JP2017069376A - Solar cell module and manufacturing method therefor - Google Patents

Abstract

Provided is a solar cell module that suppresses the PID phenomenon over a long period of time and has good initial performance as a solar cell. A translucent substrate that contains or generates ions, a solar cell that converts incident light into electricity, and a translucent substrate that is disposed between the translucent substrate and the solar cell. An ion diffusion preventing layer 15 for preventing diffusion of ions from the substrate 11 to the solar battery cell 13, and the ion diffusion preventing layer 15 is a solar cell module 10 containing magnesium oxide. [Selection] Figure 1

Description

  The present invention relates to a solar cell module and a method for manufacturing the solar cell module, and more particularly, to a solar cell module including a translucent substrate containing ions and solar cells and a method for manufacturing the solar cell module.

  At present, solar power generation technology using sunlight is attracting attention as clean energy that does not use fossil fuels. Photovoltaic power generation obtains electric power by converting light energy into electric energy in a solar battery cell by irradiating a solar battery module composed of a translucent substrate and a solar battery cell with sunlight.

  In recent years, especially in Europe where mega solar is widespread, the “PID (Potential Induced Degradation) phenomenon” in which the output of the solar cell module decreases has been a problem. The PID phenomenon is a phenomenon in which, when a high voltage is applied to the solar battery cell particularly in a high temperature and high humidity environment, current leakage occurs in the solar battery cell and the output decreases. One of the causes of the PID phenomenon is considered to be that sodium or the like contained in a light-transmitting substrate such as glass is ionized and diffuses into the solar battery cell.

  Therefore, conventionally, a solar cell module including a sodium diffusion preventing functional layer between a surface-side light transmitting member containing sodium and a solar cell element is known (see, for example, Patent Document 1). Providing such a sodium diffusion preventing functional layer prevents the sodium on the surface side light transmissive member from diffusing into the solar cell element, extending the time until the power generation performance of the solar cell element is reduced, and long-term use It is possible to provide a highly reliable solar cell module that can withstand the above.

JP 2001-218881 A (Claim 1, paragraph 0107, etc.)

  Patent Document 1 includes inorganic oxide films such as a titanium oxide film, a tin oxide film, a zinc oxide film, an aluminum oxide film, and a magnesium oxide film as a diffusion prevention layer (paragraph 0090). However, the inorganic oxide film described in the examples is only silicon oxide (paragraphs 0075 and 0086), and other inorganic oxide films are not specifically disclosed.

  The diffusion preventing layer is required to prevent the diffusion of ions over a long period and suppress the PID phenomenon. Furthermore, since the diffusion preventing layer is provided in the vicinity of the solar cell element (cell), if the diffusion preventing layer itself deteriorates the light transmittance, the initial electromotive force is lowered and the performance as a solar cell is deteriorated. For this reason, it is calculated | required that a diffusion prevention layer does not inhibit permeation | transmission of sunlight as much as possible. However, the conventional diffusion barrier layer does not satisfy both of these requirements.

  An object of the present invention is to provide a solar cell module that suppresses the PID phenomenon over a long period of time and has good initial performance as a solar cell, and a method for manufacturing the solar cell module.

  As a result of intensive studies to achieve the above object, the present inventors can suppress the PID phenomenon over a long period of time and increase the initial electromotive force by using magnesium oxide as a diffusion prevention layer. As a result, the present invention has been completed.

  That is, the present invention provides a solar cell that converts incident light into electricity, a translucent substrate that is located on the incident light side of the solar cell and contains or generates alkali metal ions, and the translucent substrate. An ion diffusion prevention layer disposed between the solar battery cells and preventing diffusion of the ions from the translucent substrate to the solar battery cells, and the ion diffusion prevention layer contains magnesium oxide It is the solar cell module characterized by doing.

Here, the magnesium oxide is preferably a powder having an average particle diameter of 1 to 500 nm. The ion diffusion prevention layer is preferably a film body in which the magnesium oxide is laminated to form a film thickness of 0.1 to 10 μm.
Moreover, it is preferable that the said photovoltaic cell is sealed with the sealing material, and the said ion diffusion prevention layer is arrange | positioned in the interface of the said translucent board | substrate and the said sealing material. Or it is preferable that the said ion diffusion prevention layer is arrange | positioned on the surface of the said photovoltaic cell.

