KR20190002129A - Organic photovoltaics module and method for manufacturing organic photovoltaics module - Google Patents

Abstract

The present invention relates to an organic solar cell and a method of manufacturing the same. More specifically, the lifetime of the organic solar cell can be extended by forming an ultraviolet blocking layer between a substrate and a lower electrode. The whole organic solar cell including the ultraviolet blocking layer can be manufactured by a solution process such as a coating method, sot that the process costs and material costs can be reduced.

Description

TECHNICAL FIELD [0001] The present invention relates to an organic photovoltaic cell,

The present invention relates to a solar cell having improved life characteristics by ultraviolet ray shielding and a method for manufacturing the same.

Generally, a solar cell is a photovoltaic cell designed to convert solar energy into electrical energy, which means a semiconductor device that converts light energy generated from the sun into electrical energy. Such a solar cell is expected to be an energy source capable of solving future energy problems because it has low pollution, has an infinite resource, and has a semi-permanent life span. In recent years, research on low-cost solar cells that reduce power generation costs and research on high-efficiency solar cells that improve conversion efficiency are under way at the same time.

Solar cells can be divided into inorganic solar cells and organic solar cells depending on the material constituting the photoactive layer among the internal constituent materials. Monocrystalline silicon is mainly used for inorganic solar cells. Such monocrystalline silicon solar cells are excellent in terms of efficiency and stability and occupy most of the solar cells that are currently mass-produced. However, It shows the limit. Organic solar cells use organic materials such as small molecules (organic molecules) and polymers, which are much cheaper than the inorganic materials used in inorganic solar cells. It is possible to supply and receive easily. Therefore, the manufacturing process can be simplified and speeded up, and application and mass production of various materials and forms can be performed, and thus interest and research on organic solar cells are being amplified.

The organic solar cell basically has a thin film structure, and is generally disposed between the anode and the cathode opposite to each other, and is disposed between the anode and the cathode. The organic solar cell includes a hole acceptor such as a conjugated polymer, And a photoactive layer including an organic material having an electron acceptor as a bonding structure, and may further include a hole transport layer and an electron transport layer on upper and lower portions of the photoactive layer, respectively, as needed.

Organic devices having such a multilayer thin film structure can be manufactured by various coating methods such as slot die coating, spin coating and gravure coating, and a roll-to-roll slot die coating method is mainly used do.

As described above, the organic solar cell can be mass-produced with ease of processability and low cost, and it is possible to manufacture a thin film by the roll-to-roll method, thereby making it possible to manufacture a large-area electronic device having flexibility.

However, in spite of the above technical and economical advantages, the organic thin film device including the organic solar cell has a problem that the organic layer, which is a constituent layer of the inside due to sunlight, is decomposed by ultraviolet rays to shorten the lifetime. Therefore, research has been continued to develop a technique for minimizing photodegradation of the organic material used in the production of such an organic solar cell.

For example, Korean Laid-Open Patent Application No. 2012-0097852 discloses an organic solar cell having an ultraviolet barrier layer formed by a vapor deposition method such as spin coating or screen printing on an ultraviolet shielding composition of an organic solar cell. However, There is a problem that an ultraviolet blocking layer is formed on the rear surface, that is, the surface on which the sunlight is incident, so that the light is easily decomposed.

Korean Patent Publication No. 2010-0010716 discloses a solar cell in which a back sheet is adhered to the back surface of a solar cell for blocking ultraviolet rays, but similarly, a back sheet for blocking ultraviolet rays is placed on a surface where sunlight is incident, There is still a problem of photodegradation of an organic material by a photolithography process, and a separate process for attaching the backsheet is required, thereby lowering the process efficiency.

Accordingly, there is a growing need to develop a technique for effectively forming a structure such as an ultraviolet barrier layer for increasing the lifetime of an organic solar cell at an appropriate position.

Korean Patent Publication No. 2012-0097852, " Composition for protecting ultraviolet rays of organic solar cells " Korean Patent Publication No. 2010-0010716, " Solar cell module using PET film as a cover and method for manufacturing the same "

As a result of various studies to solve the above problems, the present inventors have found that, by forming a UV blocking layer on the back surface of a substrate on which sunlight is incident in a solution process, the decomposition of organic matter by sunlight is minimized It is possible to increase the lifetime of the organic solar cell, and it is also confirmed that the entire process of the organic solar cell can be performed by the solution process, thereby reducing the process cost and the cost.

Accordingly, an object of the present invention is to provide an organic solar cell including an ultraviolet barrier layer.

It is another object of the present invention to provide a method of manufacturing an organic solar cell in which the whole process is performed by a solution process.

In order to achieve the above object, the present invention provides a semiconductor device comprising: a substrate; A lower electrode; An electron transport layer; A photoactive layer; A hole transport layer; And an upper electrode are sequentially stacked,

And an ultraviolet blocking layer between the substrate and the lower electrode.

