KR20180053122A - Fabrication Method of Perovskite Solar Cell - Google Patents

Abstract

The present invention provides a method for manufacturing a large-area perovskite-based solar cell able to be modularized with a cheap and simple process. The manufacturing method of an organometallic halide film of a perovskite structure according to the present invention comprises: a step (a) of applying a first solution containing a metal halide complex on a substrate; and a step (b) of pressurizing and spraying a second solution containing an organic halide to the first solution applied to the substrate, and drying the solution.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a fabrication method of a perovskite solar cell,

The present invention relates to a process for producing a perovskite solar cell containing an organometallic halide having a perovskite structure as a light absorber and more particularly to a process for producing a perovskite solar cell which has a very uniform thickness And a perovskite organic halide film having excellent crystallinity and capable of producing a large area while maintaining high efficiency.

The human life has been enriched by the technological development, but the continuous use of energy has increased the concentration of carbon dioxide, which has caused the Earth to be challenged by another human being called climate change. To cope with climate change, humankind is gradually expanding renewable energy that is environmentally friendly but also reduces carbon dioxide. There are currently 11 types of renewable energy, and the most efficient is known to be wind and solar. The dual solar cell converts solar light into electric energy, which is typical of solar cells made of silicon. To date, the best known efficiency of solar cells is more than 25%, accounting for more than 80% of the total market. However, silicon solar cells, which are referred to as first generation solar cells, are manufactured with ultrahigh purity silicon wafers, which are the most disadvantageous in that the manufacturing equipment is very expensive and the process is complicated, resulting in a very high manufacturing cost. In the case of Korea, the production unit price is 0.6-0.7 $ / Wp per cell, and it is still a limit to reach the grid parity which is the balance point where the renewable energy generation unit price becomes equal to the existing fossil energy generation unit price. Though the second-generation solar cell represented by the thin-film solar cell is advantageous in that it can be bent or applied to various products, it has a manufacturing cost similar to that of the first-generation silicon solar cell, It is true. The third-generation solar cell developed to overcome this is Dye-Sensitized Solar Cell (DSSC) or Organic Photovoltaic (OPV). A fundamental approach to this approach is to reduce manufacturing costs. For example, in the case of dye-sensitized solar cell or organic solar cell, it is possible to lower the cell manufacturing cost to less than 0.5 $ / Wp. However, the dye-sensitized solar cell maintains the world's best record light conversion efficiency of 13%, and the organic solar cell has an 11% efficiency. I can not. In addition, in the case of the dye-sensitized solar cell, the cell stability due to the leakage of the liquid electrolyte acts as the biggest obstacle, and it can be said that it is frustrated at the last stage of practical use. In the case of organic solar cells, the thin film and the advantage of bending can be said to be excellent. However, since the efficiency is reduced when exposed to oxygen, encapsulation is more costly than the manufacturing cost, and commercialization is possible. It can be said that it is not able to approach. However, with the advent of perovskite solar cells that use organometallic halides with interstitial perovskite structure as light absorbers within the last five years, solar cell technology is approaching a new era. Perovskite solar cells show 20% photoconversion efficiency through optimization of structure (Korean Patent Laid-Open No. 2014-0035284), and up to 25% corresponding to silicon solar cell in the next 2-3 years Is expected to be possible. In addition, it has a high light absorptivity capable of absorbing 90% or more of the sunlight even with a photoactive layer of about 400 to 500 nm, and can be made thin to make a solar cell capable of being flexible, It is possible to control the band-gap by controlling the metal ions, and the tandem structure with other types of solar cells is easy, so that the application possibility is very high. Another important point is that it is possible to manufacture high-efficiency solar cells even in the atmosphere of oxygen different from organic solar cells, and it is possible to lower the manufacturing cost dramatically compared to other solar cells .

However, perovskite, and if the solar cell is not yet high enough to maturity of the technology, even if the world record is 0.1cm ² it shows the efficiency of the unit cell size of the area, even if you enlarge the size of about 1cm ² The efficiency is remarkably reduced. The problem of rapidly decreasing the efficiency in the large area required for modularization is a first and foremost problem to be solved for the commercialization of the perovskite solar cell.

Korean Patent Publication No. 2014-0035284

It is an object of the present invention to provide a method of manufacturing a perovskite solar cell having a large area that can be modularized in a simple and inexpensive process and is capable of preventing defects such as pinholes from being formed and forming a high quality organic And a method of manufacturing a solar cell provided with a metal halide film (photoactive layer).

A method of manufacturing a perovskite solar cell according to the present invention comprises the steps of: a) forming a metal layer on a first charge carrier of a substrate on which a substrate, a transparent electrode, and a first charge carrier are sequentially laminated, using a slot- Sequentially applying a first solution containing a halide and a second solution containing an organic halide and then drying the solution to form a photoactive layer which is an organic metal halide film of perovskite structure; And b) sequentially forming a second charge carrier and a counter electrode of the transparent electrode over the photoactive layer.

In the method of manufacturing a solar cell according to an embodiment of the present invention, in the step a), the first solution forms a complex with a metal halide and a metal halide, and is a complex solvent which is a solvent dissolving a metal halide ≪ / RTI >

In the method of manufacturing a solar cell according to an embodiment of the present invention, the step a) includes the steps of a1) applying a first solution on the first charge carrier using a slot die, and drying the first solution; And a2) coating the second solution on the coated film of step a1) using a slot die, followed by drying.

