Composite material and preparation method thereof, luminescent device and preparation method thereof, and display device

Abstract

The invention discloses a composite material and a preparation method thereof, a luminescent device and a preparation method thereof, and a display device. The composite material comprises quantum dots and fluorine-containing organic acid radicals. The composite material disclosed by the invention has relatively high fluorescence quantum efficiency.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a composite material and its preparation method, a light-emitting device and its preparation method, and a display device. Background Technology

[0002] Quantum dots (QDs), also known as semiconductor nanocrystals, have unique luminescent properties, such as wide excitation peaks, narrow emission peaks, and tunable emission spectra, making them promising for applications in the field of optoluminescence.

[0003] The fluorescence quantum efficiency of existing quantum dots is relatively low and needs to be further improved. Summary of the Invention

[0004] In view of this, this application provides a composite material and its preparation method, a light-emitting device and its preparation method, and a display device.

[0005] The embodiments of this application are implemented as follows: a composite material comprising quantum dots and fluorinated organic acid groups.

[0006] Accordingly, this application also provides a method for preparing a composite material, comprising the following steps:

[0007] Provides quantum dots, fluorinated organic acids, and a primary solvent;

[0008] The quantum dots, the fluorinated organic acid, and the first solvent are mixed to obtain a mixed solution. The first solvent in the mixed solution is then removed to obtain the composite material.

[0009] Accordingly, this application also provides a light-emitting device, comprising an anode, a light-emitting layer, and a cathode stacked sequentially, wherein,

[0010] The light-emitting layer is a first thin film, and the first thin film includes the composite material; or

[0011] The light-emitting layer is a second thin film, which includes a light-emitting film, a first interface layer disposed between the light-emitting film and the anode, and / or a second interface layer disposed between the light-emitting film and the cathode. The light-emitting film includes quantum dots or the composite material. The materials of the first interface layer and the second interface layer each independently include fluorinated organic acids.

[0012] Accordingly, this application also provides a method for fabricating a light-emitting device, comprising the following steps:

[0013] Provide the first electrode;

[0014] A light-emitting layer is prepared on the first electrode, the light-emitting layer comprising quantum dots and fluorinated organic acid groups;

[0015] A second electrode is fabricated on the light-emitting layer to obtain a light-emitting device;

[0016] Wherein, the first electrode is the anode and the second electrode is the cathode; or, the first electrode is the cathode and the second electrode is the anode;

[0017] Wherein, the light-emitting layer is a first thin film, the first thin film including the composite material; or, the light-emitting layer is a second thin film, the second thin film including a light-emitting film, and a first interface layer disposed between the light-emitting film and the anode and / or a second interface layer disposed between the light-emitting film and the cathode, wherein the light-emitting film includes quantum dots or includes the composite material, and the materials of the first interface layer and the second interface layer each independently include fluorinated organic acids.

[0018] Accordingly, this application also provides a display device including the light-emitting device.

[0019] The composite material described in this application has a high fluorescence quantum efficiency. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart illustrating a method for preparing a composite material according to an embodiment of this application;

[0022] Figure 2 This is a schematic diagram of the structure of a light-emitting device provided in an embodiment of this application;

[0023] Figure 3 This is a schematic diagram of another light-emitting device provided in an embodiment of this application;

[0024] Figure 4 This is a schematic diagram of the structure of another light-emitting device provided in the embodiments of this application;

[0025] Figure 5 This is a schematic diagram of the structure of another light-emitting device provided in the embodiments of this application;

[0026] Figure 6 This is a flowchart of a method for fabricating a light-emitting device provided in an embodiment of this application.

[0027] Figure Labels

[0028] Light-emitting device 100; anode 10; light-emitting layer 20; first thin film 201; second thin film 202; light-emitting thin film 2021; first interface layer 2022; second interface layer 2023; cathode 30; electron transport layer 40; hole transport layer 50. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Furthermore, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application.

[0030] In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its actual use or operating state, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative purposes and do not impose numerical requirements or establish a numerical order.

[0031] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0032] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one," "at least one of the following," or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c," or "at least one of a, b, and c," can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0033] In this application, the term "on" forming another layer on a certain layer is a broad concept. It can mean that the formed other layer is adjacent to a certain layer, or it can mean that there are other spacer structures between the other layer and the certain layer. For example, when a second electrode is formed "on" a first charge carrier functional layer, the term "on" can mean that the formed second electrode is adjacent to the first charge carrier functional layer, or it can mean that there are other spacer structures between the second electrode and the first charge carrier functional layer, such as a light-emitting layer.

[0034] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, whichever applies. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the range referred to.

[0035] In this application, "substitution" means that the hydrogen atom in the substituent is replaced by the substituent.

[0036] In this application, when no linking site is specified in the group, it means that any linkable site in the group is selected as the linking site.

[0037] In this application, when the same substituent appears multiple times, it can be independently selected from different groups. If the general formula contains multiple R1s, then R1s can be independently selected from different groups.

[0038] In this application, "substituted or unsubstituted" means that the defined group may or may not be substituted. When the defined group is substituted, it should be understood that the defined group can be substituted by one or more substituents R, wherein R is selected from, but is not limited to: deuterium, cyano, isocyano, nitro or halogen, C1-30 alkyl, heterocyclic group containing 3-20 ring atoms, aromatic group containing 6-20 ring atoms, heteroaromatic group containing 5-20 ring atoms, -NR'R", silyl, carbonyl, alkoxycarbonyl, aryloxycarbonyl, carbamoyl, halocarbamoyl, etc. Formyl, isocyanate, thiocyanate, isothiocyanate, hydroxyl, trifluoromethyl, and the above groups may be further substituted with substituents acceptable in the art; it is understood that R' and R" in -NR'R" are independently selected from, but not limited to: H, deuterium, cyano, isocyano, nitro or halogen, C1-10 alkyl, heterocyclic group containing 3-20 ring atoms, aromatic group containing 6-20 ring atoms, and heteroaromatic group containing 5-20 ring atoms.

[0039] In this application, "ring atom number" refers to the number of atoms in the ring itself of a structural compound (e.g., a monocyclic compound, a fused-ring compound, a cross-linked compound, a carbocyclic compound, or a heterocyclic compound) obtained by atomic bonding to form a ring. When the ring is substituted by a substituent, the atoms contained in the substituent are not included in the ring-forming atoms. The same applies to the "ring atom number" described below unless otherwise specified. For example, a benzene ring has 6 ring atoms, a naphthalene ring has 10 ring atoms, and a thiophene group has 5 ring atoms.

[0040] In this application, "aryl or aromatic group" refers to an aromatic hydrocarbon group derived from an aromatic ring compound by removing one hydrogen atom. It can be a monocyclic aryl, a fused-ring aryl, or a polycyclic aryl. For polycyclic rings, at least one is an aromatic ring system. For example, "substituted or unsubstituted aryl having 6 to 40 ring atoms" refers to an aryl containing 6 to 40 ring atoms, preferably a substituted or unsubstituted aryl having 6 to 30 ring atoms, more preferably a substituted or unsubstituted aryl having 6 to 18 ring atoms, and particularly preferably a substituted or unsubstituted aryl having 6 to 14 ring atoms, and optionally further substituted on the aryl group; suitable examples include, but are not limited to: phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthrene, fluoranyl, triphenylene, pyrene, perylene, tetraphenyl, fluorenyl, dinaphthylphenyl, acenaphthyl and their derivatives. Understandably, multiple aryl groups can also be interrupted by short non-aromatic units (e.g., <10% non-H atoms, such as C, N, or O atoms), specifically acenaphthene, fluorene, or 9,9-diarylfluorene, triarylamine, and diaryl ether systems should also be included in the definition of aryl.

[0041] In this application, "heteroaryl or heteroaromatic group" refers to an aryl group in which at least one carbon atom is replaced by a non-carbon atom, which can be an N atom, O atom, S atom, etc. For example, "substituted or unsubstituted heteroaryl group having 5 to 40 ring atoms" refers to a heteroaryl group having 5 to 40 ring atoms, preferably a substituted or unsubstituted heteroaryl group having 6 to 30 ring atoms, more preferably a substituted or unsubstituted heteroaryl group having 6 to 18 ring atoms, and particularly preferably a substituted or unsubstituted heteroaryl group having 6 to 14 ring atoms. The heteroaryl group may optionally be further substituted, and suitable examples include, but are not limited to: thiophene, furanyl, pyrroleyl, imidazole, triazolyl, imidazoleyl, diazolyl, triazolyl, pyridyl, bipyridyl, pyrimidinyl, triazinyl, acridineyl, pyridazinyl, etc. Azinyl, quinolinyl, quinazolinyl, quinoxalinyl, phthalazinyl, pyridinylpyrimidinyl, pyridinylpyrazinyl, pyrazinylpyrazinyl, isoquinolinyl, indolyl, carbazoleyl, benzothiopheneyl, benzofuranyl, indolyl, carbazoleyl, pyrroloimidazolyl, pyrrolopyrrololyl, thienopyrrololyl, thienopyrrololyl, furanolol, furanol, thienofuranyl, benzoisoxazolyl, benzoisothiazolyl, benzoimidazolyl, quinolinyl, isoquinolinyl, o-diazonaphthyl, quinoxalinyl, phenanthridine, primidyl, quinazolinyl, quinazolinone, dibenzothiopheneyl, dibenzofuranyl, carbazoleyl and their derivatives.

[0042] In this application, "alkyl" can refer to straight-chain or branched alkyl. The number of carbon atoms in an alkyl group can be 1 to 50, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Phrases containing this term, such as "C1-9 alkyl," refer to alkyl groups containing 1 to 9 carbon atoms, and each time it appears, it can independently be C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, C6 alkyl, C7 alkyl, C8 alkyl, or C9 alkyl. Non-limiting examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, 2-ethylbutyl, 3,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 2-butylhexyl, n-heptyl, 1-methylheptyl, 2,2-dimethylheptyl, 2-ethylheptyl, 2-butylheptyl, n-octyl, tert-octyl, 2-ethyloctyl, 2-butyloctyl, 2-hexyloctyl, 3,7-dimethyloctyl, n-nonyl, n-decyl, adamantyl, 2-ethyldecyl, 2-butyldecyl, 2-hexyldecyl, 2-octyldecyl The compounds include: n-undecyl, n-dodecyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldodecyl, n-tridecyl, n-tetradecyl, n-pentadecanyl, n-hexadecyl, 2-ethylhexadecyl, 2-butylhexadecyl, 2-hexylhexadecyl, 2-octylhexadecyl, n-heptadecyl, n-octadecyl, n-heptadecyl, n-eicosyl, 2-ethyleicosyl, 2-butyleicosyl, 2-hexyleicosyl, 2-octyleicosyl, n-monodecyl, n-eicosyl, n-eicosyl, n-eicosyl, n-eicosyl, n-eicosyl, n-eicosyl, n-eicosyl, n-eicosyl, n-eicosyl, n-eicosyl, n-eicosyl, n-eicosyl, n-eicosyl, n-eicosyl, n-eicosyl, n-eicosyl, n-eicosyl, and adamantane.

[0043] In this application, "alkoxy" refers to a group with the structure "-O-alkyl", that is, an alkyl group as defined above that is attached to other groups via an oxygen atom. Suitable examples of phrases containing this term include, but are not limited to: methoxy (-O-CH3 or -OMe), ethoxy (-O-CH2CH3 or -OEt), and tert-butoxy (-OC(CH3)3 or -OtBu).

[0044] The technical solution of this application is as follows:

[0045] In a first aspect, embodiments of this application provide a composite material comprising quantum dots and fluorinated organic acid groups.

[0046] The fluorinated organic acid anion is coordinated with the quantum dot. In at least one embodiment, the fluorinated organic acid anion is coordinated with the quantum dot via its organic acid anion. Taking the fluorinated organic acid anion shown in formula (I) as an example, the fluorinated organic acid anion is coordinated with the quantum dot via POO- Coordinated with the quantum dot.

[0047] The fluorinated organic acid anion has the chemical formula shown in formula (I):

[0048]

[0049] R1 and R2 are each independently selected from, but not limited to, substituted or unsubstituted C1 to C2. 20 Straight-chain alkyl, substituted or unsubstituted C1-C 20 Straight-chain alkoxy, substituted or unsubstituted C1-C 20 Straight-chain thioalkoxy, substituted or unsubstituted C1-C 20 Branched alkyl, substituted or unsubstituted C1-C 20 Branched alkoxy, substituted or unsubstituted C1-C 20 Branched thioalkoxy groups, substituted or unsubstituted C3-C 20 Cycloalkyl, substituted or unsubstituted C3-C 20 Cyclic alkoxy groups, substituted or unsubstituted C3-C 20 Cyclic thioalkoxy, substituted or unsubstituted silyl, substituted or unsubstituted C1-C 20 Ketone, substituted or unsubstituted C2-C 20 alkoxycarbonyl, substituted or unsubstituted C7-C 20 Aryloxycarbonyl, cyano, carbamoyl, halocarboxyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxyl, nitro, amino, -CF3, -Cl, -Br, -F, -I, C2~C 20 The group consists of an olefinic group, an aromatic group having 6 to 60 substituted or unsubstituted ring atoms, a heteroaromatic group having 5 to 60 substituted or unsubstituted ring atoms, an aryloxy group having 6 to 60 substituted or unsubstituted ring atoms, a heteroaryloxy group having 5 to 60 substituted or unsubstituted ring atoms, or a combination of these groups.

[0050] Among them, at least one of R1 and R2 contains F;

[0051] Wherein, L1 and L2 are linking groups, each independently selected from, but not limited to, substituted or unsubstituted C1 to C2 groups. 30 Alkylene, substituted or unsubstituted C2-C 30 alkenyl, substituted or unsubstituted C2-C 30 alkyne group, substituted or unsubstituted C2-C 20Etheryl group, substituted or unsubstituted aryl group with 6 to 20 ring atoms, substituted or unsubstituted aryloxy group with 6 to 20 ring atoms, substituted or unsubstituted arylthio group with 6 to 20 ring atoms, substituted or substituted -(CH2) m1 CO(CH2) m2 -, or substituted -(CH2) m3 NHCO(CH2) m4 -, or substituted -(CH2) m5 CONH(CH2) m6 -, or substituted -(CH2) m7 COO(CH2) m8 - is one or more combinations of two or more, wherein m1 to m8 are each independently selected from integers from 1 to 20.

[0052] In R1, R2, L1, and L2, the substituents include halogens, hydroxyl groups, nitro groups, cyano groups, isocyano groups, silyl groups, and C1-C2 groups. 20 Alkyl, C1-C 20 Alkoxy, C1-C 20 One or more of the following: alkylthio, aryl with 6 to 60 ring atoms, aryloxy with 6 to 60 ring atoms, and arylthio with 6 to 60 ring atoms.

[0053] The composite material described in this application includes quantum dots and fluorinated organic acid ligands attached to the surface of the quantum dots. On one hand, the fluorinated organic acid ligands (fluorinated organic acids are acids, losing H+) + The fluorinated organic acid radicals no longer exhibit acidity and belong to Lewis bases; for example, fluorinated hypophosphite radicals, as Lewis bases, can effectively passivate vacancies or electron-deficient defects on the surface of quantum dots, thereby improving the stability and fluorescence quantum efficiency of quantum dots. On the other hand, there are original ligands (i.e., ligands that are coordinated with quantum dots after preparation) that have fallen off the surface of quantum dots. The fluorinated organic acid radicals can also passivate the defects caused by the loss of these original ligands, thereby further improving the stability and fluorescence quantum efficiency of quantum dots. Furthermore, the F in the fluorinated organic acid radicals has high electronegativity and can effectively carry out charge transport. Moreover, the F in the fluorinated organic acid radicals is located on the carbon chain and does not directly contact the quantum dots, which can effectively improve the stability of the quantum dots.

