KR20160139987A - Solar cell module - Google Patents

Abstract

The present invention relates to a solar cell module. The solar cell module includes a plurality of solar cells, a light transmitting sheet which is located on a first surface side of the plurality of solar cells, a front protection unit which is located between the light transmitting sheet and the plurality of solar cells, a rear sheet which is located on a second surface side of the plurality of solar cells, a rear protection unit which is located between the rear sheet and the plurality of solar cells, and a front reflection preventing film which is located on the first surface side of the plurality of solar cells. The front reflection preventing film includes a first front reflection preventing film and a second front reflecting layer whose refractive index is higher than that of the first front reflection preventing film. Accordingly, the present invention improves the efficiency of the solar cell module.

Description

Solar cell module {SOLAR CELL MODULE}

The present invention relates to a solar cell module.

Recently, interest in renewable energy due to global environmental problems and depletion of fossil fuels has been growing, and research and development of photovoltaic power generation, which is pollution-free energy, is actively under way.

BACKGROUND ART A solar cell to which a photovoltaic power generation principle is applied is a semiconductor device that converts sunlight into electric energy. Generally, the solar cell is manufactured from a single crystal or polycrystalline or amorphous silicon semiconductor, and has a basic structure similar to a diode .

Since the solar cell must be exposed to the external environment for a long time in order to easily absorb the sunlight, various packaging for protecting the cell is performed and manufactured in a unit form, Quot;

SUMMARY OF THE INVENTION It is an object of the present invention to improve the efficiency of a solar cell module.

A solar cell module according to one aspect of the present invention includes a plurality of solar cells, a light-permeable sheet positioned on a first surface side of the plurality of solar cells, a front surface protective portion positioned between the light-permeable sheet and the plurality of solar cells, A rear sheet positioned on the second surface side of the solar cell, a rear surface protection sheet positioned between the rear sheet and the plurality of solar cells, and a front antireflection film disposed on the first surface side of the plurality of solar cells.

At this time, the front antireflection film may include a first front antireflection film and a second front reflection layer having a refractive index higher than that of the first front antireflection film.

Here, the refractive index of the first front anti-reflection film may be about 1.3 to 1.5, and the refractive index of the second front anti-reflective film may be about 1.9 to 2.2.

The first and second front antireflection films are made of a silicon nitride film (SiNx) or a silicon oxide film (SiOx), the second front antireflection film is made of a combination of zirconium oxide (ZrO2) or yttria (Y2O3) and a doping material, May be at least one of europium (Eu), ytterbium (Yb), bismuth (Bi), and erbium (Er).

Further, it may further include a rear antireflection film positioned between the rear surface protection portion and the rear sheet.

According to this feature, the reflectance of the incident light can be minimized by forming the double antireflection film structure having different refractive indexes on the entire surface of the solar cell.

Further, by including a doping material made of europium (Eu), ytterbium (Yb), bismuth (Bi), erbium (Er) or the like in the antireflection film having a high refractive index, the absorption rate of light to the long wavelength band is increased, Increase efficiency.

Moreover, as the amount of doping material increases, the rate of absorption of light to the longer wavelength band is further increased.

By forming an antireflection film having a high refractive index including zirconium oxide (ZrO2) or yttria (Y2O3) on the back surface of the substrate, moisture penetration is prevented to protect the solar cell from the external environment, It is possible to increase the weather resistance and prolong the lifetime of the solar cell module.

As a result, the efficiency of the solar cell is improved, so that the efficiency of the solar cell module including a plurality of solar cells is also improved.

1 is a cross-sectional view schematically illustrating an example of a solar cell module according to an embodiment of the present invention.
FIGS. 2 and 3 are views for explaining an example of a pattern of an anti-reflection film disposed on a front surface of a solar cell module according to an embodiment of the present invention.
4 to 8 are cross-sectional views schematically showing another example of a solar cell module according to an embodiment of the present invention.
9 is a view showing a reflection path of light to which a solar cell module according to an embodiment of the present invention is applied.
10 is a graph showing the transmittance according to the wavelength of light in the solar cell module according to the embodiment of the present invention and the comparative example.
11 is a graph showing the reflectance of a solar cell module according to Examples and Comparative Examples of the present invention.
12 is a graph showing the absorption rate of light in the substrate of the solar cell module according to the embodiment of the present invention and the comparative example.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

In the drawings, the thickness is enlarged to clearly represent the layers and regions. When a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the case directly above another portion but also the case where there is another portion in between. Conversely, when a part is "directly over" another part, it means that there is no other part in the middle. Further, when a certain portion is formed as "whole" on another portion, it means not only that it is formed on the entire surface of the other portion but also that it is not formed on the edge portion.

