Quantum dot electronic ink and method of making same

Abstract

The application relates to a quantum dot electronic ink and a preparation method thereof. The quantum dot electronic ink comprises the following components in percentage by weight: 0.1-5% of quantum dot material, 0.1-5% of electronic transmission material, 1-20% of non-polar organic solvent and / or weak polar organic solvent, 60-90% of main solvent and 1-20% of polar organic solvent; wherein the main solvent is a long carbon chain fatty alcohol solvent; the boiling point of the polar organic solvent is greater than that of the non-polar organic solvent and / or weak polar organic solvent, and the boiling point of the main solvent is greater than that of the non-polar organic solvent and / or weak polar organic solvent. The quantum dot electronic ink can form a quantum dot material layer and an electronic transmission layer at one time, and the layer thickness is uniform, so that the steps of QLED device manufacturing are simplified, and the manufacturing efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a quantum dot electronic ink and its preparation method. Background Technology

[0002] Quantum dots are zero-dimensional nanomaterials, typically semiconductor nanoparticles with a particle size between 2 nm and 20 nm, hence also known as semiconductor nanocrystals. Strictly defined, they are nanocrystals with a radius smaller than or close to the exciton Bohr radius. Quantum dots possess unique optical properties such as a narrow emission spectrum, adjustable emission wavelength by controlling particle size, and good photostability, which have long attracted widespread interest and attention from scientific researchers. Especially in the display field, quantum dot electroluminescent devices—quantum dot light-emitting diode displays (QLEDs)—have advantages such as high color gamut, self-emissiveness, and fast response speed, and have become a research hotspot in recent years, considered a next-generation display after organic light-emitting diode (OLED) displays.

[0003] Quantum dots can be dispersed in solvents to formulate printing materials such as quantum dot inks, suitable for solution-based preparation. Quantum dot films can be manufactured using methods such as printing, pad printing, and spin coating. Inkjet printing technology has been widely researched and applied in optoelectronic device manufacturing in recent years, particularly for flat panel display devices such as OLED and QLED displays. It is considered an effective way to address high costs and achieve large-area displays. This technology combines solution-based functional materials with advanced inkjet printing equipment to fabricate OLED or QLED displays, improving material utilization and production efficiency, reducing manufacturing costs, and increasing production capacity.

[0004] QLED devices typically have a multi-layer structure consisting of ITO / HIL / HTL / QD / ETL / cathode. Traditional methods for fabricating QLEDs involve gradually forming the required device structure layer by layer, which is time-consuming and involves complicated steps. Summary of the Invention

[0005] Therefore, it is necessary to provide a quantum dot electronic ink. This quantum dot electronic ink can form a quantum dot material layer and an electron transport layer in a single inkjet printing process, with uniform layer thickness, simplifying the fabrication steps of QLED devices and improving manufacturing efficiency.

[0006] A quantum dot electronic ink, comprising the following components by weight percentage:

[0007] Quantum dot materials 0.1-5%, electron transport materials 0.1-5%, nonpolar organic solvents and / or weakly polar organic solvents 1-20%, main solvent 60-90%, polar organic solvents 1-20%;

[0008] Wherein, the main solvent is a long-chain fatty alcohol solvent; the boiling point of the polar organic solvent is greater than that of the non-polar organic solvent and / or the weakly polar organic solvent, and the boiling point of the main solvent is greater than that of the non-polar organic solvent and / or the weakly polar organic solvent.

[0009] In one embodiment, the quantum dot electronic ink comprises, by weight percentage, the following components:

[0010] Quantum dot materials 1-3%, electron transport materials 1-3%, nonpolar organic solvents and / or weakly polar organic solvents 5-15%, main solvent 64-88%, polar organic solvents 5-15%.

[0011] In one embodiment, the long-chain fatty alcohol has an -OH group at one end and an alkane group or aromatic group with a carbon chain length of C6-C20 at the other end, wherein the carbon chain may or may not contain aliphatic branches or aromatic group branches.

