Quantum dot composition, preparation method and display device

Abstract

The invention provides a quantum dot composition, a preparation method and a display device. The quantum dot combination comprises a quantum dot ligand and a cross-linking agent, one of the ligand and the cross-linking agent comprises an acrylate compound, the other one of the ligand and the cross-linking agent comprises a metal organic compound, and the metal organic compound is configured to be cracked to generate free radicals under the illumination condition. And carrying out a cross-linking reaction with the acrylate compound.

Description

Technical Field

[0001] The present invention relates to the field of display technologies, and particularly to a quantum dot composition, a preparation method thereof, and a display device. Background Art

[0002] Quantum dot light-emitting devices have a development history of more than twenty years. In recent years, with the continuous improvement of the performance of quantum dot materials and the continuous optimization of device fabrication processes, the efficiency and lifespan of quantum dot light-emitting diodes (QLEDs) have been greatly improved. The external quantum efficiencies (EQEs) of red, green, and blue devices can reach 25%, 20%, and 20% respectively, and the lifespans of red and green devices have also reached the mass production level. In terms of QLED patterning, currently, inkjet printing and lithography are two different paths to achieve quantum dot patterning. One important drawback of the former is that it is limited by inkjet printing equipment and difficult to break through the resolution limit.

[0003] Therefore, the current quantum dot composition, preparation method, and display device still need to be improved. Summary of the Invention

[0004] An object of the present application is to provide a quantum dot composition. The composition contains a ligand with photosensitive properties and capable of coordinating with quantum dots. Utilizing its crosslinkable property under light irradiation, it can achieve patterning of quantum dots with different emission colors such as red, green, and blue through photolithographic patterning. This photolithography process can meet various different resolution requirements of QLEDs, thereby simply realizing controllable patterning of the light-emitting layer and diversifying the product form.

[0005] To achieve the above object, according to one aspect of the present invention, a quantum dot composition is provided. The composition includes quantum dots, a ligand, and a crosslinking agent. One of the ligand and the crosslinking agent includes an acrylate compound, and the other of the ligand and the crosslinking agent includes a metal-organic compound. The metal-organic compound is configured to generate free radicals under light irradiation conditions and undergo a crosslinking reaction with the acrylate compound.

[0006] Further, the ligand has a quantum dot coordination group and a photosensitive group. The quantum dot coordination group and the photosensitive group are connected. The photosensitive group includes a double bond group in the acrylate compound or a free radical generating group in the metal-organic compound. The quantum dot coordination group includes at least one of a mercapto group, an amino group, a carboxyl group, a sulfonic acid group, a phosphoric acid group, and a phosphoxy group.

[0007] Further, the metal-organic compound has a structure satisfying the following formula:

[0008]

[0009] Wherein M is a metal that can generate free radicals by cleavage under light conditions;

[0010] Rn and Rm are each independently at least one of an alkyl group, an ester group, an aryl group, a mercapto group, a carboxyl group, and an amino group;

[0011] Both p and q are integers greater than or equal to 1 and q + p ≤ 4.

[0012] Furthermore, the metal-organic compound satisfies: when M is Ge or Ir and at least one of q and p is greater than 1, multiple Rn are the same or different, and multiple Rm are the same or different; when Rn contains an acyl group, the number of q is not greater than 2.

[0013] Furthermore, the metal-organic compound includes:

[0014] and

[0015] at least one of Formula II;

[0016] Wherein, L 1 ~L 8 are each independently selected from a single bond, O, a substituted or unsubstituted C1-11 alkylene group, a substituted or unsubstituted C1-8 alkoxy group, a substituted or unsubstituted C2-6 alkenylene group, a substituted or unsubstituted C2-6 alkenyloxy group, a substituted or unsubstituted C2-6 alkynylene group, a substituted or unsubstituted C2-6 alkynyloxy group, a substituted or unsubstituted C3-8 cycloalkylene group, a substituted or unsubstituted C3-8 epoxyalkylene group, a substituted or unsubstituted C6-12 arylene group, or a substituted or unsubstituted C6-12 heteroarylene group;

