KR102389528B1 - Organic semiconducting compounds, and organic electronic device ing the same - Google Patents

Abstract

The present invention relates to an organic semiconductor compound and an organic electronic device including the same. According to the present invention, an organic semiconductor compound capable of absorbing a larger amount of photons and improving their mobility, that is, a novel copolymer It provides excellent photoelectric conversion efficiency even when combined with electron acceptors such as fullerene compounds as well as non-fullerene compounds, and is suitable for large-area printing processes, suitable for mass production and mass production, and can be applied to eco-friendly processes. It is also possible to provide an organic electronic device with high efficiency commercially advantageously.

Description

An organic semiconductor compound and an organic electronic device comprising the same

The present invention relates to an organic semiconductor compound and an organic electronic device including the same, and in detail, the present invention provides a strong dipole moment in the same molecule due to a difference in electron affinity of each repeated unit structure, so that the charge mobility is very high. It relates to a copolymer and an organic electronic device comprising the same as an electron donor.

Recently, the development of organic materials with semiconductor properties and various application studies using them are being conducted more actively than ever before. The field of applied research using organic semiconductors, such as electromagnetic wave shielding films, capacitors, OLED displays, organic thin film transistors (OTFTs), organic solar cells, and memory devices using multiphoton absorption, continues to expand. Among them, the organic solar cell area in particular is receiving great attention in terms of enabling the infinite production of clean and safe energy among new and renewable energy technologies that are being actively researched in recent years.

The organic solar cell is a device capable of directly converting solar energy into electrical energy by applying the photovoltaic effect. A typical solar cell is made of a p-n junction by doping crystalline silicon (Si), an inorganic semiconductor. Electrons and holes generated by absorbing light diffuse to the p-n junction and are accelerated by the electric field and move to the electrode. The power conversion efficiency of this process is defined as the ratio of the power given to the external circuit and the solar power entered into the solar cell. Conventional inorganic solar cells show their limitations in terms of high production cost and material supply and demand, so the development of technologies that can improve processing convenience and lower production costs of solar cells has been progressed. As a result, low-cost, abundant organic materials Organic solar cell technology has attracted attention as a new alternative.

In addition, in order to improve the efficiency of the organic solar cell, various materials are applied to the organic layer such as the photoactive layer and the buffer layer. Research is actively underway.

Recently, many examples of organic solar cells using non-fullerene-based compounds as electron acceptor materials have been published. In addition, it is reported that the photoelectric conversion efficiency (PCE) of the organic solar cell to which this is applied is achieved more than 15%. However, since 　 non-fullerene-based compounds 　 show good efficiency only in combination with specific polymers, research on novel polymers capable of exhibiting good efficiencies with non-fullerene-based compounds is still needed.

Against this background, there is a research on organic semiconductor compounds, which are more effective materials to increase the level of commercialization as well as photoelectric conversion efficiency of organic solar cells, and materials suitable for simple manufacturing processes and eco-friendly processes that make them suitable for mass production and mass production. Research is needed.

KR 10-1763954 B1

An object of the present invention is to provide a novel copolymer having improved charge mobility and use as a material for an organic electronic device comprising the same.

In detail, an object of the present invention is to provide a novel copolymer having a very high charge mobility due to a strong dipole moment formed in the same molecule due to a difference in the electron affinity of each repeated unit structure.

Specifically, an object of the present invention is to provide a novel copolymer capable of implementing excellent photoelectric conversion efficiency even when combined with an electron acceptor such as a fullerene-based compound as well as a non-fullerene-based compound.

In detail, the present invention is a material suitable for a large-area printing process, a novel copolymer suitable for mass production and mass production and applicable to an eco-friendly process, a composition for forming an organic layer of an organic electronic device including the same, and an organic electronic device including the same It aims to provide a device.

In order to achieve the above object, in the present invention, there is provided a copolymer including a unit structure represented by the following formula (1).

[Formula 1]

[In Formula 1,

A is C ₃ -C ₅₀ heteroarylene;

B is a condensed aromatic ring including C ₃ -C ₅₀ heteroarylene;

Z ₁ is -O- or -S-;

R ₁ is hydrogen, C ₁ -C ₃₀ alkyl or C ₁ -C ₃₀ alkoxy;

R ₂ is halogen, hydroxy, cyano, carboxylic acid, haloC ₁ -C ₃₀ alkyl, C ₁ -C ₃₀ alkyl or C ₁ -C ₃₀ alkoxy;

a and b are each independently an integer of 0 or 1, but satisfy a+b≥1;

c is an integer selected from 0 to 3;

The heteroarylene of A and the condensed aromatic ring of B are each independently halogen, hydroxy, cyano, carboxylic acid, C ₁ -C ₃₀ alkyl, C ₁ -C ₃₀ alkoxy, C ₁ -C ₃₀ alkoxycar Bornyl, C ₆ -C ₃₀ aryl, C ₃ -C ₃₀ heteroaryl and may be further substituted with one or more substituents selected from combinations thereof, wherein the heteroarylene of A and the condensed aromatic ring of B are N, O and At least one heteroatom selected from S is included as a ring-forming atom.]

In the copolymer according to an embodiment of the present invention, R ₂ of Formula 1 is fluorine, chlorine, hydroxy, cyano, carboxylic acid, haloC ₁ -C ₃₀ alkyl or C ₁ -C ₃₀ alkoxy, etc. , where c may be an integer of 0 or 1.

In the copolymer according to an embodiment of the present invention, when b in Formula 1 is an integer of 0, a is an integer of 1, and A may be heteroarylene including thiophenylene.

In the copolymer according to an embodiment of the present invention, when b in Formula 1 is an integer of 1, a is an integer of 0, and B may be a condensed ring including thiophenylene.

The copolymer according to an embodiment of the present invention may include a unit structure represented by Chemical Formulas 1-1 and 2 below.

[Formula 1-1]

[Formula 2]

[In Formula 1-1 and Formula 2,

R ₁ is hydrogen or C ₁ -C ₃₀ alkyl;

R ₂ is hydrogen, fluorine, chlorine, hydroxy, cyano, carboxylic acid, haloC ₁ -C ₃₀ alkyl or C ₁ -C ₃₀ alkoxy;

R ₃ and R ₄ are each independently C ₁ -C ₃₀ alkyl, C ₆ -C ₃₀ aryl or C ₃ -C ₃₀ heteroaryl, wherein the aryl or heteroaryl is independently of each other fluorine, C ₁ -C ₃₀ alkyl and may be further substituted with one or more substituents selected from C ₁ -C ₃₀ alkoxy;

R ₁₁ and R ₁₂ are each independently hydrogen or C ₁ -C ₃₀ alkyl;

Het ₁ to Het ₃ are each independently a condensed ring including C ₃ -C ₃₀ heteroarylene or C ₃ -C ₃₀ heteroarylene, and Het ₁ and Het ₂ containing heteroarylene or heteroarylene Condensed rings are independently of each other halogen, hydroxy, cyano, carboxylic acid, C ₁ -C ₃₀ alkyl, C ₁ -C ₃₀ alkoxy, C ₁ -C ₃₀ alkoxycarbonyl, C ₆ -C ₃₀ aryl, C ₃ It may be further substituted with one or more substituents selected from -C ₃₀ heteroaryl and combinations thereof, wherein Het ₂ and Het ₃ are different from each other;

a and b are each independently an integer of 0 or 1, wherein a+b=1;

m and n are real numbers satisfying 0<m<1 and 0<n<1 as mole fractions, and m+n=1.]

