KR20180064858A - Organic Solar Cells with Low-Temperature Processed Nanostructured Hole-Transfer Layer on Active Layer and Method for Fabricating the same - Google Patents

Abstract

Proposed are an organic photovoltaic cell to which a hole transfer layer having a regular nanostructure through a low-temperature process on a photoactive layer is introduced and a fabrication method thereof. According to one embodiment of the present invention, the fabrication method comprises the steps of: forming a thin film type hole transfer layer on a photoactive layer using a solution for the hole transfer layer; forming a nanostructure having a predetermined period through a nanoimprinting process on the hole transfer layer; and performing heat treatment the hole transfer layer including the nanostructure having the predetermined period to dehydrate the hole transfer layer.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic solar cell including a hole transport layer having a regular nanostructure on a photoactive layer through a low temperature process, }

The following embodiments relate to an organic solar cell in which a nanostructure is formed through a nanoimprinting and a low temperature process on a hole transport layer on a photoactive layer in an inverse structure organic solar cell and a manufacturing method thereof.

At present, the annual energy consumption on the earth is about 13 terawatts, which is expected to increase to about 30 terawats in 2050. However, as environmental problems such as global warming caused by the decrease in the production of fossil fuels, which are the main energy sources, and the increase of carbon dioxide emissions due to the combustion of these fuels, researches on energy conversion technology to replace fossil fuels In order to solve the global environmental problems that are currently being discussed, research on environmentally friendly energy conversion technology that converts energy sources such as hydroelectric power, wind power, biomass, and solar energy into electric energy has been concentrated.

Among them, the annual amount of solar energy reaching the Earth is about 120,000 terawatts, and solar cells that can use infinite solar energy safely and environmentally friendly are attracting attention as a new energy source. Most of the currently used solar energy is inorganic solar cells using monocrystalline silicon, polycrystalline silicon, and amorphous silicon.

However, these inorganic silicon-based solar cells have disadvantages in that they are complicated and expensive to manufacture, and thus they are difficult to be supplied as general household energy sources.

In order to overcome such problems, organic solar cells are attracting attention as an alternative to silicon solar cells. The organic solar cell has a simple manufacturing process and low manufacturing cost. It can coat a large area, can form a thin film even at a low temperature, and can use almost any kind of substrate such as a glass substrate and a plastic substrate. In addition, it can be folded or folded in various forms such as curved surface and spherical shape without limitation to the substrate shape, and thus it is easy to carry. Therefore, the organic solar cell can be used not only in human clothes, but also in clothes, bags, or attached to portable electronic devices. The polymer blend thin film has high transparency to light and can be attached to a glass window of a building, It is expected that the application range will be very wide because it can be used simultaneously for design.

However, since the diffusion distance of the excitons formed by the light of the organic materials used as the photoactive layer of the organic solar cell is very short as several nanometers, the excitons are mostly extinguished during the diffusion after the formation of the excitons, And has a low efficiency compared to conventional inorganic solar cells due to its low extinction coefficient. Therefore, in order to commercialize organic solar cells, high efficiency must be achieved.

Korean Patent Laid-Open Publication No. 10-2012-0057174 relates to an organic solar cell having such a charge transport layer having a one-dimensional nanostructure and a method of manufacturing the same, and relates to an organic solar cell having a charge transport layer with improved charge transfer capability, Method.

Embodiments describe a method for forming a nanostructure through a simple nanoimprinting and a low-temperature process on a hole transporting layer above a photoactive layer in an inverted-structure organic solar cell, and more specifically, the optical and electrical characteristics of an organic solar cell are effectively And provides a technology for realizing a controlled and highly efficient organic solar cell.

Embodiments can be achieved by introducing a nanostructure having a certain period through a nanoimprinting and a low temperature dehydration process on a hole transport layer formed on a photoactive layer in an inverse structure organic solar cell, The present invention relates to a method of manufacturing an organic solar cell, which comprises: forming a photoactive layer on a surface of a photoactive layer to easily produce an organic solar cell with high efficiency by effectively controlling the optical characteristics of the organic EL device by reflection by the back electrode and plasmonic resonance, And a hole transport layer having a regular nanostructure through the process, and a method of manufacturing the organic solar cell.

A method of fabricating an organic solar cell having a hole transport layer having a regular nano structure through a low temperature process on a photoactive layer according to an embodiment includes forming a thin film type hole transport layer on a photoactive layer using a solution for a hole transport layer ; Forming a nanostructure having a predetermined period through a nanoimprinting process on the hole transport layer; And a step of heat-treating the hole transport layer including the nanostructure having the constant period to dehydrate the hole transport layer.

Here, the step of forming a thin film-type hole transport layer on the photoactive layer using the solution for the hole transport layer may include: forming an electron transport layer on the substrate on which the first electrode is formed; And forming an organic photoactive layer on the electron transporting layer.

The photoactive layer may have a single layer structure of a mixed thin film layer of a hole receptor material and an electron acceptor material or a multi-layer structure in which the hole receptor material and the electron acceptor material are laminated.

The step of forming a thin film-type hole transport layer on the photoactive layer using the solution for the hole transport layer may include at least one of dissolving the photoactive layer in a solvent or preparing the suspension in a suspension state, The hole transport layer may be formed.

The hole transport layer may be formed of poly (3,4-ethylenedioxythiophene): poly (4-styrene sulfonate), poly (3,4-ethylenedioxythiophene) ), PANI: PSS [polyaniline: poly (4-styrene sulfonate)], PANI: polyaniline: camphor sulfonic acid, PDBT [poly (4,4'-dimethoxy bithophene)], arylamine group ) And a material having at least one selected from the group consisting of a polymer, an aromatic amine group having a low molecular weight and a polymer, and a MoOx (Molybdenum Oxide) material.

The step of forming the nanostructure having a predetermined period through the nano imprinting process on the hole transport layer may include forming a nanostructure patterned with a nanostructure having a predetermined period on the surface of the hole transport layer, A part of the solution penetrates between the nanostructures by the development and the nanostructure having the constant period in the form of the nanostructure may be patterned on the hole transport layer.

