Film for solar cells, solar cell, and method for manufacturing solar cell films

Abstract

This disclosure provides a solar cell film, a solar cell, and a method for manufacturing a solar cell film that can suppress light reflection and increase the amount of light incident on the photoelectric conversion layer. [Solution] The solar cell film according to this disclosure is a solar cell film 50 provided on the light-receiving surface of a solar cell 1, comprising a film body 51 and nanoparticles 52 made of an insulator disposed within the film body 51. The nanoparticles 52 of the solar cell film 50 are in contact with the interface of the film body 51.

Description

Technical Field

[0001] The present disclosure relates to a film for a solar cell, a solar cell, and a method for manufacturing the film for a solar cell.

Background Art

[0002] In order to improve the power generation efficiency of a solar cell, it is important to increase the amount of light incident on the photoelectric conversion layer. As one method for achieving this purpose, for example, Patent Document 1 discloses a technique for suppressing the amount of light reflected on the surface of a transparent conductive layer. In Patent Document 1, the surface of the transparent conductive layer is made into a concavo-convex structure by wet etching to suppress the amount of light reflected on the surface of the transparent conductive layer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There is a need for a technique for suppressing light reflection in a solar cell, not limited to the method disclosed in Patent Document 1.

[0005] The present disclosure has been made to solve such problems, and provides a film for a solar cell, a solar cell, and a method for manufacturing the film for a solar cell that can suppress light reflection and increase the amount of light incident on the photoelectric conversion layer.

Means for Solving the Problems

[0006] The film for a solar cell according to the present disclosure is a film for a solar cell provided on the light-receiving surface of a solar cell, and includes a film body and nanoparticles made of an insulator disposed in the film body, and the nanoparticles are in contact with the interface of the film body.

[0007] The aforementioned nanoparticles may be inorganic nanoparticles containing one selected from the group consisting of SiO2, Al2O3, Y2O3, and ZrO2.

[0008] The nanoparticles comprise a first nanoparticle and a second nanoparticle having a refractive index smaller than that of the first nanoparticle, wherein the first nanoparticle is in contact with the interface, and the second nanoparticle may be in contact with the first nanoparticle on the side opposite to the interface.

[0009] The solar cell according to this disclosure comprises a solar cell, a transparent surface plate located on the light-receiving surface side of the solar cell, and a solar cell film located on the light-receiving surface of the surface plate, wherein the solar cell film comprises a film body and nanoparticles made of an insulating material disposed within the film body, and the nanoparticles are in contact with the interface between the film body and the surface plate or with the light-receiving surface of the film body.

[0010] The present disclosure relates to a method for manufacturing a solar cell film, which is provided on the light-receiving surface of a solar cell, and comprises the steps of: applying nanoparticles made of an insulator to a film body; and pressing the film body to which the nanoparticles have been applied. [Effects of the Invention]

[0011] This disclosure provides a solar cell film, a solar cell, and a method for manufacturing a solar cell film that can suppress light reflection and increase the amount of light incident on the photoelectric conversion layer. [Brief explanation of the drawing]

[0012] [Figure 1] This is a side cross-sectional view of a solar cell according to Embodiment 1. [Figure 2] This is an enlarged side cross-sectional view of a surface plate on which a solar cell film is installed. [Figure 3] This figure shows the relationship between wavelength and refractive index in each nanoparticle. [Figure 4]This is an enlarged side cross-sectional view of a surface plate with a solar cell film, another example. [Figure 5] This is a flowchart of the method for manufacturing a solar cell film according to Embodiment 1. [Figure 6] This is an enlarged side cross-sectional view of a solar cell film before and after pressing. [Modes for carrying out the invention]

[0013] The following describes specific embodiments of this disclosure in detail with reference to the drawings. However, this disclosure is not limited to the following embodiments. Also, for clarity, the following descriptions and drawings have been simplified as appropriate.

