KR20200001764A - Quantum dot complex and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a quantum dot composite and a manufacturing method thereof. The quantum dot composite according to an embodiment of the present invention comprises: an alloy-type quantum dot consisting of four kinds of elements; and a moisture barrier film formed on surfaces of quantum dots and including metallic stearate. The quantum dot composite according to an embodiment of the present invention minimizes un-bonding by being manufactured through an alloying process and provides alloy type quantum dots excellent in a moisture permeation function, thermal stability and light stability by forming a protective film on the surfaces of the quantum dots.

Description

QUANTUM DOT COMPLEX AND METHOD FOR MANUFACTURING THE SAME

The present specification relates to a quantum dot and a method for manufacturing the same, and more particularly, to a quantum dot and a method for producing the same to suppress moisture permeation and excellent thermal stability and light stability.

A quantum dot is a semiconductor material having a nano-sized crystal structure. The quantum dot is a material having high color purity, excellent light stability, thermal stability, and ease of band gap control compared to an organic material. Since these quantum dots are small in size, they have a large surface area per unit volume and exhibit quantum confinement effects, and thus have different physical and chemical properties from those of the semiconductor material itself. The quantum dot absorbs light from an excitation source and enters an energy excited state, and emits energy corresponding to the energy band gap of the quantum dot. Since quantum dots can control energy band gaps by controlling the size and composition of nanocrystals and have high color purity, they have been developed in various applications to display devices, energy devices, or bioluminescent devices.

Conventional quantum dots referred to generally refer to quantum dots of a core-shell structure in which a shell is coated on a surface of a spherical core, and the constituent elements include group II and III. Group, Group IV, Group V, Group VI compounds are used. The shell may typically consist of one or a plurality of layers, and may also be referred to as a multi-shell quantum dot when the shell consists of a plurality of layers. The quantum dot of the core-shell structure can control the optical and electrical properties of the quantum dot by adjusting the relative band gap between the core and the shell. Quantum dots of the core-shell structure have an advantage of having high luminous efficiency.

In general, a method of preparing a core-shell structured quantum dot is a method of preparing a core by first injecting an anion precursor solution into a high temperature cationic precursor solution at a high temperature, and then injecting a solution constituting the shell component to form a second shell. Use the method. At this time, depending on the number of addition of the solution constituting the shell component, it is possible to manufacture a quantum dot of the core-shell or multi-shell structure.

However, the quantum dot of the core-shell structure manufactured by the above-described manufacturing method has a problem in that a negative junction or a lattice mismatch occurs between the core and the shell, and thus, the thermal stability and the light stability of the quantum dot are degraded. .

To solve this problem, a method of protecting quantum dots has been devised by forming a silica film on the surface of the quantum dots. However, since gelation of silica requires a lot of time and requires a separate process of powdering silica, the quantum dot manufacturing process efficiency is lowered and it is difficult to process a large quantity of quantum dots.

The problem to be solved by the present invention is to provide an alloy-type quantum dot excellent in thermal stability and light stability without a negative junction between the core and the shell.

The problem to be solved by the present invention is to provide a quantum dot and a method of manufacturing the immunity to the water permeation barrier function.

The problem to be solved by the present invention is to provide a method for producing a quantum dot surface treatment of a large amount of quantum dots.

The objects of the present invention are not limited to the above-mentioned objects, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to solve the above problems, the quantum dot composite according to an embodiment of the present invention includes an alloy-type quantum dot composed of four kinds of elements and a moisture barrier film formed on the surface of the quantum dot and including metallic stearate. do. The quantum dot composite according to an embodiment of the present invention may be manufactured through an alloying process to minimize negative bonding, and by forming a protective film on the surface of the quantum dot, thereby providing an alloy-type quantum dot having excellent water permeability, thermal stability, and light stability. Can be.

Method of manufacturing a quantum dot composite according to an embodiment of the present invention comprises the steps of preparing an alloy-type quantum dot, the step of adding a metallic stearate to the solution containing the alloy-type quantum dots to obtain a first mixture, and the first mixture 50 Binding a metallic stearate to the alloyed quantum dot surface by heating to a temperature of from about 100 ° C. to about 100 ° C.

