Abstract: A method for forming a photovoltaic device comprising the steps of: providing a first conductive material on a substrate; depositing a continuous layer of a dielectric material less than 10 nm thick on the first conductive material; annealing the first conductive material and the layer of dielectric material; forming a chalcogenide light-absorbing material on the layer of dielectric material; and depositing a second material on the light-absorbing material such that the second material is electrically coupled to the light-absorbing material; wherein the first conductive material and the dielectric material are selected such that, during the step of annealing, a portion of the first conductive material undergoes a chemical reaction to form: a layer of a metal chalcogenide material at the interface between first conductive material and the dielectric material; and a plurality of openings in the layer of dielectric material; the openings being such to allow electrical coupling between the light-absorbing materia

Abstract: The present disclosure discloses an array substrate and a preparation method thereof. After a first passivation layer is formed, residual gas is directly drawn out of a closed chamber to prevent the residual gas from reacting to form an unstable layer on the first passivation layer. Furthermore, after the residual gas is drawn out, a preset gas fills the closed chamber, and is retained for a preset time period and then drawn out. The retaining of the preset gas can effectively alleviate the damage to the passivation layer by static electricity.

Abstract: A semiconductor optical device is comprised of a phonon donating material structurally connected to an indirect bandgap material to improve absorption and emission of light in the indirect bandgap material. An excitation energy source provides excitation radiation to the semiconductor optical device to excite electrons in the semiconductor optical device. Phonons from the phonon donating material present in the indirect bandgap material provide a mechanism for increased rates of electron-hole generation and recombination, and electrical leads provide an electrical connection to the semiconductor optical device.

Abstract: The present invention relates to a method for preparing an aqueous or hydro-alcoholic colloidal solution of metal chalcogenide amorphous nanoparticles notably of the Cu2ZnSnS4 (CZTS) type and to the obtained colloidal solution. The present invention also relates to a method for manufacturing a film of large-grain crystallized semi-conducting metal chalcogenide film notably of CZTS obtained from an aqueous or hydro-alcoholic colloidal solution according to the invention, said film being useful as an absorption layer deposited on a substrate applied in a solid photovoltaic device.

Abstract: A method of manufacturing a CIS solar battery includes preparing a layer-shaped member that is configured by a substrate, a first electrode layer, a CIS layer, and a second electrode layer; setting a temperature of the layer-shaped member to a second temperature that is lower than the first temperature; forming a layer of a layer forming substance having a higher linear expansion coefficient than the substrate in a solid state of the layer on the second electrode layer; and cooling the layer-shaped member. In the method, a thin-film CIS solar battery is acquired by peeling the CIS layer from the first electrode layer along with contraction of the layer of the layer forming substance caused by the cooling of the layer-shaped member.

Abstract: A compound solar cell having a higher conversion efficiency and a method for producing the compound solar cell at lower costs are provided. The compound solar cell includes a CIGS light absorbing layer, a buffer layer and a front side electrode layer provided on a substrate. An interface layer made of a mixed crystal compound having a composition represented by the following general formula is provided between the CIGS light absorbing layer and the buffer layer: Zn(Ox,S1-x) . . . (1), wherein X is 0.9<X?1.

Abstract: Various methods are used to provide a desired doping metal concentration in a CIGS-containing ink when the CIGS layer is deposited on a photovoltaic device. When the doping metal is sodium, it may be incorporated by: adding a sodium salt, for example sodium acetate, together with the copper-, indium- and/or gallium-containing reagents at the beginning of the synthesis reaction of Cu(In,Ga)(S,Se)2 nanoparticles; synthesizing Cu(In,Ga)(S,Se)2 nanoparticles and adding a sodium salt to the reaction solution followed by mild heating before isolating the nanoparticles to aid sodium diffusion; and/or, using a ligand that is capable of capping the Cu(In,Ga)(S,Se)2 nanoparticles with one end of its molecular chain and binding to sodium atoms with the other end of its chain.

Abstract: A solar cell module includes a substrate; an absorber layer formed over the substrate; a porous alumina passivation layer formed on an upper surface of the absorber layer; a buffer layer conformably formed over the passivation layer; and a transparent conducting oxide layer conformably formed over the buffer layer.

