KR102439270B1 - Novel polymer and organic electronic device using them - Google Patents

Abstract

The present invention relates to a novel polymer and an organic electronic device using the same, wherein the polymer according to the present invention has a ring comprising thiophene, selenophene, or a combination thereof in a central skeleton of an A-D-A structure comprising electron donor and electron acceptor units By introducing the system's electron donor, it has excellent chemical and thermal stability, as well as improved crystallinity, and intermolecular stacking is possible to maximize charge mobility.

Description

Novel polymer and organic electronic device using them

The present invention relates to novel polymers and organic electronic devices using the same.

Recently, as environmental pollution problems due to high oil prices and the use of fossil fuels have emerged, the demand for sustainable and eco-friendly energy sources is rapidly increasing. Examples of eco-friendly energy sources include solar power, wind power, hydro power, wave power, and geothermal heat. Among them, solar cells that can produce electric power using sunlight are attracting attention as an infinite electric energy source with the least space restrictions. It is estimated that the amount of solar energy that can be actually excavated from the 1.7×105TW of solar energy reaching the earth's surface is 600TW. At this time, if a solar power plant with 10% efficiency is available, about 60TW of power can be supplied. Compared to the Earth's estimated energy demand of 28 TW in 2050, this is an enormous amount that will more than satisfy the future demand for sustainable energy sources.

As for conventional solar cells, first-generation crystalline silicon solar cells using inorganic materials occupy 90% of the solar power generation market. However, compared to fossil fuels, the cost of power generation is 5 to 20 times higher, so it is only used for long-term medium and large-scale power generation, and its application value is low. As a result, second-generation thin-film solar cell technology (CdTe, CIGS, etc.) that replaces silicon solar cells has risen rapidly, occupying the remaining 10% of the market. However, second-generation solar cell technology also requires expensive equipment because some materials are classified as precious metals and semiconductor thin films are formed through vacuum and high-temperature processes when manufacturing devices. An organic solar cell is a low-cost solar cell that can solve these problems. Since it uses organic materials, solution processing is possible, which lowers the unit cost of solar cells, and its mechanical flexibility, ease of design, and versatility have unlimited potential for applications in clothing, portable electric and electronic products, etc.

However, for practical use of organic solar cells, efficiency improvement, life extension, large area, development of printable materials, and securing of transparent electrodes are prior issues. Among these, it can be said that the high efficiency of organic solar cells is by far the most important. Only by developing a high-dissolving, high-performance (high-efficiency and high-stability) material capable of a low-temperature solution process can dramatically lower the production cost and solve the problems of the prior art described above in a chain.

Recently, organic solar cells are divided into fullerene-based and non-fullerene-based organic solar cells according to the type of photoactive layer electron acceptor material. Currently, the organic solar cell efficiency is the highest in the world at 11.5% according to the NREL (National Renewable Energy Laboratory) certification for fullerenes, and is unofficially 13.1% for non-fullerenes. It took more than 15 years for fullerene-based organic solar cells to develop to the present level, whereas non-fullerene-based organic solar cells took only 5 years. In addition, in terms of stability of the organic solar cell, it is reported that the non-fullerene type is generally superior to the fullerene type. Representatively, in the case of PCE11, a similar derivative that shows the world's highest efficiency in fullerene-based organic solar cells, burn-in decomposition occurs when aging for 5 days in the air, resulting in a decrease in efficiency by about 39%. has been

Under this technical background, the present inventors intend to propose a novel polymer capable of realizing high performance in a non-fullerene-based system having excellent efficiency and stability and use thereof.

In order to solve the above problems, an object of the present invention is to provide a novel polymer having an extended conjugated structure and maximizing charge transfer within a molecule by stacking intermolecularly, and a use thereof.

In detail, the present invention realizes high performance in a non-fullerene system by controlling the constituents and ratios of the polymer to have appropriate crystallinity, solubility, and a relative electron donor material and an optimal HOMO (High Ocuupied Molecular Orbital) offset energy level. The object is to provide a polymer capable of

Specifically, an object of the present invention is to provide an organic electronic device having excellent light efficiency by employing the polymer of the present invention.

Specifically, an object of the present invention is to provide an organic solar cell having excellent photoelectric conversion efficiency by employing the polymer of the present invention in a photoactive layer.

For the above purpose, the present invention may include the following means.

The polymer according to an embodiment of the present invention has a compound of A-D-A consisting of a central electron donor unit (D) and a terminal electron acceptor unit (A) on both sides of the central electron donor unit (D) as a central skeleton, By introducing an electron donor, steric hindrance is minimized, solubility and oxidation stability are excellent, and it has a structure in which charge mobility is maximized, and may include repeating units represented by Chemical Formulas 1 and 2 below.

[Formula 1]

[Formula 2]

[In Formula 1 and Formula 2,

R ₁ to R ₄ are each independently C1-C30 alkyl;

X ₁ to X ₄ are each independently O, S or Se;

로 대체될 수 있으며, 상기 R은 각각 독립적으로 수소, C1-C30알킬, C1-C30알콕시, C1-C30알킬티오, 할로겐, 시아노, 니트로, 히드록시, 할로C1-C30알킬, C1-C30알킬카보닐 또는 C1-C30알킬카보닐옥시이고, 상기 융합고리는 N, O, S 및 Se로부터 선택된 하나 이상의 헤테로원자를 포함할 수 있고;V ₁ and V ₂ are each independently a fused ring having methylidene as a linking group, and the fused rings are each independently C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, haloC1- It may be further substituted with one or more substituents selected from C30 alkyl, nitro and hydroxy, and -CH ₂ - of the fused ring is carbonyl, thiocarbonyl or

may be replaced with, wherein each R is independently hydrogen, C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, nitro, hydroxy, haloC1-C30 alkyl, C1-C30 alkyl carbonyl or C 1 -C 30 alkylcarbonyloxy, wherein the fused ring may contain one or more heteroatoms selected from N, O, S and Se;

Ar is benzodithiophenylene, benzodithienothiophenylene, naphthodithiophenylene, thiophenylene, benzothienoselenophenylene, benzodiselenophenylene, benzodiselenoselenophenylene, naphthodiselenophenylene, selenophenylene, or a combination thereof, wherein Ar is each independently C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, C6-C30 aryl, C3-C30 heteroaryl; It may be further substituted with one or more substituents selected from halogen, cyano, nitro, hydroxy, and combinations thereof.]

In the polymer according to an embodiment of the present invention, the repeating unit [Ar] represented by Formula 2 may be selected from the following structure.

[In the above structure,

a is selected from an integer from 0 to 5;

R ₁₁ and R ₁₂ are each independently C1-C30 alkyl;

R ₁₃ and R ₁₄ are each independently hydrogen or C1-C30 alkyl;

Ar ₁ to Ar ₄ are each independently hydrogen or C3-C30 heteroaryl, wherein the heteroaryl is one selected from C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, hydroxy, and combinations thereof It may be further substituted with more than one substituent.]

In the polymer according to an embodiment of the present invention, Ar ₁ and Ar ₂ in the structure are each independently C3-C30 heteroaryl substituted with one or more substituents selected from C1-C30 alkyl, halogen, or a combination thereof, , Ar ₃ and Ar ₄ may be hydrogen.

