A dispersant, a preparation method of a quantum dot dispersion liquid, and an infrared detector

Abstract

The application provides a dispersant, a preparation method of a quantum dot dispersion liquid and an infrared detector. The dispersant comprises an organic structure capable of providing electrons combined with two or more surface atoms of quantum dots. The organic structure can effectively passivate the surface of the quantum dots, reduce deep defects introduced by under-coordinated atoms on the surface of the quantum dots, reduce the generated current and trap-assisted tunneling current of the quantum dot infrared detector under a reverse working bias, form a bridging structure between two or more quantum dots, effectively avoid the formation of dimers of the quantum dots to introduce a tail state, and further reduce the dark current.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sensors, and particularly relates to a dispersant, a preparation method of a quantum dot dispersion liquid, and an infrared detector. BACKGROUND

[0002] Infrared sensor devices have urgent application requirements in the fields of unmanned driving, machine vision, security monitoring, consumer electronics and the like. Current mainstream infrared detection materials use ternary semiconductors such as indium gallium arsenide and tellurium cadmium mercury, but due to their high cost, they have been difficult to popularize. The high cost mainly comes from the epitaxial growth process and the incompatibility with the silicon-based readout chip process. Colloidal quantum dots are a kind of low-cost nanomaterials, which have the advantages of adjustable band gap and low-temperature processing, and can be integrated directly on the CMOS readout circuit, which is expected to break through the limitations of the infrared market.

[0003] The existing quantum dot technology has made outstanding progress in detection performance under the condition of considering infrared response and dark noise, especially the light response has developed to a level similar to that of traditional infrared detectors. Solution process is a prominent advantage of quantum dot photoelectric materials, but the existing technology does not take into account the serious deep defects caused by the exposed state of the quantum dot surface during film formation, which leads to an increase in the dark current of the detector due to the dominant generation current and tunneling current. SUMMARY

[0004] The application provides a dispersant, a preparation method of a quantum dot dispersion liquid, and an infrared detector, which can effectively passivate the surface of quantum dots, reduce deep defects introduced by under-coordinated atoms on the surface of quantum dots, reduce the generation current of quantum dot infrared detectors under reverse working bias, and form a bridging structure between two or more quantum dots, effectively avoiding the formation of dimers by quantum dots to introduce tail states, thereby reducing the dark current.

[0005] To solve the above technical problems, the first technical solution provided by the application is to provide a dispersant, which is composed of at least one organic matter, and the organic matter includes an organic structure, wherein the organic structure is used to provide electrons combined with atoms on the surface of quantum dots.

[0006] Among them, the dispersant is composed of at least three kinds of organic matters, and at least one of the at least three kinds of organic matters contains at least two organic structures, and the two organic structures are connected.

[0007] Among them, the two organic structures are different or the same.

[0008] The dispersant comprises a first organic matter, a second organic matter, and a third organic matter; the first organic matter comprises an amide group; the second organic matter comprises a functional group, and the functional group comprises an amino group or a mercapto group; and the third organic matter comprises the organic structure.

[0009] The first organic matter is in a liquid state at room temperature; the melting point of the first organic matter is not greater than 10℃; the boiling point of the first organic matter is 50-250℃; the second organic matter is in a liquid state at room temperature; the boiling point of the second organic matter is not greater than 250℃; the second organic matter comprises one functional group, and the number of carbon atoms in the second organic matter is 2-8; the third organic matter is in a liquid state or a solid state at room temperature; the functional group of the organic structure comprises at least one of an amino group, a mercapto group, a pyridine, a piperidine, a furan, a tetrahydrofuran, a thiophene, and a pyrrole, or any combination thereof; and the skeleton connecting two organic structures comprises at least one of a carbon chain and a benzene ring, or any combination thereof.

