Method for preparing double-emission-peak quantum dots through one-pot method and application of quantum dots

Abstract

The invention relates to a method for preparing double-emission-peak quantum dots through a one-pot method and application of the quantum dots, and relates to the technical field of nanometers.The method comprises the steps that a quantum dot element source, a ligand and a solvent are mixed to obtain a base solution; a first precursor solution is thermally injected into the base solution, then a second precursor solution is thermally injected, and the double-emission-peak quantum dots are obtained, wherein the ligand comprises a combination of at least two of carboxylic acid ligands, amine ligands or phosphonic acid ligands. According to the method provided by the invention, on the basis of a common thermal injection synthesis quantum dot raw material, the size difference of the synthesized quantum is controlled by adjusting the proportion of ligands with relatively large coordinate bond activity difference in the precursor, so that two kinds of quantum dots with relatively large size difference are grown in the one-pot quantum dots; the synthesized quantum dots are controllable in difference and high in material consistency, and are ideal optical materials which can be applied to the optical LED industry.

Description

Technical Field

[0001] The present invention relates to the field of nanotechnology, and specifically to a method for preparing dual-emission peak quantum dots by a one-pot process and uses of the quantum dots, and in particular to a method for preparing dual-emission peak quantum dots by a one-pot process based on a hot injection method and uses of the obtained dual-emission peak quantum dots. Background Art

[0002] At present, the synthesis of quantum dots can usually only produce quantum dots of a single color. This is because there are "focusing of size distribution" and "defocusing of size distribution" phenomena during the growth process of quantum dots, which results in the final quantum dots being normally distributed at a certain size. This is the growth characteristic of quantum dot synthesis. Therefore, achieving the simultaneous growth of two quantum dots in the same reaction system and controlling the size difference is a technical problem that needs to be solved urgently.

[0003] To obtain quantum dots with two wavelengths in one batch, the existing technology (Ching-Che Hung, Shih-Jung Ho, Chang-Wei Yeh, The Journal of Physical Chemistry C 2017 121(51), 28373-28384) uses the method of increasing the monomer concentration before the "distribution" occurs to break through the chemical potential well, allowing smaller crystal nuclei to grow, thereby obtaining quantum dots with two peaks. However, the time before the quantum dot "distribution" occurs is extremely short, difficult to control, and difficult to operate in practice.

[0004] For example, CN115703968A discloses that quantum dots with double emission peaks can be obtained by using highly active precursors and adjusting the ratio of anionic precursors to cationic precursors. However, the required raw materials need to be specially prepared and are dangerous, which is not conducive to promotion.

[0005] In summary, there is an urgent need for a method for preparing dual-emission peak quantum dots to achieve efficient preparation of dual-emission peak quantum dots. Summary of the Invention

[0006] In view of the problems existing in the prior art, the purpose of the present invention is to provide a one-pot method for preparing dual-emission peak quantum dots and the use of quantum dots, so as to solve the defects of the current dual-peak quantum dot preparation process being complex and having low preparation efficiency.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a one-pot method for preparing dual-emission quantum dots, the method comprising:

[0009] Mixing a quantum dot element source, a ligand, and a solvent to obtain a base liquid;

[0010] Hot-injecting a first precursor liquid into the base liquid, and then hot-injecting a second precursor liquid into the base liquid to obtain dual-emission peak quantum dots;

[0011] Wherein, the ligand includes: a combination of at least two of a carboxylic acid ligand, an amine ligand or a phosphonic acid ligand.

[0012] The method provided by the present invention is based on common hot injection synthesis of quantum dot raw materials. By adjusting the proportion of ligands with large differences in coordination bond activity in the precursor, the differences in the synthesized quantum dot sizes are controlled, and then two quantum dots with large size differences are grown in one pot of quantum dots. The differences in the synthesized quantum dots are controllable and the material consistency is high. It is an ideal optical material that can be applied to the optical LED industry.

[0013] As a preferred technical solution of the present invention, the carboxylic acid ligand includes: one or a combination of at least two of oleic acid, stearic acid, lauric acid or myristic acid.

[0014] Preferably, the amine ligand includes: one or a combination of at least two of oleylamine, dodecylamine, hexadecylamine or octadecylamine.

[0015] Preferably, the phosphonic acid ligand includes: one or a combination of at least two of tetradecylphosphonic acid, octadecylphosphonic acid or diphenylphosphonic acid.