[0017] R 1 ~R 8 are each independently selected from H, a substituted or unsubstituted C1-11 alkyl group, a substituted or unsubstituted C1-8 alkoxy group, a substituted or unsubstituted C2-6 alkenyl group, a substituted or unsubstituted C2-6 alkenyloxy group, a substituted or unsubstituted C2-6 alkynyl group, a substituted or unsubstituted C2-6 alkynyloxy group, a substituted or unsubstituted C3-8 cycloalkyl group, a substituted or unsubstituted C3-8 epoxyalkyl group, a substituted or unsubstituted C6-12 aryl group, a substituted or unsubstituted C6-12 heteroaryl group, or a quantum dot coordination group; and at least one of R 1 ~R 4 is a quantum dot coordination group, and the quantum dot coordination group includes at least one of a mercapto group, an amino group, a carboxyl group, a sulfonic acid group, a phosphoric acid group, and a phosphoxy group.

[0018] Furthermore, the metal-organic compound is:

[0019] and

[0020] at least one of

[0021] wherein, L 9 ~L 12 are respectively selected from C1-11 alkylene groups;

[0022] L 9 ~L 12 and R 9 ~R 16 are respectively selected from C1-11 alkyl groups;

[0023] A 1 is a mercapto group, an amino group or a carboxyl group,

[0024] A 2 ~A 4 at least one of them is a mercapto group, an amino group or a carboxyl group.

[0025] Furthermore, the metal-organic compound is

[0026] and at least one of

[0027] Furthermore, the acrylate compound is as shown in Formula III:

[0028]

[0029] wherein, L 13 is selected from a single bond or a C1-11 alkylene group;

[0030] R 17 is selected from H, a C1-11 alkyl group or the quantum dot coordination group.

[0031] Furthermore, the acrylate compound is selected from at least one of methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate and at least one of

[0032] In another aspect of the present application, the present application provides a method for patterning a quantum dot light-emitting layer. The method includes preparing a quantum dot initial film by using the film-forming solution, where the film-forming solution contains the composition described above; performing a light irradiation treatment on a predetermined area of the quantum dot initial film; and performing a developing treatment on the quantum dot initial film after the light irradiation treatment to remove the quantum dot initial film in the non-predetermined area.

[0033] Further, the solvent used to configure the film-forming solution includes at least one of toluene, n-hexane, n-octane, tetrahydrofuran, N,N-dimethylformamide, N-methylformamide, formamide, dimethyl sulfoxide, acetonitrile, and acetone; and / or

[0034] The light treatment is ultraviolet light with a wavelength of 800 - 1000 nm and a power of 1 - 50 W.

[0035] In another aspect of the present application, the present application proposes a display device. The display device includes a substrate and a quantum dot light-emitting diode located on the substrate, and the material forming the quantum dot light-emitting diode includes the composition described above.

[0036] Further, the light-emitting layer of the quantum dot light-emitting diode includes at least one of the following structures:

[0037]

[0038] Wherein, QD is the quantum dot, and each group in Formulas IV - VI has the meaning described above.

[0039] Further, the light-emitting layer includes at least one of the following compounds:

[0040]

[0041] And at least one of Description of the Drawings:

[0042] Figure 1 Shows a schematic structural diagram of a light-emitting diode according to an example of the present application. Detailed Description of the Embodiments

[0043] In order to make the technical solutions and advantages in the embodiments of the present application clearer, the following further describes the exemplary embodiments of the present application in detail with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than an exhaustive list of all embodiments. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0044] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of an icon to another component, these terms are used in this specification only for convenience, for example, according to the directions in the examples described in the drawings. It can be understood that if the device of the icon is turned upside down, the component described as "upper" will become the component described as "lower". When a structure is "on" another structure, it may mean that a structure is integrally formed on another structure, or that a structure is "directly" disposed on another structure, or that a structure is "indirectly" disposed on another structure through another structure.

[0045] The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "comprising" and "having" are used to mean an open inclusion and mean that there may be additional elements / components / etc. in addition to the listed elements / components / etc.; the terms "first" and "second" are used only as labels and are not a limitation on the quantity of their objects.

