KR102201894B1 - Method of Stabilizing the Crystal Phase of Amidinium Ion Based Perovskite Compound Layer - Google Patents

Abstract

A method for stabilizing a phase of an amidinium-based perovskite compound film according to the present invention comprises: a step of forming an amidinium-based perovskite compound film including a monovalent amidinium-based ion, a divalent metal ion, and a halogen anion; and a phase stabilization step of applying heat and compressive force to the amidinium-based perovskite compound film through a surface of the amidinium-based perovskite compound film.

Description

Method of Stabilizing the Crystal Phase of Amidinium Ion Based Perovskite Compound Layer

The present invention relates to a method for stabilizing a phase of an amidium-based perovskite compound membrane.

Organometallic halide of perovskite structure, also referred to as organic-inorganic perovskite compound or organometal halide perovskite compound, is an organic cation (A), a metal cation (M), and a halogen anion. It consists of (X) and is a material represented by the formula of AMX ₃ .

Currently, perovskite solar cells using organic/inorganic perovskite compounds as light absorbers are the closest to commercialization among next-generation solar cells including dye-sensitized and organic solar cells, and an efficiency of up to 20% is reported (Korean Patent Publication No. 2014-0035284), and interest in organic/inorganic perovskite compounds is increasing.

Organic-inorganic perovskite compounds, which are currently known to exhibit the best photoelectric conversion efficiency, are based on amidium-based cations. However, the amidium-based cation-based perovskite compound, which exhibits the highest efficiency, exceeds instability to light, heat, and moisture, and above all, phase instability (formation of a δ-phase inactive to light and from α-phase to δ-phase. There is a problem with a phase transition).

In order to solve the phase instability, a technique of mixing a small amount of methyl ammonium or bromine ion with an amidine cation as a stabilizer for stabilizing the α-phase has been proposed, but methyl ammonium is the thermal and moisture stability of the perovskite compound. And bromine ions increase the bandgap energy of the perovskite compound, thereby reducing the photoelectric conversion efficiency.

Republic of Korea Patent Publication No. 2014-0035284

The present invention provides a phase stabilization method capable of stabilizing the phase of an amidium-based perovskite compound film without the aid of a phase stabilizer that lowers heat or light stability and causes an increase in band gap.

The phase stabilization method of the perovskite compound membrane according to the present invention is a phase stabilization method of the amidium-based perovskite compound membrane, and is an amidi comprising monovalent amidium-based ions, divalent metal ions, and halogen anions. Forming a nium-based perovskite compound film; And a phase stabilization step of applying heat and compressive forces to the amidium-based perovskite compound film through the surface of the amidium-based perovskite compound film.

In the phase stabilization method according to an embodiment of the present invention, the amidium-based perovskite compound of the film of an amidium-based perovskite compound may satisfy Formula 1 below.

(Chemical Formula 1)

AMX ₃

A is a monovalent amidinyl you umgye ion, M is a divalent metal ion, X is I ^- is a halogen ion selected from one or more of ^-, Cl ^- and F.

In the phase stabilization method according to an embodiment of the present invention, heat and compressive force in the phase stabilization step may be applied through one surface of the amidium-based perovskite compound film.

In the phase stabilization method according to an embodiment of the present invention, the phase stabilization step may be performed at a temperature of 150° C. to 220° C. and a pressure of 30 to 90 MPa.

The present invention includes a method of manufacturing an amidium-based perovskite solar cell including the phase stabilization step described above.

The method of manufacturing an amidium-based perovskite solar cell according to the present invention includes an amidium-based perovskite stabilized by the above-described phase stabilization method on a first electrode and a first charge carrier formed on the first electrode. Preparing a compound film; And sequentially forming a second charge carrier and a second electrode on the stabilized amidium-based perovskite compound film.

The present invention includes an amidium-based perovskite compound film stabilized by the phase stabilization method described above.

In the amidium-based perovskite compound film according to an embodiment of the present invention, the amidium-based perovskite compound of the film of the amidium-based perovskite compound satisfies the following Formula 1, Cu Kα The δ-phase may not exist on the X-ray diffraction pattern using the ray.

(Chemical Formula 1)

AMX ₃

A is a monovalent amidinyl you umgye ion, M is a divalent metal ion, X is I ^- is a halogen ion selected from one or more of ^-, Cl ^- and F.

