KR20190138948A - Composition for forming self-healing photoactive layer and Organic solar cells comprising the same - Google Patents

Abstract

The present invention relates to a conjugated polymer, a production method thereof, and an organic solar cell using the same. Two or more conjugated polymers is blended to have a self-healing function while maintaining intrinsic electric and physical properties of a photoactive layer, thereby being able to repair damages caused by external stimuli. The conjugated polymer of the present invention is applicable to various fields such as catalyst materials, bio-materials, drugs, nonlinear optical materials or organic electronic materials. In particular, the conjugated polymer of the present invention can be usefully used as an organic semiconductor material used in the photoactive layer of the organic solar cell, and then element service life of the organic solar cell is improved.

Description

Composition for forming self-healing photoactive layer and organic solar cell comprising same

The present invention relates to a composition for forming a self-healing photoactive layer, and more particularly, to a composition for forming a self-healing photoactive layer in which two or more types of self-healing polymers having both conductivity and self-healing function and an organic solar cell including the same are provided. It is about.

Solar cells are photoelectric conversion elements that convert solar energy into electrical energy, and are being spotlighted as next generation energy resources. Solar cells can be broadly classified into inorganic solar cells and organic solar cells, which are bilayer pn junctions in which p-type semiconductors and n-type semiconductors are formed in separate layers according to the structure of the photoactive layer. It is divided into a bulk heterojunction type in which a structure, a p-type semiconductor, and an n-type semiconductor are mixed.

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 derivative, and in early 1990, heger group The photovoltaic cell was generated using a mixed film of conjugated polymer and fullerene derivative as a photoactive layer, and the efficiency was improved to 7-8% by developing 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.

Nevertheless, organic solar cells are easily broken or deteriorated in electrical properties by defects such as cracks in the photoactive layer due to various external stimuli (or forces) such as ultraviolet rays, moisture, air, or strain. Have Due to this problem, the organic solar cell is very limited in life, so to solve this problem is required to develop a material that can effectively heal damage with improved electrical properties.

Patent Document 1. Republic of Korea Patent Publication No. 10-2014-0025621

Accordingly, the present invention has been made to solve the above problems, an object of the present invention is a composition for forming a self-healing photoactive layer blending two or more types of self-healing polymers having both conductivity and self-healing function and the organic applied thereto It is to provide a solar cell.

The present invention provides a composition for forming a self-healing photoactive layer comprising a first polymer represented by the following formula (1) or (2), a second polymer represented by the following formula (3), and a solvent.

In the above formula,

R ₁ to R ₁₃ are the same as or different from each other, and each independently hydrogen, halogen group, cyano group, nitro group, hydroxyl group, amide group, ester group, ketone group, thioester group, silyl group, substituted or unsubstituted Substituted alkyl group having 1 to 30 carbon atoms, substituted or unsubstituted alkylthioyl group having 5 to 35 carbon atoms, substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, substituted Or a heteroaryl group having 2 to 50 carbon atoms which is unsubstituted and includes any one or more of S, N, O, P, and Si, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted carbon group having 3 to 30 carbon atoms. 30 cycloalkenyl groups, substituted or unsubstituted aryl groups having 5 to 50 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 30 carbon atoms, substituted or unsubstituted aryloxy groups having 5 to 50 carbon atoms, substituted or unsubstituted An alkylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted arylamino group having 6 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 1 to 30 carbon atoms and a substituted or unsubstituted aryl silyl group having 5 to 50 carbon atoms. Selected from the group.

x + y = 1, 0.1≤x≤0.9, 0.1≤y≤0.9, m + n = 1, 0.1≤m≤0.9, 0.1≤n≤0.9, p + q = 1, 0.1≤p≤0.9, 0.1≤ q ≦ 0.9, and z, o, and r are each an integer of 5 to 100,000.

According to a specific embodiment of the present invention, the R ₁ , R ₂ , R ₃ , R ₄ , R ₆ , R ₇ , R ₉ , R ₁₀ , R ₁₂ , R ₁₃ are the same as or different from each other, and each independently hydrogen , Halogen, substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, substituted or unsubstituted alkylthioyl group having 5 to 25 carbon atoms, and substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. have.

According to a specific embodiment of the present invention, R ₅ , R ₈ , R ₁₁ are the same as or different from each other, and each independently hydrogen, halogen, substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, substituted or unsubstituted carbon number It may be any one selected from 3 to 30 cycloalkyl group.

The first polymer and the second polymer may be mixed in a weight ratio of 1: 0.5 to 1: 4.

The solvent may be any one or more selected from the group consisting of dimethylformamide, chloroform, hexane, cyclohexane, toluene, xylene, chlorobenzene, dichlorobenzene, ethylene acetate, tetrahydrofuran and N-methylallyrrolidinone. .

The composition may further comprise an n-type molecule, wherein the n-type molecule is methyl (6,6) -phenyl-C61-butyrate (PC ₆₀ BM), (6,6) -phenyl-C61-butyric Acid methyl ester (C ₆₀ -PCBM), (6,6) -phenyl-C71-butyric acid methyl ester (C ₇₀ -PCBM), (6,6) -phenyl-C77-butyric acid methyl ester (C ₇₆ -PCBM), (6,6) -phenyl-C79-butyric acid methyl ester (C ₇₈ -PCBM), (6,6) -phenyl-C81-butyric acid methyl ester (C ₈₀ -PCBM), (6 , 6) -phenyl-C83-butyric acid methyl ester (C ₈₂ -PCBM), (6,6) -phenyl-C85-butyric acid methyl ester (C ₈₄ -PCBM), bis (1- [3- ( Methoxycarbonyl) propyl] -1-phenyl) (Bis-C ₆₀ -PCBM), 3'-phenyl-3'H-cyclopropa (8,25) (5,6) fullerene-C70-bis-D5h (6) any one selected from the group consisting of -3'-butyric acid methyl ester (Bis-C ₇₀ -PCBM), indene-C60-bisadduct (ICBA), monoindenylC60 (ICMA), and combinations thereof Can be.

The present invention also provides a photoactive layer for an organic solar cell manufactured through the composition for forming a self-healing photoactive layer.

According to a specific embodiment of the present invention, the photoactive layer may be left for 1 to 30 hours, or micro-scale cracks may be self-recovered by annealing at 50 to 200 ° C. for 1 to 30 hours.

According to a specific embodiment of the present invention, when the micro-scale crack is generated by an external force on the optical microscope, 60 to 99% of the photoactive layer before the damage by the self-recovery process through time or heat treatment It may be to recover.

According to a specific embodiment of the present invention, the photoactive layer is any one selected from the group consisting of vacuum deposition, screen printing, printing, bar coating, slot die coating, spin coating, dipping and ink spraying. Through the method of may be to be formed into a thin film.

The present invention also provides a photoactive layer organic solar cell employing the photoactive layer.

According to a specific embodiment of the present invention, the organic solar cell includes a substrate; A first electrode on the substrate; A buffer layer on the first electrode; A photoactive layer positioned on the charge transport layer; And a second electrode positioned on the photoactive layer.

According to a specific embodiment of the present invention, the buffer layer may include a poly (3,4-ethylenedioxythiophene) [PEDOT: PSS] doped with a polyehthylenimine ethoxylated (PEIE) polymer or a polystyrene sulfonate.

