JP7537883B2 - Luminescent Perovskite Nanoparticles - Google Patents

Description

Article 30, paragraph 2 of the Patent Act applies [Publications, etc.] Date of issue February 25, 2019 Publication Proceedings of the 66th Spring Academic Conference of the Applied Physics Society The Applied Physics Society (distributed by CD-ROM) [Publications, etc.] Date held March 9, 2019 Meeting name and location 66th Spring Academic Conference of the Applied Physics Society Ookayama Campus, Tokyo Institute of Technology (2-12-1 Ookayama, Meguro-ku, Tokyo) [Publications, etc.] Date held June 14, 2019 Meeting name and location 3rd Symposium of Electrochemical Society Student Branch Members, Yamagata University Student Branch Yamagata University Yonezawa Campus (4-3-16 Jonan, Yonezawa, Yamagata) [Publications, etc.] Date of issue June 25, 2019 Publication Proceedings of the 10th International Conference on Organic Molecules and Bioelectronics, p. 302, The Applied Physics Society [Publications, etc.] Date held June 26, 2019 Meeting name, location 10th International Conference on Organic Molecules and Bioelectronics Nara Kasugano International Forum I-RA-KA (101 Kasugano-cho, Nara City, Nara Prefecture) [Publications, etc.] Date issued September 21, 2019 Publication Proceedings of the Tohoku Conference of Chemical Societies, p. 137, Tohoku Branch of the Chemical Society of Japan [Publications, etc.] Date held September 21, 2019 (Period: September 21, 2019 - September 22, 2019) Meeting name, location Tohoku Conference of Chemical Societies Yamagata University Kojirakawa Campus (1-4-12 Kojirakawa-cho, Yamagata City, Yamagata Prefecture) [Publications, etc.] Date issued October 10, 2019 Publication Proceedings of the 7th International Conference on Smart Systems Engineering, page 59, Yamagata University, National University Corporation, Frontier Organic Materials Systems Creation Flex Program [Publications, etc.] Date: October 11, 2019 (Dates: October 10, 2019 - October 11, 2019) Meeting name, location: 7th International Conference on Smart Systems Engineering, Yamagata University, Yonezawa Campus (3-16, Jonan 4-chome, Yonezawa City, Yamagata Prefecture) [Publications, etc.] Date: December 6, 2019 Meeting name, location: CANON Foundation Reunion 2019 (First Square East Tower 2F, 1-5-1 Otemachi, Chiyoda-ku, Tokyo) [Publications, etc.] Date: December 11, 2019 (Dates: December 11, 2019 - December 13, 2019) Meeting name, location: Materials Research Meeting 2019, Yokohama Sanbou Hall Marinellia (2 Yamashita-cho, Naka-ku, Yokohama, Kanagawa Prefecture)

Article 30, paragraph 2 of the Patent Act applies. [Publications, etc.] Date of website posting: December 11, 2019 Website address: https://iopscience.iop.org/article/10.7567/1347-4065/ab4ecd/meta

The present invention relates to perovskite-type luminescent nanoparticles.

Perovskite-type luminescent nanoparticles have excellent optical and electronic properties, and are therefore expected to be used in many fields, including organic LEDs (light emitting diodes), solar cells, laser light sources, micro LED displays, liquid crystal displays, and UV sensors (Patent Document 1).

JP 2018-525671 A

However, there is still room for improvement in the photoluminescence quantum yield (PLQY) of perovskite-type luminescent nanoparticles.

The luminescent nanoparticles of the present invention are perovskite-type luminescent nanoparticles, in which the half-width of the peak corresponding to the (110) plane in the powder X-ray diffraction pattern measured using CuKα radiation is 0.53 to 5.5°, and which contain an organic cation as the A-site cation.

The luminescent nanoparticles of the present invention may be perovskite-type luminescent nanoparticles, in which the half-width of the peak corresponding to the (100) plane in the powder X-ray diffraction pattern measured using CuKα radiation is 0.55 to 1.1°, and which contain an organic cation as the A-site cation.

The luminescent nanoparticles of the present invention are perovskite-type luminescent nanoparticles, in which the half-width of the peak corresponding to the (200) plane in the powder X-ray diffraction pattern measured using CuKα radiation is 0.55° to 1.5°, and the nanoparticles may contain an organic cation as the A-site cation.

