KR102121756B1 - Perovskite solar cell, polymer for perovskite solar cell and method for manufacturing the same - Google Patents

Abstract

상기 화학식 1에 있어서,
상기 R₁ 및 R₂는 각각 독립적으로 할로겐 또는 C₁-C₁₀알킬기이고, R₁ 및 R₂ 중 하나 이상은 할로겐이다.The present invention relates to a polymer comprising a repeating unit represented by the following Chemical Formula 1 and a manufacturing method thereof, and a perovskite solar cell comprising the same.
[Formula 1]

In Chemical Formula 1,
R ₁ and R ₂ are each independently halogen or a C ₁ -C ₁₀ alkyl group, and at least one of R ₁ and R ₂ is halogen.

Description

Perovskite solar cell, polymer for perovskite solar cell, and manufacturing method thereof{PEROVSKITE SOLAR CELL, POLYMER FOR PEROVSKITE SOLAR CELL AND METHOD FOR MANUFACTURING THE SAME}

The present invention relates to a perovskite solar cell having excellent photoelectric conversion efficiency, a polymer for a perovskite solar cell, and a method for manufacturing the same.

Due to the fear of depletion of fossil fuels, warming and climate change due to its abuse, and safety concerns that exist in nuclear energy, the need for sustainable energy, photovoltaic power generation, is higher than ever.

Solar cell technology is a technology that directly converts light into electrical energy, and most of the solar cells that are in practical use are inorganic solar cells using inorganic materials such as silicon. However, since the manufacturing cost of the inorganic solar cell is increased due to the complicated manufacturing process and the material is expensive, research on organic solar cells having a low manufacturing cost and a low material cost through a relatively simple manufacturing process has been actively conducted. However, in organic solar cells, the structure of BHJ is deteriorated by moisture or oxygen in the air, and its efficiency rapidly decreases. That is, there is a big problem in the stability of the solar cell. There is a problem of an increase but a price increase.

Therefore, currently perovskite solar cells are closest to commercialization among the next generation solar cells including dye-sensitized and organic solar cells, based on excellent photovoltaic properties, cost reduction and easy process, and full-scale studies on stability and large-area are required. . Among these, the perovskite solar cell without a hole transport material showed lower charge extraction and charge recombination at the interface than a perovskite solar cell containing a hole transport material, thereby showing a decrease in open voltage and charge rate.

Therefore, in order to show a higher power conversion efficiency (PCE), it is necessary to mitigate an increase in charge extraction and undesired charge recombination at the interface, and for this, hole transporting materials in a perovskite solar cell (Hole Transporting Materials) , HTM).

In order to further improve the photoelectric conversion efficiency, which is one of the main characteristics of the perovskite solar cell, the photoelectric conversion efficiency of the perovskite solar cell using spiro-OMeTAD as a hole transport material has recently achieved 15%. However, spiro-OMeTAD is complex, expensive to synthesize, has weak thermal stability, and has low carrier mobility of charges, and thus, the generalization of perovskite solar cells may be limited.

Therefore, in order to promote the high efficiency of the device, it is essential to design and develop an efficient hole transport material that can replace it.

In order to solve the above problems, the present invention is to provide a perovskite solar cell that can be used as a hole transport material polymer of the present invention.

In addition, the present invention is to provide a perovskite solar cell having high stability and excellent photoelectric conversion efficiency as compared to a conventional perovskite solar cell.

In addition, the present invention is to provide a method for producing a polymer of the present invention provided as a hole transport material of a perovskite solar cell.

In order to achieve the above object, the perovskite solar cell of the present invention may include a polymer comprising a repeating unit represented by Formula 1 below.

[Formula 1]

In Chemical Formula 1,

R ₁ and R ₂ are each independently halogen or a C ₁ -C ₁₀ alkyl group, and at least one of R ₁ and R ₂ is halogen.

According to an aspect of the present invention, the perovskite solar cell is R ₁ and R ₂ of Formula 1 are each independently halogen or a C ₁ -C ₃ alkyl group, and at least one of R ₁ and R ₂ is halogen Can be.

According to an aspect of the present invention, R ₁ in Formula 1 is halogen, and R ₂ may be halogen or a C ₁ -C ₃ alkyl group.

According to an aspect of the present invention, the perovskite solar cell may be a polymer including any one repeating unit selected from repeating units represented by the following structural formula:

[constitutional formula]

,

,

According to an aspect of the present invention, the perovskite solar cell may include a polymer containing a repeating unit represented by Chemical Formula 1 as a hole transport material.

According to an aspect of the present invention, an increase rate (%) of the photoelectric conversion efficiency of the perovskite solar cell may satisfy Equation 1 below.

[Equation 1]

In the above formula 1,

The PCE _a is a photoelectric conversion efficiency measured by a perovskite solar cell including a hole transport material in which R ₁ and R _{2 in} Chemical Formula 1 are -CH ₃ ,

The PCE _b is a photoelectric conversion efficiency measured by a perovskite solar cell comprising a polymer containing a repeating unit represented by Formula 1 as a hole transport material.

According to an aspect of the present invention, the energy band gap (E _g ^opt ) of the polymer including the repeating unit represented by Chemical Formula 1 may be 2.96 to 3.50 eV.

According to an aspect of the present invention, the number average molecular weight of the polymer containing the repeating unit represented by Chemical Formula 1 may be 10,000 to 500,000 g/mol.

According to an aspect of the present invention, the difference between the ionization potential of the polymer comprising the repeating unit represented by Chemical Formula 1 and the perovskite compound may be 0.02 to 0.4 eV.

According to an aspect of the present invention, the perovskite solar cell

The first electrode,

An electron transport layer formed on the first electrode,

Light absorbing layer comprising a perovskite structure compound formed on the electron transport layer,

It is formed on the light absorbing layer, a hole transport layer comprising a polymer containing a repeating unit represented by the formula (1) and

It may be to include a second electrode formed on the hole transport layer.

The present invention can be carried out in the presence of a nickel-based catalyst and a ligand represented by the following formula (2) as a method for preparing a polymer that is a hole-electron material of the perovskite solar cell.

[Formula 2]

In Chemical Formula 2,

R ₁ and R ₂ are each independently halogen or a C ₁ -C ₁₀ alkyl group, at least one of R ₁ and R ₂ is halogen, and X is halogen, which is different from the halogen of R ₁ and R ₂ .

According to an aspect of the present invention, a method for manufacturing a hole transport material of the perovskite solar cell includes the bis(1,5-cyclooctadiene) nickel(0) [Ni(COD) ₂ ], 1, 1, 3-diphenylphosphinopropane nickel(II) chloride [Ni(dppp)Cl ₂ ], 1,2-bis(diphenylphosphino)ethane nickel(II) chloride [Ni(dppe)Cl ₂ ] It may be a mixture of one or two or more.