According to a specific embodiment of the present invention, the first and second electrodes are the same as or different from each other, and are independently of Indium Tin Oxide (ITO), Fluorinated Tin Oxide (FTO), Indium Zinc Oxide (IZO), and AZO (Al). -doped Zinc Oxide), IZTO (Indium Zinc Tin Oxide), SnO2, ZnO, Carbon Nanotube, Graphene, TiO ₂ , MoO ₃ , V ₂ O ₅ , Ca, LiF, Gold, Platinum, Silver, Aluminum , Nickel and chromium may be any one or more selected from the group consisting of.

According to a specific embodiment of the present invention, the substrate is glass, polydimethylsiloxane (PDMS), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polycarbonate (PC), polyvinyl alcohol (PVA), polyacryl It may be any one selected from the group consisting of latex, polyimide (PI), polynorbornene and polyethersulfone (PES).

According to the present invention, by blending two or more conjugated polymers to have a self-healing function while maintaining the intrinsic physical and physical properties of the photoactive layer, damages caused by external stimuli can be recovered.

Therefore, the photoactive layer having the above-described advantages is excellent in lifespan and long-term stability, it can be used in various fields such as biomaterials, pharmaceuticals, nonlinear optical materials or organic electronic materials.

Since the photoactive layer according to the present invention has excellent compatibility with the florene derivative, the crystal size formed when it is mixed with the florene forming the nanocrystals is fine, and the bonding area with the florene as the electron acceptor is high. This can be enhanced to improve charge transfer and separation at the interface between the polymer and the fullerene and to effectively transfer charge.

1 is a view showing the interaction between the first polymer represented by the formula (1) and the second polymer represented by the formula (3).
FIG. 2 is a diagram illustrating an interaction between a first polymer represented by Chemical Formula 2 and a second polymer represented by Chemical Formula 3. FIG.
3 is a self-healing photoactive layer optical micrograph prepared from Example 1 before and after heat treatment.
4 is a self-healing photoactive layer optical micrograph prepared from Example 2 over time.
5 is a graph of current density voltage measurement of organic solar cells prepared from Comparative Example 2 and Examples 6 to 8. FIG.
6 is a cross-sectional view of an organic solar cell according to the present invention.

Hereinafter, various aspects and various embodiments of the present invention will be described in more detail.

One aspect of the present invention relates to a composition for forming a self-healing photoactive layer comprising a first polymer represented by Formula 1 or Formula 2, a second polymer represented by Formula 3, and a solvent.

[Formula 1]

[Formula 2]

[Formula 3]

In the above formula,

R ₁ to R ₁₃ are the same as or different from each other, and each independently hydrogen, a halogen group, a cyano group, a nitro group, a hydroxyl group, an amide group, an ester group, a ketone group, a thioester group, a silyl group, a substituted or unsubstituted group Substituted alkyl group having 1 to 30 carbon atoms, substituted or unsubstituted alkylthioyl group having 5 to 35 carbon atoms, substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, substituted Or a heteroaryl group having 2 to 50 carbon atoms which is unsubstituted and includes any one or more of S, N, O, P, and Si, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted carbon group having 3 to 30 carbon atoms. 30 cycloalkenyl groups, substituted or unsubstituted aryl groups having 5 to 50 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 30 carbon atoms, substituted or unsubstituted aryloxy groups having 5 to 50 carbon atoms, substituted or unsubstituted An alkylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted arylamino group having 6 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 1 to 30 carbon atoms and a substituted or unsubstituted aryl silyl group having 5 to 50 carbon atoms. Selected from the group.

x + y = 1, 0.1≤x≤0.9, 0.1≤y≤0.9, m + n = 1, 0.1≤m≤0.9, 0.1≤n≤0.9, p + q = 1, 0.1≤p≤0.9, 0.1≤ q ≦ 0.9, and z, o, and r are each an integer of 5 to 100,000.

More specifically, the R ₁ , R ₂ , R ₃ , R ₄ , R ₆ , R ₇ , R ₉ , R ₁₀ , R ₁₂ , R ₁₃ are the same as or different from each other, and each independently hydrogen, halogen, substituted or It may be any one selected from an unsubstituted alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted alkyl thionyl group having 5 to 25 carbon atoms, and a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, wherein R ₅ , R ₈ , R ₁₁ are the same as or different from each other, and each independently selected from hydrogen, halogen, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, or a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms Can be.

In Formulas 1, 2, and 3, x + y = 1, 0.8 ≦ x ≦ 0.9, 0.1 ≦ y ≦ 0.2, m + n = 1, 0.8 ≦ m ≦ 0.9, 0.1 ≦ n ≦ 0.2, p + q = 1 , 0.8≤p≤0.9, 0.1≤q≤0.2 is preferable, the energy efficiency is significantly lowered to 5% or less compared to the self-healing effect is increased when y, n, q exceeds 0.2, so the effect or cost It is not efficient in terms of aspects.

In the present invention, the halogen is not particularly limited as long as it is a halogen commonly used in the art, but may be any one selected from the group consisting of chlorine, iodine, fluorine and bromine in the present invention.

In the present invention, the 'substituted' may be substituted with any one selected from the group consisting of hydrogen, halogen, a straight or branched chain alkyl group having 1 to 20 carbon atoms and a straight or branched chain cycloalkyl group having 3 to 20 carbon atoms.

According to a preferred embodiment of the present invention, the first and second polymers represented by the formulas (1), (2) and (3) according to the present invention are generally polymers having a conductivity of 10 ⁻⁷ cm ⁻¹ or more. Polymer materials used in real life have been known as insulators because of their lightness and elasticity, but high-conductivity polymer materials such as polyethylene, polypyrrole, and polythiophene have been developed since the discovery of the first conductive polymer, polyacetylene. .

In the present invention, the composition for the photoactive layer is a polymer blend of two kinds of polymers, and is used to obtain a polymer having better properties than when the polymer is used alone. Specifically, the present invention refers to a structure in which the first polymer represented by Formula 1 or 2 and the second polymer represented by Formula 3 are mixed, and the first polymer represented by Formula 1 is an n-type polymer, The first polymer to be represented is a p-type polymer, and the second polymer represented by Formula 3 is a p-type polymer.

When the polymer represented by Chemical Formula 1 is used as the first polymer, by using a naphthalene diimide conjugated to the polymer main chain as a self-healing function, it can be used without introducing a separate self-healing functional group. In addition, the first polymer represented by Formula 1 has the advantage that the self-healing effect can be realized without loss of conductivity by forming a hydrogen bond (FIG. 1) with the second polymer into which the self-healing functional group is introduced into the polymer main chain. In addition, since the first polymer represented by Chemical Formula 1 is an n-type polymer, it can be utilized as a photoactive layer without attaching an n-type molecule separately, and the blend polymers (first and second) forming the photoactive layer are hydrogen-bonded with each other. Combined to have an excellent self-healing effect throughout the photoactive layer. When the photoactive layer is manufactured using the same, the self-healing function can be effectively implemented while maintaining the conjugated structure of the n-type polymer and the p-type polymer, and thus, there is an advantage of having excellent conductivity and self-healing function.

In the case of using the polymer represented by Chemical Formula 2 as the first polymer, the thymine capable of forming a hydrogen bond with the self-healing functional group of the second polymer is introduced at the terminal of the side chain of the p-type polymer having a conjugated structure, thereby minimizing conductivity. While having a loss, it is possible to implement a composition for a photoactive layer in which different p-type polymers are blended to have an excellent self-healing effect (FIG. 2). Since only p-type polymer can impart self-healing function, in order to utilize as a photoactive layer of a bulk heterojunction (BHJ), n-type molecules can be further added to the composition. That is, various n-type molecules including PCBM may be added and used as the ternary photoactive layer composition.

