Halogen mixed quantum dots and high-throughput continuous preparation method and application thereof

Abstract

This invention relates to a halogen-mixed quantum dot and its high-throughput continuous preparation method and applications. The preparation method includes: firstly, preparing a first precursor solution containing cesium oleate; mixing lead halide, TiO2, oleic acid, and oleylamine in the solution and heating to react, obtaining a second precursor solution; then reacting the first and second precursor solutions in a microchannel reactor to obtain the halogen-mixed quantum dots. Compared with existing technologies, the quantum dots prepared by this invention can be applied to white LEDs, high-resolution displays, optical communications, optical chips, optoelectronic logic gates, and other fields.

Description

Technical Field

[0001] This invention belongs to the field of fluorescent material preparation technology, and relates to a halogen mixed quantum dot and its high-throughput continuous preparation method and application. Background Technology

[0002] All-inorganic lead halide perovskite quantum dots CsPbX3 (X = Cl, Br, I) exhibit broad application prospects in display technology, solar cells, and light-emitting diodes (LEDs) due to their excellent optoelectronic properties, including narrow emission half-width, high photoluminescence quantum yield, tunable bandgap, and high carrier mobility. x I 3-x Quantum dots, with their more stable phases and higher color purity, are widely used in red quantum dot light-emitting diodes (QD-LEDs), one of the three primary colors, playing a crucial role in high-definition displays. However, these materials still face two major challenges in practical applications: the difficulty of large-scale preparation and their poor environmental stability. Traditional preparation methods, primarily the hot-injection method, struggle with precise and rapid control of parameters such as reaction temperature and time, resulting in wide size distributions and poor batch-to-batch consistency of synthesized quantum dots, failing to meet the demands of high-throughput and large-scale production. Furthermore, all-inorganic perovskite quantum dots are extremely sensitive to moisture, oxygen, light, and heat, easily undergoing phase separation, degradation, and fluorescence quenching, severely limiting their practical applications. To improve their stability, a strategy of combining them with inorganic porous materials (such as Al₂O₃, SiO₂, and CaF₂) is often employed. These materials provide confined growth space and, to some extent, shield against environmental corrosion, but often lead to a decrease in the luminescence intensity of the quantum dots. Therefore, developing a new method that balances controllable preparation with improved stability is of great significance.

[0003] Chinese patent CN118853162A discloses a highly stable full-spectrum perovskite nanocrystal and its preparation method and apparatus. The surface of nano-titanium dioxide is modified with lead halide. The perovskite nanocrystal generated by the reaction of the lead halide with a cesium precursor is in situ bonded to the nano-titanium dioxide during the synthesis process, with the nano-titanium dioxide coating the perovskite nanocrystal. The lead halide is selected from one or more of lead chloride, lead bromide, and lead iodide. The molar ratio of lead halide to nano-titanium dioxide is 1:(14), and the molar ratio of cesium to lead in the cesium precursor and lead halide is 1:(27). Compared with existing technologies, this technical solution enhances the luminescence intensity, water stability, and thermal stability of perovskite nanocrystals, and enables full-spectrum regulation and continuous controllable preparation.

[0004] Prior art CN118853162A discloses a highly stable full-spectrum perovskite nanocrystal and its preparation method and apparatus. The microfluidic reaction device includes: an injection pump, a first injector, a second injector, a microfluidic chip, a heating stage, and a collection device. The microfluidic chip includes an upper plate, a gasket, a lower plate, a first microfluidic channel, a second microfluidic channel, and a third microfluidic channel. The lower plate has the first, second, and third microfluidic channels, which are connected in a T-shaped channel configuration. The first injector is connected to the first microfluidic channel, the second injector is connected to the second microfluidic channel, and the third microfluidic channel is connected to the collection device. The first and second injectors are connected to the injection pump, which actuates the first and second injectors. The upper plate is located on the lower plate and is sealed to the lower plate via a gasket. A heating stage is located under the lower plate for heating the lower plate. However, in the microfluidic chip used in this existing technology, some nano-TiO2 will be deposited inside the pipe during the reaction process, and the gasket will leak due to corrosion by organic matter. Furthermore, this microfluidic chip cannot heat the reaction precursor and other materials evenly, and it lacks an effective means to end the reaction. It can only obtain perovskite nanocrystals, but cannot produce perovskite quantum dots. Summary of the Invention

[0005] The purpose of this invention is to provide a halogen mixed quantum dot and its high-throughput continuous preparation method and application, which can enhance the luminescence intensity and water stability of perovskite quantum dots and achieve continuous and controllable preparation.

