Solar cell module

Abstract

The present invention provides a solar cell module equipped with a function that can effectively suppress the heat of solar cells, and which, if it is lightweight or flexible, does not impair these characteristics as a result of the above function. [Solution] A film-type solar cell module is provided in which a solar cell 10 that converts visible light energy into electrical energy is provided on a transparent substrate 11, wherein the transparent substrate 11 contains an upconversion material 20 that converts infrared light into visible light, and at least one of a filler 21 that scatters infrared light and a phosphor 22 that converts ultraviolet light into visible light.

Description

Technical Field

[0001] The present invention relates to a solar cell module.

Background Art

[0002] Conventionally, a solar cell module having a structure for effectively radiating heat generated in a solar cell is known (see Patent Documents 1 and 2). According to the solar cell modules described in Patent Documents 1 and 2, heat is radiated from a heat sink or a heat dissipation sheet disposed on the outermost layer on the non-light-receiving surface side of the solar cell module through a sealing material sheet containing thermally conductive inorganic particles.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the heat dissipation structure of the solar cell modules described in Patent Documents 1 and 2 is not suitable for application to solar cell modules using organic solar cells such as perovskite solar cells. This is because attaching a heat sink or a heat dissipation sheet impairs the excellent properties of lightweight and flexibility of solar cell modules using organic solar cells.

[0005] An object of the present invention is to provide a solar cell module having a function capable of effectively suppressing the heat of a solar cell, and not impairing the properties of lightweight and flexibility when having these properties by the above function.

Means for Solving the Problems

[0006] One aspect of the present invention provides the following solar cell module to achieve the above objective.

[0007] [1] A film-type solar cell module in which solar cells that convert visible light energy into electrical energy are provided on a transparent substrate, wherein the transparent substrate contains an upconversion material that converts infrared light into visible light, and at least one of a filler that scatters infrared light and a phosphor that converts ultraviolet light into visible light. [2] The solar cell module described in [1] above, wherein the solar cell is an organic solar cell. [3] The solar cell module according to [2] above, wherein the solar cell is a perovskite solar cell. [4] The solar cell module according to any one of the above [1] to [3], wherein the solar cell is sealed in a sealing material on the transparent substrate, and the sealing material includes the upconversion material. [5] The solar cell module according to [4] above, wherein the sealing material comprises at least one of the filler and the phosphor. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a solar cell module that has a function that can effectively suppress the heat of solar cells, and that does not impair the properties of lightness and flexibility when these properties are present as a result of the above function. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a plan view of a solar cell module according to an embodiment of the present invention. [Figure 2] Figure 2(a) is a vertical cross-sectional view of a solar cell module cut along the cutting line AA shown in Figure 1. Figure 2(b) is a vertical cross-sectional view of a solar cell module cut along the cutting line BB shown in Figure 1. [Figure 3]Figure 3(a) is a conceptual diagram illustrating the effects of upconversion material and filler when they are included in a transparent substrate. Figure 3(b) is a conceptual diagram illustrating the effects of upconversion material and phosphor when they are included in a transparent substrate. [Modes for carrying out the invention]

[0010] Figure 1 is a plan view of a solar cell module 1 according to an embodiment of the present invention. Figure 2(a) is a vertical cross-sectional view of the solar cell module 1 cut along the cutting line AA shown in Figure 1. Figure 2(b) is a vertical cross-sectional view of the solar cell module 1 cut along the cutting line BB shown in Figure 1.

[0011] Solar cell module 1 is a solar cell module in which solar cells 10 that convert light energy into electrical energy are provided on a transparent substrate 11.

[0012] In the solar cell module 1, the solar cells 10 are arranged on a transparent substrate 11 and sealed with a encapsulant 12. The encapsulant 12 is a resin film such as PET or PEN, which is bonded using an adhesive such as a silicone-based or epoxy-based adhesive. In the case where the solar cell module 1 also takes in light from the encapsulant 12 side and converts it into electrical energy, the encapsulant 12 is made of a transparent material.