[0046] In this application, unless otherwise specified, the meanings of the functional groups contained in a compound have the meanings of the respective functional groups as generally understood in the art. For example, the term "C1-C11 alkyl" includes, but is not limited to, straight-chain or branched-chain alkyl groups containing 1-11 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, isohexyl, heptyl, octyl, nonyl, decyl or undecyl, etc. The term "C1-C8 alkoxy" includes, but is not limited to, straight-chain or branched-chain alkoxy groups containing 1-8 carbon atoms, such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, n-pentyloxy, isopentyloxy, n-hexyloxy, heptyloxy or octyloxy, etc. The term "C2-C6 alkenyl" includes, but is not limited to, alkenyl groups containing 2-6 carbon atoms and having an unsaturation degree of 1 or more, such as vinyl, propenyl, butenyl, pentenyl or hexenyl, etc. The term "C2-C6 alkynyl" includes, but is not limited to, alkynyl groups containing 2-6 carbon atoms and having an unsaturation degree of 2 or more, such as ethynyl, propynyl, butynyl, pentynyl or hexynyl, etc. The term "C3-C8 cycloalkyl" includes, but is not limited to, saturated cycloalkyl groups containing 3-6 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl, etc. The term "C6-C12 aryl" includes, but is not limited to, aromatic groups containing at least one benzene ring structure and having 6-12 carbon atoms, such as phenyl or naphthyl, etc.

[0047] In one aspect of the present invention, a quantum dot composition is provided. The composition includes quantum dots, ligands, and crosslinking agents. One of the ligand and the crosslinking agent includes an acrylate compound, and the other includes a metal-organic compound. The metal-organic compound is configured to generate free radicals under light illumination conditions and undergo a crosslinking reaction with the acrylate compound. Thus, the composition can form a crosslinked structure containing quantum dots in the crosslinked product under light illumination conditions. The quantum dots at the formed crosslinked structure are equivalent to being patterned, that is, the patterning of the quantum dot film layer can be controllably controlled. Furthermore, the light-emitting layer prepared using this composition can meet various different resolution requirements of QLEDs, enabling diversification of product forms.

[0048] In this composition, the ligand contains a coordination fragment capable of coordinating with the quantum dots, that is, a quantum dot coordination group, thereby realizing the binding of the ligand and the quantum dots. At the same time, the ligand also contains a photosensitive group, and the quantum dot coordination group and the photosensitive group are connected, thereby realizing crosslinking under light illumination conditions. In some examples, the photosensitive group includes, but is not limited to, fragments capable of polymerization such as free radicals. For example, the photosensitive group may specifically include a double bond group in an acrylate compound or a free radical generating group in a metal-organic compound. The composition can form various polymerizable fragments under light illumination conditions, and the above polymerizable fragments contain coordination fragments and the quantum dots coordinated therewith. Then, through polymerization methods such as crosslinking, the "fixation" of the quantum dots is achieved, that is, the quantum dots are fixed at the positions where the crosslinked structure is formed.

[0049] In some examples, the quantum dot coordination group includes at least one of a mercapto group, an amino group, a carboxyl group, a sulfonic acid group, a phosphoric acid group, and a phosphoxy group. One of the ligand and the crosslinking agent includes a metal-organic compound, and the other includes an acrylate compound. The quantum dots can form a coordination bond with the metal-organic compound or with the acrylate compound.

[0050] Taking the free radical polymerization of this composition under light illumination as an example, the crosslinking agent generates free radicals that do not coordinate with the quantum dots, and the ligand plays a role similar to a "bridge" to generate free radicals connected to the quantum dots. The two free radicals react to form a crosslinked product containing quantum dots. The crosslinked structure formed in this way has a relatively moderate steric hindrance during crosslinking, the degree of crosslinking is controllable, and the formed crosslinked structure can better fix the quantum dots.

[0051] In some examples, the metal-organic compound has a structure satisfying the following formula:

[0052]

[0053] where M is a metal that can generate free radicals by cleavage under light illumination conditions;

[0054] Rn and Rm are each independently at least one of an alkyl group, an ester group, an aryl group, a mercapto group, a carboxyl group, and an amino group;

[0055] Both p and q are integers greater than or equal to 1 and q + p ≤ 4.

[0056] The above metal-organic compound can be cleaved under light irradiation to generate free radicals, and react with an acrylate compound to form a cross-linked structure. Specifically, the metal M of the metal-organic compound can be Ge or Ir. When at least one of q and p is greater than 1, multiple Rn are the same or different, and multiple Rm are the same or different. When Rn contains an acyl group, the number of q is not more than 2. is a photosensitive group capable of generating free radicals, and can break the chain between M and the carbonyl group to generate two free radicals. Rn or Rm can be a quantum dot coordination group, but Rn and Rm are not both quantum dot coordination groups at the same time.

