WO2019194151A1

WO2019194151A1 - Solar cell module and method for manufacturing solar cell module

Info

Publication number: WO2019194151A1
Application number: PCT/JP2019/014564
Authority: WO
Inventors: 順次荒浪
Original assignee: 京セラ株式会社
Priority date: 2018-04-04
Filing date: 2019-04-02
Publication date: 2019-10-10

Abstract

This solar cell module comprises: a transparent first substrate; a second substrate opposing the first substrate; a plurality of solar cell elements that are positioned between the first substrate and second substrate and are adjacent to each other in a plan view; and a light scattering member that avoids at least a part of a first area overlapping the plurality of solar cell elements in a plan view, is positioned above the second substrate in at least a part of a second area that does not overlap the plurality of solar cell elements, and has a plurality of particles.

Description

Solar cell module and method for manufacturing solar cell module

The present disclosure relates to a solar cell module and a method for manufacturing the solar cell module.

A solar cell module in which a plurality of solar cell elements are arranged side by side between a translucent member and a back member is known (for example, JP-A-11-307791, JP-A-2015-185712, JP-A-11-298029 and JP-A-2012-104612).

A solar cell module is disclosed. In one embodiment, the solar cell module includes a first base material, a second base material, a plurality of solar cell elements, and a light scattering member. The first substrate has translucency. The second base material faces the first base material. The plurality of solar cell elements are located between the first base material and the second base material and are adjacent to each other in plan view. The light scattering member avoids at least a part of the first region overlapping with the plurality of solar cell elements in a plan view, and at least part of the second region not overlapping with the plurality of solar cell elements on the second substrate. And having a plurality of particles.

It is sectional drawing which shows an example of a structure of a solar cell module roughly. It is a top view which shows roughly an example of a structure of a part of solar cell module. It is sectional drawing which shows roughly an example of a structure of a solar cell element. It is a graph which shows roughly an example of the wavelength dependence of a solar cell element. It is a figure for demonstrating the manufacturing method of a solar cell module. It is sectional drawing which shows an example of a structure of a solar cell module roughly. It is sectional drawing which shows an example of a structure of a light-scattering member roughly. It is sectional drawing which shows an example of a structure of a light-scattering member roughly.

DESCRIPTION OF EMBODIMENTS Embodiments and various modifications of embodiments will be described below with reference to the drawings. In the drawings, parts having the same configuration and function are denoted by the same reference numerals, and redundant description is omitted in the following description. Further, the drawings are schematically shown, and the sizes and positional relationships of various structures in each drawing can be appropriately changed. In each drawing, XYZ coordinates are appropriately added to indicate the positional relationship of each component. Hereinafter, one side in the Z-axis direction is also referred to as + Z side, and the other side in the Z-axis direction is also referred to as -Z side. The same applies to the X axis and the Y axis.

<Solar cell module>
FIG. 1 is a cross-sectional view schematically showing an example of the configuration of the solar cell module 200, and FIG. 2 is a plan view schematically showing an example of a partial configuration of the solar cell module 200. The solar cell module 200 includes a pair of

base materials

210 and 220, a plurality of solar cell elements 100, a filler 230, a wiring material 240, and a light scattering member 250.

<Base material>
The

base materials

210 and 220 have, for example, a plate shape, and the thickness direction is positioned in a posture along the Z-axis direction. The

base materials

210 and 220 are positioned so as to face each other with a gap in the Z-axis direction. The distance between the base materials 210 and 220 (the distance between the −Z side main surface 210a of the base material 210 and the + Z side main surface 220a of the base material 220) is about 1.2 mm or less, for example. . The

base materials

210 and 220 have, for example, a rectangular shape in plan view (that is, viewed along the Z-axis direction), and one side thereof is positioned in a posture along the X-axis direction.

The base material 210 is located on the + Z side with respect to the base material 220. Here, it is assumed that the light source (for example, the sun) is located on the + Z side with respect to the solar cell module 200. In other words, in the solar cell module 200, the base material 210 is located on the light source side. In this case, the base material 210 is a substrate having high translucency. High translucency here means that the transmittance | permeability with respect to the light (for example, sunlight) used as the object of the photoelectric conversion of the solar cell element 100 is high. The transmittance is, for example, 60% or more. The substrate 210 can be formed of, for example, glass or a resin such as acrylic or polycarbonate. The thickness of the substrate 210 is, for example, about 3.2 [mm] or less.

The base material 220 may have high translucency or may not have high translucency. When the base material 220 has high translucency, the base material 220 can be formed of, for example, glass or a resin such as acrylic or polycarbonate, as with the base material 210. The thickness of the base material 220 is also about 3.2 [mm] or less, for example.

