CN102212363B - Preparation method of core-shell structure quantum dot - Google Patents

Abstract

A method for preparing quantum dots with a core-shell structure of the invention belongs to the technical field of nanomaterial preparation. I-III-VI nanocrystalline cores were prepared by injecting anionic monomers into the high-temperature oil phase, and 1-3 layers of II-VI nanocrystalline shells were prepared by one-step co-growth method to obtain ( _Cum Ag _1-m ) _x Quantum dots with (In _n Ga _1-n ) _y S _z as the core and ZnSe/ZnSe _p S _1-p /ZnS as the nanocrystalline shell. The invention realizes the size control of nanoparticles by changing the ligand concentration, temperature, reactant ratio and other means of the system; the prepared quantum dot has high fluorescence efficiency and shows good stability; it has the advantages of simple operation, good repeatability and low cost. Inexpensive, low toxicity characteristics. The prepared quantum dots do not contain heavy metals, which can not only meet the requirements of biomarkers and biodetection applications, but also provide excellent luminescent materials for lighting, displays and other aspects.

Description

A kind of preparation method of quantum dot with core-shell structure

technical field

The invention belongs to the technical field of semiconductor nano material preparation. It involves the preparation of quantum dots with a core-shell structure with controllable size, adjustable components, high fluorescence efficiency, and stable physical and chemical properties by regulating monomer activity and component distribution.

Background technique

When the size of the semiconductor crystal is small to a certain extent (1-20 nanometers), the electronic energy level near the Fermi level changes from the original quasi-continuous state to a discontinuous state. This phenomenon is called the quantum size effect. Correspondingly, its properties mainly depend on the size of the crystals. Typical semiconductor nanocrystals, that is, quantum dots, mainly include groups II-VI, III-V and IV-VI. These quantum dots all exhibit pronounced quantum size effects, with properties significantly different from their bulk counterparts. For example, the optical properties of quantum dots depend on the size of the particles, and their absorption and emission wavelengths vary with size. Based on these special properties, semiconductor quantum dots have important applications in biomarkers, lighting, displays and other fields.

The research on colloidal semiconductor quantum dots can be traced back to 1982, when the Brus group first reported the preparation and optical properties of water-soluble semiconductor quantum dots. Since then, some groups have carried out the synthesis and performance research of semiconductor quantum dots.

Group I-III-VI quantum dots have attracted attention because they do not contain highly toxic heavy metals. Compared with typical semiconductor quantum dots such as II-VI, III-V or IV-VI quantum dots, the work of synthesizing I-III-VI quantum dots is less, and the fluorescence efficiency of the currently prepared quantum dots is average Below 5%, and the quantum dots are not stable. For example, Castro reported in 2003 to prepare I-III-VI group quantum dots (Chem.Mater.2003,15,3142-3147) by unimolecular reaction precursor method) The quantum dot size distribution that obtains is poor, and fluorescence efficiency is less than 1 %. With the development of synthesis, in 2008, the Lu group reported the preparation of I-III-VI group quantum dots (cubic phase and hexagonal phase) with different structures by amine pyrolysis (amine injection into the reaction monomer solution). These quantum dots Sizes from 5 to 30 nm, no fluorescence emission (J. Am. Che. Soc. 2008, 130, 5620-5621). Peng group reported the preparation of I-III-VI quantum dots in 2009. In terms of improving fluorescence performance, the core-shell structure quantum dots are prepared by atomic layer continuous adsorption method (anion and cation alternately added method), and its efficiency can reach 20% (J.Am.Chem.Soc.2009, 131, 5691-5697) At present, I-III-VI quantum dots cannot be compared with typical CdSe quantum dots in terms of preparation methods and properties research. For example, the fluorescent quantum efficiency of CdSe quantum dots can reach more than 80%, while the highest efficiency of I-III-VI quantum dots reported in the literature is only about 20%, and the stability of quantum dots needs to be improved. The existing related work mainly focuses on the preparation of I-III-VI quantum dots with stoichiometric ratio (I: III: VI = 1: 1: 2). When preparing quantum dots, the system needs to be completed under vacuum conditions. For some specific sizes Quantum dots need size selection, and these methods will bring a lot of inconvenience to the synthesis of quantum dots, such as high cost and complicated operation. Moreover, from the perspective of material research, the research on the composition and performance relationship of quantum dots has not been reported. In this sense, the preparation of I-III-VI group quantum dots with high fluorescence efficiency and controllable components has been a long-term goal. is a research hotspot.

Contents of the invention

The technical problem to be solved in the present invention is to prepare I-III-VI group quantum dots by regulating the activity of cations and injecting anion monomers based on the problems existing in the background technology. The size-controllable and composition-tunable group I-III-VI quantum dots were obtained for the first time by adjusting the monomer composition and temperature. Further experiments show that quantum dots with different components exhibit different optical properties, that is, the composition of quantum dots is closely related to their fluorescence efficiency. In the experiment of preparing the shell layer, the present invention uses the co-growth method to prepare the shell-core structure quantum dots, and the obtained quantum dots have high fluorescence efficiency. This method is simple to operate, low in cost, and easy to scale up production.

The present invention constructs core-shell structure quantum dots composed of different materials based on the theory of energy band engineering, and uses the co-growth method to prepare I-III-VI group quantum dots with a composite shell not only has good stability, but also has a fluorescence efficiency of up to 60%. above. The I-III-VI group quantum dots prepared by the method of the invention can completely replace typical CdSe quantum dots in terms of optical properties, and can basically meet the application requirements in the fields of biomarkers, lighting and displays.

The quantum dot prepared by the invention is composed of two parts: I-III-VI group quantum dot core and II-VI group quantum dot shell. The materials that make up these nanocrystalline cores do not contain highly toxic heavy metal elements. The specific quantum dot core is ( _Cum Ag _1-m ) _x (In _n Ga _1-n ) _y S _z , where 1<x≤11, 1<y≤11, z changes with the value of x and y , z=(x+3y)/2 to meet the requirements of molecular valence; that is, group I elements are copper or/and silver, and the molar ratio of copper to silver is 1-m/m, 1≥m≥0; group III elements It is indium or/and gallium, and the molar ratio of indium to gallium is 1-n/n, 1≥n≥0; the group VI element is sulfur. The specific quantum dot shell is Zn(S _p Se _1-p ), that is, the group II element is zinc, the group VI element is sulfur or/and selenium, and the molar ratio of sulfur to selenium is 1-p/p, 1≥p≥ 0; Quantum dot shell can have 1~3 layers, and the shell thickness of different materials is adjustable; Quantum dot shell includes: ZnS, ZnSe, ZnSe _p S _1-p , ZnSe/ZnS and ZnSe/ZnSe _p S _{1- p} /ZnS.