[0006] The objective of this invention can be achieved through the following technical solutions: A first aspect of the present invention provides a high-throughput continuous preparation method for halogen mixed quantum dots, comprising: S1: Prepare a first precursor solution containing cesium oleate (Cs-Oleate); mix lead halide, TiO2, oleic acid (OA), and oleylamine (OAm) in the solution and heat to react, to obtain a second precursor solution; S2: The first precursor solution and the second precursor solution are reacted in a microchannel reactor to obtain TiO2-coated CsPbBr. x I 3-x Quantum dots, also known as halogen mixed quantum dots.

[0007] In some specific embodiments, in step S1, the preparation method of the first precursor solution includes: mixing cesium source, oleic acid and octadecene, stirring and reacting at 100~130°C for 1~1.5 h in a protective atmosphere, and then stirring and reacting at 140~160°C for 0.5~1 h.

[0008] In some specific embodiments, the feeding ratio of cesium, oleic acid and octadecene in the cesium source is 2.5 mmol:(2~3) mL:(30~50) mL.

[0009] In some specific embodiments, the cesium source is selected from cesium carbonate or cesium acetate.

[0010] In some specific embodiments, in step S1, the lead halide is selected from one or more of lead chloride, lead bromide, or lead iodide.

[0011] In some specific embodiments, in step S1, the feeding ratio of lead halide, TiO2, oleic acid, oleylamine and octadecene is 0.37~0.38 mmol:0.9~0.95 mmol:(0.8~1.2) mL:1 mL:(8~12) mL.

[0012] In some specific embodiments, in step S1, the heating reaction is carried out at a temperature of 100-130°C for 0.5-1 h for 1 h, and the reaction atmosphere is nitrogen.

[0013] In some specific embodiments, in step S2, the first precursor solution and the second precursor solution are mixed at a molar ratio of Cs:Pb = 1:6~7.

[0014] In some specific embodiments, in step S2, the microchannel reactor includes: an aluminum plate, a heating zone and an ice bath zone arranged side by side on the aluminum plate, a heating platform for supplying heat to the heating zone, an ice water bath in thermal contact with the ice bath zone, a microfluidic pipeline arranged in a serpentine pattern on the aluminum plate and extending from the heating zone to the ice bath zone, a feeding assembly connected to the inlet end of the microfluidic pipeline, and a collection device connected to the outlet end of the microfluidic pipeline. The microfluidic channel is a transparent cylindrical tube, preferably a transparent polytetrafluoroethylene (PTFE) cylindrical tube with an inner diameter of 300~400μm. Compared with the microfluidic channel with a larger inner diameter and square cross-section used in the prior art CN118853162A, this invention achieves spatial confinement by controlling the inner diameter of the reaction channel and successfully prepares perovskite quantum dots, avoiding the formation of nanorods or nanocrystals in the prior art CN118853162A. At the same time, the cylindrical structure can also effectively avoid the deposition of nano-TiO2 compared with the square tube structure, improving the raw material utilization rate. The feeding assembly includes a first syringe for containing a first precursor solution, a second syringe for containing a second precursor solution, an injection pump for synchronously pushing the first syringe and the second syringe, a mixer located at the inlet end of a microfluidic channel, a first microfluidic channel located between the first inlet of the mixer and the first syringe, and a second microfluidic channel located between the second inlet of the mixer and the second syringe.

[0015] In some specific embodiments, the collection device is a collection tank.

[0016] This invention uses a heating stage, an ice-water bath, and an aluminum plate to construct a microfluidic chip, which serves as the main structure of a microchannel reactor. Perovskite quantum dots are prepared by spatial confinement of the circular tube structure and the addition of an ice bath region. Furthermore, the luminescence performance and stability of the product are improved by halogen mixing and inorganic coating. Moreover, the reaction process can be observed through a transparent pipe.