[0010] The first organic matter comprises at least one of formamide, N-methyl formamide, N,N-dimethyl formamide, and N,N-dimethyl acetamide; the second organic matter comprises at least one of ethylamine, n-propylamine, n-butylamine, amylamine, n-hexylamine, n-heptylamine, n-octylamine, 2-butylamine, n-butyl mercaptan, n-amyl mercaptan, ethyl mercaptan, n-propyl mercaptan, n-hexyl mercaptan, n-heptyl mercaptan, n-octyl mercaptan, and 2-butyl mercaptan; and the third organic matter comprises at least one of 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,6-hexanedithiol, 1,7-heptanedithiol, 1,8-octanedithiol, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 1,2-phenylenedithiol, 1,3-phenylenedithiol, 1,4-phenylenedithiol, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-aminomethylpyridine, 3-aminomethylpyridine, 4-aminomethylpyridine, 2-(2-aminoethyl)pyridine, 3-(2-aminoethyl)pyridine, 4-(2-aminoethyl)pyridine, 2-furfurylamine, 3-furfurylamine, 2-thiophenylamine, 3-thiophenylamine, 2-aminopiperidine, 3-aminopiperidine, 4-aminopiperidine, 2-aminomethylpiperidine, 3-aminomethylpiperidine, 4-aminomethylpiperidine, 2-(2-aminoethyl)piperidine, 3-(2-aminoethyl)piperidine, 4-(2-aminoethyl)piperidine, 2-aminomethyltetrahydrofuran, 3-aminomethyltetrahydrofuran, 2-aminopyrrole, 3-aminopyrrole, 2-aminomethylpyrrole, 4,4'-bipyridine, 4,4-bipiperidine, 2,2'-bithiophene, 2-mercaptopyridine, 3-mercaptopyridine, 4-mercaptopyridine, 2-thiophenol, 2-methyl-3-thiophenol, 2-methyl-3-furfuryl mercaptan, and 2-methyl-3-tetrahydrofurfuryl mercaptan.

[0011] Wherein, the total material amount of the first organic matter is X, the total material amount of the second organic matter is Y, and the total material amount of the third organic matter is Z; wherein, X:Y is between 6:1 and 1:6; and X:Z is between 1:0.02 and 1:0.1.

[0012] To solve the above technical problems, the second technical solution provided by the present application is to provide a preparation method of quantum dot dispersion liquid, comprising: adding quantum dots in a dispersant to obtain a quantum dot mixture; the dispersant comprises the dispersant of any one of the above; oscillating the quantum dot mixture to obtain a quantum dot dispersion liquid.

[0013] Wherein, before the step of adding quantum dots in the dispersant to obtain a quantum dot mixture, it comprises: oscillating the dispersant so that the dispersant has no sediment; the step of oscillating the quantum dot mixture to obtain a quantum dot dispersion liquid comprises: oscillating the quantum dot mixture for 3-6 minutes to obtain the quantum dot dispersion liquid.

[0014] To solve the above technical problems, the second technical solution provided by the present application is to provide an infrared detector comprising: a quantum dot core layer, the quantum dot core layer is formed by a quantum dot dispersion liquid, the quantum dot dispersion liquid is prepared by the method of any one of the above.

[0015] The beneficial effects of the present application are different from the prior art. The dispersant of the present application contains an organic structure capable of realizing the combination of electrons and atoms. The organic structure can effectively passivate the surface of quantum dots, reduce the deep defects introduced by the under-coordinated atoms on the surface of quantum dots, reduce the current generated by the quantum dot infrared detector under reverse working bias, and form a bridging structure between two or more quantum dots, effectively avoiding the formation of dimer by quantum dots to introduce tail states, thereby reducing the dark current. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0017] Figure 1 It is a schematic diagram of an embodiment of the dispersant of the present application;

[0018] Figure 2 It is a flowchart of an embodiment of the preparation method of quantum dot dispersion liquid of the present application;

[0019] Figure 3 It is a structure schematic diagram of an embodiment of the infrared detector of the present application. Specific implementation methods

[0020] The terms "first", "second", "third" in the present application are only for descriptive purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second", "third" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise explicitly and specifically limited. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed, or can optionally include other steps or units inherent to the process, method, product or device.

