CN110157411B

CN110157411B - Preparation method and application of II-III-V-VI alloy quantum dot

Info

Publication number: CN110157411B
Application number: CN201910561708.7A
Authority: CN
Inventors: 乔培胜; 陈小朋; 高静
Original assignee: Najing Technology Corp Ltd
Current assignee: Najing Technology Corp Ltd
Priority date: 2019-06-26
Filing date: 2019-06-26
Publication date: 2021-07-27
Anticipated expiration: 2039-06-26
Also published as: WO2020259624A1; CN110157411A

Abstract

The invention relates to a preparation method and application of a II-III-V-VI alloy quantum dot, wherein the preparation method comprises the following steps: (1) mixing a first precursor containing a II secondary group element, a second precursor containing a III main group element, a third precursor containing a V main group element, a fourth precursor containing a VI main group element and a ligand to form a precursor solution A, and heating the precursor solution A to enable the precursor solution A to react to form a II-III-V-VI nanocluster compound solution; (2) and mixing the II-III-V-VI nanocluster compound solution with an activating agent, and reacting to obtain the II-III-V-VI alloy quantum dots. The invention reacts four precursors with different activities to form a II-III-V-VI nanocluster compound with mild reaction activity, and then the II-III-V-VI nanocluster compound is mixed with an activating agent, and the nucleation growth speed and the energy band structure of the II-III-V-VI quantum dots are regulated and controlled by the activating agent, so that the II-III-V-VI alloy quantum dots with uniform size and components and few luminous defects are obtained.

Description

Preparation method and application of II-III-V-VI alloy quantum dot

Technical Field

The invention relates to the technical field of quantum dots, in particular to a preparation method and application of II-III-V-VI alloy quantum dots.

Background

In the synthesis of InP and other III-V quantum dots, the activity of P and other V-containing precursors is too strong, which easily causes uneven crystal growth, wider III-V quantum dot size distribution and wider fluorescence emission peak. In addition, due to the nonradiative exciton relaxation process, unsaturated dangling bonds and the like, the quantum efficiency of the intrinsic III-V quantum dot is only about 1 percent. In order to improve the fluorescence quantum yield of the III-V quantum dots, a layer of II-VI element shell with wider band gap can be coated outside the III-V quantum dot core to form the III-V/II-VI core-shell quantum dots, so that the quantum efficiency of the III-V/II-VI core-shell quantum dots is improved to about 40%. However, the III-V/II-VI core-shell quantum dot prepared by the method has the defects of nonuniform size, large half-peak width of a fluorescence emission peak, low quantum efficiency and the like.

Therefore, the III-V/II-VI core-shell quantum dots can be improved into II-III-V-VI alloy quantum dots. The existing method for preparing II-III-V-VI alloy quantum dots comprises the following steps:

and (I) mixing the four unitary precursors, and boiling to high temperature for reaction to prepare the II-III-V-VI quantum dots. In the preparation method, due to different reaction activities of the precursors, the III precursor and the V precursor with high activity react to generate III-V quantum dots, and then the II precursor and the VI precursor react gradually to generate a structure similar to III-V/II-III-V-VI, so that the composition of various elements in a single quantum dot is not uniform, and III-V or II-VI small particles are easily generated in the whole reaction process. Therefore, the half-width of the fluorescent material is 40nm to 60nm or more, and the quantum efficiency at different fluorescence emission positions greatly fluctuates.

And (II) mixing the precursor II, the precursor III and the precursor VI, boiling to high temperature, injecting the precursor V, and reacting at high temperature to form the II-III-V-VI quantum dots. In the preparation method, after a V precursor is injected at high temperature, the V precursor and the III precursor react rapidly to form III-V quantum dots, and the II precursor and the VI precursor react with the III-V quantum dots to actually form III-V/II-VI quantum dots. Therefore, the quantum dots are similar to the traditional III-V/II-VI core-shell quantum dots, have the defects of high core-shell lattice mismatching degree and poor quantum dot uniformity, and have the fluorescence half-peak width of 42 nm-62 nm.

And (III) forming the II-VI family molecular cluster by the II precursor and the VI precursor in situ or in advance, and then adding the III precursor and the V precursor to react to generate the II-III-V-VI quantum dot. In this preparation method, although the II-VI molecular clusters are formed in situ or in advance, it is still difficult to avoid III-V nucleation alone, since III-V precursors and V precursors need to be added. Therefore, the preparation method is still difficult to form the alloy quantum dots with uniform size and composition, the half-peak width of the product is more than 50nm, and the requirement of narrow half-peak width in the novel display field cannot be met.

Disclosure of Invention

Based on the above, it is necessary to provide a preparation method and application of ii-iii-v-vi alloy quantum dots; according to the preparation method, the II-III-V-VI nanocluster compound with mild reaction activity is used as a multi-element precursor, mixed with an activating agent, and the nucleating growth speed and the energy band structure of the II-III-V-VI quantum dots are regulated and controlled by the activating agent, so that the II-III-V-VI alloy quantum dots with uniform composition and size are obtained.

A preparation method of II-III-V-VI alloy quantum dots comprises the following steps:

(1) mixing a first precursor containing a II secondary group element, a second precursor containing a III main group element, a third precursor containing a V main group element, a fourth precursor containing a VI main group element and a ligand to form a precursor solution A, and heating the precursor solution A to enable the precursor solution A to react to form a II-III-V-VI nanocluster compound solution;

(2) and mixing the II-III-V-VI nanocluster compound solution with an activating agent, heating, and reacting to obtain the II-III-V-VI alloy quantum dot.

Furthermore, in the precursor solution A, the molar ratio of the V-group element to the III-group element is 0.2: 1-1: 1.

Furthermore, the molar ratio of the VI main group element to the III main group element in the precursor solution A is 0.2: 1-2: 1.

Further, the ligand comprises at least one of trioctylphosphine, tributylphosphine, trioctylamine, dioctylamine and octylamine.

Further, in the precursor solution A, the molar ratio of the ligand to the III main group element is 5: 1-20: 1.

Further, the heating temperature of the precursor solution A in the step (1) is 50-150 ℃.

Further, the II-III-V-VI nanocluster composite solution comprises at least one of an InZnPS nanocluster composite solution and an InZnPSe nanocluster composite solution.

Further, the activator comprises at least one of alkyl phosphine, alkyl amine, fatty acid.

Further, the molar ratio of the activating agent to the III main group element in the II-III-V-VI nanocluster composite solution is 40: 1-200: 1.

Further, the heating temperature in the step (2) is 250-310 ℃.