Hereinafter, the front surface may be one surface of the semiconductor substrate to which the direct light is incident, and the rear surface may be the opposite surface of the semiconductor substrate in which direct light is not incident, or reflected light other than direct light may be incident.

In the following description, the meaning of two different components having the same length or width means that they are equal to each other within an error range of 10%.

Hereinafter, a solar cell module according to an embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a cross-sectional view schematically illustrating an example of a solar cell module according to an embodiment of the present invention.

1, a solar cell module 100a according to an embodiment of the present invention includes a plurality of solar cells 10, an interconnector 20 for electrically connecting a plurality of solar cells 10, A front protective portion 30 and a rear protective portion 40 for protecting the plurality of solar cells 10, a light-transmissive front sheet 50 positioned on the front surface of the solar cell 10, And a first front antireflection film 70a located on the front surface of the solar cell 10. The first front anti-

As shown in FIG. 1, the solar cell 10 is a conventional solar cell that receives external light through a front surface of the substrate.

1, the light-transmissive front sheet 50 is disposed on the first surface of the solar cell 10, for example, on the light-receiving surface side of the solar cell 10, and has a high transmittance and is made of tempered glass have. At this time, the tempered glass may be a low iron tempered glass having a low iron content.

The light-transmissive front sheet 50 may be embossed or textured to improve the light scattering effect. At this time, the light-transmissive front sheet 50 may have a refractive index of about 1.52.

1, the front surface protecting portion 30 and the rear surface protecting portion 40 are formed to prevent corrosion of the metal due to moisture penetration and to protect the solar cell 10 and the solar cell module 100a from impact It is an encapsulate material.

The front protective portion 30 and the rear protective portion 40 may be made of materials such as ethylene vinyl acetate (EVA), polyvinyl butyral, silicon resin, ester resin, and olefin resin. At this time, the front surface protecting portion 30 and the rear surface protecting portion 40 may be adhered to each other by lamination.

As shown in FIG. 1, the interconnector 20 connected to the plurality of solar cells 10 may be embedded in the front protective portion 30 and the rear protective portion 40. At this time, the side surface of the solar cell 10 may be in contact with both the front surface protection portion 30 and the rear surface protection portion 40. When at least a part of the interconnector 20 or the interconnector 20 and the solar cell 10 is embedded in the front surface protection portion 30, the position of the solar cell 10 is fixed by the front surface protection portion 30, The problem of misalignment in the modularization process of the present invention can be reduced.

As shown in FIG. 1, the backsheet 60 is made of a thin sheet of insulating material such as FP / PE / FP (fluoropolymer / polyeaster / fluoropolymer), but may be an insulating sheet made of another insulating material.

The rear sheet 60 protects the solar cell 10 from the external environment by preventing moisture from penetrating the rear surface of the solar cell module 100a. Such a backsheet 60 may have a multi-layer structure such as a layer preventing moisture and oxygen penetration, a layer preventing chemical corrosion, and a layer having an insulating property.

1, the front antireflection film 70a includes a first front antireflection film 72a and a second front antireflection film 72 positioned between the first front antireflection film 72a and the light transmissive front sheet 50 74a.

The first front antireflection film 72a and the second front antireflection film 74a may be sequentially disposed on the light-transmissive front sheet 50 of the solar cell 10 sequentially.

In this example, the first front antireflection film 72a may be formed of a silicon nitride film (SiNx) or a silicon oxide film (SiOx), and the second front antireflection film 74a may be formed of zirconium oxide (ZrO2) or yttrium oxide Or a combination of doping materials. The doping material may be at least one doping material selected from europium (Eu), ytterbium (Yb), bismuth (Bi), and erbium (Er).