In the polymer according to an embodiment of the present invention, V ₁ and V ₂ may each independently be represented by Formula A below.

[Formula A]

[In the formula A,

Y ₁ and Y ₂ are each independently O, S or CR _a R _b , wherein R _a and R _b are each independently halogen, cyano, nitro, hydroxy, C1-C30 alkylcarbonyl or C1-C30 alkyl carbonyloxy;

A is a C6-C20 aromatic ring or a C3-C20 heteroaromatic ring, wherein the aromatic ring and the heteroaromatic ring are C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, haloC1-C30 alkyl , may be further substituted with one or more substituents selected from nitro and hydroxy.]

In the polymer according to an embodiment of the present invention, V ₁ and V ₂ may each independently be represented by Formula B or Formula C below.

[Formula B]

[Formula C]

[In Formula B and Formula C,

Y ₁ and Y ₂ are each independently O, S or CR _a R _b , R _a and R _b are each independently halogen, cyano, nitro, hydroxy, C1-C30 alkylcarbonyl or C1-C30 alkylcarbonyl nyloxy, wherein Y ₁ and Y ₂ are different from each other;

one of Z ₂ and Z ₃ is CR _c , the other is O, S or Se, wherein R _c is hydrogen, C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, nitro , hydroxy or haloC1-C30 alkyl;

Z ₁ is CR _d or N, wherein R _d is hydrogen, C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, nitro, hydroxy or haloC1-C30 alkyl or an adjacent substituent; It may be connected with R ₂₁ or R ₂₂ to form an aromatic fused ring;

R ₂₁ to R ₂₄ are each independently hydrogen, C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, nitro, hydroxy or haloC1-C30 alkyl.]

In the polymer according to an embodiment of the present invention, V ₁ and V ₂ may each independently be represented by Formula D, Formula E, Formula F, or Formula G.

[Formula D]

[Formula E]

[Formula F]

[Formula G]

[In the above formulas D to G,

Y ₁ and Y ₂ are each independently O or S;

R _a and R _b are each independently halogen, cyano, nitro, hydroxy, C1-C30 alkylcarbonyl or C1-C30 alkylcarbonyloxy;

R _c and R _d are each independently hydrogen, C 1 -C 30 alkyl, C 1 -C 30 alkoxy, C 1 -C 30 alkylthio, halogen, cyano or haloC 1 -C 30 alkyl;

R ₂₁ to R ₂₄ are each independently hydrogen, C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano or haloC1-C30 alkyl.]

In the polymer according to an embodiment of the present invention, the polymer may specifically include a repeating unit represented by the following formula (3) and a repeating unit represented by the following formula (4).

[Formula 3]

[Formula 4]

[In Formula 3 and Formula 4,

R ₁ and R ₂ are each independently straight-chain C8-C30 alkyl;

R ₃₁ and R ₃₂ are each independently crushed C1-C7 alkyl;

x and y are each independently an integer selected from 1 to 7;

each R ₃₃ is independently hydrogen, fluoro or chloro.]

In the polymer according to an embodiment of the present invention, in the polymer, the mole fraction (p) of the repeating unit represented by Formula 1 and the mole fraction (q) of the repeating unit represented by Formula 2 are 0<p<1, 0 <q<1, and p+q=1 may be satisfied.

In addition, the present invention provides an organic electronic device including the polymer according to an embodiment.

The organic electronic device according to an embodiment of the present invention may be an organic light emitting device, an organic thin film transistor, an organic photosensor, or an organic solar cell, preferably an organic solar cell.

In the organic electronic device according to an embodiment of the present invention, the polymer may be included in the photoactive layer of the organic solar cell, preferably as an electron acceptor, may be included in the photoactive layer of the organic solar cell.

The polymer according to the present invention introduces an electron donor of a ring system including thiophene, selenophene, or a combination thereof into the central skeleton, so that it has excellent chemical and thermal stability, as well as improved crystallinity, so that intermolecular stacking is possible. In addition, it can be used as a photoactive layer material by forming a bulk heterojunction with a counter electron donor material commonly used in organic solar cells, that is, a known electron donor, as well as providing a high-performance organic solar cell.

The polymer according to the present invention can control the composition ratio of the polymer to have an optimal HOMO offset energy level, and can realize high efficiency and excellent stability of an organic solar cell employing the same despite a relatively small amount of use. In addition, it has excellent solubility and crystallinity even at low temperatures, excellent oxidation stability, and does not require pre-treatment and post-treatment processes when coating a solution containing the same through spin coating or slot die. Therefore, the heat treatment process on a large area can uniformly form a thin film, and as a material suitable for a roll-to-roll process, it can be usefully used for practical use of next-generation organic solar cells.

In addition, the polymer according to the present invention has high compatibility with known electron donors. When the photoactive layer includes the polymer according to the present invention and a known electron donor, light can be effectively absorbed, holes and electrons can be easily separated, and the separated holes and electrons can be easily transferred. That is, the organic electronic device including the polymer according to the present invention in the photoactive layer realizes high efficiency. Furthermore, the organic solar cell employing the polymer according to the present invention as an electron acceptor can improve light efficiency and improve the lifespan characteristics of the device.

With these characteristics, the polymer of the present invention can be used as a compound that can replace the fullerene derivative widely used as an electron acceptor, and thus the stability and efficiency of the organic solar cell can be remarkably improved. That is, the polymer of the present invention is highly applicable as a non-fullerene-based electron acceptor.

1 is a UV-vis absorption spectrum of the solution phase and film phase of the polymer (P(Y52BOBDT-H)) prepared in Example 1. FIG.
2 is a UV-vis absorption spectrum of the solution phase and film phase of the polymer (P(Y52BOBDT-Cl)) prepared in Example 2. FIG.
3 is a UV-vis absorption spectrum of the solution phase and film phase of the polymer (P(Y52BOBDT-F)) prepared in Example 3. FIG.
4 is a UV-vis absorption spectrum of a solution phase and a film phase of the electron acceptor compound (Y5-2BO) used in Comparative Example 1. FIG.

The novel polymer according to the present invention and an organic electronic device using the same will be described in detail below, but unless otherwise defined in technical terms and scientific terms used at this time, those of ordinary skill in the art to which this invention pertains are commonly understood Description of known functions and configurations that may unnecessarily obscure the gist of the present invention in the following description will be omitted.

Throughout this specification, unless the context requires otherwise, the terms "comprises" and "comprising" include the steps or elements presented, or groups of steps or elements, but include any other step or element, or It is to be understood that a step or group of elements is meant to be implied not to be excluded.

As used herein, the terms “substituent”, “radical”, “group”, “moiety”, and “fragment” may be used interchangeably.

As used herein, the term "C _A -C _B " means "the number of carbon atoms is greater than or equal to A and equal to or less than B".

As used herein, the term “alkyl” refers to a monovalent straight-chain or branched saturated hydrocarbon radical composed only of carbon and hydrogen atoms. The alkyl includes, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, ethylhexyl, heptyl, octyl, nonyl, decyl, dodecyl, undecyl, and the like, However, the present invention is not limited thereto.