Specific details of other embodiments are included in the detailed description and drawings.

The present invention can minimize the negative bonding by manufacturing through the alloying process, and by forming a protective film on the surface of the quantum dot, it is possible to provide an alloy-type quantum dot excellent in water transmission function, thermal stability and light stability.

The present invention can provide a method for producing a quantum dot easy to mass production.

The effects according to the present invention are not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is a schematic diagram showing the structure of a quantum dot according to an embodiment of the present invention.
2 is a flowchart schematically showing a method of manufacturing a quantum dot according to an embodiment of the present invention.
3A is a flowchart schematically illustrating a method of manufacturing an alloy type quantum dot having a single core shape, and FIG. 3B is a flowchart schematically illustrating a method of manufacturing an alloy type quantum dot composed of a central portion and a peripheral portion.

Hereinafter, preferred embodiments of the present invention will be described. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, the embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

On the other hand, the advantages and features of the present invention, and how to achieve them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the present embodiments are intended to complete the disclosure of the present invention, and the general knowledge in the art to which the present invention pertains. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims. In addition, the size and thickness of each configuration shown in the drawings are shown for convenience of description, the present invention is not necessarily limited to the size and thickness of the configuration shown.

When 'comprises', 'haves', 'consists of' and the like mentioned in the present specification, other parts may be added unless 'only' is used. In case of singular reference, the plural number includes the plural unless specifically stated otherwise.

In interpreting a component, it is interpreted to include an error range even if there is no separate description.

In the case of the description of the positional relationship, for example, if the positional relationship of the two parts is described as 'on', 'upon', 'lower', 'next to', etc. Alternatively, one or more other parts may be located between the two parts unless 'direct' is used.

When an element or layer is referred to as another element or layer, it includes any case where another element or layer is interposed on or in the middle of another element.

Although the first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another. Therefore, the first component mentioned below may be a second component within the technical spirit of the present invention.

Each of the features of the various embodiments of the present invention may be combined or combined with each other in part or in whole, various technically interlocking and driving as can be understood by those skilled in the art, each of the embodiments may be implemented independently of each other It may be possible to carry out together in an association.

1 is a schematic diagram showing the structure of a quantum dot according to an embodiment of the present invention.

Referring to FIG. 1, the quantum dot composite 100 includes an alloy-type quantum dot 110 formed of four kinds of elements, and a water barrier layer 120 formed on the surface of the quantum dot and including metallic stearate.

The alloy quantum dot 110 is a nanoparticle containing four kinds of elements. Specifically, the alloy type quantum dot 110 is an alloy (alloy) form of the semiconductor of the II-VI group. More specifically, the quantum dot 120 may include at least two or more elements selected from Group II elements and Group III elements, and at least two or more elements selected from Group V elements and Group VI elements. In this case, the group II element may be zinc (Zn), cadmium (Cd) or mercury (Hg), and the group III element may be indium (In), magnesium (Mg) or aluminum (Al). In addition, the Group V element may be phosphorus (P), arsenic (As) or nitrogen (N), and the Group VI element may be sulfur (S), selenium (Se), or tellurium (Te). Although not limited thereto, for example, the alloy-type quantum dot according to an embodiment of the present invention may have a four-component single core shape such as Cd-Se-Zn-S.

Referring to FIG. 1, the alloy type quantum dot 110 may have a structure including a central portion C composed of four components and a peripheral portion P composed of three components among four components included in the central component C. In other words, the alloy type quantum dot 110 includes a central portion C composed of four kinds of elements and a peripheral portion P composed of three kinds of elements among four kinds of elements constituting the central portion C.

At this time, the four components constituting the central portion (C) is an alloy made of a II-VI-based semiconductor as described above. Although not limited thereto, the four components constituting the central portion C of the alloy type quantum dot 110, that is, four kinds of elements may be Cd-Se-Zn-S.

