KR20200034398A - Perovskite Quantum Dots Coexisting Chalcogenide and halide and the Fabrication Method Thereof - Google Patents

Abstract

Chalcogen-introduced perovskite quantum dots according to the present invention comprise perovskite compound crystal particles; and chalcogen doped on the perovskite compound crystal particles. According to the present invention, the quantum dots have improved light and atmospheric stability and improved light emitting quantum yield.

Description

Perovskite quantum dots coexisting chalcogenide and halide and the fabrication method thereof

The present invention relates to a perovskite quantum dot in which chalcogen and halogen coexist as anions and a method for manufacturing the same.

The perovskite compound, which is an organometal halide having a perovskite structure, controls the quantum size effect and halide composition to facilitate band gap tuning, thereby enabling display devices, lasers, light emitting diodes, etc. Has attracted great attention.

In addition, the perovskite compound quantum dot has a high photoluminescence quantum yield (PLQY) of 90% or more compared to conventional inorganic quantum dots such as CdSe or CdS, FWHM (Full Width Half Maximum) has a narrow and wide color gamut.

However, since the perovskite compound quantum dots are very sensitive to external factors such as moisture and oxygen, there is a problem in that the photoluminescence properties are rapidly deteriorated, and research has been conducted to improve the stability of the perovskite compound quantum dots.

Among the various studies for improving stability, the most noticeable result is Liu et al. (Liu et al. Journal of the American Chemical Society 2017 , 139, 16708-16719), which introduces two or more metals into the perovskite compound. This is a result of remarkably improving the stability of the perovskite compound quantum dots not only in the colloidal solution phase, but also in atmospheric exposure conditions, by an alloying technique.

However, although the stability is improved, the photoluminescence quantum yield of the quantum dots is remarkably damaged by the quenching defect generated by alloying, and thus, it is difficult to practically use it in the field of optical electronics such as display devices or light emitting diodes.

Liu et al. Journal of the American Chemical Society 2017, 139, 16708-16719

The present invention provides a perovskite compound quantum dot having excellent photoluminescence quantum yield and improved stability and a method for manufacturing the same.

The chalcogen-introduced perovskite quantum dots according to the present invention include perovskite compound crystal particles; And chalcogen doped on the perovskite compound crystal particles.

In the chalcogen-introduced perovskite quantum dot according to an embodiment of the present invention, the perovskite compound may contain two or more different divalent metals different from each other.

In the chalcogen-introduced perovskite quantum dot according to an embodiment of the present invention, at least two divalent metals are Pb first metal; And a second metal selected from one or more of Cu, Ni, Co, Fe, Mn, Cr, Pd, Cd, Ge, Sn, and Yb.

In the chalcogen-introduced perovskite quantum dot according to an embodiment of the present invention, the number of moles of the total metal contained in the perovskite compound is 1, and the perovskite compound is 0.6 to 0.8 moles of Pb And 0.2 to 0.4 moles of Pb except divalent metal.

In the chalcogen-introduced perovskite quantum dot according to an embodiment of the present invention, the chalcogen may be selected from one or more of sulfur (S), selenium (Se) and tellurium (Te).

In the chalcogen-introduced perovskite quantum dot according to an embodiment of the present invention, the atomic ratio of the divalent metal: chalcogen contained in the quantum dot may be 1: 0.1 to 0.5.

In the chalcogen-introduced perovskite quantum dot according to an embodiment of the present invention, the average diameter of the perovskite compound crystal particles may be 5 to 12 nm.

In the chalcogen-introduced perovskite quantum dot according to an embodiment of the present invention, the quantum dot may further include an organic ligand surrounding the perovskite compound crystal particle surface.

In the chalcogen-introduced perovskite quantum dot according to an embodiment of the present invention, the organic ligand may include an alkyl halide or a carboxylic acid.

In the chalcogen-introduced perovskite quantum dot according to an embodiment of the present invention, a peak may exist in the binding energy corresponding to the metal-chalcogen bond on the chalcogen 2p spectrum of the X-ray photoelectron spectral spectrum of the quantum dot .

In the chalcogen-introduced perovskite quantum dot according to an embodiment of the present invention, based on the emission characteristics at a temperature of 10K, the emission wavelength of the quantum dot is the emission wavelength of the perovskite compound crystal particles according to the doping concentration of the chalcogen In the blue-shift (blue-shift) or may be red-shifted (red-shift).

The chalcogen-introduced perovskite quantum dot according to an embodiment of the present invention may satisfy Equation 1 below.

(Equation 1)

PLQY / PLQY (ref) ≥ 1.5

In Equation 1, PLQY is the quantum yield (%) of the quantum dots, and PLQY (ref) is the quantum yield (%) of the perovskite compound crystal particles having the same size as the quantum dots.

In the chalcogen-introduced perovskite quantum dot according to an embodiment of the present invention, a full width half maximum (FWHM) of an emission peak of a quantum dot at a temperature of 300K may be 50 nm or less.

In the chalcogen-introduced perovskite quantum dot according to an embodiment of the present invention, the bach energy (Urbach energy, Eu) of the quantum dot is 85% of the uvach energy of the perovskite compound crystal particles having the same size as the quantum dot It may be:

The present invention includes an optoelectronic device comprising the above-described chalcogen-introduced perovskite quantum dots.

The present invention includes a method for manufacturing the above-described chalcogen-introduced perovskite quantum dots.

The method for producing a chalcogen-introduced perovskite quantum dot according to the present invention comprises the steps of: a) preparing a chalcogen-perovskite solution containing an organic halide, metal halide, surfactant and chalcogen source; And b) preparing a chalcogen-introduced perovskite quantum dot by dropping the chalcogen-perovskite solution in an aprotic solvent.

In the method for producing a chalcogen-introduced perovskite quantum dot according to an embodiment of the present invention, the surfactant is C1-C18 carboxylic acid, C1-C18 alkylamine or C1-C18 carboxylic acid and C1-C18 alkylamineyl You can.

In the method for manufacturing a chalcogen-introduced perovskite quantum dot according to an embodiment of the present invention, the chalcogen source may be elemental chalcogen.

In the method of manufacturing a chalcogen-introduced perovskite quantum dot according to an embodiment of the present invention, the chalcogen-perovskite solution is 0.7 to 1 mole of organic halide based on 1 mole of metal halide, and 0.1 to 0.5 mole of cal Cogen source and 5 to 20 moles of surfactant.

The chalcogen-introduced perovskite quantum dot according to an embodiment of the present invention has improved light and atmospheric stability by chalcogen introduced in the perovskite compound crystal structure, but is non-radioactive in the crystal structure by chalcogen Defects are eliminated, and even an alloy perovskite compound has an advantage of significantly improved photoluminescence quantum yield.