[0012] In one embodiment, the long-chain fatty alcohol is one or more of heptanol, nonanol, 4-methyl-3-heptanol, 2-ethylhexanol, trimethylnonanol, 5-ethyl-2-nonanol, 2-hexyl-1-decanol, 2-octyldodecanol, 3-methylphenylpentanol, 7-phenyl-1-heptanol, and 1-phenyl-1-octanol.

[0013] In one embodiment, the polar organic solvent has a boiling point of 200-350°C; the non-polar organic solvent and / or weakly polar organic solvent has a boiling point of 80-180°C; and the main solvent has a boiling point of 200°C to 350°C.

[0014] In one embodiment, the polar organic solvent is one or more of glycerol, ethylene glycol, polyethylene glycol, diethylene glycol, propylene glycol, butanediol, and pentanediol.

[0015] In one embodiment, the nonpolar organic solvent is selected from one or more aliphatic or aromatic compounds with a boiling point range of 80-180°C.

[0016] In one embodiment, the weakly polar organic solvent is selected from one or more aliphatic or aromatic compounds with a boiling point range of 80-180°C.

[0017] In one embodiment, the quantum dot electronic ink has a viscosity of 3-12 cP and a surface tension of 30-42 dynes / cm.

[0018] In one embodiment, the quantum dot material is CdSe, CdS, ZnSe, ZnS, CdTe, ZnTe, CdS / ZnS, CdSe / ZnS, CdSe / CdS / ZnS, GaAs, InP, PbS / ZnS, PbSe / ZnS, CuInS2, CuInZnS, CuInGaSe, InP, CsPbCl3, CsPbBr3, CsPbI3, CsPbBr x Cl 3-x One or more of the following, where x = 1 or 2.

[0019] In one embodiment, the electron transport material is a nano-zinc oxide-based electron transport material.

[0020] In one embodiment, the nano-zinc oxide-based electron transport material is selected from at least one of ZnO, ZnMgO, ZnTiO3, ZnMgTiO3, ZnTiO3, ZnCdO, ZnWO4, ZnAlO, ZnNiO, ZnSnO3, and ZnTiSnO.

[0021] In one embodiment, the nonpolar organic solvent is an organic solvent with a dielectric constant less than 2.5; the weakly polar organic solvent is an organic solvent with a dielectric constant of 2.5-4; and the polar organic solvent is an organic solvent with a dielectric constant greater than 4.

[0022] This invention also provides a method for preparing quantum dot electronic ink, comprising the following steps:

[0023] Measure the following components by weight percentage: quantum dot material 0.1-5%, electron transport material 0.1-5%, nonpolar organic solvent and / or weakly polar organic solvent 1-20%, main solvent 60-90%, and polar organic solvent 1-20%.

[0024] Under stirring conditions, the quantum dot material is dispersed in the polar organic solvent and / or weakly polar organic solvent to obtain solution A;

[0025] Under stirring conditions, 40%-60% of the total amount of the main solvent is added to solution A to obtain solution B;

[0026] Under stirring conditions, the electron transport material is dispersed in the polar organic solvent to obtain liquid C;

[0027] Under stirring conditions, the remaining main solvent is added to solution C to obtain solution D;

[0028] Under stirring conditions, liquid D and liquid B are mixed to obtain quantum dot electronic ink.

[0029] A method for fabricating a quantum dot light-emitting diode includes the following steps:

[0030] Provide a substrate containing an anode;

[0031] An ink layer is formed on the anode using the quantum dot electronic ink. After drying, a stacked quantum dot layer and an electron transport layer are formed on the anode, wherein the quantum dot layer is composed of the quantum dot material and the electron transport layer is composed of the electron transport material.

[0032] A cathode is fabricated on the electron transport layer to obtain a quantum dot light-emitting diode.