In the copolymer according to an embodiment of the present invention, Het ₁ to Het ₃ of Formulas 1-1 and 2 are each independently furylene, pyrrolylene, pyrrolonylene, thiophenylene, imidazolylene , pyrazolylene, thiazolylene, thiadiazolylene, isothiazolylene, isoxazolylene, oxazolylene, oxadiazolylene, triazinylene, tetrazinylene, triazolylene, tetrazolylene, pura It is a heteroarylene selected from xylene, pyridylene, pyrazinylene, pyrimidinylene, pyridazinylene, and combinations thereof, or a condensed ring including the heteroarylene, and Het ₁ and Het ₂ Heteroarylene or Condensed rings are independently from each other fluorine, chlorine, hydroxy, cyano, carboxylic acid, C ₅ -C ₃₀ alkyl, C ₅ -C ₃₀ alkoxy, C ₅ -C ₃₀ alkoxycarbonyl, C ₆ -C ₁₂ aryl, It may be one that may be further substituted with one or more substituents selected from C ₃ -C ₁₂ heteroaryl and combinations thereof.

In the copolymer according to an embodiment of the present invention, Het ₁ and Het ₂ of Formulas 1-1 and 2 are independently selected from the following Structure 1, and Het ₃ of Formula 2 is the following Structure 2 may be selected from

[Structure 1]

[Structure 2]

[In Structure 1 and Structure 2,

p and q are independently of each other an integer of 0 or 1;

R is hydrogen or C ₅ -C ₃₀ alkyl;

R′ is hydrogen, C ₅ -C ₃₀ alkyl, C ₅ -C ₃₀ alkoxy or C ₅ -C ₃₀ alkoxycarbonyl;

R″ is C ₅ -C ₃₀ alkyl, C ₆ -C ₁₂ aryl or C ₃ -C ₁₂ heteroaryl, wherein the aryl or heteroaryl is independently of each other fluorine, C ₅ -C ₃₀ alkyl and C ₅ -C ₃₀ alkoxy may be further substituted with one or more substituents selected from;

X ₁ and X ₂ are each independently hydrogen, fluorine or C ₁ -C ₄ alkoxycarbonyl.]

In addition, the present invention provides a composition for forming an organic layer of an organic electronic device comprising the above-described copolymer of the present invention.

The composition for forming an organic layer of an organic electronic device according to an embodiment of the present invention may further include a non-fullerene-based compound and a solvent.

In addition, the present invention provides an organic electronic device comprising the above-described copolymer of the present invention.

The organic electronic device according to an embodiment of the present invention includes an anode, a cathode, and an organic layer disposed between the anode and the cathode. there is.

In the organic electronic device according to an embodiment of the present invention, the copolymer may be used as an electron donor.

In the organic electronic device according to an embodiment of the present invention, the organic electronic device may be selected from an organic light emitting device, an organic solar cell, an organic transistor, an organic photosensitive drum, and an organic memory device, but is not limited thereto.

The copolymer of the present invention improves pi-pi stacking in the solid phase, and a dipole moment is formed in the same molecule due to the difference in electron affinity of each repeated unit structure, thereby dramatically improving charge mobility can do it Accordingly, an organic electronic device employing it as an electron donor can realize high photoelectric conversion efficiency and stably maintain high photoelectric conversion efficiency.

The copolymer of the present invention exhibits improved properties such as solubility and thermal stability by having a unit structure including phenylene having one or more trifluoromethyl groups introduced thereinto. In particular, it is commercially advantageous because it is combined with an electron acceptor such as a non-fullerene-based compound to realize excellent photoelectric conversion efficiency and at the same time enable a mass production process using a non-halogen solvent suitable for an eco-friendly process.

Hereinafter, the novel copolymer according to the present invention and an organic electronic device including the same will be described in more detail through Examples. However, the following examples are only a reference for explaining the present invention in detail, and the present invention is not limited thereto, and may be implemented in various forms.

Also, unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description herein is for the purpose of effectively describing particular embodiments only, and is not intended to limit the present invention.

As used herein, the terms “alkyl”, “alkoxy” and other substituents containing an “alkyl” moiety include both straight-chain and comminuted forms.

In addition, the term "aryl" as used herein is an organic radical derived from an aromatic ring by removal of one hydrogen, suitably a monocyclic ring containing 4 to 7, specifically 5 or 6 ring atoms in each ring. Alternatively, it may include a polycyclic ring system, and includes a form in which a plurality of aryls are connected by a single bond.

In addition, the term “heteroaryl” described herein is an organic radical derived from an aromatic ring by removal of one hydrogen, B, N, O, S, Se, -P(=O)-, -C(=O) -, contains at least one selected from Si and P, etc. as a ring-forming atom. In addition, it may include a monocyclic or polycyclic ring system including 3 to 9 ring-forming atoms including the aforementioned heteroatoms, and includes a form in which a plurality of heteroaryls are connected by a single bond.

Also, the terms “fusion” and “condensation” described herein may be interpreted the same.

In addition, the term “condensed ring” as used herein means that two or more aromatic rings are fused or connected to each other to form a polycyclic ring system. Specifically, the condensed ring described herein is i) two or more heteroarylene These are bonded to each other to form a condensed ring, ii) at least one heteroarylene and at least one phenylene are bonded to each other to form a condensed benzo ring, iii) At least two heteroarylenes are -C(= O)- may be connected to form a condensed ring, etc. In addition, specifically, the aromatic condensed ring described in the present specification may be a condensed ring having the forms of i) and ii) above. there is.

In addition, the term “substitution” as used herein means that, in a repeating unit structure, a hydrogen atom bonded to a carbon atom is independently halogen, hydroxy, cyano, carboxylic acid, C ₁ -C ₃₀ alkyl, C ₁ -C ₃₀ alkoxy , C ₁ -C ₃₀ alkoxycarbonyl, C ₆ -C ₃₀ aryl, C ₃ -C ₃₀ heteroaryl, and combinations thereof, and the like, it means to be replaced with one or more substituents selected.

In addition, the expression "comprising" as used herein is an open-ended description having an equivalent meaning to expressions such as "comprises", "contains", "has" or "characterized by", and is not listed further It does not exclude elements, materials or processes that are not

Also, the singular form used herein may be intended to include the plural form as well, unless the context specifically dictates otherwise.

In addition, in the present specification, the unit used without special mention is based on the weight (g), for example, the unit of % or ratio means weight % or weight ratio.

As seen in the background art, the present inventors have intensified research on more effective materials for increasing the photoelectric conversion efficiency and commercialization level of organic electronic devices, which can be represented by organic solar cells and the like. As a result, it was confirmed that, in the case of a copolymer having a unit structure including phenylene introduced with one or more trifluoromethyl groups, high charge mobility was realized as well as hydrophobicity and excellent thermal stability. In addition, the copolymer satisfying these structural characteristics satisfies high solubility in common organic solvents used in organic electronic devices, confirming that it is a suitable material for a large-area printing process. Accordingly, the present inventors propose the present invention to provide a copolymer having such structural characteristics and uses thereof.

Hereinafter, the copolymer according to the present invention will be described.

The copolymer according to the present invention is characterized in that it includes a unit structure represented by the following formula (1). With such structural features, the copolymer of the present invention can realize improved charge mobility and absorb a large amount of photons.