The phase stabilization method according to the present invention, without the help of a phase stabilizer added for phase stabilization of the conventional amidium-based perovskite compounds, such as methyl ammonium, bromine, Cs+, etc., is an amidium-based perovskite with heat and compression force. There is an advantage of stabilizing the phase of the skyt compound to the α phase.

1(a) is a diagram showing a GIWAX pattern of an amidinium-based perovskite compound film prepared in Comparative Example 1, and FIG. 1(b) is a phase-stabilized amidi according to an embodiment of the present invention. It is a figure showing the GIWAX pattern of a nium-based perovskite compound film.

Hereinafter, the phase stabilization method of the present invention will be described in detail with reference to the accompanying drawings. The drawings introduced below are provided as examples in order to sufficiently convey the spirit of the present invention to those skilled in the art. Accordingly, the present invention is not limited to the drawings presented below and may be embodied in other forms, and the drawings presented below may be exaggerated to clarify the spirit of the present invention. At this time, unless there are other definitions in the technical terms and scientific terms used, they have the meanings commonly understood by those of ordinary skill in the technical field to which this invention belongs, and the gist of the present invention in the following description and accompanying drawings Descriptions of known functions and configurations that may be unnecessarily obscure will be omitted. In addition, 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. In the present specification and the appended claims, units used without special mention are based on weight, and as an example, the unit of% or ratio means weight% or weight ratio.

In the present invention, an amidinyl you umgye perovskite compound is an organic cation amidinyl nium, and the metal ion is a divalent metal ion, a halogen anion I ^-, Cl ^- and F ^- Fe selected one or more from the lobes It is an organometallic halide of skyt structure.

In the present invention, the amidium-based perovskite compound does not contain an ammonium-based cation such as methylammonium as an organic cation, does not contain monovalent metal ions (inorganic ions) such as Cs ^+, and as a halogen anion, Br ⁻ Does not contain Methylammonium, Cs ⁺ , Br ^- and the like are conventionally known as phase stabilizers for stabilizing the phase of a perovskite compound containing an amidinium cation. That is, in the present invention, the amidium-based perovskite compound does not contain a separate phase stabilizer.

In detail based on the formula, the amidium-based perovskite compound of the present invention satisfies the formula (1).

(Chemical Formula 1)

AMX ₃

A is a monovalent amidinyl you umgye ion, M is a divalent metal ion, X is I ^- is a halogen ion selected from one or more of ^-, Cl ^- and F.

According to the general formula (1), amidinyl you umgye perovskite compounds of the present invention, monovalent amidinyl umgye ion, a metal bivalent ion and I ^- is made from a halogen ion selected one or more of ^-, Cl ^- and F.

The amidinium-based cation may satisfy Formula 2.

(Chemical Formula 2)

In Formula 2, R ₁ to R ₅ are each independently hydrogen, C1-C24 alkyl, C3-C20 cycloalkyl, or C6-C20 aryl.

In Formula 2, R ₁ to R ₅ may be appropriately selected depending on the use of the perovskite compound. In detail, the size of the unit cell of the perovskite compound is related to the band gap, and the small unit cell size may have a band gap energy suitable for use as a solar cell (eg, 1.1 to 1.5V level). Accordingly, when considering a band gap energy suitable for use as a solar cell, R ₁ to R ₅ are independently of each other, hydrogen, amino or C1-C24 alkyl, specifically, hydrogen, amino or C1-C7 alkyl, More specifically, it may be hydrogen, amino or methyl, and even more specifically, R ₁ may be hydrogen, amino or methyl, and R ₂ to R ₅ may be hydrogen. As a practical example, the amidinium-based ion is a formamidinium (formamidinium, NH ₂ CH=NH ₂ ⁺ ) ion, acetamidinium (acetamidinium, NH ₂ C(CH ₃ )=NH ₂ ⁺ ) ion or guamidi Nium (Guamidinium, NH ₂ C (NH ₂ ) = NH ₂ ⁺ ) ions and the like, but are not limited thereto.

Divalent metal ions are Cu ²⁺ , Ni ²⁺ , Co ²⁺ , Fe ²⁺ , Mn ²⁺ , Cr ²⁺ , Pd ²⁺ , Cd ²⁺ , Ge ²⁺ , Sn ²⁺ , Pb ²⁺ , Eu ²⁺ , Yb ²⁺ Or any combination thereof.

