KR102492563B1 - Continuous flow manufacturing method for quantum dots and apparatus for the same - Google Patents

Abstract

A continuous flow manufacturing method of quantum dots having a ratio of core radius r1 and shell thickness r2 of quantum dots of 1: 3 to 10, wherein a core precursor solution is passed through a first heating unit provided in a first pipe and heated by the first heating unit to form a core. preparing a containing solution;
preparing a quantum dot forming solution by transferring and mixing the core-containing solution and the shell precursor solution to a mixer for preparing a quantum dot forming solution through a first pipe and a second pipe, respectively; and forming quantum dots by passing the quantum dot forming solution through a third pipe equipped with a second heating unit and heating it by the second heating unit to grow a shell, wherein the quantum dot forming solution passes through the second heating unit. Continuous flow manufacturing method of quantum dots having a ratio of core radius r1 and shell thickness r2 of 1: 3 to 10, characterized in that the time for doing so is 4 to 20 times the passage time of the first heating part of the core precursor solution and quantum dot continuation A flow manufacturing device is provided.

Description

Continuous flow manufacturing method for quantum dots and apparatus for manufacturing continuous flow of quantum dots {Continuous flow manufacturing method for quantum dots and apparatus for the same}

The present invention relates to a method for producing a continuous flow of quantum dots and an apparatus for producing a continuous flow of quantum dots.

Quantum dots exhibit special optical and electrical properties that semiconducting materials do not have in their bulk. Nano quantum dots are attracting attention as next-generation high-brightness LEDs, biosensors, lasers, and solar cell nanomaterials by using these characteristics.

Conventionally, such quantum dots have been mainly produced in a laboratory by rapidly injecting a cold precursor into a high-temperature solvent to form a nucleus and growing by applying temperature.

However, the above method is unable to control the size of the desired particles because the reaction is not controlled, and the conditions vary depending on the amount of reaction, so that only a small amount is produced due to loss of post-processing to secure uniformity. In the case of quantum dots, the size of the particles directly affects the optical and electrical properties, so the uniformity of the particle size means the quality of the quantum dots.

For example, US Patent No. 6,682,596 discloses a method of producing quantum dots by mixing a precursor and a solvent and flowing them through a high-temperature thermal conductive tube at a constant rate. However, this method has a problem in that, although the uniformity of the particle size is excellent in small-scale production, the production amount is limited to a very small amount due to the instability of the mixing step in the thin tube.

In particular, in the case of quantum dots, it is necessary to manufacture by varying the size of the core and the shell, but conventional technologies do not meet this need.

U.S. Patent No. 6,682,596

An object of the present invention is to provide a method for producing a continuous flow of quantum dots and an apparatus for producing a continuous flow of quantum dots capable of efficiently producing quantum dots having a ratio of core radius r1 and shell thickness r2 of 1: 3 to 10.

In order to achieve the above purpose,

The present invention is a continuous flow manufacturing method of quantum dots in which the ratio of the core radius r1 and the shell thickness r2 of the quantum dots is 1: 3 to 10,

Preparing a core-containing solution by passing the core precursor solution through a first heating unit provided in the first pipe and heating it by the first heating unit;

preparing a quantum dot forming solution by transferring and mixing the core-containing solution and the shell precursor solution to a mixer for preparing a quantum dot forming solution through a first pipe and a second pipe, respectively; and

Forming quantum dots by passing the quantum dot forming solution through a third pipe equipped with a second heating unit and heating it by the second heating unit to grow a shell,

The ratio of the core radius r1 and the shell thickness r2 is 1: 3 to 10, characterized in that the time for the quantum dot forming solution to pass through the second heating unit is 4 to 20 times the time for the core precursor solution to pass through the first heating unit. Provides a continuous flow manufacturing method of phosphorus quantum dots.

In addition, the present invention

A first pipe provided with a first heating unit for transferring the core precursor solution to the mixer for preparing the quantum dot forming solution;

A second pipe for transferring the shell precursor solution to the mixer for preparing the quantum dot forming solution;

a mixer for preparing a quantum dot forming solution to which ends of the first pipe and the second pipe are connected;

a third pipe connected to the mixer for preparing the quantum dot forming solution and equipped with a second heating unit for transferring the quantum dot forming solution to a quantum dot collection container;

quantum dot recovery container; and

Including; one or more pumps provided to transfer the solution in the first pipe, the second pipe, and the third pipe,

The ratio of the core radius r1 and the shell thickness r2 is 1: 3-10, characterized in that the time for the quantum dot forming solution to pass through the second heating unit is 4 to 20 times the time for the core precursor solution to pass through the first heating unit. It provides a continuous flow manufacturing apparatus for producing phosphorus quantum dots.