[0057] In some specific examples, taking M as Ge as an example, the metal-organic compound can include at least one of the compounds shown in Formula I and the compounds shown in Formula II:

[0058]

[0059]

[0060] In the above formula, L1 to L8 are each independently selected from a single bond, a substituted or unsubstituted C1-11 alkylene group, a substituted or unsubstituted C1-8 alkoxy group, a substituted or unsubstituted C2-6 alkenylene group, a substituted or unsubstituted C2-6 alkenyloxy group, a substituted or unsubstituted C2-6 alkynylene group, a substituted or unsubstituted C2-6 alkynyloxy group, a substituted or unsubstituted C3-8 cycloalkylene group, a substituted or unsubstituted C3-8 epoxyalkylene group, a substituted or unsubstituted C6-12 arylene group, or a substituted or unsubstituted C6-12 heteroarylene group. R1 to R8 are each independently selected from H, a substituted or unsubstituted C1-11 alkyl group, a substituted or unsubstituted C1-8 alkoxy group, a substituted or unsubstituted C2-6 alkenyl group, a substituted or unsubstituted C2-6 alkenyloxy group, a substituted or unsubstituted C2-6 alkynyl group, a substituted or unsubstituted C2-6 alkynyloxy group, a substituted or unsubstituted C3-8 cycloalkyl group, a substituted or unsubstituted C3-8 epoxyalkyl group, a substituted or unsubstituted C6-12 aryl group, a substituted or unsubstituted C6-12 heteroaryl group, or a quantum dot coordination group. Specifically, the quantum dot coordination group is selected from a mercapto group, an amino group, a carboxyl group, a sulfonic acid group, a phosphoric acid group, or a phosphoxy group.

[0061] In the present application, the substituted group can include, but is not limited to, a group obtained by substituting H in the corresponding group with a group such as a halogen, a hydroxyl group, a carboxyl group, an amino group, a nitro group, a sulfonic acid group, or a mercapto group.

[0062] Specifically, L1, L5, and L6 are each independently selected from a substituted or unsubstituted C2-6 alkenylene, a substituted or unsubstituted C2-6 alkenyloxy, a substituted or unsubstituted C2-6 alkynylene, a substituted or unsubstituted C2-6 alkynyloxy, a substituted or unsubstituted C6-12 arylene, or a substituted or unsubstituted C6-12 heteroarylene.

[0063] Specifically, L2, L3, L4, L7, and L8 are each independently selected from a substituted or unsubstituted C1-11 alkylene, a substituted or unsubstituted C1-8 alkoxy, a substituted or unsubstituted C3-8 cycloalkylene, or a substituted or unsubstituted C3-8 epoxyalkylene.

[0064] According to an embodiment of the present invention, R1 to R4 are each independently selected from H, a substituted or unsubstituted C1-11 alkyl, a substituted or unsubstituted C1-8 alkoxy, a substituted or unsubstituted C3-8 epoxyalkyl, or a quantum dot coordination group. In some examples, and, R1 is selected from a quantum dot coordination group, or at least one of R2 to R4 is selected from a quantum dot coordination group.

[0065] Specifically, R5 to R8 are each independently selected from H, a substituted or unsubstituted C1-11 alkyl, a substituted or unsubstituted C1-8 alkoxy, or a substituted or unsubstituted C3-8 epoxyalkyl. More specifically, R5 to R8 are each independently selected from H, a substituted or unsubstituted C1-11 alkyl.

[0066] More specifically, L1, L5, and L6 are each independently selected from a substituted or unsubstituted C6-12 arylene.

[0067] More specifically, L2, L3, L4, L7, and L8 are each independently selected from a substituted or unsubstituted C1-11 alkylene.

[0068] In a specific example, R1 to R4 are each independently selected from H, a substituted or unsubstituted C1-11 alkyl, or a quantum dot coordination group, and, R1 is selected from a quantum dot coordination group, or, R2 to R4 are all selected from a quantum dot coordination group.