Halogen anion is Br ^- may be a halogen anion, except for, as a specific example, I ^-, Cl ^-, F ^-, or combinations thereof, I In other embodiments ^-, Cl ^-, or I in any combination thereof, another embodiment ^- it can be.

As is known, an amidium-based perovskite compound containing an amidium-based ion as an organic cation exhibits the best photoelectric conversion efficiency among various perovskite compounds.

However, the amidinium-based perovskite compound has a problem of phase instability in which a δ phase that is inactive to light is generated as well as an α phase that is active against light.

In order to solve this phase instability, the conventional amidinyl nium-based perovskite compound is methyl ammonium monovalent organic ammonium cations, alkali metal ions such as Cs ^+, such as cationic, Br ^- a stabilizer (α-phase stabilizing agents such as It is common to contain ).

However, these phase stabilizers reduce the stability of the perovskite compound such as thermal stability, moisture stability, and photostability, and increase the bandgap energy. There is a limit.

The applicant of the present invention believes that in order for the perovskite compound to have the best physical properties and properties, an amidium-based perovskite compound consisting of an amidium cation, a divalent metal ion, and a halogen anion is stable without the use of a phase stabilizer. Note that it should be able to maintain the α phase, and as a result of conducting continuous research on this, a method capable of stabilizing the phase of an amidium-based perovskite compound without the aid of a phase stabilizer was found, and the present invention Completed.

The phase stabilization method according to the present invention is an α-phase stabilization method of an amidium-based perovskite compound, which forms a perovskite compound film containing a monovalent amidium-based ion, a divalent metal ion, and a halogen anion. Membrane preparation step; And a phase stabilization step of applying heat and compressive force to the perovskite compound film through the surface of the perovskite compound film.

Specifically, the phase stabilization method according to the present invention comprises the steps of forming an amidium-based perovskite compound film satisfying Formula 1; And a phase stabilization step of applying heat and compressive forces to the amidium-based perovskite compound film through the surface of the amidium-based perovskite compound film.

As described above, in the phase stabilization method according to the present invention, after forming a pure amidium-based perovskite compound film consisting of an amidium-based cation, a divalent metal ion, and a halogen anion excluding Br ^- , amidini By applying heat and compressive force to the amidium-based perovskite compound film through the surface of the um-based perovskite compound film, other phases including δ are not formed and the amidi stabilized in the α-phase A nium-based perovskite compound membrane can be prepared.

At this time, if the film is heated as a whole, or when heat and compressive force are applied through two opposite surfaces of the film opposite to each other instead of one surface, there is a risk that the α-phase stabilization does not occur smoothly. That is, only when heat and a compressive force are simultaneously applied to the film through one surface of the film, a film completely stabilized in the α-phase can be manufactured.

As a specific example, the simultaneous application of heat and compressive force through one surface of the film uses a plate-shaped member having a flat surface and heated to a set temperature, in which the flat surface of the plate-shaped member and the surface of the amidium-based perovskite compound film are in contact. After that, it can be achieved by pressing and compressing the film with a plate-like member.

In one embodiment, the phase stabilization step includes a temperature of 150° C. to 220° C. and a pressure of 30 to 90 MPa, specifically a temperature of 150 to 200° C. and a pressure of 40 to 70 MPa, more specifically a temperature of 160 to 180° C. and It can be carried out at a pressure of 40 to 60 MPa. In particular, the pressure is preferably 90 MPa, preferably 70 MPa, more preferably 60 MPa or less. This is because, when a large compressive force of 100 MPa or more is applied, δ, which is a denser structure than the α-phase, is stabilized, and there is a risk of generating δ. Heat and compressive forces are for a time during which phase stabilization can sufficiently occur, for example, 3 minutes to 60 minutes. It may be applied, but is not limited thereto. During phase stabilization, heat and compressive forces may be applied under the atmosphere or in an inert atmosphere, but are not limited thereto.

In one embodiment, the film preparation step of forming an amidium-based perovskite compound film is a solution (I) in which a perovskite compound satisfying Formula 1 is dissolved in a solvent, or a raw material to satisfy Formula 1 It can be prepared using a conventional solution coating method of applying and drying the solution (II) prepared by weighing an amidium-based halide and a metal (divalent metal) halide and dissolving it in a solvent. At this time, as proposed by the present applicant, using any known method, including the method disclosed by the present applicant, such as a method of sequentially applying a solution (I or II) and a non-solvent of a perovskite compound, etc. It is also possible to prepare a perovskite compound membrane.