As used herein, the term "aryl" is an aromatic ring monovalent organic radical derived from an aromatic hydrocarbon by removal of one hydrogen, suitably containing 4 to 7, preferably 5 or 6 ring atoms in each ring. It includes a single or fused ring system, and includes a form in which a plurality of aryls are connected by a single bond. Examples include, but are not limited to, phenyl, naphthyl, biphenyl, anthryl, indenyl, fluorenyl, and the like.

As used herein, the term "heteroaryl" refers to an aryl group containing 1 to 4 heteroatoms selected from N, O, S and Se as aromatic ring skeleton atoms, and the remaining aromatic ring skeleton atoms are carbon, 5 to 6-membered monocyclic heteroaryl, and polycyclic heteroaryl condensed with one or more benzene rings. In addition, heteroaryl in the present invention includes a form in which one or more heteroaryl is connected by a single bond. For example, furyl, thiophenyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, isoxazolyl, oxazolyl, monocyclic heteroaryl such as pyridyl, benzofuranyl, dibenzofuranyl , dibenzothiophenyl, benzothiophenyl, isobenzofuranyl, benzoimidazolyl, benzothiazolyl, benzoisothiazolyl, benzoisoxazolyl, benzoxazolyl, quinolyl, isoquinolyl, carbazolyl, etc. cyclic heteroaryl and the like.

As used herein, the term “alkoxy” refers to an —O-alkyl radical, where “alkyl” is as defined above. Examples include, but are not limited to, methoxy, ethoxy, isopropoxy, butoxy, isobutoxy, t-butoxy, and the like.

As used herein, the term "alkylthio" refers to an -S-alkyl radical, where "alkyl" is as defined above. Examples include, but are not limited to, methylthio, ethylthio, isopropylthio, butylthio, isobutylthio, t-butylthio, and the like.

As used herein, the term “halo” or “halogen” refers to a halogen element, and may be, for example, fluoro, chloro, bromo or iodo.

As used herein, the term "cyano" means -CN, "nitro" means -NO ₂ , and "hydroxy" means -OH.

As used herein, the term “haloalkyl” refers to an alkyl radical in which one or more hydrogen atoms are each replaced by a halogen atom, wherein “alkyl” and “halogen” are as defined above. Examples include, but are not limited to, fluoromethyl, difluoromethyl, trifluoromethyl, fluoroethyl, difluoroethyl, perfluoroethyl, bromomethyl, bromoethyl, bromopropyl, etc. it doesn't happen

As used herein, the term "carbonyl" refers to a divalent organic radical represented by *-C(=O)-*, and "thiocarbonyl" is a divalent organic radical represented by *-C(=S)-*. means radical.

As used herein, the term "alkylcarbonyl" refers to a -C(=O)alkyl radical, where "alkyl" is as defined above. Examples include, but are not limited to, methylcarbonyl, ethylcarbonyl, isopropylcarbonyl, propylcarbonyl, butylcarbonyl, isobutylcarbonyl, t-butylcarbonyl, and the like.

The term "alkylcarbonyloxy" in the specification refers to an -OC(=O)alkyl radical, where "alkyl" is as defined above. Examples include, but are not limited to, methylcarbonyloxy, ethylcarbonyloxy, isopropylcarbonyloxy, propylcarbonyloxy, butylcarbonyloxy, isobutylcarbonyloxy, t-butylcarbonyloxy, and the like. does not

The term "alkylene" in the specification means a divalent straight-chain or branched saturated hydrocarbon radical composed only of carbon and hydrogen atoms. Examples include, but are not limited to, methylene, ethylene, propylene, isopropylene, butylene, isobutylene, t-butylene, pentylene, hexylene, heptylene, octylene, nonylene, and the like.

Hereinafter, the polymer according to the present invention will be specifically described.

The polymer according to an embodiment of the present invention has a central skeleton of a compound of A-D-A consisting of a terminal electron acceptor unit (A) on both sides of the central electron donor unit (D) and the central electron donor unit (D), and an appropriate embodiment of the electron By introducing a donor, steric hindrance is minimized, solubility and oxidative stability are excellent, and it has a structure that maximizes charge mobility. Specifically, the polymer of the present invention may include a repeating unit represented by the following Chemical Formulas 1 and 2.

[Formula 1]

[Formula 2]

[In Formula 1 and Formula 2,

R ₁ to R ₄ are each independently C1-C30 alkyl;

X ₁ to X ₄ are each independently O, S or Se;

로 대체될 수 있으며, 상기 R은 각각 독립적으로 수소, C1-C30알킬, C1-C30알콕시, C1-C30알킬티오, 할로겐, 시아노, 니트로, 히드록시, 할로C1-C30알킬, C1-C30알킬카보닐 또는 C1-C30알킬카보닐옥시이고, 상기 융합고리는 N, O, S 및 Se로부터 선택된 하나 이상의 헤테로원자를 포함할 수 있고;V ₁ and V ₂ are each independently a fused ring having methylidene as a linking group, and the fused rings are each independently C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, haloC1- It may be further substituted with one or more substituents selected from C30 alkyl, nitro and hydroxy, and -CH ₂ - of the fused ring is carbonyl, thiocarbonyl or

may be replaced with, wherein each R is independently hydrogen, C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, nitro, hydroxy, haloC1-C30 alkyl, C1-C30 alkyl carbonyl or C 1 -C 30 alkylcarbonyloxy, wherein the fused ring may contain one or more heteroatoms selected from N, O, S and Se;

Ar is benzodithiophenylene, benzodithienothiophenylene, naphthodithiophenylene, thiophenylene, benzothienoselenophenylene, benzodiselenophenylene, benzodiselenoselenophenylene, naphthodiselenophenylene, selenophenylene, or a combination thereof, wherein Ar is each independently C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, C6-C30 aryl, C3-C30 heteroaryl; It may be further substituted with one or more substituents selected from halogen, cyano, nitro, hydroxy, and combinations thereof.]

The polymer according to the present invention exhibits maximized charge mobility by having the above-described structural characteristics, has high chemical and electrical stability, has high thermal stability, and has a high absorption coefficient for sunlight.

When the polymer according to the present invention is employed as an electron acceptor, more improved efficiency can be exhibited and thermal stability of the organic electronic device is increased. That is, the organic electronic device according to the present invention has excellent electrical characteristics and lifespan characteristics.

In addition, the polymer according to the present invention has excellent solubility in organic solvents and exhibits excellent miscibility with known electron donors. In addition, by forming a bulk heterojunction with a known electron donor, the efficiency of an organic electronic device employing the same can be greatly improved. In particular, it was confirmed that this effect was significantly improved compared to the conventional monomer compound (eg, Y5-2BO) used as an electron acceptor. Furthermore, the present invention is noted in that the organic electronic device employing the same not only has excellent atmospheric stability, but also provides high performance even at room temperature and normal humidity conditions, and exhibits an excellent effect on burn-in decomposition.

In addition, the organic electronic device according to the present invention, particularly the organic solar cell, can implement a lowered driving voltage and improved photoelectric conversion efficiency by employing the polymer as a non-fullerene-based electron acceptor, and improve lifespan characteristics.

