Classifications

• • 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
  • H01L31/02—Details
  • H01L31/0216—Coatings
  • H01L31/02161—Coatings for devices characterised by at least one potential jump barrier or surface barrier
  • H01L31/02167—Coatings for devices characterised by at least one potential jump barrier or surface barrier for solar cells
  • H01L31/02168—Coatings for devices characterised by at least one potential jump barrier or surface barrier for solar cells the coatings being antireflective or having enhancing optical properties for the solar cells
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
  • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
  • G02B1/11—Anti-reflection coatings
  • G02B1/113—Anti-reflection coatings using inorganic layer materials only
  • G02B1/115—Multilayers
• • 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

Definitions

• the invention relates to a transparent substrate, in particular glass, and provided on at least one of its faces with an antireflection coating.
• Antireflection coatings are usually made up, for the simplest, of a thin interferential layer whose refractive index is between that of the substrate and that of air, or, for the most complex, of a stack of thin layers. (In general, alternating layers based on dielectric materials with high and low refractive indices). In their most conventional applications, they are used to reduce the light reflection of the substrates, to increase the light transmission. This is for example glazing intended to protect paintings, to make counters or shop windows. Their optimization is therefore taking into account only the wavelengths in the visible range.
• elements capable of collecting light of the photovoltaic solar cell type comprise an absorbing agent ensuring the conversion of light into electrical energy.
• Ternary chalcopyrite compounds that can act as absorbers generally contain copper, indium and selenium. These are so-called CISe2 absorbent layers. It is also possible to add aluminum (ex: Cu (In, Ga) Se2 or CuGaSe2) to the absorbent layer of gallium. Cu (In, Al) Se2), or sulfur (eg CuIn (Se, S)) and are generally referred to herein as "chalcopyrite adsorbent layers".
• Another family of absorbent agent, in a thin layer, is either based on silicon, the latter may be amorphous or microcrystalline, or based on cadmium telluride (CdTe).
• CdTe cadmium telluride
• adsorbing agent based on polycrystalline silicon wafers, deposited in a thick layer, with a thickness of between 50 ⁇ m and 250 ⁇ m, unlike the amorphous or microcrystalline silicon die, which is deposited in a thin layer.
• a first solution was to use extra-clear glasses with very low iron oxide (s) content.
• glasses with very low iron oxide (s) content.
• These include, for example, glasses sold in the "DIAMANT” range by Saint-Gobain Glass or glasses marketed in the “ALBARINO” range by Saint-Gobain Glass.
• Another solution was to provide the glass, on the outside, with an antireflection coating consisting of a porous silicon oxide monolayer, the porosity of the material making it possible to lower the refractive index.
• this one-layer coating is not very efficient. It also has a durability, especially vis-à-vis moisture, insufficient.
• Another solution consisted in providing the glass, on the outer side, with an antireflection coating of thin layers of dielectric materials of alternately strong and weak refractive indices, such as those described in applications WO01 / 94989 and WO04 / 05210.
• anti-reflective coatings of this type whose high refractive index layers are based on oxide mixed tin and zinc and whose low refractive index layers are based on silicon dioxide have the major disadvantage of separating from the substrate when soaked under certain conditions and exposed to certain climatic conditions (in particular high humidity relative).
• the object of the invention is therefore the development of a new antireflection coating which is mechanically robust, whatever the conditions of the heat treatment, and which is capable of further increasing the transmission (of further reducing the reflection) through the transparent substrate that carries it, and this in a wide band of wavelengths, especially both in the visible, in the infrared, even in the ultraviolet.
• the object of the invention is the development of a new antireflection coating suitable for solar cells.
• the object of the invention is to develop such coatings which are furthermore capable of undergoing heat treatments, this being the case in particular in the case where the carrier substrate is made of glass which, in its final application, must be annealed or quenched .
• the object of the invention is to develop such coatings which are sufficiently durable for outdoor use.
• the invention therefore firstly relates to a transparent substrate, in particular a glass substrate, comprising on at least one of its faces an antireflection coating, in particular at least in the visible and in the near infrared, made of a stack of thin layers. in dielectric materials with alternately high and low refractive indices, the stack comprising successively:
• a high-index first refractive index layer at 550 nm between 1.8 and 2.3 and a geometric thickness of between 15 and 35 nm; a second low-index layer; of refractive index n2 at 550 nm between 1, 30 and 1, 70 and geometric thickness & 2 between
• a high-index third layer having a refractive index n3 at 550 nm of between 1.8 and 2.3 and a geometric thickness e3 of between 130 and 160 nm,
• a fourth layer with a low index, of refractive index n 4 at 550 nm between 1.30 and 1.70 and with a geometrical thickness e 4 between
• the second low-index layer and / or the fourth low-index layer being based on silicon oxide, silicon oxynitride and / or oxycarbide or a mixed oxide of silicon and silicon oxide.
• layer is understood to be either a single layer or a superposition of layers where each of them respects the indicated refractive index and the sum of their geometrical thicknesses also remains the value indicated for the layer in question.
