KR102119406B1 - Perovskite Compound Solution - Google Patents

Abstract

The perovskite compound solution according to the present invention includes a metal halide and an organic halide that satisfy a stoichiometric ratio of an organometallic halide or an organometallic halide having a perovskite structure; And elemental sulfur.

Description

Perovskite compound solution

The present invention relates to a perovskite compound solution, and relates to a perovskite compound solution having excellent long-term stability and not deteriorating battery efficiency.

Commonly used fuels such as petroleum or coal have limited reserves, and there is a problem of causing environmental pollution through emission of carbon dioxide. Solar cells have been developed to compensate for the shortcomings of fuels such as petroleum or coal, and are devices that produce electricity using solar energy, an infinite energy source, by converting solar energy into electrical energy.

Organic/organic hybrid perovskite compounds, also referred to as organometal halide perovskite compounds, consist of organic cations (A), metal cations (M) and halogen anions (X). It is a material represented by the chemical formula of AMX ₃ having a lobsky structure. In detail, the organic/organic hybrid perovskite compound represented by the chemical formula of AMX ₃ is a form in which A organic cations are located in the middle in a three-dimensional network in which the MX ₆ octahedron is corner-sheared. to be.

These organic/organic hybrid perovskite compounds have very low material prices, excellent low-temperature process or low-cost solution process, excellent commerciality, and have high light absorption coefficient, low exciton binding energy, and charge diffusion distance. It is actively studied as a light absorber.

Perovskite solar cells in which the organic/organic hybrid perovskite compound is a light absorber are closest to commercialization among next-generation solar cells, including dye-sensitized and organic solar cells, and have reported an efficiency of 22% or more (Registration of Korea) As it became No. 1547870), more and more attention has been raised.

As provided in Korean Patent Registration No. 1547870, perovskite solar cells (PSCs) having a high efficiency of 20% or more include a solution in which an organic/inorganic hybrid perovskite compound is dissolved and a non-solvent (anti -solvent) is produced by a so-called solvent-engineering process, which sequentially applies, and a solution containing both an amidinium-based cation and an organic ammonium cation is used to achieve higher efficiency.

Organic ammonium ions are required for phase stabilization of an amidinium-based organometal halide. Cs ions instead of organic ammonium cations can also perform similar phase stabilization, but Cs ions are more difficult to commercialize because they are more toxic and more expensive than organic ammonium.

However, the organic/organic hybrid perovskite compound solution containing both an organic ammonium ion and an amidium-based ion significantly reduces the efficiency of the perovskite solar cell produced by changing the properties over time, and the process There is a problem of deteriorating stability and reproducibility.

Republic of Korea Registered Patent No. 1547870

It is an object of the present invention to provide a solution of an organic/organic hybrid perovskite compound whose property change is prevented even after a long period of time.

Another object of the present invention is to provide an organic/organic hybrid perovskite compound solution that has long-term stability and does not cause a decrease in cell efficiency of a solar cell equipped with a perovskite compound film prepared from a solution.

The perovskite compound solution according to the present invention includes a metal halide and an organic halide that satisfy a stoichiometric ratio of an organometallic halide or an organometallic halide having a perovskite structure; And elemental sulfur.

In the perovskite compound solution according to an embodiment of the present invention, the organic cation of the organic metal halide or the organic cation of the organic halide may include organic ammonium ions and amidinium ions.

In the perovskite compound solution according to an embodiment of the present invention, the perovskite compound solution may contain 0.1 to 2.0 moles of elemental sulfur relative to 1 mole of organic ammonium ions.

In the perovskite compound solution according to an embodiment of the present invention, the total number of moles of the organic ammonium ion and the amidinium-based ion is 1, and the molar ratio of the organic ammonium ion: the amidinium-based ion is 0.7 to 0.95 : 0.3 to 0.05.

In the perovskite compound solution according to an embodiment of the present invention, the perovskite compound solution may contain an organometallic halide or metal halide in a concentration of 1 to 1.5 molar.

The perovskite compound solution according to an embodiment of the present invention may satisfy Equation 1 below.

(Equation 1)

[PCE(AF)-PCE(AG72)]/PCE(AF) * 100 ≤ 10%

PCE (AF) in Equation 1 is the efficiency (%) of a perovskite solar cell equipped with a light absorbing layer prepared from the perovskite compound solution, which is left for 1 hour after being prepared, and PCE (AG72) is produced It is the efficiency (%) of the perovskite solar cell equipped with the light absorbing layer prepared from the perovskite compound solution, which was left standing for 72 hours.

The perovskite compound solution according to an embodiment of the present invention may satisfy Equation 2 below.

(Equation 2)

0.97 ≤ PCE(AF)/PCE(ref)

In Equation 2, PCE (AF) is the efficiency (%) of a perovskite solar cell equipped with a light absorbing layer prepared from the perovskite compound solution, which is left for 1 hour after being prepared, and PCE (ref) is an element The efficiency (%) of a perovskite solar cell equipped with a light absorbing layer prepared after leaving a reference solution, which is the same solution as the perovskite compound solution, for one hour, except that it does not contain sulfur.

The present invention includes a method for producing a perovskite compound membrane using the above-described perovskite compound solution.

The method of manufacturing a perovskite compound membrane according to the present invention includes the step of applying and drying the above-described perovskite compound solution.

The present invention includes a perovskite compound membrane prepared from the perovskite compound solution described above.

The perovskite compound membrane according to the present invention is prepared from the perovskite compound solution described above, and contains elemental sulfur.

The perovskite compound solution according to the present invention contains elemental sulfur as a solution stabilizer, so that the perovskite compound solution can be effectively prevented from being deteriorated, and the perovskite compound itself is not adversely affected. Not only does the perovskite compound membrane of a high quality substantially equivalent to the conventional perovskite compound membrane be produced, but also increases the binding energy compared to perovskite composed of only monovalent halide ions as divalent sulfur anions are introduced. It has the advantage of improving the stability according to.

In addition, the perovskite compound solution according to the present invention contains elemental sulfur as a solution stabilizer, so that even when it is left for a long period of time of 192 hours, deterioration of the solution hardly occurs, and thus the perovskite compound-based device using a solution process It can be stably manufactured with reproducibility, and has the advantage of manufacturing a perovskite compound-based device through relaxed process management.