According to an aspect of the present invention, the method for manufacturing a hole transport material of the perovskite solar cell includes: 2,2-bipyridine, triphenylphosphan, alkyl-2,2-bipyridine, 4,4-di -(5-nonyl)-2,2-bipyridine, 4,4-di-(5-heptyl)-2,2-bipyridine, tris(2-aminoethyl)amine (TREN), N,N,N ',N',N"-pentamethyldiethylenetriamine, 1,1,4,7,10,10-hexamethyltriethylenetetraamine and tetramethylethylenediamine. .

The perovskite solar cell of the present invention has the advantage of being able to have a high open voltage and excellent photoelectric conversion efficiency while having high stability compared to a material used as a conventional hole transport material by including the polymer of the present invention.

The polymer provided as the hole transport material of the perovskite solar cell manufactured by the manufacturing method of the present invention has the advantage of being able to further improve the photoelectric conversion efficiency by providing excellent hole transport driving power.

1 is a result of the optical and thermal properties of the polymer according to an embodiment of the present invention and a comparative example. 1(a) is a UV-vis absorption spectrum, (b) is a differential scanning calorimeter, and (c) is a thermogravimetric analysis result.
2 is a photoelectron analysis result of the polymer according to an embodiment of the present invention and a comparative example.
3 is a result of measuring the photoelectric conversion efficiency of a polymer according to an embodiment of the present invention and a comparative example. 3(a) is a photocurrent density-voltage characteristic result, and (b) is an external quantum efficiency spectrum result.
4 is a result of measuring the photoelectric conversion efficiency of the polymer according to an embodiment and a comparative example of the present invention. 4(a) is a photocurrent density-voltage characteristic result, and (b) is an external quantum efficiency spectrum result.

Hereinafter, a perovskite solar cell according to the present invention, a polymer for a perovskite solar cell and a method for manufacturing the same will be described in more detail. However, the following examples are only one reference for explaining the present invention in detail, and the present invention is not limited thereto, and may be implemented in various forms.

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

Also, the singular form used in the specification and the appended claims may be intended to include the plural form unless otherwise indicated in the context.

Substituents containing the "alkyl", "alkoxy" and other "alkyl" moieties described in the present invention include both straight-chain or pulverized forms, and preferably 1 to 5 carbon atoms in the polymer of the present invention. , More preferably, it has 1 to 3 carbon atoms in the case of alkyl.

In addition, the "aryl" described in the present invention is an organic radical derived from an aromatic hydrocarbon by removal of one hydrogen, single or fused, preferably containing 4 to 7, preferably 5 or 6 ring atoms in each ring. It includes a ring system, and includes a form in which a plurality of aryls are connected by a single bond. Specific examples include, but are not limited to, phenyl, naphthyl, biphenyl, anthryl, indenyl, fluorenyl, and the like.

The term "cycloalkyl" described in the present invention means a non-aromatic monocyclic or multicyclic ring system having 3 to 20 carbon atoms, and the monocyclic ring is, but is not limited to, cyclopropyl, cyclobutyl , Cyclopentyl and cyclohexyl. Examples of the polycyclic cycloalkyl group include perhydronaphthyl, perhydroindenyl, and the like; Bridged polycyclic cycloalkyl groups include adamantyl and norbornyl and the like.

The present invention provides a perovskite solar cell comprising a polymer comprising a repeating unit represented by Formula 1 below.

[Formula 1]

In Chemical Formula 1,

R ₁ and R ₂ are each independently halogen or a C ₁ -C ₁₀ alkyl group, and at least one of R ₁ and R ₂ is halogen.

When the polymer comprising the repeating unit represented by Formula 1 of the present invention is used as a hole transport material of a solar cell, particularly a perovskite solar cell, the efficiency of the perovskite solar cell employing the same is remarkably improved. .

According to an aspect of the present invention, R ₁ in Formula 1 is halogen, and R ₂ may be halogen or a C ₁ -C ₃ alkyl group.

Specifically, in accordance with an aspect of the present invention, the polymer comprising the repeating unit represented by Chemical Formula 1 is substituted by halogen element groups at positions 4, 2, or 4 of the phenyl group in the triarylamine skeleton. The efficiency of the lobsky solar cell can be significantly improved.

Furthermore, in the perovskite solar cell employing a polymer containing a repeating unit represented by Formula 1 of the present invention as a hole transport material, in the repeating unit represented by Formula 1, R ₁ and R ₂ are methyl groups (-CH ₃ Compared to a perovskite solar cell employing a phosphorous polymer as a hole transport material, it can surprisingly improve the open voltage and photoelectric conversion efficiency.

That is, the perovskite solar cell of the present invention does not employ a polymer in which R ₁ and R ₂ are methyl groups (-CH ₃ ) in the repeating unit represented by Chemical Formula 1 as a hole transport material, and is represented by Chemical Formula 1 By employing a polymer containing a repeating unit as a hole transport material of a perovskite solar cell, it is possible to have excellent stability and significantly improved photoelectric conversion efficiency.

In accordance with an aspect of the present invention in terms of increasing the high temperature stability and photoelectric conversion efficiency of the perovskite solar cell, the perovskite solar cell comprises R ₁ of the polymer containing a repeating unit represented by Formula ₁ and R ₂ is each independently halogen or a C ₁ -C ₃ alkyl group, and one or more of R ₁ and R ₂ may be halogen. The halogen may be fluorine (-F), chlorine (-Cl), bromine (-Br) or iodine (-I).

In a preferred embodiment, R ₁ and R ₂ of the polymer containing the repeating unit represented by Formula 1 are each independently a fluorine (-F) or C ₁ -C ₃ alkyl group, and at least one of R ₁ and R ₂ is May be fluorine (-F). By adopting a polymer containing a repeating unit substituted with fluorine as in Chemical Formula 1, it has more improved stability and can exhibit excellent photoelectric conversion efficiency.

Preferably, according to one aspect of the present invention, the perovskite solar cell may be a polymer including any one repeating unit selected from the repeating unit represented by the following structural formula:

[constitutional formula]

,

,

According to an aspect of the present invention, the perovskite solar cell may include a polymer containing a repeating unit represented by Chemical Formula 1 as a hole transport material. As described above, the perovskite solar cell employing the polymer of the present invention as the hole transport material of the perovskite solar cell can surprisingly exhibit excellent open voltage and photoelectric conversion efficiency.

According to an aspect of the present invention, the optical band gap (E _g ^opt ) of the polymer containing the repeating unit represented by Chemical Formula 1 may be 2.96 to 3.50 eV, and preferably 2.97 to 3.50 eV. In the case of having the above-described band gap, loss due to light absorption is reduced and a low ionization potential can be secured, so it is preferable to have better photoelectric conversion efficiency based on an improved open voltage.

According to an aspect of the present invention, the number average molecular weight of the polymer comprising the repeating unit represented by Chemical Formula 1 may be 10,000 to 500,000 g/mol, preferably the number average molecular weight 10,000 to 100,000 g/mol, More preferably, it may be 10,000 to 60,000 g/mol. When having the above molecular weight, the perovskite solar cell employing the polymer of the present invention as the hole transport material of the perovskite solar cell is preferable because it can express surprisingly excellent photoelectric conversion efficiency.