Further, in the step (2), providing a solvent, heating the temperature of the solvent to 250-310 ℃, and injecting the II-III-V-VI nanocluster composite solution and the activating agent into the solvent for reaction.

Further, the step (2) also comprises providing a precursor solution B, mixing the precursor solution B with the II-III-V-VI nanocluster compound solution and the activating agent, and reacting to obtain II-III-V-VI alloy quantum dots;

wherein the precursor solution B comprises at least one of the first precursor, the second precursor and the fourth precursor.

Further, the following steps are included after the step (2):

and coating a shell layer on the II-III-V-VI alloy quantum dot, wherein the shell layer is a shell layer containing II-VI elements, and the II-III-V-VI alloy quantum dot with the II-VI element shell layer is obtained.

According to another aspect of the invention, an optoelectronic device is provided, which comprises the II-III-V-VI alloy quantum dots prepared by the preparation method.

In the preparation method, four precursors with different reaction activities react to form the II-III-V-VI nanocluster compound, and the nanocluster compound serving as a multi-element precursor has milder reaction activity compared with a unitary precursor, particularly a high-activity precursor containing a main group V element. Therefore, after the nanocluster composite is mixed with the active agent, part of the nanocluster composite is aggregated and combined to form seed crystals, part of the nanocluster composite is used as a multi-element precursor to be decomposed into quantum dot monomers under the promoting action of the active agent, and the quantum dot monomers continue to grow on the seed crystals for nucleation growth. Meanwhile, ion exchange processes may exist among single quantum dot monomers, and atom transfer processes may also exist among adjacent quantum dot monomers. Therefore, the nucleation growth speed and the energy band structure of the II-III-V-VI alloy quantum dot are regulated and controlled by the activator, and the II-III-V-VI alloy quantum dot with uniform size and components and less luminescent defects is obtained. The position of the fluorescence emission peak of the II-III-V-VI alloy quantum dot is 500 nm-580 nm, the half-peak width is 35 nm-40 nm, and the quantum efficiency is 40% -50%. After the II-III-V-VI alloy quantum dots are coated with II-VI element shells, the positions of fluorescence emission peaks are 510 nm-600 nm, the half-peak width is 35 nm-40 nm, the quantum efficiency is improved to 60% -70%, the fluorescence half-peak width is narrow, the quantum efficiency is high, and the quantum dots can be better applied to photoelectric devices to meet the requirement of narrow half-peak width in the novel display field.

Drawings

Fig. 1 is an ultraviolet absorption spectrum of an intermediate process of InZnPS quantum dot synthesis of the InZnPS nanocluster composite solution of example 1 and comparative example 1;

fig. 2 is an electron microscope picture of the InZnPS nanocluster composite solution of example 1;

FIG. 3 is an electron microscope image of InZnPS alloy quantum dots of example 1;

FIG. 4 is an X-ray diffraction (XRD) pattern of examples 1 to 2 and comparative examples 1 to 4.

Detailed Description

The preparation method and application of the II-III-V-VI alloy quantum dot provided by the invention are further explained below. Wherein, the element sequence of the II-III-V-VI only represents the composition of the II-III-V-VI alloy quantum dots, and does not represent the structural sequence of the II-III-V-VI alloy quantum dots.

The invention reacts four precursors with different activities to form a II-III-V-VI nanocluster compound with mild reaction activity, the nanocluster compound is used as a precursor and mixed with an activating agent, the nucleation growth speed and the energy band structure of II-III-V-VI alloy quantum dots can be regulated and controlled by the activating agent, so that the II-III-V-VI alloy quantum dots with uniform size and components and few luminous defects are obtained, the II-III-V-VI alloy quantum dots have narrow fluorescence half-peak width and high quantum efficiency, and can be better applied to photoelectric devices to meet the requirement of narrow half-peak width in the novel display field.

The invention provides a preparation method of II-III-V-VI alloy quantum dots, which comprises the following steps:

In the step (1), the precursor solution A can perform a preliminary reaction in the heating process, a third precursor with high activity and a second precursor are subjected to a preliminary reaction to form a III-V monomer, the first precursor, the fourth precursor, a ligand and the like are coordinated on the surface of the III-V monomer, and the II-III-V-VI nanocluster composite is integrally formed. The ligand can be surrounded on the surface of the nanocluster compound, the dispersity of the nanocluster compound is improved, and the nanocluster compound is restrained from being further combined, so that the II-III-V-VI nanocluster compound with uniform size is obtained.

In addition, in the II-III-V-VI nanocluster compound, the high-activity main group V element is consumed into the form of the III-V quantum dot monomer and exists in the II-III-V-VI nanocluster compound, so that when the nanocluster compound is used as a multi-precursor, the reaction activity is milder compared with that of a unitary precursor, the stability is better, the nanocluster compound can be stored for a long time after being prepared in a large scale, and the repeatability is better in amplification production.

In some embodiments, the heating temperature of the precursor solution a is 50 ℃ to 150 ℃. Under the heating temperature, the reaction speed of the four precursors is close, and the II-III-V-VI nanocluster compound is slowly formed, so that the composition distribution in the nanocluster compound is uniform, and the II-III-V-VI alloy quantum dots with uniform size and components and few light-emitting defects can be formed in the subsequent nucleation growth process. Preferably, the heating time of the precursor solution a is controlled to be 20 minutes to 60 minutes.

In some embodiments, the amount of group v and group vi elements in precursor solution a needs to be controlled in order to better form compositionally homogeneous ii-iii-v-vi nanocluster composites. Preferably, in the precursor solution a, the molar ratio of the group v element to the group iii element is 0.2:1 to 1:1, and the molar ratio of the group vi element to the group iii element is 0.2:1 to 2: 1.

In some embodiments, while the group II element mainly plays a role in auxiliary regulation, the molar ratio of the group II element to the group III element is preferably 0.25:1 to 2:1 in order to allow the precursor solution A to better form a II-III-V-VI nanocluster composite with uniform composition and size.

In some embodiments, in order to better inhibit further nucleation and growth of the nanocluster composite during the formation of the ii-iii-v-vi nanocluster composite, the molar ratio of the ligand to the group iii element in the precursor solution a is 5:1 to 20:1, and the ligand comprises at least one of trioctylphosphine, tributylphosphine, trioctylamine, dioctylamine and octylamine.

In the invention, the first precursor comprises a zinc precursor and a cadmium precursor, and considering that cadmium has environmental protection policy restrictions, the first precursor is preferably a zinc precursor, the zinc precursor comprises at least one of zinc acetate, zinc propionate, zinc chloride, zinc bromide, zinc iodide and zinc carboxylate, and the carbon chain length of the carboxylate radical of the zinc carboxylate is greater than or equal to 12.