[0033] The principles and advantages of this invention are as follows:

[0034] The inventors of this invention discovered that using long-chain fatty alcohols as the main solvent has a certain dispersive effect on quantum dot materials, as quantum dot materials are easily dispersed in nonpolar or weakly polar organic solvents. Since the main solvent is a long-chain fatty alcohol, one end of which is lipophilic, it does not affect the stability of the quantum dot materials. Furthermore, electron transport materials are easily dispersed in polar alcohol solvents, and since the main solvent, a long-chain fatty alcohol, contains a hydroxyl group at one end, it also has a certain dispersive effect on the electron transport materials and does not affect their stability. When a nonpolar or weakly polar organic solvent, a main solvent, a polar organic solvent, quantum dot materials, and electron transport materials are mixed to form quantum dot electronic ink, the nonpolar or weakly polar organic solvent and the polar organic solvent are present in small amounts, so they do not affect the stability of the quantum dot materials and electron transport materials. The nonpolar or weakly polar organic solvent has a lower boiling point than the polar organic solvent and does not contain hydrogen bonds, making it more volatile. The main solvent has a higher boiling point than the nonpolar and / or weakly polar organic solvents. Therefore, after the quantum dot electronic ink is printed, during the vacuum drying process at room temperature, the nonpolar or weakly polar organic solvent evaporates quickly. As the nonpolar or weakly polar organic solvent decreases, the concentration of the polar solvent increases, causing the quantum dot materials to first settle and form a quantum dot layer. Then, after the remaining organic solvent evaporates, an electron transport layer is formed.

[0035] In summary, this invention mixes a nonpolar or weakly polar organic solvent, a main solvent, a polar organic solvent, quantum dot materials, and an electron transport material to obtain quantum dot electronic ink. Using a long-chain fatty alcohol as the main solvent, and by appropriately adjusting the proportions of each component, an inkjet-printable ink suitable for inkjet printing can be obtained. After inkjet printing, the quantum dot material can undergo phase separation from the electron transport material, thus forming a two-layer structure of a quantum dot material layer and an electron transport material layer in a single printing operation with uniform layer thickness. This not only enables the fabrication of quantum dot light-emitting devices using inkjet printing but also simplifies the operation and reduces the manufacturing cost of quantum dot light-emitting devices. Detailed Implementation

[0036] The quantum dot electronic ink and its preparation method of the present invention will be further described in detail below with reference to specific embodiments.

[0037] A quantum dot electronic ink, comprising the following components by weight percentage:

[0038] The composition comprises: 0.1-5% quantum dot material, 0.1-5% electron transport material, 1-20% nonpolar organic solvent and / or weakly polar organic solvent, 60-90% main solvent, and 1-20% polar organic solvent; wherein the main solvent is a long-chain fatty alcohol solvent; the boiling point of the polar organic solvent is higher than that of the nonpolar organic solvent and / or weakly polar organic solvent, and the boiling point of the main solvent is higher than that of the nonpolar organic solvent and / or weakly polar organic solvent.

[0039] The aforementioned quantum dot electronic ink is obtained by mixing a nonpolar or weakly polar organic solvent, a main solvent, a polar organic solvent, quantum dot material, and an electron transport material. Using a long-chain fatty alcohol as the main solvent, by appropriately adjusting the proportions of each component, an inkjet-printable ink suitable for inkjet printing can be obtained. After inkjet printing, the quantum dot material can undergo phase separation from the electron transport material, thereby forming a two-layer structure of a quantum dot material layer and an electron transport material layer in a single printing process. The layer thickness is uniform, which not only realizes the fabrication of quantum dot light-emitting devices by inkjet printing, but also simplifies the operation and reduces the manufacturing cost of quantum dot light-emitting devices.

[0040] Preferably, the quantum dot electronic ink comprises the following components by weight percentage:

[0041] Quantum dot materials 1-3%, electron transport materials 1-3%, nonpolar organic solvents and / or weakly polar organic solvents 5-15%, main solvent 64-88%, polar organic solvents 5-15%.

[0042] Specifically, the aforementioned long-chain fatty alcohol has an -OH group at one end and an alkane group or aromatic group with a carbon chain length of C6-C20 at the other end. The carbon chain may also contain aliphatic branches or aromatic branching groups. Preferably, it is one or more of the following: heptanol, nonanol, 4-methyl-3-heptanol, 2-ethylhexanol, trimethylnonanol, 5-ethyl-2-nonanol, 2-hexyl-1-decanol, 2-octyldodecanol, 3-methylphenylpentanol, 7-phenyl-1-heptanol, and 1-phenyl-1-octanol.

