KR101792323B1

KR101792323B1 - Optical sheet

Info

Publication number: KR101792323B1
Application number: KR1020150024035A
Authority: KR
Inventors: 강성욱; 김현철; 고현성
Original assignee: 주식회사 엘지화학
Priority date: 2015-02-17
Filing date: 2015-02-17
Publication date: 2017-10-31
Also published as: KR20160101453A

Abstract

The present invention relates to an optical sheet and a photovoltaic module including the optical sheet. The optical sheet according to the present application is excellent in ultraviolet shielding ability to ensure properties such as long-term weatherability, Absorbed and emitted as light of a long wavelength region, thereby exhibiting superior power generation efficiency when applied to a photovoltaic module.

Description

Optical sheet {OPTICAL SHEET}

The present application relates to an optical sheet and a photovoltaic module including the same.

There is a growing interest in renewable energy and clean energy due to global environmental problems and depletion of fossil fuels. Among them, photovoltaic energy is attracting attention as a representative pollution-free energy source that can solve environmental pollution problem and fossil fuel depletion problem have.

Photovoltaic (PV) solar photovoltaic (PV) technology is a device that converts sunlight into electric energy. Since it is required to be exposed to the external environment for a long time in order to easily absorb sunlight, various packaging for protecting the cell is performed, ), And these units are referred to as photovoltaic modules.

In addition, most photovoltaic modules, such as solar cell modules, include a front member (glass or front sheet) for protecting internal components (e.g., solar cells) back sheet.

Generally, in the case of a solar cell module, the solar cell module has a structure in which a transparent front member on which light is incident, an encapsulant layer in which a plurality of solar cell cells are encapsulated, and a back sheet are sequentially laminated. As the transparent front member, a tempered glass or a front sheet is mainly used. The plurality of solar cells are electrically connected to each other, and are packed and sealed by the sealing material layer. Patent literatures 1 and 2 disclose techniques related to the above.

The solar cell module is required to have a long service life without deterioration over a long period of time. For the longevity improvement, the front and back sheets must be able to block water and oxygen which adversely affect the solar cell, and can prevent deterioration due to ultraviolet (UV) rays or the like.

Particularly, in the case of a front sheet positioned directly on the front surface of a solar cell module and directly receiving sunlight, a high light transmittance is required for high power generation efficiency. Further, since the front sheet is exposed to the outside for a long period of time, high weather resistance is required, and in particular, excellent ultraviolet shielding ability is required. When ultraviolet rays are transmitted, the weatherability of the solar cell as well as the front sheet itself is deteriorated.

For this purpose, in most cases, ultraviolet absorbers are used for ultraviolet ray shielding. For example, Patent Document 3 discloses a transparent protective film for a solar cell using an organic ultraviolet absorber such as benzotriazole, and Patent Document 4 discloses a front sheet (front sheet) for a solar cell using zinc oxide as an inorganic ultraviolet absorber. .

When the ultraviolet absorber is used as described above, the weatherability can be improved. However, when only the ultraviolet absorber is used, high power generation efficiency is hardly obtained.

Korean Patent No. 10-1022820 Korea Patent Publication No. 10-2011-0020227 Japanese Patent Application Laid-Open No. 2006-255927 Korean Patent Publication No. 10-2011-0029096

The present application provides an optical sheet and a photovoltaic module including the same.

The present application relates to an optical sheet.

The exemplary optical sheet may be an optical sheet for a photovoltaic module applicable to a photovoltaic module. More specifically, the optical sheet may be an optical sheet applicable as a front substrate or a back sheet included in the photovoltaic module, and more preferably, it may be an optical sheet applicable as a back sheet. In the present specification, the above-mentioned "optical sheet for a photovoltaic module" may be referred to as an "optical sheet".

