CN111117621A

CN111117621A - Preparation method of quantum dot core and core-shell quantum dot, quantum dot material and composition

Info

Publication number: CN111117621A
Application number: CN202010013637.XA
Authority: CN
Inventors: 乔培胜; 吴洪剑; 余文华; 苏叶华
Original assignee: Najing Technology Corp Ltd
Current assignee: Najing Technology Corp Ltd
Priority date: 2020-01-07
Filing date: 2020-01-07
Publication date: 2020-05-08
Anticipated expiration: 2040-01-07
Also published as: CN111117621B

Abstract

The application provides a preparation method of a quantum dot nucleus, which comprises the following steps: preparing a first complex: reacting the first cation precursor, the first ligand and the second ligand at a first temperature for t1 to obtain a first complex; preparing a first solution: mixing the second cation precursor, the first anion precursor, the second anion precursor and the first solvent and reacting at a second temperature to obtain a first solution containing nanoclusters; preparing a second solution: mixing a third cation precursor, a fourth cation precursor, a third anion precursor and a second solvent and reacting at a third temperature to obtain a second solution containing initial quantum dots; preparing a first mixed solution: mixing the first compound, the first solution and the second solution, and reacting to obtain a first mixed solution containing a quantum dot core; wherein the first ligand is a carboxylic acid ligand and the second ligand is a phosphine-containing ligand. The prepared quantum dot core has excellent surface performance and is beneficial to coating of a subsequent shell layer.

Description

Preparation method of quantum dot core and core-shell quantum dot, quantum dot material and composition

Technical Field

The application relates to the technical field of quantum dot materials, in particular to a preparation method of a quantum dot core, a preparation method of a core-shell quantum dot, a quantum dot material, a quantum dot composition and a quantum dot device.

Background

The III-V group quantum dots represented by InP in the quantum dots avoid the disadvantage that the conventional quantum dot material contains heavy metal Cd, and are widely concerned by people in the fields of display, photoelectricity and the like. However, the InP material has a wide fluorescence half-peak width and low light-emitting efficiency, and needs to be solved by metal doping, shell cladding, and the like. The method is one of feasible ways to add II and VI elements such as Zn, Se, S and the like into InP to form quaternary quantum dot structures such as InZnPSe, InZnPS and the like. However, the atomic radii and bonding forms of different elements are greatly different, so that the effective doping of elements such as Zn, Se and S and the luminescence property of the quaternary quantum dots do not reach an ideal level. The problems relate to the basic mechanism and the regulation and control means of quantum dot nucleation growth, surface defects, dangling bond control and the like, and a clear recognition and effective method for the basic mechanism and the regulation and control means is not provided.

In the prior art, hydrofluoric acid, carboxylic acid, organic amine and the like are often adopted for surface treatment of quantum dots, but the structure of the quantum dots is easily damaged, and the subsequent effective coating of a shell layer is difficult to solve. Therefore, a reasonable synthesis route is designed to prepare the high-performance InZnPSe/ZnSeS or InZnPS/ZnSeS core-shell quantum dot, especially the fluorescence half-peak width of the quantum dot is reduced to be below 40nm, and the fluorescence quantum yield is improved to be more than 60%, so that the requirements of the application in the novel display field are met, and the method is a huge challenge in the application of the cadmium-free quantum dot.

Disclosure of Invention

The application aims to provide a preparation method of a quantum dot nucleus, which comprises the following steps: preparing a first complex: reacting the first cation precursor, the first ligand and the second ligand at a first temperature for t1 to obtain a first complex; preparing a first solution: mixing the second cation precursor, the first anion precursor, the second anion precursor and the first solvent and reacting at a second temperature to obtain a first solution containing nanoclusters; preparing a second solution: mixing a third cation precursor, a fourth cation precursor, a third anion precursor and a second solvent and reacting at a third temperature to obtain a second solution containing initial quantum dots; preparing a first mixed solution: mixing the first compound, the first solution and the second solution, and reacting to obtain a first mixed solution containing a quantum dot core; wherein the first ligand is a carboxylic acid ligand and the second ligand is a phosphine-containing ligand.

Further, in the process of preparing the first mixed solution, the first compound and the second solution are mixed at a fourth temperature for reaction time t2 to obtain a first intermediate reaction solution, and then the first solution and the first intermediate reaction solution are mixed at a fifth temperature for reaction to obtain a solution containing the quantum dot core.

Further, the first solution and the first intermediate reaction solution are mixed in a manner that the first solution is added to the first intermediate reaction solution at a constant speed, preferably, the constant speed addition is dropwise.

Further, the dropping speed of the first solution is 0.2-2 mol/h for each 1mol of the third anion precursor.

Further, the first cation precursor and the third cation precursor are zinc precursors, the second cation precursor and the fourth cation precursor are indium precursors, the first anion precursor and the third anion precursor are phosphorus precursors, and the second anion precursor is a sulfur precursor or a selenium precursor.

Further, the molar ratio of the first cation precursor to the first ligand is 1:2 to 2:1, the molar ratio of the first cation precursor to the second ligand is 1:5 to 1:50, and the molar ratio of the first cation precursor to the third anion precursor is 5:1 to 20: 1.

Further, the carboxylic acid ligand is carboxylic acid with a carbon main chain of C10-C20, and the phosphine-containing ligand is alkyl phosphine with a carbon main chain of C1-C10.

The process according to claim 1, wherein the first temperature is 150 to 300 ℃, the second temperature is 50 to 150 ℃, the third temperature is 250 to 310 ℃, and the reaction time t1 is 20 to 60 min.

Further, the fourth temperature is 150-300 ℃, the fifth temperature is 250-310 ℃, and the reaction time t2 is 20-120 min.

The application also provides a preparation method of the core-shell quantum dot, which comprises the following steps: preparing a second complex: reacting the fifth cation precursor, the third ligand and the fourth ligand at a sixth temperature for t3 to obtain a second compound; mixing the second compound, the first mixed solution and the fifth anion precursor, and reacting to obtain a mixed solution containing the core-shell quantum dots; wherein the third ligand is a carboxylic acid ligand, and the fourth ligand is a phosphine-containing ligand.

Further, the second compound and the first mixed solution are mixed and react at a seventh temperature for t4 to obtain a second intermediate reaction solution, and then the fifth anion precursor and the second intermediate reaction solution are mixed and react at an eighth temperature to obtain a solution containing the core-shell quantum dots.

Further, the fifth cation precursor is a zinc precursor, and the fifth anion precursor is a mixed precursor of a sulfur precursor and a selenium precursor.

Further, the molar ratio of the fifth cation precursor to the third ligand is 1:2 to 2:1, and the molar ratio of the fifth cation precursor to the fourth ligand is 1:5 to 1: 50.

The process according to claim 10, wherein the sixth temperature is 150 to 300 ℃ and the reaction time t3 is 20 to 60 min.

Furthermore, the seventh temperature is 150-300 ℃, the eighth temperature is 250-310 ℃, and the reaction time t4 is 20-120 min.

The application also provides a quantum dot material which comprises the core-shell quantum dot, wherein the core-shell quantum dot is prepared by any one of the preparation methods, the half-peak width of the quantum dot material is less than 40nm, and the quantum yield of the quantum dot material is more than 70%; preferably, the half-peak width of the quantum dot material is 35-40 nm.

