Classifications

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  • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
  • C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
  • C09K11/77—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals
  • C09K11/7728—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals containing europium
  • C09K11/7734—Aluminates
• • C—CHEMISTRY; METALLURGY
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  • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
  • C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
  • C09K11/77—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals
  • C09K11/7715—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals containing cerium
  • C09K11/7726—Borates
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  • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
  • C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
  • C09K11/77—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals
  • C09K11/7766—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals containing two or more rare earth metals
  • C09K11/778—Borates
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
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  • H01L31/00—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
  • H01L31/02—Details
  • H01L31/0232—Optical elements or arrangements associated with the device
  • H01L31/02322—Optical elements or arrangements associated with the device comprising luminescent members, e.g. fluorescent sheets upon the device
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L31/00—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
  • 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
  • H01L31/042—PV modules or arrays of single PV cells
  • H01L31/048—Encapsulation of modules
  • H01L31/0481—Encapsulation of modules characterised by the composition of the encapsulation material
• • H—ELECTRICITY
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  • H01L31/00—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
  • 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
  • H01L31/054—Optical elements directly associated or integrated with the PV cell, e.g. light-reflecting means or light-concentrating means
  • H01L31/055—Optical elements directly associated or integrated with the PV cell, e.g. light-reflecting means or light-concentrating means where light is absorbed and re-emitted at a different wavelength by the optical element directly associated or integrated with the PV cell, e.g. by using luminescent material, fluorescent concentrators or up-conversion arrangements
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  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
  • H10K30/80—Constructional details
  • H10K30/87—Light-trapping means
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/60—Particles characterised by their size
  • C01P2004/64—Nanometer sized, i.e. from 1-100 nanometer
• • H—ELECTRICITY
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  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
  • H10K30/30—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation comprising bulk heterojunctions, e.g. interpenetrating networks of donor and acceptor material domains
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  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
  • H10K30/50—Photovoltaic [PV] devices
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  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
  • H10K85/10—Organic polymers or oligomers
  • H10K85/111—Organic polymers or oligomers comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene
  • H10K85/113—Heteroaromatic compounds comprising sulfur or selene, e.g. polythiophene
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  • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
  • H10K85/10—Organic polymers or oligomers
  • H10K85/111—Organic polymers or oligomers comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene
  • H10K85/113—Heteroaromatic compounds comprising sulfur or selene, e.g. polythiophene
  • H10K85/1135—Polyethylene dioxythiophene [PEDOT]; Derivatives thereof
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  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
  • H10K85/10—Organic polymers or oligomers
  • H10K85/151—Copolymers
• • 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
  • Y02E10/52—PV systems with concentrators
• • 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
  • Y02E10/549—Organic PV cells

Definitions

• the present invention relates to a luminescent composite film comprising a polymer and at least one inorganic phosphor and the use of this composite film in a photovoltaic cell.
• the object of the invention is to provide a luminescent composite film for truly improving the conversion efficiency of the cells.
• the composite according to the invention thus makes it possible to increase the absolute efficiency of conversion of the light energy into electrical energy (r) of a photovoltaic cell.
• the composite also serves to protect the cell against UV radiation.
• Another characteristic of the composite in the form of a film is that the film must have sufficient mechanical strength to be rolled up and / or delivered to customers.
• the luminescent composite characterized in that it comprises:
• EVA ethylene vinyl acetate
• polyethylene terephthalate polyethylene terephthalate
• the trétrafluoroéthylène ethylene the ethylene trifluorochloroethylene
• perfluorinated ethylene propylene polyvinyl butyral and polyurethane
• At least one inorganic phosphor based on at least one element which is chosen from rare earths, zinc and manganese and which has the following characteristics:
• ⁇ an absorption less than or equal to 10% for a wavelength greater than 440 nm
• ⁇ a maximum emission in a range of wavelengths between 440 nm and 900 nm.
• Fig. 1 represents the measured volume particle size distribution for the aionate powder of Example 4.
• US 2013/0075892 describes light emitting layers based on quantum dots-type particles or quantum dots or nanocrystals dispersed in a polymer that can be EVA, PET, PE, PP, PC, PS, PVDF, etc.
