Method for preparing high-performance colloid halide perovskite quantum dots by using heterogeneous inorganic ligand exchange strategy

Abstract

The invention provides a method for preparing a high-performance colloid halide perovskite quantum dot by using a heterogeneous inorganic ligand exchange strategy, and belongs to the technical field of photoelectric display, and the method specifically comprises the following steps: synthesizing a CsPbX3 quantum dot solution with an organic ligand in a halogen-rich environment, purifying the CsPbX3 quantum dot solution to be subjected to ligand exchange to obtain a CsPbX3 quantum dot solution to be subjected to ligand exchange, and preparing the high-performance colloid halide perovskite quantum dot by using a heterogeneous inorganic ligand exchange strategy. A CsPbX3 quantum dot solution to be subjected to ligand exchange is injected into excessive inorganic ligands, and a colloidal solution of the high-performance halide perovskite quantum dots is obtained through stirring and filtering. According to the invention, strong bonding capability between halogen dangling bonds of CsPbX3 quantum dots synthesized in a halogen-rich environment and inorganic ligands is utilized, so that the solubility of the inorganic ligands in a perovskite quantum dot solution is improved, the surfaces of the perovskite quantum dots are stabilized, controllable solid-liquid two-phase ligand exchange in a non-polar solvent is realized, and the performance of the perovskite quantum dots is improved. Damage to the perovskite quantum dots due to introduction of a polar solvent is avoided, the controllability of the ligand exchange process is higher, and the fluorescence quantum yield and stability of the perovskite quantum dots are further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of optoelectronic display, and in particular relates to a method for preparing high-performance colloidal halide perovskite quantum dots by utilizing a heterogeneous inorganic ligand exchange strategy. Background Art

[0002] With the development of technology, quantum dot display technology has received widespread attention in the field of optoelectronic display. Compared with traditional semiconductor quantum dots, lead halide perovskite quantum dots have excellent optical properties such as narrow half-width (<20nm) and wide color gamut (~140% NTSC). At the same time, the preparation conditions are simple and the cost is low. It is an ideal material for preparing new display devices.

[0003] The intrinsic luminescence peak of metal bromide perovskites represented by CsPbBr3 is located near 520nm, which is an ideal luminescent material for green LEDs. However, lead halide perovskites prepared based on conventional methods cannot achieve blue and red light emission. The luminescence spectrum can be tuned by temperature control. The molecular movement rate of synthesized blue perovskites at room temperature is slow at low temperatures, resulting in incomplete crystal growth or defects. These defects may affect the optical properties and stability of perovskite quantum dots. The ratio of ligands (oleic acid and oleylamine) commonly used in synthesis will also affect the size of quantum dots. Too high a ratio of oleic acid will reduce the size of quantum dots, while oleylamine will cause perovskites to form a lamellar structure. However, changes in the ligand ratio will also cause the formation of defects on the surface of perovskites, inhibiting photoelectric properties and reducing stability.

[0004] The researchers pointed out in the literature (Zhang, X., et al., Stable Perovskite Quantum Dots Light-Emitting Diodes with Efficiency Exceeding 24%. Advanced Science, 2023.10(36)) that the ligands commonly used to synthesize perovskite quantum dots are long-chain organic ligands oleic acid (OA) and oleylamine (OAm), but these long-chain ligands are easily lost during purification, film formation or device preparation, and new defect states are generated. At the same time, excess OA and OAm will promote the formation of undesirable clusters, resulting in uneven nucleation.

[0005] In response to the problems with organic ligands, the technology of synthesizing perovskite quantum dots using inorganic ligands has emerged. Researchers mentioned in the literature (Guo, J., et al., High Efficiency and Low Roll-Off Pure-Red Perovskite LED Enabled by Simultaneously Inhibiting Auger and Trap Recombination of Quantum Dots. Nano Letters, 2024. 24 (21): p. 6410-6416.) that the high electric dipole moment of inorganic ligands can affect the charge distribution to reduce the exciton binding energy, inhibit Auger recombination, and passivate the defects of perovskite quantum dots, thereby improving the photoelectric performance. Since inorganic ligands such as potassium bromide are easily soluble in highly polar solvents such as ethanol and N, N-dimethylformamide (DMF), they are often used in ligand exchange engineering of group II-VI and group III-V quantum dots. However, for ionic halide perovskite quantum dots, highly polar solvents such as ethanol and DMF can easily cause phase transition or even structural degradation of metal halide perovskite quantum dots, resulting in reduced yield, poor optical properties and stability. Although medium-polar solvents such as ethyl acetate have reduced destructiveness, perovskite quantum dots cannot be well dispersed in them, thereby reducing the passivation effect of inorganic ligands. Summary of the invention