In some embodiments, the second precursor includes an indium precursor, the indium precursor includes at least one of indium acetate, indium chloride, indium bromide, indium iodide, indium acetylacetonate, and indium carboxylate, and a carbon chain length of a carboxylate of the indium carboxylate is greater than or equal to 12.

In some embodiments, the third precursor comprises a phosphorous precursor comprising at least one of tris (trimethylsilyl) phosphorous, tris (triethylsilyl) phosphorous, tris (diethylamine) phosphorous, tris (dimethylamine) phosphorous.

In some embodiments, the fourth precursor includes one of a sulfur precursor including at least one of thio-octadecene and tris (trimethylsilyl) sulfide, and a selenium precursor including at least one of seleno-octadecene and tris (trimethylsilyl) selenium. The sulfur precursor and the selenium precursor are both high-activity sulfur precursors and selenium precursors, can participate in the nucleation growth of quantum dots more when the alloy quantum dots are nucleated and grow, and have a promoting effect on the effective doping of sulfur and selenium elements and the formation of alloys.

In some embodiments, the zinc precursor is preferably zinc carboxylate, and the indium precursor is preferably indium carboxylate, considering that when zinc carboxylate and indium carboxylate are used as precursors, the solubility in a solvent such as octadecene is better, and no by-product such as acetic acid is generated.

In some embodiments, zinc acetate, indium acetate, etc. can also be used as a precursor to be dissolved in a solvent, and then reacted with a long-chain acid having a carbon chain length of 12 or more, such as dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, oleic acid, etc., to form zinc carboxylate and indium carboxylate.

Specifically, if indium acetate, indium chloride, indium bromide, indium iodide, indium acetylacetonate, etc. are used as the indium precursor, and zinc acetate, zinc propionate, zinc chloride, zinc bromide, zinc iodide, etc. are used as the zinc precursor in step (1), the method is as follows: dissolving an indium precursor, a zinc precursor and long-chain acid in a solvent, wherein the solvent comprises a non-coordination solvent such as octadecene or a high boiling point solvent such as octadecane and isotridecane, heating to 150-200 ℃, and reacting for 20-60 min to fully react to form indium carboxylate and zinc carboxylate. And then, reducing the temperature of the reaction system to be below 50 ℃, and adding one of a sulfur precursor and a selenium precursor and a phosphorus precursor to avoid InP self-nucleation at high temperature.

Therefore, the ii-iii-v-vi nanocluster composite solution preferably includes at least one of an InZnPS nanocluster composite solution and an InZnPSe nanocluster composite solution.

In the step (2), after the II-III-V-VI nanocluster compound with mild reaction activity is mixed with an activating agent, part of the II-III-V-VI nanocluster compound is aggregated and combined to form seed crystals, and the other part of the II-III-V-VI nanocluster compound serving as a multi-element precursor is decomposed into quantum dot monomers under the promoting action of the activating agent and continuously grows to the seed crystals for nucleation growth. Meanwhile, the alloying process possibly accompanied with ion exchange in a single quantum dot nanocrystal forms alloy quantum dots with uniform composition and size, and an atom transfer process possibly exists between adjacent quantum dot nanocrystals, so that the size distribution of different quantum dots is more uniform. Therefore, the nucleation growth speed and the energy band structure of the II-III-V-VI quantum dots can be regulated and controlled by the activating agent, so that the II-III-V-VI nanoclusters are gradually converted into the II-III-V-VI alloy quantum dots with uniform size and components and few luminous defects.

Specifically, the activating agent is mainly used for activating the II-III-V-VI nanocluster compound at high temperature, regulating and controlling the decomposition of the II-III-V-VI nanocluster compound into monomers and monomer aggregation nucleation growth, and has small influence on the activity of unreacted unitary precursors in the precursor solution A and unitary precursors which are used for adjusting alloy quantum dots and are additionally added. Therefore, in some embodiments, in order to better control the decomposition of the II-III-V-VI nanocluster composite into quantum dot monomers and monomer aggregation nucleation growth, the molar ratio of the activator to the III main group element in the II-III-V-VI nanocluster composite solution is 40:1 to 200: 1.

In some embodiments, the activator comprises at least one of an alkyl phosphine, an alkyl amine, a fatty acid. In other embodiments, the alkyl phosphine mainly comprises alkyl phosphine with alkyl carbon atom number of 2-10 such as trioctyl phosphine, tributyl phosphine and the like, the alkylamine mainly comprises alkylamine with alkyl carbon atom number of 2-10 such as octylamine, dioctylamine and the like, and the fatty acid mainly comprises fatty acid with carboxylate carbon atom number of 8-22 such as oleic acid, capric acid and the like.

In some embodiments, in step (2), the temperature of the reaction is from 250 ℃ to 310 ℃. At this reaction temperature, the reaction time is preferably controlled to 10 to 30 min. Considering the advantage of rapid nucleation growth and alloying process of quantum dots synthesized by the thermal injection method, the II-III-V-VI nanocluster composite solution and the activating agent are preferably injected into the solvent, and the mixed solution of the II-III-V-VI nanocluster composite solution and the activating agent can be injected into the solvent, wherein the temperature of the solvent is 250-310 ℃, and the solvent comprises a non-coordination solvent such as octadecene or a high-boiling point solvent such as octadecane or isotridecane.

In some preferred embodiments, the step (2) further comprises providing a precursor solution B, mixing the precursor solution B with the ii-iii-v-vi nanocluster composite solution and the activating agent, and reacting to obtain the ii-iii-v-vi alloy quantum dots. Therefore, when the quantum dots are nucleated and grown, the precursor in the precursor solution B can continuously adjust the element composition and the nanocrystalline size of the alloy quantum dots so as to adjust and control the energy band structure and the light-emitting position.

The precursor solution B includes at least one of the first precursor, the second precursor, and the fourth precursor, considering that the third precursor is too reactive to be added separately.

In some embodiments, the II-III-V-VI alloy quantum dots obtained by the preparation method have the fluorescence emission peak position of 500 nm-580 nm, the half-peak width of 35 nm-40 nm, the quantum efficiency of 40-50% and the particle size of 3.0 nm-3.8 nm. The II-III-V-VI alloy quantum dots are uniform in size, narrow in fluorescence half-peak width and high in quantum efficiency.