의 저온 진공 챔버에서 열처리하여 탈수화시키며, 고온의 열처리 과정을 수행하지 않아 고온에 취약한 유연 기판에도 적용이 가능하다. The step of heat-treating and dehydrating the hole transport layer including the nanostructure having a constant period may include: providing a hole transport layer containing the nanostructure having the constant period in a range of 80 to 100

And the substrate can be applied to a flexible substrate susceptible to high temperature because it is not subjected to a high temperature heat treatment process.

Removing the patterned nanostructures used for the nanoimprinting process after dehydrating the hole transport layer by heat treatment; And forming a second electrode on the hole transport layer including the nanostructure having the constant period.

An organic solar cell to which a hole conduction layer having a regular nanostructure is introduced through a low temperature process on a photoactive layer according to another embodiment includes a first electrode formed on a transparent substrate having electrical conductivity; An electron hydrogen layer formed on the first electrode; A photoactive layer formed on the electron hydrogen layer; A thin film-form hole transport layer formed on the photoactive layer using a solution for the hole transport layer; And a second electrode formed on the hole transport layer. Here, the hole transport layer may be formed with a nanostructure having a certain period on the upper part through a nanoimprinting process.

The photoactive layer may have a single layer structure of a mixed thin film layer of a hole receptor material and an electron acceptor material or a multi-layer structure in which the hole receptor material and the electron acceptor material are laminated.

The hole transport layer may be formed by spin coating on the photoactive layer to dissolve or suspend one or more materials in a solvent.

The hole transport layer may be formed of poly (3,4-ethylenedioxythiophene): poly (4-styrene sulfonate), poly (3,4-ethylenedioxythiophene) ), PANI: PSS [polyaniline: poly (4-styrene sulfonate)], PANI: polyaniline: camphor sulfonic acid, PDBT [poly (4,4'-dimethoxy bithophene)], arylamine group ) And a material having at least one selected from the group consisting of a polymer, an aromatic amine group having a low molecular weight and a polymer, and a MoOx (Molybdenum Oxide) material.

The hole transport layer is formed by arranging a nano template patterned with a nano grid pattern having a predetermined period on the surface, and applying a pressure, a part of the solution penetrates through the nano template by capillary phenomenon, The nanostructure may be patterned on the hole transport layer.

의 저온 진공 챔버에서 열처리하여 탈수화시켜 형성될 수 있다. Wherein the hole transport layer comprises the hole transport layer comprising the nanostructure having the constant period,

In a low-temperature vacuum chamber, and then dehydrating it.

The second electrode may be formed on the hole transport layer containing the nanostructure having the predetermined period by removing the patterned nanostructures used for the nanoimprinting process by heat treating the hole transport layer to dehydrate, .

According to embodiments, a nano structure having a certain period is introduced into a hole transport layer formed on a photoactive layer in a reverse structure organic solar cell through a nanoimprinting process and a low temperature dehydration process, Regardless of the type of the light-emitting layer, the optical characteristics due to the reflection due to the back electrode and the plasmonic resonance phenomenon, and the electrical characteristics due to the increase in the contact area between the hole transport layer and the rear electrode, An organic solar cell into which a hole conductive layer having a regular nanostructure is introduced through a low temperature process, and a method of manufacturing the same.

According to the embodiments, the dehydrogenation process is performed in a low-temperature vacuum chamber to perform a dehydration process. Thus, the photoactive layer, which can be applied to a flexible substrate susceptible to high temperatures without being subjected to a high-temperature heat treatment process, An organic solar cell into which a hole conductive layer is introduced, and a manufacturing method thereof.

1 is a view for explaining a method of manufacturing an organic solar cell having a hole transport layer having a regular nanostructure introduced through a low temperature process on a photoactive layer according to an embodiment.
FIG. 2 is a view illustrating a structure of an organic solar cell having a hole transport layer having a regular nanostructure introduced through a low temperature process on a photoactive layer according to an embodiment. Referring to FIG.
3 is a view showing an FE-SEM of a surface of a PEDOT: PSS hole transporting layer having a certain nanostructure formed according to an embodiment.
4 is a graph showing a voltage-current curve of the organic solar cell manufactured through Example 1 and Comparative Example 1 according to an embodiment.
5 is a graph showing a voltage-current curve of the organic solar cell manufactured through Example 2 and Comparative Example 2 according to one embodiment.
6 is a graph showing a voltage-current curve of the organic solar cell fabricated through Example 3 and Comparative Example 3 according to an embodiment.

Hereinafter, embodiments will be described with reference to the accompanying drawings. However, the embodiments described may be modified in various other forms, and the scope of the present invention is not limited by the embodiments described below. In addition, various embodiments are provided to more fully describe the present invention to those skilled in the art. The shape and size of elements in the drawings may be exaggerated for clarity.

In the following embodiments, a nanostructure having a certain period in a hole transport layer is formed in a reverse structure organic solar cell structure, and a plasmonic resonance effect is induced by a metal electrode in addition to an optical effect in a conventional plasmonic organic solar cell, .

In addition, the embodiments can be applied to an organic photoactive layer and a flexible substrate that are not susceptible to heat at a high temperature because a heat treatment process is not required, thereby providing a manufacturing method for realizing a highly efficient organic solar cell device.

1 is a view for explaining a method of manufacturing an organic solar cell having a hole transport layer having a regular nanostructure introduced through a low temperature process on a photoactive layer according to an embodiment.

A method of fabricating an organic solar cell in which a hole conduction layer having a regular nanostructure is introduced through a low temperature process on a photoactive layer according to an embodiment includes forming a thin film type hole transport layer on a photoactive layer using a solution for a hole transport layer Forming a nanostructure having a predetermined period through a nanoimprinting process on the formed hole transporting layer, and dehydrating the hole transporting layer including the nanostructure having a predetermined period by heat treatment.

In addition, a method of manufacturing an organic solar cell having a hole transport layer having a regular nanostructure introduced through a low-temperature process on a photoactive layer according to an embodiment of the present invention is characterized in that the hole transport layer is dehydrated by heat treatment and then used for a nanoimprinting process Removing the patterned nanostructures, and forming a second electrode on the hole transport layer containing the nanostructure having a constant period.