  The present invention also encapsulates a solar cell that converts incident light into electricity, a translucent substrate that is located on the incident light side of the solar cell and contains or generates alkali metal ions, and the solar cell. A solar cell module, wherein at least a portion of the sealing material located between the solar battery cell and the light-transmitting substrate contains magnesium oxide. It is.

  In this case, the magnesium oxide is preferably a powder having an average particle diameter of 1 to 500 nm, and the powder is preferably dispersed and contained in the sealing material.

  Further, the present invention is a method for manufacturing a solar cell module comprising a solar cell that converts incident light into electricity and a translucent substrate that contains or generates alkali metal ions, and one surface of the translucent substrate; An application step of applying a dispersion liquid composed of a solvent in which magnesium oxide is dispersed on one or both of the other surfaces of the solar battery cell, volatilizing the solvent, and one surface of the translucent substrate and the solar battery cell An ion diffusion preventing layer forming step of forming a magnesium oxide film on one or both of the other surface, and the translucent substrate so that one surface of the translucent substrate and the other surface of the solar cell face each other And a disposing step of disposing the solar battery cells. A method for manufacturing a solar battery module, comprising:

  Or this invention is a manufacturing method of a solar cell module provided with the photovoltaic cell which converts incident light into electricity, and the translucent board | substrate which contains or produces | generates an alkali metal ion, Comprising: The said photovoltaic cell is sealed. A sealing step of sealing with a material, a coating step of applying a dispersion composed of a solvent in which magnesium oxide is dispersed on the surface of the sealing material facing the light-transmitting substrate, and volatilizing the solvent An ion diffusion prevention layer forming step of forming a magnesium oxide film on the surface of the encapsulant; and the translucent substrate and the solar cell so that the translucent substrate and the solar cell face each other with the magnesium oxide film interposed therebetween. And a disposing step of disposing solar cells. A method of manufacturing a solar cell module.

  In the above case, the magnesium oxide contained in the dispersion is preferably a powder having an average particle size of 1 to 500 nm. The dispersion is preferably applied in the application step so that the magnesium oxide film has a thickness of 0.1 to 10 μm.

  Alternatively, the present invention is a solar cell that converts incident light into electricity, a translucent substrate that contains or generates alkali metal ions, and is interposed between at least the solar cell and the translucent substrate. It is a manufacturing method of a solar cell module provided with the sealing material which seals the said photovoltaic cell, Comprising: The mixing process which mixes a magnesium oxide powder with the said sealing material in a dispersed state, The said photovoltaic cell is said sealing material And a step of integrating the solar cell and the light-transmitting substrate through the sealing material, and a method for manufacturing a solar cell module, comprising: is there.

  In this case, the magnesium oxide powder is a powder having an average particle diameter of 1 to 500 nm, and is preferably contained in the sealing material in a range of 0.1 to 30% by mass.

  ADVANTAGE OF THE INVENTION According to this invention, while suppressing the PID phenomenon over a long period of time, the solar cell module with favorable initial performance as a solar cell and its manufacturing method can be provided.

It is a schematic cross section which shows the solar cell module which concerns on the 1st Embodiment of this invention. It is a schematic cross section which shows the solar cell module which concerns on the 2nd Embodiment of this invention. It is a schematic cross section which shows the solar cell module which concerns on the 3rd Embodiment of this invention.

1. First Embodiment Hereinafter, a solar cell module of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing a solar cell module according to the first embodiment of the present invention. As shown in this figure, the solar cell module 10 includes a translucent substrate 11, a back sheet 12, solar cells 13, a sealing material 14, and an ion diffusion prevention layer 15. In the present embodiment, it is assumed that light is incident on the solar cell 13 from at least the translucent substrate 11 side.

  The translucent substrate 11 is a transparent substrate disposed on the light receiving surface side of the solar battery cell 13 and having a property of transmitting light. As a material of the translucent substrate 11, for example, an inorganic material or an organic material can be used. Examples of the inorganic material include glass, quartz, sapphire, titania and the like. Examples of the organic material include polyethylene terephthalate, polyethylene phthalate, polyimide, polystyrene, polyvinyl alcohol, fluororesin, vinyl chloride, polyolefin, cellulose, polycarbonate, and polyacrylate. Of these, glass is preferable because it is widely spread and easily available, and the diffusion preventing effect by the ion diffusion preventing layer 15 is high, and white plate glass having high transmittance at a wide wavelength is particularly preferable.