[0054] In at least some embodiments, at least one of R1 and R2 has a terminal group of -CF3. -CF3 contains a highly negatively charged F group, resulting in high electronegativity, which can give the ligand better charge transport performance, effectively transferring charge to the quantum dot and thus improving the fluorescence quantum efficiency of the quantum dot. Furthermore, when the composite material is used as the emitting layer material in a light-emitting device, on the one hand, the high electronegativity of -CF3 can enhance charge transport between the electron transport layer and hole transport layer and the emitting layer, avoiding charge accumulation at the interface and improving the device's stability, luminous efficiency, and lifetime; on the other hand, -CF3 can passivate the electron transport layer material and hole transport layer material at the interface, reducing interface defects, thereby further improving the device's stability, current efficiency, luminous efficiency, and lifetime.

[0055] In some embodiments, R1 and R2 are each independently selected from, but not limited to, substituted or unsubstituted C1 to C2. 15 Straight-chain alkyl, substituted or unsubstituted C1-C 15 Straight-chain alkoxy, substituted or unsubstituted C1-C 15 Straight-chain thioalkoxy, substituted or unsubstituted C1-C 15 Branched alkyl, substituted or unsubstituted C1-C 15 Branched alkoxy, substituted or unsubstituted C1-C 15 Branched thioalkoxy groups, substituted or unsubstituted C3-C 15 Cycloalkyl, substituted or unsubstituted C3-C 15 Cyclic alkoxy groups, substituted or unsubstituted C3-C 15 Cyclic thioalkoxy, substituted or unsubstituted silyl, substituted or unsubstituted C1-C 15 Ketone, substituted or unsubstituted C2-C 15 alkoxycarbonyl, substituted or unsubstituted C7-C 15 Aryloxycarbonyl, cyano, carbamoyl, halocarboxyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxyl, nitro, amino, -CF3, -Cl, -Br, -F, -I, C2~C 15 An olefinic group, an aromatic group having 6 to 30 substituted or unsubstituted ring atoms, a heteroaromatic group having 5 to 30 substituted or unsubstituted ring atoms, an aryloxy group having 6 to 30 substituted or unsubstituted ring atoms, a heteroaryloxy group having 5 to 30 substituted or unsubstituted ring atoms, or a combination of these groups; wherein at least one of R1 and R2 contains F.

[0056] In other embodiments, R1 and R2 are each independently selected from, but not limited to, substituted or unsubstituted C1 to C2. 10 Straight-chain alkyl, substituted or unsubstituted C1-C10 Straight-chain alkoxy, substituted or unsubstituted C1-C 10 Straight-chain thioalkoxy, substituted or unsubstituted C1-C 10 Branched alkyl, substituted or unsubstituted C1-C 10 Branched alkoxy, substituted or unsubstituted C1-C 10 Branched thioalkoxy groups, substituted or unsubstituted C3-C 10 Cycloalkyl, substituted or unsubstituted C3-C 10 Cyclic alkoxy groups, substituted or unsubstituted C3-C 10 Cyclic thioalkoxy, substituted or unsubstituted silyl, substituted or unsubstituted C1-C 10 Ketone, substituted or unsubstituted C2-C 10 alkoxycarbonyl, substituted or unsubstituted C7-C 10 Aryloxycarbonyl, cyano, carbamoyl, halocarboxyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxyl, nitro, amino, -CF3, -Cl, -Br, -F, -I, C2~C 10 An olefinic group, an aromatic group having 6 to 20 substituted or unsubstituted ring atoms, a heteroaromatic group having 5 to 20 substituted or unsubstituted ring atoms, an aryloxy group having 6 to 20 substituted or unsubstituted ring atoms, a heteroaryloxy group having 5 to 20 substituted or unsubstituted ring atoms, or a combination of these groups; wherein at least one of R1 and R2 contains F.

[0057] In some other embodiments, R1 and R2 are each independently selected from, but not limited to, substituted or unsubstituted C1-C8 straight-chain alkyl, substituted or unsubstituted C1-C8 straight-chain alkoxy, substituted or unsubstituted C1-C8 straight-chain thioalkoxy, substituted or unsubstituted C1-C8 branched alkyl, substituted or unsubstituted C1-C8 branched alkoxy, substituted or unsubstituted C1-C8 branched thioalkoxy, substituted or unsubstituted C3-C8 cyclic alkyl, substituted or unsubstituted C3-C8 cyclic alkoxy, substituted or unsubstituted C3-C8 cyclic thioalkoxy, substituted or unsubstituted silyl, substituted or unsubstituted C1-C8... 10Keto, substituted or unsubstituted C2-C8 alkoxycarbonyl, substituted or unsubstituted C7-C8 aryloxycarbonyl, cyano, carbamoyl, halocarbamoyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxyl, nitro, amino, -CF3, -Cl, -Br, -F, -I, C2-C8 olefin, substituted or unsubstituted aromatic group having 6 to 15 ring atoms, substituted or unsubstituted heteroaromatic group having 5 to 15 ring atoms, substituted or unsubstituted aryloxy group having 6 to 15 ring atoms, substituted or unsubstituted heteroaryloxy group having 5 to 15 ring atoms, or combinations of these groups; wherein at least one of R1 and R2 contains F.

[0058] In some other embodiments, R1 and R2 are each independently selected from, but not limited to, substituted or unsubstituted C1-C8 straight-chain alkyl, substituted or unsubstituted C1-C8 branched alkyl, substituted or unsubstituted C3-C8 cyclic alkyl, -CF3, -Cl, -Br, -F, -I, C2-C8 olefin, or combinations of these groups; wherein at least one of R1 and R2 contains F.

[0059] In some embodiments, L1 and L2 are each independently selected from, but not limited to, substituted or unsubstituted C1 to C2. 20 Alkylene, substituted or unsubstituted C2-C 20 alkenyl, substituted or unsubstituted C2-C 20 alkyne group, substituted or unsubstituted C2-C 15 Etheryl group, substituted or unsubstituted aryl group with 6 to 15 ring atoms, substituted or unsubstituted aryloxy group with 6 to 15 ring atoms, substituted or unsubstituted arylthio group with 6 to 15 ring atoms, substituted or substituted -(CH2) m1 CO(CH2) m2 -, or substituted -(CH2) m3 NHCO(CH2) m4 -, or substituted -(CH2) m5 CONH(CH2) m6 -, or substituted -(CH2) m7 COO(CH2) m8 - is one or more combinations of two or more, wherein m1 to m8 are each independently selected from integers from 1 to 15.

[0060] In some other embodiments, L1 and L2 are each independently selected from, but not limited to, substituted or unsubstituted C1 to C2. 15 Alkylene, substituted or unsubstituted C2-C 15 alkenyl, substituted or unsubstituted C2-C 15 alkyne group, substituted or unsubstituted C2-C10 Etheryl group, substituted or unsubstituted aryl group with 6 to 12 ring atoms, substituted or unsubstituted aryloxy group with 6 to 12 ring atoms, substituted or unsubstituted arylthio group with 6 to 12 ring atoms, substituted or substituted -(CH2) m1 CO(CH2) m2 -, or substituted -(CH2) m3 NHCO(CH2) m4 -, or substituted -(CH2) m5 CONH(CH2) m6 -, or substituted -(CH2) m7 COO(CH2) m8 - is one or more combinations of two or more, wherein m1 to m8 are each independently selected from integers from 1 to 10.

[0061] In some other embodiments, L1 and L2 are each independently selected from, but not limited to, substituted or unsubstituted C1 to C2. 10 Alkylene, substituted or unsubstituted C2-C 10 alkenyl, substituted or unsubstituted C2-C 10 Alynyl group, substituted or unsubstituted C2-C8 etheryl group, substituted or unsubstituted aryl group with 6-10 ring atoms, substituted or unsubstituted aryloxy group with 6-10 ring atoms, substituted or unsubstituted arylthio group with 6-10 ring atoms, substituted or substituted -(CH2) group. m1 CO(CH2) m2 -, or substituted -(CH2) m3 NHCO(CH2) m4 -, or substituted -(CH2) m5 CONH(CH2) m6 -, or substituted -(CH2) m7 COO(CH2) m8 - is one or more combinations of two or more, wherein m1 to m8 are each independently selected from integers from 1 to 8.

[0062] In some other embodiments, L1 and L2 are each independently selected from, but not limited to, one or more combinations of substituted or unsubstituted C1-C8 alkylene groups, substituted or unsubstituted C2-C8 alkenyl groups, substituted or unsubstituted C2-C8 alkyne groups, substituted or unsubstituted C2-C5 etheryl groups, and substituted or unsubstituted aryl groups having 6 to 10 cyclic atoms.

[0063] In some other embodiments, L1 and L2 are each independently selected from, but not limited to, one or more combinations of substituted or unsubstituted C1-C5 alkylene groups, substituted or unsubstituted C2-C5 alkenyl groups, and substituted or unsubstituted C2-C5 alkyne groups.

[0064] In some embodiments, in R1, R2, L1, L2, the substituents include halogens, hydroxyl groups, nitro groups, cyano groups, isocyano groups, silyl groups, and C1-C2 groups. 10 Alkyl, C1-C 10 Alkoxy, C1-C 10 One or more of the following: alkylthio, aryl with 6 to 30 ring atoms, aryloxy with 6 to 30 ring atoms, and arylthio with 6 to 30 ring atoms.

[0065] In other embodiments, in R1, R2, L1, L2, the substituents include one or more of halogen, hydroxyl, nitro, cyano, isocyano, silyl, C1-C5 alkyl, C1-C5 alkoxy, C1-C5 alkylthio, aryl with 6 to 15 ring atoms, aryloxy with 6 to 15 ring atoms, and arylthio with 6 to 15 ring atoms.

[0066] As an example, in some embodiments, the fluorinated organic acid anion may include, but is not limited to, (CF3CH2)2POO. - (CF3CH2CH2)2POO - (CF3CH2CH2CH2CH2CH2)2POO - (CF3CF3CF3C)2POO - One or more of them.

[0067] In some embodiments, the mass ratio of the fluorinated organic acid anion to the quantum dot is 1:(5-50), for example, 1:5, 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, and any value between two such ratios. Within this range, it is beneficial for the composite material to have higher stability and fluorescence quantum efficiency.

[0068] The quantum dots may include, but are not limited to, one or more of the following: single-structure quantum dots, core-shell structure quantum dots, and perovskite quantum dots. The core-shell structure quantum dots may have one or more shell layers.

[0069] The materials for the single-structure quantum dots, the core materials for the core-shell structure quantum dots, and the shell materials for the core-shell structure quantum dots may include, but are not limited to, one or more of group II-VI compounds, group IV-VI compounds, group III-V compounds, and group I-III-VI compounds. The group II-VI compounds may include, but are not limited to, one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe. The IV-VI group compounds may include, but are not limited to, one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe. The group III-V compounds may include, but are not limited to, one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb. The group I-III-VI compounds may include, but are not limited to, one or more of CuInS2, CuInSe2, and AgInS2.

[0070] As an example, the core-shell structured quantum dots may include, but are not limited to, one or more of CdSe / CdSeS / CdS, InP / ZnSeS / ZnS, CdZnSe / ZnSe / ZnS, CdSeS / ZnSeS / ZnS, CdSe / ZnS, CdSe / ZnSe / ZnS, ZnSe / ZnS, ZnSeTe / ZnS, CdSe / CdZnSeS / ZnS, and InP / ZnSe / ZnS.

[0071] The perovskite quantum dots may include, but are not limited to, doped or undoped inorganic perovskite quantum dots, or organic-inorganic hybrid perovskite quantum dots. The general structural formula of the inorganic perovskite quantum dots is AMX3, where A is Cs. + Ions, where M is a divalent metal cation, including Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ One or more of them, where X is a halide anion, including Cl. - ,Br - I - One or more of the following. The general structural formula of the organic-inorganic hybrid perovskite quantum dots is BMX3, where B is an organic amine cation, including CH3(CH2). n-2 NH3 + Or [NH3(CH2)] n NH3] 2+ Where n≥2, M is a divalent metal cation, including Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2 + Eu 2+ One or more of them, where X is a halide anion, including Cl. - ,Br - I - One or more of them.

[0072] In some embodiments, the average particle size of the quantum dots ranges from 5 to 20 nm, for example, 5 nm, 6 nm, 8 nm, 10 nm, 12 nm, 13 nm, 15 nm, 16 nm, 18 nm, 20 nm, and any range between two numbers.

[0073] In some embodiments, the surface of the quantum dot further includes organic ligands, including but not limited to substituted or unsubstituted C6-C. 24 Fatty acids, substituted or unsubstituted C6-C 24 Fatty amines, substituted or unsubstituted C6-C 24 Aliphatic thiols, substituted or unsubstituted C6-C 24 Aliphatic sulfides, substituted or unsubstituted C6-C 24 Aliphatic phosphine, substituted or unsubstituted C6-C 24 Aliphatic phosphine oxides, substituted or unsubstituted C8-C8 phosphine oxides 20 Aliphatic phosphates, substituted or unsubstituted C6-C 24 Aliphatic phosphates, substituted or unsubstituted C6-C 24 Aliphatic phosphorous acid and substituted or unsubstituted C6-C 24 At least one of the fatty phosphites, wherein the substituent is selected from at least one of C1-C6 alkyl, C1-C6 alkoxy and halogen.

[0074] In some embodiments, the substituted or unsubstituted C6-C 24 Fatty acids include at least one of the following: decanoic acid, undecenoic acid, tetradecanoic acid, oleic acid, linoleic acid, and stearic acid.

[0075] In some embodiments, the substituted or unsubstituted C6-C 24 Aliphatic thiols include at least one of octylthiol, dodecylthiol, and octadecylthiol.

[0076] In some embodiments, the substituted or unsubstituted C6-C 24 Fatty amines include at least one of oleylamine, octadecylamine, octylamine, dioctylamine, and trioctylamine.

[0077] In some embodiments, the substituted or unsubstituted C6-C 24 Aliphatic phosphines include trioctylphosphine.

[0078] In some embodiments, the substituted or unsubstituted C6-C 24 Aliphatic phosphine oxides include trioctylphosphine oxides.

[0079] Secondly, please refer to Figure 1This application also provides a method for preparing a composite material, comprising the following steps:

[0080] Step S11: Provide quantum dots, fluorinated organic acid, and a first solvent;

[0081] Step S12: Mix the quantum dots, the fluorinated organic acid and the first solvent to obtain a mixed solution, remove the first solvent from the mixed solution, and obtain the composite material.

[0082] The quantum dots have been described above and will not be repeated here.

[0083] The first solvent includes, but is not limited to, one or more of non-polar and polar solvents. The non-polar solvents include, but are not limited to, n-octane, isooctane, n-hexane, cyclohexane, ethyl acetate, benzene, toluene, chloroform, carbon tetrachloride, dichloromethane, dichloroethane, and carbon disulfide. The polar solvents include, but are not limited to, dimethyl ether, tetraethylene glycol dimethyl ether, propylene glycol methyl ether acetate, formamide, trifluoroacetic acid, dimethyl sulfoxide, acetonitrile, N,N-dimethylformamide, hexamethylphosphoramide, methanol, acetic acid, ethanol, isopropanol, pyridine, tetramethylethylenediamine, acetone, triethylamine, n-butanol, dioxane, tetrahydrofuran, methyl formate, tributylamine, methyl ethyl ketone, trioctylamine, dimethyl carbonate, diethyl ether, isopropyl ether, n-butyl ether, trichloroethylene, and diphenyl ether.