1 is a view showing the results of X-ray diffraction analysis using Cu-Kα of the quantum dots prepared in Example 1, Example 2, Comparative Example 1 and Comparative Example 2,
2 is a view showing a transmission electron microscope observation result of the reference quantum dot prepared in Comparative Example 1,
3 is a view showing the transmission electron microscope observation results of the sulfur-introduced perovskite quantum dots (perovskite quantum dots in which sulfur and bromine coexist) prepared in Example 2,
4 is a view showing the results of XPS (X-ray photoelectron spectroscopy) analysis of the surface of the quantum dots prepared in Example 1, Example 2 and Comparative Example 1,
5 is a diagram showing the result of a depth profile (depth profile) of sulfur analyzed for the concentration of sulfur according to the depth of the quantum dot
6 is a view showing the results of mapping the energy dispersive X-ray spectroscopy (EDS) of each element of the reference quantum dot prepared in Comparative Example 1,
7 is a view showing the results of EDS mapping for each element of the quantum dots prepared in Example 2,
8 is a view showing a steady-state absorption and emission spectrum measured at 300K temperature by irradiating a 365nm UV lamp to the quantum dots prepared in Examples 1, 2 3 and Comparative Example 1,
9 is a view showing a Time Resolved Photoluminescence (TRPL) spectrum of the quantum dots prepared in Comparative Example 1, Example 1 and Example 2,
10 is a view showing the calculation of the Ubach energy of the quantum dots prepared in Comparative Example 1, Example 1 and Example 2,
FIG. 11 is a diagram showing a chromaticity diagram showing optical color information for luminescence color and optical photographs observing luminescence color while irradiating a UV lamp (365 nm) to quantum dots prepared in Example 1, Example 2 and Comparative Example 1; And
12 is a view showing emission spectra measured at temperatures of 10K and 300K of the quantum dots prepared in Example 1, Example 2 and Comparative Example 1,
13 is a result of testing atmospheric stability and light stability of the quantum dots prepared in Example 1, Example 2 and Comparative Example 1.

Hereinafter, a perovskite compound quantum dot of the present invention and a method for manufacturing the same will be described in detail with reference to the accompanying drawings. The drawings introduced below are provided as examples in order to sufficiently convey the spirit of the present invention to those skilled in the art. Accordingly, the present invention is not limited to the drawings presented below, and may be embodied in other forms, and the drawings presented below may be exaggerated to clarify the spirit of the present invention. At this time, unless there are other definitions in the technical terms and scientific terms to be used, those skilled in the art to which this invention pertains have the meanings commonly understood, and the subject matter of the present invention in the following description and accompanying drawings Descriptions of well-known functions and configurations that may be obscured are omitted.

In the present invention, the perovskite compound may mean an organometal halide having a perovskite structure.

In the present invention, the perovskite compound crystal particles may mean perovskite compound single crystal particles, and the size of the perovskite compound crystal particles may correspond to the size of the quantum dot according to the present invention. As a specific example, the perovskite compound crystal particles may have a size equal to or less than the bore diameter, and may have a size in which a quantum confinement effect (a change in a band gap according to the size) appears. The perovskite compound or perovskite compound crystal particles may mean a base material doped with chalcogen.

In the present invention, chalcogen-introduced perovskite quantum dots, perovskite quantum dots or quantum dots, may mean a perovskite compound crystal particles containing chalcogen, specifically, chalcogen doped Perovskite compound crystal particles.

In addition, in the present invention, the chalcogen-introduced perovskite quantum dot may mean a perovskite compound crystal particle in which chalcogen and halogen coexist, and specifically, in which chalcogen and halogen coexist as anions. It may mean the lobsky compound crystal particles. The chalcogen-introduced perovskite quantum dot may also be referred to as a perovskite quantum dot, a perovskite quantum dot in which chalcogenide and halide coexist, or a quantum dot in which chalcogen and halogen coexist.

In the present invention, doping may mean that chalcogen is located in the crystal structure of the perovskite compound crystal particles, and interstitial sites, substitution sites, or interstitial sites in the crystal lattice. It can mean that it is located in a seat and a substituted seat. More substantially, it may mean that the doped chalcogen is located at the halogen site of the perovskite compound.

In the present invention, chalcogen, metal, and the like present in the quantum dot may be in an ionic state, and thus chalcogen may mean chalcogen ions, and metal may mean metal ions.

In the present invention, the quantum dot may mean that the size (diameter) of the chalcogen-doped perovskite compound is less than or equal to the bore diameter, and as a practical example, 20 nm or less, more substantially 15 nm or less. You can.

The chalcogen-introduced perovskite quantum dots according to the present invention include perovskite compound crystal particles; And chalcogen doped into perovskite compound crystal particles.

In other words, the chalcogen-introduced perovskite quantum dots according to the present invention may be perovskite compound crystal particles containing chalcogen in the crystal lattice and having a diameter equal to or less than the bore diameter.

The perovskite quantum dots according to the present invention contain chalcogen in the crystal lattice, so that defects in the quantum dots are healed by chalcogen, and significantly improved photoluminescence quantum yield (hereinafter, compared to perovskite compound crystal particles of the same size) PLQY), the perovskite compound crystal particles can be maintained more stably in the air for a few months in the air compared to the crystal grains, and the deterioration by light is also greatly reduced, thereby improving stability.

In the chalcogen-introduced perovskite quantum dot according to an embodiment of the present invention, the perovskite compound of the perovskite compound crystal particles may satisfy Formula 1 below.

(Formula 1)

AMX ₃

In formula 1, A is a monovalent organic cation, or Cs ^+, M is a divalent metal ion, X is I ^-, Br ^-, F ^- and Cl ^- can be alone or in combination of two or more selected from the. The bivalent metal ion M is Cu ²⁺ , Ni ²⁺ , Co ²⁺ , Fe ²⁺ , Mn ²⁺ , Cr ²⁺ , Pd ²⁺ , Cd ²⁺ , Ge ²⁺ , Sn ²⁺ , Pb ² One or two or more selected from ⁺ and Yb ²⁺ may be mentioned, but the present invention is not limited thereto. A may be an amidinium group ion, an organic ammonium ion, or an amidinium group ion and an organic ammonium ion. The organic ammonium ion is of the formula (R ₁ -NH ₃ ⁺ ) (R ₁ is C1-C24 alkyl, C3-C20 cycloalkyl or C6-C20 aryl) or (R ₂ -C ₃ H ₃ N ₂ ⁺ - R ₃ ) (R ₂ is C1-C24 alkyl, C3-C20 cycloalkyl or C6-C20 aryl, and R ₃ is hydrogen or C1-C24 alkyl). In one non-limiting and specific example, R ₁ may be C ₁ -C ₂₄ alkyl, preferably C ₁ -C 5 alkyl, more preferably methyl. R ₂ may be C1-C24 alkyl and R ₃ may be hydrogen or C1-C24 alkyl, preferably R ₂ may be C1-C5 alkyl and R ₃ may be hydrogen or C1-C5 alkyl, More preferably R ₂ can be methyl and R ₃ can be hydrogen.