  The translucent substrate 11 in the present invention has a characteristic of containing ions therein or generating ions in an environment such as high temperature, high humidity, and high voltage. Examples of the ions include sodium ions depending on the material of the translucent substrate 11. In particular, when the material of the translucent substrate 11 described above is glass, sodium ions contained in the glass are the cause of the PID phenomenon.

  The back sheet 12 is a substrate disposed on the side opposite to the light receiving surface side of the solar cell module 10. Examples of the back sheet 12 include a laminate in which resin films are laminated. Examples of the resin film include polyethylene terephthalate and fluorine-based resin. The laminate can include a metal layer such as an aluminum foil. In addition, when the solar cell module 10 generates electricity even with light incident from the back sheet 12 side, the back sheet 12 is preferably light-transmissive like the translucent substrate 11. Examples of the material for the light-transmitting substrate include the glass and the transparent resin described above.

  The solar cell 13 is disposed between the translucent substrate 11 and the back sheet 12 and has a property of converting incident light into electricity. As the solar battery cell 13, known ones such as silicon and compound can be used. Examples of the silicon solar cell 13 include a crystalline silicon type and an amorphous silicon type. Examples of the compound solar cell 13 include GaAs, CIS, and CIGS. Of these, crystalline silicon solar cells are preferred because of their relatively high photoelectric conversion efficiency.

  The solar cell 13 is electrically connected to the outside of the solar cell module 10 by an electrode (not shown). As an electrode, the metal electrode used with a general electronic component can be mentioned.

  The sealing material 14 has insulation and has a function of sealing and protecting the solar battery cell 13 inside. A known material can be used as the material of the sealing material 14, for example, ethylene vinyl acetate copolymer (EVA), polyethylene, ethylene acrylic copolymer, polyethylene terephthalate, polyethylene naphthalate, nylon 6 and the like. Can be mentioned. Of these, ethylene vinyl acetate copolymer (EVA) is particularly preferable because of its good adhesion to a glass substrate and the like. The form of the sealing material 14 may be a sealing mold that covers the entire periphery of the solar battery cell 13 in a mold shape, and is at least two sealing sheets sandwiched from the upper and lower surfaces of the solar battery cell 13. Also good.

  The ion diffusion preventing layer 15 is disposed between the translucent substrate 11 and the solar cell 13 and has a function of preventing diffusion of ions from the translucent substrate 11 to the solar cell 13. The ion diffusion preventing layer 15 of the present embodiment is disposed at the interface between the translucent substrate 11 and the sealing material 14.

  The ion diffusion preventing layer 15 is characterized by containing magnesium oxide. Magnesium oxide has a high insulating property and suppresses the movement of ions, so that the diffusion of ions from the translucent substrate 11 to the solar battery cell 13 can be suppressed by the ion diffusion preventing layer 15. Magnesium oxide is also characterized in that it retains the ability to prevent ion diffusion over a long period of time compared to other metal oxides. Further, magnesium oxide has high transparency, and the solar cell module 10 has a characteristic that the initial output is high because the ion diffusion preventing layer 15 does not easily inhibit light incident on the solar cell 13.

  Magnesium oxide can be used in powder form. Magnesium oxide powder can be obtained by a method in which metallic magnesium is burned and oxidized, a method in which magnesium hydroxide or magnesium carbonate is baked and thermally decomposed. As magnesium hydroxide, what precipitated by reaction of magnesium salt in seawater and calcium hydroxide can be used. Further, as magnesium carbonate, magnesite ore can be used. Furthermore, highly crystalline magnesium oxide powder obtained by pulverizing and classifying electrofused magnesium oxide can also be used. The firing temperature of magnesium oxide is not particularly limited, and any of a low-temperature fired product, a high-temperature fired product, or an electrofused product can be used. Furthermore, highly crystalline magnesium oxide powder obtained by pulverizing and classifying electrofused magnesium oxide can also be used. The firing temperature of magnesium oxide is not particularly limited, and any of a low-temperature fired product, a high-temperature fired product, or an electrofused product can be used.

  As the magnesium oxide powder, a powder having an average particle diameter in the range of 1 to 500 nm, preferably 1 to 200 nm, particularly 5 to 50 nm is desirable. If the particle size is within this range, it is easy to disperse in the solvent and can be uniformly dispersed in the solvent. Therefore, a uniform film can be formed also during the application described later. Since the particle size is small and the particles are uniformly dispersed in the solvent, the filling property is excellent. Therefore, a dense film with few voids can be formed without going through a step of reducing voids between particles such as sintering. Further, since the particle size is small and the film is dense, the film thickness can be reduced. If the average particle diameter of the magnesium oxide powder is too large, the light transmitted through the ion diffusion preventing layer 15 is easily reflected by the particles, and the initial output of the solar cell module 10 tends to be low. On the other hand, if the average particle size of the magnesium oxide powder is too small, the particles tend to aggregate and the dispersibility in a solvent described later deteriorates, and the handleability tends to deteriorate.