When the base material 220 does not have high translucency, the base material 220 is one resin of polyvinyl fluoride (PVF), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN), or these resins It may be formed of at least one kind of resin. The thickness of the base material 220 is, for example, about 0.3 [mm] to 0.5 [mm]. In addition, when the base material 220 is thin, light can permeate | transmit the base material 220 slightly. This base material 220 has translucency.

<Solar cell element>
The plurality of solar cell elements 100 are located between the pair of

base materials

210 and 220. The plurality of solar cell elements 100 have a substantially plate shape, and the thickness direction thereof is positioned in a posture along the Z-axis direction. In the example of FIG. 2, the solar cell element 100 has a substantially rectangular shape in plan view. However, in the example of FIG. 2, the corners of the solar cell element 100 are chamfered, and precisely, the solar cell element 100 has an octagonal shape. The plurality of solar cell elements 100 are positioned adjacent to each other with an interval in plan view. That is, the plurality of solar cell elements 100 are two-dimensionally positioned on the XY plane. As a more specific example, as illustrated in FIG. 2, the plurality of solar cell elements 100 are positioned in a matrix with the X-axis direction and the Y-axis direction as row and column directions, respectively.

The light transmitted through the substrate 210 from the + Z side is incident on the plurality of solar cell elements 100. When the base material 220 has translucency, light that has passed through the base material 220 from the −Z side also enters the plurality of solar cell elements 100. The solar cell element 100 converts light incident on itself into electric power. That is, the solar cell element 100 generates power based on the photovoltaic effect that converts incident light into electric power.

Although the internal structure of the solar cell element 100 does not need to be particularly limited, an example thereof will be described. FIG. 3 is a cross-sectional view schematically showing an example of the configuration of the solar cell element 100.

The solar cell element 100 has a semiconductor substrate 1 (laminated semiconductor) and electrodes 6 to 8. The semiconductor substrate 1 has a substantially plate shape. Hereinafter, the + Z side main surface of the semiconductor substrate 1 is also referred to as a first surface 1a, the −Z side main surface is also referred to as a second surface 1b, and the periphery of the first surface 1a and the periphery of the second surface 1b are connected to each other. The side surface to be called is also referred to as the third surface 1c.

The semiconductor substrate 1 includes a first semiconductor layer 2 which is a first conductivity type (for example, p-type) semiconductor region and a second conductivity type (for example, an n-type) semiconductor region which is opposite to the first conductivity type. And a semiconductor layer 3. The 1st semiconductor layer 2 and the 2nd semiconductor layer 3 are located in the state laminated | stacked mutually in the Z-axis direction between the 1st surface 1a and the 2nd surface 1b. In the example of FIG. 3, the second semiconductor layer 3 is located on the + Z side with respect to the first semiconductor layer 2.

As the semiconductor substrate 1, for example, a monocrystalline or polycrystalline silicon substrate can be adopted. Alternatively, the semiconductor substrate 1 may be an inorganic semiconductor substrate such as germanium, selenium, or gallium arsenide.

Hereinafter, an example in which a p-type semiconductor is used as the first semiconductor layer 2 will be described. When a single crystal or polycrystalline silicon substrate is employed as the semiconductor substrate 1, the thickness is, for example, about 100 to 250 [μm].

When the p-type first semiconductor layer 2 is formed using a polycrystalline silicon substrate, the first semiconductor layer 2 contains an impurity such as boron or gallium as a dopant. The second semiconductor layer 3 is formed by diffusing impurities such as phosphorus as a dopant on the first surface 1 a side with respect to the first semiconductor layer 2. In such a solar cell element 100, since the second semiconductor layer 3 is stacked on the first semiconductor layer 2, a pn junction is formed at the interface between the first semiconductor layer 2 and the second semiconductor layer 3. Electric power is generated when light enters the pn junction. That is, the semiconductor substrate 1 generates power.

3, the first surface 1a of the semiconductor substrate 1 may have a fine uneven shape (texture) for reducing the reflectance of incident light. The height of the convex portions of this texture is, for example, about 0.1 to 10 [μm], and the interval between adjacent convex portions is, for example, about 0.1 to 20 [μm]. The convex portion of the texture may have a pyramid shape, or the concave portion of the texture may have a shape along the spherical shape, for example.

The electrode 6 is located on the first surface 1 a of the semiconductor substrate 1. Since the first surface 1 a corresponds to the surface of the semiconductor substrate 1, the electrode 6 is also referred to as a surface electrode 6 hereinafter. The surface electrode 6 is electrically connected to the second semiconductor layer 3. The surface electrode 6 has, for example, a long shape extending along the X-axis direction. The length (hereinafter referred to as the width) of the surface electrode 6 in the short direction (here, the Y-axis direction) is, for example, about 0.5 to 2.5 [mm].