[0014] (Embodiment 1) <Solar cell configuration> First, the configuration of the solar cell according to this embodiment 1 will be described with reference to Figure 1. Figure 1 is a side cross-sectional view of the solar cell according to embodiment 1. As shown in Figure 1, the solar cell 1 comprises a solar cell 10, a sealing material 20, a back plate 30, a front plate 40, and a solar cell film 50.

[0015] In the following explanation, the xyz 3D Cartesian coordinate system will be used as appropriate. In this embodiment 1, the direction in which the solar cell 10, encapsulant 20, back plate 30, front plate 40, and solar cell film 50 are stacked in the solar cell 1 is defined as the z-axis direction. Furthermore, in the following explanation, the z-positive direction will be defined as the light-receiving side of the solar cell 1.

[0016] The solar cell 10 is a photoelectric conversion element formed in a thin plate shape, for example, rectangular in plan view in the xy plane. The upper surface (the surface on the +z axis direction side) of the solar cell 10 is a light-receiving surface. Note that FIG. 1 shows an example in which the sealing material 20 is interposed between the solar cell 10 and the front plate 40, but the solar cell 10 may be formed directly on the surface (the surface on the -z axis direction side) of the front plate 40. The number of solar cells 10 arranged in the solar cell 1 is not particularly limited. When there are a plurality of solar cells 10, the plurality of solar cells 10 are arranged, for example, in the xy plane direction in the solar cell 1.

[0017] The solar cell 10 can be configured using a photoelectric conversion element such as a silicon-based single crystal type, a silicon-based polycrystal type, an amorphous silicon type, a thin film silicon type, a CIGS type, an organic thin film type, a dye-sensitized type, a perovskite type, etc. In the case of a perovskite-based photoelectric conversion element, the solar cell 10 has a structure in which a substrate, a transparent electrode, an electron transport layer, a photoelectric conversion layer, a hole transport layer, and a back electrode are laminated. In this case, the photoelectric conversion layer may contain an organic-inorganic perovskite compound.

[0018] The sealing material 20 is a resin layer that covers and protects the solar cell 10. The sealing material 20 is composed of a transparent material such as, for example, ethylene vinyl acetate (EVA) resin, polyvinyl butyral (PVB), polyolefin-based resin, ionomer-based resin, or silicon resin. As shown in FIG. 1, the sealing material 20 is sandwiched between the back plate 30 and the front plate 40.

[0019] The back plate 30 covers the lower surface (the surface on the minus z-axis direction side) of the sealing material 20 and protects the solar cell 10. The back plate 30 is not particularly limited, and for example, it is a member formed in a layered, film-like, or plate-like shape from polyethylene terephthalate (PET), polycarbonate resin, acrylic resin, glass, metal (such as aluminum), etc. Further, the back plate 30 may be processed into a curved surface shape so as to follow the three-dimensional shape of, for example, the object (such as the wall surface of a building or the roof of a vehicle) to which the solar cell 1 is attached.

[0020] The front plate 40 is located on the light-receiving surface side of the solar cell 10 in the solar cell 1. More specifically, the front plate 40 covers the light-receiving surface (the surface on the plus z-axis direction side) of the sealing material 20 and protects the solar cell 10. The front plate 40 is a member formed in a layered, film-like, or plate-like shape from a transparent material such as polycarbonate resin, acrylic resin, or glass. The space between the front plate 40 and the sealing material 20 and the space between the back plate 30 and the sealing material 20 are adhered, for example, by the adhesive force of the sealing material 20.

[0021] The solar cell film 50 is located on the light-receiving surface (the surface on the plus z-axis direction side) of the front plate 40. The solar cell film 50 covers the light-receiving surface of the front plate 40 and suppresses the light reflection of the solar cell 1.

[0022] <Configuration of the solar cell film> Hereinafter, the configuration of the solar cell film 50 will be described with reference to FIGS. 2 to 4. FIG. 2 is an enlarged side cross-sectional view of the front plate provided with the solar cell film. FIG. 3 is a diagram showing the relationship between the wavelength and the refractive index of each nanoparticle. FIG. 4 is an enlarged side cross-sectional view of the front plate provided with another example of the solar cell film.