[0013] Typically, as shown in Figure 1, multiple solar cells 10 are arranged on a transparent substrate 11 and sealed with a sealing material 12. In the example shown in Figures 1 and 2(a), the multiple solar cells 10 are connected in series, and the generated power can be supplied to external devices via electrodes 13 and 14 connected to both ends.

[0014] The planar shape of the solar cell 10 is, for example, a strip (rectangle) or a square. The length of the shorter side of the planar shape of the solar cell 10 (width in the case of a strip) is preferably 10 mm or less in order to suppress electrical resistance in the planar direction.

[0015] The solar cell 10 includes a photoelectric conversion unit 100 that generates electric energy by charge separation due to light absorption, an electrode 101 provided on the surface of the photoelectric conversion unit 100 on the side of the transparent base material 11, and an electrode 102 provided on the surface of the photoelectric conversion unit 100 on the side opposite to the transparent base material 11.

[0016] The solar cell 10 may be an inorganic solar cell, but is preferably an organic solar cell that is generally superior to inorganic solar cells in terms of light weight and flexibility. Among organic solar cells, particularly, a perovskite solar cell that is excellent in conversion efficiency to electric energy is preferable.

[0017] When the solar cell 10 is an organic solar cell, the solar cell module 1 can be manufactured as a film-type solar cell module having light weight and flexibility. In this case, a film substrate is used for the transparent base material 11.

[0018] The solar cell 10 can convert the energy of visible light into electric energy. In addition to visible light, it may also be able to convert ultraviolet light into electric energy. Here, light with a wavelength of 380 to 780 nm is called visible light, light with a wavelength of less than 380 nm is called ultraviolet light, and light with a wavelength of more than 780 nm is called infrared light.

[0019] The photoelectric conversion unit 100 can take various known configurations according to the type of the solar cell 10.

[0020] For example, when the solar cell 10 is a perovskite solar cell, the photoelectric conversion unit 100 is composed of a perovskite layer in which charge separation occurs due to light absorption, an electron transport layer, and a hole transport layer sandwiching it. Electrons generated by charge separation in the perovskite layer flow to the electrode on the electron transport layer side of the electrodes 101 and 102, and holes generated by charge separation in the perovskite layer flow to the electrode on the hole transport layer side of the electrodes 101 and 102.

[0021] The solar cell module 1 receives light from the transparent substrate 11 and converts it into electrical energy. Therefore, transparent electrodes made of metal oxides such as ITO or FTO are used for electrodes 101 and 13 so as not to obstruct the light entering the photoelectric conversion unit 100 from the transparent substrate 11.

[0022] Electrode 102 is made of a metal such as Au, Al, Cu, or Ag. When electrode 102 is made of a metal, it has excellent thermal conductivity, which is advantageous in terms of heat dissipation. On the other hand, when light is also taken in from the encapsulating material 12 side and converted into electrical energy, a transparent electrode made of a metal oxide such as ITO or FTO is used for electrode 102, similar to electrode 101.

[0023] The transparent substrate 11 contains an upconversion material 20, such as cadmium sulfide, which converts infrared light into visible light. In the transparent substrate 11, for example, the particulate upconversion material 20 is dispersed in a resin film made of PET, PEN, or the like as a base material.

[0024] The upconversion material 20 contained in the transparent substrate 11 can convert infrared light contained in the light irradiated onto the solar cell module 1 into visible light in a wavelength range that the solar cell 10 can efficiently use for power generation. Therefore, by including the upconversion material 20 in the transparent substrate 11, the power generation efficiency (efficiency of converting light energy into electrical energy) of the solar cell 10 can be improved.