Although not shown, a plurality of current collecting electrodes that extend so as to intersect the surface electrode 6 and are connected to the surface electrode 6 may be located. The current collecting electrode has a linear shape, and is located, for example, in a state extending along the Y-axis direction. The width of the current collecting electrode (here, the length along the X-axis direction) is, for example, about 30 to 200 [μm]. The interval between the plurality of current collecting electrodes is, for example, about 1 to 3 [mm]. The thickness of the surface electrode 6 is, for example, 10 to 40 [μm].

Such a surface electrode 6 and a current collecting electrode are, for example, the first surface 1a of the semiconductor substrate 1 so that a metal paste mainly composed of metal (for example, silver) has a desired pattern shape by a screen printing method or the like. After coating on the substrate, the coating film can be formed by baking. In the present embodiment, the main component means that the contained mass with respect to the total components is 50 [% by mass] or more.

As illustrated in FIG. 3, the solar cell element 100 may have an antireflection layer 5. The antireflection layer 5 is located on the first surface 1 a of the semiconductor substrate 1. More specifically, it is located on a region of the first surface 1 a of the semiconductor substrate 1 that is not covered by the surface electrode 6. The antireflection layer 5 suppresses reflection of light incident on the solar cell element 100. The antireflection layer 5 has a layer made of, for example, silicon oxide, aluminum oxide, or silicon nitride. The refractive index of the antireflection layer 5 is, for example, about 1.8 to 2.5, and the thickness thereof is, for example, about 20 to 120 [nm]. The antireflection layer 5 can be formed, for example, by PECVD (Plasma-Enhanced Chemical Vapor Deposition) method.

The

electrodes

7 and 8 are electrodes located on the second surface 1b side of the semiconductor substrate 1 as shown in FIG. Since the second surface 1b corresponds to the back surface of the semiconductor substrate 1, the

electrodes

7 and 8 are also referred to as back electrodes. The

electrodes

6 and 7 are power extraction electrodes for extracting the electric power generated by the semiconductor substrate 1 to the outside.

The electrode 7 may be located in a dot shape (or island shape). For example, the plurality of electrodes 7 may be positioned in a matrix having the X-axis direction and the Y-axis direction as row and column directions, respectively. Each electrode 7 may have a long shape. Alternatively, the electrode 7 may have a linear shape extending from end to end of the semiconductor substrate 1.

The thickness of the electrode 7 is, for example, about 10 to 30 [μm], and the width thereof is, for example, about 1.3 to 7 [mm]. The electrode 7 contains, for example, a metal (for example, silver) as a main component. For example, such an electrode 7 is formed by applying a metal paste mainly composed of silver onto the second surface 1b of the semiconductor substrate 1 so as to have a predetermined pattern shape by a screen printing method or the like, and then baking. Can be formed.

As shown in FIG. 3, a passivation layer 9 may be located on the second surface 1 b side of the semiconductor substrate 1. This passivation layer 9 is located on the second surface 1 b of the semiconductor substrate 1. In the example of FIG. 3, a through hole is formed in the passivation layer 9 in a region corresponding to the electrode 7. The through hole penetrates the passivation layer 9 in the Z-axis direction, and the electrode 7 is located inside the through hole.

The electrode 8 is an electrode for collecting the electric power generated by the semiconductor substrate 1 on the electrode 7 and is located in a state of being connected to the electrode 7. As illustrated in FIG. 3, when the passivation layer 9 is located, the electrode 8 is located on the passivation layer 9. In the passivation layer 9, a plurality of through holes 22 are formed in a region facing the electrode 8. The plurality of through holes 22 penetrates the passivation layer 9 in the Z-axis direction. A part of the electrode 8 is located in a state where the through-hole 22 is filled, and is located in a state where the electrode 8 is in contact with the second surface 1 b of the semiconductor substrate 1. Thereby, the electrode 8 is positioned in a state of being electrically connected to the first semiconductor layer 2.

The passivation layer 9 has a function of reducing minority carrier recombination because it reduces defect levels that cause minority carrier recombination at the interface between the passivation layer 9 and the semiconductor substrate 1. The passivation layer 9 is an insulating film such as silicon oxide, aluminum oxide, or silicon nitride. The thickness of the passivation layer 9 is, for example, about 5 to 200 [nm].

The electrode 8 is located, for example, in a state extending in a direction intersecting with the electrode 7, and is located in a state of being connected to the electrode 7. The electrode 8 can function as a current collecting electrode. The electrode 8 may have a main component (for example, aluminum) different from the electrode 7, for example. The thickness of the electrode 8 is, for example, about 15 to 50 [μm]. The electrode 8 can be formed by, for example, applying a metal paste mainly composed of aluminum on the passivation layer 9 so as to have a predetermined pattern shape by a screen printing method or the like, and then baking the applied film.