The application also provides a quantum dot composition, and the quantum dot composition comprises the quantum dot material.

The application also provides a quantum dot device, and the quantum dot device comprises the quantum dot material or the quantum dot composition.

Compared with the prior art, the beneficial effect of this application lies in: according to the preparation method, the first cation precursor, the first ligand and the second ligand are prepared to obtain the first compound, so that the solubility of the first cation precursor in a reaction system can be improved, the activity of the first cation precursor in the reaction system can be adjusted, the situation that the reaction activity is too high and unnecessary damage is caused to the surface of the quantum dot is avoided, and the preparation method is favorable for obtaining the quantum dot core with excellent surface performance.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

The present application is further described below with reference to specific embodiments, and it should be noted that, without conflict, any combination between the embodiments or technical features described below may form a new embodiment.

It is noted that the terms first, second and the like in the description and in the claims of the present application are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It should be understood that the data so used may be interchanged under appropriate circumstances such that embodiments of the application described herein may be used. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

It should be noted that the molar ratio in the present application refers to the ratio of the reactants at the time of addition, and does not refer to the ratio dynamically during the reaction.

As described in the background art, the existing preparation method treats the surface of the InP quantum dot with hydrofluoric acid, carboxylic acid, organic amine, etc., but has limited effect on treating surface defects, dangling bonds and excess precursors of the quantum dot, resulting in the problems of quantum dot structure damage, difficulty in effectively coating a shell layer, etc. In order to solve the technical problem, the application provides a preparation method of a quantum dot nucleus, which comprises the following steps: preparing a first complex: reacting the first cation precursor, the first ligand and the second ligand at a first temperature for t1 to obtain a first complex; preparing a first solution: mixing the second cation precursor, the first anion precursor, the second anion precursor and the first solvent and reacting at a second temperature to obtain a first solution containing nanoclusters; preparing a second solution: mixing a third cation precursor, a fourth cation precursor, a third anion precursor and a second solvent and reacting at a third temperature to obtain a second solution containing initial quantum dots; preparing a first mixed solution: mixing the first compound, the first solution and the second solution, and reacting to obtain a first mixed solution containing a quantum dot core; wherein the first ligand is a carboxylic acid ligand and the second ligand is a phosphine-containing ligand.

According to the preparation method, the first cation precursor, the first ligand and the second ligand are prepared to obtain the first compound, so that the solubility of the first cation precursor in a reaction system can be improved, the activity of the first cation precursor in the reaction system can be adjusted, the situation that the reaction activity is too high and unnecessary damage is caused to the surface of the quantum dot is avoided, and the preparation method is favorable for obtaining the quantum dot core with excellent surface performance.

In some embodiments, the first solvent and the second solvent are each independently selected from non-coordinating organic solvents commonly used in the art. In some preferred embodiments, the non-coordinating organic solvent may be, but is not limited to, one or more of octadecene, squalane, paraffin oil.

In some embodiments, in the process of preparing the first mixed solution, the first compound and the second solution are mixed at the fourth temperature for reaction time t2 to obtain a first intermediate reaction solution, and then the first solution and the first intermediate reaction solution are mixed at the fifth temperature for reaction to obtain a solution containing the quantum dot core.

In the process of preparing the quantum dot core, the initial quantum dot is prepared firstly, and then the surface treatment is carried out on the initial quantum dot by adopting the first compound, so that dangling bonds and defects on the surface of the initial quantum dot are reduced, the surface performance of the quantum dot core is regulated and controlled, and the redundant fourth cation precursor is reduced. And finally, adding a first solution containing nanoclusters to grow the quantum dot cores, thereby being beneficial to obtaining the quantum dot cores with excellent surface properties.

In some embodiments, the first solution is mixed with the first intermediate reaction solution in such a way that the first solution is added to the first intermediate reaction solution at a uniform rate.

In some preferred embodiments, the first solution is mixed with the first intermediate reaction solution in such a manner that the first solution is added dropwise to the first intermediate reaction solution. The addition speed and the addition amount of the nanoclusters can be better controlled by adopting a dropwise adding mode, and the growth of quantum dot cores can be favorably regulated and controlled.

In some embodiments, the first solution is added dropwise at a rate of 0.2 to 2mol/h for each 1mol of the third anion precursor.

In some embodiments, the first and third cation precursors are zinc precursors, the second and fourth cation precursors are indium precursors, the first and third anion precursors are phosphorus precursors, and the second anion precursor is a sulfur precursor or a selenium precursor.

In some embodiments, the zinc precursor is a lower molecular weight zinc precursor. In some preferred embodiments, the zinc precursor can be, but is not limited to, zinc acetate, zinc propionate, zinc acetylacetonate, zinc chloride, zinc bromide, zinc iodide, and the like.

It is worth mentioning that the zinc precursor with small molecular weight has small solubility in the solvent commonly used in the field, can not fully contact with other reactants in the reaction process, has high reaction activity, is easy to damage the surface of the quantum dot, and has good modification effect on the surface of the quantum dot. The zinc precursor is reacted with the first ligand and the second ligand to form a zinc precursor-ligand complex, so that the solubility of the zinc precursor in a solvent is improved, and the activity of the zinc precursor is adjusted, the zinc precursor is mildly treated and activated on the surface of an initial quantum dot, and dangling bonds and defects on the surface of the initial quantum dot are reduced.

In some embodiments, the indium precursor is a carboxylic acid-containing indium precursor. In some preferred embodiments, the indium precursor can be, but is not limited to, indium myristate, indium laurate, indium palmitate, indium oleate, and the like.

In some embodiments, the phosphorus precursor is a phosphorus precursor comprising a Si-P bond. In some preferred embodiments, the phosphorus precursor can be, but is not limited to, tris (trimethylsilyl) phosphine, tris (triethylsilyl) phosphine, tris (triphenylsilyl) phosphine, and the like.

In some embodiments, the sulfur precursor can be, but is not limited to, sulfur-trioctylphosphine, sulfur-tributylphosphine, sulfur-octadecene, dodecylmercaptan, octylmercaptan.

In some embodiments, the selenium precursor may be, but is not limited to, selenium-trioctylphosphine, selenium-tributylphosphine, selenium-octadecene.

In some specific embodiments, the initial quantum dots are InZnP, and the nanoclusters are inp or inp se.

In some specific embodiments, the quantum dot core is a quaternary quantum dot core. In some particularly preferred embodiments, the quantum dot core is InZnPS or InZnPSe.

In some embodiments, the molar ratio of the first cation precursor to the first ligand is 1:2 to 2:1, the molar ratio of the first cation precursor to the second ligand is 1:5 to 1:50, and the molar ratio of the first cation precursor to the third anion precursor is 5:1 to 20: 1. In some embodiments, the molar ratio of the first cation precursor to the first ligand is from 1:2 to 1: 1.

In some embodiments, the molar ratio of the first cation precursor to the first ligand is from 1:1 to 2: 1.

In some embodiments, the molar ratio of the first cation precursor to the second ligand is from 1:5 to 1: 20.

In some embodiments, the molar ratio of the first cation precursor to the second ligand is from 1:10 to 1: 50.

In some embodiments, the molar ratio of the first cation precursor to the second ligand is from 1:20 to 1: 400.