1 is a view showing the cell efficiency according to the solution aging time of the perovskite solar cell prepared in Examples and Comparative Examples.
FIG. 2 is a diagram showing an X-ray diffraction analysis result and an optical photograph of a perovskite compound film by aging time after aging the solution in which the perovskite compound is dissolved without adding sulfur.
3 is an aging of the perovskite compound solution prepared in Example 1 for 1 hour, 24 hours, 48 hours, 72 hours and 192 hours, respectively, and then observed the perovskite compound membrane by aging time X -It is a diagram showing the result of the ray diffraction analysis and the optical picture together.
FIG. 4 shows spin coating after aging of the solution in which the perovskite compound was dissolved without adding sulfur for 1 hour (f-1), 24 hours (f-2), and 72 hours (f-3), respectively. And a scanning electron microscope photograph of the perovskite compound membrane prepared by drying and the perovskite solution prepared in Example 1 for 1 hour (g-1), 24 hours (g-2), and 72 hours (g This is a scanning electron microscope photograph of a perovskite compound film prepared by spin coating and drying after aging for -3) each time.
Figure 5 is a perovskite solar cell prepared by aging for 192 hours after aging the solution in which the perovskite compound is dissolved without addition of sulfur, a perovskite compound membrane additionally treated with MAI coating and heat treatment It is a diagram showing the voltage-current curve of the perovskite solar cell and the solar cell prepared in Example 4 (sulfur contained solution in FIG. 5).
FIG. 6 shows the results of X-ray diffraction of the perovskite compound film prepared by aging the solution in which the perovskite compound is dissolved without adding sulfur, for 192 hours, and perovskite prepared in the further treatment of MAI application and heat treatment. This is a diagram showing the results of X-ray diffraction analysis of the compound film.
7 is a view measuring the change in Pb 4f binding energy of the perovskite compound membranes prepared in Examples and Comparative Examples by XPS.
8 is a view showing the measurement of the change in efficiency with light irradiation time in the perovskite solar cell manufactured in Examples and Comparative Examples.

Hereinafter, a solution of the perovskite compound 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. Therefore, the present invention is not limited to the drawings presented below, but 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 to be used, those skilled in the art to which the present invention pertains have the meanings commonly understood, and the gist of the present invention in the following description and the accompanying drawings Descriptions of well-known functions and configurations that may be obscured are omitted.

The applicant has deterioration of the perovskite compound (organic metal halide perovskite structure, organometal halide perovskite compound, or organic/organic hybrid perovskite compound) solution, the organic ammonium ion It has been found to be due to deprotonation and conversion to alkyl amines. Based on these findings, an in-depth study was conducted to develop a perovskite compound solution with improved stability without decreasing the efficiency of the perovskite solar cell. As a result of the study, it was found that elemental sulfur forms a complex of amine-sulfur and surprisingly significantly inhibits the deprotonation of amine, significantly increasing the stability of the perovskite compound solution, and also using elemental sulfur as a stabilizer In this case, it was confirmed that the film quality of the perovskite compound film prepared from the solution did not occur, and that the efficiency of the perovskite solar cell was not substantially reduced, and thus the present invention was completed.

In the present invention, the perovskite compound refers to an organometal halide, organometal halide perovskite compound or organic/organic hybrid perovskite compound having a perovskite structure. In a specific embodiment, the perovskite compound is composed of organic cations (A), metal cations (M) and anions (X), and the compound standards satisfying the formula of AMX ₃ , MX ₆ octahedron of X (anion) It may mean a compound in which one or more anions selected from chalcogen anions and halogen anions are located.

In the present invention, the perovskite solar cell may mean a solar cell containing a perovskite compound as a light absorber, specifically, a solar cell containing a perovskite compound film as a light absorbing layer.

The perovskite compound solution in the present invention includes not only when the perovskite compound itself is dissolved in a solvent, but also when an organometal halide and a metal halide are dissolved in a solvent. At this time, the molar ratio of the organometallic halide and the metal halide may be in accordance with the stoichiometric ratio of the perovskite compound, but is not necessarily limited thereto, and if necessary, an excess of the organometallic halide or metal halide It may contain.

Leaving the perovskite solution in the present invention may mean storing the perovskite solution within 60°C, wherein the solution may be sealed or opened under white light, and independently stirred or It may be in a non-comparative state.

Elemental sulfur in the present invention (elemental sulfur) may have a cyclo-octa sulfur (cyclo-S ₈ ) structure. In addition, the elemental sulfur may mean pure sulfur having a purity of 3 or more (99.9%) or more, and specifically 4 or more (99.99%) or more. In the present invention, elemental sulfur is strictly separated from sulfur contained as a functional group, an organic/inorganic compound, or a single element constituting a molecule (including a polymer).

The perovskite compound solution according to the present invention based on the above-mentioned findings includes elemental sulfur; and organometallic halide or metal halide and organohalide having a perovskite structure.

Elemental sulfur can extremely effectively prevent deterioration of organic cations contained in the perovskite compound solution into dissimilar materials, and does not have a negative effect on the perovskite compound itself, which is produced despite a very good stabilizing action. A solar cell having substantially the same efficiency as a solar cell produced from a pure perovskite compound solution containing no solute other than the perovskite compound can be produced.

The solution stability effect by sulfur may be remarkable, and as a specific example of the perovskite solution, which is advantageous for improving solar cell efficiency, the perovskite solution may contain organic ammonium ions and amidinium ions. That is, based on the raw material input to the solvent for the preparation of the perovskite solution, the perovskite solution may contain an organometallic halide or a metal halide and an organic halide of a perovskite structure, and an organometallic The organic cation of the halide or the organic cation of the organic halide may contain organic ammonium ions and amidinium ions. The perovskite compound solution containing an organic ammonium ion and an amidinium-based ion is known as a solution in which solution deterioration over time occurs very severely.

The organic ammonium ion is an ion that causes deterioration of the perovskite compound solution, and is a material required for the α-phase stabilization of the amidinium-based perovskite compound.

When the perovskite compound solution contains an organic ammonium ion and an amidinium-based ion, when the organic ammonium ion is deprotonated and converted into an organic amine, the amidinium-based perovskite compound is not in the α phase. By forming the δ phase of the perovskite structure, the film quality of the perovskite compound film and the efficiency of the perovskite solar cell can be greatly reduced.

However, when the elemental sulfur is contained as a stabilizer according to the present invention, even if the perovskite compound solution contains organic ammonium ions and amidinium ions, deterioration of the solution over time can be surprisingly suppressed. Specifically, when the perovskite compound solution contains elemental-sulfur together with organic ammonium ions and amidinium ions, organic ammonium ions are deorganized by deprotonation even after long-term standing for up to 192 hours. It is prevented from being converted to an amine, and the amidium-based perovskite compound in δ phase may not be detected in the film prepared by applying and drying the solution during X-ray diffraction analysis.

The organic ammonium ion may satisfy the following Chemical Formulas 1 to 2.

(Formula 1)

R ₁ -NH ₃ ⁺

In Formula 1, R ₁ is C1-C24 alkyl, C3-C20 cycloalkyl or C6-C20 aryl.

(Formula 2)

R ₂ -C ₃ H ₃ N ₂ ⁺ -R ₃

In formula 2, R ₂ is C1-C24 alkyl, C3-C20 cycloalkyl or C6-C20 aryl, and R ₃ is hydrogen or C1-C24 alkyl.

The amidinium-based ion may satisfy Formula 3 below.

(Formula 3)

In Formula 3, R ₄ to R ₈ are, independently of each other, hydrogen, C1-C24 alkyl, C3-C20 cycloalkyl or C6-C20 aryl.