[Formula 1]

[In Formula 1,

A is C ₃ -C ₅₀ heteroarylene;

B is a condensed aromatic ring including C ₃ -C ₅₀ heteroarylene;

Z ₁ is -O- or -S-;

R ₁ is hydrogen, C ₁ -C ₃₀ alkyl or C ₁ -C ₃₀ alkoxy;

R ₂ is halogen, hydroxy, cyano, carboxylic acid, haloC ₁ -C ₃₀ alkyl, C ₁ -C ₃₀ alkyl or C ₁ -C ₃₀ alkoxy;

a and b are each independently an integer of 0 or 1, but satisfy a+b≥1;

c is an integer selected from 0 to 3;

The heteroarylene of A and the condensed aromatic ring of B are each independently halogen, hydroxy, cyano, carboxylic acid, C ₁ -C ₃₀ alkyl, C ₁ -C ₃₀ alkoxy, C ₁ -C ₃₀ alkoxycar Bornyl, C ₆ -C ₃₀ aryl, C ₃ -C ₃₀ heteroaryl and may be further substituted with one or more substituents selected from combinations thereof, wherein the heteroarylene of A and the condensed aromatic ring of B are N, O and At least one heteroatom selected from S is included as a ring-forming atom.]

In the copolymer according to an embodiment of the present invention, R ₂ of Formula 1 is fluorine, chlorine, hydroxy, cyano, carboxylic acid, haloC ₁ -C ₃₀ alkyl or C ₁ -C ₃₀ alkoxy, etc. , where c may be an integer of 0 or 1.

For example, when R ₂ is haloC ₁ -C ₃₀ alkyl, halo may be C ₁ -C ₃₀ alkyl including at least one selected from fluorine and chlorine.

As mentioned above, the copolymer including the unit structure represented by Chemical Formula 1 may implement high charge mobility by improving pi-pi stacking in the solid phase. Therefore, it is possible to exhibit excellent photoelectric conversion efficiency when applied to an organic electronic device. Specifically, the copolymer according to the present invention has a low HOMO energy level and can satisfy improved photoelectric parameters when applied as an electron donor of an organic layer of an organic electronic device.

In the copolymer according to an embodiment of the present invention, when b in Formula 1 is an integer of 0, a is an integer of 1, and A may be heteroarylene including thiophenylene.

In the copolymer according to an embodiment of the present invention, when b in Formula 1 is an integer of 1, a is an integer of 0, and B may be a condensed ring including thiophenylene.

Specifically, the copolymer according to an embodiment of the present invention may include a unit structure represented by Chemical Formulas 1-1 and 2 below.

[Formula 1-1]

[Formula 2]

[In Formula 1-1 and Formula 2,

R ₁ is hydrogen or C ₁ -C ₃₀ alkyl;

R ₂ is hydrogen, fluorine, chlorine, hydroxy, cyano, carboxylic acid, haloC ₁ -C ₃₀ alkyl or C ₁ -C ₃₀ alkoxy;

R ₃ and R ₄ are each independently C ₁ -C ₃₀ alkyl, C ₆ -C ₃₀ aryl or C ₃ -C ₃₀ heteroaryl, wherein the aryl or heteroaryl is independently of each other fluorine, C ₁ -C ₃₀ alkyl and may be further substituted with one or more substituents selected from C ₁ -C ₃₀ alkoxy;

R ₁₁ and R ₁₂ are each independently hydrogen or C ₁ -C ₃₀ alkyl;

Het ₁ to Het ₃ are each independently a condensed ring including C ₃ -C ₃₀ heteroarylene or C ₃ -C ₃₀ heteroarylene, and Het ₁ and Het ₂ containing heteroarylene or heteroarylene Condensed rings are independently of each other halogen, hydroxy, cyano, carboxylic acid, C ₁ -C ₃₀ alkyl, C ₁ -C ₃₀ alkoxy, C ₁ -C ₃₀ alkoxycarbonyl, C ₆ -C ₃₀ aryl, C ₃ It may be further substituted with one or more substituents selected from -C ₃₀ heteroaryl and combinations thereof, wherein Het ₂ and Het ₃ are different from each other;

a and b are each independently an integer of 0 or 1, wherein a+b=1;

m and n are real numbers satisfying 0<m<1 and 0<n<1 as mole fractions, and m+n=1.]

In the copolymer according to an embodiment of the present invention, the structural unit represented by Formula 1-1 may be specifically a structural unit represented by Formula 1-2 and Formula 1-3 below.

[Formula 1-2]

[Formula 1-3]

[In Formula 1-2 and Formula 1-3,

R ₁ to R ₄ , R ₁₁ to R ₁₂ and Het ₁ are the same as defined in Formula 1-1.]

For example, in Formulas 1-1 to 1-3, R ₁ is hydrogen or C ₅ -C ₃₀ alkyl; wherein R ₂ is fluorine, chlorine, hydroxy, cyano, carboxylic acid, haloC ₁ -C ₄ alkyl or C ₅ -C ₃₀ alkoxy; R ₃ and R ₄ are each independently C ₅ -C ₃₀ alkyl, C ₆ -C ₁₂ aryl or C ₃ -C ₁₂ heteroaryl, and the aryl or heteroaryl are each independently fluorine, C ₅ -C ₃₀ alkyl and C ₅ -C ₃₀ alkoxy and the like may be further substituted with one or more substituents; The R ₁₁ and R ₁₂ may be each independently hydrogen or C ₅ -C ₃₀ alkyl.

For example, in Formulas 1-1 to 1-3, R ₂ may be hydrogen, haloC ₁ -C ₄ alkyl, or C ₅ -C ₃₀ alkoxy.

For example, in Formulas 1-1 to 1-3, R ₂ may be hydrogen or trifluoromethyl (*-CF ₃ ).

For example, in Formulas 1-1 to 1-3, R ₂ may be C ₇ -C ₂₀ alkoxy, or C ₇ -C ₁₅ alkoxy.

For example, in Formula 1-1, Formula 1-2, and Formula 2, Het ₁ to Het ₃ are each independently a C ₃ -C ₃₀ heteroarylene or a condensed ring including a C ₃ -C ₃₀ heteroarylene. And, the condensed rings including heteroarylene or heteroarylene of Het ₁ and Het ₂ are each independently halogen, hydroxy, cyano, carboxylic acid, C ₅ -C ₃₀ alkyl, C ₅ -C ₃₀ alkoxy , C ₁ -C ₃₀ alkoxycarbonyl, C ₆ -C ₁₂ aryl, C ₃ -C ₁₂ heteroaryl and may be further substituted with one or more substituents selected from combinations thereof, wherein Het ₂ and Het ₃ are different from each other. can

For example, in Formula 1-1, Formula 1-2, and Formula 2, when at least one selected from Het ₁ to Het ₃ is a condensed ring containing heteroarylene, the condensed ring is 1) the above-described hetero Two or more heteroarylenes selected from arylene are bonded to each other to form a condensed ring, or 2) one or more heteroarylenes selected from the above-mentioned heteroarylenes and one or more phenylenes are bonded to each other to form a benzo A condensed ring may be formed, or 3) two or more heteroarylenes may be connected by -C(=O)- to form a condensed ring, and a non-limiting example of a condensed ring thereof may be illustrated as follows. may, but is not limited thereto.

In the copolymer according to an embodiment of the present invention, Het ₁ of Formulas 1-1 and 1-2 and Het ₂ of Formula 2 are each independently selected from the following structure 1, The Het ₃ may be selected from the following structure 2.