[0069] In some examples, when the M element in the metal-organic compound is Ge, free radicals can be generated under light conditions according to the chemical formula shown below:

[0070]

[0071] The above compounds each contain an acylgermyl photosensitive functional group, which can undergo a cleavage reaction (or fragmentation reaction) between the acyl group and the germyl group under light irradiation (such as ultraviolet light), forming acyl radicals and germyl radicals, and then can initiate crosslinking reactions of molecules containing functional groups such as double bonds (such as the above monomers, the compounds shown in Formula III), triple bonds, etc. At least one of the compounds shown in Formula I, the compounds shown in Formula II, and acrylate compounds contains a quantum dot coordination group. This quantum dot coordination group can coordinate with quantum dots. The acrylate compounds can undergo double bond cleavage under the initiation of the above free radicals. Therefore, after the crosslinking reaction of the acyl radicals, germyl radicals, and polymerizable groups generated by the acrylate compounds, the crosslinked product contains quantum dots, that is, crosslinked quantum dots can be formed. Thus, the photolithographic patterning of the light-emitting layer can be achieved using this composition. This lithography process can meet various different resolution requirements of QLEDs, making the product forms diverse.

[0072] In some examples, as shown in Formula I for the metal-organic compound, the compound shown in Formula I contains a quantum dot coordination group. That is, at least one of R1 to R4 is selected from quantum dot coordination groups. Thus, the compound shown in Formula I can bind quantum dots. Under light irradiation, the acylgermyl group in Formula I undergoes cleavage to form acyl radicals and germyl radicals, initiating the opening of the double bonds on the acrylate compounds to undergo crosslinking. Finally, through development, the composition in the exposed area remains, and the composition in the non-exposed area is removed, forming a patterned quantum dot light-emitting layer.

[0073] In some examples, the metal-organic compound contains a quantum dot coordination group, while the acrylate compound does not have a quantum dot coordination group. Specifically, if the compound shown in Formula I contains a quantum dot coordination group, then the composition may or may not contain the compound shown in Formula II. When the composition contains the metal-organic compound shown in Formula II, the metal-organic compound shown in Formula II may or may not contain a quantum dot coordination group.

[0074] Specifically, the metal-organic compound may include at least one of the following compounds:

[0075]

[0076] Among them, L9 to L12 are each independently selected from C1-11 alkylene groups; L9 to L12, R9 to R16 are each independently selected from C1-11 alkyl groups; A1 to A4 are each independently selected from a mercapto group, an amino group, or a carboxyl group.

[0077] According to the embodiments of the present invention, the metal-organic compound includes at least one of the following compounds:

[0078]

[0079] Those skilled in the art can choose a familiar synthetic route to synthesize the above metal-organic compounds, and the synthesis method of the above metal-organic compounds is not particularly limited. For example, according to an example of the present invention, taking tributylaminobenzoyl germanium (the structural formula is shown below) as an example, its synthetic route is described as follows:

[0080]

[0081] First, react tetrabutylaminogermanium with tert-butyllithium (LiOtBu) to remove one molecule of butylaminotert-butyl ether, generating lithium tributylaminogermanium. Then react it with a benzoyl chloride derivative to generate tributylaminobenzoyl germanium and lithium chloride, obtaining the metal-organic compound.

[0082]

[0083] Those skilled in the art can select appropriate aminogermanium and acyl chloride compounds for synthesis according to the specific composition of the metal-organic compound to obtain a metal-organic compound with corresponding groups.

[0084] The acrylate compound in the composition may include a compound represented by Formula III;

[0085]

[0086] Among them, L13 is selected from a single bond or a C1-11 alkylene group; R17 is selected from H, a C1-11 alkyl group, or a quantum dot coordination group, and the quantum dot coordination group is selected from a mercapto group, an amino group, a carboxyl group, a sulfonic acid group, a phosphoric acid group, or a phosphoxy group.

[0087] As described above, in the composition proposed in the present application, it is possible to choose to coordinate a metal-organic compound with a quantum dot, or to coordinate an acrylate compound with a quantum dot. In some examples, in order to enable the polymerizable fragments (radicals generated by light and fragments generated after the double bond of the acrylate compound breaks) in the composition to undergo a cross-linking reaction under controllable steric hindrance, it is preferred that one of the metal-organic compound and the acrylate compound contains a quantum dot coordination group.

[0088] In some examples, when the acrylate compound contains a quantum dot coordination group, R17 can be selected from the quantum dot coordination group.

