KR20180005920A - Heterocyclic compound and organic solar cell comprising the same - Google Patents

Abstract

The present invention relates to a heterocyclic compound represented by chemical formula 1 and an organic solar cell comprising the same. The heterocyclic compound can be used as a material in an organic layer of an organic solar cell. The organic solar cell comprising the same is effective in increasing open circuit voltage and short circuit current, has an excellent low band gap effect and/or is effective in increasing efficiency.

Description

HETEROCYCLIC COMPOUND AND ORGANIC SOLAR CELL COMPRISING THE SAME [0002]

The present invention relates to heterocyclic compounds and organic solar cells comprising the same.

Organic solar cells are devices that can convert solar energy directly into electric energy by applying photovoltaic effect. Solar cells can be divided into inorganic solar cells and organic solar cells depending on the material constituting the thin film. A typical solar cell is made of p-n junction by doping crystalline silicon (Si), which is an inorganic semiconductor. Electrons and holes generated by absorption of light are diffused to the p-n junction, accelerated by the electric field, and moved to the electrode. The power conversion efficiency of this process is defined as the ratio of the power given to the external circuit to the solar power entering the solar cell, and is achieved up to 24% when measured under the current standardized virtual solar irradiation conditions. However, since conventional inorganic solar cells have already been limited in economic efficiency and supply / demand of materials, organic semiconductor solar cells, which are easy to process, have various functions and are inexpensive, are seen as long-term alternative energy sources.

Solar cells are important to increase efficiency so that they can output as much electrical energy as possible from solar energy. In order to increase the efficiency of such a solar cell, it is also important to generate as much excitons as possible in the semiconductor, but it is also important to draw out generated charges without loss. One of the causes of loss of charge is that the generated electrons and holes are destroyed by recombination. Various methods have been proposed as methods for transferring generated electrons and holes to electrodes without loss, but most of them require additional processing, which may increase the manufacturing cost.

US 5331183 US 5454880

It is an object of the present invention to provide a heterocyclic compound and an organic solar cell containing the heterocyclic compound.

The present invention provides a heterocyclic compound represented by the following formula (1).

[Chemical Formula 1]

In Formula 1,

m1, m2, n1 and n2 are each an integer of 1 to 3,

When m1, m2, n1 and n2 are each 2 or more, the structures in the square brackets are equal to or different from each other,

L2 and L3 are the same or different and are each independently a direct bond; Or a divalent linking group,

R1 to R12 and R21 to R28 are the same or different from each other and each independently hydrogen; heavy hydrogen; A halogen group; A nitrile group; A nitro group; Imide; Amide group; A hydroxy group; A substituted or unsubstituted alkyl group; A substituted or unsubstituted cycloalkyl group; A substituted or unsubstituted alkoxy group; A substituted or unsubstituted aryloxy group; A substituted or unsubstituted alkylthio group; A substituted or unsubstituted arylthio group; A substituted or unsubstituted alkylsulfoxy group; A substituted or unsubstituted arylsulfoxy group; A substituted or unsubstituted alkenyl group; A substituted or unsubstituted silyl group; A substituted or unsubstituted boron group; A substituted or unsubstituted alkylamine group; A substituted or unsubstituted aralkylamine group; A substituted or unsubstituted arylamine group; A substituted or unsubstituted heteroarylamine group; A substituted or unsubstituted aryl group; Or a substituted or unsubstituted heterocyclic group containing at least one of N, O and S atoms,

G1 and G2 are the same or different and are each independently a substituted or unsubstituted branched alkyl group,

A1 and A2 are the same or different from each other and each independently has a structure which functions as an electron acceptor.

Further, the present specification discloses a plasma display panel comprising a first electrode; A second electrode facing the first electrode; And at least one organic compound layer including a photoactive layer and disposed between the first electrode and the second electrode, wherein at least one of the organic compound layers includes the above-described heterocyclic compound do.

The heterocyclic compound according to one embodiment of the present disclosure has a core having a structure containing two or more benzodithiophenes (BDT) having electron donor nature, and thus has a long effective conjugation length.

In addition, the heterocyclic compound according to one embodiment of the present disclosure has a core having a structure containing two or more benzodithiophenes (BDT), so that a compound having an increased molecular weight can be provided.

In addition, the heterocyclic compound according to one embodiment of the present invention includes a branched chain alkoxy group in the benzothiadiazole connecting two benzodithiophenes (BDT), so that the steric hindrance between the molecules becomes larger and the solubility of the compound can be controlled have.

Therefore, the heterocyclic compound can be used as an organic material layer of an organic solar cell, and an organic solar cell including the same can exhibit excellent characteristics in terms of an increase in open-circuit voltage and short-circuit current, a low band gap effect, and / or an increase in efficiency .

The heterocyclic compound according to one embodiment of the present invention can be used alone or in combination with other materials in an organic solar cell, and the lifetime of the device can be expected to be improved by improving the efficiency and the thermal stability of the compound have.

1 is a view illustrating an organic solar cell according to an embodiment of the present invention.
2 is a graph showing an NMR graph of Compound 1-1.

