WO2014193131A1

WO2014193131A1 - Laminated organic solar cell

Info

Publication number: WO2014193131A1
Application number: PCT/KR2014/004676
Authority: WO
Inventors: 장송림; 배재순; 이재철; 이지영; 이행근; 김진석; 조근; 최정민
Original assignee: 주식회사 엘지화학
Priority date: 2013-05-27
Filing date: 2014-05-26
Publication date: 2014-12-04
Also published as: KR20140139436A

Abstract

One embodiment of the present invention provides a laminated organic solar cell, comprising: at least two or more single layer organic solar cells including one or more kinds of organic layers including a first electrode, a second electrode formed to face the first electrode, and a photoactive layer formed between the first electrode and the second electrode; and adhesive layers respectively formed between the two single neighboring organic solar cells, wherein the first and the second electrode are transparent electrodes which have a light transmittance of 20%-100% inclusive in a light wavelength of 450nm.

Description

Laminated organic solar cell

This specification describes Korean Patent Application No. 10-2013-0059722 filed with the Korean Patent Office on May 27, 2013, and Korean Patent Application No. 10-2013-0059727 filed with the Korean Patent Office on May 27, 2013. Claim the benefit of the filing date, the entire contents of which are incorporated herein.

The present specification provides a laminated organic solar cell.

Currently used energy sources are oil, coal and gas. This represents 80% of the total energy source used. However, the current depletion of petroleum and coal energy is becoming a serious problem, and the increasing emissions of carbon dioxide and other greenhouse gases into the air are causing serious problems. In contrast, the use of renewable energy, pollution-free green energy, is still only about 2% of the total energy source. Therefore, the worries for solving the problem of the energy source is accelerating the research on new and renewable energy development. Among renewable energy such as wind, water and sun, the most attention is solar energy. Solar cells using solar energy are expected to be an energy source that can solve future energy problems due to low pollution, infinite resources and a semi-permanent lifetime.

Solar cells are devices that can directly convert solar energy into electrical energy by applying the photovoltaic effect. Solar cells can be divided into inorganic solar cells and organic solar cells according to the material constituting the thin film. Typical solar cells are made of p-n junctions by doping crystalline silicon (Si), an inorganic semiconductor. Electrons and holes generated by absorbing light diffuse to the p-n junction and are accelerated by the electric field to move to the electrode. The power conversion efficiency of this process is defined as the ratio of the power given to the external circuits and the solar power entered into the solar cell, and has been achieved by up to 24% when measured under current standardized virtual solar irradiation conditions. However, since the conventional inorganic solar cell has already shown a limit in the economic and material supply and demand, organic solar cells with easy processing, low cost and various functionalities are spotlighted as long-term alternative energy sources.

Early organic solar cells led the technology development at the Heeger professor group of UCSB. The organic solar cell has the advantage that the monomolecular organic material or the polymer material used is easy, fast and inexpensive and large area process is possible.

However, in the present research, the organic solar cell has a disadvantage of low energy conversion efficiency. Therefore, efficiency improvement is very important to secure competitiveness with other solar cells at this time.

[Preceding technical literature]

(Non-Patent Document 1) Two-layer organic photovoltaic cell (C.W.Tang, Appl. Phys. Lett., 48, 183. (1996))

(Non-Patent Document 2) Efficiencies via Network of Internal Donor-Acceptor Heterojunctions (G. Yu, J. Gao, J. C. Hummelen, F. Wudl, A. J. Heeger, Science, 270, 1789. (1995))

The present specification is to provide a laminated organic solar cell.

An exemplary embodiment of the present specification includes a first electrode; A second electrode provided to face the first electrode; And at least two single-layered organic solar cells including at least one organic material layer including a photoactive layer provided between the first electrode and the second electrode, each provided between two adjacent single-layered organic solar cells. And a bonding layer, wherein the first electrode and the second electrode provide a laminated organic solar cell having a light transmittance of 20% or more and 100% or less in light having a wavelength of 450 nm.

In the laminated organic solar cell of the present specification, when absorbing light in one direction, the bonding layer positioned between each single-layer organic solar cell is transparent to achieve a high light absorption rate compared to the organic solar cell having only one single-layer organic solar cell. In this way, high efficiency can be achieved.

In addition, the laminated organic solar cell of the present specification may absorb light in both directions, and may achieve high efficiency as compared with a single layer organic solar cell in the case of absorbing light in one direction only.

In addition, the laminated organic solar cell of the present specification may have a wound structure, and in the case of a cylindrical shape, may efficiently absorb light in various directions to increase efficiency.

1 to 5 illustrate a laminated organic solar cell according to one embodiment of the present specification.

6 shows graphs of current density-voltage (J-V) characteristics of organic solar cells according to Example 1, Comparative Example 1, and Comparative Example 2. FIG.

7 is a graph showing physical properties of the photoactive materials included in the photoactive layers in Comparative Examples 3 to 5. FIG. Specifically, Figure 7 is a graph measuring the absorbance of the photoactive material contained in the photoactive layer in Comparative Examples 3 to 5.

In this specification, when a member is located "on" another member, this includes not only when a member is in contact with another member but also when another member exists between the two members.

In the present specification, when a part "contains" a certain component, this means that the component may further include other components, except for the case where there is no contrary description.

Hereinafter, this specification is demonstrated in detail.

An exemplary embodiment of the present specification includes a first electrode; A second electrode provided to face the first electrode; And at least two single-layer organic solar cells including at least one organic material layer including a photoactive layer provided between the first electrode and the second electrode.

It includes a bonding layer provided between each of the two adjacent single-layer organic solar cells,

The first electrode and the second electrode provides a laminated organic solar cell having a light transmittance of 20% or more and 100% or less in light having a wavelength of 450 nm.

Specifically, according to one embodiment of the present specification, the first electrode and the second electrode may be a transparent electrode having a light transmittance of 40% or more and 90% or less in light having a wavelength of 450 nm.

An example of the multilayer organic solar cell of the present specification is illustrated in FIGS. 1 and 2. Specifically, FIG. 1 illustrates a stacked organic solar cell having a bonding layer between two single layer organic solar cells. FIG. 2 illustrates a stacked organic solar cell including three single layer organic solar cells and having a bonding layer between each single layer organic solar cell. The stacked organic solar cell according to the exemplary embodiment of the present specification is not limited to the structure of FIGS. 1 and 2 and may include a plurality of single layer organic solar cells.

The single layer organic solar cell of the present specification may operate as an individual organic solar cell even with one single layer organic solar cell. Therefore, the single layer organic solar cell may include a first electrode, a second electrode, and a photoactive layer, respectively, and may further include one or more organic material layers.

