TWI718254B - Compound having perovskite structure and light emitting material - Google Patents

Abstract

To provide a compound having a perovskite structure with a high light emitting intensity and an light emitting material containing the compound. The compound contains a perovskite-type crystal structure having each of A, B, X and M as a component, and a molar ratio [M/(M+B)], the amount of M divided by the total amount of M and B, is 0.7 or less. (A is a monovalent cation locating at each apex of a hexahedron the center of which is B in the perovskite-type crystal structure. B is a lead ion. M is a divalent or trivalent metal ion substituting a part of B in the perovskite-type crystal structure, and a cation selected from among metal ions the 6-coordinated ionic radius of which is 0.9 Å to 1.5 Å. X represents a component locating at each apex of an octahedron the center of wich is B in the perovskite-type crystal structure, and one or more kinds of ions selected from the group consisting of Cl^-, Br^-, F^-, I^- and SCN^-, and the perovskite-type crystal structure at least contains a chloride ion or a bromide ion as X.)

Description

Compounds with perovskite structure and luminescent materials

The present invention relates to compounds and luminescent materials.

This case is based on Japanese Patent Application No. 2016-30201 filed in Japan on February 19, 2016 and Japanese Patent Application No. 2016-126043 filed in Japan on June 24, 2016, and its content is used in this specification. .

In the past, organic-inorganic perovskite AMX ₃ compounds are known, which include organic cations (A), halide ions (X), and divalent metal ions (M). In recent years, there has been increased interest in the conductivity and luminescence characteristics of compounds having a perovskite structure with ions of group IV elements (Ge, Sn, and Pb) at the position (M) of metal ions.

In particular, when the aforementioned divalent metal ion is Pb(II), a strong luminescence phenomenon at room temperature is observed in the range from the ultraviolet region to the red spectral region (Non-Patent Document 1). In addition, the emission wavelength can also be adjusted by the type of halide ion (X) (Non-Patent Document 2).

[Prior Technical Literature] [Non-Patent Literature]

[Non-Patent Document 1] M. Era, A. Shimizu and M. Nagano, Rep. Prog.Polym.Phys.Jpn., 42,473-474(1999)

[Non-Patent Document 2] L. Protesescu, S. Yakunin, M.I. Bodnarchuk, F. Krieg, R. Caputo, C. H. Hendon, R. X. Yang, A. Walsh, and M. V. Kovalenko, Nano Letter. 15, 3692-3696 (2015)

However, when a compound having a perovskite structure as described in Non-Patent Document 1 or 2 is used as a luminescent material for industrial application, the luminous intensity of the aforementioned compound is required to be further improved.

The present invention was made in view of the above-mentioned problems, and aims to provide a compound having a perovskite structure with high luminous intensity when used as a luminescent material, and a luminescent material containing the aforementioned compound.

In order to solve the above-mentioned problems, the inventors of the present invention, as a result of careful examination, completed the following invention.

That is, the implementation aspects of the present invention include the following inventions [1] to [6].

[1] A compound with a perovskite crystal structure, which is composed of A, B, X, and M, and the amount of M is divided by the total molar ratio of M and B [M/(M The value of +B)] is 0.7 or less. (A is a monovalent cation located at each vertex of a hexahedron centered on B in the aforementioned perovskite crystal structure.

B series lead ion.

M is a divalent or trivalent metal ion, and is a cation selected from metal ions with an ion radius of 0.9 Å or more and 1.5 Å or less in 6 coordination, and at least a part of M is in the aforementioned perovskite crystal structure, substituted Part B.

X represents the component located at each vertex of the octahedron centered on B in the aforementioned perovskite crystal structure, and is selected from chloride ion, bromide ion, fluoride ion, iodide ion and thiocyanate One or more ions in the group of acid radical ions, and at least chloride ions or bromide ions are included as the aforementioned X)

[2] The compound according to [1], which is represented by the following general formula (1).

AB _(1-a) M _a X _(3+δ) (0<a≦0.7, 0≦δ≦0.7). . . (1) (A, B, M, and X series have the same meaning as the above)

[3] The compound according to [1] or [2], wherein the M is an ion of an alkaline earth metal.

[4] The compound according to [3], wherein the M-based calcium ion.

[5] The compound according to any one of [1] to [4], wherein the aforementioned A-based organic ammonium ion.

[6] A luminescent material containing the compound described in any one of [1] to [5].

According to the present invention, a compound having a perovskite structure with high luminous intensity and a luminescent material containing the aforementioned compound can be provided.

Hereinafter, embodiments are shown to explain the present invention in detail.

<Compound> ≪First Embodiment≫

The first embodiment of the compound of this embodiment is a compound having a perovskite crystal structure, which is obtained by dividing the amount of M by the total amount of M and B with A, B, X, and M as components The value of the molar ratio [M/(M+B)] is 0.7 or less.

In this embodiment, A is a monovalent cation located at each vertex of a hexahedron centered on B in the aforementioned perovskite crystal structure.

B is Pb ion.

M is a divalent or trivalent metal ion, and is a cation selected from metal ions with an ion radius of 0.9 Å or more and 1.5 Å or less in 6 coordination, and at least a part of M is in the aforementioned perovskite crystal structure, replacing B Part of it.

X represents the component located at each vertex of the octahedron centered on B in the aforementioned perovskite crystal structure, and is selected from chloride ion, bromide ion, fluoride ion, iodide ion and thiocyanate One or more ions in the group formed by acid radical ions. However, it contains at least chloride ion or bromide ion as X. In addition, here, when 1 Å=0.1 nm (the same applies to the following), the ionic radius of the 6 coordination of M is 0.09 nm or more and 0.15 or less.

Generally, the basic structure of a compound having a perovskite crystal structure is a three-dimensional structure or a two-dimensional structure.

When the basic structure of a 3-dimensional structure to A'B'X _'3 represents. Here, A'series means an organic cation or an inorganic cation, B'series means a metal cation, and X'series means a halide ion or a thiocyanate ion.