Three components which comprise the peripheral part P mean three types of elements among the four types of elements which comprise the center part C. As shown in FIG. For example, when the central portion C of the alloy type quantum dot 110 is made of Cd-Se-Zn-S, the peripheral portion P may be made of cadmium (Cd), zinc (Zn), and sulfur (S). have.

The alloy type quantum dot 110 shown in FIG. 1 has a structure in which components are different from each other without having a core-shell structure. For example, the alloy type quantum dot 110 according to an embodiment of the present invention may have a layered gradient composition. That is, the composition constituting the quantum dot from the center of the alloy type quantum dot 110 to the outermost may be different. In the present invention, the central portion C and the peripheral portion P constituting the alloy type quantum dot 110 are terms arbitrarily distinguished to describe the components, and the central portion C and the peripheral portion P are substantially clear boundaries or There may not be a distinct boundary. The peripheral portion P of the alloy type quantum dot 110 is composed of three kinds of elements among the four kinds of elements constituting the central portion C, and is formed on the surface of the central portion C through an additional alloying process. C) and periphery P have a continuous alloy structure rather than being clearly distinguished.

The diameter of the alloy type quantum dot 110 may be 1nm to 20nm, may be 10nm to 15nm, but is not limited thereto.

The moisture barrier layer 120 is a film or layer formed to surround the surface of the alloy type quantum dot 110. The moisture barrier layer 120 suppresses penetration of moisture and oxygen into the alloy type quantum dots 110 from the outside and protects the surface of the alloy type quantum dots 110. The moisture barrier layer 120 serves to improve thermal stability and light stability of the quantum dot composite 100.

The moisture barrier layer 120 includes a metallic stearate. The metallic stearate is arranged on the surface of the alloy type quantum dot 110 by the attraction force with the elements constituting the surface of the alloy type quantum dot 110, and can prevent the penetration of oxygen and moisture.

As the metallic stearate, a divalent metal can be used. For example, metallic stearate may be zinc stearate, calcium stearate, aluminum stearate, magnesium stearate, lithium stearate, and sodium stearate. One or more selected from the group consisting of sodium stearate, but is not limited thereto.

The quantum dot composite according to an embodiment of the present invention includes an alloy-type quantum dot composed of four kinds of elements and a moisture barrier layer formed on the surface of the quantum dot and including metallic stearate. Alloy-type quantum dots composed of four kinds of elements, unlike quantum dots of the core-shell structure, can minimize the unbonded or lattice mismatch between the core and the shell, and thus have excellent thermal and optical stability. . At the same time, by forming a water barrier film made of a metallic stearate on the alloy-type quantum dot surface, there is an advantage that can block the oxygen or moisture penetrating into the surface and the quantum dot.

Hereinafter will be described a method of manufacturing a quantum dot composite according to an embodiment of the present invention.

2 is a flowchart schematically showing a method of manufacturing a quantum dot according to an embodiment of the present invention.

Referring to Figure 2, the method of manufacturing a quantum dot composite according to an embodiment of the present invention to prepare an alloy-type quantum dot (S110), to obtain a first mixture by adding a metallic stearate to a solution containing the alloy-type quantum dots And (S130) binding the metallic stearate to the alloy-type quantum dot surface by heating the first mixture to a temperature of 50 ° C to 100 ° C.

Hereinafter, each step will be described in detail.

First, an alloy type quantum dot is manufactured (S110). Alloy-type quantum dots are nanoparticles containing a plurality of elements, and have an alloy (alloy) consisting of a II-VI-based semiconductor. In the method of manufacturing an alloy-type quantum dot of an embodiment of the present invention, the method of manufacturing the alloy-type quantum dot is not limited if it is not a quantum dot of a core-shell structure.

For example, the alloy-type quantum dot of the present invention may be an alloy-type quantum dot having a single core shape of four components, or as shown in FIG. 1, an alloy type composed of a central portion and a peripheral portion composed of partially different components. It may be a quantum dot. In the following, in order to explain in more detail the steps of manufacturing an alloy-type quantum dot, it will be described with respect to the alloy-type quantum dot having a single core shape and the method of manufacturing an alloy-type quantum dot consisting of a central portion and a peripheral portion.