[0006] In response to the above-mentioned problems of inorganic ligands in high-polarity solvents and medium-polarity solvents, the present invention provides a method for preparing high-performance colloidal halide perovskite quantum dots using a heterogeneous inorganic ligand exchange strategy, which utilizes the more abundant halogen dangling bonds on the surface of CsPbX3 perovskite quantum dots synthesized in a halogen-rich environment to enhance the binding ability of perovskite quantum dots and inorganic ligands, thereby enhancing the solubility of inorganic ligands in perovskite quantum dot solutions (based on non-polar solvents). There is no need to dissolve the inorganic ligands in polar solvents in advance, thereby avoiding the introduction of polar solvents and damaging the perovskite quantum dots.

[0007] In order to achieve the above purpose, the technical method adopted by the present invention is as follows:

[0008] A method for preparing high-performance colloidal halide perovskite quantum dots using a heterogeneous inorganic ligand exchange strategy comprises the following steps:

[0009] Step 1, synthesizing a CsPbX3 quantum dot solution with an organic ligand in a halogen-rich environment, specifically using a variety of halogen raw materials to form a halogen-rich environment during the synthesis process, and synthesizing the CsPbX3 quantum dot solution after a purification step; wherein X is Br or I element;

[0010] Step 2, secondary purification of the CsPbX3 quantum dot solution with organic ligands to remove excess organic ligands to obtain a CsPbX3 quantum dot solution to be exchanged with ligands;

[0011] Step 3: Inject the CsPbX3 quantum dot solution to be ligand exchanged into an excess of inorganic ligand, stir, and then filter to obtain a high-performance CsPbX3 quantum dot colloidal solution.

[0012] Furthermore, the specific synthesis process of step 1 is:

[0013] Step 1.1, adding cesium carbonate to octadecene and oleic acid, stirring to obtain a first precursor solution;

[0014] Step 1.2, adding halogen raw materials PbX2 and ZnX2 to octadecene, stirring to obtain a second precursor solution;

[0015] When X is Br element, the molar ratio of PbX2 to ZnX2 is 1:8;

[0016] When X is element I, the molar ratio of PbX2 to ZnX2 is 1:3;

[0017] Step 1.3, under vacuum conditions, the first precursor solution and the second precursor solution are respectively heated stepwise until the first precursor solution is heated to 100° C. and kept warm, and the second precursor solution is heated to 120° C. and kept warm, and the nitrogen ventilation operation is repeated several times, and then nitrogen is filled for standby use;

[0018] Step 1.4, injecting organic ligand oleic acid and oleylamine into the second precursor solution at 120° C., and stirring to obtain a reaction solution;

[0019] Step 1.5, quickly injecting the first precursor solution into the reaction solution, immediately taking it out and stirring and cooling it to 40° C. in an ice water bath to obtain a crude perovskite quantum dot solution;

[0020] When X is element I, the reaction solution is first heated to 165°C, and then the first precursor solution is quickly injected;

[0021] Step 1.6, add antisolvent to the crude perovskite quantum dot solution, retain the supernatant after centrifugation, add antisolvent again, remove the supernatant, disperse the resulting precipitate with a non-polar solvent, retain the supernatant after centrifugation as the CsPbX3 quantum dot solution with organic ligands.

[0022] Furthermore, the specific process of step 2 is:

[0023] The CsPbX3 quantum dot solution with organic ligands is centrifuged, the supernatant is retained, an anti-solvent is added, and the solution is centrifuged again to remove the supernatant. The resulting precipitate is dispersed with a non-polar solvent, and the supernatant is retained after centrifugation as the CsPbX3 quantum dot solution to be exchanged with the ligand.

[0024] Furthermore, the anti-solvent is methyl acetate or ethyl acetate.

[0025] Furthermore, in step 3, the inorganic ligand is KX, NaX or RbX.

