Solar cell modules

Abstract

To provide a solar cell module capable of admitting natural light without giving feeling of oppression or obstruction when installed in a window.SOLUTION: A solar cell module 1 according to an embodiment of the present invention includes a perovskite solar cell 10, a surface protective member 30 covering the surface side of the perovskite solar cell 10, a back protective member 40 covering the back side of the perovskite solar cell 10, a black front side coloring material 50 arranged between the perovskite solar cell 10 and the surface protective member 30 so as to cover the outer side of the perovskite solar cell 10 in a planar view, a back side coloring material 60 having a lighter color than the front side coloring material 50 arranged between the perovskite solar cell 10 and the back protective member 40 so as to cover the outer side of the perovskite solar cell 10 in a planar view, and a sealing material 70 filled between the front side protective member 30 and the back protective member 40.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This invention relates to a solar cell module. [Background technology]

[0002] Solar cell modules are used in which solar cells are arranged between a transparent plate-shaped surface protective member and a plate-shaped or sheet-shaped back protective member on the back side, and a sealing material is filled between the surface protective member and the back protective member. In such solar cell modules, it has been proposed to place a light-shielding film between the surface protective member and the solar cells to cover the area outside the solar cells, so that the electrodes of the solar cells and the connecting members that connect the solar cells are not visible (see, for example, Patent Document 1).

[0003] It is also being considered to install solar cell modules that transmit some light in windows, etc., to enable both photoelectric conversion and natural light entering the room. As solar cell modules that transmit some light, one possibility is to use perovskite solar cells that absorb only light in certain wavelength ranges and transmit light in other wavelength ranges. Perovskite solar cells absorb light in the short wavelength range and convert it into photoelectric light, but can transmit visible light in the long wavelength range. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-209473 [Overview of the project] [Problems that the invention aims to solve]

[0005] For solar cell modules that allow light to pass through and are installed in windows, it is conceivable to include a light-blocking area on the back protective material to conceal the wiring. When such solar cell modules are viewed from the inside, the width of the light-blocking area is large, and the area where the outdoor scenery is visible appears small, which can easily give a feeling of confinement or claustrophobia.

[0006] The present invention aims to provide a light-transmitting solar cell module that, when installed in a window, does not create a feeling of oppression or confinement. [Means for solving the problem]

[0007] A solar cell module according to one aspect of the present invention comprises a perovskite solar cell, a surface protection member covering the surface side of the perovskite solar cell, a back protection member covering the back side of the perovskite solar cell, a black front coloring material disposed between the perovskite solar cell and the surface protection member so as to cover the outside of the perovskite solar cell in a plan view, a back coloring material disposed between the perovskite solar cell and the back protection member so as to cover the outside of the perovskite solar cell in a plan view and having a lighter color than the front coloring material, and a sealing material filled between the surface protection member and the back protection member.

[0008] In the solar cell module described above, the color difference ΔE between the front-side coloring material and the back-side coloring material may be 30 or more.

[0009] In the solar cell module described above, the perovskite solar cell has, in order from the light-receiving side, a transparent substrate layer, a first electrode layer made of a transparent conductive oxide, a photoelectric conversion layer containing a perovskite compound, and a second electrode layer containing a metal, and a plurality of slits may be formed by removing the photoelectric conversion layer and the second electrode layer. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a light-transmitting solar cell module that does not give a feeling of oppression or confinement when installed in a window. [Brief explanation of the drawing]

[0011] [Figure 1] This is a plan view showing a solar cell module according to one embodiment of the present invention. [Figure 2] Figure 1 is a cross-sectional view of the solar cell module along line XX. [Figure 3] Figure 1 is an enlarged view of the YY-line cross-section of the solar cell module. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will be described below with reference to the drawings. For convenience, hatching and component reference numerals may be omitted in some cases; in such cases, refer to other drawings. Furthermore, the dimensions of various components in the drawings have been adjusted for clarity and ease of viewing.