[0021] In this document, reference to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. As those skilled in the art will readily appreciate, the various embodiments described in this document can be combined with one another in various ways.

[0022] The embodiments described in the embodiments of the present application are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0023] The dispersion liquid provided by the prior art does not consider the serious deep defects caused by the exposed state of the surface of the quantum dots in the film forming process, resulting in the increase of the dark current of the detector. Please refer to Figure 1 The dispersant 11 proposed in the present application is composed of at least one organic matter, which includes an organic structure 12 for providing the combination of electrons and surface atoms of the quantum dots, so as to effectively passivate the surface of the quantum dots, reduce the deep defects introduced by the under-coordination of the surface of the quantum dots, reduce the current generated by the quantum dot infrared detector under the reverse working bias, and at the same time form a bridging structure between two or more quantum dots, effectively avoid the formation of dimer of quantum dots to introduce tail states, and further reduce the dark current.

[0024] In one embodiment, the dispersant is composed of at least three organic substances, at least one of which comprises at least two organic structures 12, which are connected.

[0025] In one embodiment, the dispersant is composed of one or two organic substances, at least one of which comprises organic structures 12.

[0026] In another embodiment, the dispersant 11 is composed of three or more organic substances, at least one of which comprises organic structures 12. The following will be described by taking the dispersant 11 composed of three organic substances as an example.

[0027] Specifically, the dispersant comprises a first organic substance, a second organic substance, and a third organic substance.

[0028] In one embodiment, the first organic substance comprises an amide group, and is in a liquid state at room temperature (15-30°C). The melting point of the first organic substance is not greater than 10°C, and the boiling point of the first organic substance is 50-250°C. Optionally, the first organic substance comprises at least one of formamide (FA), N-methylformamide (NMF), N,N-dimethylformamide (DMF), and N,N-dimethylacetamide (DMAC).

[0029] Formamide is an amide derived from formic acid, with the formula HCONH2. It is a colorless liquid, miscible with water, and has an odor similar to ammonia. It is used in the production of sulfonamides, in the synthesis of vitamins, and as a softener for paper and textiles. Pure formamide can dissolve many ionic compounds that are insoluble in water, and is therefore also used as a solvent. N-methylformamide has the formula C2H5NO, and is a colorless, transparent liquid with an ammonia-like odor, miscible with water and ethanol, and has a melting point of -4 °C. N,N-dimethylformamide has the formula C3H7NO, and is a polar aprotic solvent. It has a slight chlorine odor, is hygroscopic, and is miscible with water, ethanol, chloroform, and diethyl ether, and is slightly soluble in benzene. N,N-dimethylacetamide has the formula CH3C(O)N(CH3)2, and is a strong polar aprotic solvent that can dissolve a wide variety of compounds, and is completely miscible with water, ethers, ketones, esters, and the like. It has high thermal stability, is not easily hydrolyzed, has low corrosivity, and has low toxicity, and has good solubility for a variety of resins, especially polyurethane resins and polyimide resins. It can be used as a solvent for heat-resistant synthetic fibers, plastic films, coatings, medicines, and acrylonitrile spinning. Dimethylacetamide is a low-toxicity, high-boiling, high-polarity aprotic solvent and chemical intermediate that has a wide range of applications in the fields of synthetic materials, medicines, pesticides, chemical fibers, petroleum processing, and organic pigments.

[0030] In one embodiment, the second organic compound includes a functional group, the functional group including an amino group or a mercapto group, the second organic compound being liquid at room temperature (15-30 °C); the second organic compound having a boiling point of no more than 250 °C; the second organic compound including one functional group, and the second organic compound including 2-8 carbon atoms. In one specific embodiment, the second organic compound includes one and only one functional group, the functional group being an amino group or a mercapto group. Specifically, the second organic compound includes at least one of ethylamine, n-propylamine, n-butylamine, amylamine, n-hexylamine, n-heptylamine, n-octylamine, 2-butylamine, n-butyl mercaptan, n-amyl mercaptan, ethyl mercaptan, n-propyl mercaptan, n-hexyl mercaptan, n-heptyl mercaptan, n-octyl mercaptan, and 2-butyl mercaptan.

