Method for manufacturing ZnSe core, method for manufacturing tellurium-doped ZnSe (Te) core, and method for manufacturing ZnSe (Te) / ZnSe / ZnS quantum dot emitting light in blue range

Abstract

The present invention provides a method for obtaining ZnSe core in a flow, a ZnSe core obtained by the method, a method for obtaining tellurium-doped ZnSe (Te) core, a method for obtaining ZnSe (Te) / ZnSe / ZnS quantum dots emitting in the blue range, and ZnSe (Te) / ZnSe / ZnS quantum dots obtained by the method.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a ZnSe seed (core), a ZnSe seed (core), a method for manufacturing a tellurium-doped ZnSe (Te) core, a method for manufacturing ZnSe(Te) / ZnSe / ZnS quantum dots that emit light in the blue light range, and ZnSe(Te) / ZnSe / ZnS quantum dots that emit light in the blue light range. Background Art

[0002] Quantum dots (QDs) are semiconductor nanocrystals with a size of about 10 nm. They are usually composed of an inorganic core and a shell layer, and their composition, size, and other parameters strongly determine the optical properties of the material. Quantum dots absorb light of a given wavelength and convert it into light of a different wavelength. Due to their unique physical and chemical properties, quantum dots have been widely used in various industrial fields, such as displays, lighting, biomedicine, anti-counterfeiting systems, and sensors. Quantum dots prove to be necessary when the new technology market requires luminescent, light-absorbing, or light-converting materials with high optical quality and good long-term stability. The demand for such nanomaterials is also attributed to the significant impact of QDs on the quality and energy efficiency of next-generation devices. QDs are alternatives to organic dyes, etc. Currently, blue light emitters are crucial in all visual applications (displays) and applications that generate white light (lighting) because three colors, RGB (red, green, blue), are required to reproduce the color range. International Patent Application WO2021030432 discloses a highly luminescent nanostructure, specifically a highly luminescent nanostructure containing a ZnSe1-xTex core and a ZnS and / or ZnSe shell layer. The nanostructure composed of a ZnSe1-xTex core and a ZnS and / or ZnSe shell layer exhibits a low full width at half maximum (FWHM) of photoluminescence and a high photoluminescence quantum yield (QY). This document also discloses a method for manufacturing such nanostructures. Specifically, this application describes a nanostructure containing a core surrounded by at least one shell layer, where the core contains ZnSe1-xTex, where 0 < x < 1, where at least one shell layer is selected from the group consisting of ZnS, ZnSe, ZnTe, and their alloys, and where the full width at half maximum (FWHM) of the photoluminescence of the nanostructure is about 20 nm to about 30 nm, and a method for obtaining this structure.

[0003] U.S. Patent Application US2019390109A1 relates to a nanostructure having a core surrounded by at least one shell, wherein the core contains ZnSe1-xTex, where 0 < x < 1, wherein at least one shell contains ZnS or ZnSe, and wherein the FWHM value of the photoluminescence spectrum is from about 10 nm to about 30 nm. This application also discloses a method for manufacturing ZnSe1-xTex nanocrystals, which includes: (a) mixing a selenium source and at least one ligand to produce a reaction mixture; and (b) contacting the reaction mixture obtained in (a) with a zinc source and a solution containing: a tellurium source, a reducing agent, and zinc carboxylate; to provide ZnSe1-xTex nanocrystals.

[0004] Chinese Patent Specification CN111201305B discloses quantum dots with an FWHM value less than 25 nm and coated with ligands (such as carboxylates, phosphines or amines).

[0005] Chinese Patent Application CN110945105A describes cadmium-free quantum dots with a photoluminescence spectrum FWHM of 40 nm or less, which have a core formed of ZnTe, ZnTeS, ZnTeSe or ZnTeSeS. Summary of the Invention

[0006] The object of the present invention is to develop a method for reproducibly obtaining uniform ZnSe seeds (cores) with specific physical and chemical parameters, and then using the obtained seeds (cores) to produce quantum dots that emit light in the blue light color range.

[0007] This object is achieved by the method and product according to the present invention.

[0008] Therefore, the object of the present invention is to provide a method for obtaining ZnSe seeds (cores) by reacting in a flow reaction reactor, and a method for subsequently obtaining tellurium-doped ZnSe (Te) cores + ZnSe / ZnS shells in a flask.