In the above-mentioned luminescent nanoparticles, it is preferable that 60 mol % or more of the A-site cations are at least one selected from the group consisting of ammonium cations, guanidium cations, imidazolium cations, pyridinium cations, pyrrolidinium cations, and protonated thiourea cations.

The present invention provides perovskite-type luminescent nanoparticles with improved PLQY.

The luminescent nanoparticles of this embodiment are perovskite-type luminescent nanoparticles, contain an organic cation as an A-site cation, and satisfy at least one of the conditions (1) to (3).
(1) The half-width of the peak corresponding to the (110) plane in the powder X-ray diffraction pattern is 0.53 to 5.5°.
(2) The half-width of the peak corresponding to the (100) plane in the powder X-ray diffraction pattern is 0.55 to 1.1°.
(3) The half-width of the peak corresponding to the (200) plane in the powder X-ray diffraction pattern is 0.55 to 1.5°.
The luminescent nanoparticles preferably satisfy two or more of the conditions (1) to (3), and preferably satisfy all of the conditions (1) to (3). In this specification, the half-width means the full width at half maximum. In addition, the powder X-ray diffraction pattern is represented by the diffraction angle (2θ) on the horizontal axis. In this specification, the powder X-ray diffraction pattern is measured using CuKα radiation (wavelength: about 0.15418 nm).

The lower limit of the half-width of the peak corresponding to the (110) plane in the powder X-ray diffraction pattern is 0.53°, and preferably 0.55°. The upper limit of the half-width of the peak corresponding to the (110) plane in the powder X-ray diffraction pattern is 5.5°, preferably 4°, more preferably 2°, even more preferably 1.5°, and particularly preferably 1.1°.

The lower limit of the half-width of the peak corresponding to the (100) plane in the powder X-ray diffraction pattern is 0.55°, and preferably 0.56°. The upper limit of the half-width of the peak corresponding to the (100) plane in the powder X-ray diffraction pattern is 1.1°, preferably 1.0°, more preferably 0.9°, even more preferably 0.8°, and particularly preferably 0.75°.

The lower limit of the half-width of the peak corresponding to the (200) plane in the powder X-ray diffraction pattern is 0.55°, preferably 0.56°, and more preferably 0.57°. The upper limit of the half-width of the peak corresponding to the (200) plane in the powder X-ray diffraction pattern is 1.5°, preferably 1.3°, more preferably 1.2°, even more preferably 1.0°, and particularly preferably 0.9°.

In powder X-ray diffraction measurements, corrections such as background correction, smoothing, and kα2 removal may be performed on the acquired data.

The luminescent nanoparticles of this embodiment are perovskite-type luminescent nanoparticles, that is, compounds represented by the general formula _ABX3 . Here, A is a chemical species occupying the A site (i.e., A-site cation), B is a chemical species occupying the B site (i.e., B-site cation), and X is a chemical species occupying the X site. Note that although the terms A-site cation and B-site cation have a formal charge of +1 and +2, respectively, they merely represent the chemical species at the A site and B site, and may not have a charge as the formal charge in the actual compound.

The A-site cations are at least one of organic and inorganic cations. Inorganic cations include alkali metal ions. Alkali metal ions include Cs ⁺ , Rb ⁺ , K ⁺ , Na ⁺ , and Li ⁺ .

The organic cation at the A site may be a nitrogen-containing organic cation. The nitrogen-containing organic cation may be at least one selected from the group consisting of ammonium cation, amidinium cation, guanidinium cation, imidazolium cation, pyridinium cation, pyrrolidinium cation, and protonated thiourea cation. More specifically, the organic cations may be cations represented by the following formulae (A-1) to (A-7), namely, primary to quaternary ammonium cations (A-1) (excluding those represented by (A-2)), pyrrolidinium cation (A-2), amidinium cation (A-3), guanidinium cation (A-4), imidazolium cation (A-5), pyridinium cation (A-6), and protonated thiourea cation (A-7).

In the formula (A-1), R each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, a benzyl group, a phenethyl group, a halogen atom, or a pseudohalogen, or two R together form an alkylene group having 2 to 6 carbon atoms.
When R is an alkyl group, examples of R include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, and a tert-butyl group.
When two R's combine together to form an alkylene group having 2 to 6 carbon atoms, examples of the alkylene group include an ethylene group, an n-propylene group, and a 2,2-dimethylpropylene group.
Examples of the cation represented by formula (A-1) include benzylammonium cation, iso-butylammonium cation, n-butylammonium cation, t-butylammonium cation, diethylammonium cation, dimethylammonium cation, ethylammonium cation, methylammonium cation (MA), phenethylammonium cation, iso-propylammonium cation, and n-propylammonium cation, and the methylammonium cation is preferable.

