A reaction device and method for narrow-band luminescent indium phosphide quantum dots

Abstract

The present invention discloses a reaction device and method for narrow-band luminescent indium phosphide quantum dots. The reaction device comprises a hypergravity device and a photothermal device. The hypergravity device comprises a housing, a motor, a turntable, a shear filler, a liquid distributor, a reaction chamber, a filler cover, a gas outlet, a liquid outlet, and a liquid inlet. The photothermal device comprises a laser heating device, a circuit and a water cooling device, a reflective layer, and a laser controller. The present invention couples an infrared laser into a hypergravity reactor, utilizes a solvent medium such as water or organic matter to absorb the infrared light and convert it into heat energy to increase its temperature, stimulates the nucleation reaction of a reactant precursor in a "micro-droplet reactor", realizes the controllable growth of quantum dots in the micro-droplet reactor, and finally obtains nanoparticles of uniform size by controlling the laser irradiation and heating time.

Description

Technical Field

[0001] The present invention relates to the technical field of quantum dot nanomaterial preparation. Specifically, it relates to a reaction device and method for producing narrow-band luminescent indium phosphide quantum dots; more specifically, it relates to a method for producing InP / ZnSeS / ZnS core-shell quantum dots and a supergravity-coupled photothermal reaction device. Background Art

[0002] The essence of chemical preparation of indium phosphide (InP) quantum dots is to achieve precise and controllable collisions, splittings, and rearrangements of 20-200 atoms at the macroscale of a reactor, which places extremely high demands on the coordination of nanoscale transport and reaction. Hot injection is currently the most mature method for preparing InP quantum dots. Using tri(trimethylsilyl)phosphine [TMS)3P] as the P source and indium carboxylate as the In source, InP quantum dots with excellent optical properties can be obtained. However, batch production is limited. Solvothermal methods offer advantages in achieving large-scale preparation of InP quantum dots. Using tri(dimethylamino)phosphine [DMA)3P] as the P source, InX3 (X = Cl, Br, I) as the In source, and oleylamine as the solvent, InP nanocrystals of varying sizes can be obtained by varying the ratios of different halogen elements. However, existing liquid-phase precipitation combined with solvothermal growth methods struggle to achieve precise control over the nucleation and growth of InP quantum dots due to limitations in molecular mixing rates within conventional stirred-tank reactors.

[0003] A supergravity reactor is a typical chemical process intensification equipment, in which the liquid medium inside flows in a porous medium in a supergravity environment that is hundreds to thousands of times larger than the earth's gravity field, and is torn into micron-scale or even nanoscale membranes, filaments and droplets (that is, a large number of rapidly updated "micro-droplet reactors" are produced), so that the molecular diffusion, microscopic mixing and mass transfer processes between molecules of different sizes are greatly enhanced. In the supergravity reactor, the microscopic molecular mixing and mass transfer processes are greatly enhanced, and the nanocrystal nucleation and growth process is carried out in a microscopically uniform ideal environment, which can form explosive uniform nucleation of nanocrystals, which is conducive to obtaining nanoparticles with small particle size and narrow distribution. For example, Chinese Patent Application No. 202110642064.1 discloses a method for preparing InP@ZnS core-shell quantum dots by a supergravity reactor and the resulting InP@ZnS core-shell quantum dots. However, the preparation of quantum dots in the InP system requires the use of external energy to break through the crystal nucleation energy barrier in order to stimulate the nucleation reaction of the precursor. Due to the existence of uneven heat flow in traditional high-gravity reactors, it is difficult to achieve explosive and uniform nucleation of InP crystal nuclei in an ideal state, resulting in poor uniformity of the product particle size distribution. The half-peak width of the resulting InP quantum dot emission spectrum is mostly above 50nm. Summary of the Invention

[0004] The first technical problem to be solved by the present invention is to provide a reaction device for narrow-band luminescent indium phosphide quantum dots.

[0005] The second technical problem to be solved by the present invention is to provide a method for producing narrow-band luminescent indium phosphide quantum dots using the above-mentioned reaction device.