3A is a flowchart schematically illustrating a method of manufacturing an alloy type quantum dot having a single core shape, and FIG. 3B is a flowchart schematically illustrating a method of manufacturing an alloy type quantum dot composed of a central portion and a peripheral portion.

Referring to Figure 3a, the step of preparing the alloy type quantum dots (S110) is a step of mixing two kinds of cation precursor and two kinds of anion precursor to obtain a second mixture (S111a) and heating the second mixture to a four-component system To prepare an alloy-type quantum dot (S112a).

First, a second mixture is obtained by mixing two kinds of cation precursors and two kinds of anion precursors (S111a). Four-component quantum dots are prepared using two kinds of cation precursors and two kinds of anion precursors.

The cation precursor may be a compound containing a Group II element or a Group III element, and the anion precursor may be a compound containing a Group V element or a Group VI element.

More specifically, Group II precursors containing Group II elements include zinc acetate, dimethyl zinc, diethyl zinc, zinc carboxylate, zinc acetylacetonate ( zinc acetylacetonate, zinc iodide, zinc bromide, zinc chloride, zinc fluoride, zinc carbonate, zinc cyanide, Zinc nitrate, zinc oxide, zinc peroxide, zinc perchlorate, zinc sulfate, zinc oleate, dimethyl cadmium ), Diethyl cadmium, cadmium oxide, cadmium carbonate, cadmium acetate dihydrate, cadmium Cadmium acetylacetonate, cadmium fluoride, cadmium chloride, cadmium iodide, cadmium bromide, cadmium perchlorate, cadmium phosphide cadmium phosphide, cadmium nitrate, cadmium sulfate, cadmium carboxylate, cadmium oleate, mercury iodide, mercury bromide Mercury fluoride, mercury cyanide, mercury nitrate, mercury perchlorate, mercury sulfate, mercury oxide, mercury oxide, mercury carbonate mercury carbonate, mercury carboxylate and precursors based on these precursors It may be at least one selected from the group consisting of sieve compounds.

Group III precursors comprising Group III elements include aluminum phosphate, aluminum acetylacetonate, aluminum chloride, aluminum fluoride, aluminum oxide, aluminum nitrate Aluminum nitrate, aluminum sulfate, gallium acetylacetonate, gallium chloride, gallium fluoride, gallium oxide, gallium nitrate ), Gallium sulfate, indium chloride, indium oxide, indium nitrate, indium sulfate, indium carboxylate and the precursors At least one selected from the group consisting of precursor compounds based on Can be.

In addition, Group V precursors comprising Group V elements include alkyl phosphine, tristrialkylsilyl phosphine (tris), trisylalkylsilyl phosphine (tris), and trisdi Dialkylamino phosphine (tris), arsenic oxide, arsenic chloride, arsenic sulfate, arsenic bromide, arsenic iodide arsenic iodide), nitric oxide (nitric oxide), nitric acid (nitric acid) and may be one or more selected from the group consisting of ammonium nitrate.

In addition, Group VI precursors comprising Group VI elements include sulfur, trialkylphosphine sulfide, trialkenylphosphine sulfide, alkylamino sulfide, alkenylamino sulfide (alkenylamino sulfide), alkylthiol, trialkylphosphine selenide, trialkenylphosphine selenide, alkylamino selenide, alkenylamino selenide based on alkenylamino selenide, trialkylphosphine telluride, trialkenylphosphine telluride, alkylamino telluride, alkenylamino telluride and the precursors It may be one or more selected from the group consisting of one precursor compound.

On the other hand, the cation precursor and the anion precursor can be mixed at a relatively low temperature, more preferably at 80 ° C to 120 ° C. At this time, by mixing at a relatively low temperature, the chemical reaction between the cationic precursor and the anionic precursor can be suppressed.

Next, the second mixture is heated to produce an alloy type quantum dot of four components (S112a).

At this time, the second mixture may be heated in a mixture state, or may be injected into an organic solvent heated to a high temperature in advance.