As shown in Figure 1, the present invention prepares I-III-VI quantum dot cores by regulating the activity of cationic monomers and injecting anion precursors. Different cationic monomers and different mercaptools form complexes. By adding different proportions of monomers and injecting anionic monomers at a certain temperature, I-III-VI quantum dot cores can be obtained. The quantum dot shell is prepared by the co-growth method. The co-growth method is a method in which the materials for the growth shell are mixed together and added to the growth quantum dot shell. The mixed monomer of the shell material is injected at low temperature, and then the solution is heated to a higher temperature to prepare the shell layer. The co-growth once is the thickness of a single molecular layer material B1 layer as shown in Figure 1, and then add different material monomers to repeat the operation Layers B2 and B3 can be prepared separately. This method is simple and easy to refine the shell thickness and material composition. The work of the background technology, such as J.Am.Chem.Soc.2009, 131, 5691-5697, is mainly to add S and Zn alternately, and does not add suitable ligands, such as mercaptools, etc., and the reaction must be carried out under vacuum conditions. conduct. The symbiosis method of the present invention can not only be produced on a large scale, but also easy to operate. More importantly, the surface of the obtained core-shell particles has a suitable ligand to passivate the surface of the quantum dots, so the obtained quantum dots have higher fluorescence efficiency.

The technical scheme of the preparation method of concrete core-shell structure quantum dots is as follows:

A preparation method of a core-shell quantum dot, wherein the core-shell quantum dot is based on I _x -III _y -S _((x+3y)/2) as the quantum dot core and Zn-VI as the quantum dot shell layer; wherein, the molar ratio of group I elements to group III elements is x/y, 1≤x≤11, 1≤y≤11; group I elements are copper or/and silver, and the molar ratio of silver to copper is 1- m/m, 1≥m≥0, group III elements are indium or/and gallium, the molar ratio of gallium to indium is 1-n/n, 1≥n≥0, group VI elements are sulfur or/and selenium, selenium and indium The molar ratio of sulfur is 1-p/p, 1≥p≥0; there are processes for preparing the quantum dot core solution and coating the quantum dot shell;

The preparation process of the quantum dot nucleus solution is to use copper or/and silver cationic monomers, indium or/and gallium cationic monomers, and elemental sulfur as raw materials, with mercaptools or/and long-chain acids as ligands, and Octadecene, octadecane or eicosene is used as a solvent; copper or/and silver cation monomer, indium or/and gallium cation monomer, and elemental sulfur are fed according to the quantum dot core component; firstly, copper or/and silver cation Add the monomer and the ligand into the first container, add the solvent and heat until the solution is clear and drop to 75-85°C to obtain a complex of copper or/and silver and the ligand; add indium or/and gallium cation single body, ligand and solvent, heated until the solution is clear, and cooled to 80°C to obtain a complex of indium or/and gallium with the ligand; the amount of the ligand is copper or/and silver cationic monomer or indium respectively in moles Or/and gallium cationic monomer 2～5 times, the amount of solvent used is 3～50mL per millimole of Cu or/and Ag cationic monomer; finally the complex of copper or/and silver and ligand and indium or/ Add the complexes of gallium and ligands into the reaction vessel, heat to 150-250°C, inject the oleylamine solution of elemental sulfur with a concentration of 0.8-2 mol/liter into the reaction vessel and keep it for 20 minutes to prepare quantum dots nuclear solution;

The coating process of the quantum dot shell layer is based on quantum dot core solution, sulfur or/and selenium anion monomer, zinc cationic monomer as raw materials, sulfur or/and selenium anion monomer and zinc cationic monomer The dosage is fed according to the quantum dot shell components; dissolve sulfur or/and selenium anion monomers, and zinc cationic monomers in oleylamine respectively, mix them and add them to the quantum dot core solution at 80-100°C; set the reaction temperature Rise to 220-280°C to grow the quantum dot shell layer for 30-45 minutes; then cool down to room temperature, add a mixed solvent of chloroform and ethanol with a volume ratio of 1:10 to precipitate the quantum dots, and then centrifuge to obtain the core-shell structure Quantum dots dispersed in toluene or n-hexane.

The core-shell structure quantum dot prepared by the method of the invention has good stability and high quantum efficiency. Chemical stability means no change in fluorescence efficiency after 6 months at room temperature. For the prepared quantum dot core, its efficiency is below 5%. The measurement of the quantum efficiency is calculated by comparing rhodamine 6G, and the experimental sample is tested by an integrating sphere, and the error of the efficiency is not more than 5%. The efficiency of quantum dots prepared by the invention is at least 25%, the efficiency of quantum dots with optimized core composition is at least 40%, and the efficiency of quantum dots obtained by further optimizing shell materials is at least 60%. The efficiencies for the prepared quantum dots also include intermediate values.

The quantum dot core and shell surface ligands prepared in the present invention are hydrophobic organic molecules, specifically including mercaptools, long-chain alkylamines or fatty acids, preferably octadecyl mercaptool, octadecyl mercaptool, octadecylamine or Oleic acid.

The quantum dots prepared by the method of the present invention show good monodispersity, the size range of the core is 1-5 nanometers, and the thickness of the shell layer is between 0.5 and 3.5 nanometers (see FIG. 3 ). The crystal structure of the prepared quantum dots is a cubic crystal phase, and the calculated particle size is consistent with the electron microscope measurement results, indicating that the prepared quantum dots have the same composition.

The quantum dots prepared by the method of the invention do not contain highly toxic heavy metal elements, and the optical luminescent wavelengths of the quantum dots cover the entire visible and near-infrared regions (450 to 1000 nanometers) by regulating the composition and components of the quantum dots. Figure 2 provides the absorption and emission spectra of a typical sample CuIn ₃ S ₅ and CuIn ₃ S ₅ /ZnS core-shell structure.

The quantum dot prepared by the method of the invention needs to regulate the activity of the cationic monomer. It is necessary to prepare complexes formed by different cations and different thiol molecules. These cationic monomers include zinc acetate, zinc nitrate, zinc octadecanoate, copper acetate, cuprous acetate, copper nitrate, cuprous nitrate, copper chloride, cuprous chloride, copper acetylacetonate, indium acetate, indium chloride, Indium acetylacetonate, silver nitrate, gallium chloride, and gallium acetylacetonate. The mercapto alcohols include dodecyl mercapto, octadecyl mercapto, and octadecyl mercapto. The materials needed to make quantum dots include copper, indium, silver, gallium, and zinc. The anionic monomers are sulfur and selenium, which are dissolved in oleylamine before injection.