[0009] A further object of the present invention is to provide ZnSe seeds (cores), tellurium-doped ZnSe (Te) cores, and doped core + shells, namely ZnSe(Te) / ZnSe / ZnS quantum dots.

[0010] More specifically, the present invention provides a method for obtaining ZnSe cores in a flow, which is characterized by including the following steps, wherein: - Prepare a mixture of zinc acetate Zn(Ac)2, oleic acid OA, and 1-octadecene ODE by stirring in a reaction vessel; - Degas the obtained mixture at room temperature, reduce the pressure to 1 mbar, then heat to 110 - 130 °C and further degas for 45 - 90 minutes; - The degassed mixture was placed in an argon atmosphere and a solution of selenium precursor in diphenylphosphine (Se-DPP) was added to generate a reaction mixture. The mixture was then incubated at 110-130°C for 30-60 minutes with continuous stirring. The reaction mixture was then passed through a tubular reactor heated to 250-300°C at a rate of 1.0 to 1.5 ml / min, and the reaction solution containing the resulting ZnSe cores was collected at the outlet of the reactor.

[0011] Preferably, zinc acetate (Zn(Ac)2), oleic acid (OA), and 1-octadecene (ODE) are used in a molar ratio ranging from 1:3:23 to 1:4:24.

[0012] Preferably, the amount of the solution Se-DPP using the selenium precursor in diphenylphosphine is such that the molar ratio of Se to Zn is in the range of 1:1.19 to 1:1.21.

[0013] Preferably, the selenium precursor mixture is passed through the tubular reactor heated to 250-300°C at a rate of 1.3 ml / min. Preferably, the selenium precursor mixture is passed through the tubular reactor heated to 250°C at a rate of 1.3 ml / min.

[0014] Preferably, the mixture of anhydrous zinc acetate (Zn(Ac)2), oleic acid (OA), and 1-octadecene (ODE) is stirred at 400-600 rpm in the reaction vessel.

[0015] The present invention also provides a ZnSe core obtained by the method defined above, which exhibits the following characteristics: The wavelength corresponding to the first exciton absorption band of the ZnSe seed crystal (core) is 335-392 nanometers. The absorbance value corresponding to the first exciton absorption band wavelength of the ZnSe seed crystal (core) is 0.20-0.45.

[0016] The present invention also includes a method for obtaining tellurium-doped ZnSe(Te) cores, characterized in that, by obtaining ZnSe cores using the above method, then: - Degas the resulting ZnSe core mixture at 90-110℃ for 10-15 minutes; - The degassed ZnSe core mixture was placed in an Ar environment, heated to 200-220°C, and a solution of tellurium in trioctylphosphine, Te-TOP, was added. The entire reaction solution was then heated to 290-310°C and incubated at 290-310°C for 45-90 minutes.

[0017] Preferably, a mixture of ZnSe core and a solution of tellurium in trioctylphosphine (Te-TOP) with a volume ratio ranging from 24:1 ml to 24.5:1 ml is used.

[0018] A further objective of this invention is to provide a method for obtaining ZnSe(Te) / ZnSe / ZnS quantum dots that emit light in the blue light range, wherein tellurium-doped ZnSe(Te) cores are obtained by the above method, and then... - A ZnSe shell is formed on the tellurium-doped ZnSe(Te) core, and then - An additional ZnS shell is formed on the tellurium-doped ZnSe(Te) core having the ZnSe shell.

