Alloy Quantum Dots and Preparation Method Thereof

Abstract

The present invention discloses alloy quantum dots and a preparation method thereof, relating to the technical field of nanomaterials. The preparation method of the alloy quantum dots includes: mixing a first cationic precursor and an anionic precursor for a reaction to form a stock solution containing clusters; mixing the stock solution and a second cationic precursor for a reaction to form quantum dots. By first controlling the formation of clusters and then preparing the quantum dots, the reaction rate of quantum dot generation can be reduced, making the reaction more controllable, and the sizes of the prepared alloy quantum dots more uniform, thereby improving the color purity, fluorescence quantum yield, stability, etc. of the quantum dots.

Description

Technical Field

[0001] The present invention relates to the technical field of nanomaterials, and particularly to alloy quantum dots and a preparation method thereof. Background Art

[0002] Quantum dot display materials are regarded as the most ideal luminescent materials in the 21st century. Quantum dot materials can be applied in the fields of display, lighting, battery, biology, etc. At present, a large number of quantum dot luminescent materials have been processed into display products and entered the market. The synthesis categories of quantum dot material systems are mainly aqueous phase and oil phase. Among them, the synthesis of quantum dots by the oil phase method mainly completes two main steps: nucleation by thermal injection and growth of the shell by the successive ionic layer adsorption and reaction method.

[0003] For quantum dots synthesized by the oil phase method, the preparation paths of different systems are different. For some systems, the luminescent quantum dots can be prepared by the conventional thermal injection nucleation and successive ionic layer growth of the shell. However, the quality of the quantum dot materials is not good, mainly reflected in several aspects such as poor color purity, low fluorescence quantum yield, and poor stability. There is still no particularly good technical solution to solve this kind of problem at present. Therefore, it has a certain restrictive effect on the subsequent related applications and product development.

[0004] In view of this, the present application is specifically proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation method of alloy quantum dots, aiming to improve the uniformity of the size of the prepared quantum dots, and further improve the color purity and stability of the quantum dot materials.

[0006] Another purpose of the present invention is to provide an alloy quantum dot, which has uniform size and good color purity and stability.

[0007] The present invention solves its technical problems by adopting the following technical solutions.

[0008] The present invention provides a preparation method of alloy quantum dots, including: mixing a first cationic precursor and an anionic precursor to react to form a stock solution containing clusters; mixing the stock solution and a second cationic precursor to react to form quantum dots.

[0009] The present invention also provides an alloy quantum dot, which is prepared by the above preparation method of alloy quantum dots.

[0010] The beneficial effects of the method for preparing alloy quantum dots provided by the embodiments of the present invention are as follows: First, a first cationic precursor and an anionic precursor are mixed and reacted to form a stock solution containing clusters, and then the stock solution and a second cationic precursor are mixed and reacted to form quantum dots. By first controlling the formation of clusters and then preparing quantum dots, the reaction rate of quantum dot generation can be reduced, making the reaction more controllable, and the sizes of the prepared alloy quantum dots more uniform, thereby improving the color purity, fluorescence quantum yield, and stability of the quantum dots, etc.

[0011] The inventors found that the poor color purity, low fluorescence quantum yield, and poor stability of the prepared alloy quantum dots are partly due to the large difference in the reaction activities of the cationic and anionic precursors during the preparation of quantum dots, resulting in problems such as poor size uniformity, many surface defects, and difficulty in control. However, the inventors have well controlled the reaction rate by first controlling the formation of clusters and then forming quantum dots, making the formation process of quantum dots more controllable. Specific embodiments

[0012] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Those not specified in the embodiments are carried out according to conventional conditions or conditions recommended by the manufacturer. Reagents or instruments not indicated by the manufacturer are all conventional products that can be obtained through commercial purchase.

[0013] The alloy quantum dots provided by the embodiments of the present invention and their preparation methods will be specifically described below.

[0014] The embodiments of the present invention provide a method for preparing alloy quantum dots, including: mixing a first cationic precursor and an anionic precursor and reacting them to form a stock solution containing clusters; mixing the stock solution and a second cationic precursor and reacting them to form quantum dots.

[0015] It should be noted that the inventors can reduce the reaction rate of quantum dot generation by first controlling the formation of clusters and then preparing quantum dots, making the reaction more controllable, and the sizes of the prepared alloy quantum dots more uniform, thereby improving the color purity, fluorescence quantum yield, and stability of the quantum dots, etc.