The solvent of the solution (I or II) may be any solvent commonly used to prepare a perovskite compound film in a conventional solution coating method. For example, the solvent may be a polar organic solvent, and the polar organic solvent is gamma-butyrolactone, formamide, N,N-dimethylformamide, diformamide, acetonitrile, tetrahydrofuran, dimethylsulfoxide , Diethylene glycol, 1-methyl-2-pyrrolidone, N,N-dimethylacetamide, acetone, α-terpineol, β-terpineol, dihydro terpineol, 2-methoxy ethanol, One or two or more selected from acetylacetone, methanol, ethanol, propanol, butanol, pentanol, hexanol, ketone, methyl isobutyl ketone, etc., but the present invention is not limited by the specific substance of the solvent. The molar concentration of the perovskite compound in the solution (I or II) may be in the range of 0.8 to 1.5M, but is not limited thereto.

Application of a solution (I or II) to form a film is inkjet printing, micro contact printing, imprinting, gravure printing, gravure-offset printing, flexographic printing, offset/reverse offset printing, slot die coating, bar coating, blade It may be performed by coating, spray coating, dip coating, roll coating, spin coating, or the like, but the present invention is not limited by the specific application method.

After application and drying of the solution (I or II), it may further include annealing the obtained film if necessary. Annealing may be performed under a heat treatment condition that is usually performed after producing a perovskite compound film using a conventional solution coating method. For example, annealing may be performed at a temperature of 80 to 150° C. for 5 to 20 minutes, but is not limited thereto.

The thickness of the amidium-based perovskite compound film prepared in the film manufacturing step may be 100 nm to 1 μm, in particular, 200 to 800 nm, but is not limited thereto.

In one embodiment, the amidium-based perovskite compound film to be phase-stabilized may be formed on a planar substrate, and the interface between the amidium-based perovskite compound film and the substrate may be planar. That is, in the amidium-based perovskite compound film, the surface facing the plate-shaped substrate may form an interface in contact with the substrate, and the surface (facing surface) forming the interface in contact with the substrate may be in a flat planar shape. have. If the interface between the substrate and the surface (opposite surface) of the film has a curved shape or has irregularities, α is not stabilized in the interface region between the film and the substrate in the phase stabilization step, and there is a risk that unwanted abnormalities remain in the film. have. Accordingly, it is preferable that the interface between the amidium-based perovskite compound film and the substrate be planar so that the α-phase can be completely stabilized in the thickness direction of the amidium-based perovskite compound film.

The present invention includes a method of manufacturing an amidium-based perovskite solar cell using the stabilization method described above.

In the present invention, an amidium-based perovskite solar cell refers to a solar cell including the above-described amidium-based perovskite compound film as a light absorption layer.

The method of manufacturing a solar cell according to the present invention includes the steps of preparing an amidium-based perovskite compound film stabilized by the above-described phase stabilization method on a first electrode and a first charge carrier formed on the first electrode; And sequentially forming a second charge carrier and a second electrode on the stabilized amidium-based perovskite compound film.

In a specific example, a method of manufacturing a solar cell includes forming a first charge carrier on a substrate on which a first electrode is formed; Preparing a film of an amidium-based perovskite compound stabilized by the above-described phase stabilization method on a first charge carrier; Forming a second charge carrier on the amidium-based perovskite compound film; And forming a second electrode that is a counter electrode of the first electrode on the second charge carrier, but is not limited thereto.

The first charge carrier and the second charge carrier may be charge carriers that transfer complementary charges. For example, when the first charge transfer body is an electron transfer body, the second charge transfer body may be a hole transfer body, and when the first charge transfer body is a hole transfer body, the second charge transfer body may be an electron transfer body.

