KR101080895B1 - Organic Solar Cells and Method of Manufacturing the Same - Google Patents

Abstract

The present invention includes an organic substrate including a photocrosslinking active layer formed between a substrate and a first electrode and a second electrode formed on the substrate, the first electrode and the second electrode, the organic semiconductor material and the photosensitive agent is photocrosslinked Provided are a solar cell and a method of manufacturing the same.

Solar cell, photosensitive

Description

Organic Solar Cells and Method for Manufacturing the Same

The present invention relates to an organic solar cell and a method of manufacturing the same.

There is a need for clean and unlimited energy that is different from the existing energy, such as a sense of crisis of exhaustion of oil resources, the entry into force of the Kyoto Protocol's climate change agreement, and the explosive demand for energy due to the economic growth of emerging BRICs. This is going on. Among the renewable energy, solar cells (Solar Cells or Photovoltaic Cells) are the core elements of photovoltaic power generation that converts sunlight directly into electricity, and are widely used for power supply from space to home. In the early days when solar cells were first made, they were mainly used for space use, but after two oil surges in the 1970s, they were attracting attention for their potential as ground power sources. It started to use for dragon. Recently, it has been used in aviation, meteorology, and communication fields, and solar vehicles and solar air conditioners are also attracting attention.

Such solar cells mainly use silicon or compound semiconductors, but because they are manufactured in the semiconductor device manufacturing process, the manufacturing cost is high, and silicon solar cells, which occupy the main part of the solar cells, have difficulty in supplying silicon raw materials. . Under these circumstances, organic solar cells using low molecular weight organic materials or polymers without using any silicon material have begun to be studied in earnest, and low cost processes are possible by printing method as well as vacuum method, and flexible solar cell manufacturing regardless of shape It is possible to receive much attention now.

The present invention can be applied to various kinds of hole transport materials having excellent performance, and can be applied to various kinds of materials for the photoactive layer, an organic solar cell and a method for manufacturing the same that can contribute to the efficiency of the finally implemented organic solar cell The purpose is to provide.

In one aspect, the present invention provides a photocrosslinking active layer formed between a substrate and a first electrode and a second electrode formed on the substrate, between the first electrode and the second electrode, and formed by photocrosslinking of an organic semiconductor material and a photosensitive agent. It provides an organic solar cell comprising.

In another aspect, the present invention is formed between the substrate and the first electrode and the second electrode formed on the substrate, the first electrode and the second electrode, the optical cross-linking active layer formed by the optical cross-linking of the organic semiconductor material and the photosensitive agent It provides a method of manufacturing an organic solar cell comprising a.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used to refer to the same components as much as possible even if displayed on different drawings. In addition, in describing the present invention, when it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

In addition, in describing the component of this invention, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are only for distinguishing the components from other components, and the nature, order or order of the components are not limited by the terms. If a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected or connected to that other component, but between components It will be understood that may be "connected", "coupled" or "connected".

The core material of the organic solar cell is a conjugated polymer. Unlike silicon solar cells, conjugated polymers have a high absorption coefficient and can absorb sunlight even with a thin film (about 100 nm). Therefore, they can be manufactured as thin devices. It has the advantage that there are various application fields other than buildings where silicon solar cells are mainly used.

The organic solar cell is composed of a junction structure of a hole acceptor (D) and an electron acceptor (A). When the visible light is absorbed, an electron-hole pair is generated at the hole acceptor. As the electrons move to the electron acceptor, electron-hole separation is performed, resulting in a photovoltaic effect.

In 1986, Eastman Kodak's C. Tang first proposed the feasibility of using solar cells as a heterojunction structure using copper pthalocyanine (CuPc) and perylene tetra carboxylic derivatives. The solar cell generating electricity using a mixed film of conjugated polymer and fullerene derivative as a photoactive layer was reported, and the efficiency was improved to 3% by developing a fullerene-modified fullerene derivative (PCBM). Since then, various researches are being conducted to obtain organic solar cells with high efficiency, and photoelectric conversion efficiency is increasing greatly.

1 is a cross-sectional view of an organic solar cell.

Referring to FIG. 1, the organic solar cell 100 includes a transparent substrate 110, a transparent electrode (anode 120), a buffer layer 130, a photoactive layer 140, and a metal electrode (cathode 150). do.

The conventional organic solar cell 100 uses indium tin oxide (ITO), which is a transparent electrode having a high work function, as a cathode material, and Al or Ca having a low work function as a cathode material. The photoactive layer 140 uses a two-layer structure or a mixed thin film [(D + A) blend] structure having a hole acceptor (D) material and an electron acceptor (A) material having a thickness of about 100 nm. Therefore, a structure [D / (D + A) / A] in which the latter mixed thin film is sandwiched between the hole acceptor (P-type semiconductor) and the electron acceptor (N-type semiconductor) layers is also used.

In addition, a hole transport layer is formed between the anode 120 and the ITO electrode and the photoactive layer 140, and an electron transport layer is formed between the cathode 150 and the photoactive layer 140 of the buffer layer 130. It can also be inserted in the form.

The operating principle of the conventional organic solar cell 100 is as follows. When the organic solar cell 100 is exposed to light, the light is absorbed by the hole acceptor through the transparent substrate 110, the anode 120, and the hole transport layer to form an electron-hole pair (exciton) in an excited state. The electron-hole pair diffuses in any direction and encounters an interface with the electron acceptor material, separating it into electrons and holes. That is, electrons move toward the electron acceptor material having a high electron affinity, and holes remain on the hole acceptor side and are separated into respective charge states. They are moved and collected to each electrode by the difference in concentration between the internal magnetic field and the accumulated charge formed by the work function difference of both electrodes 110 and 150, and finally flow through the external circuit in the form of current.

Although described above, the conventional organic solar cell 100 has a structure of a transparent substrate 110 / transparent electrode 120 / buffer layer 130 / photoactive layer 140 / metal electrode 150 as shown in FIG. The transparent electrode 120 serves as an anode and the metal electrode 150 serves as a cathode.

2 is a cross-sectional view of an inverted organic solar cell according to an embodiment.

Referring to FIG. 2, an inverted organic solar cell 200 according to an embodiment includes a transparent substrate 210, a transparent electrode 220 formed on the transparent substrate 210, and a transparent electrode formed on the transparent electrode 220. The modified layer 225, the photoactive layer 240 formed on the transparent electrode reformed layer 225, the buffer layer 230 formed on the photoactive layer 240, and the metal electrode 250 formed on the buffer layer 230 are stacked. have.

The transparent electrode 220 / transparent electrode reformed layer 225 serves as a cathode, and the metal electrode 250 serves as an anode. That is, the transparent electrode reforming layer 225 having n-type characteristics is formed on the p-type transparent electrode 220 to impart a function as a cathode, and the metal electrode 250 serves as an anode.

As described above, the conventional organic solar cell and the inverted organic solar cell using non-silicon have a merit of being able to be manufactured at low cost because of the printing method and the like.

In order to manufacture such an organic solar cell as a module, it is necessary to form a pattern of the material constituting each layer. In particular, in order to manufacture a monolithic type module, pattern formation of materials is essential. The pattern method of the material is also known as laser scribing method and hole contact wrap through method. In addition, the pattern formation of PEDOT: PSS, which is a typical hole transport layer, is known as a screen printing method and a micro-contact printing method.