[0016] Specifically, the formation of clusters is carried out under conditions lower than the quantum dot formation temperature of the cation, and the specific reaction temperature can refer to the prior art.

[0017] S1. Preparation of the stock solution

[0018] The preparation process of the stock solution includes: after heating the first cation precursor solution to the first reaction temperature, injecting the anion precursor solution into the first cation precursor solution and reacting for 10 - 300 s, then cooling down; wherein, the temperature after heating the first cation precursor solution is lower than the temperature at which the first cation precursor generates quantum dots. By controlling the reaction temperature, the anion precursor solution is rapidly injected into the first cation precursor solution, and after the reaction is completed, it is cooled down to a suitable temperature.

[0019] Specifically, after the reaction is completed, it can be cooled down until the reaction no longer proceeds, and the suitable temperature range for cooling is 25°C - 300°C. The temperature range can be divided into 25°C - 50°C, 50°C - 90°C, 90°C - 120°C, 120°C - 150°C, 150°C - 180°C, 180°C - 220°C, 220°C - 250°C, 250°C - 280°C, 280°C - 300°C according to different reaction systems.

[0020] Specifically, the first cation precursor solution is prepared by dissolving the first cation precursor in an organic solvent, such as oleic acid (OA). The reaction time can be divided into 10 - 60 s, 60 - 120 s, 120 s - 300 s according to different reaction systems.

[0021] In a preferred embodiment, before injecting the anion precursor solution, the first cation precursor solution is subjected to a vacuum treatment to remove the oxygen in the solution, and the reaction is carried out under an anaerobic condition. More preferably, before injecting the anion precursor solution, the first cation precursor solution is first subjected to a first vacuum treatment, then the first cation precursor solution is heated up once and subjected to a second vacuum treatment, and then after introducing a protective gas, the first cation precursor solution is heated or cooled to the first reaction temperature and then exhausted. Through two vacuum treatments, an anaerobic and anhydrous state can be achieved to prevent side reactions. The temperature range of the vacuum treatment is 25 - 180°C.

[0022] Specifically, the temperature range for the vacuum treatment is from room temperature to the highest vacuum temperature, which can be divided into 25°C - 80°C, 25°C - 110°C, 25°C - 150°C, and 25°C - 180°C according to different reaction systems. The first reaction temperature is 90 - 350°C, which can be divided into 90°C - 110°C, 110°C - 150°C, 150°C - 200°C, 200°C - 250°C, 250°C - 300°C, and 300°C - 350°C according to different reaction systems. The reaction temperatures of different cation precursors are different, and the temperature for forming crystal clusters can be determined according to the prior art. Specifically, in the InZnP quantum dot system, the temperature range for the vacuum treatment is 25°C - 150°C, and the first reaction temperature is 110°C - 150°C; in the CdZnSe quantum dot system, the temperature range for the vacuum treatment is 25°C - 110°C, and the first reaction temperature is 150°C - 200°C.

[0023] The first cation precursor is selected from Zn(OA) 2 , Cd(OA) 2 , Pb(OA) 2 , In 2 (OA) 3 , Cu(OA) 2 , Ag 2 (OA) 2 , Hg(OA) 2 , Zn(MA) 2 , Cd(MA) 2 , Pb(MA) 2 , In 2 (MA) 3 , Cu(MA) 2 , Ag 2 (MA) 2 , Hg(MA) 2 , Zn(PA) 2 , Cd(PA) 2 , Pb(PA) 2 , In 2 (PA) 3 , Cu(PA) 2 , Ag 2 (PA) 2 , Hg(PA) 2 , Zn(LA) 2 , Cd(LA) 2 , Pb(LA) 2 , In 2 (LA) 3 , Cu(LA) 2 , Ag 2 (LA) 2 and Hg(LA) 2at least one of them; the anion precursor is selected from S-ODE, S-TOP, S-OA, Se-TOP, S-OLA, S-TBP, Se-TBP, Te-ODE, Te-OA, Te-TOP, Te-TBP, (TMS) 3 S, (TMS) 3 P and (TMS) 3 at least one of As; the molar ratio of the first cation precursor to the anion precursor is 1-10:1. According to different reaction systems, the molar ratio range of the first cation precursor to the anion precursor can be divided into 1-2, 1-4, 1-6, and 1-10 according to different reaction systems.

