KR102594843B1 - Copolymer and electronic device comprising the same - Google Patents

Abstract

The present specification provides a copolymer containing units and conjugated monomers represented by Formula 1 and an organic solar cell containing the same.

Description

Copolymer and organic electronic device containing the same {COPOLYMER AND ELECTRONIC DEVICE COMPRISING THE SAME}

This specification relates to copolymers and organic electronic devices containing them.

An organic electronic device refers to a device that requires charge exchange between an electrode and an organic material using holes and/or electrons. Organic electronic devices can be broadly divided into two categories according to their operating principles as follows. First, excitons are formed in the organic material layer by photons flowing into the device from an external light source, these excitons are separated into electrons and holes, and these electrons and holes are transferred to different electrodes and used as a current source (voltage source). It is an electric device in the form of The second type is an electronic device that applies voltage or current to two or more electrodes to inject holes and/or electrons into the organic semiconductor that forms the interface with the electrodes, and operates by the injected electrons and holes.

Examples of organic electronic devices include organic photodiodes, organic light-emitting devices, organic solar cells, and organic transistors. Hereinafter, organic solar cells will be mainly described in detail, but electron injection or transport materials, or light-emitting materials, have similar principles. It acts as

Organic solar cells are devices that can directly convert solar energy into electrical energy by applying the photovoltaic effect. Solar cells can be divided into inorganic solar cells and organic solar cells depending on the materials that make up the thin film. A typical solar cell is made by doping crystalline silicon (Si), an inorganic semiconductor, into a p-n junction. Electrons and holes created by absorbing light diffuse to the p-n junction and are accelerated by the electric field to 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 input to the solar cell, and has been achieved up to 24% when measured under currently standardized virtual solar irradiation conditions. However, since conventional inorganic solar cells already show limitations in economics and material supply and demand, organic semiconductor solar cells that are easy to process, inexpensive, and have a variety of functions are attracting attention as a long-term alternative energy source.

It is important to increase the efficiency of solar cells so that they can output as much electrical energy as possible from solar energy. In order to increase the efficiency of these solar cells, it is important to generate as many excitons as possible inside the semiconductor, but it is also important to bring the generated charges to the outside without loss. One of the causes of charge loss is the disappearance of generated electrons and holes through recombination. Various methods have been proposed to transfer the generated electrons or holes to the electrode without loss, but most require additional processes, which may increase manufacturing costs.

Two-layer organic photovoltaic cell (C.W.Tang, Appl. Phys. Lett., 48, 183. (1986))

This specification provides a copolymer and an organic electronic device containing the same.

An exemplary embodiment of the present specification includes a unit represented by the following formula (1); and

A copolymer comprising a conjugated monomer is provided.

[Formula 1]

In Formula 1,

X1 to

R1 to R8, R and R' are the same or different from each other and are each independently hydrogen; halogen group; Substituted or unsubstituted alkyl group; Substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted aryl group; Or it is a substituted or unsubstituted heterocyclic group.

Another embodiment of the present specification includes a first electrode;

a second electrode provided opposite the first electrode; and

An organic electronic device comprising one or more organic material layers provided between the first electrode and the second electrode,

Provided is an organic electronic device wherein at least one of the organic layers includes the copolymer.

Unlike random copolymers, the copolymer according to an exemplary embodiment of the present specification is formed through alternating polymerization, so its molecular structure is clear and its synthesis reproducibility is excellent.

Although the copolymer according to an exemplary embodiment of the present specification is an alternating copolymer, it has asymmetry and has excellent solubility and viscosity, which is advantageous for solution processes, and thus has an economical advantage in terms of time and/or cost when manufacturing devices.

The copolymer according to an exemplary embodiment of the present specification can exhibit high current value (Jsc) and excellent efficiency when applied to an organic solar cell.

The compound according to an exemplary embodiment of the present specification can be used alone or mixed with other materials in an organic solar cell.

1 is a diagram showing an organic electronic device according to an exemplary embodiment of the present specification.
Figure 2 is a diagram showing an organic solar cell according to an exemplary embodiment of the present specification.
Figure 3 is a diagram showing the MS measurement results of compound a-2.
Figure 4 is a diagram showing the NMR measurement results of compound a-2.
Figure 5 is a diagram showing the MS measurement results of compound a-4.
Figure 6 is a diagram showing the NMR measurement results of compound a-4.
Figure 7 is a diagram showing the MS measurement results of compound a-5.
Figure 8 shows the DSC measurement results of copolymer 1-2.

Hereinafter, this specification will be described in detail.

An exemplary embodiment of the present specification includes a unit represented by Formula 1 above; and a conjugated monomer.

As used herein, “unit” refers to a repeating structure included in a copolymer. In other words, “unit” may mean a structure included in the form of two or more groups in a copolymer through a polymerization reaction.

In this specification, “including a unit” means included in the main chain of the copolymer.

In one embodiment of the present specification, the copolymer is provided with units represented by Formula 1 and conjugated monomers alternately within the copolymer. That is, in one embodiment of the present specification, the copolymer is an alternating copolymer.

In the present specification, the “alternating copolymer” means that two units are sequentially repeated in the copolymer. For example, when the unit represented by Formula 1 is A and the conjugated monomer is B, this means that the -ABAB- structure is continuously repeated.

In one embodiment of the present specification, the unit represented by Formula 1 may be provided to be rotated left and right and/or up and down within the copolymer. For example, the unit represented by Formula 1 may be provided in two forms in the copolymer as follows.

In one embodiment of the present specification, even if the unit represented by Formula 1 is provided by rotating left and right and/or up and down as described above, one type of monomer is used to make the unit represented by Formula 1. Accordingly, regardless of the form of the unit represented by Formula 1 in the copolymer, if the unit represented by Formula 1 and the conjugated monomer are sequentially repeated, it can be said to be an alternating copolymer.

