KR101859173B1 - Aluminium-doped Indium phosphide-based core-multi shell quantumdots and production of the same - Google Patents

Abstract

The present invention relates to production of an aluminum-containing quantum dot which is capable of improving oxidation and photochemical stability by forming a passive film, while having high quantum efficiency due to reduced difference in a lattice constant with shells through production of an AlInP core by adding aluminum to the quantum dot. Specifically, provided are a nanocrystal having a core-multishell structure such as AlInP@AlZnSeS@AlSO, and a production method thereof.

Description

[0001] The present invention relates to an aluminum-doped indium phosphide-based core-multi-shell quantum dot and a method for producing the same.

More particularly, the present invention relates to an InP-based quantum dot having improved photochemical stability while maintaining the optical characteristics of a conventional InP-based quantum dot, and a method for manufacturing the same. .

Quantum dots can easily adjust the emission wavelength according to the size, and have high quantum efficiency, narrow half width, high light stability and low light scattering property compared with the inorganic phosphors and organic dyes, and can be used for a light emitting diode, a laser, a solar cell, Imaging, and the like.

Quantum dots are applied to various fields, but heavy metals such as cadmium, lead, and mercury are included, which is a major obstacle to commercialization. In order to solve this problem, a quantum dot synthesis method of I-III-V group (CuInS), III-V group (InP and InAs), IV group (Si), or doped II- VI group (Cu: ZnSe and Mn: ZnSe) In particular, InP-based quantum dots have been used as a next generation phosphor due to their ability to control the emission wavelength in a visible light region, narrow emission width, and high quantum efficiency. However, the InP-based quantum dots have been commercialized to a limited extent due to the photochemical and oxidation stability which is significantly lower than that of conventional CdSe-based quantum dots.

In order to obtain high quantum efficiency of the InP quantum dot, it can be realized as a quantum well structure, and passivation of the dangling bond on the surface of the InP quantum dot is required as an appropriate material matching the InP and the lattice constant. Generally, ZnSeS is introduced into the shell to decrease the lattice constant difference. However, there is still a difference between lattice constant of InP (0.587 nm) and lattice constant of ZnSeS (0.542 ~ 0.567 nm depending on the ratio of Se and S) There is a limit.

In the present invention, aluminum was added to the InP core to introduce an AlInP core. It is possible to manufacture a quantum dot having a high quantum efficiency by reducing the difference between lattice constants of AlInP (0.545 to 0.587 nm, depending on the ratio of Al and In) and ZnSeS. In addition, the photochemical and oxidation stability are improved by adding aluminum capable of forming a passive film to the quantum dots.

Accordingly, the present invention provides a photochemically and thermally stable InP-based quantum dot and a manufacturing method thereof while maintaining excellent optical characteristics of the conventional InP-based quantum dot.

Korean Patent No. 10-1722638

It is an object of the present invention to provide an InP-based quantum dot containing Al, which has high quantum efficiency by reducing defects between the core and the shell, and which increases the photochemical and oxidation stability by forming a passive film, and a method of manufacturing the same.

In the present invention, aluminum is added to quantum dots to produce AlInP cores, and quantum dots having high quantum efficiency are produced by reducing the lattice constant difference with the shell. Also, quantum dots with improved photochemical and oxidation stability are prepared by adding aluminum capable of forming a passive film to the quantum dots.

According to a general embodiment, a method for preparing a mixed solution comprising: adding an indium precursor, an organic solvent, a surfactant and a zinc precursor to a reactor to obtain a first mixed solution; Mixing the first mixed solution with an aluminum precursor, phosphorus precursor, organic solvent, and surfactant to heat the second mixed solution to obtain an AlInP core; Adding a zinc precursor and a Group 16 element compound to the AlInP core dispersion and heating to obtain an AlInP @ AlZnSeS core-first shell quantum dot; After adding the aluminum precursor and the Group 16 element compound to the AlInP @ AlZnSeS core-first shell quantum dot dispersion and heating, the proton magnetic solvent is added and heated to form AlInP @ AlZnSeS @ AlSO core - first shell - second shell quantum dot ; And a step of purifying the AlInP @ AlZnSeS @ AlSO core-first shell-second shell quantum dots, and the quantum dots produced thereby.