In addition, the method of heating the second mixture may be performed through a metal heat treatment (RTP). Specifically, the second mixture in a room temperature or a low temperature state may be rapidly heated to 250 ° C. or 300 ° C. or higher, and heated using radiant heat.

Although not limited thereto, the second mixture may be heated to 250 ° C. to 350 ° C., preferably to 300 ° C. to 320 ° C. At this time, the step of heating the second mixture may be performed for 20 seconds to 90 seconds, but is not limited thereto.

The cation precursor and the anion precursor react rapidly with each other by heating, and elements are bonded to form quantum dots having an alloy form.

For example, the alloy-type quantum dots prepared are CdZnSeS, CdZnTeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, GaAlNP, GaAlNAs, GaAlPA, GaAlPA, GaAlPA, GaAlPA, However, the present invention is not limited thereto.

Referring to FIG. 3B, in step S110 of manufacturing an alloy type quantum dot, a mixture of two kinds of cationic precursors and two kinds of anion precursors is mixed, and then heated to a temperature of 250 ° C. to 350 ° C. to prepare a first quantum dot. 1 alloying process (S111b); A second alloying process of preparing a second quantum dot by mixing precursors of three elements among four elements constituting the first quantum dot in a solution including the first quantum dot, and then heating the mixture to a temperature of 250 ° C. to 350 ° C. (S112b ); And a third alloying process (S113b) of mixing the precursors of the three elements in a solution including the second quantum dots and then heating them to a temperature of 250 ° C. to 350 ° C. to produce a third quantum dots.

First, two kinds of cation precursors and two kinds of anion precursors are mixed, and then heated to a temperature of 250 ° C. to 350 ° C. to prepare a first quantum dot (S111b). Since two types of cation precursors and two types of anion precursors are the same as those described in the method for producing an alloy type quantum dot according to FIG. 3A, redundant descriptions are omitted.

Two kinds of cationic precursors and two kinds of anionic precursors are mixed based on an organic solvent, and then the mixture is heated to a temperature of 250 ° C to 350 ° C to prepare a four-component first quantum dot.

As a 1st alloying process, the alloy containing 1st quantum dot is formed from 4 types of metal ion by heating the mixture containing 4 types of precursors to high temperature, about 250 degreeC-350 degreeC. The first quantum dot serves as a seed for the final alloyed quantum dot. The first quantum dot constitutes the central portion of the alloy type quantum dot to be finally formed.

Thereafter, precursors of three of the four elements constituting the first quantum dot are mixed with a solution including the first quantum dot, and then heated to a temperature of 250 ° C. to 350 ° C. to produce a second quantum dot (S112b).

The step S112b is a step of growing a metal around the first quantum dot through an additional alloying process on the first quantum dot formed through the step S111b. Specifically, precursors of three elements among four elements constituting the first quantum dots are mixed in a solution containing the first quantum dots. For example, when the first quantum dot is a Cd-Se-Zn-S quaternary quantum dot, the precursors of Cd, Zn, and S may be added to the solution including the first quantum dot.

As a second alloying step, the second mixture is heated by heating a mixture containing a first quantum dot, which is a four-component quantum dot, and a precursor of three elements among the four elements constituting the first quantum dot, to a high temperature of about 250 ° C to 350 ° C. Quantum dots are formed. The second quantum dot is formed by growing three elements of four elements constituting the first quantum dot around the first quantum dot, which is a four-component quantum dot, on the surface of the first quantum dot. Thus, the second quantum dot is composed of a central portion composed of four components formed through step S111b and a peripheral portion composed of three components formed from step S112b. For example, the center portion of the second quantum dot may be Cd-Se-Zn-S four-component quantum dot, and the peripheral portion may be formed of Cd-Zn-S.

Thereafter, precursors of three elements are mixed in a solution including the second quantum dots, and then heated to a temperature of 250 ° C. to 350 ° C. to produce a third quantum dot (S113b).