In some embodiments, the molar ratio of the first cation precursor to the second ligand is from 1:5 to 1: 30.

The molar ratio of the first cation precursor to the third anion precursor is 5:1 to 15: 1.

The molar ratio of the first cation precursor to the third anion precursor is 10:1 to 20: 1.

The molar ratio of the first cation precursor to the third anion precursor is 15:1 to 20: 1.

The molar ratio of the first cation precursor to the third anion precursor is 5:1 to 10: 1.

Selecting the molar ratio of the first cation precursor to the first ligand within the above-mentioned ratio range facilitates sufficient reaction of the first cation precursor with the first ligand and avoids excessive amounts of the first ligand from affecting the preparation of the first complex and the surface treatment of the initial quantum dots. Selecting the molar ratio of the first cation precursor to the second ligand within the above-mentioned ratio range facilitates sufficient reaction of the first cation precursor with the second ligand and avoids the second ligand being in excess to affect the preparation of the first complex and the surface treatment of the initial quantum dot. Selecting the molar ratio of the first cation precursor to the third anion precursor in the above ratio range facilitates sufficient surface treatment of the initial quantum dot by the first complex.

In some embodiments, the carboxylic acid ligand is a carboxylic acid having a carbon backbone of C10 to C20, and the phosphine-containing ligand is a hydrocarbyl phosphine having a carbon backbone of C1 to C10.

In some preferred embodiments, the carboxylic acid may be, but is not limited to, capric acid, lauric acid, myristic acid, stearic acid, oleic acid, and the like.

In some preferred embodiments, the hydrocarbyl phosphine may be, but is not limited to, trioctylphosphine, tributylphosphine, trimethylphosphine, triphenylphosphine.

In some embodiments, the first temperature is 150 to 300 ℃, the second temperature is 50 to 150 ℃, the third temperature is 250 to 310 ℃, and the reaction time t1 is 20 to 60 min. The first temperature, the second temperature, and the third temperature are defined within the above temperature ranges to facilitate uniform and controllable preparation of the first composite, the nanoclusters, and the initial quantum dots. The reaction time t1 is defined within the above range to facilitate sufficient reaction of the reactants in the first composite preparation process.

In some embodiments, the fourth temperature is 150-300 ℃, the fifth temperature is 250-310 ℃, and the reaction time t2 is 20-120 min. The fourth temperature and the fifth temperature are each limited to the above temperature ranges to facilitate sufficient surface treatment of the initial quantum dots by the first composite and uniform, controlled preparation of the quantum dot cores. The reaction time t2 is limited to the above range to facilitate sufficient surface treatment of the initial quantum dots by the first composite.

According to the preparation method, the fifth cation precursor, the third ligand and the fourth ligand are reacted to obtain the second compound, so that the solubility of the fifth cation precursor in a reaction system can be improved, the activity of the fifth cation precursor in the reaction system can be adjusted, unnecessary damage to the surface of the quantum dot due to overhigh reaction activity is avoided, and the improvement of the uniformity and the quantum yield of the core-shell quantum dot is facilitated.

In some embodiments, the second complex is mixed with the first mixed solution and reacted at a seventh temperature for a time t4 to obtain a second intermediate reaction solution, and then the fifth anion precursor is mixed with the second intermediate reaction solution and reacted at an eighth temperature to obtain a solution containing the core-shell quantum dots.

In the process of preparing the core-shell quantum dot core, the second compound and the first mixed solution containing the quantum dot core are reacted firstly, and the second compound is utilized to carry out surface treatment on the quantum dot core, so that dangling bonds and defects on the surface of the quantum dot core are reduced, and the surface performance of the quantum dot core is regulated and controlled. And finally, adding a fifth cation precursor, and continuously coating the shell layer outside the quantum dot core, wherein the quantum dot core subjected to surface treatment is more favorable for coating of a subsequent shell layer, so that the high-performance core-shell quantum dot can be obtained.

In some embodiments, the fifth cation precursor is a zinc precursor and the fifth anion precursor is a mixed precursor of a sulfur precursor and a selenium precursor.

It is worth mentioning that the zinc precursor with small molecular weight has small solubility in the solvent commonly used in the field, can not fully contact with the quantum dot core in the reaction process, has high reaction activity and is easy to damage the surface of the quantum dot core, but has good modification effect on the surface of the quantum dot core. According to the method, a zinc precursor reacts with a third ligand and a fourth ligand to form a zinc precursor-ligand complex, so that the solubility of the zinc precursor in a solvent is improved, and the activity of the zinc precursor is adjusted, so that the zinc precursor can mildly treat and activate the surface of a quantum dot core, and dangling bonds and defects on the surface of the quantum dot core are reduced.

In some embodiments, the molar ratio of the fifth cationic precursor to the third ligand is from 1:2 to 2:1, and the molar ratio of the fifth cationic precursor to the fourth ligand is from 1:5 to 1: 50.

Selecting the molar ratio of the pentacation precursor to the third ligand within the above ratio range facilitates sufficient reaction of the pentacation precursor with the third ligand and avoids the third ligand from being excessive to affect the preparation of the second complex and the surface treatment of the quantum dot core. .

Selecting the molar ratio of the pentacation precursor to the fourth ligand within the above ratio range facilitates sufficient reaction of the pentacation precursor with the fourth ligand and avoids the excessive amount of the fourth ligand from affecting the preparation of the second complex and the surface treatment of the quantum dot core.

In some embodiments, the sixth temperature is 150 to 300 ℃ and the reaction time t3 is 20 to 60 min. The sixth temperature is limited to the temperature range described above to facilitate uniform, controlled preparation of the second composite. The reaction time t3 is defined within the above range to facilitate sufficient reaction of the reactants in the second composite preparation process.

In some embodiments, the seventh temperature is 150-300 ℃, the eighth temperature is 250-310 ℃, and the reaction time t4 is 20-120 min. The seventh temperature and the eighth temperature are limited in the temperature range, so that the second compound can fully perform surface treatment on the quantum dot core and uniformly and controllably prepare the core-shell quantum dot. The reaction time t4 is limited to the above range to facilitate sufficient surface treatment of the quantum dot core by the second composite.

The application also provides a quantum dot material which comprises the core-shell quantum dot, wherein the core-shell quantum dot is prepared by any one of the preparation methods, the half-peak width of the quantum dot material is less than 40nm, and the quantum yield of the quantum dot material is more than 70%.

In some preferred embodiments, the quantum dot material has a half-peak width of 35-40 nm.

The application also provides a quantum dot composition, such as quantum dot ink, comprising the quantum dot material prepared by the method. The quantum dot prepared by the preparation method has the advantages of narrow fluorescence half-peak width, high quantum yield and the like. Therefore, the quantum dot composition prepared on the basis also has the characteristics of narrow fluorescence half-peak width and high quantum yield.

The application also provides a quantum dot device, and the quantum dot device comprises the quantum dot material or the quantum dot composition. The quantum dot device can be a quantum dot light conversion film, a quantum dot color film and devices used in combination with LEDs, photoelectric devices such as quantum dot light emitting diodes and the like, and can also be solar cells, photoelectric detectors, biological probes and the like and devices used in combination with the same. The quantum dot material has the advantages of narrow fluorescence half-peak width, high quantum yield and the like, so that the quantum dot device also has the performances of narrow fluorescence half-peak width and high quantum yield.

