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  • H01L31/02—Details
  • H01L31/0224—Electrodes
  • H01L31/022408—Electrodes for devices characterised by at least one potential jump barrier or surface barrier
  • H01L31/022425—Electrodes for devices characterised by at least one potential jump barrier or surface barrier for solar cells
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  • H01L31/0248—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies
  • H01L31/0256—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by the material
  • H01L31/0264—Inorganic materials
  • H01L31/032—Inorganic materials including, apart from doping materials or other impurities, only compounds not provided for in groups H01L31/0272 - H01L31/0312
  • H01L31/0322—Inorganic materials including, apart from doping materials or other impurities, only compounds not provided for in groups H01L31/0272 - H01L31/0312 comprising only AIBIIICVI chalcopyrite compounds, e.g. Cu In Se2, Cu Ga Se2, Cu In Ga Se2
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  • H01L31/0248—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies
  • H01L31/036—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes
  • H01L31/0392—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate
  • H01L31/03923—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate including AIBIIICVI compound materials, e.g. CIS, CIGS
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  • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
  • H01L31/06—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by potential barriers
  • H01L31/072—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by potential barriers the potential barriers being only of the PN heterojunction type
  • H01L31/0749—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by potential barriers the potential barriers being only of the PN heterojunction type including a AIBIIICVI compound, e.g. CdS/CulnSe2 [CIS] heterojunction solar cells
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  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/02104—Forming layers
  • H01L21/02365—Forming inorganic semiconducting materials on a substrate
  • H01L21/02367—Substrates
  • H01L21/0237—Materials
  • H01L21/02422—Non-crystalline insulating materials, e.g. glass, polymers
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  • H01L21/02518—Deposited layers
  • H01L21/02521—Materials
  • H01L21/02568—Chalcogenide semiconducting materials not being oxides, e.g. ternary compounds
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  • H01L21/02612—Formation types
  • H01L21/02614—Transformation of metal, e.g. oxidation, nitridation
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E10/00—Energy generation through renewable energy sources
  • Y02E10/50—Photovoltaic [PV] energy
  • Y02E10/541—CuInSe2 material PV cells
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  • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
  • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

• the invention relates to the field of photovoltaic cells, more particularly to the field of molybdenum-based conductive substrates used to produce thin-film photovoltaic cells.
• certain thin-film photovoltaic cells use a conductive substrate based on molybdenum coated with a layer of absorber agent, generally copper chalcopyrite Cu, indium In, and selenium Se and / or S sulfur. It may be, for example, a material of the CulnSe 2 type. This type of material is known under the abbreviation CIS. It can also be CIGS, that is to say a material that also incorporates gallium.
• the electrodes are most often based on molybdenum (Mo), because this material has a number of advantages. It is a good electrical conductor (relatively low specific resistance of the order of ⁇ ⁇ . ⁇ ). It can be subjected to the necessary high heat treatments because it has a high melting point (2610 ° C). It resists, to a certain extent, selenium and sulfur. Deposition of the absorber layer most often requires contact with an atmosphere containing selenium or sulfur which tends to deteriorate most metals. Molybdenum reacts on the surface, with selenium in particular, forming MoSe 2 , but retains most of its properties, including electrical properties, and maintains adequate electrical contact with the CIS or CIGS layer. Finally, it is a material on which the CIS or CIGS type layers adhere well, molybdenum even tends to promote crystal growth.
• Mo molybdenum
• molybdenum has a significant disadvantage when considering industrial production: it is an expensive material. Indeed, the molybdenum layers are usually deposited by sputtering (magnetic field assisted). But molybdenum targets are expensive. This is all the less negligible as to obtain the desired level of electrical conductivity (a resistance per square less than or equal to 2 ⁇ / ⁇ , and preferably less than or equal to 1 or 0.5 ⁇ / ⁇ after treatment in an atmosphere containing S or Se), you need a layer of Mo relatively thick, generally of the order of 700nm to 1 micrometer.
