KR102566044B1 - Ⅲ―Ⅴquantum dot having growth layer and method for preparing thereof - Google Patents

Abstract

The method for manufacturing a quantum dot according to the present invention includes a seed forming step of forming a seed containing a group III element and a group V element; an oxidation inhibition step of suppressing oxidation on the surface of the seed by introducing a surface oxidation inhibitor after the seed formation step; and a growth layer forming step of forming a growth layer containing a group III element and a group V element or a growth layer containing a group III element, an additional metal, and a group V element after the oxidation inhibition step on the seed. It is characterized by doing.

Description

Group III-V quantum dots having a growth layer and method for preparing the same

The present invention relates to a group III-V quantum dot having a growth layer and a method for manufacturing the same.

A quantum dot (QD) is a semiconducting nano-sized particle that exhibits a quantum confinement effect and has a three-dimensionally limited size that is smaller than the exciton bore radius. exhibits excellent optical and electrical properties. For example, even if quantum dots are made of the same material, the emission wavelength is adjusted according to the size of the particles, so that the color of the emitted light may be different. Due to these characteristics, quantum dots are attracting attention as next-generation high-brightness light emitting diodes (light emitting diodes, LEDs), bio sensors, lasers, solar cell nanomaterials, and the like.

Quantum dots using group II-VI compound semiconductor composition consisting of elements of group II and group VI on the periodic table are materials that can emit light in the visible region with high luminous efficiency and photostability, and have been studied the most to date. come.

Research on representative Ⅱ-VI compound semiconductor quantum dots has attracted a lot of attention due to their advantages such as high luminous efficiency and stability, but they contain Cd ²⁺ and Se ^2-, which poses serious problems in terms of environmental hazards and toxicity. In addition, when applied to the bio field, it may have a harmful effect on the human body. Recently, III-V compound semiconductor quantum dots that can replace group II-VI quantum dots have been studied a lot.

Accordingly, environmentally friendly Ⅲ-Ⅴ-based quantum dots have been proposed, but Ⅲ-Ⅴ-based quantum dots have a problem in that quantum characteristics are lower than those of group Ⅱ-VI quantum dots. In the case of tris (trimethylsilylphosphine), a precursor mainly used in the manufacture of InP quantum dots, as a specific example of III-V quantum dots, the activity is too high and has the disadvantage of being consumed within a few seconds after being added. As a result, uniform growth is difficult while inducing a wide size distribution through Oswald Lifening, and in particular, it is difficult to synthesize quantum dots having an emission wavelength of 600 nm or more.

In addition, in order to shift the emission wavelength of III-V quantum dots, in the case of InP quantum dots, there is a change in the reactivity of the P source, a change in the precursor ratio, and additional injection of monomers. Among them, in the case of additionally injecting the monomer, the injected monomer as a growth precursor can move more effectively in changing the size of the quantum dots than other methods, but there is a disadvantage in that secondary nucleus growth may occur due to high temperature.

In particular, properly controlling the surface state of the quantum dot seed and the bonding property of the monomer precursor for the growth layer injected in the form of a complex solution is a major factor in forming the growth layer without secondary nucleus growth. Therefore, when additionally injecting monomers to form the growth layer, the secondary nucleus growth of the injected monomers is prevented, an environment used as a growth precursor is provided, and the growth layer injected in the form of a complex solution with the surface state of the quantum dot seed. It is necessary to develop a technology capable of properly controlling the binding property of the monomer precursor.

Republic of Korea Patent Registration No. 10-1462658 (registration date 2014.11.11) Republic of Korea Patent Publication No. 10-2018-0095955 (published on 2018.08.28)

One aspect of the present invention aims to provide III-V group quantum dots with improved quantum efficiency and full width at half maximum (FWHM) by reducing oxidation of the seed surface before forming the growth layer. .

A method for producing a quantum dot according to an aspect of the present invention,
A seed formation step of forming a seed containing a group III element and a group V element;
an oxidation inhibition step of suppressing oxidation on the surface of the seed by introducing a surface oxidation inhibitor after the seed formation step; and
After the oxidation inhibition step, a growth layer forming step of forming a growth layer containing a group III element and a group V element or a growth layer containing a group III element, an additional metal, and a group V element on the seed; to be characterized
At this time, it is preferable that the surface oxidation inhibitor introduced in the oxidation inhibition step is a long-chain secondary alcohol and an alkyl amine.
In addition, the surface oxidation inhibitor is preferably one or more selected from 1,2-hexanedecanediol, 1,2-octanedecanediol, and trioctylamine.
In addition, the content of the surface oxidation inhibitor is preferably a molar ratio of 1:0.5 to 1:100 of the equivalent weight of the Group III element precursor used in the seed formation step: the surface oxidation inhibitor.
In addition, the additional metal is preferably at least one selected from the group consisting of Zn, Mn, Cu, Fe, Ni, Co, Cr, Ti, Zr, Nb, Mo, Ru, and combinations thereof.
At this time, the growth layer forming step,
The 3-5 composite solution or the 3-M-5 composite solution may be injected into the solution in which the oxidation inhibition step is completed to grow on the seed.
In addition, the 3-5 composite solution,
Step a of injecting and stirring a group III element precursor and a solvent;
a step b of heating the solution of step a to a temperature of α while reducing the pressure, and then reacting the solution;
a c step of substituting the solution of step b with an inert atmosphere and then reducing the temperature to a β temperature lower than the α temperature; and
It may be prepared by including a d step of injecting a group V element precursor solution into the solution of the c step and reacting at the β temperature.
In addition, the 3-M-5 composite solution,
Step (a) of injecting and stirring a group III element precursor, a solvent, and an additional metal precursor;
a step b of heating the solution of step a to a temperature of α while reducing the pressure, and then reacting the solution;
a c step of substituting the solution of step b with an inert atmosphere and then reducing the temperature to a β temperature lower than the α temperature; and
It may be prepared by including a d step of injecting a group V element precursor solution into the solution of the c step and reacting at the β temperature.
In addition, the seed containing the group III element and group V element may further include an additional metal.
In addition, the seed formation step is a 1-1 step of injecting a group III element precursor solution, raising the temperature to A temperature for 5 to 20 minutes while reducing pressure, and then reacting for 50 to 100 minutes; and
It may include a 1-2 step of heating the solution of the 1-1 step to A temperature for several seconds to 1 hour in an inert atmosphere and injecting a group V element precursor solution.
In addition, the seed formation step is a step 1-3 of injecting a Group III element precursor solution and an additional metal precursor, raising the temperature to A temperature for 5 minutes to 20 minutes while reducing the pressure, and then reacting for 50 minutes to 100 minutes; and 1st to 4th steps of heating the solution of steps 1-3 to B temperature for several seconds to 1 hour in an inert atmosphere and injecting a group V element precursor solution.
Another aspect of the present invention provides a quantum dot manufactured by any one of the above manufacturing methods.
Another aspect of the present invention provides an electronic device including the quantum dots described above.

Group III-V quantum dots according to one aspect of the present invention provide a role of preventing oxidation of the surface of the seed by reducing the surface of the seed, and grow a growth layer on the reduced seed to improve the full width at half maximum (FWHM) and increase the quantum dot It has Quantum Efficiency.

The method for producing group III-V quantum dots according to another aspect of the present invention inhibits oxidation of the surface of the seed through an oxidation inhibition step after seed synthesis, thereby producing high-efficiency and uniform quantum dots in large quantities compared to conventional methods for synthesizing quantum dots. It has the advantage of being suitable for

1 is a diagram schematically showing that uniform growth and non-uniform growth occur when the amount of the growth layer composite solution administered increases according to the presence or absence of seed reduction treatment in the seed formation step according to one aspect of the present invention.