[0006] In order to solve the above-mentioned first technical problem, the technical solution adopted by the invention is as follows:

[0007] A reaction device for narrow-band luminescent indium phosphide quantum dots, comprising a supergravity device and a photothermal device;

[0008] The supergravity device includes a housing, a motor, a turntable, a shear filler, a liquid distributor, a reaction chamber, a filler cover, a gas outlet, a liquid outlet, and a liquid inlet;

[0009] The output shaft of the motor passes through the lower surface of the housing and extends into the housing to be fixedly connected to the turntable; at the same time, the top end of the output shaft of the motor is also fixedly connected to the liquid distributor located above the turntable;

[0010] An annular shear filler is provided on the rotating disk, and the top of the shear filler is fixedly covered with a filler cover; a hollow reaction chamber is formed between the rotating disk, the shear filler and the filler cover;

[0011] A liquid outlet is provided on the bottom of the shell; the liquid inlet passes through the shell and is communicated with the filler cover and the reaction chamber; a gas outlet is provided on the top of the shell;

[0012] The photothermal device includes a laser heating device, a circuit and a water cooling device, a reflective layer and a laser controller;

[0013] The reflective layer is arranged on the inner surface of the shell, and an interlayer is provided between the reflective layer and the shell, and a circuit and a water cooling device are provided in the interlayer; the laser heating device is arranged on the inner surface of the reflective layer, and the laser heating device is connected to the laser controller through the circuit in the interlayer.

[0014] Preferably, the filler cap is made of a transparent material to allow the laser to pass through as much as possible.

[0015] Preferably, a turntable is fixed on the output shaft of the motor and drives the turntable to rotate.

[0016] Preferably, the laser heating device includes one or more devices, which can be installed or removed as needed.

[0017] Preferably, the laser heating device is a laser with a wavelength of 980-1500 nm.

[0018] Preferably, the power of the laser heating device is 20-500W.

[0019] In order to solve the above second technical problem, the technical solution adopted by the invention is as follows:

[0020] A method for producing narrow-band luminescent indium phosphide quantum dots using the above-mentioned reaction device comprises the following steps:

[0021] 1) dissolving an indium precursor, a zinc precursor, and a phosphine precursor in an organic solvent respectively, and then introducing them into a high-gravity reactor to react after fully removing water and oxygen at a temperature of 110-130° C. to obtain InP quantum dot cores;

[0022] 2) dissolving zinc salt, sulfur powder, and selenium powder in an organic solvent, and then introducing the mixture into the high-gravity reactor containing the InP quantum dot core to react and obtain InP / ZnSeS core-shell quantum dots;

[0023] 3) introducing the zinc salt and the thiol into the above-mentioned InP / ZnSeS core-shell quantum dots to react to obtain a reaction mixture I;

[0024] 4) Adding a poor solvent to the reaction mixture after the shell coating is completed and centrifuging to obtain a precipitate that is narrow-band luminescent indium phosphide quantum dots.

[0025] Preferably, in step 1), the indium precursor is one of indium iodide, indium bromide and indium chloride.

[0026] Preferably, in step 1), the zinc precursor is one of zinc iodide, zinc bromide and zinc chloride.

[0027] Preferably, in step 1), the phosphine precursor is tris(dimethylamino)phosphine or tris(diethylamino)phosphine.

[0028] Preferably, in step 1), the organic solvent is one or more of oleylamine, octadecylamine, hexadecylamine, tetradecylamine, and dodecylamine.

[0029] Preferably, in step 1), the molar ratio of indium ions in the indium precursor to zinc ions in the zinc precursor is 1:1-1:10.

[0030] Preferably, in step 1), the molar ratio of indium ions in the indium precursor to the phosphine precursor is 1:3-1:7.

[0031] Preferably, in step 1), the molar ratio of the indium precursor to the organic solvent is 1:20-1:100.

[0032] Preferably, in step 2), the zinc salt is one or more of zinc iodide, zinc bromide, zinc chloride, zinc stearate, zinc oleate, and zinc acetate.