In the polymer according to an embodiment of the present invention, the repeating unit [Ar] represented by Formula 2 may be selected from repeating units of the following structure.

[In the above structure,

a is selected from an integer from 0 to 5;

R ₁₁ and R ₁₂ are each independently C1-C30 alkyl;

R ₁₃ and R ₁₄ are each independently hydrogen or C1-C30 alkyl;

Ar ₁ to Ar ₄ are each independently hydrogen or C3-C30 heteroaryl, wherein the heteroaryl is one selected from C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, hydroxy, and combinations thereof It may be further substituted with more than one substituent.]

In the polymer according to an embodiment of the present invention, Ar ₁ and Ar ₂ in the structure are each independently C3-C30 heteroaryl substituted with one or more substituents selected from C1-C30 alkyl, halogen, or a combination thereof, , Ar ₃ and Ar ₄ may be hydrogen.

For example, in the polymer, Ar ₁ and Ar ₂ in the structure may be C3-C30 heteroaryl substituted with at least one C1-C30 alkyl.

For example, in the polymer, wherein Ar ₁ and Ar ₂ of the structure are C3-C30 heteroaryl substituted with at least one C1-C30 alkyl, and when the heteroaryl is substituted with one halogen, surprisingly improved photoelectricity conversion efficiency can be realized.

The polymer according to an embodiment of the present invention has a structure in which a fused ring having methylidene as a linking group is introduced in order to form a conjugate extending out of the central skeleton to further improve intermolecular interaction. Specifically, the fused rings (V ₁ and V ₂ ) having methylidene as a linking group may be an electron acceptor unit, and these may each independently be represented by the following Chemical Formula A.

[Formula A]

[In the formula A,

Y ₁ and Y ₂ are each independently O, S or CR _a R _b , wherein R _a and R _b are each independently halogen, cyano, nitro, hydroxy, C1-C30 alkylcarbonyl or C1-C30 alkyl carbonyloxy;

A is a C6-C20 aromatic ring or a C3-C20 heteroaromatic ring, wherein the aromatic ring and the heteroaromatic ring are C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, haloC1-C30 alkyl , may be further substituted with one or more substituents selected from nitro and hydroxy.]

More specifically, the fused rings (V ₁ and V ₂ ) having methylidene as a linking group may be each independently represented by Formula B or Formula C below.

[Formula B]

[Formula C]

[In Formula B and Formula C,

Y ₁ and Y ₂ are each independently O, S or CR _a R _b , R _a and R _b are each independently halogen, cyano, nitro, hydroxy, C1-C30 alkylcarbonyl or C1-C30 alkylcarbonyl nyloxy, wherein Y ₁ and Y ₂ are different from each other;

one of Z ₂ and Z ₃ is CR _c , the other is O, S or Se, wherein R _c is hydrogen, C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, nitro , hydroxy or haloC1-C30 alkyl;

Z ₁ is CR _d or N, wherein R _d is hydrogen, C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, nitro, hydroxy or haloC1-C30 alkyl or an adjacent substituent; It may be connected with R ₂₁ or R ₂₂ to form an aromatic fused ring;

R ₂₁ to R ₂₄ are each independently hydrogen, C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, nitro, hydroxy or haloC1-C30 alkyl.]

More preferably, the fused rings (V ₁ and V ₂ ) having methylidene as a linking group may be each independently represented by Formula D, Formula E, Formula F, or Formula G.

[Formula D]

[Formula E]

[Formula F]

[Formula G]

[In the above formulas D to G,

Y ₁ and Y ₂ are each independently O or S;

R _a and R _b are each independently halogen, cyano, nitro, hydroxy, C1-C30 alkylcarbonyl or C1-C30 alkylcarbonyloxy;

R _c and R _d are each independently hydrogen, C 1 -C 30 alkyl, C 1 -C 30 alkoxy, C 1 -C 30 alkylthio, halogen, cyano or haloC 1 -C 30 alkyl;

R ₂₁ to R ₂₄ are each independently hydrogen, C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano or haloC1-C30 alkyl.]

For example, in Formulas D to G, Y ₁ and Y ₂ are each independently O or S; wherein R _a and R _b are each independently halogen, cyano, nitro, hydroxy, C1-C7 alkylcarbonyl or C1-C7 alkylcarbonyloxy; wherein R _c and R _d are each independently hydrogen, C 1 -C 7 alkyl, C 1 -C 7 alkoxy, C 1 -C 7 alkylthio, halogen, cyano or haloC 1 -C 7 alkyl; R ₂₁ to R ₂₄ may each independently represent hydrogen, C1-C7 alkyl, C1-C7 alkoxy, C1-C7 alkylthio, halogen, cyano or haloC1-C7 alkyl.

For example, in Formulas D to G, Y ₁ and Y ₂ are each independently O or S; wherein R _a and R _b are each independently halogen, cyano, C1-C7 alkylcarbonyl or C1-C7 alkylcarbonyloxy; wherein R _c and R _d are each independently hydrogen, C 1 -C 7 alkyl, C 1 -C 7 alkoxy, halogen, cyano or haloC 1 -C 7 alkyl; R ₂₁ to R ₂₄ may each independently represent hydrogen, C1-C7 alkyl, C1-C7 alkoxy, halogen, cyano or haloC1-C7 alkyl.

For example, the fused rings (V ₁ and V ₂ ) having methylidene as a linking group may be selected from the following structures, but are not limited thereto.

The polymer according to the present invention minimizes the quenching of the excited state by the vibronic path due to the above-described structural features, thereby realizing a higher absorption coefficient for sunlight due to less energy loss due to absorption of sunlight. In addition, the polymer has high crystallinity, so that it is possible to realize high charge mobility.

For example, in the polymer, X ₁ to X ₄ may each independently be O or S.

For example, in the polymer, X ₁ to X ₄ may be the same as each other.

For example, in the polymer, all of X ₁ to X ₄ may be S.

For example, in the polymer, all of X ₁ to X ₄ may be O.

For example, in the polymer, X ₁ and X ₄ may be the same as each other, and X ₂ and X ₃ may be the same as each other.

For example, in the polymer, X ₁ and X ₄ may be S, and X ₂ and X ₃ may be O.

For example, in the polymer, X ₁ and X ₄ may be O, and X ₂ and X ₃ may be S.

The polymer according to an embodiment of the present invention may most preferably include a repeating unit represented by the following formula (3) and a repeating unit represented by the following formula (4).

[Formula 3]

[Formula 4]

[In Formula 3 and Formula 4,

R ₁ and R ₂ are each independently straight-chain C8-C30 alkyl;

R ₃₁ and R ₃₂ are each independently crushed C1-C7 alkyl;

x and y are each independently an integer selected from 1 to 7;

each R ₃₃ is independently hydrogen, fluoro or chloro.]

More preferably, in terms of improving solubility as well as electron donation, the electron donating region may include a long-chain pulverized alkyl group as in the repeating unit represented by Formula 4 above.

For example, R ₃₁ and R ₃₂ may be each independently C1-C7 alkyl, and R ₃₃ may be each independently fluoro or chloro. In addition, it is preferable that R ₃₃ is chloro.