In other words, the first polymer having a new structure according to the present invention can improve self-healing ability and solve problems such as deterioration of performance due to conductivity loss, compared to a conjugated polymer in which only a self-healing functional group is introduced into the conjugated polymer.

The first polymer and the second polymer according to the present invention introduce a functional group having a self-healing function into the conjugated polymer main chain or side chain of Formulas 1, 2, and 3, thereby minimizing conductivity loss by the self-healing functional group serving as an insulator. Including the self-healing functional group at the maximum ratio that the self-healing function can be sufficiently exhibited, while maintaining the inherent electrical and physical properties of the conjugated polymer, and having the self-healing function of the conjugated polymer itself, A self-healing photoactive layer with excellent compatibility was implemented.

The first polymer represented by [Formula 1] may be preferably represented by the following [Formula 1a].

[Formula 1a]

The first polymer represented by [Formula 2] may be preferably represented by the following [Formula 2a].

[Formula 2a]

The second polymer represented by [Formula 3] may be preferably represented by any one selected from the following [Formula 3a] to [Formula 3d].

[Formula 3a]

[Formula 3b]

[Formula 3c]

[Formula 3d]

In Formula 3, since R ₉ , R ₁₀ , R ₁₂ , and R ₁₃ are alkylthiophenyl groups, the HOMO energy level is deeper than that of the alkoxyalkyl group, thereby increasing the Voc. Thus, Formula 3 is represented by Formulas 3c to 3d. It is most preferable to select from among them.

In Chemical Formulas 1, 2, and 3, z, o, and r are each an integer of 5 to 100,000.

The photoactive layer prepared therefrom has excellent resistance to strain, self-healing recovery, and excellent conductivity, and thus can be used in various fields such as biomaterials, pharmaceuticals, nonlinear optical materials, or organic electronic materials. .

Finally, p-type polymer or n-type molecule or additive may be further added according to the kind and purpose of the photoactive layer to be prepared, for example, bulk heterojunction structure in which n-type molecule and p-type polymer are mixed. (bulk heterojunction; BHJ), when the p-type polymer of the formula (2) is selected as the first polymer to the composition, the n-type molecule may be further attached.

The composition may further comprise an n-type molecule, wherein the n-type polymer is methyl (6,6) -phenyl-C61-butyrate (PC ₆₀ BM), (6,6) -phenyl-C61-butyric Acid methyl ester (C ₆₀ -PCBM), (6,6) -phenyl-C71-butyric acid methyl ester (C ₇₀ -PCBM), (6,6) -phenyl-C77-butyric acid methyl ester (C ₇₆ -PCBM), (6,6) -phenyl-C79-butyric acid methyl ester (C ₇₈ -PCBM), (6,6) -phenyl-C81-butyric acid methyl ester (C ₈₀ -PCBM), (6 , 6) -phenyl-C83-butyric acid methyl ester (C ₈₂ -PCBM), (6,6) -phenyl-C85-butyric acid methyl ester (C ₈₄ -PCBM), bis (1- [3- ( Methoxycarbonyl) propyl] -1-phenyl) (Bis-C ₆₀ -PCBM), 3'-phenyl-3'H-cyclopropa (8,25) (5,6) fullerene-C70-bis-D5h (6) -3'-butyric acid methyl ester (Bis-C ₇₀ -PCBM), indene-C60-bisadduct (ICBA), monoindenylC60 (ICMA), poly {[ N , N ' -bis (2- octyldodecyl) -1,4,5,8-naphthalene diimide-2,6 -diyl] - alt -5,5 '- (2,2'-bithiophene)} (PNDI2T or N2200), poly [[ N, N'-bis (2-octyldodecyl) -3,4,9,10-perylene diimide-1,7-diyl]]-alt- (thiophene-2,5-diyl) (PPDIODT), 3,9- bis (2-methylene- (3- (1,1-dicyanomethylene) -indanone))-5,5,11,11-tetrakis (4-hexylphenyl) -dithieno [2,3- d : 2 ', 3'- d ' ] -s-indaceno [1,2- b : 5,6- b' ] dithiophene (ITIC), 3,9-bis (2-methylene- (5,6-difluoro-3-oxo-2,3 -dihydro-1 H -inden-1-ylidene) malononitrile) -5,5,11,11-tetrakis (4-hexylphenyl) -dithieno [2,3- d : 2 ', 3'- d' ]- s- indaceno [1,2- b : 5,6- b ' ] dithiophene (ITIC-4F), (5 Z , 5' Z ) -5,5 '-(((4,4,9,9-tetraoctyl-4 , 9-dihydro- s -indaceno [1,2- b : 5,6- b '] dithiophene-2,7-diyl) bis (benzo [ c ] [1,2,5] thiadiazole-7,4-diyl )) bis (methanylylidene)) bis (3-ethyl-2-thioxothiazolidin-4-one) (O-IDTBR), 2,2 '-((2 Z , 2' Z )-((((4,4,9) , 9-tetrakis (4-hexylphenyl) -4,9-dihydro-sindaceno [1,2-b: 5,6-b '] dithiophene-2,7-diyl) bis (4-((2-ethylhexyl) oxy ) thiophene-5,2-diyl)) bis (methanylylidene)) bis (5,6-difluoro-3-oxo-2,3-dihydro-1 H -indene-2,1-diylidene)) dimalononitrile (IEICO-4F ), 5,5 '-(9,9'-spirobi [fluorene] -2,7-diyl) bis (2,9-dime) thylanthra [2,1,9- def : 6,5,10- d'e'f ' ] diisoquinoline-1,3,8,10 (2 H , 9 H ) -tetraone) (SF-PDI ₂ ) and these It may be any one selected from the group consisting of

The photoactive layer composition may produce a bulk heterojunction type photoactive layer, which may be applied to an organic solar cell.

Therefore, when used in an organic solar cell, it is possible to obtain an organic solar cell capable of self-recovering damage caused by external stimuli with better energy conversion efficiency.

1 and 2 illustrate the interaction for self-healing of the first and second polymers in the photoactive layer. As shown here, the first and second polymers according to the present invention have an intermolecular attraction due to hydrogen bonding. If a crack occurs due to an external force such as strain, the crack will recover over time or through annealing.

If the first and second polymers of the above-described chemical structure are not self-healing function, but due to the presence of the self-healing functional group as an insulator, there may be a problem that the first purpose electrical conductivity of the photoactive layer is greatly reduced. . In consideration of this, if the ratio of the self-healing functional group is reduced, the conductivity can be prevented from being greatly reduced, but it may cause a problem that takes more than twice as long as self-recovery.

The first polymer and the second polymer may be mixed in a weight ratio of 1: 0.5 to 1: 4. As described above, the first polymer and the second polymer are optimized for self-healing, and the mixing weight ratio of the first polymer and the second polymer may vary depending on the ratio of the self-healing functional groups, but the ratio of 1: 0.5 to 1: 4 If the mixing weight ratio is not particularly limited, more preferably 1: 0.5 to 1: 1.5 shows the best self-healing ability, when applied to the photoactive layer of the solar cell has the advantage of achieving a high photoelectric conversion efficiency. . If the weight ratio of the first polymer and the second polymer is less than 1: 0.5 or more than 1: 4, since the self-healing functional group is limited, a problem may occur that the self-healing ability is lowered.

The solvent is not particularly limited as long as it is used for fabricating the photoactive layer of the organic solar cell, but does not affect the physical properties of the first and second polymers, and has excellent solubility in dimethylformamide, chloroform, hexane, cyclohexane, toluene Preference is given to using at least one selected from the group consisting of xylene, chlorobenzene, dichlorobenzene, ethylene acetate, tetrahydrofuran and N-methylallyrrolidinone.