The indium precursor may be selected from the group consisting of indium carboxylate, indium acetate, indium acetylacetonate, indium myristate, indium stearate, indium oleate, indium sulfate, indium oxide, indium nitrate, indium hydroxide, indium fluoride, indium chloride , Indium bromide, and indium iodide.

Wherein the aluminum precursor is selected from the group consisting of aluminum carboxylates, aluminum acetates, aluminum acetylacetonates, aluminum myristates, aluminum stearates, aluminum oleates, aluminum sulphates, aluminum oxides, aluminum nitrates, aluminum hydroxides, aluminum fluorides, aluminum chlorides , Aluminum bromide, and aluminum iodide.

Wherein the zinc precursor is selected from the group consisting of zinc carboxylate, zinc acetate, zinc acetylacetonate, zinc myristate, zinc stearate, zinc oleate, zinc sulfate, zinc oxide, zinc nitrate, zinc hydroxide, zinc fluoride, zinc chloride , Zinc bromide, and zinc < RTI ID = 0.0 > iodide. ≪ / RTI >

The phosphorus precursor may include at least one selected from the group consisting of tris (trimethylsilyl) phosphine, hexamethylphosphorus triamide, and phosphine gas.

Wherein the Group 16 element compound is selected from the group consisting of hexane thiol, octanethiol, decanethiol, dodecanethiol, hexadecanethiol, sulfur-trioctylphosphine, sulfur-tributylphosphine, sulfur-triphenylphosphine, trimethylsilyl sulfur, But are not limited to, sulphide, sulphide, sulphide powder, sodium sulfide, hexane selenol, octane selenol, decane selenol, dodecane selenol, hexadecane selenol, selenium-trioctylphosphine, selenium-tributylphosphine, selenium- , Trimethylsilyl selenium, hydrogen selenide, selenium powder, and sodium selenide.

The organic solvent is selected from the group consisting of 1-octadecene, 1-hexadecene, 1-dodecene, 1-decene, octadecane, hexadecane, dodecane, decane, paraffin, mineral oil, polyalphaolefin, Phenyl, and the like.

The surfactant may be selected from the group consisting of lauric, palmitic, oleic, stearic, myristic, trioctylphosphine, tributylphosphine, triphenylphosphine, trioctylphosphine oxide, tributylphosphine oxide, And at least one member selected from the group consisting of phosphine oxide, octylamine, decylamine, dodecylamine, hexadecylamine and trioctylamine.

The protonic solvent may include one or more selected from the group consisting of water, methanol, ethanol, isopropanol, butanol, hexanol, octanol, decanol, dodecanol, hexadecanol, octadecanol and oleyl alcohol have.

The quantum dot is a quantum dot constituting the core @ first shell @ second shell structure.

The core of the quantum dot can be represented by the following formula (1).

[Chemical Formula 1]

Al _x In _{1 -x} P

In Formula 1, 0.1? X? 0.9 is satisfied.

The first shell of the quantum dot can be represented by the formula (2).

(2)

Al _y Zn _{1 - y} Se _z S _{1 - z}

In Formula 2, 0.1? Y? 0.9, and 0.1? Z? 0.9 are satisfied.

The second shell of the quantum dot can be represented by the formula (3).

(3)

AlS _a O _{1 .5-a}

In Formula 3, 0.1? A? 1.4 is satisfied.

The quantum dot may have a half width (FWHM) of 60 nm or less.

The emission wavelength of the quantum dot may be 430 nm to 650 nm.

The quantum efficiency of the quantum dot may be 50% or more.

The quantum dots (or semiconductor nanocrystals) containing aluminum and the method for producing the same according to the present invention can be used for a semiconductor device in which aluminum contained in a quantum dot forms a passive film, and photochemical and oxidation stability, which is not provided by existing InP- Making it possible to manufacture quantum dots. In addition, InP-based quantum dots can be obtained that exhibit high quantum efficiency by reducing defects occurring between the core and the shell.