In formulae (A-2) to (A-7), R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, and a tert-butyl group, and the like. A methyl group or an ethyl group is preferable, and a methyl group is more preferable. When there are multiple R ^2s in a molecule, each R ² may be different from the others or may be the same.
In formula (A-3), R ¹ represents a methyl group, a hydrogen atom, a halogen atom, or a pseudohalogen.
Examples of the cation of the formula (A-3) include an acetamidinium cation and a formamidinium cation (FA), with the formamidinium cation being preferred.
Examples of the cations of the formula (A-2) and the formulas (A-4) to (A-7) include a pyridinium cation, a guanidinium cation, an imidazolium cation, a 1-methylimidazolium cation, a pyridinium cation, a 1-methylpyridinium cation, and a protonated thiourea cation.

At least 60 mol %, preferably at least 70 mol %, more preferably at least 80 mol % of the A-site cations may be at least one selected from the group consisting of ammonium cations, guanidium cations, imidazolium cations, pyridinium cations, pyrrolidinium cations, and protonated thiourea cations. In addition, up to 40 mol %, preferably up to 30 mol %, more preferably up to 20 mol % of the A-site cations may be amidinium cations. The A-site cations may not include amidinium cations.

In particular, the A-site cation is preferably an ammonium cation, more preferably a primary ammonium cation having an alkyl group having 1 to 4 carbon atoms, and even more preferably a methylammonium cation. The ammonium cation preferably accounts for 60 mol % or more, preferably 70 mol % or more, and more preferably 80 mol % or more of the A-site cations.

Examples of B-site cations include cations of metal elements selected from Ge, Sn, Pb, Sb, Bi, Cu, Ni, Co, Fe, Mn, Cr, Pd, Cd, Eu, Yb, Ag, etc., and the cation of Pb or Sn is preferred. There may be only one type of B-site cation, or two or more types.

X is a chemical species occupying the X site. The X site is a site located at the apex of an octahedral structure centered on the element located at the B site, and corresponds to the site where oxygen exists in a perovskite oxide. Examples of X include Cl, Br, I, -CN (cyanide), -SCN (thiocyanate), -NSC (isothiocyanate), -S (sulfide), etc., which may exist as anions or may be coordinately bonded to the element occupying the B site. X is preferably Cl, Br, or I. The luminescent nanoparticles may contain one or more chemical species as X.

A, B, and X can be appropriately selected taking into consideration the potential within the luminescent nanoparticle and the sizes of the atoms contained in A, B, and X.

The luminescent nanoparticles may be surface-treated with a surfactant. There are no particular limitations on the surfactant, and it may be any of a nonionic surfactant, a cationic surfactant, a zwitterionic surfactant, and an anionic surfactant.

Preferred surfactants include amine compounds, quaternary ammonium salts, and carboxylic acids with 8 to 30 carbon atoms.

The number of carbon atoms of the carboxylic acid as the surfactant is preferably 10 to 25, and more preferably 12 to 20. The carboxylic acid may be a monocarboxylic acid or a polycarboxylic acid. The carboxyl group of the carboxylic acid may be partially or completely neutralized (that is, partially or completely may be in the form of a salt). The salt of the carboxylic acid is not particularly limited, but may include an alkali metal salt. The carboxylic acid as the surfactant may be either an aromatic carboxylic acid or an aliphatic carboxylic acid, but is preferably an aliphatic carboxylic acid. The aliphatic carboxylic acid is preferably a fatty acid.
The fatty acid preferably has 8 to 30 carbon atoms, and more preferably has 12 to 20 carbon atoms. Specific examples of the fatty acid include oleic acid, stearic acid, palmitic acid, etc., with oleic acid being preferred. Examples of the salt of the fatty acid include alkali metal salts, etc.
Examples of the aromatic carboxylic acid include 3-phenylpropionic acid, 4-phenyl-3-butenoic acid, phenylacetic acid, and benzoic acid.