In one embodiment of the present specification, the copolymer includes a structure represented by the following formula (2).

[Formula 2]

In Formula 2,

f is the mole fraction, which is a real number 0<f<1,

g is the mole fraction, which is a real number 0<g<1,

f+g=1,

n is an integer from 1 to 10,000,

E is a conjugated monomer,

X1 to

R1 to R8, R and R' are the same or different from each other and are each independently hydrogen; halogen group; Substituted or unsubstituted alkyl group; Substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted aryl group; Or it is a substituted or unsubstituted heterocyclic group.

In an exemplary embodiment of the present specification, Formula 2 represents an asymmetric structure because the unit represented by Formula 1 is provided by rotating up and down and/or left and right.

In an exemplary embodiment of the present specification, Formula 2 is an alternating copolymer because the units represented by Formula 1 and the conjugated monomer (E) are sequentially alternately provided.

In one embodiment of the present specification, the copolymer exhibits an asymmetric structure and is an alternating copolymer. Accordingly, the copolymer can simultaneously exhibit the advantages of an asymmetric structure and the advantages of an alternating copolymer. For example, since the copolymer is an alternating copolymer, the molecular structure is well-defined, synthesis reproducibility is high, and solubility is improved because it has an asymmetric structure.

In one embodiment of the present specification, f is the mole fraction and is a real number of 0.3<f<0.7, g is the mole fraction and is a real number of 0.3<g<0.7, and f+g is 1.

In one embodiment of the present specification, when the unit represented by Formula 1 is A, the conjugated monomer is B, and the unit represented by Formula 1 but rotated left and right and/or up and down is A', the aerial The merging is a mixture of the first unit represented by -AB- and the second unit represented by -A'B-. That is, the copolymer is an asymmetric alternating copolymer in which first and second units are mixed and the -AB- structure is repeated.

In one embodiment of the present specification, the copolymer includes a structure represented by the following formula (3).

[Formula 3]

In Formula 3,

n is an integer from 1 to 10,000,

E is a conjugated monomer,

X1 to

R1 to R8, R and R' are the same or different from each other and are each independently hydrogen; halogen group; Substituted or unsubstituted alkyl group; Substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted aryl group; Or it is a substituted or unsubstituted heterocyclic group.

In one embodiment of the present specification, the copolymer represented by Formula 3 has the form of a block copolymer.

In the present specification, the “block copolymer” means that identical units within the copolymer are connected block by block. For example, the unit represented by Formula 1 is A, and the conjugated monomer is B. When the unit represented by Formula 1 but provided by being rotated left and right and/or up and down is A', -[ABA'B]-[ABA 'B]- means that the structure is continuously repeated.

In one embodiment of the present specification, the block copolymer is formed due to differences in reactivity of asymmetric monomers.

In one embodiment of the present specification, when R1 causes steric hindrance with the conjugated monomer, the copolymer is formed as a block copolymer. For example, when R1 is not hydrogen but has 2 or more carbon atoms, the copolymer is formed as a block copolymer.

In one embodiment of the present specification, the copolymer includes a structure represented by Formula 2 (asymmetric alternating copolymer) or Formula 3 (block copolymer).

In an exemplary embodiment of the present specification, R1, R2, R5, and R6 are the same as or different from each other, and are each independently hydrogen; Or it is a substituted or unsubstituted alkyl group.

In an exemplary embodiment of the present specification, R2, R5, and R6 are each hydrogen.

In an exemplary embodiment of the present specification, R3 and R4 are the same as or different from each other, and are each independently hydrogen; Or it is a halogen group.

In one embodiment of the present specification, R4 is hydrogen.

In one embodiment of the present specification, Formula 3 is represented by the following Formula 3-1.

[Formula 3-1]

In Formula 3,

n is an integer from 1 to 10,000,

E1 and E2 are identical to each other and are each conjugated monomer,

X1 to

R1 and R3 are the same or different from each other and are each independently a halogen group; A substituted or unsubstituted alkyl group having 2 or more carbon atoms; Substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted aryl group; Or a substituted or unsubstituted heterocyclic group,

R and R' are the same or different from each other and are each independently hydrogen; halogen group; Substituted or unsubstituted alkyl group; Substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted aryl group; Or it is a substituted or unsubstituted heterocyclic group.

In an exemplary embodiment of the present specification, the copolymer represented by Formula 3-1 exhibits directionality.

In the present specification, “directionality” means that substituents are provided in a certain direction in the structure within the copolymer. For example, in Formula 3-1, this means that R1 is substituted at a position relatively distant from R3, and R3 is substituted at a position relatively distant from E1.

In one embodiment of the present specification, the copolymer represented by Formula 3-1 is a block copolymer.

In one embodiment of the present specification, the copolymer represented by Chemical Formula 3-1 is in a region-regular form, thereby improving crystallinity.

In one embodiment of the present specification, the unit represented by Formula 1 is A. When the unit represented by Formula 1 but provided by being rotated left and right and/or up and down is A', it is represented by Formula 3-1. The unit simultaneously includes a section with direction (A-E1-A' section) and a section without direction (E2 section). Accordingly, thermoplastic elastomer properties may be exhibited due to differences in properties between sections.

In one embodiment of the present specification, the copolymer includes a structure represented by Formula 2 (random copolymer) or Formula 3-1 (block copolymer).

In an exemplary embodiment of the present specification, R1 and R3 are the same as or different from each other, and are each independently a halogen group; or a substituted or unsubstituted alkyl group having 2 to 30 carbon atoms; Substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted aryl group; Or it is a substituted or unsubstituted heterocyclic group.