Specifically, the first total antireflection film 72a made of a silicon nitride film (SiNx) or a silicon oxide film (SiOx) has a thickness of about 80 to 120 nm, a refractive index of 1.3 to 1.5, and a zirconium oxide (ZrO2) or yttria ) And the doping material may have a thickness of about 100 nm to 160 nm and a refractive index of 1.9 to 2.2. The thickness of the first front antireflection film 72a is 100 nm, the thickness of the second front antireflection film 74a is 140 nm, the thickness of the light transmissive front sheet 50 is 3.5 mm, Is preferably 0.45 mm.

The front antireflection film 70a minimizes the reflectivity of the light incident on the front surface of the solar cell 10 and increases the selectivity of the specific wavelength region to increase the efficiency of the solar cell 10. [ That is, the efficiency of the solar cell 10 can be increased by the absorption rate of light with respect to the long wavelength band.

Specifically, since the refractive index sequentially changes from the air toward the front antireflection film 70a, for example, the air having the refractive index of 1, the first front antireflection film 72a having the refractive index of 1.3 to 1.5, The second antireflection film 74a having a refractive index sequentially changes, so that the effect of the antireflection film can be further improved.

Since the refractive index of the second front antireflection film 74a adjacent to the solar cell 10 is greater than the refractive index of the first front antireflection film 72a adjacent to the air, The thickness of the second front antireflection film 74a may be greater than the thickness of the first front antireflection film 72a in order to reduce the reflectivity of the incident light.

The absorption rate of light with respect to the long wavelength band can be increased by zirconium oxide (ZrO 2) or yttria (Y 2 O 3) contained in the second front anti-reflection film 74a and the doping material.

Specifically, Eu (yttrium), ytterbium (Yb), bismuth (Bi), erbium (Er), and the like are grown while minimizing the reflectance of light with respect to a long wavelength band by using zirconium oxide (ZrO2) or yttria The absorption rate of light with respect to the long wavelength band can be improved. At this time, as the amount of the doping material increases, the absorption rate of light to the long wavelength band can be further increased.

In addition, it is possible to prevent water penetrating the light receiving surface of the solar cell 10 by zirconium oxide (ZrO 2) or yttria (Y 2 O 3), thereby protecting the solar cell 10 from the external environment.

The front antireflection film 70a is formed on the front side of the light transmissive front sheet 50 by using various film forming methods such as PECVD (Plasma Enhanced Chemical Vapor Deposition) Antireflection film 72a and a second front antireflection film 74a formed of a combination of zirconium oxide (ZrO2) or yttria (Y2O3) and a doping material may be sequentially formed. At this time, the doping material may be formed into a particle or a layer in the second front antireflection film 74a.

The first front antireflection film 72a having such a structure minimizes the refractive index of the light incident through the front surface of the solar cell 10 by minimizing the refractive index with respect to air and the second front antireflection film 74a has a refractive index It can function as an antireflection film for increasing the absorptivity.

Also, the first front anti-reflection film 72a and the second front anti-reflective film 74a prevent moisture from penetrating the front surface of the solar cell module 100a, and can also function as a passivation film.

The front antireflection film 70a may be located at a position partially spaced corresponding to the position of the solar cell 10. That is, the front antireflection film 70a may be formed in the same size and the same position as the solar cell 10.

FIGS. 2 and 3 are views for explaining an example of a pattern of an anti-reflection film disposed on a front surface of a solar cell module according to an embodiment of the present invention.

As shown in FIG. 2, the front antireflection film 70a may be positioned on the light-transmissive front sheet 50 at a position corresponding to the position of the solar cell 10 and partially spaced from the solar cell 10 in the same size.

3, the front antireflection film 70a may be formed to have the same size as that of the light transmissive front sheet 50. As shown in FIG. That is, the entire antireflection film 70a may be positioned on the entire surface of the light transmissive front sheet 50.

4 is a cross-sectional view schematically showing another example of a solar cell module 100b according to an embodiment of the present invention.

The solar cell module 100b shown in FIG. 4 has the same structure as that of FIG. 1 except for the second front antireflection film 74b located between the light transmissive front sheet 50 and the first front antireflection film 72b. Is the same as the solar cell module 100a, and therefore only the configuration of the front antireflection film 70b will be described below.

Therefore, the same reference numerals as in FIG. 1 denote the same components as those of the solar cell module 100a shown in FIG. 1, and a detailed description thereof will be omitted.