In the first semiconductor layer 2, a BSF (Back Surface Field) layer 4 may be located in the vicinity of the interface with the electrode 8. The BSF layer 4 is a semiconductor of the same first conductivity type as the first semiconductor layer 2, and the concentration of the dopant is higher than the concentration of the dopant contained in the portion of the first semiconductor layer 2 other than the BSF layer 4. The BSF layer 4 can be formed by diffusing a dopant such as boron or aluminum. For example, when aluminum is employed as the main component of the electrode 8, the BSF layer 4 can be formed by diffusing aluminum in the metal paste by firing the metal paste.

<Wiring material>
With reference to FIG. 1 and FIG. 2, the plurality of solar cell elements 100 are located in a state of being electrically connected to each other via a wiring member 240. The wiring member 240 can be formed of metal, for example. In the example of FIG. 1,

solar cell elements

100A and 100B are shown as a pair of solar cell elements 100 that are adjacent to each other in the X-axis direction, and the wiring material 240A is a wiring material 240 that connects the

solar cell elements

100A and 100B. It is shown. Solar cell element 100A is located on the −X side with respect to solar cell element 100B.

The portion on the −X side of the wiring member 240A is located in a state of being connected to the first surface 100a (more specifically, the electrode 6) on the + Z side of the solar cell element 100A. For example, the wiring member 240A is located in a state of being connected to the electrode 6 by solder or conductive resin. The wiring member 240A extends between the

solar cell elements

100A and 100B from the first surface 100a of the solar cell element 100A and extends to the second surface 100b on the −Z side of the solar cell element 100B. is doing. The + X side portion of the wiring member 240A is located in a state of being connected to the second surface 100b (more specifically, the electrode 7) of the solar cell element 100B. For example, the wiring member 240A is positioned in a state of being connected to the electrode 7 by solder or conductive resin. Thereby, 240 A of wiring materials can connect

solar cell element

100A, 100B in series. Other wiring members 240 are also located in a state where adjacent solar cell elements 100 are connected. Thereby, the several solar cell element 100 located in a line along the X-axis direction is located in the state connected mutually in series.

In the example of FIG. 2, the two solar cell elements 100 located at the end in the X-axis direction are appropriately connected to each other in series by the wiring member 240. Specifically, the two solar cell elements 100 located at the ends in the X-axis direction are connected so that series-connected bodies including a plurality of solar cell elements 100 arranged along the X-axis direction are connected in series to each other. Located in a connected state. In the example of FIG. 2, solar cell elements 100 C and 100 D are shown as a pair of solar cell elements 100 that are located at the + X side end and are adjacent in the Y-axis direction. Material 240B is shown. The wiring member 240B is connected to the first surface 100a (more specifically, the electrode 6) of the solar cell element 100C, and extends in the Y-axis direction in the + X side region from the

solar cell elements

100C and 100D. The solar cell element 100D is positioned in a state of being connected to the second surface 100b (more specifically, the electrode 7). Thereby, the

solar cell elements

100C and 100D can be connected in series.

Note that not all of the plurality of solar cell elements 100 need to be connected in series. For example, several solar cell elements 100 may be connected in series with each other, and a plurality of the series connection bodies may be connected in parallel with each other.

The solar cell module 200 is provided with a pair of wiring members (not shown) for outputting the power generated by the plurality of solar cell elements 100 to the outside. The pair of wiring members are connected to, for example, the solar cell elements 100 positioned at both ends of the series connection body, and are positioned in a state of extending through the base material 220 to the outside, for example.

<Light scattering member>
The light scattering member 250 has a plurality of particles that scatter light. As the plurality of particles, for example, inorganic particles such as titanium oxide can be employed. The particle diameter of the particles is, for example, about 0.05 to 1 [μm], and the light scattering member 250 has a plurality of particles in a range of, for example, about 12 [g / m ³ ] or more. When light is incident on a plurality of particles, the light is scattered (for example, Mie scattering). The light scattering member 250 may have a filler (for example, silica or resin) for fixing the plurality of particles. This filler has high translucency and is formed of a material having a refractive index different from that of the particles.

The light scattering member 250 is located on the base material 220. In the example of FIG. 1, the light scattering member 250 is located on the main surface 220 a on the + Z side of the base material 220. The film thickness of the light scattering member 250 is, for example, about 3 [μm].

