KR102399835B1 - Solvent and preparation method for perovskite powder - Google Patents

Abstract

The high yield FAPbI ₃ powder manufacturing method according to an embodiment of the present disclosure is a manufacturing method using FAI and PbI ₂ , dissolving FAI (Formamidinium Iodide) in a solvent, and dissolving PbI ₂ (Lead Iodide) in a solvent. step, drying the solvent to obtain FAPbI ₃ powder.

Description

Solvent for producing perovskite powder and method for producing perovskite powder using the same

The present disclosure relates to a solvent for producing a perovskite powder and a method for producing a perovskite powder using the same, and more particularly, to a solvent for producing a perovskite powder having high phase stability with a high yield, and It relates to a method for manufacturing perovskite powder using the same.

A perovskite solar cell refers to a solid-state solar cell based on a light absorber having a perovskite (ABX ₃ ) structure. The perovskite solar cell has a high extinction coefficient, so it can effectively absorb sunlight even at sub-micrometer thickness. are receiving

As a material of the perovskite solar cell, there is a lead halide perovskite (MAPbI ₃ ) based on methylammonium (MA, Methylammonium). It has been reported that MAPbI ₃ undergoes a reversible phase transition from a tetragonal to a cubic phase in its crystal structure at about 55° C. can affect

Recently, formamidinium (FA)-based lead halide perovskite (FAPbI ₃ ) has shown promise in the field of perovskite-based optoelectronic devices due to its reduced bandgap energy, long charge diffusion distance, and excellent photostability. It shows and draws attention.

However, formamidinium-based lead halide perovskite (FAPbI ₃ ) has a low yield limit. In addition, the formamidinium lead halide perovskite (FAPbI ₃ ) may undergo a structural phase transition from black perovskite (α-FAPbI ₃ ) to yellow biperovskite (δ-FAPbI ₃ ), resulting in phase stability. There is a low problem. Since α-FAPbI ₃ has a relatively high photoelectric conversion efficiency, an approach to obtain a pure black perovskite (α-FAPbI ₃ ) powder with high phase stability is needed.

An object of the present disclosure is to provide a solvent for preparing perovskite powder in high yield and a method for preparing perovskite powder using the same.

An object of the present disclosure is to provide a solvent for preparing α-FAPbI ₃ powder with high yield and a method for preparing perovskite powder using the same.

An object of the present disclosure is to prepare pure α-FAPbI ₃ powder with high phase stability in high yield by controlling the boiling point and dielectric constant of a solvent dissolving a perovskite compound.

The method for preparing perovskite powder according to an embodiment of the present disclosure includes dissolving a first precursor including a first halide in a solvent, dissolving a second precursor including a second halide in a solvent, a solvent Filtering the precipitate contained in the solvent, and drying the precipitate at 100 ℃ or more to obtain a perovskite powder, the boiling point of the solvent is 100 ℃ or more.

The method for manufacturing perovskite powder according to an embodiment of the present disclosure includes the steps of preparing a solvent by mixing two or more different materials having different dielectric constants, dissolving the first precursor in the solvent, the second Dissolving the precursor in a solvent, filtering the precipitate contained in the solvent from the solvent, and drying the precipitate to obtain a perovskite powder.

The method for preparing perovskite powder according to an embodiment of the present disclosure includes dissolving a first precursor including a first halide in a solvent, dissolving a second precursor including a second halide in a solvent, a solvent Filtering the precipitate contained in the solvent from the solvent, and drying the precipitate to obtain a perovskite powder, the dielectric constant of the solvent is less than 17.

According to an embodiment of the present disclosure, the first halide includes Formamidinium Iodide (FAI), the second halide includes PbI ₂ (Lead Iodide), and the perovskite powder corresponds to the FAPbI ₃ powder.

According to an embodiment of the present disclosure, the solvent includes at least one of O-dichlorobenzene and O-xylene.

According to an embodiment of the present disclosure, the precipitate is dried at 100° C. or higher, and the boiling point of the solvent is 100° C. or higher.

According to an embodiment of the present disclosure, the FAPbI ₃ powder corresponds to the α-FAPbI ₃ powder.

According to an embodiment of the present disclosure, the yield of α-FAPbI ₃ powder is greater than 80%.

According to an embodiment of the present disclosure, the filtering includes filtering the precipitate included in the solvent under reduced pressure.

According to an embodiment of the present disclosure, the method further includes stirring the solvent at 100°C to 150°C.

According to an embodiment of the present disclosure, the method further includes adding a material having a boiling point of 100° C. or higher and a dielectric constant of less than 17 to the solvent.