Referring to FIG. 1, a method of fabricating an organic solar cell having a hole transport layer having a regular nanostructure through a low temperature process on a photoactive layer according to an exemplary embodiment of the present invention will be described in detail.

First, an electron transport layer is formed on a substrate including a transparent electrode, and then an organic photoactive layer is formed on the electron transport layer.

In other words, a hole transport layer in the form of a thin film can be formed on the photoactive layer using a solution for the hole transport layer. More specifically, the step of forming the thin film-type hole transport layer on the photoactive layer using the solution for the hole transport layer includes the steps of forming an electron transport layer on the substrate on which the first electrode is formed, and forming an organic photoactive layer on the electron transport layer To form a second layer.

When the substrate is provided on the side of the light incident surface of the solar cell, it is formed to have light transmittance, and it may be used that is slightly colored other than colorless transparent. For example, the substrate may be a transparent glass substrate such as soda lime glass or non-alkali glass, or a plastic film arbitrarily made of polyester, polyamide, epoxy resin or the like.

The first electrode formed on the substrate, and the transparent electrode may be any material that is electrically conductive and transparent. For example, the transparent electrode is _{In 2 O 3, ITO (indium} -tin oxide), IGZO (indium-gallium-zinc oxide), Ga 2 O 3 -In 2 O 3, ZnO, ZnO-In 2 O 3, AZO (Aluminium-zinc oxide; ZnO: Al), Zn 2 In 2 O 5 -In4Sn 3 O1 2, SnO 2, FTO (Fluorine-doped tin oxide; SnO 2: F), ATO (Aluminium-tin oxide; SnO 2: Al, or the like, or a composite oxide of a metal such as indium (In), tin (Sn), gallium (Ga), zinc (Zn), and aluminum (Al)

An electron transporting layer can be formed on a substrate including a transparent electrode. At this time, the electron transporting layer may be formed of ZnO nanoparticles, Doped-ZnO (ZnO: Al, ZnO: B, ZnO: Ga, ZnO: N) nanoparticles, SnO ₂ nanoparticles, ITO nanoparticles, TiO ₂ nanoparticles, A solution of TiO _x (1 <x <2) sol, a solution of Cs ₂ CO _{3, and a} solution of titanium (diisoproxide) bis (2,4-pentadionate).

The photoactive layer formed on the electron transporting layer can be realized in various forms, and it can be realized by (1) taking a single layer structure of a mixed thin film [(D + A) blend] layer of a hole receptor (D) material and an electron acceptor (D / A) in which the hole receptor (D) material and the electron acceptor (A) material are laminated, respectively.

The hole receptor (D) may be at least one selected from the group consisting of polybenzothiophene derivatives, polythiophene derivatives, poly (para-phenylene) derivatives, polyfluorene derivatives, polyacetylene derivatives, polypyrrole derivatives, polyvinylcarbazole derivatives, And conductive polymers and small molecules including conjugated polymers such as vinylene derivatives and conjugated low molecular materials can be used.

The electron acceptor (A) is fullerene (C60), [6,6] -phenyl-C61-butyric acid methyl ether (PCBM), [6,6] , 6] -phenyl-C71-butyric acid methyl ether (PC70BM), perylene derivatives such as perylene and 3,4,9,10 Perylene polymeric compound derivatives such as 3,4,9,10-perylenetetracarboxylic bisbenzimidazole (PTCBI) may be used.

The photoactive layer may be formed by spin coating, dip coating, chemical vapor deposition, spray coating or the like.

For example, as shown in FIG. 1A, a hole transport layer including a nanostructure having a constant period formed on a photoactive layer according to an exemplary embodiment may be formed by spin coating.

The hole-transporting layer material is composed of poly (4-styrene sulfonate): poly (3,4-ethylenedioxythiophene): poly (3,4-ethylenedioxythiophene) ), PANI: PSS [polyaniline: poly (4-styrene sulfonate)], PANI: polyaniline: camphor sulfonic acid, PDBT [poly (4,4'-dimethoxy bithophene)], arylamine group ) And a polymer, an aromatic amine group having a low molecular weight and a polymer, and a MoOx (Molybdenum Oxide) material.

In order to form a hole transporting layer on the photoactive layer through a spin coating method, one or more of the above materials may be dissolved in a solvent or prepared in a suspension state.

Next, as shown in FIG. 1B, a nanostructure having a constant period can be formed through a nano imprinting process on the formed hole transport layer.

When a nanostructure is placed on a spin-coated hole transport layer and pressure is applied, a part of the solution penetrates between the molds due to the capillary phenomenon, thereby forming a depression on the hole transport layer in the form of a nano-mold. More specifically, a nanostructure having a predetermined periodicity is patterned on the surface of the hole transport layer, and a pressure is applied to the nanostructure. As a result, a portion of the solution is permeated through the nanostructure by capillary action, A nanostructure having a constant period can be patterned on the hole transporting layer.

Then, as shown in FIG. 1C, the hole transport layer including the nanostructure having a constant periodicity can be dehydrated by heat treatment.

의 저온에서 열처리하여 탈수화 공정을 통해 광학적 특성 및 전기적 특성이 향상된 일정한 주기를 가지는 나노 구조체를 가지는 정공 수송층을 형성할 수 있다. 이와 같이 고온의 열처리 과정을 수행하지 않고 저온 진공 챔버에서 열처리하여 탈수화시킴으로써 고온에 취약한 유연 기판에도 적용할 수 있다. That is, the hole transporting layer in which the nanostructure is formed is 80 to 100

The hole transport layer having a nanostructure having a constant period with improved optical and electrical characteristics can be formed through a dehydration process. By performing dehydration by heat treatment in a low-temperature vacuum chamber without performing a high-temperature heat treatment process, the present invention can be applied to a flexible substrate susceptible to high temperatures.