In the method of manufacturing a solar cell according to an embodiment of the present invention, the step a) includes: applying a first solution on the first charge carrier using a slot die; Applying the second solution to the first solution coated on the carrier and then drying the coated solution.

In the method of manufacturing a solar cell according to an embodiment of the present invention, when the first solution is applied and the second solution is applied, the moving speed of the slot die may be independently 5 mm / sec or less.

In the method of manufacturing a solar cell according to an embodiment of the present invention, the first charge carrier may be a multilayer film including a dense film positioned on the transparent electrode layer side and a porous film located on the dense film.

In the method of manufacturing a solar cell according to an embodiment of the present invention, the porous film includes metal oxide particles, and may have an open pore structure by an empty space between metal oxide particles.

 In the method of manufacturing a solar cell according to an embodiment of the present invention, the second charge carrier may be a hole-conducting organic material.

In the method for manufacturing a solar cell according to an embodiment of the present invention, it is preferable that, in the step (a), the organic layer having a UN of not more than 5 A metal halide film can be produced.

(Relational expression 1)

In the relation 1, Tave means the average thickness of the organometallic halide film, T means the thickness of the organometallic halide film in the measurement area, T (i) means the measurement in the random measurement area of the organometallic halide film (N) is the thickness of the organometallic halide film, i is the thickness measured in the i-th random measurement region, i is the number of measurements (1 to n) The thickness of the coating film is a natural number of 10 to 50 in terms of the total number of thickness measurements.

(Relational expression 2)

In relation 2, T _ave , n, T (i) are the same as in the relational expression 1.

A method of manufacturing a solar cell according to the present invention is a method of manufacturing a photoactive layer by applying a metal halide solution and an organic halide solution by using a slot die and drying the same to obtain a uniform thickness with a uniform thickness over a large area of 20 mm x 20 mm There is an advantage that a photoactive layer having excellent crystallinity can be produced and a perovskite solar cell with a large area that can be modularized can be mass produced in a short time by a very simple and low cost method of coating and drying using a slot die.

FIG. 1 is a process diagram showing a manufacturing process of a photoactive layer in a method of manufacturing a solar cell according to an embodiment of the present invention,
FIG. 2 is another process drawing showing a manufacturing process of a photoactive layer in a method of manufacturing a solar cell according to an embodiment of the present invention,
3 is a scanning electron micrograph (FIG. 3 (a)) and an X-ray diffraction analysis result (FIG. 3 (b)) of the surface of the photoactive layer prepared in Example 1,
4 is a scanning electron micrograph (FIG. 4 (a)) and an X-ray diffraction analysis result (FIG. 4 (b)) of the surface of the photoactive layer prepared in Example 2,
5 is a scanning electron micrograph (FIG. 5 (a)) and an X-ray diffraction analysis result (FIG. 5 (b)) of the surface of the photoactive layer prepared in Example 3,
6 is a scanning electron micrograph (FIG. 6 (a)) and an X-ray diffraction analysis result (FIG. 6 (b)) of the surface of the photoactive layer prepared in Comparative Example 1,
7 is an optical photograph of the photoactive layer prepared in Example 3,
8 is a diagram showing measurement of photoelectric conversion characteristics of the solar cell manufactured in Example 1, Example 2, Example 3, and Comparative Example 1. FIG.

Hereinafter, a method of manufacturing a solar cell according to the present invention will be described in detail with reference to the accompanying drawings. The following drawings are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the following drawings, but may be embodied in other forms, and the following drawings may be exaggerated in order to clarify the spirit of the present invention. Hereinafter, the technical and scientific terms used herein will be understood by those skilled in the art without departing from the scope of the present invention. Descriptions of known functions and configurations that may be unnecessarily blurred are omitted.

As is known, an organic metal halide having a perovskite structure (hereinafter, perovskite organic metal halide) can be spontaneously crystallized by a simple process in which a solution in which only an organometallic halide is dissolved is applied and then dried Do. However, such a spontaneous crystallization makes it possible to manufacture an organic metal halide film by a simple process of applying a solution, whereas when a large-area film is manufactured or mass-produced, the crystallization process can not be controlled, .

The present applicant has proposed a perovskite-type organic metal halide film-based device, such as a perovskite solar cell, which is a major obstacle to be commercialized, As a result of efforts made to develop a technique for manufacturing a metal halide film by a simple and simple process, it has been found that the film quality produced by the coating method of the liquid for producing the perovskite organic metal halide film is greatly different It has been found that the flow of the applied liquid on the substrate should be suppressed as much as possible in order to produce a high-quality film having a uniform thickness even on a large area, preventing generation of defects such as pinholes, and having crystal grains having a great and excellent crystallinity . As a result of deepening the research based on these findings, it has been found that when a liquid containing a metal halide and a liquid containing an organic halide are successively applied using a slot-die, the flow of the liquid is suppressed to the minimum, And it has been confirmed that a high-quality film can be produced even in a large area of 20 mm x 20 mm or more. Thus, the present invention has been filed.

Based on the above discovery, a method of manufacturing a perovskite solar cell according to the present invention comprises the steps of: a) forming a first electrode on a first charge carrier of a substrate on which a substrate, a transparent electrode and a first charge carrier are sequentially stacked, a first solution containing a metal halide and a second solution containing an organic halide are successively applied and dried to form a photoactive layer which is an organic metal halide film of perovskite structure step; And b) sequentially forming a second charge carrier and a counter electrode of the transparent electrode over the photoactive layer.