In an exemplary embodiment of the present specification, R1 and R3 are the same as or different from each other, and are each independently a halogen group; Or it is a substituted or unsubstituted alkyl group having 2 to 30 carbon atoms.

In one embodiment of the present specification, R1 is a substituted or unsubstituted alkyl group having 5 to 30 carbon atoms.

In one embodiment of the present specification, R1 is a substituted or unsubstituted alkyl group having 10 to 30 carbon atoms.

In one embodiment of the present specification, R3 is a halogen group.

In one embodiment of the present specification, R3 is fluorine.

In one embodiment of the present specification, R7 and R8 are substituted or unsubstituted alkyl groups.

In one embodiment of the present specification, R7 and R8 are substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms.

In this specification, means a site that is bonded to another substituent, monomer, or binding site.

Examples of substituents in this specification are described below, but are not limited thereto.

In this specification, the term “substituted or unsubstituted” refers to deuterium; halogen group; Alkyl group; Cycloalkyl group; alkenyl group; Alkoxy group; Amine group; Aryl group; and a heterocyclic group, or is substituted with a substituent in which two or more of the above-exemplified substituents are linked, or does not have any substituent.

In this specification, the halogen group may be fluorine, chlorine, bromine, or iodine.

In the present specification, the alkyl group may be straight chain or branched, and the number of carbon atoms is not particularly limited, but is preferably 1 to 30. Specific examples include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n-pentyl. , isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n -heptyl, 1-methylhexyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 1-ethyl-propyl, Examples include 1,1-dimethyl-propyl, isohexyl, 4-methylhexyl, and 5-methylhexyl, but are not limited thereto.

In the present specification, the cycloalkyl group is not particularly limited, but preferably has 3 to 30 carbon atoms, specifically cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl, and cyclohexyl. , 3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl, 3,4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl, cyclooctyl, etc., but are limited to these. It doesn't work.

In the present specification, the aryl group may be monocyclic or polycyclic.

When the aryl group is a monocyclic aryl group, the number of carbon atoms is not particularly limited, but is preferably 6 to 30 carbon atoms. Specifically, the monocyclic aryl group may be a phenyl group, a biphenyl group, or a terphenyl group, but is not limited thereto.

If the aryl group is a polycyclic aryl group, the number of carbon atoms is not particularly limited. It is preferable to have 10 to 30 carbon atoms. Specifically, the polycyclic aryl group may be a naphthyl group, anthracenyl group, phenanthryl group, pyrenyl group, perylenyl group, chrysenyl group, fluorenyl group, etc., but is not limited thereto.

In the present specification, the heterocyclic group includes one or more atoms other than carbon and a heteroatom. Specifically, the heteroatom may include one or more atoms selected from the group consisting of O, N, Se, and S. The number of carbon atoms is not particularly limited, but is preferably 2 to 30 carbon atoms, and the heterocyclic group may be monocyclic or polycyclic. Examples of heterocyclic groups include thiophene group, furanyl group, pyrrole group, imidazolyl group, thiazolyl group, oxazolyl group, oxadiazolyl group, pyridyl group, bipyridyl group, pyrimidyl group, triazinyl group, and triazinyl group. Zolyl group, acridyl group, pyridazinyl group, pyrazinyl group, quinolinyl group, quinazolinyl group, quinoxalinyl group, phthalazinyl group, pyrido pyrimidyl group, pyrido pyrazinyl group, pyrazino pyrazinyl group , isoquinolinyl group, indolyl group, carbazolyl group, benzoxazolyl group, benzimidazolyl group, benzothiazolyl group, benzocarbazolyl group, benzothiophene group, dibenzothiophene group, benzofuranyl group, pe Examples include, but are not limited to, phenanthroline, thiazolyl, isoxazolyl, oxadiazolyl, thiadiazolyl, phenothiazinyl, and dibenzofuranyl.

In the present specification, the alkenyl group may be straight chain or branched, and the number of carbon atoms is not particularly limited, but is preferably 2 to 30. Specific examples include vinyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 3-methyl-1- Butenyl, 1,3-butadienyl, allyl, 1-phenylvinyl-1-yl, 2-phenylvinyl-1-yl, 2,2-diphenylvinyl-1-yl, 2-phenyl-2-( Naphthyl-1-yl) vinyl-1-yl, 2,2-bis (diphenyl-1-yl) vinyl-1-yl, stilbenyl group, styrenyl group, etc., but are not limited thereto.

In the present specification, the alkoxy group may be straight chain, branched chain, or ring chain. The number of carbon atoms of the alkoxy group is not particularly limited, but is preferably 1 to 30 carbon atoms. Specifically, methoxy, ethoxy, n-propoxy, isopropoxy, i-propyloxy, n-butoxy, isobutoxy, tert-butoxy, sec-butoxy, n-pentyloxy, neopentyloxy, Isopentyloxy, n-hexyloxy, 3,3-dimethylbutyloxy, 2-ethylbutyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, benzyloxy, p-methylbenzyloxy, etc. It may be possible, but it is not limited to this.

In this specification, the amine group is -NH ₂ ; Monoalkylamine group; dialkylamine group; N-alkylarylamine group; monoarylamine group; Diarylamine group; N-arylheteroarylamine group; It may be selected from the group consisting of N-alkylheteroarylamine group, monoheteroarylamine group, and diheteroarylamine group, and the number of carbon atoms is not particularly limited, but is preferably 1 to 30. Specific examples of amine groups include methylamine group, dimethylamine group, ethylamine group, diethylamine group, phenylamine group, naphthylamine group, biphenylamine group, anthracenylamine group, and 9-methyl-anthracenylamine group. , diphenylamine group, ditolylamine group, N-phenyltolylamine group, triphenylamine group, N-phenylbiphenylamine group; N-phenylnaphthylamine group; N-biphenylnaphthylamine group; N-naphthylfluorenylamine group; N-phenylphenanthrenylamine group; N-biphenylphenanthrenylamine group; N-phenylfluorenylamine group; N-phenylterphenylamine group; N-phenanthrenylfluorenylamine group; N-biphenylfluorenylamine group, etc., but is not limited thereto.