In step S113b, an additional metal is grown on the surface of the second quantum dot through an additional alloying process on the second quantum dot formed through step S112b. Specifically, the mixture containing the precursors of the three elements used in the step S112b to the solution containing the second quantum dot to obtain a mixture. For example, when the first quantum dot formed through the step S111b is a Cd-Se-Zn-S four-component quantum dot, and the precursors of Cd, Zn, and S among the components constituting the first quantum dot are used in step S112b, step S113b At Cd, Zn and S may be added to the solution containing the second quantum dot again.

In the third alloying process, a mixture containing 250 ° C to 350 ° C of a mixture comprising a central portion composed of four-component quantum dots and a second quantum dot composed of three components of three components constituting the central portion and precursors of three elements constituting the peripheral portions By heating to a high temperature of the degree, a third quantum dot is formed. The third quantum dot has a structure in which the same three elements are additionally alloyed at the periphery of the second quantum dot to increase the size of the periphery. That is, the third quantum dot is composed of a central portion composed of four components formed from the first alloying process S111b) and a peripheral portion composed of three components formed from the second alloying process (S112b) and the third alloying process (S113b). For example, the third quantum dot may be formed of a Cd-Se-Zn-S quaternary quantum dot at a central portion thereof and a peripheral portion may be formed of Cd-Zn-S. That is, the third quantum dot is composed of a central portion and a peripheral portion composed of the same components as the second quantum dot, but the difference in the size of the peripheral portion is different.

Meanwhile, the first alloying process, the second alloying process, and the third alloying process may further include cooling, purifying, and washing. Specifically, the heating may be performed, followed by cooling and purifying the resultant quantum dots. For example, the resulting first quantum dot formed through the step S111b is first cooled to room temperature, and then purified and washed to obtain a first quantum dot of the desired purity.

In the method of manufacturing the alloy-type quantum dot shown in FIG. 3B, a four-component quantum dot is first formed through a first alloying process, and then three components among the four components constituting the four-component quantum dot previously formed through a second alloying process are additionally added. By alloying and further alloying the three components alloyed through the second alloying process through the third alloying process again, it is possible to produce alloyed quantum dots that are partially different in composition without having a core-shell structure.

The alloy-type quantum dot manufacturing method according to Figure 3a and 3b, through the alloying process, it is possible to provide an alloy-type quantum dot is excellent in thermal stability and light stability to minimize the negative bonding.

Referring back to FIG. 2, the first mixture is obtained by adding metallic stearate to the solution containing the prepared alloy-type quantum dots (S120).

Alloy-type quantum dots prepared through step S110 is synthesized and then purified, and then dispersed in a solvent. In this case, the solvent may be a polar solvent or a nonpolar solvent may be used depending on the surface state of the alloy type quantum dots. Metallic stearate is added to the solution in which the alloy type quantum dots are dispersed to obtain a first mixture.

At this time, the metallic stearate added may be in the form of a powder. The content related to the metallic stearate has been described in the quantum dot composite according to an embodiment of the present invention, and overlapping information is omitted.

In this case, the content ratio of the alloy type quantum dot and the metallic stearate of the first mixture may be 10: 1 to 1:10 based on solids, but is not limited thereto. When the content of the metallic stearate satisfies the above range, it is possible to realize the effect of suppressing the penetration of moisture or oxygen, without lowering the quantum efficiency of the quantum dots, thereby improving thermal stability, light stability.

Next, the first mixture is heated to a temperature of 50 ° C to 100 ° C to bind the metallic stearate to the alloy type quantum dot surface (S130).

The first mixture of the alloyed quantum dots and the metallic stearate is heated to bond the alloyed quantum dots and the metallic stearate. For this reason, the metallic stearate is arrange | positioned on the surface of an alloy type quantum dot by the attraction force between an alloy type quantum dot and a metallic stearate, and a moisture barrier film is formed.

Although not limited thereto, the first mixture may be heated to 50 ° C. to 100 ° C., preferably to 70 ° C. to 80 ° C.

On the other hand, adding a metallic stearate to a solution containing an alloy-type quantum dot (S120) to obtain a first mixture and the first mixture is heated to a temperature of 50 ℃ to 100 ℃ to the surface of the alloy type quantum dots Binding the rate (S130) may be performed at the same time.