The polymer according to an embodiment of the present invention may be most preferably selected from the following structures, but is not limited thereto.

[In the above structure, p and q are mole fractions of each repeating unit.]

In the polymer according to an embodiment of the present invention, the mole fraction (p) of the repeating unit represented by the formula (1) and the mole fraction (q) of the repeating unit represented by the following formula (2) are 0<p<1, 0<q<1, and , p+q=1 may be satisfied.

The polymer according to an embodiment of the present invention may be 30 kDa to 1,000 kDa, 30 kDa to 1,000 kDa, 40 kDa to 1,000 kDa, 50 kDa to 1,000 kDa, 60 kDa to 1,000 kDa, 70 kDa to 1,000 kDa, 100 kDa to 1,000 kDa, 30 kDa to 800 kDa, 40 kDa to 800 kDa, 50 kDa to 800 kDa, 60 kDa to 800 kDa, 70 kDa to 800 kDa, 100 kDa to 800 kDa, 30 kDa to 500 kDa, 40 kDa to 500 kDa, 50 kDa to 500 kDa, 60 kDa to 500 kDa, 70 kDa to 500 kDa, 100 kDa to 500 kDa, 30 kDa to 250 kDa, 40 kDa to 250 kDa, 50 kDa to 250 kDa, 60 kDa to 250 kDa , 70 kDa to 250 kDa, 100 kDa to 250 kDa, 30 kDa to 150 kDa, 40 kDa to 150 kDa, 50 kDa to 150 kDa, 60 kDa to 150 kDa, 70 kDa to 150 kDa or 50 kDa to 100 kDa have. Here, the molecular weight is given as a number average molecular weight M _n measured by gel permeation chromatography (GPC) with respect to a polystyrene standard. Here, the degree of polymerization (n) means a number average degree of polymerization, provided by n = M _n /M _u (where M _n is a number average molecular weight and M _u is a molecular weight of a single repeating unit).

The polymer according to an embodiment of the present invention may be included in an organic electronic device, and among them, it is used as an electron acceptor material in the photoactive layer of an organic solar cell to replace the conventional fullerene derivative to realize improved photoelectric conversion efficiency in an organic solar cell. It is possible. Accordingly, the organic solar cell according to the present invention can realize high performance with a non-fullerene-based electron acceptor material having excellent efficiency and stability.

Of course, the polymer according to an embodiment of the present invention can be prepared through a conventional organic synthesis method, and the organic solvent used is not limited, and the reaction time and temperature are also changed within the range that does not deviate from the core of the invention. Of course, this is possible.

The present invention also provides an organic electronic device comprising the above-mentioned polymer.

The organic electronic device according to an embodiment of the present invention is not limited as long as it is a device in which the polymer of the present invention can be used, and as a non-limiting example thereof, the organic electronic device is an organic solar cell, an organic thin film transistor, an organic memory, or an organic electronic device. and a photoreceptor, an organic optical sensor, and the like, preferably an organic solar cell or an organic thin film transistor, and more preferably an organic solar cell.

The organic electronic device according to an embodiment of the present invention is an organic solar cell, and the polymer may be included in a photoactive layer of the organic solar cell.

More specifically, the polymer of the present invention is used as an electron acceptor as a substitute compound for a fullerene derivative conventionally used in an organic solar cell, and the organic solar cell employing the same has improved photoelectric conversion efficiency.

Hereinafter, a method for manufacturing an organic solar cell according to the present invention will be described with an example, but the present invention is not limited thereto.

The organic solar cell has a structure in which a hole transport layer and an electron transport layer are bonded, and when sunlight is absorbed, an electron-hole pair is generated in the hole acceptor, and electrons move to the electron acceptor, so that the electron-hole The photoelectric conversion effect is shown through the process of separation.

By employing the polymer of the present invention in an organic solar cell, it was confirmed that surprisingly improved photoelectric conversion efficiency can be achieved. In addition, the polymer of the present invention has high crystallinity and solubility and has high charge mobility, so that it can be used as an electron acceptor material in the photoactive layer of an organic solar cell to realize high efficiency.

The organic solar cell according to an embodiment of the present invention may include a substrate, a first electrode, a photoactive layer and a second electrode, and may further include a hole transport layer, an electron transport layer, and the like.

In addition, the organic solar cell according to an embodiment of the present invention may be an inverted type organic solar cell.

In addition to glass and quartz plate, the substrate is PET (polyethylene terephthalate), PEN (polyethylene naphthelate), PP (polyperopylene), PI (polyimide), PC (polycarbornate), PS (polystylene), POM (polyoxyethlene), AS resin (acrylonitrile styrene) copolymer), ABS resin (acrylonitrile butadiene styrene copolymer), and TAC (Triacetyl cellulose) may be made of a flexible and transparent material such as plastic.

In addition, the first electrode is formed by coating a transparent electrode material on one surface of the substrate or coating it in a film form using sputtering, E-Beam, thermal evaporation, spin coating, screen printing, inkjet printing, doctor blade or gravure printing method. do. The first electrode is a part functioning as an anode, and as a material having a greater work function compared to a second electrode to be described later, any material having transparency and conductivity may be used. For example, indium tin oxide (ITO), gold, silver, fluorine doped tin oxide (FTO), aluminum doped zink oxide (AZO), indium zink oxide (IZO) ), ZnO-Ga ₂ O ₃ , ZnO-Al ₂ O ₃ , and antimony tin oxide (ATO, SnO ₂ -Sb ₂ O ₃ ), etc., and it is preferable to use ITO.

The photoactive layer is made of a mixture of an electron acceptor and an electron donor, and can provide a photovoltaic effect through very fast charge transfer and separation, and the polymer of the present invention may be included as an electron acceptor, and its blending amount depends on the use. can be appropriately adjusted. In addition, the polymer of the present invention can be dissolved in an organic solvent and used as an electron acceptor material of the photoactive layer to a thickness of 60 mm or more, preferably 60 to 120 nm. In addition, as an example of the electron donor, PBDB-T (poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)-benzo[1,2-b:4,5) -b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-c: 4',5'-c']dithiophene-4,8-dione))]), PBDB-TS (poly[(2,6-(4,8-bis(5-(2-ethylhexylthio)thiophen-2- yl)-benzo[1,2-b:4,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis( 2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione))), PBDB-T-SF (Poly[(2,6-(4) ,8-bis(5-(2-ethylhexylthio)-4-fluorothiophen-2-yl)-benzo[1,2-b:4,5-b']-dithiophene))-alt-(5,5-( 1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione )]), PBDB-T-2F (poly[(2,6-(4,8-bis(5-(2-ethylhexyl)-4-fluorothiophen-2-yl)-benzo[1,2-b:4 ,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'- c:4',5'-c']dithiophene-4,8-dione)]), PBDTTT-CT (poly[(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)-benzo [1,2-b;4,5-b']dithiophene)-2,6-diyl-alt-(4-(2-ethylhexanoyl)-thieno[3,4-b]thiophene))-2,6- diyl]), PBDTTT-CF (poly[1-(6-{ 4,8-bis[(2-ethylhexyl)oxy]-6-methylbenzo[1,2- b :4,5- b ′]dithiophen-2-yl}-3-fluoro-4-methylthieno[3,4- b ]thiophen-2-yl)-1-octanone]), J51 (Poly[(5,6-difluoro-2-octyl-2H-benzotriazole-4,7-diyl)-2,5-thiophenediyl[4,8 -bis[5-(2-hexyldecyl)-2-thienyl]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl]-2,5-thiophenediyl]), PBDTT-DPP (poly{2,6'-4,8-di(5-ethylhexylthienyl)benzo[1,2-b;3,4-b]dithiophene-alt-5-dibutyloctyl-3,6-bis(5-bromothiophen- 2-yl)pyrrolo[3,4-c]pyrrole-1,4-dione}, P3HT (poly(3-hexylthiophene)), PCDTBT (poly[N-9'-heptadecanyl-2,7-carbazole-alt- 5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)]) and the like. The electron donor and the polymer of the present invention are mixed in a weight ratio of 1: 0.5 to 1: 4 and a solution dissolved in an organic solvent is used to form a photoactive layer by spin coating, spray coating, screen printing, doctor blade method, etc. have. The organic solvent is a single organic solvent or two or more organic solvents having different boiling points, specifically chlorobenzene, acetone, methanol, tetrahydrofuran, toluene, xylene, tetralin, 1,2-dichlorobenzene and chloroform. It may be one or more organic solvents selected from the group consisting of.