The solvent for dissolving the perovskite compound according to an embodiment of the present disclosure, the boiling point of the solvent is 100 ℃ or more, the dielectric constant of the solvent is less than 17.

Using various embodiments of the present disclosure, it is possible to prepare a high yield of pure perovskite powder using a solvent having an appropriate dielectric constant and boiling point.

By using various embodiments of the present disclosure, it is possible to simplify the perovskite powder manufacturing method.

By using various embodiments of the present disclosure, it is possible to improve the phase stability of the perovskite powder.

Using various embodiments of the present disclosure, yields of perovskite powder can exceed 80%.

Using various embodiments of the present disclosure, a high yield of FAPbI ₃ powder may be prepared using a solvent having an appropriate dielectric constant and boiling point.

By using various embodiments of the present disclosure, the FAPbI ₃ powder manufacturing method can be simplified.

By using various embodiments of the present disclosure, it is possible to improve the phase stability of the FAPbI ₃ powder.

Using various embodiments of the present disclosure, a solvent having a dielectric constant of less than 17 and a boiling point of 100° C. or higher may be provided.

Using various embodiments of the present disclosure, the yield of α-FAPbI ₃ powder can exceed 80%

Hereinafter, specific contents for carrying out the present disclosure will be described in detail with reference to the accompanying drawings. However, in the following description, if there is a risk of unnecessarily obscuring the gist of the present disclosure, detailed descriptions of well-known functions or configurations will be omitted.

Throughout this specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

As used throughout this specification, the term "about" and the like are used to encompass the tolerance when there is a tolerance.

Throughout this specification, the term "at least any one" included in the expression of the Markush format means including one or more selected from the group consisting of the elements described in the expression of the Markush format.

Throughout this specification, reference to "A and/or B" means "A, or B, or A and B."

Throughout this specification, "perovskite" or "PE" refers to a material having a perovskite crystal structure, and may have various perovskite crystal structures in addition to the crystal structure of ABX ₃ .

Throughout this specification, “α-FAPbI ₃ ” refers to a FAPbI ₃ perovskite material having an α phase or an α-FAPbI ₃ phase.

Throughout this specification, the terms "halide", "halogen", "halide" or "halo" refer to a material or composition in which a halogen atom belonging to Group 17 of the periodic table is included in the form of a functional group, for example, chlorine, bromine, fluorine or iodine compounds.

Throughout this specification, "precursor" may mean a precursor or reactant used to prepare perovskite, and is not limited to a specific material.

Throughout this specification, a “solvent” is a substance for dissolving a perovskite precursor. In order to control the dielectric constant of the solvent, a material having a relatively low dielectric constant but not soluble in the perovskite precursor may be added to the solvent.

The method for preparing perovskite powder according to an embodiment of the present disclosure includes dissolving a first material including a first halide in a solvent, dissolving a second material including a second halide in a solvent, a solvent Filtering the precipitate included in the solvent from the solvent, and drying the precipitate to obtain a perovskite powder.

The first halide may correspond to Formula AX, A may be an organic cation, and X may include a halide anion, but is not limited thereto. For example, the first halide may include FAI (Formamidinium Iodide), but is not limited thereto. Also, the first halide may comprise a chalcogenide anion replacing or in addition to at least a portion of the halide anion.

The organic cation means a cation containing carbon. The organic cation may further include other elements, for example, may further include hydrogen, nitrogen or oxygen.

For example, the halide may correspond to an organic halide, and the organic cation included in the organic halide may include at least one or a combination of methylammonium (MA) and formamidinium (FA). For example, the organic halide may correspond to at least one of methylammonium chloride, methylammonium bromide, methylammonium iodide, formamidinium chloride, formamidinium bromide, or formamidinium iodide.

For example, the organic cation may have the formula (R1R2R3R4N) ⁺ . In this case, R1 to R4 may correspond to hydrogen, unsubstituted or substituted C1-C20 alkyl, or unsubstituted or substituted aryl.

For example, the organic cation may have the formula (R5NH3) ⁺ , where R5 may correspond to hydrogen or substituted or unsubstituted C1-C20 alkyl.

For example, the organic cation has the formula (R6R7N=CH-NR8R9) ⁺ , in which case R6 to R9 may correspond to hydrogen, methyl, or ethyl.