In addition, the composition for forming a self-healing photoactive layer of the present invention may be formed when the fullerene derivative is mixed, the fullerene nanocrystals are large, and the junction area between the conjugated polymer and the fullerene derivative is narrow. That is, the composition for forming a self-healing photoactive layer according to the present invention has a high miscibility with a fullerene derivative, thereby increasing the bonding area, thereby improving charge transfer and separation at the interface between the polymer and the fullerene, and improving hole mobility when the active layer is manufactured. If this is used as an organic solar cell, the effect of increasing the light conversion efficiency can be expected.

The efficiency of the solar cell is determined by Voc, Isc, FF, etc. Among these, the open circuit voltage V _OC is determined by the band gap of the semiconductor. In other words, if a material with a large band gap is used, a high V _OC can be generally obtained. The smaller the band gap, the wider the wavelength range of absorbable light, but in this case, the V _OC value is also reduced. Importantly, the polymer of the present invention is characterized in that it has a bandgap of 1.5 to 2.5 eV even though it has a self-healing functional group as an insulator.

Another aspect of the present invention relates to a self-healing photoactive layer prepared through the composition for forming a self-healing photoactive layer. The photoactive layer is any one selected from the group consisting of a vacuum deposition method, a screen printing method, a printing method, a bar coating method, a slot die coating method, a spin coating method, a dipping method and an ink spraying method for forming the self-healing photoactive layer forming composition. It is characterized in that the thin film manufactured through the method.

Since the composition for forming the self-healing photoactive layer has been described in detail above, the repeated content thereof will be omitted.

The photoactive layer is left for 1 to 30 hours, or micro-scale cracks are self-recovered through heat treatment (annealing) at 50 to 200 ° C. for 1 to 30 hours, and the heat recovery time can be shortened. Specifically, when the micro-scale crack is generated by an external force on the optical microscope, 60 to 99% of the photoactive layer may be recovered before the damage due to self recovery through time or heat treatment (FIG. 3, 4).

Another aspect of the invention relates to an organic solar cell employing the self-healing photoactive layer, specifically, the substrate 110; A first electrode 120 positioned on the substrate 110; A charge transport layer 130 positioned on the first electrode 120; A photoactive layer 140 positioned on the charge transport layer 130; And a second electrode 150 positioned on the photoactive layer 140. The structure of the organic solar cell according to the present invention is shown in FIG. 6.

The substrate 110 is any one selected from the group consisting of glass, polydimethylsiloxane (PDMS), polycarbonate (PC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyisosulfonate (PES). May be a glass substrate.

The first electrode 120 or the second electrode 150 is the same as or different from each other, and is independently of indium tin oxide (ITO), fluorinated tin oxide (FTO), indium zinc oxide (IZO), and AZO (Al-doped). Zinc Oxide), IZTO (Indium Zinc Tin Oxide), SnO2, ZnO, Carbon Nanotube, Graphene, TiO ₂ , MoO ₃ , V ₂ O ₅ , Ca, LiF, Gold, Platinum, Silver, Aluminum, Nickel And it may be any one or more selected from the group consisting of chromium. Specifically, when the first electrode is ITO, the second electrode is most preferably MoO ₃ / Ag or Au, Al.

According to one embodiment of the present invention, the first electrode 120 includes a poly (3,4-ethylenedioxythiophene) [PEDOT: PSS] doped with polyehthylenimine ethoxylated (PEIE) polymer or polystyrenesulfonate. The buffer layer 130 is formed. The buffer layer may be formed to a thickness of 1 to 20 nm.

When the buffer layer includes a polymer made of polyehthylenimine ethoxylated (PEIE), it is a polyehthylenimine ethoxylated (PEIE) polymer and is formed by the surface dipole of the amine group NH ₂ included in the PEIE. 120) has the effect of lowering the work function. In addition, such an amine group improves adhesion between the first electrode 120 and the photoactive layer 140 by chemical interaction with the photoactive layer 140 formed on the PEIE polymer buffer layer 130.

In addition, when poly (3,4-ethylenedioxythiophene) [PEDOT: PSS] doped with polystyrene sulfonate is used as the buffer layer formed on the first electrode, hole mobility may be improved.

The method of forming the buffer layer is not particularly limited as long as it is a conventional lamination method used in the battery field, but may be introduced through a method such as spin coating.

The photoactive layer 140 is formed on the buffer layer 130, the composition for forming the self-healing photoactive layer in the printing method, bar coating method, slot die coating method, spin coating method, screen printing method and doctor blade method It is formed by coating or coating by any one method selected, and more preferably, spin coating can be used.

Furthermore, the present invention provides a tandem organic solar cell comprising the organic optoelectronic device as a unit cell, and including two or more optoelectronic devices in which the unit cells are vertically bonded.

Hereinafter, the present invention will be described in more detail with reference to preferred examples. However, these examples are intended to illustrate the present invention in more detail, and the scope of the present invention is not limited thereto, and various changes and modifications are possible within the scope and technical scope of the present invention. Will be self-evident.

Preparation Example 1 Synthesis of First Polymer Represented by Chemical Formula 1a (PNDI-10)

As shown by the following [Scheme 1] to prepare a first polymer represented by the formula (1a) (PNDI-10).

Scheme 1

5,5'-bis (trimethylstenyl) 2,2'-bithiophene (74.7 mg, 0.152 mmol), 4,9-dibromo-2,7-bis (2-octyldodecyl) benzo [lmn ] [3,8] phenanthroline-1,3,6,8 (2H, 7H) -tetraone (135 mg, 0.137 mmol), 4,9-dibromobenzo [lmn] [3,8] phenan Trolline-1,3,6,8 (2H, 7H) -tetraone (6.4 mg, 0.015 mmol), tris (dibenzylideneacetone) dipalladium (0) (Pd ₂ (dba) ₃ ) (4.17 mg, 4.6 μmol) and tri (ortho-tolyl) phosphine (P (o-tolyl) ₃ ) (5.55 mg, 18.2 μmol) were mixed and then dissolved in degassed toluene (8.0 mL) to prepare a reaction. . The reaction was stirred at 120 ° C. for 48 hours, cooled to room temperature, precipitated in methanol, and filtered. This was washed with Soxhlet extraction in the order of methanol, acetone, hexane, and extracted with chloroform. The extracted solution was removed by chloroform using a rotary evaporator, and then precipitated in methanol to obtain a conjugated polymer (PNDI-10) (111 mg, 78%) represented by [Formula 1a] through a filter.

Preparation Example 2 Synthesis of First Polymer (PTB7-Tm10) Represented by Chemical Formula 2a>

As shown by the following [Scheme 2] to prepare a first polymer represented by the formula (2a) (PTB7-Tm10).

Scheme 2

(1) 1- (6-bromohexyl) -5-methylpyrimidine-2,4 (1) represented by [Formula I] H , 3 H )-synthesis of dione

5-Methylpyrimidine-2,4 ( 1H , 3H ) -dione (1 g, 7.93 mmol) was added to anhydrous tetrahydrofuran (30 mL) and stirred. Potassium carbonate (1.64 g, 11.9 mmol) was added thereto, followed by stirring for 1 hour. 1,6-Dibromohexane (1.93 g, 7.93 mmol) was added to the reaction vessel, followed by sufficient reflux overnight. The organic solvent layer was extracted using dichloromethane and water. The recovered organic fractions were dried over anhydrous MgSO ₄ and purified through silica gel column chromatography to give 711 mg in 31% yield.