In some preferred embodiments, the ii-iii-v-vi alloy quantum dots comprise one of InZnPS alloy quantum dots and InZnPSe alloy quantum dots, and may replace cadmium-containing quantum dots.

In some preferred embodiments, the lattice constant of the II-III-V-VI alloy quantum dot obtained by the preparation method is slightly different between the lattice constant of the III-V structure and the lattice constant of the II-VI structure according to element composition and proportion, but is closer to the lattice constant of the II-VI structure. Therefore, the II-III-V-VI alloy quantum dot obtained by the preparation method can be better coated with a shell layer to form the quantum dot with better luminous performance and higher stability.

Therefore, the following steps are also included after the step (2): and coating a shell layer on the II-III-V-VI alloy quantum dot, wherein the shell layer is a shell layer containing II-VI elements, so that the II-III-V-VI alloy quantum dot with the II-VI element shell layer is obtained, and the quantum efficiency is improved. Wherein the II-VI element shell layer may comprise a ZnS shell layer.

Specifically, the process of coating the shell layer comprises the following steps: and mixing the II-III-V-VI alloy quantum dot with the ligand, the precursor containing the II secondary group element and the precursor containing the VI main group element to form a mixed solution, and reacting the mixed solution to obtain the II-III-V-VI alloy quantum dot with the II-VI element shell layer.

In some preferred embodiments, the molar ratio of the group II element to the group VI element in the mixed solution is 2:1 to 1: 2.

In some preferred embodiments, the reaction temperature is 230 ℃ to 300 ℃ to form uniform shell coating, since the shell is prone to be grown epitaxially too fast and non-uniform at high temperature. At the reaction temperature, the reaction time can be controlled to be 20 minutes to 60 minutes.

Therefore, the II-III-V-VI alloy quantum dot obtained by the preparation method can also have an II-VI element shell, and the II-III-V-VI alloy quantum dot is matched with the lattice constant of the II-VI structure, so that the coating effect is good. Specifically, the position of the fluorescence emission peak of the II-III-V-VI alloy quantum dot with the II-VI element shell is 510 nm-600 nm, the half-peak width is 35 nm-40 nm, the quantum efficiency is 60% -70%, and the particle size is 4.5 nm-5 nm. Compared with II-III-V-VI alloy quantum dots, the luminescent property is better and the stability is higher.

The invention also provides a photoelectric device comprising the II-III-V-VI alloy quantum dot prepared by the preparation method. The photoelectric device comprises a quantum dot film, a quantum dot tube, a quantum dot color film, a device used by combining the quantum dot color film with the LED, and a quantum dot light-emitting diode. The II-III-V-VI alloy quantum dots have narrow fluorescence half-peak width and high quantum efficiency, so that the photoelectric device has high luminous efficiency and can better meet the requirement of narrow half-peak width in the novel display field.

The following examples further illustrate the preparation of the II-III-V-VI alloy quantum dots and their use.

Example 1:

adding 0.3mmol of In (Ac)₃(indium acetate), 0.6mmol Zn (Ac)₂(Zinc acetate), 2.1mmol hexadecanoic acid and 12mL ODE (octadecene) were added to a 100mL three-necked flask, which was placed in a N₂Heating to 180 ℃ in an exhaust state, keeping the temperature at 180 ℃ for 30min, then reducing the temperature to 30 ℃, adding 0.15mmol of TMS-P (tri (trimethylsilyl) phosphate), 0.3mmol of S-ODE and 1.5mmol of TOP (trioctylphosphine) to form a precursor solution A, further heating to 50 ℃ for reaction for 30min to form an InZnPS nanocluster composite solution, and reducing the temperature to room temperature for later use. As shown in fig. 1, the InZnPS nanocluster composite solution starts to lift up at 400nm in the ultraviolet absorption spectrum, but has no obvious exciton peak, as shown in fig. 2, the InZnPS nanoclusters are shown to be about 1nm in the Transmission Electron Microscope (TEM), which indicates that the crystallization is incomplete, and the solution is in a nanocluster composite structure.

15mL of octadecene was added to a 50mL three-necked flask which was kept at N₂Heating to 300 ℃ In an exhaust state, injecting a mixed solution of InZnPS nanocluster compound solution containing 0.15mmol of In element and 6mmol of octylamine, and keeping the temperature at 300 ℃ for 10min to obtain the InZnPS alloy quantum dot solution. The InZnPS alloy quantum dot solution is subjected to fluorescence emission and transmission electron microscope tests, the data obtained by the tests are shown in table 1, and the element composition test results are shown in table 2. As shown in a transmission electron microscope picture of FIG. 3, the average size of the InZnPS alloy quantum dots is 3.0nm, the size uniformity is high, and the morphology is good. The inset in fig. 3 is a high resolution electron microscope picture of a single InZnPS alloy quantum dot, which has ordered and uniform lattice arrangement and embodies a good single-phase alloy structure.

Reducing the reaction temperature to 250 ℃, adding 6mL of octylamine and 1.5mmol of Zn (OA) into the InZnPS alloy quantum dot solution₂(zinc oleate) and 1.5mmol S-TOP (sulfur-trioctylphosphine) react for 30min at 250 ℃, and the temperature is reduced to room temperature to obtain a product system of the InZnPS alloy quantum dot containing the ZnS shell layer. Extracting twice with methanol, precipitating with acetone, centrifuging, dissolving the precipitate in toluene to obtain quantum dot solution, and performing fluorescence emission and transmission electron microscope test, wherein the test results are shown in Table 3.

Example 2:

adding 0.3mmol of In (Ac)₃、0.3mmol Zn(Ac)₂1.5mmol of hexadecanoic acid and 12mL ODE were added to a 100mL three-necked flask, which was placed in N₂Heating to 180 ℃ in an exhaust state, keeping the temperature at 180 ℃ for 30min, then reducing the temperature to 30 ℃, adding 0.3mmol TMS-P, 0.6mmol S-ODE and 3mmol TBP (tributylphosphine) to form a precursor solution A, further heating to 80 ℃ for reaction for 30min to form an InZnPS nanocluster compound solution, and reducing the temperature to room temperature for later use.

15mL of octadecene was added to a 50mL three-necked flask which was kept at N₂Heating to 250 ℃ In an exhaust state, injecting a mixed solution of InZnPS nanocluster compound solution containing 0.15mmol of In elements and 15mmol of dioctylamine, and keeping the temperature at 250 ℃ for 10min to obtain the InZnPS alloy quantum dot solution. The InZnPS alloy quantum dot solution is subjected to fluorescence emission and transmission electron microscope tests, the test results are shown in table 1, and the element composition test results are shown in table 2.