   However, the laser scribing method in the pattern forming technology of the related material has a problem that not only has to use expensive laser equipment but also a long process time. In addition, the organic solar cell manufactured using the flexible plastic substrate is also unsuitable for applying a laser scribing method because the plastic substrate may be degraded by a laser. In addition, the hole contact wrap through method has a problem in that a process such as drilling holes in the substrate and forming thin films on both sides is complicated, resulting in low reliability and high manufacturing costs. In the case of the screen method used to form PEDOT: PSS, which is widely used as a hole transport layer, it is difficult to control the film thickness. That is, in organic solar cells, PEDOT: PSS has a thickness of about several tens of nm and is excellent in efficiency. In the case of screen printing, it is almost impossible to form a thin film having a thickness of several tens of nm. In the case of the micro-contact printing method, expensive equipment is required, and it is difficult to apply to the mass production process due to the complicated process such as the manufacture of the PDMS mold and the SAM treatment process.

  The present invention provides an organic solar cell and a manufacturing method thereof, in which a charge transport layer (charge = hole + electron) pattern and a photoactive layer pattern photocrosslinked by photolithography are stacked. More specifically, the present invention provides an organic solar cell in which a photoelectric cross-linked charge transport layer using a photosensitive charge transport layer material and a photo-crosslinked photoactive layer using a photosensitive photoactive layer material are patterned by a photolithography process and a method of manufacturing the same.

3 is a conceptual diagram of an organic solar cell having a photocrosslinked thin film pattern according to an embodiment of the present invention.

In the organic solar cell 300 having the photocrosslinked thin film according to an embodiment of the present invention, the transparent substrate 310, the transparent electrode 320 formed on the transparent substrate 310, and the optical crosslinking formed on the transparent electrode 320 are provided. The hole transport layer 330, the photocrosslinked hole transport layer 330, and the photocrosslinked photoactive layer 340 formed on the photocrosslinked photoactive layer 340 include a metal electrode 350.

The transparent substrate 310 may be a transparent substrate such as soda lime silica glass, amorphous glass, and a flexible plastic such as polyimide, PET, PEN, PES, PEEK, or the like.

The transparent substrate 310 undergoes a cleaning process immediately before use, and may be ultrasonically cleaned after soaking in acetone, alcohol, water, or a mixed solution thereof. A transparent electrode pattern is formed on the transparent substrate 310.

The transparent electrode 320 is formed on the transparent substrate 310. The transparent electrode 320 may be any material having electrical conductivity and a transparent material. However, the transparent electrode 320 may be a material capable of ohmic bonding with the photocrosslinked hole transport layer and having excellent transparency. For example, the transparent electrode 320 includes In ₂ O ₃ , indium-tin oxide (ITO), indium-gallium-zinc oxide (IGZO), Ga ₂ O ₃ -In ₂ O ₃ , ZnO, ZnO-In ₂ O ₃ , AZO (Aluminum-zinc oxide; ZnO: Al), Zn ₂ In ₂ O ₅ -In ₄ Sn ₃ O ₁₂ , SnO ₂ , FTO (Fluorine-doped tin oxide; SnO ₂ : F), ATO (Aluminium-tin oxide, such as SnO ₂ : Al, may be a single or complex oxide of a metal such as indium (In), tin (Sn), gallium (Ga), zinc (Zn), and aluminum (Al).

The transparent electrode 320 may be formed by DC sputtering or otherwise by chemical vapor deposition (CVD), atomic layer deposition (ALD), sol-gel coating, electroplating, or the like. The thickness of the transparent electrode 320 may be 100 to 1,000 nm, but is not limited thereto. The pattern of the transparent electrode 320 formed as described above may be formed using a method applied in the semiconductor and display industries.

The photocrosslinked hole transport layer 330 is formed on the transparent electrode 320 and is formed under the photocrosslinked photoactive layer 340. When light flows into the photocrosslinking active layer 340 from the outside, electrons and holes are separated (generated). The photocrosslinked hole transport layer 330 serves to transport holes generated in the photocrosslinked light active layer 340 to the transparent electrode 320. However, the organic solar cell 300 according to an embodiment does not necessarily need the photocrosslinked hole transport layer 330.

The photocrosslinked hole transport layer 330 has a form in which the P-type oil-based conductor material is crosslinked by a photosensitive agent as in Scheme 1.

P-type oil-based conductor material is a material having excellent light transmittance and excellent hole transport characteristics. For example, P-type conductor materials include PEDOT: PSS [poly (3,4-ethylenedioxythiophene): poly (4-styrene sulfonate)] and G-PEDOT [poly (3,4-ethylenedioxythiophene): poly (4-styrene sulfonate): polyglycol (glycerol)], PANI: PSS [polyaniline: poly (4-styrene sulfonate)], PANI: CSA (polyaniline: camphor sulfonic acid), PDBT [poly (4,4'-dimethoxy bithophene)], aryl It may be a low molecule and a polymer having an amine group (aryl amine group), a low molecule and a polymer having an aromatic amine group.

As the photosensitizer, a compound having two or more N ₃ functional groups in one molecule may be used, as shown in Chemical Formulas 1 to 6.

For example, photosensitizers are water-soluble compounds such as 4,4'-diazido-2,2'stilbenedisulfonic acid disodium salt, 1,3-diazido-2- (azidomethyl) -2-propylammonium salt and 2,6-bis (4 -azidobenzylidene) -4-methyl cyclohexanone, 4-azidophenyl sulfone, bis (4-azidobiphenyl), bis (4-azidophenyl) methanone, 1- (4-azidophenoxy) -4-azidobenzene, bis (4-azidosulfonylbiphenyl), 2, 3-diazido-2,3-dideoxy-d-mannose, 2,4-diazido-2,4,6-trideoxy-L-hexopyranoses, 1,5-diazido-3-nitrazapentane, 1,3-diazido-2- (azidomethyl) -2-methylpropane, Bis (-azido-2N: N) bis [azido (N, N-dimethyl-1,3-propylenediamine-2N, N) copper (II)], trans-Bis (azido-N ) bis (pyridine-2-carboxamide-2N1, O2) nickel (II), Bis [-5- (pyrazin-2-yl) tetrazol-1-ido] bis [azido (2,2'-bipyridine) copper (II ), Such as oil-soluble (organic solvent solubility) compounds.

The photocrosslinked hole transport layer 330 is formed by preparing a photoresist for the hole transport layer in which a P-type oil-based conductor material and a photosensitive agent are dissolved in a suitable solvent, for example, water, alcohols, organic solvents, and the photolithography process for the hole transport layer. Coating, drying, exposure, and development may be performed on the transparent electrode to form a predetermined shape pattern.

The coating process may include spin coating, spray coating, screen printing, bar coating, doctor blade coating, flexography, gravure printing, and the like. In addition, when the P-type organic material is a low molecular organic material, it may be formed by thermal evaporation under vacuum without dissolving in a solvent. At this time, the photosensitizer is a method of thermally evaporating by mixing with the P-type oil-based conductor material and a method of co-depositing with the P-type oil-based conductor material.

The coated thin film is subjected to a drying step (no need for vacuum deposition thin film) to remove the solvent.

Subsequently, when a predetermined shape photomask is placed on the dried thin film and exposed to light, the portion exposed to light causes a reaction (cross-linking) as in Scheme 1, so that the solubility in the developer (or solvent) is extremely high. Degrades.