[0017] In some specific embodiments, in step S2, the flow rate in the microchannel reactor is 300~700 μL / min; in the mixing reaction, the reaction temperature is 140~160℃, and the reaction time is 5~10 s.

[0018] A second aspect of the present invention provides a halogen mixed quantum dot, which is prepared by the method described above.

[0019] A third aspect of the present invention provides an application of halogen mixed quantum dots, including using the halogen mixed quantum dots in one of white LEDs, high-resolution display devices, optical communication devices, optical chips, or optoelectronic logic gates.

[0020] Compared with the prior art, the present invention has the following beneficial effects: This invention utilizes a system that precisely processes and manipulates minute fluids through microfluidic channels, which can enhance the heat and mass transfer rates of reaction reagents and achieve uniform mixing of reaction reagents within seconds.

[0021] Traditional microfluidic reactions utilize glass / silicon microfluidic chips, which offer high precision but suffer from long manufacturing cycles, high costs, and difficulty in withstanding high temperatures and corrosive organic solvents. This invention uses an aluminum plate as the microfluidic chip substrate, which possesses high thermal conductivity and excellent thermal conductivity. Simultaneously, the PTFE pipes are resistant to high temperatures and organic corrosion, ensuring uniform heating of materials during the reaction process.

[0022] This invention enables the rapid, continuous, and controllable synthesis of quantum dots by precisely controlling parameters such as the preheating and reaction temperature of the reaction reagents in the microfluidic channel, as well as the flow rate in the channel. It also enables the large-scale preparation of perovskite quantum dots.

[0023] This invention utilizes nano-titanium dioxide to coat perovskite quantum dots, which not only enhances the luminescence intensity and promotes carrier migration of the perovskite quantum dots, but also improves their water stability. Based on the composition and ratio of lead halide, CsPbBr can be achieved. x I 3-xThe spectral modulation of quantum dots has facilitated the widespread application of perovskite quantum dots in the field of optoelectronic materials. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the reaction apparatus for implementing halogen mixed quantum dots according to the present invention.

[0025] Figure 2 These are the photoemission spectra of perovskite quantum dots in Examples 1 and 2 of the present invention.

[0026] Figure 3 These are X-ray diffraction (XRD) patterns of perovskite quantum dots in Examples 1 and 2 of the present invention.

[0027] Figure 4 In Example 7 of this invention, TiO2 is used to coat CsPbBr. x I 3-x Quantum dot transmission electron microscope image.

[0028] Figure 5 It is the TiO2-coated CsPbBr in Examples 2-7 of this invention. x I 3-x Photoemission spectrum of quantum dots.

[0029] Figure 6 These are line graphs showing the water stability and luminescence intensity of perovskite quantum dots in Examples 1 and 2 of this invention. Explanation of markings in the diagram: 1-Injection pump, 2-First syringe, 3-Second syringe, 4-First microfluidic channel, 5-Second microfluidic channel, 6-Aluminum plate, 7-High temperature resistant tee connector, 8-Third microfluidic channel, 9-Heating platform, 10-Ice bath area, 11-Collection device. Detailed Implementation

[0030] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0031] The present invention will now be described in detail with reference to specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0032] Unless otherwise specified, the equipment used in the following embodiments is conventional equipment in the art; unless otherwise specified, the reagents used are commercially available products or prepared by conventional methods in the art. In the following embodiments, unless otherwise described in detail, conventional experimental methods in the art can be used.

[0033] The high-throughput continuous preparation reactor used in this invention is existing. The following is only one structure of the high-throughput continuous preparation reactor that can be used in this invention.