[0016] As a preferred technical solution of the present invention, the ligand includes: a combination of a carboxylic acid ligand and a phosphonic acid ligand.

[0017] Preferably, the molar ratio of the carboxylic acid ligand to the phosphonic acid ligand in the ligand is (0.1-22):1.

[0018] Preferably, the ligand comprises a combination of a carboxylic acid ligand and an amine ligand.

[0019] Preferably, the molar ratio of the carboxylic acid ligand to the amine ligand in the ligand is 1:(0.5-10).

[0020] Preferably, the ligand comprises a combination of an amine ligand and a phosphonic acid ligand.

[0021] Preferably, the molar ratio of the amine ligand to the phosphonic acid ligand in the ligand is 1:(0.2-10).

[0022] As a preferred technical solution of the present invention, the ligand includes: a combination of oleic acid and tetradecylphosphonic acid.

[0023] Preferably, the molar ratio of oleic acid to tetradecylphosphonic acid in the ligand is (5-15):1.

[0024] Preferably, the molar ratio of oleic acid to tetradecylphosphonic acid in the ligand is (10-12):1.

[0025] As a preferred technical solution of the present invention, the quantum dot element source includes: one or a combination of at least two of a cadmium source, a zinc source, a selenium source or a sulfur source.

[0026] Preferably, the cadmium source comprises: cadmium oxide, cadmium acetate dihydrate or cadmium acetate, or a combination of at least two thereof.

[0027] Preferably, the zinc source comprises: one or a combination of at least two of zinc oxide, zinc acetate dihydrate, zinc acetate or zinc carbonate.

[0028] Preferably, the solvent comprises: one or a combination of at least two of octadecene, tri-n-octylamine or tri-n-octylphosphine oxide.

[0029] Preferably, the first precursor solution comprises: one or a combination of at least two of a cadmium precursor solution, a zinc precursor solution, a selenium precursor solution or a sulfur precursor solution.

[0030] Preferably, the second precursor solution comprises: one or a combination of at least two of a cadmium precursor solution, a zinc precursor solution, a selenium precursor solution or a sulfur precursor solution.

[0031] As a preferred technical solution of the present invention, the molar ratio of all metal cations to all ligands in the base liquid is 1:(2-10).

[0032] As a preferred technical solution of the present invention, the base liquid is deoxidized before being hot-injected into the first precursor liquid.

[0033] As a preferred technical solution of the present invention, the hot injection of the first precursor liquid includes: injecting the first precursor liquid and reacting it for 1-10 minutes when the base liquid temperature T1 is 240°C≤T1<the boiling point of the solvent.

[0034] As a preferred technical solution of the present invention, the hot injection of the second precursor liquid includes: controlling the temperature T2 of the material obtained by hot injection of the first precursor liquid to be 240°C≤T2<the boiling point of the solvent and injecting the second precursor liquid.

[0035] Preferably, the duration of injecting the second precursor solution is 10-30 minutes.

[0036] In a second aspect, the present invention provides a use of the dual-emission-peak quantum dots according to the method described in the first aspect, wherein the use includes: using the dual-emission-peak quantum dots for LED display and / or biological imaging.

[0037] Compared with the existing technical solutions, the present invention has the following beneficial effects:

[0038] (1) The present invention is based on the hot injection method, which selects ligands with large differences in coordination activity, thereby controlling the differences in the synthesized quantum size. The experimental process is simple and easy to operate.

[0039] (2) The present invention is suitable for synthesizing quantum dots by hot injection. During the synthesis process, the luminous intensity and wavelength of the quantum dots can be controlled by adjusting the synthesis parameters (such as ligand ratio and ligand combination), thereby achieving precise control of the LED light color, and has wide applicability.

[0040] (3) The present invention synthesizes bimodal quantum dots through a one-pot method, which can control quantum dots of different sizes and luminescence intensities in the same reaction process, reducing the synthesis time and complexity, making the production process simpler, and reducing the post-processing and mixing steps, thereby reducing the overall manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a spectrum of the dual-emission peak quantum dots obtained in Example 1 of the present invention;

[0042] Figure 2 This is a spectrum of the dual-emission quantum dots obtained in Example 2 of the present invention;

[0043] Figure 3 This is a spectrum of the dual-emission quantum dots obtained in Example 3 of the present invention;

[0044] Figure 4 This is a spectrum of the dual-emission quantum dots obtained in Example 4 of the present invention;

[0045] Figure 5 This is a spectrum diagram of the dual-emission peak quantum dots obtained in Example 5 of the present invention.