[0019] Preferably, the ZnSe shell is formed on the tellurium-doped ZnSe(Te) core by a method comprising the following steps: - At 190-210℃ and under argon atmosphere, add the selenium solution Se-TOP in trioctylphosphine and the zinc precursor solution Zn(OA)2 to the reaction solution containing the ZnSe(Te) core, stir at 150-250 rpm for 100-150 minutes, with the Zn to Se mass ratio in the range of 5.4:1 g to 5.8:1 g, and then allow the mixture to cool. - To precipitate the ZnSe(Te) / ZnSe reaction product from the solution, ethanol and 2-propanol in a mass ratio of approximately 1:1:2 were added to the mixture, the mixture was centrifuged at 4000-5000 rpm for 10-15 minutes and the precipitate was dried. The precipitate was then dispersed in hexane to prepare a solution. Then, on the tellurium-doped ZnSe(Te) core having the ZnSe shell, an additional ZnS shell is fabricated by a method involving the following steps, wherein: - Prepare a solution containing hexadecylamine (HDA), oleic acid (OA), trioctylamine (TOA) and anhydrous zinc acetate in a glass flask with a molar ratio of 2:3:22:1 to 2:3.5:23:1. Then stir the resulting solution at 400-600 rpm, degas it at room temperature for 5-10 minutes, reduce the pressure to 1-10 mbar, heat it to 110-130°C, and further degas it for 10-15 minutes. - Place the degassed mixture in an argon atmosphere, heat to 170-190℃ and add the previously obtained ZnSe(Te) / ZnSe; - Heat the entire reaction solution from 170-190°C to 320-340°C, and simultaneously add the sulfur precursor in trioctylphosphine and the zinc precursor in oleic acid over 60-75 minutes. The mass ratio of sulfur to zinc is in the range of 1:13.9 g to 1:14.1 g. Then allow it to cool. Subsequently, in order to precipitate the ZnSe(Te) / ZnSe / ZnS reaction product from the solution, ethanol and 2-propanol were added to the mixture in a mass ratio of approximately 1:1:2. The mixture was then centrifuged at 4000-5000 rpm for 10-15 minutes and the resulting precipitate was dried.

[0020] Another object of the present invention is to provide ZnSe(Te) / ZnSe / ZnS quantum dots that emit light in the blue light range by the above method, which have the following physical and chemical properties: - Maximum emission wavelength (PL): 442-465nm; - Photoluminescence spectrum FWHM: 10-50nm; -QY:>65%. Attached Figure Description

[0021] The object of the present invention is depicted in the accompanying drawings, wherein: - Figure 1 Example photographs of ZnSe(Te) / ZnSe / ZnS quantum dots emitting light in the blue light range, taken under an HR-TEM microscope; - Figure 2 A schematic diagram of a reactor used for flow reactions is shown; - Figure 3 This graph shows the relationship between the absorbance and photoluminescence of the selected ZnSe(Te) / ZnSe / ZnS quantum dot samples and wavelength. Detailed Implementation

[0022] The key parameters of the method according to the present invention are the flow rate and related reaction time and temperature, the wavelength of the maximum absorption spectrum (Abs) of the obtained ZnSe seed (core), and the Abs value of the ZnSe seed (core) (for the first exciton peak).

[0023] The synthesis method according to the invention, compared to standard reactions carried out in batch reactors (e.g., in flasks), results in ZnSe seed crystals (cores) with higher uniformity and reproducibility due to the absence of so-called batch-to-batch variation—that is, differences in product parameters between consecutive production batches. The method for obtaining ZnSe seed crystals (cores) according to the invention eliminates this problem due to the flow pattern of the reaction, meaning that theoretically, identical products are always produced. This enables the acquisition of ZnSe seed crystals (cores) with the desired physicochemical parameters as the matrix for further steps in quantum dot synthesis during flow.

[0024] Obtaining small and uniform ZnSe cores in batch reactors is challenging because it requires rapid start-up and subsequent rapid termination of the reaction, for example, by rapid heating and cooling of the reaction mixture. In batch reactors, it is difficult to carry out this process uniformly throughout the reaction mixture, especially at larger synthesis scales, making it difficult to obtain cores of identical size. This problem does not occur when the reaction is carried out in a flow. Therefore, another advantage of this invention is the high uniformity of the ZnSe seeds (i.e., ZnSe nanocrystal cores with sufficiently small size) formed in a flow reaction. The high uniformity of the ZnSe seeds (cores) has a direct impact on obtaining a uniform final product (i.e., quantum dots with the desired physicochemical parameters).

[0025] In the case of ZnSe-based quantum dots, the key to achieving luminescence in the 440-470 nm wavelength range lies in tellurium doping of the core. However, the nucleation process of standard doped seeds leads to a performance degradation compared to undoped seeds. On the other hand, introducing dopants into previously obtained, excessively large ZnSe cores is inefficient and may result in significant broadening of the emission spectrum, or the dopant may fail to integrate into the core structure at all. Therefore, the seed crystals obtained in the flow-mode reaction, i.e., small ZnSe cores, have the advantage of allowing tellurium doping to be introduced into them in subsequent stages to achieve emission within the desired wavelength range with a lower half-wavelength broadening of the emission spectrum. Separating the nucleation process of the ZnSe seed crystal (core) from its tellurium doping process allows for independent control of these two processes, ultimately yielding uniform ZnSe(Te) doped cores with controlled physicochemical parameters, representing a homogeneous matrix for further stages of quantum dot synthesis.