The amidinium-based ion may satisfy Formula 2 below.

(Formula 2)

At this time, in the formula (2) R ₄ to R ₈ are independently of each other, hydrogen, C1-C24 alkyl, C3-C20 cycloalkyl or C6-C20 aryl. Non-limiting and specific examples, taking into account the absorption of sunlight, R ₄ to R ₈ are independently of each other, hydrogen, amino or C1-C24 alkyl, specifically hydrogen, amino or C1-C5 alkyl, more specifically hydrogen, It can be amino or methyl. Even more specifically, R ₄ may be hydrogen, amino or methyl and R ₅ to R ₈ may be hydrogen. As a specific and non-limiting example, the amidinium-based ion is formamidinium (NH ₂ CH = NH ₂ ⁺ ) ion, acetamidinium (NH ₂ C (CH ₃ ) = NH ₂ ⁺ ) Or a guamidinium (Guamidinium, NH ₂ C (NH ₂ ) = NH ₂ ⁺ ).

The monovalent organic ions (A) of the organometal halide are monovalent organic ammonium ions of R ₁ -NH ₃ ⁺ or R ₂ -C ₃ H ₃ N ₂ ⁺ -R ₃ as described above, and the above-mentioned amidi based on the formula It may be a nimium-based ion, or an organic ammonium ion and an amidinium-based ion.

When the monovalent organic ion contains both the organic ammonium ion and the amidinium-based ion, the organohalide is A ^' _1-x A _x (A is the monovalent organic ammonium ion described above, and A ^' is the aforementioned amididi Needle umgye ion, x is I ^-, Br ^-, F ^- and Cl ^- is a halogen ion that is one or two or more selected from, x is a real number 0 <x <1, preferably from 0.3 mistake 0.05≤x≤) The formula can be satisfied. When the total number of moles of monovalent organic cations is 1, and contains amidinium ions of 0.7 to 0.95 and organoammonium ions of 0.3 to 0.05, it is possible to absorb light in a very wide wavelength band, but is faster exciton (exciton) ) Is advantageous because it enables the movement and separation, and the faster movement of photoelectrons and holes.

In one advantageous example, the perovskite compound of the perovskite compound crystal particles may be an alloy-type perovskite compound containing two or more different divalent metals.

These alloy perovskite compounds improve the stability of the quantum dots together with the doped chalcogen, change the band gap of the quantum dots independently of the size of the quantum dots, and / or reduce the use of harmful substances such as Pb It is advantageous because you can.

As described above, when the perovskite compound is an alloy-type perovskite compound, it is known that a large amount of quenching defects are generated in the quantum dots by alloying (alloying), and PLQY of the quantum dots is significantly damaged.

However, according to the present invention, when chalcogen is contained in the perovskite compound lattice, defects of quantum dots, including quenching defects by alloying (alloying), can be cured by chalcogen, thereby improving optical properties. While securing the desired effect can also be achieved by the following.

As a specific example, the perovskite compound is an alloy-type perovskite compound containing two or more divalent metals, and the two or more divalent metals include Pb (first metal); And a divalent metal (second metal) except Pb. As a more specific example, a divalent metal other than Pb may be selected from Cu, Ni, Co, Fe, Mn, Cr, Pd, Cd, Ge, Sn, and Yb, but is not limited thereto.

The alloy perovskite compound contains 0.6 to 0.8 moles of Pb and 0.2 to 0.4 moles of Pb except for the total number of metals (divalent metals) contained in the perovskite compound as 1 can do. As a specific example, the alloy-type perovskite compound has 0.6 to 0.8 moles of Pb and 0.2 to 0.4 moles of Cu and Ni with the number of moles of the total metal (divalent metal) contained in the perovskite compound as 1 , Co, Fe, Mn, Cr, Pd, Cd, Ge, Sn, and Yb.

If this is expressed by the formula, the alloy-type perovskite compound may satisfy AM1 _x M2 _(1-x) X ₃ , wherein X of A and X ₃ are similar to or identical to those described above in Formula 1, and M1 Silver Pb may be a first metal, M2 is a second metal that is a divalent metal except Pb, and x may be a real number of 0.6 ≤ x ≤ 0.8.

An advantageous example of improving the optical stability and atmospheric stability (stability to moisture, oxygen, etc.) of a quantum dot together with chalcogen, the alloy-type perovskite compound may include a first metal as Pb and a second metal as Sn. In some embodiments, the alloy-based perovskite compound may be APb _x Sn _(1-x) X ₃ (X in A and X ₃ is Chemical Formula 1). It is the same as the definition of, x may satisfy a real number of 0.6 ≤ x ≤ 0.8).

As described above, the size of the perovskite compound crystal particles may correspond to the size of the perovskite quantum dot. Accordingly, the size (diameter) of the perovskite compound crystal particles may be less than or equal to the bore diameter, and may be, for example, 1 to 20 nm, more substantially 3 to 15 nm, and even more substantially 5 to 12 nm.

In the chalcogen-introduced perovskite quantum dot according to the present invention, the chalcogen doped into the perovskite compound crystal particles may be selected from sulfur, selenium, and tellurium. At this time, it is preferable that the chalcogen contains sulfur so that the desired effect by chalcogen doping can be more easily and uniformly doped in the perovskite compound crystal structure.

The chalcogen doped into the perovskite compound crystal particles can provide a stronger bonding force than halogen, thereby improving chemical (moisture, oxygen, etc.) and optical stability of the perovskite compound, and furthermore, perovskite compound Healing of defects present in crystals (including defects due to alloying) can greatly improve optical properties.

In detail, on the chalcogen 2P spectrum of the X-ray photoelectron spectroscopy (XPS) spectrum of the perovskite quantum dot, a peak may exist (position) in the binding energy corresponding to the metal-chalcogen bond, and, in addition, an elemental knife The peak may not be located in the binding energy corresponding to elemental chalcogen binding. This chalcogen 2P spectrum is that the chalcogen contained in the perovskite quantum dot is not in the form of an elemental chalcogen or other different phase (different phase), and is in a solid state in the crystal structure of the chalcogen perovskite compound .

As a specific and practical example, in the chalcogen 2P spectrum, a peak may be located in the M-chal binding energy, which is a bond between a divalent metal ion (M) and chalcogen (chal) contained in the perovskite compound crystal particles. A specific example of the M-chal binding energy according to an advantageous example may include Pb-S, Sn-S or Pb-S and Sn-S binding binding energy.

In addition, in the perovskite quantum dot according to an embodiment of the present invention, the perovskite quantum dot of the Ubach energy (Urbach energy, Eu) is a perovskite compound having the same size as the quantum dot (perovskite with the same quantum dot Skyt compound) may be 85% or less, advantageously 55% or less, compared to the Ubach energy (Eu0) of the crystal particles. As is known, the Ubach energy is the slope of the Ubach tail, and the smaller the Ubach energy of the semiconductor, the less defects, the steeper the tail slope of the level in the valence band's energy band, and the higher the order. The Ubbach energy of the perovskite quantum dot, which is significantly reduced compared to the perovskite compound crystal particles, directly indicates that the defects present in the perovskite compound crystal are healed by chalcogen doped into the perovskite compound. will be. As a specific and practical example, the Ubach energy of the perovskite quantum dot may be 60 meV or less, and more substantially 45 meV or less.