As shown in FIG. 4, the front antireflection film 70b is located on the front surface of the solar cell 10.

The front antireflection film 70b includes a first front antireflection film 72b positioned on the light transmissive front sheet 50 and a second front antireflection film 72b located between the light transmissive front sheet 50 and the front side protection unit 30. [ And an entire antireflection film 74b.

The first front antireflection film 72b may be discontinuously positioned with the second front antireflection film 74b.

In this example, the first front anti-reflection film 72b may be made of a silicon nitride film (SiNx) or a silicon oxide film (SiOx), and the second front anti-reflective film 74b may be made of zirconium oxide (ZrO2) or yttrium oxide Or a combination of doping materials. The doping material may be at least one doping material selected from europium (Eu), ytterbium (Yb), bismuth (Bi), and erbium (Er).

The first front antireflection film 72b may be formed of the same material as the first front antireflection film 72a and the second front antireflection film 74b may be formed of the same material as the second front antireflection film 74a. have. However, the present invention is not limited thereto, and may be made of different materials.

Specifically, the first front antireflection film 72b made of a silicon nitride film (SiNx) or a silicon oxide film (SiOx) has a thickness of about 80 to 120 nm, a refractive index of 1.3 to 1.5, and a (ZrO2) or yttria The thickness of the second front antireflection film 74b made of a combination of the doping materials may be about 100 nm to 160 nm, and the refractive index may be 1.9 to 2.2. The thickness of the second front antireflection film 74b is 130 nm and the thickness of the light transmissive front sheet 50 is 3.5 mm and the thickness of the front side protection part 30 is 90 nm. Is preferably 0.45 mm.

The front antireflection film 70b minimizes the reflectivity of the light incident on the front surface of the solar cell 10 and increases the selectivity of the specific wavelength region to increase the efficiency of the solar cell 10. [ That is, the efficiency of the solar cell 10 can be increased by the absorption rate of light with respect to the long wavelength band.

Specifically, since the refractive index sequentially changes from air toward the front antireflection film 70b, for example, air having a refractive index of 1, a first front antireflection film 72b having a refractive index of 1.3 to 1.5, and a refractive index of 1.52 And the second front antireflection film 74b having a refractive index of 1.9 to 2.2, the effect of the antireflection film can be further improved.

Since the refractive index of the second front antireflection film 74b adjacent to the solar cell 10 is greater than the refractive index of the first front antireflection film 72b adjacent to the air, It may be preferable that the thickness of the second front antireflection film 74b is greater than the thickness of the first front antireflection film 72b in order to reduce the reflectivity of the incident light.

The absorption rate of light for a long wavelength band can be increased by zirconium oxide (ZrO 2) or yttria (Y 2 O 3) contained in the second front antireflection film 74 b and the doping material. (Eu), ytterbium (Yb), bismuth (Bi), erbium (Er), and the like, while minimizing the reflectance of light with respect to the long wavelength band by using zirconium oxide (ZrO2) or yttria The absorption rate of light to the long wavelength band can be improved by the doping material. At this time, as the amount of the doping material increases, the absorption rate of light to the long wavelength band further increases, and the reflectance of light can be reduced.

In addition, it is possible to prevent water penetrating the light receiving surface of the solar cell 10 by zirconium oxide (ZrO 2) or yttria (Y 2 O 3), thereby protecting the solar cell 10 from the external environment.

The front antireflection film 70b may be formed of a combination of zirconium oxide (ZrO2) or yttrium oxide (Y2O3) and a doping material on the front protective film 30 by using various film forming methods such as a plasma enhanced chemical vapor deposition (PECVD) The second front antireflection film 74b is laminated and the next front side light transmitting sheet 50 is laminated and then a first front antireflection film 72b made of a silicon nitride film (SiNx) or a silicon oxide film (SiOx) The entire antireflection film 70b can be formed. At this time, the second front anti-reflection film 74b may be formed on the light-transmissive front sheet 50 after mixing the zirconium oxide (ZrO2) or yttria (Y2O3) with the doping material. Here, the doping material may be formed into a particle or a layer in the second front antireflection film 74b.