The portion exposed by the reaction as in Scheme 1 is not dissolved by the developer in the developing process, while the non-exposed part is removed by dissolving in the developer. Thereby, the pattern of a predetermined shape can be obtained. The thickness of the photocrosslinked hole transport layer formed as described above may be 5 to 300 nm, but is not limited thereto.

Although not shown in FIG. 3, the pattern of the photocrosslinked hole transport layer 330 may be formed to the right (or left) end of the transparent electrode 320, or the transparent substrate 310 may extend beyond the right (or left) end of the transparent electrode 320. It may also be formed in the form in contact with). This is possible by controlling the area exposed to light by varying the line width of the photomask used in the exposure process.

The photocrosslinking active layer 340 is formed on the photocrosslinking hole transport layer 330. The photo-crosslinking photoactive layer 340 can be implemented in various forms, including (1) a single layer structure of a mixed thin film [(D + A) blend] layer of a hole acceptor (D) material and an electron acceptor (A) material. (2) A two-layered structure (D / A) in which a hole acceptor (D) material and an electron acceptor (A) material are laminated respectively may be taken.

As the hole acceptor (D) material, low molecular weight compounds such as phthalocyanine pigments such as copper phthalocyanine (CuPc), indigo, thioindigo pigments, melocyanine compounds, and cyanine compounds, and polyparaphenylenevinylene (poly- ρ) phenylenevinylene-based polymer derivatives such as -phenylenevinylene), polythiophene, poly [2,6- (4,4-bis- (2-ethylhexyl) -4H-cyclopenta [2,1-b; 3, 4-b1] dithiophene) -alt-4,7- (2,1,3-benzothiadiadiazole)] (PCPDTBT), poly (3-hexylthiophene) (P3HT), and other conductive polymers including thiophene-based polymer derivatives such as Can be.

The electron acceptor (A) is fullerene (C ₆₀ ), PCBM ([6,6] -phenyl-C ₆₁ -butyric acid methyl ether), PC ₇₀ BM ([6,6] -phenyl-C ₇₁ -butyric acid Fullerene derivatives such as methyl ether, perylene derivatives such as perylene and PTCBI (3,4,9,10-perylenetetracarboxylic bisbenzimidazole) may be used.

For example, in order to form the photocrosslinking active layer 340 having a one-layer structure, the electron acceptor (A) and the hole acceptor (D) are dissolved in an organic solvent at an appropriate ratio, and the photosensitive agent (N ₃ group described above) is added thereto. Dissolving two or more materials) to prepare a photosensitive liquid for a photoactive layer. The photoresist for the photoactive layer may be used to form a predetermined pattern by performing a photolithography process, for example, coating, drying, exposure, and development on the photocrosslinked hole transport layer 330.

The coating process may include spin coating, spray coating, screen printing, bar coating, doctor blade coating, flexography, gravure printing, and the like. In addition, when the material constituting the photoactive layer is a low molecular organic material, it may be formed by thermal evaporation under vacuum without dissolving in a solvent. In this case, the photosensitive agent may be mixed with the material for the photoactive layer and thermally deposited, or the method may be co-deposited with the material for the photoactive layer.

The coated thin film is subjected to a drying step (no need for vacuum deposition thin film) to remove the solvent. Subsequently, when a mask of a predetermined shape is placed on the dried thin film and exposed to light, the portion exposed to light causes a crosslinking reaction, so that the solubility in a developer (or solvent) is extremely low. That is, the part exposed by the crosslinking reaction is not dissolved by the developer during the development process, while the non-exposed part is removed by dissolving in the developer. Thereby, the pattern of a predetermined shape can be obtained.

As shown in FIG. 3, the pattern of the photocrosslinking active layer 340 may be formed in contact with the transparent substrate 310 beyond the right end of the transparent electrode 320, or may be formed only to the right end of the transparent electrode 320. You can also This pattern size can be controlled by controlling the area exposed to light by varying the line width of the photomask used in the exposure process.

If the photocrosslinking active layer 340 has a single layer structure ((A + D) blend], the photolithography process needs to be performed only once, and if the two layer structure (A / D), the photolithography process is performed twice. You have to.

In addition, the photocrosslinking active layer 340 may include inorganic nanoparticles. N-type chalcogenide-based compound nanoparticles such as CdS, ZnS, Zn (O, S), ZnSe, (Zn, In) Se, In (OH, S), In ₂ S ₃ and n-type metal oxides Nanoparticles ZnO, TiO ₂ , SnO ₂ , SrTiO ₃ , Nb ₂ O ₅ , WO _3, etc., serve as electron acceptors, and partially or all of the organic electron acceptors present in the photocrosslinking active layer 340. It can also be replaced.

In addition, p-type chalcogenide compound nanoparticles CuSe, CuInS ₂ (CIS), CuGaS ₂ (CGS), CuInSe ₂ (CISe), CuGaSe ₂ (CGSe), CuAlSe ₂ (CASe), CuInTe ₂ (CITe ), CuGaTe ₂ (CGTe), Cu (In, Ga) S ₂ (CIGS), Cu (In, Ga) Se ₂ (CIGSe), Cu ₂ ZnSnS ₄ (CZTS), CdTe, etc., will act as hole acceptors. The organic hole acceptor present in the photocrosslinking photoactive layer 340 may be replaced in part or in whole.

In this case, when the organic electron acceptor and the organic hole acceptor are both replaced with the inorganic nanoparticles described above, the photolithography process may not be performed, and thus, a minimum organic electron acceptor or organic hole acceptor may be included. The introduction of the nanoparticles may be performed during the photolithography process after the addition of the photoresist solution. The thickness of the photocrosslinked photoactive layer 340 formed as described above may be 10 to 1,000 nm, but is not limited thereto.

The metal electrode 350 is formed on the photocrosslinked active layer 340 to collect electrons (that is, to receive electrons from the photocrosslinked photoactive layer). The metal electrode 350 should have high electrical conductivity, and may be ohmic-bonded with the photocrosslinking active layer, and may be a material having excellent stability.

The material of the metal electrode 350 may be an electrode material composed of a metal having a small work function, an alloy, an electrically conductive compound, and a mixture thereof. For example, the material of the metal electrode 350 may be aluminum (Al), zinc (Zn), titanium (Ti), indium (In), alkali metal, sodium-potassium (Na: K) alloy, magnesium-silver (Ma). : Ag alloy, a lithium-aluminum (Li: Al) double layer electrode, a lithium fluoride-aluminum (LiF: Al) double layer electrode, etc. can be used.

The thickness of the metal electrode 350 may be about 0.1 to 5 μm, but is not limited thereto.

The metal electrode 350 may be formed by a DC sputtering method, thermal evaporation or a wet method such as chemical vapor deposition (CVD), atomic layer deposition (ALD), electroplating, and various printing techniques. The pattern of the metal electrode 350 by the vacuum method may use a shadow mask, and in the case of the wet method, a screen mask may be used.

Although not shown in FIG. 3, since the organic solar cell 300 may be degraded by moisture and oxygen during operation, it is necessary to block each layer formed from the atmosphere.

In the sealing process, first, a moisture absorbent capable of absorbing moisture may be attached to the center of the protective cap of the glass material, and the sealing material may be dispensed to the edge portion. Next, the fabricated device (substrate 310 / transparent electrode 320 / photocrosslinking hole receiving layer 330 / photocrosslinking active layer 340 / metal electrode 350) is disposed on the dispensed sealing material, The sealing material is cured by applying UV or heat. If the sealing material is cured using UV, UV light should not be introduced into the photoactive layer, because the photocrosslinking active layer 340 may be deteriorated by UV.

