In-situ characterization method for synthetic process of circularly polarized light-emitting quantum dots

Abstract

The invention discloses an in-situ characterization method for a synthetic process of circularly polarized light-emitting quantum dots. The in-situ characterization method comprises the following steps: step 1, preparing a quantum dot film and a shell growth solution; step 2, adding a shell growth solution on the surface of the quantum dot film fixed on the support substrate, and infiltrating the surface of the quantum dot film with the shell growth solution to form a solid / liquid interface; and step 3, placing a product in the step 2 in a test environment of a test instrument, performing in-situ monitoring on a solid / liquid interface through the test instrument, monitoring optical signal change of the quantum dot film in real time, and completing monitoring until the optical signal does not change any more to obtain the circularly polarized light-emitting quantum dot. Through a solid / liquid interface strategy, directional growth of the quantum dots is realized on a solid / liquid interface, spatial separation of a complex reaction solution and a research object is effectively realized, in-situ and real-time monitoring of optical signals in the growth process of the quantum dots is realized, and visual observation is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of nanomaterials, in particular to an in-situ characterization method for a circularly polarized luminescent quantum dot synthesis process. Background Art

[0002] Circularly polarized luminescent quantum dots have become a research hotspot in spin electronics and quantum information technology due to their outstanding potential in precisely manipulating electron spin states. This type of quantum dot can emit light with a specific rotation direction (i.e., circularly polarized light) and has important applications in spin electronics and chiral optoelectronics. Spin electronics relies on the ability to manipulate electron spin states, which is crucial for the development of advanced quantum devices. By utilizing circularly polarized luminescent quantum dots, these technological goals can be achieved more efficiently, showing broad application prospects in new data storage, quantum computing, and high-efficiency light-emitting diodes.

[0003] Although circularly polarized quantum dots offer many theoretical advantages, such as spin-orbit coupling and excellent photostability, achieving efficient circularly polarized luminescence in practical applications remains a significant challenge. The primary difficulty lies in the simultaneous optimization of both the quantum dot's fluorescence brightness and emission asymmetry, which requires precise control of the quantum dot's chiral growth and a deep understanding of the mechanism by which the circularly polarized luminescence signal is generated.

[0004] Traditional quantum dot growth is usually carried out in a homogeneous solution. Due to the mixed and dynamic changes of the reactants, it is difficult to achieve real-time monitoring of the growth process and characterization of the intermediate state. The document with application number 202211721535.9 discloses a CdSe@ZnS quantum dot and its preparation method, which prepares circularly polarized luminescent quantum dots by water / oil interface growth. This is the circularly polarized luminescent quantum dot with the best circularly polarized luminescence asymmetry and fluorescence quantum yield reported internationally. However, this method is based on the preparation of circularly polarized luminescent quantum dots in a liquid / liquid interface mixed system, in which the growth process and luminescence mechanism of the circularly polarized luminescent quantum dots cannot be clearly obtained. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide an in-situ characterization method for the synthesis process of circularly polarized luminescent quantum dots.

[0006] The technical solution of the present invention to solve the technical problem is to provide an in-situ characterization method for the synthesis process of circularly polarized luminescent quantum dots, characterized in that the method comprises the following steps:

[0007] Step 1: Preparation of quantum dot film and shell growth solution:

[0008] Preparation of a quantum dot film: oil-soluble CdSe quantum dots are cleaned to remove excess organic ligands on the surface, thereby obtaining cleaned oil-soluble CdSe quantum dots; the cleaned oil-soluble CdSe quantum dots are then dissolved in an organic solvent having a density less than that of diethylene glycol to obtain a CdSe quantum dot solution; the CdSe quantum dot solution is then dropwise added to the surface of the diethylene glycol, and immediately separated into layers, with the upper layer being the CdSe quantum dot solution and the lower layer being diethylene glycol; the volatilization rate of the organic solvent in the upper layer of the CdSe quantum dot solution is controlled, and after the organic solvent evaporates, a quantum dot film is formed on the surface of the diethylene glycol; the quantum dot film is fished out at the air / liquid interface using a supporting substrate, and then dried to remove the diethylene glycol and fix the quantum dot film, thereby obtaining a quantum dot film fixed on the supporting substrate;

[0009] Preparation of shell growth solution: After uniformly mixing the aqueous zinc ion solution and the aqueous chiral ligand molecule solution, dimethyl sulfoxide is added. At this time, white flocs will appear. Then, the pH is adjusted with an alkaline regulator until the white flocs disappear. Then, the sulfur ion solution is added and mixed uniformly to obtain the shell growth solution.