In addition, the ultraviolet barrier layer may include at least one ultraviolet blocking material selected from the group consisting of benzotriazole, benzophenone, cyclic imino ester, aryl cyanoacrylate, and triazine.

In addition, the ultraviolet barrier layer may have a thickness of 0.5 to 16 탆.

The lower electrode may be formed of ITO (Indium Tin Oxide); OMO (Oxide-Metal-Oxide); Ag nanowires; PEDOT: PSS [{poly (3,4-ethylenedioxythiophene)} / (polystyrene sulfonate)]; And a complex of Ag nanowire and PEDOT: PSS.

The upper electrode is selected from the group consisting of Ag paste (thermosetting, UV curable), Ag nanowire, PEDOT: PSS (poly (3,4-ethylenedioxythiophene) polystyrene sulfonate}, Ag nanowire and PEDOT: PSS complex It may be more than one kind.

The present invention also provides a semiconductor device comprising: a substrate; A lower electrode; An electron transport layer; A photoactive layer; A hole transport layer; And an upper electrode; A method of manufacturing an organic solar cell sequentially stacked,

And forming an ultraviolet blocking layer between the substrate and the lower electrode.

In addition, the ultraviolet barrier layer may be formed using a slot die coating method.

The coating solution for forming an ultraviolet barrier layer may further comprise at least one ultraviolet barrier material selected from the group consisting of benzotriazole, benzophenone, cyclic imino ester, arylated cyanoacrylate, and triazine; And at least one solvent selected from the group consisting of an alcohol-based solvent and an organic solvent.

An ultraviolet blocking layer on the substrate; A lower electrode; An electron transport layer; A photoactive layer; And the major transport layer may be formed by a slot die coating method, and the upper electrode may be formed by a screen printing method.

According to the organic solar cell of the present invention, since the ultraviolet ray blocking layer is formed on the entire surface of the substrate facing the lower electrode rather than the rear surface of the substrate on which sunlight is incident, it is effective for preventing photodegradation of organic substances by sunlight. It is advantageous to extend the service life.

According to another aspect of the present invention, there is provided a method of manufacturing an organic solar cell, including: forming a lower electrode on a substrate; An ultraviolet barrier layer; An electron transport layer; A photoactive layer; A hole transport layer; And the upper electrode can all be formed by a solution process such as a coating process, so that a single process can reduce the process cost, thereby reducing the cost of the organic solar cell.

1 is a schematic diagram of an organic solar cell according to an embodiment of the present invention.
FIG. 2 is a schematic diagram comparing the positions of a substrate and an ultraviolet blocking layer or an ultraviolet blocking film in the organic solar cell of Example 1 and Comparative Example 1 of the present invention.

Hereinafter, the present invention will be described in detail in order to facilitate understanding of the present invention.

The terms and words used in the present specification and claims should not be construed in an ordinary or dictionary sense and the inventor can properly define the concept of the term to describe its invention in the best possible way It should be construed as meaning and concept consistent with the technical idea of the present invention.

When a member is referred to herein as being " on " another member, it includes not only a member in contact with another member but also another member between the two members.

Whenever a component is referred to as " comprising ", it is to be understood that the component may include other components as well, without departing from the scope of the present invention.

Organic solar cell

Hereinafter, the present invention will be described in more detail with reference to the drawings.

The present invention relates to an organic solar cell including an ultraviolet blocking layer, wherein the position of the ultraviolet blocking layer is a front surface of a substrate facing the lower electrode, rather than a rear surface of the substrate on which sunlight is incident. .

1 is a schematic diagram of an organic solar cell according to an embodiment of the present invention.

Referring to FIG. 1, an organic solar cell 100 according to an embodiment of the present invention includes a substrate 10; A lower electrode 20; An electron transport layer 30; A photoactive layer (40); A hole transport layer 50; And an upper electrode 60 are stacked in this order and the substrate 10 and the lower electrode 20 may include an ultraviolet blocking layer UVL. Here, the lower electrode 20 may be referred to as a cathode, and the upper electrode 60 may be referred to as an anode.

The ultraviolet blocking layer (UVL) is a coating layer formed on the substrate 10, specifically, between the substrate 10 and the lower electrode 20. At this time, one surface of the substrate 10 on which the ultraviolet blocking layer (UVL) is formed is referred to as the front surface of the substrate 10, and the decomposition of organic matter due to sunlight can be minimized since it is the opposite surface to which sunlight is incident.

The ultraviolet blocking layer (UVL) may be formed of a UV blocking material capable of blocking ultraviolet rays to prevent decomposition of organic substances. Specific examples thereof include benzotriazole, benzophenone, cyclic imino ester, And at least one ultraviolet blocking material selected from the group consisting of cyanoacrylate and triazine.

In addition, the ultraviolet screening material may be one of the following materials.