[0046] The present invention is further described in detail below. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims. DETAILED DESCRIPTION

[0047] To better illustrate the present invention and facilitate understanding of the technical solutions of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0048] Although the preparation of dual-emission quantum dots can be achieved at present, the preparation process is difficult to control the timing or requires the use of specific substances as precursors to ensure the preparation of quantum dots, which is not conducive to the preparation of dual-emission quantum dots. Based on this, the present invention provides a hot injection method that selects ligands with large differences in coordination activity for use to achieve efficient preparation of dual-emission quantum dots, as follows:

[0049] This embodiment provides a one-pot method for preparing dual-emission quantum dots, the method comprising:

[0050] Mixing a quantum dot element source, a ligand, and a solvent to obtain a base liquid;

[0051] The base liquid is hot-injected with a first precursor liquid, and then hot-injected with a second precursor liquid to obtain double-emission peak quantum dots.

[0052] Wherein, the quantum dot element source includes: one or a combination of at least two of a cadmium source, a zinc source, a selenium source or a sulfur source.

[0053] In the present invention, the base liquid is hot-injected with a first precursor liquid to obtain a double-peak quantum dot core, and then a second precursor liquid is injected to obtain a double-emission-peak quantum dot.

[0054] Illustratively, the combination of quantum dot element sources includes: a combination of a cadmium source and a zinc source, a combination of a zinc source and a selenium source, a combination of a selenium source and a sulfur source, a combination of a zinc source, a selenium source and a sulfur source, a combination of a cadmium source, a zinc source, a selenium source and a sulfur source, and the like.

[0055] Wherein, the cadmium source includes: one or a combination of at least two of cadmium oxide, cadmium acetate dihydrate or cadmium acetate.

[0056] For example, the combination of cadmium sources may be: a combination of cadmium oxide and cadmium acetate dihydrate, a combination of cadmium acetate dihydrate and cadmium acetate, a combination of cadmium oxide and cadmium acetate, and the like.

[0057] Wherein, the zinc source includes: one or a combination of at least two of zinc oxide, zinc acetate dihydrate, zinc acetate or zinc carbonate.

[0058] Illustratively, the combination of zinc sources includes: a combination of zinc oxide and zinc acetate dihydrate, a combination of zinc acetate and zinc carbonate, a combination of zinc acetate dihydrate, zinc acetate and zinc carbonate, and the like.

[0059] The solvent comprises: one or a combination of at least two of octadecene, tri-n-octylamine or tri-n-octylphosphine oxide.

[0060] Illustratively, the combination of solvents includes: a combination of octadecene and tri-n-octylamine, a combination of tri-n-octylamine and tri-n-octylphosphine oxide, a combination of octadecene, tri-n-octylamine and tri-n-octylphosphine oxide, and the like.

[0061] Wherein, the ligand includes: a combination of at least two of a carboxylic acid ligand, an amine ligand or a phosphonic acid ligand.

[0062] Illustratively, the combination of ligands includes: a combination of carboxylic acid ligands and amine ligands, a combination of amine ligands and phosphonic acid ligands, a combination of carboxylic acid ligands and phosphonic acid ligands, and the like.

[0063] In the present invention, when the ligands are selected as carboxylic acid ligands and amine ligands, the molar ratio of the carboxylic acid ligand to the amine ligand is 1:(0.5-10), for example, it can be 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10, etc., but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements, preferably 1:(2-4).

[0064] In the present invention, when the ligands are selected as amine ligands and phosphonic acid ligands, the molar ratio of the amine ligand to the phosphonic acid ligand is 1:(0.2-10), for example, it can be 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10, etc., but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements, and are preferably 1:(0.5-2).

[0065] Wherein, the carboxylic acid ligand includes: one or a combination of at least two of oleic acid, stearic acid, lauric acid or myristic acid.

[0066] Illustratively, the combination of carboxylic acid ligands includes: a combination of oleic acid and stearic acid, a combination of stearic acid and lauric acid, a combination of lauric acid and myristic acid, a combination of stearic acid, lauric acid and myristic acid, and the like.