• the patent application WO-A-02/065554 of SAINT-GOBAIN GLASS FRANCE teaches to provide a relatively thin layer of molybdenum (less than 500 nm) and to provide one or more alkali-impermeable layers between the substrate and the layer based on molybdenum, so as to preserve the qualities of the thin layer based on molybdenum during subsequent heat treatments.
• This type of conductive substrate is nevertheless relatively expensive.
• An object of the present invention is to provide a new conductive substrate based on molybdenum whose manufacturing cost is relatively low.
• the subject of the present invention is a conductive substrate for a photovoltaic cell, comprising:
• an electrode coating formed on the substrate comprising a molybdenum-based layer
• the conductive substrate comprising a stack of several layers formed on the substrate and interposed between the substrate and the electrode coating, of which:
• a first alkali impervious layer i.e., alkali metal formed on the substrate;
• An alkali retention layer the alkali retention layer (ie with alkaline ions) being formed on the first alkali-impermeable layer and in a material other than the first alkali-impermeable layer, the ratio of the thickness of the alkali retention layer and the first alkali impervious layer being 2 or more;
• a second alkaline impervious layer i.e., alkali metal
• the second alkali impermeable layer is formed on the alkali retention layer and in another material than the alkali retention layer.
• Such a stack makes it possible to ensure an effective barrier to alkalis (ie to alkaline ions) during the heat treatments undergone by the conductive substrate, in particular during the deposition of the absorber agent based on chalcopyrite.
• alkali-proof certain materials, which we will call “alkali-proof”, are difficult to penetrate by alkaline ions and thus prevent the migration of alkali to the upper layers.
• the stack cleverly combines waterproof layer and retention layer by placing a retention layer between two impermeable layers. As a result, if the first impermeable layer is crossed, the alkaline ions will be largely trapped in the retention layer, in particular because the second impermeable layer greatly limits the possibilities for the alkaline ions to leave the retention layer.
• the layers are not here chosen to have the same thicknesses.
• the retention layer of the stack has a thickness at least two times greater than the impermeable layer on which it is deposited. It has indeed been found that substantially only the thickness of the retention layer has a significantly positive influence on the alkaline barrier properties of the stack.
• the stack is thus particularly well adapted to prevent alkaline ions from migrating to the upper layers at a relatively low cost.
• the molybdenum-based layer is not likely to be degraded by the action of alkaline ions, it is thus possible to provide a layer of molybdenum-based thin, for example about 30nm.
• the cost of the electrode coating can thus be relatively low.
• reducing the thickness of the molybdenum layer has another advantage: allowing to deposit these relatively thin layers by cathodic sputtering with deposition parameters leading to strongly constrained layers, without the delamination problems that can be encountered with thick layers. Thin layers also tend to have fewer defects known as "pinholes" (pinholes).
• Providing such a stack also makes it possible to use as a substrate a sand-silico-soda-lime type glass sheet obtained by floating, glass of a relatively low cost and which has all the qualities that are known to this type of material. as for example its transparency, its impermeability to water and its hardness.