[0033] Preferably, in step 2), the ratio of the selenium powder to the sulfur powder is 0:1-2:1.

[0034] Preferably, in step 2), the organic solvent is one of oleylamine, 1-octadecene, tri-n-octylphosphine, and tri-n-octylphosphine oxide.

[0035] Preferably, in step 1 and step 2), the molar ratio of indium ions in the indium precursor to the zinc salt is 1:3-1:10.

[0036] Preferably, in step 1 and step 2), the ratio of the sum of the molar numbers of indium ions in the indium precursor and the sulfur powder and selenium powder is 1:3-1:10.

[0037] Preferably, in step 1) and step 2), the high-gravity reactor is a high-gravity rotating packed bed reactor; the rotation speed of the high-gravity rotating packed bed reactor is 500 rpm-2000 rpm, and the reaction time is 1 s-60 min.

[0038] Preferably, in step 3), the thiol is one of dodecyl mercaptan, hexadecyl mercaptan and octyl mercaptan.

[0039] Preferably, in step 1) and step 3), the molar ratio of indium ions to the thiol in the indium precursor is 1:10-1:20.

[0040] Preferably, in step 4), the poor solvent is ethanol or acetone.

[0041] Any range described in the present invention includes the end value and any numerical value between the end values ​​and any sub-range formed by the end value or any numerical value between the end values.

[0042] Unless otherwise specified, all raw materials in the present invention can be purchased commercially, and the equipment used in the present invention can adopt conventional equipment in the relevant field or refer to the existing technology in the relevant field.

[0043] Compared with the prior art, the present invention has the following beneficial effects :

[0044] 1) The proposed high-gravity photothermal coupling reaction system uses the liquid medium obtained through the high-gravity shearing device as a "micro-droplet reactor." Within the high-gravity reactor, microscopic molecular mixing and mass transfer processes are greatly enhanced. Nanocrystal nucleation and growth occur in a microscopically uniform and ideal environment, resulting in explosive and uniform nucleation of nanocrystals, which is beneficial for obtaining nanoparticles with small size and narrow particle size distribution. Furthermore, an infrared laser is coupled into the high-gravity reactor. A solvent medium such as water or organic matter absorbs the infrared light and converts it into heat, raising its temperature. This stimulates the nucleation reaction of the reactant precursors within the "micro-droplet reactor," achieving controlled growth of quantum dots within the micro-droplet reactor. Finally, uniformly sized nanoparticles are obtained by controlling the laser irradiation and heating time.

[0045] 2) At the same time, the present invention connects the vacuum pump and the nitrogen pipeline through double-row pipes, so that the entire reaction system can be carried out under nitrogen protection, ensuring that the reaction system is free of water and oxygen, so that the high-gravity equipment can be used for quantum dot preparation technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0047] Figure 1 This is a schematic diagram of the structure of the reaction device of the narrow-band luminescent indium phosphide quantum dots of the present invention;

[0048] Figure 2 Schematic diagram of the overall structure of the reaction system in an embodiment of the present invention;

[0049] Figure 3 This is a schematic diagram of the process of synthesizing quantum dots according to the present invention;

[0050] Figure 4 Fluorescence spectra of InP / ZnSeS / ZnS quantum dots synthesized in Examples 1, 2, and 3;

[0051] Figure 5 is the X-ray diffraction (XRD) pattern of InP / ZnSeS / ZnS quantum dots synthesized in Example 1;

[0052] Figure 6 This is the X-ray photoelectron spectroscopy (XPS) spectrum of the InP / ZnSeS / ZnS quantum dots synthesized in Example 1;

[0053] Figure 7 TEM image of the InP / ZnSeS / ZnS quantum dots synthesized in Example 1;

[0054] Figure 8 TEM image of the InP / ZnSeS / ZnS quantum dots synthesized in Example 2;

[0055] Figure 9 TEM image of the InP / ZnSeS / ZnS quantum dots synthesized in Example 3;