The atomic ratio of the divalent metal: chalcogen contained in the quantum dots may be 0.10 to 0.50, preferably 0.20 to 0.50, and more preferably 0.30 to 0.45. The content of the chalcogen can be obtained by improving the stability of defects and improving stability of the perovskite compound crystal particles by the doped chalcogen, segregation of chalcogen in the perovskite compound crystal particles or elemental chalcogen It is a content that prevents the formation of an undesired abnormal phase, such as, and allows the chalcogen to be doped uniformly within the crystal structure of the perovskite compound crystal particles.

If this is represented by the formula, the perovskite quantum dot may satisfy the AMX _3-y Chal _y , y may be a real number of 0.1 to 0.5. At this time, A, M and X are the same as defined in Formula 1, Chal means doped chalcogen. When the perovskite quantum dot is an alloy type, the perovskite quantum dot according to an advantageous example may satisfy AM1 _x M2 _(1-x) X _3-y Chal _y , and x is a real number of 0.6 ≤ x ≤ 0.8, y may be a real number of 0.1 to 0.5, A and X are the same as described above in Chemical Formula 1, M1 may be a first metal that is Pb, and M2 may be a divalent metal except Pb.

The chalcogen-introduced perovskite quantum dot according to an embodiment of the present invention may further include an organic ligand surrounding the perovskite compound crystal particle surface. Organoligands may be derived from the synthesis of perovskite compound crystal particles, specifically derived from surfactants used in synthesis, or alternatively, by ligand substitution between the ligand derived from synthesis and the desired ligand. It may be produced.

The organic ligand can improve the dispersibility, durability, stability, etc. of the perovskite compound crystal particles, and can be refined to the size of nanometers. Specifically, the organic ligand may include C1-C18 carboxylic acid, C1-C18 alkylamine or C1-C18 carboxylic acid and C1-C18 alkylamine.

When the organic ligand comprises a C1-C18 carboxylic acid, the organic ligand is stearic acid, decanoic acid 4,4'-azobis (4-cyanopaleric acid) ( 4,4'-Azobis (4-cyanovaleric acid)), acetic acid, 5-aminosalicylic acid, acrylic acid, L-aspentic acid ( L-Aspentic acid, 6-Bromohexanoic acid, Promoacetic acid, Dichloro acetic acid, Ethylenediaminetetraacetic acid, Isobutyric acid, Itaconic acid, Maleic acid, r-Maleimidobutyric acid, L-Malic acid, 4-Nitrobenzoic acid, 1-Pyrenecarboxy lic acid) and oleic acid, but may include carboxylic acid selected from one or more groups, but is not limited thereto.

When the organic ligand includes a C1-C18 alkylamine, the organic ligand is ethylamine, propylamine, butylamine, pentylamine, hexylamine, octylamine ), Decylamine, hexadecylamine, octadecylamine, oleylamine and tri-n-octylamine. It may include a carboxylic acid, but is not limited thereto.

When the perovskite quantum dots further include an organic ligand, based on the total weight of the perovskite quantum dots, the perovskite quantum dots may include 0.1 to 5% by weight of organic ligands. The content of the organic ligand is a thin, uniform and stable content that can surround the surface of the perovskite compound crystal particles, but it goes without saying that the present invention cannot be limited by the specific content of the organic ligand.

The chalcogen-introduced perovskite quantum dots according to an embodiment of the present invention is based on the luminescence properties at a temperature of 10K, the emission wavelength of the quantum dots is perovskite compound crystal particles according to the doping concentration (chalcogen content) of chalcogen It may be blue shifted or red shifted at the emission wavelength of (emission center wavelength). That is, when the perovskite compound crystal particles having the same material and the same size as the quantum dot, except that they are not doped with chalcogen, are referred to as reference quantum dots, the reference quantum dots according to the content of chalcogen contained in the perovskite quantum dots The emission wavelength of the perovskite quantum dot compared to the emission wavelength of may be blue shifted or red shifted.

Specifically, when the emission wavelength of the reference quantum dot (λ ₀ nm), the emission wavelength of the perovskite quantum dot may be changed according to the content of chalcogen contained in the perovskite quantum dot. At this time, the chalcogen is introduced into the perovskite compound and the emission wavelength of the perovskite quantum dot may be blue shifted than the reference quantum dot, and the amount of the perovskite quantum dot shifted blue as the amount of chalcogen introduced increases. The emission wavelength may shift toward the longer wavelength. Accordingly, depending on the content of chalcogen contained in the perovskite quantum dot, the perovskite quantum dot may generate light of the blue shifted wavelength based on the emission wavelength of the reference quantum dot, or the red shifted wavelength based on the emission wavelength of the reference quantum dot It is also possible to emit light.

As described above, the atomic ratio of the divalent metal: chalcogen contained in the perovskite quantum dots may be 0.1 to 0.5, and in this chalcogen content range, the emission wavelength of the perovskite quantum dots is _chal λ is λ ₀ - it may be adjusted to _{50nm ≤ λ chal ≤ λ 0 +} 50nm. This means that the emission wavelength of the perovskite quantum dot can be controlled by an independent factor such as the size of the quantum dot, the material of the perovskite compound crystal particles, and the chalcogen content. This means that the width of the color realized by Skyt's quantum dots is widened, and at the same time, it is possible to finely design the color.

The chalcogen-introduced perovskite quantum dots according to an embodiment of the present invention may have a significantly improved quantum yield due to defect healing by chalcogen doping. In detail, the perovskite quantum dot may satisfy the following equation (1).

(Equation 1)

PLQY / PLQY (ref) ≥ 1.5

In Equation 1, PLQY is the quantum yield of the perovskite quantum dots (%), and PLQY (ref) is the quantum yield of the perovskite compound crystal particles having the same size as the perovskite quantum dots (%).

That is, except that chalcogen doping is not performed, chalcogen is doped into the perovskite compound crystal particles (hereinafter referred to as reference quantum dots) having the same material and the same size as the quantum dots, and thus the quantum efficiency is remarkably 150% or more. Can increase.

Further, when the chalcogen is contained so that the atomic ratio of the divalent metal: chalcogen contained in the perovskite quantum dot is 1: 0.1 to 0.5, the quantum efficiency of the perovskite quantum dot is compared to the reference quantum dot The quantum efficiency can be significantly increased by more than 180% (PLQY / PLQY (ref) ≥ 1.8). As a practical example, the PLQY of the perovskite quantum dots may be 75% or more.