[0067] The amine ligand includes one or a combination of at least two of oleylamine, dodecylamine, hexadecylamine or octadecylamine.

[0068] Illustratively, the combination of amine ligands includes: a combination of oleylamine and dodecylamine, a combination of dodecylamine and hexadecylamine, a combination of hexadecylamine and octadecylamine, a combination of oleylamine and octadecylamine, and the like.

[0069] The phosphonic acid ligand includes: one or a combination of at least two of tetradecylphosphonic acid (TDPA), octadecylphosphonic acid (ODPA) or diphenylphosphonic acid.

[0070] Among them, the combination of phosphonic acid ligands includes: a combination of tetradecylphosphonic acid (TDPA) and octadecylphosphonic acid (ODPA), a combination of octadecylphosphonic acid (ODPA) and diphenylphosphonic acid, a combination of tetradecylphosphonic acid (TDPA) and diphenylphosphonic acid, a combination of tetradecylphosphonic acid (TDPA), octadecylphosphonic acid (ODPA) and diphenylphosphonic acid, etc.

[0071] Wherein, the ligand comprises: a combination of a carboxylic acid ligand and a phosphonic acid ligand.

[0072] Wherein, the molar ratio of the carboxylic acid ligand to the phosphonic acid ligand in the ligand is (0.1-22):1, for example, it can be 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 21:1 or 22:1, etc., but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements.

[0073] Wherein, the ligand comprises: a combination of oleic acid and tetradecylphosphonic acid.

[0074] The molar ratio of oleic acid to tetradecylphosphonic acid in the ligand is (5-15):1, for example, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1 or 15:1, but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements.

[0075] The molar ratio of oleic acid to tetradecylphosphonic acid in the ligand is (10-12):1, for example, it can be 10:1, 10.2:1, 10.4:1, 10.6:1, 10.8:1, 11:1, 11.2:1, 11.4:1, 11.6:1, 11.8:1 or 12:1, etc., but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements.

[0076] The first precursor solution includes one or a combination of at least two of a cadmium precursor solution, a zinc precursor solution, a selenium precursor solution or a sulfur precursor solution.

[0077] For example, the combination of the first precursor solution may be selected as: a combination of a cadmium precursor solution and a zinc precursor solution, a combination of a zinc precursor solution and a selenium precursor solution, a combination of a selenium precursor solution and a sulfur precursor solution, and the like.

[0078] The second precursor solution includes one or a combination of at least two of a cadmium precursor solution, a zinc precursor solution, a selenium precursor solution or a sulfur precursor solution.

[0079] For example, the combination of the second precursor solution may be selected as: a combination of a cadmium precursor solution and a zinc precursor solution, a combination of a zinc precursor solution and a selenium precursor solution, a combination of a selenium precursor solution and a sulfur precursor solution, and the like.

[0080] In the present invention, the cadmium precursor solution can be selected from a solution of a cadmium source and a ligand, such as cadmium oxide and oleic acid, or cadmium oxide and oleylamine.

[0081] In the present invention, the zinc precursor solution can be selected as a solution of a zinc source and a ligand, such as a combination of zinc oxide and oleic acid, a combination of zinc oxide and oleylamine, or a combination of zinc acetate, oleic acid, and tetradecylphosphoric acid.

[0082] In the present invention, the selenium precursor solution can be selected as Se-ODE suspension, ODE refers to octadecene; Se-TBP precursor solution, TBP refers to tributyl phosphate; Se-TOP precursor solution, TOP refers to trioctyl phosphate; Se-DPP precursor solution, DPP refers to diphenylpyrazoline, etc.

[0083] In the present invention, the sulfur precursor solution can be selected as S-ODE suspension, ODE refers to octadecene; S-TBP precursor solution, TBP refers to tributyl phosphate; S-TOP precursor solution, TOP refers to trioctyl phosphate; S-DPP precursor solution, DPP refers to diphenylpyrazoline, etc.

[0084] The molar ratio of all metal cations to all ligands in the base liquid is 1:(2-10), which refers to the ratio of the molar amount of all metal cations to the molar amount of all ligands in the base liquid. For example, it can be 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10, but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements.

[0085] Wherein, the base liquid is deoxidized before being hot-injected into the first precursor liquid.