The average particle diameter of the magnesium oxide powder can be determined from the BET specific surface area value. Specifically, the average particle diameter can be calculated by conversion from the following formula. The average particle diameter calculated from the following formula is an average particle diameter in terms of a sphere, and specifically means the diameter of a sphere having the same surface area as the surface area of the particles.
Average particle diameter (μm) = 6 / (S × ρ) (wherein S is the BET specific surface area (m ² / g), and ρ is the density (g / cm ³ ) of the magnesium oxide powder) Yes, 3.58 g / cm ^3. )

  The particle shape of the magnesium oxide powder is not particularly limited, and a polyhedral shape such as a spherical shape, a cubic shape, a rectangular parallelepiped shape, an octahedron shape, and a tetrahedron shape, an irregular shape, and a fibrous shape can be used as appropriate. Further, the purity of the magnesium oxide powder is usually 90% by mass or more, preferably 95% by mass or more, more preferably 98% by mass or more, and particularly preferably 99% by mass or more.

  The film thickness of the ion diffusion preventing layer 15 is usually in the range of 0.1 to 10 μm, preferably in the range of 0.2 to 5 μm, and particularly preferably in the range of 0.5 to 2 μm. If it is this range, the quantity of the light which passes the ion diffusion prevention layer 15 can be ensured to such an extent that the output fall of the solar cell module 10 hardly arises. Moreover, if it is this range, since the ion diffusion prevention function of the ion diffusion prevention layer 15 can fully be ensured, an output fall can be suppressed over a long term. If the film thickness of the ion diffusion preventing layer 15 is less than 0.1 μm, the film thickness is too thin and the ion diffusion preventing function is not sufficiently exhibited. On the other hand, when the film thickness of the ion diffusion prevention layer 15 exceeds 10 μm, the film thickness is too thick and the influence of light reflection by the ion diffusion prevention layer 15 increases, and the initial output of the solar cell module 10 decreases. Inconvenience easily occurs. In addition, when the average particle diameter of magnesium oxide powder is 100 nm or more, the film thickness is preferably 1 μm or more.

  The ion diffusion preventing layer 15 can be formed by applying a dispersion liquid in which magnesium oxide is dispersed in a solvent to the surface of the translucent substrate 11 on the side facing the sealing material 14. Or the ion diffusion prevention layer 15 can be formed by apply | coating the dispersion liquid which disperse | distributed magnesium oxide powder in the solvent to the surface of the side which opposes the translucent board | substrate 11 among the sealing materials 14. FIG.

  Examples of the solvent in which magnesium oxide is dispersed include polar solvents. Examples of polar solvents include polar organic solvents, and more specific examples include alcohols and ketones. Examples of alcohols include monohydric alcohols such as methanol, ethanol, propyl alcohol, isopropyl alcohol (isopropanol), butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, pentyl alcohol, and isopentyl alcohol. Can do. Examples of ketones include acetone, ethyl methyl ketone, and diethyl ketone. Two or more of these alcohols and ketones may be used in combination.

  The polar organic solvent is preferably a monohydric alcohol having 1 to 5 carbon atoms, particularly preferably methanol, ethanol, isopropyl alcohol, butyl alcohol, or a mixture thereof, of which methanol is particularly preferable. .

  The concentration of magnesium oxide contained in the dispersion is not particularly limited, but can be, for example, in the range of 0.1 to 30% by mass (wt%), preferably in the range of 1% to 20% by mass. It is. The concentration of magnesium oxide contained in the dispersion can be appropriately set according to the film thickness of the ion diffusion preventing layer 15, for example. As an example, when the film thickness of the ion diffusion prevention layer 15 is increased, the concentration of magnesium oxide contained in the dispersion liquid is increased, and conversely, when the film thickness of the ion diffusion prevention layer 15 is decreased, it is included in the dispersion liquid. Reduce the concentration of magnesium oxide. In addition, when making the film thickness of the ion diffusion prevention layer 15 thick, you may repeat application | coating several times, such as coating twice, besides the above-mentioned density | concentration adjustment.