In addition to this, or independently of the perovskite quantum dot according to an embodiment of the present invention, a full width half maximum (FWHM) of a luminescence peak at a temperature of 300K and an emission peak of the quantum dot may be 50 nm or less. In this case, the emission characteristics at a temperature of 300K may refer to the emission spectrum of the perovskite quantum dots measured at a temperature of 300K by irradiating a 365nm UV lamp.

The very narrow FWHM of 50 nm or less means that excellent color purity can be realized by perovskite quantum dots. Specifically, the FWHM of the perovskite quantum dot emission peak based on the emission characteristics at a temperature of 300K may be 5 to 50 nm, more specifically 10 to 40 nm.

In the perovskite quantum dot according to an embodiment of the present invention, the emission wavelength of the perovskite quantum dot may be 450 to 650nm, the excitation wavelength to excite the quantum dots is ultraviolet, specifically 100 to 400nm wavelength band ultraviolet Can be

The present invention includes an optoelectronic device comprising the above-described perovskite quantum dots.

The optoelectronic device according to the present invention may include a light emitting film, a light emitting diode, and an LED package, as well as a display device including them.

The present invention includes a method for manufacturing the above-described chalcogen-introduced perovskite quantum dots.

A method of manufacturing a perovskite quantum dot according to the present invention comprises the steps of: a) preparing a chalcogen-perovskite solution containing an organic halide, a metal halide, a surfactant and a chalcogen source; And b) preparing a chalcogen-introduced perovskite quantum dot by dropping the chalcogen-perovskite solution in an aprotic solvent.

The organic halide may be a monovalent organic cation or a halide of Cs ⁺ , and may be represented by the formula AX. At this time, A is similar to the same as defined in Formula 1, X is I ^-, Br ^-, F ^- and Cl ^- can be alone or in combination of two or more selected from the.

The metal halide may be a halide of a divalent metal, and may be represented by the formula MX ₂ . In this case, M is similar to the same as defined in Formula 1, X is X is I ^-, Br ^-, F ^- and Cl ^- can be alone or in combination of two or more selected from the.

If an alloy-type perovskite quantum dot is to be prepared, the chalcogen-perovskite solution may contain M1X ₂ and M2X ₂ as metal halides. At this time, as described above based on Formula 1 above, M1 may be Pb, and M2 is a divalent metal except Pb, specifically, Cu, Ni, Co, Fe, Mn, Cr, Pd, Cd, Ge, Sn, and may be one or more in Yb, but is not limited thereto. In addition, by controlling the relative contents of M1X ₂ and M2X ₂ contained in the chalcogen-perovskite solution, a perovskite quantum dot having a desired alloy composition can be prepared. Specifically, the number of moles of the total metal halide contained in the chalcogen-perovskite solution is 1, and it may contain 0.6 to 0.8 moles of M1X ₂ and 0.2 to 0.4 moles of M2X ₂ .

Surfactants can be C1-C18 carboxylic acids, C1-C18 alkylamines or C1-C18 carboxylic acids and C1-C18 alkylamines. C1-C18 carboxylic acids are stearic acid, decanoic acid 4,4'-azobis (4-cyanopalic acid) (4,4'-Azobis (4-cyanovaleric acid) )), Acetic acid, 5-Aminosalicylic acid, Acrylic acid, L-Aspentic acid, 6-Brohexanoic Acid (6-Bromohexanoic acid), Promoacetic acid (Bromoacetic acid), Dichloro acetic acid, Ethylenediaminetetraacetic acid, Isobutyric acid, Itaconic Itaconic acid, Maleic acid, r-Maleimidobutyric acid, L-Malic acid, 4-Nitrobenzoic acid ), Consisting of 1-pyrenecarboxylic acid and oleic acid. Gin may be selected from the group at least one or both, it is not limited thereto. C1-C18 alkylamines are ethylamine, propylamine, butylamine, pentylamine, hexylamine, octylamine, decylamine, hexadecyl One or more may be selected from the group consisting of amines (Hexadecylamine), octadecylamine, oleylamine, and tri-n-octylamine, but is not limited thereto. Advantageously, the surfactant can include C1-C18 carboxylic acids and C1-C18 alkylamines. The C1-C18 alkylamine can influence the crystallization rate, thereby easily controlling the size of the quantum dots by controlling the alkyl length of the alkylamine. C1-C18 carboxylic acid, C1-C18 alkylamine or C1-C18 carboxylic acid and C1-C18 alkylamine can form organic ligands of quantum dots.

The chalcogen source may be elemental chalcogen, and specifically, one or more may be selected from elemental sulfur (S), selenium (Se), and tellurium (Te).

The chalcogen-perovskite solution may contain 0.7 to 1 mole of organic halide, 0.1 to 0.5 mole of chalcogen source, and 5 to 20 mole of surfactant based on 1 mole of metal halide. As the particles of the perovskite compound have a size equal to or less than the bore diameter having a quantum confinement effect, in consideration of the organic ligand binding on the surface of the quantum dot, the chalcogen-perovskite solution is 0.7 to 1 mole based on 1 mole of metal halide , Specifically, it may contain 0.7 to 0.9 mol of an organic halide. The chalcogen-perovskite solution may contain a chalcogen source to have a relative content corresponding to the desired doping concentration based on the metal halide. The surfactant is sufficient as long as it is a content conventionally used for the preparation of a conventional perovskite compound quantum dot, and in particular, the chalcogen-perovskite solution may contain 5 to 20 moles of surfactant based on 1 mole of metal halide. You can.

The solvent of the chalcogen-perovskite solution may be a polar organic solvent, dimethylformamide, gamma butyrolactone, N-methylpyrrolidone and dimethylsulfoxide ( dimethylsulfoxide), but may include one or more solvents.

The chalcogen-perovskite solution can be prepared by mixing a perovskite solution containing an organic halide, a metal halide and a surfactant with a chalcogen solution containing a chalcogen source, and a perovskite solution and cal The solvent of the cogen solution may be a homogeneous or heterogeneous polar organic solvent. However, in terms of effective dissolution of the elemental chalcogen, the chalcogen solution may contain a solvent containing an amide moiety such as dimethylformamide.

The aprotic solvent may include one or more solvents selected from dichloroethylene, trichloroethylene, chloroform, chlorobenzene, dichlorobenzene, styrene, xylene, toluene and cyclohexene, but is not limited thereto. no.

When dropping a chalcogen-perovskite solution in an aprotic solvent, the aprotic solvent is vigorously stirred, and the drop can be made, as well as such agitation and dripping are used in the manufacture of a common perovskite compound quantum dot It is enough according to the conditions.