[0089] In some examples, in order to enable the crosslinking reaction to proceed under more appropriate steric hindrance and control the number of quantum dots contained in the formed crosslinked structure, the number of quantum dot ligands in each compound capable of coordinating with quantum dots in the composition can be controlled. Specifically, the number of quantum dot ligands in each acrylate compound can be no more than 1, and the number of quantum dot ligands contained in each metal-organic compound can be no more than 2.

[0090] According to an embodiment of the present invention, the acrylate compound may be selected from methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate or

[0091]

[0092] In the present application, the quantum dots in the composition are not particularly limited. For example, the quantum dots may be selected from II-VI group nanocrystals, III-V group nanocrystals, IV-VI group nanocrystals, core-shell structure quantum dot nanocrystals, metal nanocrystals or metal oxide nanocrystals.

[0093] Specifically, the II-VI group nanocrystals are selected from at least one of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, CdxZn 1-x Se, Cd x Zn 1-x S, HgxCd1-xS, HgxCd1-xSe, HgxCd1 -x Te, Hg x Zn 1-x Te, where 0 < x < 1. The III-V group nanocrystals are selected from at least one of InP, InAs, InN, InSb, InAs 1-x Sb x , GaAs, GaN, GaP, GaSb, AlN, AlP, AlAs, where 0 < x < 1. The IV-VI group nanocrystals are selected from at least one of PbS, PbSe, PbTe.

[0094] Specifically, the core-shell structure quantum dot nanocrystals are selected from at least one of CdSe / ZnS, CdSe / CdS, CdTe / CdSe, PbS / CdS, ZnSe / CdS, ZnSe / CdSe, CuInS 2 / CuInS 2 , CuInS 2 / ZnS, HgSe / CdS, HgSe / CdSe, HgSe / CdSe / CdS, Cd 1-x Zn xAt least one of S / ZnS, where 0 < x < 1.

[0095] Specifically, the metal nanocrystals are selected from at least one of Au and FePt.

[0096] Specifically, the metal oxide nanocrystals are selected from at least one of CeO 2 , ZrO 2 , Fe 3 O 4 and so on.

[0097] It should be noted that the specific type of quantum dots in this application can be the quantum dots described above, for example, selected from at least one of II-VI group nanocrystals, III-V group nanocrystals, IV-VI group nanocrystals, core-shell structure quantum dot nanocrystals, metal nanocrystals, and metal oxide nanocrystals.

[0098] In another aspect of the present application, a method for patterning a quantum dot light-emitting layer is proposed. This method uses a film-forming solution to prepare an initial quantum dot film, and the film-forming solution contains the composition described above. Subsequently, a predetermined area of the initial quantum dot film is subjected to light treatment, and the light-treated initial quantum dot film is developed to remove the initial quantum dot film in the non-predetermined area, thereby obtaining a patterned quantum dot light-emitting layer. The film-forming solution used in this method contains all the characteristics and advantages of the aforementioned composition, which will not be elaborated here.

[0099] In a specific embodiment of the present application, a predetermined area of the formed initial quantum dot film can be subjected to light treatment to cause a cross-linking reaction and curing of the initial quantum dot film in the predetermined area. The light-treated initial quantum dot film is developed to remove the initial quantum dot film in the non-predetermined area and obtain a patterned quantum dot film.

[0100] According to an embodiment of the present invention, a film-forming solution can be configured by using a solvent and the quantum dots, acrylate compounds, and metal organic compounds in the aforementioned composition. The solvent includes at least one of toluene, n-hexane, n-octane, tetrahydrofuran, N,N-dimethylformamide, N-methylformamide, formamide, dimethyl sulfoxide, acetonitrile, and acetone.

[0101] According to an embodiment of the present invention, the conditions of the light treatment are not particularly limited. For example, the light is ultraviolet light, the wavelength is 800-1000 nm, and the power is 1-50 W.

[0102] According to an embodiment of the present invention, the quantum dot initial film can be prepared by methods such as coating, spin coating, blade coating, printing, etc. for the mixture. The light treatment of a predetermined area of the quantum dot initial film can be based on a mask plate to perform the light treatment on the predetermined area. The development treatment can be to elute the quantum dot initial film after the light treatment with a solvent to remove the quantum dot initial film in the non-predetermined area.