The light scattering member 250 avoids at least a part of a region overlapping with the solar cell element 100 (hereinafter referred to as an overlapping region) in a plan view and is a region not overlapping with the solar cell element 100 (hereinafter referred to as a non-overlapping region). Located at least in part. Since this overlapping region is a region overlapping with the plurality of solar cell elements 100, it is a matrix-like region in plan view. On the other hand, a non-overlapping area | region is an area | region which does not overlap with the some solar cell element 100, and contains a 1st area | region and a 2nd area | region. The first region is a region between the plurality of solar cell elements 100 and has a substantially lattice shape. The second region is a region surrounding the whole of the plurality of solar cell elements 100, and has a frame shape along the periphery of the base material 220.

In FIG. 2, the existing region of the light scattering member 250 is indicated by hatching of sand. In the example of FIG. 2, the light scattering member 250 is not located in the overlapping region, but is entirely located in the non-overlapping region. In other words, the light scattering member 250 is located in a lattice-shaped first region extending between the plurality of solar cell elements 100 and a frame-shaped second region surrounding the plurality of solar cell elements 100. . However, actually, the light scattering member 250 may protrude from the peripheral portion of each overlapping region. That is, the light scattering member 250 may enter so as to overlap the peripheral portion of the overlapping region. Conversely, the light scattering member 250 may not be located in a part of the non-overlapping region.

Such a light scattering member 250 is, for example, a liquid light scattering paste containing a plurality of particles (for example, silica paste containing titanium oxide particles) is applied in a predetermined pattern shape on the substrate 220 by a screen printing method or the like, Then, it can form by drying the said light-scattering paste.

<Filler>
A filler 230 is filled between the pair of

base materials

210 and 220. The filler 230 is positioned in close contact with the

main surfaces

210 a and 220 a of the

bases

210 and 220 facing each other, the light scattering member 250, the solar cell element 100, and the wiring member 240. The filler 230 is a light-transmitting insulating resin, and the filler 230 may be formed of an organic material. As a more specific example, the material of the filler 230 may be, for example, a polyester resin such as an ethylene vinyl acetate copolymer (EVA), triacetyl cellulose (TAC), or polyethylene naphthalate (PEN) having high translucency. Etc. apply. The filler 230 may be composed of two or more types of materials, for example.

The filler 230 can be formed, for example, by performing a laminating process. Specifically, the sheet that becomes the filler 230 by melting is placed between the

base materials

210 and 220 together with the solar cell element 100, the wiring material 240, and the light scattering member 250, and the structure By performing a laminating process, the filler 230 is formed. The filler 230 can fix the positional relationship among the

base materials

210 and 220, the solar cell element 100, and the wiring material 240, and can reduce the amount of moisture or the like that enters from the outside to the inside.

<Power generation by solar cell module>
When light enters the solar cell module 200 from the + Z side, a part of the light enters the plurality of solar cell elements 100 from the + Z side. This light is converted into electric power in the plurality of solar cell elements 100. Another part of the light is transmitted through the base material 210 and the filler 230 in the non-overlapping region (the region between the plurality of solar cell elements 100 or the peripheral region of the base material 210) and enters the light scattering member 250. . This light is scattered by the light scattering member 250, and a part of the light enters the solar cell element 100 from the −Z side. Therefore, the amount of light incident on the solar cell element 100 can be increased. Thereby, the electric power generation amount in the solar cell element 100 can be increased, and by extension, the electric power generation efficiency of the solar cell module 200 can be improved.

When the base material 220 has translucency, light incident on the base material 220 from the −Z side passes through the base material 220. Part of this light passes through the region where the light scattering member 250 is not located and enters the solar cell element 100 from the −Z side. That is, since the light scattering member 250 is not provided in at least a part of the overlapping region overlapping with the solar cell element 100, a part of the light incident on the base material 220 from the −Z side is not passed through the light scattering member 250. Can directly enter the solar cell element 100.

The other part of the light incident on the base material 220 from the −Z side enters the light scattering member 250. Since the light incident on the light scattering member 250 is scattered, a part of the light does not enter the solar cell element 100. Therefore, the amount of light incident on the solar cell element 100 from the −Z side can be reduced accordingly.

However, the amount of light incident on the solar cell module 200 from the −Z side is originally as small as about 20% or less of the total light incident on the solar cell module 200. In other words, light incident on the solar cell module 200 from the + Z side occupies about 80% or more of the whole. Therefore, the amount of increase in the amount of power generated by scattering the light incident on the light scattering member 250 from the + Z side and entering the solar cell element 100 is the light incident on the light scattering member 250 from the −Z side. Exceeds the reduction in power generation due to scattering. That is, the power generation efficiency can be improved by the light scattering member 250 even in the solar cell module 200 in which the base material 220 has translucency.