When the structure is a substantially two-dimensional structure, to A _'2 B'X' ₄ Fig. Here, A', B', and X'have the same meaning as described above.

When the aforementioned basic structure is the aforementioned three-dimensional structure or two-dimensional structure, it has a three-dimensional network of octahedrons with common vertices shown by _{B'X' 6 with B'as the center and vertices of X'.}

B'is a metal cation that can adopt the octahedral coordination of X'.

A'is located at each vertex of the hexahedron centered on B'.

In this embodiment, the compound having a perovskite-type crystal structure containing A, B, X, and M as components is not particularly limited, and it may have the aforementioned basic structure of three-dimensional structure, two-dimensional structure, and quasi-structure. A compound of any structure of the quasi-two-dimensional structure.

When the aforementioned basic structure is a three-dimensional structure, the perovskite crystal structure is represented by AB _(1-a) M _a X _(3+δ) .

When the structure is a substantially two-dimensional structure, a perovskite-type crystal structure based M _a X _{(4 + δ)} expressed as _{A 2 B (1-a)} .

Here, the aforementioned a represents the aforementioned molar ratio [M/(M+B)].

The aforementioned δ is a number that can be appropriately changed according to the charge balance of B and M, and is preferably 0 or more and 0.7 or less. For example, A is a monovalent cation, B is a divalent anion (Pb ion), M is a divalent or trivalent anion (metal ion), and X is a monovalent anion (selected from chloride ion, bromide ion, fluoride ion) , Iodide ion and thiocyanate ion form more than one type of ion), the aforementioned compound can be made neutral (the charge is 0) The formula chooses δ.

In this embodiment, it is found that in a compound having a perovskite crystal structure, the metal cation of the B'component is set as the Pb ion (the B component), and a part of the plural Pb ions (the B component) is set as the M component, and By substituting divalent or trivalent metal ions with cations selected from metal ions with an ion radius of 0.9 Å or more and 1.5 Å or less in 6 coordination, the luminous intensity of the aforementioned compounds can be improved.

At least a part of M in the compound having a perovskite crystal structure in this embodiment means a component that replaces a part of the lead ion shown by B.

In the compound of this embodiment, in the aforementioned basic structure, M may exist in the position where the B component (lead ion) exists, may also exist in the position where the A component exists, and may also exist in the lattice gaps constituting the skeleton of the basic structure.

The compound having a perovskite-type crystal structure with A, B, X, and M as components in this embodiment will be described later.

In the present embodiment, the perovskite crystal structure refers to a three-dimensional structure when the compound is measured by means of X-ray diffraction (XRD, Cu K α line, X'pert PRO MPD, manufactured by Spectris), for example. perovskite compound: case of _{AB (1-a) M a} X (3 + δ) , the present system typically = (001) peak of the (hkl), or at 2 θ 2 θ = 12 is the position of = to 18 ° There is a compound derived from the peak of (hkl)=(100) at the position of 18 to 25°, preferably the peak of (hkl)=(001) exists at the position of 2 θ=13 to 16°, or the peak of (hkl)=(001) exists at the position of 2 θ= compound peak values (hkl) = (100) of the site 20 to 23 ° from the present, perovskite-dimensional structure of compound 2: case _{A 2 B (1-a)} M a X (4 + δ) , the Usually it is a compound with a peak derived from (hkl)=(002) at the position of 2 θ=1 to 10°, preferably a compound derived from (hkl)=(002) exists at a position of 2 θ=2 to 8° The peak compound.

≪Second Embodiment≫

The compound of this embodiment has a perovskite structure represented by the following general formula (1), in which A is a monovalent cation, M is a divalent or trivalent metal ion, and the ionic radius selected from 6 coordination is 0.9 Cations of metal ions above Å and below 1.5Å, X is selected from more than one ion selected from the group consisting of chloride ion, bromide ion, fluoride ion, iodide ion and thiocyanate ion (except, X Contain at least chloride ion or bromide ion).

APb _(1-a) M _a X _(3+δ) (0<a≦0.7, 0≦δ≦0.7). . . (1)

For example, when A is a monovalent cation, B is a divalent anion (Pb ion), M is a divalent or trivalent anion (metal ion), and X is a monovalent anion (selected from chloride ion, bromide ion, fluorine ion) When the compound ion, iodide ion, and thiocyanate ion form one or more ions), δ can be selected so that the aforementioned compound becomes neutral (the charge is 0).

Generally speaking, the basic structure morphology of the perovskite structure is the A'B'X' ₃ structure.

Here, in this embodiment, the basic structural form of the perovskite is a three-dimensional network _{of A'B'X' 3} structure and a B'X' _{6 octahedron with a common vertex.} The B'component of the A'B'X' ₃ structure can be a metal cation with an octahedral coordination of the X'anion. The A'cation is located at each vertex of the hexahedron centered on the B'atom, and is an organic cation or an inorganic cation in this embodiment. The X'component of the A'B'X' ₃ structure is usually a halide ion in this embodiment.

As a result of careful review, the inventors found that in the basic structure of the compound with the above-mentioned perovskite structure, the metal cation of the B component is set to lead, and a part of the plural lead ions is replaced with other atoms, thereby improving the aforementioned The luminous intensity of the compound.

In this embodiment, the compound having the perovskite structure represented by the general formula (1) (hereinafter, sometimes referred to as "compound (1)") has A, Pb (lead), M, and X as main components.

Here, M means an atom that partially replaces a part of the Pb ion belonging to the metal cation. Furthermore, in the aforementioned basic structure, M may replace the position where the B component (lead ion) exists, or may replace the position where the A component exists, and may also exist in the lattice gaps constituting the skeleton of the aforementioned basic structure.

Hereinafter, the compound having a perovskite-type crystal structure with A, B, X, and M as components in the present embodiment will be described.

[A]

In the compounds of the aforementioned first embodiment and the aforementioned second embodiment, A is a monovalent cation. Among the compounds, A is preferably cesium ion or organic ammonium ion.

As for the organic ammonium ion of A, specifically, the cation represented by the following general formula (A1) can be mentioned.