Abstract: Techniques for achieving band gap grading in CZTS/Se absorber materials are provided. In one aspect, a method for creating band gap grading in a CZTS/Se absorber layer includes the steps of: providing a reservoir material containing Si or Ge; forming the CZTS/Se absorber layer on the reservoir material; and annealing the reservoir material and the CZTS/Se absorber layer under conditions sufficient to diffuse Si or Ge atoms from the reservoir material into the CZTS/Se absorber layer with a concentration gradient to create band gap grading in the CZTS/Se absorber layer. A photovoltaic device and method of forming the photovoltaic device are also provided.

Abstract: A solar cell containing a plurality of CIGS absorber sublayers has a conversion efficiency of at least 13.4 percent and a minority carrier lifetime below 2 nanoseconds. The sublayers may have a different composition from each other.

Abstract: A solar cell according to the disclosure includes a back electrode layer; and a light absorbing layer on the back electrode layer, wherein the light absorbing layer includes an undoped region and a doping region on the undoped region, and the doping region includes zinc. A method of fabricating a solar cell according to the disclosure includes forming a back electrode layer on a substrate; forming a preliminary light absorbing layer on the back electrode layer; forming a dopant supply layer on the preliminary light absorbing layer; and diffusing the dopant supply layer.

Abstract: A method and apparatus for manufacturing a nitrogen-doped CZTSSe layer for a solar cell is disclosed. A substrate is mounted in a vacuum chamber. A plurality of effusion cells are placed within the vacuum chamber in order to evaporate copper, zinc, tin, sulfur, and/or selenium to form elemental vapors in a region proximate the substrate. An RF-based nitrogen source delivers a nitrogen plasma in the region proximal to the substrate. The elemental vapors and the nitrogen plasma form a gas mixture in the region near the substrate, which then react at the substrate to form a CZTSSe absorber layer for a solar cell.

Abstract: A method and apparatus for forming a thin film of a copper indium gallium selenide (CIGS)-type material are disclosed. The method includes providing first and second targets in a common sputtering chamber. The first target includes a source of CIGS material, such as an approximately stoichiometric polycrystalline CIGS material, and the second target includes a chalcogen, such as selenium, sulfur, tellurium, or a combination of these elements. The second target provides an excess of chalcogen in the chamber. This can compensate, at least in part, for the loss of chalcogen from the CIGS-source in the first target, resulting in a thin film with a controlled stoichiometry which provides effective light absorption when used in a solar cell.

Abstract: Disclosed are a solar cell and preparing method of the same. The solar cell includes a back electrode layer on a support substrate, a molybdenum oxide layer on the back electrode layer, a light absorbing layer on the molybdenum oxide layer, and a front electrode layer on the light absorbing layer.

Abstract: The invention is directed to a method for producing non-oxide semiconductor nanoparticles, the method comprising: (a) subjecting a combination of reaction components to conditions conducive to microbially-mediated formation of non-oxide semiconductor nanoparticles, wherein said combination of reaction components comprises i) anaerobic microbes, ii) a culture medium suitable for sustaining said anaerobic microbes, iii) a metal component comprising at least one type of metal ion, iv) a non-metal component comprising at least one non-metal selected from the group consisting of S, Se, Te, and As, and v) one or more electron donors that provide donatable electrons to said anaerobic microbes during consumption of the electron donor by said anaerobic microbes; and (b) isolating said non-oxide semiconductor nanoparticles, which contain at least one of said metal ions and at least one of said non-metals.

Abstract: A direct solution method based on a versatile amine-thiol solvent mixture which dissolves elemental metals, metal salts, organometallic complexes, metal chalcogenides, and metal oxides is described. The metal containing and metal chalcogenide precursors can be prepared by dissolving single or multiple metal sources, chalcogens, and/or metal chalcogenide compounds separately, simultaneously, or stepwise. Multinary metal chalcogenides containing at least one of copper, zinc, tin, indium, gallium, cadmium, germanium, and lead, with at least one of sulfur, selenium, or both are obtained from the above-mentioned metal chalcogenide precursors in the form of thin films, nanoparticles, inks, etc. Furthermore, infiltration of metal containing compounds into a porous structure can be achieved using the amine-thiol based precursors.