The electron transporter may be an electron conductive organic material or an electron conductive inorganic material. The electron conductive organic material may be an organic material used as an n-type semiconductor in a typical organic solar cell. As a specific and non-limiting example, the electron conductive organic material is fullerene (C60, C70, C74, C76, C78, C82, C95), PCBM ([6,6]-phenyl-C61butyric acid methyl ester)) and C71-PCBM, Fulleren-derivative containing C84-PCBM, PC ₇₀ BM ([6,6]-phenyl C ₇₀ -butyric acid methyl ester), PBI (polybenzimidazole), PTCBI (3,4,9,10- perylenetetracarboxylic bisbenzimidazole), F4-TCNQ (tetra uorotetracyanoquinodimethane), diimide series (Perylene Diimide (PDI), Naphthalene Diimide.(NDI), Naphthodithiophene Diimide (NDTI))), or a mixture thereof. The electron conductive inorganic material may be an electron conductive metal oxide used for electron transfer in a conventional quantum dot-based solar cell, a dye-sensitized solar cell, or a perovskite-based solar cell. As a specific example, the electron conductive metal oxide may be an n-type metal oxide semiconductor. Non-limiting examples of n-type metal oxide semiconductors include 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 One or two or more materials selected from oxides, V oxides, Al oxides, Y oxides, Sc oxides, Sm oxides, Ga oxides, and SrTi oxides may be mentioned, and a mixture thereof or a composite thereof may be used.

The electron transporter is an electron conductive organic film, a metal oxide thin film, a metal oxide layer having surface irregularities, and a nanostructure (metal oxide particles, nanowires and/or nanotubes) of the same or different types of metal oxides on the surface of one metal oxide in a thin film shape. Including) may be formed of a composite metal oxide layer, a laminate structure in which a metal oxide thin film and a porous metal oxide layer are stacked.

However, as described above, when the electron transporter contacts the perovskite compound film to form an interface when performing the phase stabilization treatment step, the electron transporter can form an interface with the perovskite compound film in a planar form. It is preferable that it is an electron conductive organic material film or a metal oxide thin film.

The electron transporter may be formed through a deposition process such as application of a solution in which an electron-conductive organic material is dissolved, physical vapor deposition or chemical vapor deposition, or coating and heat treatment of metal oxide nanoparticles in consideration of a specific electron transporter material.

The thickness of the electron transporter may be, for example, 50 nm to 10 μm, specifically 50 nm to 5 μm, more specifically 50 nm to 1 μm, and more specifically 50 to 800 nm, but is limited thereto. It does not become.

The hole transporter may be an organic hole transporter, an inorganic hole transporter, or a laminate thereof. The inorganic hole transporter may be an oxide, a sulfide, a halide, a cyanide, or a mixture thereof having hole conductivity. An example of an inorganic hole transporter, such as NiO, CuO, CuAlO ₂ , CuGaO ₂ , PbS, PbI ₂ , carbon, VO _x , MoO _x , WO _x , Cu ₂ O, Cu ₂ ZnSnS ₄ , CuCrO ₂ , CuS, CuSCN, etc. A p-type semiconductor may be mentioned, but the present invention is not limited to the inorganic hole transport material. The inorganic hole transporter may be a porous layer or a dense layer. The dense hole transporter may be a dense film (thin film) of the p-type semiconductor described above, and the porous hole transporter may be a porous film made of particles of the p-type semiconductor.

When the hole transporter includes an organic hole transporter, the organic hole transporter may include an organic hole transport material, specifically, a single molecule or a polymer organic hole transport material (hole conductive organic material). The organic hole transport layer may be performed by applying and drying a solution containing an organic hole transport material (hereinafter, an organic hole transport solution) on the light absorption layer. The solvent used to form the hole transport layer may be a solvent in which an organic hole transport material is dissolved and does not chemically react with the perovskite compound and the material of the electron transport layer. As an example, the solvent used to form the hole transport layer may be a non-polar solvent, and as a practical example, toluene, chloroform, chlorobenzene, dichlorobenzene, anisole ( anisole), xylene, and a hydrocarbon-based solvent having 6 to 14 carbon atoms, but is not limited thereto.

One non-limiting example of a single- or low-molecular organic hole transport material, such as pentacene, coumarin 6, 3-(2-benzothiazolyl)-7-(diethylamino)coumarin), zinc phthalocyanine (ZnPC), 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), Boron subphthalocyanine chloride (SubPc) and N3 (cis -di(thiocyanato)-bis(2,2'-bipyridyl-4,4'-dicarboxylic acid)-ruthenium(II)) may be mentioned, but the material is not limited thereto.