When the perovskite compound solution contains both organic ammonium ions and amidinium-based ions, the α-phase amidinium-based perovskite compound is stably prepared to absorb light in a very wide wavelength band. Fast exciton movement and separation, faster photoelectron and photo hole movement can be achieved.

When the perovskite compound solution contains both an organic ammonium ion and an amidinium-based ion, in terms of stabilizing the amidium-based perovskite compound α, the total number of moles of the organic ammonium ion and the amidinium-based ion is As 1, the molar ratio of the alkylammonium ion: amidinium-based ion may be 0.70 to 0.95: 0.30 to 0.05, and specifically 0.80 to 0.95: 0.20 to 0.05.

Further, as is known, elemental sulfur hardly dissolves in a solvent (polar solvent) that dissolves the perovskite compound. However, when the perovskite compound solution contains organic ammonium ions, elemental sulfur can be dissolved smoothly and easily with the aid of organic ammonium ions (organic ammonium ion-sulfur complex formation).

In terms of dissolving sulfur sufficient to exhibit a stabilizing effect, the total number of moles of the organic ammonium ion and the amidinium-based ion is 1, and the molar ratio of the alkylammonium ion: the amidinium-based ion is 0.70 to 0.95: 0.30. It may satisfy 0.05 to 0.05, specifically 0.80 to 0.95: 0.20 to 0.05.

R ₁ of Formula ₁ , R ₂ to R ₃ of Formula 2, and/or R ₄ to R ₈ of Formula 3 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, in consideration of 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 1 and R ₂ to R of Formula 2 so that the application has a suitable band gap. ₃ and/or R ₄ to R ₈ of Formula 3 may be appropriately adjusted.

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 1, R ₁ may be C1-C24 alkyl, specifically C1-C7 alkyl, and more specifically methyl. .

In addition, in Formula 2, R ₂ may be C1-C24 alkyl, R ₃ may be hydrogen or C1-C24 alkyl, specifically R ₂ may be C1-C7 alkyl and R ₃ may be hydrogen or C1-C7 It may be alkyl, more specifically R ₂ may be methyl and R ₃ may be hydrogen.

In addition, R ₄ to R ₈ in Formula 3 may be independently of each other, hydrogen, amino or C1-C24 alkyl, specifically hydrogen, amino or C1-C7 alkyl, more specifically hydrogen, amino or methyl, and more More specifically, R ₄ may be hydrogen, amino or methyl and 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 ⁺ ).

However, this is an example in consideration of the use of sunlight as a light absorbing layer (the use of perovskite compounds), design of a wavelength band of light to be absorbed, design of a light emitting wavelength band when used as a light emitting layer of a light emitting device, of transistors When used as a semiconductor device, R ₁ of Formula ₁ , R ₂ to R ₃ of Formula 2, and/or R ₄ to R ₈ of Formula 3 may be appropriately selected in consideration of energy band gap and threshold voltage. have.

The perovskite compound solution is 0.1 to 2.0 moles relative to 1 mole of organic ammonium ion, advantageously 0.3 to 1.5 moles, so that deterioration of the perovskite solution over time can be substantially prevented by the stabilizing action of elemental sulfur , More advantageously it contains 0.3 to 1.2 moles, most advantageously 0.3 to 1.0 moles of elemental sulfur. When the perovskite solution contains elemental sulfur in an advantageous amount compared to the organic ammonium ion as described above, the solution stability is extremely excellent such that the δ-FAPbI ₃ phase is not formed even when the perovskite solution is left for 192 hours. The perovskite compound membrane prepared by using the solution may have a quality substantially equal to that of a conventional perovskite membrane that does not contain sulfur, resulting in a decrease in the efficiency of the solar cell due to a decrease in film quality. It is a range in which stability is improved with increasing binding energy compared to perovskite composed of only monovalent halide ions as divalent sulfur anions are introduced.

When elemental sulfur compared to 1 mol of organic ammonium ions satisfies the given range, the film quality of the perovskite compound film by sulfur introduced as a stabilizer while substantially completely preventing conversion of organic ammonium ions into organic amines by deprotonation The degradation and thus the efficiency of the perovskite solar cell may not substantially occur, and further, it is a range in which the efficiency of the perovskite solar cell can be improved.

Specifically, when the sulfur content of the element relative to 1 mole of the organic ammonium ion satisfies the suggested range, the perovskite compound solution may satisfy Equation 1 below. Specifically, [PCE(AF)-PCE(AG72)]/PCE(AF) * 100 is 9.5% or less, more specifically [PCE(AF)-PCE(AG72)]/PCE(AF) * 100 is 9.0% It may be:

(Equation 1)

[PCE(AF)-PCE(AG72)]/PCE(AF) * 100 ≤ 10%

In Equation 1, PCE (AF) is the efficiency (%) of a perovskite solar cell equipped with a light absorbing layer prepared from a perovskite compound solution that is left for 1 hour after being prepared, and PCE (AG72) is prepared. It is the efficiency (%) of the perovskite solar cell equipped with the light absorbing layer prepared from the perovskite compound solution left for 72 hours.

At this time, PCE (AF) and PCE (AG72) may be the efficiency measured in a perovskite solar cell made of the same material and structure (including dimension) except for the perovskite solution used for the light absorbing layer. Of course.

In addition, when elemental sulfur compared to 1 mole of organic ammonium ion satisfies the indicated range, the perovskite compound solution may satisfy Equation 2 below, specifically, PCE(AF)/PCE(ref) ≥ 0.99, and more Specifically, PCE(AF)/PCE(ref)>1. In addition, the present invention is not limited thereto, but PCE(AF)/PCE(ref) may be 1.3 or less.

(Equation 2)

0.97 ≤ PCE(AF)/PCE(ref)

In Equation 2, PCE (AF) is the efficiency (%) of a perovskite solar cell equipped with a light absorbing layer prepared from a perovskite compound solution that is left for 1 hour after being prepared, and PCE (ref) is elemental sulfur It is the efficiency (%) of the perovskite solar cell equipped with the light absorbing layer prepared after leaving the reference solution, which is the same solution as the perovskite compound solution for 1 hour, except that it does not contain.

At this time, PCE (AF) and PCE (ref) may be the efficiency measured in a perovskite solar cell made of the same material and structure (including dimension) except for the perovskite solution used for the light absorbing layer. Of course. In addition, in each of Equations 1 and 2, PCE (AF) may be 20% or more.

In the perovskite compound solution, the perovskite compound organometal halide may satisfy the following formula 4, formula 5, or formula 6 as the perovskite compound.

(Formula 4)

AMX ₃

In Formula 4, A is an organic cation, specifically, may be a monovalent organic cation, and as described above, A may be an organic ammonium ion or an organic ammonium ion and an amidinium-based ion. M may be a divalent metal ion, and X may be a halogen ion. In this case, the halogen ion is I ^- may be selected from at least one or both ^-, Br ^-, F ^- and Cl.