Abstract: A method of making a germanium perovskite/crystalline germanium thin-film tandem solar cell including the steps of depositing a textured oxide buffer layer on glass, depositing a Sn—Ge film from a eutectic alloy on the buffer layer; and depositing perovskite elements on the Sn—Ge film, thus forming a perovskite layer based on the Ge from the Sn—Ge film, incorporating the Ge into the perovskite layer.

Abstract: The inventive photoelectric conversion device includes a substrate, a lower electrode layer provided on the substrate, a CIGS compound semiconductor layer provided on the lower electrode layer as covering the lower electrode layer, and a transparent electrode layer provided on the compound semiconductor layer, wherein the compound semiconductor layer has a maximum Ga content variation of not less than 5% as measured in a layer thickness direction, and a maximum In content variation of not less than 6% as measured in the layer thickness direction.

Abstract: Provided is a CIGSSe thin film for a solar cell, a method for preparing the same, and a solar cell using the same. More particularly, the CIGSSe thin film for a solar cell shows a decrease in peak intensity of sulfur from the surface of the thin film to the local minimum value point of sulfur content in the depth direction, after the analysis based on the Auger electron spectroscopy, and thus controls the band-gap in the thin film. Therefore, the solar cell including the CIGSSe thin film shows an excellent effect in improving photoelectric conversion efficiency.

Abstract: The present invention provides a photovoltaic device, such as, a solar cell, having a substrate and an absorber layer disposed on the substrate. The absorber layer includes a doped or undoped composition represented by the formula: Cu1-yIn1-xGaxSe2-zSz wherein 0?x?1; 0?y?0.15 and 0?z?2; wherein the absorber layer is formed by a solution-based deposition process which includes the steps of contacting hydrazine and a source of Cu, a source of In, a source of Ga, a source of Se, and optionally a source of S, and further optionally a source of a dopant, under conditions sufficient to produce a homogeneous solution; coating the solution on the substrate to produce a coated substrate; and heating the coated substrate to produce the photovoltaic device. A photovoltaic device and a process for making same based on a hydrazinium-based chalcogenide precursor are also provided.

Abstract: Disclosed is a thin-film solar cell which has a high photoelectric conversion efficiency and is provided with a substrate (1), a backside surface electrode layer (2) formed on the substrate (1), a p-type light-absorbing layer (3) formed on the backside surface electrode layer (2), and an n-type transparent conductive film (5) formed on the p-type light-absorbing layer (3). Voids (6) are formed at the interface of the backside surface electrode layer (2) and the p-type light-absorbing layer (3).

Abstract: A method for producing a compound semiconductor composed of pentanary kesterite/stannite of the type Cu2ZnSn(S,Se)4 is described. The method has the following steps: producing at least one precursor layer stack consisting of a first precursor layer and a second precursor layer; thermally treating the at least one precursor layer stack in a process chamber; and feeding at least one process gas into the process chamber during the thermal treatment of the at least one precursor layer stack. Furthermore, a thin-film solar cell with an absorber consisting of the pentanary compound semiconductor Cu2ZnSn(S,Se)4 on a body is described.

Abstract: Photovoltaic devices such as solar cells, hybrid solar cell-batteries, and other such devices may include an active layer disposed between two electrodes, the active layer having perovskite material and other material such as mesoporous material, interfacial layers, thin-coat interfacial layers, and combinations thereof. The perovskite material may be photoactive. The perovskite material may be disposed between two or more other materials in the photovoltaic device. Inclusion of these materials in various arrangements within an active layer of a photovoltaic device may improve device performance. Other materials may be included to further improve device performance, such as, for example: additional perovskites, and additional interfacial layers.

Abstract: Copper(II) acetate, zinc(II) acetate, and tin(IV) acetate are weighed so that the total amount of metal ions is 2.0×10?4 mol and the molar ratio of ions is Cu:Zn:Sn=2:1:1, and 2.0 cm3 of oleylamine is added to prepare a mixed solution. Apart from this, 1.0 cm3 of oleylamine is added to 2.0×10?4 mol of sulfur powder to prepare a mixed solution. These mixed solutions are separately heated at 60° C. and mixed at room temperature. The pressure in a test tube is reduced, followed by nitrogen filling. The test tube is heated at 240° C. for 30 minutes and then allowed to stand until room temperature. The resultant product is separated into a supernatant and precipitates by centrifugal separation. The separated supernatant is filtered, methanol is added to produce precipitates. The precipitates are dissolved by adding chloroform to prepare a semiconductor nanoparticle solution.