The continuous flow manufacturing method and quantum dot continuous flow manufacturing apparatus having a ratio (r2/r1) of the core radius r1 and the shell thickness r2 of 1: 3 to 10 of the present invention can provide quantum dots having a sufficiently thick shell thickness in an efficient manner. there is. Since the quantum dots having a large shell thickness provide excellent durability, they can be used very usefully in various fields.

1 is a diagram schematically showing the structure of a quantum dot.
2 and 3 are diagrams schematically showing the continuous flow manufacturing method of quantum dots of the present invention.
4 is a graph showing the measurement of quantum efficiency carried out in Test Example 1 of the present invention as an example.

Hereinafter, the present invention will be described in more detail.

The present invention is a continuous flow manufacturing method of quantum dots in which the ratio of the core radius r1 and the shell thickness r2 of the quantum dots is 1: 3 to 10,

Preparing a core-containing solution by passing the core precursor solution through a first heating unit provided in the first pipe and heating it by the first heating unit;

preparing a quantum dot forming solution by transferring the core-containing solution and the shell precursor solution to a mixer for preparing a quantum dot forming solution through a first pipe and a second pipe, respectively; and

Forming quantum dots by passing the quantum dot forming solution through a third pipe equipped with a second heating unit and heating it by the second heating unit to grow a shell,

The ratio of the core radius r1 and the shell thickness r2 is 1: 3 to 10, characterized in that the time for the quantum dot forming solution to pass through the second heating unit is 4 to 20 times the time for the core precursor solution to pass through the first heating unit. It relates to a continuous flow manufacturing method of phosphorus quantum dots.

Quantum dots, as illustrated in FIG. 1 , have a structure including a core and a shell. As in the present invention, in the case of quantum dots having a core radius r1 and shell thickness r2 ratio of 1: 3 to 10, the shell is sufficiently thick, so the initial quantum efficiency is excellent, and the quantum dot is excellent over time under conditions where oxygen and moisture are supplied. It is possible to provide excellent durability in which a decrease in quantum efficiency is suppressed.

As described above, in order to manufacture a quantum dot having a sufficiently thick shell, it is required to control each reaction time when forming a core and a shell, and the present invention is characterized by providing a solution to the above problems.

When the time for the quantum dot forming solution to pass through the second heating unit is 4 to 20 times the time for the core precursor solution to pass through the first heating unit, the shell growth time is relatively long, so that a shell having a sufficient thickness can be formed. there is.

If the passage time is less than 4 times, the shell does not grow sufficiently, so quantum dots having a ratio of core radius r1 to shell thickness r2 of 1: 3 to 10 cannot be manufactured, and if it exceeds 20 times, the shell It is too large to produce quantum dots having a ratio of core radius r1 and shell thickness r2 of 1: 3 to 10. In addition, manufacturing equipment may be longer than necessary, production equipment is expensive, production speed is slow, and particles are excessively large, which is undesirable because clogging of pipes due to sedimentation may occur.

In the continuous flow manufacturing method of the quantum dots, the first heating unit means a part that heats the first pipe to 150 to 350 ° C by the first heater, and the second heating unit heats the third pipe to 200 ° C by the second heater. It means the part heated to ~350℃.

The length of the third pipe included in the second heating unit may be 4 to 20 times the length of the first pipe included in the first heating unit, more preferably 6 to 16 times.

By forming the length of the third pipe included in the second heating section to be longer than the length of the first pipe included in the first heating section in the above range, the relative passage time of the core precursor solution and the quantum dot forming solution through the heating section is within a preferred range. can be set to

The inner diameter of the first pipe is 5 μm to 5 mm, the inner diameter of the second pipe is 5 μm to 5 mm, and the inner diameter of the third pipe is 10 μm to 10 mm. When the inner diameter of the three pipes is 2 to 10 times larger than the inner diameter of the first pipe, the flow rate of the quantum dot forming solution in the third pipe is relatively slow, so that the relative passage time of the core precursor solution and the quantum dot forming solution through the heating part is preferably range can be set.

The ratio range of the time for the quantum dot forming solution to pass through the second heating unit and the time for the core precursor solution to pass through the first heating unit is adjusted by adjusting the solution transfer capacity of the pump installed in the third pipe and the first pipe, respectively. It is also possible.

In the continuous flow manufacturing method of the quantum dots, a pump for transporting a material generated in each mixer may be further provided in one or more of the first pipe, the second pipe, and the third pipe. For example, independent pumps may be provided in the first pipe, the second pipe, and the third pipe, and a single pump having a plurality of channels connected to one driving source and supplying the same flow rate may be provided.