[Structure 1]

[Structure 2]

[In Structure 1 and Structure 2,

p and q are independently of each other an integer of 0 or 1;

R is hydrogen or C ₅ -C ₃₀ alkyl;

R′ is hydrogen, C ₅ -C ₃₀ alkyl, C ₅ -C ₃₀ alkoxy or C ₅ -C ₃₀ alkoxycarbonyl;

R″ is C ₅ -C ₃₀ alkyl, C ₆ -C ₁₂ aryl or C ₃ -C ₁₂ heteroaryl, wherein the aryl or heteroaryl is independently of each other fluorine, C ₅ -C ₃₀ alkyl and C ₅ -C ₃₀ alkoxy may be further substituted with one or more substituents selected from;

X ₁ and X ₂ are each independently hydrogen, fluorine or C ₁ -C ₄ alkoxycarbonyl.]

When the copolymer according to an embodiment of the present invention includes the unit structures represented by Chemical Formulas 1 and 2 at the same time, high charge mobility can be realized by improving pi-pi stacking in the solid phase. there is. Specifically, the copolymer of the present invention may include the unit structures represented by Chemical Formulas 1-1 and 2 at the same time, and more specifically, include the unit structures represented by Chemical Formulas 1-2 and 2 at the same time. Or it may include a unit structure represented by Chemical Formulas 1-3 and 2 at the same time.

The copolymer according to an embodiment of the present invention can absorb a large amount of photons as it contains phenylene into which one or more trifluoromethyl groups are introduced in the unit structure, and the absorbed and excited excitons improve charge separation in the molecule As a result, the charge mobility is significantly increased. In particular, the copolymer of the present invention can impart synergy to the above-described effects by forming a dipole moment in the same molecule due to the difference in electron affinity of each repeated unit structure.

The copolymer according to an embodiment of the present invention may have a substituent including at least one long-chain alkyl. In this case, the long-chain alkyl may be an alkyl having 6 or more carbon atoms.

The copolymer according to an embodiment of the present invention may increase asymmetry within the same molecule by irregularly arranging donor functional groups (eg, Het ₁ to Het ₃ ) in each repeating unit structure. Accordingly, it is possible to implement more improved charge mobility, and has improved solubility in conventional organic solvents, so that it can be advantageously applied to a solution process.

In addition, the organic electronic device employing the copolymer according to an embodiment of the present invention realizes very high photoelectric conversion efficiency when manufacturing a module, and the photoelectric conversion efficiency can be stably maintained even if the mixing ratio with the electron acceptor is changed. In addition, the organic electronic device employing the copolymer according to an embodiment of the present invention is preferable because the photoelectric conversion efficiency does not change significantly even when the position and thickness of the module are variously changed during the process.

In addition, the copolymer according to an embodiment of the present invention has excellent solubility in organic solvents, and can realize high photoelectric conversion efficiency even when non-halogen solvents such as xylene, trimethylbenzene, and toluene are used. can provide In addition, it can be easily applied to various processes such as R ₂ R (roll-to-roll) process, thereby increasing the level of commercialization.

In the copolymer according to an embodiment of the present invention, it is possible to increase the charge mobility to increase the stability of the organic layer employing the same, for example, the photoactive layer.

The copolymer according to an embodiment of the present invention may be one selected from the following structure 3, but is not limited thereto.

[Structure 3]

compound 1

compound 2

compound 3

compound 4

compound 5

compound 6

compound 7

compound 8

compound 9

compound 10

compound 11

compound 12

compound 13

compound 14

compound 15

compound 16

compound 17

compound 18

compound 19

compound 20

compound 21

compound 22

compound 23

compound 24

compound 25

compound 26

compound 27

compound 28

compound 29

compound 30

[In the above structure 3,

m and n are real numbers with 0<m<1 and 0<n<1 in mole fraction, m+n=1.]

In the copolymer according to an embodiment of the present invention, the mole fractions of m and n may satisfy 0<m≤0.5 and 0.5≤n<1.

In terms of improving the excellent photoelectric conversion efficiency, stability, and commercialization level, specifically, in the copolymer of the present invention, the mole fractions of m and n may satisfy 0<m≤0.4 and 0.65≤n<1. More specifically, the mole fractions of m and n may satisfy 0<m≤0.35 and 0.7≤n<1.

The copolymer according to an embodiment of the present invention may have a weight average molecular weight of 1,000 to 1,000,000 g/mol. Specifically, the weight average molecular weight may be 10,000 to 400,000 g/mol, and more specifically, 10,000 to 200,000 g/mol in terms of enabling the formation and manufacture of a uniform thin film because solubility is not reduced while having high photoelectric conversion efficiency. It may be mol, but is not limited thereto.

In addition, in the copolymer according to an embodiment of the present invention, each repeating unit structure may be alternately or randomly arranged.

In addition, the terminal of the copolymer according to an embodiment of the present invention may or may not include a conventional terminal group, and the difference in effect thereof is insignificant.

Hereinafter, the use of the copolymer according to the present invention will be described.

One aspect of the present invention may be a composition for forming an organic layer of an organic electronic device including the copolymer, and another aspect may be an organic electronic device including the copolymer.

Specifically, the copolymer according to an embodiment of the present invention may be used as an electron donor in an organic electronic device. The organic electronic device of the present invention includes an organic light emitting diode (OLED, Organic Light Emitting Diode), an organic solar cell (OSC), an organic transistor (OTFT, Organic Thin-Film Transistor), and an organic photosensitive drum (OPD, Optical Photo). Detector) and organic memory devices may be any one selected. The organic electronic device may be any conventional organic electronic device recognized by those skilled in the art. In addition, the copolymer according to an embodiment of the present invention can further improve the performance of the organic electronic device through a combination with other various electron acceptors included in the organic electronic device. In particular, since the copolymer according to an embodiment of the present invention is used as an electron donor, high photoelectric conversion efficiency can be realized even when combined with an electron acceptor such as a fullerene-based compound as well as a non-fullerene-based compound.

Since the copolymer according to an embodiment of the present invention includes a flat structure, excellent charge mobility can be realized in an organic electronic device, and thus, high photoelectric conversion efficiency can be exhibited.

In addition, the copolymer according to an embodiment of the present invention can be used as an organic electronic device by forming a film by a solution process of dissolving it in an organic solvent and then applying it to a substrate, specifically R2R, spin coating, slot die coating , an inkjet printing method, a screen printing method, a doctor blade method, etc. may be applied and coated to form a film, but is not limited thereto. Accordingly, when the copolymer according to an embodiment of the present invention is employed, solubility is improved, so that there is an economical effect in terms of time and cost in the manufacturing process of the organic electronic device.

The composition for forming an organic layer of an organic electronic device according to an embodiment of the present invention contains the copolymer of the present invention in an amount of 0.5 wt% to 5 wt%, preferably 1 wt% to 3 wt%, based on the total weight may include

In addition, the composition for forming an organic layer of an organic electronic device according to an embodiment of the present invention may further include a non-fullerene-based compound and a solvent, or further include a fullerene-based compound and a solvent.

For example, the solvent is not limited as long as it is a conventional solvent, and it is better to use a non-halogen solvent such as xylene, trimethylbenzene, or toluene. In addition, the solvent may be included in the remaining amount of the composition for forming an organic layer of the organic electronic device.

For example, the non-fullerene-based compound and the fullerene-based compound may be electron acceptors, and may be monomolecular or polymeric compounds. In this case, the electron acceptor may be included in an amount of 0.5 wt% to 5 wt%, preferably 1 wt% to 3 wt%, based on the total weight of the composition for forming an organic layer of the organic electronic device. In addition, it may be included in an amount of 10 to 500 parts by weight based on 100 parts by weight of the copolymer of the present invention, specifically 30 to 300 parts by weight, and more specifically 50 to 250 parts by weight.