[0024] It should be added that the stock solution contains binary-phase clusters and the above-mentioned cation and anion precursors. The composition of the binary-phase clusters is the same as that of the binary-phase quantum dots. The binary-phase clusters are one of CdS, CdSe, CdTe, InP, AgS, PbS, PbSe, HgS, CuS, etc., not limited to this. The binary-phase clusters are atomic aggregates formed between single atoms and solids by the cation and anion precursors within a certain temperature range. This atomic aggregate will participate in the epitaxial growth of quantum dot nanocrystals; the rate of epitaxial crystallization of this atomic aggregate will be slower than that of separately using the cation and anion precursors.

[0025] S2, Quantum dot preparation

[0026] The process of mixing and reacting the stock solution and the second cation precursor includes: mixing the non-eutectic solvent and the second cation precursor and heating to the second reaction temperature to obtain a reaction mixture, then injecting the stock solution into the reaction mixture and reacting for 10 min - 30 min, and then cooling to a non-reacting temperature, such as 80 - 180 °C.

[0027] It should be added that after the reaction is completed, the ratio of residual clusters to quantum dots is 0-5:100, that is, the proportion of residual clusters is less than 5%, so as to obtain relatively pure quantum dots. According to different reaction systems, the ratio of residual clusters to quantum dots is 0-1:100, 1-3:100, and 3-5:100.

[0028] Specifically, the non-eutectic solvent refers to a solvent that does not dissolve two precursors simultaneously, and it is a commonly used reagent in the process of preparing quantum dots. The non-eutectic solvent is selected from at least one of octadecene, paraffin oil, and paraffin wax.

[0029] In a preferred embodiment, the volume ratio of the reaction mixture to the stock solution is 5-30:1, and the molar ratio of the second cation precursor to the first cation precursor is 0.1-4:1. By further controlling the dosage of raw materials, the quality of the obtained quantum dots, such as color purity and stability, is more ideal.

[0030] Specifically, the second cation precursor is selected from Zn(OA) 2 , Cd(OA) 2 , Pb(OA) 2 , In2(OA) 3 , Cu(OA) 2 , Ag2(OA) 2 , Hg(OA) 2 , Zn(MA) 2 , Cd(MA) 2 , Pb(MA) 2 , In 2 (MA) 3 , Cu(MA) 2 , Ag 2 (MA) 2 , Hg(MA) 2 , Zn(PA) 2 , Cd(PA) 2 , Pb(PA) 2 , In 2 (PA) 3 , Cu(PA) 2 , Ag 2 (PA) 2 , Hg(PA) 2 , Zn(LA) 2 , Cd(LA) 2 , Pb(LA) 2 , In 2 (LA) 3 , Cu(LA) 2 , Ag 2 (LA) 2 and at least one of Hg(LA) 2 ; Generally, the first cation precursor and the second cation precursor are selected differently.

[0031] The second reaction temperature is 110 - 350 °C, which can be divided into 110 °C - 150 °C, 150 °C - 180 °C, 180 °C - 210 °C, 210 °C - 250 °C, 250 °C - 300 °C, 300 °C - 350 °C according to different reaction systems. Preferably, during the preparation of the reaction mixture, before heating to the second reaction temperature, a third vacuum pumping treatment is carried out; the temperature of the third vacuum pumping treatment is 25 - 180 °C, and the second reaction temperature is raised from room temperature to the highest vacuum pumping temperature, and the highest vacuum pumping temperature can be divided into 25 °C - 80 °C, 25 °C - 110 °C, 25 °C - 150 °C, 25 °C - 180 °C according to different reaction systems.

[0032] S3. Separation of quantum dots

[0033] After the reaction between the stock solution and the reaction mixture is completed, the alloy quantum dots are separated. There are no specific restrictions on the method for separating the quantum dots, and existing separation methods can be used.

[0034] To further improve the separation effect, the inventor further improved the separation method. The process of separating the alloy quantum dots includes: first, mixing and stirring the reaction mixture with an organic reagent, and then performing centrifugal separation using a non-polar reagent and a polar reagent. By mixing the reaction mixture with the organic reagent, the freezing point of the reaction mixture can be reduced. This is mainly achieved by chemically coordinating the organic reagent with the unreacted cation precursors and incompletely reacted clusters in the reaction mixture to increase the solubility of the unreacted cation precursors and incompletely reacted clusters.

[0035] Specifically, the organic reagent is selected from at least one of trioctylphosphine, tributylphosphine, trioctylamine, oleylamine, and oleic acid; the volume ratio of the reaction mixture to the organic reagent is 4 - 20:1; the mixing and stirring time of the reaction mixture and the organic reagent is 5 - 60 min. By further controlling the selection, dosage, and mixing time of the organic reagent, the solubility of the cation precursors and incompletely reacted clusters is further increased, improving the separation effect.