According to an aspect of the present invention, the glass transition temperature (T _g ) of the polymer containing the repeating unit represented by Chemical Formula 1 may be 80 to 120° C., but is not limited thereto.

According to an aspect of the present invention, the difference between the ionization potential of the polymer comprising the repeating unit represented by Chemical Formula 1 and the perovskite compound may be 0.02 to 0.4 eV or more. According to one specific aspect, it may be 0.02 to 0.2 eV, and according to one preferred aspect, it may be 0.05 to 0.2 eV or more. When the ionization potential difference is as described above, the hole transport driving force is improved, which improves the photoelectric conversion efficiency and the stability of the solar cell.

According to an aspect of the present invention, the perovskite solar cell

The first electrode,

An electron transport layer formed on the first electrode,

Light absorbing layer comprising a perovskite structure compound formed on the electron transport layer,

It is formed on the light absorbing layer, a hole transport layer comprising a polymer containing a repeating unit represented by the formula (1) and

It may be to include a second electrode formed on the hole transport layer.

Part corresponding to each component of the perovskite solar cell according to an embodiment of the present invention, except for the hole transport layer necessarily includes a phthalocyanine derivative represented by the formula (1) International Patent PCT-KR2014-012727 It may include the contents described in.

Specifically, the first electrode according to an embodiment of the present invention may be any conductive electrode that is ohmic bonded to the electron transport layer, and the second electrode may be any conductive electrode that is ohmic bonded to the hole transport layer.

In addition, the first electrode and the second electrode may be used as long as they are commonly used as electrode materials for the front electrode or the back electrode in a solar cell. Materials of the first electrode and the second electrode are not particularly limited, but according to an aspect of the present invention, when the first electrode and the second electrode are electrode materials of the back electrode, the first electrode and the second electrode are gold. , Silver, platinum, palladium, copper, aluminum, carbon, cobalt sulfide, copper sulfide, nickel oxide, and combinations thereof. Further, according to an aspect of the present invention, when the first electrode and the second electrode are transparent electrodes, the first electrode and the second electrode are fluorine-containing tin oxide (FTO), indium-containing tin oxide (ITO) ; Indium doped Tin Oxide), ZnO, CNT (carbon nanotube), and may be any one or more inorganic conductive electrodes selected from graphene, etc., and may be organic conductive electrodes such as PEDOT:PSS. In order to provide a transparent solar cell according to an aspect of the present invention, it is preferable that the first electrode and the second electrode are transparent electrodes, and when the first electrode and the second electrode are organic conductive electrodes, a flexible solar cell or a transparent solar cell It is more preferable when you want to provide.

The first electrode may be formed by depositing or applying to a rigid or flexible substrate. Deposition may be formed using physical vapor deposition or chemical vapor deposition, and may be formed by thermal evaporation. The coating may be performed by applying a solution of the electrode material or a dispersion of the electrode material to the substrate and then drying, or optionally heat-treating the dried film. However, it goes without saying that the first electrode and the second electrode can be formed using a method used to form a front electrode or a rear electrode in a conventional solar cell.

The electron transport layer formed on the first electrode of the present invention may be an electron conductive organic material layer or an inorganic material layer. The electron-conducting organic material may be an organic material used as an n-type semiconductor in a conventional organic solar cell. As a specific and non-limiting example, the electron conductive organic material is fullerene (C ₆₀ , C ₇₀ , C ₇₄ , C ₇₆ , C ₇₈ , C ₈₂ , C ₉₅ ), PCBM([6,6]-phenyl-C61butyric acid methyl ester )) and fullerene-derivatives including C ₇₁ -PCBM, C ₈₄ -PCBM, PC ₇₀ BM ([6,6]-phenyl C ₇₀ -butyric acid methyl ester), polybenzimidazole (PBI), PTCBI (3,4,9,10-perylenetetracarboxylic bisbenzimidazole), F4-TCNQ (tetra uorotetracyanoquinodimethane), or mixtures thereof. The electron-conducting inorganic material may be an electron-conducting metal oxide used for electron transfer in a conventional quantum dot-based solar cell or a dye-sensitized solar cell. As a specific example, the electron conductive metal oxide may be an n-type metal oxide semiconductor. Non-limiting examples of the n-type metal oxide semiconductor, Ti oxide, Zn oxide, In oxide, Sn oxide, W oxide, Nb oxide, Mo oxide, Mg oxide, Ba oxide, Zr oxide, Sr oxide, Yr oxide, La Oxide, V oxide, Al oxide, Y oxide, Sc oxide, Sm oxide, Ga oxide, In oxide and SrTi oxide may be one or two or more selected materials, mixtures thereof or composites thereof. have.

The light absorbing layer formed on the electron transport layer according to an embodiment of the perovskite solar cell of the present invention includes a compound of perovskite structure, and the compound of perovskite structure is one of ordinary skill in the art of the present invention. Any compound included within the recognized range is possible.

According to an aspect of the present invention, for example, a compound containing a monovalent organic cation, a divalent metal cation, and a halogen anion, and having a perovskite structure.

As a specific example, the compound having the perovskite structure of the present invention may satisfy the following formula (3), formula (4) or formula (5).

(Formula 3)

AMX ₃

In formula (3), A is a monovalent cation, A is an organic ammonium ion, amidinium group ion or organic ammonium ion and amidinium ion, M is a divalent metal ion, and X is a halogen ion to be. In this case, the halogen ion is I ^- may be selected from at least one or both ^-, Br ^-, F ^- and Cl.

(Formula 4)

A(M _{1- a} N _a )X ₃

In the formula (4), A is a monovalent cation, A is an organic ammonium ion, an amidinium group ion or an organic ammonium ion and an amidinium ion, M is a divalent metal ion, and N is a monovalent A doped metal ion selected from one or more of metal ions and trivalent metal ions, a is a real number with 0<a≤0.1, and X is a halogen ion. In this case, the halogen ion is I ^- may be selected from at least one or both ^-, Br ^-, F ^- and Cl.

In the formula (4), the monovalent metal ion, which is a doped metal ion, includes an alkali metal ion. Alkali metal ions may be selected from one or more of Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ and Cs ⁺ ions.

In Chemical Formula 4, the doped metal ion, a trivalent metal ion, is Al ^{3 +} , Ga ^{3 +} , In ^{3 +} , Tl ^{3 +} , Sc ³⁺ , Y ³⁺ , La ^{3 +} , Ce ^{3 +} , Fe ^{3 +} , Ru One or more than ^{3 +} , Cr ^{3 +} , V ³⁺ and Ti ^{3 +} ions may be selected.

As shown in Chemical Formula 4, when the monovalent metal ion and/or the trivalent metal ion are doped, the electrical properties of the perovskite compound may be adjusted to n-type or p-type. In detail, the perovskite compound may have a p-type by doping with a monovalent metal ion. In addition, the perovskite compound may be n-type by doping with a trivalent metal ion. That is, the monovalent metal ion is similar to that of an acceptor doped in a conventional silicon semiconductor, and the trivalent metal ion is similar to that of a donor doped in a conventional silicon semiconductor. At this time, both the monovalent metal ion and the trivalent metal ion may be doped, and of course, the electrical properties of the entire perovskite compound may be controlled by the metal ions of the kind contained in a larger amount.

