JP2015207648A - Solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar cell module excellent in conversion efficiency which effectively utilizes sunlight in a wide wavelength range, and a method of manufacturing the same.SOLUTION: The solar cell module is used which includes a photoelectric conversion element 101, a first transparent resin 102 in which the photoelectric conversion element 101 is disposed, an electrode 104 electrically connected to the photoelectric conversion element 101, a back sheet 103 disposed at a lower part of the first transparent resin 102, a protective glass 105 disposed at an upper part of the first transparent resin 102, and a sol-gel cured product layer 106 disposed on the protective glass 105 and containing a phosphor. An inorganic filler is blended into the sol-gel cured product layer 106.

Description

  The present invention relates to a solar cell module in which a phosphor is disposed on the front surface of a photoelectric conversion element.

  Solar cells generally have low sensitivity characteristics in the short wavelength region and cannot effectively use light in the short wavelength region such as ultraviolet rays contained in sunlight. As a means for solving the problem, there has conventionally been a method of using a phosphor (so-called wavelength conversion material) that absorbs light in the short wavelength region and emits fluorescence in the long wavelength region. In this method, light in a short wavelength region that has not been used is converted into light in a long wavelength region. Thus, efforts have been made to increase the amount of light and improve the conversion efficiency of the solar cell.

  For example, in Patent Document 1 and Patent Document 2, a polymer obtained by dissolving an organic phosphor in a polyacrylate-based transparent resin can be efficiently converted from light having a short wavelength portion to light having a longer wavelength. The body is disclosed.

  Further, in Patent Document 3, as shown in FIG. 5, a wavelength conversion layer 12 in which a phosphor is contained in an organic transparent resin 11 such as an acrylic resin, an epoxy resin, a silicone resin, or an ethylene vinyl acetate (EVA) resin is provided. It proposes using the member to provide.

  Further, Patent Document 4 proposes to improve efficiency by blending a rare earth phosphor in an ethylene-vinyl acetate copolymer that is a protective resin for a photoelectric conversion element in a solar cell module.

JP 57-28149 A JP-A-57-189 JP 2010-219551 A WO2008 / 047427

Although efforts to solve the above problems are known, in the above-described conventional technology, the phosphor to be contained in the wavelength conversion layer is required to have high weather resistance from the viewpoint of outdoor use.
In particular, in the case of a phosphor made of an organic compound, it can be made a highly transparent layer by dissolving it in a transparent wavelength conversion layer, but its deterioration due to reaction with oxygen, water, etc. is quick, and its performance is sufficient. It cannot be maintained.

  An object of the present application is to suppress deterioration of the wavelength conversion material and maintain its performance sufficiently.

  In order to solve the above problem, a photoelectric conversion element, a first transparent resin in which the photoelectric conversion element is disposed, an electrode electrically connected to the photoelectric conversion element, and a lower portion of the first transparent resin are disposed. A solar cell module comprising a back sheet, a protective glass disposed on an upper portion of the first transparent resin, and a sol-gel cured body layer disposed on the protective glass and containing a phosphor, the sol-gel cured body layer A solar cell module characterized in that an inorganic filler is blended therein.

  In the solar cell module of the present invention, a layer in which a sol-gel polymer is filled with a filler having a refractive index close to that of the sol-gel polymer is used. This high-strength layer is formed on the glass surface of the solar cell. This layer contains a phosphor.

  Thus, a long-life wavelength conversion film can be obtained by forming a layer in which the phosphor is protected from reaction deterioration due to water or oxygen without generating cracks.

Sectional drawing of the solar cell module of 1st Embodiment (A)-(c) Sectional drawing of each process showing the assembly process of the manufacturing process of the 1st Embodiment of this invention. Sectional drawing of the solar cell module of 2nd Embodiment (A)-(c) Sectional drawing of each process showing the assembly process of the manufacturing process of the 2nd Embodiment of this invention. Sectional view of conventional photoelectric conversion element with wavelength conversion layer

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a cross-sectional view showing the structure of solar cell module 100 according to Embodiment 1 of the present invention. In the solar cell module 100 of Embodiment 1, at least the photoelectric conversion element 101, the transparent resin 102 that protects the photoelectric conversion element 101, the back sheet 103, and the current obtained by connecting the photoelectric conversion elements to each other are obtained. The electrode 104 to take out, the protective glass 105, and the sol-gel hardened body layer 106 which is formed on the protective glass and is a sol-gel polymer containing a phosphor and a filler are provided.