The substrate may be a rigid substrate or a flexible substrate, and any material having light transmittance may be used. As a specific example, the substrate may be glass, silicon, polystyrene, polyethylene terephthalate (PET), polyethersulfone (PES), polycarbonate (PC), polyethylene naphthalate (PEN), polyimide (PI) It goes without saying that the present invention can not be limited by the material of the substrate.

For example, the transparent electrode may be a transparent conductive material. For example, the transparent electrode may be a F-doped tin oxide (FTO), a zinc oxide (ZnO), a tin oxide (SnO ₂ ), an indium tin oxide (ITO, In ₂ O ₃ : Sn) cadmium stannte (CTO, Cd ₂ SnO _4), alumium zinc oxide (AZO, ZnO: Al), ITO, AZO, IMO, CTO, and the like, the above-mentioned transparent conductive material layer and Cu, a laminated multi-layer metal layers such as Al Structure.

The first charge carrier and the second charge carrier provide a transfer path of charge complementary to each other. If the first charge carrier is an electron transfer, the second charge carrier may be a hole carrier, In the case of hole transport, the second charge carrier may be an electron carrier. Hereinafter, a method of manufacturing a perovskite solar cell according to an embodiment of the present invention will be described based on the case where the first charge carrier is an electron transfer.

The electron transporting material can be used as long as it is an organic or inorganic material capable of electron transfer. Preferably, the electron carrier may comprise a porous membrane with open pores, which enhances the contact area with the light absorber (perovskite organometallic halide) and facilitates the transfer of electrons with ease It is advantageous. The porous membrane of the electron carrier may comprise metal oxide particles and / or metal oxide rods and may have an open porous structure by the voids between particles and / or rods. The metal oxide of the porous film may be at least one selected from the group consisting of Ti oxide, Sn oxide, Zn oxide, In oxide, Nb oxide, W oxide, Mo oxide, Mg oxide, Zr oxide, Ba oxide, Yr oxide, Sr oxide, La oxide, Y oxide, Sm oxide, Sc oxide, In oxide, Ga oxide and SrTi oxide, or a mixture thereof at a certain ratio thereof, or a composite thereof. The porous film of the electron carrier may be prepared by applying a slurry containing metal oxide particles and / or metal oxide rods and then heat-treating the slurry. Application of the slurry may be performed by, but not limited to, screen printing, spin coating, bar coating, gravure coating, doctor blade, roll coating and the like. The thickness of the porous film of the electron transporting material may be 50 nm to 10 μm, specifically, 50 nm to 1 μm, but is not limited thereto.

And a dense film located under the electron transporting porous film. That is, the electron transporting material may be a multilayer film structure including a dense film located on the transparent electrode layer side and a porous film located on the dense film. The dense film prevents the contact between the transparent electrode and the light absorber embedded in the porous film, and enables easy electron transfer. The dense film of the electron transporting material may be an organic material or an inorganic material capable of moving electrons independently of the porous film. As a specific example, the dense film of the electron transporting material may include Ti oxide, Sn oxide, Zn oxide, In oxide, Nb oxide, W oxide, Mo oxide, Mg oxide, Zr oxide, Ba oxide, Yr oxide, Sr oxide, La oxide, , Al oxide, Y oxide, Sm oxide, Sc oxide, In oxide, Ga oxide and SrTi oxide, a mixture thereof, and a combination thereof. The dense film of the electron carrier may be formed through conventional physical / chemical vapor deposition or pyrolysis, and may be 5-20 nm thick, but is not limited thereto.

The first solution may contain a metal halide. In this case, the first solution may contain a complex solvent which forms a complex with the metal halide and the metal halide and is a solvent which dissolves the metal halide. In this case, the first solution may be interpreted as containing a metal halide complex .

Specifically, the first solution may contain a metal halide satisfying the following formula (1).

(Formula 1)

MX ₂

In the formula (1), M is a divalent metal ion, and Mg ²⁺ , Cu ²⁺ , Mo ²⁺ , Ba ²⁺ , Si ²⁺ , Zn ²⁺ , Tc ²⁺ , Hf ²⁺ , Ca ²⁺ , Ga ^{2 +} , Ru ²⁺ , Ta ²⁺ , Ti ²⁺ , As ²⁺ , Pb ²⁺ , Re ²⁺ , Cr ²⁺ , Se ²⁺ , Ag ²⁺ , Os ²⁺ , Mn ²⁺ , Sr ²⁺ , Cd ²⁺ , Ir ²⁺ , Fe ²⁺ , Y ²⁺ , In ²⁺ , Pt ²⁺ , Co ²⁺ , Zr ²⁺ , Sn ²⁺ , Au ²⁺ , Ni ²⁺ , Nb ²⁺ and Te ^{2 +} may be one or more than one metal ion selected from, X is Cl ^- may be one or more than one halide ion is selected from ^-, Br ^-, I ^- and F.

In this case, the solvent of the first solution may be any solvent which dissolves the metal halide, and specific examples thereof include a non-aqueous polar organic solvent. As a practical example, the solvent of the first solution may be selected from the group consisting of gamma-butyrolactone, formamide, N, N- dimethylformamide, diformamide, acetonitrile, tetrahydrofuran, dimethylsulfoxide, Methyl-2-pyrrolidone, N, N-dimethylacetamide, acetone,? -Terpineol,? -Terpineol, dihydrotopeenol, 2-methoxyethanol, acetylacetone, methanol, ethanol , Propanol, butanol, pentanol, hexanol, ketone and methyl isobutyl ketone, and the like. The first solution may contain, but is not limited to, metal halides of 0.8 to 1.3 M (mol / L).