Examples of the inorganic compound include zinc oxide (ZnO), zinc sulfide (ZnS), titanium dioxide (TiO 2), titanium oxide (TiO 2) ₂ ), metallic silicon (Si), silicon carbide (SiC), oxygen-deficient silicon oxide (SiO _{2 -x} ), cerium dioxide (CeO ₂ ), _trivalent diatrix (Y ₂ O ₃ ) And sulfides and complexes thereof may be used in combination, but it is recommended that the nanosize is controlled to facilitate the synthesis of the core. More specifically, examples of the benzotriazole-based ultraviolet screening agent include 2- [2'-hydroxy-5 '- (methacryloyloxymethyl) phenyl] -2H-benzotriazole, 2- [2'- (Methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-5 '2'-hydroxy-5'- (methacryloyloxyhexyl) phenyl] -2H-benzotriazole, 2- [2'- Benzyltriazole, 2- [2'-hydroxy-5'-tert-butyl-3 '- (methacryloyloxyethyl) phenyl] -2H- [2'-hydroxy-5 '- (methacryloyloxyethyl) phenyl] -5-chloro-2H- benzotriazole, 2- [ ) Phenyl] -5-methoxy-2H-benzotriazole, 2- [2'-hydroxy-5 '- (methacryloyloxyethyl) - [2'-hydroxy-5 '- (methacryloyloxyethyl) phenyl] -5-tert-butyl-2H-benzotriazole , 2- [2'-hydroxy-5 '- (methacryloyloxyethyl) phenyl] -5-nitro-2H-benzotriazole and the like.

Examples of the benzophenone ultraviolet screening agents include 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,2' - dihydroxy-4,4'-dimethoxybenzophenone, 2,2 ' Dihydroxybenzophenone, 2-hydroxy-4-acetoxyethoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, , 2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy- 2'-dihydroxy-4,4'-dimethoxy-5,5'-disulfobenzophenone disodium salt and the like.

Examples of the cyclic imino ester ultraviolet light blocking agent include 2,2 '- (1,4-phenylene) bis (4H-3,1-benzoxazine-4-one) 3-benzoxazine-4-one, 2- (1- or 2-naphthyl) Benzooxazin-4-one, 2- (4-biphenyl) -3,1-benzoxazine-4-one, 2-p-nitrophenyl-3,1- 2-m-nitrophenyl-3,1-benzoxazine-4-one, 2-p-benzoylphenyl- , 2-o-methoxyphenyl-3,1-benzoxazine-4-one, 2-cyclohexyl-3,1-benzoxazine- benzooxazin-4-one, 2,2 '- (1,4-phenylene) bis (4H-3,1-benzoxadinone- (3-benzooxazin-4-one), 2,2'-ethylene bis (3,1- Methylenebis (3,1-benzoxazine-4-one), 2,2'-decamethylenebis (3,1-benzoxazine-4-one), 2,2'- , 1-benzoxazine-4-one), 2,2'-m-phen Benzooxazin-4-one), 2,2 '- (4,4'-diphenylene) bis (3,1- - (2,6- or 1,5-naphthalene) bis (3,1-benzoxazine-4-one), 2,2 ' (2-chloro-p-phenylene) bis (3,1-benzoxazine-4-one), 2,2 ' Phenylene) bis (3,1-benzoxazine-4-one), 2,2 '- (1,4-cyclohexylene) , 5-tri (3,1-benzoxazine-4-on-2-yl) benzene, and the like.

Further, it is also possible to use 1,3,5-tri (3,1-benzoxazine-4-on-2-yl) naphthalene and 2,4,6- (1,3) -oxazine-4,6-dione, 2,7-dimethyl-4H, 6H-benzo (1,2- -Dimethyl-4H, 9H-benzo (1,2-d; 5,4-d ') bis- (1,3) Benzo (1,2-d; 5,4-d ') bis- (1,3) -oxazine-4,6-dione, 2,7- ; 5,4-d ') bis- (1,3) -oxazine-4,6-dione, 6,6'-bis (2- , 6,6'-bis (2-ethyl-4H, 3,1-benzoxazine-4-one), 6,6'- (2-methyl-4H, 3,1-benzoxazine-4-one), 6,6'-methylenebis (2-phenyl-4H, 3-benzooxazin-4-one), 6,6'-ethylene bis (2-methyl-4H, 3,1-benzoxazine-4-one), 6,6'-butylene bis (2- Phenyl-4H, 3,1-benzoxazine-4-one), 6,6'-oxybis (2-methyl-4H, 4-one), 6,6'-oxybis (2-phenyl-4H, 3,1-benzoxazine-4-one), 6,6'-sulfonylbis Benzooxazin-4-one), 6,6'-sulfonylbis (2-phenyl-4H, (2-phenyl-4H, 3,1-benzoxazine-4-one), 7,7 ' -Methylenebis (2-phenyl-4H, 3, 1-benzoxazine-4-one), methylenebis 7,7'-bis (2-methyl-4H, 3,1-benzoxazine-4-one) Benzooxazin-4-one), 7,7'-oxybis (2-methyl-4H, (2-methyl-4H, 3,1-benzoxazine-4-one), 6,7'-bis (2-phenyl-4H, 3,1-benzoxazine-4-one), 6,7'-methylenebis 4H, 3,1-benzoxazine-4-one) and 6,7'-methylenebis (2-phenyl- It can be used as an ultraviolet blocking material