In the continuous flow manufacturing method of the quantum dots, those known in the art may be used as the core precursor solution and the shell precursor solution, and are not particularly limited.

The core of the quantum dots is a nanometer-sized semiconductor. Although any core of IIA-VIA, IIIA-VA, or IVA-VIA semiconductors can be used in the context of this disclosure, the core becomes a luminescent quantum dot when combined with a shell. The IIA-VIA semiconductor is a compound containing at least one element from group IIA and at least one element from group VIA of the periodic table, and the like. A core may contain two or more elements. In one embodiment, the core is an IIA-VIA, or IIIA-VA semiconductor that may be about 1 nm to about 250 nm, about 1 nm to 100 nm, about 1 nm to 50 nm, or about 1 nm to 10 nm in diameter. to be. In another embodiment, the core may be a IIA-VIA semiconductor and may be from 2 nm to about 10 nm in diameter. For example, the core can be GaP, GaAs and InP, ZnSe, ZnS, PbS, PbSe, or alloys.

The shell of the quantum dots is a semiconductor that is different from the semiconductor of the core and bonds to the core to form a surface layer on the core. The shell passivates the core, typically by having a larger band gap than the semiconductor. In one embodiment, the shell may be a high bandgap IIA-VIA semiconductor. For example, the shell may be ZnS. The combination of the core and the shell may be, for example, ZnS when the core is InP and the shell is not limited thereto.

Other exemplary protons include, but are not limited to, ZnSe, InAs, InP, PbTe, PbSe, PbS, HgS, HgSe, HgTe, CuInS, CoS, Co _{2 S 3} , and GaAs. The size of the shell may be about 0.1 to 10 nm, about 0.1 to 5 nm, or about 0.1 to 2 nm in diameter.

The method of forming the core and the shell is described in more detail as follows:

A method of obtaining a core precursor solution containing a group III-V compound by reacting a group III metal precursor and a group V element precursor is as follows:

First, in order to form a core, an organic solvent and an unsaturated fatty acid are added to a group III metal precursor to obtain a mixed solution, and then a group V element precursor is injected into the mixed solution and reacted by heating. At this time, a zinc precursor such as zinc acetate (Zn(OAc) ₂ ) or zinc chloride (ZnCl ₂ ) may be added to the mixed solution containing the Group III metal precursor. The zinc precursor hardly contributes to the actual core synthesis reaction and can be used to control the diameter of the core. For example, as the amount of the zinc precursor increases relative to the amount of the group III metal precursor, a quantum dot core having a long wavelength emission can be synthesized, and conversely, as the amount of the zinc precursor decreases, a quantum dot core having a short wavelength emission can be synthesized. . In addition, the zinc precursor may serve to further increase quantum efficiency by removing surface traps of the group III-V core.

The group III metal precursor to form a core may be a compound containing aluminum, gallium or indium, for example, aluminum acetylacetonate, aluminum chloride, aluminum fluoride, aluminum oxide, aluminum nitrate, aluminum sulfate, gallium acetylacetonate, gallium chloride, gallium fluoride, gallium oxide, gallium nitrate, gallium sulfate, indium chloride, indium oxide, indium nitrate, indium acetate, indium sulfate, and indium carboxylate. may be ideal However, it is not limited to these precursors.

The group V element precursor to form the core may be a compound containing nitrogen, phosphorus or arsenic, for example, alkyl phosphine, tristrialkylsilyl phosphine, trisdialkylsylphosphine, trisdialkylamino phosphine. It may be at least one selected from the group consisting of pin, arsenic oxide, arsenic chloride, arsenic sulfate, arsenic bromide, arsenic iodide, nitric oxide, nitric acid, and ammonium nitrate. However, it is not limited to these precursors.

A method for obtaining a shell precursor solution containing a group II-VI compound by reacting a group II metal precursor with a group VI element precursor is as follows:

First, in order to form a shell, an organic solvent and an unsaturated fatty acid are added to a group II metal precursor to obtain a mixed solution, and then a group VI element precursor is injected into the mixed solution to react.

A compound containing cadmium, zinc, mercury or lead may be used as the group II metal precursor, but a zinc precursor that does not contain cadmium, mercury or lead may be preferably used in terms of toxicity and environment. Zinc precursors include, for example, zinc iodide, zinc bromide, zinc chloride, zinc fluoride, dimethyl zinc, diethyl zinc, zinc acetate, zinc acetylacetonate, zinc carbonate, zinc cyanide, zinc nitrate, zinc oxide, zinc peroxide, zinc perchlorate, zinc sulfate, and the like, but are not limited thereto.