(Formula 5)

A(N ¹ _{1- b} N ² _b )X ₃

In Formula 5, A is a monovalent cation, A is an organic ammonium ion, amidinium group ion or an organic ammonium ion and an amidinium ion, N ¹ is a monovalent metal ion, and N ² is It is a trivalent metal ion, b is a real number of 0.4≤b≤0.6, and X is a halogen ion.

In Formula 5, the monovalent metal ion includes an alkali metal ion. Alkali metal ions may be selected from one or more of Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ and Cs ⁺ ions.

In Formula 5, the trivalent metal ion is Al ^{3 +} , Ga ^{3 +} , In ^{3 +} , Tl ^{3 +} , Sc ^{3 +} , Y ³⁺ , La ^{3 +} , Ce ^{3 +} , Fe ^{3 +} , Ru ^{3 +} , Cr One or more may be selected from ^{3 +} , V ³⁺ and Ti ^{3 +} ions.

Formula 5 may mean that the divalent metal ion (M) in Formula 3 is replaced by monovalent and trivalent metal ions.

At this time, similar to that described above in Formula 4, by adjusting the relative element ratio of the monovalent metal ion and the trivalent metal ion in the range of 0.4≦b≦0.6, the electrical properties of the perovskite compound according to Formula 3 are n It can be adjusted to type, intrinsic, or p-type.

In Formula 3, Formula 4 or Formula 5, the organic ammonium ion may satisfy the following Formulas 6 to 7.

(Formula 6)

R ₁ -NH ₃ ⁺

In Formula 6, R ₁ is C ₁ -C ₂₄ alkyl, C ₃ -C ₂₀ cycloalkyl or C ₆ -C ₂₀ aryl.

(Formula 7)

R ₂ -C ₃ H ₃ N ₂ ⁺ -R ₃

In Formula 7, R ₂ is C ₁ -C ₂₄ alkyl, C ₃ -C ₂₀ cycloalkyl or C ₆ -C ₂₀ aryl, and R ₃ is hydrogen or C ₁ -C ₂₄ alkyl.

In Chemical Formula 3, Chemical Formula 4 or Chemical Formula 5, the amidinium-based ion may satisfy Chemical Formula 8 below.

(Formula 8)

In the formula (8), R ₄ to R ₈ are, independently of each other, hydrogen, C ₁ -C ₂₄ alkyl, C ₃ -C ₂₀ cycloalkyl or C ₆ -C ₂₀ aryl.

In Chemical Formula 3, Chemical Formula 4 or Chemical Formula 5, A may be an organic ammonium ion, an amidinium group ion, or an organic ammonium ion and an amidinium ion. When both organic ammonium ions and amidinium ions are contained, charge mobility of the perovskite compound can be remarkably improved.

When A contains both organic ammonium ions and amidinium ions, the total number of moles of monovalent organic cations is 1, and it may contain 0.7 to 0.95 amidinium ions and 0.3 to 0.05 organic ammonium ions. have. That is, in Chemical Formula 3, Chemical Formula 4 or Chemical Formula 5, A may be A ^a _(1-x) A ^b _x , wherein A ^a is an amidinium-based ion, A ^b is an organic ammonium ion, and x is It may be a real number from 0.3 to 0.05. The molar ratio between the amidinium ions and the organic ammonium ions, i.e., 0.7 to 0.95 moles of the amidinium ions: 0.3 to 0.05 moles of the organic ammonium ions, is capable of absorbing light in a very wide wavelength band, but is faster exciton exciton), and a range in which faster photoelectron and photo hole movement can be achieved.

R ₁ of Formula 6, R ₂ to R ₃ of Formula 7 or R ₄ to R ₈ of Formula 8 may be appropriately selected according to the use of the perovskite compound.

In detail, the size of the unit cell of the perovskite compound affects the band gap of the perovskite compound. Accordingly, considering the use of a perovskite compound film such as a light emitting layer, a semiconductor layer, a light absorbing layer, and a charge storage layer, R ₁ of Formula 6 and R ₂ to R of Formula 7 so that the application has a suitable band gap. ₃ or R ₄ to R _{8 in} Chemical Formula 8 may be appropriately adjusted, which is a well-known fact for semiconductor device or optical device related workers.

As a specific example, it may have a band gap energy of 1.5 to 1.1 eV suitable for use as a solar cell that absorbs sunlight in a small unit cell size. Accordingly, when considering a band gap energy of 1.5 to 1.1 eV suitable for use as a solar cell, in Formula 6, R ₁ is C1-C24 alkyl, specifically C ₁ -C ₇ alkyl, more specifically methylyl Can be. Further, in the formula (7), R ₂ may be C ₁ -C ₂₄ alkyl, R ₃ may be hydrogen or C ₁ -C ₂₄ alkyl, specifically R ₂ may be C ₁ -C ₇ alkyl and R ₃ Can be hydrogen or C ₁ -C ₇ alkyl, more specifically R ₂ can be methyl and R ₃ can be hydrogen. Further, in the formula (8), R ₄ to R ₈ are independently of each other, hydrogen, amino or C ₁ -C ₂₄ alkyl, specifically hydrogen, amino or C ₁ -C ₇ alkyl, more specifically hydrogen, amino or methylyl R ₄ is hydrogen, amino or methyl, and more specifically R ₅ to R ₈ may be hydrogen. As a specific and non-limiting example, the amidinium-based ion is formamidinium (NH ₂ CH=NH ₂ ⁺ ) ion, acetamidinium (NH ₂ C(CH ₃ )=NH ₂ ⁺ ) Or Guamidinium (NH ₂ C(NH ₂ )=NH ₂ ⁺ ).

As described above, specific examples of the organic cation (A) are examples in consideration of the use of the perovskite compound film, that is, the use of sunlight as a light absorbing layer, design of a wavelength band of light to be absorbed, and light emitting device. When used as a light emitting layer, considering the design of the emission wavelength band, and when using as a semiconductor device of a transistor, considering energy band gap and threshold voltage, R ₁ of Formula 4, R ₂ to R ₃ of Formula 5, or Formula 6 R ₄ ~ R ₈ of can be appropriately selected.

In Formula 3 or Formula 4, M may be a divalent metal ion. As a specific example, M is M is Cu _{2 +} , Ni _{2 +} , Co _{2 +} , Fe _{2 +} , Mn _{2 +} , Cr _{2 +} , Pd _{2 +} , Cd _{2 +} , Ge _{2 +} , Sn _{2 +} , Pb _{2 It} may be one or more metal ions selected from ₊ and Yb _{2 +} .

In Formula 3, Formula 4 or Formula 5, X is a halogen anion. Halogen anion is I ^- may be selected from at least one or both ^-, Br ^-, F ^- and Cl. Specifically, the halogen anion is iodide ion (I ^-) may include a selected one or more, or both the ion, chlorine ion (Cl ^{- -)} and bromide (Br). More specifically, the halogen anion may contain iodine ion and bromine ion. When the halogen anion contains both iodine ion and bromine ion, the crystallinity and moisture resistance of the perovskite compound can be improved.