[0013] Figure 1 is a plan view of a solar cell module 1 according to one embodiment of the present invention. Figure 2 is a cross-sectional view of the solar cell module 1 of Figure 1 along line XX. Figure 3 is an enlarged view of a portion of the cross-sectional view of the solar cell module 1 of Figure 1 along line YY.

[0014] The solar cell module 1 comprises a plurality of perovskite solar cells 10, wiring material 20 connecting the plurality of perovskite solar cells 10, a surface protection member 30 covering the surface side (light-receiving surface side) of the plurality of perovskite solar cells 10, a back protection member 40 covering the back side of the plurality of perovskite solar cells 10, a front coloring material 50 placed between the perovskite solar cells 10 and the surface protection member 30, a back coloring material 60 placed between the perovskite solar cells 10 and the back protection member 40, and a sealing material 70 filled between the surface protection member 30 and the back protection member 40.

[0015] The perovskite solar cell 10 may have a configuration in which a substrate layer 11, a first electrode layer 12, a photoelectric conversion layer 13, and a second electrode layer 14 are arranged in this order. In this embodiment, the perovskite solar cell 10 has the substrate layer 11 on the light-receiving side, and a plurality of slits 15 are formed by removing at least the photoelectric conversion layer 13 and the second electrode layer 14.

[0016] The base material layer 11 is a plate-shaped or sheet-shaped structural member that ensures the strength of the perovskite solar cell 10. In the present embodiment, the base material layer 11 is transparent, and can be formed of, for example, a resin such as polyimide, polyamide, polyethylene terephthalate, or glass.

[0017] The first electrode layer 12 collects the first charges generated in the photoelectric conversion layer 13 and outputs them to the outside. In the present embodiment, the first electrode layer 12 is formed of a transparent conductive oxide (TCO: Transparent Conductive Oxide). As the transparent conductive oxide forming the first electrode layer 12, for example, indium oxide, tin oxide, zinc oxide, titanium oxide, composite oxides thereof, and the like can be used. Among these, indium-based composite oxides containing indium oxide as a main component are preferable. From the viewpoint of high conductivity and transparency, indium oxide is particularly preferable. Furthermore, in order to ensure reliability or higher conductivity, it is preferable to add a dopant to indium oxide. Examples of the dopant include Sn, W, Zn, Ti, Ce, Zr, Mo, Al, Ga, Ge, As, Si, S, and the like. As a particularly preferred example, ITO (Indium Tin Oxide), which is indium oxide doped with tin, is widely known. The first electrode layer 12 can be laminated by a method such as a sputtering method or a vacuum deposition method, for example.

[0018] As the lower limit of the thickness of the first electrode layer 12, 5 nm is preferable, and 10 nm is more preferable. On the other hand, as the upper limit of the thickness of the first electrode layer 12, 200 nm is preferable, and 100 nm is more preferable. By setting the thickness of the first electrode layer 12 to be equal to or greater than the lower limit, the electrical resistance can be reduced, so that the photoelectric conversion efficiency of the perovskite solar cell 10 can be improved. In addition, by setting the thickness of the first electrode layer 12 to be equal to or less than the upper limit, unnecessary cost increase and decrease in flexibility can be prevented. The first electrode layer 12 may have a multilayer structure such as a laminated structure of a polycrystalline ITO layer and an amorphous ITO layer, for example.

[0019] The photoelectric conversion layer 13 contains a perovskite compound, absorbs incident light, and generates photocarriers (electrons and holes). As the perovskite compound contained in the photoelectric conversion layer 13, a compound represented by ABX3 can be used, which contains an organic atom A containing at least one of monovalent organic ammonium ions and amidinium-based ions, a metal atom B that generates a divalent metal ion, and a halogen atom X containing at least one of iodide ion I, bromide ion Br, chloride ion Cl, and fluoride ion F. Above all, when the photoelectric conversion layer 13 is formed by a vapor deposition method (dry process), methylammonium MA (CH3NH3) is preferable as the organic atom A, lead Pb is preferable as the metal atom B, and at least one of iodide I, bromide ion Br and chloride ion Cl is preferable as the halogen atom X.