In the present specification, the description of the alkenyl group described above can be applied, except that the alkenylene group is a divalent group.

In the present specification, the description of the aryl group described above may be applied, except that the arylene group is a divalent group.

In the present specification, the description of the heterocyclic group described above can be applied, except that the divalent heterocyclic group is a divalent group.

In one embodiment of the present specification, the conjugated monomer includes a combination of one or two or more groups among a substituted or unsubstituted alkenylene group, a substituted or unsubstituted arylene group, and a substituted or unsubstituted divalent heterocyclic group. do.

In an exemplary embodiment of the present specification, the conjugated monomer includes any one or a combination of two or more of the following structures.

In the above structure,

_{X10 to _ _ _ _ _ _}

R110 to R133, R _d and R _e are the same or different from each other, and are each independently hydrogen; halogen group; Substituted or unsubstituted alkyl group; Substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted alkoxy group; Substituted or unsubstituted aryl group; Or it is a substituted or unsubstituted heterocyclic group.

In this specification, “combination” means connecting multiple structures or connecting different types of structures.

In an exemplary embodiment of the present specification, the conjugated monomer has any one of the following structures.

In the above structure,

_{X10 to _ _ _ _ _ _}

R110 to R115, R _d and R _e are the same or different from each other, and are each independently hydrogen; halogen group; Substituted or unsubstituted alkyl group; Substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted alkoxy group; Substituted or unsubstituted aryl group; Or it is a substituted or unsubstituted heterocyclic group.

In an exemplary embodiment of the present specification, R112 to R115 are the same as or different from each other, and are each independently a substituted or unsubstituted aryl group; Or it is a substituted or unsubstituted heterocyclic group.

In an exemplary embodiment of the present specification, the conjugated monomer has any one of the following structures.

In the above structure,

a, a', b and b' are integers from 1 to 5,

c, c', d and d' are integers from 1 to 3,

When a, a', b, b', c, c', d and d' are 2 or more, the substituents in parentheses are the same or different from each other,

_{X10 to _ _ _ _ _ _}

R110, R111, R200 to R207, R _d and R _e are the same or different from each other, and are each independently hydrogen; halogen group; Substituted or unsubstituted alkyl group; Substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted alkoxy group; Substituted or unsubstituted aryl group; Or it is a substituted or unsubstituted heterocyclic group.

In an exemplary embodiment of the present specification, X10 to X15 are each S.

In an exemplary embodiment of the present specification, R110, R111, R200 to R207 are the same as or different from each other, and are each independently hydrogen; Or it is a substituted or unsubstituted alkyl group.

In an exemplary embodiment of the present specification, R110, R111, R200 to R207 are the same as or different from each other, and are each independently hydrogen; Or it is a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms.

In an exemplary embodiment of the present specification, R110, R111, R200 to R207 are the same as or different from each other, and are each independently hydrogen; Or it is a substituted or unsubstituted alkyl group having 1 to 15 carbon atoms.

In an exemplary embodiment of the present specification, the conjugated monomer has any one of the following structures.

In one embodiment of the present specification, the copolymer has any one of the following structures.

In the above structure,

f is the mole fraction, which is a real number 0<f<1,

g is the mole fraction, which is a real number 0<g<1,

f+g=1,

n is an integer from 1 to 10,000.

In one embodiment of the present specification, n is an integer from 2 to 5,000.

In one embodiment of the present specification, n is an integer from 5 to 1,000.

In one embodiment of the present specification, the terminal group of the copolymer is a substituted or unsubstituted aryl group; Or it is a substituted or unsubstituted heterocyclic group.

In one embodiment of the present specification, the terminal group of the copolymer is a substituted or unsubstituted phenyl group; Or it is a substituted or unsubstituted thiophene group.

In an exemplary embodiment of the present specification, the number average molecular weight (Mn) of the copolymer is 5,000 g/mol to 1,000,000 g/mol. Preferably, the number average molecular weight of the copolymer is 8,000 g/mol to 100,000 g/mol. More preferably, the number average molecular weight of the copolymer is 10,000 g/mol to 100,000 g/mol.

An exemplary embodiment of the present specification includes a first electrode; a second electrode provided opposite the first electrode; and an organic electronic device including one or more organic material layers provided between the first electrode and the second electrode, wherein one or more layers of the organic material layers include the copolymer.

1 is a diagram showing an organic electronic device 100 according to an exemplary embodiment of the present specification. Specifically, Figure 1 shows a first electrode 20; a second electrode 60 provided opposite the first electrode; and an organic electronic device 100 including an organic material layer 70 provided between the first electrode and the second electrode.

In an exemplary embodiment of the present specification, the organic electronic device is selected from the group consisting of an organic photodiode, an organic transistor, an organic solar cell, and an organic light-emitting device.

In one embodiment of the present specification, the organic electronic device may be an organic photodiode. Specifically, the organic electronic device includes: a first electrode; a second electrode provided opposite the first electrode; and an organic photodiode including one or more organic material layers provided between the first electrode and the second electrode, wherein one or more layers of the organic material layers include the copolymer.