  The dispersion can be applied with a known coating apparatus such as a roll coater, a die coater, a gravure coater, a doctor coater, or a spray coater. After the application, the ion diffusion preventing layer 15 can be formed only by volatilizing the solvent by natural drying, hot air drying, or the like, without passing through a step of densifying the film such as sintering.

  Next, a method for manufacturing the solar cell module 10 will be described. When forming the ion diffusion prevention layer 15 on the surface of the translucent substrate 11, first, the dispersion liquid is applied to one surface of the translucent substrate 11 to form the ion diffusion prevention layer 15 (application process). . Next, the solvent in the dispersion is volatilized to form an ion diffusion prevention layer 15 made of a magnesium oxide film (ion diffusion prevention layer forming step). Furthermore, the circumference | surroundings of the photovoltaic cell 13 are sealed with the sealing material 14 (sealing process). An electrode (not shown) connected to the solar battery cell 13 extends outside the sealing material 14. Subsequently, the sealing material 14 is sandwiched between the translucent substrate 11 and the back sheet 12 so that the translucent substrate 11 and the back sheet 12 are in close contact (arrangement step). The close contact can be performed using a vacuum laminator or the like. Finally, the translucent substrate 11 and the back sheet 12 are fixed with a frame (not shown).

  Or when forming the ion diffusion prevention layer 15 in the surface of the sealing material 14, first, the circumference | surroundings of the photovoltaic cell 13 are sealed with the sealing material 14 (sealing process). Next, the dispersion liquid 15 is applied to the surface of the sealing material 14 to form the ion diffusion prevention layer 15 (application process). Further, the solvent in the dispersion is volatilized to form the ion diffusion prevention layer 15 made of a magnesium oxide film (ion diffusion prevention layer forming step). Finally, the placement process is performed in the same manner as described above to complete the solar cell module 10.

The solar cell module 10 having the above configuration can suppress the PID phenomenon for a long time. Specifically, when a voltage of −1000 V is applied to the solar cell module 10 under high temperature and high humidity conditions of 85 ° C. to 85% RH. The output retention after 24 hours is 80% or more, and can be 85% or more. Furthermore, the solar cell module 10 has an output retention ratio of 70% or more after the elapse of 48 hours under the above conditions, and can be 80% or more. Here, the output retention rate means a value calculated by the following equation.
Output retention rate (%) = (power output value after 24 hours / initial (time zero) power output value) × 100

  Moreover, since the solar cell module 10 has the property that the ion diffusion prevention layer 14 does not easily block the incidence of sunlight, the initial electromotive force is high and the solar cell module 10 has high output characteristics. Specifically, the output value of the initial power under the above high temperature and high humidity condition is 3.5 W or more, and can be 4.0 W or more.

2. Second Embodiment In the first embodiment described above, the ion diffusion prevention layer 15 is disposed at the interface between the translucent substrate 11 and the sealing material 14, but the ion diffusion prevention layer is limited to this. Alternatively, it can be provided as at least a part of the sealing material. Hereinafter, a second embodiment of the present invention will be described.

  FIG. 2 is a schematic cross-sectional view showing a solar cell module according to the second embodiment of the present invention. As shown in this figure, the solar cell module 20 includes a translucent substrate 21, a back sheet 22, solar cells 23, and a sealing material 24 that also serves as an ion diffusion preventing layer. Since the translucent substrate 21 can adopt the same configuration as the translucent substrate 11 of the first embodiment, the back sheet 22 can be the back sheet 12, and the solar battery cell 23 can be the same as the solar battery cell 13. Then, detailed explanation is omitted.

  Unlike the sealing material 14 of the first embodiment, the sealing material 24 of the present embodiment contains magnesium oxide. That is, the sealing material 24 of the present embodiment has a function as an ion diffusion preventing layer, in which magnesium oxide is blended with a base material such as a resin. Examples of the base material of the sealing material 24 include an ethylene vinyl acetate copolymer and the like, similar to the sealing material 14 described above. As magnesium oxide, the thing similar to 1st Embodiment mentioned above can be used.

  When the sealing material 24 is a sealing mold, magnesium oxide powder is mixed in a dispersed state with a resin or the like serving as a base material (mixing step), and is applied to the surface of the solar battery cell 23 to seal the solar battery cell 23. Stop (sealing process), and the solar battery cell 23 and the translucent substrate 21 are integrated through the sealing material 24. The concentration of magnesium oxide contained in the sealing material 24 is not particularly limited, but can be within a range of 0.1 to 30% by mass (wt%), for example, preferably 1% to 20% by mass. Within range. The average particle size of the magnesium oxide powder is not particularly limited, but is preferably in the range of 1 to 500 nm.