In one example, the optical sheet of the present application comprises a base layer; And a light conversion layer formed on at least one surface of the substrate layer. As used herein, the term " photo-conversion layer " refers to a layer that absorbs light in a specific wavelength range and emits light in a wavelength range other than the specific wavelength range, more specifically, absorbs light in a short wavelength range, Means a layer which emits light. In this specification, the terms " formed on ", " formed on one surface ", and " sheet on both surfaces " do not mean that the constituent elements are laminated in direct contact with each other. Quot; and " the " For example, the term " formed on one side " means that the second component is formed directly on one side of the first component, as well as the third component Lt; / RTI > can be further formed.

The substrate layer is not particularly limited, and various materials known in the art can be used, and can be appropriately selected depending on the required functions and applications.

As the base layer, a single sheet such as an acrylic film, a polyether film, a polyester film, a polyolefin film, a polyamide film, a polyurethane film, a polycarbonate film and a polyimide film, A laminated sheet of polymer films, or a pneumatic article, and a polyester film can be usually used, but the present invention is not limited thereto. Examples of the polyester film include at least one selected from the group consisting of a polyethylene terephthalate (PET) film, a polyethylene naphthalate (PEN) film, and a polycarbonate (PC) film , But is not limited thereto.

The thickness of the base layer is not particularly limited, but may be within a range of, for example, 20 탆 to 1000 탆, 30 탆 to 500 탆, or 50 탆 to 300 탆. By adjusting the thickness of the base layer within the above-mentioned range, the mechanical properties and handleability of the optical sheet can be improved. However, the thickness of the base layer according to the embodiments of the present application is not limited to the above-mentioned range, and it can be suitably adjusted as required.

In order to improve the adhesion to the above-mentioned photoconversion layer, the base layer is subjected to spark discharge treatment at a high frequency such as corona treatment or plasma treatment on one surface or both surfaces thereof; Heat treatment; Flame treatment; Anchor treatment; Coupling agent treatment; Primer treatment or a gas phase Lewis acid (ex. BF _3), can be done by a surface treatment such as a chemical activation treatment with sulfuric acid or hot sodium hydroxide. The surface treatment method may be carried out by any well-known means generally used in this field.

In addition, from the viewpoint of improving the physical properties such as moisture barrier properties, the substrate layer may be formed with an inorganic oxide deposited layer on one side or both sides, if necessary. The kind of the inorganic oxide is not particularly limited, and any inorganic oxide may be employed as long as it has moisture barrier properties. For example, silicon oxide or aluminum oxide can be used. The method of forming the inorganic oxide vapor deposition layer on one side or both sides of the substrate layer is not particularly limited and may be a vapor deposition method generally used in this field. When the inorganic oxide deposit layer is formed on one surface or both surfaces of the substrate layer, the above-described surface treatment may be performed on the deposition layer after the inorganic oxide deposit layer is formed on the surface of the substrate layer.

The light conversion layer is not particularly limited, but may be, for example, a layer which absorbs light in a short wavelength region and emits light in a long wavelength region. The optical sheet according to the present invention absorbs a short wavelength light having a low sensitivity to a reaction in a solar cell or the like by a phosphor included in the light conversion layer described later, and converts the light into a long wavelength with high response sensitivity, thereby improving power generation efficiency.

In one example, the short wavelength region may be 500 nm or less, and the long wavelength region may be 500 nm to 1100 nm. The lower limit of the wavelength of the short wavelength region is not particularly limited, but may be, for example, 350 nm, and the long wavelength region may preferably be 500 nm to 800 nm.

In general, most solar cells are sensitive to wavelengths from about 400 nm to 1,200 nm. Accordingly, the solar cell mainly absorbs light in the wavelength range and generates electricity. Therefore, light in a short wavelength region (about 500 nm or less) is low in sensitivity in a solar cell, and thus it is difficult to exhibit high power generation efficiency. Particularly in the case of a crystalline silicon solar cell or the like. In addition, the sensitivity of the solar cell increases as it goes to the longer wavelength region even within the above wavelength range. At this time, a high reaction sensitivity means that the light of the corresponding wavelength is absorbed at a high absorption rate, which means that the power generation efficiency of the solar cell is increased eventually. In addition, high efficiency is not achieved because the wavelength is high, and most solar cells have high power generation efficiency in the range of about 400 nm to 800 nm.