In addition, the ultraviolet barrier layer (UVL) may have a thickness of 0.5 to 16 占 퐉, preferably 4 to 12 占 퐉, and most preferably 8 to 10 占 퐉. When the thickness of the ultraviolet blocking layer (UVL) is less than the above range, the effect of blocking ultraviolet rays is insignificant. If the thickness is more than the above range, the organic solar cell 100 may be thickened,

The ultraviolet barrier layer (UVL) according to the present invention is a coating layer formed by a solution process such as a coating process such as a slot die coating method. The ultraviolet barrier layer (UVL) Can be made wide. In addition, not only the electrode but also the substrate 10, the electron transport layer 30, the photoactive layer 40, and the hole transport layer 50 can be broadly selected. In addition, since a solution process is possible, an ultraviolet ray shielding effect can be obtained through an additional coating. Further, since the electrode layer is formed on the ultraviolet blocking layer thus formed, any material can be applied as long as it is an electrode layer material that does not cause chemical damage to the ultraviolet blocking layer.

In the present invention, the substrate 10 can be used in the present invention. As such a substrate, an inorganic base film such as glass or quartz can be used. (PET), polyethylene naphthalate (PEN), polypropylene (PP), polyimide (PI), polycarbonate (PC), polystyrene (PS), polyoxymethylene (POM) (PE), acrylonitrile styrene (AS), acrylonitrile butadiene styrene (ABS), and triacetyl cellulose (PES), polyether ether ketone (TAC) resin, and the like may be used.

In particular, it may be desirable to use the substrate 10 that is flexible and has high chemical stability, mechanical strength, and transparency. More specifically, the substrate preferably has a transmittance of at least 80% or more at a visible light wavelength of 400 to 750 nm.

The thickness of the substrate 10 is not particularly limited and may be suitably determined according to the intended use, for example, it may be 1 to 500 탆.

In the present invention, the lower electrode 20 may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), indium tin oxide Tin Zinc Oxide (ITZO), Ga-doped Zinc Oxide (GZO), Al-doped Zinc Oxide (AZO), F-doped Tin Oxide In the group consisting of Zinc Tin Oxide (ZTO), Indium Gallium Oxide (IGO), ZnO-Ga ₂ O ₃ , ZnO-Al ₂ O ₃ , SnO ₂ -Sb ₂ O ₃ , A metal oxide transparent electrode to be selected; AgNW (silver nanowire) transparent electrode; A conductive transparent electrode such as a conductive polymer thin film, a graphene thin film, a graphene oxide thin film, or a carbon nanotube thin film; Or an organic-inorganic bonding transparent electrode such as a carbon nanotube thin film to which a metal is bonded. Here, the AgNW transparent electrode is not limited to a material such as AgNW, which can be subjected to a solution process. The shape of the lower electrode 20 may be a metal mesh or a grid and may be formed by plating, printing, or coating using a metal such as Ag, Cu, Al, or Au.

The thickness of the lower electrode 20 may be 10 to 3000 nm.

In the present invention, the electron transport layer 30 is positioned on the lower electrode 20 and enhances the efficiency of the organic solar cell by enhancing the transportability of electrons. In addition, it is possible to prevent oxygen and moisture introduced from the outside from affecting the photoactive layer 40.

The electron transport layer 30 may be formed of a metal oxide and an organic material, and the metal oxide may be at least one selected from the group consisting of Ti, Zn, Si, Mn, Sr, (B), potassium (K), niobium (Nb), iron (Fe), tantalum (Ta), tungsten (W), bismuth (Bi), nickel (Ni), copper (Cu), molybdenum , At least one metal oxide selected from the group consisting of cerium (Ce), platinum (Pt), silver (Ag) and rhodium (Rh). Specifically, the metal oxide thin film layer may be formed of zinc oxide (ZnO) having a wide band gap and a semiconductor property, and the organic material may be polyethyleneimine (PEI), ethoxylated-polyethylenimine (PEIE), or the like.

The average particle diameter of the metal oxide contained in the electron transport layer 30 is 10 nm or less, specifically 1 to 8 nm, and more specifically, 3 to 7 nm.

The electron transport layer 30 may be formed through a coating process, and the coating process may be performed by a method such as a slot die coating, a spin coating method, a spray coating method, a screen printing method, a bar coating method, a doctor blade coating method, However, the method can be used without limitation as long as it can coat the metal oxide. In particular, it may be advantageous for the electron transport layer 30 to use a slot die coating.