In the general formula (A1), R ¹ to R ⁴ are each independently a hydrogen atom or an alkyl group, and one of the hydrogen atoms constituting each alkyl group may be substituted with an amino group.

Regarding ^{the alkyl group of R 1} to R ⁴ , it is preferably a linear or branched alkyl group, more preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and still more preferably A straight-chain or branched-chain alkyl group with 1 to 3 carbon atoms. By making the number of alkyl groups and the number of carbon atoms of the alkyl groups small, a three-dimensional perovskite structure with luminescent properties can be obtained. In addition, the total number of carbon atoms of the alkyl groups of ^{R 1} to R ^{4 is preferably 1 to 4. Among R 1} to R ⁴ , it is particularly preferred that R ¹ is an alkyl group of 1 to 3 carbons and R ² to R ⁴ Is a hydrogen atom.

More specifically, A is preferably CH ₃ NH ₃ ⁺ , C ₂ H ₅ NH ₃ ⁺ or C ₃ H ₇ NH ₃ ⁺ , more preferably CH ₃ NH ₃ ⁺ or C ₂ H ₅ NH ₃ ⁺ , most preferably It is CH ₃ NH ₃ ⁺ (methylammonium ion).

[B]

In the compound having a perovskite structure of this embodiment, the B component is a metal cation that becomes the center of the crystal structure. In this embodiment, the B component is Pb (lead). The Pb ion in this embodiment is a divalent Pb ion.

In this embodiment, by substituting a part of the B component (Pb ion) contained in a plurality of crystal structures of the constituent compound with other atoms, the luminous intensity of the compound of this embodiment can be increased.

[M]

In the compounds of the aforementioned first embodiment and the aforementioned second embodiment, at least a part of M replaces a part of the Pb ion belonging to the metal cation.

In more detail, M is a divalent or trivalent metal ion, and is a cation selected from metal ions with an ionic radius of 0.9 Å or more and 1.5 Å or less in 6 coordination.

The ion radius of the metal ion indicated by M is preferably 0.95 Å or more and 1.4 Å or less, more preferably 0.95 Å or more and 1.3 Å or less.

From the viewpoint of maintaining the perovskite crystal structure of the compounds of the first embodiment and the second embodiment and obtaining sufficient luminous intensity, as for M, for example, barium ions (the ionic radius coordinated at 6) ：1.35Å), calcium ion (ionic radius coordinated at 6: 1.00Å), cerium ion (ionic radius coordinated at 6: 1.01Å), dysprosium ion (ionic radius coordinated at 6: 1.07Å), Lanthanum ion (ionic radius in 6 coordination: 1.03Å), samarium ion (ionic radius in 6 coordination: 1.19Å), strontium ion (ionic radius in 6 coordination: 1.18Å), or ytterbium ion (in 6 Coordinated ion radius: 1.02Å) and other element cations. Among them, M is preferably alkaline earth metal ion, more preferably calcium ion.

[a]

From the viewpoint of maintaining the crystal structure of the perovskite compound and obtaining sufficient luminous intensity, the substitution amount of the aforementioned M with respect to Pb is expressed by the molar ratio of a, M and Pb as a=M/(Pb+M) When, a is greater than 0 and 0.7 or less. a is preferably not less than 0.01 and not more than 0.7, more preferably not less than 0.02 and not more than 0.6.

In this embodiment, the value of a is the value calculated from the value measured by ICP-MS of the compound after synthesis as described in the following {Calculation method of a}.

{a's calculation method}

In the compound of this embodiment, the aforementioned a, that is, the value of the aforementioned molar ratio [M/(M+B)] can be measured using ICP-MS (ELAN DRCII, manufactured by PerkinElmer). The aforementioned measurement of the molar ratio is performed by dissolving a compound having a perovskite-type crystal structure using nitric acid or the like.

Specifically, the value of the molar ratio [M/(M+B)] is a value calculated based on the following formula (T). In the following formula (T), Mmol represents the molar number of M measured by ICP-MS, and Pbmol represents the molar number of Pb measured by ICP-MS.

[M/(M+B)]=(Mmol)/(Mmol+Pbmol). . . (T)

In this embodiment, from the viewpoint that the substitution amount of M relative to Pb in the compound after synthesis can be calculated more accurately, it is preferable to use the value calculated by the aforementioned {a calculation method} as " a".

In addition, in a simplified way, the value of a can also be adjusted by adjusting the value of a in the compounds of the aforementioned first embodiment and the aforementioned second embodiment when synthesizing the compound of the present embodiment. The value of the feed-in ratio is calculated.

[X]

X is one or more ions selected from the group consisting of chloride ion, bromide ion, fluoride ion, iodide ion, and thiocyanate ion. However, X contains at least chloride ion or bromide ion.

In X, the amount of chloride ion or bromide ion, when expressed in mole% in X, is preferably more than 10%, more preferably more than 30%, even more preferably more than 70%, especially preferred More than 80%. The upper limit is not particularly limited, and it can be arbitrarily selected as long as it is 100% or less.

Among them, X preferably contains bromide ions. When X is two or more kinds of anions, the content ratio of the anions can be appropriately selected according to the emission wavelength.

When two or more kinds of ions are selected as X, it is preferably a combination of bromide ion and chloride ion, or a combination of bromide ion and iodide ion.

Specific examples of the compounds of the aforementioned first embodiment and the aforementioned second embodiment include CH ₃ NH ₃ Pb _(1-a) Ca _a Br _(3+δ) (0<a≦0.7, 0≦δ) ≦0.7), CH ₃ NH ₃ Pb _(1-a) Sr _a Br _(3+δ) (0<a≦0.7, 0≦δ≦0.7), CH ₃ NH ₃ Pb _(1-a) La _a Br _{( 3+δ)} (0<a≦0.7, 0≦δ≦0.7), CH ₃ NH ₃ Pb _(1-a) Ba _a Br _(3+δ) (0<a≦0.7, 0≦δ≦0.7), CH ₃ NH ₃ Pb _(1-a) Dy _a Br _(3+δ) (0<a≦0.7, 0≦δ≦0.7), CH ₃ NH ₃ Pb _(1-a) Ca _a (Br ₂ Cl) _{( 3+δ)} (0<a≦0.7, 0≦δ≦0.7), or CH ₃ NH ₃ Pb _(1-a) Ca _a (Br ₂ I) _(3+δ) (0<a≦0.7, 0≦ δ≦0.7) and the like are preferable.