Abstract: Disclosed are an ink composition for manufacturing a light absorption layer including metal nano particles and a method of manufacturing a thin film using the same, more particularly, an ink composition for manufacturing a light absorption layer including copper (Cu)-enriched Cu—In bimetallic metal nano particles and Group IIIA metal particles including S or Se dispersed in a solvent and a method of manufacturing a thin film using the same.

Abstract: A method for improving a nominal output of a thin-film solar module with a laminated composite of two substrates which are connected to each other by at least one adhesive layer and between which there are solar cells connected in series is described. The method relates to solar cells being illuminated with an artificial light with an irradiance of at least 5 kW/m2.

Abstract: Disclosed are new compound semiconductors which may be used for solar cells or as thermoelectric materials, and their application. The compound semiconductor may be represented by a chemical formula: InxCo4Sb12-zSez, where 0<x?0.25 and 0.4<z?2.

Abstract: A method of producing a metal chalcogenide dispersion usable in forming a light absorbing layer of a solar cell, the method including: a metal chalcogenide nano particle formation step in which at least one metal or metal compound selected from the group consisting of a group 11, 12, 13, 14 or 15 metal or metal compound, a water-containing solvent and a group 16 element-containing compound are mixed together to obtain metal chalcogenide nano particles; and an addition step in which a compound (1) represented by general formula (1) is added to the metal chalcogenide nano particles, thereby obtaining a metal chalcogenide dispersion (wherein R1 to R4 each independently represents an alkyl group, an aryl group or a hydrogen atom; provided that at least one of R1 to R4 represents a hydrocarbon group).

Abstract: In one embodiment, a method includes depositing a photoactive layer onto a first substrate, depositing a contact layer onto the photoactive layer, attaching a second substrate onto the contact layer, and removing the first substrate from the photoactive layer, contact layer, and second substrate.

Abstract: The present invention provides strategies for making high quality CIGS photoabsorbing materials from precursor films that incorporate a sub-stoichiometric amount of chalcogen(s). Chalcogen(s) are incorporated into the CIGS precursor film via co-sputtering with one or more other constituents of the precursor. Optional annealing also may be practiced to convert precursor into more desirable chalcopyrite crystalline form in event all or a portion of the precursor has another constitution. The resultant precursors generally are sub-stoichiometric with respect to chalcogen and have very poor electronic characteristics. The conversion of these precursors into CMS photoabsorbing material via chalcogenizing treatment occurs with dramatically reduced interfacial void content. The resultant CIGS material displays excellent adhesion to other layers in the resultant photovoltaic devices.

Abstract: Methods of forming absorber layers in a TFPV device are provided. Methods are described to provide the formation of metal oxide films and heating the metal oxide films in the presence of a chalcogen to form a metal-oxygen-chalcogen alloy. Methods are described to provide the formation of metal oxide films, forming a layer of elemental chalcogen on the metal oxide film, and heating the stack to form a metal-oxygen-chalcogen alloy. In some embodiments, the metal oxide film includes zinc oxide and the chalcogen includes selenium.

Abstract: The disclosure provides a method for fabricating a solar cell, including: providing a first substrate; forming a light absorption precursor layer on the first substrate; conducting a thermal process to the light absorption precursor layer to form a light absorption layer, wherein the light absorption layer includes a first light absorption layer and a second light absorption layer, and the first absorption layer is formed on the first substrate; forming a second substrate on the second light absorption layer; removing the first substrate to expose a surface of the first light absorption layer; forming a zinc sulfide (ZnS) layer on the surface of the first light absorption layer; and forming a transparent conducting oxide (TCO) layer on the zinc sulfide (ZnS) layer.

Abstract: A compositional range of high strain point and/or intermediate expansion coefficient alkali metal free aluminosilicate and boroaluminosilicate glasses are described herein. The glasses can be used as substrates or superstrates for photovoltaic devices, for example, thin film photovoltaic devices such as CdTe or CIGS photovoltaic devices or crystalline silicon wafer devices. These glasses can be characterized as having strain points?600° C., thermal expansion coefficient of from 35 to 50×10?7/° C.