That is, by dispersing the purified alloy-type quantum dots in a separate solvent and then adding a metallic stearate to obtain a first mixture and then heating, by mixing the alloy-type quantum dots and metallic stearate in a solvent of 50 ℃ to 100 ℃ The quantum dot composite may be prepared through a self assembly process in which alloyed quantum dots and metallic stearate react without additional heating or additional processes.

In addition, in the step of preparing the alloy-type quantum dot (S110) to form an alloy-type quantum dot and then cooled to 50 ℃ to 100 ℃ in the process of cooling by mixing the metallic stearate and the alloy-type quantum dots and metallic without additional heating or additional process The quantum dot complex may be prepared through a self assembly process in which stearate reacts.

Method of manufacturing a quantum dot composite according to an embodiment of the present invention, by forming a moisture barrier film on the surface of the quantum dot by reacting the quantum dot having an alloy form and the metallic stearate, which can block the oxygen or moisture penetrating into the surface and the quantum dot Quantum dot complexes can be provided. In addition, the method of manufacturing a quantum dot composite according to an embodiment of the present invention, unlike the quantum dots of the core-shell structure through the alloy alloy-type quantum dots, it is possible to minimize the negative bonding or lattice mismatch between the core and the shell, It is possible to provide a quantum dot composite having better stability and light stability.

Hereinafter, embodiments of the present invention will be described in detail.

Example 1 Alloyed Quantum Dots Including a Central Part and a Peripheral Part

(First alloying process) After mixing 3-6 mmol of zinc and 0.3-0.6 mmol of cadmium to 5 mL of oleic acid, the temperature was raised to 150 ° C to remove acetic acid, and then 8 mL of octadecine. Addition produces a first cationic precursor comprising cadmium oleate (Cd-OA) and zinc oleate (Zn-OA). Next, 0.2 mmol of selenium and 3.5 to 4.5 mmol of sulfur are mixed with 2 to 3 mL of trioctylphosphine, and then put into a reactor and reacted at 100 ° C. for 1 hour, and trioctylphosphine selenide (sulfur trioctylphosphine selenide). , Se-TOP) and trioctylphosphine sulfide (S-TOP) to prepare a first anion precursor. Thereafter, the prepared first cation precursor and the first anion precursor are mixed at a high temperature of 300 ° C. to 350 ° C. and reacted for 1 minute to prepare a first quantum dot. Thereafter, the mixture was cooled to room temperature, and then mixed with a solvent such as ethanol, chloroform, hexane, toluene, acetone, and precipitated. After washing once through centrifugation, the first quantum dot was dispersed in octadecine.

(Second alloying step) Next, 4.5 to 5.5 mmol of sulfur was mixed with 2-3 mL of trioctylphosphine, and then placed in a reactor and reacted at 100 ° C. for 1 hour to give trioctylphosphine sulfide (S-TOP). To prepare a second anion precursor comprising. The first cationic precursor and the second anion precursor prepared above are injected into the prepared first quantum dots, mixed at a high temperature of 300 ° C to 350 ° C, and reacted for 1 minute to prepare a second quantum dot.

(Third alloying process) The first cationic precursor and the second anion precursor prepared above are injected into the prepared second quantum dots and reacted again at a high temperature of 300 ° C. to 350 ° C. to produce an alloy type quantum dot including a central portion and a peripheral portion.

(Moisture barrier film forming step) The prepared alloy type quantum dots are dispersed in a nonpolar solvent and then zinc stearate is added in a ratio of 1:10 to the alloy type quantum dots based on solid content. Thereafter, the mixed solution is reheated to 80 ° C. to prepare a quantum dot composite having a moisture barrier layer formed thereon.