• the layers are made of dielectric material, in particular of the oxide or nitride type, as will be detailed later. However, it is not excluded that at least one of them is modified so as to be at least a little conductive, for example by doping a metal oxide, this for example to possibly give the antireflection stack also a antistatic function.
• the invention is preferably interested in glass substrates, but can also be applied to transparent substrates based on polymer, for example polycarbonate.
• the invention therefore relates to a four-layer type antireflection stack. This is a good compromise because the number of layers is large enough that their interferential interaction can achieve an important antireflection effect. However, this number remains reasonable enough to be able to manufacture the product on a large scale, on an industrial line, on large substrates, for example by using a vacuum deposition technique of the sputtering type (magnetic field assisted). .
• composition selection criteria in the material forming the high refractive index layers used in the invention make it possible to obtain a broadband robust anti-reflective effect, with a significant increase in the transmission of the substrate-carrier, not only in the visible domain, but also beyond, from the ultraviolet to the near infrared. This is an anti-glare performing over a range of wavelengths extending at least between 300 and 1200 nm.
• the most suitable materials for constituting the first and / or the third layer are based on metal oxide (s) chosen from zinc oxide ZnO, tin SnO2. It may especially be a mixed Zn and Sn oxide, of the zinc stannate type, and according to a Sn / Zn ratio (expressed as an atomic percentage) greater than 1 They may also be based on nitride (s) silicon SiaN 4 .
• a nitride layer for one or other of the high index layers, in particular the third at least, makes it possible to add a feature to the stack, namely an ability to better withstand heat treatments without any noticeable deterioration of its optical properties for thicknesses less than 100 nm.
• the first and / or the third layer may in fact consist of several superimposed layers superimposed. It may especially be a bilayer SnZnO / Si3N type 4 or Si ⁇ lNU / SnZnO.
• the first high-index layer and / or the third high-index layer may consist exclusively of a mixed oxide of zinc and tin or a bilayer of the type previously mentioned, with a ratio expressed as an atomic percentage between tin and zinc greater than 1.
• the advantage is as follows: the S13N4 is substantially less absorbent than the mixed oxide of tin and zinc, which allows, at identical total thickness, to combine both the advantages of robustness of the stack and optical properties.
• the third layer which is the thickest and most important to protect the stack from possible damage resulting from a heat treatment
• the most suitable materials for constituting the second and / or the fourth layer are based on silicon oxide, oxynitride and / or silicon oxycarbide or based on a mixed oxide silicon and aluminum.
• a mixed oxide tends to have a better durability, especially chemical, than pure SiO 2 (an example is given in patent EP-791 562).
• the respective proportion of the two oxides can be adjusted to achieve the expected improvement in durability without greatly increasing the refractive index of the layer.
• the glass chosen for the substrate coated with the stack according to the invention or for the other substrates associated with it to form a glazing may be particular, for example extra-clear of the "diamond” type (low in particular iron oxides ), or for example an extra-clear laminated glass of the "Albarino” type or a standard clear-calcium-silicate glass of the "Planilux” type (three types of glass marketed by Saint-Gobain Vitrage).
• coatings according to the invention comprise the following sequences of layers: for a stack with four layers: SnZnO x / SiO 2 / SnZnO x / SiO 2 , with Sn / Zn> 1 expressed as an atomic percentage,
• Substrates of glass type, especially extra-clear, having this type of stack can thus achieve integrated transmission values between 300 and 1200 nm of at least 90%, especially for thicknesses between 2 mm and 8 mm.
• the subject of the invention is also the substrates coated according to the invention as external substrates for solar cells of the absorber type based on Si or CdTe or on the chalcopyrite agent (CIS in particular).
• This type of product is generally marketed in the form of solar cells mounted in series and arranged between two transparent rigid substrates of the glass type.
• the cells are held between the substrates by a polymeric (or more) material.
• the solar cells can be placed between the two substrates, then the hollow space between the substrates is filled with a cast polymer capable of hardening, while particularly polyurethane based on the reaction of an aliphatic isocyanate prepolymer and a polyether polyol.
• the polymer may be cured at high temperature (30 to 50 ° C.) and possibly at a slight overpressure, for example in an autoclave.
• Other polymers can be used, such as EVA ethylene vinyl acetate, and other mountings are possible (for example, laminating between the two cell glasses using one or more sheets of thermoplastic polymer) .
• the invention therefore also relates to said modules.
• the solar modules can increase their yield by a few percent at least 1, 1.5 or 2% or more (expressed in integrated current density) compared to modules using the same substrate but without the coating.
• the electric power delivered approximately, we can estimate that a square meter of solar cell can provide about 130 Watt
• each percent of additional yield increases the performance electric, and therefore the price, of a solar module of given dimensions.
• the subject of the invention is also the process for manufacturing glass substrates with antireflection coating (A) according to the invention.