[0026] The advantages of this method lie in the uniformity and reproducibility of the products. Furthermore, the product, namely the ZnSe seed crystals (cores), can be collected at selected times, and the product sample taken at this stage, i.e., the quantum dot matrix, can be used for further reaction steps. This is technically impossible when performing this synthesis step in a flask. Moreover, in flask-guided synthesis, tellurium dopant must be implanted within seconds of the start of ZnSe nucleation. Implantation delays have a significant negative impact on the physicochemical properties of the final product (i.e., quantum dots).

[0027] In view of the above, and considering the nucleation of seed crystals in flow patterns and the doping of small cores in a separate process, the synthesis procedure allows for process-controlled modification of the product.

[0028] Key numerical ranges of the method and product according to the present invention: 1. Methods for obtaining ZnSe seed crystals (cores): - Temperature range for the reaction: 250-300 degrees Celsius; - The flow rate of the reaction solution through the reactor: 300-2000 μL / min.

[0029] 2. Product and matrix—ZnSe seed crystals (core): The wavelength corresponding to the first exciton absorption band of the ZnSe seed crystal (core) is 335-392 nanometers. The absorbance value of the first exciton absorption band of the ZnSe seed crystal (core) at the corresponding wavelength is 0.20-0.45.

[0030] 3. A method for obtaining tellurium-doped ZnSe(Te) cores: - Temperature range for the reaction: up to 300 degrees Celsius; - Reaction time in the reactor: 30-60 minutes; - Amount of tellurium added: 0.00-0.00026 mol; 4. Final product—ZnSe(Te) / ZnSe / ZnS quantum dots that emit light in the blue light range: - Maximum emission wavelength (PL): 442-465nm; - Photoluminescence spectrum FWHM: 10-50nm; -QY:>65% Additional information and measurements: Photoluminescence spectra were measured to determine the position and broadening of the photoluminescence peaks. The wavelength of maximum emission (PL) and the half-width at half-maximum (FWHM) of the photoluminescence spectrum were measured using a PerkinElmer FL 8500 fluorescence spectrometer (excitation wavelength set to 405 nm) or an Avantes AvaSpec-2048XL spectrometer (excitation wavelength set to 365 nm). Absorbance was measured using a PerkinElmer Lambda 364 UV-VIS spectrophotometer. The photoluminescence quantum yield was measured using a Hamamatsu Quantaurus-QY absolute PL quantum yield spectrometer C11347-11. Quantum dot size was measured using an Anton-Paar Litesizer 500 (DLS). The morphology of the quantum dots was observed using a high-resolution transmission electron microscope (HR-TEM) (FEI Titan G2 60-300).

[0031] Example images of ZnSe(Te) / ZnSe / ZnS quantum dots emitting light in the blue light range, taken under an HR-TEM microscope, are shown below. Figure 1 As shown.

[0032] The particle size (DLS) distribution results of three selected samples of the final product (i.e., ZnSe(Te) / ZnSe / ZnS quantum dots that emit light in the blue light range).

[0033]

[0034] A schematic diagram of a flow reaction reactor is shown below. Figure 2 As shown.

[0035] Parameters of a flow reaction reactor: - Maximum temperature: 1100℃; - Power: 13.8 kW; - Heating zone length: 117 cm.

[0036] The quantum yield (QY) and maximum emission wavelength values ​​of the photoluminescence (PL) spectra of three selected samples of the final product (i.e., ZnSe(Te) / ZnSe / ZnS quantum dots that emit light in the blue light range).

[0037]

[0038] Figure 3 This diagram shows the relationship between absorbance and photoluminescence versus wavelength for selected ZnSe(Te) / ZnSe / ZnS quantum dot samples.

[0039] in conclusion: The purpose of this invention is to synthesize ZnSe seed crystals (cores) in a flow manner, which provide a matrix for further quantum dot synthesis.