In the preparation of complexes of different ligands and monomers, an appropriate amount of fatty acid is added to further regulate the particle size. For example, when the acid concentration increases to the same volume as the solvent, the prepared particle size can reach 15 nanometers, and the ratio of acid to solvent When the ratio is 1:10, the particle size is only 3 nm. Long-chain acids mainly include octadecanoic acid, myristic acid and octadecanoic acid.

The present invention prepares quantum dot cores and quantum dot shells by an oil phase method, and the solvent used for the reaction is a non-coordinating solvent, such as octadecene, octadecane, eicosene and the like. Since the surface of the quantum dots is long-chain alkylamine, acid and/or mercaptool, adding an appropriate amount of acetone or ethanol will cause the quantum dots to precipitate, and then redisperse them in organic solvents such as toluene or n-hexane. During the purification process, the quantum dots maintain their original physical and chemical properties with constant efficiency.

In summary, the biggest features of the present invention are: 1. The obtained quantum dots have extremely high quantum efficiency. 2. The composition of the particles is regulated by the feeding ratio. 3. There is no need for particle size selection. , 4. The reaction does not require vacuuming, the operation is simple, and it is closer to "green".

Description of drawings

Fig. 1 is a schematic diagram of the preparation process of quantum dots with core-shell structure of the present invention.

Fig. 2 is the absorption and emission spectrum diagrams of CuIn ₃ S ₅ quantum dots and CuIn ₃ S ₅ /ZnS core-shell quantum dots prepared in the present invention.

Fig. 3 is a transmission electron micrograph of CuIn ₃ S ₅ /ZnS core-shell structure quantum dots prepared in the present invention.

Detailed ways:

The first part: preparation of I-III-VI group quantum dot core (embodiment 1～32)

Provided here is that the present invention has different components I _x -III _y -S _((x+3y)/2) quantum dot core, wherein x, y are arbitrary values greater than zero, that is: 11≥x≥1,11 ≥y≥1. The elements constituting group I and group III in the present invention are as follows: I= _Cum Ag _1-m ; III=In _n Ga _1-n . The composition of quantum dots can be expressed as (Cum _{Ag 1-m} ) _x (In _n Ga _1-n ) _y S _((x+3y)/2) , where the values of m and n are any values between 0 and 1 And include 0 and 1. That is: 1≥m≥0, 1≥n≥0. The remarkable feature of the method of the invention is that the feeding molar ratio of the particles is completely consistent with the composition of the obtained particles.

Example 1:

When m=1, n=1, the typical synthesized quantum dot is Cu _x In _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be adjusted arbitrarily:

When x:y>1, a typical quantum dot Cu ₄ In ₂ S ₅ synthesis example is as follows:

Firstly, complexes of copper, indium and mercaptool are prepared. Add 0.4mmol of copper acetate and 0.8mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat until the solution is clear and then drops to 80°C. In another flask, add 0.2mmol indium acetate, 0.6mmol octamercaptool and 0.8ml octadecene, heat the solution to 150°C until the solution is clear and then cool down to 80°C. The mercaptool complex of copper and indium was added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 240 degrees, inject 0.5mmol elemental sulfur (dissolved in 1ml oleylamine) into the reaction solution quickly and keep it for 20 minutes to prepare Cu ₄ In ₂ S ₅ quantum dot solution.

Example 2:

When m=1, n=1, the typical synthesized quantum dot is Cu _x In _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be adjusted arbitrarily:

When x:y<1, a typical quantum dot Cu ₂ In ₄ S ₇ synthesis example is as follows:

Firstly, complexes of copper, indium and mercaptool are prepared. Add 0.2mmol of copper acetate and 0.4mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. Add 0.4mmol indium acetate, 1.2mmol octamercapto and 0.8ml octadecene to another flask, heat the solution until the solution is clear and then lower the temperature to 80°C. The mercaptool complex of copper and indium was added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 240 degrees, inject 0.7mmol elemental sulfur (dissolved in 1ml oleylamine) into the reaction solution quickly and keep it for 20 minutes to prepare Cu ₂ In ₄ S ₇ quantum dot solution.

Example 3:

When m=1, n=1, the typical synthesized quantum dot is Cu _x In _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be adjusted arbitrarily:

When x:y=1, a typical quantum dot _CuInS2 synthesis example is as follows:

Firstly, complexes of copper, indium and mercaptool are prepared. Add 0.4mmol of copper acetate and 0.8mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. Add 0.4mmol indium acetate, 1.2mmol octamercapto and 0.8ml octadecene to another flask, heat the solution until the solution is clear and then lower the temperature to 80°C. The mercaptool complex of copper and indium was added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. The cationic monomer solution was heated to any temperature between 150 and 240 degrees, and 0.8 mmol of elemental sulfur (dissolved in 1 ml of oleylamine) was quickly injected into the reaction solution and kept for 20 minutes to prepare a CuInS ₂ quantum dot solution.

The reaction solution was heated to prepare _CuInS2 QDs of different sizes.

Example 4:

When m=1, n=0.5, a typical synthesized quantum dot is Cu _x (In _0.5 Ga _0.5 ) _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be arbitrary Adjust its scale:

When x:y>1, a typical quantum dot Cu ₄ InGaS ₅ synthesis example is as follows:

Firstly, complexes of copper, indium, gallium and mercaptool are prepared. Add 0.4mmol of copper acetate and 0.8mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. Add 0.1mmol indium acetate, 0.1mmol gallium acetate, 0.6mmol octamercapto and 0.8ml octadecene to another flask, heat the solution until the solution is clear and then lower the temperature to 80°C. The mercaptool complexes of copper, gallium and indium were added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 250 degrees, inject 0.5 mmol elemental sulfur (dissolved in 1 ml oleylamine) into the reaction solution quickly and keep it for 20 minutes to prepare Cu ₄ InGaS ₅ quantum dot solution.

Example 5:

When m=1, n=0.5, a typical synthesized quantum dot is Cu _x (In _0.5 Ga _0.5 ) _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be arbitrary Adjust its scale:

When x:y<1, a typical quantum dot Cu ₂ In ₂ Ga ₂ S ₇ synthesis example is as follows:

Firstly, complexes of copper, indium, gallium and mercaptool are prepared. Add 0.2mmol of copper acetate and 0.4mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. Add 0.2mmol indium acetate, 0.2mmol gallium acetate, 1.2mmol octamercapto and 0.8ml octadecene to another flask, heat the solution to 150°C until the solution is clear and then cool down to 80°C. The mercaptool complexes of copper, gallium and indium were added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 250 degrees, inject 0.7mmol elemental sulfur (dissolved in 1ml oleylamine) into the reaction solution quickly and keep it for 20 minutes to prepare Cu ₂ In ₂ Ga ₂ S ₇ quantum dots solution.