1 is an XRD result of InAlP @ AlZnSeS and InAlP @ AlZnSeS @ AlSO synthesized in Example 1 of the present invention.
2 is a PL spectrum of an InP-based quantum dot synthesized in Example 1 and Comparative Example 1 of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art.

Example 1. InP-based quantum dot synthesis with green luminescent aluminum

2.51 g of zinc oleate, 13.81 g of 1-octadecene, and 0.044 g of indium chloride are placed in a 100 mL flask and maintained at 110 DEG C for 30 minutes under vacuum.

Then, nitrogen (N ₂₎ fill in the gas cooling, the temperature inside the flask at 60 ℃ and then aluminum chloride (aluminium chloride), 0.027 g, and tris (trimethylsilyl) phosphine (tris (trimethylsilyl) phosphine) 0.10 g of injections do.

Thereafter, the temperature of the flask was rapidly raised to 300 캜 rapidly, and then an AlInP core was formed for 1 hour.

Thereafter, 2.51 g of zinc oleate, 1 mL of 2.0 M TOPSe (selenium-trioctylphosphine) and 1 mL of 2.0 M TOPS (sulfur-trioctylphosphine) were poured into the flask and reacted for 10 minutes AlInP @ AlZnSeS core - The quantum dots of the shell structure are synthesized.

Thereafter, the temperature was cooled to 200 ° C, 1.74 g of aluminum oleate and 1 mL of 1-dodecanethiol were injected, and the temperature of the flask was raised to 250 ° C. and reacted for 1 hour .

Then, 2 mL of 1-octanol is added dropwise to the flask, reacted for 1 hour, and then cooled to room temperature to synthesize quantum dots of AlInP @ AlZnSeS @ AlSO core-multi-shell structure.

Thereafter, the reaction mixture was dispersed in toluene, ethanol was added, and the process of agglomerating the semiconductor nanocrystals synthesized by centrifugal separation was repeated three times and then dispersed in toluene to prepare AlInP @ AlZnSeS @ AlSO core - quantum dots of multi- To prepare a dispersion.

Comparative Example  1. Green light InP-based Qdot  Produce

2.51 g of zinc oleate, 13.81 g of 1-octadecene, and 0.088 g of indium chloride are placed in a 100 mL flask and maintained at 110 DEG C for 30 minutes under vacuum.

Then, nitrogen (N ₂₎ gas fill in the road cooling the temperature inside the flask 60 ℃ then injects the tris (trimethylsilyl) phosphine (tris (trimethylsilyl) phosphine) 0.10g.

Thereafter, the temperature of the flask was quickly raised to 300 ° C, and the InP core was formed for 1 hour.

Then, 1 mL of 2.0 M TOPSe and 1 mL of 2.0 M TOPS were injected into the flask and reacted for 10 minutes. After cooling to 200 ° C, 1 mL of 1-dodecanethiol was injected, Time reaction to synthesize quantum dots of InP @ ZnSeS core-shell structure.

Then, the reaction mixture was dispersed in toluene, ethanol was added, and the process of agglomerating the semiconductor nanocrystals synthesized by using a centrifuge was repeated three times and dispersed in toluene to prepare a quantum dot dispersion of InP @ ZnSeS core-shell structure do.

Evaluation 1. Quantum dot  Configuration

Based on the ICP-AES analysis, Table 1 shows the component consumption of the InP-based quantum dots synthesized in Example 1 containing aluminum. Also, FIG. 1 shows the peak changes of InAlP @ AlZnSeS and InAlP @ AlZnSeS @ AlSO synthesized in Example 1 through XRD analysis.

In Al Zn P S Se AlInP QD One 0.743 - 1.693 - - AlInP @ AlZnSeS QD One 0.986 4.816 1.621 2.195 2.326 AlInP @ AlZnSeS @ AlSO QD One 1.915 8.251 1.632 4.271 2.353

Evaluation 2. Luminescence characteristics of quantum dots

The PL peak and internal quantum efficiency of the InP-based quantum dot containing aluminum synthesized in Example 1 and the InP-based quantum dot synthesized in Comparative Example 1 were measured using QE-2100 (Otsuka Electronics Co., Ltd.) And Fig. However, the quantum dots were excited with UV energy of about 400 nm.