The second halide may correspond to formula BX ₂ , wherein B is Pb, Sn, Cu, Ni, Co, Fe, Mn, Cr, Pd, Cd, Yb, Ge, Ca, Sr, Eu, and combinations thereof. It includes a metal cation selected from the group consisting of, and X may include a halide anion, but is not limited thereto. For example, the second halide may correspond to PbI ₂ , but is not limited thereto. In addition, the second halide may comprise a chalcogenide anion replacing or in addition to at least a portion of the halide anion.

The solvent may contain one or more elements selected from oxygen, nitrogen, fluorine, chlorine, bromine and iodine. An example of a solvent for dissolving the perovskite compound, N,N-dimethylacetamide (Dimethylacetamid), 1,4-dioxane (dioxane), diethylamine (diethylamine), ethyl acetate (ethylacetate), tetrahydrofuran (tetrahydrofuran), pyridine, methanol, ethanol, 2-Methoxy ethanol (2ME), dichlorobenzene, glycerin and dimethyl sulfoxide (DMSO, dimethyl sulfoxide), N, At least one or a mixture of two or more of N-dimethylformamide (DMF, dimethylformamide) may correspond to the mixture.

The solvent may additionally include a material having a low dielectric constant in order to lower the dielectric constant of the solvent. According to an embodiment, the solvent may include a material having a dielectric constant of less than 10. For example, the solvent may include at least one of O-dichlorobenzene (dielectric constant: about 9.93) or O-xylene (dielectric constant: about 2.57).

The method for preparing perovskite powder according to an embodiment of the present disclosure includes dissolving a first material including a first halide in a solvent, dissolving a second material including a second halide in a solvent, a solvent It comprises the steps of stirring (stirring) at about 100 ℃ ~ 150 ℃, filtering the precipitate contained in the solvent from the solvent, and drying the precipitate at about 100 ℃ or more.

In the step of stirring the solvent, perovskite crystals are precipitated to form a precipitate. Filtering the precipitate included in the solvent from the solvent may include filtering the solvent under reduced pressure. The use of reduced pressure filtering has the advantage of being able to filter a large amount of material. It is sufficient to filter the perovskite powder dissolved in the solvent by using a method commonly used for solid-liquid separation. As an example, centrifugal separation, reduced pressure filtering, etc. may be mentioned, but is not limited thereto.

The method for preparing perovskite powder according to an embodiment of the present disclosure includes dissolving a first material including a first halide in a solvent, dissolving a second material including a second halide in a solvent, a solvent Stirring at about 100 ° C. to 150 ° C. for about 10 to 30 minutes, filtering the precipitate contained in the solvent from the solvent, and drying the precipitate at about 150 ° C. for about 10 minutes. .

When the solvent is stirred at about 100 ° C. to 150 ° C., or the filtered precipitate is dried at about 100 ° C. or more or about 150 ° C., the effect of improving the phase stability of the resulting perovskite powder was found. In particular, when the perovskite powder corresponds to the FAPbI ₃ powder, the effect of improving the stability of the phase was remarkable. At this time, the first halide includes FAI (Formamidinium Iodide), the second halide includes PbI ₂ (Lead Iodide), and the perovskite powder corresponds to FAPbI ₃ powder.

FAPbI ₃ has a higher crystallization temperature than MAPbI ₃ and, unlike MAPbI ₃ , has a polymorph of a perovskite structure and a non-perovskite structure. The non-perovskite structure has a one-dimensional structure in which the [PbI ₆ ] octahedron is face-sharing, unlike the perovskite structure in which the inorganic [PbI ₆ ] octahedron has corner-sharing and is connected to a three-dimensional network. is in the form For perovskite structure, it is called α-FAPbI ₃ phase with P3m1 space group of monoclinic crystal system, and non-perovskite structure is called δ-FAPbI ₃ phase with P63mc space group of hexagonal crystal system. . Although the δ-FAPbI ₃ phase is thermodynamically stable, it is not suitable as a light absorber for solar cells due to its wide band gap (~2.3 eV) and poor charge transfer characteristics due to the one-dimensional PbI ₂ framework. Since the α-FAPbI ₃ phase and the δ-FAPbI ₃ phase can be reversibly transferred, when the perovskite powder is transferred to the δ-FAPbI ₃ phase, there is a problem in that it cannot be used as a light absorber of a solar cell. Therefore, it is necessary to stably maintain the perovskite powder on δ-FAPbI ₃ .

The α-FAPbI ₃ phase is stably maintained in the perovskite powder prepared by stirring the solvent in which the precursor is dissolved at about 100° C. to 150° C., or drying the filtered precipitate at about 100° C. or more or about 150° C. phenomenon was found. In order to use this phenomenon, the boiling point of the solvent needs to be 100° C. or higher.