Embodiment 6:

When m=1, n=0.5, a typical synthesized quantum dot is Cu _x (In _0.5 Ga _0.5 ) _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be arbitrary Adjust its scale:

When x:y=1, a typical quantum dot Cu ₂ InGaS ₄ synthesis example is as follows:

Firstly, complexes of copper, indium, gallium and mercaptool are prepared. Add 0.4mmol of copper acetate and 0.8mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. Add 0.4mmol indium acetate, 1.2mmol octamercaptool and 0.8ml octadecene to another flask, heat the solution to 120°C until the solution is clear and then cool down to 80°C. The mercaptool complexes of copper, gallium and indium were added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 250 degrees, inject 0.8mmol elemental sulfur (dissolved in 1ml oleylamine) into the reaction solution quickly and keep it for 20 minutes to prepare Cu ₂ InGaS ₄ quantum dot solution.

Embodiment 7:

When m=1, n=0, a typical synthesized quantum dot is Cu _x Ga _y S _((x+3y)/2) , in which the composition of group I elements and group III elements that make up the quantum dots can be adjusted arbitrarily:

When x:y>1, a typical quantum dot Cu ₄ Ga ₂ S ₅ synthesis example is as follows:

Copper, gallium and mercapto alcohol complexes are first prepared. Add 0.4mmol of copper acetate and 0.8mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. In another flask, add 0.2mmol gallium acetate, 0.6mmol octamercaptool and 0.8ml octadecene, heat the solution to 150°C until the solution is clear and cool down to 80°C. The mercaptool complex of copper and gallium was added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 250 degrees, inject 0.5mmol elemental sulfur (dissolved in 1ml oleylamine) into the reaction solution quickly and keep it for 20 minutes to prepare Cu ₄ Ga ₂ S ₅ quantum dot solution.

Embodiment 8:

When m=1, n=0, the typical synthesized quantum dot is Cu _x Ga _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be adjusted arbitrarily:

When x:y<1, a typical quantum dot Cu ₂ Ga ₄ S ₇ synthesis example is as follows:

Copper, gallium and mercapto alcohol complexes are first prepared. Add 0.2mmol of copper acetate and 0.4mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. Add 0.4mmol gallium acetate, 1.2mmol octamercapto and 0.8ml octadecene to another flask, heat the solution to 150°C until the solution is clear and then lower the temperature to 80°C. The mercaptool complex of copper and gallium was added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 250 degrees, inject 0.7 mmol of elemental sulfur (dissolved in 1 ml of oleylamine) into the reaction solution quickly and keep it for 20 minutes to prepare Cu ₂ Ga ₄ S ₇ quantum dot solution.

Embodiment 9:

When m=1, n=0, the typical synthesized quantum dot is Cu _x Ga _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be adjusted arbitrarily:

When x:y=1, a typical quantum dot CuGaS ₂ synthesis example is as follows:

Copper, gallium and mercapto alcohol complexes are first prepared. Add 0.4mmol of copper acetate and 0.8mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. Add 0.4mmol gallium acetate, 1.2mmol octamercapto and 0.8ml octadecene to another flask, heat the solution to 150°C until the solution is clear and then lower the temperature to 80°C. The mercaptool complex of copper and gallium was added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. The cationic monomer solution was heated to any temperature between 150 and 250 degrees, and 0.8 mmol of elemental sulfur (dissolved in 1 ml of oleylamine) was quickly injected into the reaction solution and kept for 20 minutes to prepare a CuGaS ₂ quantum dot solution.

Example 10:

When m=0.5, n=1, the typical synthesized quantum dots are (Ag _0.5 Cu _0.5 ) _x In _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be arbitrary Adjust its scale:

When x:y>1, a typical synthesis example of quantum dots Ag ₂ Cu ₂ In ₂ S ₅ is as follows:

Firstly, complexes of silver, copper, indium and mercaptool are prepared. Add 0.2mmol of silver acetate, 0.2mmol of copper acetate and 0.8mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. In another flask, add 0.2mmol indium acetate, 0.6mmol octamercaptool and 0.8ml octadecene, heat the solution to 150°C until the solution is clear and then cool down to 80°C. The mercaptool complexes of silver, copper and gallium were added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 250 degrees, inject 0.5mmol elemental sulfur (dissolved in 1ml oleylamine) into the reaction solution quickly and keep it for 20 minutes to prepare Ag ₂ Cu ₂ In ₂ S ₅ quantum dots solution.

Example 11:

When m=0.5, n=1, the typical synthesized quantum dots are (Ag _0.5 Cu _0.5 ) _x In _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be arbitrary Adjust its scale:

When x:y<1, a typical quantum dot AgCuIn ₄ S ₇ synthesis example is as follows:

Firstly, complexes of silver, copper, indium and mercaptool are prepared. Add 0.1mmol of silver acetate, 0.1mmol of copper acetate and 0.6mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. In another flask, add 0.4mmol indium acetate, 1.2mmol octamercaptool and 0.8ml octadecene, heat the solution to 150°C until the solution is clear and then cool down to 80°C. The mercaptool complexes of silver, copper and gallium were added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 250 degrees, inject 0.7 mmol of elemental sulfur (dissolved in 1 ml of oleylamine) into the reaction solution quickly and keep it for 20 minutes to prepare the AgCuIn ₄ S ₇ quantum dot solution.

Example 12:

When m=0.5, n=1, the typical synthesized quantum dots are (Ag _0.5 Cu _0.5 ) _x In _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be arbitrary Adjust its scale:

When x:y=1, a typical quantum dot AgCuGa ₂ S ₄ synthesis example is as follows:

First, complexes of silver, copper, gallium and mercaptools are prepared. Add 0.2mmol of silver acetate, 0.2mmol of copper acetate and 0.6mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. Add 0.4mmol gallium acetate, 1.2mmol octamercapto and 0.8ml octadecene to another flask, heat the solution to 150°C until the solution is clear and then lower the temperature to 80°C. The mercaptool complexes of silver, copper and gallium were added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. The cationic monomer solution was heated to any temperature between 150 and 250 degrees, and 0.8 mmol of elemental sulfur (dissolved in 1 ml of oleylamine) was quickly injected into the reaction solution and kept for 20 minutes to prepare a CuGaS ₂ quantum dot solution.

Example 13

When m=0.5, n=0.5, the typical synthesized quantum dots are (Ag _0.5 Cu _0.5 ) _x (In _0.5 Ga _0.5 ) _y S _((x+3y)/2) : the group I elements and III The composition of group elements can adjust its ratio arbitrarily:

When x:y>1, a typical quantum dot Ag ₂ Cu ₂ InGaS ₅ synthesis example is as follows:

Firstly, complexes of silver, copper, indium, gallium and mercaptool are prepared. Add 0.2mmol of silver acetate, 0.2mmol of copper acetate and 0.6mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. Add 0.1mmol indium acetate, 0.1mmol gallium acetate, 0.6mmol octamercapto and 0.8ml octadecene to another flask, heat the solution to 150°C until the solution is clear and then lower the temperature to 80°C. The mercaptool complexes of silver, copper, indium and gallium were added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 250 degrees, inject 0.5 mmol of elemental sulfur (dissolved in 1 ml of oleylamine) into the reaction solution quickly and keep it for 20 minutes to prepare the Ag ₂ Cu ₂ InGaS ₅ quantum dot solution.