[0010] Step 2: adding a shell growth liquid to the surface of the quantum dot film fixed on the supporting substrate, so that the shell growth liquid infiltrates the surface of the quantum dot film to form a solid / liquid interface;

[0011] Step 3: Place the product of step 2 in the test environment of the test instrument, perform in-situ monitoring of the solid / liquid interface through the test instrument, and monitor the optical signal changes of the quantum dot film in real time until the optical signal no longer changes, thereby completing the monitoring and obtaining circularly polarized luminescent quantum dots.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] (1) The present invention adopts a solid / liquid interface strategy to first fix the quantum dots into a membrane structure, and then introduce the required growth reaction solution on the membrane surface, thereby achieving directional growth at the solid / liquid interface, effectively realizing the spatial separation of the complex reaction solution and the research object (quantum dots), and realizing in situ and real-time monitoring of fluorescence, chirality, absorption and circularly polarized luminescence signals during the growth process of quantum dots, realizing visual observation, and then clarifying the process of circularly polarized luminescence generation, further clarifying the mechanism of circularly polarized luminescence generation, significantly improving the controllability and monitoring accuracy of the growth process, and not being interfered by the complex components of the reaction solution, guiding the future synthesis of circularly polarized luminescent quantum dots.

[0014] (2) The present invention realizes in-situ, real-time monitoring of fluorescence, chirality, absorption, and circularly polarized luminescence signals during the growth process of quantum dots. This monitoring capability is due to the solid / liquid interface growth system constructed. Its spectral characterization method is significantly innovative and can obtain rich intermediate information during the growth process, which is of great significance to scientific research and quality control in the production process.

[0015] (3) This invention not only enables real-time monitoring of changes in the shell growth process of circularly polarized luminescent quantum dots and their optical signal changes, but also allows the production of quantum dot film materials with circularly polarized luminescence properties, providing a new technical approach for the synthesis and application of efficient circularly polarized luminescent quantum dots. This method is applicable to the synthesis of different materials and is of great significance for guiding synthesis and exploring the mechanism of signal changes.

[0016] (4) The quantum dot material finally obtained by the present invention has excellent circularly polarized luminescence characteristics and fluorescence quantum yield, and has broad application potential in chiral substance interactions, polarization imaging and bioanalysis systems, especially in the field of bioimaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the experimental device and process of Example 1 of the present invention;

[0018] Figure 2 This is the real-time monitoring of the changes in the optical signal of the in-situ growth of ZnS shells on CdSe quantum dots at the solid / liquid interface in Example 1 of the present invention. In the figure, a is the fluorescence spectrum, b is the circularly polarized luminescence spectrum, c is the UV-visible absorption spectrum, and d is the circular dichroism spectrum.

[0019] Figure 3 Result graph of fluorescence quantum yield of the quantum dots obtained in step 1 of Example 1 of the present invention, and circularly polarized luminescent CdSe@ZnS quantum dots prepared in Example 1, Example 2, and Comparative Example 1;

[0020] Figure 4 This is a graph showing the luminescence asymmetry factor of the quantum dots obtained in step 1 of Example 1 of the present invention, and the circularly polarized luminescent CdSe@ZnS quantum dots obtained in Example 1, Example 2, and Comparative Example 1;

[0021] Figure 5 This is a result diagram of the absorption asymmetry factor of the quantum dots obtained in step 1 of Example 1 of the present invention, and the circularly polarized luminescent CdSe@ZnS quantum dots prepared in Example 1, Example 2 and Comparative Example 1. DETAILED DESCRIPTION

[0022] The specific embodiments of the present invention are given below. The specific embodiments are only used to further illustrate the present invention and do not limit the scope of protection of the present invention.