In the step of stirring the solvent at about 100° C. to 150° C., perovskite crystals are precipitated to form a precipitate. The first halide includes Formamidinium Iodide (FAI), the second halide includes PbI ₂ (Lead Iodide), and when the perovskite powder corresponds to the FAPbI ₃ powder, a black powder of α-FAPbI ₃ is precipitated. falls to When the precipitate is dried at about 100° C. or higher or about 150° C., a powder of α-FAPbI ₃ is finally prepared. After the black powder of α-FAPbI ₃ is produced as a precipitate in a high temperature solvent and filtered, the filtered black powder is subjected to high temperature drying post-treatment to further improve the phase stability of the perovskite.

The method for preparing perovskite powder according to an embodiment of the present disclosure includes dissolving a first precursor including a first halide in a solvent, dissolving a second precursor including a second halide in a solvent, a solvent Filtering the precipitate contained in the solvent from the solvent, and drying the precipitate to obtain a perovskite powder, the dielectric constant of the solvent corresponds to less than 17.

As the solvent, a solvent that dissolves the perovskite compound may be used. A solvent for dissolving the precursor including FAI and PbI ₂ may be used if the perovskite compound is dissolved. The solvent may mean a polar organic solvent, and may mean an organic solvent in which the solubility of the perovskite compound is 0.5M or more, specifically 0.8M or more, under 1 atm at 20°C.

The solvent in which the precursor is dissolved may be a solvate of a perovskite compound and a solvent dissolving the same. The solvate may refer to a higher-order compound formed between a molecule or ion of a solute (perovskite compound) and a molecule or ion of a solvent.

The solvent is a solvent composed of polar molecules and has a dielectric constant. In order to lower the dielectric constant of the solvent, the dissolution rate of the perovskite precursor is low, but a material having a low dielectric constant may be additionally included. According to an embodiment, the solvent may include a material having a dielectric constant of less than 10. For example, the solvent may include at least one of O-dichlorobenzene (dielectric constant: about 9.93) or O-xylene (dielectric constant: about 2.57).

The perovskite powder manufacturing method according to an embodiment of the present disclosure includes the steps of preparing a solvent by mixing two or more different materials having different dielectric constants, and adding a first precursor including a first halide to the solvent. Dissolving, dissolving a second precursor comprising a second halide in a solvent, filtering a precipitate contained in the solvent from the solvent, and drying the precipitate to obtain a perovskite powder.

The step of preparing the solvent by mixing two or more different materials having different dielectric constants may be performed before or after the step of dissolving the first precursor including the first halide in the solvent.

[Table 1] is a table summarizing the experimental data used to prepare the FAPbI ₃ powder using various solvents. Boiling point (BP, unit: ℃) of solvent used, dielectric constant, yield of FAPbI ₃ powder (Yield, unit: %), amount of solvent (unit: ml), amount of precursor (unit: ml) is a table organized. As a precursor, PbI ₂ and FAI were used in a 1:1 ratio. The data shown in [Table 1] may change some data depending on the working temperature and the amount of solute dissolved in the solvent.

According to an embodiment of the present disclosure, in the case of O-dichlorobenzene or O-xylene, solubility is low but dielectric constant is low, so it may be added to other solvents to lower the dielectric constant of the solvent. For example, when 2-Methoxy ethanol (2ME) and O-dichlorobenzene were mixed at a ratio of 9:1, the dielectric constant was lowered to less than 17, and the yield was improved to 85% (refer to No. 7 in [Table 1]). When 2-Methoxy ethanol (2ME) and O-dichlorobenzene are mixed at 8:2 by increasing the ratio of O-dichlorobenzene, the dielectric constant can be adjusted lower than when mixed at 9:1 (that is, the dielectric constant is 17 Corresponding to excessive), the yield was improved to 90% (refer to No. 8 in [Table 1]).

When 2-Methoxy ethanol (2ME) and O-xylene were mixed at 9:1, the dielectric constant was adjusted to less than 17 (that is, the dielectric constant was less than 17), and the yield was improved to 82% ([ See No. 9 in Table 1]). When the ratio of O-xylene was increased and 2-Methoxy ethanol (2ME) and O-xylene were mixed at 8:2, the dielectric constant could be adjusted lower than when mixed at 9:1, and the yield was improved to 85%. (Refer to number 10 of [Table 1]).