1 H NMR (400 MHz, CDCl ₃ ) δ (ppm): 0.97 (s, 1H), 6.97 (d, 1H), 3.70 (t, 2H), 3.41 (t, 2H), 1.93 (d, 3H), 1.87 (m, 2H), 1.70 (m, 2H), 1.50 (m, 2H), 1.35 (m, 2H)

(2) Synthesis of 6- (5-methyl-2,4-dioxo-3,4-dihydropyrimidin-1 (2H) -yl) hexyl propionate represented by [Formula II]

1- (6-bromohexyl) -5-methylpyrimidine-2,4 ( 1H , 3H ) -dione (1 g) represented by Chemical Formula I synthesized through the process (1) of Preparation Example 2 , 3.46 mmol) and potassium carbonate (0.96 g, 6.92 mmol) were dissolved in dimethylformamide (12 mL) and tetrahydrofuran (6 mL), followed by stirring in an argon atmosphere to prepare a reaction product. Propionic acid (0.51 g, 6.92 mmol) was added to the reaction vessel containing the reactant, and the mixture was sufficiently stirred at 75 ° C. overnight. The organic solvent layer was extracted using chloroform and water. The recovered organic fractions were dried over anhydrous MgSO ₄ and purified through silica gel column chromatography to give 762 mg in 78% yield.

1 H NMR (400 MHz, CDCl ₃ ) δ (ppm): 9.50 (s, 1H), 7.01 (d, 1H), 4.06 (t, 2H), 3.70 (t, 2H), 2.31 (q, 2H), 1.92 (d, 3H), 1.78-1.55 (m, 4H), 1.48-1.28 (m, 4H), 1.14 (t, 3H)

(3) 1- (6-hydroxyhexyl) -5-methylpyrimidine-2,4 (1) represented by [Formula III] H , 3 H Synthesis of Dione

6- (5-methyl-2,4-dioxo-3,4-dihydropyrimidi-1 (2H) -yl) hexyl pro represented by Chemical Formula II synthesized through step (2) of Preparation Example 2 Cypionate (1.5 g, 5.3 mmol) and sodium hydroxide (1.06 g, 26.5 mmol) were dissolved in distilled water (15 mL) and acetone (15 mL), followed by stirring at room temperature. The organic solvent layer was extracted using ethyl acetate and water. The recovered organic fractions were dried over anhydrous MgSO ₄ and purified through silica gel column chromatography to obtain 947 mg, 79% yield.

1 H NMR (400 MHz, CDCl ₃ ) δ (ppm): 10.00 (s, 1H), 6.98 (d, 1H), 3.65 (t, 2H), 3.57 (t, 2H), 2.64 (s, 1H), 1.63 (m, 2H), 1.51 (m, 2H), 1.42-1.24 (m, 4H)

(4) 6- (5-methyl-2,4-dioxo-3,4-dihydropyrimidin-1 (2H) -yl) hexyl 4,6-dibromo-3-fluorothieno [3,4] Synthesis of -b] thiophene-2-carboxylate

1- (6-hydroxyhexyl) -5-methylpyrimidine-2,4 ( 1H , 3H ) -dione (786 mg, 3.47 mmol) represented by Chemical Formula III synthesized through (3) of Preparation Example 2. ), 4,6-dibromo-3-fluorothieno [3,4-b] thiophene-2-carboxylic acid (0.5 g, 1.39 mmol), N, N' -dicyclohexylcarbodiimide (430 mg) , 2.09 mmol) and 4-dimethylaminopyridine (17 mg, 0.14 mmol) were dissolved in chloroform (10 mL) and sufficiently stirred at room temperature. This was extracted with an organic solvent layer using chloroform and water. The recovered organic fractions were dried over anhydrous MgSO ₄ and purified via silica gel column chromatography to give 261 mg, 33% yield.

(5) Synthesis of First Polymer (PTB7-Tm10) Represented by [Formula 2a]

6- (5-methyl-2,4-dioxo-3,4-dihydropyrimidi-1 (2H) -yl) hexyl-4 represented by Formula IV synthesized through (4) of Preparation Example 2 , 6-dibromo-3-fluorothieno [3,4- b ] thiophene-2-carboxylate (10.8 mg, 19 μmol), 2'-ethylhexyl 4,6-dibromo-3-fluoro Roteno [3,4- b ] thiophene-2-carboxylate (82.6 mg, 0.175 mmol), 2,6-beads (trimethyltin) -4,8-beads (2-ethylhexyloxy) The mixture was mixed by mixing benzo [1,2- b : 4,5- b '] dithiophene (150 mg, 0.194 mmol) and tetrakis (triphenylphosphine) palladium (0) (9.4 mg, 8.15 μmol). Prepared. The mixture was dissolved in degassed toluene (3.2 mL) and dimethylformamide (0.8 mL) to prepare a reactant. The reactant was stirred at 120 ° C. for 48 hours, cooled to room temperature, and precipitated in methanol. Filtered. This was washed with Soxhlet extraction in the order of methanol, acetone, hexane, and extracted with chloroform. The extracted solution was removed by chloroform using a rotary evaporator, and then precipitated in methanol to obtain a conjugated polymer (PTB7-Tm10) represented by Formula 2a (131 mg, 88%) through a filter.

PTB7-Tm10 (Formula 2a) prepared through the above-described process is dissolved in warm chloroform conditions or room temperature chlorobenzene (CB) and 1,2-dichlorobenzene (DCB), The molecular weight was confirmed by gel permeation chromatography (GPC) using chlorobenzene as an eluent at 60 ° C. M _n for PTB7-Tm10 is 74.5 kg / mol and M _w / M _n is 2.68.

Preparation Example 3 Synthesis of Second Polymer (PTB7-Py10) Represented by Chemical Formula 3a>

As shown by the following [Scheme 3] to prepare a second polymer represented by the formula (3a).

Scheme 3

(1) represented by [Formula V] N, N Synthesis of '-(pyridine-2,6-diyl) bis (thiophene-2-carboxamide)

Pyridine-2,6-diamine (3 g, 27.5 mmol) and triethylamine (9.7 mL, 69 mmol) were dissolved in tetrahydrofuran (50 mL) in a 250 mL round bottom flask, followed by stirring at 0 ° C. Thiophene-2-carbonyl chloride (8.87 g, 60.5 mmol) was dissolved in tetrahydrofuran (20 mL), and then slowly added to a reaction flask at 0 ° C. to prepare a reaction product. After the reaction was sufficiently stirred at room temperature overnight, the organic solvent layer was extracted using dichloromethane and water. The recovered organic fractions were dried over anhydrous MgSO ₄ and purified via silica gel column chromatography to give 6.7 g in 74% yield.

1 H NMR (400 MHz, CDCl ₃ ) δ (ppm): 8.14 (s, 2H), 8.04 (d, 2H), 7.80 (t, 1H), 7.67 (dd, 2H), 7.60 (dd, 2H), 7.16 (dd, 2H)

(2) represented by the formula (VI) N, N Synthesis of '-(pyridine-2,6-diyl) bis (5-bromothiophene-2-carboxamide)

N, N '-(pyridi-2,6-dinyl) bis (thiophene-2-carboxamide) represented by formula (V) synthesized through step (1) of Preparation Example 3 (1 g, 3.04 mmol) Tetrahydrofuran (30 mL) was added thereto, and the mixture was stirred in an argon atmosphere to prepare a reaction product. The flask containing the reaction was covered with aluminum foil, and slowly added N-bromosuccinimide (1.3 g, 7.29 mmol) under dark atmosphere and stirred well overnight. Dichloromethane and water were added thereto, the organic solvent layer was extracted, dried over anhydrous MgSO ₄ , and purified through silica gel column chromatography to obtain 1.29 g in 87% yield.