Example 1

1mmol of Zn (Pr)₂(Zinc propionate), 1mmol of oleic acid, 10mmol of TOP (trioctylphosphine) were charged to a 100mL three-necked flask and the flask was placed in N₂Heating to 200 deg.C under exhaust condition, maintaining at 200 deg.C for 20min to form Zn precursor-ligand complex A1, and cooling to room temperature.

1mmol of ZnCl₂(Zinc chloride), 1mmol of myristic acid, 10mmol of TBP (tributylphosphine) were charged into a 100mL three-necked flask, and the three-necked flask was placed in N₂Heating to 150 ℃ in a degassing state, keeping the temperature at 150 ℃ for 40min, forming a Zn precursor-ligand complex B1, and cooling to room temperature for later use.

Adding 0.4mmol of In (MA)₃Indium tetradecanoate, 0.2mmol of TMS-P (tris (trimethylsilyl) phosphine), 1mL of 0.2mmol/mL S-ODE solution, and 9mL of ODE (octadecene) were charged into a 100mL three-necked flask₂Heating to 120 ℃ in an exhaust state, keeping the temperature at 120 ℃ for 30min to form an InPS nanocluster solution, and cooling to room temperature for later use.

Adding 0.4mmol of In (MA)₃Indium tetradecanoate (Takara acid), 0.2mmol Zn (MA)₂(Zinc myristate), 0.2mmol TMS-P (tris (trimethylsilyl) phosphine), and 15mL ODE (octadecene) were added to a 100mL three-necked flask₂Heating to 300 ℃ in an exhaust state, and keeping the temperature at 300 ℃ for 5min to form an InZnP quantum dot solution. Cooling to 200 ℃, adding Zn precursor-ligand complex A1, keeping at 200 ℃ for 40min, and then heating to 300 ℃. Then, the InPS nanocluster solution (corresponding to 1mol of TMS-P added in the preparation of InZnP quantum dots) is dripped at the speed of 5mL/h0.5mol/h) and dropwise adding for 2h to obtain the InZnPS quantum dot core solution.

Cooling the InZnPS quantum dot core solution to 200 ℃, adding a Zn precursor-ligand compound B1, keeping the temperature at 200 ℃ for 60min, and heating to 300 ℃. 0.5mmol of Se-TOP (selenium-trioctylphosphine) and 0.5mmol of S-TOP (sulfur-trioctylphosphine) were added and reacted at 300 ℃ for 90 min. Cooling to room temperature to obtain a product system containing InZnPS/ZnSeS. Extracting twice with methanol, precipitating with acetone, centrifuging, and dissolving the precipitate in toluene to obtain InZnPS/ZnSeS quantum dot solution.

Example 2

1mmol of Zn (Pr)₂(Zinc propionate), 1mmol of oleic acid, 10mmol of TOP (trioctylphosphine) were charged to a 100mL three-necked flask and the flask was placed in N₂Heating to 200 deg.C under exhaust condition, maintaining at 200 deg.C for 20min to form Zn precursor-ligand complex A2, and cooling to room temperature.

1mmol of ZnCl₂(Zinc chloride), 1mmol of myristic acid, 10mmol of TBP (tributylphosphine) were charged into a 100mL three-necked flask, and the three-necked flask was placed in N₂Heating to 150 ℃ in a degassing state, keeping the temperature at 150 ℃ for 40min, forming a Zn precursor-ligand complex B2, and cooling to room temperature for later use.

Adding 0.4mmol of In (MA)₃Indium tetradecanoate, 0.2mmol of TMS-P (tris (trimethylsilyl) phosphine), 1mL of 0.2mmol/mL Se-ODE solution, and 9mL of ODE (octadecene) were charged into a 100mL three-necked flask₂Heating to 120 ℃ in an exhaust state, keeping the temperature at 120 ℃ for 30min to form an InPSe nanocluster solution, and cooling to room temperature for later use.

0.4mmol of In (MA)3 (indium tetradecanoate), 0.2mmol of Zn (MA)₂(Zinc myristate), 0.2mmol TMS-P (tris (trimethylsilyl) phosphine), and 15mL ODE (octadecene) were added to a 100mL three-necked flask₂Heating to 300 ℃ in an exhaust state, and keeping the temperature at 300 ℃ for 5min to form an InZnP quantum dot solution. Cooling to 150 ℃, adding Zn precursor-ligand complex A2, keeping at 150 ℃ for 20min, and then heating to 300 ℃. Then dropping InPSe nanocluster solution (corresponding to 1mol of TMS-P added in preparation of InZnP quantum dots, of InPSe nanocluster solution) at the speed of 5mL/hThe dropping speed is 0.5mol/h), and the solution containing the InZnPSe quantum dot core is obtained after 2h of dropping.

Cooling the InZnPSe quantum dot core solution to 150 ℃, adding a Zn precursor-ligand compound B2, keeping the temperature at 150 ℃ for 40min, and then heating to 300 ℃. 0.5mmol of Se-TOP (selenium-trioctylphosphine) and 0.5mmol of S-TOP (sulfur-trioctylphosphine) were added and reacted at 300 ℃ for 90 min. Cooling to room temperature to obtain a product system containing InZnPSe/ZnSeS. Extracting twice with methanol, precipitating with acetone, centrifuging, and dissolving the precipitate in toluene to obtain InZnPSe/ZnSeS quantum dot solution.

Example 3

2mmol of zinc acetylacetonate, 1mmol of MA (tetradecanoic acid), 10mmol of TBP (tributylphosphine) were placed in a 100mL three-necked flask₂Heating to 150 ℃ in a degassing state, keeping the temperature at 150 ℃ for 40min, forming a Zn precursor-ligand complex A3, and cooling to room temperature for later use.

2mmol of Zn (Pr)₂(Zinc propionate), 1mmol of decaacid, 10mmol of TOP (trioctylphosphine) were added to a 100mL three-necked flask, which was placed in N₂Heating to 200 deg.C under exhaust condition, maintaining at 200 deg.C for 20min to form Zn precursor-ligand complex B3, and cooling to room temperature.

Adding 0.4mmol of In (MA)₃Indium tetradecanoate, 0.2mmol of TMS-P (tris (trimethylsilyl) phosphine), 1mL of 0.2mmol/mL S-ODE solution, and 9mL of ODE (octadecene) were charged into a 100mL three-necked flask₂Heating to 50 ℃ in an exhaust state, maintaining at 120 ℃ for 30min to form an InPS nanocluster solution, and cooling to room temperature for later use.

Adding 0.4mmol of In (MA)₃Indium tetradecanoate (Takara acid), 0.2mmol Zn (MA)₂(Zinc myristate), 0.2mmol TMS-P (tris (trimethylsilyl) phosphine), and 15mL ODE (octadecene) were added to a 100mL three-necked flask₂Heating to 250 ℃ in an exhaust state, and keeping the temperature at 250 ℃ for 5min to form an InZnP quantum dot solution. Adding Zn precursor-ligand complex A3, keeping at 250 deg.C for 60min, and heating to 300 deg.C. Then dropping InPS nanocluster solution (corresponding to 1mol of TMS-P added in preparation of InZnP quantum dots, of InPS nanocluster solution) at the speed of 2mL/hThe dropping speed is 0.2mol/h), and the solution containing the InZnPS quantum dot core is obtained after 2h of dropping.