[0031] Among them, n-propylamine is also known as n-propylamine, mono-n-propylamine (English name n-Propylaminwe), aminopropane, colorless transparent, volatile, high toxicity liquid at room temperature and normal pressure, alkaline, with strong ammonia smell. Molecular formula is C3H9N, structural formula is CH3CH2CH2NH2. Boiling point is 48℃, can be dissolved in water, ethanol, ether, acetone, benzene and other organic solvents. Can burn, can form explosive mixture with air. Use for organic synthesis raw materials, mainly used for synthesis of pesticides, medicines, dyes, etc. Mono-n-butylamine is a chemical substance, chemical formula C4H11N, colorless transparent liquid, no mechanical impurities, boiling point is 48℃. N-pentylamine molecular formula is C5H14N, which is colorless liquid, with ammonia smell. Melting point-55℃, boiling point 104℃, relative density (20 / 4℃) 0.7547, refractive index (20℃) 1.4118, viscosity (20℃) 1.018 mPa·s, flash point 7℃. Can be mixed with water, methanol, acetone, diethyl ether, aliphatic hydrocarbons, benzene and other solvents. N-hexylamine molecular formula is C6H15N, which is colorless liquid. Solidification point-19℃, boiling point 131.4℃, relative density 0.7660 (20 / 4℃), refractive index 1.4180, flash point 8℃. Can be mixed with ethanol, diethyl ether, slightly soluble in water. With ammonia smell. Butyl mercaptan is also known as n-butyl mercaptan, molecular formula is C4H10S, which is a colorless liquid with a skunk odor, slightly soluble in water, easily soluble in ethanol, diethyl ether, melting point-115.7℃, boiling point 98.4℃, belongs to flammable, toxic, mainly used as solvent, organic synthesis intermediates.

[0032] The third organic material includes the organic structure, and specifically, the third organic material is in liquid or solid state at room temperature (15-30 °C); the functional group of the organic structure includes at least one or any combination of amino, mercapto, pyridine, piperidine, furan, tetrahydrofuran, thiophene, and pyrrole; and the skeleton connecting the two organic structures includes at least one or any combination of carbon chain and benzene ring. In a specific embodiment, the third organic material includes two organic structures, which can be the same or different, and the functional group of the two organic structures includes at least one or any combination of amino, mercapto, pyridine, piperidine, furan, tetrahydrofuran, thiophene, and pyrrole. The skeleton connecting the two organic structures includes at least one or any combination of carbon chain and benzene ring. Alternatively, in an embodiment, the two organic structures can also be directly bonded. Specifically, when the functional group of the two organic structures is amino or mercapto and the skeleton of the two organic structures is only carbon chain, the number of carbon atoms is greater than or equal to 6. Optionally, the third organic material includes at least one of 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,6-hexanedithiol, 1,7-heptanedithiol, 1,8-octanedithiol, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 1,2-benzenedithiol, 1,3-benzenedithiol, 1,4-benzenedithiol, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-aminomethylpyridine, 3-aminomethylpyridine, 4-aminomethylpyridine, 2-(2-aminoethyl)pyridine, 3-(2-aminoethyl)pyridine, 4-(2-aminoethyl)pyridine, 2-furanmethanamine, 3-furanmethanamine, 2-thiophenemethanamine, 3-thiophenemethanamine, 2-aminopiperidine, 3-aminopiperidine, 4-aminopiperidine, 2-aminomethylpiperidine, 3-aminomethylpiperidine, 4-aminomethylpiperidine, 2-(2-aminoethyl)piperidine, 3-(2-aminoethyl)piperidine, 4-(2-aminoethyl)piperidine, 2-aminomethyltetrahydrofuran, 3-aminomethyltetrahydrofuran, 2-aminopyrrole, 3-aminopyrrole, 2-aminomethylpyrrole, 4,4'-bipyridine, 4,4-bipiperidine, 2,2'-bithiophene, 2-mercaptopyridine, 3-mercaptopyridine, 4-mercaptopyridine, 2-thiophenethiol, 2-methyl-3-thiophenethiol, 2-methyl-3-furanethiol, and 2-methyl-3-tetrahydrofuranethiol.