In one example, the light conversion layer may include at least two or more kinds of phosphors. In the present specification, the term " at least two or more " means that the upper limit is not particularly limited as long as it is two or more, and the lower limit is necessarily two.

The phosphor may be at least one selected from the group consisting of an oxazole-based compound, a pyrene-based compound, a perillin-based compound, a naphthalimide-based compound, a rhodamine-based compound, an anthraquinone-based compound, a thiamine- Preferably, it is a perillin-based compound and / or a naphthalimide-based compound, but is not limited thereto.

In one example, the phosphor is selected from the group consisting of naphthalimide, 4,5-dimethyloxy-N- (2-ethylhexyl) naphthalimide, perillin, isobutyl 4,10- -Dicarboxylate, perylene-3,4,9,11-tetracarboxylic acid bis- (2 ', 6'-diisopropylanilide) and perylene-1,8,7,12-tetraphenoxy -3,4,9,10-tetracarboxylic acid bis- (2 ', 6'-diisopropylanilide), but the present invention is not limited thereto.

In another example, the phosphor may include a compound represented by the following formula (1).

[Chemical Formula 1]

In the above formula (1), M is a rare earth element and n is an integer of 1 or more.

In the above formula (1), the rare earth element M may be selected from, for example, Eu, La, Ce, Pr, Nd, Gd, Tb, Dy and Lu. In Formula 1, n is an integer of 1 or more. The upper limit of n is not limited, but may be, for example, 100 or less. In the above formula (1), n may be, for example, 1 to 100 or 1 to 50. M in Formula 1 may be Eu. Specifically, the phosphor may include a compound represented by the following formula (2). In the following formula (2), n is as described in formula (1).

(2)

In Formula 2, n is an integer of 1 or more.

In one example, the light conversion layer may further include a fluorinated polymer and an acrylic polymer.

The fluoropolymer may be at least one selected from the group consisting of vinylidene fluoride, vinyl fluoride, tetrafluoroethylene hexafluoropropylene, chlorotrifluoroethylene, trifluoroethylene, hexafluoroisobutylene, perfluorobutylethylene, perfluoromethyl Vinyl ether, perfluoroethyl vinyl ether, perfluoropropyl vinyl ether, perfluorohexyl vinyl ether, perfluoro-2,2-dimethyl-1,3-dioxole and perfluoro-2- -Methyl-1,3-dioxolane, in a polymerized form, but are not limited to, homopolymers, copolymers, or mixtures thereof.

(Meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, (Meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (Meth) acrylate, n-decyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl Tetradecyl (meth) acrylate, and the like, but is not limited thereto.

For example, in the case where the photoconversion layer contains a fluorine-based polymer and an acrylic polymer, for example, the photoconversion layer may contain 60 to 90 parts by weight of the fluorine-based polymer, 65 to 85 parts by weight of the fluorine- Or 70 parts by weight to 80 parts by weight; 10 to 40 parts by weight, 15 to 35 parts by weight or 20 to 30 parts by weight of an acrylic polymer; And 0.1 part by weight to 20 parts by weight of the phosphor and 0.3 parts by weight to 5 parts by weight of the phosphor. By controlling the content ratio of the components included in the light conversion layer within the above-described range, it is possible to further enhance the power conversion efficiency of the photovoltaic module by increasing the wavelength conversion capability.

The thickness of the light conversion layer is not particularly limited, but may be within a range of, for example, 0.5 to 300 m, 2 to 200 m, or 5 to 80 m. By controlling the thickness of the light conversion layer within the above-mentioned range, the physical properties such as the wavelength conversion ability of the optical sheet can be further improved. However, the thickness of the light conversion layer according to the embodiments of the present application is not limited to the above-mentioned range, which can be appropriately adjusted as needed.

In one example, the optical sheet may further include an ultraviolet blocking layer on the other surface of the substrate layer having the light conversion layer formed on one side thereof.