[0036] Furthermore, the polar reagent is selected from at least one of ethanol, methanol, butanol, and isopropanol; the non-polar reagent is selected from at least one of toluene, chloroform, n-hexane, and n-heptane; the volume ratio of the non-polar reagent to the reaction mixture is 1 - 5:10; the volume ratio of the polar reagent to the reaction mixture is 5 - 15:10. By further controlling the selection and dosage of the polar reagent and non-polar reagent, the separation efficiency is further improved, enabling more complete separation of the quantum dots.

[0037] The embodiment of the present invention also provides an alloy quantum dot, which is prepared by the above-mentioned preparation method of the alloy quantum dot. This alloy quantum dot is a quantum core and can be further reacted subsequently to form a core-shell structured quantum dot.

[0038] The features and properties of the present invention will be further described in detail below in conjunction with embodiments.

[0039] Example 1

[0040] This example provides a method for preparing an alloy quantum dot, including the following steps:

[0041] (1) Preparation of indium oleate / In 2 (OA) 3 Take 1 mmol of InCl 33 mL of oleic acid (OA) was added to a 50 mL three-necked flask. First, vacuum treatment was carried out at low temperature for 10 min, and then the mixed solution was heated to 110 °C and vacuumed for 2 h. After the vacuuming was completed, it was then changed to normal pressure and protected by nitrogen gas, and the solution was heated to 120 °C to exhaust gas for 30 min and kept warm for standby.

[0042] (2) Preparation of InP nanoclusters: 0.3 mmol of (TMS) 3 P was evenly dispersed in 1 mL of octadecene. The phosphorus source was quickly injected into the above (1) using a syringe and reacted for 2 min, and then cooled to room temperature to obtain a liquid containing InP nanoclusters for standby.

[0043] (3) Preparation of alloy InZnP quantum dots: 10 mL of octadecene and 0.5 mmol of zinc oleate were added to another 50 mL three-necked flask for low-temperature vacuum treatment, then changed to exhaust gas treatment and heated to 280 °C. Then, the mixed solution containing InP nanoclusters was quickly injected into the high-temperature octadecene (ODE) containing zinc oleate and reacted for 20 min to obtain alloy InZnP quantum dots. Subsequently, the temperature was cooled to 160 °C, 2 mL of trioctylphosphine reagent was added, stirred for 20 min, and then the heating was stopped to cool the solution to room temperature.

[0044] (4) Cleaning of InZnP quantum dots: 3 mL of toluene reagent and 15 mL of ethanol reagent were added to the above (3) to make the solution form a turbid liquid, and then the mixed solution was centrifuged by centrifugation to obtain the required InZnP quantum dots.

[0045] Example 2

[0046] This example provides a method for preparing alloy quantum dots, including the following steps:

[0047] (1) Preparation of cadmium oleate / Cd(OA) 2 : 1 mmol of CdO and 3 mL of oleic acid (OA) were added to a 50 mL three-necked flask. First, vacuum treatment was carried out at low temperature for 10 min, and then the mixed solution was heated to 110 °C and vacuumed for 2 h. After the vacuuming was completed, it was then changed to normal pressure and protected by nitrogen gas, and the solution was heated to 180 °C to exhaust gas for 30 min and kept warm for standby.

[0048] (2) Preparation of CdSe nanoclusters: 0.3 mmol of Se-TOP was evenly dispersed in 1 mL of octadecene. The selenium source was quickly injected into the above (1) using a syringe and reacted for 5 min, and then cooled to room temperature to obtain a mixed solution containing CdSe nanoclusters for standby.

[0049] (3) Preparation of alloy CdZnSe quantum dots: Take 10 mL of octadecene and 0.5 mmol of zinc oleate and add them to another 50 mL three-necked flask. After low-temperature vacuum pumping, switch to exhaust treatment and heat up to 300 °C. Then, quickly inject the mixed solution containing CdSe clusters into high-temperature octadecene (ODE) and react for 20 min to obtain alloy CdZnSe quantum dots. Subsequently, cool the temperature to 160 °C, add 2 mL of trioctylphosphine reagent, stir for 20 min, and then stop heating to let the solution cool to room temperature.

[0050] (4) Cleaning of CdZnSe quantum dots: Add 3 mL of toluene reagent and 15 mL of ethanol reagent to the above (3) to make the solution form a turbid liquid, and then use centrifugation to centrifuge the mixed solution to obtain the required CdZnSe quantum dots.