[0020] Specifically, preferable perovskite compounds include methylammonium lead halide MAPbX3 (CH3NH3PbX3), MAPbI3, MAPbBr3, MAPbCl3, and the like. Note that a plurality of types of halogen atoms X may be contained. Examples of perovskite compounds containing iodide I and another halogen atom X include methylammonium lead iodide MAPbI y X (3-y) (CH3NH3PbI y X (3-y) ), MAPbI y Br (3-y) , MAPbI y Cl (3-y) and the like (y is any positive integer).

[0021] For the photoelectric conversion layer 13 containing a perovskite compound, when the perovskite compound is methylammonium lead halide (MAPbX3 (CH3NH3PbX3)), the photoelectric conversion layer 13 can be formed by sequentially forming a film of a lead halide (PbX2) material and a methylammonium halide (MAX) material, and reacting thin films of these materials at a reaction temperature. For example, when the perovskite compound is methylammonium lead iodide (MAPbI y X (3-y) (CH3NH3PbIy X (3-y) In this case, the photoelectric conversion layer 13 is formed by sequentially depositing a lead halide (PbX2) material and a methylammonium iodide (MAI) material, and then reacting these thin films at the reaction temperature. The photoelectric conversion layer 13 can also be formed by methods such as the sol-gel method, in which a perovskite compound is synthesized in a liquid-phase coating film, or the coating method, in which a solution containing a pre-synthesized perovskite compound is applied.

[0022] The thickness of the photoelectric conversion layer 13 depends on the forming material, but it is preferable to set it to 100 nm to 2000 nm in order to increase the light absorption rate while minimizing the distance the generated charge travels.

[0023] The second electrode layer 14 is an electrode paired with the first electrode layer 12. The second electrode layer 14 may be formed from a transparent conductive oxide, but it is preferable that it be formed from a conductive material containing metal. Specifically, the second electrode layer 14 can be formed from a composition in which metal or metal particles are bound together with a binder. By placing the second electrode layer 14, whose conductivity is ensured by metal, on the back side in this way, the current collection resistance of the perovskite solar cell 10 can be reduced. Furthermore, the second electrode layer 14, formed from a material containing metal, can improve the photoelectric conversion efficiency by reflecting the light transmitted through the photoelectric conversion layer 13 and re-incidentating it into the photoelectric conversion layer 13. The second electrode layer 14 can be formed by laminating metal by methods such as sputtering and plating, or by coating and firing a conductive composition containing metal particles.

[0024] The lower limit of the thickness of the second electrode layer 14 is preferably 5 nm, and more preferably 10 nm. On the other hand, the upper limit of the thickness of the second electrode layer 14 is preferably 200 nm, and more preferably 100 nm. By making the thickness of the second electrode layer 14 above the lower limit, the current collection resistance can be sufficiently reduced. Furthermore, by making the thickness of the second electrode layer 14 below the upper limit, the formation of the slit 15 becomes easier.

[0025] The slits 15 are formed to remove the light-absorbing layer and transmit light across the entire wavelength range, thereby improving the light-gathering ability (light transmittance to the back side) of the solar cell module 1. Furthermore, because numerous thin slits 15 are formed in parallel, viewers on the back side of the solar cell module 1 can see the outside scenery more clearly through the solar cell module 1 without being aware of the individual slits 15.

[0026] The lower limit of the width of the slit 15 is preferably 10 μm, and more preferably 100 μm. On the other hand, the upper limit of the width of the slit 15 is preferably 10 mm, and more preferably 1 mm. By setting the width of the slit 15 to be above the lower limit, the variation in the amount of light transmitted due to errors in the width of the slit 15 can be relatively reduced, so that light can be collected evenly. Also, by setting the width of the slit 15 to be below the upper limit, the individual slits 15 can be made less conspicuous. The pitch of the slits 15 is appropriately designed according to the light collection rate to be obtained, but for example, it can be 100 μm or more and 1 mm or less.