[0025] For example, if the solar cell 10 is a perovskite solar cell having a perovskite layer made of a material having a perovskite structure in which at least one of Cs, MA, and FA is present at site A, Pb is present at site B, and at least one of I and Br is present in the halogen, then it is preferable to use cadmium sulfide as the upconversion material 20.

[0026] Furthermore, since an endothermic reaction occurs when the upconversion material 20 converts infrared light into visible light, which has higher energy than infrared light, the temperature of the solar cell module 1 can be lowered. Generally, the base materials such as the transparent substrate 11 and the resin of the encapsulant 12 that cover the solar cell 10 have low thermal conductivity and cannot effectively dissipate the heat generated in the solar cell 10. However, by including the upconversion material 20, heat can be absorbed and the temperature of the solar cell module 1 can be lowered.

[0027] When generating electricity using solar cell module 1 outdoors, the temperature of solar cell module 1 rises due to strong direct sunlight and heat generated by the solar cell module 1 itself. This temperature rise in solar cell module 1 can lead to a decrease in power generation efficiency and cause malfunctions.

[0028] In particular, when the solar cell 10 consists of an organic film solar cell such as a perovskite solar cell, the decrease in power generation efficiency due to temperature rise is significant, so the effect of temperature reduction by including an upconversion material in the transparent substrate 11 becomes important.

[0029] Furthermore, the method of including the upconversion material 20 in the transparent substrate 11 to lower the temperature of the solar cell module 1 differs from methods that use heat dissipation components such as heat sinks or heat dissipation sheets in that it hardly impairs the lightweight and flexible properties of the solar cell module 1, and does not restrict the degree of freedom in installing the solar cell module 1.

[0030] Furthermore, if the solar cell 10 is a perovskite solar cell or similar, which is susceptible to degradation from infrared light, the amount of infrared light irradiated onto the solar cell 10 can be reduced by using the upconversion material 20, thereby suppressing degradation.

[0031] Furthermore, in the solar cell module 1, in addition to the transparent substrate 11, the encapsulant 12 may also contain an upconversion material 20. In this case, when light is taken in from the encapsulant 12 side and converted into electrical energy, the upconversion material 20 can also exert its effect on the light taken in from the encapsulant 12 side.

[0032] Furthermore, the transparent substrate 11 contains at least one of a filler 21 that scatters infrared light and a phosphor 22 that converts ultraviolet light into visible light. The filler 21 and phosphor 22 are dispersed in the base material of the transparent substrate 11, for example, in the form of particles.

[0033] Figure 3(a) is a conceptual diagram illustrating the effects of the upconversion material 20 and filler 21 when they are included in the transparent substrate 11.

[0034] Filler 21 is a material that is included in the light irradiated onto the solar cell module 1, and the upconversion material 20 is visible light L vis Infrared light L in the wavelength range that can be converted IR This allows the infrared light L to be scattered. Therefore, by including the filler 21 in the transparent substrate 11, the infrared light L can be scattered into the upconversion material 20. IR Efficiently absorbs infrared light L by the upconversion material 20. IR From visible light L vis This allows for efficient conversion and further improves the power generation efficiency of the solar cell 10.

[0035] Furthermore, infrared light L is used to illuminate the upconversion material 20 using the filler 21. IR By efficiently absorbing the heat, the endothermic reaction associated with the wavelength conversion of light by the upconversion material 20 is also increased, making it possible to more effectively suppress the heat of the solar cell 10.

[0036] Furthermore, if the solar cell 10 is a perovskite solar cell or otherwise has properties that cause degradation due to infrared light, the amount of infrared light irradiated onto the solar cell 10 can be further reduced by using the filler 21, thereby suppressing degradation.

[0037] The wavelength of light scattered by the filler 21 contained in the transparent substrate 11 is determined by the material and particle size of the filler 21. For example, inorganic fillers, carbon graphite, diamond fillers, etc., can be used as the filler 21.

[0038] The concentration of the filler 21 in the transparent substrate 11 is, for example, 0.01 to 5% by mass, but is preferably 0.01 to 0.5% by mass in order to suppress a decrease in light transmittance.