The group VI element precursor is a compound containing sulfur, selenium or tellurium, for example, hexane thiol, octane thiol, decane thiol, dodecane thiol, hexadecane thiol, and mercapto propyl silane. alkyl thiol compounds, sulfur-trioctylphosphine, sulfur-tributylphosphine, sulfur-triphenylphosphine, sulfur-trioctylamine, trimethylsilyl sulfur, ammonium sulfide, sodium sulfide, selenium-trioctylphosphine, selenium-tributylphosphine, selenium-triphenylphosphine, tellurium-trioctylphosphine, tellurium-tributylphosphine, or tellurium-triphenylphosphine; and the like, but are not limited thereto.

An organic solvent is used for mixing the precursors of the core and the shell, and the organic solvent includes 1-octadecene, 1-nonadecene, cis-2-methyl-7- Octadecene (cis-2-methyl-7-octadecene), 1-heptadecene (1-heptadecene), 1-hexadecene (1-hexadecene), 1-pentadecene (1-pentadecene), 1-tetradecene (1 -tetradecene), 1-tridecene, 1-undecene, 1-dodecene, 1-decene, octylamine, trioctylamine, Or a combination thereof may be used, but is not limited thereto.

When mixing the precursors of the core and shell, unsaturated fatty acids may be added for uniform dispersion. Examples of the unsaturated fatty acids include lauric acid, palmitic acid, oleic acid, stearic acid, myristic acid, elaidic acid, Eicosanoic acid, heneicosanoic acid, tricosanoic acid, docosanoic acid, tetracosanoic acid, hexacosanoic acid, hep heptacosanoic acid, octacosanoic acid, or cis-13-docosenoic acid, or combinations thereof, and the like, but are not limited thereto.

In the method of continuous flow production of quantum dots, it is preferable that the core precursor composition includes In and P precursors, and the shell precursor composition includes Zn and S precursors.

In the continuous flow manufacturing method of the quantum dots, as illustrated in FIGS. 2 and 3, the core precursor solution is prepared in the first mixer 10 and passed through the first pipe 12 equipped with the first heating unit. The shell precursor solution may be prepared in the second mixer 20 and transferred to the quantum dot forming solution preparation mixer 30 through the second pipe 22.

Reactors known in the art may be used as the first mixer, the second mixer, and the mixer (third mixer) for preparing the quantum dot forming solution, and are not particularly limited. The first mixer, the second mixer, and the third mixer may be equipped with stirrers for facilitating mixing and/or stirring of the reactants.

In the continuous flow manufacturing method of the quantum dots, as illustrated in FIGS. 2 and 3, the first pipe 12 connects the first mixer 10 and the third mixer 30, and the second pipe 22 connects the second mixer 20 and the third mixer 30, and the third pipe 32 connects the third mixer 30 and the quantum dot collection container 40.

The first heating unit serves to heat the first pipe 12 to a required temperature, and the shape known in the art may be used without limitation, and is not particularly limited. For example, as illustrated in FIGS. 2 and 3 , the first heating unit may be configured with a heater 14 having a first pipe accommodated therein.

The second heating unit serves to heat the third pipe 32 to a required temperature, and the shape known in the art may be used without limitation, and is not particularly limited. For example, as illustrated in FIGS. 2 and 3 , the second heating unit may be configured with a heater 34 having a third pipe 32 accommodated therein.

In addition, the present invention, as shown in Figures 2 and 3, the first pipe 12 provided with a first heating unit for transferring the core precursor solution to the quantum dot forming solution manufacturing mixer 30; A second pipe 22 for transferring the shell precursor solution to the quantum dot forming solution preparation mixer 30; a quantum dot forming solution preparation mixer 30 to which ends of the first pipe 12 and the second pipe 22 are connected; a third pipe 32 having a second heating unit connected to the quantum dot forming solution preparation mixer 30 and transferring the quantum dot forming solution to the quantum dot recovery container 40; Quantum dot recovery container 40; and one or more pumps 16, 26, 36 provided to transfer the solution in the first pipe, the second pipe, and the third pipe, and the time for the quantum dot forming solution to pass through the second heating unit is It relates to a continuous flow manufacturing apparatus for producing quantum dots having a ratio of core radius r1 and shell thickness r2 of 1: 3 to 10, characterized in that the core precursor solution is configured to be 4 to 20 times the passage time of the first heating unit.

The first heating part refers to a part that heats the first pipe 12 to 150 to 350 ° C by the first heater 14, and the second heating part heats the third pipe 32 to the second heater 34 It means the part heated to 200 ~ 350 ℃ by.