  The photoelectric conversion element 101 is not particularly limited, but may be a silicon semiconductor such as a single crystal silicon, a polycrystalline silicon, or an amorphous silicon, or a compound semiconductor such as gallium arsenide or cadmium telluride.

  The electrode 104 can be a metal material or an alloy material.

  The transparent resin 102 is not particularly limited, and may be an ethylene vinyl acetate copolymer, a bisphenol epoxy resin cured product, an acrylic resin, a silicone resin, a polycarbonate resin, or the like.

  The transparent resin 102 may contain a known ultraviolet absorber that absorbs light of 350 nm or less that has low sensitivity characteristics and causes deterioration for the photoelectric conversion element 101.

  The protective glass 105 is not particularly limited, and can be a plate-like glass having translucency and water shielding properties.

  The sol-gel cured body layer 106 is disposed on the protective glass 105. The sol-gel cured body layer 106 includes a phosphor and a filler. The filler is a filler having a refractive index close to that of the sol-gel cured body layer 106.

<Sol-gel hardened body layer 106>
The sol-gel cured body layer 106 is made of a sol-gel polymer formed by polymerization of at least one kind of metal alkoxide. Further, the sol-gel polymer is mixed and dispersed with a phosphor and a filler that is an inorganic filler having a refractive index close to that of the sol-gel polymer.

  When the metal alkoxide is a silicon alkoxide, the sol-gel polymer is composed of a siloxane skeleton, a structure in which they are cross-linked, and a polymerization when an organic functional group described later is bonded to a silicon atom. A three-dimensional network polymer may be formed.

  The filler has a dense glass structure such as a silica filler. For this reason, since air cannot permeate and the filler occupies a certain part of the volume, cracks due to shrinkage during the dehydration condensation of the sol-gel polymer can be suppressed, and the contained phosphor can be treated with water or oxygen. Can be protected from.

  The refractive index of the sol-gel polymer and the filler is about 1.4 to 1.5, and the refractive index of the sol-gel cured body layer 106 is also about 1.4 to 1.5.

  On the other hand, the refractive index of the protective glass 105 is 1.5, and therefore high efficiency can be expected due to the antireflection effect on incident light. In addition to the wavelength conversion effect by the phosphor, the photoelectric conversion efficiency can be further increased.

<Configuration of sol-gel cured body layer 106>
Although it does not limit as the sol-gel hardened | cured material layer 106, it is comprised from the sol-gel polymer, the filler mix | blended with the sol-gel polymer, and fluorescent substance.

  The sol-gel polymer uses at least one kind of alkoxysilane as a starting material. The sol-gel polymer is a cured product based on a siloxane skeleton, and is formed by a sol-gel method in a liquid phase by dehydration condensation between silanol groups generated by hydrolysis of an alkoxy group of alkoxysilane. The refractive index is about 1.4 to 1.5.

<Method for producing sol-gel cured body layer 106>
(Sol adjustment)
First, a mixture of alkoxysilane and water is heated under an acidic catalyst to hydrolyze the alkoxy group to produce a silanol group to obtain a sol.

As alkoxysilane, the alkoxy group number can be made into 2-4, and it is represented by Si (OR1) _x (R2) _4-x . x is an integer of 2 to 4, and 2 or 3 is preferable.

  When x is 1, alkoxysilane has only one alkoxy group, and a siloxane skeleton cannot be formed by polymerization. When x is 4, alkoxysilanes can be polymerized, but the number of reaction points increases, so that shrinkage increases and cracks are likely to occur.