The reaction temperature is adjusted to 270 ℃, 6mL of dioctylamine and 3mmol of Zn (OA) are added into the InZnPS alloy quantum dot solution₂And 1.5mmol of S-TOP, at 270 ℃ for 20 min. And cooling to room temperature to obtain a product system of the InZnPS alloy quantum dots containing the ZnS shell layer. Extracting twice with methanol, precipitating with acetone, centrifuging, dissolving the precipitate in toluene to obtain quantum dot solution, and performing fluorescence emission and transmission electron microscope test, wherein the test results are shown in Table 3.

Example 3:

adding 0.3mmol of In (Ac)₃、0.075mmol Zn(Ac)₂1.05mmol of palmitic acid and 12mL of ODE were placed in a 100mL three-necked flask₂Heating to 180 ℃ in an exhaust state, keeping the temperature at 180 ℃ for 30min, then cooling to 30 ℃, adding 0.06mmol of TMS-P, 0.06mmol of S-TMS (tris (trimethylsilyl) sulfide) and 4.5mmol of TOA (trioctylamine) to form a precursor solution A, then heating to 50 ℃ for reaction for 30min to form an InZnPS nanocluster composite solution, and cooling to room temperature for later use.

15mL of octadecene was added to a 50mL three-necked flask which was kept at N₂Heating to 270 deg.C under exhaust condition, and injecting In containing 0.1mmol of In elementAnd (3) keeping the mixed solution of the ZnPS nanocluster compound solution and 15mmol of oleic acid at 270 ℃ for 10min to obtain an InZnPS alloy quantum dot solution. The InZnPS alloy quantum dot solution is subjected to fluorescence emission and transmission electron microscope tests, and the test results are shown in Table 1.

Adjusting the reaction temperature to 300 ℃, adding 6mL of octylamine and 3mmol of Zn (OA) into the InZnPS alloy quantum dot solution₂And 1.5mmol of S-TOP, at 300 ℃ for 40 min. And cooling to room temperature to obtain a product system of the InZnPS alloy quantum dots containing the ZnS shell layer. Extracting twice with methanol, precipitating with acetone, centrifuging, dissolving the precipitate in toluene to obtain quantum dot solution, and performing fluorescence emission and transmission electron microscope test, wherein the test results are shown in Table 3.

Example 4:

adding 0.3mmol of In (Ac)₃、0.6mmol Zn(Ac)₂2.1mmol of hexadecanoic acid and 12mL ODE were added to a 100mL three-necked flask, which was kept under N₂Heating to 180 ℃ in an exhaust state, keeping the temperature at 180 ℃ for 30min, then reducing the temperature to 30 ℃, adding 0.15mmol of TMS-P, 0.3mmol of S-TMS and 6mmol of dioctylamine to form a precursor solution A, further heating to 50 ℃ for reaction for 30min to form an InZnPS nanocluster compound solution, and reducing the temperature to room temperature for later use.

15mL of octadecene was added to a 50mL three-necked flask which was kept at N₂Heating to 310 ℃ In an exhaust state, injecting a mixed solution of InZnPS nanocluster compound solution containing 0.05mmol of In element and 10mmol of decanoic acid, and keeping the temperature at 310 ℃ for 30min to obtain the InZnPS alloy quantum dot solution. The InZnPS alloy quantum dot solution is subjected to fluorescence emission and transmission electron microscope tests, and the test results are shown in Table 1.

Adjusting the reaction temperature to 300 ℃, adding 4mL of octylamine and 1.5mmol of Zn (OA) into the InZnPS alloy quantum dot solution₂And 1.5mmol of S-TOP, at 300 ℃ for 60 min. And cooling to room temperature to obtain a product system of the InZnPS alloy quantum dots containing the ZnS shell layer. Extracting twice with methanol, precipitating with acetone, centrifuging, dissolving the precipitate in toluene to obtain quantum dot solution, and performing fluorescence emission and transmission electron microscope test, wherein the test results are shown in Table 3.

Example 5:

adding 0.3mmol of In (Ac)₃、0.6mmol Zn(Ac)₂2.1mmol of hexadecanoic acid and 12mL ODE were added to a 100mL three-necked flask, which was kept under N₂Heating to 180 deg.C under exhaust condition, maintaining at 180 deg.C for 30min, and cooling to 30 deg.C. Adding 0.15mmol TMS-P, 0.3mmol S-TMS and 3mmol octylamine to form a precursor solution A, further heating to 120 ℃ to react for 30min to form an InZnPS nanocluster compound solution, and cooling to room temperature for later use.

0.2mmol of In (Ac)₃、0.2mmol Zn(Ac)₂1.0mmol of octadecanoic acid and 20mL of octadecene were charged into a 100mL three-necked flask, and the three-necked flask was placed in N₂Heating to 180 ℃ in an exhaust state, and keeping the temperature at 180 ℃ for 30min to form a precursor solution B. And heating the precursor solution B to 300 ℃, injecting a mixed solution of InZnPS nanocluster compound solution containing 0.15mmol of In elements and 15mmol of oleic acid, and keeping the temperature at 300 ℃ for 20min to obtain the InZnPS alloy quantum dot solution. The InZnPS alloy quantum dot solution is subjected to fluorescence emission and transmission electron microscope tests, and the test results are shown in Table 1.

Keeping the reaction temperature at 300 ℃, adding 6mL of oleic acid and 1.5mmol of Zn (OA) into the InZnPS alloy quantum dot solution₂And 3mmol of S-TOP, at 300 ℃ for 30 min. And cooling to room temperature to obtain a product system of the InZnPS alloy quantum dots containing the ZnS shell layer. Extracting twice with methanol, precipitating with acetone, centrifuging, dissolving the precipitate in toluene to obtain quantum dot solution, and performing fluorescence emission and transmission electron microscope test, as shown in Table 3.

Example 6:

0.3mmol indium tetradecanoate, 0.6mmol zinc oleate and 12mL ODE were added to a 100mL three-necked flask, which was placed in N₂Heating to 100 ℃ in an exhaust state, keeping the temperature at 100 ℃ for 10min, reducing the temperature to 30 ℃, adding 0.15mmol TMS-P, 0.3mmol S-ODE and 3mmol TOP to form a precursor solution A, further heating to 120 ℃ for reaction for 30min to form an InZnPS nanocluster compound solution, and reducing the temperature to room temperature for later use.