[0033] In a specific embodiment, the total amount of the first organic material is X, the total amount of the second organic material is Y, and the total amount of the third organic material is Z; wherein X:Y is between 6:1 and 1:6; and X:Z is between 1:0.02 and 1:0.1.

[0034] In the present application, the connection between two organic structures can precisely control the spacing of quantum dots by the length of the skeleton connecting the two organic structures, thereby effectively reducing the electronic wave function coupling between quantum dots, suppressing energy band narrowing, reducing the band tail state generated by the mutual attraction coupling effect between quantum dots, and further reducing the tunneling current of the quantum dot infrared detector under reverse working bias.

[0035] Specifically, the size of the dark current is related to the tunneling current and the generated current under reverse working bias. In the present application, the dispersant includes an organic structure for realizing the combination of electrons and atoms, which can reduce the deep defects introduced by the surface undercoordination of quantum dots, reduce the generated current and trap-assisted tunneling current of the quantum dot infrared detector under reverse working bias, and form a bridging structure between two or more quantum dots to effectively avoid the formation of dimers by quantum dots to introduce band tail states and reduce the dark current. Further, the dispersant of the present application includes two organic structures, and the spacing of quantum dots is precisely controlled by the length of the skeleton connecting the two organic structures, thereby effectively reducing the electronic wave function coupling between quantum dots, suppressing energy band narrowing, reducing the band tail state, reducing the tunneling current of the quantum dot infrared detector under reverse working bias, and further reducing the size of the dark current.

[0036] The present application provides a variety of component selections of the dispersant, which has a great control space in terms of material properties such as boiling point, polarity, dielectric constant, concentration, and film thickness, and is universal and compatible for preparing quantum dot infrared detectors of different wavebands and different application occasions.

[0037] The present application also provides a preparation method of a quantum dot dispersion liquid, please refer to Figure 2 The preparation method of the quantum dot dispersion liquid comprises:

[0038] Step S21: adding quantum dots in the dispersant to obtain a quantum dot mixture.

[0039] Specifically, the dispersant is the dispersant described above, and the quantum dots are added in the dispersant to obtain a quantum dot mixture.

[0040] In an embodiment, when the quantum dots are added in the dispersant, the dispersant is oscillated so that there is no precipitation in the dispersant. Specifically, the dispersant is oscillated for 2-5 min. Then, the quantum dot powder treated by the polar ligand and dried is weighed and added in the dispersant according to the concentration.

[0041] In an embodiment, the quantum dots suitable for applying the dispersant provided by the present application can be one or more of lead sulfide PbS, lead selenide PbSe, lead telluride PbTe, the diameter distribution of the quantum dots is 2-20 nm, the first exciton absorption peak of the quantum dots is within 600-3000 nm, the surface of the quantum dots is covered by a polar ligand, and the polar ligand includes but is not limited to lithium iodide, lithium bromide, lead iodide, lead bromide, lead chloride, cadmium chloride, cadmium iodide, stannous chloride, stannous iodide, potassium iodide, potassium bromide, sodium iodide, ammonium iodide, ammonium acetate, sodium acetate, methylamine iodide, methylamine bromide, cesium iodide, cesium bromide, lead iodide methylamine, lead bromide methylamine, cesium lead iodide, cesium lead bromide, lithium thiocyanate, sodium thiocyanate, lead thiocyanate.

[0042] In an embodiment, the concentration of the quantum dots in the dispersant is 50-800 mg / mL.

[0043] Step S22: oscillating the quantum dot mixture to obtain a quantum dot dispersion.