The compound with the perovskite structure of this embodiment can be synthesized by a self-organizing reaction using a solution.

For example, the compound containing Pb and the above X, and the compound containing the above M The compound of the above-mentioned X and the compound containing the above-mentioned A and the above-X are applied in a solvent and the solvent is removed, whereby the compound with the perovskite structure of this embodiment can be synthesized.

In another method, a solution obtained by dissolving a compound containing Pb and the aforementioned X, and a compound containing the aforementioned M and the aforementioned X in a solvent is applied, and the solvent is removed to form a coating film. Then, a solution obtained by dissolving the compound containing the aforementioned A and the aforementioned X in a solvent is applied to the aforementioned coating film, and the solvent is removed, whereby the compound having a perovskite structure of this embodiment can be synthesized.

At the time of synthesis, the type and amount of the compound to be formulated may be adjusted so that a and δ in the compound of the first embodiment and the second embodiment become desired values.

≪Luminescence spectrum≫

The compound with the perovskite structure of this embodiment is a luminous body that emits fluorescence in the visible wavelength region. When X is bromide ion, it usually emits a wavelength range of 480 nm or more, preferably 500 nm or more, and more preferably 520 nm or more. The Fluorescent. In addition, it is usually a phosphor that emits a wavelength range of 700 nm or less, preferably 600 nm or less, and more preferably 580 nm or less.

The above upper limit and lower limit can be combined arbitrarily.

The maximum luminous intensity of the compound with the perovskite structure of this embodiment can be obtained from the maximum intensity in the visible wavelength region measured by a fluorometer and the transmittance of excitation light measured by an ultraviolet-visible light absorbance photometer. .

As for the fluorometer, for example, a fluorometer (FT-6500) manufactured by Japan Separation Co., Ltd. can be used. As for the ultraviolet-visible light absorbance photometer, for example, an ultraviolet-visible light absorbance photometer (trade name: V-670) manufactured by JASCO Corporation can be used.

In this embodiment, the maximum luminous intensity of the aforementioned compound is a value corrected according to the following formula (S). In the following formula (S), Pmax represents the maximum intensity in the visible light wavelength region, and Ep represents the transmittance (%) of excitation light.

Pmax/(100-Ep)×100. . . (S)

<Luminescent Material>

This embodiment provides a luminescent material containing the compound of the aforementioned first embodiment and the aforementioned second embodiment.

The luminescent material using the compounds of the aforementioned first embodiment and the aforementioned second embodiment may have components other than the aforementioned compounds of the aforementioned first embodiment and the aforementioned second embodiment. For example, some impurities and compounds that do not have a perovskite structure, and may further contain compounds having the same or similar composition as the compounds of the aforementioned first embodiment and the aforementioned second embodiment.

The form of the luminescent material containing a compound having a perovskite structure is not particularly limited, and can be appropriately determined depending on the application. The compound of the aforementioned first embodiment and the aforementioned second embodiment may be a film-like coating, or it may be an adsorbent made of a powder and adsorbed to a substrate.

The film or adsorbent of the compound having the perovskite structure of this embodiment can be combined with the first embodiment and the second embodiment described above. After the compound in the state is dissolved in an organic solvent, it is formed by a coating method such as a gravure coating method, a bar coating method, a printing method, a spray method, a spin coating method, a dipping method, or a die coating method.

烷、1,3-二氧雜環戊烷、4-甲基二氧雜環戊烷、四氫呋喃、甲基四氫呋喃、苯甲醚、或苯乙醚等醚類；甲醇、乙醇、1-丙醇、2-丙醇、1-丁醇、2-丁醇、第三丁醇、1-戊醇、2-甲基-2-丁醇、甲氧基丙醇、二丙酮醇、環己醇、2-氟乙醇、2,2,2-三氟乙醇、或2,2,3,3-四氟-1-丙醇等醇類；乙二醇單甲基醚、乙二醇單乙基醚、乙二醇單丁基醚、乙二醇單乙基醚乙酸酯、或三乙二醇二甲基醚等二醇醚類；N,N-二甲基甲醯胺、乙醯胺、或N,N-二甲基乙醯胺等醯胺系有機溶劑；乙腈、異丁腈、丙腈、或甲氧基乙腈等腈系有機溶劑；碳酸伸乙酯、或碳酸伸丙酯等碳酸酯系有機溶劑；氯化亞甲基、二氯甲烷、或氯仿等鹵化烴系有機溶劑；正戊烷、環己烷、正己 烷、苯、甲苯、或二甲苯等烴系有機溶劑；或二甲基亞碸等。 The organic solvent is not particularly limited as long as it can dissolve the aforementioned A, Pb, M, X, and other components before dissolution into ions. The organic solvent is a variety of organic compounds and may have a branched structure or a cyclic structure, and may have a plurality of functional groups such as -O-, -CO-, -COO-, or -OH, and hydrogen atoms may be substituted by halogen atoms such as fluorine. As for organic solvents, for example, esters such as methyl formate, ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate, or pentyl acetate; γ-butyrolactone, N- Methyl-2-pyrrolidone, acetone, dimethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, or methyl cyclohexanone and other ketones; diethyl ether, methyl tertiary butyl Base ether, diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-di

Ethers such as alkane, 1,3-dioxolane, 4-methyldioxolane, tetrahydrofuran, methyltetrahydrofuran, anisole, or phenylethyl ether; methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, tertiary butanol, 1-pentanol, 2-methyl-2-butanol, methoxypropanol, diacetone alcohol, cyclohexanol, 2 -Alcohols such as fluoroethanol, 2,2,2-trifluoroethanol, or 2,2,3,3-tetrafluoro-1-propanol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, Glycol ethers such as ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, or triethylene glycol dimethyl ether; N,N-dimethylformamide, acetamide, or Amine-based organic solvents such as N,N-dimethylacetamide; Nitrile-based organic solvents such as acetonitrile, isobutyronitrile, propionitrile, or methoxyacetonitrile; carbonates such as ethylene carbonate or propylene carbonate Organic solvents; halogenated hydrocarbon-based organic solvents such as chlorinated methylene, dichloromethane, or chloroform; hydrocarbon-based organic solvents such as n-pentane, cyclohexane, n-hexane, benzene, toluene, or xylene; or dimethyl Keaqi et al.