0.4mmol of In (Ac)₃、0.3mmol Zn(Ac)₂1.8mmol of octadecanoic acid and 20mL of octadecene were added100mL three-neck flask, and placing the three-neck flask in N₂Heating to 180 ℃ in an exhaust state, and keeping the temperature at 180 ℃ for 30min to form a precursor solution B. And heating the precursor solution B to 300 ℃, injecting a mixed solution of InZnPS nanocluster compound solution containing 0.15mmol of In elements and 15mmol of oleic acid, and keeping the temperature at 300 ℃ for 20min to obtain the InZnPS alloy quantum dot solution. The InZnPS alloy quantum dot solution is subjected to fluorescence emission and transmission electron microscope tests, and the test results are shown in Table 1.

Example 7:

0.3mmol of indium tetradecanoate, 0.6mmol of zinc tetradecanoate and 12mL of ODE were put into a 100mL three-necked flask, and the three-necked flask was placed in N₂Heating to 100 deg.C under exhaust condition, maintaining at 100 deg.C for 10min, and cooling to 30 deg.C. Adding 0.15mmol TMS-P, 0.3mmol S-ODE and 3mmol TOP to form a precursor solution A, further heating to 150 ℃ for reaction for 30min to form an InZnPS nanocluster compound solution, and cooling to room temperature for later use.

0.6mmol of Zn (OA)₂0.6mmol of S-TBP (thio-tributylphosphine) in N₂And mixing the components in an exhaust state to form a precursor solution B. 15mL of octadecene was added to a 50mL three-necked flask which was kept at N₂Heating to 300 ℃ In an exhaust state, injecting a mixed solution of the precursor solution B, the InZnPS nanocluster compound solution containing 0.15mmol of In elements and 15mmol of dioctylamine, and keeping the temperature at 300 ℃ for 30min to obtain the InZnPS alloy quantum dot solution. The InZnPS alloy quantum dot solution is subjected to fluorescence emission and transmission electron microscope tests, and the test results are shown in Table 1.

Reducing the reaction temperature to 270 ℃, adding 6mL decanoic acid and 1.5mmol Zn (OA) into the InZnPS alloy quantum dot solution₂And 1.5mmol of S-TOP at 27The reaction was carried out at 0 ℃ for 30 min. And cooling to room temperature to obtain a product system of the InZnPS alloy quantum dots containing the ZnS shell layer. Extracting twice with methanol, precipitating with acetone, centrifuging, dissolving the precipitate in toluene to obtain quantum dot solution, and performing fluorescence emission and transmission electron microscope test, wherein the test results are shown in Table 3.

Example 8:

0.3mmol indium palmitate, 0.6mmol zinc oleate and 12mL ODE were added to a 100mL three-necked flask, which was placed in N₂Heating to 100 ℃ in an exhaust state, keeping the temperature at 100 ℃ for 10min, reducing the temperature to 30 ℃, adding 0.15mmol TMS-P, 0.3mmol S-ODE and 3mmol TOP to form a precursor solution A, further heating to 150 ℃ for reaction for 30min to form an InZnPS nanocluster compound solution, and reducing the temperature to room temperature for later use.

0.4mmol of Zn (OA)₂0.4mmol of S-TOP in N₂And mixing the components in an exhaust state to form a precursor solution B. 15mL of octadecene was added to a 50mL three-necked flask which was kept at N₂And heating to 300 ℃ In an exhaust state, injecting a mixed solution of the precursor solution B, the InZnPS nanocluster compound solution containing 0.15mmol of In elements and 15mmol of trioctylphosphine, and keeping the temperature at 300 ℃ for 30min to obtain the InZnPS alloy quantum dot solution. The InZnPS alloy quantum dot solution is subjected to fluorescence emission and transmission electron microscope tests, and the test results are shown in Table 1.

Reducing the reaction temperature to 250 ℃, adding 2mL decanoic acid and 1.5mmol Zn (OA) into the InZnPS alloy quantum dot solution₂And 1.5mmol of S-TOP, at 250 ℃ for 30 min. And cooling to room temperature to obtain a product system of the InZnPS alloy quantum dots containing the ZnS shell layer. Extracting twice with methanol, precipitating with acetone, centrifuging, dissolving the precipitate in toluene to obtain quantum dot solution, and performing fluorescence emission and transmission electron microscope test, wherein the test results are shown in Table 3.

Example 9:

0.3mmol of indium palmitate, 0.6mmol of zinc palmitate and 12mL of ODE were placed in a 100mL three-necked flask₂Heating to 100 deg.C under exhausting condition, maintaining at 100 deg.C for 10min, cooling to 30 deg.C, adding 0.15mmol TMS-P, 0.3mmol Se-ODE suspension and3mmol TOP to form a precursor solution A, then heating to 50 ℃ to react for 30min to form an InZnPSe nanocluster compound solution, and cooling to room temperature for later use.

15mL of octadecene was added to a 50mL three-necked flask which was kept at N₂Heating to 300 ℃ In an exhaust state, injecting a mixed solution of InZnPSe nanocluster compound solution containing 0.15mmol of In element and 15mmol of trioctylphosphine, and keeping the temperature at 300 ℃ for 10min to obtain the InZnPSe alloy quantum dot solution. The InZnPSe alloy quantum dot solution is subjected to fluorescence emission and transmission electron microscope tests, and the details are shown in Table 1.

The reaction temperature was lowered to 230 ℃ and 6mL of octylamine, 1.5mmol of Zn (OA) were added to the InZnPSe alloy solution₂And 1.5mmol of S-TOP, at 230 ℃ for 30 min. And cooling to room temperature to obtain a product system of the InZnPSe alloy quantum dots containing ZnS shell layers. Extracting twice with methanol, precipitating with acetone, centrifuging, dissolving the precipitate in toluene to obtain quantum dot solution, and performing fluorescence emission and transmission electron microscope test, wherein the test results are shown in Table 3.

Comparative example 1:

adding 0.3mmol of In (Ac)₃、0.6mmol Zn(Ac)₂2.1mmol of hexadecanoic acid and 12mL ODE were added to a 100mL three-necked flask, which was kept under N₂Heating to 180 deg.C under exhausting condition, maintaining at 180 deg.C for 30min, cooling to 30 deg.C, and adding 0.15mmol TMS-P and 0.3mmol DDT (n-dodecyl mercaptan) to form a mixture of multiple precursors. And heating the precursor mixed solution to 300 ℃ for reaction for 20min to obtain the InZnPS quantum dot solution. In the middle of the synthesis process, a sample heated to 200 ℃ is taken to be subjected to ultraviolet absorption spectrum test (see fig. 1), the position of the sample is lifted to be about 500nm, and a broad peak region appears at about 420nm, which indicates that InP is subjected to primary nucleation, the size of the nanocrystal is large, and the size distribution is not uniform. Compared with the InZnPS nanocluster composite solution in example 1, the reaction of the precursor solution a at a low temperature in example 1 to form a nanocluster composite solution is more beneficial to control of cluster size and structure. The InZnPS quantum dot solution is subjected to fluorescence emission and transmission electron microscope tests, and is specifically shown in table 1, and the element composition test results are specifically shown in table 2.