According to an exemplary embodiment of the present specification, the multilayer organic solar cell may include two to ten single layer organic solar cells. Specifically, two to five single layer organic solar cells may be included. As the number of single-layer organic solar cells increases, the single-layer organic solar cells on the opposite side of the light receiving surface may have no light to absorb and thus may not contribute to the increase in efficiency. Therefore, the multilayer organic solar cell may be manufactured by controlling the number of single-layer organic solar cells in consideration of manufacturing cost and light absorption rate.

When the laminated organic solar cell according to an exemplary embodiment of the present specification absorbs light in both directions, the laminated organic solar cell may absorb light from both sides, so that light absorption efficiency may increase. Furthermore, when the laminated organic solar cell absorbs light on both sides, the single layer organic solar cell on the other side absorbs excess light that is not absorbed by the single layer organic solar cell on the light receiving side as in the case of receiving light on one side. It is also possible to increase the light absorption rate. As an example of the case where the laminated organic solar cell receives light from both sides, the laminated organic solar cell may be disposed in a direction of reducing the incident angle of light without absorbing the stacked organic solar cell perpendicular to the light to absorb the light on both sides. In this case, since many solar cells can be arrange | positioned in the same area, high current value can be obtained. In addition, when the laminated organic solar cell is disposed perpendicular to the ground, even if the south mid-high altitude of the sun in the place where the laminated organic solar cell is changed, the sunlight can be absorbed on both sides, so the sunlight during the time the sun is floating It is possible to increase the light absorption by having a portion having a high incident angle of.

According to an exemplary embodiment of the present specification, the first electrode and the second electrode may each independently be a transparent conductive oxide layer or a metal electrode having a thickness of 20 nm or less.

According to an exemplary embodiment of the present specification, the metal electrode may be 10 nm or less.

According to one embodiment of the present specification, the metal electrode may include a metal such as 20 nm or less of transparent Ag, Al, Au, or a mixture of the metals. Furthermore, according to one embodiment of the present specification, when the metal electrode has a thickness of 20 nm or less, light may transmit 30% to 100%.

According to an exemplary embodiment of the present specification, the transparent conductive oxide layer is in addition to glass and quartz plate, polyethylene terephthalate (PET), polyethylene naphthelate (PEN), polyperopylene (PP), polyimide (PI), polycarbornate (PC), polystyrene (PS) ), Conductive materials on flexible and transparent materials such as POM (polyoxyethlene), AS resin (acrylonitrile styrene copolymer), ABS resin (acrylonitrile butadiene styrene copolymer) and plastics including TAC (Triacetyl cellulose), PAR (polyarylate), etc. This doped one can be used. Specifically, indium tin oxide (ITO), fluorine doped tin oxide (FTO), aluminum doped zink oxide (AZO), indium zink oxide (IZO), ZnO-Ga ₂ O ₃ , ZnO-Al ₂ O ₃ and antimony tin oxide (ATO), and the like, and more specifically ITO.

According to the exemplary embodiment of the present specification, the forming of the first electrode or the second electrode using the transparent conductive oxide layer may sequentially wash the patterned ITO substrate with a detergent, acetone, and isopropanol (IPA), and then remove moisture. For 1 to 30 minutes at 100 ℃ to 250 ℃, specifically for 10 minutes at 250 ℃ in a heating plate, and when the substrate is completely cleaned, the surface of the substrate can be modified to hydrophilic. Pretreatment techniques for this are a) surface oxidation using parallel planar discharge, b) oxidation of the surface through ozone generated using UV ultraviolet light in a vacuum state, and c) oxygen radicals generated by plasma. To oxidize. Through the surface modification as described above, the bonding surface potential can be maintained at a level suitable for the surface potential of the hole injection layer, the formation of the polymer thin film on the ITO substrate can be facilitated, and the quality of the thin film can be improved. One of the above methods is selected according to the state of the substrate. In any of these methods, the effective effect of pretreatment can be expected by preventing oxygen escape from the surface of the substrate and restraining the remaining of moisture and organic matter as much as possible.

In the examples described below, a method of oxidizing a surface through ozone generated by using UV was used, and after ultrasonic cleaning, the patterned ITO substrate was baked on a hot plate, dried well, and then placed in a chamber. Injecting and operating a UV lamp cleans the ITO substrate patterned by ozone generated by oxygen gas reacting with UV light. However, the surface modification method of the patterned ITO substrate in this invention does not need to specifically limit, Any method may be used as long as it is a method of oxidizing a substrate.

The multilayer organic solar cell of the present specification may be formed by bonding the two or more single layer organic solar cells using a bonding layer. The laminated organic solar cell may absorb light in one direction or absorb light in both directions.

When the laminated organic solar cell of the present specification absorbs light in one direction, the bonding layer between two single-layer organic solar cells may be a transparent bonding layer. The transparent bonding layer can absorb light per unit area over two or more single layer organic solar cells. That is, both the upper single layer organic solar cell and the lower single layer organic solar cell in contact with light may absorb light to achieve high light absorption in the same area. The stacked organic solar cell according to the exemplary embodiment of the present specification may increase efficiency by improving a current value due to a high light absorption rate per unit area.

According to an exemplary embodiment of the present specification, the bonding layer is glass; Transparent adhesive; And it may be selected from the group consisting of a transparent insulator.

Transparency in this specification may mean that light may be passed through. Specifically, it may mean that the light can transmit 50% to 100%. More specifically, it may mean that can pass 70% to 100% light.

According to one embodiment of the present specification, the transparent bonding member and / or the transparent insulator may be a solid or liquid adhesive; Transparent double-sided tape; And transparent sealant materials.

Specifically, the solid or liquid conjugate is a transparent acrylic adhesive; Transparent epoxy adhesives; Transparent PVC adhesive, or the like. However, the present invention is not limited thereto. In addition, the transparent double-sided tape may be a general transparent double-sided tape, including a transparent PVC-based double-sided insulating tape. The transparent sealant of the present specification may be a surlyn film, a bynel film, or the like, but is not limited thereto.

According to one embodiment of the present specification, at least one of the two surfaces facing the single layer organic solar cell of the junction layer may have a bonding area of 10% or more and 80% or less for the single layer organic solar cell. Specifically, according to one embodiment of the present specification, at least one of two surfaces facing the single layer organic solar cell of the junction layer has a bonding area of 10% or more and 50% or less, or 10% for the single layer organic solar cell. Or more than 40%.

The bonding area may mean an area of a region in which two single-layer organic solar cells are bonded by glass, a transparent adhesive, a transparent insulator, or the like. In addition, the region except for the bonding area of the bonding layer is a region that is not provided with a separate material, which has an advantage that there is no loss of light wavelength, thereby increasing the light absorption of the single layer organic solar cell of the lower layer. have.

According to an exemplary embodiment of the present specification, the shape of the bonding surface of the bonding layer is a shape including only the border region of the bonding layer; Or a mesh shape.