The amine compound as a surfactant may be any of a primary amine compound, a secondary amine compound, and a tertiary amine compound, and may be either an aromatic amine or an aliphatic amine.
Examples of the hydrocarbon group contained in the amine compound as a surfactant include an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, etc., and the alkyl group is preferable. The alkyl group may be a straight-chain or branched-chain alkyl group.
The aliphatic amine compound is preferably a primary aliphatic monoamine compound. Examples of the primary aliphatic amine compound include primary aliphatic amine compounds having an aliphatic hydrocarbon group having 2 to 20 carbon atoms, more specifically, propylamine, butylamine, pentylamine, octylamine, hexadecylamine, octadecylamine, etc., with octylamine being preferred. Examples of the aliphatic amine compound include aliphatic diamines such as 1,8-octyldiamine.
Examples of aromatic amines include benzylamine, phenethylamine, 3-phenyl-2-propen-1-amine, phenylmethylamine, 2,2'-iminodibenzoic acid, aniline, 3-phenylpropylamine, and 4-phenylbutylamine.
Examples of the quaternary ammonium salt as a surfactant include aliphatic quaternary ammonium salts, such as didodecyldimethylammonium and 3-(N,N-dimethyloctadecylammonio)propanesulfonate.

The surfactant may contain a phosphorus-containing compound such as phosphonic acid or phospholipid. Examples of phosphonic acid include octylphosphonic acid and tetradecylphosphonic acid. Examples of phospholipid include trioctylphosphine oxide.
The surfactant may also contain an alkylthiol. The alkylthiol may be an alkylthiol having 6 to 20 carbon atoms, and a specific example thereof is 1-octanethiol.

The luminescent nanoparticles may be surface-treated with a metal halide compound. The metal of the metal halide compound may be a metal other than the B-site metal, more specifically, Zn, Mn, Ga, In, etc. The metal halide compound may be _ZnBr2 , _MnBr2 , _GaBr2 , _InBr2 , etc. When modified with a metal halide compound, the luminescent nanoparticles are preferably one in which the chemical species occupying the A-site is a metal element.

The luminescent nanoparticles of this embodiment have excellent PLQY. As shown in Patent Document 1 and the like, conventional perovskite-type luminescent nanoparticles have a very small half-width of the peak corresponding to the (110), (100), or (200) plane in the powder X-ray diffraction pattern, for example, about 0.1°. However, after extensive research, the present inventors have found that the PLQY is improved when the half-width of the peak corresponding to the (110), (100), or (200) plane in the powder X-ray diffraction pattern is in a range larger than the conventional range (i.e., in the range of conditions (1) to (3)). The reason for this is not necessarily clear, but it is believed that the widening of the half-width indicates the formation of an amorphous structure, and that the amorphous state of the nanocrystal surface acts as a passivation layer, improving the PLQY.

The method for producing the perovskite-type luminescent nanoparticles of this embodiment is not particularly limited, but can be, for example, produced by the LARP method (Ligand Assisted Reprecipitation).

In the LARP method, a precursor solution is first prepared by dissolving the raw materials and ligands in a good solvent. Next, a poor solvent is added to the precursor solution to precipitate luminescent nanoparticles. If the poor solvent is added batchwise to the precursor solution in one reaction vessel, luminescent nanoparticles that satisfy at least one of the above conditions (1) to (3) can be easily obtained.

Examples of raw materials for luminescent nanoparticles include raw materials containing A-site chemical species, raw materials containing B-site chemical species, and compounds containing X-site chemical species. The raw materials for luminescent nanoparticles may be any material capable of supplying any of A, B, and X in the general formula _ABX3 , and may contain multiple A, B, and X chemical species.

Examples of raw materials containing A-site chemical species include compounds containing A-site chemical species and X. For example, when the A-site cation contains an alkali metal ion, the raw material containing the A-site cation is preferably a salt of an alkali metal and X, and is preferably an alkali metal halide, but may also be a compound that does not contain X, such as an alkali metal carbonate or an alkali metal acetate.

When the chemical species at the A site is an organic cation, examples of the raw material containing the chemical species at the A site include salts of the organic cation and X. More specifically, examples of the raw material containing the chemical species at the A site include at least one compound selected from the group consisting of ammonium salts, amidinium salts, guanidinium salts, imidazolium salts, pyridinium salts, pyrrolidinium salts, and salts of protonated thiourea, and these salts are preferably halide salts, and more preferably bromide salts, iodide salts, or chloride salts. Examples of the raw material containing the chemical species at the A site include ammonium halide salts such as methylammonium bromide, and formamidinium halide salts such as formamidinium bromide.