Hereinafter, it will be described in detail with reference to embodiments of the present invention. In describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description will be omitted.

Also, terms such as first, second, A, B, (a), and (b) may be used in describing the components of the present invention. These terms are only used to distinguish the component from other components, and the nature, order, or order of the corresponding component is not limited by the term. When an element is described as being “connected,” “coupled to,” or “connected” to another element, that element is or may be directly connected to the other element, but there is another element between the elements. It will be understood that elements may be “connected”, “coupled” or “connected”.

Also, when a component such as a layer, film, region, or plate is said to be “on” or “on” another component, this is not only when it is “directly on” the other component, but also when there is another component in between. It should be understood that the case may also be included. Conversely, when an element is said to be “directly on” another part, it should be understood that there is no intervening part. In addition, to be "on" or "on" a reference part means to be located above or below the reference part, and to necessarily be located "above" or "on" in the opposite direction of gravity does not mean no.

In addition, in describing the present invention, when a part "includes" a certain component, it means that it may further include other components, not excluding other components unless otherwise stated. do.

In addition, in describing the present invention, "planar" means when a target part is viewed from above, and "cross-section" means a cross section of the target part cut vertically when viewed from the side.

As used in this specification and the appended claims, unless otherwise indicated, the following terms have the following meanings.

As used herein, the term "precursor" is a chemical substance prepared in advance to react quantum dots, and refers to all compounds including metals, ions, elements, compounds, complexes, complexes, and clusters. It is not necessarily limited to the final material of any reaction, and means a material that can be obtained at any stage arbitrarily determined.

As used herein, the term “cluster” refers to a single atom, molecule, or particle in which tens to thousands of atoms of different types are aggregated or combined.

As used herein, the term "active metal" refers to a metal having an activity that is included in a seed, an active layer, a shell, etc. during the manufacture of quantum dots and contributes to the improvement of optical properties.

As used herein, the term “halo” or “halogen” is fluorine (F), bromine (Br), chlorine (Cl), or iodine (I) unless otherwise specified.

As used herein, unless otherwise specified, the term "alkyl" or "alkyl group" has a single bond of 1 to 60 carbon atoms, and includes a straight-chain alkyl group, a branched-chain alkyl group, a cycloalkyl (alicyclic) group, an alkyl-substituted cycloalkyl group, and the like. A radical of a saturated aliphatic functional group, including an alkyl group, a cycloalkyl-substituted alkyl group.

As used herein, the term "alkenyl group", "alkenyl group" or "alkynyl group" has a double bond or triple bond of 2 to 60 carbon atoms, respectively, and includes a straight chain or branched chain group, unless otherwise specified. , but is not limited thereto.

As used herein, the term "cycloalkyl" refers to, but is not limited to, a ring-forming alkyl having 3 to 60 carbon atoms, unless otherwise specified.

As used herein, the term "alkoxyl group", "alkoxy group", or "alkyloxy group" refers to an alkyl group to which an oxygen radical is attached, and has 1 to 60 carbon atoms, unless otherwise specified, and is limited thereto. It is not.

As used herein, the term "aryloxyl group" or "aryloxy group" refers to an aryl group to which an oxygen radical is attached, and has 6 to 60 carbon atoms unless otherwise specified, but is not limited thereto.

The terms "aryl group" and "arylene group" used herein have 6 to 60 carbon atoms, respectively, unless otherwise specified, but are not limited thereto. In the present invention, an aryl group or an arylene group refers to a single-ring or multi-ring aromatic ring, and includes an aromatic ring formed by bonding or reacting with adjacent substituents. For example, the aryl group may be a phenyl group, a biphenyl group, a fluorene group, or a spirofluorene group.

The prefix “aryl” or “ar” refers to a radical substituted with an aryl group. For example, an arylalkyl group is an alkyl group substituted with an aryl group, an arylalkenyl group is an alkenyl group substituted with an aryl group, and a radical substituted with an aryl group has carbon atoms described herein. Also, when the prefixes are named consecutively, it means that the substituents are listed in the order listed first. For example, an arylalkoxy group means an alkoxy group substituted with an aryl group, an alkoxylcarbonyl group means a carbonyl group substituted with an alkoxyl group, and an arylcarbonylalkenyl group means an alkenyl group substituted with an arylcarbonyl group. Wherein the arylcarbonyl group is a carbonyl group substituted with an aryl group.

The term "heterocyclic group" as used herein, unless otherwise specified, includes at least one heteroatom, has 2 to 60 carbon atoms, includes at least one of a single ring and multiple rings, and includes a heteroaliphatic ring and a heterocyclic ring. Contains an aromatic ring. It may also be formed by combining adjacent functional groups.

As used herein, the term "heteroatom" refers to N, O, S, P or Si unless otherwise specified.

In addition, the "heterocyclic group" may include a ring containing SO ₂ instead of carbon forming the ring. For example, "heterocyclic group" includes the following compounds.

As used herein, the term "fluorenyl group" or "fluorenylene group" means a monovalent or divalent functional group in which R, R' and R" are all hydrogen in the following structure, respectively, unless otherwise specified, " Substituted fluorenyl group" or "substituted fluorenyl group" means that at least one of the substituents R, R', R" is a substituent other than hydrogen, and R and R' are bonded to each other to form a This includes cases where they form a spy compound together.

As used herein, the term "spiro compound" has a 'spiro union', which means a connection formed by two rings sharing only one atom. At this time, the atoms shared by the two rings are called 'spiro atoms', and according to the number of spiro atoms in a compound, they are called 'monospiro-', 'dispiro-', and 'trispiro-', respectively. ' It's called a compound.

Unless otherwise specified, the term "aliphatic" as used herein means an aliphatic hydrocarbon ring having 1 to 60 carbon atoms, and "aliphatic ring" means an aliphatic hydrocarbon ring having 3 to 60 carbon atoms.

Unless otherwise specified, the term "ring" used herein refers to a fused ring composed of an aliphatic ring having 3 to 60 carbon atoms, an aromatic ring having 6 to 60 carbon atoms, a heterocyclic ring having 2 to 60 carbon atoms, or a combination thereof, Contains saturated or unsaturated rings.

Other hetero compounds or heteroradicals other than the aforementioned hetero compounds include, but are not limited to, one or more heteroatoms.

In addition, unless explicitly stated otherwise, “substituted” in the term “substituted or unsubstituted” as used herein means deuterium, halogen, amino group, nitrile group, nitro group, C ₁ ~ C ₂₀ alkyl group, C ₁ ~ C ₂₀ alkoxyl group, C ₁ ~ C ₂₀ alkylamine group, C ₁ ~ C ₂₀ alkylthiophene group, C ₆ ~ C ₂₀ arylthiophene group, C ₂ ~ C ₂₀ alkenyl group, C ₂ ~ C ₂₀ alkynyl group, C ₃ ~ C ₂₀ cycloalkyl group, C ₆ ~ C ₂₀ aryl group, deuterium-substituted C ₆ ~ C ₂₀ aryl group, C ₈ ~ C ₂₀ arylalkenyl group, silane group, boron group, germanium group, and C ₂ ~ C ₂₀ means substituted with one or more substituents selected from the group consisting of heterocyclic groups, but is not limited to these substituents.

In addition, unless explicitly stated otherwise, the chemical formula used in the present invention applies the same as the substituent definition by the exponential definition of the following chemical formula.