Hereinafter, the present specification will be described in detail.

The present invention provides a heterocyclic compound represented by the above formula (1).

는 다른 치환기에 연결되는 부위를 의미한다.In the present specification,

Quot; refers to a moiety that is connected to another substituent.

In this specification, when a part is referred to as "including " an element, it is to be understood that it may include other elements as well, without departing from the other elements unless specifically stated otherwise.

Examples of such substituents are described below, but are not limited thereto.

The term "substituted" means that the hydrogen atom bonded to the carbon atom of the compound is replaced with another substituent, and the substituted position is not limited as long as the substituent is a substitutable position, , Two or more substituents may be the same as or different from each other.

As used herein, the term " substituted or unsubstituted " A halogen group; An alkyl group; An alkenyl group; An alkoxy group; Ester group; A carbonyl group; A carboxyl group; A hydroxy group; A cycloalkyl group; Silyl group; An arylalkenyl group; An aryloxy group; An alkyloxy group; An alkylsulfoxy group; Arylsulfoxy group; Boron group; An alkylamine group; An aralkylamine group; An arylamine group; A heterocyclic group; An arylamine group; An aryl group; A nitrile group; A nitro group; A hydroxy group; And a heterocyclic group containing at least one of N, O and S atoms, or does not have any substituent (s).

The substituents may be substituted or unsubstituted with an additional substituent.

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

In the present specification, the number of carbon atoms of the imide group is not particularly limited, but is preferably 1 to 25 carbon atoms. Specifically, it may be a compound having the following structure, but is not limited thereto.

In the present specification, the amide group may be mono- or di-substituted by nitrogen of the amide group with hydrogen, a straight-chain, branched-chain or cyclic alkyl group having 1 to 25 carbon atoms or an aryl group having 6 to 25 carbon atoms. Specifically, it may be a compound of the following structural formula, but is not limited thereto.

In the present specification, the alkyl group may be linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 1 to 50. Specific examples include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec- N-pentyl, 3-dimethylbutyl, 2-ethylbutyl, heptyl, n-hexyl, N-octyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethyl Heptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl, 2-methylpentyl, 4-methylhexyl and 5-methylhexyl.

In the present specification, the cycloalkyl group is not particularly limited, but preferably has 3 to 60 carbon atoms. Specific examples thereof include cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl, But are not limited to, 3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl, 3,4,5-trimethylcyclohexyl, 4-tert- butylcyclohexyl, cycloheptyl and cyclooctyl Do not.

In the present specification, the alkoxy group may be linear, branched or cyclic. The number of carbon atoms of the alkoxy group is not particularly limited, but is preferably 1 to 20 carbon atoms. Specific examples include methoxy, ethoxy, n-propoxy, isopropoxy, i-propyloxy, n-butoxy, isobutoxy, tert-butoxy, sec-butoxy, n-pentyloxy, neopentyloxy, N-hexyloxy, n-hexyloxy, 3,3-dimethylbutyloxy, 2-ethylbutyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, benzyloxy and p- But is not limited thereto.

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 40. Specific examples include vinyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, Butenyl, allyl, 1-phenylvinyl-1-yl, 2-phenylvinyl-1-yl, (Diphenyl-1-yl) vinyl-1-yl, stilbenyl, and styrenyl groups.

In the present specification, the silyl group specifically includes a trimethylsilyl group, a triethylsilyl group, a t-butyldimethylsilyl group, a vinyldimethylsilyl group, a propyldimethylsilyl group, a triphenylsilyl group, a diphenylsilyl group, But are not limited thereto.

In the present specification, the aryl group may be a monocyclic aryl group or a polycyclic aryl group, and includes a case where an alkyl group having 1 to 25 carbon atoms or an alkoxy group having 1 to 25 carbon atoms is substituted. In addition, an aryl group in the present specification may mean an aromatic ring.

When the aryl group is a monocyclic aryl group, the number of carbon atoms is not particularly limited, but is preferably 6 to 25 carbon atoms. Specific examples of the monocyclic aryl group include phenyl group, biphenyl group, terphenyl group, and the like, but are not limited thereto.

When the aryl group is a polycyclic aryl group, the number of carbon atoms is not particularly limited. And preferably has 10 to 24 carbon atoms. Specific examples of the polycyclic aryl group include, but are not limited to, a naphthyl group, an anthracenyl group, a phenanthryl group, a pyrenyl group, a perylenyl group, a klycenyl group and a fluorenyl group.

In the present specification, a fluorenyl group is a structure in which two cyclic organic compounds are connected through one atom.

In the present specification, the fluorenyl group may be substituted, and adjacent substituents may be bonded to each other to form a ring.

,

,

및

등이 될 수 있다. 다만, 이에 한정되는 것은 아니다.When the fluorenyl group is substituted,

,

,

And

And the like. However, the present invention is not limited thereto.