[0023] As shown in FIG. 2, the solar cell film 50 includes a film body 51 and nanoparticles​The film body 51 is formed from a transparent material. For example, a flexible film made of polyethylene or PVC, or a thermosetting film made of epoxy resin or urethane resin may be used as the film body 51.

[0024] As shown in Figure 2, the nanoparticles 52 are arranged on the film body 51 so as to be in contact with the interface of the film body 51. When the solar cell film 50 is provided on the surface plate 40, there are two arrangement methods: the interface S of the film body 51 that the nanoparticles 52 are in contact with is on the surface plate 40 side (negative z-axis direction side) as shown in the upper diagram of Figure 2, and the light-receiving surface side (positive z-axis direction side) as shown in the lower diagram of Figure 2.

[0025] As shown in the upper diagram of Figure 2, in the solar cell 1, when the interface S of the film body 51 in contact with the nanoparticles 52 is on the surface plate 40 side (negative z-axis direction side), the nanoparticles 52 are arranged on the light-receiving surface of the surface plate 40 on which the solar cell film 50 is provided. That is, an uneven surface is formed on the light-receiving surface of the surface plate 40 by the nanoparticles 52. Due to the uneven surface formed by the nanoparticles 52, the solar cell 1 can suppress light reflection on the surface plate 40.

[0026] Furthermore, as shown in the lower diagram of Figure 2, in the solar cell 1, if the interface S of the film body 51 in contact with the nanoparticles 52 is on the light-receiving surface side (positive z-axis direction side), the nanoparticles 52 become the outermost surface on the light-receiving side of the solar cell 1. This makes it possible to suppress light reflection at the interface S between the solar cell film 50 and the air.

[0027] The nanoparticles 52 are inorganic nanoparticles, for example, made of an insulator or semiconductor. More specifically, the nanoparticles 52 may be inorganic nanoparticles containing one selected from the group consisting of SiO2, Al2O3, Y2O3, and ZrO2, as shown in Figure 3.

[0028] Note that the nanoparticles 52 are not limited to one type but may be of multiple types. In the example shown in Figure 4, the nanoparticles 52 include first nanoparticles 521 and second nanoparticles 522. The first nanoparticles 521 are arranged in the film body 52 in contact with the interface S. The second nanoparticles 522 are arranged in the film body 52 in contact with the first nanoparticles 521 on the opposite side of the interface S (the positive z-axis side).

[0029] Here, the refractive index of the second nanoparticle 522 is smaller than that of the first nanoparticle 521. That is, the first nanoparticle 521 is an inorganic nanoparticle containing one selected from the group consisting of SiO2, Al2O3, Y2O3, and ZrO2 shown in Figure 3. The second nanoparticle 522 is an inorganic nanoparticle containing one different from the first nanoparticle 521, selected from the group consisting of SiO2, Al2O3, Y2O3, and ZrO2 shown in Figure 3. For example, if the first nanoparticle 521 is ZrO2, the second nanoparticle 522 can be selected from Al2O3, Y2O3, and ZrO2. In this way, by gradually increasing the refractive index of the nanoparticle 52 layer from the light-receiving side (positive z-axis direction side), the solar cell 1 can further suppress light reflection at the surface plate 40.

[0030] By arranging nanoparticles 52 on the light-receiving surface of the surface plate 40, the solar cell 1 can effectively suppress light reflection on the surface plate 40 and increase the amount of light incident on the photoelectric conversion layer. However, simply arranging nanoparticles 52 on the surface plate 40 may cause the nanoparticles 52 to peel off from the surface plate 40 due to friction or to deteriorate over time. Furthermore, if the nanoparticles 52 become contaminated with dust or other debris and foreign matter gets trapped between them, the light reflection suppression effect of the nanoparticles 52 may decrease.