1 H NMR (400 MHz, CDCl ₃ ) δ (ppm): 8.46 (s, 2H), 8.14 (s, 1H), 7.71 (dd, 2H), 7.61 (dd, 2H), 7.15 (dd, 2H)

3) Synthesis of the second polymer (PTB7-Py10) represented by [Formula 3a]

N, N '-(pyridi-2,6-dinyl) bis (5-bromothiophene-2-carboxamide) represented by the formula (VI) synthesized through step (2) of Preparation Example 3 (9.3) Mg, 19 μmol), 2'-ethylhexyl 4,6-dibromo-3-fluorothieno [3,4- b ] thiophene-2-carboxylate (82.6 mg, 0.175 mmol), 2,6 Bead (trimethyltin) -4,8-bead (2-ethylhexyloxy) benzo [1,2-b: 4,5-b '] dithiophene (150 mg, 0.194 mmol) and tetrakis ( Triphenylphosphine) palladium (0) (9.4 mg, 8.15 μmol) was mixed and then dissolved in degassed toluene (3.2 mL) and dimethylformamide (0.8 mL). The reaction was stirred at 120 ° C. for 48 hours, cooled to room temperature, precipitated in methanol, and filtered. This was washed with Soxhlet extraction in the order of methanol, acetone, hexane, and extracted with chloroform. The extracted solution was removed by chloroform using a rotary evaporator, and then precipitated in methanol to obtain a second conjugated polymer (PTB7-Py10) (131 mg, 89%) represented by Chemical Formula 3a through a filter.

PTB7-Py10 (Formula 3a) prepared through the above-described process is dissolved in warm chloroform conditions or room temperature chlorobenzene (CB) and 1,2-dichlorobenzene (DCB), The molecular weight was confirmed by gel permeation chromatography (GPC) using chlorobenzene as an eluent at 60 ° C. M _n for PTB7-Py10 is 68.6 kg / mol and M _w / M _n is 1.56.

Preparation Example 4 Synthesis of Second Polymer (PTB7-Py20) Represented by Chemical Formula 3b>

A second polymer represented by Chemical Formula 3b is prepared as represented by the following [Scheme 4].

Scheme 4

N, N ' -(pyridi-2,6-dinyl) bis (5-bromothiophene-2-carboxamide) represented by Chemical Formula VI synthesized through step (2) of Preparation Example 3 (19) Mg, 39 μmol), 2'-ethylhexyl 4,6-dibromo-3-fluorothieno [3,4- b ] thiophene-2-carboxylate (73.2 mg, 0.155 mmol), 2,6 Bead (trimethyltin) -4,8-bead (2-ethylhexyloxy) benzo [1,2- b : 4,5- b '] dithiophene (150 mg, 0.194 mmol) and tetrakis ( Triphenylphosphine) palladium (0) (9.4 mg, 8.15 μmol) was mixed to prepare a mixture. The mixture was dissolved in degassed toluene (3.2 mL) and dimethylformamide (0.8 mL) to prepare a reaction. The reaction was stirred at 120 ° C. for 48 hours, cooled to room temperature, precipitated in methanol and filtered. This was washed with Soxhlet extraction in the order of methanol, acetone, hexane, and extracted with chloroform. The extracted solution was removed by chloroform using a rotary evaporator, and then precipitated in methanol to obtain a conjugated polymer (PTB7-Py20) (128 mg, 87%) represented by Chemical Formula 3b through a filter.

Preparation Example 5 Synthesis of Second Polymer (PTB-Th-Py10) Represented by Chemical Formula 3c>

A second polymer represented by Chemical Formula 3c is prepared as represented by the following [Scheme 5].

Scheme 5

N, N '-(pyridi-2,6-dinyl) bis (5-bromothiophene-2-carboxamide) represented by Chemical Formula VI synthesized through step (2) of Preparation Example 3 (11) Mg, 22 μmol), 2'-ethylhexyl 4,6-dibromo-3-fluorothieno [3,4-b] thiophene-2-carboxylate (94 mg, 0.199 mmol), 2,6 Bead (trimethyltin) -4,8-bead (2-ethylhexyloxy) benzo [1,2- b : 4,5- b '] dithiophene (200 mg, 0.221 mmol) and tetrakis ( Triphenylphosphine) palladium (0) (5.1 mg, 4.42 μmol) was mixed to prepare a mixture. The mixture was dissolved in degassed toluene (5 mL) and dimethylformamide (1 mL) to prepare a reaction. The reaction was stirred at 120 ° C. for 48 hours, cooled to room temperature, precipitated in methanol, and filtered. This was washed with Soxhlet extraction in the order of methanol, acetone, hexane, and extracted with chloroform. The extracted solution was removed by chloroform using a rotary evaporator, and then precipitated in methanol to obtain a conjugated polymer (PTB-Th-Py10) (169 mg, 86%) represented by Chemical Formula 3c through a filter.

Preparation Example 6 Synthesis of Second Polymer (PTB-Th-Py20) Represented by Chemical Formula 3d>

A second polymer represented by Chemical Formula 3d is prepared as represented by the following [Scheme 6].

Scheme 6

N, N '-(pyridi-2,6-dinyl) bis (5-bromothiophene-2-carboxamide) represented by Formula VI synthesized through step (2) of Preparation Example 3 (21.4 Mg, 44 μmol), 2'-ethylhexyl 4,6-dibromo-3-fluorothieno [3,4-b] thiophene-2-carboxylate (83.6 mg, 0.177 mmol), 2,6 Bead (trimethyltin) -4,8-bead (2-ethylhexyloxy) benzo [1,2- b : 4,5- b '] dithiophene (200 mg, 0.221 mmol) and tetrakis ( Triphenylphosphine) palladium (0) (5.1 mg, 4.42 μmol) was mixed to prepare a mixture. The mixture was dissolved in degassed toluene (5 mL) and dimethylformamide (1 mL) to prepare a reaction. The reaction was stirred at 120 ° C. for 48 hours, cooled to room temperature, precipitated in methanol, and filtered. This was washed with Soxhlet extraction in the order of methanol, acetone, hexane, and extracted with chloroform. The extracted solution was removed by chloroform using a rotary evaporator, and then precipitated in methanol to obtain a conjugated polymer (PTB-Th-Py20) (168 mg, 85%) represented by Chemical Formula 3d through a filter.

<Examples 1 and 2. Preparation of self-healing photoactive layer>

A first solution was prepared in which chlorobenzene and 1,8-dioodooctane were mixed in a 97: 3 volume mixing ratio, respectively. The first polymer synthesized in Preparation Example 1 and the second polymer prepared in Preparation Example 5 were mixed at a weight ratio of 1: 1, and this was added to 1 ml of the first solution to prepare a composition for forming a self-healing photoactive layer. It was. (Example 1) The first polymer synthesized in Preparation Example 2 and the second polymer prepared in Preparation Example 3 were mixed at a weight ratio of 1: 1, and this was added to 1 ml of the first solution to prepare a self-healing photoactive layer. A composition for formation was prepared (Example 2).