[0044] After the quantum dots are added to the dispersant to obtain a quantum dot mixture, the quantum dot mixture is further oscillated to obtain a quantum dot dispersion. In an embodiment, the quantum dot mixture is oscillated for 3-6 min to further obtain the quantum dot dispersion.

[0045] It can be understood that, since the dispersant of the present application includes an organic structure for realizing the combination of electrons and atoms, the deep defects introduced by the under-coordination of the surface of the quantum dots can be reduced, the current generated by the quantum dot infrared detector under a reverse working bias can be reduced, and the size of the dark current can be reduced. Further, the dispersant of the present application includes two organic structures, the distance between the quantum dots is accurately controlled by the length of the skeleton connecting the two organic structures, so that the electronic wave function coupling between the quantum dots is effectively reduced under the condition of ensuring the light responsivity, the energy band narrowing is inhibited, the tail state is reduced, the tunneling current of the quantum dot infrared detector under a reverse working bias is reduced, and the size of the dark current is further reduced. Then, the quantum dot dispersion prepared also inherits the advantages possessed by the dispersant.

[0046] The quantum dot dispersion prepared can be further used to prepare an infrared detector. Specifically, the present application also provides an infrared detector, which is specifically described in combination with Figure 3 The infrared detector includes a quantum dot core layer 31, which is prepared by the quantum dot dispersion described above. The preparation methods include but are not limited to spin coating, drop coating, blade coating, inkjet printing, and the prepared thin film needs to be annealed for 10-15 min at an annealing temperature of 70-90 ℃.

[0047] In a specific embodiment, the infrared detector further comprises a bottom electrode 32, a first functional layer 33, a second functional layer 34, and a top electrode 35. The bottom electrode 32, the first functional layer 33, the quantum dot core layer 31, the second functional layer 34, and the top electrode 35 are sequentially arranged from bottom to top or from top to bottom. The bottom electrode 32 is composed of a transparent conductive oxide, including but not limited to indium tin oxide and fluorine-doped tin oxide. The top electrode 35 is composed of a metal film, including but not limited to gold, silver, aluminum, tungsten, and titanium. The first functional layer 33 and the second functional layer 34 are an electron transport layer and a hole transport layer, respectively, including but not limited to titanium oxide, nickel oxide, molybdenum oxide, zinc oxide, tin oxide, and cuprous oxide. The preparation process includes but is not limited to thermal evaporation, electron beam evaporation, magnetron sputtering, and atomic layer deposition.

[0048] It can be understood that the infrared detector of the present application inherits the advantages of the dispersant. It can reduce the generation of dark current.

[0049] The above is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent flow transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the present application.

Claims

1. A dispersant characterized by, The dispersant is composed of at least one organic matter, the organic matter is composed of two organic structures and a skeleton; The functional groups of the organic structure include at least one or any combination of amino groups and sulfydryl groups; the skeleton connecting the two organic structures includes a carbon chain; the number of carbon atoms in the carbon chain is greater than 6; The organic structure is used to provide electrons to combine with surface atoms of quantum dots, reduce deep defects introduced by undersaturation atoms on the surface of quantum dots, and form a bridging structure between two or more quantum dots; The dispersant includes a first organic matter, a second organic matter, and a third organic matter; The first organic matter includes an amide group; The second organic matter includes at least one of ethylamine, n-propylamine, n-butylamine, amylamine, n-hexylamine, n-heptylamine, n-octylamine, 2-butylamine, n-butyl mercaptan, n-amyl mercaptan, ethyl mercaptan, n-propyl mercaptan, n-hexyl mercaptan, n-heptyl mercaptan, n-octyl mercaptan, and 2-butyl mercaptan; The third organic matter includes the organic structure.

2. The dispersant of claim 1, wherein The two organic structures are different or the same.

3. The dispersant of claim 1, wherein The first organic matter is in a liquid state at room temperature; the melting point of the first organic matter is not greater than 10°C; and the boiling point of the first organic matter is between 50°C and 250°C; The second organic matter is in a liquid state at room temperature; the boiling point of the second organic matter is not greater than 250°C; the second organic matter includes one functional group, and the number of carbon atoms in the second organic matter is between 2 and 8; The third organic matter is in a liquid state or a solid state at room temperature.