• Quantum boxes are particles whose size is critical for light to be emitted. The particle size ranges from 2 to 10 nm in general (in [0006] from US 2013/0075692: 2-50 nm).
• the phosphor particles of the invention have a size that is greater than 20 nm, or even greater than 30 nm, or greater than 50 nm.
• the composite film according to the invention does not include particles of the quantum dot or quantum dots type.
• WO 2009/115435 discloses submicron particles of barium aluminate and magnesium which can be used in luminescent devices or as markers in semitransparent inks.
• the particles can be incorporated into a polymer matrix such as PC, PM A or silicone. This application does not therefore describe the same polymers as those of the present application.
• the mass fraction of particles may be between 20 and 99%, that is to say a proportion greater than that contemplated in the present invention.
• the thickness of the layer comprising the particles dispersed in the polymer is between 30 nm and 10 ⁇ m. There is also no mention of the photovoltaic application.
• FR 2792460 discloses a photovoltaic generator comprising a photovoltaic cell and a transparent matrix which may be PMMA.
• WO 2012/032880 describes a composition useful for the manufacture of a photovoltaic module made of a transparent resin and a phosphor of formula (Bai. X. A M 'x) (y Mgi. B M') (A " z ⁇ ⁇ ⁇ ) ⁇ 0 Oi 7:... b Eu a Mn
• the resulting resin preferably polyaddition
• This is preferably an acrylic resin particles may have a size varying from 0 00Q1 (0 1 nm) at 100 ⁇ ⁇ >>>> ⁇ ⁇ >-> 1 ⁇ m
• the reduced sizes of the particles are obtained using coarse grinding techniques (mill ball mill, jet mill. ) But these techniques do not allow to obtain aluminates having a d50 as in claim 1,
• FR 2993409 discloses a transparent matrix containing a plurality of optically active components absorbing light energy in a first absorption wavelength and re-emitting energy in a second wavelength greater than the first wavelength.
• the transparent matrix may be PMMA, PVC, silicone, EVA, PVDF.
• Rare earth means the elements of the group consisting of tetrium and the elements of the Periodic Table with an atomic number included between 57 and 71.
• the external quantum efficiency (QE) under an excitation wavelength ⁇ exc is evaluated by the ratio, expressed in percentage, between the integration of the photon emission of the phosphor of the composite of the invention, in the range emission 400 nm - 900 nm, and the number of emitted photons pa a reference phosphor, in the same range of emission wavelength, when excited at the wavelength k mc, measurement can be carried out after acquisition of the emission spectrum of the dried suspension on a Jobin-Yvon type spectrofluorometer.
• 200 ml of boehmite sol ie 0.3 mol of Al
• the salt solution 150 ml
• the luminophore thus obtained constitutes the reference phosphor.
• the particle size characteristics and in particular the particle sizes given in the present application are measured using a laser diffractometer which is a Malvern Mastersizer 2000 device or a Malvern Zeta sizer Nano ZS device. The Mastersizer is used for a d50> 200 nm and Zetasizer Nano ZS for a d50 ⁇ 200 nm. Distributions are in volume.
• the average size is the average size (d50) by volume, measured on a suspension diluted in the water of the phosphor, without ultrasound and without dispersion additive.
• An example of an illustrative granulometric curve is given in FIG. 1 for the aluminate of example 4.
• the term "dispersion index" refers to the ratio;
• d 84 is the particle diameter for which 84% of the particles have a diameter of less than 84 ;
• - di 6 is the particle diameter for which 16% of the particles have a diameter less than d ";
• d 50 is the average diameter of the particles.
• Absorption means the percentage of light absorbed in the wavelength range between 400 nm and 780 nm, measured by diffuse reflection on a Visible UV spectrometer of Perkin Elmer Lambda 900 type.
• this (also denoted P1) can be chosen from ethylene vinyl acetate (EVA), polyethylene terephthalate (PET), a fluorinated polymer, polyvinyl butyrai and polyurethane.