(Formula 5)

A(M _1-a N _a )X ₃

In Formula 5, A and X are each as defined in Formula 4, M is a divalent metal ion, N is a doped metal ion selected from one or more of a monovalent metal ion and a trivalent metal ion, and a is 0< It is a real number with a≤0.1.

In Chemical Formula 5, 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 5, 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.

(Formula 6)

A(N ¹ _1-b N ² _b )X ₃

In Formula 6, A and X are the same as defined in Formula 4, respectively, N ¹ is a monovalent metal ion, N ² is a trivalent metal ion, and b is a real number of 0.4 ≤ b ≤ 0.6.

In the formula (6), 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 the formula (6), 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 6 may mean that the divalent metal ion (M) in Formula 4 is replaced with monovalent and trivalent metal ions.

In Formula 4, Formula 5 or Formula 6, 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 Chemical Formula 4, Chemical Formula 5 or Chemical Formula 6, X may be X ^a _(1-y) X ^b _y , and X ^a and X ^b may be different from each other halogen ions (iodine ion (I ⁻ ), chlorine ion ( Cl ^-) and bromide (Br ^-) are different from each other a halogen ion selected from) and, y can be a real number 0 <y <1. More specifically, in Chemical Formula 1, 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, the total number of moles of halogen anions contained in the perovskite compound solution is 1, and the perovskite compound solution may contain iodine ions of 0.7 to 0.95 and bromine ions of 0.3 to 0.05.

As an example of a specific and non-limiting perovskite compound, taking Pb ²⁺ as a representative M as an example, the perovskite compound is CH ₃ NH ₃ PbI _x Cl _y (real number of 0≤x≤3, 0 ≤y≤3 real and x+y=3), CH ₃ NH ₃ PbI _x Br _y (0≤x≤3 real, 0≤y≤3 real and x+y=3), CH ₃ NH ₃ PbCl _x Br _y (reality with 0≤x≤3, real with 0≤y≤3 and x+y=3), CH ₃ NH ₃ PbI _x F _y (real with 0≤x≤3, 0≤y≤3 Phosphorus real and x+y=3), NH ₂ CH=NH ₂ PbI _x Cl _y (real as 0≤x≤3, real as 0≤y≤3 and x+y=3),NH ₂ CH=NH ₂ PbI _x Br _y (reality with 0≤x≤3, real with 0≤y≤3 and x+y=3), NH ₂ CH=NH ₂ PbCl _x Br _y (real with 0≤x≤3, 0≤y ≤3 real and x+y=3), NH ₂ CH=NH ₂ PbI _x F _y (0≤x≤3 real, 0≤y≤3 real 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 ( 0≤x≤3 real number, 0≤y≤3 real number and x+y=3), NH ₂ C(CH ₃ )=NH ₂ PbI _x Br _y (0≤x≤3 real number, 0≤y≤ 3 real and x+y=3), NH ₂ C(CH ₃ )=NH ₂ PbCl _x Br _y (0≤x≤3 real, 0≤y≤3 real 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 a real number with 0<y<1) , 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), 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, 0≤y ≤3 real and x+y=3), NH ₂ C(NH ₂ )=NH ₂ PbI _x F _y (0≤x≤3 real, 0≤y≤3 real 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 Phosphorus 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 0.05 ≤y≤0.3 real) or NH ₂ C(NH ₂ )=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) And the like.

In the perovskite compound solution, the metal halide is previously a metal cation (M, N, N ¹ and/or N ² ) and a halogen ion (X) in the perovskite compound based on Formula 4, Formula 5 or Formula 6. ).

That is, the metal halide may satisfy the following Chemical Formula 7, Chemical Formula 8 or Chemical Formula 9.

(Formula 7)

MX ₂

In the formula (7), M is a divalent metal ion, 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.

(Formula 8)

(M _1-a N _a )X ₂

In Formula 8, M is a divalent metal ion, N is a doped metal ion selected from one or more of a monovalent metal ion and a trivalent metal ion, 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.

(Formula 9)

(N ¹ _1-b N ² _b )X ₂

In the formula (9), N ¹ is a monovalent metal ion, N ² is a trivalent metal ion, b is a real number of 0.4 ≤ b ≤ 0.6, 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 perovskite compound solution, the organohalide may mean a compound of an organic cation (A) and a halogen ion (X) in the perovskite compound based on Chemical Formula 4, Chemical Formula 5 or Chemical Formula 6 above. It can be represented by AX.

In an embodiment, the organohalide may be represented by Chemical Formula 10 below.

(Formula 10)

AX

In the formula (10), A is an organic cation, specifically a monovalent organic cation, A is an organic ammonium ion, or an organic ammonium ion and an amidinium-based ion, 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.

According to an advantageous example described above, when the organic cation includes both an organic ammonium ion and an amidinium-based ion, the organic halide may satisfy Formula 11 below.

(Formula 11)

A ^a _(1-x) A ^b _x X

In Formula 11, A ^b is a monovalent organic ammonium ion, A ^a is an amidinium-based ion, X is a halogen ion, x is a real number of 0<x<1, specifically x is a real number of 0.3 to 0.05, More specifically, x is a real number from 0.2 to 0.05. In this case, the halogen ion is I ^- may be selected from at least one or both ^-, Br ^-, F ^- and Cl.

The solvent of the perovskite compound solution is N,N-dimethylformamide (DMF), gamma-butyrolactone (GBL), 1-methyl-2-pyrrolidone (1 -Methyl-2-pyrolidinone, N,N-dimethylacetamide, dimethylsulfoxide (DMSO), N,N-dimethylformamide DMF or mixed solvents thereof However, it is not necessarily limited to this.

The perovskite compound solution may contain an organometallic halide or metal halide at a concentration of 1 to 1.5 molar in terms of forming a stable perovskite compound film by simple application and drying. It goes without saying that the present invention cannot be limited by the concentration of organometal halide or metal halide in solution. In addition, when the perovskite compound solution contains a metal halide and an organic halide, the metal halide satisfies the stoichiometric ratio (eg, a molar ratio of 1: 1) of the organometal halide of the perovskite structure. It may contain cargo and organic halides, but is not necessarily limited thereto, and may contain excess metal halide or organic halide if necessary.

The present invention includes a method for producing a perovskite compound membrane using the above-described perovskite compound solution.

In detail, the method of manufacturing a perovskite compound membrane according to the present invention includes applying and drying a perovskite compound solution.

As the perovskite compound solution has a long-term stability that does not change its properties with time, it is possible to manufacture a high-quality perovskite compound film with reproducibility, and strict management in the process from manufacturing to manufacturing storage application of the solution. And since no control is required, processability is increased, and a high-quality perovskite compound film can be stably and reproducibly mass produced.