[0027] The perovskite solar cell 10 may be divided into multiple regions, or subcells, that independently extract power in a plan view. Furthermore, the perovskite solar cell 10 may have additional layers, such as a charge transport layer or an anti-reflective layer.

[0028] The wiring material 20 connects the perovskite solar cells 10 and leads the power output from multiple perovskite solar cells 10 to the outside. Examples of wiring materials 20 include metal foil, metal wire, and metal braided wire. Furthermore, the material and shape of the wiring material 20 may differ depending on its location. The wiring material 20 is arranged so as not to obstruct sunlight, except for the portion connected to the perovskite solar cells 10, and so as not to overlap with the perovskite solar cells 10. In other words, the wiring material 20 is primarily arranged to extend outside the perovskite solar cells 10 in a plan view.

[0029] The surface protection member 30 protects the perovskite solar cell 10 by covering its surface via the sealing material 70. The surface protection member 30 can be formed from a plate-shaped or sheet-shaped material, and preferably has excellent light transmission, water-blocking properties, scratch resistance, and weather resistance. Specifically, the material of the surface protection member 30 can be, for example, a transparent resin such as acrylic resin or polycarbonate resin, or glass. Furthermore, the surface of the surface protection member 30 may be processed to have an uneven surface or covered with an anti-reflective coating layer to suppress light reflection.

[0030] The back surface protection member 40 protects the perovskite solar cell 10 by covering its back surface via the sealing material 70. The back surface protection member 40 can be formed from a plate-like material similar to that of the front surface protection member 30.

[0031] The front-side coloring material 50 is made of a black material and is arranged to cover the outside of the perovskite solar cell 10 in a plan view. The front-side coloring material 50 covers and conceals components that would detract from the aesthetics, such as wiring materials 20, so that they cannot be seen from the front. For this reason, it is preferable that the front-side coloring material 50 is arranged overlapping the outer edge of the perovskite solar cell 10 so that only a light-transmitting area is open on the back side of the perovskite solar cell 10. Accordingly, the front-side coloring material 50 can be provided to extend not only around the outer periphery of the solar cell module 1 but also between the perovskite solar cells 10.

[0032] The front-side coloring material 50 may also be used as a sealing member for the outer edge of the solar cell module 1, or it may be a sheet inserted solely to perform a light-shielding function, or it may be configured as a coating film formed on the back surface of the surface protection member 30. The color of the front-side coloring material 50 (CIE1976) is preferably such that the L*, a*, and b* values ​​are 10 or less, and more preferably 5 or less.

[0033] The back-side coloring material 60 is positioned to cover the outside of the perovskite solar cell 10 in a plan view. The front-side coloring material 50 covers and conceals components that would detract from the aesthetics, such as wiring materials 20, so that they cannot be seen from the back. It is preferable that the back-side coloring material 60 is formed to be the same shape as the front-side coloring material 50 so that it overlaps with it in a plan view.

[0034] The back-side coloring material 60 may also serve as a sealing member for the outer edge of the solar cell module 1, or it may be a sheet that only performs the function of light shielding, or it may be configured as a coating formed on the back surface protective member 40. The back-side coloring material 60 has a brighter color than the front-side coloring material 50. In other words, the back-side coloring material 60 has a higher lightness L* (CIE1976) value than the front-side coloring material 50. As a result, when the space on the back of the solar cell module 1 is darker than the space on the front, the color difference between the solar cell module 1, which transmits light from the front, and the back-side coloring material 60 becomes smaller when the solar cell module 1 is viewed from the back, and the sense of unity between the solar cell module 1 and the back-side coloring material 60 increases. As a result, the presence of the back-side coloring material 60 is reduced, and the sense of unity of the view seen through multiple solar cell modules 1 increases. Therefore, when the solar cell modules 1 are installed in a window, people inside the room will perceive the effective area of ​​the window as larger, reducing feelings of oppression and confinement and improving the sense of openness.