When the first solution contains a metal halide complex, the metal halide complex may be a compound between a metal halide and a solvent that dissolves the metal halide. If the first solution contains a metal halide complex, it is advantageous to be able to convert to perovskite organometallic halides at lower temperatures.

The metal halide complex may satisfy the following general formula (2).

(2)

MX ₂ -Y (solvent)

In the formula (1), M is a divalent metal ion, and Mg ²⁺ , Cu ²⁺ , Mo ²⁺ , Ba ²⁺ , Si ²⁺ , Zn ²⁺ , Tc ²⁺ , Hf ²⁺ , Ca ²⁺ , Ga ^{2 +} , Ru ²⁺ , Ta ²⁺ , Ti ²⁺ , As ²⁺ , Pb ²⁺ , Re ²⁺ , Cr ²⁺ , Se ²⁺ , Ag ²⁺ , Os ²⁺ , Mn ²⁺ , Sr ²⁺ , Cd ²⁺ , Ir ²⁺ , Fe ²⁺ , Y ²⁺ , In ²⁺ , Pt ²⁺ , Co ²⁺ , Zr ²⁺ , Sn ²⁺ , Au ²⁺ , Ni ²⁺ , Nb ²⁺ and Te ^{2 +} may be one or two or more selected metal ion in, X is Cl ^-, Br ^-, I ^- and F ^- in may be one or a halogen ion selected two or more, Y is dimethyl sulfoxide (Dimethylsolfoxide, DMSO), N N-methyl pyrrolidinone (NMP), 1,2-dimethylhydrazine, aniline, butylamine, decylamine, dimethylcetylamine ), Ethanolamine, ethylamine, hydrazine, methylamine, methylhydarzine, nonylamine, piperidine, pyridine, and the like. ) And quinoline. ≪ / RTI >

When the first solution contains a metal halide complex, the first solution forms a complex with a metal halide, a metal halide, and contains a complex solvent which is a solvent dissolving the metal halide and a different solvent which is different from the complex solvent Of course. That is, the first solution containing the metal halide complex may mean a solution in which the metal halide is dissolved in a solvent (complex solvent) forming the complex and a mixed solvent in which the two different solvents are mixed. Specifically, the first solution is a metal halide; Dimethyl sulfoxide (DMSO), N-methyl pyrrolidinone (NMP), 1,2-dimethylhydrazine, aniline, butylamine, decyl It is preferable to use an organic solvent such as decylamine, dimethylcetylamine, ethanolamine, ethylamine, hydrazine, methylamine, methylhydarzine, nonylamine, piperidine piperidine, pyridine, and quinoline; a complex solvent selected from one or more of piperidine, pyridine, and quinoline; And N, N-dimethylacetamide, tetrahydrofuran, tetrahydrofuran, diethylene glycol, 1-methyl-2-pyrrolidone, N, N-dimethylacetamide, Acetone, methanol, ethanol, propanol, butanol, pentanol, hexanol, ketone and methyl esters such as acetone, methyl acetamide, acetone,? -Terpineol,? -Terpineol, dihydrotopeenol, 2-methoxyethanol, And one or more solvents selected from isobutyl ketone. In this case, the first solution may contain a metal halide complex of 0.8 to 1.3 M (mol / L) based on the metal halide, and the volume ratio of the complex solvent to the heterogeneous solvent in the first solution is 1: 1 to 5 But is not limited thereto.

The organic halide of the second solution can form a perovskite crystal structure with the metal halide and can be used as long as it is a compound between a monovalent organic cation and a halogen ion. Specifically, the organic halide of the second solution may satisfy the following formula (3).

(Formula 3)

AX

In formula (3), A may be a monovalent cation selected from monovalent organic ammonium ions, K ⁺ , Rb ⁺ and Cs ⁺ , one or more of which is selected from the group consisting of Cl ^- , Br ^- , I ^- and F ^- Two or more selected halogen ions.

The solvent of the second solution may be any solvent that dissolves the organic halide. As a specific example, the solvent of the second solution may be a non-aqueous polar organic solvent, independently of the first solution, and the non-aqueous polar organic solvent may include gamma-butyrolactone, formamide, N, N- dimethylformamide, Methyl-2-pyrrolidone, N, N-dimethylacetamide, acetone,? -Terpineol,? -Tetrahydrofuran, diethyleneglycol, It is possible to use one or two or more kinds of solvents selected from terpineol, dihydropterone, 2-methoxyethanol, acetylacetone, methanol, ethanol, propanol, butanol, pentanol, hexanol, ketone and methylisobutyl ketone . At this time, the second solution may contain organic halides of 0.8 to 1.3 M (mol / L), but is not limited thereto.

As described above, in order to produce a high-quality perovskite organometallic halide film having a large area of 20 mm x 20 mm or more, the flow of the first liquid or the second liquid on the substrate and the applied liquid must be suppressed as much as possible, The area should also be applied so that the molar ratio between the metal halide and the organic halide can be kept homogeneous according to the stoichiometric ratio.

The slot die coating is advantageous for large area coating because there is no substantial restriction on the coating area as the die head moves and the fluidized bed supplied by the pump is discharged to the discharge port between the mold plates called the slot die. Further, by reducing the moving speed of the slot die, the slot die coating can remarkably suppress the flow of the applied liquid and the applied liquid during the application of the first and second liquids, and the clearance between the ejection openings and the pump pressure The amount of the first liquid to be applied per unit area and the amount of the second liquid can be precisely controlled.