Hereinafter, an organic solar cell which is an aspect as an organic electronic device will be described.

The organic solar cell according to an embodiment of the present invention may include a positive electrode, a negative electrode, and an organic layer disposed between the positive electrode and the negative electrode, and the organic layer may include the copolymer of the present invention.

Specifically, an organic solar cell according to an embodiment of the present invention includes a first electrode (cathode); a photoactive layer (organic layer) positioned on the first electrode and including the copolymer; and a second electrode (anode) positioned on the photoactive layer. In addition, the photoactive layer may further include an electron acceptor selected from a non-fullerene-based compound and a fullerene-based compound, and preferably include a non-fullerene-based compound. Accordingly, the organic solar cell according to an embodiment of the present invention may constitute a bulk heterojunction (BHJ). The bulk heterojunction means that an electron donor and an electron acceptor are mixed with each other in the photoactive layer.

The organic solar cell of the present invention may further include a substrate. The substrate may be a transparent substrate. The substrate may be, for example, plastic or glass such as polyethylene terephthalate (PET), polypropylene (PP), polyimide (PI), polyethylene naphthalate (PEN), and triacetyl cellulose (TAC).

The first electrode may be a transparent electrode, and may also be a cathode. Specifically, it may be an indium tin oxide (ITO) film, an indium oxide (IO) film, a tin oxide (TO) film, a fluorinated tin oxide (FTO) film, an indium zinc oxide (IZO) film, or a zinc oxide (ZO) film. .

In addition, a first charge transport layer may be further formed between the first electrode and the photoactive layer. In addition, a second charge transport layer may be further formed between the photoactive layer and the second electrode. The first charge transport layer may be a hole transport layer. For example, it may be a metal oxide layer such as PEDOT:PSS (poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate), MoO ₃ , WO ₃ ).

The photoactive layer may use the copolymer of the present invention as an electron donor, and at least one compound selected from a fullerene-based compound and a non-fullerene-based compound may be used as an electron acceptor. In addition, the photoelectric conversion material of the photoactive layer is preferably blended in an amount of 50 to 250 parts by weight of the electron acceptor based on 100 parts by weight of the copolymer of the present invention. At this time, it is not particularly limited as long as the object of the invention is achieved, but when the content of the electron acceptor relative to the copolymer content of the present invention satisfies the above range, the electron accepting action of the electron acceptor is actively generated and the mobility of the generated electrons is very It is good that the light absorption of the copolymer is made efficiently.

For example, the electron acceptor is PC ₆₁ BM ([6,6]-phenyl-C ₆₁ -butyric acid methyl ester), PC ₇₁ BM ([6,6]-phenyl-C ₇₁ -butyric acid methyl ester), mono -oQDMC ₆₀ (mono-o-quino-dimethane C ₆₀ ), bis-oQDMC ₆₀ (bis-o-quino-dimethane C ₆₀ ), ICBA (indene-C ₆₀ -bis-adduct) and bis-PCBM (bis-[ 6,6]-phenyl-C ₆₁ -butyric acid methyl ester) may be a fullerene-based compound selected from, and the like, may be a non-fullerene-based compound such as ITIC. In addition, in the organic solar cell according to the present invention, by using the fullerene-based compound and the non-fullerene-based compound together, the efficiency of the organic solar cell can be further improved by compensating for the disadvantages of each other.

The photoactive layer may be prepared by mixing the copolymer of the present invention and the above-described electron acceptor, and may be prepared by dissolving in a single organic solvent or two or more organic solvents having different boiling points. The organic solvent used includes at least one organic solvent selected from the group consisting of chloroform, chlorobenzene, 1,2-dichlorobenzene, toluene, xylene, trimethylbenzene, etc., and 1,8-diiodooctane, 1-chloro An organic active material selected from naphthalene, diphenyl ether, etc. may be mixed in an organic solvent, but the present invention is not limited thereto. It is preferable to prepare the organic solvent to contain 1.0 to 3.0 vol% of the solid content of the organic active material. At this time, it is not particularly limited as long as the object of the present invention is achieved, but when the above range is satisfied, the copolymer of the present invention may form a more uniformly thin film with an appropriate thickness. In addition, the copolymer of the present invention can implement a high photoelectric conversion efficiency even when a non-halogen solvent such as xylene, trimethylbenzene, toluene is used, and thus can provide a more environmentally friendly process.

Then, the solution in which the organic active material is dissolved is applied by any one method selected from vacuum deposition, screen printing, printing, bar coating, slot die coating, spin coating, dipping, and ink spraying. By coating, it is possible to prepare a photoactive layer having a thickness of 30 to 800 nm, preferably 80 to 400 nm. In addition, according to the present invention, it is very advantageous even in a large area coating process in which the drying rate of the solvent is slow, such as a bar coating method.

The second electrode is an anode, and in a state in which the photoactive layer is introduced, a metal material having a low work function, such as aluminum, is vacuum thermally deposited at a thickness of 80 to 200 nm at a vacuum degree of about 10 ^-6 torr or less on the upper portion of the photoactive layer. can be stacked. Materials that can be used as the second electrode include, specifically, gold, aluminum, copper, silver or alloys thereof, calcium/aluminum alloy, magnesium/silver alloy, aluminum/lithium alloy, and the like, preferably aluminum or aluminum/lithium alloy. A calcium alloy may be used, but is not limited thereto.

Hereinafter, the copolymer of the present invention, a method for preparing the same, and an organic electronic device containing the same will be described in more detail through Examples. However, the following examples are only a reference for describing the present invention in detail, and the present invention is not limited thereto, and may be implemented in various forms.

Further, unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description herein is for the purpose of effectively describing particular embodiments only and is not intended to limit the present invention. In addition, the unit of additives not specifically described in the specification may be weight %.

[Method of measuring physical properties]

1. NMR Spectroscopy

¹ H NMR and ¹³ C NMR spectroscopy were measured using a Bruker AM-300, AM-400 or AM-500 spectrometer.

2. Weight average molecular weight measurement

The weight average molecular weight is a weight average molecular weight value in terms of standard polystyrene measured by gel permeation chromatography (GPC) using chloroform or hexafluoroiopropanol as a solvent.

GPC equipment: M930 of Younglin Kigi,

Column: Agilent's PLgel 5um Mixed-D

Column temperature: 30 ℃

Input amount: 300 μl

Flow rate: 1.0 ml/min

(Example 1)

Step 1. Preparation of compound 1-1

2.7 g (4.43 mmol) of 1,3-bis(2-ethylhexyl)-5,7-di(thiophen-2-yl)-4H,8H-benzo[1,2-c:4,5-c ']Dithiophene-4,8-dione (1,3-bis(2-ethylhexyl)-5,7-di(thiophen-2-yl)-4H,8H-benzo[1,2-c:4 ,5-c']dithiophene-4,8-dione) was dissolved in 50 ml of tetrahydrofurane (THF, tetrahydrofurane) with 1.9 g (10.63 mmol) of bromosuccinimide (NBS, n-Bromosuccinimide) and stirred at room temperature (25° C.) for 3 hours. After the reaction was terminated by adding distilled water to the reaction product, the organic layer was extracted using chloroform (CHCl _{3 ,} Chloroform), dehydrated using anhydrous magnesium sulfate (MgSO ₄ ), and all solvents were removed through a vacuum concentrator.

Through column chromatography using hexane:methylene chloride (5:1) as a mobile phase, 1,3-bis(5-bromothiophen-2-yl)5,7-bis(2-ethylhexyl)-4H, 2.4 g (71%) of 8H-benzo[1,2-c:4,5-c']dithiophene-4,8-dione (Compound 1-1) was obtained as a red solid.