The shape including only the edge region of the bonding layer may mean that the bonding surface is not formed in the center region of the bonding layer. Specifically, the shape including only the edge region of the bonding layer may mean that the area of the center portion where the bonding surface is not formed is 20% or more, 40% or more, or 60% or more with respect to the total area of the bonding layer. .

According to one embodiment of the present specification, when the shape of the bonding layer bonding surface is a shape including only an edge region of the bonding layer, the bonding layer may be transparent or opaque.

According to one embodiment of the present specification, the bonding layer may include a bonding surface including a region except for a region corresponding to the photoactive layer. Alternatively, according to one embodiment of the present specification, the bonding layer may partially overlap the region corresponding to the photoactive layer to form a bonding surface.

According to an exemplary embodiment of the present specification, the shape including only the border region of the bonding surface may mean that the bonding surface is formed in the border region except for the region corresponding to the photoactive layer.

The mesh shape may include a pattern of closed figures of triangles, squares, hexagons, or polygons.

According to the exemplary embodiment of the present specification, each of the single layer organic solar cells may further include a transparent substrate, and the first electrode may be provided on the transparent substrate.

According to one embodiment of the present specification, at least one of the bonding layers may be provided on a bottom surface of the transparent substrate.

According to one embodiment of the present specification, at least one of the bonding layers may be provided between the transparent substrates of the two single layer organic solar cells adjacent to each other.

According to an exemplary embodiment of the present specification, the transparent substrate is larger than the area of the photoactive layer provided on the transparent substrate, the bonding layer may be formed on the junction region of the substrate except for the region corresponding to the photoactive layer. have.

According to the exemplary embodiment of the present specification, in the multilayer organic solar cell, an electrode adjacent to an upper surface or a lower surface of the bonding layer may be a metal electrode.

The adjacent electrode of the present specification may mean an electrode close to a bonding layer among the first electrode or the second electrode of the single layer organic solar cell. Specifically, the adjacent electrode and the bonding layer may be directly connected, and an additional layer may be located between the adjacent electrode and the bonding layer. In addition, according to one embodiment of the present specification, the multilayer organic solar cell may further include a transparent substrate between the metal electrode and the bonding layer.

The laminated organic solar cell of the present specification includes a bonding layer between two single-layer organic solar cells, and the metal electrode of the single-layer organic solar cell may contact the bonding layer. Specifically, the transparent metal electrode of the single layer organic solar cell may contact the bonding layer. When the stacked organic solar cell absorbs light in one direction, the metal electrode of the upper single layer organic solar cell that receives light may be a transparent metal electrode having a thickness of 20 nm or less. The transparent metal electrode may absorb excess light remaining in the upper single layer organic solar cell and pass the remaining light downward. Through this, it is possible to efficiently absorb the light of the unit area.

Furthermore, when the single layer organic solar cell of the present specification includes a metal electrode, the metal electrode may be located on a substrate. The substrate may be a transparent substrate. When the single layer organic solar cell includes a substrate, the organic solar cell may be formed by contacting the substrate of the single layer organic solar cell.

According to an exemplary embodiment of the present specification, the first electrode may be a cathode.

According to an exemplary embodiment of the present specification, the second electrode may be an anode.

According to an exemplary embodiment of the present specification, the bonding layer may be adjacent to the anode of each single layer organic solar cell. Alternatively, according to one embodiment of the present specification, the bonding layer may be adjacent to the cathode of each single layer organic solar cell. Alternatively, according to one embodiment of the present specification, the anode of one single layer organic solar cell may be adjacent to the cathode of the other single layer organic solar cell.

The adjoining may mean contacting the bonding layer and the electrode of the anode or cathode. Alternatively, the adjacent may mean a positional relationship with the electrode close to the bonding layer. Specifically, the adjacent may mean a positional relationship with an electrode closer to the bonding layer among the anode or the cathode of the single layer organic solar cell.

According to one embodiment of the present specification, at least one of the single layer organic solar cells further includes a transparent substrate, a first electrode is provided on the transparent substrate, the first electrode is a cathode, and the second electrode is It may be an inverted structure that is an anode.

According to the exemplary embodiment of the present specification, when any one of the single layer organic solar cells has an inverted structure, a bonding layer is provided on a lower surface of the substrate of the single layer organic solar cell of the inverted structure, and the light incident surface is It may be a surface provided with the anode of the single layer organic solar cell of the inverted structure.

According to the exemplary embodiment of the present specification, an electrode adjacent to the upper or lower surface of the bonding layer may be a metal electrode having a thickness of 20 nm or less.

According to an exemplary embodiment of the present specification, a photochemical upconversion layer may be further included between at least one pair of adjacent two single layer organic solar cells. An example of the stacked organic solar cell including the photochemical upconversion layer of the present specification is illustrated in FIG. 5. Specifically, FIG. 5 shows a photochemical upconversion layer between two single layer organic solar cells. However, the stacked organic solar cell according to the exemplary embodiment of the present specification is not limited to the structure of FIG. 5, and only one photochemical upconversion layer may be provided in the structure of FIG. 5.

The photochemical upconversion layer of the present specification may mean a layer that converts light into a wavelength that is easy to absorb light. The photochemical upconversion layer allows light to be converted into wavelengths in the region that can be better absorbed in the photoactive layer. According to an exemplary embodiment of the present specification, the upconversion layer is positioned between the two single-layer organic solar cells, the light passing through the upper single-layer organic solar cell receiving the light when absorbing light in one direction, the lower portion It is possible to increase the efficiency of the organic solar cell by converting the light of a wavelength that is easy to absorb in the single-layer organic solar cell.

According to an exemplary embodiment of the present specification, the material included in the upconversion layer is PQ ₄ Pd / Rubrene (PQ ₄ Pd / rubrene), PQ ₄ PdNA / Rubrene (PQ ₄ PdNA / rubrene), Pd (II ) octaethylporphyrin / diphenylanthracene (Pd (II) octaethylporphyrin / diphenylanthracene), [Ru (dmb) ₃ ] ²⁺ / anthracene ([Ru (dmb) ₃ ] ²⁺ / anthracene).

According to an exemplary embodiment of the present specification, the multilayer organic solar cell may further include one or more reflective layers provided to face the light receiving surface. 3 and 4 illustrate an example of a stacked organic solar cell having a reflective layer according to one embodiment of the present specification.

Specifically, FIG. 3 illustrates a case in which light absorption of the single-layer organic solar cell is increased by providing reflective layers on the upper and lower surfaces of the bonding layer, respectively, when light is received in both directions. In addition, FIG. 4 illustrates a case in which light is passed through two or more single-layer organic solar cells to receive extra light that is not absorbed by the photoactive layer and is transferred back to the photoactive layer when light is received in one direction. However, the multilayer organic solar cell according to the exemplary embodiment of the present specification is not limited to the structure of FIGS. 3 and 4, and may further include an additional configuration.