The electron transporting layer 30 may have a thickness of 1 to 100 nm, and when the thickness is outside the range of the thickness defined above, the electron transporting ability may be deteriorated.

In the present invention, the photoactive layer (40) is located on the electron transport layer (30) and has a bulk heterojunction structure in which a hole receptor and an electron acceptor are mixed.

The hole acceptor includes an organic semiconductor such as an electrically conductive polymer or an organic low-molecular semiconductor material. The electrically conductive polymer may be at least one member selected from the group consisting of polythiophene, polyphenylenevinylene, polyfulorene, polypyrrole, and copolymers thereof. The organic low-molecular semiconductor material may include one or more selected from the group consisting of pentacene, anthracene, tetracene, perylene, oligothiophene, and derivatives thereof. can do.

Specifically, the hole acceptor may be a poly-3-hexylthiophene (P3HT), a poly-3-octylthiophene (P3OT), a poly- polyvinylidene fluoride (PPV), poly (9,9'-dioctylfluorene), poly (2-methoxy-5- (2-ethyl-hexyloxy) , 2-methoxy-5- (2-ethyl-hexyloxy) -1,4-phenylenevinylene (MEH-PPV) -Dimethyloctyloxy)) - 1,4-phenylene vinylene (MDMOPPV), which is a compound selected from the group consisting of poly (2-methyl-5- And may include one or more species.

The electron acceptor may include at least one selected from the group consisting of fullerene (C60), fullerene derivatives such as C70, C76, C78, C80, C82 and C84, CdS, CdSe, CdTe and ZnSe.

Specifically, the electron acceptor is (6,6) -phenyl-C61-butyric acid methyl ester ((6,6) -phenyl-C61-butyric acid methyl ester; PCBM) Butyric acid methyl ester ((6,6) -thienyl (C7-PCBM), (6,6) -thienyl-C61- -C6-butyric acid methyl ester (ThCBM), and carbon nanotubes.

More preferably, the photoactive layer 40 comprises a mixture of P3HT and PCBM as a hole acceptor, wherein the mixing weight ratio of P3HT and PCBM may be 1: 0.1 to 1: 2.

The thickness of the photoactive layer 40 may be 10 to 1000 nm, specifically 100 to 500 nm. When the thickness of the photoactive layer 40 is less than the above range, it is impossible to sufficiently absorb the sunlight, and the photocurrent is lowered and the efficiency is expected to decrease. Conversely, when the thickness exceeds the above range, excited electrons and holes can not move to the electrode, Problems can arise.

In the present invention, the hole transport layer 50 may be formed on the photoactive layer 30 and may extend over the entire surface of the photoactive layer 30.

The hole transport layer 50 allows the holes generated in the photoactive layer 30 to be more smoothly transferred to the upper electrode 60 to be described later and prevents the penetration of impurities and metal ions from the anode 50 So that the photoactive layer 30 can be protected.

The hole transport layer 50 may have a light transmittance of 70 to 90% considering the efficiency of the cell.

The hole transport layer 50 may be formed of at least one selected from the group consisting of poly (3,4-ethylenedioxythiophene; PEDOT), poly (styrene sulfonate) (PSS), polyaniline, phthalocyanine, (T-butyl) diphenylacetylene, poly (trifluoromethyl) diphenylacetylene, copper phthalocyanine (Cu-PC) poly (bistrifluoromethyl) acetylene, polybis (T-butyldiphenyl) acetylene, poly (trimethylsilyl) diphenylacetylene, poly (carbazole) diphenylacetylene, polydiacetylene, polyphenylacetylene, polypyridine acetylene, polymethoxyphenylacetylene, polymethylphenylacetylene, Butyl) phenylacetylene, polynitrophenylacetylene, poly (trifluoromethyl) phenylacetylene, and poly (trimethylsilyl) phenylacetylene. Specifically, the first hole transport 51 may comprise a mixture of poly (3,4-ethylenedioxythiophene) and poly (styrene sulfonate).

The thickness of the hole transporting layer 50 may be 0.1 to 10 nm, specifically 500 to 1000 nm. When the thickness of the hole transporting layer 50 is less than the above range, the hole transporting property improving effect can not be obtained. On the contrary, when the thickness of the hole transporting layer 50 is more than the above range, the transmittance of the organic solar battery may be lowered.

In the present invention, the upper electrode 60 is located on the above-described positive hole transport layer 50, that is, on the first positive hole transport layer 1 and the second positive hole transport layer 52, (52) region of the first hole transport layer (1) and the region of the second hole transport layer (52) of the first hole transport layer (1) on which no pattern is formed.