• One method consists of depositing all the layers, successively, by a vacuum technique, in particular magnetic field assisted cathode sputtering or corona discharge.
• the oxide layers can be deposited by reactive sputtering of the metal in question in the presence of oxygen and the nitride layers in the presence of nitrogen.
• SiO 2 or SiaN 4 one can start from a silicon target that is slightly doped with a metal such as aluminum to make it sufficiently conductive.
• FIG. 1 a substrate provided with a four-layer antireflection stack A according to the invention
• FIG. 2 a solar module integrating the substrate according to FIG. 1.
• FIG. 1 very diagrammatic, shows in section a glass 6 surmounted by a four-layer antireflection stack (A) 1, 2, 3, 4.
• A four-layer antireflection stack
• the antireflection stack used is the following
• This example 1 is a first example of the prior art.
• This example 2 constitutes a second example of the prior art with a Sn / Zn ratio (expressed as an atomic percentage) equal to 0.18.
• This example 3 constitutes a third example of the prior art with a Sn / Zn ratio (expressed as an atomic percentage) equal to 0.55
• the 4-layer antireflection stack of these examples is deposited on a substrate 6 made of extra-clear glass 4 mm thick, of the aforementioned DIAMANT range.
• the antireflection stack used is the following
• This example 4 is an example according to the invention with a Sn / Zn ratio (expressed as an atomic percentage) equal to 1.65.
• the antireflection stack used is the following
• This example 5 is another example according to the invention with a Sn / Zn ratio (expressed as an atomic percentage) equal to 1.65.
• the third layer is a bi-layer comprising a layer of silicon nitride coated with a mixed zinc-tin oxide layer according to the Sn / Zn ratio previously expressed.
• the antireflection stack used is the following
• This example 6 is yet another example according to the invention with a Sn / Zn ratio (expressed as an atomic percentage) equal to 1.65.
• the third layer is a bi layer comprising an oxide layer mixed zinc and tin according to the Sn / Zn ratio previously expressed coated with a layer of coated silicon nitride.
• the layer (3) comprises 100 nm of SnZnO and 50 nm of Si 3 N 4 .
• This test is a test of resistance to moist heat. It determines whether the sample is able to withstand the effects of long-term moisture penetration.
• FIG. 2 very schematically represents a solar module 10 according to the invention.
• the module 10 is constituted as follows: the glass 6 provided with the antireflection coating (A) is associated with a glass 8, said "inner” glass.
• This glass 8 is tempered glass, 4 mm thick, and clear extra-clear type ("Planidur DIAMANT").
• the solar cells 9 are placed between the two glasses, then a polyurethane-based curable polymer 7 is poured into the window according to the teaching of the aforementioned patent EP 0 739 042.
• Each solar cell 9 consists, in known manner, of silicon wafers forming a p / n junction and printed front and rear electrical contacts. Silicon solar cells can be replaced by solar cells using other semiconductors (such as based on chalcopyrite agent of the type for example based on CIS, CdTe, a-Si, GaAs, GaInP).
• the present substrate constitutes an improvement of the inventions described in international patent applications WO0003209 and WOO 194989 which relate to antireflection coatings adapted for optimizing the antireflection effect with non-perpendicular incidence in the visible (in particular aimed at applications for the windshields of vehicles). Characteristics (nature of layers, index, thickness) are indeed close to those previously described.
• the coatings according to the present invention have layers whose thicknesses are more restricted and in particular selected for an advantageous application in the field of solar modules.
• a third thicker layer (generally at least 120 nm and not at most 120 nm) and whose composition, in particular an Sn / Zn ratio of the mixed oxide of zinc and tin, expressed as a percentage atomic, greater than 1, makes it possible to obtain more robust stacks.
• this particular selection it becomes possible to obtain layers that do not delaminate over time, even after undergoing quenching.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Sustainable Development (AREA)
• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Computer Hardware Design (AREA)
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• Condensed Matter Physics & Semiconductors (AREA)
• Sustainable Energy (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Power Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Optics & Photonics (AREA)
• Surface Treatment Of Glass (AREA)
• Laminated Bodies (AREA)
• Surface Treatment Of Optical Elements (AREA)
• Photovoltaic Devices (AREA)

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• 2008
  • 2008-03-10 FR FR0851510A patent/FR2928461B1/fr not_active Expired - Fee Related
• 2009
  • 2009-03-10 AU AU2009227775A patent/AU2009227775A1/en not_active Abandoned
  • 2009-03-10 WO PCT/FR2009/050387 patent/WO2009115757A2/fr active Application Filing
  • 2009-03-10 CN CN2009801084730A patent/CN102027599A/zh active Pending
  • 2009-03-10 CA CA2715714A patent/CA2715714A1/fr not_active Abandoned
  • 2009-03-10 BR BRPI0909650A patent/BRPI0909650A2/pt not_active IP Right Cessation
  • 2009-03-10 KR KR1020107020133A patent/KR20100133378A/ko not_active Application Discontinuation
  • 2009-03-10 EA EA201071052A patent/EA017400B1/ru not_active IP Right Cessation
  • 2009-03-10 JP JP2010550240A patent/JP2011513101A/ja active Pending
  • 2009-03-10 EP EP09722088A patent/EP2263260A2/fr not_active Withdrawn
  • 2009-03-10 US US12/921,898 patent/US20110100424A1/en not_active Abandoned
  • 2009-03-10 MX MX2010009557A patent/MX2010009557A/es active IP Right Grant

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