• EVA designates a copolymer of ethylene and vinyl acetate.
• the EVA may consist solely of these two monomers or be composed of these two monomers and at least one other comonomer chosen from vinyl esters such as, for example, vinyl propionate or vinyl benzoate, the (meth) ) C1-C6 alkyl acrylates such as, for example, methyl acrylate or butyl acrylate, or (meth) acrylic acids or their salts, such as, for example, methacrylic acid.
• the EVA may be formed from 55 to 95% weight of ethylene, 5 to 40% by weight of vinyl acetate, 0 to 5% by weight of another comonomer.
• the proportion of vinyl acetate may be between 30 and 35%.
• the polymer is capable of being extruded into a film form.
• the choice of the polymer is important also because it must make it possible to prepare a film that is able to be rolled up and delivered to the user customers.
• the polymer is also important to obtain a good compromise of mechanical and optical properties necessary for the use of the composite in the intended application.
• This polymer may be especially PET or EVA.
• the polymer of the composite may be crosslinkable or not.
• the phosphor that is dispersed in the composite must have a number of characteristics as to its absorption and emission properties. It must therefore have a higher external quantum efficiency than or equal to 40% for at least a length of excitation wavelength between 350 nm and 440 nm. This external quantum efficiency may be more particularly greater than 50% for at least one excitation wavelength between 350 nm and 440 nm.
• the phosphor absorbs well in the UV and little or not in the visible (440-700 nm). Thus, it has an absorption less than or equal to 10% for a wavelength greater than 440 nm, preferably less than 5% and more particularly less than 3%.
• the phosphors of the composite of the invention also have a specific particle size distribution. In fact, they consist of particles of which at least 50% have a diameter less than 1pm, this average size d50 may be at most 0.7 ⁇ , especially at most 0.5 pm and more particularly of at plus 0.3 ⁇ m. This average size d50 is at least 30 nm, more particularly at least 50 nm.
• the phosphor may have a d50 of between 80 and 400 nm, preferably between 80 and 300 nm.
• these particles may have a narrow particle size dispersion; more precisely their dispersion index may be at most 1, preferably at most 0.7 and even more preferably at most 0.5.
• the luminophore of the composite of the invention is chosen from luminophores which contain at least one element chosen from rare earths, zinc and manganese. According to one embodiment, they contain at least one element chosen from rare earths, in particular the rare earths M 1 described below. aluminate doped with a rare earth and or manganese
• the phosphor may be chosen from rare earth doped aluminates and / or manganese. These aluminates can be of the formulas AMgAl 10 Oi 7 : Eu + or AMgAI 10 Oi 7 : Eu 2+ , n 2+ , where A represents the elements Ba, Sr, Ca alone or in combination. Examples of these aluminates are given below.
• aluminates that may be mentioned are those of formula a (Mi.DEdO) .b (gi MneO) .c (Al 2 O 3) in which:
• M denotes Ba, Sr and Ca or combinations thereof; and a, b, c, d, and e verify relationships:
• the phosphors may also be chosen from europium doped phosphates. These phosphates can be of formula ABF in which A represents the elements U, Na, K alone or in combination and B the elements Ba, Sr, Ca alone or in combination. Examples of this type of products are given below,
• UBaP0 4 Eu 2+
• the europium doped halophosphates may also be suitable in the context of the invention. These products may correspond to the formula A5 (PO 4 ) 3: Eu 2+ in which A represents the elements Ba, Sr, Ca alone or in combination, X being OH, F and Cl. Examples of these are given below.
• halophosphate rare earth oxysulfides
• the rare earth oxysulfides doped with europium can also be used as luminophores. These products have a formulation of Lna0 2 S: Eu 3+ type with Ln representing the elements La, Gd, Y, Lu, alone. An example of such an oxysulfide is given below.
• La 2 O 2 S Eu 3+ vanadates rare earth doped europium
• Vanadates of rare earth doped europium are also phosphors. They generally have a formula of the type LnV0 4 : Eu 3+ , Bi 3 with Ln representing the elements La, Gd, Y, Lu, alone or in combination. An example is given below.