In addition, the sealing process may use a method of forming a passivation layer by forming a multilayer thin film under vacuum. These sealing processes are already well established in the organic light emitting device industry. In addition, the sealing process may be performed by using an adhesive, an EVA film, a back sheet, and the like, which are conventionally applied in the silicon and thin film solar cell industries.

According to another embodiment of the present invention, a method of manufacturing an organic solar cell includes (1) forming a transparent electrode on a transparent substrate by a vacuum method or a wet method, and (2) forming a photocrosslinked hole transport layer (pattern) on the transparent electrode. Forming by a photolithography process, (3) forming a photocrosslinked photoactive layer (pattern) on the photocrosslinked hole transport layer by photolithography process, and (4) forming a metal electrode on the photocrosslinked photoactive layer by vacuum or wet method. Forming.

Each step of the organic solar cell according to the exemplary embodiment of the present invention has been described above with reference to FIG. 3, and thus a detailed description thereof will be omitted.

4 is a conceptual diagram of an organic solar cell having a photocrosslinked thin film pattern according to another exemplary embodiment of the present invention.

 Referring to FIG. 4, the organic solar cell 400 having the photocrosslinked thin film pattern forms a three-layer structure between two electrodes. The organic solar cell 400 includes a transparent substrate 410, a transparent electrode 420 formed on the transparent substrate 410, a photocrosslinked hole transport layer 430 formed on the transparent electrode 420, and a photocrosslinked hole transport layer 430. It includes a photo-crosslinking photoactive layer 440, an electron transport layer 445 formed on the photocrosslinking active layer 440 and a metal electrode 450 formed on the electron transport layer 445.

In this case, the transparent substrate 410, the transparent electrode 420, the photocrosslinked hole transport layer 430, and the photocrosslinked photoactive layer 440 of the organic solar cell 400 having the photocrosslinked thin film pattern according to another embodiment of the present invention. ), The metal electrode 450 is a transparent substrate 310, transparent electrode 320, optical crosslink of the organic solar cell 300 having a photocrosslinked thin film pattern according to another embodiment of the present invention described with reference to FIG. Since the hole transport layer 330, the photocrosslinking active layer 340, and the metal electrode 350 are the same as or substantially the same, the detailed description thereof will be replaced with those described with reference to FIG. 3.

The electron transport layer 445 is formed on the photocrosslinking photoactive layer 440, and may be a photocrosslinked electron transport layer, or may be pure electron transport without light crosslinking.

The electron transport layer 445 may form a pattern using an inkjet method, an offset printing method, or a gravure printing method using a metal precursor sol (or solution). In addition, the n-type metal oxide nanoparticles may be prepared and dispersed in the dispersion medium with additives to prepare in the form of ink, slurry, paste, and the like to form a pattern by the printing method. Such metal oxide sol (or solution) and metal oxide nanoparticles include ZnO-based nanoparticles, Doped-ZnO (ZnO: Al, ZnO: B, ZnO: Ga, ZnO: N, etc.) nanoparticles, SnO ₂ nanoparticles, ITO nanoparticles, TiO ₂ nanoparticles, TiOx (1 <x <2) sol, Cs ₂ CO ₃ solution It may be a titanium (diisoproxide) bis (2,4-pentadionate) solution, but is not limited thereto.

In addition, the electron transport layer 445 may be composed of an organic material. The electron acceptor (A) mentioned in the process of explaining the organic solar cell 330 having the photocrosslinked thin film was dissolved in an organic solvent together with a photosensitive agent (a compound having two or more N ₃ groups in a molecule) for the electron transport layer. To prepare a photoresist. The photoresist may contain trace amounts of p-type dopants such as rodamine B, pyronin B, crystal violet, malachite green, and the like. In this case, the electron transport characteristic is improved.

The prepared photoresist for the electron transport layer may be used to form a predetermined pattern by performing a photolithography process, for example, coating, drying, exposure, and development on a photocrosslinking active layer.

The coating process may include spin coating, spray coating, screen printing, bar coating, doctor blade coating, flexography, gravure printing, and the like. In addition, when the material constituting the electron transport layer is a low molecular organic material, it may be formed by thermal evaporation under vacuum without dissolving in a solvent. In this case, the photosensitive agent may be mixed with the material for the electron transport layer and thermally deposited, or the method may be co-deposited with the material for the electron transport layer.

The coated thin film is subjected to a drying step (no need for vacuum deposition thin film) to remove the solvent. Subsequently, when a mask having a predetermined shape is disposed on the dried thin film and exposed to light, the portion exposed to light causes a reaction as in Scheme 1, so that the solubility in a developer (or solvent) is extremely reduced. That is, the portion exposed by the reaction as in Scheme 1 is not dissolved by the developer in the developing process, while the non-exposed part is removed by dissolving in the developer. Thereby, the electron transport layer pattern of a predetermined shape can be obtained, and this case corresponds to the light crosslinked electron transport layer.

In particular, in the case of a low molecular organic material, the electron transport layer may be formed in a form not containing a photoreceptor. That is, when the low molecular organic material is thermally evaporated under vacuum, by arranging the shadow mask, only a specific desired portion may be deposited to form an electron transport layer pattern.

Although not shown in FIG. 4, the pattern of the photocrosslinking electron transport layer 445 may be formed only to the right end of the transparent electrode 420, or may be formed to the end of the photocrosslinking active layer 440 beyond the right end of the transparent electrode 420. It may be formed to be in contact with the transparent substrate 410 beyond the photocrosslinking active layer 440 end. This is possible by controlling the area exposed to light by varying the line width of the photomask used in the exposure process.

In addition, the electron transport layer 445 may be configured in an organic-inorganic hybrid form. That is, the organic electron acceptor (A), the photosensitive agent and the metal oxide sol (or solution) or the metal oxide nanoparticles in the form of a mixed solution (or slurry or ink or paste) can be prepared to form a pattern by a photolithography process. have.

The thickness of the electron transport layer 445 may be 5 ~ 500 nm, but is not limited thereto.

 According to another embodiment of the present invention, a method of manufacturing a three-layered organic solar cell having a photocrosslinked thin film includes (1) forming a transparent electrode on a transparent substrate by vacuum or wet method, and (2) on a transparent electrode. Forming a photocrosslinked hole transport layer (pattern) by a photolithography process, (3) forming a photocrosslinked photoactive layer (pattern) on a photocrosslinked hole transport layer by photolithography process, and (4) on a photocrosslinked photoactive layer Forming an electron transport layer (pattern) by a vacuum method or a wet method, and (5) forming a metal electrode on the electron transport layer by a vacuum method or a wet method. .

Each step is the same as the manufacturing steps of the layers of the organic solar cell according to the exemplary embodiment of the present invention with reference to FIG. 3, and the steps of forming the electron transport layer are described above, and thus, detailed descriptions thereof will be omitted.

5 is a conceptual diagram of an inverted organic solar cell having an optical crosslinked thin film according to another embodiment of the present invention.