[0026] Furthermore, the non-polar solvent is n-octane or n-hexane.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The method proposed in the present invention for preparing high-performance colloidal halide perovskite quantum dots using a heterogeneous inorganic ligand exchange strategy is to first synthesize CsPbX3 perovskite quantum dots with more abundant halogen dangling bonds on the surface in a halogen-rich environment, and then utilize the strong bonding ability between halogen dangling bonds and inorganic ligands to improve the solubility of inorganic ligands in perovskite quantum dot solutions (based on non-polar solvents), thereby more accurately introducing inorganic ligands and stabilizing the surface of perovskite quantum dots, and realizing controllable solid-liquid two-phase ligand exchange in non-polar solvents;

[0029] 2. Compared with the traditional method of first dissolving the inorganic ligand in a polar solvent and then performing liquid-phase ligand exchange with the perovskite quantum dot solution, the present invention does not need to dissolve the inorganic ligand in a polar solvent in advance, but directly performs solid-liquid two-phase ligand exchange with the perovskite quantum dot solution in the form of a solid phase, thereby avoiding damage to the perovskite quantum dots caused by the introduction of polar solvents. At the same time, the ligand exchange process is more controllable, further improving the fluorescence quantum yield and stability of the perovskite quantum dots. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 The following are actual photos of the CsPbBr3 blue light quantum dot solutions synthesized in Example 1 and Comparative Example 1 under ultraviolet light;

[0032] Figure 2 The fluorescence spectra of CsPbBr3 blue light quantum dots synthesized in Example 1 and Comparative Example 1 are shown;

[0033] Figure 3 TEM images of Example 1 and Example 2; wherein (a) is the CsPbBr3 blue light quantum dots synthesized in Example 1, and (b) is the CsPbI3 red light quantum dots synthesized in Example 2;

[0034] Figure 4 The fluorescence spectrum and photoluminescence quantum yield of CsPbBr3 blue light quantum dots synthesized in Example 1;

[0035] Figure 5 The fluorescence spectrum and photoluminescence quantum yield of the CsPbI3 red light quantum dots synthesized in Example 2. DETAILED DESCRIPTION

[0036] In order to further understand the present invention, the preferred embodiments of the present invention are described below in conjunction with the examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the invention. All raw materials of the present invention are not particularly limited in their sources, and can be purchased on the market or prepared according to conventional methods well known to those skilled in the art.

[0037] Example 1

[0038] This embodiment provides a method for preparing high-performance colloidal halide perovskite quantum dots using a heterogeneous inorganic ligand exchange strategy, specifically synthesizing CsPbBr3 blue light quantum dots, comprising the following steps:

[0039] Step 1, add 10 ml of octadecene and 0.7 ml of oleic acid into a three-necked flask, weigh 100 mg of cesium carbonate and add it into the flask, put it into a heating mantle, start magnetic stirring at a speed of 300 r / min, and obtain a first precursor solution;

[0040] Step 2, add 10 ml of octadecene to a three-necked flask, and add 138 mg of lead bromide and 677 mg of zinc bromide to the flask, put it in a heating mantle, and start magnetic stirring at a speed of 400 r / min to obtain a second precursor solution;

[0041] Step 3, turn on the vacuum pump, select vacuum on the Schleck device, and perform step-wise heating of the first precursor solution and the second precursor solution for 10 minutes at the same time. The temperature of the heating jacket where the three-necked flask of the first precursor solution is located is set to 40°C, 60°C, and 100°C, wherein the heating timing from 60°C to 100°C is 20 minutes, and the temperature of the heating jacket where the three-necked flask of the second precursor solution is located is set to 40°C, 60°C, 100°C, and 120°C; when the first precursor solution and the second precursor solution reach the final temperature at the same time, keep them warm, and select to close the Schleck device, turn on the nitrogen switch of the Schleck device in turn, and fill nitrogen into the two three-necked flasks. After completion, the Schleck device is selected to close. After the two three-necked flasks complete the operation, select vacuum on the Schleck device, evacuate for 5 minutes, and the ventilation operation is completed. Repeat twice, and fill nitrogen into the two three-necked flasks again. After the operation is completed, turn off the vacuum pump and maintain nitrogen;