In addition, when the hole transport layer is applied to an organic solar cell, it is possible to form a metal nanostructure having a constant period. Therefore, it is possible not only to increase the absorbance by inducing a plasmonic resonance effect by the metal electrode, It is possible to provide an organic solar cell whose efficiency is improved by improvement of electrical characteristics such as increase in area and prevention of recombination.

As shown in FIG. 1D, after the hole transport layer is dehydrated by heat treatment, a nano template patterned with nano meshes used for the nanoimprinting process can be removed.

As shown in FIG. 1E, the second electrode may be formed on the hole transport layer including the nanostructure having a constant period.

The second electrode may be formed of a metal electrode such as silver (Ag), nickel (Ni), aluminum (Al), and gold (Au) on the hole transport layer into which the nanostructure having the constant period is introduced. Electrodes can be used.

As described above, according to one embodiment, after the PEDOT: PSS thin film is formed, the optical effect can be expected by simply forming the nano structure on the rear electrode without heat treatment through the nanoimprinting process.

In addition, by forming the nanostructure on the photoactive layer directly with a certain period of time, a hole transport layer is formed on the front electrode to form the nanostructure, and then the incident light is refracted to increase the path of light passing through the upper organic thin film, It is possible to increase the substantial absorbance by inducing the plasmonic resonance effect by the rear electrode which is a metal.

FIG. 2 is a view illustrating a structure of an organic solar cell having a hole transport layer having a regular nanostructure introduced through a low temperature process on a photoactive layer according to an embodiment. Referring to FIG.

Referring to FIG. 2, an organic solar cell 200 including a hole transport layer having a regular nano structure through a low temperature process on a photoactive layer according to an embodiment includes a first electrode 210, an electron hydrogen layer 220 A photoactive layer 230, a hole transport layer 240, and a second electrode 250. Here, the organic solar cell 200 in which a hole conductive layer having a regular nanostructure is introduced through the low temperature process on the photoactive layer 230 according to an embodiment can form an organic solar cell having an inverted structure.

The first electrode 210 is electrically conductive and may be formed on a transparent substrate.

Here, the substrate is formed to have light transmittance when it is provided on the light incident surface side of the solar cell, and it may be used that is slightly colored other than colorless transparent. For example, the substrate may be a transparent glass substrate such as soda lime glass or non-alkali glass, or a plastic film arbitrarily made of polyester, polyamide, epoxy resin or the like.

The first electrode 210 formed on the substrate may be referred to as a transparent electrode, and the transparent electrode may be any material that is electrically conductive and transparent. For example, the transparent electrode is _{In 2 O 3, ITO (indium} -tin oxide), IGZO (indium-gallium-zinc oxide), Ga 2 O 3 -In 2 O 3, ZnO, ZnO-In 2 O 3, AZO (Aluminium-zinc oxide; ZnO: Al), Zn 2 In 2 O 5 -In4Sn 3 O1 2, SnO 2, FTO (Fluorine-doped tin oxide; SnO 2: F), ATO (Aluminium-tin oxide; SnO 2: Al, or the like, or a composite oxide of a metal such as indium (In), tin (Sn), gallium (Ga), zinc (Zn), and aluminum (Al)

The electron-hydrogen layer 220 may be formed on the first electrode 210. At this time, the electron transporting layer may be formed of ZnO nanoparticles, Doped-ZnO (ZnO: Al, ZnO: B, ZnO: Ga, ZnO: N) nanoparticles, SnO ₂ nanoparticles, ITO nanoparticles, TiO ₂ nanoparticles, A solution of TiO _x (1 <x <2) sol, a solution of Cs ₂ CO _{3, and a} solution of titanium (diisoproxide) bis (2,4-pentadionate).

The photoactive layer 230 may be formed on the electron-hydrogen layer 220. The photoactive layer 230 formed on such an electron transport layer can be implemented in various forms, and the photoactive layer 230 can be formed by a single layer structure of a mixed thin film layer of a hole receptor material and an electron acceptor material, or a single layer structure of a hole receptor material and an electron acceptor material Layered structure.

More specifically, the photoactive layer 230 formed on the electron transporting layer may have a single layer structure of (1) a mixed thin film of a hole receptor (D) material and an electron acceptor (A) (D / A) in which a hole receptor (D) material and an electron acceptor (A) material are stacked, respectively.

The hole receptor (D) may be at least one selected from the group consisting of polybenzothiophene derivatives, polythiophene derivatives, poly (para-phenylene) derivatives, polyfluorene derivatives, polyacetylene derivatives, polypyrrole derivatives, polyvinylcarbazole derivatives, And conductive polymers and small molecules including conjugated polymers such as vinylene derivatives and conjugated low molecular materials can be used.

The electron acceptor (A) is fullerene (C60), [6,6] -phenyl-C61-butyric acid methyl ether (PCBM), [6,6] , 6] -phenyl-C71-butyric acid methyl ether (PC70BM), perylene derivatives such as perylene and 3,4,9,10 Perylene polymeric compound derivatives such as 3,4,9,10-perylenetetracarboxylic bisbenzimidazole (PTCBI) may be used. The photoactive layer 230 may be formed by spin coating, dip coating, chemical vapor deposition, spray coating, or the like.

The hole transport layer 240 may be formed as a thin film on the photoactive layer 230 using a solution for the hole transport layer 240. Here, the hole transport layer 240 may be formed with a nanostructure having a predetermined period on the top of the nanoimprinting process.

The hole transport layer 240 may be formed by spin coating on the photoactive layer 230 by dissolving one or more materials in a solvent or by preparing them in a suspension state.

For example, the hole transport layer 240 may be formed of a poly (3,4-ethylenedioxythiophene): poly (4-styrene sulfonate) sulfonate): polyglycol (glycerol)], PANI: poly (4-styrene sulfonate), PANI: camphor sulfonic acid, PDBT [poly (4,4'-dimethoxy bithophene) A material having at least one selected from the group consisting of a low molecular substance having an aryl amine group and a polymer, a low molecular substance having an aromatic amine group and a polymer, and a MoOx (Molybdenum Oxide) substance.