  Referring to FIG. 5, an inverted organic solar cell 500 having an optical cross-linked thin film according to another embodiment of the present invention is a transparent substrate 510, a transparent electrode 520 formed on the transparent substrate 510, and transparent. The transparent electrode reformed layer 525 formed on the electrode 520, the photocrosslinked photoactive layer 540 formed on the transparent electrode reformed layer 525, and the photocrosslinked hole transport layer 530 formed on the photocrosslinked photoactive layer 540. And a metal electrode 550 formed on the photocrosslinked hole transport layer 530.

  In this case, the transparent substrate 510, the transparent electrode 520, the photocrosslinking hole transport layer 530, and the photocrosslinking active layer 540 of the organic solar cell 500 having the photocrosslinked thin film pattern according to another exemplary embodiment of the present invention. ) Are transparent substrates 310 and 410 and transparent electrodes 320 and 420 of the organic solar cells 300 and 400 having a photocrosslinked thin film pattern according to another embodiment of the present invention described with reference to FIG. 3 or 4. Since the light cross-linking hole transport layers 330 and 430 and the light cross-linking active layer 340 and 440 are the same as or substantially the same, the detailed description will be replaced with those described with reference to FIGS. 3 and 4.

The transparent electrode reforming layer 525 serves to modify the characteristics of the transparent electrode 520. In detail, when the transparent electrode 520 exhibits p-type semiconductor characteristics, the transparent electrode 520 forms a transparent electrode modification layer having n-type semiconductor characteristics, thereby changing the characteristics of the transparent electrode 520. If the photoactive layer 540 is formed directly on the p-type transparent electrode 520, the ohmic bonding may not be performed, and thus the function of the solar cell 500 may be significantly degraded. Therefore, by forming a transparent electrode reformed layer 525 having n-type semiconductor characteristics between the photoactive layer 540 and the transparent electrode 520 having p-type semiconductor characteristics, ohmic contact is possible, thereby inducing a smooth flow of electrons. .

The transparent electrode reformed layer 525 may be formed using a metal precursor sol (or solution) in an inkjet method, an offset printing method, or a gravure printing method. In addition, metal oxide nanoparticles and chalcogenide compound nanoparticles having n-type characteristics can be prepared and dispersed in an dispersion medium with additives to form the ink, slurry, paste, etc. to form a pattern using the printing method described above. have. Examples of the metal oxide sol (or solution) include TiOx (1 <x <2) sol, Cs ₂ CO ₃ solution titanium (diisoproxide) bis (2,4-pentadionate) solution, and the like. ZnO-based nanoparticles, Doped-ZnO (ZnO: Al, ZnO: B, ZnO: Ga, ZnO: N, etc.)-Based nanoparticles, SnO ₂ nanoparticles, ITO nanoparticles, TiO ₂ nanoparticles and the like. In addition, the chalcogenide compound nanoparticles of the n-type characteristics may be CdS, ZnS, MnS, Zn (O, S), ZnSe, (Zn, In) Se, In (OH, S), In ₂ S ₃ However, it is not limited thereto.

In addition, the organic transparent electrode reformed layer may also be applied, and may be a low molecular weight polymer such as tetrakis (dimethylamino) ethylene or poly (ethylene oxide) and a self assembly monolayer such as hexadecanthiol, 1H, 1H, 2H, 2H-perfluoro decanethiol, but is not limited thereto. It doesn't work.

Metal oxides and n-type chalcogenide compounds may be formed by attaching a shadow mask to a vacuum device in addition to the printing method described above. In particular, in the case of chalcogenide compounds, chemical bath deposition or ILGAR may be applied. In this case, except for the portion where the transparent electrode modification layer 525 is to be formed using a photoresist or the like, a protective film is formed, and a thin film pattern is formed by the chemical vapor deposition method as described above, and then the protective film is removed. The transparent electrode modified layer pattern can be formed. Such a protective film is intended to prevent the formation of a thin film in an unnecessary portion in the chemical vapor deposition process.

The thickness of the transparent electrode reformed layer 525 may be 5 to 500 nm, but is not limited thereto.

The transparent electrode reformed layer 525 has the same characteristics as the material for the electron transport layer described above with reference to FIG. 3 since a material having an n-type semiconductor characteristic is applied. Therefore, the transparent electrode modified layer material mentioned in the present embodiment may be applied to the electron transport layer material, and vice versa, the electron transport layer material mentioned in the present embodiment may be applied to the transparent electrode modified layer material.

Although not shown in FIG. 5, the pattern of the transparent electrode reformed layer 525 may be formed only up to the right end of the transparent electrode 520, and may be formed in contact with the transparent substrate 510 beyond the right end of the transparent electrode 520. It may be. This is possible by varying the line width of the mask applied to the printing process, changing the line width of the shadow mask applied to the vacuum process, or controlling the size of the protective film pattern applied to the chemical bath deposition process.

The metal electrode 550 is formed on the photocrosslinked hole transport layer 530 to collect holes (that is, to transfer electrons from the metal electrode A to the HOMO level of the photocrosslinked hole transport layer). The metal electrode 550 may be a material having high electrical conductivity, ohmic bonding with the photocrosslinked hole transport layer, and excellent stability. For example, the material of the metal electrode 550 is silver (Ag), platinum (Pt), tungsten (W), copper (Cu), molybdenum (Mo), gold (Au), nickel (Ni), and the like. It may be a metal. The thickness of the metal electrode 550 may be 0.1 to 5 μm, but is not limited thereto. The metal electrode 550 may be formed by a DC sputtering method, thermal evaporation, or alternatively, by a wet method such as chemical vapor deposition (CVD), atomic layer deposition (ALD), electroplating, and various printing techniques.

Inverted organic solar cell manufacturing method having an optical cross-linked thin film according to another embodiment of the present invention comprises the steps of (1) forming a transparent electrode on the transparent substrate by vacuum or wet method, (2) on the transparent electrode Forming a transparent electrode reformed layer by a vacuum process or a wet process, (3) forming a photocrosslinked active layer (pattern) on the transparent electrode modified layer by a photolithography process, (4) forming a photocrosslinked active layer (pattern) Forming a photo-cross-linked hole transport layer (pattern) by a photolithography process, (5) forming a metal electrode on the photo-crosslinked transport layer (pattern) by a vacuum method or a wet method.

Each step is the same as the manufacturing steps of the layers of the organic solar cell according to the embodiments of the present invention with reference to FIGS. 3 and 4 and the steps of forming the transparent electrode reformed layer and the metal electrode have been described above. Omit.

In the present embodiment, the method of manufacturing each layer may be a vacuum method, or a wet method may be applied. The vacuum method refers to the formation of a unit thin film or a thin film pattern in a vacuum chamber, and thermal deposition, sputter deposition, chemical vapor deposition (CVD), and electron beam deposition may be applied according to the type of each layer. have. In addition, the wet method refers to ink jet printing, screen printing, gravure printing, flexography, doctor blade coating, electroplating after dissolving or dispersing a corresponding material in a liquid medium. It means the formation of a thin film by the method, electrophoresis method, chemical bath deposition.

Embodiments have been described above with reference to the drawings, but the present invention is not limited thereto.

In the organic solar cell having the photocrosslinked thin film according to the embodiments of the present invention implemented by the above-described structure and manufacturing process, a grid electrode may be additionally formed on (or under) the transparent electrode. The grid electrode mainly consists of a metal contact layer and can be formed through an electron beam system or other method, and mainly Ni, Al, Ag, or the like can be used.