The reaction temperature was lowered to 250 ℃ and 6mL of octylamine, 1.5mmol of Zn (OA) was added to the InZnPS solution₂And 1.5mmol of S-TOP, at 250 ℃ for 30 min. Cooling to room temperature to obtain a product system containing InZnPS/ZnS. Extracting twice with methanol, precipitating with acetone, centrifuging, dissolving the precipitate in toluene to obtain InZnPS/ZnS quantum dot solution, and performing fluorescence emission and transmission electron microscope test, wherein the test results are shown in Table 3.

Comparative example 2:

adding 0.3mmol of In (Ac)₃0.9mmol hexadecanoic acid, 1mL trioctylphosphine, and 12mL ODE were added to a 100mL three-necked flask, which was placed in N₂Heating to 180 deg.C under exhaust condition, maintaining at 180 deg.C for 30min, and heating to 300 deg.C. And injecting 0.15mmol TMS-P at 300 ℃, and reacting for 10min to obtain the InP quantum dot solution. The InP quantum dot solution is subjected to fluorescence emission and transmission electron microscope tests, and the test results are shown in Table 1.

The reaction temperature was lowered to 250 ℃ and 6mL of octylamine, 1.5mmol of Zn (OA) was added to the InP quantum dot solution₂And 1.5mmol of S-TOP, at 250 ℃ for 30 min. And cooling to room temperature to obtain a product system containing InP/ZnS. Extracting with methanol twice, precipitating with acetone, centrifuging, dissolving the precipitate in toluene to obtain InP/ZnS quantum dot solution, and performing fluorescence emission and transmission electron microscope test to obtain the final product shown in Table 3 and the element composition shown in Table 2.

Comparative example 3:

adding 0.3mmol of In (Ac)₃、0.3mmol Zn(Ac)₂1.5mmol of hexadecanoic acid and 12mL ODE were added to a 100mL three-necked flask, which was placed in N₂Heating to 180 deg.C under exhaust, maintaining at 180 deg.C for 30min, adding 0.3mmol DDT, and heating to 300 deg.C. And injecting 0.15mmol TMS-P at 300 ℃, and reacting for 10min to obtain the InZnPS quantum dot solution. The InZnPS quantum dot solution is subjected to fluorescence emission and transmission electron microscope tests, the test results are shown in table 1, and the element composition test results are shown in table 2.

The reaction temperature was lowered to 250 ℃ and 6mL of octylamine, 1.5mmol of Zn (OA) was added to the InZnPS solution₂And 1.5mmol of S-TOP at 250The reaction was carried out at room temperature for 30 min. Cooling to room temperature to obtain a product system containing InZnPS/ZnS. Extracting twice with methanol, precipitating with acetone, centrifuging, dissolving the precipitate in toluene to obtain InZnPS/ZnS quantum dot solution, and performing fluorescence emission and transmission electron microscope test, wherein the test results are shown in Table 3.

Comparative example 4:

adding 0.6mmol of Zn (Ac)₂1.2mmol of palmitic acid and 12mL of ODE were placed in a 100mL three-necked flask₂Heating to 180 ℃ in a degassing state, keeping the temperature at 180 ℃ for 30min, adding 0.3mmol S-ODE and 5mmol TOP, raising the temperature to 250 ℃ and reacting for 20min to form ZnS quantum dot solution. Then, 0.2mmol of In (Ac) was injected₃And mixed solution of 0.1mmol TMS-P and 3mL octylamine is heated to 300 ℃ and kept for 10min to obtain InZnPS solution. The InZnPS quantum dot solution is subjected to fluorescence emission and transmission electron microscope tests, and is specifically shown in table 1, and the element composition test results are specifically shown in table 2.

The reaction temperature was lowered to 250 ℃ and 6mL of octylamine, 1.5mmol of Zn (OA) was added to the InZnPS solution₂And 1.5mmol of S-TOP, at 250 ℃ for 30 min. Cooling to room temperature to obtain a product system containing InZnPS/ZnS. Extracting twice with methanol, precipitating with acetone, centrifuging, dissolving the precipitate in toluene to obtain InZnPS/ZnS quantum dot solution, and performing fluorescence emission and transmission electron microscope tests, as shown in Table 3.

As shown in fig. 4, the method is used for characterizing and analyzing the nano-crystalline form and the crystal structure of the InZnPS quantum dots obtained in examples 1 to 2 and comparative examples 1 to 4. Wherein, the black straight line and the dotted line are standard card peaks of zinc blende structures of InP and ZnS respectively. As shown in Table 2, the elemental composition analysis for characterizing and analyzing the InZnPS quantum dots obtained in examples 1 to 2 and comparative examples 1 to 4 was performed by ICP-AES (inductively coupled plasma emission Spectroscopy) test. The molar ratios of the elements In, Zn, P and S are shown.

As can be seen from the XRD spectrum of the InZnPS alloy quantum dot in example 1, the three characteristic peaks have high peak intensity, are single peaks with high symmetry, and are respectively between the InP and ZnS standard peaks, for example, the main peak (27.4 degrees) is between the InP main peak (26.3 degrees) and the ZnS main peak (28.6 degrees). This shows that the InZnPS is also of a sphalerite structure, has higher crystallization degree and more complete alloying and embodies an alloy structure with uniform composition and uniform structure. The element composition of which is In as measured by ICP-AES_0.2Zn_0.45P_0.15S_0.2In proportion to each precursor added In the synthesis_0.22Zn_0.45P_0.11S_0.22And the method is similar to the method, and shows good regulation and control of the element composition of the alloy quantum dots.

Example 2 is also a single peak with a high degree of symmetry, and the main peak position is slightly shifted (27.7 degrees), indicating a peak position deviation caused by the difference in elemental composition from example 1. The element composition of which is In as measured by ICP-AES_0.22Zn_0.2P_0.18S_0.4In proportion to each precursor added In the synthesis_0.2Zn_0.2P_0.2S_0.4And the method is similar to the method, and shows good regulation and control of the element composition of the alloy quantum dots.