In one embodiment of the present specification, the organic electronic device may be an organic solar cell. Specifically, the organic electronic device includes: a first electrode; a second electrode provided opposite the first electrode; And an organic solar cell including one or more organic material layers provided between the first electrode and the second electrode, wherein one or more layers of the organic material layers include the copolymer.

In one embodiment of the present specification, the organic material layer includes a photoactive layer.

Hereinafter, descriptions of the first electrode, the organic material layer including the photoactive layer, and the second electrode are commonly applied to organic solar cells and organic photodiodes.

In one embodiment of the present specification, the photoactive layer includes the copolymer.

In one embodiment of the present specification, the photoactive layer includes an electron donor and an electron acceptor, and the electron donor includes the copolymer.

In one embodiment of the present specification, the electron acceptor includes fullerene, fullerene derivative, vasocuproin, semiconducting compound, non-fullerene derivative, or a combination thereof.

As used herein, “fullerene derivative” refers to a substance whose molecules have one or more spherical shell structures formed of carbon. For example, fullerene as a spherical shell-shaped molecule; Fullerene derivatives having an inorganic or organic group bonded to carbon-based fullerene; There are fullerene derivatives in which fullerene or a spherical shell structure constituting the fullerene derivative is bonded directly or through one or more elements.

In an exemplary embodiment of the present specification, the fullerene derivative is PC ₆₀ BM (phenyl C ₆₀ -butyric acid methyl ester), PC ₆₁ BM (phenyl C ₆₁ -butyric acid methyl ester), or PC ₇₁ BM (phenyl C ₇₁ -butyric acid methyl ester), ICBA (1′,1′′,4′,4′′-Tetrahydro-di[1,4]methanophthaleno[1,2:2′,3′,56,60:2′′,3 ′′][5,6]fullerene-C ₆₀ ) may be included.

In one embodiment of the present specification, the non-fullerene derivative refers to a compound that does not contain fullerene. For example, the bifullerene derivative is ITIC (3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno [2,3-d:2',3'-d']-s-indaceno[1,2-b:5,6-b']dithiophene).

In one embodiment of the present specification, the electron donor and electron acceptor constitute a bulk heterojunction (BHJ).

Bulk heterojunction means that electron donor materials and electron acceptor materials are mixed together in the photoactive layer.

In one embodiment of the present specification, the electron donor and electron acceptor may be mixed at a weight ratio of 1:10 to 10:1. Specifically, electron donors and electron acceptors may be mixed at a weight ratio of 1:1 to 1:10, and more specifically, electron donors and electron acceptors may be mixed at a weight ratio of 1:1 to 1:5. If necessary, the electron donor and electron acceptor may be mixed at a weight ratio of 1:1 to 1:3.

In one embodiment of the present specification, the photoactive layer has a bilayer thin film structure including an n-type organic material layer and a p-type organic material layer, and the p-type organic material layer includes the copolymer.

In one embodiment of the present specification, the organic solar cell and the organic photodiode may further include an additional organic material layer. The organic solar cell and organic photodiode can reduce the number of organic material layers by using organic materials that have multiple functions at the same time.

In one embodiment of the present specification, the organic solar cell and the organic photodiode are one selected from the group consisting of a hole injection layer, a hole transport layer, a hole blocking layer, a charge generation layer, an electron blocking layer, an electron injection layer, and an electron transport layer. Or it further includes two or more organic layers.

In one embodiment of the present specification, the organic material layer includes a hole transport layer, a hole injection layer, or a layer that performs hole transport and hole injection simultaneously, and the hole transport layer, the hole injection layer, or a layer that performs hole transport and hole injection simultaneously Includes the above copolymer.

In another embodiment, the organic material layer includes an electron injection layer, an electron transport layer, or a layer that performs electron injection and electron transport simultaneously, and the electron injection layer, the electron transport layer, or a layer that performs electron injection and electron transport simultaneously Includes the above copolymer.

In one embodiment of the present specification, the organic solar cell and the organic photodiode include a first electrode, a photoactive layer, and a second electrode. The organic solar cell and organic photodiode may further include a substrate, a hole transport layer, and/or an electron transport layer.

In one embodiment of the present specification, the organic solar cell and the organic photodiode further include a substrate, an electron transport layer, and a hole transport layer.

2 shows a substrate 10, a first electrode 20, an electron transport layer 30, a photoactive layer 40, a hole transport layer 50, and a second electrode 60 according to an embodiment of the present specification. This is a diagram showing an organic solar cell.

In one embodiment of the present specification, the first electrode is an anode and the second electrode is a cathode. In another embodiment of the present specification, the first electrode is a cathode and the second electrode is an anode.

In an exemplary embodiment of the present specification, the organic solar cell and the organic photodiode have a normal structure. In the normal structure, a substrate, a first electrode, a hole transport layer, an organic material layer including a photoactive layer, an electron transport layer, and a second electrode may be stacked in that order.

In one embodiment of the present specification, the organic solar cell and the organic photodiode have an inverted structure. In the inverted structure, a substrate, a first electrode, an electron transport layer, an organic material layer including a photoactive layer, a hole transport layer, and a second electrode may be stacked in that order.

In this specification, the substrate may be a glass substrate or a transparent plastic substrate with excellent transparency, surface smoothness, ease of handling, and waterproofness, but is not limited thereto, and may be any substrate commonly used in organic solar cells and/or organic photodiodes. It doesn't work. Specifically, there are glass, PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PP (polypropylene), PI (polyimide), and TAC (triacetyl cellulose). It is not limited to this.

The first electrode may be made of a transparent and highly conductive material, but is not limited thereto. Metals such as vanadium, chromium, copper, zinc, gold, or alloys thereof; metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); Combinations of metals and oxides such as ZnO:Al or SnO ₂ :Sb; Conductive polymers such as poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene](PEDOT), polypyrrole, and polyaniline are included, but are not limited to these.