Emission peak Quantum efficiency Half width Example 1 AlInP QD 510 nm 12% 40 nm AlInP @ AlZnSeS QD 513 nm 62% 43 nm AlInP @ AlZnSeS @ AlSO QD 522 nm 75% 53 nm Comparative Example 1 526 nm 45% 48 nm

Evaluation 3. Characteristic of luminescence stability of Qdot

Production Example 1. Quantum dot coating liquid preparation

23.9 g of DPHA, 4.7 g of IBOA, 60.9 g of PETA and 5.5 g of CP-4 were placed in a 250 mL beaker and stirred for 1 hour using a stirrer to prepare a binder. After adding the quantum dot solution dispersed in lauryl acrylate to the binder, the coating solution containing the quantum dots is prepared by stirring for 30 minutes using a stirrer.

Evaluation Example 1. Fabrication of LEDs including a quantum dot.

0.3 mL of each of the quantum dot coating solution prepared in Preparation Example 1 and the quantum dot coating solution prepared in Production Example 2 was dropped onto the GaN LED chip, and then the UV light of 1000 mJ / cm ² was irradiated to cure the resin. .

Using a Colorimetry CS-900A instrument, a power supply (3 V, 50 mA) was applied to the manufactured LED and the emission spectrum was measured with time. The emission stability of the quantum dot according to the following formula 1 is shown in Table 3 using the emission spectrum.

[Equation 1]

A _QD is the area of the quantum dot (QD) spectrum in the LED emission spectrum in which the quantum dots are formed

A _{QD, the initial value} of the quantum dot (QD) spectrum at the time of power application in the LED emission spectrum in which the quantum dot is formed

A _GaN represents the area of the GaN spectrum in the LED emission spectrum in which the quantum dots are formed

A _{GaN, initially,} in the LED emission spectrum in which the quantum dots are formed, the area of the GaN spectrum

10 minutes 30 minutes 1 hours 3 hours 6 hours 12 hours 24 hours 48 hours 72 hours Example 0.99 0.95 0.88 0.82 0.71 0.65 0.53 0.23 0.05 Comparative Example 0.91 0.84 0.71 0.53 0.33 0.12 0 - -

Referring to Table 3, it can be seen that the LED having the quantum dot formed on the blue LED chip according to the embodiment has a stability of 0.5 or more after the application of the power of 3 V and 50 mA to the LED after lapse of 24 hours . In Equation (1), A _{QD , initial,} A _{GaN , initial} means the area of the spectrum measured within one minute after power is applied to the LED.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Those skilled in the art will recognize that many modifications and variations are possible in light of the above teachings.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (13)

Adding an indium precursor, an organic solvent, a surfactant, and a zinc precursor to a reactor to obtain a first mixed solution;
Mixing the first mixed solution with an aluminum precursor, phosphorus precursor, organic solvent, and surfactant to heat the second mixed solution to obtain an AlInP core;
Adding a zinc precursor and a Group 16 element compound to the core dispersion and heating to obtain an AlInP @ AlZnSeS core-first shell quantum dot;
After adding the aluminum precursor and the Group 16 element compound to the AlInP @ AlZnSeS core-first shell quantum dot dispersion and heating, the proton magnetic solvent is added and heated to form AlInP @ AlZnSeS @ AlSO core - first shell - second shell quantum dot ; And
And purifying the AlInP @ AlZnSeS @ AlSO core - first shell - second shell quantum dot,
Wherein the core is represented by the following Formula 1, the first shell is represented by the following Formula 2, the second shell is represented by the following Formula 3,
Wherein the stability of a quantum dot according to the following formula (1) is 0.5 or more.
???????? Al _x In _1-x P
In Formula 1, 0.1? X? 0.9 is satisfied.
???????? Al _y Zn _1-y Se _z S _1-z ?????
In Formula 2, 0.1? Y? 0.9, and 0.1? Z? 0.9 are satisfied.
(3)
AlS _a O _1.5-a
In Formula 3, 0.1? A? 1.4 is satisfied.
[Formula 1]

