxGa1-x)(Sy, Se1-y)2 nanoparticles and combinations thereof, wherein 0?x?1 and 0?y?1.

Abstract: The textured transparent conductive layer according to the invention is deposited on a substrate intended for a photoelectric device and exhibiting a surface morphology formed from a sequence of humps and hollows. It is characterized in that its hollows have a rounded base with a radius of more than 25 nm; the said hollows are virtually smooth, which is to say that, where they exhibit microroughnesses, these microroughnesses have a height on average of less than 5 nm; and its flanks form an angle with the plane of the substrate whose median of the absolute value is between 30° and 75°.

Abstract: Processes for making a photovoltaic layer on a substrate by depositing a first layer of an ink onto the substrate, wherein the ink contains one or more compounds having the formula MB(ER)3, wherein MB is In, Ga, or Al, E is S or Se, and depositing a second layer of one or more copper chalcogenides or a CIGS material.

Abstract: A solution for forming at least a portion of an active layer of an electronic or electro-optic device includes a solvent, an additive mixed with the solvent to provide a solvent-additive blend, and a solute that includes at least one of a transition metal, an alkali metal, an alkaline earth metal, Al, Ga, In, Ge, Sn, or Sb dissolved in elemental form in the solvent-additive blend. The additive is selected from the group of additives consisting of NR1R2NHCOOH, NH2N—HCONHNH2, NH2COOH.NH3, NH2NHC(?NH)NH2.H2CO3, NH2NHCSNHNH2, NH2NHCSSH and all combinations thereof. R1 and R2 are each independently selected from hydrogen, aryl, methyl, ethyl and a linear, branched or cyclic alkyl of 3-6 carbon atoms. Methods of producing the solution, a method of producing a Kesterite film on a substructure and devices made with the solutions and methods are also provided.

Abstract: Volume compensation in photovoltaic device is provided. The photovoltaic device has an outer transparent casing and a substrate that, together, define an inner volume. At least one solar cell is on the substrate. A filler layer seals the at least one solar cell within the inner volume. A container within the inner volume has an opening in fluid communication with the filler layer. A diaphragm is affixed to the opening thereby sealing the interior of the container from the filler layer. The diaphragm is configured to decrease the volume within the container when the filler layer thermally expands and to increase the volume within the container when the filler layer thermally contracts. In some instances, the substrate is hollowed and the container is formed within this hollow. The container can have multiple openings, each sealed with a diaphragm. There can be multiple containers within the photovoltaic device.

Abstract: A selenium/Group 3a ink, comprising (a) a selenium/Group 3a complex which comprises a combination of, as initial components: a selenium component comprising selenium; a carboxylic acid component having a formula R—COOH, wherein R is selected from a C1-10 alkyl, C1-10 haloalkyl and a C1-10 mercaptoalkyl; a Group 3a complex, comprising at least one Group 3a material selected from aluminum, indium, gallium and thallium complexed with a multidentate ligand; and, (b) a liquid carrier; wherein the selenium/Group 3a complex is stably dispersed in the liquid carrier.

Abstract: Methods for depositing a kesterite film comprising a compound of the formula: Cu2?xZn1+ySn(S1?zSez)4+q, wherein 0?x?1; 0?y?1; 0?z?1; ?1?q?1, generally include contacting a hydrazine-based solvent, a source of Cu, a source of Sn, a source of Zn carboxylate, a source of at least one of S and Se, under conditions sufficient to form a solution substantially free of solid particles; applying the solution onto a substrate to form a thin layer; and annealing the thin layer at a temperature, pressure, and length of time sufficient to form the kesterite film. Also disclosed are hydrazine-based precursor solutions for forming a kesterite film and a photovoltaic device including the kesterite film formed by the above method.

Abstract: Designs of extremely high efficiency solar cells are described. A novel alternating bias scheme enhances the photovoltaic power extraction capability above the cell band-gap by enabling the extraction of hot carriers. When applied in conventional solar cells, this alternating bias scheme has the potential of more than doubling their yielded net efficiency. When applied in conjunction with solar cells incorporating quantum wells (QWs) or quantum dots (QDs) based solar cells, the described alternating bias scheme has the potential of extending such solar cell power extraction coverage, possibly across the entire solar spectrum, thus enabling unprecedented solar power extraction efficiency. Within such cells, a novel alternating bias scheme extends the cell energy conversion capability above the cell material band-gap while the quantum confinement structures are used to extend the cell energy conversion capability below the cell band-gap.