Here, when a is an integer of 0, substituent R ¹ does not exist, and when a is an integer of 1, one substituent R ¹ is bonded to any one of the carbon atoms forming the benzene ring, and when a is an integer of 2 or 3 Each is combined as follows, wherein R ¹ may be the same or different from each other, and when a is an integer of 4 to 6, it is bonded to the carbon of the benzene ring in a similar manner, while indicating the hydrogen bonded to the carbon forming the benzene ring. is omitted.

In adding reference numerals to the components of each drawing, it should be noted that the same components have the same numerals as much as possible even if they are displayed on different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description will be omitted.

In addition, in order to clearly describe the present invention, parts irrelevant to the description have been omitted, and the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of description, so the present invention is not limited to those shown. In the drawings, the thicknesses of various layers and regions are enlarged and exaggerated for convenience of description.

The present invention provides a quantum dot comprising a seed, a growth layer and a shell.

The seed is a group III element Al, Ga, In, Ti or a combination thereof and a group V element P, As, Sb, Bi or a combination thereof, for example, GaN, GaP, GaAs, GaSb, AlN, AlP A binary element compound selected from the group consisting of AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof; A ternary compound selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, InGaP, InZnP, and mixtures thereof; and a quaternary compound selected from the group consisting of GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, GaAlNP, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and mixtures thereof; do.

When the seed is alloyed with a group III element or a combination thereof, or a group V element or a combination thereof, an additional metal may be alloyed so as to play a role of stabilizing the crystal lattice in the seed and compensating for defects.

As the additional metal, at least one selected from the group consisting of Zn, Mn, Mg, Cu, Fe, Ni, Co, Cr, Ti, Zr, Nb, Mo, Ru, and combinations thereof, which may have various oxidation numbers, is used. can

The additional metal is alloyed by being injected into a solution containing a group III element precursor or a group V element precursor in the form of an additional metal precursor. The additional metal precursor is included in the solution in the form of an additional metal-carboxylate or an additional metal oxide-carboxylate. and the reaction proceeds. In particular, when the additional metal precursor is used in the form of an additional metal oxide-carboxylate, the additional metal is activated while forming a nano-cluster, preventing precursor depletion and producing uniform quantum dots, especially with high full width at half maximum (FWHM) and quantum efficiency. Therefore, in order to distinguish this, the additional metal alloyed with the group III element or group V element when the additional metal oxide-carboxylate is injected as a precursor is independently named an active metal.

At this time, the molar ratio of the group III element of the seed to the additional metal may be, for example, 1:0.01 to 1:30, preferably 1:0.1 to 1:30. In particular, when the additional metal is an active metal, the molar ratio of the Group III element to the additional metal is preferably 1:3 to 1:20. When the concentration of the additional metal exceeds the above range, there is a problem in that the growth of the quantum dots is limited, and when the concentration is below the above range, the growth is quickly saturated and the stability of the crystal lattice is lowered, thereby reducing the efficiency of the quantum dots.

In addition, the molar ratio of the group III element and the group V element of the seed may be, for example, 1:0.1 to 1:2, preferably 1:0.5 to 1:1. When the molar ratio of the group III element and the group V element exceeds the above range, there is a problem that it is difficult to obtain a quantum dot in a desired wavelength range, and when the molar ratio is less than the above range, uniform growth is inhibited.

The growth layer is a semiconductor layer grown on the outer surface of the seed. The growth layer is a group III-V semiconductor layer composed of a group III element or a combination thereof and a group V element or a combination thereof, and the group III element and group V element included in the seed. It may be made of the same kind of semiconductor material as the seed, but it is preferable to have a different molar ratio from the group Ⅲ and group Ⅴ elements of the seed, and may include an additional metal. In this case, when both the seed and the growth layer include an additional metal, the additional metal of the growth layer may be made of the same type as the additional metal included in the seed.

When the additional metal is alloyed with a group III element or a combination thereof and a group V element or a combination thereof, the additional metal serves to stabilize the crystal lattice in the seed and growth layers and compensate for defects.

In addition, the molar ratio of the group III element of the growth layer and the group V element of the growth layer may be, for example, 1:0.5 to 1:2, preferably 1:0.5 to 1:1. When the concentration of the group V element of the growth layer exceeds the above range, there is a problem in that the stability of the synthesized quantum dot is lowered, and when it is less than the concentration, there may be difficulty in growth because sufficient group V precursor is not injected.

When the additional metal is included, the molar ratio of the Group III element of the growth layer and the additional metal of the growth layer may be, for example, 1: 0.1 to 1: 2, preferably 1: 0.1 to 1: 1, and more preferably 1: 0.1 to 1: 1. Preferably, it may be 1:0.1 to 1:0.8. When the concentration of the additional metal exceeds the above range, the growth of the growth layer is inhibited, making it difficult to control the wavelength of the nanocrystal.

At this time, the thickness of the growth layer may be, for example, 0.1 nm to 3.5 nm, and preferably 0.5 nm to 3 nm. If it exceeds the above range, there is a problem of deviating from the desired wavelength range, and if it is below the above range, there is a problem in that the stability of the quantum dot is lowered.

The growth layer may further include a supplementary element. The supplementary element is included in the growth layer and changes the characteristics of the quantum dots according to the content. For example, when an element such as Al, Ga, Ti, Mg, Na, Li, or Cu is included, growth of a growth layer may be accelerated and emission wavelength may be changed.

At this time, the ratio of the supplementary element of the growth layer and the group III element of the growth layer may be, for example, 1:1 to 1:200, preferably 1:5 to 1:100. When the molar ratio of the supplementary elements for the growth layer exceeds the above range, the growth of the growth layer is accelerated and non-uniform quantum dots are synthesized.

In addition, the ratio of the supplementary element of the growth layer and the group V element of the growth layer may be, for example, 1:3 to 1:100, preferably 1:5 to 1:80. When the molar ratio of the supplementary elements of the growth layer exceeds the above range, the growth of the growth layer is promoted more quickly, resulting in the synthesis of non-uniform quantum dots.

In addition, when the additional metal and supplementary element are included in the growth layer, the molar ratio of the supplementary element of the growth layer and the additional metal of the growth layer may be, for example, 1:3 to 1:100, preferably 1:4 to 1:100. It could be 1:70. When the molar ratio of the supplementary elements of the growth layer exceeds the above range, the growth of the growth layer is promoted more quickly, resulting in the synthesis of non-uniform quantum dots.

The shell is formed surrounding the outer surface of the growth layer. The shell may increase stability by preventing surface defects of the nanocrystal by coating the outer surfaces of the seed and growth layer.

The shell may be selected from the group consisting of a II-VI group semiconductor, a III-V group semiconductor, and a IV-VI group semiconductor material. Specifically, it is preferable to use a II-VI group semiconductor for the shell.

As the group II element, one or more from the group consisting of Zn, Cd, Hg, Mg or combinations thereof may be used, and as the group III element, one from the group consisting of Al, Ga, In, Ti or a combination thereof More can be used.

In addition, as the group IV element, one or more from the group consisting of Si, Ge, Sn, Pb, or combinations thereof may be used, and as the group VI element, the group consisting of O, S, Se, Te, or combinations thereof may be used. One or more may be used in

Examples of the shell material in the present invention are CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, PbS, PbSe, PbSeS, PbTe, GaAs, GaP, InP, InGaP, InZnP, InAs, CuS, InN, GaN, InGaN , AlP, AlAs, InAs, GaAs, GaSb, InSb, AlSb, HgS, HgTe, HgCdTe, ZnCdS, ZnCdSe, CdSeTe, CuInSe2, CuInS2, AgInS2 and SnTe, but not limited thereto.