The photoactive layer uses the polymer according to the present invention as an electron acceptor, and no change in its state is observed even under a wide range of temperature conditions, so it can have excellent performance and morphology. In addition, in order to control the morphology and crystallinity of the photoactive layer, an additional additive may be further included. Examples of the additive include 1,8-diiodooctane (DIO: 1,8-diiodooctane), 1-chloronaphthalene (1-CN: 1-chloronaphthalene), diphenyl ether (DPE: diphenylether), octanedithiol (octane dithiol), tetrabromothiophene, etc. may be mentioned, and may be appropriately combined according to the use.

In addition, the photoactive layer including the polymer according to the present invention has a high electron density, and thus a short circuit current density and an open circuit voltage are increased to improve the photoelectric conversion efficiency. That is, the polymer according to the present invention is used as an electron acceptor as an alternative compound to the fullerene derivative used in the prior art in organic solar cells, and the organic solar cell employing the same has improved photoelectric conversion efficiency.

In addition, the second electrode may be deposited using a thermal evaporator in a state in which the electron transport layer is introduced. At this time, usable electrode materials include lithium fluoride/aluminum, lithium fluoride/calcium/aluminum, aluminum/calcium, barium/aluminum fluoride, barium fluoride/barium/aluminum, barium/aluminum, aluminum, gold, silver, magnesium: silver and It may be selected from lithium:aluminum, and it is preferable to use an electrode made of silver, aluminum, aluminum/calcium or barium fluoride/barium/aluminum structure.

Also, the materials of the electron transport layer and the hole transport layer may be used differently from general types of electron transport layer and hole transport layer. Examples of the electron transport layer material include TiO _x , ZnO, TiO ₂ , ZrO ₂ , MgO, HfO ₂ , and the like, and examples of the hole transport layer material include NiO, Ta ₂ O ₃ , MoO ₃ , Ru ₂ O ₃ , and the like. of metal oxides. In addition, it goes without saying that an organic conjugated polymer electrolyte having a cation or an anion in addition to the above-described metal oxide may be used as a material for the electron transport layer or the hole transport layer.

Hereinafter, the present invention will be described in detail by way of Examples. However, the following examples are only for illustrating the present invention, and the content of the present invention is not limited by the following examples. At this time, if there is no other definition in the technical terms and scientific terms used, those of ordinary skill in the art to which this invention belongs have the meanings commonly understood. In addition, repeated description of the same technical configuration and operation as in the prior art will be omitted.

[Example 1]

Preparation of P(Y52BOBDT-H)

Step 1: Preparation of compound (2)

Compound (1) (8.1 g, 10.8 mmol) was added to a three-necked flask, 5-(bromomethyl l) undecane (5-(bromomethyl) undecane, 3.72 g, 15 mmol), potassium hydroxide, 2 g, 35.64 mmol) and dimethylformamide (DMF) were added, and then oxygen was removed with argon gas for 15 minutes. The mixture was refluxed at 80° C. for 15 hours. Then, after removing the solvent, extraction was performed using ethyl acetate and distilled water (H ₂ O). The organic layer was dried over MgSO ₄ , and then column chromatography was performed. Column chromatography was carried out with dichloromethane / petroleum ether = 1:1 (vol:vol), and a red solid compound (2) was obtained (4.7 g, 40%).

¹ H NMR (300 MHz, C4D20) δ 8.96 (s, 1H), 6.49 (d, J = 7.7 Hz, 2H), 4.61 (t, J = 7.6 Hz, 2H), 3.88 (s, 1H), 3.80 - 3.56 (m, 2H), 3.34 - 2.96 (m, 17H), 2.99 - 2.49 (m, 18H), 2.50 - 2.24 (m, 8H).

Step 2: Preparation of compound (3)

n-BuLi (0.69ml, 1.6M in hexane) was slowly added to a solution of compound (2) (0.46g, 0.5mmol) dissolved in tetrahydrofuran (THF) under nitrogen at -78°C. Thereafter, the mixture was stirred at the same temperature for 1.5 hours and then stirred at 0° C. for 0.5 hours. The mixture was dropped to -78°C, and then DMF was added. The solution was brought to room temperature (25° C.) and stirred for 12 hours. After pouring water, extraction was performed using dichloromethane. The organic layer was dried over MgSO ₄ , and then column chromatography was performed. Column chromatography was carried out with dichloromethane / petroleum ether = 1:1 (vol:vol), and a red solid compound (3) was obtained (0.34 g, 60%).

¹ H NMR (300 MHz, CD2Cl2) δ 10.06 (s, 1H), 4.74 - 4.37 (m, 2H), 3.13 (t, J = 7.6 Hz, 2H), 2.04 - 1.91 (m, 1H), 1.90 - 1.77 (m, 2H), 1.44 - 1.12 (m, 17H), 1.08 - 0.65 (m, 18H), 0.63 - 0.46 (m, 8H).

Step 3: Preparation of compound (4)

Compound (3) (0.17 g, 0.15 mmol), 2- (6-bromo-3-oxo-2,3-dihydro-1H-inden-1-ylidene) malononitrile (2- (6-bromo) -3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile, 0.25 g, 0.91 mmol), pyridine (1ml) and chloroform (chloroform, 45ml) were placed in a round-bottom flask with nitrogen flow. . The mixed solution was stirred at 65° C. for 12 hours. After raising the temperature to room temperature and pouring methanol, the filter was performed. Column chromatography was performed with silica gel. Column chromatography was carried out at dichloromethane/petroleum ether = 1:1 (vol:vol), and a dark blue solid compound (4) was obtained (0.14 g, 57%).