[0084] The fluorinated organic acid has the chemical formula shown in (II):

[0085]

[0086] R1 and R2 are each independently selected from, but not limited to, substituted or unsubstituted C1 to C2. 20 Straight-chain alkyl, substituted or unsubstituted C1-C 20 Straight-chain alkoxy, substituted or unsubstituted C1-C 20 Straight-chain thioalkoxy, substituted or unsubstituted C1-C 20 Branched alkyl, substituted or unsubstituted C1-C 20 Branched alkoxy, substituted or unsubstituted C1-C 20 Branched thioalkoxy groups, substituted or unsubstituted C3-C 20 Cycloalkyl, substituted or unsubstituted C3-C 20 Cyclic alkoxy groups, substituted or unsubstituted C3-C 20 Cyclic thioalkoxy, substituted or unsubstituted silyl, substituted or unsubstituted C1-C 20 Ketone, substituted or unsubstituted C2-C 20 alkoxycarbonyl, substituted or unsubstituted C7-C 20Aryloxycarbonyl, cyano, carbamoyl, halocarboxyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxyl, nitro, amino, -CF3, -Cl, -Br, -F, -I, C2~C 20 The group consists of an olefinic group, an aromatic group having 6 to 60 substituted or unsubstituted ring atoms, a heteroaromatic group having 5 to 60 substituted or unsubstituted ring atoms, an aryloxy group having 6 to 60 substituted or unsubstituted ring atoms, a heteroaryloxy group having 5 to 60 substituted or unsubstituted ring atoms, or a combination of these groups.

[0087] Among them, at least one of R1 and R2 contains F;

[0088] Wherein, L1 and L2 are linking groups, each independently selected from, but not limited to, substituted or unsubstituted C1 to C2 groups. 30 Alkylene, substituted or unsubstituted C2-C 30 alkenyl, substituted or unsubstituted C2-C 30 alkyne group, substituted or unsubstituted C2-C 20 Etheryl group, substituted or unsubstituted aryl group with 6 to 20 ring atoms, substituted or unsubstituted aryloxy group with 6 to 20 ring atoms, substituted or unsubstituted arylthio group with 6 to 20 ring atoms, substituted or substituted -(CH2) m1 CO(CH2) m2 -, or substituted -(CH2) m3 NHCO(CH2) m4 -, or substituted -(CH2) m5 CONH(CH2) m6 -, or substituted -(CH2) m7 COO(CH2) m8 - is one or more combinations of two or more, wherein m1 to m8 are each independently selected from integers from 1 to 20.

[0089] In R1, R2, L1, and L2, the substituents include halogens, hydroxyl groups, nitro groups, cyano groups, isocyano groups, silyl groups, and C1-C2 groups. 20 Alkyl, C1-C 20 Alkoxy, C1-C 20 One or more of the following: alkylthio, aryl with 6 to 60 ring atoms, aryloxy with 6 to 60 ring atoms, and arylthio with 6 to 60 ring atoms.

[0090] After mixing quantum dots, fluorinated organic acids, and a first solvent and then removing the first solvent, the fluorinated organic acid anions in the fluorinated organic acid coordinate and attach to the surface of the quantum dots, passivating the surface defects of the quantum dots, thereby obtaining a composite material with good stability and fluorescence quantum efficiency.

[0091] In at least some embodiments, at least one of R1 and R2 has a terminal group of -CF3. -CF3 contains a highly negatively charged F group, resulting in high electronegativity, which can give the ligand better charge transport performance, effectively transferring charge to the quantum dot and thus improving the fluorescence quantum efficiency of the quantum dot. Furthermore, when the composite material is used as the emitting layer material in a light-emitting device, on the one hand, the high electronegativity of -CF3 can enhance charge transport between the electron transport layer and hole transport layer and the emitting layer, avoiding charge accumulation at the interface and improving the device's stability, luminous efficiency, and lifetime; on the other hand, -CF3 can passivate the electron transport layer material and hole transport layer material at the interface, reducing interface defects, thereby further improving the device's stability, luminous efficiency, and lifetime.

[0092] In some embodiments, R1 and R2 are each independently selected from, but not limited to, substituted or unsubstituted C1 to C2. 15 Straight-chain alkyl, substituted or unsubstituted C1-C 15 Straight-chain alkoxy, substituted or unsubstituted C1-C 15 Straight-chain thioalkoxy, substituted or unsubstituted C1-C 15 Branched alkyl, substituted or unsubstituted C1-C 15 Branched alkoxy, substituted or unsubstituted C1-C 15 Branched thioalkoxy groups, substituted or unsubstituted C3-C 15 Cycloalkyl, substituted or unsubstituted C3-C 15 Cyclic alkoxy groups, substituted or unsubstituted C3-C 15 Cyclic thioalkoxy, substituted or unsubstituted silyl, substituted or unsubstituted C1-C 15 Ketone, substituted or unsubstituted C2-C 15 alkoxycarbonyl, substituted or unsubstituted C7-C 15 Aryloxycarbonyl, cyano, carbamoyl, halocarboxyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxyl, nitro, amino, -CF3, -Cl, -Br, -F, -I, C2~C 15An olefinic group, an aromatic group having 6 to 30 substituted or unsubstituted ring atoms, a heteroaromatic group having 5 to 30 substituted or unsubstituted ring atoms, an aryloxy group having 6 to 30 substituted or unsubstituted ring atoms, a heteroaryloxy group having 5 to 30 substituted or unsubstituted ring atoms, or a combination of these groups; wherein at least one of R1 and R2 contains F.

[0093] In other embodiments, R1 and R2 are each independently selected from, but not limited to, substituted or unsubstituted C1 to C2. 10 Straight-chain alkyl, substituted or unsubstituted C1-C 10 Straight-chain alkoxy, substituted or unsubstituted C1-C 10 Straight-chain thioalkoxy, substituted or unsubstituted C1-C 10 Branched alkyl, substituted or unsubstituted C1-C 10 Branched alkoxy, substituted or unsubstituted C1-C 10 Branched thioalkoxy groups, substituted or unsubstituted C3-C 10 Cycloalkyl, substituted or unsubstituted C3-C 10 Cyclic alkoxy groups, substituted or unsubstituted C3-C 10 Cyclic thioalkoxy, substituted or unsubstituted silyl, substituted or unsubstituted C1-C 10 Ketone, substituted or unsubstituted C2-C 10 alkoxycarbonyl, substituted or unsubstituted C7-C 10 Aryloxycarbonyl, cyano, carbamoyl, halocarboxyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxyl, nitro, amino, -CF3, -Cl, -Br, -F, -I, C2~C 10 An olefinic group, an aromatic group having 6 to 20 substituted or unsubstituted ring atoms, a heteroaromatic group having 5 to 20 substituted or unsubstituted ring atoms, an aryloxy group having 6 to 20 substituted or unsubstituted ring atoms, a heteroaryloxy group having 5 to 20 substituted or unsubstituted ring atoms, or a combination of these groups; wherein at least one of R1 and R2 contains F.

[0094] In some other embodiments, R1 and R2 are each independently selected from, but not limited to, substituted or unsubstituted C1-C8 straight-chain alkyl, substituted or unsubstituted C1-C8 straight-chain alkoxy, substituted or unsubstituted C1-C8 straight-chain thioalkoxy, substituted or unsubstituted C1-C8 branched alkyl, substituted or unsubstituted C1-C8 branched alkoxy, substituted or unsubstituted C1-C8 branched thioalkoxy, substituted or unsubstituted C3-C8 cyclic alkyl, substituted or unsubstituted C3-C8 cyclic alkoxy, substituted or unsubstituted C3-C8 cyclic thioalkoxy, substituted or unsubstituted silyl, substituted or unsubstituted C1-C8...10 Keto, substituted or unsubstituted C2-C8 alkoxycarbonyl, substituted or unsubstituted C7-C8 aryloxycarbonyl, cyano, carbamoyl, halocarbamoyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxyl, nitro, amino, -CF3, -Cl, -Br, -F, -I, C2-C8 olefin, substituted or unsubstituted aromatic group having 6 to 15 ring atoms, substituted or unsubstituted heteroaromatic group having 5 to 15 ring atoms, substituted or unsubstituted aryloxy group having 6 to 15 ring atoms, substituted or unsubstituted heteroaryloxy group having 5 to 15 ring atoms, or combinations of these groups; wherein at least one of R1 and R2 contains F.

[0095] In some other embodiments, R1 and R2 are each independently selected from, but not limited to, substituted or unsubstituted C1-C8 straight-chain alkyl, substituted or unsubstituted C1-C8 branched alkyl, substituted or unsubstituted C3-C8 cyclic alkyl, -CF3, -Cl, -Br, -F, -I, C2-C8 olefin, or combinations of these groups; wherein at least one of R1 and R2 contains F.

[0096] In some embodiments, L1 and L2 are each independently selected from, but not limited to, substituted or unsubstituted C1 to C2. 20 Alkylene, substituted or unsubstituted C2-C 20 alkenyl, substituted or unsubstituted C2-C 20 alkyne group, substituted or unsubstituted C2-C 15 Etheryl group, substituted or unsubstituted aryl group with 6 to 15 ring atoms, substituted or unsubstituted aryloxy group with 6 to 15 ring atoms, substituted or unsubstituted arylthio group with 6 to 15 ring atoms, substituted or substituted -(CH2) m1 CO(CH2) m2 -, or substituted -(CH2) m3 NHCO(CH2) m4 -, or substituted -(CH2) m5 CONH(CH2) m6 -, or substituted -(CH2) m7 COO(CH2) m8 - is one or more combinations of two or more, wherein m1 to m8 are each independently selected from integers from 1 to 15.

[0097] In some other embodiments, L1 and L2 are each independently selected from, but not limited to, substituted or unsubstituted C1 to C2. 15 Alkylene, substituted or unsubstituted C2-C 15 alkenyl, substituted or unsubstituted C2-C 15alkyne group, substituted or unsubstituted C2-C 10 Etheryl group, substituted or unsubstituted aryl group with 6 to 12 ring atoms, substituted or unsubstituted aryloxy group with 6 to 12 ring atoms, substituted or unsubstituted arylthio group with 6 to 12 ring atoms, substituted or substituted -(CH2) m1 CO(CH2) m2 -, or substituted -(CH2) m3 NHCO(CH2) m4 -, or substituted -(CH2) m5 CONH(CH2) m6 -, or substituted -(CH2) m7 COO(CH2) m8 - is one or more combinations of two or more, wherein m1 to m8 are each independently selected from integers from 1 to 10.

[0098] In some other embodiments, L1 and L2 are each independently selected from, but not limited to, substituted or unsubstituted C1 to C2. 10 Alkylene, substituted or unsubstituted C2-C 10 alkenyl, substituted or unsubstituted C2-C 10 Alynyl group, substituted or unsubstituted C2-C8 etheryl group, substituted or unsubstituted aryl group with 6-10 ring atoms, substituted or unsubstituted aryloxy group with 6-10 ring atoms, substituted or unsubstituted arylthio group with 6-10 ring atoms, substituted or substituted -(CH2) group. m1 CO(CH2) m2 -, or substituted -(CH2) m3 NHCO(CH2) m4 -, or substituted -(CH2) m5 CONH(CH2) m6 -, or substituted -(CH2) m7 COO(CH2) m8 - is one or more combinations of two or more, wherein m1 to m8 are each independently selected from integers from 1 to 8.

[0099] In some other embodiments, L1 and L2 are each independently selected from, but not limited to, one or more combinations of substituted or unsubstituted C1-C8 alkylene groups, substituted or unsubstituted C2-C8 alkenyl groups, substituted or unsubstituted C2-C8 alkyne groups, substituted or unsubstituted C2-C5 etheryl groups, and substituted or unsubstituted aryl groups having 6 to 10 cyclic atoms.

[0100] In some other embodiments, L1 and L2 are each independently selected from, but not limited to, one or more combinations of substituted or unsubstituted C1-C5 alkylene groups, substituted or unsubstituted C2-C5 alkenyl groups, and substituted or unsubstituted C2-C5 alkyne groups.

[0101] In some embodiments, in R1, R2, L1, L2, the substituents include halogens, hydroxyl groups, nitro groups, cyano groups, isocyano groups, silyl groups, and C1-C2 groups. 10 Alkyl, C1-C 10 Alkoxy, C1-C 10 One or more of the following: alkylthio, aryl with 6 to 30 ring atoms, aryloxy with 6 to 30 ring atoms, and arylthio with 6 to 30 ring atoms.

[0102] In other embodiments, in R1, R2, L1, L2, the substituents include one or more of halogen, hydroxyl, nitro, cyano, isocyano, silyl, C1-C5 alkyl, C1-C5 alkoxy, C1-C5 alkylthio, aryl with 6 to 15 ring atoms, aryloxy with 6 to 15 ring atoms, and arylthio with 6 to 15 ring atoms.

[0103] As an example, in some embodiments, the fluorinated organic acid includes, but is not limited to, one or more of (CF3CH2)2POOH, (CF3CH2CH2)2POOH, (CF3CH2CH2CH2CH2CH2)2POOH, and (CF3CF3CF3C)2POOH.

[0104] The mass ratio of the fluorinated organic acid to the quantum dots is 1:(1-10), for example, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, and any range between two ratios. Within this range, it is beneficial to prepare composite materials with good stability and high fluorescence quantum efficiency.

[0105] In the mixed solution, the concentration of the quantum dots ranges from 5 to 30 mg / mL, for example, 5 mg / mL, 10 mg / mL, 15 mg / mL, 20 mg / mL, 25 mg / mL, 30 mg / mL, etc. Within this range, it is advantageous to prepare composite materials with good stability and high fluorescence quantum efficiency.

[0106] It is understood that the method for removing the first solvent can be drying, and the drying can be a known drying method such as vacuum drying, reduced pressure drying, heating drying, freeze drying, etc.

[0107] Thirdly, please refer to Figures 2-5This application provides a light-emitting device 100, comprising an anode 10, a light-emitting layer 20, and a cathode 30 stacked sequentially. The light-emitting layer 20 includes quantum dots and fluorinated organic acid groups.

[0108] Please see Figure 2 In some embodiments, the light-emitting layer 20 is a first thin film 201, which includes the composite material.

[0109] Please see Figures 3-5 In other embodiments, the light-emitting layer 20 is a second thin film 202, which includes a light-emitting thin film 2021, a first interface layer 2022 disposed between the light-emitting thin film 2021 and the anode 10, and / or a second interface layer 2023 disposed between the light-emitting thin film and the cathode 30. The light-emitting thin film 2021 includes quantum dots or the composite material. The materials of the first interface layer 2022 and the second interface layer 2023 each independently include the fluorinated organic acid used in the preparation method of the composite material described above.

[0110] The composite material and the organic acid are as described above and will not be repeated here.

[0111] It is understood that the materials of the first interface layer 2022 and the second interface layer 2023 may be the same or different. In other words, the types of fluorinated organic acids in the first interface layer 2022 and the types of fluorinated organic acids in the second interface layer 2023 may be the same or different.

[0112] In some embodiments, the thickness of the first thin film 201 ranges from 5 to 30 nm, for example, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, and any range between two numbers.

[0113] In some embodiments, the thickness of the light-emitting thin film 2021 ranges from 5 to 30 nm, for example, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, and any range between two numbers.

[0114] In some embodiments, the thickness range of the first interface layer 2022 and the thickness range of the second interface layer 2023 are each independently 1 to 2 nm, for example, 1 nm, 1.2 nm, 1.3 nm, 1.5 nm, 1.6 nm, 1.8 nm, 2 nm, and any range between two numbers. Within the thickness range, the carrier transport efficiency of the light-emitting device can be effectively improved, thereby enhancing the stability, current efficiency, luminous efficiency, and lifetime of the light-emitting device 100.

[0115] In some embodiments, the light-emitting device 100 further includes an electron transport layer 40 located between the light-emitting layer 20 and the cathode 30. Further, when the light-emitting layer 20 includes a second interface layer 2023, the second interface layer 2023 is located between the electron transport layer 40 and the light-emitting thin film 2021.

[0116] In some embodiments, the light-emitting device 100 further includes a hole transport layer 50 located between the anode 10 and the light-emitting layer 20. Further, when the light-emitting layer 20 includes a first interface layer 2022, the first interface layer 2022 is located between the hole transport layer 50 and the light-emitting thin film 2021.