• Phosphors of formula LnPVO 4 may also be mentioned.
• Ln designating a rare earth.
• the compounds of zinc doped with manganese, zinc, silver and / or copper may also be suitable as phosphors. Examples of these compounds are given below.
• Rare earth borates doped with cerium can also be used as phosphors. These borates are generally in a formula of the type LnB0 3 : Ce 3+ or LnB0 3 iCe 3+ , Tfa 3+ in which Ln represents the elements La, Gd, Y, Lu alone or in combination.
• the phosphors mentioned above can advantageously be prepared by a process of the type described below.
• This method comprises a first step in which a medium is formed comprising a colloidal suspension and / or salts of the constituent elements (other than oxygen) of the phosphor that is to be prepared.
• a precipitation is then carried out by adding a basic compound to the medium previously formed.
• the precipitate is then separated from the liquid medium, it is dried and then calcined in air at a temperature generally between 200 ° C and 900 ° C, preferably between 60CTC and 900 ° C.
• a second calcination is then carried out under air or under a reducing atmosphere, which makes it possible to obtain a luminophore.
• the phosphor is then wet milled to obtain the particle size necessary for the implementation of the present invention.
• the phosphor used as a component of the composite of the invention in the preparation thereof is derived from the separation of the solid product from the liquid phase from a specific suspension. More specifically, it is a liquid phase suspension of particles of a rare earth borate, these particles being substantially monocrystalline and having an average size of between 100 and 400 nm.
• the particles of the suspension may more particularly have a mean size of between 100 and 300 nm and a dispersion index of at most 0.7.
• the constitutive rare earth borate belongs to the group including fyttrium, gadolinium. lanthanum lutetium and scandium L- wate may comprise '.- OI 1 "dopant, at least one element selected from muth antimoii and rare earths other than that of the constitutive borate, the rare earth dopant being more particularly cerium, terbium, europium, thalium, erbium and praseodymium,
• the slurry is obtained by a process in which a rare earth borocarbonate or hydrogenoxy carbonate is calcined at a temperature sufficient to form a borate and to obtain a product having a specific surface area of at least 3 m 2 / g; the product resulting from the calcination is then wet-milled.
• a rare earth borocarbonate or hydroxyborocarbonate is used which was obtained by reaction of a rare earth carbonate or hydroxycarbonate with boric acid, the starting reaction medium being in the form of an aqueous solution.
• the phosphor used as a component of the composite of the invention in the preparation thereof is derived from the separation of the solid product from the liquid phase from a specific suspension. More specifically, it is a liquid phase suspension of a barium aluminate and magnesium consisting of substantially single-crystal particles of average size between 80 nm and 400 nm.
• a characteristic of the constitutive particles of alumina according to this embodiment of the invention is their monocrystallinity. Indeed, essentially, that is to say for at least about 90% ss st and preferably for all of them, these particles consist of a single crystal.
• This monocrystalline aspect of the particles can be demonstrated by the transmission electron microscopy (TEM) analysis technique.
• TEM transmission electron microscopy
• the monocrystalline appearance Particle size can also be demonstrated by comparing the average particle size measured by the laser diffraction technique mentioned above with the value of the crystal size or coherent domain measurement obtained from the diffraction analysis of the particles.
• X-ray (XRD) X-ray
• the Scherrer model as described in the book Theory and Technique of Radiocrystallography, A.Guinier, Dunod, Paris, 1956, is used for this measurement. It is specified here that the value measured in XRD corresponds to the size of the domain. coherent calculated from the diffraction line corresponding to the crystallographic plane of the main diffraction peak (eg crystallographic plane [102]). Both values: average laser diffraction size and DRX in fact have the same order of magnitude, that is to say they are in a ratio (measurement value of 50 measurement value XRD) less than 2, more particularly of at most 1, 5. Example 1 illustrates this.