Abstract: In one example embodiment, a method includes sputtering one or more absorber layers over a substrate. In a particular embodiment, the substrate is pre-heated to a substrate temperature of at least approximately 300 degrees Celsius prior to the sputtering and during the sputtering of each of one or more of the absorber layers, and the sputtering of at least one of the absorber layers is performed in a sputtering atmosphere having a pressure of at least 0.5 Pascals. Additionally, in a particular embodiment, the sputtering of at least one of the absorber layers comprises sputtering from a sputter target that comprises a chalcogenide alloy that comprises copper (Cu) and one or more of sulfur (S), selenium (Se), or tellurium (Te).

Abstract: The present invention provides improved chalcogen-containing, photovoltaic structures as well as related compositions, photovoltaic devices incorporating these structures, methods of making these structures and devices, and methods of using these structures and devices. According to principles of the present invention, the adhesion of PACB compositions is improved through the use of chalcogen-containing tie layers.

Abstract: A CIGS film production method is provided which ensures that a CIGS film having a higher conversion efficiency can be produced at lower costs at higher reproducibility even for production of a large-area device. A CIGS solar cell production method is also provided for producing a CIGS solar cell including the CIGS film. The CIGS film production method includes: a stacking step of stacking a layer (A) containing indium, gallium and selenium and a layer (B) containing copper and selenium in a solid phase in this order over a substrate; and a heating step of heating a stacked structure including the layer (A) and the layer (B) to melt a compound of copper and selenium of the layer (B) into a liquid phase to thereby diffuse copper from the layer (B) into the layer (A) to permit crystal growth to provide a CIGS film.

Abstract: The present invention relates to a layer system (1) for thin-film solar cells and solar modules based on CIS-absorbers (4). The layer system (1) according to the invention has a buffer layer (4) made of In2(S1?x,Sex)3+?, wherein 0?x?1 and ?1???1. Additionally, the buffer layer (5) is amorphously designed. With this buffer layer (5), the disadvantages of CdS-buffers frequently used to date, namely toxicity and poor process integration, are overcome, whereby in addition to high efficiency, high long-term stability is also achieved; and thus again the disadvantages of conventional buffer layers alternative to CdS do not exist.

Abstract: A photovoltaic device includes a substrate; a back contact layer disposed on the substrate; an absorber layer for photo absorption disposed above the back contact layer; a buffer layer disposed above the absorber layer; a front contact layer disposed above the buffer layer; and a plasmonic nanostructured layer having a plurality of nano-particles, wherein the plasmonic nanostructured layer is between a topmost back contact layer surface and the absorber layer.

Abstract: A photoelectric conversion efficiency of a photoelectric conversion device is improved. A photoelectric conversion device comprises an electrode layer, a first semiconductor layer disposed on the electrode layer and including a group I-III-VI compound and oxygen element, and a second semiconductor layer disposed on the first semiconductor layer and forming a pn junction with the first semiconductor layer, and an atomic concentration of the oxygen element in the first semiconductor layer is lower in a surface portion on the electrode layer side than in a central portion of the first semiconductor layer in a lamination direction thereof.

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 photovoltaic device includes a first contact and a hybrid absorber layer. The hybrid absorber layer includes a chalcogenide layer and a semiconductor layer in contact with the chalcogenide layer. A buffer layer is formed on the absorber layer, and a transparent conductive contact layer is formed on the buffer layer.

Abstract: This invention describes a semiconductor material of general formula (I) Me12Me21-xMe3xMe4(C11-yC2y)4, in which x stands for a numeric value from 0 to 1, and y stands for a numeric value of 0 to 1, as well as its use as an absorber material in a solar cell. The metal Mel is a metal which is selected from the metals in group 11 of the periodic table of the elements (Cu, Ag or Au). The metals Me2 and Me3 are selected from the elements of the 12th group of the periodic table of elements (Zn, Cd & Hg). The metal Me4 is a metal which is selected from the 4th main group of the periodic table of elements (C, Si, Ge, Sn and Pb). The non-metals C1 and C2 are selected from the group of chalcogenides (S, Se and Te).