In the present specification, the heteroaryl group is a heteroaryl group containing at least one of O, N and S as a hetero atom. The number of carbon atoms is not particularly limited, but is preferably 2 to 60 carbon atoms. Examples of the heteroaryl group include a thiophene group, a furane group, a furyl group, an imidazole group, a thiazole group, an oxazole group, an oxadiazole group, a pyridyl group, a bipyridyl group, a pyrimidyl group, , A pyridazinyl group, a pyrazinyl group, a quinolinyl group, a quinazolinyl group, a quinoxalinyl group, a phthalazinyl group, a pyridopyrimidinyl group, a pyridopyranyl group, a pyrazinopyranyl group, an isoquinoline group, , A carbazole group, a benzoxazole group, a benzoimidazole group, a benzothiazole group, a benzocarbazole group, a benzothiophene group, a dibenzothiophene group, a benzofuranyl group, a phenanthroline, a thiazolyl group, , A thiadiazolyl group, a thiadiazolyl group, a benzothiadiazolyl group, a benzothiazolyl group, a phenothiazinyl group, and a dibenzofuranyl group, but the present invention is not limited thereto.

In the present specification, the heterocyclic group may be monocyclic or polycyclic, and may be an aromatic, aliphatic or aromatic and aliphatic condensed ring, and examples thereof may be selected from the above heteroaryl groups.

In the present specification, examples of the arylamine group include a substituted or unsubstituted monoarylamine group, a substituted or unsubstituted diarylamine group, or a substituted or unsubstituted triarylamine group. The aryl group in the arylamine group may be a monocyclic aryl group or a polycyclic aryl group. The arylamine group having at least two aryl groups may contain a monocyclic aryl group, a polycyclic aryl group, or a monocyclic aryl group and a polycyclic aryl group at the same time.

Specific examples of the arylamine group include phenylamine, naphthylamine, biphenylamine, anthracenylamine, 3-methylphenylamine, 4-methyl-naphthylamine, 2-methyl- But are not limited to, cenylamine, diphenylamine, phenylnaphthylamine, ditolylamine, phenyltolylamine, carbazole and triphenylamine groups.

In the present specification, the heteroaryl group in the heteroarylamine group can be selected from the examples of the above-mentioned heterocyclic group.

In the present specification, the aryl group in the aryloxy group, arylthioxy group, arylsulfoxy group and aralkylamine group is the same as the aforementioned aryl group. Specific examples of the aryloxy group include phenoxy, p-tolyloxy, m-tolyloxy, 3,5-dimethyl-phenoxy, 2,4,6-trimethylphenoxy, Naphthyloxy, 4-methyl-1-naphthyloxy, 5-methyl-2-naphthyloxy, 1-anthryloxy, 2-anthryl Phenanthryloxy, 9-phenanthryloxy and the like. Examples of the arylthioxy group include phenylthio group, 2-methylphenylthio group, 4-tert-butylphenyl And the like. Examples of the aryl sulfoxy group include a benzene sulfoxy group and a p-toluenesulfoxy group, but the present invention is not limited thereto.

In the present specification, the alkyl group in the alkylthio group and the alkylsulfoxy group is the same as the alkyl group described above. Specific examples of the alkyloxy group include a methylthio group, an ethylthio group, a tert-butylthio group, a hexylthio group and an octylthio group. Examples of the alkylsulfoxy group include a mesyl group, an ethylsulfoxy group, a propylsulfoxy group, But are not limited thereto.

In the present specification, the divalent linking group is a substituted or unsubstituted alkylene group; A substituted or unsubstituted arylene group; And divalent heterocyclic groups including at least one of substituted or unsubstituted N, O, S, Si, and Ge.

In the present specification, an alkylene group means that the alkyl group has two bonding positions, i.e., divalent. The description of the above-mentioned alkyl groups can be applied, except that they are each 2 groups.

In the present specification, an arylene group means a divalent group having two bonding positions in an aryl group. The description of the aryl group described above can be applied except that each of these is 2 groups.

In the present specification, the heteroarylene group means that the heteroaryl group has two bonding positions, that is, divalent. The description of the above-mentioned heteroaryl groups can be applied, except that they are each 2 groups.

According to one embodiment of the present invention, L2 and L3 in Formula 1 are the same or different and are each independently a direct bond; A substituted or unsubstituted alkylene group; A substituted or unsubstituted arylene group; And a divalent heterocyclic group containing at least one of substituted or unsubstituted N, O, S, Si, and Ge.

According to one embodiment of the present invention, L2 and L3 are the same or different from each other, and are each independently a direct bond; And a divalent heterocyclic group containing at least one of substituted or unsubstituted unsubstituted N, O, S, Si, and Ge.

According to one embodiment of the present disclosure, L2 and L3 are direct bonds.

According to one embodiment of the present invention, in Formula 1, A1 and A2 are the same or different from each other, and each independently is any one of the following structures.