FIG. 1 is a process diagram showing a photoactive layer forming step in a method of manufacturing a perovskite solar cell according to an embodiment of the present invention. Referring to FIG.

1, the photoactive layer forming step is performed on the first charge carrier 130 of the base material in which the substrate 110, the transparent electrode 120, and the first charge carrier 130 are sequentially stacked, The first solution is applied using the first slot die 210 and the second solution is coated on the applied first solution using the second slot die 220 to form a coating film, The organometallic halide film 140 can be prepared.

In this case, the application of the first solution and the application of the second solution may be sequentially performed. As shown in FIG. 1, during the application of the first solution, Application can be performed. This simultaneous application may be performed by moving the first slot die 210 for applying the first solution and the second slot die 220 for applying the second solution at the same distance and spaced apart by a certain distance.

However, it should be understood that the present invention is not limited to simultaneous application of a first solution and a second solution using two slot die spaced apart from each other, and may include a first charge carrier 130, The application of the second solution using the second slot die 220 may be performed after the application of the first solution through the second slot die 220 is completed.

1, the application of the second solution using the slot die is performed in a state in which the solvent of the first charge transporting body 130, that is, the first solution coated on the electron transporting body, is present, that is, The application of the second solution can be performed in a state where the first solution is not dried.

2, application of the first solution is completed using the first slot die 210, and the coated first solution is dried to form a metal halide film 141, It is advantageous to apply the second solution by using the second slot die 220 onto the metal halide film 141 (or the metal halide complex film).

In this case, the application of the second solution is originally prevented from flowing the coating film of the first solution, so that a perovskite organometallic halide film of coarse crystal with better crystallinity can be produced, A perovskite organometallic halide film having a thickness can be produced. Here, drying of the applied first solution may be performed at a temperature of 50 to 100 ° C, but is not limited thereto.

When applying the first solution and applying the second solution, it is advantageous for the slot die to move independently of each other at a slow speed of 5 mm / sec or less, more preferably 4 mm / sec. As described above, when a large area perovskite organometallic halide film having a size of 20 mm x 20 mm or more is to be prepared, the flow of the applied liquid during and after the application (before drying) of the first solution and the second solution should be suppressed as much as possible . When the slot die movement speed exceeds 5 mm / sec and relatively fast application is performed for the application of the first solution or the application of the second solution, the flow of the discharged first solution (or the second solution) There is a risk that a film having a significantly lowered uniformity is produced.

However, when the excessively slow moving speed causes a decrease in productivity, the moving speed of the slot die may be substantially 0.1 mm / sec or more when applying the first solution or applying the second solution, and more practically, 0.5 mm / sec or more.

The discharge amount of the first solution and the discharge amount of the second solution per unit surface area of the base material are determined such that the stoichiometric ratio of the perovskite organometallic halide or an amount thereof close to the discharge It is needless to say that the clearance between the discharge ports and the pressure of the pump (the supply pump for supplying the first solution or the second solution) (the solution transfer rate) can be adjusted. As a specific example, when the metal halide concentration in the first solution and the concentration of the organic halide in the second solution are the same, the first slot die and the second slot die are formed so that the first solution and the second solution of the same volume per unit area are applied Can have the same outlet clearance and solution delivery speed (pump pressure). The amount of the first solution and the amount of the second solution discharged are controlled so that the first solution and the second solution are discharged at a stoichiometric ratio or a ratio close to the stoichiometric ratio as described above and the perovskite organic metal compound film It is a matter of course that the thickness can be adjusted. As a practical, non-limiting example, in terms of effective absorption of light and prevention of excessive series resistance increase, the thickness of the perovskite organic metal compound film may be 50 nm to 2 탆. As a practical example for producing the perovskite organometallic compound film having the above-mentioned thickness at the above-mentioned feed rate of the slot die, the outlet interval of the slot die (the first slot die or the second slot die) may be 0.01 to 0.1 mm , And the transfer speed of the solution may be 50 μl / min to 500 μl / min.

After the sequential application of the first solution and the second solution using the slot die is performed, drying of the coating film can be performed. The drying can be carried out at a low temperature of 70 to 100 DEG C and can be carried out at normal pressure for 5 to 20 minutes. At this time, the conversion to the perovskite organometallic halide can be accomplished only by low-temperature drying at a temperature of 100 ° C or less. However, if necessary, a heat treatment at 130 to 160 ° C is further performed for improving the crystallinity or increasing the grain size Of course.

A perovskite organometallic halide film satisfying the following Chemical Formula 4 can be prepared by sequential application of a first solution and a second solution using a slot die and drying of a coating film.

(Formula 4)

AMX ₃

In Formula 4, A may be a monovalent cation selected from monovalent organic ammonium ions, K ⁺ , Rb ^+, and Cs ⁺ , wherein M is a divalent metal ion, Mg ²⁺ , Cu ²⁺ , Mo ²⁺ , Ba ²⁺ , Si ²⁺ , Zn ²⁺ , Tc ²⁺ , Hf ²⁺ , Ca ²⁺ , Ga ²⁺ , Ru ²⁺ , Ta ²⁺ , Ti ²⁺ , As ²⁺ , Pb ²⁺ , Re ²⁺ , Cr ²⁺ , Se ²⁺ , Ag ²⁺ , Os ²⁺ , Mn ²⁺ , Sr ²⁺ , Cd ²⁺ , Ir ²⁺ , Fe ²⁺ , Y ²⁺ , In ^{2 +,} and ^{Pt 2+, Co 2+, Zr 2+} , Sn 2+, Au 2+, Ni 2+, Nb 2+ and one or more than one metal ion selected from Te ^2+, X is Cl ^-, Br ^- , I ^- it may be one or more than one halide ion is selected from ^- and F.