[0042] Step 4: Use a syringe to draw 4.5 ml of oleic acid and 4.5 ml of oleylamine respectively, and inject oleic acid and oleylamine into all the second precursor solutions at a temperature of 120° C., increase the speed to 700 r / min, and obtain a reaction solution after stirring and dissolving;

[0043] Step 5, 1.6 ml of the first precursor solution is drawn from the three-necked flask and quickly injected into the reaction solution of step 4, and then immediately taken out and stirred and cooled to 40° C. in an ice water bath to obtain a crude perovskite quantum dot solution;

[0044] Step 6: add 45 ml of methyl acetate to the crude perovskite quantum dot solution of step 5, centrifuge at 10000 r / min for 1 min, retain the supernatant, add 25 ml of methyl acetate again, centrifuge at 10000 r / min for 1 min, pour out the supernatant, blow dry the residual methyl acetate, rinse with 1 ml of n-octane, centrifuge again at 8000 r / min for 1 min, and the obtained supernatant is a CsPbBr3 quantum dot solution with organic ligands;

[0045] Step 7, centrifuge the CsPbBr3 quantum dot solution with organic ligands in step 6, retain the supernatant after centrifugation at 12000r / min for 1min, add 2.5ml of methyl acetate again, centrifuge at 12000r / min for 1min, pour out the supernatant, blow dry the residual methyl acetate, rinse with 400μl of n-octane, centrifuge again at 8000r / min for 1min, and the obtained supernatant is the CsPbBr3 quantum dot solution to be exchanged with the ligand;

[0046] Step 8. Add the CsPbBr3 quantum dot solution to be ligand exchanged in step 7 directly into 57 mg of KBr, and stir at 500 r / min for 1.5 h. Then, aspirate the resulting mixed solution into a syringe, and quickly filter the mixed solution through a filter into an Agilent vial to obtain a colloidal solution of CsPbBr3 blue light quantum dots.

[0047] Comparative Example 1

[0048] This comparative example synthesized a CsPbBr3 blue light quantum dot. The synthesis process was different from that of Example 1 except that step 7 and step 8 were adjusted as follows:

[0049] Step 7, weigh 8 mg of KBr, add 4 ml of anhydrous ethanol to the KBr, stir and dissolve, and obtain an inorganic ligand precursor solution;

[0050] Step 8. Take 444 μl of the inorganic ligand precursor solution of step 7 and inject it into the CsPbBr3 quantum dot solution with organic ligands in step 6. Shake it up and down for 1 min. After mixing evenly, add 2.5 ml of methyl acetate and centrifuge it at 12000 r / min for 1 min. Pour out the supernatant, dry the residual methyl acetate and anhydrous ethanol, rinse with 400 μl of n-octane, centrifuge it again at 8000 r / min for 1 min, transfer the supernatant to an Agilent vial to obtain a colloidal solution of CsPbBr3 blue light quantum dots.

[0051] The other synthesis processes remain unchanged.

[0052] Example 2

[0053] This embodiment provides a method for preparing high-performance colloidal halide perovskite quantum dots using a heterogeneous inorganic ligand exchange strategy, specifically synthesizing CsPbI3 red light quantum dots, comprising the following steps:

[0054] Step 1, add 10 ml of octadecene and 0.7 ml of oleic acid into a three-necked flask, weigh 100 mg of cesium carbonate and add it into the flask, put it into a heating mantle, start magnetic stirring at a speed of 350 r / min, and obtain a first precursor solution;

[0055] Step 2, add 10 ml of octadecene to a three-necked flask, and add 173 mg of lead iodide and 380 mg of zinc iodide to the flask, put it in a heating mantle, start magnetic stirring at a speed of 400 r / min, to obtain a second precursor solution;

[0056] Step 3, turn on the vacuum pump, select vacuum on the Schleck device, and perform step-wise heating of the first precursor solution and the second precursor solution for 10 minutes at the same time. The temperature of the heating jacket where the three-necked flask of the first precursor solution is located is set to 40°C, 60°C, and 100°C, wherein the heating timing from 60°C to 100°C is 20 minutes, and the temperature of the heating jacket where the three-necked flask of the second precursor solution is located is set to 40°C, 60°C, 100°C, and 120°C; when the first precursor solution and the second precursor solution reach the final temperature at the same time, keep them warm, and select to close the Schleck device, turn on the nitrogen switch of the Schleck device in turn, and fill nitrogen into the two three-necked flasks. After completion, the Schleck device is selected to close. After the two three-necked flasks complete the operation, select vacuum on the Schleck device, evacuate for 5 minutes, and the ventilation operation is completed. Repeat twice, and fill nitrogen into the two three-necked flasks again. After the operation is completed, turn off the vacuum pump and maintain nitrogen;