In the quantum dots, the average diameter of the seed is, for example, 1 nm to 5 nm, and the thickness of the shell is preferably, for example, 0.5 nm to 7 nm. In addition, the thickness of the growth layer is preferably 0.5 nm to 3.5 nm. If it is out of the above range, the emission wavelength may not match or the efficiency may decrease.

The quantum dot of the present invention has an emission wavelength of about 520 nm to 780 nm, preferably 530 nm to 700 nm, and more preferably 550 nm to 650 nm.

In addition, in the case of a full width at half maximum, it is about 60 nm or less, preferably 20 nm to 60 nm, and more preferably 30 to 57 nm.

Hereinafter, the quantum dot described above of the present invention can be prepared through the following manufacturing method.

The method of manufacturing the quantum dots includes a seed formation step (step 1), an oxidation inhibition step (step 2), a growth layer formation step (step 3), a shell formation step (step 4), and a purification step (step 5). The name of each stage is a name given to distinguish each stage from other stages and does not include all the technical meanings of each stage. In addition, at this time, the shell formation step and the purification step may be optionally included.

The seed formation step (step 1) is a step of forming a seed by reacting a solution containing a group III element precursor and a group V element precursor to synthesize the seed.

That is, seeds may be formed by reacting the group III element precursor solution and the group V element precursor solution.

The group III element precursor solution includes a group III element precursor, a solvent, and a surfactant. As the group III element precursor, all precursors containing the group III element, such as halogen salts of the group III element, may be used.

For example, when the group III element is indium, the group III element precursor is indium acetylacetonate, indium (III) chloride, indium (III) acetate, trimethyl Indium (Trimethyl indium), Alkyl Indium, Aryl Indium, Indium (III) Myristate, Indium (III) Myristate Acetate (Indium (III) Myristate Acetate) or Indium Myristate 2 Acetate ( At least one may be selected from the group consisting of Indium(III) Myristate 2 Acetate), and preferably may be indium chloride or indium acetylacetonate.

The solvents used in the group Ⅲ element precursor solution are 2,6,10,15,19,23-hexamethyltetrachosan (Squalane), 1-octadecene (ODE), trioctylamine (TOA), tributylphosphine oxide , Octadecene, octadecylamine, trioctylphosphine (TOP), or trioctylphosphine oxide (TOPO) may be selected from at least one.

The surfactant may be optionally used, and may be a carboxylic acid compound, a phosphonic acid compound, or a mixture of these two compounds.

Carboxylic acid compounds are composed of oleic acid, palmitic acid, stearic acid, linoleic acid, myristic acid and lauric acid. At least one may be selected from the group, and the phosphonic acid compound is hexylphosphonic acid, octadecylphosphonic acid, tetradecylphosphonic acid, hexadecylphosphonic acid, At least one may be selected from the group consisting of decylphosphonic acid, octylphosphonic acid, or butylphosphonic acid.

The group V element precursor solution includes a group V element precursor and a solvent.

Group V element precursors are tris(trimethylsilyl)phosphine ((Tris(trimethylsilyl)phosphine, TMSP), aminophosphine, white phosphorus, tris(pyrazolyl)phosphane), calcium phosphine Organometallic phosphorus such as calcium phosphide may be used, preferably tris(trimethylsilyl)phosphine (TMSP) or aminophosphine.

Trioctylphosphine (TOP), tributylphosphine (TBP), octadecene (ODE), or amines (primary amine, secondary amine, third amine) may be used as the solvent used for the group V element precursor solution. The molar concentration of the group element precursor solution is preferably 0.001M to 2M, for example.

At this time, an alkylphosphine-based surfactant may be additionally added to the group V element precursor solution. When the group V element and the alkylphosphine-based surfactant are added, the group V element and the alkylphosphine-based surfactant are combined to form a new organic complex, whereby a more stable reaction is possible, making it more suitable for mass production. Moreover, the size of quantum dots can be adjusted according to the type or concentration of the alkylphosphine-based surfactant.

The alkyl phosphine surfactant is triethyl phosphine, tributyl phosphine, trioctyl phosphine, triphenyl phosphine or tricyclohexyl phosphine. phosphine) may be selected from one or more.

The seed formation step (step 1) specifically includes steps 1-1 and 1-2.

Step 1-1 is a step of reacting for 50 to 100 minutes after injecting the Group III element precursor solution, raising the temperature to A temperature for 5 to 20 minutes while reducing the pressure. The temperature A is, for example, 60 °C to 160 °C or 100 °C to 150 °C. At a temperature lower than the above range, there is a possibility that impurities in the precursor may not be removed, and when the temperature is higher than the range, the concentration of the solution changes, which may interfere with efficient quantum dot growth.

Step 1-2 is a step of heating the solution of step 1-1 to B temperature for several seconds to 1 hour in an inert atmosphere and injecting a group V element precursor solution. The temperature B is higher than the temperature A, and is preferably 200°C to 400°C. When the temperature is lower than the above temperature range, quantum dot formation does not occur effectively, and when the temperature is higher than the above temperature range, it is difficult to control the emission wavelength.

On the other hand, when the additional metal in the seed is alloyed with the group Ⅲ element and the group Ⅴ element, a precursor treatment step (step 0) is further included prior to the seed formation step, and the seed formation step at this time is 1-3 steps, It consists of steps including steps 1-4.

Specifically, the precursor processing step (step 0) includes the 0-1st step, the 0-2nd step, the 0-3rd step, and the 0-4th step.

Step 0-1 is a step of reducing the pressure by mixing the additional metal pre-precursor and carboxylic acid.

For example, when the additional metal is zinc, the additional metal pre-precursor is dimethyl zinc, diethyl zinc, zinc acetate, zinc acetate dihydrate, zinc acetyl Zinc acetylacetonate, Zinc acetylacetonate hydrate, Zinc iodide, Zinc bromide, Zinc chloride, Zinc fluoride, Zinc Zinc fluoride tetrahydrate, Zinc carbonate, Zinc cyanide, Zinc nitrate, Zinc nitrate hexahydrate, Zinc oxide , Zinc peroxide, Zinc perchlorate, Zinc perchlorate hexahydrate, Zinc sulfate, Diphenyl zinc, Zinc naphthenate, or At least one may be selected from the group consisting of zinc stearate. Preferably, it may be zinc acetate or zinc chloride.

In the case where the additional metal is not zinc, the same applies as above.

Carboxylic acid is required to react with an additional metal precursor to produce an additional metal-carboxylate, which is an additional metal precursor, and palmitic acid, myristate acid, oleic acid, stearic acid, and the like can be used.

A mixed solution is prepared by mixing the additional metal pre-precursor and the carboxylic acid in a molar ratio of, for example, 1:1 to 1:3. If it is out of the above range, unreacted excess salt or acid may unintentionally participate in subsequent processes, which may cause problems. In addition, the reduced pressure is preferably 100 torr to 0.001 torr. If it is out of the above range, the removal of impurities or additionally generated products may not be smooth.

Step 0-2 is a step of first reacting the mixed solution after raising the temperature of the mixed solution after step 0-1 to a first temperature. The range of the first temperature is different depending on the type of carboxylic acid used, but, for example, a room temperature of 25° C. to 200° C. is preferable. At this time, the pressure remains the same. In addition, at this time, the temperature rise time is, for example, 10 minutes to 1 hour, and the reaction time is preferably 10 minutes to 3 hours, for example. The product produced after step 0-2 is an additional metal-carboxylate.