The perovskite organometallic halide film produced using the slot die coating described above has an extremely uniform uniformity of UN determined by the relational expression 2 according to the following relational expression 1 on the basis of a large area film having an area of at least 20 mm x 20 mm or more Is an organometallic halide film having a thickness of about 10 nm.

(Relational expression 1)

In the relation 1, Tave means the average thickness of the organometallic halide film, T means the thickness of the organometallic halide film in the measurement area, T (i) means the measurement in the random measurement area of the organometallic halide film (N) is the thickness of the organometallic halide film, i is the thickness measured in the i-th random measurement region, i is the number of measurements (1 to n) The thickness of the coating film is a natural number of 10 to 50 in terms of the total number of thickness measurements.

(Relational expression 2)

In relation 2, T _ave , n, T (i) are the same as in the relational expression 1.

Furthermore, when the first solution contains an organometallic halide complex, a high-quality film composed of granules with excellent crystallinity and having an extremely uniform thickness with a UN of not more than 5 is produced at a large area of 20 mm x 20 mm or more, Do. The crystal grains having excellent crystallinity are advantageous not only to smooth the movement of the photocurrent but also to prevent the destruction due to the recombination of the photoelectric charges.

More specifically, when the first solution and the second solution are applied using a slot die, the second solution is applied after drying the coating film of the first solution, and when the first solution contains the organometallic halide complex, The solar cell manufactured by the manufacturing method according to an embodiment of the present invention can have a photoelectric conversion efficiency as high as 11% although it has a large area of 20 mm x 20 mm or more.

A step of forming a hole transporting material (second charge transporting material) on top of the photoactive layer may be performed after the photoactive layer, which is a perovskite organic metal halide film, is formed using a slot die.

The hole transporting material may be an organic or inorganic material capable of transporting holes. As a specific example, the hole transporting material may be a hole-conducting organic material, specifically, a hole-transporting organic material. The hole-conducting organic material may be a single molecule or a conjugated polymer semiconductor. Non-limiting examples of the hole-conducting organic material include Spiro-MeOTAD ([2,22 ', 7,7'-tetrkis (N, N-di-pmethoxyphenylamine) -9,9,9'- spirobifluorine], PTAA (3-hexylthiophene), MDMO-PPV (poly [2-methoxy-5- (3 ', 7'-dimethyloctyloxyl)] - 1,4- poly (3-octyl thiophene), POT (poly (octyl thiophene)), poly (ethylene oxide) -phenylenevinylene (MEH-PPV) Poly (3-decyl thiophene), poly (3-dodecyl thiophene), poly (p-phenylene vinylene), poly (9,9'-dioctylfluorene- butylphenyl) diphenyl amine, Polyaniline, CuSCN, CuI, PCPDTBT (Poly [2,1,3-benzothiadiazole-4,7-diyl4,4-bis (2-ethylhexyl-4H-cyclopenta [ : 3,4-b '] dithiophene-2,6-diyl]], Si-PCPDTBT (poly [(4,4'-bis (2-ethylhexyl) dithieno [3,2- d] silole) -2,6-diyl-alt- (2,1,3-benzothiadiazole) -4,7-diyl]), PBDTTPD (poly ((4,8-diethylhexyloxyl) benzo [ : 4,5-b '] dithiophene) -2,6-diyl) -one - ((5-octylthieno [3,4-c] py 9,6-dione) -1,3-diyl), PFDTBT (poly [2,7- (9- (2-ethylhexyl) -9- , 7-di-2-thienyl-2 ', 1', 3'-benzothiadiazole)]), PFO-DBT (poly [2,7-9,9- (dioctyl-fluorene) - (4 ', 7'-di-2-thienyl-2', 1 ', 3'-benzothiadiazole)], PSiFDTBT (poly [(2,7-dioctylsilafluorene) 4,7-bis (2-thienyl) -2,1,3-benzothiadiazole) -5,5'-diyl], PSBTBT (poly [(4,4'-bis (2-ethylhexyl) dithieno [ (2,1,3-benzothiadiazole) -4,7-diyl]), PCDTBT (Poly [[9- (1- 2,9-benzothiadiazole-4,7-diyl-2,5-thiophenediyl), PFB (poly (9,9 ' bis (N, N'- (4, butylphenyl)) bis (N, N'-phenyl-1,4-phenylene) diamine), F8BT (poly (9,9'-dioctylfluorene-cobenzothiadiazole) PEDOT: poly (3,4-ethylenedioxythiophene), PEDOT: poly (3,4-ethylenedioxythiophene) poly (styrenesulfonate) and copolymers thereof. The hole transporting material may be prepared by a method commonly used in the manufacture of a hole transporting material in a solar cell. For example, the hole transporting material may be prepared by applying a liquid containing a hole-transporting organic material and drying the applied material. The thickness of the hole transporting material may be 10 nm to 500 nm, but is not limited thereto.