[0057] Step 4: Use a syringe to draw 3 ml of oleic acid and 3 ml of oleylamine respectively, and inject oleic acid and oleylamine into all the second precursor solutions at a temperature of 120° C., increase the speed to 800 r / min, and obtain a reaction solution after stirring and dissolving;

[0058] Step 5, heating the reaction solution of step 4 to 165° C., taking 1.6 ml of the first precursor solution from the three-necked flask, and quickly injecting it into the reaction solution, immediately taking it out and stirring and cooling it to 40° C. in an ice water bath to obtain a crude perovskite quantum dot solution;

[0059] Step 6: add 35 ml of methyl acetate to the crude perovskite quantum dot solution of step 5, centrifuge at 10000 r / min for 1 min, retain the supernatant, add 30 ml of methyl acetate again, centrifuge at 10000 r / min for 1 min, pour out the supernatant, blow dry the residual methyl acetate, rinse with 1 ml of n-octane, centrifuge again at 8000 r / min for 1 min, and the obtained supernatant is a CsPbI3 quantum dot solution with organic ligands;

[0060] Step 7, centrifuge the CsPbI3 quantum dot solution with organic ligands in step 6, retain the supernatant after centrifugation at 12000r / min for 1min, add 2.5ml of methyl acetate again, centrifuge at 12000r / min for 1min, pour out the supernatant, blow dry the residual methyl acetate, rinse with 400μl of n-octane, centrifuge again at 8000r / min for 1min, and the obtained supernatant is the CsPbI3 quantum dot solution to be exchanged with the ligand;

[0061] Step 8. Add the CsPbI3 quantum dot solution to be ligand exchanged in step 7 directly into 80 mg of KI, and stir at 500 r / min for 1.5 h. Then, aspirate the resulting mixed solution into a syringe, and quickly filter the mixed solution through a filter into an Agilent vial to obtain a colloidal solution of CsPbI3 red light quantum dots.

[0062] The materials synthesized in Examples 1, 2 and Comparative Example 1 are characterized below.

[0063] Figure 1 These are actual pictures of the CsPbBr3 blue quantum dot solutions synthesized in Example 1 and Comparative Example 1 under ultraviolet light, wherein the solution in the Agilent vial on the left is the CsPbBr3 blue quantum dot solution synthesized in Example 1, and the solution in the Agilent vial on the right is the CsPbBr3 blue quantum dot solution synthesized in Comparative Example 1. Under uniform irradiation with a 350nm ultraviolet lamp, it can be seen that the light emitted by the CsPbBr3 blue quantum dot solution in Comparative Example 1 using anhydrous ethanol as a solvent is significantly green, indicating that the CsPbBr3 blue quantum dot solution in Comparative Example 1 undergoes an obvious phase change during the inorganic ligand-ligand exchange process, while the CsPbBr3 blue quantum dot solution in Example 1 can maintain stable blue light emission, indicating that no obvious phase change occurs.

[0064] Figure 2 This is a fluorescence spectrum (PL spectrum) diagram of the CsPbBr3 blue light quantum dots synthesized in Example 1 and Comparative Example 1. It can be seen that the CsPbBr3 blue light quantum dots in Comparative Example 1 show obvious tailing phenomenon after the wavelength of 490nm, while the fluorescence spectrum of the CsPbBr3 blue light quantum dots in Example 1 is more symmetrical, indicating that the CsPbBr3 blue light quantum dots in Comparative Example 1 have more defects and some CsPbBr3 blue light quantum dots are damaged.

[0065] Figure 3 TEM images of CsPbX3 quantum dots synthesized in Example 1 and Example 2, Figure 3 (a) is the CsPbBr3 blue light quantum dots synthesized in Example 1, Figure 3 (b) is the CsPbI3 red light quantum dots synthesized in Example 2. It can be seen from the figure that after the heterogeneous inorganic ligand exchange, the obtained perovskite quantum dots have uniform size and distribution under the electric field.