[0034] refer to Figure 1 The high-throughput continuous preparation reactor used includes: a syringe pump 1, a first syringe 2, a second syringe 3, a first microfluidic channel 4, a second microfluidic channel 5, an aluminum plate 6, a high-temperature resistant tee connector 7, a third microfluidic channel 8, a heating platform 9, an ice bath zone 10, and a collection device 11. The first syringe 2 is connected to the third microfluidic channel 8 via the first microfluidic channel 4 and the high-temperature resistant tee connector 7. The second syringe 3 is connected to the third microfluidic channel 8 via the second microfluidic channel 5 and the high-temperature resistant tee connector 7. The third microfluidic channel 8 is connected to the collection device 11 via a transparent PTFE tube through the ice bath zone 10. The aluminum plate 6 has grooves for accommodating the first microfluidic channel 4, the second microfluidic channel 5, the high-temperature resistant tee connector 7, and the third microfluidic channel 8.

[0035] Example 1: A halogen mixed quantum dot and its high-throughput continuous preparation method are described below: S1. Preparation of precursor solution: Weigh 0.814 g of cesium carbonate (Cs2CO3), 2.5 mL of oleic acid (OA), and 40 mL of octadecene (ODE) into a 100 mL three-necked flask. Stir magnetically at 120 °C for 60 min under nitrogen atmosphere, then raise the temperature to 150 °C and stir magnetically for 30 min. Cs2CO3 and OA react completely to obtain cesium oleate (Cs-Oleate) solution. Take 0.5 mL of Cs-Oleate solution into a 50 mL three-necked flask, add 11.5 mL of ODE to dilute, and stir magnetically at 120 °C for 5 min under nitrogen atmosphere until the solution is clear. This is the first precursor solution. S2. Weigh 0.057g PbBr2, 0.101g PbI2, 1mL oleic acid (OA), 1mL oleylamine (OAm) and 10mL octadecene (ODE) into a 50mL three-necked flask, and stir magnetically at 120℃ for 30min under a nitrogen atmosphere until the solution is clear to obtain a PbBr2 / PbI2 solution as the second precursor solution. S3. Prepare the first and second precursor solutions at a molar ratio of Cs:Pb = 1:6, and assemble them into the first syringe 2 and the second syringe 3, respectively. Pump these solutions into the preparation zones (first microfluidic channel 4 and second microfluidic channel 5) of transparent polytetrafluoroethylene (PTFE) tubes with an inner diameter of 300 μm and an outer diameter of 1600 μm using a precision syringe pump 1. Mix the precursor solutions through a high-temperature resistant tee connector 7 and allow them to flow into the PTFE reaction zone (third microfluidic channel 8) with an inner diameter of 300 μm, an outer diameter of 160 μm, and a length of 1000 mm. Control the heating stage 9 to raise the temperature to 160°C and adjust the flow rate of syringe pump 1 to 400 μL / min, allowing the lead halide perovskite (CsPbBr) to react. 1.25 I 1.75 Quantum dots were synthesized in a pipeline with a reaction time of approximately 5 seconds. After the reaction, the mixture was held in an ice bath for approximately 3 seconds. Purification was performed by centrifugation at 8000 rpm for 5 minutes, discarding the supernatant to obtain CsPbBr. 1.25 I 1.75 Quantum dot precipitate was washed with an appropriate amount of n-hexane at 8000 rpm for 5 min, and then the purified CsPbBr was... 1.25 I 1.75 The quantum dot precipitate was stored in hexane.

[0036] To ensure successful synthesis of halogen mixed quantum dots, the experimental temperature needs to be controlled between 140-160℃, preferably 160℃ in this embodiment; the experimental flow rate needs to be controlled between 300-700μL / min, preferably 400μL / min in this embodiment.