After the formation of the hole carrier, a step of forming a counter electrode of the transparent electrode may be performed on the upper portion of the hole carrier. The counter electrode may be formed of gold (Au), silver (Ag), aluminum (Al) Indium tin oxide (ITO), fluorine tin oxide (FTO), indium zinc oxide (IZO), aluminum-containing zinc oxide (AZO) One of the indium zinc tin oxide (IZTO), molybdenum (Mo), ZnO-Ga ₂ O ₃ , ZnO-Al ₂ O ₃ , SnO 2 -Sb ₂ O ₃ , tin oxide and zinc oxide Or two or more materials selected from the group consisting of, but not limited to.

(Example 1)

After FTO (F-doped SnO ₂ ) substrate (7 ohms / cm ² ) was cut to 20 × 20 mm, the FTO was removed using a laser scriber at 0.5 mm at one end. A 80 nm TiO ₂ dense film was formed on the FTO substrate by spray pyrolysis (450 ° C) of a solution of Ti-acac (Titanium acetylacetone): EtOH (1: 9 v / v%).

Then, a paste solution containing titanium dioxide (TiO ₂ ) nanoparticles having an average particle size of 40 nm on a TiO ₂ compacted film was spin-coated and heat-treated at 550 ° C for 60 minutes in air to prepare a TiO ₂ porous film having a thickness of 120 nm.

The red DI iodide (PbI ₂₎ dimethylformamide (DMF) was dissolved in 1.2M concentration in a solvent of red DI iodide (PbI ₂₎ was prepared in a solution, methyl ammonium iodide (CH ₃ NH ₃ I) 2-propanol was dissolved at a concentration of 1.2 M to prepare a methylammonium iodide solution. A red diazide solution and a methyl ammonium iodide solution were applied on the TiO ₂ porous film using a two slot die. At this time, the gap between the two slot die was maintained at 10 cm, and a methylammonium iodide solution was applied onto the coating film of the red diazide solution. The moving speed of the two slot die was 3 mm / sec, the slot spacing of the slot die was 0.06 mm, and the transfer rate of the solution was 150 μl / min.

After the application using the slot die was completed, the substrate was dried at 100 DEG C and atmospheric pressure for 10 minutes to prepare a photoactive layer.

Then, Spiro-MeOTAD on the photoactive layer 2.31 mg of LiTFSI (lithium bis (fluorosulfonyl) imide) and 6.2 mg of tBP (tertiary butyl pyridine) were added to the dichlorobenzene solution in which 8 wt% was dissolved, and then spin coated at 5000 rpm for 10 seconds to form a transfer layer Respectively. A counter electrode was prepared by coating Au with a thickness of 80 nm using a thermal evaporator (5 × 10 ^-6 Torr or less) on top of the hole transport layer.

3 is a scanning electron micrograph (FIG. 3 (a)) of the surface of the photoactive layer prepared in Example 1 and an X-ray diffraction analysis result (FIG. 3 (b) . As can be seen from FIG. 3, it can be seen that a high-purity film composed of perovskite organometallic halide was produced, and a dense and high-quality thin film was produced. In addition, 10 random surface areas were observed to include the center and edge of the photoactive layer prepared using a scanning electron microscope. As a result, it was found that the microstructure (average grain size, degree of defect) It was confirmed that a compound film was produced. The cross-section of the photoactive layer prepared by the method of Example 1 was observed with a scanning electron microscope, and the cross-section of 10 random regions including the edge region and the central region was observed to measure the thickness of the perovskite organometallic halide film Respectively. As a result of the measurement, it was confirmed that a photoactive layer having a T _ave of 978 nm and a UN of 11.9 was produced.

(Example 2)

Red diazide (PbI ₂ ) was dissolved in dimethylformamide (DMF) / dimethylsulfoxide (DMSO) / N-methylpyrrolidinone (NMP) (8/1) instead of the red diazide solution in Example 1, 1 v / v / v) mixed solvent at a concentration of 1.2 M, a solar cell was prepared in the same manner as in Example 1.

4 is a scanning electron micrograph (FIG. 4 (a)) of the surface of the photoactive layer prepared in Example 2 and an X-ray diffraction analysis result (FIG. 4 (b) . As can be seen from FIG. 4, it can be seen that a high-purity film composed of perovskite organometallic halide was produced. When a metal halide complex was used, a thinner film having a higher quality than that of the photoactive layer prepared in Example 1 . In addition, 10 random surface areas including the center and edges of the photoactive layer prepared using a scanning electron microscope were observed. As a result, microstructure (average grain size, degree of defect) was observed similarly to the photoactive layer prepared in Example 1. As a result, It was confirmed that the substantially uniform perovskite organic metal compound film was produced. The cross-section of the photoactive layer prepared by the method of Example 2 was observed with a scanning electron microscope, and the cross-section of 10 random regions including the edge region and the central region was observed to measure the thickness of the perovskite organometallic halide film Respectively. As a result of the measurement, it was confirmed that a photoactive layer having a T _ave of 990 nm and a UN of 10.1 was produced.

(Example 3)

After the slot die coating of the first solution was completed using the same solution as in Example 2, the coated film of the applied first solution was dried for 10 minutes at 50 ° C and atmospheric pressure, then the second solution was slot-die coated, And dried for 10 minutes to prepare a photoactive layer. A solar cell was fabricated in the same manner as in Example 1.