In the following steps 0-3 and 0-4, the additional metal oxide-carboxylate (hereinafter referred to as active metal nanocluster) is obtained by thermally decomposing the additional metal-carboxylate prepared in steps 0-1 and 0-2. It is an optional step in manufacturing.

Step 0-3 is a step of raising the temperature of the mixed solution after step 0-2 to a second temperature higher than the first temperature and then subjecting the mixed solution to a secondary reaction. The range of the second temperature may be within the range of 200 ° C to 500 ° C, for example, and is preferably a temperature higher than the first temperature. At this time, the pressure remains the same. In addition, at this time, the temperature rise time is, for example, 10 minutes to 1 hour, and the reaction time is preferably 10 minutes to 3 hours, for example.

At this time, when the range of the second temperature is less than the above range, thermal decomposition does not occur, and additional metal oxide-carboxylate is not formed, and when it exceeds the above range, active metal nanoclusters are converted into active metal oxide nanoparticles. , Active metal oxide nanoparticles have very low reactivity, so they do not participate in the seed reaction, and the content of additional metal alloyed with the seed is reduced.

Steps 0-4 are steps of injecting the mixed solution into a solvent under an inert atmosphere and then lowering the temperature to a third temperature (reducing the temperature). The solvent is for adjusting the concentration of the mixed solution, and both a coordinating solvent and a non-coordinating solvent are available, and octadecene may be generally used. The range of the third temperature may be room temperature, and the pressure may be maintained at normal pressure. As for the temperature reduction time, 20 minutes - 2 hours are preferable.

After steps 0-4, an active metal nano-cluster solution is prepared.

The active metal nanocluster may be represented by Formula 1 below.

[Formula 1] T _x O _y (Carboxylate) _z

In Formula 1,

T is an active metal and may be selected from the group consisting of Zn, Mn, Cu, Fe, Ni, Co, Cr, Ti, Zr, Nb, Mo, Ru, and combinations thereof, which may have various oxidation numbers.

x, y, and z are natural numbers, and x>y satisfies the relation of x+y=z or 2x=2y+z.

For example, the value of x of the two or more types of active metal nanoclusters different from each other may be 2 to 10.

Two or more active metal nanoclusters having different x values may satisfy the relationship of x+y=z, respectively. For example, Zn ₄ O (carboxylate) ₅ , Zn ₇ O ₂ (carboxylate) ₉ , and the like may be included.

Two or more active metal nanoclusters having different values of x may each satisfy a relationship of 2x=2y+z. For example, Zn ₄ O (carboxylate) ₆ , Zn ₇ O ₂ (carboxylate) ₁₀ and the like may be included.

Carboxylate is a salt or carboxylate ester of a carboxylic acid. The salt of carboxylic acid may be represented by Formula 2, and the carboxylate ester may be represented by Formula 3.

[Formula 2] M (RCOO) _n

[Formula 3] RCOOR'

In Formula 2 or 3,

M is a metal, n is a natural number, and R and R' are hydrogen or an organic group.

The metal refers to metals such as alkali metals, alkaline earth metals, and transition metals shown in the periodic table, and natural numbers mean positive integers.

The organic group is deuterium; halogen; silane group; boron group; Germanium group; amide group; amide group; amino group; cyano group; nitrile group; nitro group; C ₆ ~ C ₆₀ aryl group; fluorenyl group; A C ₂ -C ₆₀ heterocyclic group containing at least one heteroatom selected from the group consisting of O, N, S, Si and P; C ₃ ~ C ₆₀ aliphatic ring and C ₆ ~ C ₆₀ aromatic ring fused ring group; C ₁ ~ C ₅₀ Alkyl group; C ₁ ~ C ₅₀ alkoxyl group; C ₆ ~ C ₅₀ aryloxy group; C ₁ ~ C ₅₀ Alkylamine group; C ₆ ~ C ₅₀ Arylamine group; C ₁ ~ C ₅₀ Alkylthio group; C ₆ ~C ₅₀ Arylthio group; A C ₂ ~C ₅₀ alkenyl group; C ₂ ~ C ₅₀ alkynyl group; A C ₃ ~C ₅₀ cycloalkyl group; C ₈ ~ C ₅₀ arylalkenyl group; C ₇ ~ C ₅₀ arylalkyl group; Or one or more may be selected from the group consisting of combinations thereof, but is not limited thereto.

When the organic group is an aryl group, it is preferably a C ₆ -C ₃₀ aryl group, more preferably a C ₆ -C ₁₈ aryl group, such as phenyl, biphenyl, naphthyl, terphenyl, and the like.

When the organic group is a heterocyclic group, it may be preferably a C ₂ ~ C ₃₀ heterocyclic group, more preferably a C ₂ ~ C ₁₆ heterocyclic group.

When the organic group is a fluorenyl group, it may be 9,9-dimethyl-9H-fluorene, 9,9-diphenyl-9H-fluorenyl, 9,9'-spirobifluorene, or the like.

When the organic group is an alkyl group, it may be preferably a C ₁ -C ₂₀ alkyl group, more preferably a C ₁ -C ₁₀ alkyl group, such as methyl or t-butyl.

When the organic group is an alkoxy group, it may be preferably a C ₁ to C ₂₀ alkoxyl group, more preferably a C ₁ to C ₁₀ alkoxyl group such as methoxy, t-butoxy, and the like.

When the organic group is an aryloxy group, it is preferably a C ₆ -C ₃₀ aryloxy group, more preferably a C ₆ -C ₁₈ aryloxy group.

When the organic group is an alkylamine group, it may be preferably a C ₁ ~ C ₂₀ alkylamine group, more preferably a C ₁ ~ C ₁₀ alkylamine group.

When the organic group is an arylamine group, it may be preferably a C ₆ ~ C ₃₀ arylamine group, more preferably a C ₆ ~ C ₂₀ arylamine group.

When the organic group is an alkylthio group, it may be preferably a C ₁ to C ₂₀ alkylthio group, more preferably a C ₁ to C ₁₀ alkylthio group.

When the organic group is an arylthio group, it is preferably a C ₆ ~ C ₃₀ arylthio group, more preferably a C ₆ ~ C ₂₀ arylthio group.

When the organic group is an alkenyl group, it may be preferably a C ₂ ~ C ₂₀ alkenyl group, more preferably a C ₂ ~ C ₁₀ alkenyl group.

When the organic group is an alkynyl group, it may be preferably a C ₂ ~ C ₂₀ alkynyl group, more preferably a C ₂ ~ C ₁₀ alkynyl group.

When the organic group is a cycloalkyl group, it may be preferably a C ₃ -C ₃₀ cycloalkyl group, more preferably a C ₃ -C ₂₀ cycloalkyl group.

When the organic group is an arylalkenyl group, it is preferably a C ₈ ~ C ₃₀ arylalkenyl group, more preferably a C ₈ ~ C ₂₀ arylalkenyl group.

When the organic group is an arylalkyl group, it may be preferably a C ₇ -C ₃₀ arylalkyl group, more preferably a C ₇ -C ₂₀ arylalkyl group.