In addition, an antireflection layer may be additionally formed inside or outside the transparent substrate. MgF ₂ , silicon nitride (SiNx), etc. are used as the anti-reflective layer to reduce the reflection loss of sunlight incident on the solar cell and further increase efficiency. The thickness is 600 by electron beam evaporation, chemical vapor deposition (CVD), etc. It can be used to form about ~ 1000 kPa.

As described above, the organic solar cell having the photocrosslinked thin film pattern and the manufacturing method thereof according to the embodiments of the present invention have been described.

By forming such a photocrosslinked thin film pattern by a photolithography process, a process is simpler than a monolithic organic solar cell manufactured by a conventional laser scribing method, and a high resolution pattern can be formed, and a plastic There is an advantage that can be applied to organic solar cells using a substrate.

In addition, the conventional organic solar cell is made of a solution to proceed to thin film, it was very difficult to form a laminated structure by dissolving the thin film of the lower layer in which the solvent present in the solution is already formed. Therefore, the conventional organic solar cell can only be a form in which the lipophilic thin film is stacked on the upper (or lower) of the hydrophilic thin film, and for this reason, the materials applicable to the organic solar cell are extremely limited. In other words, the hole transport layer for a conventional organic solar cell can be applied to water-soluble PEDOT: PSS only, and has a higher p-type conductivity polymer [aryl-amine group (aryl amine group), aromatic amine polymer having a group) is not applicable.

However, due to the implementation of the organic solar cell having the optical cross-linked thin film according to the embodiments of the present invention can be applied to various kinds of hole transport material having excellent performance, and for the same reason can be applied to various kinds of materials for the photoactive layer There is an advantage that can contribute to the improvement of the efficiency of the finally implemented organic solar cell.

Hereinafter, an embodiment of an embodiment of an organic solar cell having a photocrosslinked thin film according to the embodiments of the present invention will be embodied by way of examples, but the present invention is limited to the following examples, which are only presented to aid the understanding of the present invention. It is not.

Example 1

1. Transparent substrate / transparent electrode

A substrate (hereinafter referred to as an ITO substrate) having an ITO (sheet resistance of 15 Ω / sq, thickness of 1,500 kW) was formed on the glass substrate. The ITO substrate was immersed in acetone, semicoclean (manufactured by Plough Science, Inc.), and isopropyl alcohol, and then ultrasonically cleaned for 15 minutes and then dried. Next, the ITO substrate was subjected to surface treatment for 3 minutes in an atmospheric plasma surface treatment apparatus. A pattern was formed.

2. Formation of optical cross-linked hole transport layer

The formation process of the photocrosslinked hole transport layer formed on the transparent electrode (ITO pattern) is as follows. A photosensitive solution was prepared by adding 0.27 g of 4,4'diazido-2,2'stilbenedisulfonic acid disodium salt, a water-soluble photosensitive agent, to 10 g of polyethylenedioxythiophene: polystyrenesulfonate (manufactured by Stalk, PEDOT: PSS). Filtration was carried out using a 0.45 μm filter to remove impurities. The prepared photoresist was coated on the ITO pattern by the screen printing coating method, and then dried at 140 ° C. for 15 minutes. A stripe type photomask was placed on top of the dry film (PEDOT: PSS + photosensitive agent) and exposed to UV light for 60 seconds. The mask was removed and the substrate was dipped (or sprayed) in water (or alcohol) to remove the PEDOT: PSS + photosensitizer film in the non-exposed areas to form a photocrosslinked hole transport layer pattern.

3. Formation of Photocrosslinked Photoactive Layer

15 g of regioregular polytrihexylthiophene (Rieke Metals, abbreviated P3HT) as hole acceptor material and [6,6] -phenylC61-butyric acid methyl ester (Nano) as fullerene derivative as electron acceptor material 12 g of -C product, abbreviated as PCBM) was dissolved in 1 L of chlorobenzene to prepare a solution for the photoactive layer. 0.7 g of 2,6-bis (4-azidobenzylidene) -4-methylcyclohexanone as a photosensitizer was dissolved therein to prepare a photosensitive liquid for photocrosslinking active layer. The prepared photoresist was coated on the photocrosslinked hole transport layer by a doctor blade coating method, and then dried at 60 ° C. for 40 minutes. A stripe type photomask was placed on top of the dry film (P3HT: PCBM + photosensitizer) and exposed to UV light for 82 seconds. The mask was removed and the substrate was immersed (or sprayed) in chlorobenzene to remove the P3HT: PCBM + photosensitizer film in the non-exposed areas to form a photocrosslinked active layer pattern.

4. Formation and sealing process of metal electrode C

The substrate on which the photocrosslinked photoactive layer pattern was formed was mounted on the vacuum chamber, and a shadow mask was disposed on the bottom of the substrate, and LiF and Al were thermally deposited under high vacuum (10 ⁻⁶ torr). After the deposition is completed, the substrate is subjected to a sealing process in a glove box to obtain a monolithic type organic solar cell module having a layer structure of glass / ITO pattern / photocrosslinked PEDOT: PSS pattern / photocrosslinked P3HT: PCBM pattern / LiF: Al. Completed.

5. Photoelectric conversion efficiency measurement

The photoelectric conversion efficiency of the fabricated organic solar cell was measured. Only one cell was selected representatively from the plurality of cells constituting the module to evaluate the current-voltage characteristics. The voltage-current density of the organic solar cell device was measured using Keithley 236 Source Measurement and Solar Simulator (300W simulator models 81150 and 81250, Spectra physics Co.) under standard conditions (AM 1.5, 100 mW / cm ² , 25 ° C). Was measured, and the results are shown in FIG. 6. The open circuit voltage (V _oc ) was 0.60V, the short circuit current (J _sc ) was 14.9 mA / cm ² , and the fill factor was 62%, resulting in 5.4% photoelectric conversion efficiency. FIG. 6 shows current-voltage characteristics of an organic solar cell having a photocrosslinked thin film pattern according to Example 1. FIG.

Example 2

1. Transparent substrate / transparent electrode

The glass substrate of Example 1 was changed to PEN [poly (ethylene naphthalate)], and AZO (Al-doped SnO ₂ ) was used as the transparent electrode. As the transparent electrode was changed to AZO, 0.01% dilute nitric acid was used as the etching solution for AZO pattern formation (photolithography process), and the other conditions were the same.

2. Formation of optical cross-linked hole transport layer

In place of PEDOT: PSS shown in Example 1, the following Chemical Formula 7 was used, and as a photosensitizer, 2,6-bis (4-azidobenzylidene) -4-methyl cyclohexanone was used, and the developing solution was not water but THF. Except for using a mixed solvent and EtOH was the same as in <Formation of optical cross-linked transport layer> of Example 1. The photocrosslinked hole transport layer pattern formed on the transparent electrode was as shown in FIG. 7. 7 shows the pattern of the photocrosslinked hole transport layer formed by the photolithography process (50 times).

3. Formation of Photocrosslinked Photoactive Layer

PCPDTBT was used instead of P3HT, the hole receptor shown in Example 1, and PC ₇₀ BM was used instead of PCBM as the electron acceptor material, and all the same except that the photosensitive agent was replaced with bis (4-azidobiphenyl). To form a photocrosslinking active layer.