[0023] The present invention provides an in-situ characterization method for the synthesis process of circularly polarized luminescent quantum dots (hereinafter referred to as the method), characterized in that the method comprises the following steps:

[0024] Step 1: Preparation of quantum dot film and shell growth solution:

[0025] Preparation of quantum dot film: oil-soluble CdSe (cadmium selenide) quantum dots are cleaned to remove excess organic ligands on the surface to facilitate subsequent solid / liquid interface reaction, thereby obtaining cleaned oil-soluble CdSe quantum dots; the cleaned oil-soluble CdSe quantum dots are then dissolved in an organic solvent having a density less than that of diethylene glycol to obtain a CdSe quantum dot solution; the CdSe quantum dot solution is then dropwise added to the surface of the diethylene glycol, and immediately separated into layers after the addition, with the upper layer being the CdSe quantum dot solution and the lower layer being diethylene glycol; the volatilization rate of the organic solvent in the upper layer of the CdSe quantum dot solution is controlled, and after the organic solvent evaporates, a quantum dot film is formed on the surface of the diethylene glycol; the quantum dot film is fished out at the gas / liquid interface using a supporting substrate, and then dried to remove the diethylene glycol and fix the quantum dot film, thereby obtaining a quantum dot film fixed on the supporting substrate;

[0026] Preparation of shell growth solution: After uniformly mixing the aqueous zinc ion solution and the aqueous chiral ligand molecule solution, dimethyl sulfoxide is added. At this time, white flocs will appear. Then, the pH is adjusted with an alkaline regulator until the white flocs disappear. Then, the sulfur ion solution is added and mixed uniformly to obtain the shell growth solution.

[0027] Preferably, in step 1, the cleaning process is: mixing anhydrous ethanol and an oil-soluble CdSe quantum dot solution to precipitate the quantum dots; after centrifugation, discarding the supernatant and retaining the precipitate; the volume ratio of anhydrous ethanol to the oil-soluble CdSe quantum dot solution is 6 to 8:1; the centrifugation process is: the speed is 10,000 to 15,000 rpm, the time is 5 to 15 minutes, and it is preferably carried out in a centrifuge.

[0028] Preferably, in step 1, the organic solvent is chloroform, n-hexane, ether, acetone or ethyl acetate, to ensure that a quantum dot film is formed at the gas-liquid interface after the solvent evaporates.

[0029] Preferably, in step 1, the concentration of the CdSe quantum dot solution is 5 to 15 mg / mL.

[0030] Preferably, in step 1, during the quantum dot film formation process, the evaporation rate of the organic solvent in the upper layer of the CdSe quantum dot solution needs to be controlled, with the evaporation time for 5 mL of organic solvent being controlled within 5 to 7 hours. Excessive evaporation can cause quantum dots to aggregate at the interface, forming a multilayer film. This can be achieved by adjusting the ventilation, temperature, and humidity of the reaction environment.

[0031] Preferably, in step 1, the supporting substrate is a quartz glass sheet or a PDMS substrate, which facilitates subsequent spectral testing.

[0032] Preferably, in step 1, the drying temperature is not less than 80° C. (preferably 80-120° C.) and the drying time is at least 2 hours (preferably 12-24 hours) to ensure that the residual diethylene glycol is completely dried and the quantum dot film is fixed to the supporting substrate. Preferably, the drying is carried out in an oven.

[0033] Preferably, in step 1, the concentration of the zinc ion aqueous solution is 2-8 mmol / L; the concentration of the chiral ligand molecule aqueous solution is 100-400 mmol / L; and the volume ratio of the zinc ion aqueous solution to the chiral ligand molecule aqueous solution is 1:1-4.

[0034] Preferably, in step 1, the zinc ion is any one of inorganic zinc salts, specifically zinc chloride or zinc sulfate.

[0035] Preferably, in step 1, the chiral ligand molecule is a chiral amino acid or a water-soluble chiral small molecule; the chiral amino acid is chiral L-histidine, chiral D-histidine, chiral L-cysteine, chiral D-cysteine, chiral L-arginine, chiral D-arginine, chiral L-lysine or chiral D-lysine (preferably chiral L-histidine and chiral D-histidine); the water-soluble chiral small molecule is chiral L-glutathione, chiral D-glutathione, chiral L-penicillamine or chiral D-penicillamine.