Experimental Example-Evaluation of stability in high temperature and high temperature and high humidity environment

The red and green quantum dot structures according to Example 1 are mixed together with an ultraviolet curing agent and a scattering agent, and cured by placing them between upper and lower PETs from which a barrier film is excluded. The produced quantum dot sheet is placed on the top of the blue BLU, and the initial luminance and color coordinates are measured using a luminance meter (CA-2000, Minolta). This was stored for 1152 hours at 60 ℃ / RH 95% high temperature / high humidity environment, 85 ℃ high temperature environment, and then the luminance and color coordinates were measured by the above method to measure the luminance retention and color deviation characteristics.

Specific results are shown in Table 1 below.

Example measurement environment Initial properties 1152 Time Lapse Maintain brightness Color deviation Color deviation Lv CIE x CIE y Lv CIE x CIE y ΔLv (%) ΔCIE x ΔCIE y One 85 ℃ 37.74 0.2422 0.2241 35.8 0.2411 0.2172 94.86 0.0011 0.0069 2 60 ℃ / RH95% 38.96 0.2487 0.2368 38.86 0.2512 0.2386 99.74 -0.0025 -0.0018

Referring to Table 1, the quantum dot composite according to Example 1 has a brightness retention of 94.86% in an 85 ° C. high temperature environment and a 99.74% brightness retention in a 60 ° C./RH95% high temperature / high humidity environment. That is, it can be confirmed that the rate of change of luminance of the quantum dot composite according to Example 1 in a high temperature and high temperature and high humidity environment is very small. Similarly, the quantum dot composite according to Example 1 can be confirmed that the color deviation is not large in a high temperature and high temperature and high humidity environment. That is, it can be seen that the quantum dot composite including the moisture barrier film made of the metallic stearate has excellent stability in a high temperature and high humidity environment. Although the embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention. . Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100: quantum dot composite
110: quantum dot
120: moisture barrier

Claims (9)

Alloy-type quantum dots consisting of four kinds of elements; And
A quantum dot composite is formed on the surface of the quantum dot and comprises a moisture barrier film containing a metallic stearate. The method of claim 1,
The alloy-type quantum dot is a quantum dot composite consisting of a central portion composed of the four kinds of elements and a peripheral portion composed of three kinds of elements among the four kinds of elements. The method of claim 1,
The metallic stearate is zinc stearate, calcium stearate, aluminum stearate, magnesium stearate, lithium stearate, sodium stearate, and sodium stearate. Stearate) any one or more selected from the group consisting of, quantum dot complex. Preparing an alloy type quantum dot;
Adding a metallic stearate to the solution containing the alloying quantum dots to obtain a first mixture; And
Binding the metallic stearate to the alloyed quantum dot surface by heating the first mixture to a temperature of 50 ° C. to 100 ° C. 2. The method of claim 4, wherein
The content ratio of the alloy type quantum dot to the metallic stearate in the first mixture is 10: 1 to 1:10 of the solid content, method of producing a quantum dot composite. The method of claim 4, wherein
The metallic stearate is zinc stearate, calcium stearate, aluminum stearate, magnesium stearate, lithium stearate, sodium stearate, and sodium stearate. Stearate) any one or more selected from the group consisting of, quantum dot composite manufacturing method. The method of claim 4, wherein
Producing the alloy type quantum dot,
Mixing two kinds of cationic precursors and two kinds of anionic precursors to obtain a second mixture; And
Heating the second mixture to produce a four-component alloy type quantum dot, the method of manufacturing a quantum dot composite. The method of claim 4, wherein
A first alloying process of mixing two kinds of cation precursors and two kinds of anion precursors, followed by heating to a temperature of 250 ° C. to 350 ° C. to produce a first quantum dot;
A second alloying process of preparing a second quantum dot by mixing a precursor of three elements of the four elements constituting the first quantum dot in a solution containing the first quantum dot, and then heated to a temperature of 250 ℃ to 350 ℃ ; And
And a third alloying process of mixing the precursors of the three elements in a solution including the second quantum dots, and then heating to a temperature of 250 ° C. to 350 ° C. to produce a third quantum dot. The method of claim 8,
In the first alloying process, the second alloying process and the third alloying process, the heating step is each independently performed for 20 seconds to 90 seconds, the method of manufacturing a quantum dot composite.

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