[0117] The anode 10 and the cathode 30 are anodes and cathodes known in the art for use in light-emitting devices. For example, they can be independently, but are not limited to, doped metal oxide particle electrodes, composite electrodes, graphene electrodes, carbon nanotube electrodes, elemental metal electrodes, or alloy electrodes. The material of the doped metal oxide particle electrode can be, but is not limited to, one or more of indium-doped tin oxide (ITO), fluorine-doped tin oxide (FTO), antimony-doped tin oxide (ATO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), indium-doped zinc oxide (IZO), magnesium-doped zinc oxide (MZO), and aluminum-doped magnesium oxide (AMO). The composite electrode is a composite electrode in which a metal is sandwiched between doped or undoped transparent metal oxide particles, such as AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, ZnS / Al / ZnS, etc., where " / " indicates a stacked structure. For example, AZO / Ag / AZO represents a composite electrode comprising sequentially stacked AZO, Ag, and AZO layers. The material of the elemental metal electrode may include, but is not limited to, one or more of Ag, Al, Cu, Mo, Au, Pt, Ca, Mg, and Ba.

[0118] The material of the electron transport layer 40 is a material known in the art for use in electron transport layers, such as one or more selected from, but not limited to, inorganic and organic electron transport materials. The inorganic electron transport material includes, but is not limited to, one or more of the following: first doped metal oxide particles, first undoped metal oxide particles, IIB-VIA group semiconductor materials, IIIA-VA group semiconductor materials, and IB-IIIA-VIA group semiconductor materials. The material of the first undoped metal oxide particles includes, but is not limited to, one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5. The metal oxide in the first doped metal oxide particles includes, but is not limited to, one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3. The doping element in the first doped metal oxide particles includes, but is not limited to, one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, and Ga. The IIB-VIA group semiconductor materials include, but are not limited to, one or more of ZnS, ZnSe, and CdS. The IIIA-VA group semiconductor materials include, but are not limited to, one or more of InP and GaP. The IB-IIIA-VIA group semiconductor materials include, but are not limited to, one or more of CuInS and CuGaS. The organic electron transport material includes one or more of the following: quinoxaline compounds, imidazole compounds, triazine compounds, fluorene-containing compounds, and hydroxyquinoline compounds.

[0119] The material of the hole transport layer 50 can be any material known in the art for hole transport layers, such as, but not limited to, one or more of inorganic and organic hole transport materials. The inorganic hole transport material includes, but is not limited to, one or more of second-doped metal oxide particles, second-undoped metal oxide particles, metal sulfides, metal selenides, and metal nitrides. The metal oxides in the second-doped metal oxide particles and the metal oxides in the second-undoped metal oxide particles each independently include, but are not limited to, one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, and V2O5. The doping elements in the second-doped metal oxide particles include, but are not limited to, one or more of Mo, W, Ni, Cr, Cu, and V. The metal sulfides include, but are not limited to, one or more of CuS, MoS3, and WS3. The metal selenides include, but are not limited to, one or more of MoSe3 and WSe3. The metal nitrides include, but are not limited to, p-type gallium nitride.The organic hole transport materials include, but are not limited to, 4,4'-N,N'-dicarbazolyl-biphenyl (CBP), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4”-diamine (α-NPD), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (TPD), poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)biphenylamine) (Poly-TPD), N,N'- Bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro(spiro-TPD), N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine (DNTPD), 4,4',4'-tris(N-carbazolyl)-triphenylamine (TCTA), 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA), poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))](TFB), poly(N-vinylcarbazole)(PVK) ) and its derivatives, N,N'-di(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4-4'-diamine (NPB), spiroNPB, poly(phenylenevinylene) (PPV), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene] (MOMO-PPV), 2,2',7,7'-tetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (spiro-omeT) AD), 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline] (TAPC), 1,3-bis(carbazole-9-yl)benzene (MCP), polyaniline, polypyrrole, poly(p-)phenylenevinylene, aromatic tertiary amine, polynuclear aromatic tertiary amine, 4,4'-bis(p-carbazole)-1,1'-biphenyl compounds, N,N,N',N'-tetraarylbenzidine, PEDOT:PSS and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, doped graphene, undoped graphene, and one or more of C60.

[0120] In some embodiments, the light-emitting device 100 further includes a hole injection layer. The material of the hole injection layer can be a material known in the art for hole injection layers, such as, but not limited to, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzphenanthrene (HAT-CN), PEDOT, PEDOT:PSS, a derivative of PEDOT:PSS doped with s-MoO3 (PEDOT:PSS:s-MoO3), 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA), tetracyanoquinone dimethyl ether (F4-TCQN), copper phthalocyanine, nickel oxide, molybdenum oxide, tungsten oxide, vanadium oxide, molybdenum sulfide, tungsten sulfide, and copper oxide.

[0121] In some embodiments, the thickness of the anode 10 is 100–200 nm; the thickness of the cathode 30 is 30–80 nm; the thickness of the electron transport layer 40 is 20–60 nm; and the thickness of the hole transport layer 50 is 20–60 nm.

[0122] It is understood that the light-emitting device 100 may also be provided with some functional layers that are conventionally used in light-emitting devices and help to improve the performance of the light-emitting device, such as electron blocking layer, hole blocking layer, electron injection layer, interface modification layer, etc.

[0123] It is understood that the materials of each layer of the light-emitting device 100 can be adjusted according to the light-emitting requirements of the light-emitting device 100.

[0124] In some embodiments, the light-emitting device 100 further includes a substrate disposed on the side of the anode 10 away from the light-emitting layer 20, or the substrate disposed on the side of the cathode 30 away from the light-emitting layer 20.

[0125] The substrate can be a rigid substrate or a flexible substrate. In some embodiments, the substrate material may include, but is not limited to, one or more of glass, silicon wafer, polycarbonate, polymethyl methacrylate, polyethylene terephthalate, polyethylene naphthalate, polyamide, and polyethersulfone.

[0126] It is understood that the light-emitting device 100 can be a normally positioned light-emitting device or an inverted light-emitting device. The light-emitting device 100 can be a quantum dot light-emitting device or an organic light-emitting device.

[0127] Fourthly, please refer to Figure 6 This application also provides a method for fabricating a light-emitting device 100, comprising the following steps:

[0128] Step S21: Provide the first electrode;

[0129] Step S22: Prepare a light-emitting layer 20 on the first electrode, wherein the light-emitting layer 20 includes quantum dots and fluorinated organic acid groups;

[0130] Step S23: Prepare a second electrode on the light-emitting layer 20 to obtain the light-emitting device 100.

[0131] Wherein, the first electrode is the anode 10 and the second electrode is the cathode 30; or, the first electrode is the cathode 30 and the second electrode is the anode 10.

[0132] The light-emitting layer 20 is a first thin film 201, which includes a composite material; or, at least one sub-functional layer is a second thin film 202, which includes a light-emitting film 2021, a first interface layer 2022 disposed between the light-emitting film 2021 and the anode 10, and / or a second interface layer 2023 disposed between the light-emitting film 2021 and the cathode 30. The light-emitting film 2021 includes quantum dots or a composite material, and the materials of the first interface layer 2022 and the second interface layer 2023 each independently include the fluorinated organic acid used in the preparation method of the composite material described above.

[0133] The composite material, the quantum dot, and the fluorinated organic acid are described above and will not be repeated here.

[0134] It is understood that the fluorinated organic acid in the first interface layer 2022, the fluorinated organic acid in the second interface layer 2023, and the fluorinated organic acid in the composite material may be the same or different.

[0135] In some embodiments, the method for preparing the first thin film 201 includes:

[0136] A1. A dispersion is provided, wherein the dispersion comprises the quantum dots, a fluorinated organic acid, and a second solvent;

[0137] A2. Deposit the dispersion to obtain the first film 201.

[0138] In the dispersion, the mass ratio of the fluorinated organic acid to the quantum dots is 1:(1-10), for example, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, and any range between two such ratios. Within this range, it is advantageous to prepare a first thin film 201 with good stability and high fluorescence quantum efficiency.

[0139] The second solvent includes, but is not limited to, one or more of non-polar and polar solvents. The non-polar solvents include, but are not limited to, n-octane, isooctane, n-hexane, cyclohexane, ethyl acetate, benzene, toluene, chloroform, carbon tetrachloride, dichloromethane, dichloroethane, and carbon disulfide. The polar solvents include, but are not limited to, dimethyl ether, tetraethylene glycol dimethyl ether, propylene glycol methyl ether acetate, formamide, trifluoroacetic acid, dimethyl sulfoxide, acetonitrile, N,N-dimethylformamide, hexamethylphosphoramide, methanol, acetic acid, ethanol, isopropanol, pyridine, tetramethylethylenediamine, acetone, triethylamine, n-butanol, dioxane, tetrahydrofuran, methyl formate, tributylamine, methyl ethyl ketone, trioctylamine, dimethyl carbonate, diethyl ether, isopropyl ether, n-butyl ether, trichloroethylene, and diphenyl ether.

[0140] In the dispersion, the concentration of the quantum dots ranges from 5 to 30 mg / mL, for example, 5 mg / mL, 10 mg / mL, 15 mg / mL, 20 mg / mL, 25 mg / mL, 30 mg / mL, etc. Within this range, it is advantageous to prepare a first thin film 201 with better film-forming properties.

[0141] In some embodiments, a first annealing is included after depositing the dispersion and before obtaining the first film 201. The temperature range of the first annealing is 80–160°C, for example, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, etc.; the time range of the first annealing is 5–60 min, for example, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, etc. Within the temperature and time range, it is beneficial to prepare a first film 201 with good luminescent properties and stability.

[0142] In some embodiments, the method for preparing the light-emitting thin film 2021 includes: providing a first quantum dot solution, the first quantum dot solution comprising quantum dots and a third solvent, depositing the first quantum dot solution to obtain the light-emitting thin film 2021.

[0143] In some other embodiments, the method for preparing the light-emitting thin film 2021 includes: providing a second quantum dot solution, the second quantum dot solution comprising quantum dots, a fluorinated organic acid and a third solvent, depositing the second quantum dot solution to obtain the light-emitting thin film 2021.

[0144] In some embodiments, the method for preparing the first interface layer 2022 includes: providing a first fluorinated organic acid solution, the first fluorinated organic acid solution comprising a first fluorinated organic acid and a fourth solvent, depositing the first fluorinated organic acid solution to obtain the first interface layer 2022.

[0145] In some embodiments, the method for preparing the second interface layer 2023 includes: providing a second fluorinated organic acid solution, the second fluorinated organic acid solution comprising a second fluorinated organic acid and a fifth solvent, depositing the second fluorinated organic acid solution to obtain the second interface layer 2023.

[0146] The first fluorinated organic acid and the second fluorinated organic acid are each independently selected from the fluorinated organic acids used in the preparation method of the composite material described above. It is understood that the first fluorinated organic acid, the second fluorinated organic acid, and the fluorinated organic acid in the composite material may be the same or different.

[0147] The quantum dots and the fluorinated organic acids have been described above and will not be repeated here.

[0148] In some embodiments, the concentration of quantum dots in the first quantum dot solution ranges from 5 to 30 mg / mL, for example, 5 mg / mL, 10 mg / mL, 15 mg / mL, 20 mg / mL, 25 mg / mL, 30 mg / mL, etc. Within this concentration range, it is advantageous to prepare a luminescent thin film 2021 with good luminescent properties and stability.

[0149] In some embodiments, the concentration of quantum dots in the second quantum dot solution ranges from 5 to 30 mg / mL, for example, 5 mg / mL, 10 mg / mL, 15 mg / mL, 20 mg / mL, 25 mg / mL, 30 mg / mL, etc. Within this concentration range, it is advantageous to prepare a luminescent thin film 2021 with good luminescent properties and stability.

[0150] In some embodiments, the mass ratio of the fluorinated organic acid to the quantum dots in the second quantum dot solution is 1:(1-10), for example, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, and any range between two ratios. Within this range, it is advantageous to prepare a luminescent thin film 2021 with good luminescent properties and stability.

[0151] In some embodiments, the concentration of the first fluorinated organic acid in the first fluorinated organic acid solution ranges from 2 to 20 mg / mL, for example, 2 mg / mL, 5 mg / mL, 10 mg / mL, 15 mg / mL, 20 mg / mL, etc. Within this concentration range, it is advantageous to prepare a first interface layer 2022 with good film-forming properties.

[0152] In some embodiments, the concentration of the second fluorinated organic acid in the second fluorinated organic acid solution ranges from 2 to 20 mg / mL, for example, 2 mg / mL, 5 mg / mL, 10 mg / mL, 15 mg / mL, 20 mg / mL, etc. Within this concentration range, it is advantageous to prepare a second interface layer 2023 with good film-forming properties.

[0153] The third, fourth, and fifth solvents are each independently included, but are not limited to, one or more of non-polar and polar solvents. The non-polar solvents include, but are not limited to, n-octane, isooctane, n-hexane, cyclohexane, ethyl acetate, benzene, toluene, chloroform, carbon tetrachloride, dichloromethane, dichloroethane, and carbon disulfide. The polar solvents include, but are not limited to, dimethyl ether, tetraethylene glycol dimethyl ether, propylene glycol methyl ether acetate, formamide, trifluoroacetic acid, dimethyl sulfoxide, acetonitrile, N,N-dimethylformamide, hexamethylphosphoramide, methanol, acetic acid, ethanol, isopropanol, pyridine, tetramethylethylenediamine, acetone, triethylamine, n-butanol, dioxane, tetrahydrofuran, methyl formate, tributylamine, methyl ethyl ketone, trioctylamine, dimethyl carbonate, diethyl ether, isopropyl ether, n-butyl ether, trichloroethylene, and diphenyl ether.

[0154] In some embodiments, after depositing the first quantum dot solution and before obtaining the luminescent thin film 2021, a second annealing process is further included. The temperature range of the second annealing is 80–180°C, for example, 80°C, 90°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 160°C, 170°C, 180°C, etc.; the time range of the second annealing is 1–30 min, for example, 1 min, 3 min, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 12 min, 15 min, 20 min, 25 min, 30 min, etc. Within the temperature and time range, it is advantageous to prepare the luminescent thin film 2021 with good luminescent performance and stability.

[0155] In some embodiments, after depositing the second quantum dot solution and before obtaining the luminescent thin film 2021, a third annealing is further included. The temperature range of the third annealing is 80–160°C, for example, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, etc.; the time range of the third annealing is 5–60 min, for example, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, etc. Within the temperature and time range, it is beneficial to prepare the luminescent thin film 2021 with good luminescence performance and stability.

[0156] In some embodiments, after depositing the first fluorinated organic acid solution and before obtaining the first interface layer 2022, the process further includes: a first heat treatment, wherein the temperature of the first heat treatment is 80–150°C, for example, 80°C, 90°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, etc., and the time of the first heat treatment is 10–100 min, for example, 10 min, 12 min, 15 min, 20 min, 25 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, etc. Within the temperature and time range, it is beneficial to facilitate the interaction between the fluorinated organic acid and the quantum dots in the luminescent film 2021, and to facilitate the passivation of defects on the surface of the quantum dots on the surface of the luminescent film 2021 by the fluorinated organic acid ions.

[0157] In some embodiments, after depositing the second fluorinated organic acid solution and before obtaining the second interface layer 2023, a second heat treatment is further included. The temperature of the second heat treatment is 80–150°C, for example, 80°C, 90°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, etc., and the time of the second heat treatment is 10–100 min, for example, 10 min, 12 min, 15 min, 20 min, 25 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, etc. Within the temperature and time range, it is beneficial to facilitate the interaction between the fluorinated organic acid and the quantum dots in the luminescent film 2021, and to facilitate the passivation of defects on the surface of the quantum dots on the surface of the luminescent film 2021 by the fluorinated organic acid ions.

[0158] In some embodiments, the first electrode is an anode 10 and the second electrode is a cathode 30. The fabrication of the light-emitting layer 20 on the first electrode includes: sequentially fabricating a hole transport layer 50 and a light-emitting layer 20 on the first electrode.