• the particles of the aluminate of the invention are in a well separated and individualized form. There are no or few particle agglomerates. This good individualization of the particles can be demonstrated by comparing the so measured by the laser diffraction technique and that measured from an image obtained by transmission electron microscopy ( TEM). It is possible to use a transmission electron microscope giving access to magnifications up to 800 000. The principle of the method consists in examining under microscope different regions (approximately 0) and in measuring the dimensions of 250 particles deposited on a support (for example after deposition on the support of a suspension of the particles and allowing the solvent to evaporate), considering these particles as spherical particles.
• a particle is considered identifiable when at least half of its perimeter can be defined.
• the MET value corresponds to the diameter of the circle correctly reproducing the circumference of the particle.
• the identification of exploitable particles can be done using ImageJ software, Adobe Photoshop or Analysis. After measuring the particle sizes by the above method, we deduce a granulometric distribution cumi ⁇ s particles that are grouped into several size classes ranging from 0 at 500 nm, the width of each class being 10 nm. The number of particles in each class is the basic datum to represent the particle size distribution, The MET value is the median diameter such that 50% of the particles (in number) counted on MET plates have a diameter smaller than this value .
• the barium aluminate of this embodiment can have the formula (I) below:
• M 1 denotes a rare earth which may be more particularly gadolinium, terbium, iyftriutn, ytterbium, europium, neodymium and dysprosium;
• M 2 denotes zinc, manganese or cobalt
• M 1 can be even more particularly the europium.
• M 2 may be more particularly manganese.
• e 0.
• d 0.1.
• the aluminate may be that of Example 1.
• the aluminate can be obtained by a multistage process.
• Step 1 forming a liquid mixture comprising water of aluminum compounds and other components used in the composition of the aluminate.
• the mixture is a solution, a suspension or a gel.
• the starting compounds may be inorganic salts or hydroxides or carbonates.
• salts mention may preferably be made of nitrates, such as for barium, aluminum, europium and magnesium.
• aluminum sulfate or chloride or Itates it is also possible to use a soil or a colloidal dispersion of aluminum whose particle size can be between 1 and 300 nm.
• Aluminum may be present in the form of boehmite.
• step i dry the mixture obtained in the 1 st step.
• the drying can preferably be done by atomization which has the advantage of controlling the size of the particles resulting from drying.
• Spray drying involves spraying the mixture of the 1st step by means of a spray nozzle.
• the person skilled in the art knows how to adapt the parameters of the spray drying (temperature of the mixture before spraying, flow of the mixture, characteristics of the spray nozzle, pressure in the spray chamber in which the mixture is sprayed, etc.). to obtain dry particles.
• the atomization can be carried out using an apple-watering-type nozzle or other. It is also possible to use so-called turbine atomizers.
• the gases thus perform a dual function: on the one hand, the spraying, that is to say the transformation into fine droplets, of the initial mixture, and on the other hand, the drying of the droplets obtained.
• the extremely low residence time (for example less than 1/10 of a second or so) of the particles in the reactor has the advantage, among other things, of limiting any risk of overheating as a result of too long contact with the reactor. the hot agz.
• This reactor consists of a combustion chamber and a contact chamber composed of a double cone or a truncated cone with the part superior diverges.
• the combustion chamber opens into the contact chamber through a reduced passage.
• the upper part of the combustion chamber is provided with an opening allowing the introduction of the fuel phase.
• the combustion chamber comprises a coaxial inner cylinder, thus defining inside it a central zone and an annular peripheral zone, with perforations situated for the most part towards the upper part of the apparatus.
• the chamber comprises at least six perforations distributed over at least one circle, but preferably on several circles spaced axially.
• the total area of the perforations located in the lower part of the chamber may be very small, of the order of 1/10 to 1/100 of the total surface area of the perforations of said coaxial inner cylinder.
• the perforations are usually circular and have a very small thickness.
• the ratio of the diameter thereof to the thickness of the wall is at least 5, the minimum thickness of the wall being limited only by the mechanical requirements.
• an angled pipe opens into the reduced passage, the end of which opens in the axis of the central zone.
• the gas phase animated by a helical movement (hereinafter called helicoidal phase) is composed of a gas, generally air, introduced into an orifice made in the annular zone, preferably this orifice is situated in the lower part of said zone.