  OR1 is preferably one that has little steric hindrance during hydrolysis and easily reacts with a silanol group. Also, the alcohol generated by hydrolysis should have a small molecular weight and easily volatilize. From these viewpoints, an alkyl group having 1 to 5 carbon atoms is preferable.

  Although it does not limit as R2, For example, it can be set as a C1-C10 organic functional group. When the functional group has a carbon number greater than 11, the steric hindrance increases, and when the sol-gel hardened body is formed by polymerization, the polymerization is inhibited and the formation of the polymer becomes difficult.

  Methyl group, ethyl group, vinyl group, propyl group, butyl group, hexyl group, phenyl group, cyclohexyl group, octyl group, decyl group, allyl hydrocarbon group, and γ-chloropropyl, and hydrogen is fluorine And substituted hydrocarbon groups such as γ-mercaptopropyl, γ-methacryloyloxypropyl, and the like.

  The alkoxysilane may have a reactive organic functional group. In this case, it is an alkoxysilane represented by YnSi (OR) 4-n, and Y is, for example, a glycidoxypropyl group, It can be a styryl group, an acrylate group, a methyl methacrylate group, a vinyl group and derivatives thereof, a thiolpropyl group, an aminopropyl group, etc., and a reaction inducing method such as photoreaction, thermal reaction, or a combination thereof can be appropriately selected. .

  Two or more of the above alkoxysilanes may be used in combination. In particular, a thiolpropyl group or an aminopropyl group can be used by being suitably mixed with a glycidoxypropyl group because a glycidoxypropyl group can be polymerized.

(Formulation of filler)
A filler is added and dispersed in the sol thus obtained. In order to enhance the dispersibility of the filler, a volatile organic solvent may be added, and the sol dispersion of the filler is adjusted.

  Although it does not limit as a filler, it can be set as a silica filler as a thing with a refractive index close | similar to a sol-gel polymer, and can be set as a fused silica, a crushing filler, etc.

  Further, it is more preferable to treat the silica filler surface with an alkoxysilane by a known method in that compatibility between the treated surface and the sol-gel polymer is improved, and aggregation of fillers is suppressed.

  The average particle size of the filler is not limited, but can be 0.2 μm or more and 100 μm or less. If it is smaller than 0.2 μm, it becomes easy to aggregate and difficult to uniformly disperse, resulting in white turbidity. If it is larger than 100 μm, it is difficult to disperse vigorously and uniformly.

  The refractive index of the filler can be set to 1.3 or more and 1.6 or less from the viewpoint of being close to the refractive index of the sol-gel polymer from the need to ensure transparency after being dispersed, and 1.4 or more and 1.5 or less. Below, it is the same as the refractive index of the sol-gel polymer and can be very transparent.

  If it is smaller than 1.3 or larger than 1.6, the transparency of the sol-gel cured body layer 106 becomes low, which impedes the incident light to the solar battery cell and causes a decrease in efficiency.

  The amount of the filler added may be 1% or more and 70% or less, more preferably 2% or more and 50% or less with respect to the weight of the sol adjusted as described above. it can.

  If it is less than 1%, the strength of the cured sol-gel cured body layer will be insufficient. If it is larger than 70%, it tends to aggregate and it becomes difficult to maintain transparency. In the case of 2% or more, it is more preferable from the viewpoint of improving gas barrier properties. If it is less than 50%, it is more preferable because it is easy to maintain dispersibility and make it transparent.

  Further, the filler may have a refractive index close to that of the sol-gel polymer and may be 1.3 or more and 1.6 or more. For example, aluminite, sodium fluoride, calcium fluoride, lanthanum fluoride, lithium fluoride, fluoride Magnesium, strontium fluoride, anhydrous silica, fluorite, kaolin, talc, sericite, polystyrene, polyethylene, polymethyl methacrylate, vinyl resin, and the like can be used.

(Phosphor mix)
The phosphor is added and dissolved in the filler-dispersed sol thus obtained. In order to increase the solubility of the phosphor, a volatile organic solvent may be added to adjust the sol solution of the phosphor. The obtained phosphor sol solution is applied to glass and dried, and a sol-gel hardened body containing a filler and a phosphor previously blended by advancing a dehydration condensation reaction between silanols in the sol solution by a sol-gel reaction. A stock solution of the layer can be obtained.