[0043] The aforementioned polar organic solvents have boiling points of 200-350℃; the non-polar or weakly polar organic solvents have boiling points of 80-180℃; and the main solvent has a boiling point of 200℃-350℃. This is more conducive to the stratification of quantum dot materials and electron transport materials. The polar organic solvent is preferably one or more of glycerol, ethylene glycol, polyethylene glycol, diethylene glycol, propylene glycol, butane glycol, and pentane glycol, which can effectively disperse the electron transport material. The non-polar or weakly polar organic solvents are each preferably one or more aliphatic or aromatic compounds with a boiling point range of 80-180℃, specifically such as one or more of octane, heptane, nonane, benzene, toluene, xylene, and trimethylbenzene.

[0044] The quantum dot material can be selected from CdSe, CdS, ZnSe, ZnS, CdTe, ZnTe, CdS / ZnS, CdSe / ZnS, CdSe / CdS / ZnS, GaAs, InP, PbS / ZnS, PbSe / ZnS, CuInS2, CuInZnS, CuInGaSe, InP, CsPbCl3, CsPbBr3, CsPbI3, CsPbBr x Cl 3-x One or more of the following, wherein x = 1 or 2, and the quantum dot material is selected from oil-soluble quantum dots, making it easy to disperse in nonpolar or weakly polar organic solvents. The electron transport material is a nano-zinc oxide-based electron transport material; the nano-zinc oxide-based electron transport material is selected from ZnO, ZnMgO, ZnTiO. 3、 At least one of ZnMgTiO3, ZnTiO3, ZnCdO, ZnWO4, ZnAlO, ZnNiO, ZnSnO3, and ZnTiSnO.

[0045] The nonpolar organic solvent is an organic solvent with a dielectric constant less than 2.5; the weakly polar organic solvent is an organic solvent with a dielectric constant of 2.5-4; and the polar organic solvent is an organic solvent with a dielectric constant greater than 4.

[0046] Preferably, the viscosity of the quantum dot electronic ink is 3-12 cP and the surface tension is 30-42 dynes / cm.

[0047] Understandably, the aforementioned quantum dot electronic ink may also include additives, including one or more of surfactants, defoamers, and humectants; the content of the aforementioned additives in the quantum dot electronic ink can be set according to existing technology, such as a mass percentage of 0.01-4%. The surfactants are selected from stearic acid, oleic acid, lauric acid, sodium dodecyl sulfonate, triethanolamine, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, quaternary ammonium compounds, hydroxypropyl cellulose, sodium alginate, sodium pectate, hydroxymethyl cellulose, methacrylic acid grafted starch, chitosan, vinylpyridine copolymer, polysiloxane, polyvinyl ether, polyvinyl alcohol, polyacrylamide, polyethyleneimine, maleic acid copolymer, and block copolymers of polyoxyethylene, polyethyleneimine, polyoxypropylene, polyoxybutylene, and polystyrene, as well as Air Chemicals 465, Bayer N-75, Dow Corning DC-29, and EFKA-35. 80, BYK-345, BYK-020, or any combination of one or more of these in any proportion; the defoamer is selected from one or more of polysiloxane, polyether, emulsified silicone oil, higher alcohols, tributyl phosphate, higher alcohol fatty acid ester complex, polyoxypropylene or polyether modified organosilicon, mixed in any proportion; the humectant is selected from one or more of ethylene glycol, polyethylene glycol, xylitol, propylene glycol, diethylene glycol, glycerin, triethylene glycol butyl ether, NMP, DMSO, 1,5-pentanediol, trimethylolpropane, 1,6-hexanediol, 2-methyl-2,4-pentanediol, PVP, or any comparative combination.

[0048] The preparation method of the above quantum dot electronic ink is as follows:

[0049] After measuring each component, the quantum dot material is dispersed in the nonpolar or weakly polar organic solvent under stirring conditions to obtain solution A;

[0050] Under stirring conditions, 40-60% of the main solvent is added to solution A to obtain solution B;

[0051] Under stirring conditions, the electron transport material is dispersed in the polar organic solvent to obtain liquid C;

[0052] Under stirring conditions, the remaining main solvent is added to solution C to obtain solution D;

[0053] Under stirring conditions, liquid D and liquid B are mixed to obtain quantum dot electronic ink.