¹ H NMR (400 MHz, CDCl ₃ ): δ (ppm) 7.39 (d, 2H); 7.03 (d, 2H); 3.27 (m, 4H); 1.74 (m, 2H); 1.41-1.32 (m, 16H), 0.94-0.90 (m, 12H).

Step 2. Preparation of compound 1-2

2.0 g (3.25 mmol) of 4,8-bis(5-(2-ethylhexyl)-4-fluorothiophen-2-yl in 15 ml of anhydrous tetrahydrofurane (THF, tetrahydrofurane) in an argon atmosphere flask )benzo[1,2-b:4,5-b']dithiophene (4,8-bis(5-(2-ethylhexyl)-4-fluorothiophen-2-yl)benzo[1,2-b: 4,5-b']dithiophene) was added and the reaction temperature was lowered to -78 °C. After adding 5.1 mL (8.13 mmol) of n-butyllithium solution (n-BuLi, n-Butyllithium solution 1.6 M in hexanes) with a concentration of 1.6 mol (M), and stirring for 1 hour, 1 mol (M) ), 8.1 mL (8.13 mmol) of a trimethyltin chloride solution 1.0 M in THF was added and stirred at room temperature for 2 hours. After the reaction was terminated by adding water, the organic layer was extracted with a potassium fluoride (KF, Potassium fluoride) solution and hexane as a solvent. The organic layer was dehydrated with anhydrous magnesium sulfate (MgSO ₄ ), and then the solvent was removed using a rotary concentrator.

Pure white crystalline solid 4,8-bis(5-(2-ethylhexyl)-4-fluorothiophen-2-yl)-benzo[1,2-b:4,5 b' through recrystallization using ethanol ] 2.0 g (67%) of dithiophene-2,6-dynyl)bis(trimethylstenene) (compound 1-2) was obtained.

¹ H NMR (400 MHz, CDCl ₃ ): δ(ppm) 7.67 (t, 2H); 7.16 (s, 2H); 2.81-2.79 (d, 4H); 1.69 (m, 2H); 1.36 (m, 16H); 0.97 (m, 12H); 0.42 (t, 18H).

Step 3. Preparation of copolymer of compound 1a

The compound 1-1 77.4 mg (0.101 mmol), the compound 1-2 100 mg (0.106 mmol), 1,4-dibromo-2,5-bis (trifluoromethyl) benzene (1,4-dibromo- 2,5-bis(trifluoromethyl)benzene) 1.9 mg (0.005 mmol) and tetrakis(triphenylphosphine)palladium(Pd(PPh ₃ ) ₄ ,Tetrakis(triphenylphosphine) palladium(0)) 4.9 mg(4 mol%) was placed in the reaction tube in the glovebox and capped. Using a syringe, 2 ml of anhydrous toluene was injected, the solvent was purged in an argon atmosphere for 10 minutes, and then the reaction was carried out at 110° C. in a reactor for 48 hours. After the reaction solution was precipitated in 50 mL of methanol, the precipitated solid was recovered through a filter.

The recovered precipitate was filtered through Soxhlet and sequentially extracted with methanol, acetone, hexane, methylene chloride and chloroform solvent. The final extracted solution was concentrated, precipitated in methanol, and dried to obtain a copolymer of compound 1a. The copolymer yield of compound 1a = 83%, 115 mg.

GPC: Mn = 73.2 kDa, Mw = 191.0 kDa, PDI = 2.61

(Example 2)

Step 1. Preparation of copolymer of compound 3a

Compound 1-1 77.4 mg (0.101 mmol), Compound 1-2 100 mg (0.106 mmol), 1,4-dibromo-2- (tetrafluoromethyl) benzene (1,4-dibromo-2- (tetrafluoromethyl) benzene) 1.6 mg (0.005 mmol) and tetrakis(triphenylphosphine)palladium (Pd(PPh ₃ ) ₄ , Tetrakis(triphenylphosphine)palladium(0)) 4.9 mg (4 mol%) were placed in a reaction tube in a glove box. closed the stopper Using a syringe, 2 ml of anhydrous toluene was injected, the solvent was purged in an argon atmosphere for 10 minutes, and then the reaction was carried out at 110° C. in a reactor for 48 hours. After the reaction solution was precipitated in 50 mL of methanol, the precipitated solid was recovered through a filter.

The recovered precipitate was filtered through Soxhlet and sequentially extracted with methanol, acetone, hexane, methylene chloride, and chloroform solvent. The final extracted solution was concentrated, precipitated in methanol, and dried to obtain a copolymer of compound 3a. The copolymer yield of compound 3a = 86%, 112 mg.

GPC: Mn = 68.5 kDa, Mw = 172.6 kDa, PDI = 2.52

(Example 3)

Step 1. Preparation of copolymer of compound 4a

Compound 1-1 77.4 mg (0.101 mmol), compound 1-2 100 mg (0.106 mmol), 1,3-dibromo-2-(octyloxy)-5-(trifluoromethyl)benzene (1,3- Dibromo-2-(octyloxy)-5-(trifluoromethyl)benzene) 1.6 mg (0.005 mmol) and palladium catalyst as tetrakis(triphenylphosphine)palladium(Pd(PPh ₃ ) ₄ , Tetrakis(triphenylphosphine)palladium(0) ) 4.9 mg (4 mol%) was placed in a reaction tube in a glove box and capped. Using a syringe, 2 ml of anhydrous toluene was injected, the solvent was purged in an argon atmosphere for 10 minutes, and then the reaction was carried out at 110° C. in a reactor for 48 hours. After the reaction solution was precipitated in 50 mL of methanol, the precipitated solid was recovered through a filter.

The recovered precipitate was filtered through Soxhlet and sequentially extracted with methanol, acetone, hexane, methylene chloride, and chloroform solvent. The final extracted solution was concentrated, precipitated in methanol, and dried to obtain a copolymer of compound 4a. The copolymer yield of compound 4a = 76%, 99 mg.

GPC: Mn = 66.7 kDa, Mw = 162.1 kDa, PDI = 2.43

(Example 4)

Step 1. Preparation of compound 5-1

5,8-dibromothiophene [3',2':3,4;2'',3'':5,6]benzo[1,2-c][1,2,5 in an argon atmosphere flask ]Thiadiazole (5,8-dibromodithieno[3',2':3,4;2'',3'':5,6]benzo[1,2-c][1,2,5]thiadiazole ) 480 mg (1.18 mmol) and 1.5 g (3.54 mmol) of trimethyl (4- (2-butyloctyl) thiophen-2-yl) stannane was added and 30 mL of anhydrous toluene was added. After purging the solvent in an argon atmosphere for 10 minutes, tetrakis (triphenylphosphine) palladium (Pd (PPh ₃ ) ₄ , Tetrakis (triphenylphosphine) palladium (0)) 136 mg (10 mol%) with a palladium catalyst was added, heated to 110 °C, stirred and refluxed for 12 hours. Then, all of the solvent was removed through a vacuum concentrator.

The residue was subjected to column chromatography using hexane:methylene chloride (1:1) as a solvent mobile phase, and 5,8-bis(4-(2-butyloctyl)thiophen-2-yl)dithieno[3' ,2':3,4;2'',3'':5,6]benzo[1,2-c][1,2,5]thiadiazole (compound 5-1) 400 mg (45%) ) was obtained.