  The phosphor and composition are not limited in both composition and system, but inorganic compounds, organic compounds, inorganic-organic complex compounds, etc. can be used alone or in combination as appropriate. In the first embodiment, light having a wavelength with low sensitivity characteristics of the solar cell is absorbed, light having a wavelength with high sensitivity characteristics is emitted as fluorescence, and ultraviolet light having a wavelength of 400 nm or less is absorbed from the viewpoint of improving photoelectric conversion efficiency. It is preferable to emit fluorescence having a wavelength longer than 400 nm.

  In addition, when two types of phosphors are used, if the phosphors are selected so that the fluorescence wavelength emitted by the first phosphor and the absorption wavelength of the second phosphor overlap, fluorescence having a wider range of wavelengths can be obtained. From the viewpoint of improving photoelectric conversion efficiency.

  The concentration of the phosphor depends on the extinction coefficient at each wavelength of the phosphor and the thickness of the sol-gel cured body layer. For example, the concentration at which the absorbance at the absorption peak wavelength of each phosphor is greater than 0.1 and less than 10 It can be. This is because if the absorbance is less than 0.1, a sufficient amount of fluorescence cannot be obtained, and if the absorbance is greater than 10, the luminous efficiency is reduced by concentration quenching due to absorption of the phosphor itself.

  The inorganic phosphor is not particularly limited, and a known phosphor can be used. Generally, an oxide, nitride, sulfide, etc. in which a metal element is activated as a luminescent ion in a mother crystal can be used. it can. One or more elements such as B, Gd, O, S, Al, Ga, Ba, Sr, K, V, La, Cl, P, In, Zn, Y, Ca, and Mg are used, and Zn, Ho are used as luminescent ions. , Tb, Nd, Ag, Mn, Ce, Eu, Dy, Tm and the like, and an inorganic phosphor in which one or more types are activated and used.

  In addition, oxides, nitrides, and sulfides in which the metal elements are activated as luminescent ions on the surface of the silica particles are also suitable from the viewpoint that the refractive index is close to that of the sol-gel hardened body and it is easy to ensure transparency. Can be used. In addition, when using inorganic fluorescent substance for this invention, it is desirable for the particle size to be smaller than 300 nm and larger than 30 nm.

  In the case of 300 nm or more, light having a wavelength with high sensitivity characteristics for the photoelectric conversion element is lost due to scattering by the particles of the inorganic phosphor.

  This is because when the thickness is 30 nm or less, the influence of surface defects of the inorganic phosphor is increased and the light emission efficiency is lowered.

Although it does not specifically limit as an organic fluorescent substance, For example, a hydrocarbon type can be used. In general, hydrocarbons are defined as C _n H _{2n + 2-2a-2b-} , where a, b, and c are the number of rings, the number of double bonds between carbons, and the number of triple bonds between carbons, _{respectively. Although} it is represented by _4c , it is possible to use a material that emits fluorescence when n is larger than 5 and smaller than 40.

  In the case of 5 or less, few hydrocarbons function as phosphors that absorb ultraviolet rays as hydrocarbons and emit phosphors having a wavelength longer than 400 nm, which has high sensitivity characteristics.

  In the case of 40 or more, the absorption wavelength shifts to the longer wavelength side, and light having high sensitivity characteristics is absorbed, leading to a decrease in photoelectric conversion efficiency of the photoelectric conversion element.

  In the above structural formula, the part corresponding to carbon may be appropriately replaced by an oxygen atom, a nitrogen atom or a sulfur atom, and it is not limited whether it is ionized or not. From the viewpoint of properties, for example, a fused ring compound such as anthracene, phenanthrene, pentacene, pyrene, perylene, benzpyrene, coronene, or a derivative thereof can be preferably used.