In a specific embodiment, in Formula 3, Formula 4 or Formula 5, X may be X ^a _(1-y) X ^b _y , X ^a And X ^b are different from each other halogen ions (iodide ion (I ^-), chlorine ion (Cl ^-) and bromide (Br ^-) are different from each other a halogen ion selected from), y is 0 <y be <1 mistakes have. More specifically, in Chemical Formula 3, X may be X ^a _(1-y) X ^b _y , X ^a iodine ion, X ^b is bromine ion, and y is a real number of 0.05≤y≤0.3, specifically 0.1 ≤y≤0.15. That is, in order to significantly prevent deterioration due to moisture and to have excellent crystallinity even at a low temperature process of 100° C. or less, when the halogen anion contains both iodine ion and bromine ion, the total number of moles of the anion is 1, and 0.7 to 0.95. It may contain an iodine ion and a bromine ion of 0.3 to 0.05.

Based on the aforementioned bar, a M by Pb ^{+ 2,} and specifically, for example of a non-limiting perovskite compounds, the perovskite compound is _{CH 3 NH 3 PbI x Cl y} (0≤x≤3 Is real, 0≤y≤3 is real and x+y=3), CH ₃ NH ₃ PbI _x Br _y (real is 0≤x≤3, real is 0≤y≤3 and x+y=3), CH ₃ NH ₃ PbCl _x Br _y (real number with 0≤x≤3, real number with 0≤y≤3 and x+y=3), CH ₃ NH ₃ PbI _x F _y (real number with 0≤x≤3, 0 ≤y≤3 real and x+y=3), NH ₂ CH=NH ₂ PbI _x Cl _y (0≤x≤3 real, 0≤y≤3 real and x+y=3),NH ₂ CH=NH ₂ PbI _x Br _y (real number with 0≤x≤3, real number with 0≤y≤3 and x+y=3), NH ₂ CH=NH ₂ PbCl _x Br _y (real number with 0≤x≤3 , Real number of 0≤y≤3 and x+y=3), NH ₂ CH=NH ₂ PbI _x F _y (real number of 0≤x≤3, real number of 0≤y≤3 and x+y=3), NH ₂ CH=NH _2(1-x) CH ₃ NH _3x Pb(I _(1-y) Br _y ) ₃ (x is a real number with 0<x<1, y is a real number with 0<y<1), NH ₂ CH=NH _2(1-x) CH ₃ NH _3x Pb(I _(1-y) Br _y ) ₃ (x is a real number with 0.05≤x≤0.3, y is a real number with 0.05≤y≤0.3), NH ₂ CH=CH _2(1-x) CH ₃ NH _3x Pb(I _(1-x) Br _x ) ₃ (x is a real number with 0.05≤x≤0.3), NH ₂ C(CH ₃ )=NH ₂ PbI _x Cl _y (real number with 0≤x≤3, real number with 0≤y≤3 and x+y=3), NH ₂ C(CH ₃ )=NH ₂ PbI _x Br _y (real number with 0≤x≤3, 0≤y≤3 real number and x+y=3), NH ₂ C(CH ₃ )=NH ₂ PbCl _x Br _y (0≤x≤3 real number, 0≤y≤3 real number and x+y= 3), NH ₂ C(CH ₃ )=NH ₂ PbI _x F _y (real number with 0≤x≤3, real number with 0≤y≤3 and x+y=3), NH ₂ C(CH ₃ )=NH _2(1-x) CH ₃ NH _3x Pb(I _(1-y) Br _y ) ₃ (x is a real number with 0<x<1, y is 0<y<1 Phosphorus real number), NH ₂ C(CH ₃ )=NH _2(1-x) CH ₃ NH _3x Pb(I _(1-y) Br _y ) ₃ (x is a real number with 0.05≤x≤0.3, y is 0.05 ≤y≤0.3 real number), NH ₂ C(CH ₃ )=CH _2(1-x) CH ₃ NH _3x Pb(I _(1-x) Br _x ) ₃ (x is a real number with 0.05≤x≤0.3) , NH ₂ C(NH ₂ )=NH ₂ PbI _x Cl _y (real number with 0≤x≤3, real number with 0≤y≤3 and x+y=3),NH ₂ C(NH ₂ )=NH ₂ PbI _x Br _y (real number with 0≤x≤3, real number with 0≤y≤3 and x+y=3), NH ₂ C(NH ₂ )=NH ₂ PbCl _x Br _y (real number with 0≤x≤3, Real number of 0≤y≤3 and x+y=3), NH ₂ C(NH ₂ )=NH ₂ PbI _x F _y (real number of 0≤x≤3, real number of 0≤y≤3 and x+y= 3), NH ₂ C(NH ₂ )=NH _{2(1- x)} CH ₃ NH _3x Pb(I _(1-y) Br _y ) ₃ (x is a real number with 0<x<1, y is 0<y<1 real number), NH ₂ C(NH ₂ )=NH _2(1-x) CH ₃ NH _3x Pb(I _(1-y) Br _y ) ₃ (x is a real number with 0.05≤x≤0.3, y is a real number with 0.05≤y≤0.3) or NH ₂ C(NH ₂ )=CH _2(1-x) CH ₃ NH _3x Pb(I _(1-x) Br _x ) ₃ (x is 0.05≤x≤0.3 Mistakes).

Preferably, the light absorbing layer according to an embodiment of the present invention may be a compound of perovskite structure containing lead.

In one particularly preferred embodiment, the perovskite compound is any one or two or more selected from CH ₃ NH ₃ PbI ₃ (methylammonium lead iodide, MAPbI ₃ ) and CH(NH ₂ ) ₂ PbI ₃ (formamidinium lead iodide, FAPbI ₃ ). It can be a mixture. The photoelectric conversion efficiency of the perovskite solar cell is further improved by using a compound having a perovskite structure satisfying this as a light absorber and using a polymer containing a repeating unit represented by Chemical Formula 1 of the present invention as a hole transport material. It can be improved, which is desirable.

According to an aspect of the present invention, the hole transport layer of the perovskite solar cell necessarily includes a polymer including a repeating unit represented by Formula 1 of the present invention.

Specifically, the hole transport layer of the present invention must include a polymer comprising a repeating unit represented by Formula 1 of the present invention as a hole transporting material, and may include it alone, and a repeating unit represented by Formula 1 In addition to the polymer containing the organic hole transport material, it may further include an inorganic hole transport material or a mixture thereof. When the hole transport material is an inorganic hole transport material, the inorganic hole transport material may be an oxide semiconductor, a sulfide semiconductor, a halide semiconductor, or a mixture thereof having a hole conductivity, that is, a p-type semiconductor. Examples of the oxide semiconductor include NiO, CuO, CuAlO ₂ , and CuGaO ₂ , and examples of the sulfide semiconductor include PbS, and examples of the halide semiconductor include PbI ₂ and the like, but are not limited thereto.