[0103] This method can simply achieve the patterning of the quantum dot light-emitting layer.

[0104] According to another aspect of the present invention, a display device is proposed. The display device includes a substrate and a quantum dot light-emitting diode located on the substrate. The material for forming the quantum dot light-emitting diode includes the composition described above. Thus, the display device has at least one of the advantages such as being easily patterned, the position of the quantum dot light-emitting diode being controllable, and relatively high production accuracy.

[0105] In one embodiment, referring to Figure 1 , the quantum dot light-emitting diode includes: a quantum dot light-emitting layer 200. The quantum dot light-emitting layer 200 can be located on the substrate 100. For simplicity of illustration, Figure 1 other structures of the quantum dot light-emitting diode, such as an anode, a cathode, and each film layer for improving the light-emitting performance of the diode, such as but not limited to a hole / electron transport layer, a hole / electron blocking layer, etc., are not shown in

[0106] As described above, the material for forming the light-emitting layer of the quantum dot light-emitting diode includes the composition described above. For example, it can be obtained by configuring the foregoing composition into a film-forming solution and performing a patterning process. Thus, the light-emitting layer includes a crosslinked structure containing quantum dots obtained after crosslinking the foregoing composition. Specifically, the crosslinked structure containing quantum dots can include at least one of the compounds shown in Formula IV, the compounds shown in Formula V, and the compounds shown in Formula VI:

[0107]

[0108] Among them, in Formula IV: R1 is selected from a quantum dot coordination group; L1 is selected from a single bond, a substituted or unsubstituted C1-C11 alkylene group, a substituted or unsubstituted C1-C8 alkoxy group, a substituted or unsubstituted C2-C6 alkenylene group, a substituted or unsubstituted C2-C6 alkenyloxy group, a substituted or unsubstituted C2-C6 alkynylene group, a substituted or unsubstituted C2-C6 alkynyloxy group, a substituted or unsubstituted C3-C8 cycloalkyl group, a substituted or unsubstituted C3-C8 epoxyalkyl group, a substituted or unsubstituted C6-C12 aryl group, or a substituted or unsubstituted C6-C12 heteroaryl group; L13 is selected from a single bond or a C1-C11 alkylene group; R17 is selected from H or a C1-C11 alkyl group;

[0109] In Formula V: R2, R3, and R4 are each independently selected from H, substituted or unsubstituted C1-C11 alkyl, substituted or unsubstituted C1-C8 alkoxy, substituted or unsubstituted C2-C6 alkenyl, substituted or unsubstituted C2-C6 alkenyloxy, substituted or unsubstituted C2-C6 alkynyl, substituted or unsubstituted C2-C6 alkynyloxy, substituted or unsubstituted C3-C8 cycloalkyl, substituted or unsubstituted C3-C8 epoxyalkyl, substituted or unsubstituted C6-C12 aryl, substituted or unsubstituted C6-C12 heteroaryl, or a quantum dot coordination group; and at least one of R2-R4 is selected from a quantum dot coordination group; L2, L3, and L4 are each independently selected from a single bond, substituted or unsubstituted C1-C11 alkylene, substituted or unsubstituted C1-C8 alkyleneoxy, substituted or unsubstituted C2-C6 alkenylene, substituted or unsubstituted C2-C6 alkenyleneoxy, substituted or unsubstituted C2-C6 alkynylene, substituted or unsubstituted C2-C6 alkynyleneoxy, substituted or unsubstituted C3-C8 cycloalkylene, substituted or unsubstituted C3-C8 epoxyalkylene, substituted or unsubstituted C6-C12 arylene, or substituted or unsubstituted C6-C12 heteroarylene; L13 is selected from a single bond or C1-C11 alkylene; R17 is selected from H or C1-C11 alkyl;