  Specific examples of other organic phosphors include rhodamines, coumarin derivatives, quinacridone derivatives, benzoxazole derivatives, arylamine derivatives, distyrylpyrazine derivatives, carbazole derivatives, silole derivatives, spiro compounds, triphenylamine derivatives, naphthalimide derivatives, Trifumanylamine derivative, pyrazoloquinoline derivative, hydrazone derivative, pyridine ring compound, fluorene derivative, benzoxazinone derivative, phenanthroline derivative, quinazolinone derivative, quinophthalone derivative, phenylene compound, perinone derivative, rubrene derivative, styryl derivative (distyrylbenzene derivative) , Distyrylarylene derivatives, stilbene derivatives), thiophene derivatives (oligothiophene derivatives), dienes (cyclopentadiene derivatives) , Tetraphenylbuta derivatives), azole derivatives (oxadiazole derivatives, oxazole derivatives, triazole derivatives, benzoazatriazole derivatives), pyrazole derivatives (pyrazoline derivatives), pyrrole derivatives (porphyrin derivatives, phthalocyanine derivatives) Etc.

  The complex phosphor described here is not particularly limited, but based on a general definition, at least one kind of ligand is at least one or more kinds of central metal atoms by coordination bond or hydrogen bond. It is a molecular compound in which one or more are coordinated and the central metal atom is the emission center, and whether or not the central metal atom is an ion is not limited.

  Examples of the central metal atom serving as the emission center include transition metals such as Fe, Cu, Zn, Al, and Au. In particular, Gd, Yb, Y, Eu, Tb, Yb, Nd, Er, and the like belonging to the lanthanoid series. Sm, Dy, Ce, and the like are preferable because they have advantages such as a large difference between the wavelength of light to be absorbed and the wavelength of light to be emitted, a small decrease in light emission efficiency due to fluorescence reabsorption, and high quantum efficiency.

  The solvent for dissolving the phosphor is not limited, but a solvent in which the phosphor is dissolved and has an affinity for sol and is allowed to stand at room temperature or at a temperature below the decomposition temperature of the phosphor is preferable. As such a solvent, known solvents such as alcohols such as methanol, ethanol, n-propanol, i-propanol and butanol, acetone, dimethylformamide, toluene, xylene, benzene and the like can be used.

  In this embodiment, a dimethylformamide solution is used. The appropriate concentration of the phosphor in the solution varies depending on the internal quantum efficiency of the phosphor to be used. For example, the absorbance at the absorption peak wavelength of each phosphor may be a concentration larger than 0.1 and smaller than 10. it can. This is because if the absorbance is less than 0.1, a sufficient amount of fluorescence cannot be obtained, and if the absorbance is greater than 10, the luminous efficiency is reduced by concentration quenching due to absorption of the phosphor itself.

<Method for manufacturing solar cell>
Although it does not limit as a manufacturing process of Embodiment 1, the construction method which is demonstrated below, for example is possible. 2 (a) to 2 (c) are cross-sectional views of the steps representing the assembly process of the first embodiment. First, a sol is prepared from alkoxysilane, and then a filler is added and dispersed therein. Further, a phosphor is added and dispersed to obtain a stock solution of the sol-gel cured body layer.

  A specific production method is described below.

(1) Preparation of sol A mixed solution of 30 g of phenyltrimethoxysilane, 17.2 g of dimethyldiethoxysilane, 0.48 g of acetic acid, and 41.2 g of water as alkoxysilane was prepared and stirred and mixed at 120 ° C. for 90 minutes. did. In this process, water is volatilized after being used for hydrolysis of alkoxysilane.

(2) Blending of filler A fused spherical silica filler having an average particle diameter of 1 μm and a refractive index of 1.47 was used as the filler. 1.2 g of silica filler was dispersed in 75.1 g of xylene by a known method, and the dispersion was added to 30 g of sol and left at room temperature for 12 hours.

(3) Preparation of sol solution of phosphor Next, a phosphor solution in which an appropriate phosphor is dissolved in an appropriate solvent is prepared and added to the sol solution described above. When the phosphor solution is added, if the filler blended in the above is settled, stirring is performed and dispersed again. In this embodiment, (1,10-Phenanthroline) tris [4,4,4-trifluoro-1- (2-thienyl) -1,3-buteanionato] europium (III), which is an Eu (trivalent) complex, is converted to dimethyl 12 g of a formamide blended with 0.6 wt% was added to the sol solution blended with the filler prepared above.