Example 14

When m=0.5, n=0.5, the typical synthesized quantum dots are (Ag _0.5 Cu _0.5 ) _x (In _0.5 Ga _0.5 ) _y S _((x+3y)/2) : the group I elements and III The composition of group elements can adjust its ratio arbitrarily:

When x:y<1, a typical quantum dot AgCuIn ₂ Ga ₂ S ₇ synthesis example is as follows:

Firstly, complexes of silver, copper, indium, gallium and mercaptool are prepared. Add 0.1mmol of silver acetate, 0.1mmol of copper acetate and 0.6mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. Add 0.2mmol indium acetate, 0.2mmol gallium acetate, 1.2mmol octamercapto and 0.8ml octadecene to another flask, heat the solution to 150°C until the solution is clear and then cool down to 80°C. The mercaptool complexes of silver, copper, indium and gallium were added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. The cationic monomer solution was heated to any temperature between 150 and 250°C, and 0.7mmol elemental sulfur (dissolved in 1ml oleylamine) was quickly injected into the reaction solution and kept for 20 minutes to prepare the AgCuIn ₂ Ga ₂ S ₇ quantum dot solution.

Example 15:

When m=0.5, n=0.5, the typical synthesized quantum dots are (Ag _0.5 Cu _0.5 ) _x (In _0.5 Ga _0.5 ) _y S _((x+3y)/2) : the group I elements and III The composition of group elements can adjust its ratio arbitrarily:

When x:y=1, a typical synthesis example of quantum dot _AgCuGaInS4 is as follows:

Firstly, complexes of silver, copper, indium, gallium and mercaptool are prepared. Add 0.2mmol of silver acetate, 0.2mmol of copper acetate and 0.6mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. Add 0.2mmol gallium acetate, 0.2mmol indium acetate, 1.2mmol octamercapto and 0.8ml octadecene to another flask, heat the solution to 150°C until the solution is clear and then lower the temperature to 80°C. The mercaptool complexes of silver, copper, indium and gallium were added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. The cationic monomer solution was heated to any temperature between 150 and 250 degrees, and 0.8 mmol of elemental sulfur (dissolved in 1 ml of oleylamine) was quickly injected into the reaction solution and kept for 20 minutes to prepare the AgCuGaInS ₄ quantum dot solution.

Example 16:

When m=0.5, n=0, a typical synthesized quantum dot is (Ag _0.5 Cu _0.5 ) _x Ga _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be arbitrary Adjust its scale:

When x:y>1, a typical synthesis example of quantum dots Cu ₂ Ag ₂ Ga ₂ S ₅ is as follows:

Firstly, complexes of copper, indium gallium and mercaptool are prepared. Add 0.2mmol of silver acetate, 0.2mmol of copper acetate and 0.6mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. In another flask, add 0.2mmol gallium acetate, 0.6mmol octamercaptool and 0.8ml octadecene, heat the solution to 150°C until the solution is clear and cool down to 80°C. The mercaptool complexes of silver, copper and gallium were added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 250 degrees, inject 0.5mmol elemental sulfur (dissolved in 1ml oleylamine) into the reaction solution quickly and keep it for 20 minutes to prepare Cu ₂ Ag ₂ Ga ₂ S ₅ quantum dots solution.

Example 17:

When m=0.5, n=0, a typical synthesized quantum dot is (Ag _0.5 Cu _0.5 ) _x Ga _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be arbitrary Adjust its scale:

When x:y<1, a typical quantum dot CuAgGa ₄ S ₇ synthesis example is as follows:

Firstly, complexes of copper, silver gallium and mercaptool are prepared. Add 0.1mmol of silver acetate, 0.1mmol of copper acetate and 0.6mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. Add 0.4mmol gallium acetate, 1.2mmol octamercapto and 0.8ml octadecene to another flask, heat the solution to 150°C until the solution is clear and then lower the temperature to 80°C. The mercaptool complexes of silver, copper and gallium were added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 250 degrees, inject 0.7 mmol of elemental sulfur (dissolved in 1 ml of oleylamine) into the reaction solution quickly and keep it for 20 minutes to prepare CuAgGa ₄ S ₇ quantum dot solution.

Example 18:

When m=0.5, n=0, a typical synthesized quantum dot is (Ag _0.5 Cu _0.5 ) _x Ga _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be arbitrary Adjust its scale:

When x:y=1, a typical quantum dot AgCuGa ₂ S ₄ synthesis example is as follows:

First, complexes of silver, copper, gallium and mercaptools are prepared. Add 0.2mmol of silver acetate, 0.2mmol of copper acetate and 0.6mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. Add 0.4mmol gallium acetate, 1.2mmol octamercapto and 0.8ml octadecene to another flask, heat the solution to 150°C until the solution is clear and then lower the temperature to 80°C. The mercaptool complexes of silver, copper and gallium were added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. The cationic monomer solution was heated to any temperature between 150 and 250 degrees, and 0.8 mmol elemental sulfur (dissolved in 1 ml oleylamine) was quickly injected into the reaction solution and kept for 20 minutes to prepare the AgCuGa ₂ S ₄ quantum dot solution.

Example 19:

When m=0, n=1, a typical synthesized quantum dot is Ag _x In _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be adjusted arbitrarily:

When x:y>1, a typical quantum dot Ag ₄ In ₂ S ₅ synthesis example is as follows:

A complex of silver, indium and mercaptool is first prepared. Add 0.4mmol of silver acetate and 0.4mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. In another flask, add 0.2mmol indium acetate, 0.6mmol octamercaptool and 0.8ml octadecene, heat the solution to 150°C until the solution is clear and then cool down to 80°C. The thiol complex of silver and indium was added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 250 degrees, inject 0.5 mmol of elemental sulfur (dissolved in 1 ml of oleylamine) into the reaction solution quickly and keep it for 20 minutes to prepare the Ag ₄ In ₂ S ₅ quantum dot solution.