Furthermore, it is preferable to apply a solution obtained by dissolving the compound of the aforementioned first embodiment and the aforementioned second embodiment in the aforementioned organic solvent, and then performing any one or more of decompression, drying and air blowing as necessary to make the organic The solvent evaporates. Drying can be carried out at room temperature or heating. The temperature during heating can be appropriately determined in consideration of the time required for drying and the heat resistance of the substrate, and is preferably 50 to 200°C, more preferably 50 to 100°C.

In addition, the technical scope of this embodiment is not limited to the above-mentioned embodiment, and various changes can be added within the range which does not deviate from the summary of this embodiment.

(Example)

Hereinafter, the implementation aspects of the present invention will be described in more detail based on examples and comparative examples, but the present invention is not limited to the following examples.

(Synthesis of compounds with perovskite structure) [Example 1]

Prepare a 2.5cm×2.5cm size glass substrate. The glass substrate was subjected to ozone UV treatment.

_{Lead bromide (PbBr 2} ) was dissolved in N,N-dimethylformamide (hereinafter referred to as "DMF") solvent at 70°C to prepare a lead bromide solution with a concentration of 0.1M. Similarly, calcium bromide (CaBr ₂ ) was dissolved in a DMF solvent at 70°C to prepare a 0.1M calcium bromide solution. Then, methyl ammonium bromide (CH ₃ NH ₃ Br) was dissolved in a DMF solvent at 70° C. to prepare a 0.1 M methyl ammonium bromide solution.

The above-mentioned lead bromide solution and calcium bromide solution were mixed in molar ratio so that Ca/(Ca+Pb) became 0.03 to prepare a solution. The obtained mixed solution and the above-mentioned methylammonium bromide solution are further mixed in molar ratio so that methylammonium bromide/(Ca+Pb)=1.

The solution was applied to the glass substrate by spin coating at a rotation speed of 1000 rpm, and dried in the atmosphere at 100° C. for 10 minutes to obtain a coating film of a compound having a perovskite structure.

The compound of the aforementioned coating film was measured by means of X-ray diffraction (XRD, Cu K α line, X'pert PRO MPD, manufactured by Spectris), and it was confirmed that the compound at 2 θ=14° has a source ( hkl) = the peak of (001) and is a 3-dimensional perovskite structure.

[Example 2]

Except that Ca/(Ca+Pb) was set to 0.05, a coating film of a compound having a perovskite structure was obtained in the same manner as in Example 1 above.

[Example 3]

Except that Ca/(Ca+Pb) was set to 0.1, a coating film of a compound having a perovskite structure was obtained in the same manner as in Example 1 above.

[Example 4]

Except that Ca/(Ca+Pb) was set to 0.2, a coating film of a compound having a perovskite structure was obtained in the same manner as in Example 1 above.

[Comparative Example 1]

Prepare a 2.5cm×2.5cm size glass substrate. The glass substrate was subjected to ozone UV treatment.

_{Lead bromide (PbBr 2} ) was dissolved in DMF solvent at 70°C to prepare a lead bromide solution with a concentration of 0.1M. Methyl ammonium bromide (CH ₃ NH ₃ Br) was dissolved in DMF solvent at 70° C. to prepare a 0.1 M methyl ammonium bromide solution. Then, in terms of molar ratio, the solution was mixed so that methylammonium bromide/Pb=1.

The solution was applied to the glass substrate by spin coating at a rotation speed of 1000 rpm, and dried at 100° C. for 10 minutes to obtain a coating film of a compound having a perovskite structure.

[Comparative Example 2]

Prepare a 2.5cm×2.5cm size glass substrate. The glass substrate was subjected to ozone UV treatment.

_{Lead iodide (PbI 2} ) was dissolved in DMF solvent at 70°C to prepare a lead iodide solution with a concentration of 0.1M. Methyl ammonium iodide (CH ₃ NH ₃ I) was dissolved in DMF solvent at 70° C. to prepare a 0.1 M concentration of methyl ammonium iodide solution. Then, in terms of molar ratio, the solution was mixed so that methylammonium iodide/Pb=1.

The solution was applied to the glass substrate by spin coating at a rotation speed of 1000 rpm, and dried at 100° C. for 10 minutes to obtain a coating film of a compound having a perovskite structure.

[Comparative Example 3]

Prepare a 2.5cm×2.5cm size glass substrate. The glass substrate was subjected to ozone UV treatment.

_{Lead iodide (PbI 2} ) was dissolved in DMF solvent at 70°C to prepare a lead iodide solution with a concentration of 0.1M. Similarly, calcium iodide (CaI ₂ ) was dissolved in DMF solvent at 70°C to prepare a calcium iodide solution with a concentration of 0.1M.

The above-mentioned lead iodide solution and calcium iodide solution were mixed in molar ratio so that Ca/(Ca+Pb) became 0.05 to prepare a solution. The obtained mixed solution and the methylammonium bromide solution described in [Example 1] were further mixed in molar ratio so that methylammonium bromide/(Ca+Pb)=1.

The solution was applied to the glass substrate by spin coating at a rotation speed of 1000 rpm, and dried in the atmosphere at 100° C. for 10 minutes to obtain a coating film of a compound having a perovskite structure.