5 is a scanning electron micrograph (FIG. 5 (a)) showing the surface of the photoactive layer prepared in Example 3 and FIG. 5 (b) showing the result of X-ray diffraction analysis to be. As can be seen from FIG. 5, it can be seen that a film of high purity composed of the perovskite organometallic halide is produced. 3 to 5, when a metal halide complex solution is coated with a slot die, followed by drying, and then the organic halide solution is coated with a slot die and dried to produce a photoactive layer, It can be seen that a perovskite organometallic halide film having excellent crystallinity composed of coarse crystal grains is produced and that a thin film of a higher quality than that of the photoactive layer prepared in Examples 1 and 2 is produced . FIG. 6 is an optical photograph of a photoactive layer prepared by the method of Example 3. As can be seen from FIG. 6, it can be seen that a perovskite organometallic halide is produced in a perfect film form even with a large- have. Further, ten random surface areas including the center and edges of the photoactive layer prepared using a scanning electron microscope were observed. As a result, it was found that the microstructure (average grain size , Degree of defect) of the perovskite organic metal compound film was substantially uniform. The cross-section of the photoactive layer prepared by the method of Example 3 was observed with a scanning electron microscope, and the cross-section of 10 random regions including the edge region and the central region was observed to measure the thickness of the perovskite organometallic halide film Respectively. As a result of the measurement, it was confirmed that a remarkably uniform thin film having a T _ave of 997 nm and a UN of 2.12 was produced despite having a large area of 20 mm × 20 mm.

(Comparative Example 1)

In Example 1, methyl ammonium iodide (CH ₃ NH ₃ I) and red diiodide (PbI ₂ ) were mixed in a molar ratio of 1: 1 in place of the methyl ammonium iodide solution and the red diazide solution, dimethylformamide dimethyl ammonium concentration of 1.2M is prepared by dissolving the (DMF) Red tree iodide (CH ₃ NH ₃ PbI ₃₎ the sun in the same way as in example 1 except that the slot die coating to a single solution of A battery was prepared.

6 is a scanning electron micrograph (FIG. 6 (a)) showing the surface of the photoactive layer prepared in Comparative Example 1 and FIG. 6 (b) showing the result of X-ray diffraction analysis to be. As can be seen from FIG. 6, it can be seen that a low quality photoactive layer was produced. As a result of X-ray diffraction analysis, a peak was observed at 2? = 12.7 °, Quality photoactive layer in which the reaction product remains. The cross-section of the prepared photoactive layer was observed by a scanning electron microscope. As a result, it was confirmed that a large amount of defects having an average thickness of about 1.1 탆 was formed and a photoactive layer having a very uniform thickness was produced.

The photoelectric characteristics of the perovskite solar cells manufactured in Examples 1, 2, and 3 and Comparative Example 1 were measured under a condition of 1.5 AM using a solar simulator equipped with a source meter and a xenon lamp , And FIG. 8 shows the short-circuit current density, the open-circuit voltage, the filling rate (%), and the photoelectric conversion efficiency (%). As can be seen from FIG. 8, in the case of the solar cell manufactured according to the embodiment of the present invention, the solar cell has a high open voltage and a short-circuit current, and has an improved fill factor and has remarkably improved photoelectric conversion efficiency. . As can be seen from Table 1, the solar cell produced in Example 3 had a photoelectric conversion efficiency of 11.0%, 1.7 times larger than that of the solar cell manufactured in Comparative Example 1, even though the solar cell had a large area of 20 mm x 20 mm or more It can be seen that the photoelectric conversion efficiency is enhanced.

(Table 1)

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Those skilled in the art will recognize that many modifications and variations are possible in light of the above teachings.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (9)

a) a first solution containing a metal halide and an organic halide, using a slot die, on a first charge carrier of a substrate on which a substrate, a transparent electrode and a first charge carrier are sequentially laminated, And sequentially drying the solution to form a photoactive layer, which is an organic metal halide film of perovskite structure; And
and b) sequentially forming a second charge carrier and a counter electrode of the transparent electrode over the photoactive layer. The method according to claim 1,
In the step (a), the first solution forms a complex with the metal halide and the metal halide, and contains a complex solvent which is a solvent dissolving the metal halide. 3. The method of claim 2,
The step a)
a1) applying and drying the first solution on the first charge carrier using a slot die; And
a2) applying a second solution on a coated film of the dried a1) step using a slot die, and then drying the applied solution. 3. The method of claim 2,
The step a) may include applying a first solution on the first charge carrier using a slot die, applying a second solution to the first solution coated on the first charge carrier using a slot die, The method comprising the steps of: preparing a perovskite solar cell; The method according to claim 1,
Wherein the rate of movement of the slot die during the application of the first solution and the application of the second solution is 5 mm / sec or less independently of each other. The method according to claim 1,
Wherein the first charge carrier is a multi-layer film including a dense film positioned on the transparent electrode layer side and a porous film located on the dense film, the perovskite type solar cell. The method according to claim 6,
Wherein the porous film comprises metal oxide particles and has a pore structure opened by an empty space between metal oxide particles. The method according to claim 1,
Wherein the second charge carrier is a hole-conducting organic material. The method of claim 3,
A method for producing a perovskite type solar cell, wherein, in the step (a), an organometallic halide film having a UN of not more than 5, which is defined by the relational expression (2), is produced in accordance with the following relational expression 1 on the basis of a large area film having an area of at least 20 mm x 20 mm or more.
(Relational expression 1)

(Where Tave means the average thickness of the organometallic halide film, T means the thickness of the organometallic halide film in the measurement region, and T (i) I denotes the number of measurements (1 to n), and n denotes a measurement range of the organometallic halide film in the random measurement region, The thickness of the halide film is a natural number of 10 to 50 in terms of the total number of thickness measurement times measured)
(Relational expression 2)

(In the relational expression 2, T _ave , n, T (i) are the same as in the relational expression 1)

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