[0036] Preferably, in step 1, the solvent of the shell growth solution is a mixture of dimethyl sulfoxide and water, ensuring that the quantum dots can stably exist in the form of a film during the reaction, ensuring the stability of the quantum dot film during the solid / liquid interface reaction, and that a clear optical signal can be observed. The addition of dimethyl sulfoxide is beneficial to the stability of the quantum dot film, and the volume ratio of dimethyl sulfoxide to water is 1-4:6-9 (preferably 4:6, the fluorescence, chirality, and circularly polarized luminescence signals obtained by the system are the best). The water comes from the solvent in the zinc ion aqueous solution, the chiral ligand molecule aqueous solution, and the sulfide ion aqueous solution.

[0037] Preferably, in step 1, the alkaline regulator is sodium hydroxide or potassium hydroxide, and the pH is adjusted to ≥9.

[0038] Preferably, in step 1, the sulfide ion is thiourea, sodium sulfide or thioacetamide.

[0039] Preferably, in step 1, the molar ratio of zinc ions to sulfur ions is 1:1.

[0040] Step 2: adding a shell growth liquid to the surface of the quantum dot film fixed on the supporting substrate, so that the shell growth liquid completely infiltrates the surface of the quantum dot film to form a solid / liquid interface;

[0041] Preferably, step 2 is performed at room temperature.

[0042] Preferably, step 2 is performed in a cuvette, specifically: placing the quantum dot film fixed on the supporting substrate in the cuvette, and then adding shell growth liquid thereto, the shell growth liquid infiltrates the surface of the quantum dot film to form a solid / liquid interface.

[0043] Step 3: Place the container containing the quantum dot film and shell growth liquid (i.e., the product of step 2) in the test environment of the test instrument, perform in-situ monitoring of the solid / liquid interface through the test instrument, continuously monitor the entire growth process of the quantum dots through continuous testing of the test instrument, and monitor the optical signal changes of the quantum dot film in real time until the optical signal no longer changes, thereby completing the monitoring and obtaining circularly polarized luminescent quantum dots.

[0044] Preferably, step 3 is performed at room temperature.

[0045] Preferably, in step 3, the testing instrument is a fluorescence spectrometer, an ultraviolet-visible absorption spectrometer, a circularly polarized luminescence spectrometer, and / or a circular dichroism spectrometer. Specifically, the corresponding testing instrument is selected according to the needs for testing: a fluorescence spectrometer is used to test the fluorescence of the quantum dot film, a UV-visible absorption spectrometer is used to test the absorption change of the quantum dot film, a circular dichroism spectrometer is used to test the chiral signal of the quantum dot film, and a circularly polarized luminescence spectrometer is used to test the circularly polarized luminescence of the quantum dot film.

[0046] Preferably, in step 3, the optical signal is a fluorescence spectrum, an ultraviolet-visible absorption spectrum, a circularly polarized luminescence spectrum and / or a circular dichroism spectrum.

[0047] Preferably, in step 3, the solid / liquid interface is monitored in situ every 30 s to 5 h (preferably 30 s to 10 min, more preferably 2 to 5 min), and the entire test time is at least 5 h (preferably 6 to 12 h).

[0048] Preferably, in step 3, during the test, the chirality and circularly polarized luminescence signals of the quantum dot film gradually emerge, and the fluorescence signal of the quantum dot film gradually increases.

[0049] Example 1:

[0050] Step 1, preparation of oil phase quantum dot film: 8 ml of anhydrous ethanol and 1 ml of oil-soluble CdSe quantum dot solution were mixed to precipitate the quantum dots; then centrifuged at 15000 rpm for 10 min, discarded the supernatant and retained the precipitate; then the washed oil-soluble CdSe quantum dots were dissolved in n-hexane to obtain a CdSe quantum dot solution with a concentration of 10 mg / mL; then the CdSe quantum dot solution was added dropwise to the surface of diethylene glycol, and immediately separated into layers after the addition, with the upper layer being the CdSe quantum dot solution and the lower layer being diethylene glycol; the evaporation rate of the upper organic solvent was controlled, and the evaporation time of 5 mL of organic solvent was controlled to be 7 h; after the n-hexane in the upper CdSe quantum dot solution evaporated, a quantum dot film was formed on the surface of diethylene glycol, and the quantum dot film was fished out at the gas / liquid interface using a quartz glass substrate, and dried in a high temperature environment of 120°C for 2 h to obtain a quantum dot film fixed on the supporting substrate;

[0051] Preparation of shell growth solution: Mix 1 mL of 4 mmol / L zinc chloride solution and 1 mL of 150 mmol / L chiral L-histidine aqueous solution. Then add 1 mL of dimethyl sulfoxide. White flocs will appear. Then adjust the pH to 11 with sodium hydroxide until the white flocs disappear. Then add 1 mL of 4 mmol / L thiourea solution and mix thoroughly to obtain the chiral L-histidine-mediated ZnS shell growth solution.