The single layer organic solar cell of the present specification includes one or more photoactive layers. The photoactive layer forms excitons in which the electron donor material pairs electrons and holes by photoexcitation, and the excitons are separated into electrons and holes at the interface of the electron donor / electron acceptor. The separated electrons and holes move to the electron donor material and the electron acceptor material, respectively, and are collected by the first electrode and the second electrode, respectively, so that they can be used as electrical energy from the outside. In the present specification, the photoactive material may mean the electron donor material and the electron acceptor material.

The single layer organic solar cell may be a bi-layer junction type or a bulk heterojunction junction type depending on the structure of the photoactive layer. The bi-layer junction type includes a photoactive layer composed of two layers, an electron acceptor layer and an electron donor layer. The bulk heterojunction (BHJ) junction type includes a photoactive layer in which an electron donor material and an electron acceptor material are blended. Specifically, in the photoactive layer of the present specification, the electron donor material and the electron acceptor material may form a bulk heterojunction (BHJ). The photoactive layer of the present specification may be annealed at 30 to 300 ° C. for 1 second to 24 hours to maximize properties after the electron donor material and the electron acceptor material are mixed.

According to the exemplary embodiment of the present specification, the photoactive layers of the two single layer organic solar cells may each independently include an electron donor material and an electron acceptor material. Furthermore, according to one embodiment of the present specification, the mass ratio of the electron donor material and the electron acceptor material may be 1:10 to 10: 1. Specifically, the mass ratio of the electron donor material and the electron acceptor material of the present specification may be 1: 0.4 to 1: 5.

According to an exemplary embodiment of the present specification, the photoactive layer is a poly 3-hexyl thiophene [P3HT: poly 3-hexyl thiophene] as an electron donor, [6,6] -phenyl-C ₆₁ -butyl acid methyl ester (PC ₆₁ BM) and / or [6,6] -phenyl-C ₇₁ -butyl acid methyl ester (PC ₇₁ BM) as the electron acceptor material. According to an exemplary embodiment of the present specification, the mass ratio of the electron donor material P3HT and the electron acceptor material (PC ₆₁ BM) and / or (PC ₇₁ BM) may be 1: 0.4 to 1: 5, specifically 1: 0.7. However, the photoactive layer is not limited to the above material.

The photoactive materials are dissolved in an organic solvent and then the solution is introduced into the photoactive layer in a thickness of 30 nm to 400 nm, specifically, 50 nm to 280 nm by spin coating or the like. In this case, the photoactive layer may be applied to a method such as dip coating, screen printing, spray coating, doctor blade, brush painting.

In addition, the electron acceptor may include other fullerene derivatives such as C70, C76, C78, C80, C82, C84, including PC ₆₁ BM, and the coated thin film may be heat-treated at 80 ° C. to 160 ° C. to determine the conductive polymer. It is good to increase the sex.

Specifically, according to one embodiment of the present specification, the single layer organic solar cell may have an inverted structure, and in this case, pre-annealing may be performed at 120 ° C.

The organic solar cell of the reverse structure of the present specification may mean that the anode and the cathode of the organic solar cell of the general structure is configured in the reverse direction. Al layer used in the organic solar cell of the general structure is very vulnerable to oxidation reaction in the air, it is difficult to ink, there is a limitation in commercializing it through the printing process. However, since the organic solar cell of the reverse structure of the present specification can use Ag instead of Al, it is more stable to the oxidation reaction than the organic solar cell of the general structure, and the production of Ag ink is easy, which is advantageous for commercialization through the printing process. There is this.

On top of the pretreated photoactive layer, a hole transport layer may be introduced through spin coating, dip coating, inkjet printing, gravure printing, spray coating, doctor blade, bar coating, gravure coating, brush painting, thermal deposition, and the like. In this case, poly (3,4-ethylenedioxythiophene): poly (4-styrenesulfonate) [PEDOT: PSS] is mainly used as a conductive polymer solution, and is used as a hole-extracting metal oxides material. Molybdenum oxide (MoO _x ), vanadium oxide (V ₂ O ₅ ), nickel oxide (NiO), tungsten oxide (WO _x ) and the like can be used. According to one embodiment of the present specification, the hole transport layer may be formed to a thickness of 5 nm to 20 nm MoO ₃ through a thermal deposition system.

According to an exemplary embodiment of the present specification, the electron donor material is at least one electron donor; Or a polymer of at least one kind of electron acceptor and at least one kind of electron donor. The electron donor may include at least one kind of electron donor. In addition, the electron donor includes a polymer of at least one kind of electron acceptor and at least one kind of electron donor.

Specifically, the electron donor material is thiophene-based, fluorene-based, carbazole-based, etc. starting with MEH-PPV (poly [2-methoxy-5- (2'-ethyl-hexyloxy) -1,4-phenylene vinylene]) It can be a variety of high molecular and monomolecular materials.

Specifically, the monomolecular substance is copper (II) phthalocyanine, zinc phthalocyanine, tris [4- (5-dicynomethylidemethyl-2-thienyl) phenyl] Amine (tris [4- (5-dicyanomethylidenemethyl-2-thienyl) phenyl] amine), 2,4-bis [4- (N, N-dibenzylamino) -2,6-dihydroxyphenyl] squalane (2,4-bis [4- (N, N-dibenzylamino) -2,6-dihydroxyphenyl] squaraine), benz [b] anthracene, and pentacene It may include one or more materials.

Specifically, the polymer material is poly 3-hexyl thiophene (P3HT: poly 3-hexyl thiophene), PCDTBT (poly [N-9'-heptadecanyl-2,7-carbazole-alt-5,5- (4'-) 7'-di-2-thienyl-2 ', 1', 3'-benzothiadiazole)]), PCPDTBT (poly [2,6- (4,4-bis- (2, ethylhexyl) -4H-cyclopenta [2, 1-b; 3,4-b '] dithiophene) -alt-4,7- (2,1,3-benxothiadiazole)]), PFO-DBT (poly [2,7- (9,9-dioctyl-fluorene) ) -alt-5,5- (4,7-di 2-thienyl-2,1,3-benzothiadiazole)]), PTB7 (Poly [[4,8-bis [(2-ethylhexyl) oxy] benzo [1 , 2-b: 4,5-b '] dithiophene-2,6-diyl] [3-fluoro-2-[(2-ethylhexyl) carbonyl] thieno [3,4-b] thiophenediyl]]), PSiF- 1 selected from the group consisting of DBT (Poly [2,7- (9,9-dioctyl-dibenzosilole) -alt-4,7-bis (thiophen-2-yl) benzo-2,1,3-thiadiazole]) It may include more than one species.