The upper electrode 60 includes a common metal having a low work function and is made of a metal such as silver (Ag), copper (Cu), gold (Au), platinum (Pt), titanium (Ti) Metal particles such as nickel (Ni), zirconium (Zr), iron (Fe), and manganese (Mn); Or, for the precursor, for containing the metal elements of silver nitrate _{(AgNO 3), Cu (HAFC} ) 2 (Cu (hexafluoroacetylacetonate) 2), Cu (HAFC) (1,5-Cyclooctanediene), Cu (HAFC) (1, 5-Dimethylcyclooctanediene), Cu (HAFC ) (4-Methyl-1-pentene), Cu (HAFC) (Vinylcyclohexane), Cu (HAFC) (DMB), Cu (TMHD) 2 (Cu (tetramethylheptanedionate) 2), DMAH ( dimethylaluminum hydride), TMEDA (tetramethylethylenediamine) , DMEAA (dimethylethylamine alane, NMe 2 Et · AlH 3), TMA (trimethylaluminum), TEA (triethylaluminum), TBA (triisobutylaluminum), TDMAT (tetra (dimethylamino) titanium), TDEAT (tetra ( dimethylamino) titanium, and the like.

The transmittance of the upper electrode 60 may be 50 to 90% considering the efficiency of the battery.

The thickness of the upper electrode 60 may be 0.01 to 20 占 퐉.

Manufacturing method of organic solar cell

The present invention also relates to a substrate, as described above, comprising: a substrate; A lower electrode; An electron transport layer; A photoactive layer; A hole transport layer; And an upper electrode; The present invention relates to a method of manufacturing an organic solar cell comprising sequentially forming an ultraviolet blocking layer between the substrate and a lower electrode.

2 is a schematic view illustrating a process of manufacturing an organic solar cell according to an embodiment of the present invention.

Referring to FIG. 2, the manufacturing method of the organic solar cell may include the following steps (S1) to (S6):

(S1) forming an ultraviolet barrier layer on the substrate;

(S2) forming a lower electrode on the ultraviolet blocking layer;

(S3) forming an electron transport layer (ETL) on the lower electrode;

(S4) forming a photoactive layer on the electron transporting layer;

(S5) forming a hole transport layer on the photoactive layer; And

(S6) forming an upper electrode on the hole transport layer.

At this time, all of the steps (S1) to (S6) may be performed by a solution process such as a coating process. Hereinafter, the present invention will be described in more detail.

(S1)

(S1), an ultraviolet blocking layer may be formed on the substrate.

Specifically, the coating liquid for forming an ultraviolet blocking layer may be coated on the substrate by a slot die coating method.

At this time, the coating solution for forming an ultraviolet barrier layer may be formed by dissolving an ultraviolet barrier material in a solvent, and the ultraviolet barrier material may be at least one selected from the group consisting of benzotriazole, benzophenone, cyclic imino ester, arylated cyanoacrylate and triazine And the solvent may be at least one selected from the group consisting of an alcohol-based solvent and an organic solvent. When the concentration of the coating solution is less than 1%, the content of the ultraviolet screening material is decreased, and the ultraviolet screening effect is insufficient. When the concentration of the coating solution is more than 50%, the ultraviolet screening layer The process may be difficult to proceed.

In addition, prior to the formation of the ultraviolet barrier layer, at least one selected from the group consisting of an O 2 plasma treatment method, a UV / ozone cleaning, a surface cleaning using an acid or an alkali solution, a nitrogen plasma treatment method and a corona discharge cleaning The surface of the substrate can be pretreated by the method of FIG.

(S2)

(S2), a lower electrode may be formed on the ultraviolet blocking layer.

The lower electrode may also be formed by a slot die coating, and the composition for forming the lower electrode may be formed by thermal vapor deposition, electron beam deposition, RF or magnetron sputtering, chemical vapor deposition or the like.

(S3)

In the step (S3), the electron transport layer 30 may be formed on the lower electrode 20 by using a composition for forming an electron transport layer.

The composition for forming an electron transport layer is prepared by dissolving the above-mentioned metal oxide in a solvent, and applying the composition to form a coating film.

The solvent is not particularly limited as long as it can dissolve or disperse the metal oxide. Examples of the solvent include water, 2-ethylhexanol, 2-butoxyhexanol, n-propyl alcohol, At least one selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol and dipropylene glycol can be used.

The solvent may be contained in an amount of the remainder in the composition for forming an electron transport layer, specifically, 1 to 95% by weight based on the total weight of the composition for forming an electron transport layer. When the content of the solvent exceeds 95 wt%, it is difficult to obtain the function of the desired coating layer. When the content of the solvent is less than 1 wt%, it is difficult to form a thin film having a uniform thickness.

The application may be performed by slot die coating.

After the coating film is formed by the composition for forming an electron transport layer, a post-treatment process of drying or heat-treating the coated substrate may be selectively performed. The drying may be performed by hot air drying, NIR drying, or UV drying at 50 to 400 ° C, specifically, at 70 to 200 ° C for 1 to 30 minutes.