Cooling the InZnPS quantum dot core solution to 250 ℃, adding a Zn precursor-ligand compound B3, keeping the temperature at 250 ℃ for 20min, adding 0.5mmol of Se-TOP (selenium-trioctylphosphine) and 0.5mmol of S-TOP (sulfur-trioctylphosphine), and reacting for 90min at 250 ℃. Cooling to room temperature to obtain a product system containing InZnPS/ZnSeS. Extracting twice with methanol, precipitating with acetone, centrifuging, and dissolving the precipitate in toluene to obtain InZnPS/ZnSeS quantum dot solution.

Example 4

4mmol of zinc chloride, 8mmol of MA (tetradecanoic acid), 40mmol of TBP (tributylphosphine) were placed in a 100mL three-necked flask, which was placed in a N atmosphere₂Heating to 250 ℃ in a degassing state, keeping the temperature at 250 ℃ for 60min, forming Zn precursor-ligand complex A4, and cooling to room temperature for later use.

4mmol of zinc bromide, 8mmol of dodecanoic acid and 40mmol of TBP (tributylphosphine) were charged in a 100mL three-necked flask, which was placed in a N atmosphere₂Heating to 250 ℃ in a degassing state, keeping the temperature at 250 ℃ for 60min, forming a Zn precursor-ligand complex B4, and cooling to room temperature for later use.

Adding 0.4mmol of In (MA)₃Indium tetradecanoate, 0.2mmol of TMS-P (tris (trimethylsilyl) phosphine), 1mL of 0.2mmol/mL S-ODE solution, and 9mL of ODE (octadecene) were charged into a 100mL three-necked flask₂Heating to 150 ℃ in an exhaust state, maintaining at 120 ℃ for 30min to form an InPS nanocluster solution, and cooling to room temperature for later use.

Adding 0.4mmol of In (MA)₃Indium tetradecanoate (Takara acid), 0.2mmol Zn (MA)₂(Zinc myristate), 0.2mmol TMS-P (tris (trimethylsilyl) phosphine), and 15mL ODE (octadecene) were added to a 100mL three-necked flask₂Heating to 310 ℃ in an exhaust state, and keeping the temperature at 310 ℃ for 5min to form an InZnP quantum dot solution. Cooling to 150 ℃, adding Zn precursor-ligand complex A4, keeping at 150 ℃ for 20min, and then heating to 250 ℃. Then dropping an InPS nanocluster solution (corresponding to 1mol of TMS-P added in the preparation of InZnP quantum dots, the dropping speed of the InPS nanocluster solution is 1mol/h) at the speed of 10mL/h,dropwise adding the solution for 2 hours to obtain the InZnPS quantum dot core-containing solution.

Keeping the temperature of the InZnPS quantum dot core solution at 300 ℃, adding a Zn precursor-ligand compound B4, keeping the temperature at 300 ℃ for 90min, and heating to 310 ℃. 0.5mmol of Se-TOP (selenium-trioctylphosphine) and 0.5mmol of S-TOP (sulfur-trioctylphosphine) were added and reacted at 310 ℃ for 90 min. Cooling to room temperature to obtain a product system containing InZnPS/ZnSeS. Extracting twice with methanol, precipitating with acetone, centrifuging, and dissolving the precipitate in toluene to obtain InZnPS/ZnSeS quantum dot solution.

Example 5

4mmol of zinc bromide, 8mmol of decaacid and 40mmol of TBP (tributylphosphine) were placed in a 100mL three-necked flask, which was placed in a N atmosphere₂Heating to 300 ℃ in a degassing state, keeping the temperature at 300 ℃ for 60min, forming a Zn precursor-ligand complex A5, and cooling to room temperature for later use.

4mmol of zinc iodide, 8mmol of palmitic acid and 40mmol of TOP (trioctylphosphine) were placed in a 100mL three-necked flask₂Heating to 300 ℃ in a degassing state, keeping the temperature at 300 ℃ for 60min, forming a Zn precursor-ligand complex B5, and cooling to room temperature for later use.

Adding 0.4mmol of In (MA)₃Indium tetradecanoate (Takara acid), 0.2mmol Zn (MA)₂(Zinc myristate), 0.2mmol TMS-P (tris (trimethylsilyl) phosphine), and 15mL ODE (octadecene) were added to a 100mL three-necked flask₂Heating to 300 ℃ in an exhaust state, and keeping the temperature at 300 ℃ for 5min to form an InZnP quantum dot solution. Adding Zn precursor-ligand complex A5, keeping at 300 deg.C for 90min, and heating to 310 deg.C. Then dropping an InPS nanocluster solution (corresponding to TMS-P added in the preparation of 1mol of InZnP quantum dots, the dropping speed of the InPS nanocluster solution is 2mol/h) at the speed of 20mL/h, and obtaining the InZnPS quantum dots-containing solution after dropping for 2hAnd (4) a nucleation solution.

Cooling the InZnPS quantum dot core solution to 150 ℃, adding a Zn precursor-ligand compound B5, keeping the temperature at 150 ℃ for 120min, and heating to 300 ℃. 0.5mmol of Se-TOP (selenium-trioctylphosphine) and 0.5mmol of S-TOP (sulfur-trioctylphosphine) were added and reacted at 300 ℃ for 90 min. Cooling to room temperature to obtain a product system containing InZnPS/ZnSeS. Extracting twice with methanol, precipitating with acetone, centrifuging, and dissolving the precipitate in toluene to obtain InZnPS/ZnSeS quantum dot solution.

Example 6

4mmol of zinc iodide, 8mmol of dodecanoic acid and 40mmol of TBP (tributylphosphine) were charged in a 100mL three-necked flask, which was placed in a N atmosphere₂Heating to 250 ℃ in a degassing state, keeping the temperature at 250 ℃ for 60min, forming Zn precursor-ligand complex A6, and cooling to room temperature for later use.

4mmol of zinc chloride, 8mmol of octadecanoic acid, 40mmol of TOP (trioctylphosphine) were charged into a 100mL three-necked flask, which was placed in a N atmosphere₂Heating to 250 ℃ in a degassing state, keeping the temperature at 250 ℃ for 60min, forming a Zn precursor-ligand complex B6, and cooling to room temperature for later use.

Adding 0.4mmol of In (MA)₃Indium tetradecanoate (Takara acid), 0.2mmol Zn (MA)₂(Zinc myristate), 0.2mmol TMS-P (tris (trimethylsilyl) phosphine), and 15mL ODE (octadecene) were added to a 100mL three-necked flask₂Heating to 300 ℃ in an exhaust state, and keeping the temperature at 300 ℃ for 5min to form an InZnP quantum dot solution. Cooling to 200 ℃, adding Zn precursor-ligand complex A6, keeping at 200 ℃ for 120min, and then heating to 300 ℃. Then dripping the InPS nanocluster solution (corresponding to TMS-P added in the preparation of 1mol of InZnP quantum dots, the dripping speed of the InPS nanocluster solution is 0.5mol/h) at the speed of 5mL/h, and dripping for 2h to obtain a core solution containing the InZnPS quantum dots。

Cooling the InZnPS quantum dot core solution to 200 ℃, adding a Zn precursor-ligand compound B6, keeping the temperature at 200 ℃ for 60min, and heating to 300 ℃. 0.5mmol of Se-TOP (selenium-trioctylphosphine) and 0.5mmol of S-TOP (sulfur-trioctylphosphine) were added and reacted at 300 ℃ for 90 min. Cooling to room temperature to obtain a product system containing InZnPS/ZnSeS. Extracting twice with methanol, precipitating with acetone, centrifuging, and dissolving the precipitate in toluene to obtain InZnPS/ZnSeS quantum dot solution.