Example 20:

When m=0, n=1, a typical synthesized quantum dot is Ag _x In _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be adjusted arbitrarily:

When x:y<1, a typical quantum dot Ag ₂ In ₄ S ₇ synthesis example is as follows:

A complex of silver, indium and mercaptool is first prepared. Add 0.2mmol of silver acetate and 0.2mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. In another flask, add 0.4mmol indium acetate, 1.2mmol octamercaptool and 0.8ml octadecene, heat the solution to 150°C until the solution is clear and then lower the temperature to 80°C. The thiol complex of silver and indium was added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 250 degrees, inject 0.7mmol elemental sulfur (dissolved in 1ml oleylamine) into the reaction solution quickly and keep it for 20 minutes to prepare the Ag ₂ In ₄ S ₇ quantum dot solution.

Example 21:

When m=0, n=1, a typical synthesized quantum dot is Ag _x In _y S _((x+3y)/2) , where the composition of group I elements and group III elements that make up the quantum dots can be adjusted arbitrarily:

When x:y=1, a typical synthesis example of quantum dot _AgInS2 is as follows:

A complex of silver, indium and mercaptool is first prepared. Add 0.4mmol of silver acetate and 0.8mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. In another flask, add 0.4mmol indium acetate, 1.2mmol octamercaptool and 0.8ml octadecene, heat the solution to 150°C until the solution is clear and then lower the temperature to 80°C. The thiol complex of silver and indium was added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. The cationic monomer solution was heated to any temperature between 150 and 250 degrees, and 0.8 mmol of elemental sulfur (dissolved in 1 ml of oleylamine) was quickly injected into the reaction solution and kept for 20 minutes to prepare the AgInS ₂ quantum dot solution.

Example 22:

When m=0, n=0.5, a typical synthesized quantum dot is Ag _x (In _0.5 Ga _0.5 ) _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be arbitrary Adjust its scale:

When x:y>1, a typical quantum dot Ag ₄ InGaS ₅ synthesis example is as follows:

Firstly, complexes of silver, indium, gallium and mercaptool are prepared. Add 0.4mmol of silver acetate and 0.8mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. Add 0.1mmol indium acetate, 0.1mmol gallium acetate, 0.6mmol octamercapto and 0.8ml octadecene to another flask, heat the solution to 150°C until the solution is clear and cool down to 80°C. The mercaptool complexes of silver, gallium and indium were added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 250 degrees, inject 0.5 mmol of elemental sulfur (dissolved in 1 ml of oleylamine) into the reaction solution quickly and keep it for 20 minutes to prepare the Ag ₄ InGaS ₅ quantum dot solution.

Example 23:

When m=0, n=0.5, a typical synthesized quantum dot is Ag _x (In _0.5 Ga _0.5 ) _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be arbitrary Adjust its scale:

When x:y<1, a typical quantum dot Ag ₂ In ₂ Ga ₂ S ₇ synthesis example is as follows:

Firstly, complexes of silver, indium, gallium and mercaptool are prepared. Add 0.2mmol of silver acetate and 0.4mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. Add 0.2mmol indium acetate, 0.2mmol gallium acetate, 1.2mmol octamercapto and 0.8ml octadecene to another flask, heat the solution to 150°C until the solution is clear and then cool down to 80°C. The mercaptool complexes of silver, gallium and indium were added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 250 degrees, inject 0.7mmol elemental sulfur (dissolved in 1ml oleylamine) into the reaction solution quickly and keep it for 20 minutes to prepare Ag ₂ In ₂ Ga ₂ S ₇ quantum dots solution.

Example 24:

When m=0, n=0.5, a typical synthesized quantum dot is Ag _x (In _0.5 Ga _0.5 ) _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be arbitrary Adjust its scale:

When x:y=1, a typical quantum dot Ag ₂ InGaS ₄ synthesis example is as follows:

Firstly, complexes of silver, indium, gallium and mercaptool are prepared. Add 0.4mmol of silver acetate and 0.8mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. In another flask, add 0.4mmol indium acetate, 1.2mmol octamercaptool and 0.8ml octadecene, heat the solution to 150°C until the solution is clear and then lower the temperature to 80°C. The mercaptool complexes of silver, gallium and indium were added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 250 degrees, inject 0.8mmol elemental sulfur (dissolved in 1ml oleylamine) into the reaction solution quickly and keep it for 20 minutes to prepare Ag ₂ InGaS ₄ quantum dot solution.

Example 25:

When m=0, n=0, a typical synthesized quantum dot is Ag _x Ga _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be adjusted arbitrarily:

When x:y>1, a typical quantum dot Ag ₄ Ga ₂ S ₅ synthesis example is as follows:

A complex of silver, gallium and mercaptool is first prepared. Add 0.4mmol of silver acetate and 0.4mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. In another flask, add 0.2mmol gallium acetate, 0.6mmol octamercaptool and 0.8ml octadecene, heat the solution to 150°C until the solution is clear and cool down to 80°C. The mercaptool complex of silver and gallium was added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 250 degrees, inject 0.5 mmol of elemental sulfur (dissolved in 1 ml of oleylamine) into the reaction solution quickly and keep it for 20 minutes. Prepare Ag ₄ Ga ₂ S ₅ quantum dot solution.

Example 26:

When m=0, n=0, a typical synthesized quantum dot is Ag _x Ga _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be adjusted arbitrarily:

When x:y<1, a typical quantum dot Ag ₂ Ga ₄ S ₇ synthesis example is as follows:

A complex of silver, gallium and mercaptool is first prepared. Add 0.2mmol of silver acetate and 0.2mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. Add 0.4mmol gallium acetate, 1.2mmol octamercapto and 0.8ml octadecene to another flask, heat the solution to 150°C until the solution is clear and then lower the temperature to 80°C. The mercaptool complex of silver and gallium was added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 250 degrees, inject 0.7 mmol of elemental sulfur (dissolved in 1 ml of oleylamine) into the reaction solution quickly and keep it for 20 minutes. Prepare Ag ₂ Ga ₄ S ₇ quantum dot solution.

Example 27:

When m=0, n=0, a typical synthesized quantum dot is Ag _x Ga _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dots can be adjusted arbitrarily:

When x:y=1, a typical quantum dot AgGaS ₂ synthesis example is as follows:

A complex of silver, gallium and mercaptool is first prepared. Add 0.4mmol of silver acetate and 0.4mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 120°C until the solution is clear and then drops to 80°C. Add 0.4mmol gallium acetate, 1.2mmol octamercapto and 0.8ml octadecene to another flask, heat the solution to 150°C until the solution is clear and then lower the temperature to 80°C. The mercaptool complex of copper silver and gallium was added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 250 degrees, inject 0.8 mmol of elemental sulfur (dissolved in 1 ml of oleylamine) into the reaction solution quickly and keep it for 20 minutes. Preparation of _AgGaS2 quantum dot solution

Example 28:

When m=1, n=1, the typical synthesized quantum dot is Cu _x In _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dot core can be adjusted arbitrarily in proportion:

When x:y<1, a typical quantum dot CuIn ₁₁ S ₁₇ synthesis example is as follows:

Firstly, complexes of copper, indium and mercaptool are prepared. Add 0.1mmol of copper chloride and 0.8mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 140°C until the solution is clear and then drops to 80°C. Add 1.1mmol indium acetate, 3.3mmol octamercaptool and 0.7ml octadecene to another flask, heat the solution to 150°C until the solution is clear and then lower the temperature to 80°C. The mercaptool complex of copper and indium was added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. The cationic monomer solution is heated to any temperature between 150 and 250 degrees, and 1.7 mmol of elemental sulfur (dissolved in 1.5 ml of oleylamine) is quickly injected into the reaction solution and kept for 20 minutes to prepare a nanocrystal nucleus solution. CuIn ₁₁ S ₁₇ quantum dot solution was prepared.