In the above structure,

a is an integer of 1 to 7,

b and c are each an integer of 1 to 4,

When a is 2 or more, two or more R < 15 > s are the same as or different from each other,

When b is 2 or more, two or more R < 16 > s are the same as or different from each other,

When c is 2 or more, two or more R < 17 > s are the same as or different from each other,

R14 to R20 are the same or different from each other, and each independently hydrogen; heavy hydrogen; A halogen group; A nitrile group; A nitro group; Imide; Amide group; A hydroxy group; A substituted or unsubstituted alkyl group; A substituted or unsubstituted cycloalkyl group; A substituted or unsubstituted alkoxy group; A substituted or unsubstituted aryloxy group; A substituted or unsubstituted alkylthio group; A substituted or unsubstituted arylthio group; A substituted or unsubstituted alkylsulfoxy group; A substituted or unsubstituted arylsulfoxy group; A substituted or unsubstituted alkenyl group; A substituted or unsubstituted silyl group; A substituted or unsubstituted boron group; A substituted or unsubstituted alkylamine group; A substituted or unsubstituted aralkylamine group; A substituted or unsubstituted arylamine group; A substituted or unsubstituted heteroarylamine group; A substituted or unsubstituted aryl group; Or a substituted or unsubstituted heterocyclic group containing at least one of N, O and S atoms.

According to one embodiment of the present invention, in the general formula (1), R 1 to R 12 and R 21 to R 28 are the same or different and each independently hydrogen; Or a substituted or unsubstituted straight or branched alkyl group.

According to one embodiment of the present disclosure, R 1 to R 12 and R 21 to R 28 are the same or different and each independently hydrogen; Or a substituted or unsubstituted, linear or branched alkyl group having 1 to 30 carbon atoms.

According to one embodiment of the present disclosure, R 1 to R 12 and R 21 to R 28 are the same or different and each independently hydrogen; Or a substituted or unsubstituted, linear or branched alkyl group having 1 to 20 carbon atoms.

According to one embodiment of the present disclosure, R 1 to R 12 and R 21 to R 28 are the same or different and each independently hydrogen; Or a substituted or unsubstituted, linear or branched alkyl group having 1 to 10 carbon atoms.

According to one embodiment of the present disclosure, R 1 to R 12 and R 21 to R 28 are the same or different and each independently hydrogen; A substituted or unsubstituted octyl group; Or a substituted or unsubstituted 2-ethylhexyl group.

According to one embodiment of the present disclosure, R 1 to R 12 and R 21 to R 28 are the same or different and each independently hydrogen; Octyl group; Or a 2-ethylhexyl group.

According to one embodiment of the present disclosure, R4, R8, R24 and R28 are 2-ethylhexyl groups.

According to one embodiment of the present invention, R9 to R12 are the same or different from each other, and each independently hydrogen; Or an octyl group.

이고,According to one embodiment of the present disclosure, A1 and A2 are the same or different and each independently

ego,

R14 is a substituted or unsubstituted straight-chain or branched alkyl group.

이다.According to one embodiment of the present disclosure,

to be.

이다.According to one embodiment of the present disclosure,

to be.

According to one embodiment of the present invention, R14 is a substituted or unsubstituted straight or branched alkyl group.

According to one embodiment of the present invention, R14 is a substituted or unsubstituted C1 to C15 linear or branched alkyl group.

According to one embodiment of the present invention, R14 is a substituted or unsubstituted ethyl group.

According to one embodiment of the present disclosure, R14 is an ethyl group.

According to one embodiment of the present disclosure, m1 is one.

According to one embodiment of the present disclosure, m2 is one.

According to one embodiment of the present disclosure, n1 is 3.

According to one embodiment of the present disclosure, n2 is 3.

According to one embodiment of the present invention, in the general formula (1), G1 and G2 are the same or different and each independently represents a substituted or unsubstituted, branched alkyl group having 3 to 10 carbon atoms.

According to one embodiment of the present invention, in the above formula (1), G1 and G2 are the same or different and each independently a substituted or unsubstituted 2-ethylhexyl group.

According to one embodiment of the present invention, in the above formula (1), G1 and G2 are 2-ethylhexyl groups.

According to one embodiment of the present invention, the formula 1 is represented by the following formula 1-1.

[Compound 1-1]

The above heterocyclic compound can be produced based on the following production example.

According to one embodiment of the present invention, the heterocyclic compound is obtained by bonding the structure in square brackets of m1 and the structure in square brackets of m2 through benzothiadiazole substituted with a branching chain alkoxy group, , And then a compound of the structure obtained through this is bonded to a compound having an aldehyde-introduced structure at the terminal of n1, n2. Thereafter, A1 and A2 are introduced to prepare the heterocyclic compound represented by the formula (1) as well as the heterocyclic compound represented by the compound (1-1).

The heterocyclic compound according to one embodiment of the present disclosure can be prepared by a multistage chemical reaction. After the monomers are prepared through alkylation, Grignard reaction, Suzuki coupling reaction, and Stille coupling reaction, the monomers are reacted through a carbon-carbon coupling reaction such as a steel coupling reaction, Can be prepared. When the substituent to be introduced is a boronic acid or a boronic ester compound, it can be prepared through a Suzuki coupling reaction. When the substituent to be introduced is tributyltin or trimethyltin ) Compound, it may be prepared through a steel coupling reaction, but the present invention is not limited thereto.