¹ H NMR (300 MHz, CD2Cl2) δ 9.07 - 8.90 (m, 2H), 8.67 (s, 1H), 8.42 (d, J = 8.5 Hz, 1H), 7.96 (d, J = 1.9 Hz, 1H), 7.83 (dd, J = 8.0, 1.4 Hz, 1H), 7.78 (dd, J = 8.4, 1.9 Hz, 1H), 7.72 (d, J = 8.0 Hz, 1H), 4.76 (d, J = 7.2 Hz, 4H) ), 3.11 (s, 4H), 2.17 (s, 2H), 1.77 (dd, J = 14.4, 7.4 Hz, 4H), 1.49 - 1.33 (m, 4H), 1.36 - 0.69 (m, 68H), 0.69 - 0.49 (m, 12H).

Step 4: Preparation of P(Y52BOBDT-H): Polymer 1

Compound (4) (200 mg, 0.121 mmol), (4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b']diti Opene-2,6-diyl)bis(trimethylstannane) ((4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b'] 50 dithiophene-2,6-diyl)bis(trimethylstannane), 109 mg, 0.121 mmol), Pd ₂ (dba) ₃ (2.4 mg, 0.0026 mmol) and P (o-tol) ₃ (3.2 mg, 0.011 mmol) 50 ml 2 neck flask. The mixture was reacted at 85° C. for 12 hours, then cooled to room temperature and the reaction mixture was poured into methanol (200 ml). The precipitate was filtered and extracted using Soxhlet in the order of methanol, dichloromethane and chloroform. The extracted chloroform was concentrated, precipitated in 200 ml of methanol, and filtered. It was dried under vacuum to give Polymer 1 as a dark solid (160 mg, 63 %) (Mn = 12 kg mol -1 , -= 1.6, p=0.5).

¹ H NMR (300MHz, CDCl3) δ9.26-8.65 (broad, 4H), 8.2-7.8 (broad, 4H), 7.82-751 (broad, 6H), 4.85-4.65 (m, 4H), 3.22-3.03 ( m, 4H), 2.97-2.81 (m, 4H), 1.9 (m, 4H), 1.84 (m, 2H), 1.55 (m, 4H), 1.45 - 0.88 (m, 82H), 0.98 - 0.52 (m, 24H)).

[Examples 2 to 4]

It was carried out in a manner similar to that of Example 1, except that in step 4, (4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b '] By using the monomer compounds of Table 1 below instead of dithiophene-2,6-diyl)bis(trimethylstannane), the polymers of Table 1 were obtained.

The light absorption regions of the polymers prepared in Examples 1 to 3 were measured in a solution state (solution: CHCl ₃ ) and a film state, and the results are shown in FIGS. 1 to 3 below. In addition, the optical properties of the polymers prepared in Examples 1 to 3 are shown in Table 2 below, and the band gap (Eg) was obtained at the UV absorption wavelength in the film state.

[Comparative Example Compound]

[Examples 5 to 8]

Organic solar cell production

In order to evaluate the performance of the polymer of the present invention for use as an electron acceptor for an organic solar cell, an organic solar cell was prepared as follows.

Immerse the glass substrate coated with ITO (Indium Tin Oxide) as the anode transparent electrode (first electrode) in deionized water containing a cleaning solution, wash in an ultrasonic cleaner for 15 minutes, and again with deionized water, acetone, isopropyl alcohol (IPA) ) was washed three times each, and then dried in an oven at 130° C. for 5 hours. After UV/ozone treatment for 15 minutes on the washed ITO glass substrate, spin-coated ZnO NPs (zinc oxide nanoparticles), and heat treatment at 100° C. for 10 minutes on a hot plate to form a 30 nm-thick ZnO NPs layer formed.

After transferring the device to a glove box filled with argon, a photoactive layer was formed.

To form the photoactive layer, the polymer of the present invention (each polymer prepared in Examples 1 to 4) as an electron acceptor and PBDB-T as an electron donor in a weight ratio of 1:1 in chlorobenzene (CB) After dissolving at a concentration of 20 mg/mL, DIO (1,8-diiodooctane) was added at 0.5 v/v% and stirred to prepare an organic semiconductor solution.

After filtering the organic semiconductor solution through a 0.45 μm (PTFE) syringe filter, spin coating on the ZnO·NPs layer, and annealing at 160° C. for 30 minutes to prepare a photoactive layer with a thickness of 100 nm did. Subsequently, a 10 nm thick MoO ₃ , 100 nm thick Ag electrode as the top electrode was deposited on the photoactive layer under 3 x 10 ^-6 torr vacuum in a thermal evaporator [Glass/ITO/ZnO/photoactive layer (polymer of the present invention) : PBDB-T)/MoO ₃ /Ag], an organic solar cell having a conventional structure was fabricated.

In order to investigate the photoelectric power characteristics of the fabricated organic solar cell, 100 mW sunlight under AM 1.5 condition was generated using a solar simulator and a radiant power meter, and a 1 kW solar simulator (Newport 91192) was used. was used to measure the current density-voltage characteristics of the organic solar cell.

Open-circuit voltage (V _oc ), short-circuit current (J _sc ), FF (Fill Factor), and photoelectric conversion efficiency (PCE), which are electrical characteristics of the produced organic solar cell, were checked, and the results are shown in Table 3 below. shown.

Each of V _oc (V) and J _sc (mA/cm ² ) represents a voltage value when the current is 0 and a current value when the voltage is 0 in the current-voltage curve of the fabricated device.

In addition, FF (fill factor) is calculated from the following Equation (1).

[Equation 1]

FF = V _mpp ㆍJ _mpp /V _oc ㆍJ _sc

(In Equation 1, each of V _mpp and J _mpp represents the voltage and current value at the point showing the maximum power when measuring the current-voltage of the manufactured device, and V _oc (V) and J _sc (mA/ cm ² ) Each represents a voltage value when the current is 0 and a current value when the voltage is 0 in the current-voltage curve of the fabricated device.)

Furthermore, the photoelectric conversion efficiency (%) is calculated from Equation 2 below.

[Equation 2]

Photoelectric conversion efficiency (%) = 100×FF×V _oc ㆍJ _sc /P _in

(In Equation 2, FF, V _oc and J _sc are as defined in Equation 1, and P _in represents the total energy of light incident on the device.)

[Comparative Example 1]

Fabrication of organic solar cells

An organic solar cell was fabricated in the same manner as in Example 5 using Y5-2BO exemplified as the comparative compound instead of the polymer of the present invention, and its characteristics were confirmed.

[Comparative Example 2]

Fabrication of organic solar cells

An organic solar cell was manufactured in the same manner as in Example 5 using P(NDI2OB-T2) exemplified as the comparative compound instead of the polymer of the present invention, and its characteristics were confirmed.

As shown in Table 2, in the polymer according to the present invention, no change in the film state was observed despite the change in temperature. Accordingly, the photoactive layer prepared using the polymer according to the present invention can implement excellent performance and morphology.

In addition, as shown in Table 3, it was confirmed that the organic solar cell employing the polymer according to the present invention as an electron acceptor in the photoactive layer can realize very high photoelectric conversion efficiency. It can be seen that this results from the characteristic substituents and structural features of the polymer according to the invention.