The glass substrate was washed with an ultrasonic cleaner for 10 minutes in diluted water, 10 minutes in distilled water, 10 minutes in acetone, and 10 minutes in isopropyl alcohol, and then dried. Next, polyvinyl alcohol (PVA) (5 mg) was added to 1 ml distilled water to prepare a mixed solution. On the dried glass substrate, the PVA mixed solution prepared through the above-described process was spin-coated at a speed of 2000 rpm at room temperature, and dried at 100 ° C. for 10 minutes to produce a polyvinyl alcohol (PVA) thin film.

Subsequently, a coating solution and a molding agent were mixed at a ratio of 10: 1 using Dow corning, Sylgard: 1 184 SILICONE ELASTOMER KIT, to prepare a polydimethylsiloxane (PDMS) mixed solution. On the dried polyvinyl alcohol thin film, the PDMS mixed solution prepared through the above-described process was spin-coated at a speed of 1000 rpm at room temperature, and dried for 3 hours at 80 ° C. in vacuum to form a glass substrate / PVA / PDMS film. Was produced.

On the prepared PDMS thin film, 0.1 mL of the composition for forming the self-healing photoactive layer was spin-coated at a speed of 1000 rpm to obtain a self-healing photoactive layer. In the prepared glass substrate / PVA / PDMS / self-healing photoactive layer film, the PDMS / self-healing photoactive layer film was peeled from the glass substrate.

3 is a self-healing photoactive layer optical micrograph prepared from Example 1 immediately after exfoliation and after 12 hours. Specifically, the self-healing photoactive layer prepared in Example 1 was peeled off, and it was confirmed that microcracks occurred on the surface. Next, after leaving the self-healing photoactive layer in which the crack occurred at room temperature for 12 hours, it was confirmed that more than 80% of the micro cracks disappeared. It can be seen that% is recovered.

4 is a self-healing photoactive layer optical micrograph prepared from Example 2 before and after heat treatment. Specifically, the self-healing photoactive layer prepared in Example 2 was peeled off (before heat treatment), and it was confirmed that microcracks occurred on the surface. Next, as a result of annealing the self-healing photoactive layer in which cracks occurred at 100 ° C. for 1 hour, it was confirmed that more than 80% of the micro cracks disappeared. It can be seen that to 99% to recover.

<Examples 3 to 5. Self-healing Photoactive Layer (Polymer: PCB)>

A first solution was prepared in which chlorobenzene and 1,8-dioodooctane were mixed in a 97: 3 volume mixing ratio, respectively. The first polymer synthesized from Preparation Examples 2 to 4 was mixed with a florene compound (PC ₇₁ BM) in a weight ratio of 1: 1.2, and it was added to 1 ml of the first solution.

The indium-tin-oxide (ITO) substrate was used for 10 minutes in dilute water, 10 minutes in distilled water, 10 minutes in acetone, 10 minutes in isopropyl alcohol, and then dried using an ultrasonic cleaner. The polyethyleneimine ethoxylated (PEIE) solution was spin coated on the dried indium-tin-oxide (ITO) substrate, and then dried at 100 ° C. for 10 minutes.

On the PEIE-coated ITO substrate, a photoactive layer thin film was prepared by spin coating the mixed solution prepared through the above-described process at a speed of 1000 rpm at room temperature.

<Examples 6 to 8. Organic Solar Cell Manufacturing>

The structure of the manufactured organic solar cell is as follows.

: ITO / PEIE / photoactive layer / MoO ₃ / Ag

The organic solar cell having the above structure was manufactured through the following process. 4 nm of MoO ₃ was deposited on the photoactive layers prepared in Examples 3 to 5, and an aluminum electrode was deposited on the MoO ₃ to a thickness of 100 nm.

Comparative Example 1. Fabrication of PTB7-based photoactive layer

A first solution was prepared in which chlorobenzene and 1,8-dioodooctane were mixed in a 97: 3 volume mixing ratio, respectively. Known PTB7 polymer was mixed with the florenic compound (PC ₇₁ BM) in a 1: 1.2 weight ratio and added to 1 ml of the first solution.

The indium-tin-oxide (ITO) substrate was used for 10 minutes in dilute water, 10 minutes in distilled water, 10 minutes in acetone, 10 minutes in isopropyl alcohol, and then dried using an ultrasonic cleaner. The polyethyleneimine ethoxylated (PEIE) solution was spin coated on the dried indium-tin-oxide (ITO) substrate, and then dried at 100 ° C. for 10 minutes. On the PEIE-coated ITO substrate, a photoactive layer thin film was prepared by spin coating the mixed solution prepared through the above-described process at a speed of 1000 rpm at room temperature.

Comparative Example 2. Fabrication of Organic Solar Cell

The structure of the manufactured organic solar cell is as follows.

: ITO / PEIE / photoactive layer / MoO ₃ / Ag

The organic solar cell having the above structure was manufactured through the following process. 4 nm of MoO ₃ was deposited on the photoactive layer prepared in Comparative Example 1, and an aluminum electrode was deposited on the MoO ₃ to a thickness of 100 nm.

5 is a current density voltage measurement graph of the organic solar cells prepared from Comparative Example 2 and Examples 6 to 8, and the results are summarized in Table 1.

division Photo-opening voltage
(V _oc , V) Photo Short Circuit Current
(J _SC, mA / cm ² ) Fill factor
(FF) Energy conversion efficiency
(PCE,%) Comparative Example 2
(PTB7) 0.75 16.71 70.9 8.84 Example 6
(PTB7-Tm10) 0.74 15.09 59.4 6.59 Example 7
(PTB7-Py10) 0.71 15.25 61.8 6.67 Example 8
(PTB7-Py20) 0.75 13.28 51.6 5.13

According to FIG. 5 and Table 1, as a result of comparing the characteristics of the organic solar cells prepared from Examples 6 to 8, the optical short-circuit current and the fill factor of the organic solar cells prepared from Examples 6 to 8 were 13 to 17 mA / cm, respectively. ² , 51 ~ 70 FF was confirmed. In addition, the energy conversion efficiency of the organic solar cells prepared from Examples 6 to 8 was confirmed that the efficiency of 60 to 80% compared to Comparative Example 2 which is a conventional organic solar cell, through the results of the photoactive layer of the present invention is an insulator Although it contains a self-healing functional group, it can be seen that compared with the conventional organic solar cell, the formation of charge carriers and the reduction or loss of charge mobility are small.

In addition, as described above, it was confirmed that damage (crack) caused by an external force was self-recovered by time or temperature. In summary, the photoactive layer according to the present invention has excellent electric conductivity and self-healing ability. In addition, it can be seen that not only can be usefully used as a photoactive layer for an organic solar cell, but also when applied to the organic solar cell, not only energy conversion efficiency but also life and long-term stability are significantly improved compared to the conventional organic solar cell.