1 is a view showing an exemplary optical sheet of the present application. As shown in FIG. 1, the optical sheet 100 of the present application includes a base layer 111; A photo-conversion layer (112) formed on one side of the substrate layer; And an ultraviolet blocking layer 110 on the other side of the base layer on which the light conversion layer is formed.

In one example, the ultraviolet barrier layer may include a fluorine-based polymer, an acrylic polymer, and an ultraviolet screening agent.

The contents of the fluoropolymer and the acrylic polymer are the same as those of the fluoropolymer and the acrylic polymer that can be contained in the light conversion layer.

The ultraviolet ray shielding member is not particularly limited as long as it has an ultraviolet shielding function by absorbing ultraviolet rays. The ultraviolet absorber may be, for example, a compound capable of absorbing an ultraviolet wavelength of about 400 nm or less, more specifically, about 100 nm to 400 nm. When the optical sheet including the ultraviolet screening agent is applied to the photovoltaic module, it is possible to improve water resistance such as prevention of deterioration inside the photovoltaic cell due to ultraviolet absorption and weatherability.

Examples of the ultraviolet screening agent may include at least one selected from the group consisting of benzophenone compounds, benzotriazole compounds, triazine compounds, and oxalic aniline compounds, and benzophenone compounds may be preferably used , But is not limited thereto.

Examples of the benzophenone compound include benzophenone, benzhydrol, 4-hydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 2,2 ' -Dihydroxy-4-methoxybenzophenone and / or 2,3,4-trihydroxybenzophenone. As the benzophenone compound, commercially available products such as UV 531 product can be used.

When the ultraviolet ray blocking layer is included, the content of the fluorine-based polymer, the acrylic polymer and the ultraviolet ray blocking agent in the ultraviolet blocking layer is not particularly limited, but may be, for example, from 60 to 90 parts by weight, Or 70 parts by weight to 80 parts by weight; 10 to 40 parts by weight, 15 to 35 parts by weight or 20 to 30 parts by weight of an acrylic polymer; And 0.1 part by weight to 20 parts by weight of an ultraviolet screening agent; and 1 part by weight to 7.5 parts by weight of an ultraviolet screening agent. By controlling the content ratio of the components contained in the ultraviolet blocking layer within the above-described range, it is possible to block ultraviolet rays due to higher ultraviolet absorption, thereby improving deterioration of the inside of the photovoltaic module and improving weather resistance.

The thickness of the ultraviolet blocking layer is not particularly limited, but may be within a range of, for example, 0.5 to 300 m, 1 to 200 m, or 5 to 100 m. By adjusting the thickness of the ultraviolet blocking layer within the above-described range, physical properties such as ultraviolet blocking ability of the optical sheet can be further improved. However, the thickness of the ultraviolet blocking layer according to the embodiments of the present application is not limited to the above-mentioned range, and can be appropriately adjusted as needed.

The optical sheet of the present application may further include various functional layers known in the industry as needed in addition to the above-described layers.

Examples of the functional layer include an adhesive layer or an insulating layer. The adhesive layer and the insulating layer may be sequentially formed on the other surface of the substrate layer when the reflective layer is formed on one surface of the substrate layer.

The adhesive layer or insulating layer may be formed in various ways known in the art. The insulating layer may be, for example, a layer composed of ethylene vinyl acetate (EVA) or low density linear polyethylene (LDPE). The layer composed of the ethylene vinyl acetate (EVA) or the low density linear polyethylene (LDPE) functions not only as an insulating layer but also an adhesive force with an encapsulant of the photovoltaic module, thereby making it possible to reduce manufacturing cost, It is possible to simultaneously perform the function of maintaining excellent.

The present application also relates to photovoltaic modules.

In one example, the photovoltaic module comprises a front substrate; And a sealing material layer disposed between the front substrate and the back sheet and including two or more photovoltaic cells spaced apart from each other.

The specific types of the front substrate and the photovoltaic cell that can be used in the above are not particularly limited. For example, the front substrate may be a conventional plate glass; Or a transparent composite sheet obtained by laminating a glass, a fluororesin sheet, a weather-resistant film and a barrier film. The photovoltaic cell may be, for example, an active layer of the silicon wafer type or a thin film active layer formed by chemical vapor deposition . In addition, the photovoltaic cell may be an n-type cell or a p-type cell, and may be an n-type cell, but is not limited thereto.