The method of forming the first electrode is not particularly limited, but is applied to one side of the substrate or in the form of a film using, for example, sputtering, E-beam, thermal evaporation, spin coating, screen printing, inkjet printing, doctor blade, or gravure printing. It can be formed by coating.

When forming the first electrode on a substrate, it may undergo cleaning, moisture removal, and hydrophilic modification processes.

For example, the patterned ITO substrate was sequentially cleaned with a detergent, acetone, and isopropyl alcohol (IPA), and then washed on a heating plate at 100°C to 150°C for 1 minute to 30 minutes, preferably at 120°C for 10 minutes to remove moisture. After drying and completely cleaning the substrate, the surface of the substrate is modified to be hydrophilic.

Through the surface modification described above, the bonding surface potential can be maintained at a level suitable for the surface potential of the photoactive layer. Additionally, during modification, the formation of a polymer thin film on the first electrode may become easier and the quality of the thin film may be improved.

Pretreatment techniques for forming the first electrode include a) a surface oxidation method using parallel plate discharge, b) a method of oxidizing the surface through ozone generated using UV ultraviolet rays in a vacuum, and c) a method of oxidizing the surface using plasma. There is a method of oxidation using the generated oxygen radicals.

One of the above methods can be selected depending on the state of the first electrode or substrate. However, whichever method is used, it is generally desirable to prevent oxygen escape from the surface of the first electrode or substrate and to suppress the remaining moisture and organic matter as much as possible. At this time, the practical effect of pre-processing can be maximized.

As a specific example, a method of oxidizing the surface through ozone generated using UV light can be used. At this time, after ultrasonic cleaning, the patterned ITO substrate is baked on a hot plate and dried well, then placed in a chamber, and a UV lamp is applied to produce ozone generated when oxygen gas reacts with UV light. The patterned ITO substrate can be cleaned.

However, the method for modifying the surface of the patterned ITO substrate in this specification does not need to be particularly limited, and any method may be used as long as it oxidizes the substrate.

The second electrode may be a metal with a low work function, but is not limited thereto. Specifically, metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin and lead, or alloys thereof; It may be a multi-layered material such as LiF/Al, LiO ₂ /Al, LiF/Fe, Al:Li, Al:BaF ₂ , Al:BaF ₂ :Ba, but is not limited thereto.

The second electrode may be formed by depositing inside a thermal evaporator with a vacuum of 5x10 ^{- 7} torr or less, but the method is not limited to this method.

The hole transport layer and/or electron transport layer material serves to efficiently transfer electrons and holes separated from the photoactive layer to the electrode, and the material is not particularly limited.

The hole transport layer includes hole transport materials such as PEDOT:PSS (Poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonic acid)), molybdenum oxide (MoO _x ); vanadium oxide (V ₂ O ₅ ); Nickel oxide (NiO); and tungsten oxide (WO _x ), etc., but is not limited to these.

The electron transport layer may include electron-extracting metal oxides as an electron transport material, specifically a metal complex of 8-hydroxyquinoline; Complex containing Alq ₃ ; Metal complexes containing Liq; LIF; Ca; Titanium oxide (TiO _x ); zinc oxide (ZnO); and cesium carbonate (Cs ₂ CO ₃ ), but is not limited to these.

In one embodiment of the present specification, the photoactive layer is formed by dissolving a photoactive material such as an electron donor and/or an electron acceptor in an organic solvent, and then applying the solution to spin coating, dip coating, screen printing, spray coating, doctor blade, brush painting, etc. It can be formed by the following methods, but is not limited to these methods.

The method for producing the copolymer and the production of an organic solar cell containing the same will be described in detail in the following Preparation Examples and Examples. However, the following examples are for illustrating the present specification, and the scope of the present specification is not limited thereto.

Manufacturing Example 1.

(1) Preparation of compound a-2

Compound a-1 (5.0 g, 9 mmol) was dissolved in 250 mL of THF, and 1M lithium diisopropylamide (LDA) (15 mL, 15 mmol) was slowly injected at -78°C. After reacting for 1 hour, trimethyltin chloride (Me ₃ SnCl) (1M, 15 mmol) was slowly added, the temperature was raised to room temperature, and the mixture was stirred at room temperature for 5 hours. Afterwards, it was washed with an aqueous sodium chloride (NaCl) solution, and the solvent was evaporated under vacuum conditions to obtain 5.84 g of compound a-2. (Yield: 90%)

Figure 3 is a diagram showing the MS measurement results of compound a-2.

Figure 4 is a diagram showing the NMR measurement results of compound a-2.

(2) Preparation of compound a-4

Dissolve compound a-2 (2.89g, 4mmol) and compound a-3 (2.41g, 4mmol) in 50mL toluene, and tetrakis(triphenylphosphine)palladium(0) catalyst (Pd(PPh ₃ ) ₄ ) (0.058g, 0.05mmol) was added, heated gradually, and reacted at 110°C for 48 hours. The residue produced upon cooling was precipitated in methanol, filtered, and washed with water. Afterwards, the solvent is evaporated through a drying process, and the remaining product is purified through flash chromatography using methylene chloride and chloroform, and then recrystallized using methylene chloride and methanol. A solid was obtained. The solid was washed with methanol and dried under vacuum conditions for 24 hours to obtain 2.1 g of compound a-4. (Yield: 49%)

Figure 5 is a diagram showing the MS measurement results of compound a-4.

Figure 6 is a diagram showing the NMR measurement results of compound a-4.