The application of perovskite compound solution can be spray, inkjet printing, slot die coating, gravure printing, flexographic printing, doctor blade coating, screen printing, electrostatic hydraulic printing, micro contact printing, imprinting, reverse offset printing, bar -Coating, gravure offset printing, roll coating, spin coating, etc. may be performed, but the present invention is not limited thereto. Drying may be performed at a temperature of room temperature to 200°C, and stably at a temperature of room temperature to 150°C, but is not limited thereto.

Upon application, a two-step application of sequentially applying a non-solvent after applying the perovskite compound solution may be performed. Two-step coating is advantageous for forming a dense perovskite compound film, but a perovskite compound film may be formed using other known methods. For example, the preparation of a perovskite compound membrane using a solution coating may be performed with reference to Applicants' Patent Publication No. 2014-0035285, Patent Publication No. 2014-0035284, or Patent Publication No. 2014-0035286. The contents of the applicant's published patent applications 2014-0035285, published patent applications 2014-0035284 and published patent applications 2014-0035286 are entirely included.

The substrate on which the perovskite compound solution is applied, that is, the substrate on which the perovskite compound film is formed, is an electronic device such as a transistor, a light emitting device generating light, a memory device, a photovoltaic device (solar cell), a sensor, etc. , According to the basic structure of the device provided with the perovskite compound film, a component provided under the perovskite compound film may be a preformed substrate.

If a person in the related field, such as an electronic device such as a transistor, a light emitting device that generates light, a memory device, a photovoltaic device (solar cell), a sensor, etc., considers the basic structure of the desired device and manufactures the desired device In order to form a perovskite compound film after forming a lower component on a support before forming a perovskite compound film, and then forming an upper component located on top of the perovskite compound film suitable for the device , Can produce the desired device.

Among various applications of the perovskite compound, an example of a perovskite solar cell in which a commercially important perovskite compound film is provided as a light absorbing layer is described in more detail.

The present invention includes a method of manufacturing a perovskite solar cell using the above-described perovskite compound solution.

A method of manufacturing a perovskite solar cell according to the present invention includes a first electrode; Forming a light absorbing layer which is a perovskite compound film by applying and drying the perovskite compound solution described above on a substrate on which the first charge carrier is formed; And forming a second charge carrier and a second electrode over the light absorbing layer.

The first charge carrier and the second charge carrier may be charge carriers that transfer complementary charges to each other. For example, when the first charge carrier is an electron carrier, the second charge carrier may be a hole carrier. The electron transporting body can be formed by application or vapor deposition. Specifically, a solution (or slurry) in which an electron transport material is dispersed, such as a solution in which an organic electron transport material is dissolved or an electron conductive metal oxide, may be coated and dried, or optionally, a dried product may be heat-treated. Alternatively, the electron transporter may be formed using vapor deposition such as physical vapor deposition or chemical vapor deposition. As an example of the porous electron transporter, the electron transporter may be manufactured by applying a slurry containing metal oxide particles on an electrode, drying and heat treatment.

When the charge carrier is a major transport, the major transport may be formed by application or vapor deposition. Specifically, a solution in which an organic hole transport material is dissolved or a dispersion (or slurry) in which an inorganic hole transport material is dispersed may be coated and dried, or optionally, a dried product may be heat-treated. Alternatively, the hole transporter may be formed using deposition such as physical vapor deposition or chemical vapor deposition of a hole-conducting inorganic material.

The present invention includes a perovskite compound membrane prepared using the above-described perovskite compound solution. The perovskite compound film according to the present invention contains sulfur, specifically element-sulfur, and element-sulfur may be in a state homogeneously contained in the perovskite compound film.

In the perovskite compound membrane derived from the perovskite compound solution described above, the perovskite compound may be similar to or the same as described above based on the above-described formulas 4, 5, and 6, and the perovskite compound membrane It may contain 0.5 to 1 mole of elemental sulfur relative to 1 mole of organic ammonium ions.

The present invention includes a device comprising a perovskite compound film derived from the perovskite compound solution described above.

At this time, the device may include an electronic device such as a transistor, a light emitting device, a memory device, a photovoltaic device (solar cell), a sensor, or the like.

As a typical example, the device may be a perovskite solar cell, and the perovskite solar cell according to the present invention includes a first electrode; A first charge carrier; A perovskite compound membrane derived from the above-described perovskite compound solution; A second charge carrier; And a second electrode.

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

The electron carrier may be a metal oxide used for electron transfer in a conventional quantum dot-based solar cell, dye-sensitized solar cell, or perovskite-based solar cell. As a specific example, the metal oxide is titanium oxide, zinc oxide, indium oxide, tin oxide, tungsten oxide, niobium oxide, molybdenum oxide, magnesium oxide, barium oxide, zirconium oxide, strontium oxide, lanthanum oxide, vanadium oxide, aluminum Oxides, yttrium oxides, scandium oxides, samarium oxides, gallium oxides, and strontium-titanium oxides, and mixtures thereof or mixtures thereof (including solids).

The electron transporting body may have a structure in which a porous metal oxide film and a dense metal oxide film are stacked. The thickness of the porous metal oxide film may be 50 nm to 10 μm, specifically 50 nm to 1000 nm. In the case of a porous membrane, the specific surface area may be 10 to 100 m ² /g. The porous metal oxide film may have a porous structure due to empty spaces between the metal oxide particles, and the average particle diameter of the metal oxide particles may be 5 to 500 nm, but is not limited thereto. As described above, when the electron transporter includes a porous metal oxide film, a dense film of a metal oxide may be further provided below the porous film. The dense film of the metal oxide serves to prevent contact between the light absorber (perovskite compound) and the electrode, and at the same time, it can serve to transfer electrons. The thickness of the dense film of the metal oxide may be substantially 10 nm or more, more substantially 10 nm to 100 nm, and even more substantially 50 nm to 100 nm.

The hole transporter may be an organic hole transporter. The organic hole transporter may include an organic hole transport material, specifically, a single molecule to a polymer 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 or perovskite-based solar cell using an inorganic semiconductor quantum dot as a dye.

Non-limiting examples of organic hole transporters, pentacene, coumarin 6, 3-(2-benzothiazolyl)-7-(diethylamino)coumarin), ZnPC (zinc phthalocyanine), CuPC (copper phthalocyanine) , TiOPC (titanium oxide phthalocyanine), Spiro-OMeTAD (2,2,2',7,7,7'-tetrakis(N,N-di-p-methoxyphenyl amine)-9,9,9'-spirobi fluorene) , 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), N3(cis-di(thiocyanato)-bis(2,2'-bipyridyl-4,4'-dicarboxylic acid)-ruthenium(II)),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-c o-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 their And materials selected from one or more of the copolymers.

As a non-limiting and specific example, the hole transporter may be a thin film of an organic hole transport material, and the thickness of the thin film may be 10 nm to 500 nm. Typically, the organic material-based hole transporter has tertiary butyl pyridine (TBP), lithium bisSI (trifluoro methanesulfonyl) imide) and tris(2-(1H-pyrazol-1-yl)pyridine)cobalt for improving properties such as conductivity improvement It may contain additives such as (III).