Here, for comparison, a case where a reflective material is employed instead of the light scattering member 250 will be considered. In this structure, light that passes between the plurality of solar cell elements 100 from the + Z side and enters the reflecting material substantially perpendicularly is reflected by the reflecting material substantially vertically and passes between the solar cell elements 100 again. To do. Therefore, this light does not enter the solar cell element 100 and does not contribute to power generation. On the other hand, the light that passes between the plurality of solar cell elements 100 and enters the light scattering member 250 substantially perpendicularly is scattered by the light scattering member 250, and a part of the light enters the solar cell element 100 − Incident from the Z side. Therefore, the amount of light incident on the solar cell element 100 increases. Since the solar cell module 200 is often installed with its installation angle adjusted so that light is likely to be incident vertically, the effective use of such light is particularly beneficial for improving power generation efficiency.

Also, light incident on the reflecting material from the −Z side is reflected on the −Z side, and therefore does not enter the solar cell element 100. On the other hand, the light scattering member 250 can scatter part of the light incident from the −Z side to the + Z side. Therefore, the amount of light incident on the solar cell element 100 can be improved as compared with a structure that employs a reflector.

In the above example, the light scattering member 250 separate from the base material 220 is located. For comparison, the case where a scatterer is formed by processing the main surface 220a of the substrate 220 to form irregularities will also be considered. In this case, a portion having a large thickness and a portion having a small thickness are generated in the base material 220, and the strength of the base material 220 can be reduced. In addition, foreign matters are likely to adhere to the irregularities of the main surface 220a of the base material 220. On the other hand, in the present embodiment, since the light scattering member 250 separate from the base material 220 is located, it is not necessary to form irregularities on the main surface 220a of the base material 220. Strength reduction and adhesion of foreign matter can be suppressed. In addition, mechanical damage due to the temperature cycle is unlikely to occur in the base material 220, and the long-term reliability of the base material 220 and thus the solar cell module 200 can be improved.

In the above example, the light scattering member 250 is located on the main surface 220 a of the base material 220. Therefore, the light scattering member 250 is positioned between the

base materials

210 and 220 and is surrounded by the filler 230. Since the light scattering member 250 is protected by these, the reliability of the light scattering member 250 can be improved.

In the above example, titanium oxide is used as the particles of the light scattering member 250. Titanium oxide can absorb ultraviolet rays. This is suitable when there is a member vulnerable to ultraviolet rays on the −Z side of the solar cell module 200. Alternatively, even when there is a person on the −Z side with respect to the solar cell module 200, the amount of ultraviolet rays to the person can be reduced.

<Particle size>
The particle size of the particles of the light scattering member 250 may be set according to the wavelength of light that is a target of photoelectric conversion of the solar cell element 100. More specifically, the solar cell element 100 may be set to a particle size at which scattering is likely to occur in a wavelength range (high absorption band) in which the amount of power generation is high in the wavelength band of light targeted for photoelectric conversion. The high absorption band here can be defined as, for example, a band where the power generation amount is higher than at least the average value of the power generation amount in the wavelength band.

According to this, the light scattering member 250 can scatter light that is easily absorbed by the solar cell element 100 (that is, easily converted into electric power) with high scattering properties. Therefore, light that is easily absorbed by the solar cell element 100 can easily enter the solar cell element 100 from the −Z side, and the amount of power generation in the solar cell element 100 can be effectively improved.

FIG. 4 is a graph schematically illustrating an example of wavelength dependency in the solar cell element 100. In FIG. 4, the result in the solar cell module which does not have the light-scattering member 250 is shown.

As shown in FIG. 4, the solar cell element 100 easily absorbs light having a medium wavelength (for example, from 350 [nm] to 750 [nm]). In other words, the solar cell element 100 is easy to photoelectrically convert medium wavelength light. Therefore, the particle size of the particles of the light scattering member 250 may be set so that the scattering property of the wavelength in the middle wavelength band is increased. For example, when setting the particle size in this way, the particle size is, for example, about 0.13 to 1 [μm].

As illustrated in FIG. 4, the solar cell element 100 hardly absorbs light having a short wavelength (for example, 350 [nm] or less). This is due to the following reason. That is, short-wavelength light is absorbed by the base material 210, the filler 230, and the like and hardly reaches the solar cell element 100 in the first place. Therefore, the amount of power generated by the solar cell element 100 based on short-wavelength light is small.

That is, even if light having a short wavelength is scattered by the light scattering member 250 and incident on the solar cell element 100, the light is absorbed by another member, so that the effective power generation amount of the solar cell element 100 is increased. Does not contribute. This is because the light path from the −Z side to the solar cell element 100 via the light scattering member 250 is longer than the light path directly from the + Z side to the solar cell element 100 without passing through the light scattering member 250, so This is because light of a wavelength is further absorbed by the filler 230.