[0056] Figure 10 These are photos of the InP / ZnSeS / ZnS quantum dot dispersions synthesized in Examples 1, 2, and 3 under sunlight and 365nm excitation light;

[0057] Figure 11 Fluorescence spectra of InP / ZnSeS / ZnS quantum dots at different supergravity levels synthesized in Example 4;

[0058] Figure 12The full width at half maximum (FWHM) and quantum yield (PLQY) of InP / ZnSeS / ZnS quantum dots with different supergravity levels synthesized in Example 4;

[0059] Figure 13 This is the fluorescence spectrum of InP / ZnS quantum dots synthesized in Comparative Example 1.

[0060] Figure 14 This is a comparison chart of the quantum yield of InP / ZnSeS / ZnS quantum dots synthesized in Comparative Example 2.

[0061] Figure 15 This is the fluorescence spectrum of InP / ZnSeS / ZnS quantum dots synthesized in Comparative Example 3.

[0062] Figure 16 This is the UV-visible absorption spectrum of InP quantum dots synthesized in Comparative Example 4.

[0063] Digital Marking:

[0064] 1- shell;

[0065] 2-motor;

[0066] 3- Turntable;

[0067] 4-shear filler;

[0068] 5-Liquid distributor;

[0069] 6- reaction chamber;

[0070] 7- stuffing cover;

[0071] 8-Gas outlet;

[0072] 9 liquid outlet;

[0073] 11-first liquid inlet;

[0074] 12- second liquid inlet;

[0075] 21-Laser heating device;

[0076] 22-Circuit and water cooling device;

[0077] 23-reflection layer;

[0078] 24-Laser controller. DETAILED DESCRIPTION

[0079] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. Similar components in the accompanying drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the following detailed description is illustrative rather than restrictive and should not be used to limit the scope of protection of the present invention.

[0080] For ease of description, the descriptions of "first", "second", etc. in the present invention are provided for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0081] See also Figure 1 and Figure 2 As shown, as one aspect of the present invention, the present invention provides a reaction device for narrow-band luminescent indium phosphide quantum dots, including a supergravity device and a photothermal device;

[0082] The supergravity device includes a housing 1, a motor 2, a turntable 3, a shear filler 4, a liquid distributor 5, a reaction chamber 6, a filler cover 7, a gas outlet 8, a liquid outlet 9, and liquid inlets 11 and 12;

[0083] The output shaft of the motor 2 extends through the lower surface of the housing 1 into the housing 1 and is fixedly connected to the turntable 3. At the same time, the top end of the output shaft of the motor 2 is also fixedly connected to the liquid distributor 5 located above the turntable 3. The fluid distributor 5 is fixed in the center of the reaction chamber and sprays the reaction material into the entire space.

[0084] An annular shear filler 4 is provided on the turntable 3, and a filler cover 7 is fixedly covered on the top of the shear filler 4; a hollow reaction chamber 6 is formed between the turntable 3, the shear filler 4 and the filler cover 7;

[0085] A liquid outlet 9 is provided on the bottom of the housing 1;

[0086] In the present invention, there are two liquid inlets, including a first liquid inlet 11 and a second liquid inlet 12. The liquid inlet passes through the shell 1 and the packing cover 7 to communicate with the reaction chamber 6; a gas outlet 8 is provided on the top of the shell 1;

[0087] The photothermal device includes a laser heating device 21, a circuit and water cooling device 22, a reflective layer 23 and a laser controller 24;

[0088] The reflective layer 23 is arranged on the inner surface of the shell 1, and an interlayer is provided between the reflective layer 23 and the shell 1, and a circuit and a water cooling device 22 are provided in the interlayer; the laser heating device 21 is arranged on the inner surface of the reflective layer 23, and the laser heating device 21 is connected to the laser controller 24 through the circuit in the interlayer.

[0089] In some embodiments of the present invention, the filler cap is made of a transparent material to allow the laser to pass through as much as possible.

[0090] In some embodiments of the present invention, a turntable is fixed on the output shaft of the motor and drives the turntable to rotate.