[0159] In some embodiments, the first electrode is an anode 10 and the second electrode is a cathode 30. The fabrication of the second electrode on the light-emitting layer 20 includes: sequentially fabricating an electron transport layer 40 and a second electrode on the light-emitting layer 20.

[0160] In some embodiments, the first electrode is a cathode 30, the second electrode is an anode 10, and a light-emitting layer 20 is prepared on the first electrode: an electron transport layer 40 and a light-emitting layer 20 are sequentially prepared on the first electrode.

[0161] In some embodiments, the first electrode is a cathode 30 and the second electrode is an anode 10. The fabrication of the second electrode on the light-emitting layer 20 includes: sequentially fabricating a hole transport layer 50 and the second electrode on the light-emitting layer 20.

[0162] The methods for preparing the second electrode, the electron transport layer 40, and the hole transport layer 50 described in this application can be implemented using conventional techniques in the art, such as chemical or physical methods. Chemical methods include chemical vapor deposition, continuous ion layer adsorption and reaction, anodic oxidation, electrolytic deposition, and co-precipitation. Physical methods include physical deposition and solution methods. Physical deposition methods include thermal evaporation deposition, electron beam evaporation deposition, magnetron sputtering, multi-arc ion deposition, physical vapor deposition, atomic layer deposition, pulsed laser deposition, etc.; solution methods can include spin coating, printing, inkjet printing, blade coating, dip coating, immersion coating, spraying, roller coating, casting, slot coating, and strip coating, etc.

[0163] It is understood that when the light-emitting device 100 also includes functional layers that are conventionally used in light-emitting devices to help improve the performance of the light-emitting device, such as electron blocking layers, hole blocking layers, interface modification layers, etc., the method of fabricating the light-emitting device 100 may also include the step of fabricating the above-mentioned functional layers using conventional techniques in the art.

[0164] Fifthly, embodiments of this application also provide a display device, the display device including the light-emitting device 100.

[0165] The display device can be any electronic product with display function, including but not limited to smartphones, tablets, laptops, digital cameras, digital camcorders, smart wearable devices, smart weighing scales, in-vehicle displays, televisions, or e-book readers. Among them, smart wearable devices can be, for example, smart bracelets, smartwatches, virtual reality (VR) headsets, etc.

[0166] The present application will be specifically described below through specific embodiments. The following embodiments are only some embodiments of the present application and are not intended to limit the present application.

[0167] Composite Material Example 1

[0168] A dispersion is provided, wherein the dispersion comprises ZnCdSe / ZnSe / ZnS quantum dots, (CF3CF3CF3C)2POOH (fluorinated organic acid) and n-hexane (solvent), wherein the mass ratio of (CF3CF3CF3C)2POOH to quantum dots is 1:5, and the concentration of quantum dots in the dispersion is 10 mg / ml;

[0169] The dispersion was spin-coated onto a substrate at a speed of 2000 rpm for 30 seconds, followed by annealing at 100°C for 5 minutes to obtain a 20 nm thick film. The film is a composite material comprising ZnCdSe / ZnSe / ZnS quantum dots and (CF3CF3CF3C)2POO bonded to the surface of the quantum dots. - Ligands.

[0170] Composite Material Example 2

[0171] This embodiment is basically the same as that of composite material embodiment 1, except that (CF3CH2)2POOH is used in this embodiment to replace (CF3CF3CF3C)2POOH in composite material embodiment 1.

[0172] Composite Material Example 3

[0173] This embodiment is basically the same as that of composite material embodiment 1, except that (CF3CH2CH2CH2CH2CH2)2POOH is used in this embodiment to replace (CF3CF3CF3C)2POOH in composite material embodiment 1.

[0174] Composite Material Example 4

[0175] This embodiment is basically the same as the composite material embodiment 1, except that the mass ratio of (CF3CF3CF3C)2POOH to quantum dots in this embodiment is 1:1.

[0176] Composite Material Example 5

[0177] This embodiment is basically the same as the composite material embodiment 1, except that in this embodiment, the mass ratio of (CF3CF3CF3C)2POOH to quantum dots is 1:10.

[0178] Composite Material Example 6

[0179] This embodiment is basically the same as the composite material embodiment 1, except that CdSe / ZnSe / ZnS quantum dots are used to replace the ZnCdSe / ZnSe / ZnS quantum dots in the composite material embodiment 1.

[0180] Composite Material Comparative Example 1

[0181] This comparative example is basically the same as that of the composite material example 1, except that the dispersion in this comparative example does not contain fluorinated organic acids, and the material in the prepared film does not contain fluorinated organic acid radicals. In other words, the material of the film in this comparative example is ZnCdSe / ZnSe / ZnS quantum dots.

[0182] Composite Material Comparative Example 2

[0183] This comparative example is basically the same as the composite material comparative example 1, except that in this comparative example, CdSe / ZnSe / ZnS quantum dots are used to replace the ZnCdSe / ZnSe / ZnS quantum dots in the composite material comparative example 1.

[0184] Comparative Example 3 of Composite Materials

[0185] This comparative example is basically the same as that of the composite material example 1, except that methyl ammonium hypophosphite is used in this comparative example to replace (CF3CF3CF3C)2POOH in the composite material example 1.

[0186] Composite Material Comparative Example 4

[0187] This comparative example is basically the same as that of the composite material example 1, except that phenyl hypophosphite is used in this comparative example to replace (CF3CF3CF3C)2POOH in the composite material example 1.

[0188] Thin films were prepared using the preparation methods of composite material Examples 1-6 and Comparative Examples 1-4, respectively. The fluorescence quantum efficiency and stability of the prepared thin films were then tested, and the test results are shown in Table 1.

[0189] The fluorescence quantum efficiency was tested using a steady-state fluorescence spectrometer from Edinburgh Instruments, model FS5, with the SC-30 accessory for measuring fluorescence quantum yield.

[0190] Stability testing method: QYd represents the PLQY decay of the film after being placed at 80℃ for 7 days. The testing method is as follows: a steady-state fluorescence spectrometer from Edinburgh Instruments (model FS5) is used for testing, and the corresponding accessory for measuring fluorescence quantum yield is SC-30. PLQY1 is tested; then, the film is placed in an environment with a temperature of 80℃ and a relative humidity of 80% for 7 days, and PLQY2 is tested. The calculated QYd (%) is: PLQY2 / PLQY1 × 100%. The larger the QYd, the higher the stability of the composite material; conversely, the smaller the QYd, the lower the stability of the composite material.

[0191] Table 1:

[0192] PLQY (%) QYd(%) Composite Material Example 1 48 74.8 Composite Material Example 2 45 67.0 Composite Material Example 3 47 72.2 Composite Material Example 4 38 60.0 Composite Material Example 5 41 62.6 Composite Material Example 6 43 65.8 Composite Material Comparative Example 1 33 49.8 Composite Material Comparative Example 2 30 44.0 Comparative Example 3 of Composite Materials 35 52.0 Composite Material Comparative Example 4 36 57.6

[0193] As shown in Table 1:

[0194] Compared to the films prepared from quantum dots in Comparative Examples 1-2 and the composite materials in Comparative Examples 3-4, the films prepared from the composite materials in Examples 1-6 exhibit higher PLQY and QYd. This demonstrates that adding the fluorinated organic acid described in this application during the quantum dot film preparation process can effectively improve the fluorescence quantum efficiency and stability of the quantum dot film. The reasons may be as follows: Firstly, the fluorinated organic acid ligand can effectively passivate surface defects of the quantum dots, improving their stability and fluorescence quantum efficiency. Secondly, the F in the fluorinated organic acid ligand has high electronegativity, enabling effective charge transport. Thirdly, the F in the fluorinated organic acid ligand is located on the carbon chain and does not directly contact the quantum dots, effectively improving their stability. Furthermore, when the end group of the fluorinated organic acid ligand is -CF3, -CF3 contains highly negatively charged F, resulting in high electronegativity, which can give the ligand better charge transport performance, effectively transferring charge to the quantum dots and thus improving their fluorescence quantum efficiency.

[0195] Device Example 1

[0196] The structure of the light-emitting device in this embodiment is ITO / PEDOT:PSS / TFB / (ZnCdSe / ZnSe / ZnS quantum dots)@(CF3CF3CF3C)2POO - Ligand / ZnO / Cathode.

[0197] The method for fabricating the light-emitting device in this embodiment includes:

[0198] Step 1: Provide an ITO anode 10 glass substrate. Use a cotton swab dipped in a small amount of soapy water to wipe the ITO surface to remove visible impurities. Then, use deionized water, acetone, ethanol, and isopropanol for ultrasonic cleaning for 15 minutes. Finally, dry it with nitrogen gas for later use.

[0199] Step 2: Spin-coat PEDOT:PSS material onto the anode at a speed of 5000 rpm for 30 seconds, and anneal at 250°C for 30 minutes to obtain a hole injection layer with a thickness of 20 nm.

[0200] Step 3: Spin coat the hole injection layer with TFB material at a speed of 3000 rpm for 30 seconds, and anneal at 200°C for 30 minutes to obtain a hole transport layer with a thickness of 30 nm.

[0201] Step 4: Prepare a first thin film on the hole transport layer using the preparation method of composite material Example 1 to obtain the light-emitting layer;

[0202] Step 5: Spin-coat an ethanol solution of ZnO onto the light-emitting layer at a spin speed of 4000 rpm for 30 seconds, followed by annealing at 80°C for 10 minutes to obtain an electron transport layer with a thickness of 30 nm.

[0203] Step 6: In a vacuum coating machine, thermal evaporation is performed, with a vacuum level not exceeding 3×10⁻⁶. -4 Al was deposited by thermal evaporation at a rate of 1 Å / s for 100 seconds, forming an Al layer with a thickness of 10 nm; the evaporation was carried out under a vacuum level not exceeding 3 × 10⁻⁶. -4 Pa, Ag is vaporized at a rate of 1 angstrom / second for 200 seconds to form an Ag layer with a thickness of 20 nm, thus obtaining the cathode;

[0204] Step 7: Package the device to obtain the light-emitting device.

[0205] Device Examples 2-6

[0206] Device Examples 2 to 6 are basically the same as Device Example 1, except that the light-emitting layer of Device Examples 2 to 6 is prepared using the same method as that used in the composite material examples 2 to 6.

[0207] Device Example 7

[0208] The structure of the light-emitting device in this embodiment is ITO / PEDOT:PSS / TFB / (ZnCdSe / ZnSe / ZnS quantum dot) / (CF3CF3CF3C)2POOH interface layer / ZnO / cathode.

[0209] The method for fabricating the light-emitting device in this embodiment includes:

[0210] Step 1: Provide an ITO anode glass substrate. Use a cotton swab dipped in a small amount of soapy water to wipe the ITO surface to remove visible impurities. Then, use deionized water, acetone, ethanol, and isopropanol for ultrasonic cleaning for 15 minutes. Finally, dry it with nitrogen gas for later use.

[0211] Step 2: Spin-coat PEDOT:PSS material onto the anode at a speed of 5000 rpm for 30 seconds, and anneal at 250°C for 30 minutes to obtain a hole injection layer with a thickness of 20 nm.

[0212] Step 3: Spin coat the hole injection layer with TFB material at a speed of 3000 rpm for 30 seconds, and anneal at 200°C for 30 minutes to obtain a hole transport layer with a thickness of 30 nm.

[0213] Step 4: Spin-coat a ZnCdSe / ZnSe / ZnS quantum dot solution (hexane as solvent) onto the hole transport layer at a speed of 2000 rpm for 30 seconds, followed by annealing at 100°C for 5 minutes to form a luminescent film (hole transport film) with a thickness of 20 nm; spin-coat a (CF3CF3CF3C)2POOH solution (hexane as solvent) onto the luminescent film at a speed of 4000 rpm for 30 seconds, and dry to form an interface layer with a thickness of 1.5 nm, thus obtaining a second film comprising the luminescent film and the interface layer, wherein the second film is the luminescent layer;

[0214] Step 5: Spin-coat an ethanol solution of ZnO onto the light-emitting layer at a spin speed of 4000 rpm for 30 seconds, followed by annealing at 80°C for 10 minutes to obtain an electron transport layer with a thickness of 30 nm.

[0215] Step 6: In a vacuum coating machine, thermal evaporation is performed, with a vacuum level not exceeding 3×10⁻⁶. -4 Al was deposited by thermal evaporation at a rate of 1 Å / s for 100 seconds, forming an Al layer with a thickness of 10 nm; the evaporation was carried out under a vacuum level not exceeding 3 × 10⁻⁶. -4 Pa, Ag is vaporized at a rate of 1 angstrom / second for 200 seconds to form an Ag layer with a thickness of 20 nm, thus obtaining the cathode;

[0216] Step 7: Package the device to obtain the light-emitting device.

[0217] Device Example 8

[0218] This embodiment is basically the same as device embodiment 7, except that (CF3CH2)2POOH is used in this embodiment to replace (CF3CF3CF3C)2POOH in embodiment 7.

[0219] Device Example 9

[0220] This embodiment is basically the same as device embodiment 7, except that the thickness of the interface layer in this embodiment is 1nm.

[0221] Device Example 10

[0222] This embodiment is basically the same as device embodiment 7, except that the thickness of the interface layer in this embodiment is 2nm.

[0223] Device Example 11

[0224] This embodiment is basically the same as device embodiment 7, except that CdSe / ZnSe / ZnS quantum dots are used to replace the ZnCdSe / ZnSe / ZnS quantum dots in embodiment 7.

[0225] Device Example 12

[0226] This embodiment is basically the same as device embodiment 7, except that in this embodiment, after spin-coating the (CF3CF3CF3C)2POOH solution onto the light-emitting film, a heat treatment at 100°C for 10 minutes is also included.

[0227] Device Example 13

[0228] This embodiment is basically the same as device embodiment 12, except that the heat treatment temperature in this embodiment is 80°C.

[0229] Device Example 14

[0230] This embodiment is basically the same as device embodiment 12, except that the heat treatment temperature in this embodiment is 150°C.

[0231] Device Example 15

[0232] This embodiment is basically the same as device embodiment 7, except that a (CF3CF3CF3C)2POOH layer is also provided between the hole transport layer and the light-emitting film in this embodiment. Step 4 of this embodiment is as follows:

[0233] A (CF3CF3CF3C)2POOH solution (hexane as solvent) was spin-coated onto the hole transport layer at a speed of 4000 rpm for 30 seconds, and then dried to form an interface layer with a thickness of 1.5 nm. A ZnCdSe / ZnSe / ZnS quantum dot solution (hexane as solvent) was spin-coated onto the interface layer at a speed of 2000 rpm for 30 seconds, followed by annealing at 100°C for 5 minutes to form a light-emitting film with a thickness of 20 nm. A (CF3CF3CF3C)2POOH solution (hexane as solvent) was spin-coated onto the light-emitting film at a speed of 4000 rpm for 30 seconds, and then dried to form an interface layer with a thickness of 1.5 nm, resulting in a second film comprising the sequentially stacked interface layer, the light-emitting film, and the interface layer, wherein the second film is the light-emitting layer.

[0234] Device Example 16

[0235] The structure of the light-emitting device in this embodiment is ITO / PEDOT:PSS / TFB / (ZnCdSe / ZnSe / ZnS quantum dot) / (CF3CF3CF3C)2POOH interface layer / ZnO / cathode.

[0236] The method for fabricating the light-emitting device in this embodiment includes:

[0237] Step 1: Provide a cathode glass substrate, wherein the cathode comprises an Ag layer with a thickness of 20 nm and an Al layer with a thickness of 10 nm stacked sequentially on the substrate;

[0238] Step 2: Spin-coat an ethanol solution of ZnO onto the cathode at a speed of 4000 rpm for 30 seconds, followed by annealing at 80°C for 10 minutes to obtain an electron transport layer with a thickness of 30 nm.

