Solar cell module

Abstract

To provide a light transmission type solar cell module capable of suppressing deterioration of a solar cell and having a large light transmission amount.SOLUTION: A solar cell module 1 includes a perovskite solar cell 30 in which a plurality of light-transmitting grooves 31 are formed, and a low-emissivity layer 40 that is disposed on a front side of the perovskite solar cell 30 and blocks infrared rays, wherein the low-emissivity layer 40 has a plurality of daylighting grooves 41 formed by linearly removing a material so as to overlap the light-transmitting grooves 31 in a plan view.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] As the applications of solar cells expand, the installation of light-transmitting solar cell modules that transmit part of the light in windows and the like is also being considered. A known technique for improving the thermal insulation of ordinary glass windows is to provide a low-emissivity layer (Low-E film) that blocks infrared rays on the glass. For this reason, it has been proposed to provide a low-emissivity layer in light-transmitting solar cell modules as well (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. WO2019 / 176861 Summary of the Invention [Problem to be solved by the invention]

[0004] Among solar cells, perovskite solar cells are at risk of degradation due to heat and ultraviolet rays. For this reason, it is conceivable to provide a low-emissivity layer that blocks infrared and ultraviolet rays on the front side (light-receiving surface side) of the solar cell. The low-emissivity layer has wavelength selectivity, but also blocks a small amount of visible light. For this reason, providing a low-emissivity layer in a light-transmitting solar cell module further reduces the amount of light that can be transmitted. Therefore, an object of the present invention is to provide a light-transmitting solar cell module that can suppress degradation of the solar cell and has a large amount of light transmission. [Means for solving the problem]

[0005] A solar cell module according to one aspect of the present invention comprises a perovskite solar cell having a plurality of light-transmitting grooves formed therein, and a low-emissivity layer disposed on the front side of the perovskite solar cell and blocking infrared rays, the low-emissivity layer having a plurality of light-receiving grooves formed by linearly removing material so as to overlap the light-transmitting grooves in a planar view. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a light-transmitting solar cell module that can suppress deterioration of the solar cells and transmits a large amount of light. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic plan view of a solar cell module according to one embodiment of the present invention. [Figure 2] 2 is a schematic cross-sectional view of the solar cell module of FIG. 1 taken along line XX. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. For convenience, hatching and component reference numerals may be omitted. In such cases, reference should be made to other drawings. Furthermore, the dimensions of various components in the drawings have been adjusted for clarity.

[0009] Fig. 1 is a schematic plan view of a solar cell module 1 according to one embodiment of the present invention. Fig. 2 is a schematic cross-sectional view of the solar cell module 1 taken along line XX in Fig. 1. The solar cell module 1 includes a surface protection material 10, a support substrate 20, perovskite solar cells 30, a low-emission layer 40, a peripheral closure material 50, a back surface protection material 60, and a sealing material 70.

[0010] The surface protective material 10 is disposed so as to cover the front side of the low-emissivity layer 40, with a gap between it and the support substrate 20 to form a space for thermal insulation. Furthermore, the surface protective material 10 seals the space in which the low-emissivity layer 40 is disposed, isolating the low-emissivity layer 40 from the outside air and suppressing deterioration of the low-emissivity layer 40. The surface protective material 10 can be formed from a plate-shaped material, and preferably has excellent light-transmitting properties, water-blocking properties, scratch resistance, and weather resistance. Specifically, examples of materials for the surface protective material 10 include transparent resins such as acrylic resins and polycarbonate resins, and glass, with glass being particularly preferred. In this specification, the term "front side" refers to the side from which light primarily enters the solar cell module 1, such as the outdoor side when the module is installed on a window, and the term "rear side" refers to the opposite side, such as the indoor side.

[0011] The support substrate 20 is formed from a translucent plate- or sheet-shaped material. The support substrate 20 supports the perovskite solar cells 30 on its back side and the low-emissivity layer 40 on its front side. By providing the support substrate 20 on which the perovskite solar cells 30 and the low-emissivity layer 40 are laminated, the relative positions of the perovskite solar cells 30 and the low-emissivity layer 40 can be accurately determined. The material of the support substrate 20 can be the same as the material of the surface protection material 10, and glass is preferably used. Note that because the support substrate 20 is not directly subjected to external forces, the thickness of the support substrate 20 may be smaller than the thickness of the surface protection material 10. Furthermore, in order to suppress changes in the relative positions of the perovskite solar cells 30 and the low-emissivity layer 40 based on the transmission direction of light whose incident direction changes, the thickness of the support substrate 20 is preferably as small as possible within a range that ensures the necessary strength.