[0091] In certain embodiments of the present invention, the laser heating device includes one or more devices, which can be installed or removed as needed; the laser heating device uses a laser controller to control the power of the laser heating.

[0092] In certain embodiments of the present invention, the laser heating device is a laser with a wavelength of 980-1500 nm; the laser heating device uses a water cooling system to ensure the normal operating temperature of the laser.

[0093] In some embodiments of the present invention, the power of the laser heating device is 20-500W.

[0094] The present invention couples an infrared laser into a high-gravity reactor, utilizing a solvent medium such as water or organic matter to absorb the infrared light and convert it into heat, raising its temperature and stimulating the nucleation reaction of the reactant precursors within the "droplet reactor." Because infrared light heating utilizes the principle of electromagnetic radiation heat transfer, it directly transfers heat to stimulate the reaction, thus avoiding the energy loss caused by heating air. This not only saves energy but also is fast and efficient. Furthermore, infrared light has a certain penetrating power. The solvent medium within and on the surface of the "droplet reactor" absorbs the infrared radiation energy simultaneously at a certain depth, generating heat uniformly. This promotes uniform nucleation and growth of particles within the droplets, facilitating the production of high-quality nanoparticle products. The high-gravity coupled photothermal reactor, formed by the fusion of high-gravity and photothermal technologies, can greatly facilitate mass transfer. The interfacial reflection and scattering effects of a large number of microdroplets can more evenly distribute the light radiation throughout the high-gravity reactor cavity, improving the absorption and utilization of the light radiation energy. This approach overcomes the difficulty of achieving uniform heat distribution at higher temperatures in conventional high-gravity reactors and can be used to produce narrow-band luminescent indium phosphide quantum dots with a half-width less than 50 nm. As a sustainable energy source, the utilization of light energy has received close attention from researchers. Photothermal conversion is a ubiquitous energy conversion process in nature and human-developed systems. Due to its potential applications such as photothermal therapy, photothermal conversion has been widely studied. With the rapid development of nanotechnology in recent years, photothermal conversion at the micro-nano scale has received attention in many fields and played a key role. Since infrared light heating uses the principle of electromagnetic radiation heat transfer to transfer heat in a direct manner to achieve the purpose of stimulating the reaction, it avoids the energy loss caused by heating the air, which not only saves energy but also is fast and efficient. In addition, infrared rays have a certain penetrating ability, and the internal and surface solvent media of a certain depth of the "droplet reactor" absorb infrared radiation energy at the same time, generating heat evenly, which promotes the uniform nucleation and growth of particles in the droplets, and is conducive to obtaining high-quality nanoparticle products, such as Figure 3 shown.

[0095] The supergravity-coupled photothermal reactor formed by the fusion of supergravity technology and photothermal technology can greatly promote the mass transfer process. The interface reflection and scattering effects of a large number of microdroplets can make the light radiation more evenly distributed in the entire supergravity reactor cavity, thereby improving the absorption and utilization of light radiation energy.

[0096] As another aspect of the present invention, a method for producing narrow-band luminescent indium phosphide quantum dots using the above-mentioned reaction device comprises the following steps:

[0097] 1) dissolving an indium precursor, a zinc precursor, and a phosphine precursor in an organic solvent respectively, and then introducing them into a high-gravity reactor to react after fully removing water and oxygen at a temperature of 110-130° C. to obtain InP quantum dot cores;

[0098] 2) dissolving zinc salt, sulfur powder, and selenium powder in an organic solvent, and then introducing the mixture into the high-gravity reactor containing the InP quantum dot core to react and obtain InP / ZnSeS core-shell quantum dots;

[0099] 3) introducing the zinc salt and the thiol into the above-mentioned InP / ZnSeS core-shell quantum dots to react to obtain a reaction mixture I;

[0100] 4) Adding a poor solvent to the reaction mixture after the shell coating is completed and centrifuging to obtain a precipitate that is narrow-band luminescent indium phosphide quantum dots.