A non-limiting example of a high molecular organic hole transport material, P3HT (poly[3-hexylthiophene]), MDMO-PPV (poly[2-methoxy-5-(3',7'-dimethyloctyloxyl)]-1,4-phenylene vinylene), MEH-PPV(poly[2-methoxy -5-(2''-ethylhexyloxy)-p-phenylene vinylene]), P3OT(poly(3-octyl thiophene)), POT(poly(octyl thiophene)), P3DT(poly(3-decyl thiophene)), P3DDT(poly(3-dodecyl thiophene), PPV(poly(p-phenylene vinylene)), TFB(poly(9,9'-dioctylfluorene-co-N-(4- butylphenyl)diphenyl amine), Polyaniline, Spiro-MeOTAD ([2,22′,7,77′-tetrkis (N,N-di-p-methoxyphenyl amine)-9,9,9′-spirobi fluorine]), PCPDTBT (Poly[2,1,3-benzothiadiazole- 4,7-diyl[4,4-bis(2-ethylhexyl-4H- cyclopenta [2,1-b:3,4-b']dithiophene-2,6- diyl]], Si-PCPDTBT(poly[(4,4′-bis(2-ethylhexyl)dithieno[3,2-b:2′,3′-d]silole)-2,6-diyl-alt-( 2,1,3-benzothiadiazole)-4,7-diyl]), PBDTTPD(poly((4,8-diethylhexyloxyl) benzo([1,2-b:4,5-b']dithiophene)-2,6 -diyl)-alt-((5-octylthieno[3,4-c]pyrrole-4,6-dione)-1,3-diyl)), PFDTBT(poly[2,7-(9-(2-ethylhexyl) )-9-hexyl-fluorene)-alt-5,5-(4', 7, -di-2-thienyl-2',1' , 3'-benzothiadiazole)]), PFO-DBT(poly[2,7-.9,9-(dioctyl-fluorene)-alt-5,5-(4',7'-di-2-.thienyl- 2', 1', 3'-benzothiadiazole)]), PSiFDTBT(poly[(2,7-dioctylsilafluorene)-2,7-diyl-alt-(4,7-bis(2-thienyl)-2,1, 3-benzothiadiazole)-5,5′-diyl]), PSBTBT(poly[(4,4′-bis(2-ethylhexyl)dithieno[3,2-b:2′,3′-d]silole)-2 ,6-diyl-alt-(2,1,3-benzothiadiazole)-4,7-diyl]), PCDTBT(Poly [[9-(1-octylnonyl)-9H-carbazole-2,7-diyl] -2 ,5-thiophenediyl -2,1,3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl]), PFB (poly(9,9′-dioctylfluorene-co-bis(N,N′-(4, butylphenyl))bis(N,N′-phenyl-1,4-phenylene)diamine), F8BT(poly(9,9′-dioctylfluorene-co-benzothiadiazole), PEDOT (poly(3,4-ethylenedioxythiophene))), PEDOT :PSS (poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate)), PTAA (poly(triarylamine)), poly(4-butylphenyl-diphenyl-amine), and one or more selected materials from their copolymers. However, it is not limited thereto.

The hole transport layer is TBP (tertiary butyl pyridine), LiTFSI (Lithium Bis (Trifluoro methanesulfonyl) Imide), HTFSI (bis (trifluoromethane) sulfonimide), 2,6-lutidine and Tris(2-(1H-pyrazol-1-yl) Of course, it may further contain known additives such as pyridine) cobalt (III).

However, as described above, when the hole transporter contacts the perovskite compound film to form an interface when performing the phase stabilization treatment step, the hole transporter may form an interface with the perovskite compound film in a planar form. It is preferable that it is an organic hole transport material film or a p-type semiconductor thin film.

The thickness of the hole transport body may be 50 nm to 10 μm, specifically 10 nm to 1000 nm, and more specifically 10 nm to 500 nm, but is not limited thereto.

Each of the first electrode and the second electrode may be a material commonly used as an electrode in perovskite solar cells, and may be manufactured using a conventional method. For example, the first electrode and the second electrode may be manufactured through a physical vapor deposition method such as thermal evaporation or sputtering, a chemical vapor deposition method, or coating a slurry containing a conductive material such as silver nanowires or CNTs, respectively. .

When the first electrode is a transparent electrode, the first electrode may be a transparent conductive electrode that is ohmic-bonded with the electron carrier. As a specific example, the first electrode, which is a transparent electrode, includes fluorine doped tin oxide (FTO), indium doped tin oxide (ITO), ZnO, carbon nanotube, graphene ( graphene) and composites thereof. The second electrode may be a transparent or opaque electrode independently from the first electrode, and in the case of a transparent electrode, it may be a transparent conductive electrode that is ohmic-bonded with the hole transporter. When the second electrode is an opaque electrode, the second electrode may include any one or two or more materials selected from gold, silver, platinum, palladium, copper, aluminum, carbon, cobalt sulfide, copper sulfide, nickel oxide, and a composite thereof. However, it is not limited thereto.