4. Formation of electron transport layer

TiOx (1 <x <2) sol was used as the material for the electron transport layer, and an electron transport layer was formed on the photocrosslinked photoactive layer by inkjet printing. Such TiOx sol was prepared in a known manner. 10 ml of titanium (IV) isoproxide was mixed with 50 ml of 2-methoxyethanol and 5 ml of ethanolamine. The mixed solution was heated to 80 ° C. and stirred for 2 hours. Subsequently, after heating up to 120 degreeC, it stirred for 1 hour and manufactured TiOx sol.

5. Formation and sealing process of metal electrode C

It is necessary to form the metal electrode C on the electron transport layer (TiOx), and PEN / AZO pattern / optical cross-linking formula 1 in the same manner except for using Mg: Ag alloy instead of LiF: Al presented in Example 1 A monolithic type organic solar cell module having a layer structure of pattern / photocrosslink PCPDTBT: PC ₇₀ BM pattern / TiOx pattern / Mg: Ag was completed.

6. Photoelectric conversion efficiency measurement

The photoelectric conversion efficiency of the three-layered organic solar cell having the photocrosslinked thin film fabricated as described above was measured. As a result of measuring the current-voltage characteristics under the same conditions as in Example 1, the open circuit voltage (V _oc ) is 0.64 V, the short circuit current (J _sc ) is 13.3 mA / cm ² , and the fill factor is 55%. This resulted in 4.7% photoelectric conversion efficiency.

Example 3

1. Transparent substrate / transparent electrode

It was made the same as the conditions shown in Example 1.

2. Formation of Transparent Electrode Modification Layer

A ZnS transparent electrode reformed layer was formed on the ITO pattern by chemical bath deposition. First, a protective film pattern (photoresist pattern) of a predetermined shape was formed on the upper portion of the ITO to expose only the portion where the ZnS was to be formed. Zinc sulfate, Thiourea, and Ammonia were used to form the ZnS thin film, which is a transparent electrode modification layer. First, 0.05-9.5 mol / l ZnSO ₄ and 0.2-1.5 mol / l NH ₂ CSNH ₂ are added to distilled water and heated to 70-90 ° C. If this is the first solution, 25% of NH ₃ corresponding to about one third of the first solution was added. A white precipitate formed upon addition of the second solution, which was dissolved again by stirring. In addition, before the ITO substrate was added to the reaction solution, ZnS was formed by dipping for 10 minutes after treatment with a solution of ammonia and water. After ZnS film formation, the protective film pattern was stripped to obtain a pure ZnS pattern.

3. Formation of Photocrosslinked Photoactive Layer

A photocrosslinking active layer was formed on the transparent electrode reformed layer. First, copper phthalocyanine (CuPc), a hole acceptor material, was co-deposited (heated) in a vacuum chamber with a photoresist bis (4-azidophenyl) methanone to form a thin film on the transparent electrode reformed layer. At this time, the pattern was formed by using a predetermined shadow mask. Subsequently, a mixture of the electron acceptor fullerene (C60) and the photosensitive agent 1,3-diazido-2- (azidomethyl) -2-methylpropane was thermally deposited in a vacuum chamber to form an upper portion of the hole acceptor / photoreceptor thin film pattern. A pattern was formed using a shadow mask. After the deposition was completed, the substrate was exposed to UV, and both layers were subjected to a photocrosslinking reaction to form a photocrosslinking active layer having a two-layer structure (D / A).

4. Formation of optical cross-linked hole transport layer

In place of PEDOT: PSS shown in Example 1, a mixture of Formula 8 and Formula 9 was used, and as a photosensitizer, 2,6-bis (4-azidobenzylidene) -4-methyl cyclohexanone was used. The developer was the same as the formation of the photocrosslinked hole transport layer of Example 1, except that THF and EtOH mixed solvents were used instead of water.

5. Formation and Sealing Process of Metal Electrode A

Ag ink was used as the metal electrode formed on the photocrosslinked hole transport layer pattern. Ag ink was coated on the top of the photocrosslinking and transport layer by screen printing and then dried to form a metal electrode A layer, which was transferred to a glove box in a nitrogen atmosphere and subjected to a sealing process through Glass / ITO / ZnS / CuPc / Inverted organic solar cell module (monolithic type) having a photo-crosslinked thin film pattern having the same structure as the photo-crosslinked C60 / photo-crosslinked formula (8 + formula 9) / Ag.

6. Photoelectric conversion efficiency measurement

The photoelectric conversion efficiency of the inverted organic solar cell having the photocrosslinked thin film fabricated as described above was measured. As a result of measuring the current-voltage characteristic under the same conditions as in Example 1, the open circuit voltage (V _oc ) is 0.64 V, the short circuit current (J _sc ) is 13.45 mA / cm ² , and the fill factor is 53%. This resulted in a photoelectric conversion efficiency of 4.5%.

Example 4

Among the contents presented in Example 1, PANI: PSS was used instead of PEDOT: PSS used in forming the photocrosslinked hole transport layer, and ZnO nanoparticles were used instead of PCBM as the material for the electron accepting layer used in forming the photocrosslinked active layer pattern. Except for all the same conditions except for a conventional organic solar cell having a cross-linked thin film pattern was prepared. In the conventional organic solar cell having the photocrosslinked thin film pattern, the Voc value was 0.63 V, the Jsc value was 12.5 mA / cm ² , the fill factor was 55%, and the photoelectric conversion rate was 4.3%.

Example 5

Except for changing the electron transport layer formation of the contents shown in Example 2 as in the same, a three-layer structured organic solar cell having a light-crosslinked thin film pattern was prepared. The electron transport layer forming process is summarized as follows. First, 7 g of PTCBI was dissolved in 0.4 L of chlorobenzene, and 0.17 g of bis (4-azidosulfonylbiphenyl), a photosensitive agent, was dissolved therein to prepare a photosensitive liquid for an electron transport layer. The prepared photoresist was coated on the photocrosslinking active layer by a doctor blade coating method and then dried at 60 ° C. for 40 minutes. A stripe type photomask was placed on top of the dry film (PTCBI + photoresist) and exposed to UV light for 2 minutes. The mask was removed and the substrate was immersed (or sprayed) in chlorobenzene to remove the PTCBI + photoresist film in the non-exposed areas to form a photocrosslinked electron transport layer pattern. The VOC value of 0.63 V, Jsc value of 14.3 mA / cm ² , Fill factor of 55%, and photoelectric conversion efficiency of the three-layered organic solar cell having the photocrosslinked thin film pattern were 4.9%.

Example 6

An inverted organic solar cell having a photocrosslinked thin film pattern was manufactured in the same manner except that the formation of the transparent electrode modification layer was changed as follows. A process of forming In _x (OH, S) _y , which is a transparent electrode modification layer, is as follows. Indium (III) chloride and Thioacetamide were used to form In _x (OH, S) _{y as} a transparent electrode reformer. First, 0.005 M InCl ₃ and 0.15 M CH ₃ CSNH ₂ were added to distilled water and heated to 70 ° C. The ITO substrate was deposited on the prepared solution and stirred for a predetermined time to form an In _x (OH, S) _y thin film on the ITO. At this time, the pH value was 1.8 and the deposition time was about 20 minutes. The inverted organic solar cell having the photocrosslinked thin film pattern had a Voc value of 0.58 V, a Jsc value of 15.30 mA / cm ² , a fill factor of 52%, and a photoelectric conversion rate of 4.6%.