Comparative example 1 is an InZnPS quantum dot prepared by mixing In, Zn, P, S precursors and then raising the temperature to a high temperature, the main peak is a single peak trailing from the right side, which is not easy to judge, but the secondary peak shows obvious mixed peak structures (45.9 and 47.2 degrees), and compared with the InP secondary peak (43.6 degrees) and the ZnS secondary peak (47.5 degrees), it is shown that the structure is closer to the InZnPS/ZnS core-shell structure with uneven structure, and the position of the main peak is closer to cause the single peak trailing from the right side after the mixed peak. The element composition of which is In as measured by ICP-AES_0.4Zn_0.2P_0.3S_0.1In proportion to each precursor added In the synthesis_0.22Zn_0.45P_0.11S_0.22The difference is large, the content of Zn and S elements is small, and the situation that the elements are difficult to dope into an InP crystal lattice is reflected.

The comparative example 2 is the InP/ZnS core-shell quantum dot, the peak intensity is weak, and the InP/ZnS core-shell quantum dot is embodied as a mixed peak structure, which proves that the InP/ZnS core-shell quantum dot has independent two-phase crystal structure and low crystallization degree. The element composition of which is In as measured by ICP-AES_0.3Zn_0.25P_0.2S_0.25Although the content of Zn and S elements is increased, the Zn and S elements are distributed in the shell layer, and an alloy structure cannot be formed.

Comparison ofExample 3 is an InZnPS quantum dot prepared by injecting a P precursor into an In, Zn and S mixed precursor at a high temperature, and the peak intensity is lower, and the main peak position is closer to InP, which shows that the InZnPS quantum dot is closer to an InP/ZnS structure. The element composition of which is In as measured by ICP-AES_0.4Zn_0.1P_0.4S_0.1In proportion to each precursor added In the synthesis_0.28Zn_0.28P_0.28S_0.16The difference is large, the content of Zn and S elements is small, and the situation that the elements are difficult to dope into an InP crystal lattice is reflected.

In comparative example 4, ZnS quantum dots are formed as seed crystals, and then the mixed precursor of In and P is injected into the prepared InZnPS quantum dots, the peak intensity is low, the XRD main peak is close to the mixed peak structure and the peak position is closer to ZnS, which indicates that the XRD main peak is closer to the ZnS/InP structure. The element composition of which is In as measured by ICP-AES_0.1Zn_0.5P_0.1S_0.3In proportion to each precursor added In the synthesis_0.16Zn_0.5P_0.09S_0.25Compared with the In content, the method has the advantage that the element composition is difficult to well regulate and control.

Therefore, the InZnPS quantum dots prepared by the InZnPS nanocluster composite are of alloy structures, the distribution of the composition elements is uniform, the crystallization degree is high, the distribution of the composition elements is greatly different compared with various quantum dots prepared by a comparative example, and the structure obtained by the comparative example 4 is more like a core-shell structure.

TABLE 1

In the comparative example 2, the InP quantum dots have too many intrinsic InP defects, weak fluorescence emission, and too low quantum efficiency, and thus there are no fluorescence test and quantum efficiency results.

As can be seen from Table 1, the II-III-V-VI alloy quantum dots prepared by the embodiment of the invention have the advantages that the fluorescence emission peak position is 500-580 nm, the half-peak width is narrower than that of the comparative example and is 35-40 nm, the quantum efficiency is 40-50% higher than that of the comparative example, and the requirement of narrow half-peak width in the novel display field can be met.

TABLE 2

TABLE 3

As can be seen from Table 3, after the II-III-V-VI alloy quantum dots are coated with the II-VI element shell layer, the quantum efficiency is improved to 60-70%, and the requirement of narrow half-peak width in the novel display field can be better met. The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A preparation method of II-III-V-VI alloy quantum dots is characterized by comprising the following steps:

(1) mixing a first precursor containing a second subgroup element, a second precursor containing a third main group element, a third precursor containing a V main group element, a fourth precursor containing a VI main group element and a ligand to form a precursor solution A, heating the precursor solution A at the temperature of 50-150 ℃ to enable the precursor solution A to react to form a II-III-V-VI nanocluster compound solution, wherein the first precursor comprises a zinc precursor, the second precursor comprises an indium precursor, the third precursor comprises a phosphorus precursor, the fourth precursor comprises one of a sulfur precursor and a selenium precursor, and the ligand comprises at least one of trioctylphosphine, tributylphosphine, trioctylamine, dioctylamine and octylamine;

(2) and mixing the II-III-V-VI nanocluster compound solution with an activating agent and heating, wherein the heating temperature is 250-310 ℃, and reacting to obtain the II-III-V-VI alloy quantum dot, wherein the activating agent comprises at least one of alkyl phosphine, alkylamine and fatty acid.

2. The method for preparing the II-III-V-VI alloy quantum dot according to claim 1, wherein the molar ratio of the group V element to the group III element in the precursor solution A is 0.2:1 to 1: 1.

3. The method for preparing the II-III-V-VI alloy quantum dot as claimed in claim 1, wherein the molar ratio of the VI main group element to the III main group element in the precursor solution A is 0.2: 1-2: 1.

4. The method for preparing the II-III-V-VI alloy quantum dot as claimed in claim 1, wherein the molar ratio of the ligand to the III main group element in the precursor solution A is 5: 1-20: 1.

5. The method of claim 1, wherein the II-III-V-VI alloy quantum dot solution comprises at least one of an InZnPS nanocluster composite solution and an InZnPSe nanocluster composite solution.

6. The method for preparing the II-III-V-VI alloy quantum dot according to claim 1, wherein the molar ratio of the activating agent to the III main group element in the II-III-V-VI nanocluster composite solution is 40: 1-200: 1.

7. The method for preparing the II-III-V-VI alloy quantum dot according to claim 1, wherein in the step (2), a solvent is provided, the temperature of the solvent is heated to 250-310 ℃, and then the II-III-V-VI nanocluster composite solution and the activating agent are injected into the solvent for reaction.

8. The method for preparing the II-III-V-VI alloy quantum dot according to claim 1, wherein the step (2) further comprises providing a precursor solution B, mixing the precursor solution B with the II-III-V-VI nanocluster composite solution and the activating agent, and reacting to obtain the II-III-V-VI alloy quantum dot;

9. The method for preparing the II-III-V-VI alloy quantum dots according to any one of claims 1 to 8, further comprising the following steps after the step (2):

10. An optoelectronic device comprising the II-III-V-VI alloy quantum dot prepared by the preparation method of any one of claims 1 to 9.