When the hole transport material is an organic hole transport material, it may include a single molecule to a high molecular organic hole transport material (hole conducting organic material). The organic hole transport material may be used as long as it is an organic hole transport material used in a conventional inorganic semiconductor-based solar cell using an inorganic semiconductor quantum dot as a dye. Non-limiting examples of single- or low-molecular organic hole transporters, pentacene, coumarin 6, 3-(2-benzothiazolyl)-7-(diethylamino)coumarin), ZnPC (zinc phthalocyanine), CuPC (copper phthalocyanine), TiOPC (titanium oxide phthalocyanine), Spiro-MeOTAD(2,2',7,7'-tetrakis(N,Np-dimethoxyphenylamino)-9,9'-spirobifluorene), F16CuPC(copper(II) 1 ,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadecafluoro-29H,31H-phthalocyanine), SubPc (boron subphthalocyanine chloride) and N3 (cis Substances selected from one or more of -di(thiocyanato)-bis(2,2'-bipyridyl-4,4'-dicarboxylic acid)-ruthenium(II)) may be mentioned, but are not limited thereto. It is not limited by materials.

The photoelectric conversion efficiency is significantly improved by the combination of such perovskite solar cells, and the light stability is excellent, so that the photoelectric conversion efficiency can be maintained for a long time even after a long time.

Specifically, according to an aspect of the present invention, the rate of increase (%) of the photoelectric conversion efficiency of the perovskite solar cell may satisfy Equation 1 below.

[Equation 1]

In the above formula 1,

The PCE _a is a photoelectric conversion efficiency measured by a perovskite solar cell including a hole transport material in which R ₁ and R _{2 in} Chemical Formula 1 are -CH ₃ ,

The PCE _b is a photoelectric conversion efficiency measured by a perovskite solar cell comprising a polymer containing a repeating unit represented by Formula 1 as a hole transport material.

According to an aspect of the present invention, when the polymer of the present invention is employed as a hole transport material of a perovskite solar cell, a polymer in which R ₁ and R ₂ are methyl groups (CH ₃ ) in the repeating unit represented by Formula 1 It is preferable that the photoelectric conversion efficiency is significantly improved compared to that used as a transfer material.

According to an aspect of the present invention, when the polymer of the present invention is employed as a hole transport material of a perovskite solar cell, the photoelectric conversion efficiency may be 21.5% or more. At this time, when R ₁ and R ₂ are provided as a hole transporting material for a methyl group (CH ₃ ) polymer as a hole transporting material of a perovskite solar cell on a conventional repeating carbon represented by Formula 1, the photoelectric conversion efficiency is Less than 21.5%, it has a low photoelectric conversion efficiency compared to the polymer of the present invention.

That is, in the perovskite solar cell, R ₁ and R ₂ in the repeating unit represented by Chemical Formula 1 do not employ a methyl group (CH ₃ ) polymer as a hole transport material, and include a repeating unit represented by Chemical Formula 1 By employing the polymer as the hole transport material of the perovskite solar cell, it is possible to have excellent stability and significantly improved photoelectric conversion efficiency.

At this time, the photoelectric conversion efficiency is based on the one measured at a constant temperature and humidity condition with a sunlight intensity of 1,000 W/m 2, temperature 30° C., and humidity 25%.

The present invention can be carried out in the presence of a nickel-based catalyst and a ligand for the compound represented by the following formula (2) as a method for preparing a polymer that is a hole transport material of the perovskite solar cell.

[Formula 2]

In Chemical Formula 2,

R ₁ and R ₂ are each independently halogen or a C ₁ -C ₁₀ alkyl group, at least one of R ₁ and R ₂ is halogen, and X is halogen, which is different from the halogen of R ₁ and R ₂ .

Specifically,

According to an aspect of the present invention, first, a catalyst complex is prepared by using a nickel catalyst and a ligand under an organic solvent, and then a polymerization compound can be added to the catalyst complex reactant to perform polymerization.

According to an aspect of the present invention, the nickel-based catalyst comprises bis(1,5-cyclooctadiene) nickel(0) [Ni(COD) ₂ ], 1,3-diphenylphosphinopropane nickel(II) chloride [Ni (dppp)Cl ₂ ], 1,2-bis(diphenylphosphino)ethane nickel(II) chloride [Ni(dppe)Cl ₂ ].

According to an aspect of the present invention, the ligand is 2,2-bipyridine, triphenylphosphan, alkyl-2,2-bipyridine, 4,4-di-(5-nonyl)-2,2-bipyridine, 4,4-di-(5-heptyl)-2,2-bipyridine, tris (2-aminoethyl)amine (TREN), N,N,N',N',N"-pentamethyldiethylenetriamine , 1,1,4,7,10,10-hexamethyltriethylenetetraamine and tetramethylethylenediamine.

According to an aspect of the present invention, the organic solvent is dichloromethane, trichloromethane, tetrachloromethane, chlorobenzene, o-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, 1,8-diiodooctane, 1-chloronaphthalene, 1,8-octane-dithiol, anisole, 2,5 -Di-methylanisole, 2,4-dimethylanisole, toluene, o-xylene, m-xylene, p-xylene, xylene mixture of o-, m-, and p-isomers, 1, 2,4-trimethylbenzene, mesitylene cyclohexane, 1-methylnaphthalene, 2-methylnaphthalene, 1,2-dimethylnaphthalene, tetralin, decalin, indane, 1-methyl-4-(1-methyl to Tenyl)-cyclohexene (d-limonene), 6,6-dimethyl-2-methylenebicyclo[3.1.1]heptane (β-pinene), methyl benzoate, ethyl benzoate, nitrobenzene, benzaldehyde, tetra Hydrofuran, 1,4-dioxane, 1,3-dioxane, morpholine, acetone, methylethylketone, ethyl acetate, n-butyl acetate, N,N-dimethylformamide, dimethylacetamide and dimethylsulfoxide It may be any one or more mixed solvents selected from the like, but is not limited thereto.

After performing the polymerization according to an aspect of the present invention, the polymer may be precipitated, purified, and washed to obtain a final polymer, and the precipitation, purification, and washing methods in a conventionally used method are not particularly limited, but preferably fast-release. It can be obtained through soxhlet extraction.

When the polymer is produced by the manufacturing method of the present invention, if the polymer is employed as a hole transport material of a perovskite solar cell, it may have excellent photovoltaic stability and significantly improved photoelectric conversion efficiency.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples. However, the following examples and comparative examples are only examples for explaining the present invention in more detail, and the present invention is not limited by the following examples and comparative examples.

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

In addition, the unit of the additive not specifically described in the specification may be weight%.

[Production Example 1]

1F-PTAA polymer synthesis.