In Equation (1), stability is a value measured after 24 hours from the application of a power of 3 V and 50 mA to the LED having the quantum dots formed therein, and A _QD is an area of a quantum dot (QD) spectrum in the LED emission spectrum in which the quantum dots are formed, A _QD is an area of a quantum dot (QD) spectrum at the time of power application in an LED emission spectrum in which the quantum dots are formed, A _GaN is an area of GaN spectrum in an LED emission spectrum in which the quantum dots are formed, A _GaN, In the formed LED emission spectrum, it is the area of the GaN spectrum at the time of power application.
The method according to claim 1,
The indium precursor may be selected from the group consisting of indium carboxylate, indium acetate, indium acetylacetonate, indium myristate, indium stearate, indium oleate, indium sulfate, indium oxide, indium nitrate, indium hydroxide, indium fluoride, indium chloride , Indium bromide, and indium iodide.
The method according to claim 1,
Wherein the aluminum precursor is selected from the group consisting of aluminum carboxylates, aluminum acetates, aluminum acetylacetonates, aluminum myristates, aluminum stearates, aluminum oleates, aluminum sulphates, aluminum oxides, aluminum nitrates, aluminum hydroxides, aluminum fluorides, aluminum chlorides , Aluminum bromide, and aluminum iodide.
The method according to claim 1,
Wherein the zinc precursor is selected from the group consisting of zinc carboxylate, zinc acetate, zinc acetylacetonate, zinc myristate, zinc stearate, zinc oleate, zinc sulfate, zinc oxide, zinc nitrate, zinc hydroxide, zinc fluoride, zinc chloride , Zinc bromide, and zinc iodide.
The method according to claim 1,
Wherein the phosphorus precursor comprises at least one selected from the group consisting of tris (trimethylsilyl) phosphine, hexamethylphosphorus triamide, and phosphine gas.
The method according to claim 1,
Wherein the Group 16 element compound is selected from the group consisting of hexane thiol, octanethiol, decanethiol, dodecanethiol, hexadecanethiol, sulfur-trioctylphosphine, sulfur-tributylphosphine, sulfur-triphenylphosphine, trimethylsilyl sulfur, But are not limited to, sulphide, sulphide, sulphide powder, sodium sulfide, hexane selenol, octane selenol, decane selenol, dodecane selenol, hexadecane selenol, selenium-trioctylphosphine, selenium-tributylphosphine, selenium- , Trimethylsilyl selenium, hydrogen selenide, selenium powder, and sodium selenide.
The method according to claim 1,
The organic solvent is selected from the group consisting of 1-octadecene, 1-hexadecene, 1-dodecene, 1-decene, octadecane, hexadecane, dodecane, decane, paraffin, mineral oil, polyalphaolefin, Phenyl. ≪ / RTI >
The method according to claim 1,
The surfactant may be selected from the group consisting of lauric, palmitic, oleic, stearic, myristic, trioctylphosphine, tributylphosphine, triphenylphosphine, trioctylphosphine oxide, tributylphosphine oxide, And at least one selected from the group consisting of phosphine oxide, octylamine, decylamine, dodecylamine, hexadecylamine and trioctylamine.
The method according to claim 1,
Wherein the protic solvent comprises at least one selected from the group consisting of water, methanol, ethanol, isopropanol, butanol, hexanol, octanol, decanol, dodecanol, hexadecanol, octadecanol, Gt;
A core represented by Formula 1, a first shell represented by Formula 2, and a second shell represented by Formula 3,
Having a half width (FWHM) of 60 nm or less,
The emission wavelength is 430 nm to 650 nm,
Quantum efficiency is more than 50% core @ first shell @ second shell quantum dot.
[Chemical Formula 1]
Al _x In _1-x P
In Formula 1, 0.1? X? 0.9 is satisfied.
(2)
Al _y Zn _1-y Se _z S _1-z
In Formula 2, 0.1? Y? 0.9, and 0.1? Z? 0.9 are satisfied.
(3)
AlS _a O _1.5-a
In Formula 3, 0.1? A? 1.4 is satisfied.
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