[0054] This invention also relates to a method for fabricating a quantum dot light-emitting diode, comprising the following steps:

[0055] Provides a substrate containing an anode.

[0056] An ink layer is formed on the anode using the quantum dot electronic ink. After drying, a stacked quantum dot layer and an electron transport layer are formed on the anode, wherein the quantum dot layer is composed of the quantum dot material and the electron transport layer is composed of the electron transport material.

[0057] A cathode is fabricated on the electron transport layer to obtain a quantum dot light-emitting diode.

[0058] Specifically, the steps of forming an ink layer on the anode using the quantum dot electronic ink, and then forming a stacked quantum dot layer and electron transport layer on the anode after drying include inkjet printing the quantum dot electronic ink on the anode to form an ink layer, and then vacuum drying the ink layer to cause the non-polar organic solvent and / or weakly polar organic solvent, the main solvent and the polar organic solvent to evaporate, and the quantum dot material and electron transport material to settle, forming a stacked quantum dot layer and electron transport layer.

[0059] Because the boiling point of the non-polar or weakly polar organic solvent is lower than that of the polar organic solvent, after the electronic inkjet printing is completed, the non-polar or weakly polar organic solvent evaporates faster during the vacuum drying process, causing the quantum dot material to settle first and form a quantum dot layer. Then, after the polar organic solvent has completely evaporated, the electron transport material forms an electron transport layer.

[0060] Preferably, before the step of forming an ink layer on the anode with the quantum dot electronic ink, the step further includes forming a hole functional layer on the anode; then, the ink layer is formed with the quantum dot electronic ink, such that the ink layer is formed on the hole functional layer, wherein the hole functional layer includes at least one of a hole injection layer and a hole transport layer.

[0061] The above-mentioned method for fabricating quantum dot light-emitting devices enables the fabrication of quantum dot light-emitting devices by inkjet printing. Moreover, it forms a two-layer structure of quantum dot light-emitting devices, namely the quantum dot layer and the electron transport layer, in a single printing process, which simplifies the operation and reduces the manufacturing cost of quantum dot light-emitting devices.

[0062] The following are specific embodiments, in which the viscosity tester used in each embodiment is a Brookfield DV2T viscometer, and the surface tension tester used is a SITA pro line T15 surface tension meter.

[0063] Example 1

[0064] This embodiment describes an electronic dot ink, the composition of which and its preparation method are as follows:

[0065] Under stirring, 1g of CdS oil-soluble quantum dots were dispersed in 5g of toluene to obtain solution A; under stirring, 44g of trimethylnonanol was added to solution A to obtain solution B; under stirring, 1g of ZnO nanoparticles were dispersed in 5g of glycerol to obtain solution C; under stirring, 44g of trimethylnonanol was added to solution C to obtain solution D; under stirring, solutions D and B were mixed to obtain quantum dot electronic ink.

[0066] The viscosity of the aforementioned quantum dot electronic ink is 6.5 cp (25℃), and the surface tension is 35.4 dynes / cm (25℃).

[0067] The quantum dot ink can be used to fabricate devices by inkjet printing, forming a two-layer structure of quantum dot material layer and electron transport material layer in one printing, with uniform layer thickness.

[0068] Example 2

[0069] This embodiment describes an electronic dot ink, the composition of which and its preparation method are as follows:

[0070] Under stirring, 2g of CdSe / CdS / ZnS was dispersed in 11g of toluene to obtain solution A; under stirring, 37.5g of 4-methyl-3-heptanol was added to solution A to obtain solution B; under stirring, 1g of ZnO nanoparticles was dispersed in 11g of glycerol to obtain solution C; under stirring, 37.5g of 4-methyl-3-heptanol was added to solution C to obtain solution D; under stirring, solutions D and B were mixed to obtain quantum dot electronic ink.