The encapsulant layer encapsulates the photovoltaic cell, which may include, for example, a front encapsulant layer and a back encapsulant layer. In this case, the photovoltaic cell may be packed or fixed between the front encapsulant layer and the rear encapsulant layer.

The sealing material constituting the sealing material layer is not limited. The encapsulating material constituting the encapsulating material layer is not particularly limited as long as it has adhesiveness and insulating properties, and may include, for example, a conventionally used EVA resin, that is, an ethylene-vinyl acetate copolymer. As the sealing material constituting the sealing material layer, other resins than the EVA resin may be used. As the sealing material constituting the sealing material layer, for example, a polyolefin-based sealing material or the like can be used. More specifically, polyolefins such as polyethylene, polypropylene, ethylene / propylene copolymer, and ethylene / propylene / butadiene copolymer can be used.

In the photovoltaic module of the present application, the front substrate or the back sheet may be the optical sheet described above.

Figs. 2 and 3 are diagrams illustrating the structure of the photovoltaic module of the present application. Fig.

2, the photovoltaic module of the present application includes a UV-blocking layer 110, a base layer 111, and a photoconversion layer 112, An optical sheet 100 sequentially laminated; An encapsulant layer 200 including a front encapsulant layer 210, a photovoltaic cell C and a rear encapsulant layer 220; And a back sheet may be sequentially laminated.

3 shows a structure in which the above-described optical sheet is used as a back sheet in a photovoltaic module, which includes a front substrate 400; An encapsulant layer 200 including a front encapsulant layer 210, a photovoltaic cell C and a rear encapsulant layer 220; And an optical sheet 100 in which a light conversion layer 112, a base layer 111, and an ultraviolet blocking layer 110 are sequentially laminated. When the optical sheet of the present application is used as a back sheet, it is preferable that the light conversion layer 112 is attached to the sealing material layer 200 as shown in FIG.

Further, the photovoltaic module of the present application may additionally include a rear member (not shown) according to an exemplary embodiment. This backing member may be provided on the back surface of the back sheet 300. The rear member may be selectively included depending on the type of the photovoltaic module and the installation place, and may be selected from a rigid substrate such as the glass (for example, tempered glass) or a transparent plastic plate.

The optical sheet according to the present application is excellent in ultraviolet ray shielding ability to ensure physical properties such as long-term weatherability and also absorbs light in a short wavelength region by introducing a light conversion layer and emits light in a long wavelength region, It can exhibit excellent power generation efficiency.

1 schematically shows an optical sheet of the present application.
2 schematically shows the structure of a photovoltaic module when the optical sheet of the present application is used as a front sheet.
3 schematically shows the structure of a photovoltaic module when the optical sheet of the present application is used as a back sheet.

Hereinafter, the present application will be described in more detail by way of examples according to the present application and comparative examples not complying with the present application, but the scope of the present application is not limited by the following examples.

The physical properties in Examples and Comparative Examples were evaluated in the following manner.

1. Measurement and evaluation of average luminescence intensity

The optical sheets prepared in Examples and Comparative Examples were irradiated with light to measure their PL (photoluminescence) spectra, and then the average emission intensity at 550 nm to 700 nm in the wavelength range suitable for the solar cell in the measured PL spectrum luminous intensity was measured using a Fluorolog-3 spectrofluorometer system (HORIBA), and evaluated according to the following criteria.

< Evaluation Criteria >

○: When the measured light emission intensity value is 2.00E or more

X: When the measured light emission intensity value is 2.00E or less

&Lt; Preparation of composition >

Manufacturing example 1. Preparation of resin composition (A)

75 g of polyvinylidene fluoride (PVDF) and 25 g of polymethylmethacrylate (PMMA) were mixed and a benzophenone-based compound (UV 531 product, manufactured by Songwon Co., Ltd.) having the formula C ₂₁ V ₂₆ O ₃ )) Was added and mixed to prepare a composition (A).