• the above device further comprises one or more of the following technical characteristics, taken separately or in any technically possible combination:
• the ratio of the thickness of the alkali retention layer to the first alkali impermeable layer is 3 or more;
• the first alkali-impermeable layer has a thickness greater than or equal to 3 nm, for example greater than or equal to 5 nm;
• the first alkali-impermeable layer has a thickness of less than or equal to 30 nm, for example less than or equal to 20 nm, for example less than or equal to 15 nm;
• the alkali retention layer has a thickness greater than or equal to 20 nm, for example greater than or equal to 25 nm;
• the retention layer of the alkalis has a thickness of less than or equal to 60 nm, for example less than or equal to 40 nm, for example less than or equal to 35 nm;
• the alkali retention layer is in contact with the first alkaline impervious layer
• the ratio between the thickness of the alkali retention layer and the second alkaline impervious layer is equal to 2 or more, for example equal to 3 or more;
• the second alkali-impermeable layer has a thickness greater than or equal to 3 nm, for example greater than or equal to 5 nm;
• the second alkali-impermeable layer has a lower thickness or equal to 30 nm, for example less than or equal to 20 nm, for example less than or equal to 15 nm;
• the second alkali-impermeable layer is in contact with the alkali retention layer
• the first alkali-impermeable layer and the second alkali-impermeable layer are in the same material
• said stack comprises only the first alkaline impervious layer, the alkali retention layer and the second alkaline impervious layer;
• said stack comprising a second alkali retention layer formed on the second alkaline impervious layer, said stack comprising a third alkaline impermeable layer formed on the second alkali retention layer;
• the ratio between the thickness of the second alkali retention layer and the second alkaline impervious layer is equal to 2 or more, for example equal to 3 or more;
• the ratio between the thickness of the second alkali retention layer and the third alkali-impermeable layer is 2 or more, for example 3 or more;
• each layer impervious to alkalis is based on silicon nitride
• the or each alkali retention layer is based on silicon oxide or tin oxide, for example a mixed tin oxide and zinc;
• the molybdenum-based layer has a thickness of at least 20 nm, for example at least 50 or 80 nm;
• the layer based on molybdenum Mo is at most 500 nm thick, for example at most 400 nm, for example at most 300 nm or for example at most 200 nm.
• the invention also relates to a semiconductor device comprising a conductive substrate as described above and a layer of a light-absorbing agent, for example based on chalcopyrite, the layer being formed on the conductive substrate.
• the invention also relates to a photovoltaic cell comprising a semiconductor device as described above.
• the subject of the invention is also a method of manufacturing a substrate conductor comprising steps of:
• the ratio of the alkali retention layer thickness to the alkali impermeable first layer being 2 or more and the alkali retention layer being made of a material other than the first alkali-impermeable layer;
• an electrode coating comprising a layer based on molybdenum, on the second alkali-impermeable layer.
• the above method further comprises one or more of the following technical characteristics, taken separately or in any technically possible combination:
• the ratio of the thickness of the alkali retention layer to the first alkali impermeable layer is 3 or more;
• the first alkali-impermeable layer has a thickness greater than or equal to 3 nm, for example greater than or equal to 5 nm;
• the first alkali-impermeable layer has a thickness of less than or equal to 30 nm, for example less than or equal to 20 nm, for example less than or equal to 15 nm;
• the alkali retention layer has a thickness greater than or equal to 20 nm, for example greater than or equal to 25 nm;
• the retention layer of the alkalis has a thickness of less than or equal to 60 nm, for example less than or equal to 40 nm, for example less than or equal to 35 nm;
• the alkali retention layer is formed directly on the first alkaline impervious layer
• the ratio between the thickness of the alkali retention layer and the second alkaline impervious layer is equal to 2 or more, for example equal to 3 or more;
• the second alkali-impermeable layer has a thickness greater than or equal to 3 nm, for example greater than or equal to 5 nm;
• the second alkali-impermeable layer has a thickness of less than or equal to 30 nm, for example less than or equal to 20 nm, for example less than or equal to 15 nm;
• the second alkali-impermeable layer is formed directly on the alkali retention layer
• the first alkali-impermeable layer and the second alkali-impermeable layer are in the same material
• the first alkali-impermeable layer, the alkali-retaining layer and the second alkali-impermeable layer are formed on the substrate prior to formation of the electrode coating, or even prior to formation of the molybdenum-based layer;
• the method comprises a step of forming a second alkali retention layer on the second alkaline impervious layer and a step of forming a third alkali impermeable layer on the second alkali retention layer;
• the ratio between the thickness of the second alkali retention layer and the second alkaline impervious layer is equal to 2 or more, for example equal to 3 or more;
• the ratio between the thickness of the second alkali retention layer and the third alkali-impermeable layer is 2 or more, for example 3 or more;
• each layer impervious to alkalis is based on silicon nitride
• the or each alkali retention layer is based on silicon oxide or tin oxide, for example a mixed tin oxide and zinc;
• the molybdenum-based layer has a thickness of at least 20 nm, for example at least 50 or 80 nm;
• the layer based on molybdenum Mo is at most 500 nm thick, for example at most 400 nm, for example at most 300 nm or for example at most 200 nm;
• FIG. 1 is a diagrammatic sectional view of a conductive substrate
• FIG. 2 is a similar view illustrating a photovoltaic cell comprising the conductive substrate of FIG.