According to an exemplary embodiment of the present specification, the electron acceptor material may be a fullerene derivative or a nonfullerene derivative. Specifically, the fullerene derivative may be a C60 fullerene derivative or a C70 fullerene derivative.

According to an exemplary embodiment of the present specification, the C60 fullerene derivative or C70 fullerene derivative are each independently hydrogen; heavy hydrogen; Halogen group; Nitrile group; Nitro group; Imide group; Amide group; Hydroxyl group; Substituted or unsubstituted alkyl group; A substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted alkoxy group; Substituted or unsubstituted aryloxy group; Substituted or unsubstituted alkylthioxy group; Substituted or unsubstituted arylthioxy group; Substituted or unsubstituted alkyl sulfoxy group; Substituted or unsubstituted aryl sulfoxy group; Substituted or unsubstituted alkenyl group; Substituted or unsubstituted silyl group; Substituted or unsubstituted boron group; Substituted or unsubstituted alkylamine group; A substituted or unsubstituted aralkylamine group; Substituted or unsubstituted arylamine group; Substituted or unsubstituted heteroarylamine group; Substituted or unsubstituted aryl group; A substituted or unsubstituted fluorenyl group; Substituted or unsubstituted carbazole group; And a substituted or unsubstituted heteroring group including one or more of N, O, and S atoms, or two adjacent substituents may be further substituted with a substituent to form a condensed ring.

According to an exemplary embodiment of the present specification, the fullerene derivative may be selected from the group consisting of C76 fullerene derivative, C78 fullerene derivative, C84 fullerene derivative, and C90 fullerene derivative.

According to an exemplary embodiment of the present specification, the C76 fullerene derivative, C78 fullerene derivative, C84 fullerene derivative and C90 fullerene derivative are each independently hydrogen; heavy hydrogen; Halogen group; Nitrile group; Nitro group; Imide group; Amide group; Hydroxyl group; Substituted or unsubstituted alkyl group; A substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted alkoxy group; Substituted or unsubstituted aryloxy group; Substituted or unsubstituted alkylthioxy group; Substituted or unsubstituted arylthioxy group; Substituted or unsubstituted alkyl sulfoxy group; Substituted or unsubstituted aryl sulfoxy group; Substituted or unsubstituted alkenyl group; Substituted or unsubstituted silyl group; Substituted or unsubstituted boron group; Substituted or unsubstituted alkylamine group; A substituted or unsubstituted aralkylamine group; Substituted or unsubstituted arylamine group; Substituted or unsubstituted heteroarylamine group; Substituted or unsubstituted aryl group; A substituted or unsubstituted fluorenyl group; Substituted or unsubstituted carbazole group; And a substituted or unsubstituted heteroring group including one or more of N, O, and S atoms, or two adjacent substituents may be further substituted with a substituent to form a condensed ring.

The fullerene derivative has an ability to separate electron-hole pairs (exciton, electron-hole pair) and charge mobility compared to the non-fullerene derivative, which is advantageous for efficiency characteristics.

According to an exemplary embodiment of the present specification, the nonfullerene derivative has a LUMO energy level of -2.0 to -6.0 eV. In another exemplary embodiment, the nonfullerene derivative has a LUMO energy level of -2.5 to -5.0 eV. In another exemplary embodiment, the nonfullerene derivative has an LUMO energy level of -3.5 to -4.5 eV.

Since the LUMO energy level can easily inject electrons within the above range, there is an advantage that the efficiency of the organic solar cell is increased.

In particular, when the LUMO energy level of the non-fullerene derivative is -3.5 to -4.5 eV, charge separation is possible while maximizing the difference with the HOMO energy level of the electron donor, thereby forming a high open voltage and current density. There is an advantage to that.

According to an exemplary embodiment of the present specification, the nonfullerene derivative is a single molecule or a polymer that is not spherical.

According to one embodiment of the present specification, at least two of the single layer organic solar cells may absorb light of the same wavelength band.

According to one embodiment of the present specification, at least two of the single layer organic solar cells may absorb light of different wavelength bands.

The term “different wavelength band” in the present specification means that the wavelength ranges are different from each other, and this may mean a case in which the ranges of the minimum wavelength and the maximum wavelength are different, even though there are ranges in which wavelengths overlap each other. Or it may mean the case where neither wavelength of each wavelength band overlaps each other.

According to one embodiment of the present specification, at least two of the single layer organic solar cells may have different wavelength bands of absorbing light. When the wavelength band of light absorbed by each single layer organic solar cell is different, the amount of light absorbed in the same area may be increased, thereby increasing the efficiency of the battery.

When the laminated organic solar cell receives light to one side, the photoactive layer of the uppermost single layer organic solar cell that receives the light absorbs light in the short wavelength region, and the photoactive layer of the single layer organic solar cell becomes longer in the lower wavelength region. By absorbing light, the absorption of light in a unit area can be maximized. When the photoactive layer of the lower single layer organic solar cell absorbs the light of the long wavelength region, only the light of the short wavelength region is absorbed in the upper single layer organic solar cell, and the light of the extra long wavelength region passing through the upper single layer organic solar cell It can be absorbed efficiently in a single layer organic solar cell.

When the laminated organic solar cell receives light from both sides, the photoactive layer of the uppermost and lowermost single layer organic solar cells that receive the light absorbs light of the short wavelength region, and the photoactive layer of the single layer organic solar cell of the middle portion has a long wavelength region. The absorption of light in the unit area can be increased by absorbing light. When the photoactive layer of the single layer organic solar cell in the middle absorbs light in the long wavelength region, only the light in the short wavelength region is absorbed by the top and bottom single layer organic solar cells, and the extra long wavelength passed through the top and bottom single layer organic solar cells. The light of the region can be efficiently absorbed in the photoactive layer of the single layer organic solar cell in the middle portion.

According to one embodiment of the present specification, any one single layer organic solar cell absorbs light having a wavelength of 300 nm to 700 nm, and the other single layer organic solar cell absorbs light having a wavelength of 400 nm to 800 nm. It may be.

According to one embodiment of the present specification, any one single layer organic solar cell absorbs light having a wavelength of 300 nm to 700 nm, and the other single layer organic solar cell absorbs light having a wavelength of 400 nm to 800 nm. In another embodiment, the single layer organic solar cell may absorb light having a wavelength of 450 nm to 850 nm.

According to one embodiment of the present specification, at least two of the single layer organic solar cells may include a photoactive material absorbing light of different wavelength bands.

According to one embodiment of the present specification, at least two of the single layer organic solar cells may adjust the photoactive material concentration of each photoactive layer to absorb light of different wavelengths.

Further, according to one embodiment of the present specification, at least two of the single layer organic solar cells may absorb light of different wavelength bands by using photoactive materials that absorb wavelengths of different wavelength bands, respectively.