Abstract: A method for forming a photovoltaic device by depositing at least one wetting layer onto a substrate where the wetting layer is ?100 nm and sputtering a photovoltaic material onto the wetting layer where the wetting layer interacts with the photovoltaic material. Also disclosed is the related photovoltaic device made by this method. The wetting layer may comprise any combination of In2Se3, CuSe2, Cu2Se, Ga2Se3, In2S3, CuS2, Cu2S, Ga2S3, CuInSe2, CuGaSe2, InxGa2-xSe3 where 0?x?2, CuInS2, CuGaS2, InxGa2-xS3 where 0?x?2, In2Se3-xSx where 0?x?3, CuSe2-xSx where 0?x?2, Cu2Se1-xSx, (0?x?1), Ga2Se3-xSx where 0?x?3, and InxGa2-xS3-ySy where 0?x?2, 0?y?3. The photovoltaic material may be a CIGS (copper indium gallium diselenide) material or a variation of a CIGS material where a CIGS component is replaced or supplemented with any combination of sulfur, tellurium, aluminum, and silver.

Abstract: To provide a photoelectric conversion device having a high photoelectric conversion efficiency, a photoelectric conversion device 21 includes a substrate 1, a plurality of lower electrodes 2 on the substrate 1 comprising a metal element, a plurality of photoelectric conversion layers 33 comprising a chalcogen compound semiconductor formed on the plurality of lower electrodes 2 and separated from one another on the lower electrodes 2, a metal-chalcogen compound layer 8 comprising the metal element and a chalcogen element included in the chalcogen compound semiconductor formed between the lower electrode 2 and the photoelectric conversion layer 33, an upper electrode 5 formed on the photoelectric conversion layer 33, and a connection conductor 7 electrically connecting, in a plurality of the photoelectric conversion layers 33, the upper electrode 5 to the lower electrode 2 without interposition of the metal-chalcogen compound layer 8.

Abstract: The present invention provides an improved redox couple for electrochemical and optoelectronic devices. The redox couple is based on a complex of a first row transition metal, said complex containing at least one mono-, bi-, or tridentate ligand comprising a substituted or unsubstituted ring or ring system comprising a five-membered N-containing heteroring and/or a six-membered ring comprising at least two heteroatoms, at least one of which being a nitrogen atom, said five- or six-membered heteroring, respectively, comprising at least one double bond. The invention also relates to electrolytes and to the devices containing the complex, and to the use of the complex as a redox couple. The invention further provides electrochemical and/or optoelectronic devices comprising a first and a second electrode and, between said first and second electrode, a charge transport layer, said a charge transport layer comprising tetracyanoborate ([B(CN)4]?) and a cationic metal complex functioning as redox-couple.

Abstract: A thin film solar cell is disclosed comprising the following layers deposited on a substrate: a microcrystalline p- or n-layer, an intermediate microcrystalline silicon i-layer applied by a hot-wire chemical-vapor deposition (HWCVD) method on the microcrystalline p- or n-layer a), an additional i-layer of microcrystalline silicon, which is formed by depositing on the intermediate microcrystalline silicon i-layer, by a plasma enhanced chemical vapor deposition (PECVD), a sputtering process, or a photo-CVD method whereby layers b) and c) together form an i-layer, and if a p-layer is present as the layer of step a), an n-layer, and if an n-layer is present as the layer of step a), a p-layer that is either microcrystalline or amorphous.

Abstract: Solar cell structures formed using molecular beam epitaxy (MBE) that can achieve improved power efficiencies in relation to prior art thin film solar cell structures are provided. A reverse p-n junction solar cell device and methods for forming the reverse p-n junction solar cell device using MBE are described. A variety of n-p junction and reverse p-n junction solar cell devices and related methods of manufacturing are provided. N-intrinsic-p junction and reverse p-intrinsic-n junction solar cell devices are also described.

Abstract: A photoelectric conversion element of an embodiment includes: a light absorbing layer containing copper (Cu), at least one Group IIIb element selected from the group including aluminum (Al), indium (In) and gallium (Ga), and sulfur (S) or selenium (Se), and having a chalcopyrite structure; and a buffer layer formed from zinc (Zn) and oxygen (O) or sulfur (S), wherein the molar ratio represented by S/(S+O) of the buffer layer is equal to or greater than 0.7 and equal to or less than 1.0, and the crystal grain size is equal to or greater than 10 nm and equal to or less than 100 nm.