Moreover, as shown in FIG. 4, the solar cell element 100 hardly absorbs light having a long wavelength (for example, 750 [nm] or more). This is due to the following reason. That is, long-wavelength light passes through the substrate 210 and the filler 230 and reaches the solar cell element 100, but is slightly photoelectrically converted in the solar cell element 100, and most of the light passes through the solar cell element 100. is there.

However, if light having a long wavelength is scattered by the light scattering member 250, unlike the light having a short wavelength, the light is not easily absorbed by the filler 230 and enters the solar cell element 100 from the −Z side. Therefore, the long wavelength light contributes to power generation as compared with the short wavelength light. Therefore, as the particle size of the light scattering member 250, a particle size that can easily scatter light in the medium wavelength band and the long wavelength band may be adopted. Conversely, the short wavelength light scattering property may be low. When the particle size is set in this way, the particle size is, for example, about 0.13 to 10 [μm].

<Manufacturing method>
FIG. 5 is a diagram illustrating an example of a method for manufacturing the solar cell module 200. First, in step S 1, the light scattering member 250 is disposed on the main surface 220 a of the base material 220. For example, the light scattering paste is applied on the main surface 220a of the base material 220 in a predetermined pattern shape (for example, the same shape as the non-overlapping region), and then dried. Thereby, the light scattering member 250 is fixed on the main surface 220 a of the base material 220.

Next, in step S 2, a plurality of solar cell elements 100 connected to each other by the wiring material 240 are placed on the main surface 220 a of the base material 220, and a sheet that becomes the filler 230 is placed thereon. Then, the base material 210 is placed thereon.

Next, in step S3, a laminating process is performed. Specifically, laminating is performed on the structures obtained in steps S1 and S2. A laminating device (laminator) is used to integrate the structures. For example, in a laminator, the structure is placed on a heater panel in the chamber, and the structure is reduced from about 50 [Pa] to about 150 [Pa] while the structure is 100 [° C.] to 200 [° C.]. Heated to a degree. At this time, the sheet is melted by heating and becomes flowable. In this state, the structure is pressed by a diaphragm sheet or the like, so that the structure is integrated. Thereby, the filler 230 filled between the

base materials

210 and 220 is formed, and the solar cell module 200 is formed.

According to such a manufacturing method, since the light scattering member 250 is already fixed to the base material 220 during the laminating process, the light scattering member 250 and the solar cell element 100 are positioned with higher accuracy. The laminating process can be performed.

<Position of light scattering member>
FIG. 6 is a cross-sectional view schematically showing an example of the configuration of the solar cell module 200A. This solar cell module 200 A is the same as the solar cell module 200 except for the position of the light scattering member 250. In the solar cell module 200A, the light scattering member 250 is located on the −Z side main surface 220b of the base material 220. The existence region in plan view of the light scattering member 250 is as described above. The light scattering member 250 is formed, for example, by applying a light scattering paste in a predetermined pattern shape on the main surface 220b of the substrate 220 and then drying it.

According to this solar cell module 200A, part of the light from the + Z side causes the base material 210, the filler 230, and the base material 220 in the region between the plurality of solar cell elements 100 or the peripheral region of the base material 210. The light passes through and enters the light scattering member 250. Since the light scattering member 250 scatters the incident light, part of the light is again transmitted through the base material 220 and the filler 230 and enters the solar cell element 100 from the −Z side. Therefore, the amount of light incident on the solar cell element 100 can be increased, and as a result, the power generation efficiency of the solar cell module 200A can be improved.

Moreover, in this solar cell module 200A, the light scattering member 250 is located on the −Z side main surface 220b of the base material 220. Therefore, the light scattering member 250 can be easily attached to an existing solar cell module that does not have the light scattering member 250. Thereby, the power generation efficiency of a solar cell module can be improved.

<Light scattering member>
FIG. 7 is a cross-sectional view illustrating another example of the configuration of the light scattering member 250. In the example of FIG. 7, the light scattering member 250 is located on one main surface of the film-like substrate 260. The film-like substrate 260 has high translucency and can be formed of glass or the like, for example. The thickness of the substrate 260 is, for example, about several hundreds [μm] or less, and is separate from the substrate 220. The base body 260 has, for example, a rectangular shape in plan view, and the light scattering member 250 is located on the main surface. The light scattering member 250 is formed, for example, by applying a light scattering paste in a predetermined pattern shape on one main surface of the substrate 260 and then drying it. The substrate 260 is a substrate for fixing the light scattering member 250.

The structure composed of the light scattering member 250 and the base body 260 is disposed on the main surface 220a or the main surface 220b of the base material 220, and is fixed to the base material 220 with, for example, a resin.