(Luminescence spectrum measurement)

Using a fluorometer (manufactured by JASCO Corporation, trade name FT-6500, wavelength cut-off filter below 430nm, excitation light 430nm, high sensitivity) was used to measure the perovskite structure compounds obtained in Examples 1 to 4 and Comparative Example 1 Luminescence spectrum of coated film. In addition, the transmittance (%) of the aforementioned coating film was measured using an ultraviolet-visible light absorbance photometer. As for the ultraviolet visible light absorbance photometer, the product name V-670 manufactured by JASCO Corporation (the same machine is also used below).

In addition, the comparison of the luminous intensity between the aforementioned coating films was performed by correcting the maximum luminous intensity near the wavelength of 530 nm by the following formula (S)-1.

[Maximum luminous intensity near wavelength 530nm/(100-wavelength 430nm penetration Rate)]×100. . . (S)-1

(Luminescence spectrum measurement)

The coating film of the compound with the perovskite structure obtained in Comparative Examples 2 and 3 was measured using a fluorometer (manufactured by JASCO Corporation, trade name FT-6500, wavelength cut-off filter below 600nm, excitation light 550nm, high sensitivity) Luminescence spectrum. In addition, the transmittance of the aforementioned coating film was measured using an ultraviolet-visible light absorbance photometer.

In addition, the comparison of the luminous intensity between the aforementioned coating films was performed by correcting the maximum luminous intensity near the wavelength of 750 nm with the following formula (S)-2.

[Maximum luminous intensity near wavelength 750nm/(100-transmittance at wavelength 550nm)]×100. . . (S)-2

In the following Table 1, the constitution and the maximum luminous intensity of the solutions of the compounds with the perovskite structure of Examples 1 to 4 and Comparative Examples 1 to 3 are described. In Table 1, "M/(M+Pb)" is the value in the feed ratio of "a" in the above general formula (1).

From the above results, it can be confirmed that the luminescent materials of Examples 1 to 4 containing the perovskite structure compound of this embodiment have superior luminous intensity compared with the perovskite structure compound of Comparative Examples 1 to 3.

(Synthesis of compounds with perovskite structure) [Example 5]

Prepare a 2.5cm×2.5cm size glass substrate. The glass substrate was subjected to ozone UV treatment.

_{Lead bromide (PbBr 2} ) was dissolved in DMF solvent at 70°C to prepare a lead bromide solution with a concentration of 0.1M. Similarly, strontium bromide (SrBr ₂ ) was dissolved in DMF solvent at 70° C. to prepare a 0.1 M concentration of strontium bromide solution. Then, methyl ammonium bromide (CH ₃ NH ₃ Br) was dissolved in a DMF solvent at 70° C. to prepare a 0.1 M methyl ammonium bromide solution.

The above-mentioned lead bromide solution and strontium bromide solution were mixed in molar ratio so that Sr/(Sr+Pb) became 0.1 to prepare a solution. The obtained mixed solution and the above-mentioned methyl ammonium bromide solution are further mixed in a molar ratio such that methyl ammonium bromide/(Sr+Pb)=1.

The solution was applied to the glass substrate by spin coating at a rotation speed of 1000 rpm, and dried in the atmosphere at 100° C. for 10 minutes to obtain a coating film of a compound having a perovskite structure.

[Example 6]

Except that Sr/(Sr+Pb) is set to 0.2, it is the same as the above embodiment 5 In this way, a coating film of a compound with a perovskite structure is obtained.

[Example 7]

Except that Sr/(Sr+Pb) was set to 0.3, a coating film of a compound having a perovskite structure was obtained in the same manner as in Example 5 above.

[Example 8]

Except that Sr/(Sr+Pb) was set to 0.5, a coating film of a compound having a perovskite structure was obtained in the same manner as in Example 5 above.

[Example 9]

Prepare a 2.5cm×2.5cm size glass substrate. The glass substrate was subjected to ozone UV treatment.

_{Lead bromide (PbBr 2} ) was dissolved in DMF solvent at 70°C to prepare a lead bromide solution with a concentration of 0.1M. Similarly, lanthanum bromide (LaBr ₃ ) was dissolved in DMF solvent at 70° C. to prepare a 0.1 M concentration of lanthanum bromide solution. Then, methyl ammonium bromide (CH ₃ NH ₃ Br) was dissolved in a DMF solvent at 70° C. to prepare a 0.1 M methyl ammonium bromide solution.

The above-mentioned lead bromide solution and lanthanum bromide solution were mixed in molar ratio so that La/(La+Pb) became 0.05 to prepare a solution. The obtained mixed solution and the above-mentioned methyl ammonium bromide solution are further mixed in a molar ratio such that methyl ammonium bromide/(La+Pb)=1.

The solution was applied to the glass substrate by spin coating at a rotation speed of 1000 rpm, and dried in the atmosphere at 100°C for 10 minutes to obtain Coating film of compound with perovskite structure.

[Example 10]

Except that La/(La+Pb) was set to 0.1, a coating film of a compound having a perovskite structure was obtained in the same manner as in Example 9.

(Luminescence spectrum measurement)

The comparison method of the luminous intensity was performed in the same manner as in the above-mentioned Examples 1 to 4 and Comparative Example 1.

Table 2 below describes the structure and maximum luminous intensity prepared by the solution of the compound with the perovskite structure of Examples 5 to 10 and Comparative Example 1. In Table 2, "M/(M+Pb)" is the value of the feed-in ratio of "a" in the above general formula (1).

From the above results, the luminescent materials of Examples 5 to 10 containing the compound with the perovskite structure of this embodiment are compared with Comparative Example 1. Compared with the compound with perovskite structure, it can be confirmed that it has excellent luminous intensity.

≪Measurement by ICP-MS≫

1 mL of nitric acid was added to the compound having the perovskite crystal structure on the glass substrate obtained in Examples 5 to 8 to dissolve the compound having the perovskite crystal structure. Use ion-exchanged water to make a total of 10 ml of the dissolved solution, measure the amount of Pb and M by ICP-MS (ELAN DRCII, manufactured by PerkinElmer), and substitute the amount of M contained in the compound with a perovskite crystal structure In the formula of (M)/(M+Pb), evaluate.

As a result of the measurement performed by ICP-MS, the value of [M/(M+Pb)] in Example 5 is 0.10.