[0040] The obtained ZnSe seed crystals (cores) are doped with tellurium and coated with a shell to obtain blue light-emitting quantum dots composed of tellurium-doped ZnSe(Te) cores coated with ZnSe / ZnS shells.

[0041] Example Example 1: Flow synthesis of ZnSe seed crystals (cores) and tellurium doping of the resulting ZnSe seed crystals (cores). The system used for flow synthesis consists of a furnace (tubular reactor) and a steel tube 160 cm long and 0.3175 cm (1 / 8 inch) in diameter, through which the flow of the reaction solution is guided. It also includes a flow meter, a peristaltic pump, an argon gas source, and a flexible tube with high chemical and heat resistance, which is surrounded by a heating belt connected to a temperature controller.

[0042] Measure 1.1 g (0.006 mol) of anhydrous zinc acetate (Zn(Ac)2), 5.37 g (0.019 mol) of oleic acid (OA) and 35.51 g (0.14 mol) of 1-octadecene (ODE) and place all components in a glass flask.

[0043] Under a fume hood, connect the system to the Schlenk line and place the flask containing the reagents in a heating basket connected to a temperature controller set on a magnetic stirrer (500 rpm). Pre-degas the solution at room temperature for 5 minutes, gradually reducing the pressure inside the flask until it reaches 1 mbar. Then, heat the solution to 120°C over approximately 12 minutes. At this temperature, degas the solution again for 1 hour. Then, connect the system to argon and rapidly inject a solution of 1.5 mol of selenium precursor (0.237 g selenium) in diphenylphosphine (1.56 g diphenylphosphine) (Se-DPP), and incubate the solution at 120°C for 30 minutes.

[0044] Subsequently, a peristaltic pump set to a speed of 1.3 mL / min was started, and the reaction solution was passed through a tubular reactor heated to 250 °C, which was part of the flow synthesis system. For the first 10 minutes, the reaction solution was collected in a separate beaker. Then, the reaction solution containing the obtained ZnSe seed crystals (cores) was collected in a flask for approximately 42 minutes until a volume of 54 mL was reached. The collected solution was degassed again at 100 °C for 10 minutes. The argon supply was shut off, and the solution was heated to 210 °C. A solution of 0.056 mol of tellurium (0.016 g of tellurium) in trioctylphosphine (1.86 g of trioctylphosphine) (Te-TOP) was then injected into the reaction mixture. The solution was then heated to 300 °C and incubated at 300 °C for 60 minutes. The resulting ZnSe (Te) cores were further used in the synthesis, specifically in the growth of the ZnSe shell.

[0045] Example 2 Synthesis of ZnSe shell In an anaerobic environment, 60 mL of a solution of 0.75 M zinc precursor (8.25 g zinc) in oleic acid (26.73 g OA), 12.46 g TOP, and 12.13 g trioctylamine (TOA) was melted on a hot plate at 180 °C and then transferred to a glass vial. A solution of 15.12 mL of 1.2 M selenium (1.48 g Se) in trioctylphosphine (12.47 g TOP) (Se-TOP) was drawn into a syringe.

[0046] Under the fume hood, connect the tubing and needle to a syringe equipped with Se-TOP. Place the syringe in an infusion pump with the flow rate set to 126 μL / min.

[0047] Place the zinc precursor bottle on a heating plate set to 180°C and stirred at 200 rpm. Cover the bottle with a ring cap and pass the hose attached to the peristaltic pump through one of the rings (feed rate 501 μL / min). Connect the argon feed hose to the other ring and turn on the argon gas.

[0048] After incubating the ZnSe(Te) core solution obtained in the previous steps at 300°C, the precursor solution is supplied by connecting a tubing with a needle and septum to the flask, and the injection of Se-TOP (126 μL / min) and Zn(OA)₂ (501 μL / min) begins. Each injection should last 120 minutes. After injection, the heating basket is closed, and the flask is left in the basket to cool the reaction solution.

[0049] The reaction solution was poured into a container and weighed. Ethanol, corresponding to the mass of the reaction solution, and 2-propanol, corresponding to twice the mass of the reaction solution, were added to the container. The solution was centrifuged at 4500 rpm for 10 minutes. After centrifugation, the precipitate was dried and dispersed in 17.5 g (0.2 mol) of n-hexane. The resulting ZnSeTe / ZnSe product was used in a further part of the synthesis, specifically in the growth of the ZnS shell.