• FIG. 1 a conductive substrate for a photovoltaic cell comprising:
• a layer A formed (or deposited) on a layer B a layer A formed either directly on the layer B and therefore in contact with the layer B, or formed on the layer B with interposition of one or more layers between layer A and layer B.
• the illustrated alkaline barrier stack 2 comprises three layers only:
• the alkaline barrier stack 2 comprises more than three layers, for example an odd number of layers, the alternating stack preferably alkaline impervious layer and alkali retention layer.
• the first impervious layer 2A is not deposited directly on the glass substrate 1.
• the alkaline barrier stack 2 comprises:
• a second alkaline impervious layer 2A ' formed on the alkali retention layer 2A', for example directly on the alkali retention layer 2B.
• the alkali retention layer 2B is formed of a material other than the first alkaline impervious layer 2A.
• the ratio of the alkali retention layer 2B thickness to the alkali-impermeable first layer 2A is 2 or more; for example equal to 3 or more.
• alkali-impermeable layer is understood to mean a layer composed of an alkali-impermeable material, that is to say a material whose penetration by alkaline ions is difficult, and by retention layer is meant alkali a layer composed of an alkali retention material, namely a material having an ability to retain alkaline ions within the material.
• a glass substrate with a minimum thickness of 2 mm and a concentration of at least 5% by weight of sodium ions Cverre is used.
• the material to be tested is deposited directly on the substrate in a layer 10Onm thick of this material.
• the assembly is then annealed at 600 ° C. in air for 30 minutes at 600 ° C. under air at a pressure of approximately 1 atm.
• the mass concentration of sodium ions is measured at 50nm depth in the layer by SIMS (Secondary Ion Mass Spectroscopy) method. It is rated C50. This concentration is also measured on a control sample before annealing for the test of the retention material, and also denoted C50.
• the alkali retention material test is successful if C50 / Cverre ⁇ 0.001 before annealing and C50 / Cverre> 0.3 after annealing.
• SIMS measurements are for example carried out with the following parameters to determine the concentrations of sodium ions:
• the measurement method above is provided as an example.
• the analysis of the mass concentration of sodium ions is of any suitable type.
• An alkaline impervious material is, for example, silicon nitride or aluminum nitride.
• An alkali retention material is for example silicon oxide or tin oxide or a mixed tin and zinc oxide, zinc oxide being then a minority.
• nitrides and oxides may be substoichiometric, stoichiometric or super-stoichiometric respectively in nitrogen and oxygen.
• the alkali retention layer and / or the alkali-impermeable layer is for example doped with a metal, for example with aluminum, especially in the case of a magnetron deposition of the layer.
• the first alkaline-impervious layer 2A has, for example, a thickness greater than or equal to 3 nm, for example greater than or equal to 5 nm, and for example has a thickness less than or equal to 30 nm, for example less than or equal to 20 nm, for example less than or equal to 15nm.
• the alkali retention layer 2B has, for example, a thickness greater than or equal to 20 nm, for example greater than or equal to 25 nm, and for example a thickness less than or equal to 60 nm, for example less than or equal to 40 nm, for example less than or equal to 35 nm.
• the second alkaline-impervious layer 2A ' has, for example, a thickness greater than or equal to 3 nm, for example greater than or equal to 5 nm, and for example a thickness of less than or equal to 30 nm, for example less than or equal to 20 nm, for example less than or equal to 15nm.
• the alkaline barrier stack comprises at least two additional layers, namely a second alkali retention layer formed on the second alkali-impermeable layer, for example directly above, and a third alkaline-impermeable layer formed on the second retention layer alkali, for example directly above.
• the second alkali retention layer has, for example, a thickness greater than or equal to 20 nm, for example greater than or equal to 25 nm, and a thickness less than or equal to 60 nm, for example less than or equal to 40 nm, for example less than or equal to 35 nm. .