[0239] Step 3: Spin-coat a ZnCdSe / ZnSe / ZnS quantum dot solution (hexane as solvent) onto the electron transport layer at a speed of 2000 rpm for 30 seconds, followed by annealing at 100°C for 5 minutes to form a luminescent film with a thickness of 20 nm; spin-coat a (CF3CF3CF3C)2POOH solution (hexane as solvent) onto the luminescent film at a speed of 4000 rpm for 30 seconds, and dry to form an interface layer with a thickness of 1.5 nm, thus obtaining a luminescent layer comprising the luminescent film and the interface layer;

[0240] Step 4: Spin-coat TFB material onto the light-emitting layer at a speed of 3000 rpm for 30 seconds, and anneal at 200°C for 30 minutes to obtain a hole transport layer with a thickness of 30 nm.

[0241] Step 5: Spin-coat PEDOT:PSS material onto the hole transport layer at a spin speed of 5000 rpm for 30 seconds, and anneal at 250°C for 30 minutes to obtain a hole injection layer with a thickness of 20 nm.

[0242] Step 6: In a vacuum coating machine, thermal evaporation is performed, with a vacuum level not exceeding 3×10⁻⁶. -4 Pa, ITO anode is formed by vapor deposition;

[0243] Step 7: Package the device to obtain the light-emitting device.

[0244] Device Comparison Examples 1-4

[0245] The devices in Comparative Examples 1 to 4 are basically the same as those in Device Example 1, except that the light-emitting layers of the devices in Comparative Examples 1 to 4 are prepared using the same methods as those used in Comparative Examples 1 to 4 for preparing composite materials.

[0246] Device Comparison Example 5

[0247] This comparative example is basically the same as device example 16, except that the method for preparing the light-emitting layer in this comparative example includes:

[0248] A quantum dot solution with a concentration of 10 mg / ml (solvent: n-hexane) was spin-coated onto the electron transport layer 40 at a spin speed of 2000 rpm for 30 seconds, followed by annealing at 100 °C for 5 min to obtain a light-emitting layer with a thickness of 20 nm.

[0249] Device Comparison Example 6

[0250] This comparative example is basically the same as device example 7, except that sodium hypophosphite is used to replace (CF3CF3CF3C)2POOH in device example 14.

[0251] Device Comparison Example 7

[0252] This comparative example is basically the same as device example 16, except that sodium hypophosphite is used to replace (CF3CF3CF3C)2POOH in device example 23.

[0253] The current efficiency (CE), lifetime (T95@1000nit), and high-temperature current efficiency stability of the light-emitting devices in Examples 1-16 and Comparative Examples 1-7 were tested. The test results are shown in Table 2.

[0254] The test method for current efficiency (CE) is as follows: using the Fostar FPD optical property measurement equipment, an efficiency test system is built by controlling the QE PRO spectrometer, Keithley 2400, and Keithley 6485 through LabVIEW, and parameters such as voltage, current, brightness, and emission spectrum are measured, and the current efficiency is calculated.

[0255] The lifetime test method T95@1000nit is as follows: In CDA gas, under constant current or voltage drive, the time it takes for the device brightness to decay to a certain percentage of its maximum brightness is measured. The time for the brightness to decay to 95% of the maximum brightness is defined as T95, and this lifetime is the measured lifetime. To shorten the lifetime testing cycle, device lifetime testing is usually performed at high brightness by accelerating device aging, and the lifetime at low brightness is obtained by fitting the decay fitting formula. For example, the lifetime at 1000 nits is denoted as T95@1000nits, and the calculation formula is:

[0256]

[0257] Among them, T95 L The lifespan at low brightness is typically taken as the lifespan at 1000 nits, T95. H The lifetime at high brightness, i.e., the measured lifetime, L H L is the maximum brightness that the device accelerates to. L The typical value is 1000 nits, where A is the acceleration factor, taken as 1.7. The constant current is 2 mA.

[0258] Current efficiency and lifespan test conditions: conducted at room temperature with an air humidity of 50%.

[0259] High-Temperature Current Efficiency Stability: C.Ed represents the CE decay of the light-emitting device after being placed at 80℃ for 7 days. The test method for current efficiency CE and current efficiency stability C.Ed is as follows: After placing the light-emitting device in an environment with a temperature of 80℃ and a relative humidity of 80% for 7 days, the brightness value of the light-emitting device is intermittently collected within the voltage range of 0V to 8V, with a collection every 0.2V. The brightness value collected each time is divided by the corresponding current density to obtain the current efficiency of the light-emitting device under that collection condition. The initial current efficiency is C.E1, and the obtained current density is 32mA / cm. 2 The current efficiency (C.E2, cd / A) is calculated as C.Ed(%) = C.E2 / C.E1 × 100%. The larger the C.Ed, the higher the stability of the current efficiency of the light-emitting device. Conversely, the smaller the C.Ed, the lower the stability of the current efficiency of the light-emitting device.

[0260] Table 2:

[0261]

[0262]

[0263] As shown in Table 2:

[0264] Compared with the light-emitting devices of Comparative Examples 1 to 7, the light-emitting devices of Examples 1 to 16 have higher current efficiency, longer lifetime and higher high-temperature current efficiency stability. It can be seen that adding the fluorinated organic acid described in this application during the preparation of the light-emitting layer of the light-emitting device can effectively improve the fluorescence quantum efficiency and stability of the quantum dot film. The reasons may be as follows: Firstly, the fluorinated organic acid ligand can effectively passivate surface defects of quantum dots, improving their stability and fluorescence quantum efficiency. Secondly, the F in the fluorinated organic acid ligand has high electronegativity, enabling effective charge transport. Thirdly, the F in the fluorinated organic acid ligand is located on the carbon chain and does not directly contact the quantum dot, effectively improving its stability. Furthermore, when the end group of the fluorinated organic acid ligand is -CF3, -CF3 contains highly negatively charged F, resulting in high electronegativity, which can give the ligand good charge transport performance, effectively transferring charge to the quantum dot and thus improving its fluorescence quantum efficiency. Further, the high electronegativity of -CF3 can enhance charge transport between the electron transport layer and hole transport layer and the luminescent layer, preventing charge accumulation at the interface and improving device stability, luminous efficiency, and lifetime. Additionally, -CF3 can passivate the electron transport layer and hole transport layer materials at the interface, reducing interface defects and further improving device stability, current efficiency, luminous efficiency, and lifetime.

[0265] The technical solutions provided by the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A composite material, characterized by, The quantum dot and the fluorine-containing organic acid root.

2. The composite material of claim 1, wherein, The fluorine-containing organic acid root has a chemical formula as shown in the following formula (I): wherein R1and R2are each independently selected from substituted or unsubstituted C1-C 20 linear alkyl, substituted or unsubstituted C1-C 20 linear alkoxy, substituted or unsubstituted C1-C 20 linear thioalkoxy, substituted or unsubstituted C1-C 20 branched alkyl, substituted or unsubstituted C1-C 20 branched alkoxy, substituted or unsubstituted C1-C 20 branched thioalkoxy, substituted or unsubstituted C3-C 20 cyclic alkyl, substituted or unsubstituted C3-C 20 cyclic alkoxy, substituted or unsubstituted C3-C 20 cyclic thioalkoxy, substituted or unsubstituted silyl, substituted or unsubstituted C1-C 20 ketone, substituted or unsubstituted C2-C 20 alkoxycarbonyl, substituted or unsubstituted C7-C 20 aryloxycarbonyl, cyano, carbamoyl, halogenformyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxyl, nitro, amine, -CF3, -Cl, -Br, -F, -I, C2-C 20 olefinic group, substituted or unsubstituted aromatic group having 6 to 60 ring atoms, substituted or unsubstituted heteroaromatic group having 5 to 60 ring atoms, substituted or unsubstituted aryloxy group having 6 to 60 ring atoms, substituted or unsubstituted heteroaryloxy group having 5 to 60 ring atoms, or a combination thereof; At least one of R1 and R2 contains F; L1and L2are linking groups, each independently selected from the group consisting of a substituted or unsubstituted C1-C20alkylene, a substituted or unsubstituted C2-C20alkenylene, a substituted or unsubstituted C2-C20alkynylene, a substituted or unsubstituted C6-C20arylene, a substituted or unsubstituted C6-C20aryloxy, a substituted or unsubstituted C6-C20arylthio, a substituted or unsubstituted -(CH2)m1-, 30 a substituted or unsubstituted C2-C20alkenylene, a substituted or unsubstituted C2-C20alkynylene, 30 a substituted or unsubstituted C2-C20alkenylene, a substituted or unsubstituted C2-C20alkynylene, 30 a substituted or unsubstituted C2-C20alkenylene, a substituted or unsubstituted C2-C20alkynylene, 20 a substituted or unsubstituted C6-C20arylene, a substituted or unsubstituted C6-C20aryloxy, a substituted or unsubstituted C6-C20arylthio, a substituted or unsubstituted -(CH2)m1-, m1 CO(CH2)m1-, m2 -; a substituted or unsubstituted C6-C20arylene, a substituted or unsubstituted C6-C20aryloxy, a substituted or unsubstituted C6-C20arylthio, a substituted or unsubstituted -(CH2)m1-, m3 NHCO(CH2)m1-, m4 -; a substituted or unsubstituted C6-C20arylene, a substituted or unsubstituted C6-C20aryloxy, a substituted or unsubstituted C6-C20arylthio, a substituted or unsubstituted -(CH2)m1-, m5 CONH(CH2)m1-, m6 -; a substituted or unsubstituted C6-C20arylene, a substituted or unsubstituted C6-C20aryloxy, a substituted or unsubstituted C6-C20arylthio, a substituted or unsubstituted -(CH2)m1-, m7 COO(CH2)m1-, m8 -; a substituted or unsubstituted C6-C20arylene, a substituted or unsubstituted C6-C20aryloxy, a substituted or unsubstituted C6-C20arylthio, a substituted or unsubstituted -(CH2)m1-, wherein each of m1to m8is independently selected from an integer from 1 to 20; R1, R2, L1, L2, the substituted substituent includes halogen, hydroxyl, nitro, cyano, isocyano, silyl, C1-C 20 alkyl, C1-C 20 alkoxy, C1-C 20 alkylthio, aryl of 6 to 60 ring atoms, aryloxy of 6 to 60 ring atoms, arylthio of 6 to 60 ring atoms.

3. The composite material of claim 2, wherein, Further comprising at least one of the following features (1) to (10): (1) R1 and R2 are each independently selected from substituted or unsubstituted C1 to C2. 15 Straight-chain alkyl, substituted or unsubstituted C1-C 15 Straight-chain alkoxy, substituted or unsubstituted C1-C 15 Straight-chain thioalkoxy, substituted or unsubstituted C1-C 15 Branched alkyl, substituted or unsubstituted C1-C 15 Branched alkoxy, substituted or unsubstituted C1-C 15 Branched thioalkoxy groups, substituted or unsubstituted C3-C 15 Cycloalkyl, substituted or unsubstituted C3-C 15 Cyclic alkoxy groups, substituted or unsubstituted C3-C 15 Cyclic thioalkoxy, substituted or unsubstituted silyl, substituted or unsubstituted C1-C 15 Ketone, substituted or unsubstituted C2-C 15 alkoxycarbonyl, substituted or unsubstituted C7-C 15 Aryloxycarbonyl, cyano, carbamoyl, halocarboxyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxyl, nitro, amino, -CF3, -Cl, -Br, -F, -I, C2~C 15 An olefinic group, an aromatic group having 6 to 30 substituted or unsubstituted ring atoms, a heteroaromatic group having 5 to 30 substituted or unsubstituted ring atoms, an aryloxy group having 6 to 30 substituted or unsubstituted ring atoms, a heteroaryloxy group having 5 to 30 substituted or unsubstituted ring atoms, or a combination of these groups; wherein at least one of R1 and R2 contains F; (2) R1 and R2 are each independently selected from substituted or unsubstituted C1 to C2. 10 Straight-chain alkyl, substituted or unsubstituted C1-C 10 Straight-chain alkoxy, substituted or unsubstituted C1-C 10 Straight-chain thioalkoxy, substituted or unsubstituted C1-C 10 Branched alkyl, substituted or unsubstituted C1-C 10 Branched alkoxy, substituted or unsubstituted C1-C 10 Branched thioalkoxy groups, substituted or unsubstituted C3-C 10 Cycloalkyl, substituted or unsubstituted C3-C 10 Cyclic alkoxy groups, substituted or unsubstituted C3-C 10 Cyclic thioalkoxy, substituted or unsubstituted silyl, substituted or unsubstituted C1-C 10 Ketone, substituted or unsubstituted C2-C 10 alkoxycarbonyl, substituted or unsubstituted C7-C 10 Aryloxycarbonyl, cyano, carbamoyl, halocarboxyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxyl, nitro, amino, -CF3, -Cl, -Br, -F, -I, C2~C 10 An olefinic group, an aromatic group having 6 to 20 substituted or unsubstituted ring atoms, a heteroaromatic group having 5 to 20 substituted or unsubstituted ring atoms, an aryloxy group having 6 to 20 substituted or unsubstituted ring atoms, a heteroaryloxy group having 5 to 20 substituted or unsubstituted ring atoms, or a combination of these groups; wherein at least one of R1 and R2 contains F; (3) R1and R2are each independently selected from the group consisting of substituted or unsubstituted C1-C8linear alkyl, substituted or unsubstituted C1-C8linear alkoxy, substituted or unsubstituted C1-C8linear thioalkoxy, substituted or unsubstituted C1-C8branched alkyl, substituted or unsubstituted C1-C8branched alkoxy, substituted or unsubstituted C1-C8branched thioalkoxy, substituted or unsubstituted C3-C8cyclic alkyl, substituted or unsubstituted C3-C8cyclic alkoxy, substituted or unsubstituted C3-C8cyclic thioalkoxy, substituted or unsubstituted silyl, substituted or unsubstituted C1-C8alkylsilyl, substituted or unsubstituted C1-C8alkylcarbonyl, substituted or unsubstituted C1-C8alkoxycarbonyl, substituted or unsubstituted C7-C8aryloxycarbonyl, cyano, carbamoyl, halogenformyl, formyl, isocyano, isocyanate, isothiocyanate, hydroxyl, nitro, amine, -CF3, -Cl, -Br, -F, -I, C2-C8alkenyl, substituted or unsubstituted aromatic group having 6 to 15 ring atoms, substituted or unsubstituted heteroaromatic group having 5 to 15 ring atoms, substituted or unsubstituted aryloxy group having 6 to 15 ring atoms, substituted or unsubstituted heteroaryloxy group having 5 to 15 ring atoms, or a combination thereof; wherein at least one of R1and R2contains F; and 10 carbonyl, substituted or unsubstituted C1-C8alkoxycarbonyl, substituted or unsubstituted C7-C8aryloxycarbonyl, cyano, carbamoyl, halogenformyl, formyl, isocyano, isocyanate, isothiocyanate, hydroxyl, nitro, amine, -CF3, -Cl, -Br, -F, -I, C2-C8alkenyl, substituted or unsubstituted aromatic group having 6 to 15 ring atoms, substituted or unsubstituted heteroaromatic group having 5 to 15 ring atoms, substituted or unsubstituted aryloxy group having 6 to 15 ring atoms, substituted or unsubstituted heteroaryloxy group having 5 to 15 ring atoms, or a combination thereof; wherein at least one of R1and R2contains F; and (4) R1 and R2 are each independently selected from substituted or unsubstituted C1-C8 linear alkyl, substituted or unsubstituted C1-C8 branched alkyl, substituted or unsubstituted C3-C8 cyclic alkyl, -CF3, -Cl, -Br, -F, -I, C2-C8 alkenyl, or a combination of these groups; wherein at least one of R1 and R2 contains F; (5) L1 and L2 are each independently selected from substituted or unsubstituted C1 to C2. 15 Alkylene, substituted or unsubstituted C2-C 15 alkenyl, substituted or unsubstituted C2-C 15 alkyne group, substituted or unsubstituted C2-C 10 Etheryl group, substituted or unsubstituted aryl group with 6 to 12 ring atoms, substituted or unsubstituted aryloxy group with 6 to 12 ring atoms, substituted or unsubstituted arylthio group with 6 to 12 ring atoms, substituted or substituted -(CH2) m1 CO(CH2) m2 -, or substituted -(CH2) m3 NHCO(CH2) m4 -, or substituted -(CH2) m5 CONH(CH2) m6 -, or substituted -(CH2) m7 COO(CH2) m8 - One or more combinations of the following, wherein m1 to m8 are each independently selected from integers from 1 to 10; (6) L1 and L2 are each independently selected from substituted or unsubstituted C1 to C2. 10 Alkylene, substituted or unsubstituted C2-C 10 alkenyl, substituted or unsubstituted C2-C 10 Alynyl group, substituted or unsubstituted C2-C8 etheryl group, substituted or unsubstituted aryl group with 6-10 ring atoms, substituted or unsubstituted aryloxy group with 6-10 ring atoms, substituted or unsubstituted arylthio group with 6-10 ring atoms, substituted or substituted -(CH2) group. m1 CO(CH2) m2 -, or substituted -(CH2) m3 NHCO(CH2) m4 -, or substituted -(CH2) m5 CONH(CH2) m6 -, or substituted -(CH2) m7 COO(CH2) m8 - One or more combinations of the following, wherein m1 to m8 are each independently selected from integers from 1 to 8; (7) L1 and L2 are each independently selected from one or more combinations of substituted or unsubstituted C1-C8 alkylene, substituted or unsubstituted C2-C8 alkenylene, substituted or unsubstituted C2-C8 alkynylene, substituted or unsubstituted C2-C5 etherylene, and substituted or unsubstituted arylene with 6 to 10 ring atoms; (8) L1 and L2 are each independently selected from one or more combinations of substituted or unsubstituted C1-C5 alkylene, substituted or unsubstituted C2-C5 alkenylene, and substituted or unsubstituted C2-C5 alkynylene; (9) R1, R2, L1, L2, the substituted substituent includes halogen, hydroxyl, nitro, cyano, isocyano, silyl, C1-C 10 alkyl, C1-C 10 alkoxy, C1-C 10 alkylthio, aryl of 6 to 30 ring atoms, aryloxy of 6 to 30 ring atoms, arylthio of 6 to 30 ring atoms one or more; (10) Among R1, R2, L1, and L2, the substituted substituent includes one or more of halogen, hydroxyl, nitro, cyano, isocyano, silyl, C1-C5 alkyl, C1-C5 alkoxy, C1-C5 alkylthio, aryl with 6 to 15 ring atoms, aryloxy with 6 to 15 ring atoms, and arylthio with 6 to 15 ring atoms.