[0012] The perovskite solar cell 30 contains a perovskite compound that absorbs light to generate photocarriers (electrons and holes), collects the photocarriers, and outputs them as electricity. The perovskite solar cell 30 is formed by stacking various materials on the rear main surface of the support substrate 20. For example, the perovskite solar cell 30 may be configured such that a first transparent electrode layer, a first charge transport layer, a photoelectric conversion layer, a second charge transport layer, and a second transparent electrode layer are stacked in this order. The perovskite solar cell 30 also has a plurality of light-transmitting grooves 31 formed parallel to one another. The width of the light-transmitting grooves 31 may be, for example, 0.1 mm or more and 3 mm or less. The pitch of the light-transmitting grooves 31 may be, for example, 1.2 times or more and 50 times or less the width of the light-transmitting grooves 31. The perovskite solar cell 30 may be divided into a plurality of subcells each of which independently performs photoelectric conversion and is electrically connected in series, and each of which has a first separation groove extending in a direction intersecting the light-transmitting groove 31 to cut the first transparent electrode layer, a second separation groove parallel to the first separation groove to cut the first charge transport layer, the photoelectric conversion layer, and the second charge transport layer, and a third separation groove parallel to the first separation groove and the second separation groove to cut the second electrode layer. The perovskite solar cell 30 may also be configured to have ineffective regions on both sides of the active regions (plurality of subcells) that contribute to photoelectric conversion, in which external electrodes to which wiring materials for outputting power are connected are provided.

[0013] The first and second transparent electrode layers may be formed of a transparent conductive oxide (TCO) having electrical conductivity and optical transparency, a thin semiconductor layer, or the like. Examples of the transparent conductive oxide that can be used to form the first and second transparent electrode layers include indium oxide, tin oxide, zinc oxide, titanium oxide, and composite oxides thereof. Among these, indium-based composite oxides containing indium oxide as the main component are preferred. Indium oxide is particularly preferred from the viewpoints of high electrical conductivity and transparency. Furthermore, it is preferable to add a dopant to indium oxide to ensure reliability or higher electrical conductivity. Examples of dopants include Sn, W, Zn, Ti, Ce, Zr, Mo, Al, Ga, Ge, As, Si, and S. For example, ITO (indium tin oxide), in which tin is added to indium oxide, is widely known.

[0014] The first charge transport layer and the second charge transport layer selectively pass charges of opposite polarities. That is, one of the first charge transport layer and the second charge transport layer is an electron transport layer that passes electrons, and the other of the first charge transport layer and the second charge transport layer is a hole transport layer that passes holes. Examples of the main material of the electron transport layer include fullerene and PCBM. Examples of fullerene include C60, C70, their hydrides, oxides, metal complexes, and derivatives with alkyl groups added thereto, such as PCBM ([6,6]-Phenyl-C61-Butyric Acid Methyl Ester). In particular, forming the electron transport layer from a material containing fullerene encapsulating lithium (Li) can improve electron transport efficiency. The hole transport layer can be formed from a film of a hole transport layer-forming compound that forms a hole-permeable self-assembled monolayer (SAM). The hole transport layer-forming compound that forms the self-assembled monolayer that becomes the hole transport layer can be a compound having a functional group capable of transporting holes, such as a carbazole-based, phenothiazine-based, or dimethylacridine-based compound, and a self-assembling terminal group, such as phosphoric acid or carboxylic acid. The hole transport layer-forming compound preferably has a linear structure, such as an alkyl chain, between the functional group and the self-assembling terminal group to impart passivation properties to the hole transport layer. The alkyl chain preferably has four or more carbon atoms. Specific examples of the hole transport layer-forming compound include Me-4PACz ([4-(3,6-Dimethyl-9H-carbazol-9-yl)butyl]phosphonic Acid)) and Me-6PACz ([6-(3,6-Dimethyl-9H-carbazol-9-yl)butyl]phosphonic Acid)).