In the continuous flow manufacturing apparatus for producing quantum dots of the present invention, the length of the third pipe 32 included in the second heating unit may be 4 to 20 times the length of the first pipe 12 included in the first heating unit. And, more preferably, it may be 6 to 16 times.

By forming the length of the third pipe included in the second heating unit to be longer than the length of the first pipe included in the first heating unit in the above range, the relative passage time of the core precursor solution and the quantum dot forming solution is preferably range can be set.

In the above, the first pipe 12 included in the first heating unit means a portion of the first pipe 12-1 heated to 150 to 350 ° C by the first heater 14, and the second heating unit The third pipe 32 included in refers to a portion of the third pipe 32-1 heated to 200 to 350 ° C by the second heater 34.

In the above, the first pipe 12 included in the first heating unit means a part of the first pipe 12-1 directly heated by the first heater 14 in a narrow sense, and in the above, the second pipe 12 The third pipe 32-1 included in the heating unit means a portion of the third pipe 32 directly heated by the second heater 34 in a narrow sense.

The first pipe included in the first heating unit and the third pipe included in the second heating unit may be formed in a spiral tube shape.

In the continuous flow manufacturing apparatus for producing quantum dots of the present invention, the inner diameter of the first pipe is 5 μm to 5 mm, the inner diameter of the second pipe is 5 μm to 5 mm, and the inner diameter of the third pipe is 5 μm to 50 mm. In particular, when the inner diameter of the third pipe is 2 to 10 times larger than the inner diameter of the first pipe, the flow rate of the quantum dot forming solution in the third pipe is relatively slow, so the core precursor solution The relative passage time of the quantum dot forming solution and the heating unit may be set within a preferred range.

In the continuous flow manufacturing apparatus for producing quantum dots of the present invention, at least one of the first pipe 10, the second pipe 10, and the third pipe 30 has a pump for transferring the material produced by each mixer (Fig. 3, 16, 26, 36) may be further provided. For example, independent pumps may be provided in the first pipe, the second pipe, and the third pipe, or a single pump having a plurality of channels connected to one driving source and supplying the same flow rate is provided. It could be.

In the continuous flow manufacturing apparatus for producing quantum dots of the present invention, the pump is not particularly limited, and a pump known in the art may be installed and used in a known form.

In the continuous flow manufacturing method of quantum dots and the continuous flow manufacturing apparatus of quantum dots of the present invention, the structure of the manufacturing apparatus and parts related to its operation are equally applied.

Hereinafter, preferred embodiments are presented to aid understanding of the present invention, but these embodiments are only illustrative of the present invention and do not limit the scope of the appended claims, and embodiments within the scope and spirit of the present invention It is obvious to those skilled in the art that various changes and modifications to the are possible, and it is natural that these variations and modifications fall within the scope of the appended claims.

Example One: quantum dot Manufacture of manufacturing equipment

As shown in FIG. 3, a first mixer 10 for mixing the core precursor, a second mixer 20 for mixing the shell precursor, and mixing the products transferred from the first mixer and the second mixer a quantum dot forming solution preparation mixer (third mixer, 30) and a quantum dot recovery container 40; The first pipe 12 connecting the first mixer and the third mixer, the second pipe 22 connecting the second mixer and the third mixer 22, and the third mixer and the quantum dot recovery container 40 It has a third pipe 32 to connect; mounting a first heater 14 outside the first pipe to form a first heating part, and mounting a second heater 34 outside the third pipe to form a second heating part; An apparatus for manufacturing quantum dots having pumps 16, 26, and 36 provided in the first pipe, the second pipe, and the third pipe, respectively, was manufactured.

In the above, the diameters of the first pipe, the second pipe, and the third pipe are all configured to be 0.5 mm, and the length of the first pipe 12-1 accommodated inside the heater of the first heating unit is configured to be 15 m, The length of the third pipe 32-1 accommodated inside the heater of the second heating unit was configured to be 60 m. The residence time of the core precursor solution in the first heating unit was 5 minutes, and the residence time of the quantum dot forming solution in the second heating unit was adjusted to be 20 minutes.

Example 2: quantum dot Manufacture of manufacturing equipment

As shown in FIG. 3, a first mixer 10 for mixing the core precursor, a second mixer 20 for mixing the shell precursor, and mixing the products transferred from the first mixer and the second mixer a quantum dot forming solution preparation mixer (third mixer, 30) and a quantum dot recovery container 40; The first pipe 12 connecting the first mixer and the third mixer, the second pipe 22 connecting the second mixer and the third mixer 22, and the third mixer and the quantum dot recovery container 40 It has a third pipe 32 to connect; mounting a first heater 14 outside the first pipe to form a first heating part, and mounting a second heater 34 outside the third pipe to form a second heating part; An apparatus for manufacturing quantum dots having pumps 16, 26, and 36 provided in the first pipe, the second pipe, and the third pipe, respectively, was manufactured.