Wherein R and R' are each deuterium; halogen; A silane group unsubstituted or substituted with a C ₁ -C ₂₀ alkyl group or a C ₆ -C ₂₀ aryl group; Siloxane group; boron group; Germanium group; cyano group; nitro group; C ₁ -C ₂₀ Alkylthio group; C ₁ -C ₂₀ alkoxy group; C ₆ -C ₂₀ aryloxy group; C ₆ -C ₂₀ arylthio group; C ₁ -C ₂₀ Alkyl group; A C ₁ -C ₂₀ alkylamine group; A C ₆ -C ₂₀ arylamine group; C ₂ -C ₂₀ alkenyl group; C ₂ -C ₂₀ alkynyl group; C ₆ -C ₂₀ aryl group; fluorenyl group; A C ₂ -C ₂₀ heterocyclic group containing at least one heteroatom selected from the group consisting of O, N, S, Si and P; C ₃ -C ₂₀ aliphatic ring group; C ₇ -C ₂₀ arylalkyl group; And a C ₈ -C ₂₀ arylalkenyl group; may be further substituted with one or more substituents selected from the group consisting of.

The average particle diameter of the clusters is preferably 2.5 nm or less, for example, and a lower limit of the average particle diameter of 0.5 nm is more preferable because it can suppress rapid saturation of quantum dot growth.

At this time, the active metal nanocluster is prepared by synthesizing an additional metal-carboxylate by reacting an additional metal pre-precursor with carboxylic acid and then thermally decomposing it, and then converting all of the additional metal oxide into particles to participate in alloying. .

That is, in the embodiments of the present invention, an active metal nanocluster solution is formed through multi-stage control of the thermal decomposition temperature, and the active metal nanocluster solution is used as a raw material for additional metal oxide.

Unlike the prior art, by using the active metal nanocluster solution, it is possible to manufacture quantum dots having an alloy bond between group III elements and group V elements, resulting in improved FWHM and improved quantum efficiency. , it is possible to provide an effect of efficiently growing the quantum dots by suppressing the rapid saturation of the growth of the quantum dots.

For example, in the case of using zinc as an active metal, Zn oleate is first synthesized by the reaction of oleic acid as a carboxylate with Zn acetate, which is an active metal precursor.

When this is thermally decomposed by temperature control in steps 0-3, active metal nanoparticles such as Zn ₄ O (carboxylate) ₅ , Zn ₇ O ₂ (carboxylate) ₉ , Zn ₄ O (carboxylate) ₆ , Zn ₇ O ₂ (carboxylate) ₁₀ cluster is synthesized.

That is, the active metal nanocluster improves the full width at half maximum (FWHM) and increases the quantum efficiency (Quantum Efficiency) when producing quantum dots.

In the case of alloying an additional metal, the seed is synthesized in steps 1-3 and 1-4 below.

In the first to third steps, after injecting the group III element precursor solution and the additional metal precursor (additional metal-carboxylate or active metal nanocluster generated through the precursor treatment step), the pressure is reduced for 5 to 20 minutes to the temperature A. It is a step of reacting for 50 minutes to 100 minutes after raising the temperature. The temperature A is, for example, 60 °C to 160 °C or 100 °C to 150 °C. At a temperature lower than the above range, there is a possibility that impurities in the precursor may not be removed, and when the temperature is higher than the range, the concentration of the solution changes, which may interfere with efficient quantum dot growth.

Steps 1-4 are steps in which the solution of steps 1-3 is heated up to B temperature for several seconds to 1 hour in an inert atmosphere, and a group V element precursor solution is injected. The B temperature is higher than the A temperature, and is preferably 200°C to 400°C. When the temperature is lower than the above temperature range, quantum dot formation does not occur effectively, and when the temperature is higher than the above temperature range, it is difficult to control the emission wavelength.

On the other hand, the mechanism when the group III element, the group V element, and the additional metal are alloyed with the seed is estimated to be as follows.

When the additional metal-carboxylate is used as the additional metal precursor, when the Group III element precursor, the Group V element precursor, and the additional metal-carboxylate are mixed, the reactivity between the additional metal and the Group V element is higher than that of the Group III element and the Group V element. Since the reactivity of the liver is greater, the Group III element-Group V element is alloyed first, and then the Group III element-additional metal-Group V element is formed.

In addition, when the active metal nanocluster is used as the additional metal precursor, the reactivity between the group V element and the additional metal is very high, so that the additional metal-group V element is alloyed first, and then the group III element-additional metal-group V element is formed.

In the present invention, the oxidation inhibition step (step 2) is a step of inhibiting oxidation of the surface of the seed by introducing a surface oxidation inhibitor after the seed formation step (step 1).

As the surface oxidation inhibitor usable at this time, for example, long-chain dihydric alcohols and amine-based alcohols may be used, and for example, diols having 2 to 30 carbon atoms may be used as the long-chain dihydric alcohols. Specific examples thereof include 1,2-hexanedecanediol, 1,2-octanedecanediol, and trioctylamine.

That is, it serves as a reducing agent, and in the present invention, by preferentially performing an oxidation-reduction reaction with an Oxygen source, which is a by-product generated by heating in a group III element precursor solution containing carboxylic acid and phosphonic acid, on the surface of the quantum dots. It is believed to be the principle that prevents oxidation reactions.

Therefore, the surface oxidation inhibitor preferably has appropriate reducing power, and when a material having too strong reducing property is used, activation of the bonding between materials in the complex solution introduced to form the growth layer becomes severe, resulting in unwanted secondary nucleus growth. However, if the reducing power is too weak, it is difficult to obtain the desired surface oxidation inhibitory effect because the quantum dot seed tends to be oxidized first before performing the oxidation-reduction reaction with the oxygen source described above.

The surface oxidation inhibitor may be used in an amount of 1:0.5 to 1:100 in a molar ratio of the group III element precursor equivalent to the surface oxidation inhibitor used in the seed formation step. Preferably it is 1:20 to 1:80. At this time, it is preferable to provide an oxidation inhibitory effect during the formation of the seed and growth layer.

In the present invention, the growth layer forming step (step 3) is characterized by forming a growth layer on the outer surface of the seed whose surface oxidation is suppressed after the oxidation inhibition step (step 2). At this time, the surface oxidation inhibitor introduced in the seed oxidation inhibition step may provide an effect of appropriately controlling the binding property of the complex solution to be described later, which is introduced to form the growth layer.

Here, the growth layer is formed on the seed by introducing a solution containing a group III element-group V element or a solution containing a group III element-additional metal-group V element at the time when the oxidation inhibition step (step 2) is completed. It is preferably a group element-group V element growth layer or a group III element-additional metal-group V element growth layer.

At this time, the solution containing the group III element and group V element is hereinafter referred to as 3-5 composite solution or the solution containing group III element, additional metal, and group V element is hereinafter referred to as 3-M-5 composite solution.

In the growth layer formation step (step 3), the 3-5 composite solution or the 3-M-5 composite solution is injected into the solution in which the oxidation inhibition step (step 2) has been completed and reacted, and in an inert atmosphere, for example, at 130 ° C to 170 ° C. cool down The reason for reducing the temperature is to inject the shell precursor, and when the temperature is higher than the above temperature range, there is a problem in that the half width is widened because the shell coating is not uniform.

Meanwhile, the 3-5 composite solution or the 3-M-5 composite solution used in the growth layer formation step (step 3) is prepared by including step a, step b, step c, and step d.

Step a is a group III element precursor and a solvent or, in the case of alloying an additional metal to the growth layer, a group III element precursor, solvent, and additional metal precursor (additional metal-carboxylate or active metal nanocluster generated through the precursor treatment step) ) was injected and stirred.

The group III element precursor in this step is as defined in the seed formation step, and the solvent is as defined in the solvent used for the group III element precursor solution.

Step b is a step in which the solution in step a is heated to α temperature for 5 to 20 minutes while reducing the pressure, and then reacted for 50 to 100 minutes. The α temperature may be, for example, 100 °C to 150 °C, and preferably 110 °C to 130 °C. When the temperature is higher than the above range, the amount of the solvent may change and the concentration may change, and when the temperature is lower than the above range, impurities may not be properly removed.