Manufacturing example 2. Preparation of composition (B)

75 g of polyvinylidene fluoride (PVDF) and 25 g of polymethylmethacrylate (PMMA) were mixed and then 3 g of Lumogen F Violet 570 (naphthalimide compound, BASF) was added and mixed as a fluorescent material Composition (B) was prepared.

Manufacturing example 3. Preparation of Composition (C)

75 g of polyvinylidene fluoride (PVDF) and 25 g of polymethylmethacrylate (PMMA) were mixed and then 0.5 g of Lumogen F Vellow 083 (perylene-based compound, BASF) was added as a phosphor and mixed to prepare a composition C).

Manufacturing example 4. Preparation of Composition (D)

75 g of polyvinylidene fluoride (PVDF) and 25 g of polymethylmethacrylate (PMMA) were mixed and then 0.5 g of Lumogen F Red 305 (perylene-based compound, BASF Co., Ltd.) D).

Manufacturing example 5. Preparation of composition (E)

75 g of polyvinylidene fluoride (PVDF) and 25 g of polymethylmethacrylate (PMMA) were mixed. Then, 3 g of Lumogen F Violet 570 (naphthalimide compound, BASF Co.) as a phosphor and 3 g of Lumogen F Vellow 083 (Perylene-based compound, BASF Co., Ltd.) were added and mixed to prepare a composition (E).

Manufacturing example 6. Preparation of composition (F)

75 g of polyvinylidene fluoride (PVDF) and 25 g of polymethyl methacrylate (PMMA) were mixed. Then, 3 g of Lumogen F Violet 570 (naphthalimide compound, BASF Co.) as a phosphor and 3 g of Lumogen F Red 305 (F) was prepared by adding and mixing 0.5 g of an antioxidant (perylene-based compound, BASF).

< Optical sheet Manufacturing>

Example One

After coating the thus-prepared composition (A) on one side (upper side) of a PET (poly (ethylene terephthalate)) film (thickness: 250 탆) to form an ultraviolet blocking layer, The composition (E) prepared above was coated on one surface (lower surface) to a thickness of about 10 mu m and dried to prepare an optical sheet.

Example 2

An optical sheet was prepared in the same manner as in Example 1, except that the composition (F) prepared in Preparation Example 6 was used instead of the composition (E) used in the lower portion of Example 1.

Comparative Example One

An optical sheet was prepared in the same manner as in Example 1, except that the composition (B) prepared in Preparation Example 2 was used instead of the composition (E) used in the base portion of Example 1.

Comparative Example 2

An optical sheet was prepared in the same manner as in Example 1, except that the composition (C) prepared in Preparation Example 3 was used instead of the composition (E) used in the base portion of Example 1.

Comparative Example 3

An optical sheet was prepared in the same manner as in Example 1, except that the composition (D) prepared in Preparation Example 4 was used instead of the composition (E) used in the lower portion of Example 1.

The physical properties and evaluation results of the above Examples and Comparative Examples are shown in Table 1 below.

division Example Comparative Example One 2 One 2 3 Average emission intensity 2.72E + 06 3.19E + 06 0.07E + 06 1.93E + 06 0.93E + 06 Average light emission intensity evaluation ○ ○ × × ×

As shown in Table 1, the optical sheets of the present application (Examples 1 and 2) are superior to the optical sheets (Comparative Examples 1 to 3) including only one phosphor in the light conversion layer, It is possible to show excellent power generation efficiency.

100: Optical sheet
110: UV barrier layer
111: substrate layer
112: photo-conversion layer
200: encapsulant layer
210: front encapsulant layer
220: rear sealing material layer
300: back sheet
400: front substrate
C: photovoltaic cell

Claims

A base layer;
A light conversion layer formed on at least one surface of the substrate layer; And
And an ultraviolet blocking layer formed on the other surface of the substrate layer on which the light conversion layer is formed,
Wherein the light conversion layer comprises a fluoropolymer, an acrylic polymer, and two kinds of phosphors which absorb light in a short wavelength region and emit light in a long wavelength region,
The two phosphors are one kind of a perillin compound and one kind of a naphthalimide compound,
Wherein the ultraviolet blocking layer comprises a fluorine-based polymer, an acrylic polymer, and an ultraviolet screening agent.