[0050] Example 3 Synthesis of ZnS shell Measure 8.69 g (0.036 mol) of hexadecylamine (HDA), 16.11 g (0.057 mol) of oleic acid (OA), 145.65 g (0.412 mol) of trioctylamine (TOA), and 3.3 g (0.018 mol) of anhydrous zinc acetate, and place all components together in a glass flask. Under anaerobic conditions, melt 54 mL of a 0.75 M zinc precursor (7.43 g Zn) solution in oleic acid (24.06 g OA) on a hot plate at 180 °C, and transfer the melt to a glass bottle. Draw 13.5 mL of a 1.2 M sulfur precursor (0.53 g sulfur) solution in trioctylphosphine (11.22 g TOP) into a syringe.

[0051] Under a fume hood, connect the tubing and needle to the syringe containing the sulfur precursor. Place the syringe in a syringe pump set to a flow rate of 225 μL / min. Place the vial containing the zinc precursor on a heating plate set to 180°C and stirred at 200 rpm. Cap the vial with a ring cap and pass the tubing from the peristaltic pump (feed rate 900 μL / min) through one ring, connect the argon feed tubing to the other ring, and turn on the argon gas. The sulfur and zinc precursors are ready to be added in the next stage of the synthesis.

[0052] Under a fume hood, connect the system to the Schlenk line and place the flask containing the reagents measured in the first step (HDA, OA, TOA, and anhydrous zinc acetate) in a heating basket, connected to a temperature controller set on a magnetic stirrer (500 rpm). Initially, pre-degas the solution at room temperature for 5 minutes, gradually reducing the pressure in the flask until it reaches 1-10 mbar. Then, heat the solution to 120°C over approximately 12 minutes. At this temperature, degas the solution again for 10 minutes. Then, connect the system with argon and heat the solution to 180°C. Subsequently, draw the ZnSeTe / ZnSe product obtained in the previous stage (dissolved in hexane) into a syringe and forcefully inject it into the solution over approximately 1 minute. Heat the solution to 185°C and begin simultaneous administration of the prepared zinc and sulfur precursors over approximately 60 minutes. Simultaneously, heat the solution to 330°C while adding the precursors. Once 330°C is reached and both precursors have been fed, close the heating basket and leave the flask in the basket to cool.

[0053] Pour the reaction solution into a container and weigh it. Add an amount of ethanol corresponding to the mass of the reaction solution, and an amount of 2-propanol corresponding to twice the mass of the reaction solution. Centrifuge the solution at 4500 rpm for 10 minutes. After centrifugation, dry the precipitate and disperse it in toluene to achieve a final product concentration of approximately 100 mg / mL.

Claims

1. A method for obtaining ZnSe cores in a flowing stream, characterized in that, Includes the following steps, wherein: - A mixture of anhydrous zinc acetate (Zn(Ac)2), oleic acid (OA), and 1-octadecene (ODE) was prepared by stirring in a reaction vessel; - The resulting mixture was degassed at room temperature, the pressure was reduced to 1 mbar, and then heated to 110-130°C and further degassed for 45-90 minutes; - The degassed mixture was placed in an argon atmosphere and a solution of selenium precursor in diphenylphosphine (Se-DPP) was added to generate a reaction mixture. The mixture was then incubated at 110-130°C for 30-60 minutes with continuous stirring. The reaction mixture was then passed through a tubular reactor heated to 250-300°C at a rate of 1.0 to 1.5 ml / min, and the reaction solution containing the resulting ZnSe cores was collected at the outlet of the reactor.

2. The method according to claim 1, characterized in that, Zinc acetate (Zn(Ac)2), oleic acid (OA), and 1-octadecene (ODE) were used in molar ratios ranging from 1:3:23 to 1:4:

24.

3. The method according to claim 1 or claim 2, characterized in that, The amount of the solution Se-DPP using the selenium precursor in diphenylphosphine is such that the molar ratio of Se to Zn is in the range of 1:1.19 to 1:1.

21.

4. The method according to any one of claims 1 to 3, characterized in that, The selenium precursor mixture is passed through the tubular reactor heated to a temperature range of 250-300°C at a rate of 1.3 ml / min.