As a result of the measurement performed by ICP-MS, the value of [M/(M+Pb)] in Example 6 is 0.20.

As a result of the measurement by ICP-MS, the value of [M/(M+Pb)] in Example 7 is 0.29.

As a result of the measurement performed by ICP-MS, the value of [M/(M+Pb)] in Example 8 is 0.51.

[Example 11]

Prepare a 2.5cm×2.5cm size glass substrate. The glass substrate was subjected to ozone UV treatment.

_{Lead bromide (PbBr 2} ) was dissolved in N,N-dimethylformamide (hereinafter referred to as "DMF") solvent at 70°C to prepare a lead bromide solution with a concentration of 0.1M. Similarly, barium bromide (BaBr ₂ ) was dissolved in DMF solvent at 70°C to prepare a barium bromide solution with a concentration of 0.1M. Then, methyl ammonium bromide (CH ₃ NH ₃ Br) was dissolved in a DMF solvent at 70° C. to prepare a 0.1 M methyl ammonium bromide solution.

The above-mentioned lead bromide solution and barium bromide solution were mixed in molar ratio so that Ba/(Ba+Pb) became 0.03 to prepare a solution. The obtained mixed solution and the above-mentioned methyl ammonium bromide solution are further mixed in a molar ratio such that methyl ammonium bromide/(Ba+Pb)=1.

The solution was applied to the glass substrate by spin coating at a rotation speed of 1000 rpm, and dried in the atmosphere at 100° C. for 10 minutes to obtain a coating film of a compound having a perovskite structure.

[Example 12]

Except that Ba/(Ba+Pb) was set to 0.05, a coating film of a compound having a perovskite structure was obtained in the same manner as in Example 11 above.

[Example 13]

Except that Ba/(Ba+Pb) was set to 0.1, a coating film of a compound having a perovskite structure was obtained in the same manner as in Example 11 above.

[Example 14]

Prepare a 2.5cm×2.5cm size glass substrate. The glass substrate was subjected to ozone UV treatment.

_{Lead bromide (PbBr 2} ) was dissolved in N,N-dimethylformamide (hereinafter referred to as "DMF") solvent at 70°C to prepare a lead bromide solution with a concentration of 0.1M. Similarly, dysprosium bromide (DyBr ₃ ) was dissolved in a DMF solvent at 70°C to prepare a 0.1M dysprosium bromide solution. Then, methyl ammonium bromide (CH ₃ NH ₃ Br) was dissolved in a DMF solvent at 70° C. to prepare a 0.1 M methyl ammonium bromide solution.

The above-mentioned lead bromide solution and dysprosium bromide solution are mixed in molar ratio so that Dy/(Dy+Pb) becomes 0.1 to prepare a solution. The obtained mixed solution and the above-mentioned methyl ammonium bromide solution are further mixed in a molar ratio such that methyl ammonium bromide/(Dy+Pb)=1.

The solution was applied to the glass substrate by spin coating at a rotation speed of 1000 rpm, and dried in the atmosphere at 100° C. for 10 minutes to obtain a coating film of a compound having a perovskite structure.

[Example 15]

Prepare a 2.5cm×2.5cm size glass substrate. The glass substrate was subjected to ozone UV treatment.

Lead bromide (PbBr ₂ ) was dissolved in N,N-dimethylformamide (hereinafter, referred to as "DMF") solvent at 70°C to prepare a lead bromide solution with a concentration of 0.1M. Similarly, calcium bromide (CaBr ₂ ) was dissolved in a DMF solvent at 70°C to prepare a 0.1M calcium bromide solution. Then, methyl ammonium chloride (CH ₃ NH ₃ Cl) was dissolved in a DMF solvent at 70° C. to prepare a 0.1 M concentration of methyl ammonium chloride solution.

The above-mentioned lead bromide solution and calcium bromide solution were mixed so that Ca/(Ca+Pb) became 0.1 in molar ratio to prepare a solution. Will get The mixed solution and the above-mentioned methyl ammonium chloride solution are further mixed in a molar ratio such that methyl ammonium chloride/(Ca+Pb)=1.

The solution was applied to the glass substrate by spin coating at a rotation speed of 1000 rpm, and dried in the atmosphere at 100° C. for 10 minutes to obtain a coating film of a compound having a perovskite structure.

[Example 16]

Prepare a 2.5cm×2.5cm size glass substrate. The glass substrate was subjected to ozone UV treatment.

_{Lead bromide (PbBr 2} ) was dissolved in N,N-dimethylformamide (hereinafter referred to as "DMF") solvent at 70°C to prepare a lead bromide solution with a concentration of 0.1M. Similarly, calcium bromide (CaBr ₂ ) was dissolved in a DMF solvent at 70°C to prepare a 0.1M calcium bromide solution. Next, methyl ammonium iodide (CH ₃ NH ₃ I) was dissolved in a DMF solvent at 70° C. to prepare a 0.1 M methyl ammonium iodide solution.

The above-mentioned lead bromide solution and calcium bromide solution are mixed in molar ratio so that Ca/(Ca+Pb) becomes 0.1 to prepare a solution. The obtained mixed solution and the above-mentioned methyl ammonium iodide solution are further mixed in a molar ratio such that methyl ammonium iodide/(Ca+Pb)=1.

The solution was applied to the glass substrate by spin coating at a rotation speed of 1000 rpm, and dried in the atmosphere at 100° C. for 10 minutes to obtain a coating film of a compound having a perovskite structure.

[Comparative Example 4]

Prepare a 2.5cm×2.5cm size glass substrate. The glass substrate was subjected to ozone UV treatment.

_{Lead bromide (PbBr 2} ) was dissolved in N,N-dimethylformamide (hereinafter referred to as "DMF") solvent at 70°C to prepare a lead bromide solution with a concentration of 0.1M. Then, methyl ammonium chloride (CH ₃ NH ₃ Cl) was dissolved in a DMF solvent at 70° C. to prepare a 0.1 M concentration of methyl ammonium chloride solution. Then, in terms of molar ratio, the solution was further mixed so that methylammonium chloride/(Pb)=1.