The optical sheet for a photovoltaic module according to claim 1, wherein the short wavelength region is 500 nm or less and the long wavelength region is 500 nm to 1100 nm.

The optical sheet of claim 1, wherein the short wavelength region is from 350 nm to 500 nm and the long wavelength region is from 500 nm to 800 nm.

[2] The method according to claim 1, wherein the substrate layer is a layer selected from the group consisting of an acrylic film, a polyether film, a polyester film, a polyolefin film, a polyamide film, a polyurethane film, a polycarbonate film and a polyimide film Optical sheet for photovoltaic modules with more than two species.

The optical sheet for a photovoltaic module according to claim 1, wherein the thickness of the base layer is 20 占 퐉 to 1000 占 퐉.

delete

2. The method according to claim 1, wherein the naphthalimide compound is naphthalimide or 4,5-dimethyloxy-N- (2-ethylhexyl) naphthalimide, and the perylene compound is perylene, isobutyl 4, (2 ', 6'-diisopropylanilide) and perylene-1, 2-dicyclohexylcarbodiimide , 8,7,12-tetraphenoxy-3,4,9,10-tetracarboxylic acid bis- (2 ', 6'-diisopropylanilide).

delete

The method according to claim 1, wherein the fluorinated polymer is at least one selected from the group consisting of vinylidene fluoride, vinyl fluoride, tetrafluoroethylene hexafluoropropylene, chlorotrifluoroethylene, trifluoroethylene, hexafluoroisobutylene, perfluorobutylethylene , Perfluoromethyl vinyl ether, perfluoroethyl vinyl ether, perfluoropropyl vinyl ether, perfluorohexyl vinyl ether, perfluoro-2,2-dimethyl-1,3-dioxole and perfluoro- Methylene-4-methyl-1,3-dioxolane in the form of a polymer in the form of a polymer, a copolymer or a mixture thereof.

The acrylic polymer according to claim 1, wherein the acrylic polymer is at least one selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n- butyl (meth) Octyl (meth) acrylate, isooctyl (meth) acrylate, n-hexyl (meth) acrylate, (Meth) acrylate, n-decyl (meth) acrylate, n-decyl (meth) acrylate, Acrylate, and n-tetradecyl (meth) acrylate.

The optical sheet for a photovoltaic module according to claim 1, wherein the light conversion layer comprises 60 to 90 parts by weight of the fluorinated polymer, 10 to 40 parts by weight of the acrylic polymer, and 0.1 to 20 parts by weight of the phosphor.

The optical sheet as claimed in claim 1, wherein the thickness of the light conversion layer is 0.5 mu m to 300 mu m.

delete

The optical sheet for a photovoltaic module according to claim 1, wherein the ultraviolet light blocking agent comprises at least one member selected from the group consisting of a benzophenone compound, a benzotriazole compound, a triazine compound, and an oxalic acid aniline compound.

The optical sheet for a photovoltaic module according to claim 1, wherein the ultraviolet barrier layer comprises 60 to 90 parts by weight of the fluorine-based polymer, 10 to 40 parts by weight of the acrylic polymer, and 0.5 to 20 parts by weight of the ultraviolet screening agent.

The optical sheet for a photovoltaic module according to claim 1, wherein the thickness of the ultraviolet barrier layer is from 0.5 mu m to 300 mu m.

A front substrate; Back sheet; And an encapsulant layer disposed between the front substrate and the back sheet and including at least two photovoltaic cells spaced apart from each other,
Wherein the front substrate or the back sheet is an optical sheet for a photovoltaic module according to claim 1.

The photovoltaic module according to claim 21, wherein a light conversion layer of the optical sheet is attached to the sealing material layer.