At this time, the substrate on which the first electrode is located may be a rigid transparent substrate (support) or a flexible transparent substrate (support), and the first electrode is physical vapor deposition or chemical vapor deposition on the substrate. It may be formed through a vapor deposition process such as (chemical vapor deposition), and specifically, may be formed by thermal evaporation. As an example of a transparent substrate (support), a hard substrate such as a glass substrate, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polycarbonate (PC), polypropylene (PP), triacetyl A flexible substrate such as cellulose (TAC) or polyethersulfone (PES) may be mentioned, but the present invention is of course not limited to the specific material of the substrate.

The present invention includes an amidium-based perovskite compound film stabilized by the phase stabilization method described above.

The amidium-based perovskite compound film according to the present invention may be a film of the perovskite compound according to Formula 1, and there is no more phase including the δ-phase on the X-ray diffraction pattern using Cu Kα rays. That is, it may be a perovskite compound film in which only the α phase is present on the X-ray diffraction pattern using Cu Kα rays.

(Chemical Formula 1)

AMX ₃

A is a monovalent amidinyl you umgye ion, M is a divalent metal ion, X is I ^- is a halogen ion selected from one or more of ^-, Cl ^- and F.

The present invention includes an amidium-based perovskite solar cell including an amidium-based perovskite compound film stabilized by the above-described phase stabilization method as a light absorbing layer.

(Example 1)

A 200 nm-thick TiO ₂ thin film was formed on an FTO substrate (a glass substrate coated with fluorine-containing tin oxide, FTO; F-doped SnO ₂ , 8 ohms/cm ² , Pilkington) and used as a substrate.

NN-dimethylformamide (DMF): formamidinium iodide (formamidinium = FA, formamidinium) in a mixed solvent in which dimethyl sulfoxide (DMSO) is mixed in a volume ratio of 8: 1 Iodide = FAI) and PbI ₂ were dissolved in a 1:1 molar ratio to prepare a solution of 1.2M concentration based on FAPbI ₃ .

The FAPbI ₃ solution prepared on the TiO ₂ thin film was spin-coated at 1000 rpm for 5 seconds and 5000 rpm for 20 seconds, but 1 ml of diethyl ether was injected 17 seconds after the start of coating during the spin coating of the FAPbI ₃ solution. After the spin coating was completed, the obtained film was dried and annealed at 150 DEG C for 30 minutes in a nitrogen atmosphere to prepare an amidium-based perovskite compound film.

Thereafter, the surface of the prepared amidium-based perovskite compound film was subjected to a phase stabilization treatment by pressing for 20 minutes with a metal plate-shaped member capable of controlling the temperature. During phase stabilization, the temperature of the metal plate member was 170°C, and the compressive force applied to the film was 50 MPa.

After the phase stabilization treatment was performed, the organic hole transport solution was spin-coated on the stabilized amidium-based perovskite compound film at 2000 rpm for 30 seconds to form an organic hole transport layer. At this time, the organic hole transport solution was added to Chlorobenzene so that Spiro-OMeTAD was 100 mg/1.1 ml, and 23 μl of Li-TFSI (Li-bis(trifluoromethanesulfonyl)imide) acetonitrile solution (540 mg/ml), 10 μl of tris(2-(1H-pyrazol-1-yl)-4-tert-butylpyridine)cobalt(III) tri[bis(trifluoromethane)sulfonimide] acetonitrile solution (376 mg/ml), and 39 μl of t BP (4 -tert-butylpyridine) was prepared by mixing.

Thereafter, an Au electrode (70 nm thick) was formed on the organic hole transport layer using a thermal evaporator to manufacture an amidium-based perovskite solar cell.

(Comparative Example 1)

Except that the amidium-based perovskite compound film prepared in Example 1 was not subjected to a phase stabilization treatment, and the hole transport layer was directly formed on the annealed amidium-based perovskite compound film, Similarly, an amidine perovskite solar cell was manufactured.

The characteristics of the manufactured solar cell are 100mW/cm ² (1 SUN) standard using a solar simulator (Newport Oriel Class A 91195A) using a Keithley 2420 source meter and a 450W Xe-lamp equipped with an AM 1.5 G filter. Measured under. Current density versus voltage (JV) was measured with a 10mV step in the range of 0V to 1.5V and a scan rate of 10 ms with a delay time.