¹ H NMR (CDCl ₃ , 400 MHz, δ/ppm): 8.01 (s, 2H); 7.15 (s, 2H); 6.90 (s, 2H); 2.57 (d, J = 6.8 Hz, 4H); 1.65-1.64 (m, 2H); 1.35-1.29 (m, 32H); 0.92-0.86 (m, 12H).

Step 2. Preparation of compound 5-2

400 mg (0.53 mmol) of 5,8-bis(4-(2-butyloctyl)thiophen-2-yl)dithieno[3',2':3,4;2'',3'' :5,6]benzo[1,2-c][1,2,5]thiadiazole (5,8-bis(4-(2-butyloctyl)thiophen-2-yl)dithieno[3',2 ':3,4;2'',3'':5,6]benzo[1,2-c][1,2,5]thiadiazole) in 30 ml of chloroform (CHCl ₃ ,chloroform) 217 mg (1.22 mmol) of bromosuccinimide (NBS, n-Bromosuccinimide) was added and stirred at room temperature for 3 hours. After the reaction was terminated by adding distilled water to the reaction product, the organic layer was extracted using chloroform, dehydrated using anhydrous magnesium sulfate (MgSO ₄ ), and all solvents were removed through a vacuum concentrator.

Through column chromatography using hexane:methylene chloride (1:1) as a mobile phase, 5-(5-bromo-4-(2-buta-1,3-dien-1-yl)octyl)thiophene- 2-Nyl)-8-(5-bromo-4-(2-butyloctyl)thiophen-2-yl)dithieno[3',2':3,4;2'',3'' :5,6]benzo[1,2-c][1,2,5]thiadiazole (Compound 5-2, DTBT-Br) was obtained as a red solid, 400 mg (80%).

¹ H NMR (CDCl ₃ , 400 MHz, δ/ppm): 7.91 (s, 2H); 6.98 (s, 2H); 2.51 (d, J = 7.1 Hz, 4H); 1.72-1.70 (s, 2H); 1.32-1.29 (m, 32H); 0.93-0.87 (m, 12H).

Step 3. Preparation of copolymer of compound 5a

Compound 1-1 71.6 mg (0.079 mmol), Compound 5-2 106 mg (0.113 mmol) 10.3 mg (0.034 mmol) and tridibenzylideneacetone dipalladium (Pd ₂ (dba) ₃ ,Tris(dibenzylideneacetone)dipalladium(0) )) 3.1 mg (3 mol%) and 10.3 mg (30 mol%) of tri(o-tolyl)phosphine (P(o-Tol) ₃ ,Tri(o-tolyl)phosphine) as a phosphine ligand in a glovebox It was placed in a reaction tube and capped. 2 ml of anhydrous toluene was injected using a syringe, the solvent was purged in an argon atmosphere for 10 minutes, and then the reaction was carried out in a microwave reactor at 140° C. for 3 hours. After the reaction solution was precipitated in 50 mL of methanol, the precipitated solid was recovered through a filter.

The recovered precipitate was filtered through Soxhlet and sequentially extracted with methanol, acetone, hexane, methylene chloride, and chloroform solvent. The final extracted solution was concentrated, precipitated in methanol, and dried to obtain a copolymer of compound 5a. The copolymer yield of compound 5a = 45%, 61 mg.

GPC: Mn = 96.6 kDa, Mw = 281.1 kDa, PDI = 2.91

Fabrication of organic solar cells

Soak the organic substrate coated with ITO (Indium Tin Oxide) as the transparent electrode (first electrode) in deionized water containing the cleaning solution, wash in an ultrasonic cleaner for 15 minutes, and then wash 3 times each with deionized water, acetone, and IPA After that, it was dried in an oven at 130° C. for 5 hours. The washed ITO glass substrate was subjected to UV/ozone treatment for 15 minutes, and then ZnO·NPs having a thickness of 30 nm were spin-coated on the ITO substrate. And the substrate coated with ZnO·NPs was heat treated at 100° C. for 10 minutes on a hot plate. A 0.4wt% poly(ethyleneimine)-ethoxylated (PEIE) solution was applied on the ZnO·NPs layer by spin coating to a thickness of 3 nm.

Then, the device was moved to a glove box filled with argon to apply the photoactive layer. The photoactive layer included Examples of the copolymer of the present invention as an electron donor, and the compound shown in Table 1 below as an electron acceptor, and these were combined in a weight ratio of 1:1.2. In addition, a solution was prepared by dissolving it in the organic solvent described in Table 1 below, and an organic semiconductor solution filtered through a 0.45 μm (PTFE) syringe filter was applied on the PEIE layer through a spin coating method.

An organic solar cell was completed by depositing a 10 nm thick MoO ₃ , 100 nm thick Ag electrode as an uppermost electrode on the photoactive layer under a 3 X 10 ^-6 torr vacuum in a thermal evaporator for the obtained device structure.

The open circuit voltage (V _oc ), short-circuit current density (J _SC ), fill factor (FF) and photoelectric conversion efficiency (PCE), which are electrical characteristics of each manufactured organic solar cell, are shown in Table 1 below. it was

The photovoltaic cell current density-voltage (J-V) characteristics of each of the organic solar cells prepared by the above method were measured under illumination simulating sunlight at 100 mW/cm 2 (AM 1.5 G) by Newport 1000W solar simulator. Electrical data were recorded using a Keithley 236 source-measure unit, and all characteristics were performed under room temperature atmospheric environment. Illuminance was calibrated by NREL (National Renewable Energy Labortary) PV measurements Inc. was calibrated by a standard Si photodiode detector. Incident photon-to-current conversion efficiency (IPCE) was measured as a function of wavelength in the range of 300 to 1000 nm (PV measurement Inc.) with a xenon lamp as a light source and calibrated using a silicon standard photodiode. The thickness of the thin film was measured with an accuracy of ± 1 nm with a KLA Tencor Alpha-step IQ surface profilometer.

The results are summarized in Table 1 below. That is, the photoelectric parameters (open circuit voltage, V _oc ), short-circuit current density (J _SC ), fill factor (FF), and power conversion efficiency (PCE) of the photoelectric parameters ( photovoltaic parameters) are summarized below. Among the photoelectric parameters, a fill factor and a photoelectric conversion efficiency were calculated by Equations 1 and 2 below.

[Formula 1]

Fill factor = (V _mp × I _mp )/(V _oc × J _SC )

(In Equation 1, V _mp is the voltage value at the maximum power point, I _mp is the current density, V _oc is the open-circuit voltage, and J _SC is the short-circuit current density.)

[Formula 2]

Photoelectric conversion efficiency = (fill factor) × (J _SC × V _oc )/100

(In Equation 2, J _SC is the short-circuit current density, and V _oc is the open-circuit voltage.)

As shown in Table 1, the organic solar cell employing the copolymer of the present invention has a relatively high fill factor, and specifically, the organic solar cell employing the copolymer of the present invention has a maximum of 14.87. It can be confirmed that the photoelectric conversion efficiency of % is realized. In particular, the novel copolymer of the present invention is used as an electron donor and can produce an organic solar cell using xylene, an eco-friendly solvent, in combination with a non-fullerene-based electron acceptor. features can be provided.

Fabrication of organic solar cell modules

An organic solar cell module in which 11 indium tin oxide (ITO), a transparent electrode (first electrode) with a width of 8 mm and a length of 100 mm, is connected in series, but with a photoactive layer and an electron transport layer (ZnO), Bar- All processes except for using a large-area process using a coater were manufactured using the same process as the organic solar cell.