[0039] Figure 3(b) is a conceptual diagram illustrating the effects of the upconversion material 20 and phosphor 22 when they are included in the transparent substrate 11.

[0040] The phosphor 22 absorbs ultraviolet light L contained in the light irradiated onto the solar cell module 1. UV High energy conversion efficiency of visible light L by solar cell 10 vis It can be converted to this. Therefore, by including the phosphor 22 in the transparent substrate 11, the power generation efficiency of the solar cell 10 can be further improved.

[0041] Furthermore, by using the phosphor 22, the ultraviolet light irradiated onto the solar cell 10 can be reduced, thereby suppressing the degradation of the solar cell 10. In particular, if the solar cell 10 is a perovskite solar cell, the perovskite crystal contained in the photoelectric conversion unit 100 is susceptible to degradation by ultraviolet light, so reducing the ultraviolet light irradiated onto the solar cell 10 is important.

[0042] For example, phosphors such as YAG, LUAG, CASN, SCASN, and β-SiAlON can be used as the phosphor 22. For example, if the solar cell 10 is a perovskite solar cell having a perovskite layer made of a material having a perovskite structure in which at least one of Cs, MA, and FA is present at site A, Pb is present at site B, and at least one of I and Br is present in the halogen, then it is preferable to use at least one of YAG, LUAG, CASN, SCASN, and β-SiAlON as the phosphor 22.

[0043] The concentration of the phosphor 22 in the transparent substrate 11 is, for example, 30% by mass or less, but it is preferably less than 1% by mass in order to suppress a decrease in light transmittance.

[0044] The transparent substrate 11 may contain both the filler 21 and the phosphor 22.

[0045] Furthermore, in the solar cell module 1, in addition to the transparent substrate 11, the encapsulant 12 may contain at least one of the filler 21 and the phosphor 22. In this case, when light is taken in from the encapsulant 12 side and converted into electrical energy, the filler 21 and phosphor 22 can also exert their effects on the light taken in from the encapsulant 12 side.

[0046] The surface of the sealing material 12 may be coated with a heat-dissipating paint to improve heat dissipation. In addition, the bottom surface of the transparent substrate 11 and the surface of the sealing material 12 may be provided with irregularities to increase the surface area and improve heat dissipation.

[0047] (Effects of the embodiment) According to the solar cell module 1 of the above-described embodiment of the present invention, the heat of the solar cell 10 can be effectively suppressed by using an upconversion material 20 or the like. Furthermore, since no heat sink or heat dissipation sheet is used, if the solar cell module 1 is lightweight or flexible, these properties will not be impaired.

[0048] Although embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention. Furthermore, the components of the above embodiments can be arbitrarily combined without departing from the spirit of the invention. Moreover, the above embodiments do not limit the invention as defined in the claims. It should also be noted that not all combinations of features described in the embodiments are necessarily essential for solving the problem of the invention. [Explanation of Symbols]

[0049] 1. Solar cell module 10 solar cells 11 Transparent base material 12. Sealing material 20 Upconversion Materials 21 Filler 22 Phosphors

Claims

1. A film-type solar cell module in which solar cells that convert visible light energy into electrical energy are provided on a transparent substrate, The transparent substrate contains an upconversion material that converts infrared light into visible light, and at least one of a filler that scatters infrared light and a phosphor that converts ultraviolet light into visible light. Solar cell module.

2. The aforementioned solar cell is an organic solar cell. The solar cell module according to claim 1.

3. The aforementioned solar cell is a perovskite solar cell. The solar cell module according to claim 2.

4. The solar cell is sealed with a sealing material on the transparent substrate, The sealing material includes the upconversion material, A solar cell module according to any one of claims 1 to 3.

5. The sealing material comprises at least one of the filler and the phosphor. The solar cell module according to claim 4.

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