The perovskite compound film derived from the perovskite compound solution contains sulfur, specifically element-sulfur, and the element-sulfur may be in a state homogeneously contained in the perovskite compound membrane. The perovskite compound membrane may contain 0.5 to 1 mole of elemental sulfur relative to 1 mole of organic ammonium ions.

In the perovskite compound membrane derived from the perovskite compound solution, the perovskite compound may be similar to or the same as described above based on the above formulas 4, 5 and 6. The thickness of the perovskite compound solution-derived perovskite compound film may be 100 nm to 2 μm, more specifically 200 to 1 μm, and more specifically 300 nm to 800 nm, but is not limited thereto.

At least one of the first electrode and the second electrode may be a transparent electrode. The transparent electrode material may be any material that is commonly used as an electrode material for the front electrode in a solar cell. The other electrode is sufficient as long as it is a material commonly used as an electrode material for the front electrode (transparent electrode) or rear electrode (opaque electrode).

The electrode material of the back electrode (opaque electrode) may be one or more materials selected from gold, silver, platinum, palladium, copper, aluminum, carbon, cobalt sulfide, copper sulfide, nickel oxide, and combinations thereof. As a non-limiting example, the electrode material of the front electrode (transparent electrode) includes fluorine-containing tin oxide (FTO), indium-doped tin oxide (ITO), ZnO, CNT (carbon nanotube) , Inorganic conductive electrodes such as graphene, or carbon nanotubes. Conductive nanostructure network-based electrodes based on conductive nanostructures such as graphene, silver nanowires, and metal nanowires, or organic conductive electrodes such as PEDOT:PSS (poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate)) have.

Hereinafter, in order to test the stability of the prepared perovskite compound solution, a perovskite solar cell was prepared to examine its efficiency, and the prepared perovskite compound membrane was analyzed, but the device according to the present invention was perovskite. Of course, it cannot be limited to the skye solar cell.

(Production Example 1)

Preparation of CH ₃ NH ₃ I (CH ₃ NH ₃ =MA, MAI)

Using a 250 mL round bottom flask, 27.86 mL of an aqueous methyl amine solution (40 wt%, Aldrich) and 30 mL of an aqueous hydroiodic acid solution (HI, 57 wt%, Aldrich) were reacted at 0° C. for 3 hours with stirring. Subsequently, the precipitated MAI was recovered by evaporating at 60° C. for 3 hours. The recovered MAI was dissolved in ethanol, recrystallized using diethyl ether, and dried in a vacuum oven overnight at room temperature.

Preparation of CH ₃ NH ₃ Br (CH ₃ NH ₃ =MA, MABr)

MABr was prepared in the same manner as in the MAI preparation, using HBr aqueous solution instead of HI aqueous solution.

Preparation of NH ₂ CH=NH ₂ I (NH ₂ CH=NH ₂ =FA, FAI)

20 mg of formamidine acetate salt (99%, Alfa) was synthesized by reacting with 30 mL of aqueous hydroiodic acid solution (HI, 57 wt%, Aldrich). The evaporation and recrystallization process was the same as in MAI.

Preparation of FAPbI ₃

FAPbI ₃ black powder was prepared by adding a mixture of FAI and lead iodide (PbI ₂ , Alfa) in a 1:1 molar ratio to 2-methoxy ethanol (2ME) and recovering the precipitate by heating.

Preparation of MAPbBr ₃

MAPbBr ₃ powder was prepared by adding MABr and lead bromide (PbBr ₂ , Alfa) in a 1:1 molar ratio to dimethylformamide (DMF) and recovering the precipitate by heating.

(Example 1)

Precursor by adding and dissolving FAPbI ₃ and MAPbBr ₃ in a mixed solvent of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (DMF: DMSO volume ratio = 4: 1) so that the molar ratio of FAPbI ₃ : MAPbBr ₃ is 0.95: 0.05. After preparing the solution, a perovskite compound solution was prepared by adding sulfur so that the molar ratio of MA (MA=CH ₃ NH ₃ ): elemental sulfur was 1: 0.5. At this time, the molar concentration of the metal (Pb, or Pb halide) of the perovskite compound solution was 1.326M.

(Example 2)

In Example 1, a perovskite compound solution was prepared in the same manner as in Example 1, except that sulfur was added so that the molar ratio of MA (MA=CH ₃ NH ₃ ): elemental sulfur was 1:1.

(Example 3)

On a glass substrate (FTO; F-doped SnO ₂ , TEC8, hereinafter referred to as FTO substrate) coated with fluorine-containing tin oxide (first electrode), a dense TiO ₂ thin film (thickness=30 nm) was formed by spray pyrolysis. Spray pyrolysis was carried out at 450° C. using a 20 mM titanium diisopropoxide bis (acetylacetonate) solution.

A TiO2 paste of TiO ₂ powder having an average particle size of 50 nm was spin coated on a TiO ₂ thin film of an FTO substrate at 1500 rpm for 50 seconds and heat-treated at 500° C. for 1 hour to prepare a porous electron transport layer having a thickness of about 200 μm. Did.

Spin coating the perovskite compound solution prepared in Example 1 on the porous electron transport layer (anti-solvent distribution in 10 seconds out of 500 rpm 5 seconds 1000 rpm 5 seconds 5000 rpm 50 seconds) and heat treatment at 150° C. and 100° C. for 10 minutes each. Thus, a 500 nm thick perovskite compound film was prepared. At this time, in order to test the stability of the perovskite compound solution, the perovskite compound solution (hereinafter, constant) was placed in a flask immediately after preparation of the solution, and then stirred at a rate of 60° C. and 500 rpm and left for a certain period of time. Perovskite compound membranes were prepared using time-aged perovskite solutions).

A hole transport layer was formed by spin coating (3000 rpm, 30 sec) a hole transport organic solution of spiro-OMeTAD chlorobenzene (100 mg/mL) on a perovskite compound membrane. The hole transport organic solution was 39.5 μL of TBP (4-tert-Butylpyridine), 23 μL of Li-TFSI acetonitrile solution (520 mg/mL, Li-TFSI=Li-bis(trifluoromethanesulfonyl) imide) and 10 μL of Co(III) -TFSI was added as an additive. Thereafter, a gold electrode having a thickness of 70 nm was formed over the hole transport layer using a thermal evaporation method to manufacture a perovskite solar cell.

(Example 4)

Perovskite in the same manner as in Example 3, except that the perovskite compound membrane was prepared using the perovskite compound solution prepared in Example 2, rather than the perovskite compound solution prepared in Example 1 Skyt Solar Cells were manufactured.

(Comparative Example 1)

A perovskite solar cell was prepared in the same manner as in Example 3, except that the perovskite compound film was prepared using the precursor solution in which sulfur was not added in Example 1.

The efficiency of the solar cell was performed using a solar simulator (Newport, Oriel Sol3A Class AAA) under AM1.5G standard irradiation conditions (100 mW/cm ² ).