According to one embodiment of the present disclosure, there is provided a liquid crystal display comprising: a first electrode; A second electrode facing the first electrode; And at least one organic compound layer including a photoactive layer disposed between the first electrode and the second electrode, wherein at least one of the organic compound layers includes the heterocyclic compound.

An organic solar cell according to an embodiment of the present invention includes a first electrode, a photoactive layer, and a second electrode. The organic solar cell may further include a substrate, a hole transporting layer, and / or an electron transporting layer.

According to one embodiment of the present invention, when the organic solar cell receives photons from an external light source, electrons and holes are generated between the electron beams and the electron acceptors. The generated holes are transported to the anode through the electron donor layer.

According to one embodiment of the present invention, the organic material layer includes a hole transporting layer, a hole injecting layer, or a layer simultaneously transporting holes and holes, and the hole transporting layer, the hole injecting layer, or the layer simultaneously transporting holes and injecting holes And the above heterocyclic compound.

In another embodiment, the organic material layer may include an electron injection layer, an electron transport layer, or a layer that simultaneously performs electron injection and electron transport, and the electron injection layer, the electron transport layer, And the above heterocyclic compound.

1 illustrates an organic solar cell according to an embodiment of the present invention.

According to one embodiment of the present invention, when the organic solar cell receives photons from an external light source, electrons and holes are generated between the electron beams and the electron acceptors. The generated holes are transported to the anode through the electron donor layer.

According to one embodiment of the present disclosure, the organic solar cell may further include an additional organic layer. The organic solar cell can reduce the number of organic layers by using organic materials having various functions at the same time.

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

According to one embodiment of the present disclosure, the organic solar cell may be arranged in the order of the cathode, the photoactive layer, and the anode, and may be arranged in the order of the anode, the photoactive layer, and the cathode.

In another embodiment, the organic solar cell may be arranged in the order of an anode, a hole transporting layer, a photoactive layer, an electron transporting layer and a cathode, and may be arranged in the order of a cathode, an electron transporting layer, a photoactive layer, a hole transporting layer, , But is not limited thereto.

According to one embodiment of the present invention, the organic solar cell has a normal structure. In the normal structure, the substrate, the anode, the organic material layer including the photoactive layer, and the cathode may be stacked in this order.

According to one embodiment of the present invention, the organic solar cell is an inverted structure. In the inverted structure, the substrate, the cathode, the organic material layer including the photoactive layer, and the anode may be stacked in this order.

According to one embodiment of the present invention, the organic solar cell is a tandem structure.

The organic solar cell according to one embodiment of the present disclosure may have one photoactive layer or two or more layers. In the tandem structure, two or more photoactive layers may be included.

In another embodiment, a buffer layer may be provided between the photoactive layer and the hole transporting layer or between the photoactive layer and the electron transporting layer. At this time, a hole injection layer may be further provided between the anode and the hole transport layer. Further, an electron injecting layer may be further provided between the cathode and the electron transporting layer.

According to one embodiment of the present invention, the photoactive layer includes one or more selected from the group consisting of an electron donor and a donor, and the electron donor material includes the heterocyclic compound.

According to one embodiment of the present disclosure, the electron acceptor material may be selected from the group consisting of fullerene, fullerene derivatives, vicocloin, semiconducting elements, semiconducting compounds, and combinations thereof. (6,6) -phenyl-C61-butyric acid-methylester) or PCBCR ((6,6) -phenyl-C61-butyric acid-cholesteryl ester), perylene perylene, polybenzimidazole (PBI), and 3,4,9,10-perylene-tetracarboxylic bis-benzimidazole (PTCBI).

According to one embodiment of the present disclosure, the electron donor and the electron acceptor constitute a bulk heterojunction (BHJ).

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

According to an embodiment of the present invention, the photoactive layer is a bilayer structure including an n-type organic layer and a p-type organic layer, and the p-type organic layer includes the heterocyclic compound.

In this specification, the substrate may be a glass substrate or a transparent plastic substrate having excellent transparency, surface smoothness, ease of handling, and waterproofness, but is not limited thereto, and is not limited as long as it is a substrate commonly used in organic solar cells. Specific examples include glass or polyethylene terephthalate, polyethylene naphthalate (PEN), polypropylene (PP), polyimide (PI), and triacetyl cellulose (TAC) But is not limited thereto.

The anode electrode may be a transparent material having excellent conductivity, but is not limited thereto. Metals such as vanadium, chromium, copper, zinc, and gold, or alloys thereof; Metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); ZnO: Al or SNO _2: a combination of a metal and an oxide such as Sb; And conductive polymers such as poly (3-methylthiophene), poly [3,4- (ethylene-1,2-dioxy) thiophene] (PEDOT), polypyrrole and polyaniline, but are not limited thereto .

The method of forming the anode electrode is not particularly limited and may be applied to one surface of the substrate or may be coated in a film form using, for example, sputtering, E-beam, thermal evaporation, spin coating, screen printing, inkjet printing, doctor blade or gravure printing . ≪ / RTI >

When the anode electrode is formed on a substrate, it may undergo cleaning, moisture removal and hydrophilic reforming processes.