[0037] Example 2 A method for the high-throughput continuous preparation of halogen mixed quantum dots includes the following steps: S1. Preparation of precursor solution: Weigh 0.814 g of cesium carbonate (Cs2CO3), 2.5 mL of oleic acid (OA), and 40 mL of octadecene (ODE) into a 100 mL three-necked flask. Stir magnetically at 120 °C for 60 min under nitrogen atmosphere, then raise the temperature to 150 °C and stir magnetically for 30 min. Cs2CO3 and OA react completely to obtain cesium oleate (Cs-Oleate) solution. Take 0.5 mL of Cs-Oleate solution into a 50 mL three-necked flask, add 11.5 mL of ODE to dilute, and stir magnetically at 120 °C for 5 min under nitrogen atmosphere until the solution is clear. This is the first precursor solution. S2. Weigh 0.057g PbBr2, 0.101g PbI2, 0.075g TiO2, 1mL oleic acid (OA), 1mL oleylamine (OAm), and 10mL octadecene (ODE) into a 50mL three-necked flask. Stir magnetically at 120℃ for 30min under a nitrogen atmosphere. The surface of nano-TiO2 is fully modified by PbBr2 and PbI2 to form lead halide / nano-titanium dioxide (PbBr2 / PbI2 / TiO2). PbBr2 / PbI2 / TiO2 reacts completely with OA and OAm to obtain a PbBr2 / PbI2 / TiO2 solution as the second precursor solution. S3. Prepare the first precursor solution and the second precursor solution with a molar ratio of Cs:Pb = 1:6, and assemble them into the first syringe 2 and the second syringe 3, respectively. Pump them into the preparation area pipelines (first microfluidic pipeline 4 and second microfluidic pipeline 5) of transparent polytetrafluoroethylene (PTFE) tubes with an inner diameter of 300 μm and an outer diameter of 1600 μm through the syringe pump 1 (precision syringe pump). Mix the precursor solutions through the high-temperature resistant tee connector 7 and flow into the PTFE reaction zone pipeline (third microfluidic pipeline 8) with an inner diameter of 300 μm, an outer diameter of 1600 μm, and a length of 1000 mm. Control the heating stage to heat the temperature to 160℃ and adjust the flow rate of syringe pump 1 to 400 μL / min to make the lead halide perovskite (CsPbBr1) react. 25 I 1.75 TiO2 quantum dots were synthesized in a pipeline with a reaction time of approximately 5 seconds. After the reaction, the mixture was held in an ice bath for approximately 3 seconds. Purification was performed by centrifugation at 8000 rpm for 5 minutes, discarding the supernatant to obtain CsPbBr. 1.25 I 1.75 / TiO2 quantum dot precipitate, washed with an appropriate amount of n-hexane by centrifugation at 8000 rpm for 5 min, and then purified CsPbBr 1.25 I 1.75 / TiO2 quantum dot precipitates were dispersed in n-hexane for storage.

[0038] Examples 3 to 7 A method for the high-throughput continuous preparation of halogen mixed quantum dots is basically the same as that in Example 2, and the steps are as follows: Different PbX2 compositions and ratios were used, namely Br:I=0:3, Br:I=2:1, Br:I=1.5:1.5, Br:I=1:2 and Br:I=3:0.

[0039] S1. Preparation of precursor solution: Weigh 0.814 g of cesium carbonate (Cs2CO3), 2.5 mL of oleic acid (OA), and 40 mL of octadecene (ODE) into a 100 mL three-necked flask. Stir magnetically at 120 °C for 60 min under nitrogen atmosphere, then raise the temperature to 150 °C and stir magnetically for 30 min. Cs2CO3 and OA react completely to obtain cesium oleate (Cs-Oleate) solution. Take 0.5 mL of Cs-Oleate solution into a 50 mL three-necked flask, add 11.5 mL of ODE to dilute, and stir magnetically at 120 °C for 5 min under nitrogen atmosphere until the solution is clear. This is the first precursor solution. S2. Weigh PbX2 with different halogen molar ratios. The total molar amount of different halogens weighed is 0.376 mmol. The molar ratios are Br:I=0:3, Br:I=2:1, Br:I=1.5:1.5, Br:I=1:2 and Br:I=3:0. Add 0.075 g of nano TiO2, 1 mL of OA, 1 mL of oleylamine (OAm) and 10 mL of ODE to a 50 mL three-necked flask. Stir magnetically at 120 °C for 30 min under a nitrogen atmosphere. The surface of nano TiO2 is fully modified by PbX2 to form lead halide / nano titanium dioxide (PbX2 / TiO2). PbX2 / TiO2 reacts completely with OA and OAm to obtain a PbX2 / TiO2 solution as the second precursor solution. S3. Prepare the first and second precursor solutions at a molar ratio of Cs:Pb = 1:6, and assemble them into the first syringe 2 and the second syringe 3, respectively. Pump them into the preparation area channels (first microfluidic channel 4 and second microfluidic channel 5) of transparent polytetrafluoroethylene (PTFE) tubes with an inner diameter of 300 μm and an outer diameter of 1600 μm using the injection pump 1 (precision injection pump). Mix the precursor solutions through the high-temperature resistant tee connector 7 and flow into the PTFE reaction zone channel (third microfluidic channel 8) with an inner diameter of 300 μm, an outer diameter of 1600 μm, and a length of 1000 mm. Control the heating stage 9 to raise the temperature to 160°C and adjust the flow rate of the injection pump 1 to 400 μL / min to allow the lead halide perovskite (CsPbBr) to react. x I 3-x TiO2 quantum dots were synthesized in a pipeline with a reaction time of approximately 5 seconds. After the reaction, the mixture was held in an ice bath for approximately 3 seconds. Purification was performed by centrifugation at 8000 rpm for 5 minutes, discarding the supernatant to obtain CsPbBr. x I 3-x / TiO2 quantum dot precipitate, washed with an appropriate amount of n-hexane by centrifugation at 8000 rpm for 5 min, and then purified CsPbBr x I 3-x / TiO2 quantum dot precipitates were dispersed in n-hexane for storage.