In the above, the diameters of the first pipe and the second pipe are all configured to be 0.5 mm, the diameter of the third pipe is configured to be 3 mm, and the length of the first pipe 12-1 accommodated inside the heater of the first heating unit. was composed of 15 m, and the length of the second pipe (32-1) accommodated inside the heater of the second heating part was composed of 150 m. The flow rate of the solution transported through the first and second pipes was set to 59 ml/min, and the flow rate of the solution transported through the third pipe was set to 118 ml/min so that the core precursor solution stayed in the first heating unit. The time was adjusted to 5 minutes, and the residence time of the quantum dot forming solution in the second heating unit was 50 minutes.

Example 3: quantum dot Manufacture of manufacturing equipment

As shown in FIG. 3, a first mixer 10 for mixing the core precursor, a second mixer 20 for mixing the shell precursor, and mixing the products transferred from the first mixer and the second mixer a quantum dot forming solution preparation mixer (third mixer, 30) and a quantum dot recovery container 40; The first pipe 12 connecting the first mixer and the third mixer, the second pipe 22 connecting the second mixer and the third mixer 22, and the third mixer and the quantum dot recovery container 40 It has a third pipe 32 to connect; mounting a first heater 14 outside the first pipe to form a first heating part, and mounting a second heater 34 outside the third pipe to form a second heating part; An apparatus for manufacturing quantum dots having pumps 16, 26, and 36 provided in the first pipe, the second pipe, and the third pipe, respectively, was manufactured.

In the above, the diameters of the first pipe, the second pipe, and the third pipe are all configured to be 0.5 mm, and the length of the first pipe 12-1 accommodated inside the heater of the first heating unit is configured to be 15 m, The length of the third pipe 32-1 accommodated inside the heater of the second heating unit was configured to be 300 m. The retention time of the core precursor solution in the first heating unit was 5 minutes, and the residence time of the quantum dot forming solution in the second heating unit was adjusted to 100 minutes.

comparative example One: quantum dot Manufacture of manufacturing equipment

The length of the first pipe 12-1 accommodated inside the heater of the first heating unit was 15 m, and the length of the second pipe 12-1 accommodated inside the heater of the second heating unit was configured to be 45 m, so that the core precursor solution A quantum dot manufacturing apparatus was manufactured in the same manner as in Example 1, except that the residence time of the first heating unit was adjusted to 5 minutes and the residence time of the quantum dot forming solution to the second heating unit was adjusted to 15 minutes.

Example 4: of quantum dots Produce

Using the apparatus for manufacturing quantum dots prepared in Example 1, quantum dots were manufactured in the following manner.

Through one inlet of the first mixer 10, an indium precursor solution prepared by dissolving 2.130 g of indium oleate in 120 ml of 1-octadecene and tris (trimethylsilyl) phosphine (tris ( A phosphorus precursor solution prepared by mixing 0.58 ml of trimethylsilyl)phosphine and 6 ml of 1-octadecene was injected while stirring with a stirrer, and nitrogen gas was injected through the remaining inlets. The core precursor solution mixed in the first mixer 10 was transferred to the first heating unit 14 through the first pipe 12 by the first pump 16 . In the first heating unit, the core precursor solution was heated at 300° C. to form InP nanocrystals. The solution containing the InP nanocrystals was injected into a mixer (third mixer, 30) for preparing a quantum dot forming solution.

Meanwhile, 2.2 g of zinc acetate is mixed with 120 ml of trioctylamine and oleic acid in one inlet of the second mixer 20 together with the first mixer 10.

A zinc (Zn) and sulfur (S) precursor solution prepared by dissolving in 6.8 ml of oleic acid and mixing 2.5 ml of 1-octanethiol was injected while stirring with a stirrer, and the remaining inlet Nitrogen gas was injected. The shell precursor solution mixed in the second mixer 20 was injected into the quantum dot forming solution preparation mixer 30 through the second pipe 22 by the second pump 26.

The core-containing solution and the shell precursor solution were mixed while stirring in a mixer 30 for preparing a quantum dot forming solution. Then, it was transferred to the second heating unit 34 through the third pump 36. The quantum dot formation solution was heated at 350° C. by the second heating unit 34 to form InP/ZnS quantum dots having a ZnS outer shell on the InP nanocrystal. InP/ZnS quantum dots were recovered from the quantum dot collection container 40. The recovered quantum dots were separated by a centrifuge to remove the liquid, and the quantum dots attached to the wall were dissolved in toluene to obtain a quantum dot solution.