Example 29:

When m=1, n=1, the typical synthesized quantum dot is Cu _x In _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dot core can be adjusted arbitrarily in proportion:

When x:y<1, a typical quantum dot CuIn ₇ S ₁₁ synthesis example is as follows:

Firstly, complexes of copper, indium and mercaptool are prepared. Add 0.1mmol of copper nitrate and 0.6mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 130°C until the solution is clear and then drops to 80°C. Add 0.7mmol indium acetate, 2.1mmol octamercapto and 0.9ml octadecene to another flask, heat the solution to 150°C until the solution is clear and then lower the temperature to 80°C. The mercaptool complex of copper and indium was added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. The cationic monomer solution is heated to any temperature between 180 and 240 degrees, and 1.1 mmol of elemental sulfur (dissolved in 1.2 ml of oleylamine) is quickly injected into the reaction solution and kept for 20 minutes to prepare a nanocrystal nucleus solution. CuIn ₇ S ₁₁ quantum dot solution was prepared.

Example 30:

When m=1, n=1, the typical synthesized quantum dot is Cu _x In _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dot core can be adjusted arbitrarily in proportion:

When x:y<1, a typical quantum dot CuIn ₅ S ₈ synthesis example is as follows:

Firstly, complexes of copper, indium and mercaptool are prepared. Add 0.1mmol of cuprous acetate and 0.2mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 130°C until the solution is clear and then drops to 80°C. Add 0.5mmol indium acetate, 1.5mmol octamercaptool and 0.5ml octadecene to another flask, heat the solution to 150°C until the solution is clear and then lower the temperature to 80°C. The mercaptool complex of copper and indium was added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heating the reaction cationic monomer solution to any temperature between 180 and 240°C, injecting 0.8mmol elemental sulfur (dissolved in 1.0ml oleylamine) into the reaction solution quickly and maintaining it for 20 minutes to prepare a nanocrystal nucleus solution. A CuIn ₅ S ₈ quantum dot solution was prepared.

Example 31:

When m=1, n=1, the typical synthesized quantum dot is Cu _x In _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dot core can be adjusted arbitrarily in proportion:

When x:y>1, a typical quantum dot Cu ₁₁ InS ₇ synthesis example is as follows:

Firstly, complexes of copper, indium and mercaptool are prepared. Add 1.1mmol of cuprous chloride and 2.2mmol of octadecylmercaptan into the flask, add 0.5ml of octadecene and heat to 100°C until the solution is clear and then drops to 80°C. Add 0.1mmol indium acetate, 0.5mmol octamercaptool and 0.5ml octadecene to another flask, heat the solution to 110°C until the solution is clear and then lower the temperature to 80°C. The mercaptool complex of copper and indium was added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 230° C., inject 0.8 mmol of elemental sulfur (dissolved in 0.8 ml of oleylamine) into the reaction solution quickly and keep it for 20 minutes to prepare a nanocrystal nucleus solution. A solution of Cu ₁₁ InS ₇ quantum dots was prepared.

Example 32:

When m=1, n=1, the typical synthesized quantum dot is Cu _x In _y S _((x+3y)/2) : the composition of group I elements and group III elements that make up the quantum dot core can be adjusted arbitrarily in proportion:

When x:y>1, a typical quantum dot Cu ₇ InS ₅ synthesis example is as follows:

Firstly, complexes of copper, indium and mercaptool are prepared. Add 0.7mmol copper acetylacetonate and 1.4mmol stearyl mercapto to the flask, add 0.5ml octadecene and heat to 120°C until the solution is clear and then drops to 80°C. Add 0.1mmol indium acetate, 0.3mmol octamercaptool and 0.5ml octadecene to another flask, heat the solution to 120°C until the solution is clear and then lower the temperature to 80°C. The mercaptool complex of copper and indium was added to the reaction flask, and 3ml of octadecene and 0.5mmol of octadecanoic acid were added. Heat the cationic monomer solution to any temperature between 150 and 240° C., inject 0.6 mmol of elemental sulfur (dissolved in 0.6 ml of oleylamine) into the reaction solution quickly and keep it for 20 minutes to prepare a nanocrystal nucleus solution. Prepare Cu ₇ InS ₅ quantum dot solution.

Part II: Preparation of I-III-VI/II-VI core-shell quantum dots (Example 33-35)

Example 33:

Presented here is a typical example of the present invention to synthesize I-III-VI quantum dots with core and ZnS as shell quantum dots. A typical synthesis is as follows: the I-III-VI quantum dot solution of Examples 1 to 32 is set at 80 degrees, 0.3mmol sulfur (0.3mmol sulfur is dissolved in 1ml oleylamine) and 0.3mmol zinc octadecanoate (0.3mmol octadecanoate Zinc acid is dissolved in the mixed solution of 0.5ml oleylamine solution) and is added in the prepared I-III-VI quantum dot solution, and then the solution is heated to 220 degrees to grow the ZnS shell layer. After 30 minutes, the solution is reduced to 100 degrees, and the 0.4 A mixed solution of mmol sulfur (0.4mmol sulfur dissolved in 1ml oleylamine) and 0.4mmol zinc octadecanoate (0.4mmol zinc octadecanoate dissolved in 0.5ml oleylamine solution) was added to the reaction solution, and the temperature was raised to 280 degrees to grow ZnS shell. After 30 minutes of reaction time, the solution was heated to 240° and held for 10 minutes. Finally, the solution was cooled to room temperature. 10ml of ethanol and 1ml of chloroform were added to the solution and centrifuged, and the obtained quantum dot precipitate could be redispersed in n-hexane.