의 저온 진공 챔버에서 열처리하여 탈수화 공정을 통해 광학적 특성 및 전기적 특성이 향상된 일정한 주기를 가지는 나노 구조체를 가지는 정공 수송층(240)을 형성할 수 있다.The hole transport layer 240 formed with the nanostructure has a thickness of 80 to 100

And a hole transport layer 240 having a nanostructure having a constant period with improved optical characteristics and electrical characteristics can be formed through a dehydration process.

The hole transport layer 240 is formed by arranging a nano template patterned with a nano grid having a predetermined period on the surface, and applying a pressure, a part of the solution penetrates between the nano template by capillary phenomenon, The nanostructure can be patterned on the hole transport layer 240. [

The second electrode 250 may be formed on the hole transport layer 240. For example, the second electrode 250 may be a metal electrode such as silver (Ag), nickel (Ni), aluminum (Al), or gold (Au)

The second electrode 250 is formed by dehydrating the hole transport layer 240 by heat treatment, removing the nano template patterned with the nano grid used for the nanoimprinting process, and forming the hole transport layer 240 including the nano structure having a constant period (Not shown).

As described above, according to one embodiment, a hole transport layer 240 including a nanostructure having a predetermined period is formed on the photoactive layer 230 of the reverse-structured organic solar cell through a nanoimprinting process and a low-temperature dehydration process , Thereby realizing a highly efficient organic solar cell with improved optical characteristics and electrical characteristics.

According to one embodiment, by introducing the nanostructure having a constant period, the optical characteristic due to the reflection by the back electrode and the plasmonic resonance phenomenon, and the characteristics of the hole transport layer and the rear electrode It is possible to easily manufacture a highly efficient organic solar cell by effectively controlling the electrical characteristics by increasing the contact area.

In addition, according to one embodiment, because there is no heat treatment process at a high temperature, the present invention can be applied to a flexible substrate susceptible to high temperature, thereby realizing the production of a highly efficient flexible organic solar cell, and further promoting commercialization of the organic solar cell.

Hereinafter, the present invention will be described in more detail with reference to the following Experimental Examples and Examples. The following Experimental Examples and Examples are illustrative of the present invention, and the contents of the present invention are not limited by the following Examples.

Example  One

As shown in FIG. 1, a uniform nano-grid can be formed on the surface of the PEDOT: PSS used as a hole transport layer through a nanoimprinting process using a capillary pressure using a nanotube having a constant periodicity.

의 저온에서 열처리하여 탈수화 공정을 통해 용매를 제거한 후, 나노 주형을 분리할 수 있다. The mixture PEDOT: PSS can be composed of two kinds of polymeric materials, PEDOT and PSS. A PEDOT: PSS thin film having a thickness of about 40 nm was spin-coated on a glass substrate at 3000 rpm for 30 seconds to form a nano-scale nano-scale with a certain period of time on the thin film. 80 to 100

To remove the solvent through the dehydration process, and then to separate the nanostructures.

During this process, the capillary phenomenon causes the PEDOT: PSS solution to enter between the nanostructures of the template, forming a nanostructure with a constant period on the PEDOT: PSS surface.

3 is a view showing an FE-SEM of a surface of a PEDOT: PSS hole transporting layer having a certain nanostructure formed according to an embodiment.

3, an FE-SEM image of the surface of a PEDOT: PSS thin film formed by the nanoimprinting process using the capillary pressure described above is shown. More specifically, a nanoimprinting process using a capillary pressure using a PDMS template Shows an FE-SEM image of the surface of a PEDOT: PSS hole transport layer where a certain nanostructure was formed.

As can be seen from the FE-SEM image of the surface of the PEDOT: PSS hole transport layer having a certain nanostructure formed, it can be confirmed that a nano grating having a constant period on the surface of the PEDOT: PSS is successfully formed.

Example  2

의 시트 저항을 가지는 ~1,500

두께의 투명 ITO를 기판으로 사용할 수 있다. In order to introduce a hole transport layer containing a nanostructure having a constant period on the photoactive layer of an organic solar cell, 15

~ 1500 with sheet resistance of

Transparent ITO can be used as the substrate.

에서 1 시간 건조시킬 수 있다. The glass substrate on which ITO as the first electrode is formed can be cleaned by ultrasonic cleaning with acetone and isopropyl alcohol for 15 minutes, and then dried. Next, the surface treatment of the ITO substrate can be performed in an atmospheric pressure plasma surface treatment apparatus for 10 minutes. The ZnO sol-gel solution was spin-coated on the ITO substrate at 6000 rpm for 30 seconds, then 200

Lt; / RTI &gt; for 1 hour.

에서 20 분 건조시킬 수 있다. Next, a photoactive layer solution in which PTB7 and PC70BM were mixed in a weight ratio of 1: 1.5 and dissolved in a mixed solvent of dichlorobenzene and 1,8-diiodooctane (0.97 ml: 0.03 ml volume ratio) was added to the ZnO on the ZnO at 2500 rpm Spin coating for 30 seconds to form a photoactive layer thin film, and then 70

Lt; / RTI &gt; for 20 minutes.

의 저온에서 열처리하여 탈수화 공정을 통해 용매를 제거 후, 나노 주형을 분리시킬 수 있다. Immediately after the PEDOT: PSS thin film with a thickness of about 40 nm was spin-coated on the photoactive layer on a glass substrate at 3000 rpm for 30 seconds on the photoactive layer, a nanotube with a predetermined period of nano grid was formed on the thin film 80 to 100

The solvent can be removed through a dehydration process, and then the nanostructure can be separated.

During this process, the capillary phenomenon causes the PEDOT: PSS solution to enter between the nanostructures of the template, forming a nanostructure having a constant period on the surface of the PEDOT: PSS.

Thereafter, an organic thin film can be obtained by forming an Ag thin film having a film thickness of 100 nm in a vacuum chamber of 1 x 10 ^{&lt; -7} &gt; on the hole transporting layer and a second electrode using a vacuum deposition method.

Hereinafter, examples and comparative examples of the present invention will be compared and described.

4 is a graph showing a voltage-current curve of the organic solar cell manufactured through Example 1 and Comparative Example 1 according to an embodiment.