[0066] Figure 4 The PL spectrum and photoluminescence quantum yield (PLQY) of the CsPbBr3 blue light quantum dots synthesized in Example 1 are: Figure 5The PL spectrum and PLQY of the CsPbI3 red light quantum dots synthesized in Example 2 show that the PLQY of both are relatively high, indicating that the exchange strategy of the heterogeneous inorganic ligand KX can effectively passivate the surface defects of the perovskite quantum dots, improve the radiation recombination, and show good optical properties without causing damage to the perovskite.

[0067] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enables any technician in the field to practice the present invention, including making and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements that are not different from the text of the claims, or if they include equivalent structural elements that are not substantially different from the text of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A method for preparing high-performance colloidal halide perovskite quantum dots using a heterogeneous inorganic ligand exchange strategy, characterized in that: The following steps are involved: Step 1, synthesizing a CsPbX3 quantum dot solution with an organic ligand in a halogen-rich environment, specifically using a variety of halogen raw materials to form a halogen-rich environment during the synthesis process, and synthesizing the CsPbX3 quantum dot solution after a purification step; wherein X is Br or I element; Step 2, secondary purification of the CsPbX3 quantum dot solution with organic ligands to remove excess organic ligands to obtain a CsPbX3 quantum dot solution to be exchanged with ligands; Step 3: Inject the CsPbX3 quantum dot solution to be ligand exchanged into an excess of inorganic ligand, stir, and then filter to obtain a high-performance CsPbX3 quantum dot colloidal solution.

2. The method for preparing high-performance colloidal halide perovskite quantum dots using a heterogeneous inorganic ligand exchange strategy according to claim 1, characterized in that: The specific synthesis process of step 1 is: Step 1.1, adding cesium carbonate to octadecene and oleic acid, stirring to obtain a first precursor solution; Step 1.2, adding halogen raw materials PbX2 and ZnX2 to octadecene, stirring to obtain a second precursor solution; When X is Br element, the molar ratio of PbX2 to ZnX2 is 1:8; When X is element I, the molar ratio of PbX2 to ZnX2 is 1:3; Step 1.3, under vacuum conditions, the first precursor solution and the second precursor solution are respectively heated stepwise until the first precursor solution is heated to 100° C. and kept warm, and the second precursor solution is heated to 120° C. and kept warm, and the nitrogen ventilation operation is repeated several times, and then nitrogen is filled for standby use; Step 1.4, injecting organic ligand oleic acid and oleylamine into the second precursor solution at 120° C., and stirring to obtain a reaction solution; Step 1.5, quickly injecting the first precursor solution into the reaction solution, immediately taking it out and stirring and cooling it to 40° C. in an ice water bath to obtain a crude perovskite quantum dot solution; When X is element I, the reaction solution is first heated to 165°C, and then the first precursor solution is quickly injected; Step 1.6, add antisolvent to the crude perovskite quantum dot solution, retain the supernatant after centrifugation, add antisolvent again, remove the supernatant, disperse the resulting precipitate with a non-polar solvent, retain the supernatant after centrifugation as the CsPbX3 quantum dot solution with organic ligands.

3. The method for preparing high-performance colloidal halide perovskite quantum dots using a heterogeneous inorganic ligand exchange strategy according to claim 2, characterized in that: The specific process of step 2 is: The CsPbX3 quantum dot solution with organic ligands is centrifuged, the supernatant is retained, an anti-solvent is added, and the solution is centrifuged again to remove the supernatant. The resulting precipitate is dispersed with a non-polar solvent, and the supernatant is retained after centrifugation as the CsPbX3 quantum dot solution to be exchanged with the ligand.

4. The method for preparing high-performance colloidal halide perovskite quantum dots using a heterogeneous inorganic ligand exchange strategy according to claim 3, characterized in that: The anti-solvent is methyl acetate or ethyl acetate.

5. The method for preparing high-performance colloidal halide perovskite quantum dots using a heterogeneous inorganic ligand exchange strategy according to any one of claims 1 to 4, characterized in that: In step 3, the inorganic ligand is KX, NaX or RbX.

6. The method for preparing high-performance colloidal halide perovskite quantum dots using a heterogeneous inorganic ligand exchange strategy according to any one of claims 1 to 4, characterized in that: The non-polar solvent is n-octane or n-hexane.

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