From this, it can be confirmed that the lower the dielectric constant of the solvent, the higher the yield of the perovskite powder. When the dielectric constant of the solvent is lowered to less than 17, the FAPbI ₃ powder It was confirmed that the yield exceeded 80%.

number menstruum
(Solvent) boiling point
(BP, ℃) dielectric constant
(Dielectric
constant) yield
(Yield, %) solvent amount
(ml) PbI ₂ +FAI
(1:1,
Unit: g) One N,N-dimethylformamide (DMF) 153 36.7 30 12 12.36 2 Dimethyl sulfoxide (DMSO) 189 46.7 20 12 12.36 3 2-Methoxy ethanol (2ME) 124 17 80 12 12.36 4 γ-bytyrolactone (GBL) 204 39.1 50 12 12.36 5 O-dichlorobenzene 181 9.93 - - 6 O-xylene 144 2.57 - - 7 2-Methoxy ethanol (2ME) and O-dichlorobenzene (9:1) over 100 under 17 85 12 12.36 8 2-Methoxy ethanol (2ME) and O-dichlorobenzene (8:2) over 100 17 too little 90 12 12.36 9 2-Methoxy ethanol (2ME) and O-xylene (9:1) over 100 under 17 82 12 12.36 10 2-Methoxy ethanol (2ME) and O-xylene (8:2) over 100 17 too little 85 12 12.36

Example 1: Numbers 7 and 8 of Table 1

Mix 2ME (2-methoxy ethanol) and o-dichlorobenzene in a ratio of 9:1 or 8:2 in a 70ml vial to prepare 12ml of solvent, and then 3.44g (0.02mol) of FAI (Formamidinium Iodide) is dissolved in the solvent. After that, the same equivalent of PbI ₂ (Lead Iodide) 9.22 g (0.02 mol) is added to a 70 ml glass bottle in which FAI is dissolved, and mixed for 3 hours until PbI ₂ is dissolved. After that, the solvent is stirred in the oil bath prepared at about 100 ~ 150℃ for 10 ~ 30 minutes until the black powder (powder) of α-FAPbI ₃ falls as a precipitate. However, the black precipitate formation time may vary depending on the external temperature. Thereafter, the precipitate was filtered under reduced pressure from the solvent, and the filtered precipitate was dried on a hot plate prepared at 150° C. for 10 minutes to obtain black α-FAPbI ₃ in a yield of 85% or 90%. The above-described method can be similarly applied to numbers 9 and 10 of Table 1.

Example 2: Number 3 of Table 1

Dissolve 3.44 g (0.02 mol) of FAI (Formamidinium Iodide) in 12 ㎖ of 2ME (2-methoxy ethanol) in a 70 ㎖ glass bottle. After that, the same equivalent of PbI ₂ (Lead Iodide) 9.22 g (0.02 mol) is added to a 70 ml glass bottle in which FAI is dissolved, and stirred for 3 hours until PbI ₂ is dissolved. After that, mix the solvent in the oil bath prepared at 100 ~ 150℃ for 10 ~ 30 minutes until the black powder (powder) of α-FAPbI ₃ falls as a precipitate. However, the black precipitate formation time may vary depending on the external temperature. Thereafter, the precipitate is filtered under reduced pressure from the solvent, and the filtered precipitate is dried on a hot plate prepared at 150° C. for 10 minutes to obtain black α-FAPbI ₃ with a yield of 80%.

Comparing Example 1 and Example 2, when a substance having a low dielectric constant such as O-dichlorobenzene or O-xylene is added to the solvent to lower the dielectric constant, it can be seen that the yield of α-FAPbI ₃ powder is improved.

The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to various modifications without departing from the spirit or scope of the disclosure. Accordingly, this disclosure is not intended to be limited to the examples set forth herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Although the present disclosure has been described with reference to some embodiments herein, it should be understood that various modifications and changes can be made without departing from the scope of the present disclosure as understood by those skilled in the art to which the present disclosure pertains. something to do. Further, such modifications and variations are intended to fall within the scope of the claims appended hereto.

Claims (11)

A method for preparing perovskite powder, comprising:
Dissolving the perovskite precursor in a solvent containing 2-Methoxy ethanol (2ME);
filtering the precipitate contained in the solvent from the solvent; and
Drying the precipitate to obtain a perovskite powder
Containing, perovskite powder manufacturing method.
According to claim 1,
The solvent further comprises O-dichlorobenzene or O-xylene, perovskite powder manufacturing method.
3. The method of claim 2,
The boiling point of the solvent is 100 ℃ or more, the dielectric constant of the solvent is less than 17, the perovskite powder manufacturing method.
A perovskite powder prepared according to any one of claims 1 to 3. delete delete delete delete delete delete delete