Example 7

4mmol of zinc acetate, 8mmol of octadecanoic acid and 40mmol of TBP (tributylphosphine) were charged into a 100mL three-necked flask, and the three-necked flask was placed in a N atmosphere₂Heating to 250 ℃ in a degassing state, keeping the temperature at 250 ℃ for 60min, forming Zn precursor-ligand complex A7, and cooling to room temperature for later use.

4mmol of zinc acetylacetonate, 8mmol of oleic acid and 40mmol of TBP (tributylphosphine) were placed in a 100mL three-necked flask which was placed in a N atmosphere₂Heating to 250 ℃ in a degassing state, keeping the temperature at 250 ℃ for 60min, forming a Zn precursor-ligand complex B7, and cooling to room temperature for later use.

Adding 0.4mmol of In (MA)₃Indium (tetradecanoate), 0.2mmol Zn (MA)2 (zinc myristate), 0.2mmol TMS-P (tris (trimethylsilyl) phosphine), and 15mL ODE (octadecene) were added to a 100mL three-necked flask₂Heating to 300 ℃ in an exhaust state, and keeping the temperature at 300 ℃ for 5min to form an InZnP quantum dot solution. Cooling to 200 ℃, adding Zn precursor-ligand complex A7, keeping at 200 ℃ for 40min, and then heating to 300 ℃. Then, an InPS nanocluster solution (corresponding to TMS-P added in the preparation of 1mol of InZnP quantum dots, the dropping speed of the InPS nanocluster solution is 0.5mol/h) is dropped at the speed of 5mL/h, and a solution containing InZnPS quantum dots cores is obtained after the solution is dropped for 2 h.

Cooling the InZnPS quantum dot core solution to 200 ℃, adding a Zn precursor-ligand compound B7, keeping the temperature at 200 ℃ for 60min, and heating to 300 ℃. 0.5mmol of Se-TOP (selenium-trioctylphosphine) and 0.5mmol of S-TOP (sulfur-trioctylphosphine) were added and reacted at 300 ℃ for 90 min. Cooling to room temperature to obtain a product system containing InZnPS/ZnSeS. Extracting twice with methanol, precipitating with acetone, centrifuging, and dissolving the precipitate in toluene to obtain InZnPS/ZnSeS quantum dot solution.

Example 8

1mmol of Zn (Pr)₂(Zinc propionate), 1mmol eicosanoic acid, 20mmol tridecylphosphine were added to a 100mL three-necked flask, which was placed in N₂Heating to 200 deg.C under exhaust condition, maintaining at 200 deg.C for 20min to form Zn precursor-ligand complex A8, and cooling to room temperature.

1mmol of ZnCl₂(Zinc chloride), 1mmol of eicosanoic acid, 20mmol of tridecylphosphine were added to a 100mL three-necked flask, which was placed in a N-neck flask₂Heating to 150 ℃ in a degassing state, keeping the temperature at 150 ℃ for 40min, forming a Zn precursor-ligand complex B8, and cooling to room temperature for later use.

Adding 0.4mmol of In (MA)₃Indium tetradecanoate, 0.2mmol of TMS-P (tris (trimethylsilyl) phosphine), 1mL of 0.2mmol/mL S-ODE solution, and 9mL of ODE (octadecene) were charged into a 100mL three-necked flask₂Heating to 50 ℃ in an exhaust state, keeping the temperature at 50 ℃ for 30min to form an InPS nanocluster solution, and cooling to room temperature for later use.

Adding 0.4mmol of In (MA)₃Indium tetradecanoate (Takara acid), 0.2mmol Zn (MA)₂(Zinc myristate), 0.2mmol TMS-P (tris (trimethylsilyl) phosphine), and 15mL ODE (octadecene) were added to a 100mL three-necked flask₂Heating to 280 ℃ in an exhaust state, and keeping the temperature at 280 ℃ for 5min to form an InZnP quantum dot solution. Zn precursor-ligand complex A8 was added and held at 280 ℃ for 40 min. Then, an InPS nanocluster solution (corresponding to TMS-P added in the preparation of 1mol of InZnP quantum dots, the dropping speed of the InPS nanocluster solution is 0.5mol/h) is dropped at the speed of 5mL/h, and a solution containing InZnPS quantum dots cores is obtained after the solution is dropped for 2 h.

Cooling the InZnPS quantum dot core solution to 200 ℃, adding a Zn precursor-ligand compound B8, keeping the temperature at 200 ℃ for 60min, and heating to 280 ℃. 0.5mmol of Se-TOP (selenium-trioctylphosphine) and 0.5mmol of S-TOP (sulfur-trioctylphosphine) were added and reacted at 280 ℃ for 90 min. Cooling to room temperature to obtain a product system containing InZnPS/ZnSeS. Extracting twice with methanol, precipitating with acetone, centrifuging, and dissolving the precipitate in toluene to obtain InZnPS/ZnSeS quantum dot solution.

Example 9

Adding 3mmol Zn (Pr)₂(Zinc propionate), 3mmol of oleic acid, 90mmol of trimethylphosphine were placed in a 100mL three-necked flask and the flask was kept at N₂Heating to 200 deg.C under exhaust condition, maintaining at 200 deg.C for 20min to form Zn precursor-ligand complex A9, and cooling to room temperature.

3mmol of ZnCl₂(Zinc chloride), 3mmol of tetradecanoic acid, and 90mmol of trimethylphosphine were placed in a 100mL three-necked flask, which was placed in a N atmosphere₂Heating to 150 ℃ in a degassing state, keeping the temperature at 150 ℃ for 40min, forming a Zn precursor-ligand complex B9, and cooling to room temperature for later use.

0.4mmol of indium hexadecanoate, 0.2mmol of TMS-P (tris (trimethylsilyl) phosphine), 1mL of 0.2mmol/mL S-ODE solution, and 9mL of ODE (octadecene) were charged into a 100mL three-necked flask₂Heating to 80 ℃ in an exhaust state, keeping the temperature at 80 ℃ for 30min to form an InPS nanocluster solution, and cooling to room temperature for later use.

0.4mmol of indium hexadecanoate, 0.2mmol of Zn (MA)₂(Zinc myristate), 0.2mmol TMS-P (tris (trimethylsilyl) phosphine), and 15mL ODE (octadecene) were added to a 100mL three-necked flask₂Heating to 300 ℃ in an exhaust state, and keeping the temperature at 300 ℃ for 5min to form an InZnP quantum dot solution. Cooling to 200 ℃, adding Zn precursor-ligand complex A9, keeping at 200 ℃ for 40min, and then heating to 300 ℃. Then, an InPS nanocluster solution (corresponding to TMS-P added in the preparation of 1mol of InZnP quantum dots, the dropping speed of the InPS nanocluster solution is 0.5mol/h) is dropped at the speed of 5mL/h, and a solution containing InZnPS quantum dots cores is obtained after the solution is dropped for 2 h.