[0015] The photoelectric conversion layer absorbs incident light to generate photocarriers (electrons and holes). The photoelectric conversion layer can be formed from a material containing a perovskite compound. As the perovskite compound, a compound represented by ABX3 can be used, which contains an organic atomic group A containing at least one of a monovalent organic ammonium ion and an amidinium ion, a metal atom B that generates a divalent metal ion, and a halogen atom X containing at least one of an iodide ion I, a bromide ion Br, a chloride ion Cl, and a fluoride ion F. In addition, perovskite compounds in which part or all of the organic atomic group A is substituted with an alkali metal Am are also not excluded from the present invention.

[0016] Examples of the organic atomic group A include methylammonium MA (CH3NH3) and formamidinium FA (CH3N2). Examples of the alkali metal Am include potassium K, cesium Cs, and rubidium Rb. Among these, when the power generation efficiency of the perovskite solar cell 30 is important, cesium Cs and rubidium Rb are preferred as the alkali metal Am, and cesium Cs is particularly preferred from the standpoints of cost and availability. Examples of the metal atom B include lead Pb and tin Sn. The amounts of lead and tin are adjusted depending on the required band gap. The halogen atom X is preferably at least one of iodide I, bromide Br, and chloride Cl.

[0017] Specifically, preferred perovskite compounds include methylammonium lead halides (MAPbX3) such as MAPbI3, MAPbBr3, and MAPbCl3, and formamidinium lead halides (FAPbX3) such as FAPbI3, FAPbBr3, and FAPbCl3. Note that the halogen atom X may contain multiple types, and FA compounds containing both methylammonium and formamidinium as the organic atomic group A are also suitable. y MA 1-y PbX3. When the alkali metal Am is contained, Am y FA z MA 1-y-z PbIX, Am y FA 1-yPbIX, etc. Am may be a single species of Cs, Rb, or K, or may contain multiple species (where y and z are any positive integers).

[0018] The low-emissivity layer 40 is a low-emissivity film that blocks infrared rays. The low-emissivity layer 40 is disposed on the front side of the perovskite solar cell 30 and reduces the amount of infrared rays that enter the perovskite solar cell 30, thereby suppressing deterioration of the perovskite solar cell 30 due to overheating caused by the infrared rays. The low-emissivity layer 40 preferably also blocks ultraviolet rays, which can accelerate deterioration of the perovskite solar cell 30. The low-emissivity layer 40 can be formed from a metal film such as tin oxide or silver.

[0019] The low emissivity layer 40 has a plurality of light-admitting grooves 41 formed by linearly removing material so as to overlap with the light-transmitting grooves 31 in a planar view. This ensures that the low emissivity layer 40 can suppress deterioration of the perovskite solar cell 30, while increasing the amount of light that passes through the light-transmitting grooves 31 to the back side of the solar cell module 1. In order to accurately align the positions of the light-admitting grooves 41 and the light-transmitting grooves 31, the light-admitting grooves 41 may be formed by irradiating the low emissivity layer 40 with a laser, and then the light-transmitting grooves 31 may be formed by irradiating the perovskite solar cell 30 with a laser through the formed light-admitting grooves 41.

[0020] The width of the light-admitting grooves 41 is preferably smaller than the width of the light-transmitting grooves 31. This makes it possible to prevent light from entering the effective area of ​​the perovskite solar cell 30 adjacent to the light-transmitting grooves 31 through the light-admitting grooves 41 when light is incident on the solar cell module 1 at an angle. A specific width of the light-admitting grooves 41 may be, for example, 80% or more and less than 100% of the width of the light-transmitting grooves 31. Furthermore, by offsetting the light-admitting grooves 41 in the width direction relative to the light-transmitting grooves 31 in the direction of light incidence, the amount of light entering the effective area of ​​the perovskite solar cell 30 through the light-admitting grooves 41 can be more effectively prevented. Specifically, when solar cell module 1 is disposed vertically, solar cell module 1 is oriented so that the center line of light-admitting groove 41 is located above the center line of the corresponding light-transmitting groove 31, and when solar cell module 1 is disposed horizontally, solar cell module 1 is oriented so that the center line of light-admitting groove 41 is located south of the center line of the corresponding light-transmitting groove 31, thereby increasing the amount of light transmitted to the back side of solar cell module 1 and suppressing deterioration of perovskite solar cell 30. The offset amount of light-admitting groove 41 with respect to light-transmitting groove 31 is preferably within a range where the entire light-admitting groove 41 is encompassed by light-transmitting groove 31 in plan view.