In addition, according to one embodiment of the present specification, at least two of the single layer organic solar cells may adjust the mass ratio of the electron donor material and the electron acceptor material of the photoactive layer to absorb light of different wavelengths.

In addition, according to one embodiment of the present specification, at least two of the single layer organic solar cells may have different thicknesses of the photoactive layer, thereby absorbing light of different wavelength bands.

According to an exemplary embodiment of the present specification, the mass ratio of the electron donor material and the electron acceptor material of the photoactive layer of the two or more single layer organic solar cells may be the same or different from each other.

The laminated organic solar cell of the present specification may be manufactured using two or more identical single-layer organic solar cells and a bonding layer. Alternatively, it may be prepared using different single-layer organic solar cells and bonding layers.

According to an exemplary embodiment of the present specification, when the mass ratio of the electron donor material and the electron acceptor material of the photoactive layer of the two or more single layer organic solar cells are different from each other, the electron donor material of the photoactive layer of any one single layer organic solar cell The mass ratio of the electron acceptor material is 1:10 to 10: 1, and the mass ratio of the electron donor material and the electron acceptor material of the photoactive layer of the other single layer organic solar cell may be 1: 5 to 5: 1.

According to an exemplary embodiment of the present specification, the concentration of the photoactive material of each of the single layer organic solar cells may be different from each other. Specifically, the concentration of the photoactive material of any one single layer organic solar cell of the present specification is greater than 3% and 10% or less, and the concentration of the photoactive material of another single layer organic solar cell may be 0.01% or more and 3% or less. . More specifically, the concentration of the photoactive material of any one single layer organic solar cell of the present specification is greater than 3% and 7% or less, and the concentration of the photoactive material of another single layer organic solar cell may be 0.01% or more and 3% or less. .

In addition, according to the exemplary embodiment of the present specification, the electron donor material and the electron acceptor material of the photoactive layers of the two single layer organic solar cells may be used as different materials.

According to an exemplary embodiment of the present specification, the thickness of the photoactive layer of the two or more single layer organic solar cells may be different from each other. Specifically, the thickness of the photoactive layer of any one single layer organic solar cell of the present specification is greater than 100 nm and 500 nm or less, and the thickness of the photoactive layer of another single layer organic solar cell may be 1 nm or more and 100 nm or less. More specifically, the thickness of the photoactive layer of any one single layer organic solar cell of the present specification is greater than 100 nm and 300 nm or less, and the thickness of the photoactive layer of another single layer organic solar cell may be 10 nm or more and 100 nm or less.

According to an exemplary embodiment of the present specification, when the concentration and thickness of the photoactive material of the two or more single layer organic solar cells are different from each other, the concentration of the photoactive layer of any one single layer organic solar cell is more than 3% 10% or less, The thickness may be greater than 100 nm and 500 nm or less, and the concentration of the remaining photoactive layer of the single layer organic solar cell may be 0.01% or more and 3% or less, and the thickness may be 1 nm or more and 100 nm or less. More specifically, when the concentration and thickness of the photoactive material of the two or more single layer organic solar cells are different from each other, the concentration of the photoactive layer of any one single layer organic solar cell is more than 3% and 7% or less, and the thickness is more than 100 nm. 300 nm or less, the concentration of the photoactive layer of the other single layer organic solar cell may be 0.01% or more and 3% or less, and the thickness may be 10 nm or more and 100 nm or less.

That is, when the laminated organic solar cell receives light to one side, the mass ratio and concentration of the electron donor material and the electron acceptor material of the photoactive layer of the upper single layer organic solar cell to receive light and the photoactive layer of the lower single layer organic solar cell And the thickness of the layer may be different from each other. In this case, the light absorption of the photoactive layer of the lower single layer organic solar cell may be higher than that of the photoactive layer of the upper single layer organic solar cell to receive light, thereby increasing light absorption in a unit area. When the light absorption rate of the photoactive layer of the lower single layer organic solar cell is higher, the excess light passing through the upper single layer organic solar cell can be efficiently absorbed by the lower single layer organic solar cell.

According to an exemplary embodiment of the present specification, each of the single layer organic solar cells includes a hole injection layer; Hole transport layer; Interlayers; Hole blocking layer; Charge generating layer; Electron blocking layer; And one or more organic material layers selected from the group consisting of electron transport layers.

The hole transport layer and / or the electron transport layer material of the present specification may be a material that increases the probability that the generated charge is transferred to the electrode by efficiently transferring electrons and holes to the photoactive layer, but is not particularly limited.

The hole transport layer of the present specification may be an anode buffer layer.

According to an exemplary embodiment of the present specification, the hole transport layer is PEDOT: PSS; Molybdenum oxide (MoO _x ); Vanadium oxide (V ₂ O ₅ ); Nickel oxide (NiO); And tungsten oxide (WO _x ) It may include one or more selected from the group consisting of.

The electron transport layer of the present specification may be a cathode buffer layer.

According to an exemplary embodiment of the present specification, the electron transport layer may be electron-extracting metal oxides, specifically, titanium oxide (TiO _x ); Zinc oxide (ZnO); And cesium carbonate (Cs ₂ CO ₃ ) It may include one or more selected from the group consisting of.

The electron transport layer of the present specification is applied to one surface of the first electrode or the second electrode or coated in the form of a film using sputtering, E-Beam, thermal deposition, spin coating, screen printing, inkjet printing, doctor blade or gravure printing method It can be formed by.

According to an exemplary embodiment of the present specification, the multilayer organic solar cell may be a flexible organic solar cell. In this case, the substrate may comprise a flexible material. Specifically, the substrate may be a glass, plastic substrate, or film substrate in the form of a thin film that can be bent.

The material of the plastic substrate is not particularly limited, but in general, may include a film such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether ether ketone (PEEK), and polyimide (PI) in the form of a single layer or a multilayer. have.

According to an exemplary embodiment of the present specification, the laminated organic solar cell may have a wound structure. Specifically, the laminated organic solar cell may be manufactured in a flexible film form, and may be rolled into a cylindrical shape to form a solar cell having a hollow structure. When the laminated organic solar cell is a wound structure, it may be installed in a manner of standing on the ground. In this case, while the sun at the position where the laminated organic solar cell is installed moves from east to west, it is possible to secure a portion where the incident angle of light is maximum. Therefore, while the sun is floating, there is an advantage to increase the efficiency by absorbing as much light as possible. Furthermore, it may also have the advantage of increasing the light absorption rate, including the above-mentioned single-layer organic solar cell of the upper and lower.

An exemplary embodiment of the present specification provides a method of manufacturing the laminated organic solar cell. Specifically, one embodiment of the present specification comprises the steps of preparing two or more single-layer organic solar cells; The method may include connecting two or more single layer organic solar cells to a bonding layer.