[0101] In certain embodiments of the present invention, in step 1), the indium precursor is one of indium iodide, indium bromide, and indium chloride.

[0102] In certain embodiments of the present invention, in step 1), the zinc precursor is one of zinc iodide, zinc bromide, and zinc chloride.

[0103] In certain embodiments of the present invention, in step 1), the phosphine precursor is tris(dimethylamino)phosphine or tris(diethylamino)phosphine.

[0104] In certain embodiments of the present invention, in step 1), the organic solvent is one or more of oleylamine, octadecylamine, hexadecylamine, tetradecylamine, and dodecylamine.

[0105] In certain embodiments of the present invention, in step 1), the molar ratio of indium ions in the indium precursor to zinc ions in the zinc precursor is 1:1-1:10.

[0106] In certain embodiments of the present invention, in step 1), the molar ratio of indium ions in the indium precursor to the phosphine precursor is 1:3-1:7.

[0107] In certain embodiments of the present invention, in step 1), the molar ratio of the indium precursor to the organic solvent is 1:20-1:100.

[0108] In certain embodiments of the present invention, in step 2), the zinc salt is one or more of zinc iodide, zinc bromide, zinc chloride, zinc stearate, zinc oleate, and zinc acetate.

[0109] In certain embodiments of the present invention, in step 2), the ratio of the selenium powder to the sulfur powder is 0:1-0:2, preferably.

[0110] In certain embodiments of the present invention, in step 2), the organic solvent is one of oleylamine, 1-octadecene, tri-n-octylphosphine, and tri-n-octylphosphine oxide.

[0111] In certain embodiments of the present invention, in step 1 and step 2), the molar ratio of indium ions to the zinc salt in the indium precursor is 1:3-1:10.

[0112] In certain embodiments of the present invention, in step 1 and step 2), the ratio of the sum of the molar numbers of indium ions in the indium precursor and the selenium powder and sulfur powder is 1:3-1:10.

[0113] In certain embodiments of the present invention, in step 1) and step 2), the high-gravity reactor is a high-gravity rotating packed bed reactor; the rotation speed of the high-gravity rotating packed bed reactor is 500 rpm-2000 rpm, and the reaction time is 1 s-60 min.

[0114] In certain embodiments of the present invention, in step 3), the thiol is one of dodecyl mercaptan, hexadecyl mercaptan, and octyl mercaptan.

[0115] In certain embodiments of the present invention, in step 1) and step 3), the molar ratio of indium ions to the thiol in the indium precursor is 1:10-1:20.

[0116] In certain embodiments of the present invention, in step 4), the poor solvent is ethanol or acetone.

[0117] Example 1

[0118] The supergravity photothermal coupling device of the present invention is used to synthesize InP / ZnSeS / ZnS quantum dots.

[0119] 2.23g of indium iodide, 4.90g of zinc bromide, and 50ml of oleylamine were fully dehydrated and oxygenated at 120℃ for 60min. First, start the motor and laser heating device, set the speed and temperature to 1500r / min and 100℃ respectively, and pass the precursor solution into the supergravity device through a peristaltic pump. Turn on the vacuum pump to a vacuum gauge pressure of -0.086MPa, continue for 5min, and then introduce nitrogen. Repeat this process 3 times, then adjust the laser heating device to 180℃, and fully react under supergravity conditions for 30min to obtain InP quantum dot cores with uniform size.

[0120] Under nitrogen protection, 30g of zinc stearate, 0.43g of selenium powder dissolved in 10ml of tri-n-octylphosphine, and 0.35g of sulfur powder were added to 100ml of octadecene at 120 degrees Celsius. The mixture was introduced into a high-gravity reactor via a peristaltic pump. The laser heating device was adjusted to raise the temperature to 240°C for shell coating. The reaction was carried out for 30 minutes to obtain InP / ZnSeS quantum dots.