(3) Preparation of compound a-5

Compound a-4 (0.67 g, 0.62 mmol) and N-bromosuccinimide (NBS) (0.142 g, 0.8 mmol) were added to 40 mL of THF at 0°C and stirred at room temperature for 24 hours. Afterwards, the solvent was evaporated, and the residue was purified through flash chromatography (eluent (hexane to hexane:methylene chloride)) to obtain 0.46 g of compound a-5. (yield: 68%)

Figure 7 is a diagram showing the MS measurement results of compound a-5.

(4) Preparation of Copolymer 1-1 and Copolymer 1-2

9 mL of toluene, 3 mL of dimethylformamide (DMF), compound a-5 (0.41 mmol), and compound b-1 (0.41 mmol) were added to a 100 mL flask under a nitrogen (N ₂ ) atmosphere, and nitrogen was bubbled for 30 minutes. Afterwards, tetrakis(triphenylphosphine)palladium(0) catalyst (Pd(PPh ₃ ) ₄ ) (2 mol%) was added and stirred at 110°C for 72 hours. 0.5 mL of Br-Benzotrifluoride was added, stirred for 24 hours, and cooled to room temperature. Afterwards, the product was poured into chloroform, passed through a short column with silica, poured into a mixed solution (180 mL methanol + 20 mL HCl (2M concentration)), and the precipitate was filtered. Afterwards, the product was subjected to soxhlet extraction in the following order: methanol, acetone, hexane, methylene chloride, and chloroform. The extract extracted with chloroform was added to methanol to form a precipitate. The resulting precipitate was collected, purified, and dried under vacuum conditions to prepare copolymers 1-1 and 1-2. At this time, the number average molecular weight (Mn) was measured to confirm that copolymer 1-1 or 1-2 was produced. (Yield: 94%, Mn=31,400g/mol, PDI=2.2)

When preparing copolymer 1-2 as in Preparation Example 1, a steric hindrance may exist between compound a-5, in which a bulky alkyl chain is introduced on one side, and compound b-1. Accordingly, the non-bulky portion of compound a-5 and compound b-1 may react first. Accordingly, the following compound J may be produced first before copolymer 1-2 is produced.

However, in the manufacturing method of copolymer 1-2, since the same amount of compound a-5 and compound b-1 are added, the remaining b-1 after forming the above structure is additionally combined to form copolymer 1-2. is manufactured.

However, since the compound J is not produced first in all reactions, it is ultimately prepared by mixing copolymer 1-1 (asymmetric alternating copolymer) and copolymer 1-2 (block copolymer).

Figure 8 shows the DSC measurement results of copolymer 1-2.

From Figure 8, it can be confirmed that it has a melting point around 280°C and crystallization around 270°C. Through this, it can be confirmed that copolymer 1-2 (block form) is formed more (dominantly) and has excellent crystallinity.

Manufacturing example 2.

In Preparation Example 1, copolymers 2-1 and 2-2 were prepared in the same manner as Preparation Example 1, except that compound b-2 was used instead of compound b-1. At this time, it was confirmed that copolymers 2-1 and 2-2 were produced by measuring the number average molecular weight (Mn). (Yield: 67%, Mn=32,500g/mol, PDI=2.7)

Manufacturing example 3.

In Preparation Example 1, copolymers 3-1 and 3-2 were prepared in the same manner as Preparation Example 1, except that compound b-3 was used instead of compound b-1. At this time, it was confirmed that copolymers 3-1 and 3-2 were produced by measuring the number average molecular weight (Mn). (Yield: 72%, Mn=35,100g/mol, PDI=2.4)

Comparative Manufacturing Example 1.

Add 8 mL of toluene, 2 mL of DMF, compound c-1 (0.07 mmol), compound c-2 (0.07 mmol), and compound b-1 (0.14 mmol) to a 100 mL flask under a nitrogen (N2) atmosphere and bubble with nitrogen for 30 minutes. did. Afterwards, tetrakis(triphenylphosphine)palladium(0) catalyst (Pd(PPh ₃ ) ₄ ) (2 mol%) was added and stirred at 110°C for 72 hours. 0.5 mL of Br-Benzotrifluoride was added, stirred for 24 hours, and cooled to room temperature. Afterwards, the product was poured into chloroform, passed through a short column with silica, poured into a mixed solution (180 mL methanol + 20 mL HCl (2M concentration)), and the precipitate was filtered. Afterwards, the product was subjected to soxhlet extraction in the following order: methanol, acetone, hexane, methylene chloride, and chloroform. The extract extracted with chloroform was added to methanol to form a precipitate. The resulting precipitate was collected, purified, and dried under vacuum conditions to obtain copolymer K. At this time, it was confirmed that copolymer K was produced by measuring the number average molecular weight (Mn). (Mn=21,200g/mol, PDI=2.6)

Example 1. Preparation of organic solar cells

Copolymers 1-1 and 1-2 prepared in Preparation Example 1 were used as donors, and ITIC was dissolved in chlorobenzene (CB) at a 1:1.5 ratio using ITIC as an acceptor to form a composite solution. Manufactured. At this time, the concentration was adjusted to 2.0 wt%, and the organic solar cell had the structure of ITO/ZnO/photoactive layer/MoO ₃ /Ag. The ITO-coated glass substrate was ultrasonically cleaned using distilled water, acetone, and 2-propanol, and the ITO surface was treated with ozone for 10 minutes, followed by spin coating with a ZnO precursor solution and heat treatment at 120°C for 10 minutes. Afterwards, the composite solution was filtered through a 0.45μm PTFE syringe filter and then spin-coated to form a photoactive layer. Afterwards, MoO ₃ was deposited on the photoactive layer to a thickness of 5 nm to 20 nm at a speed of 0.4 Å/s in a thermal evaporator to prepare a hole transport layer. Afterwards, Ag was deposited to a thickness of 10 nm on the hole transport layer at a speed of 1 Å/s inside a thermal evaporator to manufacture an organic solar cell.