All the examples to which the trifluoromethyl group according to the present invention is applied may be very advantageous even in a large area coating process in which a solvent drying rate is slow, such as bar coating. Specifically, as shown in Table 2, it can be confirmed that improved fill factor and photoelectric conversion efficiency are realized even in the case of manufacturing an organic solar cell module through bar coating. From these results, it can be seen that the copolymer of the present invention has excellent molecular alignment properties even when large-area coating processes, such as bar coating, slot die, screen printing, etc., in which the solvent drying rate is slow, is employed. can be advantageous for actual commercialization as it can be processed in eco-friendly solvents such as xylene.

Although the embodiments of the present invention have been described in detail as described above, 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 teachings of the present invention.

Claims (15)

A copolymer comprising a unit structure represented by the following formula (1):
[Formula 1]

In Formula 1,
A is C ₃ -C ₅₀ heteroarylene;
B is a condensed aromatic ring including C ₃ -C ₅₀ heteroarylene;
Z ₁ is -O- or -S-;
R ₁ is hydrogen, C ₁ -C ₃₀ alkyl or C ₁ -C ₃₀ alkoxy;
R ₂ is halogen, hydroxy, cyano, carboxylic acid, haloC ₁ -C ₃₀ alkyl, C ₁ -C ₃₀ alkyl or C ₁ -C ₃₀ alkoxy;
a and b are each independently an integer of 0 or 1, but satisfy a+b≥1;
c is an integer selected from 0 to 3;
The heteroarylene of A and the condensed aromatic ring of B are each independently halogen, hydroxy, cyano, carboxylic acid, C ₁ -C ₃₀ alkyl, C ₁ -C ₃₀ alkoxy, C ₁ -C ₃₀ alkoxycar It may be further substituted with one or more substituents selected from bornyl, C ₆ -C ₃₀ aryl, C ₃ -C ₃₀ heteroaryl and combinations thereof, wherein the heteroarylene of A and the condensed aromatic ring of B are N, O and At least one heteroatom selected from S is included as a ring-forming atom. The method of claim 1,
In Formula 1, R ₂ is fluorine, chlorine, hydroxy, cyano, carboxylic acid, haloC ₁ -C ₃₀ alkyl or C ₁ -C ₃₀ alkoxy, and c is an integer of 0 or 1, the copolymer. The method of claim 1,
When b in Formula 1 is an integer of 0,
Wherein a is an integer of 1, wherein A is a heteroarylene including thiophenylene, the copolymer. The method of claim 1,
When b in Formula 1 is an integer of 1,
Wherein a is an integer of 0, and B is a condensed ring comprising thiophenylene, the copolymer. The method of claim 1,
The copolymer is
A copolymer comprising a unit structure represented by the following Chemical Formulas 1-1 and 2:
[Formula 1-1]

[Formula 2]

In Formulas 1-1 and 2,
R ₁ is hydrogen or C ₁ -C ₃₀ alkyl;
R ₂ is hydrogen, fluorine, chlorine, hydroxy, cyano, carboxylic acid, haloC ₁ -C ₃₀ alkyl or C ₁ -C ₃₀ alkoxy;
R ₃ and R ₄ are each independently C ₁ -C ₃₀ alkyl, C ₆ -C ₃₀ aryl or C ₃ -C ₃₀ heteroaryl, wherein the aryl or heteroaryl is independently of each other fluorine, C ₁ -C ₃₀ alkyl and may be further substituted with one or more substituents selected from C ₁ -C ₃₀ alkoxy;
R ₁₁ and R ₁₂ are each independently hydrogen or C ₁ -C ₃₀ alkyl;
Het ₁ to Het ₃ are each independently a condensed ring including C ₃ -C ₃₀ heteroarylene or C ₃ -C ₃₀ heteroarylene, and Het ₁ and Het ₂ containing heteroarylene or heteroarylene Condensed rings are independently of each other halogen, hydroxy, cyano, carboxylic acid, C ₁ -C ₃₀ alkyl, C ₁ -C ₃₀ alkoxy, C ₁ -C ₃₀ alkoxycarbonyl, C ₆ -C ₃₀ aryl, C ₃ It may be further substituted with one or more substituents selected from -C ₃₀ heteroaryl and combinations thereof, wherein Het ₂ and Het ₃ are different from each other;
a and b are each independently an integer of 0 or 1, wherein a+b=1;
m and n are real numbers satisfying 0<m<1 and 0<n<1 in terms of mole fraction, and m+n=1. 6. The method of claim 5,
In Formulas 1-1 and 2, Het ₁ to Het ₃ are each independently furylene, pyrrolylene, pyrrolonylene, thiophenylene, imidazolylene, pyrazolylene, thiazolylene, thiadiazolylene , isothiazolylene, isoxazolylene, oxazolylene, oxadiazolylene, triazinylene, tetrazinylene, triazolylene, tetrazolylene, furazanylene, pyridylene, pyrazinylene, pyrimidinylene, It is a heteroarylene selected from pyridazinylene and combinations thereof, or a condensed ring including the heteroarylene, and the heteroarylene or condensed rings of Het ₁ and Het ₂ are each independently fluorine, chlorine, hydroxy, cyano, carboxylic acid, C ₅ -C ₃₀ alkyl, C ₅ -C ₃₀ alkoxy, C ₅ -C ₃₀ alkoxycarbonyl, C ₆ -C ₁₂ aryl, C ₃ -C ₁₂ heteroaryl and combinations thereof which may be further substituted with one or more substituents. 6. The method of claim 5,
In Formulas 1-1 and 2, Het ₁ and Het ₂ are each independently selected from Structure 1, and Het ₃ of Formula 2 is selected from Structure 2:
[Structure 1]

[Structure 2]

In Structure 1 and Structure 2,
p and q are independently of each other an integer of 0 or 1;
R is hydrogen or C ₅ -C ₃₀ alkyl;
R′ is hydrogen, C ₅ -C ₃₀ alkyl, C ₅ -C ₃₀ alkoxy or C ₅ -C ₃₀ alkoxycarbonyl;
R″ is C ₅ -C ₃₀ alkyl, C ₆ -C ₁₂ aryl or C ₃ -C ₁₂ heteroaryl, wherein the aryl or heteroaryl is independently of each other fluorine, C ₅ -C ₃₀ alkyl and C ₅ -C ₃₀ alkoxy It may be further substituted with one or more substituents selected from;
X ₁ and X ₂ are each independently hydrogen, fluorine or C ₁ -C ₄ alkoxycarbonyl. The method of claim 1,
A copolymer selected from the following structure 3:
[Structure 3]

In the above structure 3,
EH means a 2-Ethylhexyl substituent;
m and n are real numbers with 0<m<1 and 0<n<1 in mole fraction, and m+n=1. 9. The method of claim 8,
The copolymer is
Wherein the mole fractions of m and n satisfy 0<m≤0.5, 0.5≤n<1, the copolymer. 10. A composition for forming an organic layer of an organic electronic device, comprising the copolymer according to any one of claims 1 to 9. 11. The method of claim 10,
The composition is
A composition for forming an organic layer of an organic electronic device, which further comprises a non-fullerene-based compound and a solvent. 10. An organic electronic device comprising the copolymer according to any one of claims 1 to 9. 13. The method of claim 12,
An anode, a cathode, and an organic layer disposed between the anode and the cathode,
The organic layer will include the copolymer and the non-fullerene-based compound, an organic electronic device. 13. The method of claim 12,
The copolymer is
An organic electronic device, which is used as an electron donor. 13. The method of claim 12,
The organic electronic device,
An organic electronic device that is selected from an organic light emitting device, an organic solar cell, an organic transistor, an organic photosensitive drum, and an organic memory device.