(Example 1)

Dimethylformamide (DMF) 5 ml, methylammonium bromide (MABr) 0.16 mM, SnBr ₂ (tin bromide, SnBr ₂ ) 0.05 mM, PbBr ₂ 0.15 mmol, n-octylamine 20 μl and oleic acid (oleic) acid) 0.5 ml was added and dissolved to prepare a perovskite solution. A solution of 0.04 mM sulfur (S) dissolved in 1 ml of DMF was added to the perovskite solution and stirred and mixed for 10 minutes to prepare a sulfur-perovskite solution. The sulfur-perovskite solution prepared in 10 ml of toluene was added dropwise while stirring 0.1 ml slowly, and stirring was continued for 10 minutes. Thereafter, the perovskite quantum dots prepared by centrifugation (7000 rpm) were separated and collected.

(Example 2)

Dimethylformamide (DMF) 5 ml, methylammonium bromide (MABr) 0.16 mM, SnBr ₂ (tin bromide, SnBr ₂ ) 0.05 mM, PbBr ₂ 0.15 mmol, n-octylamine 20 μl and oleic acid (oleic) acid) 0.5 ml was added and dissolved to prepare a perovskite solution. A solution of 0.08 mM sulfur (S) dissolved in 1 ml of DMF was added to the perovskite solution and stirred and mixed for 10 minutes to prepare a sulfur-perovskite solution. The sulfur-perovskite solution prepared in 10 ml of toluene was added dropwise while stirring 0.1 ml slowly, and stirring was continued for 10 minutes. Thereafter, the perovskite quantum dots prepared by centrifugation (7000 rpm) were separated and collected.

(Example 3)

Dimethylformamide (DMF) 5 ml, methylammonium bromide (MABr) 0.16 mM, SnBr ₂ (tin bromide, SnBr ₂ ) 0.05 mM, PbBr ₂ 0.15 mmol, n-octylamine 20 μl and oleic acid (oleic) acid) 0.5 ml was added and dissolved to prepare a perovskite solution. A solution of 0.10 mM sulfur (S) dissolved in 1 ml of DMF was added to the perovskite solution and stirred and mixed for 10 minutes to prepare a sulfur-perovskite solution. The sulfur-perovskite solution prepared in 10 ml of toluene was added dropwise with 0.1 ml of dropwise stirring with vigorous stirring, and stirring was continued for 10 minutes. Thereafter, the perovskite quantum dots prepared by centrifugation (7000 rpm) were separated and collected.

(Comparative Example 1)

In Example 1, it was carried out in the same manner as in Example 1, except that sulfur was not doped into the perovskite compound crystal particles by dropping a perovskite solution instead of a sulfur-perovskite solution in toluene. MAPb _0.75 Sn _0.25 Br ₃ quantum dots (reference quantum dots), which are sulfur undoped alloy perovskite compounds, were prepared.

(Comparative Example 2)

Instead of perovskite compound crystal particles of MAPb _0.75 Sn _0.25 Br ₃ in Comparative Example 1, raw materials were added so that MAPbBr ₃ was prepared, and the same procedure as Comparative Example 1 was performed except that Perovskite solution was prepared. Doped non-alloy perovskite compound quantum dots (MAPbSnBr ₃ quantum dots) were prepared.

Elemental chalcogen is a diagram showing the results of X-ray diffraction analysis using Cu-Kα of the quantum dots prepared in Example 1, Example 2, Comparative Example 1 and Comparative Example 2.

As can be seen in Figure 1, it can be seen that all of the manufactured quantum dots have a perovskite structure. In addition, it can be seen that the crystal lattice contracts as the MAPbBr ₃ (Comparative Example 2) to MAPb _0.75 Sn _0.25 Br ₃ (Comparative Example 1) shrinks and the 2θ of the diffraction peak slightly increases. In addition, from the X-ray diffraction patterns of Comparative Examples 1 and 1 to 2, it can be seen that phase change or secondary phase is not generated by introduction of sulfur, and the perovskite structure is stably maintained, and within the crystal structure. It can be seen that sulfur is uniformly introduced and the 2θ of the diffraction peak is slightly increased.

FIG. 2 is a transmission electron microscope image (FIG. 2 (a)) observing the reference quantum dot (MAPb _0.75 Sn _0.25 Br ₃ quantum dot) prepared in Comparative Example 1, and observing a region shown by a yellow square in FIG. 2 (a). Fast Fourier Transform (FFT) of particles shown as yellow squares in FIGS. 2 (b) and 2 (b) showing high magnification transmission electron microscopy (HR-TEM) pictures and results of SAED (Selected Area Electron Diffraction). It is an image showing an image. FIG. 3 is a transmission electron microscope image (FIG. 3 (a)) observing the sulfur-introduced perovskite quantum dots prepared in Example 2, and high magnification transmission electrons observing a region shown by a yellow square in FIG. 3 (a). FIG. 3 (b) and 3 (b) show a Fast Fourier Transform (FFT) image of particles shown as yellow squares in a microscope (HR-TEM) photograph and SAED (Selected Area Electron Diffraction). It is one drawing.

As can be seen in FIGS. 2 and 3, it can be seen that even after the introduction of sulfur, it has substantially the same size and size distribution as the reference quantum dot before sulfur introduction. In detail, it can be confirmed that in Example 2, a quantum dot having a size of 9-10 nm and being uniform and spherical was prepared, and it was confirmed that the quantum dot of Example 2 had substantially the same size, size distribution, and shape as the reference quantum dot before sulfur introduction. You can. In addition, through the transmission electron microscope analysis results of FIGS. 2 and 3, it can be confirmed that a secondary phase or elemental sulfur (S ⁰ ) was not formed by sulfur as in the X-ray diffraction results. In addition, it can be confirmed that the perovskite crystal structure is stably maintained even after the introduction of sulfur through FIGS. 2 (b), 2 (c), 3 (b), and 3 (c). Later high magnification transmission electron micrographs and high-speed Fourier transform images show excellent crystallinity of quantum dots.

4 is a view showing the results of X-ray photoelectron spectroscopy (XPS) analysis of the surfaces of quantum dots prepared in Example 1, Example 2 and Comparative Example 1, and FIG. 3 (a) shows Pb (4f) XPS Spectrum, FIG. 3 (b) shows the Sn (3d) XPS spectrum, FIG. 3 (c) shows the Br (3d) spectrum, and FIG. 3 (d) shows the S (2p) spectrum.

As can be seen in Figure 4, the halogen (Br) contained in the quantum dot, as conventionally known, 67.7eV and 68.7eV peaks can be seen at the binding energy, Sn is 3d _5/2 and 3d of the divalent Sn _It was confirmed that peaks were formed at 486.5 eV and 495.4 eV corresponding to _3/2 . It was confirmed that, in addition to the 3d _5/2 and 3d _3/2 peaks of the divalent Sn, there were no other state peaks, such as metal Sn (Sn ⁰ ) or Sn in the oxidized state.

Looking at the 2p XPS spectrum of chalcogen (sulfur) in Figure 4, it can be seen that a peak appears at 161.2 eV corresponding to the metal-sulfur bond energy, and a peak appears at 165.5 eV associated with SO ₃ ^- formation. . In addition, it was confirmed that there is no peak due to elemental sulfur (S ⁰ ) in both the quantum dots prepared in Example 1 and Example 2.