[0121] 15 ml of dodecyl mercaptan was introduced into the high-gravity reactor via a peristaltic pump and reacted for 10 min to obtain InP / ZnSeS / ZnS quantum dots;

[0122] The discharge solution was collected; anhydrous ethanol was added and centrifuged and purified three times to obtain a precipitate which was dispersed in n-hexane by ultrasonication to obtain the final product, InP / ZnSeS / ZnS core-shell quantum dot dispersion.

[0123] Figure 4 The emission spectrum of the obtained InP / ZnSeS / ZnS core-shell quantum dots shows a green emission peak at 529 nm with a half-peak width of 50 nm and a quantum yield of 71.46%.

[0124] Figure 5 The X-ray diffraction (XRD) pattern of the obtained InP / ZnSeS / ZnS core-shell quantum dots shows that the obtained product has an InP matching peak and a good crystal form. Figure 6 The X-ray photoelectron spectroscopy (XPS) spectrum of the obtained InP@ZnS core-shell quantum dots shows the presence of In, P, Zn, S, and Se elements. Figure 7 Figure 3 is a transmission electron microscope (TEM) image of the obtained InP / ZnSeS / ZnS core-shell quantum dots, which show good dispersion.

[0125] Figure 10 (a) is a photograph of the dispersion of the obtained InP / ZnSeS / ZnS core-shell quantum dots under sunlight 365nm excitation light. It can be seen that the prepared core-shell quantum dots exhibit bright fluorescence.

[0126] Example 2

[0127] The indium precursor and zinc precursor were replaced with 1 g indium chloride and 7 g zinc iodide, and the rest of the reaction process and conditions remained unchanged.

[0128] Figure 4 This is the emission spectrum of the obtained InP / ZnSeS / ZnS core-shell quantum dots, which has an emission peak of 540 nm, green light, a half-peak width of 47 nm, and a quantum yield of 70.93%. Figure 8 Figure 3 is a transmission electron microscope (TEM) image of the obtained InP / ZnSeS / ZnS core-shell quantum dots, which show good dispersion. Figure 10 (b) is a photograph of the dispersion of the obtained InP / ZnSeS / ZnS core-shell quantum dots under sunlight 365nm excitation light. It can be seen that the prepared core-shell quantum dots exhibit bright fluorescence.

[0129] Example 3

[0130] Example 1 was repeated, except that the zinc precursor was replaced with 3 g of zinc chloride, and the rest of the reaction process and conditions remained unchanged.

[0131] Figure 4The emission spectrum of the obtained InP / ZnSeS / ZnS core-shell quantum dots shows a yellow emission peak at 577 nm with a half-peak width of 44 nm and a quantum yield of 62.25%.

[0132] Figure 9 Figure 2 is a transmission electron microscope (TEM) image of the obtained InP / ZnSeS / ZnS core-shell quantum dots, which show good dispersion.

[0133] Figure 10 (c) is a photograph of the dispersion of the obtained InP / ZnSeS / ZnS core-shell quantum dots under sunlight 365nm excitation light. It can be seen that the prepared core-shell quantum dots exhibit bright fluorescence.

[0134] Example 4

[0135] Example 1 was repeated except that the rotation speed of the high gravity rotating packed bed reactor was set to 0 rpm, 500 rpm, 1000 rpm, 1500 rpm, and 2000 rpm, and the rest of the reaction process and conditions remained unchanged.

[0136] Figure 11 is the emission spectrum of the obtained InP / ZnSeS / ZnS core-shell quantum dots, Figure 12 A comparison chart of the half-maximum width and quantum yield of the obtained InP / ZnSeS / ZnS core-shell quantum dots.

[0137] Comparative Example 1

[0138] Replace the indium precursor and zinc precursor with 1g indium chloride and 3g zinc chloride, and use the supergravity device that is not currently coupled to the photothermal device to prepare InP / ZnS quantum dots. The steps are as follows:

[0139] InP / ZnS quantum dots were synthesized in a supergravity reactor without a coupled photothermal device. The motor was started and the speed was set to 1500 r / min. The InP core Zn precursor mixed oil phase precursor and sodium sulfide nonahydrate aqueous phase precursor were preheated respectively. The precursors were introduced into the supergravity device through a peristaltic pump. The heat from the preheated precursors was used to fully react under supergravity conditions for 30 minutes. Samples were taken at regular intervals and their luminescence properties were tested.