Example 7

An inverted organic solar cell having a photocrosslinked thin film pattern was manufactured in the same manner except that the formation of the transparent electrode modification layer was changed as follows.

TiOx (1 <x <2), a transparent electrode modifying layer, was subjected to the same materials and process conditions as those mentioned in forming the electron transport layer of Example 2. That is, a transparent electrode reformed layer was formed on the transparent electrode by inkjet printing using a TiO x sol. Such TiOx sol was prepared in a known manner. 10 ml of titanium (IV) isoproxide was mixed with 50 ml of 2-methoxyethanol and 5 ml of ethanolamine. The mixed solution was heated to 80 ° C. and stirred for 2 hours. Subsequently, after heating up to 120 degreeC, it stirred for 1 hour and manufactured TiOx sol. As described above, the transparent electrode reforming layer material used in the inverted organic solar cell can be cross-used with the electron transport layer material used in the organic solar cell of the three-layer structure. The inverted organic solar cell having the photocrosslinked thin film pattern had a Voc value of 0.61 V, a Jsc value of 14.40 mA / cm ² , a fill factor of 55%, and a photoelectric conversion rate of 4.8%.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. Accordingly, the embodiments disclosed herein are intended to be illustrative rather than limiting, and the spirit and scope of the present invention are not limited by these embodiments.

The protection scope of the present invention should be interpreted by the following claims, and all the technologies within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 is a cross-sectional view of an organic solar cell.

2 is a cross-sectional view of an inverted organic solar cell.

3 is a flowchart of a manufacturing method of an inverted organic solar cell according to another embodiment.

4 is a graph showing current density-voltage characteristics of an inverted organic solar cell according to Comparative Example 1. FIG.

5 is a graph showing the current density-voltage characteristics of the inverted organic solar cell according to Example 1. FIG.

Claims (14)

Board; First and second electrodes formed on the substrate; And a photocrosslinking active layer formed between the first electrode and the second electrode and formed by photocrosslinking an organic semiconductor material and a photosensitive agent, wherein the photosensitive agent has two or more N ₃ functional groups in a molecule thereof. Solar cells. The method of claim 1, The photoactive layer has (1) a single layer structure in which a mixed thin film [(A + D) blend] layer of an electron acceptor (A) material and a hole acceptor (D) material is formed, (2) an electron acceptor (A) material and a hole acceptor (D) The organic solar cell, characterized in that the two-layered structure of the material (A / D) laminated each. The method of claim 1, An organic solar cell further comprising a photocrosslinked hole transport layer formed by photocrosslinking an organic semiconductor material and a photosensitive agent between the first electrode and the photocrosslinking active layer or between the second electrode and the photocrosslinking active layer. The method of claim 1, An organic solar cell comprising one of an electron transport layer or an electrode reforming layer formed between one of the first electrode or the second electrode and the photocrosslinking active layer. The method of claim 1, The organic semiconductor material is a hole acceptor and an electron acceptor, The photo-crosslinking photoactive layer is formed by photocrosslinking by photolithography using a photoresist for the photoactive layer including the hole acceptor, the electron acceptor, and the photosensitive agent. The method of claim 5, The hole acceptor (D) is a phthalocyanine-based pigment, indigo, thioindigo-based pigment, melancyanine compound, cyanine compound, phenylenevinylene-based polymer derivative, polythiophene, poly [2,6- (4 , 4-bis- (2-ethylhexyl) -4H-cyclopenta [2,1-b; 3,4-b1] dithiophene) -alt-4,7- (2,1,3-benzothiadiadiazole)] (PCPDTBT), Organic solar cell, characterized in that one or more selected from the group consisting of thiophene-based polymer derivatives.  The method of claim 5, The electron acceptor (A) is fullerene (C ₆₀ ), [6,6] -phenyl-C ₆₁ -butyric acid methyl ether (PCBM), [6,6] -phenyl-C ₇₁ -butyric acid methyl ether ( Fullerene derivatives such as PC ₇₀ BM), perylene derivatives, CdS, ZnS, Zn (O, S), ZnSe, (Zn, In) Se, In (OH, S), In ₂ S ₃ Or one or more organic solar cells. delete 6. The method according to claim 1 or 5, The photosensitizer is a water-soluble compound of 4,4'-diazido-2,2'stilbenedisulfonic acid disodium salt, 1,3-diazido-2- (azidomethyl) -2-propylammonium salt and 2,6-bis (4-azidobenzylidene)- 4-methyl cyclohexanone, 4-azidophenyl sulfone, bis (4-azidobiphenyl), bis (4-azidophenyl) methanone, 1- (4-azidophenoxy) -4-azidobenzene, bis (4-azidosulfonylbiphenyl), 2,3-diazido- 2,3-dideoxy-d-mannose, 2,4-diazido-2,4,6-trideoxy-L-hexopyranoses, 1,5-diazido-3-nitrazapentane, 1,3-diazido-2- (azidomethyl)- 2-methylpropane, 1,3-diazido-2- (azidomethyl) -2-methylpropane, Bis (-azido-2N: N) bis [azido (N, N-dimethyl-1,3-propylenediamine-2N, N) copper (II)], trans-Bis (azido-N) bis (pyridine-2-carboxamide-2N1, O2) nickel (II), Bis [-5- (pyrazin-2-yl) tetrazol-1-ido] bis [ azido (2,2'-bipyridine) copper (II)] organic solar cell, characterized in that one or more selected from the group consisting of oil-soluble compounds. The method of claim 3, The organic semiconductor material is PEDOT: PSS [poly (3,4-ethylenedioxythiophene): poly (4-styrene sulfonate)], G-PEDOT [poly (3,4-ethylenedioxythiophene): poly (4-styrene sulfonate): polyglycol ( glycerol)], PANI: PSS [polyaniline: poly (4-styrene sulfonate)], PANI: CSA (polyaniline: camphor sulfonic acid), PDBT [poly (4,4'-dimethoxy bithophene)], aryl amine An organic solar cell comprising one or more P-type oil-based conductor materials selected from the group consisting of low molecules and polymers having a group) and low molecules and polymers having an aromatic amine group. 5. The method of claim 4, The electrode reformed layer is composed of (1) a metal oxide of one of TiOx (1 <x <2), TiO ₂ , ZnO: Al, ZnO: B, ZnO: Ga, ZnO: N, SnO ₂ , ITO, or ( 2) composed of one organic-metal compound of Cs ₂ CO ₃ , titanium (diisoproxide) bis (2,4-pentadionate), or (3) CdS, ZnS, MnS, Zn (O, S), ZnSe, (Zn N-type properties of chalcogenide compounds of (In) Se, In (OH, S), In ₂ S ₃ , or (4) low molecular weight and polymer of tetrakis (dimethylamino) ethylene, poly (ethylene oxide), hexadecanthiol 1H, 1H, 2H, 2H-perfluoro decanethiol organic solar cell, characterized in that one or more of the form consisting of organic compounds. The method of claim 5, The hole acceptor or the electron acceptor is an organic solar cell, characterized in that some or all of the inorganic nanoparticles. Preparing a substrate; Forming a first electrode and a second electrode on the substrate; And Forming a photocrosslinking active layer formed by photocrosslinking an organic semiconductor material and a photosensitive agent between the first electrode and the second electrode. The method of claim 13, And forming one of an electron transporting layer or an electrode reforming layer between one of the first electrode or the second electrode and the photocrosslinking active layer.

Images