[0086] Among them, the hot injection of the first precursor liquid includes: injecting the first precursor liquid for reaction for 1-10 minutes when the base liquid temperature T1 is 240℃≤T1<solvent boiling point, for example, it can be 1min, 2min, 3min, 4min, 5min, 6min, 7min, 8min, 9min or 10min, etc., but is not limited to the listed values. Other values ​​not listed within the range also meet the requirements.

[0087] The hot injection of the second precursor liquid comprises: controlling the temperature T2 of the material obtained by hot injection of the first precursor liquid to be 240° C. ≤ T2 < the boiling point of the solvent and injecting the second precursor liquid at the same time.

[0088] Among them, the duration of injecting the second precursor liquid is 10-30 minutes, for example, it can be 10 minutes, 12 minutes, 14 minutes, 16 minutes, 18 minutes, 20 minutes, 22 minutes, 24 minutes, 26 minutes, 28 minutes or 30 minutes, but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements.

[0089] In the present invention, the second precursor solution may be injected by dropwise addition or continuous injection.

[0090] Furthermore, this embodiment provides uses of the dual-emission-peak quantum dots obtained by the aforementioned method, which include: using the dual-emission-peak quantum dots for LED display and / or biological imaging.

[0091] In the present invention, the prepared bimodal quantum dots include: CdZnSe / CdZnS bimodal quantum dots, CdZnSe / CdZnS bimodal quantum dots, CdSe / CdS bimodal quantum dots, CdSeS / CdS bimodal quantum dots, CdZnSeS / ZnS bimodal quantum dots, etc. During the preparation process, the amount and type of the quantum dot element source, solvent, first precursor liquid and second precursor liquid can be reasonably selected according to the requirements of the obtained quantum dots.

[0092] Further, in order to illustrate that the method for preparing dual-emission peak quantum dots provided by the present invention in one pot is a method for preparing dual-emission peak quantum dots, the following actual example is used for illustration, as follows:

[0093] Example 1

[0094] This embodiment provides a one-pot synthesis process for preparing controllable dual-emission quantum dots, as follows:

[0095] 1 mmol of cadmium oxide, 0.5 mmol of zinc oxide, 0.4 mmol of tetradecylphosphonic acid, 5.6 mmol of oleic acid, and 20 mL of octadecene were added to a three-necked flask, and the mixture was vacuumed at 140°C for 1 h to remove water and oxygen to obtain a base solution in which the molar ratio of all metal cations to all ligands was 1:4;

[0096] The base liquid was then heated to 300°C, and 0.6 mmol Se-ODE suspension was quickly injected to react for 1 min. Then, 2 mmol S-TOP and 1.5 mmol Cd-OA were added dropwise in a three-necked flask for 10 min to prepare CdZnSe / CdZnS dual-emission quantum dots.

[0097] The spectrum of the obtained CdZnSe / CdZnS dual emission peak quantum dots is shown in Figure 1 As shown by Figure 1 It can be seen that CdZnSe / CdZnS dual-emission quantum dots have two emission peaks.

[0098] Example 2

[0099] This embodiment provides a one-pot synthesis process for preparing controllable dual-emission quantum dots, as follows:

[0100] 1 mmol of cadmium oxide, 5 mmol of zinc oxide, 0.8 mmol of tetradecylphosphonic acid, 5.2 mmol of oleic acid, and 20 mL of octadecene were added to a three-necked flask, and the mixture was vacuumed at 140°C for 1 h to remove water and oxygen to obtain a base solution in which the molar ratio of all metal cations to all ligands was 1:4.

[0101] Then the base liquid was heated to 300℃, and 5mmol Se-ODE suspension was quickly injected to react for 10min. Then, 2mmol S-TOP and 1.5mmol Cd-OA were added dropwise in a three-necked flask at the same time and added dropwise for 10min to prepare CdZnSe / CdZnS dual-emission quantum dots. The spectrum is shown in the figure. Figure 2 shown.

[0102] Example 3

[0103] This embodiment provides a one-pot synthesis process for preparing controllable dual-emission quantum dots, as follows:

[0104] 6 mmol of cadmium oxide, 2 mmol of tetradecylphosphonic acid, 22 mmol of oleic acid, and 20 mL of octadecene were added to a three-necked flask, and the mixture was vacuumed at 140°C for 1 h to remove water and oxygen to obtain a base solution in which the molar ratio of all metal cations to all ligands was 1:4.