(Example 5)

Precursor by adding and dissolving FAPbI ₃ and MAPbBr ₃ in a mixed solvent of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (DMF: DMSO volume ratio = 4: 1) so that the molar ratio of FAPbI ₃ : MAPbBr ₃ is 0.95: 0.05. A perovskite compound solution was prepared by adding sulfur so that the molar ratio of MA (MA=CH ₃ NH ₃ ): elemental sulfur was 1: 0.5 to the precursor solution. The prepared perovskite compound solution was applied and simply dried or heat-treated in air at 150° C. for 4 hours to prepare a thin perovskite compound thin film. A hole transport layer was formed by spin coating (3000 rpm, 30 sec) a hole transport organic solution of spiro-OMeTAD chlorobenzene (100 mg/mL) on the prepared perovskite compound membrane. The hole transport organic solution is 39.5 μL of TBP (4-tert-Butylpyridine), 23 μL of Li-TFSI acetonitrile solution (520 mg/mL, Li-TFSI=Li-bis(trifluoromethanesulfonyl) imide) and 10 μL of Co(III) -TFSI was added as an additive. Thereafter, a gold electrode having a thickness of 70 nm was formed over the hole transport layer using a thermal evaporation method to manufacture a perovskite solar cell.

(Comparative Example 2)

A perovskite solar cell was prepared in the same manner as in Example 5, except that instead of the perovskite compound solution in Example 5, a precursor solution in which sulfur was not added was used.

In the following drawings, 0.03M refers to the result with the perovskite compound solution prepared in Example 1, and 0.06M refers to the result with the perovskite compound solution prepared in Example 2.

Figure 1 is the efficiency of the perovskite solar cell prepared using the aged perovskite solution for each hour of 1 hour, 24 hours, 48 hours, 72 hours and 192 hours in Example 3 and Example 4 (PCE) and Comparative Example 1 in Example 1, 24 hours, 48 hours, 72 hours and 192 hours of efficiency of each perovskite solar cell prepared using an aging precursor solution (PCE) And a comparative example.

As can be seen in Figure 1, when the stabilizer does not contain elemental sulfur (Comparative Example 1), it can be seen that the efficiency of the solar cell is already lowered to 5% or less at the time of aging (leaving) for 72 hours, and perovskite. It can be seen that the solution in which the compound was dissolved rapidly deteriorated.

However, as in Examples 3 and 4, when the elemental sulfur is contained as a stabilizer, it can be seen that it is maintained at 18.99% (Example 3) and 18.93% (Example 4) at the time of 72 hours of aging (leaving), 192 It can be seen that even when the time is aging (left), the efficiency of 18% or more is maintained.

Table 1 below is a table showing the characteristics of a solar cell prepared using a 1 hour aged perovskite solution or precursor solution, and Table 2 uses a 72 hour aged perovskite solution or precursor solution. It is a table showing the characteristics of the solar cell manufactured by. In Tables 1 and 2, Jsc is the short-circuit current density (mAcm ^-2 ), V _OC is the open voltage (V), FF is the fill factor (%), and PCE is the photoelectric conversion efficiency (%).

(Table 1)

(Table 2)

2 is X of the perovskite compound membrane prepared by aging and spin coating and drying the precursor solution without sulfur in Example 1 for 1 hour, 24 hours, 48 hours, 72 hours, and 192 hours, respectively. -It is a diagram showing optical results of perovskite compound films observed by ray diffraction analysis results and aging time.

As can be seen in Figure 2, as the aging time increases, it can be confirmed that α-FAPbI ₃ phase (main peak 2θ=13.9°) becomes unstable and δ-FAPbI ₃ phase (main peak 2θ=11.8°) is generated, In addition, it can be seen that a metal halide (PbI2, main peak 2θ=12.6°) is also produced. In addition, it can be seen that the α-FAPbI ₃ phase is hardly formed and only the δ-FAPbI ₃ phase is detected at the aging time of 192 hours. As a result of X-ray diffraction analysis, it can be seen that the decrease in efficiency of the perovskite solar cell with time in FIG. 1 is due to the generation of the δ-FAPbI ₃ phase.

FIG. 3 is a perovskite compound prepared by aging the perovskite compound solution prepared in Example 1 for 1 hour, 24 hours, 48 hours, 72 hours, and 192 hours, followed by spin coating and drying. It is a diagram showing the optical images of the perovskite compound film observed by the aging time and the result of X-ray diffraction analysis of the film.

As can be seen in FIG. 3, it can be seen that the δ-FAPbI ₃ phase is not detected even at the 192 hour aging time point, and it can be seen that the stable α-FAPbI ₃ phase is formed and maintained independently of the aging time.

4 is aging the precursor solution without addition of sulfur in Example 1 for 1 hour (f-1), 24 hours (f-2) and 72 hours (f-3), respectively, followed by spin coating and drying. Scanning electron microscope images of the prepared perovskite compound membranes and the perovskite solutions prepared in Example 1 were 1 hour (g-1), 24 hours (g-2) and 72 hours (g-3). It is a view showing a scanning electron microscope photograph of a perovskite compound membrane prepared by spin coating and drying after aging for each time.

As can be seen in Figure 4, in the case of a solution containing no elemental sulfur, δ-FAPbI ₃ phase is formed and it is found that a low quality film is formed with a large amount of cracks and pin-holes with increasing surface roughness. In the case of a solution containing elemental sulfur as a stabilizer, it can be seen that a dense perovskite compound film of α-FAPbI ₃ having a similar microstructure is substantially independent of the aging time.

FIG. 5 shows that in Comparative Example 1, the precursor solution in which sulfur of Example 1 was not added was aged for 192 hours, and then spin coated and dried to prepare a perovskite compound film, followed by MAI (methyl) on the perovskite compound film. Ammonium iodine) perovskite solar cell (Recovery by MAI in FIG. 5) prepared by applying a solution followed by heat treatment (150° C., 10 minutes), the precursor solution in which sulfur of Example 1 was not added in Comparative Example 1 was 192 Voltage-current curves of a perovskite solar cell (No Sulfur solution in FIG. 5) equipped with a perovskite compound film prepared by aging for a period of time, and a solar cell prepared in Example 4 (sulfur contained solution in FIG. 5) It is a diagram showing.

6 is an X-ray diffraction result of the perovskite compound film (δ-FAPbI ₃ ) prepared by aging the precursor solution without sulfur in Example 1 for 192 hours, and perovskite prepared by aging for 192 hours. This is a diagram showing the results of X-ray diffraction analysis of a film prepared by additionally applying and heat-treating MAI to a compound compound film (MAI recovery).

As can be seen from the X-ray diffraction results, it can be seen that the film, in which only the δ-FAPbI ₃ phase was completely detected, is converted to α-FAPbI ₃ by additional application and heat treatment of MAI. However, it can be seen that the PCE of the film converted by the additional application and heat treatment of MAI is only 9.24%, so that complete conversion is not achieved.