First, a comparative example will be described with reference to FIG.

Comparative Example  One

An organic solar cell including a hole transport layer in which a certain nanostructure is not introduced can be manufactured.

의 시트 저항을 가지는 ~1,500

두께의 투명 ITO를 유리 기판 상에 제조할 수 있다. 양극 층인 ITO가 형성된 유리 기판을 아세톤과 이소프로필 알코올으로 각 15 분간 초음파 세정을 행한 후, 건조시킬 수 있다. 그리고 대기압 플라즈마 표면처리 장치에서 10 분간, 상기 ITO 기판의 표면처리를 수행할 수 있다. The first electrode is 15

~ 1500 with sheet resistance of

Transparent ITO can be manufactured on the glass substrate. The glass substrate on which ITO as the anode layer is formed can be ultrasonically washed with acetone and isopropyl alcohol for 15 minutes, and then dried. Then, the surface treatment of the ITO substrate can be performed in an atmospheric pressure plasma surface treatment apparatus for 10 minutes.

에서 1 시간 건조시킬 수 있다. Next, a ZnO sol-gel solution was spin-coated on the ITO substrate at 6000 rpm for 30 seconds,

Lt; / RTI &gt; for 1 hour.

에서 15 분 건조시킬 수 있다. Thereafter, the solution was transferred to a glove box with a dry nitrogen atmosphere of 1 ppm or less of oxygen and mixed with PCDTBT and PC70BM in a weight ratio of 4 mg: 16 mg to dissolve a dichlorobenzene solvent (1 ml) in a nitrogen atmosphere. And then spin-coated at 1100 rpm for 60 seconds to form a photoactive layer thin film. Then, 80

Lt; / RTI &gt; for 15 minutes.

에서 1 시간 건조시킬 수 있다. Immediately after the PEDOT: PSS thin film having a thickness of about 40 nm was spin-coated on the photoactive layer on the glass substrate at 3000 rpm for 30 seconds,

Lt; / RTI &gt; for 1 hour.

Thereafter, an organic thin film can be obtained by forming an Ag thin film having a film thickness of 100 nm in a vacuum chamber of 1 x 10 ^{&lt; -7} &gt; on the hole transporting layer and a second electrode using a vacuum deposition method.

Referring to FIG. 4, the measurement results of the voltage-current density of the organic solar cell device including the hole transport layer having no constant nanostructure prepared in Comparative Example 1 can be confirmed.

The VOC value of the fabricated organic solar cell is 0.86, the Jsc value is 9.97, the FF value is 58%, and the photoelectric conversion rate is 4.95%.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.

Example  One

An organic solar cell including a hole transport layer into which a certain nano structure is introduced can be manufactured.

의 저온에서 열처리하여 탈수화 공정을 통해 용매를 제거한 후, 나노 주형을 분리시킬 수 있다. In this embodiment, a PEDOT: PSS thin film having a thickness of about 40 nm was prepared by spin coating a PEDOT: PSS aqueous solution on a photoactive layer on a glass substrate at 3000 rpm for 30 seconds in the solar cell manufacturing process described in Comparative Example 1 described above Immediately thereafter, a nano-scale mold having a predetermined period of a nano grid was placed on the thin film,

The solvent may be removed through a dehydration process, and the nanostructures may be separated.

During this process, the organic solar cell can be manufactured in the same manner except that the PEDOT: PSS solution is introduced between the nanostructures of the template by the capillary phenomenon to form a nanostructure having a constant period on the surface of the PEDOT: PSS .

The prepared organic solar cell has a Voc value of 0.87, a Jsc value of 11.24 and a FF of 59%, and a photoelectric conversion rate of 5.75%. Referring to FIG. 4, the voltage-current density measurement result of the device can be confirmed.

5 is a graph showing a voltage-current curve of the organic solar cell manufactured through Example 2 and Comparative Example 2 according to one embodiment.

Comparative Example  2

An organic solar cell including a hole transport layer in which a certain nanostructure is not introduced can be manufactured.

의 시트 저항을 가지는 ~1,500

두께의 투명 ITO를 유리 기판 상에 제조할 수 있다. 양극 층인 ITO가 형성된 유리 기판을 아세톤과 이소프로필 알코올으로 각 15 분간 초음파 세정을 행한 후, 건조시킬 수 있다. 그리고 대기압 플라즈마 표면처리 장치에서 10 분간, 상기 ITO 기판의 표면처리를 수행할 수 있다. The first electrode is 15

~ 1500 with sheet resistance of

Transparent ITO can be manufactured on the glass substrate. The glass substrate on which ITO as the anode layer is formed can be ultrasonically washed with acetone and isopropyl alcohol for 15 minutes, and then dried. Then, the surface treatment of the ITO substrate can be performed in an atmospheric pressure plasma surface treatment apparatus for 10 minutes.

에서 1 시간 건조시킬 수 있다. Next, a ZnO sol-gel solution was spin-coated on the ITO substrate at 6000 rpm for 30 seconds,

Lt; / RTI &gt; for 1 hour.

에서 20 분 건조시킬 수 있다. Then, PTB7-Th and PC70BM were mixed at a weight ratio of 1: 1.5, and the mixture was mixed with a mixed solvent of dichlorobenzene and 1,8-diiodooctane (0.97 ml: 0.03 ml volume ratio) The dissolved photoactive layer solution was spin coated on ZnO at 2500 rpm for 30 seconds under a nitrogen atmosphere to form a photoactive layer thin film,

Lt; / RTI &gt; for 20 minutes.

에서 1 시간 건조시킬 수 있다. Immediately after the PEDOT: PSS thin film having a thickness of about 40 nm was spin-coated on the photoactive layer on the glass substrate at 3000 rpm for 30 seconds,

Lt; / RTI &gt; for 1 hour.

Thereafter, an organic thin film can be obtained by forming an Ag thin film having a film thickness of 100 nm in a vacuum chamber of 1 x 10 ^{&lt; -7} &gt; on the hole transporting layer and a second electrode using a vacuum deposition method.