4. The composite material of claim 2, wherein: The fluorine-containing organic acid root is coordinatedly connected to the quantum dot; and / or At least one of R1 and R2 has a terminal group of -CF3; and / or The mass ratio of the fluorine-containing organic acid root to the quantum dot is 1:(5-50); and / or said fluorine-containing organic acid radical comprises one or more of (CF3CH2)2POO - , (CF3CH2CH2)2POO - , (CF3CH2CH2CH2CH2CH2)2POO - , (CF3CF3CF3C)2POO - ; and / or The quantum dots include one or more of single-structure quantum dots, core-shell quantum dots including one or more shell layers, and perovskite semiconductor materials, the materials of the single-structure quantum dots, the core materials of the core-shell quantum dots, and the shell layer materials of the core-shell quantum dots are independently selected from one or more of II-VI compounds, IV-VI compounds, III-V compounds, and I-III-VI compounds, the II-VI compounds include one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe, the IV-VI compounds include one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe, the III-V compounds include one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb, the I-III-VI compounds include one or more of CuInS2, CuInSe2, and AgInS2, the perovskite semiconductor materials include doped or non-doped inorganic perovskite semiconductors or organic-inorganic hybrid perovskite semiconductors, the inorganic perovskite semiconductors have a general structure of AMX3, where A is a Cs + ion, M is a divalent metal cation including Pb 2+ , Sn 2+ , Cu 2+ , Ni 2+ , Cd 2+ , Cr 2+ , Mn 2+ , Co 2+ , Fe 2+ , Ge 2+ , Yb 2+ , Eu 2+ one or more of Cl - , Br - , I - ; the structure general formula of the organic-inorganic hybrid perovskite type semiconductor is BMX3, wherein B is an organic amine cation, including CH3(CH2) n-2 NH3 + or [NH3(CH2) n NH3] 2+ , wherein n≥2, M is a divalent metal cation, including one or more of Pb 2+ , Sn 2+ , Cu 2+ , Ni 2+ , Cd 2+ , Cr 2+ , Mn 2+ , Co 2+ , Fe 2+ , Ge 2+ , Yb 2+ , Eu 2+ one or more of Cl - , Br - , I - ; and / or The average particle size of the quantum dot ranges from 5 to 20 nm.

5. A method of producing a composite material, characterized by, The method comprises the following steps: Providing a quantum dot, a fluorine-containing organic acid, and a first solvent; Mixing the quantum dot, the fluorine-containing organic acid, and the first solvent to obtain a mixed solution, removing the first solvent from the mixed solution to obtain the composite material.

6. The production method according to claim 5, wherein The fluorine-containing organic acid has a chemical formula as shown in the following formula (II): wherein R1and R2are each independently selected from substituted or unsubstituted C1-C 20 linear alkyl, substituted or unsubstituted C1-C 20 linear alkoxy, substituted or unsubstituted C1-C 20 linear thioalkoxy, substituted or unsubstituted C1-C 20 branched alkyl, substituted or unsubstituted C1-C 20 branched alkoxy, substituted or unsubstituted C1-C 20 branched thioalkoxy, substituted or unsubstituted C3-C 20 cyclic alkyl, substituted or unsubstituted C3-C 20 cyclic alkoxy, substituted or unsubstituted C3-C 20 cyclic thioalkoxy, substituted or unsubstituted silyl, substituted or unsubstituted C1-C 20 keto, substituted or unsubstituted C2-C 20 alkoxycarbonyl, substituted or unsubstituted C7-C 20 aryloxycarbonyl, cyano, carbamoyl, halogenformyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxyl, nitro, amine, -CF3, -Cl, -Br, -F, -I, C2-C 20 olefinic group, substituted or unsubstituted aromatic group having 6 to 60 ring atoms, substituted or unsubstituted heteroaromatic group having 5 to 60 ring atoms, substituted or unsubstituted aryloxy group having 6 to 60 ring atoms, substituted or unsubstituted heteroaryloxy group having 5 to 60 ring atoms, or a combination thereof; At least one of R1 and R2 contains F; L1and L2are linking groups, each independently selected from the group consisting of a substituted or unsubstituted C1-C20alkylene, a substituted or unsubstituted C2-C20alkenylene, a substituted or unsubstituted C2-C20alkynylene, a substituted or unsubstituted C6-C20arylene, a substituted or unsubstituted C6-C20aryloxy, a substituted or unsubstituted C6-C20arylthio, a substituted or unsubstituted -(CH2)m1-, 30 a substituted or unsubstituted C2-C20alkenylene, a substituted or unsubstituted C2-C20alkynylene, 30 a substituted or unsubstituted C2-C20alkenylene, a substituted or unsubstituted C2-C20alkynylene, 30 a substituted or unsubstituted C2-C20alkenylene, a substituted or unsubstituted C2-C20alkynylene, 20 a substituted or unsubstituted C6-C20arylene, a substituted or unsubstituted C6-C20aryloxy, a substituted or unsubstituted C6-C20arylthio, a substituted or unsubstituted -(CH2)m1-, m1 CO(CH2)m1-, m2 -; a substituted or unsubstituted -(CH2)m1-, m3 NHCO(CH2)m1-, m4 -; a substituted or unsubstituted -(CH2)m1-, m5 CONH(CH2)m1-, m6 -; a substituted or unsubstituted -(CH2)m1-, m7 COO(CH2)m1-, m8 -; and m1to m8are each independently selected from an integer from 1 to 20. R1, R2, L1, L2, the substituted substituent includes halogen, hydroxyl, nitro, cyano, isocyano, silyl, C1-C 20 alkyl, C1-C 20 alkoxy, C1-C 20 alkylthio, aryl of 6 to 60 ring atoms, aryloxy of 6 to 60 ring atoms, arylthio of 6 to 60 ring atoms.

7. The production method according to claim 6, wherein Further comprising at least one of the following features (1) to (10): (1) R1 and R2 are each independently selected from substituted or unsubstituted C1 to C2. 15 Straight-chain alkyl, substituted or unsubstituted C1-C 15 Straight-chain alkoxy, substituted or unsubstituted C1-C 15 Straight-chain thioalkoxy, substituted or unsubstituted C1-C 15 Branched alkyl, substituted or unsubstituted C1-C 15 Branched alkoxy, substituted or unsubstituted C1-C 15 Branched thioalkoxy groups, substituted or unsubstituted C3-C 15 Cycloalkyl, substituted or unsubstituted C3-C 15 Cyclic alkoxy groups, substituted or unsubstituted C3-C 15 Cyclic thioalkoxy, substituted or unsubstituted silyl, substituted or unsubstituted C1-C 15 Ketone, substituted or unsubstituted C2-C 15 alkoxycarbonyl, substituted or unsubstituted C7-C 15 Aryloxycarbonyl, cyano, carbamoyl, halocarboxyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxyl, nitro, amino, -CF3, -Cl, -Br, -F, -I, C2~C 15 An olefinic group, an aromatic group having 6 to 30 substituted or unsubstituted ring atoms, a heteroaromatic group having 5 to 30 substituted or unsubstituted ring atoms, an aryloxy group having 6 to 30 substituted or unsubstituted ring atoms, a heteroaryloxy group having 5 to 30 substituted or unsubstituted ring atoms, or a combination of these groups; wherein at least one of R1 and R2 contains F; (2) R1 and R2 are each independently selected from substituted or unsubstituted C1 to C2. 10 Straight-chain alkyl, substituted or unsubstituted C1-C 10 Straight-chain alkoxy, substituted or unsubstituted C1-C 10 Straight-chain thioalkoxy, substituted or unsubstituted C1-C 10 Branched alkyl, substituted or unsubstituted C1-C 10 Branched alkoxy, substituted or unsubstituted C1-C 10 Branched thioalkoxy groups, substituted or unsubstituted C3-C 10 Cycloalkyl, substituted or unsubstituted C3-C 10 Cyclic alkoxy groups, substituted or unsubstituted C3-C 10 Cyclic thioalkoxy, substituted or unsubstituted silyl, substituted or unsubstituted C1-C 10 Ketone, substituted or unsubstituted C2-C 10 alkoxycarbonyl, substituted or unsubstituted C7-C 10 Aryloxycarbonyl, cyano, carbamoyl, halocarboxyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxyl, nitro, amino, -CF3, -Cl, -Br, -F, -I, C2~C 10 An olefinic group, an aromatic group having 6 to 20 substituted or unsubstituted ring atoms, a heteroaromatic group having 5 to 20 substituted or unsubstituted ring atoms, an aryloxy group having 6 to 20 substituted or unsubstituted ring atoms, a heteroaryloxy group having 5 to 20 substituted or unsubstituted ring atoms, or a combination of these groups; wherein at least one of R1 and R2 contains F; (3) R1and R2are each independently selected from the group consisting of substituted or unsubstituted C1-C8linear alkyl, substituted or unsubstituted C1-C8linear alkoxy, substituted or unsubstituted C1-C8linear thioalkoxy, substituted or unsubstituted C1-C8branched alkyl, substituted or unsubstituted C1-C8branched alkoxy, substituted or unsubstituted C1-C8branched thioalkoxy, substituted or unsubstituted C3-C8cyclic alkyl, substituted or unsubstituted C3-C8cyclic alkoxy, substituted or unsubstituted C3-C8cyclic thioalkoxy, substituted or unsubstituted silyl, substituted or unsubstituted C1-C8alkylsilyl, substituted or unsubstituted C1-C8alkylcarbonyl, substituted or unsubstituted C1-C8alkoxycarbonyl, substituted or unsubstituted C7-C8aryloxycarbonyl, cyano, carbamoyl, halogenformyl, formyl, isocyano, isocyanate, isothiocyanate, hydroxyl, nitro, amine, -CF3, -Cl, -Br, -F, -I, C2-C8alkenyl, substituted or unsubstituted aromatic group having 6 to 15 ring atoms, substituted or unsubstituted heteroaromatic group having 5 to 15 ring atoms, substituted or unsubstituted aryloxy group having 6 to 15 ring atoms, substituted or unsubstituted heteroaryloxy group having 5 to 15 ring atoms, or a combination thereof; wherein at least one of R1and R2contains F; and 10 (3) R1and R2are each independently selected from the group consisting of substituted or unsubstituted C1-C8linear alkyl, substituted or unsubstituted C1-C8linear alkoxy, substituted or unsubstituted C1-C8linear thioalkoxy, substituted or unsubstituted C1-C8branched alkyl, substituted or unsubstituted C1-C8branched alkoxy, substituted or unsubstituted C1-C8branched thioalkoxy, substituted or unsubstituted C3-C8cyclic alkyl, substituted or unsubstituted C3-C8cyclic alkoxy, substituted or unsubstituted C3-C8cyclic thioalkoxy, substituted or unsubstituted silyl, substituted or unsubstituted C1-C8alkylsilyl, substituted or unsubstituted C1-C8alkylcarbonyl, substituted or unsubstituted C1-C8alkoxycarbonyl, substituted or unsubstituted C7-C8aryloxycarbonyl, cyano, carbamoyl, halogenformyl, formyl, isocyano, isocyanate, isothiocyanate, hydroxyl, nitro, amine, -CF3, -Cl, -Br, -F, -I, C2-C8alkenyl, substituted or unsubstituted aromatic group having 6 to 15 ring atoms, substituted or unsubstituted heteroaromatic group having 5 to 15 ring atoms, substituted or unsubstituted aryloxy group having 6 to 15 ring atoms, substituted or unsubstituted heteroaryloxy group having 5 to 15 ring atoms, or a combination thereof; wherein at least one of R1and R2contains F; and (4) R1 and R2 are each independently selected from substituted or unsubstituted C1-C8 linear alkyl, substituted or unsubstituted C1-C8 branched alkyl, substituted or unsubstituted C3-C8 cyclic alkyl, -CF3, -Cl, -Br, -F, -I, C2-C8 alkenyl, or a combination of these groups; wherein at least one of R1 and R2 contains F; (5) L1 and L2 are each independently selected from substituted or unsubstituted C1 to C2. 15 Alkylene, substituted or unsubstituted C2-C 15 alkenyl, substituted or unsubstituted C2-C 15 alkyne group, substituted or unsubstituted C2-C 10 Etheryl group, substituted or unsubstituted aryl group with 6 to 12 ring atoms, substituted or unsubstituted aryloxy group with 6 to 12 ring atoms, substituted or unsubstituted arylthio group with 6 to 12 ring atoms, substituted or substituted -(CH2) m1 CO(CH2) m2 -, or substituted -(CH2) m3 NHCO(CH2) m4 -, or substituted -(CH2) m5 CONH(CH2) m6 -, or substituted -(CH2) m7 COO(CH2) m8 - One or more combinations of the following, wherein m1 to m8 are each independently selected from integers from 1 to 10; (6) L1 and L2 are each independently selected from substituted or unsubstituted C1 to C2. 10 Alkylene, substituted or unsubstituted C2-C 10 alkenyl, substituted or unsubstituted C2-C 10 Alynyl group, substituted or unsubstituted C2-C8 etheryl group, substituted or unsubstituted aryl group with 6-10 ring atoms, substituted or unsubstituted aryloxy group with 6-10 ring atoms, substituted or unsubstituted arylthio group with 6-10 ring atoms, substituted or substituted -(CH2) group. m1 CO(CH2) m2 -, or substituted -(CH2) m3 NHCO(CH2) m4 -, or substituted -(CH2) m5 CONH(CH2) m6 -, or substituted -(CH2) m7 COO(CH2) m8 - One or more combinations of the following, wherein m1 to m8 are each independently selected from integers from 1 to 8; (7) L1 and L2 are each independently selected from one or more combinations of substituted or unsubstituted C1-C8 alkylene, substituted or unsubstituted C2-C8 alkenylene, substituted or unsubstituted C2-C8 alkynylene, substituted or unsubstituted C2-C5 etherylene, and substituted or unsubstituted arylene with 6 to 10 ring atoms; (8) L1 and L2 are each independently selected from one or more combinations of substituted or unsubstituted C1-C5 alkylene, substituted or unsubstituted C2-C5 alkenylene, and substituted or unsubstituted C2-C5 alkynylene; (8) L1 and L2 are each independently selected from one or more than two combinations of substituted or unsubstituted C1-C5 alkylene, substituted or unsubstituted C2-C5 alkenylene, and substituted or unsubstituted C2-C5 alkynylene; (9) R1, R2, L1, L2, the substituted substituent includes halogen, hydroxyl, nitro, cyano, isocyano, silyl, C1-C 10 alkyl, C1-C 10 alkoxy, C1-C 10 alkylthio, aryl of 6 to 30 ring atoms, aryloxy of 6 to 30 ring atoms, arylthio of 6 to 30 ring atoms one or more; (10) In R1, R2, L1, and L2, the substituted substituent includes one or more of halogen, hydroxyl, nitro, cyano, isocyano, silyl, C1-C5 alkyl, C1-C5 alkoxy, C1-C5 alkylthio, aryl having 6 to 15 ring atoms, aryloxy having 6 to 15 ring atoms, and arylthio having 6 to 15 ring atoms.