Cooling the InZnPS quantum dot core solution to 200 ℃, adding a Zn precursor-ligand compound B9, keeping the temperature at 200 ℃ for 60min, and heating to 300 ℃. 0.5mmol of Se-TOP (selenium-trioctylphosphine) and 0.5mmol of thio-octadecene were added and reacted at 300 ℃ for 90 min. Cooling to room temperature to obtain a product system containing InZnPS/ZnSeS. Extracting twice with methanol, precipitating with acetone, centrifuging, and dissolving the precipitate in toluene to obtain InZnPS/ZnSeS quantum dot solution.

Example 10

1mmol of Zn (Pr)₂(Zinc propionate), 1mmol of oleic acid, 40mmol of TOP (trioctylphosphine) were charged to a 100mL three-necked flask and the flask was placed in N₂Heating to 200 deg.C under exhaust condition, maintaining at 200 deg.C for 20min to form Zn precursor-ligand complex A10, and cooling to room temperature.

1mmol of ZnCl₂(Zinc chloride), 1mmol of myristic acid, 40mmol of TBP (tributylphosphine) were charged into a 100mL three-necked flask, and the three-necked flask was placed in N₂Heating to 150 ℃ in a degassing state, keeping the temperature at 150 ℃ for 40min, forming a Zn precursor-ligand complex B10, and cooling to room temperature for later use.

0.4mmol of indium dodecanoate, 0.2mmol of tris (triphenylsilyl) phosphine, 1mL of 0.2mmol/mL S-ODE solution, and 9mL of paraffin oil were added to a 100mL three-necked flask₂Heating to 100 ℃ in an exhaust state, keeping the temperature at 100 ℃ for 30min to form an InPS nanocluster solution, and cooling to room temperature for later use.

0.4mmol of indium dodecanoate and 0.2mmol of Zn (MA)₂(Zinc myristate), 0.2mmol of tris (triphenylsilyl) phosphine, and 15mL of paraffin oil were added to a 100mL three-necked flask₂Heating to 300 ℃ in an exhaust state, and keeping the temperature at 300 ℃ for 5min to form an InZnP quantum dot solution. Cooling to 200 ℃, adding Zn precursor-ligand complex A10, keeping at 200 ℃ for 40min, and then heating to 300 ℃. Then, an InPS nanocluster solution (corresponding to TMS-P added in the preparation of 1mol of InZnP quantum dots, the dropping speed of the InPS nanocluster solution is 0.5mol/h) is dropped at the speed of 5mL/h, and a solution containing InZnPS quantum dots cores is obtained after the solution is dropped for 2 h.

Cooling the InZnPS quantum dot core solution to 200 ℃, adding a Zn precursor-ligand compound B10, keeping the temperature at 200 ℃ for 60min, and heating to 300 ℃. 0.5mmol of selenium-octadecene and 0.5mmol of sulfur-tributylphosphine were added and reacted at 300 ℃ for 90 min. Cooling to room temperature to obtain a product system containing InZnPS/ZnSeS. Extracting twice with methanol, precipitating with acetone, centrifuging, and dissolving the precipitate in toluene to obtain InZnPS/ZnSeS quantum dot solution.

Example 11

1mmol of Zn (Pr)₂(Zinc propionate), 1mmol of oleic acid, 50mmol of triphenylphosphine were charged in a 100mL three-necked flask, and the three-necked flask was placed in a N₂Heating to 200 deg.C under exhaust condition, maintaining at 200 deg.C for 20min to form Zn precursor-ligand complex A11, and cooling to room temperature.

1mmol of ZnCl₂(Zinc chloride), 1mmol of tetradecanoic acid, and 50mmol of triphenylphosphine were placed in a 100mL three-necked flask, which was placed in a N-neck flask₂Heating to 150 ℃ in a degassing state, keeping the temperature at 150 ℃ for 40min, forming a Zn precursor-ligand complex B11, and cooling to room temperature for later use.

0.4mmol of indium oleate, 0.2mmol of tris (triethylsilyl) phosphine, 1mL of a 0.2mmol/mL S-ODE solution, and 9mL of squalane were charged into a 100mL three-necked flask, and the three-necked flask was placed in N₂Heating to 150 ℃ in an exhaust state, keeping the temperature at 150 ℃ for 30min to form an InPS nanocluster solution, and cooling to room temperature for later use.

Adding 0.4mmol indium oleate, 0.2mmol Zn (MA)₂(Zinc myristate), 0.2mmol of tris (triethylsilyl) phosphine, and 15mL of squalane were added to a 100mL three-necked flask, which was placed in N₂Heating to 300 ℃ in an exhaust state, and keeping the temperature at 300 ℃ for 5min to form an InZnP quantum dot solution. Cooling to 200 ℃, adding Zn precursor-ligand complex A11, keeping at 200 ℃ for 40min, and then heating to 300 ℃. Then, an InPS nanocluster solution (corresponding to TMS-P added in the preparation of 1mol of InZnP quantum dots, the dropping speed of the InPS nanocluster solution is 0.5mol/h) is dropped at the speed of 5mL/h, and a solution containing InZnPS quantum dots cores is obtained after the solution is dropped for 2 h.

Cooling the InZnPS quantum dot core solution to 200 ℃, adding a Zn precursor-ligand compound B11, keeping the temperature at 200 ℃ for 60min, and heating to 300 ℃. 0.5mmol of selenium-tributylphosphine and 0.5mmol of dodecyl mercaptan were added and reacted at 300 ℃ for 90 min. Cooling to room temperature to obtain a product system containing InZnPS/ZnSeS. Extracting twice with methanol, precipitating with acetone, centrifuging, and dissolving the precipitate in toluene to obtain InZnPS/ZnSeS quantum dot solution.

Comparative example 1

Adding 0.4mmol of In (MA)₃Indium tetradecanoate (Takara acid), 0.2mmol Zn (MA)₂(Zinc myristate), 0.2mmol TMS-P (tris (trimethylsilyl) phosphine), and 15mL ODE (octadecene) were added to a 100mL three-necked flask₂Heating to 300 ℃ in an exhaust state, and keeping the temperature at 300 ℃ for 5min to form an InZnP quantum dot solution. And then dripping the InPS nanocluster solution at the speed of 5mL/h for 2h to obtain an InZnPS quantum dot core-containing solution.

0.5mmol of Se-TOP (selenium-trioctylphosphine) and 0.5mmol of S-TOP (sulfur-trioctylphosphine) were added and reacted at 300 ℃ for 90 min. Cooling to room temperature to obtain a product system containing InZnPS/ZnSeS. Extracting twice with methanol, precipitating with acetone, centrifuging, dissolving the precipitate in toluene to obtain InZnPS/ZnSeS quantum dot solution, and performing fluorescence emission, transmission electron microscope and quantum yield test.

Comparative example 2

Adding 0.4mmol of In (MA)₃Indium tetradecanoate (Takara acid), 0.2mmol Zn (MA)₂(Zinc myristate), 0.2mmol TMS-P (tris (trimethylsilyl) phosphine), and 15mL ODE (octadecene) were added to a 100mL three-necked flaskThe three-neck flask is in the number N₂Heating to 300 ℃ in an exhaust state, and keeping the temperature at 300 ℃ for 5min to form an InZnP quantum dot solution. Cooling to 200 deg.C, adding 4mmol zinc acetate, maintaining at 200 deg.C for 40min, and heating to 300 deg.C. And then dripping the InPS nanocluster solution at the speed of 5mL/h for 2h to obtain an InZnPS quantum dot core-containing solution.