Example 2.

An organic solar cell was manufactured in the same manner as Example 1, except that Copolymers 2-1 and 2-2 were used instead of Copolymers 1-1 and 1-2.

Example 3.

An organic solar cell was manufactured in the same manner as Example 1, except that Copolymers 3-1 and 3-2 were used instead of Copolymers 1-1 and 1-2.

Comparative Example 1.

An organic solar cell was manufactured in the same manner as Example 1, except that Copolymer K was used instead of Copolymers 1-1 and 1-2.

The photoelectric conversion characteristics of the organic solar cells manufactured in Examples 1 to 3 and Comparative Example 1 were measured under 100 mW/cm ² (AM 1.5) conditions, and the results are shown in Table 1.

V _oc
(V) J _sc
(mA/ ^cm2 ) FF η
(%) Example 1 0.87 15.27 0.62 8.23 Example 2 0.83 16.19 0.59 7.93 Example 3 0.82 16.75 0.60 8.24 Comparative Example 1 0.78 10.50 0.51 4.18

In Table 1, Voc stands for open-circuit voltage, Jsc stands for short-circuit current density, FF stands for fill factor, and PCE stands for energy conversion efficiency. The open-circuit voltage and short-circuit current density are the X-axis and Y-axis intercepts in the fourth quadrant of the voltage-current density curve, respectively, and the higher these two values, the higher the efficiency of the solar cell. Additionally, the fill factor is the maximum area of a rectangle that can be drawn inside the curve divided by the product of the short-circuit current density and the open-circuit voltage. Energy conversion efficiency can be obtained by dividing these three values by the intensity of the irradiated light, and higher values are more desirable.

From Table 1, it can be seen that Examples 1 to 3 have superior performance compared to Comparative Example 1.

10: substrate
20: first electrode
30: Electron transport layer
40: Photoactive layer
50: hole transport layer
60: second electrode
70: Organic layer
100: Organic electronic device

Claims (13)

A unit represented by the following formula (1); and
Copolymers containing conjugated monomers:
[Formula 1]

In Formula 1,
X1 to
R1 to R8, R and R' are the same or different from each other and are each independently hydrogen; halogen group; Substituted or unsubstituted alkyl group; Substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted aryl group; Or it is a substituted or unsubstituted heterocyclic group. In claim 1,
A copolymer in which the units represented by Formula 1 and conjugated monomers are alternately provided within the copolymer. In claim 1,
The conjugated monomer is a copolymer comprising a combination of one or two or more groups selected from a substituted or unsubstituted alkenylene group, a substituted or unsubstituted arylene group, and a substituted or unsubstituted divalent heterocyclic group. In claim 1,
The conjugated monomer is a copolymer comprising any one or a combination of two or more of the following structures:

In the above structure,
_{X10 to _ _ _ _ _ _}
R110 to R133, R _d and R _e are the same or different from each other, and are each independently hydrogen; halogen group; Substituted or unsubstituted alkyl group; Substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted alkoxy group; Substituted or unsubstituted aryl group; Or it is a substituted or unsubstituted heterocyclic group. In claim 1,
The copolymer is a copolymer comprising a structure represented by the following formula (2):
[Formula 2]

In Formula 2,
f is the mole fraction, which is a real number 0<f<1,
g is the mole fraction, which is a real number 0<g<1,
f+g=1,
n is an integer from 1 to 10,000,
E is a conjugated monomer,
X1 to
R1 to R8, R and R' are the same or different from each other and are each independently hydrogen; halogen group; Substituted or unsubstituted alkyl group; Substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted aryl group; Or it is a substituted or unsubstituted heterocyclic group. In claim 1,
The copolymer is a copolymer comprising a structure represented by the following formula (3):
[Formula 3]

In Formula 3,
n is an integer from 1 to 10,000,
E is a conjugated monomer,
X1 to
R1 to R8, R and R' are the same or different from each other and are each independently hydrogen; halogen group; Substituted or unsubstituted alkyl group; Substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted aryl group; Or it is a substituted or unsubstituted heterocyclic group. In claim 1,
The copolymer is a copolymer comprising any one of the following structures:

In the above structure,
f is the mole fraction, which is a real number 0<f<1,
g is the mole fraction, which is a real number 0<g<1,
f+g=1,
n is an integer from 1 to 10,000. first electrode;
a second electrode provided opposite the first electrode; and
An organic electronic device comprising one or more organic material layers provided between the first electrode and the second electrode,
An organic electronic device wherein at least one of the organic layers includes the copolymer according to any one of claims 1 to 7. In claim 8,
The organic electronic device is selected from the group consisting of organic photodiodes, organic transistors, organic solar cells, and organic light-emitting devices. In claim 8,
The organic electronic device is an organic photodiode,
The organic photodiode includes a first electrode;
a second electrode provided opposite the first electrode; and
Comprising one or more organic layers provided between the first electrode and the second electrode,
An organic electronic device wherein at least one layer of the organic material layer includes the copolymer. In claim 10,
The organic material layer includes a photoactive layer,
The photoactive layer includes an electron donor and an electron acceptor,
An organic electronic device wherein the electron donor includes the copolymer. In claim 8,
The organic electronic device is an organic solar cell,
The organic solar cell includes a first electrode;
a second electrode provided opposite the first electrode; and
Comprising one or more organic layers provided between the first electrode and the second electrode,
An organic electronic device wherein at least one layer of the organic material layer includes the copolymer. In claim 12,
The organic material layer includes a photoactive layer,
The photoactive layer includes an electron donor and an electron acceptor,
An organic electronic device wherein the electron donor includes the copolymer.