For example, the patterned ITO substrate is sequentially washed with a cleaning agent, acetone, and isopropyl alcohol (IPA), and then dried on a heating plate at 100 to 150 ° C for 1 to 30 minutes, preferably 120 ° C for 10 minutes , And the substrate surface is hydrophilically reformed when the substrate is completely cleaned.

Through such surface modification, the junction surface potential can be maintained at a level suitable for the surface potential of the photoactive layer. Further, in the modification, the formation of the polymer thin film on the anode electrode is facilitated, and the quality of the thin film may be improved.

Pretreatment techniques for the anode electrode include a) surface oxidation using a parallel plate discharge, b) a method of oxidizing the surface through ozone generated using UV ultraviolet radiation in vacuum, and c) oxygen radicals generated by the plasma And the like.

One of the above methods can be selected depending on the state of the anode electrode or the substrate. However, whichever method is used, it is preferable to prevent oxygen from escaping from the surface of the anode electrode or the substrate and to suppress the residual of moisture and organic matter as much as possible. At this time, the substantial effect of the pretreatment can be maximized.

As a specific example, a method of oxidizing the surface through ozone generated using UV can be used. At this time, the ITO substrate patterned after the ultrasonic cleaning is dried by baking on a hot plate, and then put into a chamber. Then, by the action of a UV lamp, ozone generated by reaction of oxygen gas with UV light The patterned ITO substrate can be cleaned.

However, the method of modifying the surface of the patterned ITO substrate in the present specification is not particularly limited, and any method may be used as long as it is a method of oxidizing the substrate.

The cathode electrode may be a metal having a small 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; Or a multilayer structure material such as LiF / Al, LiO ₂ / Al, LiF / Fe, Al: Li, Al: BaF ₂ and Al: BaF ₂ : Ba.

The cathode may be deposited in a thermal evaporator having a degree of vacuum of 5 x 10 ^{< -7} > torr or less, but the method is not limited thereto.

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

The hole transport layer material may include poly (3,4-ethylenediocythiophene) doped with poly (styrenesulfonic acid) (PEDOT: PSS), molybdenum oxide (MoO _x ); Vanadium oxide (V ₂ O ₅ ); Nickel oxide (NiO); And tungsten oxide (WO _x ), but the present invention is not limited thereto.

The electron transport layer material may be electron-extracting metal oxides, specifically a metal complex of 8-hydroxyquinoline; Complexes containing Alq ₃ ; Metal complexes including Liq; LiF; Ca; Titanium oxide (TiO _x ); Zinc oxide (ZnO); And cesium carbonate (Cs ₂ CO ₃ ), but the present invention is not limited thereto.

The photoactive layer can be 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 by spin coating, dip coating, screen printing, spray coating, doctor blade, brush painting, But is not limited to the method.

The production method of the heterocyclic compound and the production of the organic solar cell including the heterocyclic compound will be described in detail in the following Production Examples and Examples. However, the following examples are intended to illustrate the present specification, and the scope of the present specification is not limited thereto.

Production Example 1. Preparation of Compound 1-1

1) Preparation of Compound A

2.9 g of starting material 1 was dissolved in 20 mL of anhydrous tetrahydrofuran and then cooled to -78 ° C. 2.0 mL of 2.5 M n-BuLi was poured into the resulting solution, followed by stirring for 2 hours. After 5.4 mL of 1.0 M Me ₃ SnCl 2 was added to the reaction mixture, the reaction mixture was warmed to room temperature and stirred for 12 hours. To the reaction mixture obtained, 20 mL of water was added to the reaction mixture, and the organic layer was extracted three times with 20 mL of ethyl acetate. The organic layer thus obtained was dried over MgSO ₄ and filtered. The resulting solution was depressurized to remove the solvent to obtain Compound A.

2) Preparation of compound B

After adding 45 mg of Pd ₂ (dba) ₃ and 26 mg of P ( o- tolu) ₃ to the reaction vessel, a solution obtained by dissolving 1.57 g of Compound A and 389 mg of starting material 2 in 13 mL of toluene was injected Respectively. The resulting reaction mixture was stirred at 90 for 3 days, cooled to room temperature and extracted three times with 20 mL of water and the same amount of chloroform. The organic layer thus obtained was dried over MgSO ₄ and filtered. The resulting solution was reduced in pressure to remove the solvent to obtain a red oil. The oil was flash columned with chloroform: hexane (1: 2 by volume) as eluent to give Compound B in 90% yield.

3) Preparation of compound C

1.9 g of Compound B was dissolved in 50 mL of anhydrous tetrahydrofuran and then cooled to -78. To this solution, 4.9 mL of 1.0 M lithium diisopropylamide (LDA) was added and stirred for 2 hours. To the resulting reaction mixture was added 4.9 mL of 1.0 M Me ₃ SnCl, the reaction mixture was warmed to room temperature and stirred for 12 hours. 50 mL of water was added to the reaction mixture obtained thereby, and the organic layer was extracted three times with 30 mL of chloroform. The organic layer thus obtained was dried over MgSO ₄ and filtered, and the resulting solution was depressurized to remove the solvent to obtain the compound C.