In a nitrogen-substituted round flask, 413 mg of Ni(COD) ₂ , 234 mg of 2,2-bipyridine and 180 μl of 1,5-cyclooctadiene were dissolved in 10 mL of THF, and stirred at room temperature for 30 minutes to activate the catalyst complex. Was prepared. 4-Bromo-N-(4-bromophenyl)-N-(4-fluoro-2-methylphenyl)benzeneamine (4-bromo-N-(4-bromophenyl)-N-(4-fluoro) -2-methylphenyl)benzenamine, 435 mg, 1 mmol was dissolved in 5 mL of THF and then polymerized for 24 hours at 60° C. After completion of the reaction, the catalyst was removed by column chromatography and reprecipitated using THF to polymer. After removing impurities through a Soxhelt device, the obtained polymer was dried in a vacuum oven for 24 hours The number average molecular weight of the obtained polymer was 25,000 g/mol, and the polydispersity index was 1.90.

[Formula 9]

[Production Example 2]

2F-PTAA polymer synthesis.

4-bromo-N-(4-bromophenyl) in place of 4-bromo-N-(4-bromophenyl)-N-(4-fluoro-2-methylphenyl)benzeneamine in Preparation Example 1 It was prepared in the same manner except for using -N-(2,4-difluorophenyl)benzeneamine (4-bromo-N-(4-bromophenyl)-N-(2,4-difluorophenyl)benzenamine). The number average molecular weight of the obtained polymer was 29,700 g/mol, and the polydispersity index was 2.00.

[Formula 10]

[Comparative Production Example 1]

PTAA polymer synthesis.

4-bromo-N-(4-bromophenyl) in place of 4-bromo-N-(4-bromophenyl)-N-(4-fluoro-2-methylphenyl)benzeneamine in Preparation Example 1 It was prepared in the same manner except that -N-(2,4-dimethylphenyl)benzeneamine (4-bromo-N-(4-bromophenyl)-N-(2,4-dimethylphenyl)benzenamine) was used. The obtained polymer had a number average molecular weight of 17,600 g/mol and a polydispersity index of 1.94.

[Formula 11]

[Experimental Example 1]

The optical and thermal properties of the polymers (PTAA) containing repeating units represented by Preparation Examples 1 and 2 and the following Chemical Formula 11 were measured and are shown in Table 1 and FIG. 1 below.

λ _max (nm) E _g ^opt (eV) T _g (℃) T _d (℃) μ _h
(㎠/Vs) PTAA 374 2.95 103.1 507 3.12x10 ^-5 1F-PTAA 372 2.97 95.3 501 2.77x10 ^-5 2F-PTAA 355 3.07 92.1 611 4.33x10 ^-5

As shown in FIG. 1, 1F-PTAA of the comparative example PTAA increased 0.2eV optical band gap, and 2F-PTAA increased 0.12eV optical band gap. In addition, it was confirmed that the peak of the 2F-PTAA in which the optical band gap was significantly increased is a blue-shift of about 20 nm in the light absorption spectrum in FIG. 1(a). It was confirmed through FIG. 1(b) that the glass transition temperature of 1F-PTAA and 2F-PTAA of the present invention was decreased as fluorine was introduced, and as shown in FIG. 1(c), When the 5% decomposition temperature was compared to the initial weight, it was confirmed that the polymer of the present invention was more excellent in thermal stability, and in particular, 2F-PTAA was more excellent in thermal stability.

As shown in Figure 2, the ionization potential of the polymer of the present invention and PTAA was confirmed by photoelectron analysis. The ionization potentials of PTAA, 1F-PTAA and 2F-PTAA appear to be easy with hole-transmitting power, with a difference in ionization conversion from the perovskite compound (FAPbI ₃ ) _0.85 (MAPbBr ₃ ) _{0.15 used.} In the case of 1F-PTAA, it was confirmed that the difference in the band gap in the energy relationship with the perovskite compound was more excellent in hole transport driving force.

[Example 1-2] Preparation of perovskite solar cell

-Preparation of porous TiO ₂ thin film substrate

After cutting a fluorine-containing tin oxide coated glass substrate (FTO; F-doped SnO ₂ , 8 ohms/㎠, Pilkington, hereinafter FTO substrate (first electrode)) to a size of 25 x 25 mm, the end part is etched The FTO was partially removed.

On the cut and partially etched FTO substrate, a 50 nm thick TiO ₂ dense film as a metal oxide thin film was prepared by spray pyrolysis. Spray pyrolysis was performed using a 20 mM titanium diisopropoxide bis (acetylacetonate) solution (Aldrich), and the thickness was controlled by repeating the method of spraying for 3 seconds on a FTO substrate placed on a hot plate maintained at 450° C. and stopping for 10 seconds. Did.

TiO ₂ powder with an average particle size (diameter) of 50 nm (prepared by hydrothermal treatment of a titanium peroxocomplex aqueous solution in which 1% by weight of TiO ₂ is dissolved at 250° C. for 12 hours), ethyl cellulose at 10% by weight Ethyl cellulose solution dissolved in ethyl alcohol, TiO ₂ After adding 5 ml per 1 g of powder and adding 5 g per 1 g of TiO ₂ powder and mixing, ethyl alcohol was removed by distillation under reduced pressure to prepare a TiO ₂ paste.

2-Methoxyethanol was added to the prepared TiO ₂ powder paste to prepare a TiO ₂ slurry for spin coating. TiO _{2 on} FTO substrate On the thin film, coated with a spin coating method using a TiO ₂ slurry for spin coating, heat treated at 500° C. for 60 minutes, immersed in a 30 mM TiCl ₄ aqueous solution at 60° C., and left to stand for 30 minutes, Washed and dried with deionized water and ethanol, and then heat-treated at 500°C for 30 minutes to prepare a porous TiO ₂ thin film (porous electron transporter, thickness; 100 nm).

-Preparation of light absorber solution

PbI ₂ and PbBr dissolved in a mixed solution of NH ₂ CH=NH ₂ I (=FAI) and CH ₃ NH ₃ Br(=MABr) in DMF:DMSO(8:1, v/v) in a 250 mL 2-neck round flask _By mixing in ₂ , a (FAPbI ₃ ) _x (MAPbBr ₃ ) _1-x ( x =0.02 to 0.20) perovskite solution at a concentration of 1.05 M was prepared.

-Manufacture of perovskite light absorbers

Light absorber solution prepared above ((FAPbI ₃ ) _x (MAPbBr ₃ ) _1-x perovskite solution) on the porous TiO ₂ thin film substrate (mp-TiO ₂ /bl-TiO ₂ /FTO) prepared above Was coated at 1000 rpm for 5 seconds, and then coated at 5,000 rpm for 1 second, dried at 150° C. for 10 minutes to prepare a light absorber. Here, in the second spin coating step, 1 mL of diethyl ether was droppedwise onto the substrate.

-Preparation of a hole transport layer solution for forming a hole transport layer

To form a hole transport layer, a polymer prepared in Preparation Example 1 or Preparation Example 2 was dissolved in toluene as a hole transport material to prepare a hole transport layer solution having a concentration of 10 g/L, and 2 μl Li-bis as an additive thereto. (trifluoromethanesulfonyl) imide (Li-TFSI)/acetonitrile (340 mg/1 ml) and 2 μl TBP (4-tert-Butylpyridine) were added to prepare a hole transport layer solution.