Examples of raw materials containing B-site cations include B-site metal-containing compounds, such as salts of B-site cations and X. The B-site metal-containing compounds are preferably compounds containing at least one metal element selected from the group consisting of Ge, Sn, Pb, Sb, Bi, Cu, Ni, Co, Fe, Mn, Cr, Pd, Cd, Eu, Yb, and Ag. More specifically, B-site metal-containing compounds include halides (fluorides, chlorides, bromides, or iodides) of Ge, Sn, Pb, Sb, or Bi, with bromides, iodides, or chlorides of Ge, Sn, Pb, Sb, or Bi being preferred.

Compounds containing X-site species include compounds containing the above-mentioned A-site or B-site species and X-site species, as well as compounds such as HCl and HI that contain neither A-site nor B-site species.

The ligands include those exemplified as surfactants above, but when an aliphatic monoamine (preferably having an alkyl group with 3 to 16 carbon atoms) or an aromatic amine is used in combination with a carboxylic acid with 8 to 30 carbon atoms, luminescent nanoparticles that satisfy at least one of the above conditions (1) to (3) are easily obtained. The alkyl group of the aliphatic monoamine as a ligand may be either a branched or straight chain alkyl group, but a straight chain alkyl group is preferable. The number of carbon atoms of the alkyl group of the aliphatic monoamine is preferably 3 to 16, more preferably 4 to 12, and even more preferably 4 to 8. Specific examples of the alkyl group of the aliphatic monoamine include an n-propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.

Aromatic amines as ligands include amines having an aryl group, and particularly preferred are amines having a phenyl group or a substituted phenyl group. Among them, compounds having a structure in which a phenyl group or a substituted phenyl group is linked to a nitrogen atom via an alkylene group having 2 to 6 carbon atoms are included, and specifically, 2-phenylethylamine, 3-phenylpropylamine, and 4-phenylbutylamine are preferred, and 2-phenylethylamine is particularly preferred. Examples of the substituents that the substituted phenyl group has include halogen atoms. The substituted phenyl group preferably has one or two substituents per phenyl group. Examples of aromatic amines having a substituted phenyl group include 2-phenylethylamine, 3-phenylpropylamine, and 4-phenylbutylamine, in which the hydrogen atom of the phenyl group is substituted with a substituent (e.g., a halogen atom).

As the carboxylic acid as a ligand, a carboxylic acid having 8 to 30 carbon atoms is preferable, a carboxylic acid having 10 to 20 carbon atoms is more preferable, and a carboxylic acid having 12 to 20 carbon atoms is even more preferable. Specific examples of the carboxylic acid as a ligand include oleic acid, stearic acid, palmitic acid, etc.

Good solvents include those that have a solubility (25°C) of 1 g/L or more for the raw material, and specific examples include N-methylpyrrolidone (NMP) and N,N-dimethylformamide (DMF).

Examples of poor solvents include those with a solubility (25°C) of less than 1 g/L in the raw material. Specific examples include hydrocarbon solvents such as toluene, hexane, and octadecene, and halogenated hydrocarbon solvents such as chlorobenzene and chloroform. The solubility of the poor solvent in the raw material is preferably 10 mg/L or less, and more preferably 1 mg/L or less.

The amount of poor solvent used is preferably 10 times or more, and more preferably 15 times or more, by volume relative to the precursor solution, in order to prevent redissolution of the luminescent nanoparticles after their precipitation.

The amount of the ligand used (amount added) is not limited as long as it is equal to or less than the saturation solubility (the maximum amount of surfactant that dissolves in the dispersion medium at the reaction temperature), and is preferably equal to or less than 1 mass% of the total amount of the raw materials for the luminescent nanoparticles. The ligand used during production may be removed from the luminescent nanoparticles by washing after the luminescent nanoparticles are produced, or the ligand may be almost completely removed. In addition, from the viewpoint of suppressing the aggregation of the luminescent nanoparticles, the luminescent nanoparticles may be surface-treated with another surfactant after the removal of the ligand. Alternatively, a surfactant may be added to the obtained luminescent nanoparticles without removing the ligand, and further surface treatment may be performed.