[0071] The viscosity of the aforementioned quantum dot electronic ink is 5.1 cp (25℃), and the surface tension is 37.3 dynes / cm (25℃).

[0072] The quantum dot ink can be used to fabricate devices by inkjet printing, forming a two-layer structure of quantum dot material layer and electron transport material layer in one printing, with uniform layer thickness.

[0073] Example 3

[0074] This embodiment describes an electronic dot ink, the composition of which and its preparation method are as follows:

[0075] Under stirring, 3g of CdS / ZnS was dispersed in 10g of xylene to obtain solution A; under stirring, 38g of 4-methyl-3-heptanol was added to solution A to obtain solution B; under stirring, 1g of ZnO nanoparticles was dispersed in 10g of ethylene glycol to obtain solution C; under stirring, 38g of 4-methyl-3-heptanol was added to solution C to obtain solution D; under stirring, solutions D and B were mixed to obtain quantum dot electronic ink.

[0076] The viscosity of the aforementioned quantum dot electronic ink is 6.2 cp (25℃), and the surface tension is 35.2 dynes / cm (25℃).

[0077] The quantum dot ink can be used to fabricate devices by inkjet printing, forming a two-layer structure of quantum dot material layer and electron transport material layer in one printing, with uniform layer thickness.

[0078] Example 4

[0079] This embodiment describes an electronic dot ink, the composition of which and its preparation method are as follows:

[0080] Under stirring, 3g of CdSe / ZnS was dispersed in 15g of nonane to obtain solution A; under stirring, 32g of 2-octyldodecyl alcohol was added to solution A to obtain solution B; under stirring, 3g of ZnO nanoparticles were dispersed in 15g of diethylene glycol to obtain solution C; under stirring, 32g of 2-octyldodecyl alcohol was added to solution C to obtain solution D; under stirring, solutions D and B were mixed to obtain quantum dot electronic ink.

[0081] The viscosity of the aforementioned quantum dot electronic ink is 6.5 cp (25℃), and the surface tension is 34.2 dynes / cm (25℃).

[0082] The quantum dot ink can be used to fabricate devices by inkjet printing, forming a two-layer structure of quantum dot material layer and electron transport material layer in one printing, with uniform layer thickness.

[0083] Comparative Example 1

[0084] This comparative example is an electronic dot ink, the composition and preparation method of which are the same as in Example 1, except that: octadecylamine is used instead of trimethylnonanol. After replacing trimethylnonanol, ZnO nanoparticles agglomerate and precipitate, affecting the stability of the ink, clogging the printhead, and making printing impossible.

[0085] The viscosity of the aforementioned quantum dot electronic ink is 7.4 cp (25℃), and the surface tension is 32.5 dynes / cm (25℃).

[0086] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0087] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A quantum dot electronic ink, characterized in that, By weight percentage, it comprises the following components: The composition includes 0.1-5% quantum dot material, 0.1-5% electron transport material, 1-20% nonpolar organic solvent and / or weakly polar organic solvent, 60-90% main solvent, and 1-20% polar organic solvent; the electron transport material is a nano-zinc oxide-based electron transport material. Wherein, the main solvent is a long-chain fatty alcohol solvent; the boiling point of the polar organic solvent is greater than that of the non-polar organic solvent and / or the weakly polar organic solvent, and the boiling point of the main solvent is greater than that of the non-polar organic solvent and / or the weakly polar organic solvent. The long-chain fatty alcohol solvent is one or more of 4-methyl-3-heptanol, trimethylnonanol, and 2-octyldodecyl alcohol; The polar organic solvent is one or more of glycerol, polyethylene glycol, diethylene glycol, butanediol, and pentanediol; The nano-zinc oxide-based electron transport material is selected from ZnO, ZnMgO, and ZnTiO. 3、 At least one of ZnMgTiO3, ZnTiO3, ZnCdO, ZnWO4, ZnAlO, ZnNiO, ZnSnO3, and ZnTiSnO.