(4) Formation of Phosphor-Containing Sol-Gel Cured Material Layer 106 A phosphor sol solution containing the above silica is spin-coated on a protective glass 105 for solar cells, heated at 100 ° C. for 1 hour, and further 120 The protective material 108 in which a sol-gel hardened material layer 106 containing a phosphor and a filler in a sol-gel polymer as shown in FIG. 2A is arranged on the surface of the protective glass 105 as shown in FIG. it can.

  The sol-gel cured body layer 106 thus obtained has a refractive index of 1.47. In the sol-gel polymer, a siloxane skeleton is formed by dehydration condensation of alkoxysilane-derived silanol groups, and silica is dispersed. Therefore, shrinkage is suppressed, cracks are not generated, and a phosphor is blended.

  Next, in FIG. 2B, the protective material 108, the transparent resin 102a disposed on the front side of the photoelectric conversion element 101 in the solar cell module 100, the transparent resin 102b disposed on the back side, and the electrode 104 are electrically joined. The obtained photoelectric conversion element 101 and the back sheet 103 are laminated.

  As a result, the phosphor is protected by the sol-gel cured body layer 106, and the fluorescence emitted from the phosphor reaches the photoelectric conversion element 101 with a long lifetime efficiently, and further has a refractive index lower than that of the protective glass 105. A solar cell module with high power generation efficiency can be obtained due to the antireflection effect due to the body layer 106 being disposed on the incident surface (FIG. 2C).

<Effects and differences from conventional examples>
Since the sol-gel hardened body layer 106 is filled with a silica filler, cracks due to shrinkage in the polymerization process during dehydration condensation of the sol-gel polymer do not occur, and oxygen and water vapor hardly enter.

  As a result, the sol-gel hardened body layer 106 is a film having a high gas barrier property, and uses a phosphor with high sublimation properties that could not be used conventionally, or a phosphor that has not been subject to deterioration due to the invasion of oxygen or water vapor. Can do.

  Further, the phosphor can be protected with a longer life than the conventional example using an epoxy resin for the cured body layer due to the above effects. In the standing test at a temperature of 85 ° C. and a humidity of 85%, in the conventional example, the time during which the light emission intensity from the initial stage is maintained at 90% or more is 500 hours, whereas in this embodiment, the light emission is maintained for 1100 hours.

(Embodiment 2)
FIG. 3 is a cross-sectional view showing the structure of solar cell module 100 according to Embodiment 2. The difference from the first embodiment is that in the sol-gel polymer, the surface of the filler to be filled is modified with a reactive organic functional group, and at least one kind of alkoxysilane used as the raw material of the sol-gel polymer. And a reactive organic functional group that reacts with a reactive organic functional group that modifies the surface of the filler.

  Here, that the surface of the filler is modified with a reactive organic functional group means that the surface of the filler is chemically bonded to the reactive organic functional group.

  Furthermore, the reactive organic functional group contained in the sol-gel polymer and the reactive organic functional group that modifies the surface of the filler to be filled are bonded by reaction, and the others are the same as in the first embodiment.

  In the solar cell module 100 of Embodiment 2, at least the photoelectric conversion element 101, the transparent resin 102 that protects the photoelectric conversion element 101, the back sheet 103, and the current obtained by connecting the photoelectric conversion elements to each other are obtained. An electrode 104 to be taken out, a protective glass 105, and a sol-gel cured body layer 107 including a sol-gel polymer, a phosphor, and a filler on the protective glass 105 are provided.

<Method for manufacturing solar cell>
The manufacturing process of the second embodiment is not limited, but for example, a construction method as described below is possible. FIG. 4A to FIG. 4D are cross-sectional views of each process representing the assembly process of the second embodiment. First, a sol is prepared from an alkoxysilane having at least one type of reactive organic functional group, and then a filler whose surface is modified with a reactive organic functional group is filled and dispersed therein. Further, a phosphor is added and dispersed to obtain a stock solution of the sol-gel cured body layer.