The first front antireflection film 72b having such a structure minimizes the reflectivity of the light incident through the front surface of the solar cell 10 while minimizing the refractive index with air and the second front antireflection film 74b has a refractive index It can function as an antireflection film for increasing the absorptivity.

In addition, the first front anti-reflection film 72b and the second front anti-reflective film 74b prevent moisture from penetrating the front surface of the solar cell module 100a and can also function as a passivation film.

3, the front antireflection film 70b may be formed to have the same size as that of the light transmissive front sheet 50. As shown in FIG. That is, the first front anti-reflection film 72b may be positioned on the entire surface of the light-transmissive front sheet 50, and the second anti-reflective film 74b may be positioned on the entire surface of the front protective unit 30. [

2, at least one of the front antireflection film 70b, the first front antireflection film 72b, and the second front antireflection film 74b may have the same size as that of the solar cell 10 The solar cell 10 may be located at a position corresponding to the position of the solar cell 10.

5 is a cross-sectional view schematically showing another example of a solar cell module 100c according to an embodiment of the present invention.

The solar cell module 100c shown in FIG. 5 is obtained by adding a rear antireflection film 80a to the rear surface of the solar cell module 100c. The remaining components except for the rear antireflection film 80a are the solar cell 100c shown in FIG. Module 100a. Therefore, only the configuration of the rear antireflection film 80a will be described below.

Therefore, the same reference numerals as in FIG. 1 denote the same components as those of the solar cell module 100a shown in FIG. 1, and a detailed description thereof will be omitted.

As shown in FIG. 5, the solar cell 10 is a back contact solar cell that receives external light through the rear surface of the substrate.

 As shown in FIG. 5, the rear antireflection film 80a may be located on the rear surface of the solar cell 10.

Specifically, the rear antireflection film 80a may be positioned between the rear protective portion 40 and the rear sheet 60. [

The rear antireflection film 80a includes a first rear antireflection film 82a and a first rear antireflection film 82a and a rear sheet 60, And a second rear antireflection film 84a located on the second rear antireflection film 82a.

The first rear antireflection film 82a may be sequentially or sequentially positioned with the second rear antireflection film 84a.

In this example, the first rear antireflection film 82a may be formed of a silicon nitride film (SiNx) or a silicon oxide film (SiOx), and the second rear antireflection film 84a may be composed of zirconium oxide (ZrO2) or yttrium oxide Or a combination of doping materials. The doping material may be at least one doping material selected from europium (Eu), ytterbium (Yb), bismuth (Bi), and erbium (Er).

The rear antireflection film 80a may be made of the same material as the front antireflection film 70a. However, the present invention is not limited thereto, and may be made of different materials.

In this example, the first rear antireflection film 82a made of a silicon nitride film (SiNx) or a silicon oxide film (SiOx) has a thickness of about 80 to 120 nm, a refractive index of 1.3 to 1.5, and a zirconium oxide (ZrO2) Y2O3) and the doping material may be about 100 nm to 160 nm, and the refractive index may be 1.9 to 2.2.

The rear antireflection film 80a prevents moisture from penetrating the rear surface of the solar cell module 100c to protect the solar cell 10 from the external environment. In particular, moisture penetrating through the rear sheet 60 can be more effectively prevented by zirconium oxide (ZrO2) or yttria (Y2O3) of the second rear antireflection film 84a. Therefore, the solar cell 10 is more safely protected from external impacts, pollutants, and the like, and the weather resistance of the solar cell module is increased, so that the life of the solar cell module 100c can be extended.

The rear antireflection film 80a may be formed of a silicon nitride film (SiNx) or a silicon oxide film (SiOx) between the rear protective film 40 and the back sheet 60 by using various film forming methods such as a plasma enhanced chemical vapor deposition (PECVD) And a second rear antireflection film 84a made of a combination of zirconium oxide (ZrO2) or yttria (Y2O3) and a doping material may be sequentially formed on the first antireflection film 82a. At this time, the second rear antireflection film 84a may be formed on the first rear antireflection film 82a after mixing the doping material with zirconium oxide (ZrO2) or yttria (Y2O3). The doping material may be formed into a particle or a layer in the second rear antireflection film 84a.

The rear antireflection film 80a having such a structure can prevent the moisture from penetrating from the rear surface of the solar cell module 100c, thereby protecting the solar cell 10 from the external environment.