  On the other hand, when the sealing material 24 is a sealing sheet, magnesium ion can be apply | coated to the surface at the side of the photovoltaic cell 23 among sheets, and it can also be set as an ion diffusion prevention layer. The film thickness of the ion diffusion preventing layer at this time is usually in the range of 0.1 to 10 μm, preferably in the range of 0.2 to 5 μm, and particularly preferably in the range of 0.5 to 2 μm. The application of magnesium oxide to the sealing sheet can be performed by the same method as in the first embodiment described above.

  In the present embodiment, unlike the first embodiment, since the sealing material 24 also serves as an ion diffusion prevention layer, it is not necessary to apply an ion diffusion prevention layer as in the first embodiment, and the solar cell module. The manufacturing cost of 20 can be reduced. Further, unlike the first embodiment, in this embodiment, since there is no ion diffusion prevention layer between the translucent substrate 11 and the sealing material 14, the close contact between the translucent substrate 21 and the sealing material 24. Is not hindered by the ion diffusion preventing layer, and the adhesion between them is improved.

3. Third Embodiment In the above-described first embodiment, the ion diffusion prevention layer 15 is disposed at the interface between the translucent substrate 11 and the sealing material 14. It is not limited, You may be arrange | positioned in the interface of the sealing material 14 and the photovoltaic cell 13. FIG. Hereinafter, a third embodiment of the present invention will be described.

  FIG. 3 is a schematic view showing a solar cell module according to the third embodiment of the present invention. As shown in this figure, the solar cell module 30 includes a translucent substrate 31, a back sheet 32, solar cells 33, a sealing material 34, and an ion diffusion preventing layer 35. Since the translucent substrate 31 can adopt the same configuration as the translucent substrate 11 of the first embodiment, the back sheet 32 can have the back sheet 12, and the solar cell 33 can adopt the same configuration as the solar cell 13. Then, detailed explanation is omitted.

  The ion diffusion preventing layer 35 of the present embodiment is provided between the solar battery cell 33 and the sealing material 34. In the figure, the ion diffusion preventing layer 35 covers the entire solar cell 33, but the ion diffusion preventing layer 35 of the present invention covers at least the surface of the solar cell 33 on the side of the translucent substrate 31. For example, diffusion of ions from the translucent substrate 31 to the solar battery cell 33 can be prevented.

  Thus, since the ion diffusion prevention layer 35 containing magnesium oxide covers the surface of the solar battery cell 33, the ion diffusion prevention layer 35 is passivated (inactivated) particularly when the solar battery cell 33 is silicon-based. It also has a function as a layer. Here, the passivation layer is a layer having a function of improving the photoelectric conversion efficiency of the solar battery cell 33 by suppressing carrier recombination on the surface of the solar battery cell 33.

  The solar cell module 30 of the present embodiment is manufactured by applying magnesium oxide to the surface of the solar cell 33 to form the ion diffusion prevention layer 35, and then sealing the solar cell 33 with a sealing material 34. be able to. The film thickness of the ion diffusion preventing layer 35 is usually in the range of 0.1 to 10 μm, preferably in the range of 0.2 to 5 μm, particularly preferably in the range of 0.5 to 2 μm. The application of magnesium oxide to the solar battery cell 33 can be performed by the same method as in the first embodiment described above.

  In the present embodiment, since the ion diffusion preventing layer 35 covers the solar battery cell 33, ion diffusion from the translucent substrate 31 to the solar battery cell 33 is prevented and the surface of the solar battery cell 33 is electrically Inactivation can be performed.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, these do not limit the objective of this invention, Moreover, this invention is not limited to these Examples.

1. Example 1
(1) Constituent Member of Solar Cell Module The following members were used as members constituting the solar cell module.
-Translucent substrate: white plate glass (single-sided embossing: white plate heat-treated glass made by Nakajima Glass Industry)
・ Back sheet: Back sheet (PET base: SPE-35 manufactured by SFC)
-Solar cell: polycrystalline silicon cell (IMTEC B156 made by MOTEC)
Sealing material: Sealing sheet (EVA: JINHEUNG JH-40NF)

(2) Formation of ion diffusion preventing layer on glass substrate Dispersion liquid of magnesium oxide powder (average particle size 10 nm) produced by oxidizing metal magnesium vapor using methanol as a solvent to a concentration of 2.5 wt% Was prepared. Next, after forming a film of the dispersion on the white plate glass using a spin coater (rotation speed: 100 rpm), the solvent was evaporated by drying at 120 ° C. The film thickness was measured by cross-sectional observation with SEM.