Example 34:

Presented here is a typical example of the present invention to synthesize I-III-VI quantum dot core and /ZnSe as shell quantum dots. Typical synthesis is as follows: Example 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22 , 23, 24, 25, 26 and 27 I-III-VI quantum dot solutions were set at 90, 0.3mmol selenium (0.3mmol selenium was dissolved in 1ml oleylamine) and 0.3mmol zinc octadecanoate (0.3mmol octadecanoate Zinc acid is dissolved in the mixed solution of 0.5ml oleylamine solution) and is added in the prepared I-III-VI quantum dot solution, and then the solution is heated to 220 degrees to grow the ZnSe shell layer. After 30 minutes, the solution is reduced to 85 degrees, and the 0.4 A mixed solution of mmol selenium (0.4mmol selenium dissolved in 1ml oleylamine) and 0.4mmol zinc octadecanoate (0.4mmol zinc octadecanoate dissolved in 0.5ml oleylamine solution) was added to the reaction solution, and the temperature was raised to 260 degrees Growth of the ZnSe shell. This cycle was repeated 4 times, and the obtained quantum dot solution was cooled to room temperature. 10ml of ethanol and 1ml of chloroform were added to the solution and centrifuged, and the obtained quantum dot precipitate could be redispersed in n-hexane.

Example 35:

Presented here is a typical example of the present invention to synthesize QDs with I-III-VI QD core and ZnSe/ZnSeS/ZnS composite shell. Typical synthesis is as follows: Example 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22 , 23, 24, 25, 26 and 27 I-III-VI quantum dot solutions are set at 80 degrees, 0.35mmol selenium (dissolved in 1ml oleylamine solution) and 0.3mmol zinc octadecanoate (dissolved in 0.5ml oil A mixed solution of amine solution) was added to the prepared AgCuInGaSe quantum dot solution, and then the reaction was heated to 230 degrees to grow the ZnSe shell. After 30 minutes, the temperature of the reaction solution was lowered to 100° C., and the above-mentioned ZnS shell growth experiment was repeated. After growing the ZnSe layer of 2 molecular thicknesses, the solution was down to 90 degrees, 0.2mmol selenium (dissolved in 0.5ml oleylamine solution), 0.25mmol sulfur (dissolved in 0.5ml oleylamine solution) and 0.45mmol zinc octadecanoate ( dissolved in 0.5ml oleylamine solution) were added together to the above-prepared reaction solution, and then the temperature was raised to 225° C. for 30 minutes to grow the ZnSeS alloy shell. Then the reaction is easily lowered to 80 degrees. Then 0.75mmol sulfur (dissolved in 0.7ml oleylamine solution) and 0.75mmol zinc octadecanoate (dissolved in 1ml oleylamine solution) were simultaneously added to the reaction solution and heated to 240 degrees. After growing the ZnS shell for 30 minutes, the solution was lowered to 100°C and the ZnS shell was repeatedly grown. A mixed solution of 1mmol sulfur and 1mmol zinc octadecanoate was added to the reaction solution and heated to 260°C for 30 minutes to grow the ZnS shell. Finally, the reaction solution was heated to 280 degrees and kept for 5 minutes. Finally, the reaction solution was lowered to room temperature, and a mixed solvent of chloroform and ethanol (1:10 in volume ratio) was added to precipitate the quantum dots, and then centrifuged, and the obtained quantum dot particles were redispersed in toluene.

Claims (3)

1. a preparation method of a core-shell structure quantum dot, the core-shell structure quantum dot is to take I _x -III _y -S _((x+3y)/2) as the quantum dot core, Zn-VI as the quantum dot Point shell; wherein, the molar ratio of group I elements to group III elements is x/y, 1≤x≤11, 1≤y≤11; group I elements are copper or/and silver, and the molar ratio of silver to copper is 1-m/m, 1≥m≥0, group III elements are indium or/and gallium, the molar ratio of gallium to indium is 1-n/n, 1≥n≥0, group VI elements are sulfur or/and selenium, The molar ratio of selenium to sulfur is 1-p/p, 1≥p≥0; there are processes for preparing the quantum dot core solution and coating the quantum dot shell; The preparation process of the quantum dot nucleus solution is to use copper or/and silver cation monomer, indium or/and gallium cation monomer, elemental sulfur as raw materials, and octadecene, octadecane or eicosene as solvent ; Copper or/and silver cation monomer, indium or/and gallium cation monomer, elemental sulfur are fed according to the quantum dot core components; first, copper or/and silver cation monomer and ligand octadecylmercapto are added to the first container , add solvent and heat until the solution is clarified and drops to 75-85°C to obtain a complex of copper or/and silver and ligand; add indium or/and gallium cation monomer, ligand octamercaptool and solvent to the second container, Heating until the solution is clear, lowering the temperature to 80°C to obtain a complex of indium or/and gallium and a ligand; wherein the amount of the ligand is copper or/and silver cationic monomer or indium or/and gallium cationic monomer in moles 2 to 5 times of that, the amount of solvent used is 3 to 50 mL per mmol of Cu or/and Ag cationic monomer; finally, the complexes of copper or/and silver and ligands and the complexes of indium or/and gallium and ligands Adding it into a reaction vessel, heating to 150-250°C, injecting an oleylamine solution of elemental sulfur with a concentration of 0.8-2 mol/liter into the reaction vessel and maintaining it for 20 minutes to obtain a quantum dot nucleus solution; The coating process of the quantum dot shell layer is based on quantum dot core solution, sulfur or/and selenium anion monomer, zinc cationic monomer as raw materials, sulfur or/and selenium anion monomer and zinc cationic monomer The dosage is fed according to the quantum dot shell components; dissolve sulfur or/and selenium anion monomers, and zinc cationic monomers in oleylamine respectively, mix them and add them to the quantum dot core solution at 80-100°C; set the reaction temperature Rise to 220-280°C to grow the quantum dot shell layer for 30-45 minutes; then cool down to room temperature, add a mixed solvent of chloroform and ethanol with a volume ratio of 1:10 to precipitate the quantum dots, and then centrifuge to obtain the core-shell structure Quantum dots dispersed in toluene or n-hexane. 2. the preparation method of core-shell structure quantum dot according to claim 1 is characterized in that, described copper or/and silver cationic monomer, is copper acetate, cuprous acetate, cupric nitrate, cuprous nitrate, chlorine Copper chloride, cuprous chloride, copper acetylacetonate, silver acetate or silver nitrate; the indium or/and gallium cationic monomer is indium acetate, indium chloride, indium acetylacetonate, gallium chloride or gallium acetylacetonate; The cationic monomer of zinc is zinc acetate, zinc nitrate or zinc octadecanoate; the anionic monomer of sulfur and/or selenium is elemental sulfur, elemental selenium or selenium. 3. The preparation method of the core-shell quantum dot according to claim 1 or 2, characterized in that, the coating process of the quantum dot shell is repeated 2 to 3 times to form 2 particles on the quantum dot core. ～3 layers of Zn-VI quantum dot shell layers; in the adjacent quantum dot shell layers, ZnS, ZnSe or ZnSeS are alternated.

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