  Here, the sol-gel hardened body contains a metal alkoxide having at least one kind of reactive organic functional group as a raw material.

  Although it does not limit as a reactive organic functional group, For example, it may be set as glycidoxypropyl group, styryl group, acrylate group, methyl methacrylate group, vinyl group and its derivative, thiolpropyl group, aminopropyl group. The reaction induction method such as photoreaction, thermal reaction, or a combination thereof can be appropriately selected.

  Two or more of these functional groups may be used in combination. In particular, a thiolpropyl group or an aminopropyl group can be used by being suitably mixed with a glycidoxypropyl group because a glycidoxypropyl group can be polymerized.

  Further, the combination of the reactive organic functional group used in the sol-gel polymer and the reactive organic functional group for modifying the surface of the filler described later is not limited, and for example, different combinations may be used in the above, It is preferable to make it the same from a viewpoint of reacting efficiently.

  By adopting such a configuration, the surface of the filler blended in the sol-gel polymer is firmly adhered to the sol-gel polymer by chemical bonding, and cracks are less likely to occur. It becomes difficult for molecules to penetrate, and a highly efficient solar cell module with high reliability can be formed.

  A specific production method will be described below in order from the production method of the sol-gel cured product.

(1) Preparation of sol A mixed solution of 12.0 g of phenyltrimethoxysilane, 17.2 g of dimethyldiethoxysilane, 21.4 g of glycidoxypropyltrimethoxysilane, 0.48 g of acetic acid and 41.2 g of water as alkoxysilane It was prepared and stirred for 90 minutes at 120 ° C. to obtain a sol. In this process, water is volatilized after being used for hydrolysis of alkoxysilane.

(2) Surface modification and blending of filler A fused spherical silica filler having an average particle diameter of 1 μm and a refractive index of 1.47 was used as the filler. The surface treatment of the filler was performed as follows. 2.5 g of silica filler is added to 29.55 g of acetone, and 0.05 g of water and 0.27 g of glycidoxypropyltrimethoxysilane are added. This mixture was stirred for 8 hours at room temperature in a closed system. The mixed solution after the stirring was dried in an open system at 100 ° C. for 1 hour, and the remaining silica filler was recovered. The surface of the recovered silica filler is modified by replacing existing silanol groups with glycidoxypropyl groups.

  Thus, 1.2 g of the silica filler whose surface modification was completed was dispersed in 75.1 g of xylene by a known method, and the dispersion was added to 30 g of the sol prepared as described above, and left at room temperature for 12 hours.

(3) Preparation of sol solution of phosphor Next, a phosphor solution in which an appropriate phosphor is dissolved in an appropriate solvent is prepared and added to the sol solution described above. When adding the phosphor solution, if the silica filler compounded above is settled, it is stirred again and dispersed again. In this embodiment, (1,10-Phenanthroline) tris [4,4,4-trifluoro-1- (2-thienyl) -1,3-buteanionato] europium (III), which is an Eu (trivalent) complex, is converted to dimethyl 12 g of a formamide blended with 0.6 wt% was added to the sol solution blended with the filler prepared above.

(4) Formation of Phosphor-Containing Sol-Gel Cured Body Layer The assembly process of Embodiment 2 will be described using the cross-sectional views of FIGS. 4 (a) to 4 (d).

  The sol solution containing the silica filler and the phosphor is spin-coated on the protective glass 105 for solar cells, heated at 100 ° C. for 1 hour, and further heated at 120 ° C. for 5 hours, as shown in FIG. The protective material 109 in which the sol-gel cured body layer 107 containing such a phosphor is disposed on the surface of the protective glass 105 can be manufactured.