Figure 1 (a) is a view showing a grazing incidence wide angle X-ray scattering (GIWAXS; Grazing Incidence Wide Angle X-ray Scattering) pattern of the FaPbI ₃ film prepared in Comparative Example, Figure 1 (b) is a This is a diagram showing the GIWAXS pattern of the phase-stabilized FAPbI ₃ film. As can be seen from FIG. 1, it can be seen that an intact α-phase FAPbI ₃ film in which no other abnormalities including δ phases were formed without addition of a phase stabilizer was prepared. On the other hand, in the case of Comparative Example 1, as is known, it can be seen that the FAPbI ₃ film in which the α phase and the δ phase coexist was prepared.

As a result of measuring the photoelectric conversion efficiency of the solar cells prepared in Example 1 and Comparative Example 1, in the case of Comparative Example 1, the photoelectric conversion efficiency was only 10% due to the δ phase inactive to light, but in the case of Example 1 20 It was confirmed that it has a very high photoelectric conversion efficiency above %.

In order to check the stabilized α phase retention ability, light was continuously irradiated under the condition of 1 SUN and the photoelectric conversion efficiency was measured over time. As a result, the photoelectric conversion efficiency did not deteriorate even at the time of continuous irradiation for 10 hours, and immediately after manufacture. It was confirmed that the efficiency of was maintained as it was.

As described above, the present invention has been described by specific matters and limited embodiments and drawings, but this is provided only to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments, and the present invention is Those of ordinary skill in the relevant field can make various modifications and variations from this description.

Therefore, the spirit of the present invention is limited to the described embodiments and should not be defined, and all things that are equivalent or equivalent to the claims as well as the claims to be described later fall within the scope of the spirit of the present invention. .

Claims (7)

A stabilizer comprising ^a-described phase perovskite with agent compound is coated with a dissolved solution of a perovskite, but the compound film is formed, ammonium cation, a monovalent metal ion and a Br containing Cs ^+, including methyl ammonium Forming a film of an amidium-based perovskite compound that does not contain a monovalent amidium-based ion, a divalent metal ion, and a halogen anion excluding Br ⁻ ; And
Using a plate-shaped member heated to a set temperature, the plate-shaped member and the surface of the amidium-based perovskite compound film are brought into contact, and then the amidium-based perovskite compound film is pressed and compressed with the plate-shaped member. By applying heat and compressive force at a temperature of 160 to 180°C and a pressure of 40 to 60 MPa to the amidium-based perovskite compound film through the surface of the medium-based perovskite compound film, X using Cu Kα ray -A phase stabilization step of preparing a phase-stabilized amidium-based perovskite compound film in which the δ-phase on the line diffraction pattern does not exist;
A method for stabilizing the phase of an amidium-based perovskite compound film comprising a. The method of claim 1,
The amidium-based perovskite compound of the amidium-based perovskite compound film is a phase stabilization method of an amidium-based perovskite compound film satisfying the following formula (1).
(Chemical Formula 1)
AMX ₃
(A is a monovalent amidinyl you umgye ion, M is a divalent metal ion, X is I ^-, Cl ^- and F ^- is a halogen ion selected from one or more) The method of claim 2,
The heat and compressive force in the phase stabilization step is applied through one surface of the amidium-based perovskite compound film. delete Using the first electrode and the first charge transfer body formed on the first electrode as a substrate, on the first charge transfer body, the amidium-based pen stabilized by the phase stabilization method according to any one of claims 1 to 3 Preparing a Lobskyite compound membrane; And
A method of manufacturing an amidium-based perovskite solar cell comprising: sequentially forming a second charge carrier and a second electrode on the stabilized amidium-based perovskite compound film. Amidium-based perovskite compound membrane stabilized by the phase stabilization method according to any one of claims 1 to 3. The method of claim 6,
The amidium-based perovskite compound of the amidium-based perovskite compound film satisfies the following formula (1), and the δ-phase does not exist in the X-ray diffraction pattern using Cu Kα rays. Lobskyite compound membrane.
(Chemical Formula 1)
AMX ₃
(A is a monovalent amidinyl you umgye ion, M is a divalent metal ion, X is I ^-, Cl ^- and F ^- is a halogen ion selected from one or more)

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