[0105] Then the base liquid was heated to 300℃, and 6mmol Se-ODE suspension was quickly injected to react for 1min. Then, 2mmol S-TOP and 2mmol Cd-OA were added dropwise to the three-necked flask at the same time and added dropwise for 10min to prepare CdSe / CdS dual emission peak quantum dots. The spectrum is shown in the figure below. Figure 3 shown.

[0106] Example 4

[0107] This embodiment provides a one-pot synthesis process for preparing controllable dual-emission quantum dots, as follows:

[0108] 1 mmol of cadmium oxide, 0.4 mmol of tetradecylphosphonic acid, 3.6 mmol of oleic acid, and 20 mL of octadecene were added to a three-necked flask, and the mixture was vacuumed at 140°C for 1 h to remove water and oxygen to obtain a base solution in which the molar ratio of all metal cations to all ligands was 1:4.

[0109] Then the base liquid was heated to 300℃, and 0.6mmol S / Se-ODE suspension was quickly injected to react for 1min. Then, 2mmol S-TOP and 2mmol Cd-OA were added dropwise to the three-necked flask at the same time and added dropwise for 10min to prepare CdSeS / CdS dual-emission quantum dots. The spectrum is shown in the figure below. Figure 4 shown.

[0110] Example 5

[0111] This embodiment provides a one-pot synthesis process for preparing controllable dual-emission quantum dots, as follows:

[0112] 1 mmol of cadmium oxide, 5 mmol of zinc oxide, 2 mmol of tetradecylphosphonic acid, 22 mmol of oleic acid, and 20 mL of octadecene were added to a three-necked flask, and the mixture was vacuumed at 140°C for 1 h to remove water and oxygen to obtain a base solution in which the molar ratio of all metal cations to all ligands was 1:4;

[0113] Then the base liquid was heated to 300℃, 4mmol S / Se-TOP was quickly injected and reacted for 1min. Then 2mmol S-TOP was added dropwise to the three-necked flask for 10min to prepare CdZnSeS / ZnS dual emission peak quantum dots. The spectrum is shown in the figure. Figure 5 shown.

[0114] Example 6

[0115] The only difference from Example 1 is that tetradecylphosphonic acid is replaced by an equimolar amount of octadecylphosphonic acid.

[0116] Example 7

[0117] The only difference from Example 1 is that the ligands are controlled to be equal amounts of octadecylamine and tetradecylphosphonic acid, with a molar ratio of 1:5.

[0118] Example 8

[0119] The only difference from Example 1 is that the control ligands are equal amounts of oleic acid and octadecylamine, with a molar ratio of 1:5.

[0120] Comparative Example 1

[0121] The only difference from Example 1 is that tetradecylphosphonic acid is replaced by an equimolar amount of oleic acid.

[0122] Comparative Example 2

[0123] The only difference from Example 1 is that oleic acid is replaced by an equimolar amount of tetradecylphosphonic acid.

[0124] Example 9

[0125] The only difference from Example 1 is that the molar ratio of all metal cations to all ligands in the base liquid is 1:15, which is achieved by increasing the amount of ligands.

[0126] Example 10

[0127] The only difference from Example 1 is that the molar ratio of oleic acid to tetradecylphosphonic acid is controlled to be 0.05:1.

[0128] Example 11

[0129] The only difference from Example 1 is that the molar ratio of oleic acid to tetradecylphosphonic acid is controlled to be 25:1.

[0130] Example 12

[0131] The only difference from Example 7 is that the molar ratio of octadecylamine to tetradecylphosphonic acid is controlled to be 6:1.

[0132] Example 13

[0133] The only difference from Example 7 is that the molar ratio of octadecylamine to tetradecylphosphonic acid is controlled to be 1:15.

[0134] Example 14

[0135] The only difference from Example 7 is that the molar ratio of oleic acid to octadecylamine is controlled to 3:1.

[0136] Example 15

[0137] The only difference from Example 7 is that the molar ratio of oleic acid to octadecylamine is controlled to be 1:15.

[0138] The relevant detection and analysis statistics of the quantum dots obtained in the above examples and comparative examples are detailed in Table 1 below.