Example 5: of quantum dots Produce

InP / ZnS quantum dots were manufactured in the same manner as in Example 4, except that the quantum dot manufacturing apparatus prepared in Example 2 was used.

Example 6: of quantum dots Produce

InP / ZnS quantum dots were manufactured in the same manner as in Example 4, except that the quantum dot manufacturing apparatus prepared in Example 3 was used.

comparative example 2: of quantum dots Produce

InP / ZnS quantum dots were prepared in the same manner as in Example 4, except that the quantum dot manufacturing apparatus prepared in Comparative Example 1 was used.

test example One: of quantum dots durability test

The size and structure of the quantum dots prepared in Examples and Comparative Examples were analyzed, and quantum efficiency and durability of the quantum dots according to the structure were evaluated.

<The radius of the core and of the shell How to measure thickness>

(1) Measure the radius of the core

The radius of the core is predicted by measuring the wavelength of the fluorescence. That is, since it is known that fluorescence of 550 nm is emitted when the diameter of the InP core is about 2 nm, the radius is predicted by the fluorescence wavelength.

In the case of this embodiment and comparative example, since it was confirmed that both emit fluorescence of 550 nm, it is possible to predict R1 = 1 nm.

(2) of the shell thickness measurement

The thickness of the shell was calculated by measuring the particle size (radius: r3) using a particle size analyzer and calculating r3-r1.

<Particle size analysis method>

The QD particle size was measured using a particle size analyzer (ELS-2000, Otsuka Electronics Co.).

Particle size analysis equipment is a device that measures using dynamic light scattering and can measure particle diameters in the range of 0.1 to 10,000 nm.

The QD sample was diluted and analyzed by adjusting the QD concentration to a level of about 1 to 0.01%. In the case of QD, since fluorescence is generated by light scattering laser incident, the analysis was performed by installing a fluorescence filter.

After removing foreign matter except QD from the diluted sample using a PVDF filter (pole size 0.45 um), injecting it into the sample cell of the particle size analysis equipment, average the results of 50 to 100 measurements per sample, 3 samples was analyzed to determine the particle size using the average value.

<Quantum Efficiency Evaluation Method>

Quantum efficiency was evaluated using a quantum efficiency measurement system (QE-2000, Otsuka Electronics). After the QD sample was diluted to 0.1% in toluene and injected into the sample cell (transmission cell length: 1 cm), an excitation wavelength of 450 nm was irradiated. Here, the QD absorption level at the excitation wavelength of 450 nm was about 0.2 to 1.0 based on absorbance.

Fluorescence appears by the 450 nm excitation wavelength, and the fluorescence peak was measured by using the intensity of the fluorescence peak versus the excitation wavelength absorption using the peak in the 500 ~ 600 nm peak area in the case of Green QD. An example of quantum efficiency measurement is shown in FIG. 4 .

<Durability evaluation method>

After the sample diluted to 0.1% in toluene was left for 7 days at 25 ° C and 80% humidity, toluene was added as much as volatilized to adjust the concentration to the same concentration, and the quantum efficiency (QY1) was measured to determine the amount of QY decrease ( QY0-QY1) was measured to confirm durability.

t1 (min) t2 (min) t1/t2 r1(nm) r2(nm) Initial quantum efficiency (QY0%)
Quantum Efficiency After Duration
(QY1%) durability
(QY0-QY1)% Example 4 5 20 4 One 3.5 86% 79% 7% Example 5 5 50 10 One 6 89% 83% 6% Example 6 5 100 20 One 9.5 90% 85% 5% Comparative Example 2 5 15 3 One 0.75 82% 55% 27%

main)

t1: Passing time of the first heating unit

t2: Passing time of the second heating unit

r1: average of the radii of the core

r2: mean shell thickness

10: first mixer 12: first pipe
14: first heater 16: first pump
20: second mixer 22: second pipe
26: second pump 30: quantum dot forming solution preparation mixer (third mixer)
32: 3rd pipe 34: 2nd heater
36: third pump 40: quantum dot recovery container

Claims (13)