Unlike the present embodiment, the rear antireflection film 80a may be formed of a single film composed of a combination of zirconium oxide (ZrO2) or yttria (Y2O3) and a doping material.

The rear antireflection film 80a may be formed to have the same size as that of the rear sheet 60. That is, the rear antireflection film 80a may be positioned on the entire surface of the rear sheet 60.

2, at least one of the rear antireflection film 80a, the first rear antireflection film 82a, and the second rear antireflection film 84a is formed on the rear surface protective portion 40 and the rear surface And may be located between the sheets 60 in the same size as that of the solar cell 10, partially corresponding to the position of the solar cell 10.

6 to 8 are cross-sectional views schematically showing another example of a solar cell module according to an embodiment of the present invention.

As shown in FIGS. 6 to 8, the solar cell 10 is a bifacial solar cell that receives external light through the front and rear surfaces of the substrate, respectively.

The front antireflection film 70d may be positioned on the front surface of the solar cell 10 and the rear antireflection film 80b may be positioned on the rear surface of the solar cell 10. [

6, the front antireflection film 70d includes a first front antireflection film 72d and a second front antireflection film 74d continuously disposed on the light transmissive front sheet 50, The first rear antireflection film 80b may include a first rear antireflection film 82b and a second rear antireflection film 84b that are continuously positioned between the rear protective film 40 and the rear sheet 60.

The front antireflection film 70d may be partially spaced corresponding to the position of the solar cell 10. That is, the front antireflection film 70d may be formed to have the same size as the solar cell 10.

The rear antireflection film 80b may be formed to have the same size as that of the rear sheet 50 between the rear sheet 60 and the rear protective film 40. [ At this time, the rear antireflection film 80b may be formed as a single film.

At least one of the rear antireflection film 80b, the first rear antireflection film 82b and the second rear antireflection film 84b is provided between the rear protective part 40 and the rear sheet 60, And may be located at the same size as the cell 10 and partially spaced corresponding to the position of the solar cell 10.

On the other hand, as shown in FIG. 7, the entire antireflection film 70e may be positioned on the entire surface of the light-transmissive front sheet 50. FIG. That is, the front antireflection film 70e may be formed to have the same size as the light-transmissive front sheet 50.

8, the front antireflection film 70f includes a first front antireflection film 72f, a light transmissive front sheet 50, and a front side protection film 30, which are disposed on the entire surface of the light transmissive front sheet 50, The rear antireflection film 80d includes a first rear antireflection film 82d continuously positioned between the rear side protective film 40 and the rear sheet 60 and a second antireflection film 82d positioned between the rear side protective film 40 and the rear sheet 60, 2 rear antireflection film 84d.

2, at least one of the front antireflection film 70f, the first front antireflection film 72f, and the second front antireflection film 74f may have the same size as that of the solar cell 10 The solar cell 10 may be located at a position corresponding to the position of the solar cell 10.

At least one of the rear antireflection film 80d, the first rear antireflection film 82d and the second rear antireflection film 84d is provided between the rear protective film 40 and the rear sheet 60, And may be located at the same size and partially spaced corresponding to the position of the solar cell 10. [

After the front antireflection film 70 is formed on the front surface of the solar cell 10, the rear antireflection film 80 may be formed on the rear surface of the solar cell 10. However, the front antireflection film 70 may be formed after the rear antireflection film 80 is formed, or the front antireflection film 70 and the rear antireflection film 80 may be formed at the same time.

9 is a view showing a reflection path of light to which a solar cell module according to an embodiment of the present invention is applied.

Hereinafter, referring to FIG. 9, the reflection path of light to which the solar cell module according to the present invention is applied when light of the entire wavelength band is incident will be described below.

First, in the first path (1), light for the propagation wavelength band can be absorbed into the front surface of the solar cell 10.

(Eu), ytterbium (Yb), and ytterbium (Yb), while minimizing the refractive index of air with respect to the long wavelength band incident through the front surface of the solar cell 10 by minimizing the refractive index with air by the double antireflection film structure having a low refractive index and a high refractive index. ), Bismuth (Bi), erbium (Er), and the like can be improved by the doping material.

Accordingly, the efficiency of the solar cell module 100 can be improved by absorbing light uniformly with respect to the propagation wavelength band, thereby increasing the absorption rate of light with respect to the short wavelength band as well as the short wavelength band.