The solution was applied to the glass substrate by spin coating at a rotation speed of 1000 rpm, and dried in the atmosphere at 100° C. for 10 minutes to obtain a coating film of a compound having a perovskite structure.

[Comparative Example 5]

Prepare a 2.5cm×2.5cm size glass substrate. The glass substrate was subjected to ozone UV treatment.

_{Lead bromide (PbBr 2} ) was dissolved in N,N-dimethylformamide (hereinafter referred to as "DMF") solvent at 70°C to prepare a lead bromide solution with a concentration of 0.1M. Next, methyl ammonium iodide (CH ₃ NH ₃ I) was dissolved in a DMF solvent at 70° C. to prepare a 0.1 M methyl ammonium iodide solution. Then, in terms of molar ratio, the solution was further mixed so that methylammonium iodide/(Pb)=1.

The solution was applied to the glass substrate by spin coating at a rotation speed of 1000 rpm, and dried in the atmosphere at 100° C. for 10 minutes to obtain a coating film of a compound having a perovskite structure.

(Luminescence spectrum measurement)

The luminescence spectrum of the coating film of the compound having the perovskite structure obtained in Examples 11 to 14 was measured using a fluorometer (manufactured by JASCO Corporation, trade name FT-6500, excitation light 430 nm, high sensitivity). In addition, the transmittance (%) of the aforementioned coating film was measured using an ultraviolet-visible light absorbance photometer.

In addition, the comparison of the luminous intensity between the aforementioned coating films was performed by correcting the maximum luminous intensity around the wavelength of 530 nm with the following formula (S)-3.

[Maximum luminous intensity near wavelength 530nm/(100-transmittance at wavelength 430nm)]×100. . . (S)-3

(Luminescence spectrum measurement)

The luminescence spectrum of the coating film of the compound having the perovskite structure obtained in Example 15 and Comparative Example 4 was measured using a fluorometer (manufactured by JASCO Corporation, trade name FT-6500, excitation light 430 nm, high sensitivity). In addition, the transmittance (%) of the aforementioned coating film was measured using an ultraviolet-visible light absorbance photometer.

In addition, the comparison of the luminous intensity between the aforementioned coating films was performed by correcting the maximum luminous intensity near the wavelength of 500 nm by the following formula (S)-4.

[Maximum luminous intensity near wavelength 500nm/(100-transmittance at wavelength 430nm)]×100. . . (S)-4

(Luminescence spectrum measurement)

The luminescence spectrum of the coating film of the compound having the perovskite structure obtained in Example 16 and Comparative Example 5 was measured using a fluorometer (manufactured by JASCO Corporation, trade name FT-6500, excitation light 430 nm, high sensitivity). In addition, the transmittance (%) of the aforementioned coating film was measured using an ultraviolet-visible light absorbance photometer.

In addition, the comparison of the luminous intensity between the aforementioned coating films is performed by correcting the maximum luminous intensity near the wavelength of 540 nm by the following formula (S)-5.

[Maximum luminous intensity near wavelength 540nm/(100-transmittance at wavelength 430nm)]×100. . . (S)-5

In the following Table 3 and Table 4, the constitution and the maximum luminous intensity of the solution prepared of the compound with the perovskite structure of Examples 11 to 14 and Comparative Examples 4 to 5 are described. In Table 3 and Table 4, "M/(M+Pb)" is the value in the feed-in ratio of "a" in the above general formula (1).

As shown by the above results, the maximum luminous intensity of Examples 11 to 13 using barium ions as divalent or trivalent metal ions and Example 14 using dysprosium ions of this embodiment is higher than that of non-application of this embodiment. Comparative example 1 of morphology.

In addition, the maximum luminous intensity of Example 15 using two types of halide ions (Br and Cl) as X and applying this embodiment was higher than that of Comparative Example 4 not applying this embodiment.

Similarly, the maximum luminous intensity of Example 16 using two types of halide ions (Br and I) as X and applying this embodiment is higher than that of Comparative Example 5 not applying this embodiment.

(Industrial availability)

According to this embodiment, a compound having a perovskite structure with high luminous intensity and a luminescent material containing the aforementioned compound can be provided.

Therefore, the compound having the perovskite structure of the present embodiment and the light-emitting material using the aforementioned compound can be suitably used in the field of light-emitting-related materials.

Claims (6)

A compound with a perovskite crystal structure, which is composed of A, B, X, and M, and the molar ratio obtained by dividing the amount of M by the total amount of M and B [M/(M+B) ] Is greater than 0 and less than 0.7; where A is a monovalent cation located at each vertex of a hexahedron centered on B in the aforementioned perovskite crystal structure; B is a Pb ion; M is a divalent cation Or trivalent metal ions, and are selected from metal ions with an ionic radius of 0.9 Å or more and 1.5 Å or less in 6 coordination and are barium ions, calcium ions, cerium ions, dysprosium ions, lanthanum ions, samarium ions, strontium ions, or The cation of ytterbium ion, and at least a part of M replaces a part of B in the aforementioned perovskite crystal structure; X represents the component at each vertex of the octahedron centered on B in the aforementioned perovskite crystal structure , Is one or more ions selected from the group consisting of chloride ion, bromide ion, fluoride ion, iodide ion and thiocyanate ion, and contains at least chloride ion or bromide ion as the aforementioned X. The compound described in item 1 of the scope of patent application, which is represented by the following general formula (1): AB _(1-a) M _a X _(3+δ) (0<a≦0.7, 0≦δ≦ 0.7)...(1) A, B, M, and X series have the same meaning as the above. The compound described in item 1 or item 2 of the scope of patent application, wherein the aforementioned M is an ion of alkaline earth metal. The compound described in item 3 of the scope of patent application, wherein the aforementioned M Department of calcium ions. The compound described in item 1 or item 2 of the scope of patent application, wherein the aforementioned A is an organic ammonium ion. A luminescent material, which contains the compound described in any one of items 1 to 5 in the scope of the patent application.