A continuous flow manufacturing method of quantum dots having a ratio of the core radius r1 and the shell thickness r2 of the quantum dots of 1: 3 to 10,
Preparing a core-containing solution by passing the core precursor solution through a first heating unit provided in the first pipe and heating it by the first heating unit;
preparing a quantum dot forming solution by transferring and mixing the core-containing solution and the shell precursor solution to a mixer for preparing a quantum dot forming solution through a first pipe and a second pipe, respectively; and
Forming quantum dots by passing the quantum dot forming solution through a third pipe equipped with a second heating unit and heating it by the second heating unit to grow a shell,
The ratio of the core radius r1 and the shell thickness r2 is 1: 3-10, characterized in that the time for the quantum dot forming solution to pass through the second heating unit is 4 to 20 times the time for the core precursor solution to pass through the first heating unit. Continuous flow manufacturing method of phosphorus quantum dots. The method according to claim 1, wherein the first heating unit is a part that heats the first pipe to 150 ~ 350 ℃ by a first heater, the second heating unit is to heat the third pipe to 200 ~ 350 ℃ by a second heater A continuous flow manufacturing method of quantum dots having a ratio of core radius r1 and shell thickness r2 of 1: 3 to 10, characterized in that the part. The method according to claim 2, wherein the length of the third pipe included in the second heating unit is 4 to 20 times the length of the first pipe included in the first heating unit, characterized in that the ratio of the core radius r1 and the shell thickness r2 1: Continuous flow manufacturing method of 3-10 quantum dots. The method according to claim 2, wherein the inner diameter of the first pipe is 5㎛ ~ 5mm, Continuous flow manufacturing of quantum dots having a ratio of core radius r1 and shell thickness r2 of 1: 3 to 10, characterized in that the inner diameter of the second pipe is 5 μm to 5 mm and the inner diameter of the third pipe is 5 μm to 50 mm Way. The continuous flow of quantum dots according to claim 4, wherein the ratio of the core radius r1 and the shell thickness r2 is 1: 3 to 10, characterized in that the inner diameter of the third pipe is 2 to 10 times larger than the inner diameter of the first pipe. manufacturing method. The method according to claim 1, wherein at least one of the first pipe, the second pipe, and the third pipe is further provided with a pump for transferring the material produced in each mixer, and the ratio of the core radius r1 and the shell thickness r2 is 1: Continuous flow manufacturing method of 3-10 quantum dots. The method according to claim 1, wherein the core precursor solution is prepared in a first mixer and transferred to a mixer for preparing a quantum dot forming solution by passing through a first pipe equipped with a first heating unit,
The shell precursor solution is prepared in the second mixer and transferred to the quantum dot forming solution manufacturing mixer through the second pipe. . The method according to claim 1, wherein the core precursor composition includes a precursor of In and P, and the shell precursor composition includes a precursor of Zn and S, characterized in that the ratio of the core radius r1 and the shell thickness r2 is 1: 3 to 10 Method of manufacturing quantum dots. A first pipe provided with a first heating unit for transferring the core precursor solution to the mixer for preparing the quantum dot forming solution;
A second pipe for transferring the shell precursor solution to the mixer for preparing the quantum dot forming solution;
a mixer for preparing a quantum dot forming solution to which ends of the first pipe and the second pipe are connected;
a third pipe connected to the mixer for preparing the quantum dot forming solution and equipped with a second heating unit for transferring the quantum dot forming solution to a quantum dot collection container;
quantum dot recovery container; and
Including; one or more pumps provided to transfer the solution in the first pipe, the second pipe, and the third pipe,
The ratio of the core radius r1 and the shell thickness r2 is 1: 3-10, characterized in that the time for the quantum dot forming solution to pass through the second heating unit is 4 to 20 times the time for the core precursor solution to pass through the first heating unit. Continuous flow manufacturing apparatus for producing phosphorus quantum dots. The method according to claim 9, wherein the first heating unit is a part that heats the first pipe to 150 ~ 350 ℃ by the first heater, the second heating unit is to heat the third pipe to 200 ~ 350 ℃ by the second heater The ratio of the core radius r1 and the shell thickness r2 is 1: 3 to 10, characterized in that the part, continuous flow manufacturing apparatus for producing quantum dots. The method according to claim 10, wherein the ratio of the core radius r1 and the shell thickness r2, characterized in that the length of the third pipe included in the second heating unit is 4 to 20 times the length of the first pipe included in the first heating unit 1: Continuous flow manufacturing device for manufacturing 3-10 quantum dots. The method according to claim 10, characterized in that the third pipe included in the second heating unit and the first pipe included in the first heating unit have a spiral tube shape, characterized in that the ratio of the core radius r1 and the shell thickness r2 is 1: 3 ~ 10 Continuous flow manufacturing device for quantum dot production. The method according to claim 9, wherein the inner diameter of the third pipe is 2 to 10 times larger than the inner diameter of the first pipe, characterized in that the ratio of the core radius r1 and the shell thickness r2 is 1: 3 to 10 continuous flow for producing quantum dots manufacturing device.

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