• the gaseous phase is preferably introduced at low pressure into the aforementioned orifice, that is to say at a pressure of less than 1 bar and more particularly at a pressure comprised between between 0.2 and 0.5 bar above the pressure in the contact chamber.
• the speed of this helicoidal phase is generally between 10 and 100 m / s and preferably between 30 and 60 m / s.
• a fuel phase which may in particular be methane, is injected axially through the above-mentioned opening in the central zone at a speed of approximately 100 to 150 m / s.
• the mixture to be treated in the form of liquid is then introduced through the aforementioned pipe.
• the liquid is then fractionated into a multitude of drops, each of which is transported by a volume of gas and subjected to a movement creating a centrifugal effect.
• the flow rate of the liquid is between 0.03 and 10 m / s.
• the ratio of the intrinsic momentum of the helical phase to that of the liquid mixture must be high. In particular, it is at least 100 and preferably between 1000 and 10000.
• the amounts of movement at the reduced passage are calculated as a function of the inlet flow rates of the gas and of the mixture to be treated, as well as the section of the passage. An increase in flow leads to a growth in the size of the drops. Under these conditions, the proper movement of the gases is imposed in its direction and its intensity to the drops of the mixture to be treated, separated from each other in the convergence zone of the two currents. The speed of the liquid mixture is further reduced to the minimum necessary to obtain a continuous flow.
• the atomization is generally carried out with a solid exit temperature of between 100 ° C. and 300 ° C.
• the calcination is at a temperature which is sufficiently high to obtain a crystalline phase. This temperature is at least 1100 ° C., more particularly at least 1200 ° C. It can be at most 1500 S C. It can be between 1200 and 1400X.
• the calcination is carried out under air and / or under a reducing atmosphere, for example under hydrogen mixed in nitrogen or argon. The duration of this calcination is for example between 30 minutes and 10 hours. It is possible to perform calcination in air followed by calcination in a reducing atmosphere.
• a preliminary calcination at the calcination described above that is to say between ia 2nd and 3rd stage.
• This preliminary calcination is carried out at a temperature slightly lower than that given above, for example below 1000X, in particular between 900 and 1000 ° C.
• step i consists in carrying out a wet grinding of the product resulting from the 3 rd step.
• the wet grinding can be carried out in water or in a water / solvent mixture which is miscible with water.
• the solvent may be an alcohol (eg methanol, ethanol) or a glycol (eg ethylene glycol) or a ketone (eg acetone).
• a dispersant whose function is to contribute to the stability of the suspension can be used for grinding. Wet grinding is known to those skilled in the art.
• aluminate is recovered in powder form by a liquid / solid separation, such as filtration, optionally followed by drying.
• the suspension is started as obtained after wet grinding and the solid product is separated from the liquid phase using any known separation technique, for example by filtration.
• the process for preparing the aluminate does not include a step of calcining a precursor of the phosphor with a flux such as MgF 2 as for the reference product described above. Indeed, in the presence of such a step, it is difficult to grind the aluminate so as to obtain the particles of the phosphor according to claim 1.
• this is obtained by mixing the polymer and the phosphor for example by extrusion of such a mixture. It is possible to directly extrude the mixture of the polymer and the phosphor powder or to use a masterbatch.
• the compound may also include additives customary in the field of solar cell films.
• the composite may comprise one or more additives selected from antistatic additives, antioxidants, réticulanis ,,,,
• the crosslinker can be for example one of those disclosed in US 2013/0328149, These additives are introduced during the extrusion.
• the polymer of the composite film which has been described above (P1) is extruded and a masterbatch comprising the phosphor predispersed in a polymer (P2).
• the polymer of the masterbatch P2 may be of the same type as the polymer (P1) of the composite film or different.
• the two polymers P1 and P2 are preferably compatible with each other so as to form a homogeneous mixture.
• P1 is an EVA
• P2 it is possible to use a masterbatch based on a polymer P2 which is the same grade of EVA or another EVA or else a polymer compatible with P1, for example a polyethylene.
• the masterbatch is itself prepared by extrusion in an extruder or using a kneader.