Cooling the InZnPS quantum dot core solution to 200 ℃, adding 4mmol of zinc acetylacetonate, keeping the temperature at 200 ℃ for 20min, and heating to 300 ℃. 0.5mmol of Se-TOP (selenium-trioctylphosphine) and 0.5mmol of S-TOP (sulfur-trioctylphosphine) were added and reacted at 300 ℃ for 90 min. Cooling to room temperature to obtain a product system containing InZnPS/ZnSeS. Extracting twice with methanol, precipitating with acetone, centrifuging, dissolving the precipitate in toluene to obtain InZnPS/ZnSeS quantum dot solution, and performing fluorescence emission, transmission electron microscope and quantum yield test.

And (3) separating and purifying the product solution containing the core-shell quantum dots, and finally dissolving the core-shell quantum dots obtained by separation and purification in a solvent. Fluorescence emission spectra were used to test the fluorescence emission peak, fluorescence half-peak width, and fluorescence quantum yield of the core-shell quantum dots of examples 1-11 and comparative examples 1-2. The fluorescence quantum yield of the quantum dots of the above embodiments is tested, and the detection method of the fluorescence quantum yield is as follows: the method comprises the following steps of using a 450nm blue LED lamp as a light source, using an integrating sphere to respectively test the spectrum of the blue light source and the spectrum after the blue light source penetrates through a quantum dot solution, and using the integral area of a spectrogram to calculate the quantum efficiency, wherein the fluorescence quantum yield is the quantum dot emission peak area/(blue backlight peak area-unabsorbed blue peak area after the blue backlight peak area penetrates through the quantum dot solution) × 100%, and the test results are shown in the following table:

from the table above, it can be seen that the fluorescence quantum yield of the quantum dots obtained in examples 1 to 11 is higher than that of the quantum dots obtained in comparative examples 1 and 2, and the half-peak width is narrower and can reach 35nm at the minimum. Therefore, the core-shell quantum dot prepared by the preparation method has the characteristics of high fluorescence quantum yield and narrow half-peak width.

The foregoing has described the general principles, principal features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are merely illustrative of the principles of the invention, but that various changes and modifications may be made without departing from the spirit and scope of the invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A preparation method of quantum dot nuclei is characterized by comprising the following steps:

preparing a first complex: reacting the first cation precursor, the first ligand and the second ligand at a first temperature for t1 to obtain a first complex;

preparing a first solution: mixing a second cation precursor, a first anion precursor, a second anion precursor and a first solvent and reacting at a second temperature to obtain the first solution containing nanoclusters;

preparing a second solution: mixing a third cation precursor, a fourth cation precursor, a third anion precursor and a second solvent and reacting at a third temperature to obtain a second solution containing initial quantum dots;

preparing a first mixed solution: mixing the first compound, the first solution and the second solution, and reacting to obtain a first mixed solution containing the quantum dot core;

wherein the first ligand is a carboxylic acid ligand and the second ligand is a phosphine-containing ligand.

2. The preparation method according to claim 1, wherein in the process of preparing the first mixed solution, the first complex and the second solution are mixed at a fourth temperature for reaction time t2 to obtain a first intermediate reaction solution, and then the first solution and the first intermediate reaction solution are mixed at a fifth temperature for reaction to obtain a solution containing the quantum dot core.

3. The preparation method according to claim 2, wherein the first solution and the first intermediate reaction solution are mixed in such a way that the first solution is added to the first intermediate reaction solution at a constant speed, preferably, the constant speed addition is dropwise.

4. The preparation method according to claim 3, wherein the dropping speed of the first solution is 0.2 to 2mol/h per 1mol of the third anion precursor.

5. The method according to claim 1, wherein the first cation precursor and the third cation precursor are zinc precursors, the second cation precursor and the fourth cation precursor are indium precursors, the first anion precursor and the third anion precursor are phosphorus precursors, and the second anion precursor is a sulfur precursor or a selenium precursor.

6. The method according to claim 5, wherein the molar ratio of the first cation precursor to the first ligand is 1:2 to 2:1, the molar ratio of the first cation precursor to the second ligand is 1:5 to 1:50, and the molar ratio of the first cation precursor to the third anion precursor is 5:1 to 20: 1.

7. The method according to claim 1, wherein the carboxylic acid ligand is a carboxylic acid having a carbon backbone of C10-C20, and the phosphine-containing ligand is a hydrocarbyl phosphine having a carbon backbone of C1-C10.

8. The method according to claim 1, wherein the first temperature is 150 to 300 ℃, the second temperature is 50 to 150 ℃, the third temperature is 250 to 310 ℃, and the reaction time t1 is 20 to 60 min.

9. The method according to claim 2, wherein the fourth temperature is 150 to 300 ℃, the fifth temperature is 250 to 310 ℃, and the reaction time t2 is 20 to 120 min.

10. A preparation method of the core-shell quantum dot is characterized by comprising the following steps:

preparing a second complex: reacting the fifth cation precursor, the third ligand and the fourth ligand at a sixth temperature for t3 to obtain the second complex;

mixing the second compound, the first mixed solution and a fifth anion precursor, and reacting to obtain a mixed solution containing the core-shell quantum dots;

wherein the third ligand is a carboxylic acid ligand, and the fourth ligand is a phosphine-containing ligand.

11. The preparation method according to claim 10, wherein the second complex is mixed with the first mixed solution and reacted at a seventh temperature for t4 to obtain a second intermediate reaction solution, and the fifth anion precursor is mixed with the second intermediate reaction solution and reacted at an eighth temperature to obtain a solution containing the core-shell quantum dots.

12. The method of claim 10, wherein the fifth cation precursor is a zinc precursor and the fifth anion precursor is a mixed precursor of a sulfur precursor and a selenium precursor.

13. The method according to claim 12, wherein the molar ratio of the fifth cation precursor to the third ligand is 1:2 to 2:1, and the molar ratio of the fifth cation precursor to the fourth ligand is 1:5 to 1: 50.

14. The method according to claim 10, wherein the carboxylic acid ligand is a carboxylic acid having a carbon backbone of C10 to C20, and the phosphine-containing ligand is a hydrocarbyl phosphine having a carbon backbone of C1 to C10.

15. The method according to claim 10, wherein the sixth temperature is 150 to 300 ℃ and the reaction time t3 is 20 to 60 min.

16. The method according to claim 11, wherein the seventh temperature is 150 to 300 ℃, the eighth temperature is 250 to 310 ℃, and the reaction time t4 is 20 to 120 min.

17. A quantum dot material is characterized by comprising core-shell quantum dots, wherein the core-shell quantum dots are prepared by the preparation method of any one of claims 10 to 16, the half-peak width of the quantum dot material is less than 40nm, and the quantum yield of the quantum dot material is greater than 70%; preferably, the half-peak width of the quantum dot material is 35-40 nm.

18. A quantum dot composition, comprising the quantum dot material of claim 17.

19. A quantum dot device comprising the quantum dot material of claim 17, or the quantum dot composition of claim 18.