2. The quantum dot electronic ink according to claim 1, characterized in that, By weight percentage, it comprises the following components: Quantum dot materials 1-3%, electron transport materials 1-3%, nonpolar organic solvents and / or weakly polar organic solvents 5-15%, main solvent 64-88%, polar organic solvents 5-15%.

3. The quantum dot electronic ink according to claim 1, characterized in that, The polar organic solvent has a boiling point of 200-350℃; the non-polar organic solvent and / or weakly polar organic solvent has a boiling point of 80-180℃; and the main solvent has a boiling point of 200℃~350℃.

4. The quantum dot electronic ink according to claim 1, characterized in that, The nonpolar organic solvent is selected from one or more aliphatic or aromatic compounds with a boiling point range of 80-180℃.

5. The quantum dot electronic ink according to claim 1, characterized in that, The weakly polar organic solvent is selected from one or more aliphatic or aromatic compounds with a boiling point range of 80-180℃.

6. The quantum dot electronic ink according to any one of claims 1-5, characterized in that, The quantum dot electronic ink has a viscosity of 3-12 cP and a surface tension of 30-42 dynes / cm.

7. The quantum dot electronic ink according to any one of claims 1-5, characterized in that, The quantum dot materials are CdSe, CdS, ZnSe, ZnS, CdTe, ZnTe, CdS / ZnS, CdSe / ZnS, CdSe / CdS / ZnS, GaAs, InP, PbS / ZnS, PbSe / ZnS, CuInS2, CuInZnS, CuInGaSe, InP, CsPbCl3, CsPbBr3, CsPbI3, and CsPbBr. x Cl 3- x One or more of the following, where x = 1 or 2.

8. The quantum dot electronic ink according to any one of claims 1-5, characterized in that, The nonpolar organic solvent is an organic solvent with a dielectric constant less than 2.5; the weakly polar organic solvent is an organic solvent with a dielectric constant of 2.5-4; and the polar organic solvent is an organic solvent with a dielectric constant greater than 4.

9. A method for preparing quantum dot electronic ink, characterized in that, Includes the following steps: The following components are measured in weight percentages: quantum dot material 0.1-5%, electron transport material 0.1-5%, nonpolar organic solvent and / or weakly polar organic solvent 1-20%, main solvent 60-90%, and polar organic solvent 1-20%; the electron transport material is a nano-zinc oxide-based electron transport material. The main solvent is one or more of 4-methyl-3-heptanol, trimethylnonanol, and 2-octyldodecyl alcohol; Under stirring conditions, the quantum dot material is dispersed in the nonpolar organic solvent and / or weakly polar organic solvent to obtain solution A; Under stirring conditions, add 40%-60% of the total amount of the main solvent to solution A to obtain solution B; Under stirring conditions, the electron transport material is dispersed in the polar organic solvent to obtain liquid C; Under stirring conditions, the remaining main solvent is added to solution C to obtain solution D; Under stirring conditions, liquid D and liquid B are mixed to obtain quantum dot electronic ink; Wherein, the boiling point of the polar organic solvent is greater than that of the non-polar organic solvent and / or the weakly polar organic solvent, and the boiling point of the main solvent is greater than that of the non-polar organic solvent and / or the weakly polar organic solvent. The polar organic solvent is one or more of glycerol, polyethylene glycol, diethylene glycol, butanediol, and pentanediol; The nano-zinc oxide-based electron transport material is selected from ZnO, ZnMgO, and ZnTiO. 3、 At least one of ZnMgTiO3, ZnTiO3, ZnCdO, ZnWO4, ZnAlO, ZnNiO, ZnSnO3, and ZnTiSnO.

10. A method for fabricating a quantum dot light-emitting diode, characterized in that, Includes the following steps: Provide a substrate containing an anode; A quantum dot electronic ink prepared by the preparation method of quantum dot electronic ink according to any one of claims 1-8 or quantum dot electronic ink according to claim 9 is used to form an ink layer on the anode. After drying, a stacked quantum dot layer and an electron transport layer are formed on the anode, wherein the quantum dot layer is composed of the quantum dot material and the electron transport layer is composed of the electron transport material. A cathode is fabricated on the electron transport layer to obtain a quantum dot light-emitting diode.