[0052] Step 2: Place the quantum dot film fixed on the supporting substrate in a cuvette at room temperature, and then add a shell growth liquid thereto. The shell growth liquid then infiltrates the surface of the quantum dot film to form a solid / liquid interface.

[0053] Step 3. At room temperature, place the cuvette containing the quantum dot film and shell growth liquid in the testing instrument, perform in situ monitoring of the solid / liquid interface every 2 minutes, and observe the changes in the fluorescence, chirality, UV-visible absorption and circularly polarized luminescence signals of the quantum dots in real time. Continue the test for 6 hours until the optical signal no longer changes, and complete the monitoring to obtain circularly polarized luminescent CdSe@ZnS quantum dots.

[0054] Testing has shown that the quantum dots exhibit distinct circularly polarized luminescence at the exciton absorption peak, with an luminescence asymmetry factor of 0.0057. The quantum dots also exhibit distinct chirality, with a significant Cotton effect near 500nm and an absorption asymmetry factor of 0.002. The fluorescence quantum yield reaches a high of 56.8%. This material combines high brightness with significant luminescence asymmetry, making it a high-performance circularly polarized luminescent quantum dot with excellent optical properties.

[0055] Depend on Figure 2It can be seen that the fluorescence, circularly polarized luminescence, ultraviolet-visible absorption and circular dichroism signals of the quantum dot film gradually increase and stabilize over time during the growth process. The quantum dot film finally prepared exhibits excellent circularly polarized luminescence characteristics.

[0056] Example 2:

[0057] This example is identical to Example 1, except that in step 1, the chiral L-histidine aqueous solution is replaced with a chiral D-histidine aqueous solution.

[0058] Testing revealed a quantum dot luminescence asymmetry factor of 0.0058, an absorption asymmetry factor of 0.002, and a fluorescence quantum yield of 57.4%. The fluorescence, circularly polarized luminescence, UV-visible absorption, and circular dichroism signals of the quantum dot film gradually increased and stabilized over time during the growth process. The resulting quantum dot film exhibited excellent circularly polarized luminescence properties.

[0059] Comparative Example 1:

[0060] This comparative example is exactly the same as Example 1, except that in step 1, the chiral L-histidine aqueous solution is replaced by a racemic DL-histidine aqueous solution.

[0061] Testing revealed virtually no signal from the quantum dot luminescence asymmetry factor and absorption asymmetry factor, with a fluorescence quantum yield as high as 57.2%. The fluorescence and UV-visible absorption signals of the quantum dot film gradually increased and stabilized over time during growth. However, no significant signal was detected in its circular dichroism and circularly polarized luminescence spectra, indicating that the resulting quantum dot film lacked circularly polarized luminescence properties.

[0062] Depend on Figure 3 As can be seen, quantum dot films with different configurations have very similar fluorescence quantum yields, and compared to the pre-reaction oil-phase quantum dot film (i.e., the product of Step 1, whose fluorescence quantum yield is 5.3%), there is a significant signal boost. The quantum dot growth process, with the fluorescence quantum yield gradually increasing from 5.3%, can be visualized.

[0063] Depend on Figure 4 and Figure 5 It can be seen that the L and D-configured circularly polarized luminescent quantum dots have obvious chiral signals and circularly polarized luminescence signals, while the DL-configured quantum dots and the oil-phase quantum dots before the reaction have no obvious chiral optical activity. This shows that the chiral optical activity originates from the growth of the solid / liquid interface shell mediated by the chiral ligand.

[0064] Comparative Example 2:

[0065] This comparative example is identical to Example 1, except that: in step 1, the shell growth solution is prepared by uniformly mixing 1 mL of a 150 mmol / L chiral L-histidine aqueous solution and 3 mL of water, and then adjusting the pH to 11 with sodium hydroxide to obtain a shell growth solution;

[0066] After testing, the fluorescence, circularly polarized luminescence, ultraviolet-visible absorption and circular dichroism signals of the quantum dot film did not show any significant enhancement over time, and the quantum dot film finally prepared did not have the circularly polarized luminescence characteristic.