The organic solar cell according to the present invention has excellent thermal and chemical stability as well as improved photoelectric conversion efficiency. In addition, the organic solar cell employing the compound according to the present invention has excellent long-term stability, and despite the passage of a long period of time, no significant change in photoelectric conversion efficiency is observed and the initial value is maintained and thus excellent in durability. The polymer has improved electron affinity compared to the conventional fullerene-based electron acceptor PC71BM as well as Comparative Example 1 or Comparative Example 2, which are known non-fullerene-based electron acceptors. efficiency was shown. At the same time, it was confirmed that the polymer of the present invention can be applied as a compound that replaces the fullerene-based electron acceptor by showing the effect of significantly increasing the open circuit voltage (V _oc ) and the short-circuit current (J _sc ).

Therefore, when the polymer according to the present invention is employed as a non-fullerene-based electron acceptor, high short-circuit current (J _sc ) and FF can be realized as well as excellent photoelectric conversion efficiency, so the fullerene-based electron acceptor widely used in the prior art Used as a compound that can replace the electron acceptor, it is possible to improve the photoelectric conversion efficiency of an organic solar cell, and at the same time significantly improve stability and durability.

As described above, although the embodiments of the present invention have been described in detail, those of ordinary skill in the art to which the present invention pertains within the scope not departing from the technical spirit of the present invention as defined in the appended claims. The present invention may be practiced with various modifications. Accordingly, modifications of future embodiments of the present invention will not depart from the technology of the present invention.

Claims (13)

A polymer for an organic electronic device comprising a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2):
[Formula 1]

[Formula 2]

In the above formulas 1 and 2,
R ₁ to R ₄ are each independently C1-C30 alkyl;
X ₁ to X ₄ are each independently O, S or Se;
V ₁ and V ₂ are each independently a fused ring having methylidene as a linking group, and the fused rings are each independently C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, haloC1- It may be further substituted with one or more substituents selected from C30 alkyl, nitro and hydroxy, and -CH ₂ - of the fused ring is carbonyl, thiocarbonyl or

may be replaced with, wherein each R is independently hydrogen, C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, nitro, hydroxy, haloC1-C30 alkyl, C1-C30 alkyl carbonyl or C 1 -C 30 alkylcarbonyloxy, wherein the fused ring may contain one or more heteroatoms selected from N, O, S and Se;
Ar is benzodithiophenylene, benzodithienothiophenylene, naphthodithiophenylene, thiophenylene, benzothienoselenophenylene, benzodiselenophenylene, benzodiselenoselenophenylene, naphthodiselenophenylene, selenophenylene, or a combination thereof, wherein Ar is each independently C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, C6-C30 aryl, C3-C30 heteroaryl; It may be further substituted with one or more substituents selected from halogen, cyano, nitro, hydroxy, and combinations thereof. The method of claim 1,
The repeating unit represented by Formula 2 is,
A polymer selected from the structure:

In the above structure,
a is selected from an integer from 0 to 5;
R ₁₁ and R ₁₂ are each independently C1-C30 alkyl;
R ₁₃ and R ₁₄ are each independently hydrogen or C1-C30 alkyl;
Ar ₁ to Ar ₄ are each independently hydrogen or C3-C30 heteroaryl, wherein the heteroaryl is one selected from C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, hydroxy, and combinations thereof It may be further substituted with more than one substituent. 3. The method of claim 2,
In the above structure, Ar ₁ and Ar ₂ are each independently C3-C30 heteroaryl substituted with one or more substituents selected from C1-C30 alkyl, halogen, or a combination thereof, and Ar ₃ and Ar ₄ are hydrogen. . The method of claim 1,
The V ₁ and V ₂ are,
Each of which is independently represented by the following formula (A), a polymer:
[Formula A]

In the formula A,
Y ₁ and Y ₂ are each independently O, S or CR _a R _b , wherein R _a and R _b are each independently halogen, cyano, nitro, hydroxy, C1-C30 alkylcarbonyl or C1-C30 alkyl carbonyloxy;
A is a C6-C20 aromatic ring or a C3-C20 heteroaromatic ring, wherein the aromatic ring and the heteroaromatic ring are C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, haloC1-C30 alkyl , may be further substituted with one or more substituents selected from nitro and hydroxy. 5. The method of claim 4,
The V ₁ and V ₂ are,
Each of which is independently represented by Formula B or Formula C, a polymer:
[Formula B]

[Formula C]

In Formula B and Formula C,
Y ₁ and Y ₂ are each independently O, S or CR _a R _b , R _a and R _b are each independently halogen, cyano, nitro, hydroxy, C1-C30 alkylcarbonyl or C1-C30 alkylcarbonyl nyloxy, wherein Y ₁ and Y ₂ are different from each other;
one of Z ₂ and Z ₃ is CR _c , the other is O, S or Se, wherein R _c is hydrogen, C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, nitro , hydroxy or haloC1-C30 alkyl;
Z ₁ is CR _d or N, wherein R _d is hydrogen, C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, nitro, hydroxy or haloC1-C30 alkyl or an adjacent substituent; It may be connected with R ₂₁ or R ₂₂ to form an aromatic fused ring;
R ₂₁ to R ₂₄ are each independently hydrogen, C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, nitro, hydroxy or haloC1-C30 alkyl. 6. The method of claim 5,
The V ₁ and V ₂ are,
Each of which is independently represented by Formula D, Formula E, Formula F, or Formula G, a polymer:
[Formula D]

[Formula E]

[Formula F]

[Formula G]

In the above formulas D to G,
Y ₁ and Y ₂ are each independently O or S;
R _a and R _b are each independently halogen, cyano, nitro, hydroxy, C1-C30 alkylcarbonyl or C1-C30 alkylcarbonyloxy;
R _c and R _d are each independently hydrogen, C 1 -C 30 alkyl, C 1 -C 30 alkoxy, C 1 -C 30 alkylthio, halogen, cyano or haloC 1 -C 30 alkyl;
R ₂₁ to R ₂₄ are each independently hydrogen, C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano or haloC1-C30 alkyl. The method of claim 1,
The polymer is
A polymer comprising a repeating unit represented by the following formula (3) and a repeating unit represented by the following formula (4):
[Formula 3]

[Formula 4]

In Formulas 3 and 4,
R ₁ and R ₂ are each independently straight-chain C8-C30 alkyl;
R ₃₁ and R ₃₂ are each independently crushed C1-C7 alkyl;
x and y are each independently an integer selected from 1 to 7;
each R ₃₃ is independently hydrogen, fluoro or chloro. The method of claim 1,
The mole fraction (p) of the repeating unit represented by the formula (1) and the mole fraction (q) of the repeating unit represented by the formula (2) are 0<p<1, 0<q<1, and satisfy p+q=1 phosphorus, polymer. An organic electronic device comprising the polymer according to any one of claims 1 to 8. 10. The method of claim 9,
The organic electronic device,
An organic electronic device, which is an organic solar cell, an organic thin film transistor, an organic memory, an organophotoreceptor or an organic photosensor. 10. The method of claim 9,
The organic electronic device is an organic solar cell. 10. The method of claim 9,
The polymer is
Which is included in the photoactive layer of the organic solar cell, an organic electronic device. 11. The method of claim 10,
The polymer is
An organic electronic device that is used as an electron acceptor.

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