-Perovskite solar cell manufacturing

The hole transport layer solution prepared above was spin coated at 3000 rpm for 30 seconds on a composite layer formed with the light absorbing structure prepared above on the porous electrode prepared above to form a hole transport layer.

Subsequently, Au was vacuum-deposited on a high-vacuum (5x10 ^-6 torr or less) thermal evaporator on the top of the hole transport layer to form an Au electrode (second electrode) having a thickness of 70 nm to form Au/1F-PTAA Alternatively, a 2F-PTAA/(FAPbI ₃ ) _x (MAPbBr ₃ ) _1-x /mp-TiO ₂ /bl-TiO ₂ /FTO type solar cell was manufactured.

The active area of this electrode was 0.092 cm ² .

The characteristics of the manufactured solar cell are shown in FIGS. 1 to 4.

[Comparative Example 1]

A perovskite solar cell was manufactured in the same manner as in Example 1, except that the polymer (PTAA) prepared in Comparative Example 1 was used as the hole transport material in Example 1.

Table 2 below shows the device measurement direction of the perovskite solar cell by applying the perovskite compound (FAPbI ₃ ) _0.85 (MAPbBr ₃ ) _0.15 of the photoactive layer (-0.2 V --> 1.5 V and 1.5 V-- > -0.2 V).

J _sc
(mA/cm ² ) Voc
(V) FF
(%) PCE
(%) Example 1 23.4 1.12 79.8 20.9 Example 2 23.2 1.09 75.2 19.0 Comparative Example 1 23.4 1.09 80.0 20.4

As shown in Table 2, the perovskite solar cell of Example 1 employing the polymer prepared in Preparation Example 1 in which the present invention is substituted with fluorine, compared to the comparative example using conventional PTAA that does not contain fluorine As a result, it was found that the photoelectric conversion efficiency was significantly increased. That is, it is understood that the perovskite solar cell of Example 1 of the present invention has a photoelectric conversion efficiency of about 2.3% or higher that is not a level that can be easily derived by those skilled in the art than the perovskite solar cell of Comparative Example 1 Could.

To further clarify this, even when the photoelectric conversion efficiency was measured by applying the perovskite compound as (FAPbI ₃ ) _0.95 (MAPbBr ₃ ) _0.05 as a photoactive layer, it was confirmed that it shows excellent photoelectric conversion efficiency as shown in FIG. 4. Did. On the other hand, when applying PTAA, it was confirmed that it has a lower photoelectric conversion efficiency than the present invention.

In addition, in the case of 2F-PTAA of the present invention, when the perovskite compound having a larger energy potential difference was applied as a photoactive layer, it was confirmed that it has a higher photoelectric conversion efficiency than PTAA.

That is, it was confirmed that even when a perovskite compound having a different energy level is applied as a photoactive layer, it has a high open circuit voltage and excellent photoelectric conversion efficiency.

As described above, in the present invention, the perovskite solar cell, the polymer for perovskite solar cell, and a method for manufacturing the same have been described through specific matters and limited examples, but this is provided to help the overall understanding of the present invention. However, the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains can make various modifications and variations from these descriptions.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and it will be said that not only the claims to be described later, but also all those with equivalent or equivalent modifications to the claims are included in the scope of the spirit of the present invention.

Claims (13)

A perovskite solar cell comprising a polymer comprising a repeating unit represented by Formula 1, wherein the number average molecular weight of the polymer is 10,000 to 500,000 g/mol.
[Formula 1]

In Chemical Formula 1,
R ₁ and R ₂ are each independently halogen or a C ₁ -C ₁₀ alkyl group, and at least one of R ₁ and R ₂ is halogen. According to claim 1,
The R ₁ and R ₂ of Formula 1 are each independently halogen or a C ₁ -C ₃ alkyl group, and one or more of R ₁ and R ₂ are halogen perovskite solar cells. According to claim 1,
R ₁ of Formula 1 is halogen, R ₂ is a halogen or a C ₁ -C ₃ alkyl group perovskite solar cell. According to claim 1,
The formula 1 is a perovskite solar cell is a polymer containing any one repeating unit selected from the repeating unit represented by the following structural formula.
[constitutional formula]

,

According to claim 1,
The polymer comprising the repeating unit represented by Chemical Formula 1 is a perovskite solar cell used as a hole transport material. According to claim 1,
The perovskite solar cell is a perovskite solar cell that the increase rate (%) of the photoelectric conversion efficiency satisfies the following equation 1.
[Equation 1]

In the above formula 1,
The PCE _a is a photoelectric conversion efficiency measured by a perovskite solar cell including a hole transport material in which R ₁ and R _{2 in} Chemical Formula 1 are -CH ₃ ,
The PCE _b is a photoelectric conversion efficiency measured by a perovskite solar cell comprising a polymer containing a repeating unit represented by Chemical Formula 1 as a hole transport material. According to claim 1,
The perovskite solar cell having an energy band gap (E _g ^opt ) of a polymer comprising a repeating unit represented by Chemical Formula 1 is 2.96 to 3.50 eV. delete According to claim 1,
The difference between the ionization potential of the polymer containing the repeating unit represented by Chemical Formula 1 and the perovskite compound is 0.02 to 0.4 eV. According to claim 1,
The perovskite solar cell
The first electrode,
An electron transport layer formed on the first electrode,
Light absorbing layer comprising a perovskite structure compound formed on the electron transport layer,
It is formed on the light absorbing layer, a hole transport layer comprising a polymer containing a repeating unit represented by the formula (1) and
A perovskite solar cell comprising a second electrode formed on the hole transport layer. Preparation of a hole transporting material for a perovskite solar cell by performing a compound represented by the following formula (2) in the presence of a nickel-based catalyst and a ligand to prepare a polymer hole transporting material comprising a repeating unit represented by the following formula (1) Way.
[Formula 1]

[Formula 2]

In Chemical Formula 2,
R ₁ and R ₂ are each independently halogen or a C ₁ -C ₁₀ alkyl group, at least one of R ₁ and R ₂ is halogen, and X is halogen, which is different from the halogen of R ₁ and R ₂ . The method of claim 11,
The nickel-based catalyst is bis(1,5-cyclooctadiene) nickel(0) [Ni(COD) ₂ ], 1,3-diphenylphosphinopropane nickel(II) chloride [Ni(dppp)Cl ₂ ], Method for manufacturing a hole transport material of a perovskite solar cell which is a mixture of any one or two or more selected from 1,2-bis(diphenylphosphino)ethane nickel(II) chloride [Ni(dppe)Cl ₂ ]. The method of claim 11,
The ligand is 2,2-bipyridine, triphenylphosphine, alkyl-2,2-bipyridine, 4,4-di-(5-nonyl)-2,2-bipyridine, 4,4-di-( 5-heptyl)-2,2-bipyridine, tris(2-aminoethyl)amine (TREN), N,N,N',N',N"-pentamethyldiethylenetriamine, 1,1,4, Method for manufacturing a hole transport material of a perovskite solar cell which is a mixture of any one or two or more selected from 7,10,10-hexamethyltriethylenetetraamine and tetramethylethylenediamine.

Images