[0051] Comparative Example 1

[0052] This comparative example provides a method for preparing alloy quantum dots. The same raw materials of cationic and anionic precursors are used as in Example 1, but traditional steps are used to directly form quantum dots. The specific steps are as follows:

[0053] Synthesize CdZnSe quantum dots by high-temperature thermal injection method; use CdO and ZnO as raw materials, with ZnO in excess; add 0.5 mmol of CdO and 5 mmol of ZnO to a three-necked flask, then add 4 ml of oleic acid and 6 ml of octadecene, heat up to 130 °C within 20 min, and the system is accompanied by vacuum pumping during the heating process. Then, continue to pump vacuum at 130 °C for 30 min. Subsequently, when heating up to 300 °C in an inert gas environment, inject 1 mmol of Se-ODE dispersion liquid, keep warm for 10 min, and then end the reaction to obtain CdZnSe quantum dots.

[0054] Comparative Example 2

[0055] This comparative example provides a method for preparing alloy quantum dots. The difference from Example 1 is only that: in step (1), the mixed solution is heated to 250 °C and vacuum pumped for 2 h.

[0056] Comparative Example 3

[0057] This comparative example provides a method for preparing alloy quantum dots. The difference from Example 1 is only that: in step (1), the mixed solution is heated to 90 °C and vacuum pumped for 2 h.

[0058] Test Example 1

[0059] Test the fluorescence wavelength, full width at half maximum, and quantum dot yield of the quantum dots prepared in Examples 1-2 and Comparative Examples 1-3. The results are shown in Table 1.

[0060] Table 1 Performance test results of alloy quantum dots

[0061]

[0062] As can be seen from the above table, the present invention provides a method for preparing alloy quantum dots. Compared with the traditional preparation method, both the full width at half maximum and the quantum dot yield are improved. In addition, the change of the reaction temperature in step 1 has a great influence on the size of the clusters and alloy quantum dots. A higher reaction temperature will lead to overreaction, and the proportion of clusters in the cluster-quantum dot system is too low, while a lower reaction temperature will lead to incomplete reaction, and the proportion of clusters in the cluster-quantum dot system is too high. Whether the proportion of clusters is too high or too low, it will destroy the uniformity of the quantum dot size, and the quantum dot yield will also decrease.

[0063] In summary, the method for preparing alloy quantum dots provided by the present invention first forms a stock solution containing clusters by mixing a first cationic precursor and an anionic precursor, and then mixes the stock solution with a second cationic precursor to form quantum dots. By first controlling the formation of clusters and then preparing quantum dots, the reaction rate of quantum dot generation can be reduced, making the reaction more controllable, and the size of the prepared alloy quantum dots more uniform, thereby improving the color purity, fluorescence quantum yield, stability, etc. of the quantum dots.

[0064] The embodiments described above are some, but not all, of the embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of the present invention.