Such a light scattering member 250 and the substrate 260 can be handled independently of the substrate 220. Therefore, when the solar cell module 200 (200A) is assembled, the light scattering member 250 can be easily disposed on the main surface 220a or the main surface 220b of the substrate 220.

<Multilayer structure>
The light scattering member 250 may have a multilayer structure. FIG. 8 is a diagram illustrating an example of the configuration of the light scattering member 250. The light scattering member 250 has scattering

layers

250a and 250b. The scattering layers 250a and 250b are stacked in the Z-axis direction. For example, the scattering layer 250a is located on the + Z side with respect to the scattering layer 250b. The scattering layer 250a includes a plurality of particles 251a and a filler 252a, and the scattering layer 250b includes a plurality of particles 251b and a filler 252b. The

particles

251a and 251b may be formed of the same material or different materials. The

particles

251a and 251b are made of, for example, titanium oxide.

The filler 252a is a filler for fixing the plurality of particles 251a and has translucency. The filler 252b is a filler for fixing the plurality of particles 251b and has translucency. The

fillers

252a and 252b may be formed of the same material or different materials. However, the

fillers

252a and 252b are formed of a material different from that of the

particles

251a and 251b, respectively. The

fillers

252a and 252b are, for example, silica or resin.

The scattering layer 250b is formed, for example, by applying a light scattering paste including a plurality of particles 251b on the main surface 220a or the main surface 220b of the substrate 220 in a predetermined pattern shape, and then drying. The scattering layer 250a is formed, for example, by applying a light scattering paste including a plurality of particles 251a on the scattering layer 250b and then drying.

It should be noted that the light scattering member 250 may not be directly formed on the substrate 220 but may be formed on another substrate 260 and then the substrate 260 may be disposed on the substrate 220.

The particle size (average value) of the particles 251a is different from the particle size (average value) of the particles 251b, and is set to be small, for example. For example, the particle diameter (average value) of the particles 251a is about 0.13 to 1 [μm] corresponding to the medium wavelength band, and the particle diameter (average value) of the particles 251b is 0.25 to 10 corresponding to the long wavelength band. It is about [μm].

According to this, light having a wavelength corresponding to the particle size of the particle 251a is easily scattered by the scattering layer 250a, and light having a wavelength corresponding to the particle size of the particle 251b is easily scattered by the scattering layer 250b. That is, high scattering can be realized in a wider wavelength band. Thereby, the quantity of the light which injects into the solar cell element 100 can further be increased, and the power generation efficiency of the solar cell module 200 can be further improved.

<Black pigment>
The light scattering member 250 may further include a black pigment. According to this, the solar cell module 200 viewed from the −Z side is entirely black, and a black module can be realized.

As described above, the solar cell module has been described in detail, but the above description is an example in all aspects, and the disclosure is not limited thereto. The various modifications described above can be applied in combination as long as they do not contradict each other. And it is understood that many modifications which are not illustrated may be assumed without departing from the scope of this disclosure.

DESCRIPTION OF SYMBOLS 100 Solar cell element 200,200A Solar cell module 210 1st base material (base material)
220 Second base material (base material)
250 light scattering member 250a first scattering layer (scattering layer)
250b Second scattering layer (scattering layer)
251a First particle (particle)
251b Second particle (particle)

Claims

A solar cell module,
A first base material having translucency;
A second substrate positioned in a state of facing the first substrate;
A plurality of solar cell elements positioned between the first base material and the second base material and positioned adjacent to each other in plan view;
Positioned on the second base material in at least part of the second region that does not overlap with the plurality of solar cell elements while avoiding at least part of the first region overlapping with the plurality of solar cell elements in plan view And a light scattering member having a plurality of particles.
The solar cell module according to claim 1,
The said light-scattering member is a solar cell module located on the main surface by the side of the said 1st base material among the said 2nd base materials.
The solar cell module according to claim 1,
The said light-scattering member is a solar cell module located on the main surface on the opposite side to the said 1st base material among the said 2nd base materials.
The solar cell module according to any one of claims 1 to 3, wherein
The light scattering member is
A first scattering layer comprising a plurality of first particles;
A solar cell module comprising: a second scattering layer that is stacked on the first scattering layer and includes a plurality of second particles having a diameter different from that of the plurality of first particles.
The solar cell module according to any one of claims 1 to 4, wherein
A film-like substrate on which the light scattering member is located;
The solar cell module, wherein the substrate is located on the second substrate.
It is a manufacturing method of the solar cell module according to any one of claims 1 to 5,
Disposing the light scattering member on the second substrate and fixing the light scattering member to the second substrate;
On the second substrate, the plurality of solar cell elements, a sheet that is melted to become a filler, and a step of placing the first substrate;
And a step of performing a laminating process for heating the sheet.