[0067] This method not only fails to enhance fluorescence, chirality, and circularly polarized luminescence, but can even significantly reduce the original fluorescence signal of the oil-phase quantum dots. This demonstrates the importance of the solid / liquid interface shell growth solution for the growth of circularly polarized luminescent quantum dots.

[0068] Comparative Example 3:

[0069] This comparative example is identical to Example 1, except that in step 1, in the preparation of the oil-phase quantum dot film, the oil-soluble CdSe quantum dots are replaced with oil-soluble CdSe@ZnS quantum dots. The shell growth solution is prepared by uniformly mixing 1 mL of a 150 mmol / L chiral L-histidine aqueous solution with 3 mL of water, and then adjusting the pH to 11 with sodium hydroxide to obtain the shell growth solution.

[0070] The preparation of the oil phase quantum dot film is as follows: 8 ml of anhydrous ethanol and 1 ml of oil-soluble CdSe@ZnS quantum dot solution are mixed to precipitate the quantum dots; then the mixture is centrifuged at 15000 rpm for 10 min, the supernatant is discarded and the precipitate is retained; the washed oil-soluble CdSe@ZnS quantum dots are dissolved in n-hexane to obtain a CdSe@ZnS quantum dot solution with a concentration of 10 mg / mL; the CdSe@ZnS quantum dot solution is then added dropwise to diethylene glycol monohydrate. The surface of the alcohol was immediately separated after the addition, with the upper layer being the CdSe@ZnS quantum dot solution and the lower layer being diethylene glycol; the evaporation rate of the upper organic solvent was controlled, and the evaporation time of 5 mL of the organic solvent was controlled within 7 h; after the n-hexane in the upper CdSe@ZnS quantum dot solution evaporated, a quantum dot film was formed on the surface of the diethylene glycol, and the quantum dot film was fished out at the gas / liquid interface using a quartz glass substrate and dried in a high-temperature environment of 120°C for 2 h to obtain a quantum dot film fixed on the supporting substrate.

[0071] After testing, no obvious changes in fluorescence signals were observed, and there was no obvious chiral optical activity.

[0072] Comparative Example 4:

[0073] According to the document with application number 202211721535.9, circularly polarized luminescent CdSe@ZnS quantum dots can be obtained by using an oil-phase CdSe seed solution as the lower layer and an aqueous shell growth solution as the upper layer through a liquid / liquid interface reaction. However, this process is always stirred, and the solution is a two-phase mixed system, making it impossible to monitor the changes during the process in real time through instrumentation.

[0074] Any matters not described in the present invention are applicable to the prior art.

Claims

1. An in-situ characterization method for the synthesis process of circularly polarized luminescent quantum dots, characterized in that: The method comprises the following steps: Step 1: Preparation of quantum dot film and shell growth solution: Preparation of a quantum dot film: oil-soluble CdSe quantum dots are cleaned to remove excess organic ligands on the surface, thereby obtaining cleaned oil-soluble CdSe quantum dots; the cleaned oil-soluble CdSe quantum dots are then dissolved in an organic solvent having a density less than that of diethylene glycol to obtain a CdSe quantum dot solution; the CdSe quantum dot solution is then dropwise added to the surface of the diethylene glycol, and immediately separated into layers, with the upper layer being the CdSe quantum dot solution and the lower layer being diethylene glycol; the volatilization rate of the organic solvent in the upper layer of the CdSe quantum dot solution is controlled, and after the organic solvent evaporates, a quantum dot film is formed on the surface of the diethylene glycol; the quantum dot film is fished out at the air / liquid interface using a supporting substrate, and then dried to remove the diethylene glycol and fix the quantum dot film, thereby obtaining a quantum dot film fixed on the supporting substrate; Preparation of shell growth solution: After uniformly mixing the aqueous zinc ion solution and the aqueous chiral ligand molecule solution, dimethyl sulfoxide is added. At this time, white flocs will appear. Then, the pH is adjusted with an alkaline regulator until the white flocs disappear. Then, the sulfur ion solution is added and mixed uniformly to obtain the shell growth solution. Step 2: adding a shell growth liquid to the surface of the quantum dot film fixed on the supporting substrate, so that the shell growth liquid infiltrates the surface of the quantum dot film to form a solid / liquid interface; Step 3: Place the product of step 2 in the test environment of the test instrument, perform in-situ monitoring of the solid / liquid interface through the test instrument, and monitor the optical signal changes of the quantum dot film in real time until the optical signal no longer changes, thereby completing the monitoring and obtaining circularly polarized luminescent quantum dots.