Through the results of FIGS. 5 and 6, it can be confirmed that the α-FAPbI ₃ phase is stabilized by MAI, and infer that deterioration of the solution in which the perovskite compound is dissolved is due to degradation or reduction of MA. can do.

To directly confirm this, the elemental sulfur was added to the PbI ₂ solution (DMF:DMSO=4:1v/v), and then UV-Vis absorbance was tested. The test results, sulfur ion species was confirmed that the absorption band does not appear (400nm, 600nm) may appear in the ^{_{(S 2 -, S 3 -}} -, S 4, S 4 2-, S 8 2-), further, adding elemental sulfur It was confirmed that the PbI ₂ solution exhibited the same absorbance regardless of presence or absence. In addition, when elemental sulfur was added to the PbI ₂ solution, it was confirmed that PbS was not produced.

In addition, when an interaction between sulfur and iodoplumbate added to the PbI ₂ solution occurs, the colloid size of iodine plumbate should be changed, but through the colloidal size analysis using dynamic light scattering (DLS), sulfur is added. It was confirmed that the iodine plumbate colloid size remained constant with or without.

Through this, although not necessarily limited to this interpretation, in the perovskite compound solution, the elemental sulfur and the organic ammonium ion injected preferentially interact strongly, and the nucleophilic attack of nitrogen against the sulfur prevents the ring opening of S ₈ . It can be interpreted as causing an organic ammonium N-polythioamine salt having an NS bond.

As represented by reaction _{formula, R 2 NH + S 8 ↔} R 2 N + HS 8 - can be represented by ^{_{-, R 2 N + HS 8}} - + R 2 NH ↔ R 2 N + H 2 + R 2 NS 8.

As described above, it can be interpreted that the input elemental sulfur forms a complex with the organic ammonium cation, and inhibits the conversion of the organic ammonium cation to an organic amine, through which the organic ammonium cation in the perovskite solution is aged (left) Therefore, it can be interpreted as being stably maintained unchanged and preventing formation of the δ-FAPbI ₃ phase.

In addition, to examine whether the perovskite compound membrane prepared using the perovskite compound solution contains sulfur, the sulfur content is analyzed using a time-of-flight secondary ion mass spectrometry (TOF-SIMS) and the thickness of the membrane. As a result of analyzing the content in the direction, it was confirmed that the membrane was homogeneously containing sulfur, and it was confirmed that a perovskite compound membrane containing sulfur was prepared at a concentration contained in the perovskite compound solution.

Example 5 and Comparative Example 2 are examples showing an improvement in thermal stability (heat resistance) by adding sulfur. In detail, a solar cell comprising a perovskite compound film prepared in Example 5 and prepared by simple drying without heat treatment at 150° C. for 4 hours, a perovskite compound film prepared by heat treatment at 150° C. for 4 hours A solar cell comprising a solar cell comprising and a perovskite compound film prepared in Comparative Example 2 and heat-treated at 150° C. for 4 hours, each of the solar cells at an AM1.5G standard irradiation condition (100 mW/cm ² ) Comparison was made using a simulator (Newport, Oriel Sol3A Class AAA). As a result, the efficiency of the solar cell heat-treated with a perovskite thin film to which sulfur is not added at 150° C. for 4 hours was about 25% lower than that of a solar cell not heat-treated at 150° C., but when sulfur was introduced The efficiency drop was less than 15%.

7 is a view of the change in Pb 4f binding energy of the perovskite compound membranes prepared in Example 3 and Comparative Example 1 by XPS, and FIG. 8 is a perovskite prepared in Examples and Comparative Examples In the solar cell, it is a diagram showing the measurement of the efficiency change according to the light irradiation time. As can be seen in FIG. 7, it can be seen that the sulfur contained in the perovskite compound film has increased chemical binding energy compared to a thin film composed of pure halide perovskite. Through the results of FIG. 8 and Comparative Example 2, light stability ( 8) and the effect of increasing the heat resistance (Comparative Example 2) can also be seen to occur.

As described above, the present invention has been described by specific matters and limited embodiments and drawings, but it is provided to help a more comprehensive understanding of the present invention, and the present invention is not limited to the above embodiments, and the present invention Various modifications and variations can be made by those skilled in the art.

Accordingly, the spirit of the present invention should not be limited to the described embodiments, and should not be determined, and all claims that are equivalent or equivalent to the scope of the claims as well as the claims to be described later belong to the scope of the spirit of the invention. .

Claims (9)

Metal halides and organohalides that satisfy the stoichiometric ratios of perovskite organometallic halide or organometallic halide; And cyclo-octa page to sulfur (cyclo-S ₈₎ comprises elemental sulfur (elemental sulfur) of the structure, the organic cation of the organic metal organic cation or the organic halide of the halide comprises an organic ammonium ion perovskite Compound solution. According to claim 1,
The organic cation of the organometal halide or the organic cation of the organohalide is a perovskite compound solution further comprising an amidinium-based ion together with the organoammonium ion. According to claim 2,
The perovskite compound solution is a perovskite compound solution containing 0.1 to 2.0 moles of elemental sulfur relative to 1 mole of organic ammonium ions. According to claim 2,
The total number of moles of the organoammonium ions and amidinium ions is 1, and the molar ratio of the organoammonium ions: amidinium ions is 0.7 to 0.95: 0.3 to 0.05. According to claim 2,
The perovskite compound solution is a perovskite compound solution containing an organometallic halide or metal halide in a concentration of 1.0 to 1.5 molar. According to claim 3,
A perovskite compound solution satisfying the following formula 1.
(Equation 1)
[PCE(AF)-PCE(AG72)]/PCE(AF) * 100 ≤ 10%
(PCE (AF) in Equation 1 is the efficiency (%) of a perovskite solar cell equipped with a light absorbing layer prepared from the perovskite compound solution, which is left for 1 hour after being prepared, and PCE (AG72) is The efficiency (%) of a perovskite solar cell equipped with a light-absorbing layer prepared from a perovskite compound solution that was allowed to stand for 72 hours after being prepared) According to claim 3,
A perovskite compound solution satisfying the following formula 2.
(Equation 2)
0.97 ≤ PCE(AF)/PCE(ref)
(PCE (AF) in Equation 2 is the efficiency (%) of a perovskite solar cell equipped with a light absorbing layer prepared from the perovskite compound solution, which is left for 1 hour after being prepared, and PCE (ref) is The efficiency (%) of the perovskite solar cell equipped with the light absorbing layer prepared after leaving the reference solution, which is the same solution as the perovskite compound solution for 1 hour, except that it does not contain elemental sulfur) A method for producing a perovskite compound membrane comprising the step of applying and drying the perovskite compound solution according to any one of claims 1 to 7. A perovskite compound membrane prepared from the perovskite compound solution according to any one of claims 1 to 7, and containing elemental sulfur having a cyclo-octa sulfur (cyclo-S ₈ ) structure.

Images