4. The dispersant of claim 1, wherein The first organic matter includes at least one of formamide, N-methyl formamide, N,N-dimethyl formamide, and N,N-dimethyl acetamide; The third organic matter includes at least one of 1,7-heptanediamine, 1,8-octanediamine, 1,7-heptanedithiol, 1,8-octanedithiol, and the like.

5. The dispersant of claim 1, wherein The total amount of the first organic matter is X, the total amount of the second organic matter is Y, and the total amount of the third organic matter is Z; X:Y is between 6:1 and 1:6; and X:Z is between 1:0.02 and 1:0.

1.

6. A dispersant characterized by, The dispersant is composed of at least one organic matter, the organic matter is composed of two organic structures and a skeleton; The functional groups of the organic structure include at least one or any combination of amino groups, sulfydryl groups, pyridine, piperidine, furan, tetrahydrofuran, thiophene, and pyrrole; the skeleton connecting the two organic structures includes a benzene ring; The organic structure is used to provide electrons to combine with surface atoms of quantum dots, reduce deep defects introduced by undersaturation atoms on the surface of quantum dots, and form a bridging structure between two or more quantum dots; The organic matter includes at least one of 1,2-benzene dithiol, 1,3-benzene dithiol, 1,4-benzene dithiol, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-aminomethylpyridine, 3-aminomethylpyridine, 4-aminomethylpyridine, 2-(2-aminoethyl)pyridine, 3-(2-aminoethyl)pyridine, 4-(2-aminoethyl)pyridine, 2-furanmethylamine, 3-furanmethylamine, 2-thiophenemethylamine, 3-thiophenemethylamine, 2-aminopiperidine, 3-aminopiperidine, 4-aminopiperidine, 2-aminomethylpiperidine, 3-aminomethylpiperidine, 4-aminomethylpiperidine, 2-(2-aminoethyl)piperidine, 3-(2-aminoethyl)piperidine, 4-(2-aminoethyl)piperidine, 2-aminomethyltetrahydrofuran, 3-aminomethyltetrahydrofuran, 2-aminopyrrole, 3-aminopyrrole, 2-aminomethylpyrrole, 4,4'-bipyridine, 4,4-bipiperidine, 2,2'-bithiophene, 2-thiopyridine, 3-thiopyridine, 4-thiopyridine, 2-thiophenethiol, 2-methyl-3-thiophenethiol, 2-methyl-3-furanethiol, 2-methyl-3-tetrahydrofuranethiol; The dispersant includes a first organic matter, a second organic matter, and a third organic matter; The first organic matter includes an amide group; The second organic matter includes at least one of ethylamine, n-propylamine, mono-n-butylamine, amylamine, n-hexylamine, n-heptylamine, n-octylamine, 2-butylamine, n-butyl mercaptan, n-amyl mercaptan, ethyl mercaptan, n-propyl mercaptan, n-hexyl mercaptan, n-heptyl mercaptan, n-octyl mercaptan, and 2-butyl mercaptan; The third organic matter includes the organic structure.

7. A method for producing a quantum dot dispersion liquid, characterized by comprising: The method includes: adding quantum dots into a dispersant to obtain a quantum dot mixture; the dispersant includes the dispersant in any one of claims 1-6; oscillating the quantum dot mixture to obtain a quantum dot dispersion.

8. The method of claim 7, wherein, Before the step of adding quantum dots into a dispersant to obtain a quantum dot mixture, the method includes: oscillating the dispersant to make the dispersant free of precipitation; The step of oscillating the quantum dot mixture to obtain a quantum dot dispersion includes: oscillating the quantum dot mixture for 3-6 minutes to obtain the quantum dot dispersion.

9. An infrared detector, characterized by It includes: a quantum dot core layer formed by a quantum dot dispersion prepared by the method in any one of claims 7-8.

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