• the phosphor particles are dispersed in spherical or substantially spherical polymer particles, which themselves are dispersed in the polymer of the composite. These particles are prepared by emulsion or suspension polymerization.
• the polymeric particles are PMMA-based example as in Example 1 of US 2013/00328149
• the proposed dispersion in US 2013/0328149 requires to adjust the nature of the polymeric particles to the polymer composite. It also requires an additional step of preparing the polymeric particles. In the context of the present invention, this technique thus described in US 2013/00328149 is preferably not used, so that the composite does not comprise such polymeric particles.
• the invention also relates to a process for preparing a composite according to the invention in which one extrudes a polymer P1 and the phosphor or the polymer P1 and a masterbatch comprising the phosphor predispersed in a polymer P2.
• the amount of phosphor in the polymer can vary between 0, 1% and 5%, especially between 0 0 and 2% and more particularly 0.5% to 1% by mas .--->the; together iuminophore-polymè ', ⁇ >.
• the amount of phosphor is related to the phosphor-polymer assembly of the polymer composite film P1 of the masterbatch P2.
• This composite may be in the form of a film whose average thickness may be between 25 ⁇ m and 800 ⁇ m and more particularly from 100 ⁇ m to 500 ⁇ m.
• the thickness of the film is adjusted by adjusting the thickness of the lips.
• the average thickness is measured at 25X on the film using a micrometer from 20 measurements taken at random over the entire surface of the film.
• This film can be obtained by extrusion.
• An extruder such as that described in the examples can be used.
• composition according to the invention is also characterized by the fact that in the form of a film, the latter can have a total transmission (TT) of at least 85%, measured for a film thickness of 250 ⁇ m.
• the film may also have a determined haze of at most 10%, measured for a film thickness of 250 ⁇ m.
• the total transmission and the haze are determined with a Perkin Elmer Lambda 900 UV-Vis device under the conditions recalled later at a wavelength of 550 nm.
• the photovoltaic cell comprises a luminescent composite as described above.
• the invention may relate more specifically to conventional solar cells, crystalline silicon. It can also be applied to second-generation solar cells, called “thin films", which are, for example, cells based on amorphous silicon, cadmium telluride (CdTe) or indium, copper and gallium (CIGS) seienide. and their counterparts. Finally, it can be applied to third generation cells such as organic photovoltaic systems (OPV) and dye solar cells (DSSC).
• OOV organic photovoltaic systems
• DSSC dye solar cells
• the composite generally in the form of a film, may be placed on the front face of the active elements of the cell, for example directly as an encapsulant of these elements or in place of the cell glass or in a layer deposited on top of the cell.
• An active element of the cell is an element that converts light energy into electricity.
• the composite film makes it possible to increase the absolute conversion efficiency of the light energy into electrical energy (r) of the active elements of the cell, once affixed to the photovoltaic cell. It makes it possible to convert the UV into visible radiation absorbed by the active elements, which increases the number of usable solar photons.
• the film of the invention is such that the absolute efficiency of a cell to which is applied the composite film of the invention is greater than the absolute cell efficiency when applied is a composite film of the same thickness and consisting of the same polymer and of the same additives but not loaded with luminophore: efficiency r of the cell in the presence of a composite film affixed> efficiency of the cell in the presence of a composite film of the same thickness and consisting of the same polymer and the same additives but not charged with phosphor (r ref ).
• the improvement (r - r ref) / r ref x 100 may be at least 5%, or even at least 7%.
• the invention is therefore also related to the use of a composite film for increasing the conversion efficiency of light energy into electrical energy of a photovoltaic cell.
• the invention also relates to a process for converting light energy into electrical energy using a photovoltaic cell of increasing using the composite according to the invention the number of solar photons usable by the elements assets for the conversion of light energy into electricity.
• a phosphor is used as described in Example 1 of the application WO 2009/1 1 435 and of formula Bao.gEuo.iMgAlioO, 7 .
• the product used here is the powder obtained after drying, in an oven and at 60 ° C., the suspension which was obtained at the end of the wet milling step described in this example 1. In the preparation of this luminophore, no flow like gF. has not been used.