4) Preparation of Compound E

After adding 69 mg of Pd ₂ (dba) ₃ and 39 mg of P ( o- tolu) ₃ to the reaction vessel, 2.0 g of Compound C and 1.9 g of Compound D were dissolved in 45 mL of toluene, Respectively. The resulting reaction mixture was stirred at 90 for 3 days, cooled to room temperature and extracted three times with 40 mL of water and chloroform in the same volume. The organic layer thus obtained was dried over MgSO ₄ and filtered. The resulting solution was reduced in pressure to remove the solvent to obtain a red oil. The oil was flash columned with dichloromethane: hexane (3: 4 by volume) as eluent to give compound B in 43% yield.

5) Preparation of Compound 1-1

1.2 g of the compound E was dissolved in 30 mL of chloroform, and 4 drops of piperidine and 760 mg of 2-ethylrhodanin were added to the solution, followed by stirring at 70 for 12 hours. Then, the reaction mixture was cooled to room temperature, filtered through silica gel using chloroform, and then the solvent was removed through reduced pressure. The resulting mixture was subjected to flash column chromatography using hexane and chloroform, and recrystallized from ethyl acetate and dichloromethane to obtain Compound 1-1 in a yield of 67%.

The NMR data of the compound 1-1 are shown in FIG.

Example 1. Preparation of organic solar cell

Compound 1-1 and PC ₇₁ BM were dissolved in chloroform (CF) at a ratio of 1: 2 to prepare a composite solution. At this time, the concentration was adjusted to 4 wt%, and the organic solar cell had an inverted structure of ITO / ZnO / photoactive layer / MoO ₃ / Ag.

The glass substrate coated with 1.5 × 1.5 cm ² of ITO in a bar type was ultrasonically cleaned using distilled water, acetone, and 2-propanol, and the ITO surface was subjected to ozone treatment for 10 minutes. Then, the ZnO precursor solution ZnO nanoparticle 25 mg / ml in butanol) was spin-coated at 4000 rpm for 40 seconds and heat-treated at 100 for 10 minutes to remove the remaining solvent, . For coating the photoactive layer, a composite solution of Polymer 1 and PC ₇₁ BM was spin-coated at 1000 rpm for 20 seconds. In the thermal evaporator, a hole transport layer was prepared by depositing MoO ₃ at a thickness of 10 nm at a rate of 0.2 Å / s. In this order, Ag was deposited in a thermal evaporator at a rate of 1 Å / s to form a 100 nm organic solar cell.

Example 2. Preparation of organic solar cell

An organic solar cell was prepared in the same manner as in Example 1, except that chlorobenzene (CB) was used instead of chloroform.

Example 3: Preparation of organic solar cell

An organic solar cell was prepared in the same manner as in Example 1, except that o -xylene was used instead of chloroform.

Comparative Example 1. Preparation of Organic Solar Cell

An organic solar cell was prepared in the same manner as in Example 1, except that the following compound 1 was used instead of the compound 1-1.

[Comparative Example Compound 1]

Comparative Example 2: Production of organic solar cell

An organic solar cell was prepared in the same manner as in Comparative Example 1, except that chlorobenzene (CB) was used instead of chloroform.

Comparative Example 3: Production of organic solar cell

An organic solar cell was prepared in the same manner as in Comparative Example 1, except that o -xylene was used instead of chloroform.

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

V _OC (V) J _SC (mA / cm ² ) FF (%) PCE (%) Example 1 0.936 10.720 0.542 5.44 Example 2 0.941 9.171 0.533 4.60 Example 3 0.836 11.605 0.599 5.99 Comparative Example 1 0.835 12.366 0.576 5.94 Comparative Example 2 0.908 4.639 0.544 2.29 Comparative Example 3 0.878 8.931 0.369 2.89

According to Table 1, the organic solar cell made of the heterocyclic compound according to one embodiment of the present invention, in which G1 and G2 of Formula 1 include an alkyl group in the branched chain, has the same structure as that of Formula 1 described in Comparative Examples 1 to 3 It can be confirmed that the efficiency is higher than that of the organic solar cell prepared in Comparative Example Compound 1 in which G1 and G2 are linear alkyl groups.

V _oc denotes an open-circuit voltage, J _sc denotes a short-circuit current, FF denotes a fill factor, and PCE (η) denotes an energy conversion efficiency. The open-circuit voltage and the short-circuit current are the X-axis and Y-axis intercepts in the fourth quadrant of the voltage-current density curve, respectively. The higher the two values, the higher the efficiency of the solar cell. The fill factor is the width of the rectangle that can be drawn inside the curve divided by the product of the short-circuit current and the open-circuit voltage. The energy conversion efficiency can be obtained by dividing these three values by the intensity of the irradiated light, and a higher value is preferable. As a result of the above Table 1, it can be confirmed that the heterocyclic compound according to one embodiment of the present invention shows high efficiency.