Next, in the second path (2), light for a long wavelength band can be transmitted through the solar cell 10, reflected by the rear sheet 60, and re-incident on the rear surface of the solar cell 10.

The light of the long wavelength is reflected and absorbed by the rear surface of the solar cell 10, so that the back surface of the solar cell 10 can be generated and the efficiency of the solar cell module 100 can be further improved.

Conventionally, moisture penetrated through the rear sheet 60 to reduce the light absorption rate, thereby decreasing the efficiency of the solar cell 10. However, since the rear antireflection film 80 is positioned between the rear protective film 40 and the rear sheet 60, the solar cell 10 can be more safely protected from external impacts or contaminants, have. Thus, the efficiency of the solar cell 10 can be increased.

In the third path (3), a part of the light reflected by the solar cell 10 with respect to the long wavelength band can be reflected by the front anti-reflection film 70 and absorbed to the front surface of the solar cell 10. The reflectance of light with respect to the long wavelength band can be reduced by the doping material included in the second front antireflection film 74.

Accordingly, the efficiency of the solar cell 10 can be improved by increasing the absorption rate of the light with respect to the long wavelength band and thereby generating the front surface of the solar cell 10.

As described above, the refractive index with respect to air is minimized by the first front anti-reflection film 72 having a low refractive index to minimize the reflectance of light with respect to the long wavelength band, and the doping material contained in the second front anti- The absorption rate of light to the long wavelength band can be increased.

The light for the long wavelength band incident on the front surface of the solar cell 10 is incident on the front surface of the solar cell 10 due to the doping material of the front antireflection film 70, Is reflected by the rear sheet 60 to be incident on the rear surface of the solar cell 10 and reflected by the front surface 50 of the solar cell 10, (③) to the front. As a result, the front and rear surfaces of the solar cell 10 are generated, and the efficiency of the solar cell module 100 can be improved.

FIG. 10 is a graph showing the transmittance according to the wavelength of light in the solar cell module according to the embodiment of the present invention and the comparative example, FIG. 11 is a graph showing the reflectance of the solar cell module according to the embodiment of the present invention and the comparative example And FIG. 12 is a graph showing the absorption rate of light in the substrate of the solar cell module according to the embodiment of the present invention and the comparative example.

First Embodiment In the case of the first embodiment of the present invention, a first front anti-reflection film 72 and a second front anti-bottom film 74 are successively deposited on a light transmissive front sheet 50 on the front surface of the solar cell 10 Respectively. At this time, the thickness of the first front antireflection film 72 is 100 nm, the thickness of the second front antireflection film 74 is 140 nm, the thickness of the light transmissive front sheet 50 is 3.5 mm, Is preferably 0.45 mm.

In the case of Embodiment 2, the first front anti-reflection film 72 is formed on the light-transmissive front sheet 50 on the front surface of the solar cell 10, and the first front anti-reflective film 72 is formed between the light- And the second front antireflection film 74 is formed by being discontinuously deposited. At this time, the thickness of the first front antireflection film 72 is 90 nm, the thickness of the second front antireflection film 74 is 130 nm, the thickness of the light transmissive front sheet 50 is 3.5 mm, Is preferably 0.45 mm.

The comparative example shows a case in which the light-transmissive front sheet 50 is formed without including the front antireflection film 70.

Referring to FIG. 10, it can be seen that the transmittance of light in the propagation band is increased in Examples 1 and 2 as compared with Comparative Example.

The effect of the antireflection film increases because the refractive index sequentially changes from the air toward the front antireflection film 70 side and the reflectance of light for the long wavelength band is reduced by the doping material contained in the second front antireflection film 74, Can be increased. At this time, as the content of the doping material increases, the light absorption rate may increase.

Referring to Fig. 11, the reflectance of Example 1 of the present invention is 1.2%, that of Example 2 is 1.6%, and that of Comparative Example is 5.3%.

Specifically, in Examples 1 and 2, the first antireflection film 72 having a low refractive index and the second antireflection film 74 having a high refractive index sequentially change the refractive index from the air toward the antireflection film 70 side The effect of the antireflection film can be maximized.