The molar ratio of the raw material containing the A-site chemical species to the raw material containing the B-site chemical species in the above mixture is not particularly limited, but the raw material containing the B-site chemical species can be used in excess of the raw material containing the A-site chemical species. For example, the molar ratio of the A-site chemical species to the B-site chemical species is preferably 1.0:1.0 to 1.0:35, and more preferably 1.0:1.0 to 1.0:7. The raw material containing the A-site chemical species can also be used in excess of the raw material containing the B-site chemical species. In that case, the molar ratio of the A-site chemical species to the B-site chemical species is preferably 1.0:1.0 to 70:1.0, and more preferably 1.0:1.0 to 14:1.0.

The resulting luminescent nanoparticles can be recovered by separation methods such as decantation, filtration, and centrifugation.

The luminescent nanoparticles of this embodiment can be used in organic LEDs, solar cells, laser light sources, micro LED displays, liquid crystal displays, UV sensors, and the like. The luminescent nanoparticles of this embodiment can be used as a composition containing the luminescent nanoparticles and a binder. The binder can be a resin, which may be either a thermoplastic resin or a thermosetting resin. In order to increase the dispersibility in the binder, the surface of the luminescent nanoparticles of this embodiment may be surface-modified with a dispersant such as a silane coupling agent.

(Production Examples 1 to 7)
As raw materials, 3.6 mg of methylammonium bromide and 14.7 mg of lead(II) bromide were dissolved in 1 mL of N,N-dimethylformamide, and 4 μL of an amine compound shown in Table 1 and 5 μL of oleic acid were added as ligands to prepare a precursor solution.
The obtained precursor solution was added to chloroform in a volume ratio of 25 times to obtain a dispersion liquid in which luminescent nanoparticles were dispersed.

The dispersions obtained in Production Examples 1 to 7 were centrifuged at 9000 rpm for 10 minutes. After centrifugation, a precipitate layer was collected from the dispersion, applied onto a glass plate, and dried overnight to obtain a measurement sample.
The powder X-ray diffraction pattern was measured using the above measurement sample. The device used was a "Fully Automatic Multipurpose X-ray Diffraction Device SmartLab 9kW" manufactured by Rigaku Corporation, and the radiation source used was CuKα radiation. The obtained powder X-ray diffraction measurement data was introduced into Rigaku Integrated Powder X-ray Analysis Software, and "background correction, smoothing, kα2 removal" processing was performed. The results are shown in Table 2.

The fluorescence intensity of the luminescent nanoparticles was measured using a fluorescence spectrophotometer (manufactured by HORIBA, product name: FluoroMax-2) to measure the emission peak wavelength of the luminescent nanoparticles. In addition, the PLQY was measured using an absolute PL quantum yield device (manufactured by Hamamatsu Photonics, product name: C9920-01). The results are shown in Table 2.

Claims (4)

Luminescent nanoparticles of the perovskite type comprising a compound represented by the general formula _ABX3 ,
The half-width of the peak corresponding to the (110) plane in the powder X-ray diffraction pattern measured using CuKα radiation is 0.53 to 5.5°;
a nitrogen-containing organic cation is included as an A-site cation, the A-site cation being an A-site cation (excluding those including a nitrogen-containing organic cation having an alkyl group having two or more carbon atoms);
containing at least one of Pb and Sn as a B site cation,
A luminescent nanoparticle, wherein X comprises Br . Luminescent nanoparticles of the perovskite type comprising a compound represented by the general formula _ABX3 ,
The half-width of the peak corresponding to the (100) plane in the powder X-ray diffraction pattern measured using CuKα radiation is 0.55 to 1.1°,
a nitrogen-containing organic cation is included as an A-site cation, the A-site cation being an A-site cation (excluding those including a nitrogen-containing organic cation having an alkyl group having two or more carbon atoms);
containing at least one of Pb and Sn as a B site cation,
A luminescent nanoparticle, wherein X comprises Br . Luminescent nanoparticles of the perovskite type comprising a compound represented by the general formula _ABX3 ,
The half-width of the peak corresponding to the (200) plane in the powder X-ray diffraction pattern measured using CuKα radiation is 0.55 to 1.5°;
a nitrogen-containing organic cation is included as an A-site cation, the A-site cation being an A-site cation (excluding those including a nitrogen-containing organic cation having an alkyl group having two or more carbon atoms);
containing at least one of Pb and Sn as a B site cation,
A luminescent nanoparticle, wherein X comprises Br . The luminescent nanoparticles according to any one of claims 1 to 3, wherein 60 mol% or more of the A-site cations are at least one selected from the group consisting of ammonium cations, guanidium cations, imidazolium cations, pyridinium cations, pyrrolidinium cations, and protonated thiourea cations.