101: substrate
102: first electrode
103: Hole transport layer
104: photoactive layer
105: second electrode

Claims (12)

A heterocyclic compound represented by the following formula (1):
[Chemical Formula 1]

In Formula 1,
m1, m2, n1 and n2 are each an integer of 1 to 3,
When m1, m2, n1 and n2 are each 2 or more, the structures in the square brackets are equal to or different from each other,
L2 and L3 are the same or different and are each independently a direct bond; Or a divalent linking group,
R1 to R12 and R21 to R28 are the same or different from each other and each independently hydrogen; heavy hydrogen; A halogen group; A nitrile group; A nitro group; Imide; Amide group; A hydroxy group; A substituted or unsubstituted alkyl group; A substituted or unsubstituted cycloalkyl group; A substituted or unsubstituted alkoxy group; A substituted or unsubstituted aryloxy group; A substituted or unsubstituted alkylthio group; A substituted or unsubstituted arylthio group; A substituted or unsubstituted alkylsulfoxy group; A substituted or unsubstituted arylsulfoxy group; A substituted or unsubstituted alkenyl group; A substituted or unsubstituted silyl group; A substituted or unsubstituted boron group; A substituted or unsubstituted alkylamine group; A substituted or unsubstituted aralkylamine group; A substituted or unsubstituted arylamine group; A substituted or unsubstituted heteroarylamine group; A substituted or unsubstituted aryl group; Or a substituted or unsubstituted heterocyclic group containing at least one of N, O and S atoms,
G1 and G2 are the same or different and are each independently a substituted or unsubstituted branched alkyl group,
A1 and A2 are the same or different from each other and each independently has a structure which functions as an electron acceptor. [2] The compound according to claim 1, wherein L2 and L3 are the same or different from each other, and each independently is a direct bond; A substituted or unsubstituted alkylene group; A substituted or unsubstituted arylene group; And a divalent heterocyclic group containing at least one of substituted or unsubstituted N, O, S, Si, and Ge. The heterocyclic compound according to claim 1, wherein A1 and A2 are the same or different and each independently is any one of the following structures:

In the above structure,
a is an integer of 1 to 7,
b and c are each an integer of 1 to 4,
When a is 2 or more, two or more R < 15 > s are the same as or different from each other,
When b is 2 or more, two or more R < 16 > s are the same as or different from each other,
When c is 2 or more, two or more R < 17 > s are the same as or different from each other,
R14 to R20 are the same or different from each other, and each independently hydrogen; heavy hydrogen; A halogen group; A nitrile group; A nitro group; Imide; Amide group; A hydroxy group; A substituted or unsubstituted alkyl group; A substituted or unsubstituted cycloalkyl group; A substituted or unsubstituted alkoxy group; A substituted or unsubstituted aryloxy group; A substituted or unsubstituted alkylthio group; A substituted or unsubstituted arylthio group; A substituted or unsubstituted alkylsulfoxy group; A substituted or unsubstituted arylsulfoxy group; A substituted or unsubstituted alkenyl group; A substituted or unsubstituted silyl group; A substituted or unsubstituted boron group; A substituted or unsubstituted alkylamine group; A substituted or unsubstituted aralkylamine group; A substituted or unsubstituted arylamine group; A substituted or unsubstituted heteroarylamine group; A substituted or unsubstituted aryl group; Or a substituted or unsubstituted heterocyclic group containing at least one of N, O and S atoms. The compound according to claim 1, wherein R1 to R12 and R21 to R28 are the same or different from each other and each independently hydrogen; Or a substituted or unsubstituted straight or branched chain alkyl group. The compound according to claim 1, wherein A1 and A2 are the same or different and each independently

ego,
And R14 is a substituted or unsubstituted straight or branched alkyl group. The heterocyclic compound according to claim 1, wherein the compound represented by Formula 1 is represented by the following Formula 1-1:
[Compound 1-1]

A first electrode; A second electrode facing the first electrode; And at least one organic layer provided between the first electrode and the second electrode and including a photoactive layer, wherein at least one of the organic layers comprises a heterocyclic compound according to any one of claims 1 to 6, Organic solar cells. [Claim 7] The organic electroluminescent device according to claim 7, wherein the organic material layer comprises a hole transporting layer, a hole injecting layer or a layer simultaneously transporting holes and holes,
Wherein the hole transporting layer, the hole injecting layer, or the layer simultaneously transporting the holes and the hole injecting layer comprises the heterocyclic compound. The organic electroluminescent device according to claim 7, wherein the organic material layer includes an electron injection layer, an electron transport layer, or a layer that simultaneously performs electron injection and electron transport,
Wherein the electron injecting layer, the electron transporting layer, or the layer which simultaneously injects electrons and transports electrons comprises the heterocyclic compound. [7] The photoactive layer according to claim 7, wherein the photoactive layer comprises one or more selected from the group consisting of an electron donor and an electron donor,
Wherein the electron donor comprises the heterocyclic compound. 11. The organic solar cell according to claim 10, wherein the electron donor and the electron acceptor constitute bulk heterojunction (BHJ). [7] The method of claim 7, wherein the photoactive layer is a bilayer structure including an n-type organic compound layer and a p-type organic compound layer,
Wherein the p-type organic compound layer comprises the heterocyclic compound.

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