[0021] The peripheral closing material 50 is disposed on the outer periphery between the surface protection material 10 and the supporting substrate 20, and functions as a spacer that determines the gap between the surface protection material 10 and the supporting substrate 20, and also adheres to the surface protection material 10 and the supporting substrate 20 to close the internal space between them. This forms an air layer for achieving a heat insulating effect, and isolates the low-emissivity layer 40 from the outside air, suppressing deterioration of the low-emissivity layer 40. A suitable material for the peripheral closing material 50 is rubber that adheres to the surface protection material 10 and the supporting substrate 20 to improve airtightness, and a specific example is a butyl rubber-based thermoplastic adhesive.

[0022] The rear surface protective material 60 is disposed on the rear side of the perovskite solar cell 30 to protect the perovskite solar cell 30. The rear surface protective material 60 can be formed from the same material as the front surface protective material 10.

[0023] The encapsulant 70 is filled between the support substrate 20 and the back surface protection material 60, i.e., in the space around the perovskite solar cells 30. The encapsulant 70 bonds the support substrate 20 and the back surface protection material 60 and prevents moisture and the like from coming into contact with the perovskite solar cells 30. Suitable examples of the encapsulant 70 include translucent 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, and silicone resin. The encapsulant 70 is preferably formed from a material that has thermoplasticity that fluidizes and penetrates into gaps between components and minute recesses in the perovskite solar cells 30 during the manufacturing stage of the solar cell module 1 (during heat pressing), and that loses its thermoplasticity in the final product, thereby maintaining its shape even when the temperature of the solar cell module 1 increases. In other words, it is preferable that the sealing material 70 be formed from a resin composition that is primarily made of a thermoplastic resin and contains a cross-linking agent that is activated at a temperature higher than the softening point of the thermoplastic resin and cross-links and hardens the thermoplastic resin.

[0024] The solar cell module 1 having the above configuration suppresses deterioration of the perovskite solar cell 30 due to infrared rays and the like by providing the low-emissivity layer 40, and increases the amount of light transmitted to the back side by forming light-collecting grooves 41 in the low-emissivity layer 40 that overlap with the light-transmitting grooves 31 of the perovskite solar cell 30.

[0025] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and various modifications and variations are possible. For example, in the solar cell module according to the present invention, the low emissivity layer may be formed on the back surface of the surface protection material, and the perovskite solar cell may be formed on the surface of the back surface protection material. [Explanation of symbols]

[0026] 1. Solar cell module 10 Surface protection material 20 Supporting base material 30 Perovskite solar cells 31 Light-transmitting groove 40 Lower radiation layer 41 Light-transmitting trench 50 Peripheral locking material 60 protective materials 70 sealing material

Claims

1. a perovskite solar cell having a plurality of light-transmitting grooves formed therein; a low-emissivity layer disposed on the front side of the perovskite solar cell and blocking infrared rays; Equipped with the low-emissivity layer has a plurality of light-receiving grooves formed by removing material linearly so as to overlap the light-transmitting grooves in a planar view.

2. 2. The solar cell module according to claim 1, further comprising a transparent plate- or sheet-shaped support substrate on which the perovskite solar cell and the low emissivity layer are laminated.

3. a transparent surface protective material disposed on the front side of the support substrate; a back surface protection material disposed on the back side of the support substrate; a sealing material filled between the supporting substrate and the back surface protection material; The solar cell module according to claim 2 , further comprising:

4. The solar cell module according to claim 1 , wherein a width of the light-receiving groove is smaller than a width of the light-transmitting groove.

5. The solar cell module according to claim 4 , wherein the light-receiving groove is offset in the width direction from the light-transmitting groove.

Images