• the third alkali-impermeable layer has, for example, a thickness greater than or equal to 3 nm, for example greater than or equal to 5 nm, and for example has a thickness less than or equal to 30 nm, for example less than or equal to 20 nm, for example less than or equal to at 15nm.
• the electrode coating 4 is particular in that it comprises at least one layer based on molybdenum. This is for example an electrode coating as described in WO-A-02/065554.
• electrode coating means a current supply coating comprising at least one electronically conductive layer, that is to say the conductivity of which is ensured by the mobility of the electrons.
• molybdenum-based is used throughout the text to mean a material composed of a substantial amount of molybdenum, that is to say either a material consisting solely of molybdenum (hence metallic), or a material metal alloy mainly comprising molybdenum, ie a molybdenum-based compound, for example a molybdenum disulphide, a diselenide molybdenum, a Mo (S, Se) 2 molybdenum disulfide and diselenide compound, or a Mo (O, N) oxide, nitride or oxynitride.
• the notation (S, Se) indicates that it is a combination of SxSel -x with 0 ⁇ x ⁇ 1
• the electrode coating 4 comprises for example a single layer, as illustrated in FIGS. 1 and 2, which layer is in molybdenum and has a thickness of between 300 nm and 500 nm, for example between 300 nm and 450 nm.
• a single layer a layer of the same material. This single layer can nevertheless be obtained by the superposition of several layers of the same material, between which there is an interface that can be characterized, as described in WO-A-2009/080931.
• the upper layer of the coating 4 is for example a molybdenum layer, so as to ensure the resistance to the selenization of the electrode coating 4.
• the upper molybdenum layer can then be thin, for example with a thickness less than or equal to
• the conductive substrate formed by the dielectric substrate 1, the alkaline barrier stack 2 and the electrode coating 4 is intended to be at the rear of the photoactive layer with respect to the light source, that is to say at receive the incident light after the photoactive layer. It is thus a conductive substrate called "back”.
• the dielectric substrate 1 is for example a sheet with a glass function. But alternatively, it is not transparent.
• the sheet may be flat or curved, and have any type of dimensions, including at least one dimension greater than 1 meter.
• the glass may be clear or extra-clear, or tinted, for example in blue, green, amber, bronze or gray.
• the thickness of the glass sheet is typically between 0.5 and 19 mm, especially between 2 and 12 mm, or even between 4 and 8 mm. It may also be a film-like glass with a thickness greater than or equal to 50 ⁇ m (in this case, the barrier stack and the electrode coating are deposited for example by a roll-to-roll process).
• the substrate is of any suitable type and contains alkalis, for example sodium and / or potassium ions.
• the substrate is for example a silico-soda-lime glass.
• a silico-soda-lime type glass can be obtained by floating. This is a relatively low cost glass and has all the qualities that are known to this type of material, such as its transparency, water impermeability and hardness.
• Silica-soda-lime glass is understood to mean a glass whose composition comprises silica (SiO 2) as forming oxide and oxides of sodium (sodium Na 2 O) and calcium (CaO lime).
• This composition preferably comprises the following constituents in a content varying within the weight limits defined below:
• BaO 0 - 5% preferably 0.
• the dielectric substrate is made of a silica-based glass whose composition of constituents has at least 5% by weight of Na2O.
• the invention also relates to a method of manufacturing the conductive substrate described above.
• the method comprises steps of:
• the alkaline retention layer 2B on the first alkaline-impervious layer 2A, for example directly on it, the ratio between the thickness of the alkaline retention layer 2B and the first alkaline-impervious layer 2A being equal to 2 or plus and the alkali retention layer 2B being made of a material other than the first alkaline impervious layer 2A;
• the electrode coating 4 comprising a layer based on molybdenum, on the second alkali-impermeable layer, for example directly on it.
• the invention also relates to a semiconductor device comprising a conductive substrate as described above and a layer of a light-absorbing agent, for example based on chalcopyrite, formed on the conductive substrate.