Referring to FIG. 5, the measurement results of the voltage-current density of the organic solar cell device including the hole transport layer having no constant nanostructure prepared in Comparative Example 1 can be confirmed.

The prepared organic solar cell has a Voc value of 0.78, a Jsc value of 15.70 and a FF of 65%, and a photoelectric conversion rate of 7.94%.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.

Example  2

An organic solar cell including a hole transport layer into which a certain nano structure is introduced can be manufactured.

의 저온에서 열처리하여 탈수화 공정을 통해 용매를 제거한 후, 나노 주형을 분리시킬 수 있다. In this example, a PEDOT: PSS thin film having a thickness of about 40 nm was prepared by spin coating a PEDOT: PSS aqueous solution on a photoactive layer on a glass substrate at 3000 rpm for 30 seconds in the solar cell manufacturing process described in Comparative Example 2 described above Immediately thereafter, a nano-scale mold having a predetermined period of a nano grid was placed on the thin film,

The solvent may be removed through a dehydration process, and the nanostructures may be separated.

During this process, the organic solar cell can be manufactured in the same manner except that the PEDOT: PSS solution enters the nanostructures of the template by capillary action to form a nanostructure having a constant period on the PEDOT: PSS surface .

The prepared organic solar cell has a Voc value of 0.78, a Jsc value of 15.83 and a FF of 69%, and a photoelectric conversion rate of 8.48%. Referring to FIG. 5, the voltage-current density measurement result of the device can be confirmed.

6 is a graph showing a voltage-current curve of the organic solar cell fabricated through Example 3 and Comparative Example 3 according to an embodiment.

Comparative Example  3

An organic solar cell including a hole transport layer in which a certain nanostructure is not introduced can be manufactured.

의 저온에서 건조하여 약 20 nm의 두께의 MoO₃ 박막을 형성한 것을 제외하고는 모두 동일한 방법으로 유기 태양 전지를 제조할 수 있다.In the solar cell manufacturing process shown in Comparative Example 2, a MoO ₃ thin film was formed by spin-coating an aqueous solution of MoO ₃ instead of the PEDOT: PSS aqueous solution on the photoactive layer for 30 seconds at 1000 rpm on a glass substrate,

To form a MoO ₃ thin film having a thickness of about 20 nm. The organic solar cell can be manufactured in the same manner as described above.

The prepared organic solar cell has a Voc value of 0.79, a Jsc value of 15.04 and a FF of 68%, and a photoelectric conversion rate of 8.13%. Referring to FIG. 6, the voltage-current density measurement result of the device can be confirmed.

Example  3

An organic solar cell including a hole transport layer into which a certain nano structure is introduced can be manufactured.

의 저온에서 열처리하여 탈수화 공정을 통해 용매를 제거한 후, MoO₃ 표면상에 일정한 주기를 가지는 나노 구조체를 형성한 것을 제외하고는 모두 동일한 방법으로 유기 태양 전지를 제조할 수 있다.In the solar cell manufacturing process described in Example 2, a MoO ₃ aqueous solution was spin-coated on a glass substrate at a rate of 1000 rpm for 30 seconds in place of the PEDOT: PSS aqueous solution on the photoactive layer to form a MoO ₃ thin film, Was placed on the thin film and 100

The organic solar cell can be manufactured in the same manner except that the solvent is removed through a dehydration process and then a nanostructure having a certain period is formed on the MoO ₃ surface.

The prepared organic solar cell has a Voc value of 0.80, a Jsc value of 15.97 and a FF of 70%, and a photoelectric conversion rate of 8.99%. Referring to FIG. 6, the voltage-current density measurement result of the device can be confirmed.

As described above, the embodiments are directed to a method for forming a nanostructure having a certain period through a nanoimprinting process and a low temperature dehydration process on a hole transport layer on a photoactive layer in an inverse structure organic solar cell, It is possible to realize a highly efficient organic solar cell in which electrical characteristics are effectively controlled.

Conventionally, studies on the introduction of nanostructures having a certain period to induce plasmonic resonance in an organic solar cell have been generally performed by forming a metal electrode along a nanostructure formed by directly introducing a nanostructure directly onto the surface of the organic photoactive layer . However, poly [N-9 '' - hepta-decanyl-2,7-carbazole-alt-5,5- (4 ', 7', - di- 2 -thienyl-2 ', 1', 3'-benzothiadiazole) In the case of an amorphous polymer having a high glass transition temperature such as PCDTBT, or an organic photoactive layer composed of a monomolecular material, it is difficult to form a nanostructure through a nanoimprinting process. In addition, a high temperature drying process accompanies damage of the photoactive layer Therefore, fabrication of a plasmonic organic solar cell using these materials is limited to synthesis and introduction of nanoparticles.

According to embodiments, a nano structure having a certain period is introduced into a hole transport layer formed on a photoactive layer in a reverse structure organic solar cell through a nanoimprinting process and a low temperature dehydration process, It is possible to easily manufacture a highly efficient organic solar cell by effectively controlling the optical characteristics by the reflection by the back electrode and the plasmonic resonance phenomenon, and the electric characteristics by the increase of the contact area between the hole transport layer and the back electrode,

In addition, according to the embodiments, since there is no heat treatment process at a high temperature, it is applicable to a flexible substrate susceptible to high temperature.