[0031] Therefore, in this disclosure, as shown in Figures 2 and 4, the solar cell 1 protects the nanoparticles 52 from wear, deterioration, and contamination by arranging the nanoparticles 52 within the film body 51. Furthermore, by arranging the nanoparticles 52 so as to be in contact with the interface S of the film body 51, the solar cell 1 ensures the effect of suppressing light reflection by the nanoparticles 52. When the solar cell film 50 is provided on the surface plate 40, the interface S may be on either the surface plate 40 side (negative z-axis direction side) as shown in the upper figure 2, or the light-receiving surface side (positive z-axis direction side) as shown in the lower figure 2.

[0032] <Method for manufacturing solar cell films> Next, a method for manufacturing a solar cell film according to Embodiment 1 will be described. Figure 5 is a flowchart of the method for manufacturing a solar cell film according to Embodiment 1. Figure 6 is an enlarged view of a side cross-sectional view of the solar cell film before and after pressing.

[0033] First, nanoparticles 52 are coated onto the interface S of the film body 51 (step S101). The coating method is not particularly limited, but for example, a dispersion containing nanoparticles 52 and a solvent may be coated onto the film body 51. As shown in the upper diagram of Figure 6, nanoparticles 52 are deposited on the interface S of the film body 51 by this step S101.

[0034] Next, the film body 51 coated with nanoparticles 52 is pressed (step S102). As shown in Figure 6, the pressing pushes the nanoparticles 52 into the film body 51, stabilizing the film body 51 with the nanoparticles 52 positioned within it. This forms a solar cell film 50 with the nanoparticles 52 positioned on the film body 51 in contact with the interface S of the film body 51, as shown in the lower part of Figure 6. Note that in step 102, the pressing may be performed with the film body 51 aligned to the shape of the object on which the solar cell film 50 will be provided.

[0035] As described above, the solar cell film 50 according to this embodiment 1 protects the nanoparticles 52 from wear, deterioration, and contamination by positioning them within the film body 52. ​​By arranging the nanoparticles 52 so as to be in contact with the interface S of the film body 51, the solar cell 1 equipped with the solar cell film 50 can suitably suppress light reflection and increase the amount of light incident on the photoelectric conversion layer.

[0036] It should be noted that the present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention. [Explanation of symbols]

[0037] 1. Solar cell 10 solar cells 20 Sealing material 30 Back plate 40 Surface plate 50 Solar cell films 51 Film body 52 nanoparticles 521 First Nanoparticle 522 Second Nanoparticle S interface

Claims

1. A film for solar cells, which is provided on the light-receiving surface of a solar cell, The film itself, The film body comprises nanoparticles made of an insulating material, The nanoparticles are in contact with the interface of the film body. Film for solar cells.

2. The aforementioned nanoparticles are SiO ２ Al ２ O ３ , Y ２ O ３ , ZrO ２ It is an inorganic nanoparticle containing one selected from the group consisting of the following: The solar cell film according to claim 1.

3. The nanoparticle comprises a first nanoparticle and a second nanoparticle having a refractive index smaller than that of the first nanoparticle. The first nanoparticle is in contact with the interface, The second nanoparticle is in contact with the first nanoparticle on the side opposite to the interface. A solar cell film according to claim 1 or 2.

4. Solar cells and A transparent surface plate located on the light-receiving side of the solar cell, The solar cell film is located on the light-receiving surface of the surface plate, The solar cell film comprises a film body and nanoparticles made of an insulating material disposed within the film body. The nanoparticles are in contact with the interface between the film body and the surface plate or with the light-receiving surface of the film body. Solar cell.

5. A method for manufacturing a solar cell film to be provided on the light-receiving surface of a solar cell, The steps include: coating the film body with nanoparticles made of an insulator, The process includes the step of pressing the film body to which the nanoparticles have been coated. A method for manufacturing films for solar cells.

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