[0040] The raw material composition and process parameters for preparing the first precursor solution and the second precursor solution in the comparative examples and embodiments are shown in Table 1.

[0041] Table 1. Preparation process parameters of Examples 1-7 The emission spectra of the above quantum dots were measured using a fluorescence spectrometer (HITACHI F-7000) to determine their spectral properties at 365 nm.

[0042] like Figure 2 As shown, under 365nm excitation, the CsPbBr composite with nano-TiO2 in Example 2... x I 3-x The luminescence intensity of the quantum dots was significantly higher than that of CsPbBr in Example 1. x I 3-x The luminescence intensity of quantum dots, CsPbBr x I 3-x The luminescence intensity of TiO2 compared to CsPbBr x I 3-x The luminous intensity increased by 1.3 times.

[0043] The quantum dots were tested using X-ray diffraction (XRD).

[0044] like Figure 3 As shown, the diffraction peaks in Examples 1 and 2 are consistent with those on standard cards PDF#97-016-1481, PDF#97-018-1287 and PDF#00-021-1272.

[0045] In Example 7, TiO2-coated CsPbBr was photographed. x I 3-x Transmission electron microscope image of quantum dots.

[0046] like Figure 4 As shown, CsPbBr in Example 7 x I 3-x / TiO2 quantum dot surface CsPbBr x I 3-x The presence of a TiO2 lattice outside the crystal indicates that Example 7 successfully prepared TiO2-coated CsPbBr. x I 3-x Quantum dots.

[0047] The emission spectra of a halogen mixed quantum dot and its high-throughput continuous preparation method in Examples 2-7 were tested using a fluorescence spectrometer at their respective optimal excitation wavelengths.

[0048] like Figure 5As shown, the emission wavelength can be tuned in the 518-690nm band, indicating that TiO2 coating of CsPbBr can be achieved by adjusting the composition and ratio of lead halide. x I 3-x The spectral modulation of quantum dots has facilitated the widespread application of perovskite quantum dots in the field of optoelectronic materials.

[0049] The TiO2 dispersed in n-hexane in Example 2 was coated with CsPbBr. x I 3-x Quantum dots and CsPbBr dispersed in n-hexane in Example 1 x I 3-x Quantum dots were mixed with deionized water at a 1:1 volume ratio, and CsPbBr was recorded every 5 min and 30 min. x I 3-x Quantum dots and TiO2-coated CsPbBr x I 3-x Spectral changes of quantum dots.

[0050] like Figure 6 As shown, although the luminescence intensity of the quantum dots in Examples 1 and 2 decreased with time, the luminescence intensity of CsPbBr after being combined with nano-TiO2 in Example 2... x I 3-x The decreasing trend in luminescence intensity of quantum dots is significantly weaker than that of CsPbBr in Example 1. x I 3-x Quantum dots, CsPbBr in Example 1 x I 3-x The quantum dots exhibited fluorescence quenching after 150 minutes, while the CsPbBr composite with nano-TiO2 in Example 2... x I 3-x The luminescence intensity of the quantum dots remained at 84% of the initial value after 150 min, indicating that the composite with nano-TiO2 enhanced the luminescence intensity of CsPbBr. x I 3-x The water stability of quantum dots.