2. The in-situ characterization method for the synthesis process of circularly polarized luminescent quantum dots according to claim 1, characterized in that: In step 1, the cleaning process is: mixing anhydrous ethanol and an oil-soluble CdSe quantum dot solution to precipitate the quantum dots; after centrifugation, discarding the supernatant and retaining the precipitate; The volume ratio of anhydrous ethanol to the oil-soluble CdSe quantum dot solution is 6-8:1; the centrifugal process is: the rotation speed is 10000-15000 rpm, and the time is 5-15 minutes.

3. The in-situ characterization method for the synthesis process of circularly polarized luminescent quantum dots according to claim 1, characterized in that: In step 1, the organic solvent is chloroform, n-hexane, ether, acetone or ethyl acetate; and the concentration of the CdSe quantum dot solution is 5 to 15 mg / mL.

4. The in-situ characterization method for the synthesis process of circularly polarized luminescent quantum dots according to claim 1, characterized in that: In step 1, the volatilization rate of the organic solvent in the upper layer of the CdSe quantum dot solution is: the volatilization time of 5 mL of organic solvent is controlled within 5 to 7 hours; In step 1, the supporting substrate is a quartz glass sheet or a PDMS substrate; In step 1, the drying temperature is not less than 80° C. and the drying time is at least 2 hours.

5. The in-situ characterization method for the synthesis process of circularly polarized luminescent quantum dots according to claim 1, characterized in that: In step 1, the concentration of the zinc ion aqueous solution is 2 to 8 mmol / L; the concentration of the chiral ligand molecule aqueous solution is 100 to 400 mmol / L; and the volume ratio of the zinc ion aqueous solution to the chiral ligand molecule aqueous solution is 1:1 to 4; In step 1, the molar ratio of zinc ion to sulfur ion is 1:1; In step 1, the volume ratio of dimethyl sulfoxide to all water in the zinc ion aqueous solution, the chiral ligand molecule aqueous solution and the sulfide ion aqueous solution is 1-4:6-9.

6. The in-situ characterization method for the synthesis process of circularly polarized luminescent quantum dots according to claim 1, characterized in that: In step 1, the zinc ion is any one of inorganic zinc salts; In step 1, the chiral ligand molecule is a chiral amino acid or a water-soluble chiral small molecule; In step 1, the alkali regulator is sodium hydroxide or potassium hydroxide, and the pH is adjusted to ≥9.

7. The in-situ characterization method for the synthesis process of circularly polarized luminescent quantum dots according to claim 6, characterized in that: In step 1, the zinc ion is zinc chloride or zinc sulfate; In step 1, the chiral amino acid is chiral L-histidine, chiral D-histidine, chiral L-cysteine, chiral D-cysteine, chiral L-arginine, chiral D-arginine, chiral L-lysine or chiral D-lysine; The water-soluble chiral small molecule is chiral L-glutathione, chiral D-glutathione, chiral L-penicillamine or chiral D-penicillamine; In step 1, the sulfide ion is thiourea, sodium sulfide or thioacetamide.

8. The in-situ characterization method for the synthesis process of circularly polarized luminescent quantum dots according to claim 1, characterized in that: Both steps 2 and 3 were performed at room temperature.

9. The in-situ characterization method for the synthesis process of circularly polarized luminescent quantum dots according to claim 1, characterized in that: In step 3, the solid / liquid interface is monitored in situ every 30 seconds to 5 hours, and the entire test time is at least 5 hours.

10. The in-situ characterization method for the synthesis process of circularly polarized luminescent quantum dots according to claim 1, characterized in that: In step 3, the optical signal is a fluorescence spectrum, an ultraviolet-visible absorption spectrum, a circularly polarized luminescence spectrum, or a circular dichroism spectrum.

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