[0035] The lower limit of the color difference ΔE (CIE1976) between the front coloring material 50 and the back coloring material 60 is preferably 30, and more preferably 40. On the other hand, the upper limit of the color difference ΔE between the front coloring material 50 and the back coloring material 60 is preferably 70, and more preferably 60. By setting the color difference ΔE between the front coloring material 50 and the back coloring material 60 to be above the lower limit, the presence of the back coloring material 60 can be sufficiently reduced when the space on the front side is bright. Furthermore, by setting the color difference ΔE between the front coloring material 50 and the back coloring material 60 to be below the upper limit, that is, by not making the brightness and saturation of the back coloring material 60 too high, the back coloring material 60 can be prevented from being excessively conspicuous when the space on the back side is bright.

[0036] The sealing material 70 is filled between the light-receiving surface of the perovskite solar cell 10 and the surface protection member 30, between the back surface of the perovskite solar cell 10 and the back protection member 40, and in the gaps between the perovskite solar cells 10 themselves. The sealing material 70 adheres the perovskite solar cell 10 to the surface protection member 30 and the back protection member 40, and eliminates gaps around the perovskite solar cell 10, thereby preventing moisture and other substances from coming into contact with the perovskite solar cell 10.

[0037] As the encapsulant 70, suitable examples include light-transmitting resins such as ethylene / vinyl acetate copolymer (EVA), ethylene / α-olefin copolymer, ethylene / vinyl acetate / triallyl isocyanurate (EVAT), polyvinyl butyrate (PVB), acrylic resin, urethane resin, or silicone resin. Preferably, the encapsulant 70 is made of a material that has thermoplastic properties to penetrate the gaps of the perovskite solar cell 10 during the manufacturing stage, and loses its thermoplastic properties in the final product so that it can maintain its shape even when the temperature of the solar cell module 1 rises. In other words, preferably, the encapsulant 70 is made of a resin composition mainly composed of a thermoplastic resin and containing a crosslinking agent that is activated at a temperature higher than the softening point of the thermoplastic resin and crosslinks and hardens the thermoplastic resin.

[0038] As described above, the solar cell module 1 of this embodiment comprises a plurality of light-transmitting perovskite solar cells 10, a black front-side coloring material 50, and a back-side coloring material 60 having a lighter color than the front-side coloring material 50. Therefore, when the solar cell module 1 is installed in a window or the like and the brighter outdoors is viewed from inside the room, there is a strong sense of unity between the perovskite solar cells 10 and their surroundings, and the plurality of perovskite solar cells 10 can be seen as a single unit, so that it does not give people inside the room a feeling of oppression or confinement.

[0039] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications and variations are possible. [Explanation of symbols]

[0040] 1. Solar cell module 10 Perovskite Solar Cells 11 Base material layer 12 1st electrode layer 13 Photoelectric conversion layer 14 Second electrode layer 15 slits 20 Wiring material 30 Surface protection material 40. Back surface protective material 50 Front side coloring material 60 Backside coloring material 70 Sealing material

Claims

1. Perovskite solar cells and A surface protection member that covers the surface side of the perovskite solar cell, A back surface protective member that covers the back side of the perovskite solar cell, A black surface coloring material is placed between the perovskite solar cell and the surface protection member so as to cover the outside of the perovskite solar cell in a plan view, Between the perovskite solar cell and the back surface protective member, a back surface coloring material is disposed so as to cover the outside of the perovskite solar cell in a plan view, and has a lighter color than the front surface coloring material, A sealing material is filled between the surface protective member and the back protective member, A solar cell module equipped with the following features.

2. The solar cell module according to claim 1, wherein the color difference ΔE between the front coloring material and the back coloring material is 30 or more.

3. The perovskite solar cell has, in order from the light-receiving side, a transparent substrate layer, a first electrode layer made of a transparent conductive oxide, a photoelectric conversion layer containing a perovskite compound, and a second electrode layer containing a metal, and a plurality of slits are formed by removing the photoelectric conversion layer and the second electrode layer, as described in claim 1 or 2.

Images