Organic solar cells, on the other hand, can be applied to most fields requiring energy harvesting in everyday life, such as mobile phone chargers and military equipment, due to their low cost and light weight. It is also suitable for installation on the outer wall of the building or on the ceiling of a car because the color is various and the appearance is beautiful. Organic solar cells, which are widely regarded as a next generation energy source, have not been commercialized because of their low photoelectric conversion efficiency compared to inorganic solar cells, despite their large commercialization and numerous applications. According to the embodiments, a highly efficient organic solar cell in which optical characteristics and electrical characteristics are effectively controlled can be manufactured, and commercialization of the organic solar battery can be accelerated.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. For example, it is to be understood that the techniques described may be performed in a different order than the described methods, and / or that components of the described systems, structures, devices, circuits, Lt; / RTI &gt; or equivalents, even if it is replaced or replaced.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

Claims (15)

Forming a thin film-type hole transporting layer on the photoactive layer using a solution for the hole transporting layer;
Forming a nanostructure having a predetermined period through a nanoimprinting process on the hole transport layer; And
A step of heat-treating the hole transport layer including the nanostructure having the predetermined period to dehydrate
Wherein a hole conduction layer having a regular nanostructure is introduced through a low temperature process on the photoactive layer. The method according to claim 1,
The step of forming a thin film-type hole transport layer using the solution for the hole transport layer on the photoactive layer includes:
Forming an electron transport layer on the substrate on which the first electrode is formed; And
Forming an organic photoactive layer on the electron transporting layer
Wherein a hole conduction layer having a regular nanostructure is introduced through a low temperature process on the photoactive layer. The method according to claim 1,
Wherein the photoactive layer comprises:
A single layer structure of a mixed thin film layer of a hole receptor material and an electron acceptor material or a multilayer structure in which the hole receptor material and the electron acceptor material are laminated
Wherein a hole conduction layer having a regular nanostructure is introduced through a low temperature process onto the photoactive layer. The method according to claim 1,
The step of forming a thin film-type hole transport layer using the solution for the hole transport layer on the photoactive layer includes:
One or more materials are dissolved in a solvent or a suspension state is formed on the photoactive layer, and the hole transport layer is formed by spin coating
Wherein a hole conduction layer having a regular nanostructure is introduced through a low temperature process onto the photoactive layer. The method according to claim 1,
The hole-
Poly (4-styrene sulfonate): poly (3,4-ethylenedioxythiophene): poly (4-styrene sulfonate) : PSS [polyaniline: poly (4-styrene sulfonate)], PANI: polyaniline: camphor sulfonic acid, PDBT [poly (4,4'-dimethoxy bithophene)], arylamine group And a material comprising at least one member selected from the group consisting of a polymer, an aromatic amine group, and a MoOx (Molybdenum Oxide) material
Wherein a hole conduction layer having a regular nanostructure is introduced through a low temperature process onto the photoactive layer. The method according to claim 1,
The step of forming a nanostructure having a predetermined period through the nanoimprinting process on the hole transport layer may include:
A nanostructure having a predetermined periodicity is patterned on the surface of the hole transport layer and a pressure is applied to the nanostructure to cause a part of the solution to permeate through the nanostructure by capillary phenomenon, And the nanostructure is patterned on the hole transport layer
Wherein a hole conduction layer having a regular nanostructure is introduced through a low temperature process onto the photoactive layer. The method according to claim 1,
The step of dehydrating the hole transport layer including the nanostructure having the predetermined period by heat treatment may include:
Wherein the hole transport layer containing the nanostructure having the constant period is formed at a thickness of 80 to 100

And is applicable to a flexible substrate which is susceptible to high temperatures because it is not subjected to a high temperature heat treatment process
Wherein a hole conduction layer having a regular nanostructure is introduced through a low temperature process onto the photoactive layer. The method according to claim 1,
Removing the patterned nanostructures used for the nanoimprinting process after dehydrating the hole transport layer by heat treatment; And
Forming a second electrode on the hole transport layer including the nanostructure having the constant period
And a hole conduction layer having a regular nanostructure through a low temperature process is introduced onto the photoactive layer. A first electrode formed on a transparent substrate having electrical conductivity;
An electron hydrogen layer formed on the first electrode;
A photoactive layer formed on the electron hydrogen layer;
A thin film-form hole transport layer formed on the photoactive layer using a solution for the hole transport layer; And
A second electrode formed on the hole transport layer,
/ RTI &gt;
The hole transport layer may be formed by a nanoimprinting process in which a nanostructure having a predetermined period is formed
And a hole conduction layer having a regular nanostructure is introduced through a low temperature process on the photoactive layer. 10. The method of claim 9,
Wherein the photoactive layer comprises:
A single layer structure of a mixed thin film layer of a hole receptor material and an electron acceptor material or a multilayer structure in which the hole receptor material and the electron acceptor material are laminated
And a hole conduction layer having a regular nanostructure is introduced through a low temperature process on the photoactive layer. 10. The method of claim 9,
The hole-
One or more materials formed on the photoactive layer by dissolving in a solvent or in a suspension state and spin coating
And a hole conduction layer having a regular nanostructure is introduced through a low temperature process on the photoactive layer. 10. The method of claim 9,
The hole-
Poly (4-styrene sulfonate): poly (3,4-ethylenedioxythiophene): poly (4-styrene sulfonate) : PSS [polyaniline: poly (4-styrene sulfonate)], PANI: polyaniline: camphor sulfonic acid, PDBT [poly (4,4'-dimethoxy bithophene)], arylamine group And a material comprising at least one member selected from the group consisting of a low molecular substance having a polymer and an aromatic amine group, a polymer, and a MoOx (Molybdenum Oxide) substance
And a hole conduction layer having a regular nanostructure is introduced through a low temperature process on the photoactive layer. 10. The method of claim 9,
The hole-
A nanostructure patterned with a nanostructured lattice pattern having a predetermined period on the surface is arranged and a part of the solution penetrates between the nanostructures due to capillary action as a result of applying pressure to form a nanostructure having the constant period in the form of the nanostructure The one patterned on the hole transport layer
And a hole conduction layer having a regular nanostructure is introduced through a low temperature process on the photoactive layer. 10. The method of claim 9,
The hole-
Wherein the hole transport layer including the nanostructure having the constant period is formed at a thickness of 80 to 100

Which is formed by dehydrating by heat treatment in a low-temperature vacuum chamber of
And a hole conduction layer having a regular nanostructure is introduced through a low temperature process on the photoactive layer. 10. The method of claim 9,
Wherein the second electrode comprises:
The hole transport layer is dehydrated by heat treatment and then the nano grid used for the nanoimprinting process is removed to form a nanostructure on the hole transport layer containing the nanostructure having the constant period
And a hole conduction layer having a regular nanostructure is introduced through a low temperature process on the photoactive layer.

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