  The sol-gel cured body layer 107 thus obtained has a refractive index of 1.47. In the sol-gel polymer, a siloxane skeleton is formed by dehydration condensation of silanol groups derived from alkoxysilane. Silica filler is further dispersed by the reaction between the glycidoxy group in which silica is dispersed and the surface of the silica filler is modified, and the glycidoxy group derived from glycidoxypropyltrimethoxysilane contained in the sol-gel polymer. Further, it is supported more firmly in the sol-gel polymer. As a result, shrinkage is suppressed, cracks are not generated, and a phosphor is blended.

  Next, in FIG. 4B, the protective material 109, the transparent resin 102a disposed on the front side of the photoelectric conversion element 101 in the solar cell, the transparent resin 102b disposed on the back side, and the electrode 104 were electrically joined. The photoelectric conversion element 101 and the back sheet 103 are laminated.

  As a result, the phosphor contained in the transparent material is protected by the sol-gel hardened material layer 107 containing the silica filler. Fluorescence emitted from the phosphor efficiently reaches the photoelectric conversion element 101 with a long lifetime.

  Further, an antireflection effect is produced by the sol-gel hardened material layer 107 having a refractive index lower than that of the protective glass 105 being disposed on the incident surface. It can be set as the solar cell module 100 with higher electric power generation efficiency than this. (FIG. 4 (c)).

  In the sol-gel hardened body layer 107, a glycidoxy group contained in an alkoxysilane that is a raw material reacts with a glycidoxy group that modifies the silica filler surface. For this reason, the silica filler and the sol-gel polymer are more closely adhered.

  As a result, the sol-gel hardened body layer 107 is a film having a high gas barrier property, and a sol-gel containing a phosphor having high sublimation properties that could not be used in the past and a phosphor that has not been subject to deterioration due to invasion of oxygen or water vapor. It can be contained in the cured body layer 107.

<Effect>
In the first embodiment, a filler is blended in the sol-gel cured body layer 107, and the filler surface and the sol-gel cured body are physically in close contact. However, in the second embodiment, the filler surface and the sol-gel hardened body layer 107 are in chemical contact with each other, so that the gas barrier property is higher, and the phosphor is protected with a longer lifetime than in the first embodiment. can do.

  In the conventional example in which an epoxy resin is used for the sol-gel cured body layer 107 in the standing test at an air temperature of 85 ° C. and a humidity of 85%, the time during which the emission intensity from the initial stage is maintained at 90% or more is 500 hours in the conventional example. there were. On the other hand, light emission is maintained in the first embodiment for 1100 hours and in the second embodiment for 1300 hours.

  As described above, the solar cell module of the present invention is widely used as a solar cell with higher efficiency than before.

DESCRIPTION OF SYMBOLS 11 Transparent resin 12 Wavelength conversion layer 100 Solar cell module 101 Photoelectric conversion element 102 Transparent resin 102a Transparent resin 102b Transparent resin 103 Back sheet 104 Electrode 105 Protection glass 106 Sol gel hardening body layer 107 Sol gel hardening body layer 108 Protection material 109 Protection material

Claims (5)

A photoelectric conversion element;
An electrode electrically connected to the photoelectric conversion element;
A first transparent resin containing the photoelectric conversion element and the electrode inside;
A back sheet disposed under the first transparent resin;
A protective glass disposed on top of the first transparent resin;
A sol-gel hardened body layer that is disposed on the protective glass and contains a phosphor, and
A solar cell module comprising:
An inorganic filler is blended in the sol-gel hardened body layer. The solar cell module according to claim 1, wherein a refractive index of the inorganic filler is larger than 1.3 and smaller than 1.6. The surface of the inorganic filler is modified with a first reactive organic functional group;
The sol-gel cured body layer has a second reactive organic functional group,
The solar cell module according to claim 1 or 2, wherein the first reactive organic functional group and the second reactive organic functional group are bonded. The first reactive organic functional group is any one of a glycidoxypropyl group, a styryl group, an acrylate group, a methyl methacrylate group, a vinyl group, a thiolpropyl group, and an aminopropyl group, or a combination thereof. Item 4. The solar cell module according to any one of Items 1 to 3. 5. The solar cell module according to claim 1, wherein the phosphor is one of an inorganic phosphor, an organic phosphor, a complex phosphor, or a combination thereof.

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