The manufacturing step of the single layer organic solar cell may be the same as the manufacturing step of a general organic solar cell. Furthermore, after manufacturing one single layer organic solar cell and another single layer organic solar cell, the three or more single layer organic solar cells may be brought into contact with each other using the above-described bonding layer. This can increase the process rate compared to raising the organic material layer in tandem on one substrate, it can significantly lower the defective rate.

According to an exemplary embodiment of the present specification, the manufacturing of the single layer organic solar cell may include preparing a substrate; Forming a first electrode on the substrate; Forming a photoactive layer on the first electrode; The method may include forming a second electrode on the photoactive layer.

As used herein, “phase” does not mean merely being located in contact with one layer, but may mean being positioned on a location. That is, the layers located on either layer may have other layers in between.

According to the exemplary embodiment of the present specification, the manufacturing of the single layer organic solar cell may further include forming a hole transport layer and forming an electron transport layer.

According to one embodiment of the present specification, the forming of the first electrode may include modifying the surface to be hydrophilic after cleaning.

Each step may be the same as the method of manufacturing the first electrode, the second electrode, the photoactive layer, the electron transport layer, and the hole transport layer.

Hereinafter, the present invention will be described in detail with reference to Examples. However, embodiments according to the present disclosure may be modified in various other forms, and the scope of the present disclosure is not interpreted to be limited to the embodiments described below. The embodiments of the present specification are provided to more fully describe the present specification to those skilled in the art.

[실시예 1] 적층 유기태양전지의 제조Example 1 Fabrication of Multilayer Organic Solar Cell

(1) Cleaning the Patterned ITO Substrate

In order to clean the surface of the patterned ITO glass (surface resistance: ~ 11.5 Ω / sq, Shinan SNP) substrate, ultrasonic cleaning was performed sequentially using a detergent, acetone, and isopropanol (IPA) for 20 minutes, and then dried with nitrogen. After blowing completely, the mixture was dried at 250 ° C. for 10 minutes to completely remove moisture. Once the cleaning of the patterned ITO substrate was completed, the surface was modified for 30 minutes in a UVO cleaner (UVO cleaner, Ahtech LTS, Korea).

(2) Preparation of electron transport layer

The ZnO precursor solution was prepared by using a hydrolysis reaction in advance, and the ZnO precursor solution was spin coated on the ITO substrate, and then heat-treated to remove the remaining solvent to complete the electron transport layer.

(3) Preparation of Photoactive Layer

The photoactive layer material mixed with P3HT and PC ₆₁ BM in a weight ratio of 1: 0.7 was dissolved in a chlorobenzene solvent at a concentration of 2% by weight or 4% by weight, and spin-coated on the electron transport layer, respectively, about 80 nm or A 240 nm photoactive layer was formed.

(4) Manufacture of hole transport layer

A hole transport layer was prepared by depositing MoO ₃ on the photoactive layer at a thickness of 5 nm to 20 nm at a rate of 0.2 dl / s in a thermal evaporator.

(5) Fabrication of single layer organic solar cell

After manufacturing in this order, Ag was deposited at 10 nm on the hole transport layer at a rate of 1 Å / s in a thermal evaporator having a vacuum degree of 5 × 10 ⁻⁷ torr or less to prepare a single layer organic solar cell.

(6) Fabrication of Laminated Organic Solar Cell

After producing the single-layer organic solar cell comprising a single-layer organic solar cell with photoactive layer using a 4% by weight of P3HT and the PC ₆₁ BM containing the photoactive layer with a 2% by weight of P3HT and the PC ₆₁ BM, transparent adhesive A sieve was attached to the edges of two single-layer organic solar cells, and thus a laminated organic solar cell was manufactured.

[비교예 1] 단층 유기태양전지의 제조 Comparative Example 1 Fabrication of Single Layer Organic Solar Cell

A single layer organic solar cell using a concentration of 2% by weight of P3HT and PC ₆₁ BM was manufactured under the same method and conditions as the method for manufacturing the single layer organic solar cell of Example 1.

[비교예 2] 단층 유기태양전지의 제조Comparative Example 2 Fabrication of Single Layer Organic Solar Cell

A single layer organic solar cell using 4 wt% concentration of P3HT and PC ₆₁ BM was prepared in the same method and conditions as the method of manufacturing the single layer organic solar cell of Example 1.

In order to measure the electro-optical characteristics of the organic solar cells prepared in Examples 1 and 2, the current-voltage density was measured under standard conditions (Air mass 1.5 Global, 100 mW / cm ² ) using an ABET solar simulator. Measured.

Optical short-circuit current density ( J _sc ), photo-opening voltage ( V _oc ), fill factor (FF) and energy conversion efficiency of the organic solar cells are shown in Tables 1 and 2 below.

Where FF is the voltage value ( V _max ) × current density ( J _max ) / ( V _oc × J _sc ) at the maximum power point, and the energy conversion efficiency is FF × ( J _sc × V _oc ) / P _in , P _in = It calculated as 100 [dl / cm <2>].

In Table 1, Comparative Example 1 measured the current-voltage density of a single-layer organic solar cell including a photoactive layer using a concentration of 2% by weight of P3HT and PC ₆₁ BM, Comparative Example 2 of the P3HT and PC ₆₁ BM The current-voltage density of the single-layer organic solar cell including the photoactive layer using 4 wt% concentration was measured. In addition, Comparative Examples 1-1 and 2-1 are values measured by inverting the single-layer organic solar cells of Comparative Examples 1 and 2 and giving light in opposite directions, respectively.

In Comparative Examples 1 and 2, the light incident surface is a surface provided with an ITO substrate. In Comparative Examples 1-1 and 2-1, the light incident surface is a surface provided with Ag.

In Table 1, Example 1 is a single-layer organic solar cell including a photoactive layer using a concentration of 2% by weight of P3HT and PC ₆₁ BM is provided at the position where light is incident, 4% by weight of P3HT and PC ₆₁ BM The single-layer organic solar cell including the photoactive layer was measured so as to be in the bottom, and Example 1-1 was measured by reversing the surface where light enters in Example 1, that is, inverted. At this time, in both Example 1 and Example 1-1, the light incident surface of the upper single layer organic solar cell is ITO, and the surface incident light of the lower single layer organic solar cell is Ag.