8. The preparation method of claim 6, wherein a mass ratio of the fluorine-containing organic acid to the quantum dots is 1:(1-10); and / or a concentration of the quantum dots in the mixed solution is in a range of 5-30 mg / mL; and / or an end group of at least one of R1 and R2 is -CF3; and / or the fluorine-containing organic acid includes one or more of (CF3CH2)2POOH, (CF3CH2CH2)2POOH, (CF3CH2CH2CH2CH2CH2)2POOH, and (CF3CF3CF3C)2POOH; and / or an average particle size of the quantum dots is in a range of 5-20 nm; and / or the first solvent includes one or more of a non-polar solvent and a polar solvent, wherein the non-polar solvent includes n-octane, iso-octane, n-hexane, cyclohexane, ethyl acetate, benzene, toluene, chloroform, carbon tetrachloride, dichloromethane, dichloroethane, carbon disulfide, and the polar solvent includes one or more of dimethyl ether, tetraethylene glycol dimethyl ether, propylene glycol methyl ether acetate, formamide, trifluoroacetic acid, dimethyl sulfoxide, acetonitrile, N,N-dimethylformamide, hexamethylphosphoramide, methanol, acetic acid, ethanol, isopropanol, pyridine, tetramethylethylenediamine, acetone, triethylamine, n-butanol, dioxane, tetrahydrofuran, methyl formate, tributylamine, methylethyl ketone, trioctylamine, dimethyl carbonate, diethyl ether, isopropyl ether, n-butyl ether, trichloroethylene, and diphenyl ether. including an anode, a light-emitting layer, and a cathode which are sequentially stacked, wherein the light-emitting layer is a first thin film, and the first thin film includes the composite material of any one of claims 1-5; or the light-emitting layer is a second thin film, and the second thin film includes a light-emitting thin film and a first interface layer disposed between the light-emitting thin film and the anode and / or a second interface layer disposed between the light-emitting thin film and the cathode, wherein the light-emitting thin film includes quantum dots or the composite material of any one of claims 1-5, and a material of the first interface layer and a material of the second interface layer each independently include the fluorine-containing organic acid used in the preparation method of any one of claims 6-8.

10. The light-emitting device of claim 9, wherein The quantum dots include one or more of single-structure quantum dots, core-shell quantum dots including one or more shell layers, and perovskite semiconductor materials, the materials of the single-structure quantum dots, the core materials of the core-shell quantum dots, and the shell layer materials of the core-shell quantum dots are independently selected from one or more of II-VI compounds, IV-VI compounds, III-V compounds, and I-III-VI compounds, the II-VI compounds include one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe, the IV-VI compounds include one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe, the III-V compounds include one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb, the I-III-VI compounds include one or more of CuInS2, CuInSe2, and AgInS2, the perovskite semiconductor materials include doped or non-doped inorganic perovskite semiconductors or organic-inorganic hybrid perovskite semiconductors, the inorganic perovskite semiconductors have a general structure of AMX3, where A is a Cs + ion, M is a divalent metal cation including Pb 2+ , Sn 2+ , Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ Ge 2+ Yb 2+ Eu 2+ one or more of Cl - Br - I - ; the structure general formula of the organic-inorganic hybrid perovskite type semiconductor is BMX3, wherein B is an organic amine cation, including CH3(CH2) n-2 NH3 + or [NH3(CH2) n NH3] 2+ , wherein n > 2, M is a divalent metal cation, including one or more of Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ Ge 2+ Yb 2+ Eu 2+ one or more of Cl - Br - I - ; and / or a thickness of the first thin film is in a range of 5-30 nm; and / or a thickness of the light-emitting thin film is in a range of 5-30 nm; and / or 9. A light-emitting device, characterized in that, a thickness of the first interface layer and a thickness of the second interface layer are each independently in a range of 1-2 nm. ​ ​ ​ ​ ​ ​ 11. The light-emitting device of claim 9, wherein: the anode and the cathode each independently comprise a doped metal oxide particle electrode, a composite electrode, a graphene electrode, a carbon nanotube electrode, a metal element electrode or an alloy electrode, the doped metal oxide particle electrode comprises one or more of indium-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, indium-doped zinc oxide, magnesium-doped zinc oxide and aluminum-doped magnesium oxide, the composite electrode comprises one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS or ZnS / Al / ZnS, the metal element electrode comprises one or more of Ag, Al, Cu, Mo, Au, Pt, Ca, Mg and Ba; and / or the light-emitting device further comprises an electron transport layer between the light-emitting layer and the cathode, and further, when the light-emitting layer comprises a second interface layer, the second interface layer is between the electron transport layer and the light-emitting film, the electron transport layer comprises one or more of inorganic electron transport materials and organic electron transport materials, the inorganic electron transport materials comprise one or more of first doped metal oxide particles, first non-doped metal oxide particles, IIB-VIA group semiconductor materials, IIIA-VA group semiconductor materials and IB-IIIA-VIA group semiconductor materials, the first non-doped metal oxide particles comprise one or more of ZnO, TiO2, SnO2, ZrO2 and Ta2O5, the metal oxide in the first doped metal oxide particles comprises one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5 and Al2O3, the doping elements in the first doped metal oxide particles comprise one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce and In, the IIB-VIA group semiconductor materials comprise one or more of ZnS, ZnSe and CdS, the IIIA-VA group semiconductor materials comprise one or more of InP and GaP, the IB-IIIA-VIA group semiconductor materials comprise one or more of CuInS and CuGaS, the organic electron transport materials comprise one or more of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene-containing compounds and hydroxyquinoline compounds; and / or The light-emitting device further comprises a hole transport layer between the anode and the light-emitting layer, and further, when the light-emitting layer comprises a first interface layer, the first interface layer is between the hole transport layer and the light-emitting film, the material of the hole transport layer comprises one or more of inorganic hole transport material and organic hole transport material, the inorganic hole transport material comprises one or more of second doped metal oxide particles, second non-doped metal oxide particles, metal sulfide, metal selenide and metal nitride, the metal oxide in the second doped metal oxide particles and the metal oxide in the second non-doped metal oxide particles each independently comprises one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, V2O5, the doping element in the second doped metal oxide particles comprises one or more of Mo, W, Ni, Cr, Cu, V, the metal sulfide comprises one or more of CuS, MoS3, WS3, the metal selenide comprises one or more of MoSe3, WSe3, and the metal nitride comprises P-type gallium nitride;The organic hole transport material includes one or more of 4,4'-N,N'-dicarbazolyl-biphenyl, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4"-diamine, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine, poly(N,N'bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine), N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro, N,N'-di(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-tris(N-carbazolyl)-triphenylamine, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-buty lphenyl)benzidine)], poly(N-vinylcarbazole) and derivatives thereof, N,N'-di(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4-4'-diamine, Spiro NPB, poly(phenylenevinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene], poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene], 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene, 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)benzidine], 1,3-bis(carbazol-9-yl)benzene, polyaniline, polypyrrole, poly(p-phenylenevinylene), aromatic tertiary amine, polynuclear aromatic tertiary amine, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compound, N,N,N',N'-tetraarylbenzidine, PEDOT:PSS and derivatives thereof, polymethacrylate and derivatives thereof, poly(9,9-octylfluorene) and derivatives thereof, poly(spirofluorene) and derivatives thereof, doped graphene, non-doped graphene, one or more of C60.

12. A method for fabricating a light-emitting device, characterized in that, comprising the steps of: providing a first electrode; preparing a light-emitting layer on the first electrode, the light-emitting layer comprising quantum dots and fluorine-containing organic acid roots; preparing a second electrode on the light-emitting layer to obtain a light-emitting device; The first electrode is an anode and the second electrode is a cathode, or the first electrode is a cathode and the second electrode is an anode. The light-emitting layer is a first film, and the first film comprises the composite material according to any one of claims 1-5; or the light-emitting layer is a second film, and the second film comprises a light-emitting film and a first interface layer arranged between the light-emitting film and the anode and / or a second interface layer arranged between the light-emitting film and the cathode, wherein the light-emitting film comprises quantum dots or the composite material according to any one of claims 1-5, and the material of the first interface layer and the material of the second interface layer each independently comprises the fluorine-containing organic acid used in the preparation method according to any one of claims 6-8.

13. The production method according to claim 12, wherein The preparation method of the first film comprises: providing a dispersion liquid comprising the quantum dots, the fluorine-containing organic acid and a second solvent; depositing the dispersion liquid to obtain the first film.

14. The preparation method according to claim 13, wherein the concentration of the quantum dots in the dispersion liquid ranges from 5 to 30 mg / mL; and / or the mass ratio of the fluorine-containing organic acid to the quantum dots in the dispersion liquid is 1:(1-10); and / or after the dispersion liquid is arranged on the first electrode and before the first film is obtained, the method further comprises first annealing, wherein the temperature of the first annealing ranges from 80 to 160 ℃, and the time of the first annealing ranges from 5 to 60 min; and / or the second solvent comprises one or more of a non-polar solvent and a polar solvent, wherein the non-polar solvent comprises n-octane, iso-octane, n-hexane, cyclohexane, ethyl acetate, benzene, toluene, chloroform, carbon tetrachloride, dichloromethane, dichloroethane, carbon disulfide, and the polar solvent comprises one or more of dimethyl ether, tetraethylene glycol dimethyl ether, propylene glycol methyl ether acetate, formamide, trifluoroacetic acid, dimethyl sulfoxide, acetonitrile, N,N-dimethylformamide, hexamethylphosphoramide, methanol, acetic acid, ethanol, isopropanol, pyridine, tetramethyl ethylenediamine, acetone, triethylamine, n-butanol, dioxane, tetrahydrofuran, methyl formate, tributylamine, methyl ethyl ketone, trioctylamine, dimethyl carbonate, diethyl ether, isopropyl ether, n-butyl ether, trichloroethylene, diphenyl ether.

15. The preparation method according to claim 12, wherein the preparation method of the light-emitting film comprises: providing a first quantum dot solution comprising quantum dots and a third solvent, and depositing the first quantum dot solution to obtain the light-emitting film; or providing a second quantum dot solution comprising quantum dots, a fluorine-containing organic acid and a third solvent, and depositing the second quantum dot solution to obtain the light-emitting film; and / or ​ The preparation method of the first interface layer comprises: providing a first fluorine-containing organic acid solution comprising a first fluorine-containing organic acid and a fourth solvent, and depositing the first fluorine-containing organic acid solution to obtain the first interface layer, wherein the first fluorine-containing organic acid is the fluorine-containing organic acid used in the preparation method of any one of claims 6-8; and / or The preparation method of the second interface layer comprises: providing a second fluorine-containing organic acid solution comprising a second fluorine-containing organic acid and a fifth solvent, and depositing the second fluorine-containing organic acid solution to obtain the second interface layer, wherein the second fluorine-containing organic acid is the fluorine-containing organic acid used in the preparation method of any one of claims 6-8.

16. The preparation method of claim 15, wherein, In the first quantum dot solution, the concentration of the quantum dots ranges from 5 to 30 mg / mL; and / or In the second quantum dot solution, the concentration of the quantum dots ranges from 5 to 30 mg / mL; and / or In the second quantum dot solution, the mass ratio of the fluorine-containing organic acid to the quantum dots is 1:(1-10); and / or In the first fluorine-containing organic acid solution, the concentration of the first fluorine-containing organic acid ranges from 2 to 20 mg / mL; and / or In the second fluorine-containing organic acid solution, the concentration of the second fluorine-containing organic acid ranges from 2 to 20 mg / mL; and / or The first fluorine-containing organic acid and the second fluorine-containing organic acid are the same or different; and / or After depositing the first quantum dot solution and before obtaining the light-emitting thin film, a second annealing is further included, wherein the temperature of the second annealing ranges from 80 to 180°C, and the time of the second annealing ranges from 1 to 30 min; and / or After depositing the second quantum dot solution and before obtaining the light-emitting thin film, a third annealing is further included, wherein the temperature of the third annealing ranges from 80 to 160°C, and the time of the second annealing ranges from 5 to 60 min; and / or After depositing the first fluorine-containing organic acid solution and before obtaining the first interface layer, a first heat treatment is further included, wherein the temperature of the first heat treatment is 80-150°C, and the time of the first heat treatment is 10-100 min; and / or After depositing the second fluorine-containing organic acid solution and before obtaining the second interface layer, a second heat treatment is further included, wherein the temperature of the second heat treatment is 80-150°C, and the time of the second heat treatment is 10-100 min; and / or The third solvent, the fourth solvent and the fifth solvent each independently include one or more of non-polar solvents and polar solvents, wherein the non-polar solvents include n-octane, iso-octane, n-hexane, cyclohexane, ethyl acetate, benzene, toluene, chloroform, carbon tetrachloride, dichloromethane, dichloroethane, carbon disulfide, and the polar solvents include one or more of dimethyl ether, tetraethylene glycol dimethyl ether, propylene glycol methyl ether acetate, formamide, trifluoroacetic acid, dimethyl sulfoxide, acetonitrile, N,N-dimethylformamide, hexamethylphosphoramide, methanol, acetic acid, ethanol, isopropanol, pyridine, tetramethyl ethylenediamine, acetone, triethylamine, n-butanol, dioxane, tetrahydrofuran, methyl formate, tributylamine, methyl ethyl ketone, trioctylamine, dimethyl carbonate, diethyl ether, isopropyl ether, n-butyl ether, trichloroethylene, diphenyl ether.

17. The preparation method of claim 12, wherein, the first electrode is an anode and the second electrode is a cathode, and the preparing the light-emitting layer on the first electrode comprises sequentially preparing a hole transport layer and a light-emitting layer on the first electrode; or the first electrode is an anode and the second electrode is a cathode, and the preparing the second electrode on the light-emitting layer comprises sequentially preparing an electron transport layer and a second electrode on the light-emitting layer; or the first electrode is a cathode and the second electrode is an anode, and the preparing the light-emitting layer on the first electrode comprises sequentially preparing an electron transport layer and a light-emitting layer on the first electrode; or the first electrode is a cathode and the second electrode is an anode, and the preparing the second electrode on the light-emitting layer comprises sequentially preparing a hole transport layer and a second electrode on the light-emitting layer.

18. A display device comprising: The light-emitting device comprising the light-emitting device of any one of claims 9-11, or the light-emitting device prepared by the preparation method of any one of claims 12-17.

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