5. The method according to any one of claims 1 to 4, characterized in that, The mixture of anhydrous zinc acetate (Zn(Ac)2), oleic acid (OA), and 1-octadecene (ODE) was stirred at 400-600 rpm in the reaction vessel.

6. A ZnSe core obtained by the method according to any one of claims 1 to 5, characterized in that, It exhibits the following characteristics: The wavelength corresponding to the first exciton absorption band of the ZnSe seed crystal (core) is 335-392 nanometers. The absorbance value corresponding to the first exciton absorption band wavelength of the ZnSe seed crystal (core) is 0.20-0.

45.

7. A method for obtaining tellurium-doped ZnSe(Te) cores, characterized in that, ZnSe cores are obtained by the method of any one of claims 1 to 5, and then: - Degas the resulting ZnSe core mixture at 90-110℃ for 10-15 minutes; - The degassed ZnSe core mixture was placed in an Ar environment, heated to 200-220°C, and a solution of tellurium in trioctylphosphine, Te-TOP, was added. The entire reaction solution was then heated to 290-310°C and incubated at 290-310°C for 45-90 minutes.

8. The method according to claim 7, characterized in that, Use a ZnSe core mixture with a solution of tellurium in trioctylphosphine in a volume ratio ranging from 24:1 ml to 24.5:1 ml (Te-TOP).

9. A method for obtaining ZnSe(Te) / ZnSe / ZnS quantum dots that emit light in the blue light range, characterized in that, The tellurium-doped ZnSe(Te) core is obtained by the method of any one of claims 7 to 8, and then - A ZnSe shell is formed on the tellurium-doped ZnSe(Te) core, and then - An additional ZnS shell is formed on the tellurium-doped ZnSe(Te) core having the ZnSe shell.

10. The method according to claim 9, characterized in that, - The ZnSe shell is formed on the tellurium-doped ZnSe(Te) core by a method comprising the following steps: - At 190-210℃ and under argon atmosphere, add the selenium solution Se-TOP in trioctylphosphine and the zinc precursor solution Zn(OA)2 to the reaction solution containing the ZnSe(Te) core, stir at 150-250 rpm for 100-150 minutes, with the Zn to Se mass ratio in the range of 5.4:1 g to 5.8:1 g, and then allow the mixture to cool. - To precipitate the ZnSe(Te) / ZnSe reaction product from the solution, ethanol and 2-propanol in a mass ratio of approximately 1:1:2 were added to the mixture, the mixture was centrifuged at 4000-5000 rpm for 10-15 minutes and the precipitate was dried. The precipitate was then dispersed in hexane to prepare a solution. - On the tellurium-doped ZnSe(Te) core having the ZnSe shell, an additional ZnS shell is formed by a method involving the following steps, wherein: - Prepare a solution containing hexadecylamine (HDA), oleic acid (OA), trioctylamine (TOA) and anhydrous zinc acetate in a glass flask with a molar ratio of 2:3:22:1 to 2:3.5:23:

1. Then stir the resulting solution at 400-600 rpm, degas it at room temperature for 5-10 minutes, reduce the pressure to 1-10 mbar, heat it to 110-130°C, and further degas it for 10-15 minutes. - Place the degassed mixture in an argon atmosphere, heat to 170-190℃ and add the previously obtained ZnSe(Te) / ZnSe; - Heat the entire reaction solution from 170-190°C to 320-340°C, and simultaneously add the sulfur precursor in trioctylphosphine and the zinc precursor in oleic acid over 60-75 minutes. The mass ratio of sulfur to zinc is in the range of 1:13.9 g to 1:14.1 g. Then allow it to cool. - To precipitate the ZnSe(Te) / ZnSe / ZnS reaction product from the solution, ethanol and 2-propanol are added to the mixture in a mass ratio of approximately 1:1:

2. The mixture is then centrifuged at 4000-5000 rpm for 10-15 minutes and the resulting precipitate is dried.

11. The method according to any one of claims 9 to 10, wherein the resulting ZnSe(Te) / ZnSe / ZnS quantum dots emitting light in the blue light range are characterized in that, It has the following physical and chemical properties: - Maximum emission wavelength (PL): 442-465nm; - Photoluminescence spectrum FWHM: 10-50nm; -QY:>65%.

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