[0140] Figure 13 This is the emission spectrum of the obtained InP / ZnS core-shell quantum dots, which have an emission peak at 613 nm, orange light, a half-peak width of 88 nm, and a quantum yield of 7.38%.

[0141] Comparative Example 2

[0142] Example 1 was repeated except that the rotation speed of the high-gravity rotating packed bed reactor was set to 500 rpm, samples were taken at different reaction times, and the rest of the reaction process and conditions remained unchanged.

[0143] Figure 14 The graph of the quantum yield of the obtained InP / ZnSeS / ZnS core-shell quantum dots changes with time. The quantum dots have the highest quantum yield when the reaction is 30 minutes.

[0144] Comparative Example 3

[0145] Example 1 was repeated, except that the rotation speed of the high gravity rotating packed bed reactor was set to 500 rpm, and the ratio of selenium powder to sulfur powder was changed from 0:1 to 2:1.

[0146] Figure 15 Figure 2 is the fluorescence spectrum of the obtained InP / ZnSeS / ZnS core-shell quantum dots. When the ratio is 0.5:1, the obtained InP / ZnSeS / ZnS core-shell quantum dots have the highest quantum yield of 79.86% and the narrowest half-peak width of 58 nm.

[0147] Comparative Example 4

[0148] Example 1 was repeated, except that the molar ratio of indium ions in the indium precursor to the phosphine precursor was changed from 1:3 to 1:7 to synthesize only InP cores.

[0149] Figure 16 The UV-visible absorption spectrum of the obtained InP quantum dots is shown in Figure 2. As the amount of phosphine precursor increases, the first exciton peak of the quantum dots becomes less and less obvious, indicating that the size uniformity of the quantum dots deteriorates.

[0150] Comparative Example 5

[0151] Example 1 was repeated, except that the molar ratio of indium ions in the indium precursor to the phosphine precursor was 1:2, and only InP cores were synthesized.

[0152] The color of the solution obtained at this time is very light, indicating that the content of phosphine precursor is too low, making nucleation difficult.

[0153] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications based on the above description are possible. It is not possible to enumerate all embodiments here. Any obvious variations or modifications arising from the technical solution of the present invention remain within the scope of protection of the present invention.

Claims

1. A reaction device for narrow-band luminescent indium phosphide quantum dots, characterized in that: Including supergravity device and photothermal device; The supergravity device includes a housing, a motor, a turntable, a shear filler, a liquid distributor, a reaction chamber, a filler cover, a gas outlet, a liquid outlet, and a liquid inlet; The output shaft of the motor passes through the lower surface of the housing and extends into the housing to be fixedly connected to the turntable; at the same time, the top end of the output shaft of the motor is also fixedly connected to the liquid distributor located above the turntable; An annular shear filler is provided on the rotating disk, and the top of the shear filler is fixedly covered with a filler cover; a hollow reaction chamber is formed between the rotating disk, the shear filler and the filler cover; A liquid outlet is provided on the bottom of the shell; the liquid inlet passes through the shell and is communicated with the filler cover and the reaction chamber; a gas outlet is provided on the top of the shell; The photothermal device includes a laser heating device, a circuit and a water cooling device, a reflective layer and a laser controller; The reflective layer is arranged on the inner surface of the shell, and an interlayer is provided between the reflective layer and the shell, and a circuit and a water cooling device are provided in the interlayer; the laser heating device is arranged on the inner surface of the reflective layer, and the laser heating device is connected to the laser controller through the circuit in the interlayer.

2. The reaction device of narrow-band luminescent indium phosphide quantum dots according to claim 1, characterized in that: The filler cover is made of a transparent material to allow the laser to pass through; The laser heating device includes one or more devices, which can be installed or removed as needed; The laser heating device is a laser with a wavelength of 980-1500nm; The power of the laser heating device is 20-500W.

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