[0051] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A high-throughput continuous method of preparation of halogen mixed quantum dots, characterized in that, include: S1: Prepare a first precursor solution containing cesium oleate; Lead halide, TiO2, oleic acid, and oleylamine are mixed in solution and heated to react, yielding a second precursor solution. S2: The first precursor solution and the second precursor solution are reacted in a microchannel reactor to obtain halogen mixed quantum dots.

2. The method of claim 1, wherein the method is a high-throughput continuous preparation method of halogen-mixed quantum dots. In step S1, the preparation method of the first precursor solution includes: mixing cesium source, oleic acid and octadecene, stirring and reacting at 100~130℃ for 1~1.5 h in a protective atmosphere, and then stirring and reacting at 140~160℃ for 0.5~1 h.

3. The method of claim 2, wherein the method is a high-throughput continuous preparation method of halogen-mixed quantum dots. The feed ratio of cesium, oleic acid, and octadecene in the cesium source is 2.5 mmol:(2~3) mL:(30~50) mL; The cesium source is selected from cesium carbonate or cesium acetate.

4. The method of claim 1, wherein the method is a high-throughput continuous preparation method of halogen-mixed quantum dots. In step S1, the lead halide is selected from one or more of lead chloride, lead bromide, or lead iodide.

5. The method of claim 1, wherein the method is a high-throughput continuous preparation method of halogen-mixed quantum dots. In step S1, the feeding ratio of lead halide, TiO2, oleic acid and oleylamine is 0.37~0.38 mmol:0.9~0.95 mmol:(0.8~1.2)mL:1 mL:(8~12) mL.

6. The method of claim 1, wherein the method is a high-throughput continuous preparation method of halogen-mixed quantum dots. In step S1, the heating reaction is carried out at a temperature of 100-130°C for 0.5-1 h for 1 h, and the reaction atmosphere is nitrogen.

7. The method of claim 1, wherein the method is a high-throughput continuous preparation method of halogen-mixed quantum dots. In step S2, the first precursor solution and the second precursor solution are mixed at a molar ratio of Cs:Pb = 1:6~7.

8. The method of claim 1, wherein the method is a high-throughput continuous preparation of halogen-mixed quantum dots. In step S2, the microchannel reactor includes: an aluminum plate (6), a heating zone and an ice bath zone (10) arranged side by side on the aluminum plate (6), a heating platform (9) for supplying heat to the heating zone, an ice water bath in thermal contact with the ice bath zone (10), a microfluidic pipeline arranged in a serpentine pattern on the aluminum plate (6) and extending from the heating zone to the ice bath zone (10), a feeding assembly connected to the inlet end of the microfluidic pipeline, and a collection device (11) connected to the outlet end of the microfluidic pipeline. The microfluidic channel is a transparent circular tube with an inner diameter of 300~400 μm; The feeding assembly includes a first syringe (2) for containing a first precursor solution, a second syringe (3) for containing a second precursor solution, an injection pump (1) for synchronously pushing the first syringe (2) and the second syringe (3), a mixer located at the inlet end of the microfluidic channel, a first microfluidic channel (4) located between the first inlet of the mixer and the first syringe (2), and a second microfluidic channel (5) located between the second inlet of the mixer and the second syringe (3). In the microchannel reactor, the flow rate is 300~700 μL / min; in the mixing reaction, the reaction temperature is 140~160℃ and the reaction time is 5~10 s.

9. A halogen mixed quantum dot, characterized in that, It is prepared by the method described in any one of claims 1 to 8.

10. Use of halogen mixed quantum dots according to claim 9, characterized in that, The halogen mixed quantum dots are used in one of the following: white LEDs, high-resolution display devices, optical communication devices, optical chips, or optoelectronic logic gates.

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