Claims

1. A method for preparing alloy quantum dots, characterized in that, comprising: Mixing a first cationic precursor and an anionic precursor to react to form a stock solution containing clusters; Mixing the stock solution and a second cationic precursor to react to form quantum dots; The preparation process of the stock solution includes: after heating the first cationic precursor solution to a first reaction temperature, injecting the anionic precursor solution into the first cationic precursor solution and reacting for 10 - 300 s, and then cooling down; wherein, the temperature after heating the first cationic precursor solution is lower than the temperature at which the first cationic precursor forms quantum dots; The process of mixing and reacting the stock solution and the second cationic precursor includes: mixing a non - eutectic solvent and the second cationic precursor and heating to a second reaction temperature to obtain a reaction mixture, then injecting the stock solution into the reaction mixture and reacting for 10 min - 30 min, and then cooling down; The first reaction temperature is 90 - 350 °C; The second reaction temperature is 110 - 350 °C, and after the reaction is completed, it is cooled down to 80 - 180 °C; The first cation precursor is selected from Zn(OA) 2 , Cd(OA) 2 , Pb(OA) 2 , In 2 (OA) 3 , Cu(OA) 2 , Ag 2 (OA) 2 , Hg(OA) 2 , Zn(MA) 2 , Cd(MA) 2 , Pb(MA) 2 , In 2 (MA) 3 , Cu(MA) 2 , Ag 2 (MA) 2 , Hg(MA) 2 , Zn(PA) 2 , Cd(PA) 2 , Pb(PA) 2 , In 2 (PA) 3 , Cu(PA) 2 , Ag 2 (PA) 2 , Hg(PA) 2 , Zn(LA) 2 , Cd(LA) 2 , Pb(LA) 2 , In 2 (LA) 3 , Cu(LA) 2 , Ag 2 (LA) 2 and at least one of Hg(LA) 2 ; The anion precursor is selected from at least one of S-ODE, S-TOP, S-OA, Se-TOP, S-OLA, S-TBP, Se-TBP, Te-ODE, Te-OA, Te-TOP, Te-TBP, (TMS) 3 S, (TMS) 3 P and (TMS) 3 As; the molar ratio of the first cation precursor to the anion precursor is 1-10:1; The second cation precursor is selected from Zn(OA) 2 , Cd(OA) 2 , Pb(OA) 2 , In2(OA) 3 , Cu(OA) 2 , Ag2(OA) 2 , Hg(OA) 2 , Zn(MA) 2 , Cd(MA) 2 , Pb(MA) 2 , In 2 (MA) 3 , Cu(MA) 2 , Ag 2 (MA) 2 , Hg(MA) 2 , Zn(PA) 2 , Cd(PA) 2 , Pb(PA) 2 , In 2 (PA) 3 , Cu(PA) 2 , Ag 2 (PA) 2 , Hg(PA) 2 , Zn(LA) 2 , Cd(LA) 2 , Pb(LA) 2 , In 2 (LA) 3 , Cu(LA) 2 , Ag 2 (LA) 2 and at least one of Hg(LA) 2 ; The cation species in the first cationic precursor and the second cationic precursor are different; The non - eutectic solvent is selected from at least one of octadecene, paraffin oil, and liquid paraffin.

2. The method for preparing alloy quantum dots according to claim 1, characterized in that, Before injecting the anionic precursor solution, the first cationic precursor solution is subjected to a vacuum treatment.

3. The method for preparing alloy quantum dots according to claim 2, characterized in that, Before injecting the anionic precursor solution, first subject the first cationic precursor solution to a first vacuum treatment, then heat the first cationic precursor solution once and perform a second vacuum treatment, then introduce a protective gas and heat or cool the first cationic precursor solution to the first reaction temperature and then exhaust.

4. The method for preparing alloy quantum dots according to claim 1, characterized in that, The volume ratio of the reaction mixture to the stock solution is 5 - 30:

1.

5. The method for preparing alloy quantum dots according to claim 3, characterized in that, During the preparation process of the reaction mixture, before heating to the second reaction temperature, a third vacuum treatment is performed.

6. The method for preparing alloy quantum dots according to claim 5, characterized in that, The temperature of the third vacuum treatment is 25 - 180 °C.

7. The method for preparing alloy quantum dots according to claim 4, characterized in that, After the reaction between the stock solution and the reaction mixture is completed, the ratio of residual clusters to quantum dots is 0 - 5:

100.

8. The method for preparing alloy quantum dots according to claim 1, characterized in that, The molar ratio of the second cationic precursor to the first cationic precursor is 0.1 - 4:

1.

9. The method for preparing alloy quantum dots according to claim 1, characterized in that, After the reaction between the stock solution and the reaction mixture is completed, the alloy quantum dots are separated.

10. The method for preparing alloy quantum dots according to claim 9, characterized in that, The process of separating the alloy quantum dots includes: first, mixing and stirring the reaction mixture with an organic reagent, and then performing centrifugal separation using a non-polar reagent and a polar reagent; wherein, the organic reagent is selected from at least one of trioctylphosphine, tributylphosphine, trioctylamine, oleylamine, and oleic acid.

11. The method for preparing alloy quantum dots according to claim 10, characterized in that the volume ratio of the reaction mixture to the organic reagent is 4 - 20:

1.

12. The method for preparing alloy quantum dots according to claim 10, characterized in that the mixing and stirring time of the reaction mixture and the organic reagent is 5 - 60 min.

13. The method for preparing alloy quantum dots according to claim 10, characterized in that the polar reagent is selected from at least one of ethanol, methanol, butanol, and isopropanol.

14. The method for preparing alloy quantum dots according to claim 10, characterized in that the non-polar reagent is selected from at least one of toluene, chloroform, n-hexane, and n-heptane.

15. The method for preparing alloy quantum dots according to claim 14, characterized in that the volume ratio of the non-polar reagent to the reaction mixture is 1 - 5:

10.

16. The method for preparing alloy quantum dots according to claim 15, characterized in that the volume ratio of the polar reagent to the reaction mixture is 5 - 15:10.

Images