Step c is a step of replacing the solution of step b with an inert atmosphere and then reducing the temperature to β temperature. The β temperature is preferably room temperature conditions around 15 °C to 25 °C considering the reactivity of the Group V precursor to be added later. At this time, the β temperature is lower than the α temperature.

Step d is a step of injecting a solution of the group V element precursor into the solution of step c and reacting at room temperature for 50 minutes to 100 minutes. This room temperature condition is to prevent Group III-V seeds from going in the form of particles due to the high reactivity of the Group V element precursor.

Here, the group V element precursor solution is as defined in the seed formation step.

The shell formation step (step 4) is a step of forming a shell on the surface of the growth layer after the growth layer formation step (step 3). The shell formation step includes a 4-1 step, a 4-2 step, and a 4-3 step.

Step 4-1 reduces the temperature of the solution in the step of forming the growth layer to C temperature. After that, the shell is formed by injecting one or both of the group III element precursor solution and the group V element precursor solution, or by injecting one or both of the group II element precursor solution and the group VI element precursor solution. That is, the shell is formed by injecting a group II element precursor or/and a group VI element precursor or a group III element precursor or/and a group V element precursor.

Specifically, the shell is preferably made of a II-VI group semiconductor.

At this time, the C temperature is preferably 100 ° C to 250 ° C.

Group II elements are, for example, one selected from the group consisting of Zn, Cd, Hg, Mg, or combinations thereof, and Group III elements, for example, Al, Ga, In, Ti, or one selected from the group consisting of combinations thereof. As the group A and IV elements, for example, one selected from the group consisting of Si, Ge, Sn, Pb, Sn, Zr, or a combination thereof may be used, and as the group VI element, for example, O, S, Se, Te Or one selected from the group consisting of combinations thereof may be used.

Step 4-2 is a step in which the solution in step 4-1 is heated to D°C for 10 to 120 minutes and then reacted for 2 to 4 hours. The range of D temperature is preferably 200 ° C to 400 ° C. When out of the above temperature range, there is a problem in that effective shell coating is not performed.

Step 4-3 is a step of cooling the solution in step 4-2 to room temperature while blowing it with an inert gas. If blowing with an inert gas is not performed, there is a problem in that the surface of the quantum dots is oxidized due to the injection of air at a high temperature.

The purification step (step 5) includes the 5-1st step, the 5-2nd step, and the 5-3rd step.

In step 5-1, the solution after the shell formation step is put in a centrifugal container, and for example, an alcohol solvent and a polar solvent (eg, 2-propanol) are added and centrifuged to discard the supernatant and obtain a precipitate. It is a step.

In addition, the number of rotations during centrifugation is preferably 1000 rpm to 20000 rpm, for example.

Step 5-2 is a step of dissolving the precipitate in an organic solvent such as hexane, toluene, octadecane, or heptane.

Step 5-3 is a step in which the step 5-1 and step 5-2 are repeated at least once and stored in a dissolved state in a non-polar solvent.

Another aspect of the present invention is an electronic device including quantum dots according to the above-described embodiments. At this time, the electronic device may be a light emitting device, a high luminance light emitting diode (light emitting diode, LED), a bio sensor, and the like.

In addition, another aspect of the present invention is an electronic device including the above-described electronic device. The electronic device may be a display device, a solar cell, a bio-diagnosis device, and the like. At this time, the display device may include a display panel having a light emitting device including quantum dots and the above-described controller for controlling the display panel.

Applications to various electronic devices and devices using quantum dots can be easily applied by those skilled in the art, so a detailed description thereof will be omitted.

Hereinafter, examples according to the present invention will be described in detail as synthesis examples and experimental examples, but the present invention is not limited to the following examples.

synthesis example

(1) Example 1 (manufacture of Zn Oleate)

1. Zinc acetate and oleic acid were put in a 250ml three neck flask, heated at room temperature to 120℃ under reduced pressure, and filled with an inert gas after 1 hour to create a Zn(Oleate)2 solution. . At this time, the number of moles of Zn and oleic acid were set to 0.1 mmol and 0.2 mmol, respectively.

(2) Example 2 (preparation of Zn-OXO)

1. Zinc acetate and oleic acid were put in a 250ml three neck flask, heated at room temperature to 120℃ under reduced pressure, and filled with an inert gas after 1 hour to create a Zn(Oleate)2 solution. . At this time, the number of moles of Zn and oleic acid were set to 0.1 mmol and 0.2 mmol, respectively.

2. The resulting Zn(Oleate)2 solution is heated to 300℃ to form active nano clusters.

3. Then, octadecene was injected and the temperature was reduced to room temperature. The concentration of the mixed solution was 0.5M.

(3) Example 3 (In-P composite solution)

1. In(acac)3, oleic acid and ODE were injected into a three-neck flask and stirred (acac is acetylacetonate). At this time, the number of moles of In and oleic acid were set to 0.1 mmol and 0.3 mmol, respectively.

2. The solution was heated to 120° C. for 10 minutes while reducing the pressure, and then reacted for 1 hour.

3. After replacing the solution with an Ar atmosphere, it was cooled to RT.

4. A TMSP solution was added to the solution and reacted for 1 hour to prepare an In-P composite solution. At this time, the number of moles of P was 0.07 mmol.

(4) Example 4 (In-Zn-P composite solution)

1. In(acac)3, Zn(acac)2, oleic acid and ODE were injected into a three-neck flask and stirred (acac is acetylacetonate). At this time, the number of moles of In, Zn, and oleic acid were set to 0.1 mmol, 0.05 mmol, and 0.4 mmol, respectively.

2. The solution was heated to 120° C. for 10 minutes while reducing the pressure, and then reacted for 1 hour.

3. After replacing the solution with an Ar atmosphere, it was cooled to RT.

4. A TMSP solution was added to the solution and reacted for 1 hour to prepare an In-Zn-P composite solution. At this time, the number of moles of P was 0.07 mmol.

(5) Example 5 (Preparation of InP/InP@ZnS quantum dots)

1. To prepare seeds, ODE, In acetate, and Oleic acid were put in a three-neck flask and stirred. At this time, the number of moles of In and oleic acid were set to 0.1 mmol and 0.3 mmol, respectively.

2. The solution was heated up to 120°C for 10 minutes while reducing the pressure, and reacted at 120°C for 1 hour.

3. After replacing the solution with an Ar atmosphere, the temperature was raised to 280° C. for 10 minutes, and then the TMSP solution was injected to form InP seeds. At this time, the number of moles of P was 0.07 mmol.

4. After reducing the temperature of the solution, about 2 mmol of Trioctylamine (TOA) was injected to inhibit oxidation of the surface of the seed.

5. A total of 5 mL of Example 3 was continuously injected into the InP seed synthesized above at a rate of 1 mL/h.

6. After injecting 5 mL, cooling to 150° C. while blowing with Ar, to prepare quantum dots having an InP growth layer on the InP seed at the same time as the InP seed growth.

7. When the solution containing the seed and growth layer synthesized through the above steps reached 150°C, Example 1 and TOP-S were injected. The amount of S entered at this time was 0.3 mmol.

8. After adding all the shell materials, the solution was heated up to 300°C for 20 minutes and reacted for 3 hours.

9. The solution was cooled to RT while blowing with Ar to prepare InP/InP@ZnS quantum dots.

(6) Example 6 (Preparation of InP/InZnP@ZnS quantum dots)

In Example 5, InP/InZnP@ZnS quantum dots were prepared in the same manner as in Example 5, except that Example 4 was injected instead of Example 3.