Abstract: A photoelectric conversion element of an embodiment includes: a light absorbing layer containing Cu, at least one Group IIIb element selected from the group including Al, In and Ga, and S or Se, and having a chalcopyrite structure; and a buffer layer formed from Zn and O or S, in which the ratio S/(S+O) in the area extending in the buffer layer up to 10 nm from the interface between the light absorbing layer and the buffer layer, is equal to or greater than 0.7 and equal to or less than 1.0.

Abstract: A quantum dot thin film solar cell is provided, which at least includes a first electrode layer, an optical active layer, and a second electrode layer sequentially deposited on a substrate. A plurality of quantum dots is formed in the optical active layer. Since the plurality of quantum dots and the optical active layer are formed through co-sputtering, an interface adhesion between the plurality of quantum dots and the optical active layer is good in this quantum dot thin film solar cell.

Abstract: A solar cell which can increase its open-circuit voltage, short-circuit current, and fill factor (F.F.), thereby enhancing its conversion efficiency is provided. The solar cell of the present invention comprises a p-type semiconductor layer and an n-type semiconductor layer, formed on the p-type semiconductor layer, containing a compound expressed by the following chemical formula (1): ZnO1-x-ySxSey??(1) where x?0, y>0, and 0.2<x+y<0.65.

Abstract: This invention provides compositions and the processes for preparing the compositions that are useful for preparing films of CZTS and its selenium analogues on a substrate. Such films are useful in preparing photovoltaic devices. This invention also provides processes for preparing a semiconductor layer comprising CZTS/Se microparticles embedded in an inorganic matrix. This invention also provides processes for making a photovoltaic devices and the photovoltaic devices so produced.

Abstract: A composition includes a chemical reaction product defining a first surface and a second surface, characterized in that the chemical reaction product includes a segregated phase domain structure including a plurality of domain structures, wherein at least one of the plurality of domain structures includes at least one domain that extends from a first surface of the chemical reaction product to a second surface of the chemical reaction product. The segregated phase domain structure includes a segregated phase domain array. The plurality of domain structures includes i) a copper rich. indium/gallium deficient Cu(In,Ga)Se2 domain and ii) a copper deficient, indium/gallium rich Cu(In,Ga)Se2 domain.

Abstract: A method of manufacture of I-III-VI-absorber photovoltaic cells involves sequential deposition of films comprising one or more of silver and copper, with one or more of aluminum indium and gallium, and one or more of sulfur, selenium, and tellurium, as compounds in multiple thin sublayers to form a composite absorber layer. In an embodiment, the method is adapted to roll-to-roll processing of photovoltaic cells. In an embodiment, the method is adapted to preparation of a CIGS absorber layer having graded composition through the layer of substitutions such as tellurium near the base contact and silver near the heterojunction partner layer, or through gradations in indium and gallium content. In a particular embodiment, the graded composition is enriched in gallium at a base of the layer, and silver at the top of the layer. In an embodiment, each sublayer is deposited by co-evaporation of copper, indium, gallium, and selenium, which react in-situ to form CIGS.

Abstract: A solar cell module includes a substrate, a lower electrode on the substrate, a light absorption layer on the lower electrode, an upper electrode on the light absorption layer, and a protective layer on the upper electrode, the protective layer extending along sidewalls of the light absorption layer to the lower electrode, the protective layer including a moisture absorbing material.

Abstract: Low-temperature sulfurization/selenization heat treatment processes for photovoltaic devices are provided. In one aspect, a method for fabricating a photovoltaic device is provided. The method includes the following steps. A substrate is provided that is either (i) formed from an electrically conductive material or (ii) coated with at least one layer of a conductive material. A chalcogenide absorber layer is formed on the substrate. A buffer layer is formed on the absorber layer. A transparent front contact is formed on the buffer layer. The device is contacted with a chalcogen-containing vapor having a sulfur and/or selenium compound under conditions sufficient to improve device performance by filling chalcogen vacancies within the absorber layer or the buffer layer or by passivating one or more of grain boundaries in the absorber layer, an interface between the absorber layer and the buffer layer and an interface between the absorber layer and the substrate.