[0139] Table 1

[0140]

[0141]

[0142] As can be seen from Table 1, the solution provided by the present invention is based on common hot injection synthesis of quantum dot raw materials. By adjusting the proportion of ligands with large differences in coordination bond activity in the precursor, the difference in the size of the synthesized quantum dots is controlled, and then two quantum dots with large size differences are grown in one pot of quantum dots. The differences in the synthesized quantum dots are controllable and the material consistency is high. It is an ideal optical material that can be applied to the optical LED industry.

[0143] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0144] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0145] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A one-pot method for preparing dual-emission quantum dots, characterized in that: The method comprises: Mixing a quantum dot element source, a ligand, and a solvent to obtain a base liquid; Hot-injecting a first precursor liquid into the base liquid, and then hot-injecting a second precursor liquid into the base liquid to obtain dual-emission peak quantum dots; Wherein, the ligand includes: a combination of at least two of a carboxylic acid ligand, an amine ligand or a phosphonic acid ligand.

2. The method according to claim 1, wherein The carboxylic acid ligand includes: one or a combination of at least two of oleic acid, stearic acid, lauric acid or myristic acid; Preferably, the amine ligand comprises: one or a combination of at least two of oleylamine, dodecylamine, hexadecylamine or octadecylamine; Preferably, the phosphonic acid ligand includes: one or a combination of at least two of tetradecylphosphonic acid, octadecylphosphonic acid or diphenylphosphonic acid.

3. The method according to claim 1 or 2, wherein: The ligand includes: a combination of a carboxylic acid ligand and a phosphonic acid ligand; Preferably, the molar ratio of the carboxylic acid ligand to the phosphonic acid ligand in the ligand is (0.1-22):1; Preferably, the ligand comprises: a combination of a carboxylic acid ligand and an amine ligand; Preferably, the molar ratio of the carboxylic acid ligand to the amine ligand in the ligand is 1:(0.5-10); Preferably, the ligand comprises: a combination of an amine ligand and a phosphonic acid ligand; Preferably, the molar ratio of the amine ligand to the phosphonic acid ligand in the ligand is 1:(0.2-10).

4. The method according to claim 3, wherein The ligand includes: a combination of oleic acid and tetradecylphosphonic acid; Preferably, the molar ratio of oleic acid to tetradecylphosphonic acid in the ligand is (5-15):1; Preferably, the molar ratio of oleic acid to tetradecylphosphonic acid in the ligand is (10-12):

1.

5. The method according to any one of claims 1 to 4, characterized in that The quantum dot element source includes: one or a combination of at least two of a cadmium source, a zinc source, a selenium source or a sulfur source; Preferably, the cadmium source comprises: one or a combination of at least two of cadmium oxide, cadmium acetate dihydrate or cadmium acetate; Preferably, the zinc source comprises: one or a combination of at least two of zinc oxide, zinc acetate dihydrate, zinc acetate or zinc carbonate; Preferably, the solvent comprises: one or a combination of at least two of octadecene, tri-n-octylamine or tri-n-octylphosphine oxide; Preferably, the first precursor solution comprises: one or a combination of at least two of a cadmium precursor solution, a zinc precursor solution, a selenium precursor solution or a sulfur precursor solution; Preferably, the second precursor solution comprises: one or a combination of at least two of a cadmium precursor solution, a zinc precursor solution, a selenium precursor solution or a sulfur precursor solution.

6. The method according to any one of claims 1 to 5, characterized in that The molar ratio of all metal cations to all ligands in the base liquid is 1:(2-10).

7. The method according to any one of claims 1 to 6, wherein: The base liquid is deoxidized before hot injection into the first precursor liquid.

8. The method according to any one of claims 1 to 7, wherein: The hot injection of the first precursor liquid includes: injecting the first precursor liquid and reacting it for 1-10 minutes when the base liquid temperature T1 is 240° C.≤T1<the boiling point of the solvent.

9. The method according to any one of claims 1 to 8, wherein The hot injection of the second precursor liquid comprises: controlling the temperature T2 of the material obtained by hot injection of the first precursor liquid to be 240° C. ≤ T2 < the boiling point of the solvent and injecting the second precursor liquid; Preferably, the duration of injecting the second precursor solution is 10-30 minutes.

10. Use of the dual-emission quantum dots obtained by the method according to any one of claims 1 to 9, characterized in that: The use includes: using the dual-emission peak quantum dots for LED display and / or biological imaging.

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