Abstract: A method for fabricating a thin film photovoltaic device is provided. The method includes providing a substrate comprising a surface region made of a thin-film photovoltaic absorber including copper, indium, gallium, selenium, and sulfur species. Additionally, the method includes applying a dip-in chemical bath deposition process for forming a buffer layer containing at least zinc-ogygen-sulfide material but substantially free of cadmium species. Furthermore, the method includes producing a chemical bath including steps of heating a bath of water to about 75° C., adding aqueous ammonia to mix with the bath of water, adding a solution of sodium hydroxide, adding zinc salt solution, and adding a solution of thiourea. The dip-in chemical bath deposition process includes immersing a plurality of substrates formed with the thin-film photovoltaic absorber substantially vertically in the chemical bath for 30 minutes to form the zinc-oxygen-sulfide buffer layer followed by a cleaning and drying process.

Abstract: A photovoltaic cell structure for manufacturing a photovoltaic device. The photovoltaic cell structure includes a substrate including a surface region. A first conductor layer overlies the surface region. The photovoltaic cell structure includes a lower cell structure. The lower cell structure includes a first P type absorber layer using a first semiconductor metal chalcogenide material and/or other semiconductor material overlying the first conductor layer. The first P type absorber material is characterized by a first bandgap ranging from about 0.5 eV to about 1.0 eV, a first optical absorption coefficient greater than about 104 cm?1. The lower cell structure includes a first N+ type window layer comprising at least a second metal chalcogenide material and/or other semiconductor material overlying the first P absorber layer. The photovoltaic cell structure includes an upper cell structure.

Abstract: A method for forming a photovoltaic device includes forming an absorber layer with a granular structure on a conductive layer; conformally depositing an insulating protection layer over the absorber layer to fill in between grains of the absorber layer; and planarizing the protection layer and the absorber layer. A buffer layer is formed on the absorber layer, and a top transparent conductor layer is deposited over the buffer layer.

Abstract: Exemplary embodiments of the present disclosure are directed to improve p-type doping (p-doping) of cadmium telluride (CdTe) for CdTe-based solar cells, such as cadmium Sulfide (Cds)/CdTe solar cells. Embodiments can achieve improved p-doping of CdTe by creating a high density of cadmium (Cd) vacancies (VCd) and subsequently substituting a high density of substitutional defects and/or defect complexes for the Cd vacancies that were created. Formation of a high density of substitutional defects and defect complexes as a p-dopant can improve light-to-electricity conversion efficiency, doping levels or hole concentrations, junction band bending, and/or ohmic contact associated with p-type CdTe (p-CdTe) based solar cells.

Abstract: The present disclosure relates to a Se or S based thin film solar cell and a method for fabricating the same, which may improve the structural and electrical characteristics of an upper transparent electrode layer by controlling a structure of a lower transparent electrode layer in a thin film solar cell having a Se or S based light absorption layer. In the Se or S based thin film solar cell having a light absorption layer and a front transparent electrode layer, the front transparent electrode layer comprises a lower transparent electrode layer and an upper transparent electrode layer, and the lower transparent electrode layer comprises an oxide-based thin film obtained by blending an impurity element into a mixed oxide in which Zn oxide and Mg oxide are mixed (also, referred to as an ‘impurity-doped Zn—Mg-based oxide thin film’).

Abstract: A photovoltaic device is presented. The photovoltaic device includes a layer stack; and an absorber layer is disposed on the layer stack. The absorber layer comprises selenium, wherein an atomic concentration of selenium varies across a thickness of the absorber layer. The photovoltaic device is substantially free of a cadmium sulfide layer.

Abstract: Disclosed are a solar cell and preparing method of the same. The solar cell includes a back electrode layer on a support substrate, a molybdenum oxide layer on the back electrode layer, a light absorbing layer on the molybdenum oxide layer, and a front electrode layer on the light absorbing layer.

Abstract: Photovoltaic (PV) devices and solution-based methods of making the same are described. The PV devices include a CIGS-type absorber layer formed on a molybdenum substrate. The molybdenum substrate includes a layer of low-density molybdenum proximate to the absorber layer. The presence of low-density molybdenum proximate to the absorber layer has been found to promote the growth of large grains of CIGS-type semiconductor material in the absorber layer.