(3) Preparation of sample A polycrystalline silicon solar cell was set between two sealing sheets, and this was further set between a white sheet glass on the light receiving surface side and a back sheet on the back surface side. This was laminated using a vacuum laminator and then attached to an aluminum frame to obtain a solar cell module sample.

(4) PID evaluation test A solar cell module using polycrystalline silicon solar cells was subjected to a PID generation confirmation test over time. First, the IV characteristic test before a test was implemented on the conditions of 25 degreeC-50% RH. Next, the sample was arrange | positioned in the constant temperature and humidity chamber of 85 degreeC-85% RH setting. After reaching the set temperature and humidity conditions, the shorted output terminal was connected to the negative electrode, the aluminum frame was connected to the positive electrode, and the voltage application of -1000 V was started. After 24 hours, a sample was taken out and an IV characteristic test was performed. Once again, the sample was placed in a constant temperature and humidity chamber, and after reaching the set conditions, voltage application of 1000 V was started and the test was resumed. After 24 hours from the restart, a sample was taken out and an IV characteristic test was performed. The maximum output was calculated from the obtained IV characteristics. The retention rate obtained by dividing the output after the lapse of 24 hours and the output after the lapse of 48 hours by the initial output was also calculated. The obtained results are shown in Table 1.

2. Example 2
A sample was prepared in the same manner as in Example 1 except that the concentration of the magnesium oxide dispersion was 5 wt% and the film thickness was 1 μm, and a PID evaluation test was performed. The obtained results are shown in Table 1.

3. Example 3
A sample was prepared in the same manner as in Example 1 except that the concentration of the magnesium oxide dispersion was 10 wt% and the film thickness was 2 μm, and a PID evaluation test was performed. The obtained results are shown in Table 1.

4). Comparative Example 1
In Example 1, a sample was prepared without forming an ion diffusion preventing layer on white plate glass, and a PID evaluation test was performed. The obtained results are shown in Table 1.

5. Comparative Example 2
In the dispersion liquid of Example 1, isopropanol was used as a solvent, and titanium oxide powder (average particle size 13 nm) was adjusted to a concentration of 5 wt%. In the same manner as in Example 1, when the dispersion was formed into a film on white glass and the film thickness was measured, it was 1 μm. A sample was prepared in the same manner as in Example 1 and a PID evaluation test was performed. The obtained results are shown in Table 1.

6). Comparative Example 3
In Example 1, isopropanol was used as a solvent, and zirconium oxide powder (average particle size 12 nm) was adjusted to a concentration of 10 wt%. In the same manner as in Example 1, when the dispersion was formed into a film on white glass and the film thickness was measured, it was 1 μm. A sample was prepared in the same manner as in Example 1 and a PID evaluation test was performed. The obtained results are shown in Table 1.

  Comparing Examples 1 to 3 having an ion diffusion preventing layer with Comparative Example 1 having no ion diffusion preventing layer, Examples 1 to 3 having an ion diffusion preventing layer were 24 hours and 48 hours later. It can be seen that the output retention rate is high. Moreover, when Examples 1-3 using magnesium oxide and Comparative Example 2 using titanium oxide are compared, Examples 1-3 using magnesium oxide have higher output retention after 48 hours. Recognize. Furthermore, when Examples 1-3 using magnesium oxide are compared with Comparative Example 3 using zirconium oxide, it can be seen that Examples 1-3 using magnesium oxide have higher initial output values.

  As described above, by including magnesium oxide in the ion diffusion preventing layer, the initial output value is higher than that in the case of including other metal oxides, and the output is maintained for a long time (suppressing output decrease due to PID). I found out that I could do it.

  In addition, when Examples 1 to 3 are compared, Example 2 with a film thickness of 1 μm has a higher output retention after 48 hours than Example 1 with a film thickness of 0.5 μm, and the film thickness is 1 μm. It can be seen that Example 3 having a film thickness of 2 μm has a higher output retention after 48 hours than Example 2. Therefore, it was found that the film thickness of the ion diffusion preventing layer is preferably 1 μm or more, and most preferably around 2 μm.