(S4)

(S4), a photoactive layer may be formed on the electron transporting layer using a composition for forming a photoactive layer.

The composition for forming a photoactive layer is prepared by dissolving the above-described hole receptor and electron acceptor in a solvent, and applying the composition to form a coating film.

The solvent can be used without particular limitation, as long as it can dissolve or disperse the electron acceptor and the hole acceptor. In one example, the solvent is water; Alcohols such as ethanol, methanol, propanol, isopropyl alcohol and butanol; Or an organic solvent such as acetone, pentane, toluene, benzene, diethyl ether, methyl butyl ether, N-methylpyrrolidone, tetrahydrofuran, dimethylformamide, dimethylacetamide, dimethylsulfoxide, carbon tetrachloride, dichloromethane, Organic solvents such as trichlorethylene, chloroform, chlorobenzene, dichlorobenzene, trichlorobenzene, cyclohexane, cyclopentanone, cyclohexanone, dioxane, terpineol and methyletherketone, or mixtures thereof, It is preferable that the electron transport layer is appropriately selected from the above-mentioned solvents depending on the kind of the target material when the composition for forming an electron transport layer is prepared.

The application may be performed by slot die coating.

After the coating layer is formed with the composition for forming a photoactive layer, a post-treatment process of drying or heat-treating the coated substrate may be selectively performed. The drying may be performed by hot air drying, NIR drying, or UV drying at 50 to 400 ° C, specifically, at 70 to 200 ° C for 1 to 30 minutes.

For example, in the case of a photoactive layer, post-treatment may be performed after drying and heat treatment at 25 to 150 ° C for 5 to 145 minutes after the coating process. By appropriately controlling the drying step and the heat treatment step, appropriate phase separation can be induced between the electron acceptor and the hole acceptor, and the orientation of the electron acceptor can be induced. If the temperature is less than 25 ° C, the mobility of the electron acceptor and the hole acceptor may be low and the heat treatment effect may be insignificant. If the annealing temperature exceeds 150 ° C, Can be degraded. If the heat treatment time is less than 5 minutes, the mobility of the electron acceptor and the hole acceptor may be low and the heat treatment effect may be insufficient. If the heat treatment time exceeds 145 minutes, the performance deteriorates due to deterioration of the electron acceptor .

(S5)

(S5), a hole transporting layer may be formed on the photoactive layer using a composition for forming a hole transporting layer.

The composition for forming a hole transport layer may be a paste including a hole transport material and a solvent.

The hole transporting material may be one selected from the group consisting of poly (3,4-ethylenedioxythiophene) (PEDOT) and poly (styrene sulfonate) (PSS) And at least one selected from the group consisting of these.

The solvent contained in the composition for forming a hole transport layer is not particularly limited as long as it is used for uniformly mixing the hole transport material and controlling the viscosity and is generally used in the art. Specific examples of the solvent include alcohols. Examples of the solvent include alcohols such as 2-ethylhexanol, 2-butoxyhexanol, n-propyl alcohol, isopropyl alcohol, ethylene glycol, diethylene glycol, triethylene Glycols, tetraethylene glycol, propylene glycol, and dipropylene glycol.

(S6)

(S6), an upper electrode may be formed on the hole transport layer.

The upper electrode may be formed by a method such as screen printing, gravure printing, gravure-offset printing, thermal vapor deposition, electron beam deposition, RF or magnetron sputtering, chemical vapor deposition .

In the present invention, at the time of forming each layer on the substrate, the speed at which the substrate is transported by the roll-to-roll method may be 0.01 m / min to 20 m / min, specifically 0.1 m / min to 5 m / min Lt; / RTI > The conveying speed can be optimally used according to the coating and drying speed of the individual layers using the roll-to-roll equipment.

Hereinafter, embodiments of the present invention will be described in detail 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.

Example  And Comparative Example : Manufacture of Organic Solar Cells

[Example 1]

The PET film was transported in a roll-to-roll manner, and a coating liquid for forming an ultraviolet blocking layer was coated on the top surface of the PET film in a stripe form and then dried at 120 ° C. to form a UV blocking layer having a thickness of 10 μm. Was prepared by dissolving a benzotriazole derivative in alcohol at a concentration of 1%.

Then, an ITO layer was formed as a lower electrode and a lower electrode layer on the ultraviolet blocking layer by a slot die coating method.

A coating solution for forming an electron transport layer containing zinc oxide and polyethyleneimine at a weight ratio of 1: 0.1 was slot-coated on the ITO layer in a striped form while the substrate film having the lower electrode layer was transferred in a roll-to-roll manner, An electron transporting layer having a thickness of 30 nm was formed. The slot die coating was performed at a line speed of 5 mm / sec, a slot die height of 100 m, and a coating liquid flow rate of 0.2 ml / min.