(7) Example 7 (Preparation of InZnP/InP@ZnS quantum dots)

1. To prepare seeds, ODE, Example 1, and In chloride solution were put in a three-neck flask and stirred. At this time, the number of moles of each precursor was In: 0.1 mmol, Zn: 2 mmol.

2. The solution was heated up to 120°C for 10 minutes while reducing the pressure, and reacted at 120°C for 1 hour.

3. After replacing the solution with an Ar atmosphere, the temperature was raised to 280° C. for 10 minutes, and then a TMSP solution was injected to form InZnP seeds. At this time, the number of moles of P was 0.07 mmol.

4. After reducing the temperature of the solution, about 2 mmol of Trioctylamine (TOA) was injected to inhibit oxidation of the surface of the seed.

5. A total of 5 mL of Example 3 was continuously injected into the InZnP seed synthesized above at a rate of 1 mL/h.

6. After injecting 5 mL, cooling to 150 ° C while blowing with Ar, to prepare quantum dots having an InP growth layer on the InZnP seed at the same time as growing the InZnP seed.

7. When the solution containing the seed and growth layer synthesized through the above steps reached 150°C, TOP-S was injected. The amount of S entered at this time was 0.3 mmol.

8. After adding all the shell materials, the solution was heated up to 300°C for 20 minutes and reacted for 3 hours.

9. The solution was cooled to RT while blowing with Ar to prepare InZnP/InP@ZnS quantum dots.

(8) Example 8 (Preparation of InZnP/InZnP@ZnS quantum dots)

In Example 7, InZnP/InZnP@ZnS quantum dots were prepared in the same manner as in Example 7, except that Example 4 was injected instead of Example 3.

(9) Example 9 (Preparation of InZnP/InZnP@ZnS quantum dots)

It was prepared in the same manner as in Example 8 except for injecting 0.5 mmol of TOA instead of 2 mmol in Example 8.

(10) Example 10 (Preparation of InZnP/InZnP@ZnS quantum dots)

In Example 8, it was prepared in the same manner as in Example 8, except that the solution of Example 2 containing the active metal was injected instead of Example 1.

(11) Example 11 (Preparation of InZnP/InZnP@ZnS quantum dots)

It was prepared in the same manner as in Example 8, except that 1,2-Hexadecandiol was injected instead of TOA in Example 8.

(12) Comparative Example 1

Quantum dots were manufactured by the same process as in Example 5, except that the step of injecting TOA was omitted in Example 5.

Experimental example

The photoluminescence data [emission peak, emission peak, Quantum Yield, Full Width at Half Maximum (FWHM)] were confirmed. Table 1 below shows the results of evaluating photoluminescence data.

division emission peak FWHM QY Example 5 627.9 57.5 75.6 Example 6 627.6 56.3 76.9 Example 7 625.1 56.0 77.3 Example 8 626.2 54.7 79.2 Example 9 625.8 56.5 76.5 Example 10 622.4 53.2 84.1 Example 11 624.3 54.5 79.4 Comparative Example 1 625.0 61.1 68.4

Looking at the results of Table 1, it can be seen that Examples 5 to 11 using a reducing agent show significantly better results in full width at half maximum (FWHM) and efficiency than Comparative Example 1 without using a reducing agent. That is, comparing Examples 5 to 11 using a reducing agent and Comparative Example 1 without using a reducing agent, when using a reducing agent, surface oxidation of the core can be prevented before growing the growth layer, and through this, the half width and efficiency and It is judged that the same optical characteristics are significantly improved.

In addition, looking at Figure 1, when a small amount of the complex solution (Complex) is injected to grow the growth layer, the difference between not using a reducing agent and using a reducing agent is not large, but it can be seen that the half width is greatly improved when the complex solution is injected in an amount of 3 mL or more. can That is, it is judged that the role of the reducing agent is greatly acted upon as the injected amount of the complex solution increases.

The above description is merely illustrative of the present invention, and those skilled in the art will be able to make various modifications without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in this specification are intended to explain, not limit, the present invention, and the spirit and scope of the present invention are not limited by these embodiments. The protection scope of the present invention should be construed according to the following claims, and all technologies within the equivalent range should be construed as being included in the scope of the present invention.

Claims (13)

A seed formation step of forming a seed containing a group III element and a group V element;
an oxidation inhibition step of suppressing oxidation on the surface of the seed by introducing a surface oxidation inhibitor after the seed formation step; and
After the oxidation inhibition step, a growth layer forming step of forming a growth layer containing a group III element and a group V element or a growth layer containing a group III element, an additional metal, and a group V element on the seed; A method for producing quantum dots. According to claim 1,
The method for producing quantum dots, characterized in that the surface oxidation inhibitors introduced in the oxidation inhibition step are long-chain secondary alcohols and alkyl amines. According to claim 1,
The surface oxidation inhibitor is a method for producing quantum dots, characterized in that at least one selected from 1,2-hexanedecanediol, 1,2-octanedecanediol, and trioctylamine. According to claim 1,
The amount of the surface oxidation inhibitor is a method for producing a quantum dot, characterized in that the molar ratio of the Group III element precursor used in the seed formation step: the surface oxidation inhibitor is 1:0.5 to 1:100. According to claim 1,
The additional metal is a method for producing quantum dots, characterized in that at least one or more selected from the group consisting of Zn, Mn, Cu, Fe, Ni, Co, Cr, Ti, Zr, Nb, Mo, Ru and combinations thereof. According to claim 1,
The growth layer forming step,
A method for producing quantum dots in which the 3-5 composite solution or the 3-M-5 composite solution is injected into the solution in which the oxidation inhibition step is completed to grow on the seed. According to claim 6,
The 3-5 complex solution,
Step a of injecting and stirring a group III element precursor and a solvent;
a step b of heating the solution of step a to a temperature of α while reducing the pressure, and then reacting the solution;
a c step of substituting the solution of step b with an inert atmosphere and then reducing the temperature to a β temperature lower than the α temperature; and
A method for producing a quantum dot comprising a d step of injecting a group V element precursor solution into the solution of the c step and reacting at the β temperature. According to claim 6,
The 3-M-5 complex solution,
Step (a) of injecting and stirring a group III element precursor, a solvent, and an additional metal precursor;
a step b of heating the solution of step a to a temperature of α while reducing the pressure, and then reacting the solution;
a c step of substituting the solution of step b with an inert atmosphere and then reducing the temperature to a β temperature lower than the α temperature; and
A method for producing a quantum dot comprising a d step of injecting a group V element precursor solution into the solution of the c step and reacting at the β temperature. According to claim 1,
The method of producing a quantum dot, characterized in that the seed containing the group III element and group V element further comprises an additional metal. According to claim 1,
The seed forming step is a 1-1 step of injecting a group III element precursor solution, raising the temperature to A temperature for 5 to 20 minutes while reducing the pressure, and then reacting for 50 to 100 minutes; and
Method for producing a quantum dot comprising a first-second step of heating the solution of step 1-1 to A temperature for several seconds to 1 hour in an inert atmosphere and injecting a group V element precursor solution. According to claim 9,
The seed formation step is a step 1-3 of injecting a Group III element precursor solution and an additional metal precursor, raising the temperature to A temperature for 5 to 20 minutes while reducing the pressure, and then reacting for 50 to 100 minutes; and 1st to 4th steps of heating the solution of steps 1 to 3 in an inert atmosphere to a temperature B for several seconds to 1 hour and injecting a group V element precursor solution. delete delete