In order to examine the distribution of elements inside the quantum dots rather than the surface of the quantum dots, Ar ⁺ etching and XPS were combined to measure the distribution of elements inside the quantum dots.

5 is a view showing a result of a depth profile (depth profile) of sulfur by analyzing the sulfur concentration according to the depth of the quantum dots prepared in Example 1. As can be seen in FIG. 5, it can be confirmed that sulfur is uniformly distributed inside the quantum dot, and it can be seen that sulfur is not uniformly doped on the surface of the quantum dot but is uniformly doped in the perovskite crystal structure.

FIG. 6 is a diagram showing the results of energy dispersive X-ray spectroscopy (EDS) mapping for each element of the reference quantum dot prepared in Comparative Example 1, and FIG. 7 is a diagram showing the results of EDS mapping for each element of quantum dots prepared in Example 2 It is a drawing. As can be seen from FIG. 6 and FIG. 7, which are mapping results by elements, it can be seen that no secondary phase is formed (or precipitated) by the introduction of sulfur, and it can be seen that all elements including sulfur are homogeneously distributed.

As a result of performing EDS analysis and XPS analysis, the atomic ratio of the total divalent metal: sulfur of the quantum dots prepared in Example 1 was 0.2, and the total atomic ratio of the total divalent metal: sulfur of the quantum dots prepared in Example 2 (aromic ratio) was 0.4, and the atomic ratio (aromic ratio) of the total divalent metal: sulfur produced in Example 3 was 0.5.

8 is 300K by irradiating the 405 nm laser with the UV-Vis spectrophotometer (JASCO V-780) and the photoluminescence (PL) measurement system (PICO QUANT Fluo time 300) of the quantum dots prepared in Examples 1, 2 3 and Comparative Example 1. It is a plot showing the steady-state absorption (Fig. 8 (a)) and emission (Fig. 8 (b)) spectrum measured at temperature.

As can be seen in FIG. 8, it can be seen that as sulfur is doped, the excitation peak and emission spectrum shift to energy higher than the reference quantum dot, and as the concentration of sulfur increases, the excitation peak and emission spectrum move to energy lower than the reference quantum dot (shift). The optical band gap was calculated using a tau plot, which is summarized in Table 1 below.

(Table 1)

As summarized in Table 1, it can be confirmed that the band gap energy of the quantum dots is changed as sulfur is introduced, which is a result directly proving that sulfur was introduced into the perovskite crystal structure (crystal lattice).

As can be seen in Figure 8 (b), the emission center wavelength of the reference quantum dot (center wavelength of the emission peak, emission wavelength) was 501 nm, FWHM was 40 nm, PLQY was 40%, and Example 1, Example 2, and sulfur were introduced. The quantum dot emission center wavelengths of Example 3 were 495 nm, 510 nm and 510 nm, PLQY was 62%, 75%, and 56%, and FWHM was 35-40 nm.

In addition, as sulfur is introduced into the perovskite compound crystal particles (reference quantum dots), it can be seen that the emission intensity is significantly increased, and the largest emission intensity appears in the quantum dots prepared in Example 2 Able to know.

Figures inserted in the upper right of FIG. 8 (b) show PLQY of Comparative Example 1 (0mM in FIG.), Example 1 (0.04mM in FIG.), Example 2 (0.08mM in FIG.), And Example 3 (0.10mM in FIG.). It is a diagram showing the summary. As is known, in the case of alloy-type perovskite compounds containing Sn together with Pb, there is a problem of exhibiting low PLQY due to a large amount of quenching defects caused by aloe. However, as can be seen from FIG. 8 (b), as sulfur is introduced into the alloy-type perovskite compound, quenching bonds or trap sites that cause non-radiative recombination are healed (disappear). ) It can be seen that the emission intensity and PLQY of the quantum dots are significantly increased.

9 is a view showing a Time Resolved Photoluminescence (TRPL) spectrum of quantum dots prepared in Comparative Example 1, Example 1 and Example 2. The short lived time component (t1) and the long lived time component (t2) can be known through exponential fitting of the PL decay (Photoluminescence decay). Table 2 is a table showing the t1 and t2 of the quantum dots prepared in Comparative Example 1, Example 1 and Example 2.

(Table 2)

As can be seen in Table 2, it can be seen that both t1 and t2 decrease as sulfur is introduced into the reference quantum dot. In particular, the reduction of t2 by the introduction of sulfur indicates a reduction in non-radioactive pathways such as quenching defects caused by rowing.

FIG. 10 is a diagram showing the Ubach energy of the quantum dots prepared in Comparative Example 1, Example 1 and Example 2, and the Ubach energy of each quantum dot was calculated according to Equation 1 below.

(Equation 1)

In equation 1, α (E) is the absorption coefficient according to the photon energy E, E0 and α0 are material properties, σ (T) is the stiffness factor, k _B is the Boltzmann constant, and T is the absolute temperature to be.

As can be seen in FIG. 10, it can be seen that the Ubach energy value decreases as sulfur is introduced into the reference quantum dot, and this reduction in Ubach energy means that defects present in the quantum dot are greatly reduced. The result of FIG. 10 is a result consistent with the increase of PLQY by the introduction of sulfur and the decrease of t1 and t2.

FIG. 11 is a diagram showing a chromaticity diagram showing optical color information on quantum dots prepared in Example 1, Example 2 and Comparative Example 1, irradiating a UV lamp (365 nm) and observing the emission color, and optical color information on the emission color. to be.

12 is a view showing emission spectra measured at temperatures of 10K and 300K by irradiating a 325 nm excitation laser source to the quantum dots prepared in Example 1, Example 2 and Comparative Example 1.

It can be seen that as the temperature decreases, the luminescence intensity increases at all quantum dots and the wavelength of the emission center shifts to a long wavelength (red shift). It is known that the red shift due to the decrease in temperature is due to the thermal expansion of the yarn or the change in the forbidden gap of the semiconductor due to the electron-phonon interaction, and the enhancement of the luminescence intensity is known to be due to the non-radioactive recombination process being thermally inactive.

As can be seen in FIG. 12, in the case of the reference quantum dot, a single emission peak (main peak, A) is shown at 300K, but it can be seen that two additional peaks (B and C) appear as the temperature decreases to 10K. It is known that when the diameter is very small, less than 12 nm, the binding effect is more complex than the weaker quantum dots. As the average size (diameter) of the reference quantum dot is 8-9 nm, the additional peak at 10K can be interpreted as being due to the very fine size of the quantum dot, or due to structural disorder or phase transition due to a decrease in temperature. have.