Therefore, the reflectance of Example 1 is 4.1% lower than that of the comparative example, and the reflectance of Example 2 is 3.7% lower.

Thus, by reducing the reflectance of Examples 1 and 2, referring to Fig. 12, the absorption rate of light absorbed in the solar cell 10 can be increased.

Specifically, the comparative example has an absorption rate of 91.7%, Example 1 has an absorption rate of 96.1%, and Example 2 has an absorption rate of 95.6%.

As a result, it can be seen that the absorption rate of Example 1 is increased by 4.4% as compared with that of Comparative Example, and that of Example 2 is increased by 3.9% as compared with Comparative Example.

Therefore, if the reflectance of light to the long wavelength band is reduced, the light transmittance and absorption rate are increased, and the efficiency of the solar cell can be further increased.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

10: Solar cell 20: Interconnect connector
30: front protection part 40: rear protection part
50: light transmissive front sheet 60: rear sheet
70: front antireflection film 72: first front antireflection film
74: second front antireflection film 80: rear antireflection film
82: first rear anti-reflection film 82: second rear anti-reflection film
100: solar cell module

Claims (18)

A plurality of solar cells,
A light-transmitting sheet disposed on a first surface side of the plurality of solar cells,
A front protective portion positioned between the light-transmitting sheet and the plurality of solar cells,
A back sheet positioned on a second surface side of the plurality of solar cells,
A rear surface protection sheet positioned between the rear sheet and the plurality of solar cells,
A front antireflection film positioned on a first surface side of the plurality of solar cells,
/ RTI >
Wherein the front antireflection film comprises a first front antireflection film and a second front antireflection film having a higher refractive index than the first front antireflection film. The method according to claim 1,
Wherein a refractive index of the first front antireflection film is about 1.3 to 1.5, and a refractive index of the second front antireflection film is about 1.9 to 2.2. The method according to claim 1,
Wherein a thickness of the first front antireflection film is smaller than a thickness of the second front antireflection film. The method according to claim 1,
Wherein the first front antireflection film and the second front antireflection film are made of different materials. 5. The method of claim 4,
Wherein the first front anti-reflection film is made of a silicon nitride film (SiNx) or a silicon oxide film (SiOx), and the second front anti-reflection film is made of a combination of zirconium oxide (ZrO2) or yttria (Y2O3) . 6. The method of claim 5,
Wherein the doping material is at least one of europium (Eu), ytterbium (Yb), bismuth (Bi), and erbium (Er). The method according to claim 1,
Wherein the front antireflection film is partially formed on the light-permeable sheet. 8. The method of claim 7,
Wherein the second front antireflection film is disposed on the light transmitting sheet and the first front antireflection film is continuously disposed on the second front antireflection film and the second front antireflection film. 8. The method of claim 7,
Wherein the second front antireflection film is positioned between the light transmitting sheet and the front protecting part and the first front antireflection film is disposed discontinuously with the second front antireflection film on the light transmitting sheet. 8. The method of claim 7,
Wherein the front anti-reflection film is formed to have the same size as the plurality of solar cells. The method according to claim 1,
Wherein the front antireflection film is formed on the entire surface of the light-transmitting sheet. 12. The method of claim 11,
Wherein the second front antireflection film is disposed on the light transmitting sheet and the first front antireflection film is continuously disposed on the second front antireflection film and the second front antireflection film. 12. The method of claim 11,
Wherein the second front antireflection film is positioned between the light transmitting sheet and the front protecting part and the first front antireflection film is disposed discontinuously with the second front antireflection film on the light transmitting sheet. The method according to claim 1,
Wherein the first total antireflection film has a thickness of about 80 to 120 nm and the second total antireflection film has a thickness of about 100 to 160 nm. The method according to claim 1,
And a rear antireflection film disposed between the rear surface protection part and the rear sheet. 16. The method of claim 15,
Wherein the rear antireflection film comprises a first rear antireflection film and a second rear antireflection film having a refractive index higher than that of the first rear antireflection film. 17. The method of claim 16,
Wherein the first rear antireflection film is positioned on the rear surface protection portion and the second rear surface antireflection film is positioned on the first rear surface antireflection film. 17. The method of claim 16,
The first rear antireflection film is made of the same material as the first front antireflection film and the second rear antireflection film is made of the same material as the second front antireflection film.

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