• the average product size measured by laser diffraction is 140 ⁇ dispersion o: 0.6.
• the size of the coherent domain calculated from the diffraction line corresponding to the plane [102] is 101 nm.
• the value of the d50 (laser) and that of the size of the coherent domain (DRX) have the same order of magnitude, which confirms the monocrystalline nature of the particles.
• the phosphor has an absorption of at most 8% in the wavelength range between 500 nm and 750 nm. Its external quantum yield is 51% under an excitation wavelength ⁇ ex of 380 nm. Its maximum emission is 450 nm.
• a composite film is prepared from a mixture of 696.5 g of Eastar 6763 PET copolyester resin and 3.5 g of phosphor previously described, which corresponds to a proportion by weight of 0.5%.
• the formulation is premixed in a rotary mixer and then extruded in a Leistritz LSM 30/34 co-rotating twin-screw extruder with a diameter of 34 mm and a length / diameter ratio of 35.
• the extrusion temperature is 250X.
• the films are directly implemented at the extruder outlet.
• a flat die is fitted on the convergent. This makes it possible to put the extruded material in the form of a ply 300 mm wide and 250 ⁇ m thick.
• the filmmaker is composed of:
• the films obtained are characterized in total (TT) and diffuse (TD) transmissions using a Perkin Elmer Lambda 900 UV-Vis spectrometer equipped with an integrating sphere.
• PET - phosphor has a total transmission of 88.6% in the same wavelength range.
• the transmission values given above show that the presence of the phosphor does not lead to a significant change in transparency.
• the films mentioned above were then tested in OPV devices (organic photovoltaic).
• the solar cell used for this test is of direct structure with anode on the front face.
• a polymer film PEDOT-PSS Poly (3,4-ethylenedioxythiophene-polystyrene sulfonate) was deposited by spin-coating .
• the film is composed of photoactive PCDTBT (poly [N-9'-heptadécanyI-2,7-carbazol ⁇ a] t-5 I 5 ⁇ 4 i 7-di-2-thienyl-2, I 1,, 3 ' benzothiadiazole), mixed with PC70BM (methyl [6,6] -phenyl-Cro-butanoate) in a solvent mixture chloroform: orthodichlorobenzene No heat treatment was carried out
• cathode contacts are evaporated thermally under high vacuum through a mask which defines on each substrate 6 pixels of 0.045 cm 2 of active surface. Each pixel corresponds to a small OPV cell. Electrical tests
• the J / V tests are carried out outside the glove box in a chamber in an inert atmosphere comprising a quartz window.
• the PET - phosphor films are applied to this quartz window.
• the PET-phosphor film measurements are made by comparison with the measurements made by applying the comparative PET film (uncharged phosphor).
• the electrical tests are carried out under an illumination equivalent to 1 sun, through a standardized filter AM 1.5.
• the intensity of the solar simulator is calibrated thanks to a silicon photovoltaic cell.
• a voltage is applied to the cell (between -1 to 5V 1 5V) and the current produced is measured using a Keithley jrant generator which applies an electric field across a system and the Surer resulting electric current.
• the comparative PET film is applied to the photovoltaic device and the absolute yield of the cell is recorded. Three measurements are made per sample, then the average value is used. The same measurements are then made with PET-phosphor film.
• barium aluminate according to the invention has a compromise of properties.
• the polymer used is the same as for example 1 and the film prepared has the same thickness of 250 .mu.m.
• the absolute yield of the cell with the reference film (2.54%), that is to say with the composite film of the same thickness and consisting of the same polymer and the same additives but not loaded with phosphor.
• Example 1 illustrates the invention and shows that the property compromise allows an improvement of 7.9% for a proportion of 0.5% even though, surprisingly, the QE yield is lower for the aluminate of this type. example for the aluminates of Example 2 or Example 4.
• Examples 5 and 6 were made with EVA.
• the composite film was obtained by extruding the EVA and the type of phosphor aluminate 0.5% The film thickness is 250 pm.
• eicgn i uses the barium aluminate of Example 1 (0.5%)

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