DESCRIPTION OF SYMBOLS 10 Solar cell module, 11 Translucent substrate, 12 Back sheet, 13 Solar cell, 14 Sealing material, 15 Ion diffusion prevention layer, 20 Solar cell module, 21 Translucent substrate, 22 Back sheet, 23 Solar cell , 24 Sealing material (ion diffusion preventing layer), 30 Solar cell module, 31 Translucent substrate, 32 Back sheet, 33 Solar cell, 34 Sealing material, 35 Ion diffusion preventing layer

Claims (13)

Solar cells that convert incident light into electricity;
Located on the incident light side of the solar cell, a translucent substrate containing or generating alkali metal ions,
An ion diffusion preventing layer disposed between the translucent substrate and the solar cell and preventing diffusion of the ions from the translucent substrate to the solar cell,
The said ion diffusion prevention layer contains magnesium oxide, The solar cell module characterized by the above-mentioned.   The solar cell module according to claim 1, wherein the magnesium oxide is a powder having an average particle diameter of 1 to 500 nm.   The solar cell module according to claim 1 or 2, wherein the ion diffusion preventing layer is a film body in which the magnesium oxide is laminated and has a thickness of 0.1 to 10 µm.   The said photovoltaic cell is sealed with the sealing material, The said ion diffusion prevention layer is arrange | positioned in the interface of the said translucent board | substrate and the said sealing material, The Claim 1-3 characterized by the above-mentioned. The solar cell module in any one.   The solar cell module according to claim 1, wherein the ion diffusion preventing layer is disposed on a surface of the solar cell. Solar cells that convert incident light into electricity;
Located on the incident light side of the solar cell, a translucent substrate containing or generating alkali metal ions,
A sealing material for sealing the solar cell,
Magnesium oxide is contained in the part located between the said photovoltaic cell and the said translucent board | substrate of the said sealing material, The solar cell module characterized by the above-mentioned.   The solar cell module according to claim 6, wherein the magnesium oxide is a powder having an average particle diameter of 1 to 500 nm, and the powder is dispersed and contained in the sealing material. A method for manufacturing a solar cell module comprising a solar cell that converts incident light into electricity and a translucent substrate that contains or generates alkali metal ions,
An application step of applying a dispersion liquid composed of a solvent in which magnesium oxide is dispersed on one or both of one surface of the translucent substrate and the other surface of the solar battery cell;
An ion diffusion preventing layer forming step of volatilizing the solvent to form a magnesium oxide film on one or both of one surface of the translucent substrate and the other surface of the solar cell;
And a disposing step of disposing the translucent substrate and the solar cell so that one surface of the translucent substrate faces the other surface of the solar cell. Method. A solar cell module manufacturing method comprising a solar cell that converts incident light into electricity and a translucent substrate that contains or generates alkali metal ions,
A sealing step of sealing the solar battery cell with a sealing material;
An application step of applying a dispersion liquid composed of a solvent in which magnesium oxide is dispersed on the surface of the sealing material facing the translucent substrate;
An ion diffusion prevention layer forming step of volatilizing the solvent to form a magnesium oxide film on the surface of the sealing material;
A solar cell module comprising: an arrangement step of arranging the translucent substrate and the solar cell so that the translucent substrate and the solar cell face each other with the magnesium oxide film interposed therebetween. Manufacturing method.   The method for manufacturing a solar cell module according to claim 8 or 9, wherein the magnesium oxide contained in the dispersion is a powder having an average particle diameter of 1 to 500 nm.   The solar cell module according to any one of claims 8 to 10, wherein the dispersion is applied in the application step so that a film thickness of the magnesium oxide film is 0.1 to 10 µm. Manufacturing method. A solar cell that converts incident light into electricity, a translucent substrate that contains or generates alkali metal ions, and at least the solar cell and the translucent substrate are interposed to seal the solar cell. A solar cell module manufacturing method comprising a sealing material to be stopped,
A mixing step of mixing the sealing material with magnesium oxide powder in a dispersed state;
A sealing step of sealing the solar cells with the sealing material;
And a step of integrating the solar battery cell and the translucent substrate with the sealing material interposed therebetween.   13. The solar cell according to claim 12, wherein the magnesium oxide powder is a powder having an average particle diameter of 1 to 500 nm and is contained in the sealing material in a range of 0.1 to 30% by mass. Module manufacturing method.

Images