(Manufactured by mixing 15 mg of PV-D4610 (Merck), 30 mg of PV-A700 (Merck), and xylene: 1-methylnaphthalene = 85: 15 (volume ratio)) on the electron transporting layer, Was coated on a slot die and dried at 80 DEG C to prepare a 300 nm thick photoactive layer. The slot die coating was performed at a line speed of 8 mm / sec, a slot die height of 100 m, and a coating liquid flow rate of 0.5 ml / min.

A coating solution for forming a hole transport layer (Clevios HTL Solar (Heraeus)) was coated on the photoactive layer by slot die coating and dried at 150 ° C to form a 800 nm thick hole transport layer. , A slot die height of 100 탆, a coating fluid flow rate of 1.5 ml / min, and dried at 150 캜.

Subsequently, an organic solar cell was prepared by forming a silver electrode having a thickness of 15 占 퐉 thinner on a major-transportation layer using a screen printer to form an upper electrode.

Finally, the organic solar cell having the entire constituent layer formed thereon is cut into a unit module having a size of 10 x 10 cm, and then double-side-coated with a barrier film to produce a final organic solar cell.

[Comparative Example 1]

Except that a UV-blocking film (3M) in the form of a film was attached to the incident surface of the barrier film without forming an ultraviolet blocking layer to prepare an organic solar cell.

Experimental Example : Life Evaluation of Organic Solar Cells

Since the organic solar cell must always receive the sunlight, it is required to minimize the deterioration of performance through ultraviolet rays or heat generation in the sunlight to prolong the life of the battery. There is a problem that when the battery is irradiated with sunlight, the organic material is decomposed by the sunlight and the lifetime of the battery is lowered.

Accordingly, in order to evaluate the lifetime of the organic solar cell of the present invention, the power conversion efficiency (PCE) performance over time was evaluated by irradiating sunlight to the organic solar cell manufactured in each of Example 1 and Comparative Example 1 .

The evaluation is performed by setting the initial power conversion efficiency E0 to (E1 / E0) * 100 when the efficiency after elapsing time is E1, and it is preferable that the initial power conversion efficiency is maintained for a long time.

As a result, in the case of Example 1, the initial power conversion efficiency of the organic solar battery was maintained for 1000 hours or more, but in the case of Comparative Example 1, the initial power conversion efficiency sharply decreased over 700 hours.

The results are similar to those of Example 1 except that the position of the ultraviolet blocking layer of the organic solar cell of Example 1, that is, the front side of the substrate facing the lower electrode, Which is a coating layer formed by a non-solution process (FIG. 2).

100: Organic solar cell
10: substrate
20: Lower electrode (cathode)
UVL: UV protection layer
30: electron transport layer
40: photoactive layer
50: hole transport layer
60: upper electrode (anode)

Claims (10)

Board; A lower electrode; An electron transport layer; A photoactive layer; A hole transport layer; And an upper electrode are sequentially stacked,
And an ultraviolet blocking layer between the substrate and the lower electrode. The method according to claim 1,
Wherein the ultraviolet blocking layer comprises at least one ultraviolet blocking material selected from the group consisting of benzotriazole, benzophenone, cyclic imino ester, arylated cyanoacrylate, and triazine. The method according to claim 1,
Wherein the ultraviolet blocking layer has a thickness of 0.5 to 16 占 퐉. The method according to claim 1,
The lower electrode may be formed of indium tin oxide (ITO); OMO (Oxide-Metal-Oxide); Ag nanowires; PEDOT: PSS [{poly (3,4-ethylenedioxythiophene)}: (polystyrene sulfonate)]; And a complex of Ag nanowire and PEDOT: PSS. The method according to claim 1,
The upper electrode may be formed of Ag paste, Ag nanowire, PEDOT: {poly (3,4-ethylenedioxythiophene)} (polystyrene sulfonate)]; And a complex of Ag nanowire and PEDOT: PSS. Board; A lower electrode; An electron transport layer; A photoactive layer; A hole transport layer; And an upper electrode; A method of manufacturing an organic solar cell sequentially stacked,
And forming an ultraviolet blocking layer between the substrate and the lower electrode. The method according to claim 6,
Wherein the ultraviolet blocking layer is formed using a slot die coating method. The method according to claim 6,
The coating liquid for forming an ultraviolet blocking layer
At least one ultraviolet blocking material selected from the group consisting of benzotriazole, benzophenone, cyclic imino ester, arylated cyanoacrylate, and triazine; And
And at least one solvent selected from the group consisting of alcohol solvents and organic solvents. The method according to claim 6,
Wherein the concentration of the coating liquid for forming an ultraviolet blocking layer is 1 to 50%. The method according to claim 6,
An ultraviolet blocking layer on the substrate; A lower electrode; An electron transport layer; A photoactive layer; Wherein the upper electrode and the upper electrode are formed by a slot die coating method and the upper electrode is formed by a screen printing method.

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