• Such a method in combination with the presence of an alkaline barrier stack preventing the diffusion of the alkaline ions to the absorber, has the advantage of allowing a precise dosage of the addition of the alkaline ions in the agent layer. absorber.
• the invention also relates to a photovoltaic cell comprising a semiconductor device as described above.
• the conductive substrate is intended to be at the rear of the photoactive layer with respect to the light source, that is to say to be traversed by the incident light after the photoactive layer.
• the cell comprises for example, as illustrated in FIG.
• a p-type doped layer 6 of Cu (In, Ga) Se 2 formed directly on the electrode coating 4 comprising a layer based on molybdenum; a n-type doped layer 8 called buffer, for example composed of CdS, formed on the Cu (ln, Ga) Se2 layer;
• the cell does not comprise a buffer layer, the Cu (ln, Ga) Se2 layer itself being able to form a homojunction p-n.
• the light-absorbing agent layer is a kesterite or stannite layer of Cu2 (Sn, Zn) (S, Se) 4 or a chalcopyrite-based layer not necessarily formed by selenization alone. metal compounds but for example also by a sulphurization such as a Cu y (ln, Ga) type layer (S, Se) 2.
• the p-type or homojunction p-n layer is a photoactive layer obtained by addition of alkaline elements.
• the buffer layer 16 is for example based on ln x S y , Zn (O, S) or ZnMgO.
• the transparent electrode coating 18 alternatively comprises a layer of zinc oxide doped with gallium, or boron, or a layer of ITO.
• TCO transparent conductive material
• a metal gate is then optionally deposited on the transparent electrode coating 10, for example through a mask, for example by electron beam (not shown in Figure 2). It is for example a grid of Al (aluminum) for example of about 2 ⁇ thick on which is deposited a grid of Ni (nickel) for example of about 50nm thick to protect the Al layer. .
• the cell is then protected.
• it comprises a counter-substrate V, as illustrated, covering the front electrode coating 10 and laminated to the substrate 1 by means of a lamination interlayer 14 made of thermosetting plastic material. This is for example a lamination interlayer EVA, PU or PVB.
• the invention further relates to a method of manufacturing the semiconductor device and the photovoltaic cell above, which method comprises a step of forming a light-absorbing agent the electrode coating 4.
• the step of forming the light-absorbing agent comprises a selenization and / or sulphurization step carried out in an atmosphere comprising a gas based on selenium and / or sulfur and at a temperature above 300 ° C.
• the absorber layer is for example a layer of CIGS formed as follows.
• a Cu, In, and Ga metal stack is deposited by sputtering at ambient temperature, on the electrode coating 6, and then selenized in a high temperature selenium-based atmosphere, for example at about 600 ° C.
• the alkaline ions have been introduced by deposition on the electrode coating 4 of a layer of sodium selenide (Na.sub.2Se) such as to introduce, for example, of the order of 2 ⁇ 10 15 sodium atoms per cm 2 .
• a layer of sodium selenide Na.sub.2Se
• the metal stack is deposited on this layer of sodium selenide
• the metal stack has, for example, a multilayer structure of the Cu / In / Ga / Cu / In / Ga ... type. However, it is a variant of a Cu-Ga / ln or three-layer alloy bilayer structure. layers of Cu / ln / Ga type.
• a selenium layer is then for example deposited on the metal stack by thermal evaporation.
• the metal stack is then heated to at least 300 ° C, for example at least 400 ° C for example 600 ° C in an atmosphere composed for example sulfur gas, for example based on S or H2S, thus forming a layer of Cu (In, Ga) (S, Se) 2.
• the selenization is obtained without the deposition of a layer of selenium but with an atmosphere containing selenium gas, for example based on Se or H 2 Se, prior to exposure to a sulfur-rich atmosphere.
• the sulphurization step may optionally abstain from the buffer layer, for example CdS.

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• 2011
  • 2011-06-27 FR FR1155712A patent/FR2977078B1/fr not_active Expired - Fee Related
• 2012
  • 2012-06-25 EP EP12734986.8A patent/EP2724379A1/fr not_active Withdrawn
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