Table 1

	Photoactive layer concentration	J _sc (mA / cm ² )	V _oc (V)	FF	η (%)
Comparative Example 1	2% (up)	6.06	0.630	0.652	2.49
Comparative Example 1-1	2% (back)	3.75	0.604	0.586	1.33
Comparative Example 2	4% (up)	9.38	0.616	0.459	2.65
Comparative Example 2-1	4% (back)	7.26	0.608	0.498	2.20
Example 1	2% (up) + 4% (down)	12.17	0.604	0.548	4.02
Example 1-2	4% (up) + 2% (down)	10.68	0.600	0.477	3.05

As can be seen in Table 1 and Figure 6, the photo-opening voltage of the embodiment is increased compared to the single-layer organic solar cell in the laminated organic solar cell including two single-layer organic solar cell while maintaining a similar value while increasing the optical short circuit current density The photoelectric conversion efficiency was about 2.49%, and Example 1 showed an efficiency increase of up to 60% or more from 4.02%.

[비교예 3]Comparative Example 3

After dissolving the photoactive layer material in which the photoactive material 1 and PCBM having the properties of FIG. Except, a single layer organic solar cell was manufactured by the same method as the method of manufacturing the single layer organic solar cell of Example 1.

[비교예 4][Comparative Example 4]

After dissolving the photoactive layer material having the properties of Figure 7 and the PCBM in a weight ratio of 1: 0.7 dissolved in a chlorobenzene solvent at a concentration of 2% by weight, spin coating on the electron transport layer to form a photoactive layer Except, a single layer organic solar cell was manufactured by the same method as the method of manufacturing the single layer organic solar cell of Example 1.

[비교예 5][Comparative Example 5]

After dissolving the photoactive layer material having the properties of FIG. Except, a single layer organic solar cell was manufactured by the same method as the method of manufacturing the single layer organic solar cell of Example 1.

[실시예 2]Example 2

After the single layer organic solar cells of Comparative Examples 3 to 5 were prepared, three layers of laminated organic solar cells were manufactured by attaching a transparent adhesive to the edge of each single layer organic solar cell. In manufacturing the laminated organic solar cell, a single layer organic solar cell absorbing light in a short wavelength region is disposed above the light inflow, and a single layer solar cell absorbing light in a long wavelength region is disposed below the light. It was able to absorb efficiently. Therefore, a single layer organic solar cell including the photoactive material 1, a single layer organic solar cell including the photoactive material 2, and a single layer organic solar cell including the photoactive material 3 are listed in the order of the absorption wavelengths in the order of the stacked organic solar cells. Prepared by batch.

In order to measure the electro-optical characteristics of the organic solar cells prepared in Example 2, Comparative Examples 3 to 5, current-voltage density was measured under standard conditions (Air mass 1.5 Global, 100 mW / cm ² ) using an ABET solar simulator. Measured.

Optical short-circuit current density ( J _sc ), photo-opening voltage ( V _oc ), fill factor (FF) and energy conversion efficiency of the organic solar cells are shown in Table 2 below.

At this time, Fill Factor (FF) is the voltage value ( V _max ) × current density ( J _max ) / ( V _oc × J _sc ) at the maximum power point, and the energy conversion efficiency is FF × ( J _sc × V _oc ) / P _in , P _in = 100 [dl / cm 2].

In Table 2, Comparative Examples 3 to 5 measured current-voltage density of each single-layer organic solar cell, and Example measured current-voltage density of a laminated organic solar cell, and the photoactive material having the shortest absorption wavelength. The single layer organic solar cell including 1 was disposed in an upward direction in which light is introduced.

TABLE 2

	Photoactive layer	J _sc (mA / cm ² )	V _oc (V)	FF	η (%)
Comparative Example 3	Photoactive Substances 1	2.30	0.646	0.300	0.44
Comparative Example 4	Photoactive Substance 2	6.08	0.622	0.606	2.29
Comparative Example 5	Photoactive Substance 3	8.61	0.842	0.474	3.44
Example 2	Photoactive substances 1 to 3	11.60	0.784	0.504	4.58

In Table 2, it can be seen that the optical short-circuit current density of the laminated organic solar cell composed of three layers increases compared to the single-layer organic solar cell. Therefore, it can be seen that the efficiency of the stacked organic solar cell increases from 1.3 times to 10 times.

Claims

A first electrode; A second electrode provided to face the first electrode; And at least two single-layer organic solar cells including at least one organic material layer including a photoactive layer provided between the first electrode and the second electrode.

It includes a bonding layer provided between each of the two adjacent single-layer organic solar cells,

And the first electrode and the second electrode are transparent electrodes having a light transmittance of 20% or more and 100% or less in light having a wavelength of 450 nm.
The method according to claim 1,

The first and second electrodes are each independently a transparent conductive oxide layer or a metal electrode having a thickness of 20 nm or less laminated organic solar cell.
The method according to claim 1,

The bonding layer is glass; Transparent adhesive; And a laminated organic solar cell is selected from the group consisting of a transparent insulator.
The method according to claim 1,

At least one of the two surfaces facing the single layer organic solar cell of the junction layer is a laminated organic solar cell of 10% or more and 80% or less in the junction area to the single layer organic solar cell.
The method according to claim 1,

The shape of the bonding surface of the bonding layer is a shape including only the border region of the bonding layer; Or a laminated organic solar cell having a mesh shape.
The method according to claim 1,

Each of the single layer organic solar cells further comprises a transparent substrate, wherein the first electrode is provided on the transparent substrate laminated organic solar cell.
The method according to claim 6,

At least one of the bonding layer is a laminated organic solar cell provided on the lower surface of the transparent substrate.
The method according to claim 6,

At least one of the bonding layer is provided between the transparent substrate of the two adjacent single-layer organic solar cell laminated organic solar cell.
The method according to claim 1,

At least one of the single layer organic solar cells further includes a transparent substrate, a first electrode is provided on the transparent substrate,

The first electrode is a cathode, the second electrode is a laminated organic solar cell having an inverted structure of the anode.
The method according to claim 1,

The electrode adjacent to the upper or lower surface of the bonding layer is a metal electrode having a thickness of 20 nm or less.
The method according to claim 1,

Laminated organic solar cell further comprises a photochemical upconversion layer between at least two adjacent pairs of single layer organic solar cells.
The method according to claim 1,

The multilayer organic solar cell further comprises one or more reflective layers provided to face the light receiving.
The method according to claim 1,

At least two of the single layer organic solar cells are laminated organic solar cells that absorb light of different wavelengths.
The method according to claim 1,

One of the single layer organic solar cell absorbs light of the wavelength of 300 nm to 700 nm, and the other of the single layer organic solar cell absorbs light of the wavelength of 400 nm to 800 nm.
The method according to claim 1,

The single layer organic solar cell includes a hole injection layer, respectively; Hole transport layer; Interlayers; Hole blocking layer; Charge generating layer; Electron blocking layer; And at least one organic material layer selected from the group consisting of an electron transport layer.
The method according to claim 1,

The laminated organic solar cell is a laminated organic solar cell is a flexible organic solar cell.
The method according to claim 1,

The laminated organic solar cell is a laminated organic solar cell having a wound structure.