Claims (15)

A composition for forming a self-healing photoactive layer comprising a first polymer represented by Formula 1 or Formula 2, a second polymer represented by Formula 3, and a solvent:
[Formula 1]

[Formula 2]

[Formula 3]

In the above formula,
R ₁ to R ₁₃ are the same as or different from each other, and each independently hydrogen, a halogen group, a cyano group, a nitro group, a hydroxyl group, an amide group, an ester group, a ketone group, a thioester group, a silyl group, a substituted or unsubstituted group Substituted alkyl group having 1 to 30 carbon atoms, substituted or unsubstituted alkylthioyl group having 5 to 25 carbon atoms, substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, substituted Or a heteroaryl group having 2 to 50 carbon atoms which is unsubstituted and includes any one or more of S, N, O, P, and Si, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted carbon group having 3 to 30 carbon atoms. 30 cycloalkenyl groups, substituted or unsubstituted aryl groups having 5 to 50 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 30 carbon atoms, substituted or unsubstituted aryloxy groups having 5 to 50 carbon atoms, substituted or unsubstituted An alkylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted arylamino group having 6 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 1 to 30 carbon atoms and a substituted or unsubstituted aryl silyl group having 5 to 50 carbon atoms. Selected from the group.
x + y = 1, 0.1≤x≤0.9, 0.1≤y≤0.9, m + n = 1, 0.1≤m≤0.9, 0.1≤n≤0.9, p + q = 1, 0.1≤p≤0.9, 0.1≤ q≤0.9,
Z, o, and r are each an integer of 5 to 100,000. The method of claim 1,
R ₁ , R ₂ , R ₃ , R ₄ , R ₆ , R ₇ , R ₉ , R ₁₀ , R ₁₂ , R ₁₃ are the same as or different from each other, and each independently hydrogen, halogen, substituted or unsubstituted carbon number Any one selected from an alkoxy group having 1 to 10, a substituted or unsubstituted alkylthioyl group having 5 to 25 carbon atoms, and a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
R ₅ , R ₈ , and R ₁₁ are the same as or different from each other, and are each independently selected from hydrogen, a halogen, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, and A composition for self-healing photoactive layer formation, characterized in that any one. The method of claim 1,
The first polymer and the second polymer is a composition for forming a self-healing photoactive layer, characterized in that mixed in a 1: 0.5 to 1: 4 weight ratio. The method of claim 1,
The solvent is any one or more selected from the group consisting of dimethylformamide, chloroform, hexane, cyclohexane, toluene, xylene, chlorobenzene, dichlorobenzene, ethylene acetate, tetrahydrofuran and N-methylallyrrolidinone A composition for self-healing photoactive layer formation. The method of claim 1,
The composition is a composition for self-healing photoactive layer formation, characterized in that it further comprises an n-type polymer. The method of claim 4, wherein
The n-type polymer is methyl (6,6) -phenyl-C61-butyrate (PC ₆₀ BM), (6,6) -phenyl-C61-butyric acid methyl ester (C ₆₀ -PCBM), (6, 6) -phenyl-C71-butyric acid methyl ester (C ₇₀ -PCBM), (6,6) -phenyl-C77-butyric acid methyl ester (C ₇₆ -PCBM), (6,6) -phenyl-C79 -Butyric acid methyl ester (C ₇₈ -PCBM), (6,6) -phenyl-C81-butyric acid methyl ester (C ₈₀ -PCBM), (6,6) -phenyl-C83-butyric acid methyl ester (C ₈₂ -PCBM), (6,6) -phenyl-C85-butyric acid methyl ester (C ₈₄ -PCBM), bis (1- [3- (methoxycarbonyl) propyl] -1-phenyl) ( Bis-C ₆₀ -PCBM), 3'-phenyl-3'H-cyclopropa (8,25) (5,6) fullerene-C70-bis-D5h (6) -3'-butyric acid methyl ester (Bis- C ₇₀ -PCBM), indene-C60-bisadduct (ICBA), monoindenylC60 (ICMA), poly {[ N , N ' -bis (2-octyldodecyl) -1,4,5,8-naphthalene diimide -2,6-diyl] - alt -5,5 ' - (2,2'-bithiophene)} (PNDI2T or N2200), poly [[N, N'-bis (2-octyldodecyl) -3,4,9 , 10-perylene diimide-1,7- diyl]]-alt- (thiophene-2,5-diyl) (PPDIODT), 3,9-bis (2-methylene- (3- (1,1-dicyanomethylene) -indanone))-5,5,11, 11-tetrakis (4-hexylphenyl) -dithieno [2,3- d : 2 ', 3'- d' ] -s-indaceno [1,2- b : 5,6- b ' ] dithiophene (ITIC), 3 , 9-bis (2-methylene- (5,6-difluoro-3-oxo-2,3-dihydro-1 H -inden-1-ylidene) malononitrile) -5,5,11,11-tetrakis (4- hexylphenyl) -dithieno [2,3- d : 2 ', 3'- d' ] -s -indaceno [1,2- b : 5,6- b ' ] dithiophene (ITIC-4F), (5 Z , 5 'Z) -5,5' - (( (4,4,9,9-tetraoctyl-4,9-dihydro- s -indaceno [1,2- b: 5,6- b '] dithiophene-2,7 -diyl) bis (benzo [ c ] [1,2,5] thiadiazole-7,4-diyl)) bis (methanylylidene)) bis (3-ethyl-2-thioxothiazolidin-4-one) (O-IDTBR), 2,2 '-((2 Z , 2' Z )-(((4,4,9,9-tetrakis (4-hexylphenyl) -4,9-dihydro-sindaceno [1,2-b: 5,6 -b '] dithiophene-2,7-diyl) bis (4-((2-ethylhexyl) oxy) thiophene-5,2-diyl)) bis (methanylylidene)) bis (5,6-difluoro-3-oxo- 2,3-dihydro-1 H -indene-2,1-diylidene)) dimalononitrile (IEICO-4F), 5,5 '-(9,9'-spirobi [fluorene] -2,7-diyl) bis (2 , 9-dimethylanthra [2,1,9- def : 6,5,10- d'e'f ' ] diisoquinoline-1 , 3,8,10 (2 H, 9 H ) -tetraone) (SF-PDI 2) and any one of the composition for a self-healing, characterized in photoactive layer is formed is selected from the group consisting of. Self-healing photoactive layer prepared through the composition for forming a self-healing photoactive layer according to claim 1. The method of claim 7, wherein
The photoactive layer is left for 1 to 30 hours, or self-healing photoactive layer, characterized in that micro-scale cracks are self-recovered by annealing at 50 to 200 ℃ 1 to 30 hours. The method of claim 7, wherein
The photoactive layer is self-healing photoactive, characterized in that 60 to 99% of the photoactive layer is recovered before the damage by the self-recovery process through time or heat treatment when a micro-scale crack is generated by an external force on an optical microscope layer. The method of claim 7, wherein
The photoactive layer may be formed into a thin film by any one method selected from the group consisting of vacuum deposition, screen printing, printing, bar coating, slot die coating, spin coating, dipping and ink spraying. Self-healing photoactive layer characterized in that. An organic solar cell employing the self-healing photoactive layer according to claim 7. The method of claim 11,
The organic solar cell
Board;
A first electrode on the substrate;
A buffer layer on the first electrode;
A photoactive layer positioned on the hole injection layer; And
An organic solar cell comprising a second electrode positioned on the photoactive layer. The method of claim 12,
The buffer layer is an organic solar cell comprising a poly (3,4-ethylenedioxythiophene) [PEDOT: PSS] doped with a polyehthylenimine ethoxylated (PEIE) polymer or polystyrenesulfonate. The method of claim 12,
The first and second electrodes are the same as or different from each other, and are independently of indium tin oxide (ITO), fluorinated tin oxide (FTO), indium zinc oxide (IZO), al-doped zinc oxide (AZO), and indium (IZTO). Zinc Tin Oxide), SnO2, ZnO, carbon nanotubes, graphene, TiO ₂ , MoO ₃ , V ₂ O ₅ , Ca, LiF, gold, platinum, silver, aluminum, nickel and chromium Organic solar cell, characterized in that any one or more. The method of claim 12,
The substrate is any one selected from the group consisting of glass, polydimethylsiloxane, polyethylene naphthalate, polyethylene terephthalate, polycarbonate, polyvinyl alcohol, polyacrylate, polyimide, polynorbornene and polyethersulfone Organic solar cells.

Images