As is known, an additional peak (C) appearing at an energy lower than the main emission peak at low temperature is a peak due to impurities, and sulfur is introduced into the reference quantum dot, and the impurities present in the quantum dot structure are removed by introduction of sulfur. Can be interpreted. In addition, as a result of measuring the emission spectrum while changing the temperature in the range of 10K-300K, it was found that the intensity of the additional peak (B) appearing in the energy higher than the main emission peak increases with decreasing temperature, and the additional peak (B It was confirmed that the line width of) hardly changed with temperature up to 150K. Accordingly, it can be interpreted that the additional peak (B) is due to the disorder and imperfection of the aloe perovskite, not due to phase transition or coexistence of the two phases.

On the other hand, as can be seen through FIG. 12, it can be seen that, unlike the reference quantum dot, in the case of a quantum dot having sulfur introduced there is no new peak other than the main peak even at a low temperature of 10K. The result that no additional peak is generated even at 10K can be interpreted as sulfur being introduced into a defect in the perovskite crystal structure and healing (removing) the defect, which is a result of a significant increase in PLQY of quantum dots due to sulfur introduction. Matches.

13 is a result of testing atmospheric stability and light stability of the quantum dots prepared in Example 1, Example 2 and Comparative Example 1. In detail, Figure 13 (a) is a view showing the PLQY (%) according to the exposure time after exposing the prepared quantum dots to the atmosphere, Figure 13 (b) is in Example 1, Example 2 and Comparative Example 1 The manufactured quantum dots are continuously irradiated with ultraviolet light (365 nm, 6 W), showing changes in luminescence intensity according to ultraviolet irradiation time, and FIG. 13 (c) is a view showing changes in FWHM of emission peaks with ultraviolet irradiation time. to be.

As can be seen in FIG. 13 (a), it can be seen that in the case of the reference quantum dot in which sulfur was not introduced, the efficiency rapidly decreased to only 27% of the initial efficiency by exposure for 30 days. However, in the case of quantum dots in which sulfur is introduced, the efficiency up to 58% (Example 1) and 42% (Example 2) of the initial efficiency is maintained even after 30 days of atmospheric exposure, and atmospheric stability is significantly increased by introduction of sulfur. Was confirmed.

As ultraviolet rays were continuously irradiated to the quantum dots prepared in Example 1, Example 2, and Comparative Example 1, it was confirmed that a red shift occurred in which the emission center wavelengths of all the quantum dots moved to long wavelengths. In detail, the red shift of the reference quantum dot is 22 nm at the irradiation time 110 minutes, and the red shift of the quantum dot to which sulfur is introduced is 10 nm (Example 1) and 3 nm (Example 2). It can be seen that structural changes (photochemical changes) and thermal stress caused by light irradiation are significantly suppressed.

13 (b) and 13 (c), the PL intensity deterioration (intensity change value / initial intensity value) of the reference quantum dot is 0.80, but when the sulfur is introduced into the reference quantum dot, the PL intensity deterioration is 0.55. It can be seen that (Example 1) and 0.65 (Example 2) significantly decrease. In addition, it can be seen that when sulfur is introduced into the reference quantum dot, a constant FHWM value is maintained irrespective of the ultraviolet irradiation time.

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

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

Claims (20)

Perovskite compound crystal particles; And chalcogen doped into the perovskite compound crystal particles. According to claim 1,
The perovskite compound is a chalcogen-introduced perovskite quantum dot containing two or more different divalent metals. According to claim 2,
The two or more divalent metals are Pb first metals; And a second metal selected from one or more selected from Cu, Ni, Co, Fe, Mn, Cr, Pd, Cd, Ge, Sn, and Yb. According to claim 2,
With the number of moles of the total metal contained in the perovskite compound being 1, the perovskite compound is a chalcogen-introduced Fe containing a divalent metal excluding 0.6 to 0.8 moles of Pb and 0.2 to 0.4 moles of Pb. Robesky quantum dots. According to claim 1,
The chalcogen is one or more chalcogen-introduced perovskite quantum dots selected from sulfur (S), selenium (Se) and tellurium (Te). According to claim 1,
The atomic ratio of the divalent metal: chalcogen contained in the quantum dots is 1: 0.1 to 0.5 chalcogen-introduced perovskite quantum dots. According to claim 1,
The perovskite compound crystal particles have an average diameter of 5 to 12 nm, a chalcogen-introduced perovskite quantum dot. According to claim 1,
The quantum dot is a chalcogen-introduced perovskite quantum dot further comprises an organic ligand surrounding the perovskite compound crystal particle surface. The method of claim 8,
The organic ligand is a chalcogen-introduced perovskite quantum dot comprising an alkyl halide or a carboxylic acid. According to claim 1,
A chalcogen-introduced perovskite quantum dot having a peak at a binding energy corresponding to a metal-chalcogen bond on the chalcogen 2p spectrum of the X-ray photoelectron spectroscopy spectrum of the quantum dot. The method according to any one of claims 1 to 10,
Based on the luminescence properties at a temperature of 10K, the emission wavelength of the quantum dot is a blue-shifted or red-shifted chalcogen-introduced perovskite quantum dot at the emission wavelength of the perovskite compound crystal particles according to the doping concentration of the chalcogen. According to claim 1,
The quantum dot is a chalcogen-introduced perovskite quantum dot satisfying the following formula 1.
(Equation 1)
PLQY / PLQY (ref) ≥ 1.5
(In the equation 1, PLQY is the quantum dot quantum yield (%), PLQY (ref) is the quantum dot perovskite compound crystal particles having the same size as the quantum yield (%)) According to claim 1,
Based on the light emission characteristics at a temperature of 300K, the full width half maximum (FWHM) of the emission peak of the quantum dots is a chalcogen-introduced perovskite quantum dot of 50 nm or less. According to claim 1,
The bach energy of the quantum dots (Urbach energy, Eu) is a chalcogen-introduced perovskite quantum dot of 85% or less compared to the ubabach energy of the perovskite compound crystal particles having the same size as the quantum dots. According to claim 1,
The quantum dots are chalcogen-introduced perovskite quantum dots having a photoluminescence quantum yield (PLQY) of 75% or more. A light emitting device comprising the chalcogen-introduced perovskite quantum dot according to any one of claims 1 to 10. a) preparing a chalcogen-perovskite solution containing an organic halide, a metal halide, a surfactant and a chalcogen source; And
b) preparing a chalcogen-introduced perovskite quantum dot by dropping the chalcogen-perovskite solution in an aprotic solvent;
Method of producing a chalcogen-introduced perovskite quantum dot comprising a. The method of claim 17,
The surfactant is a C1-C18 carboxylic acid, a C1-C18 alkylamine or a C1-C18 carboxylic acid and a C1-C18 alkylamine, a method for producing a chalcogen-introduced perovskite quantum dot. The method of claim 17,
The chalcogen source is an elemental chalcogen, a method for producing a chalcogen-introduced perovskite quantum dot. The method of claim 17,
The chalcogen-perovskite solution is a chalcogen-introduced perovskite containing 0.7 to 1 mole of organic halide, 0.1 to 0.5 mole of chalcogen source, and 5 to 20 mole of surfactant based on 1 mole of metal halide. Method of manufacturing quantum dots.

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