[0110] In Formula VI: R17 is selected from a quantum dot coordination group; L13 is selected from a single bond or C1-C11 alkylene; L7 and L8 are each independently selected from a single bond, substituted or unsubstituted C1-C11 alkylene, substituted or unsubstituted C1-C8 alkyleneoxy, substituted or unsubstituted C2-C6 alkenylene, substituted or unsubstituted C2-C6 alkenyleneoxy, substituted or unsubstituted C2-C6 alkynylene, substituted or unsubstituted C2-C6 alkynyleneoxy, substituted or unsubstituted C3-C8 cycloalkylene, substituted or unsubstituted C3-C8 epoxyalkylene, substituted or unsubstituted C6-C12 arylene, or substituted or unsubstituted C6-C12 heteroarylene; R7 and R8 are each independently selected from H, substituted or unsubstituted C1-C11 alkyl, substituted or unsubstituted C1-C8 alkoxy, substituted or unsubstituted C2-C6 alkenyl, substituted or unsubstituted C2-C6 alkenyloxy, substituted or unsubstituted C2-C6 alkynyl, substituted or unsubstituted C2-C6 alkynyloxy, substituted or unsubstituted C3-C8 cycloalkyl, substituted or unsubstituted C3-C8 epoxyalkyl, substituted or unsubstituted C6-C12 aryl, substituted or unsubstituted C6-C12 heteroaryl, or a quantum dot coordination group;

[0111] In Formulas IV, V, and VI, QD represents the inorganic part of the crosslinked quantum dots. The quantum dot coordination group is selected from a mercapto group, an amino group, a carboxyl group, a sulfonic acid group, a phosphoric acid group, or a phosphoxy group.

[0112] It should be noted that the specific type of the inorganic part of the crosslinked quantum dots can be the quantum dots described above, such as selected from II-VI group nanocrystals, III-V group nanocrystals, IV-VI group nanocrystals, core-shell structure quantum dot nanocrystals, metal nanocrystals or metal oxide nanocrystals.

[0113] According to an embodiment of the present invention, in Formula IV, L1 is selected from substituted or unsubstituted C6-12 arylene groups;

[0114] In Formula V, R2 to R4 are each selected from quantum dot coordination groups; L2, L3, and L4 are each selected from substituted or unsubstituted C1-11 alkylene groups;

[0115] In Formula VI, L7 and L8 are each selected from substituted or unsubstituted C1-11 alkylene groups; R7 and R8 are each selected from H, substituted or unsubstituted C1-11 alkyl groups;

[0116] In Formulas IV, V, and VI, the quantum dot coordination groups can be the aforementioned quantum dot coordination groups.

[0117] According to an embodiment of the present invention, the crosslinked quantum dots include at least one of the following compounds:

[0118]

[0119] The reaction principles of crosslinked quantum dot 1, crosslinked quantum dot 2, and crosslinked quantum dot 3 will be described below.

[0120] For crosslinked quantum dot 1, referring to the following reaction roadmap, where R can be ethyl, the metal-organic compound acts as a ligand of the quantum dot and coordinates with the quantum dot. The composition contains an acrylate compound. Under light irradiation (hv), the acylgermyl group breaks to form an acyl radical and a germyl radical, which initiates the opening of the double bond on the acrylate compound, causing crosslinking between quantum dot ligand molecules. Finally, through development, the quantum dots in the exposed area are left, and the quantum dots in the non-exposed area are removed, forming patterned quantum dots.

[0121] For crosslinked quantum dot 1, refer to the following reaction roadmap.

[0122]

[0123] There will be side reactions in the reaction roadmap, and the side reaction products can be removed in the subsequent development process without affecting the crosslinked quantum dots cured in the exposed area:

[0124]

[0125] For crosslinked quantum dots 2, referring to the following reaction roadmap, this metal-organic compound can serve as a ligand on the surface of the quantum dots. By adding ethyl acrylate to the quantum dot solution and under light irradiation, the acylgermyl group breaks to form acyl radicals and germyl radicals. After the germyl radicals initiate the opening of the double bond on ethyl acrylate, crosslinking can occur between the quantum dot ligand molecules. Finally, through development, the quantum dots in the exposed area are left, and the quantum dots in the non-exposed area are removed, forming patterned quantum dots.

[0126]

[0127] For crosslinked quantum dots 2, referring to the following reaction roadmap, side reactions will occur in the reaction process, and the side reaction products can be removed in the subsequent development process without affecting the crosslinked quantum dots cured in the exposed area.

[0128]

[0129] For crosslinked quantum dots 3, referring to the following reaction roadmap, the Ge atom of this metal-organic compound has two acyloxy groups. Under light irradiation, the bond between the acyloxy group and the germyl group breaks to form germyl radicals and acyloxy radicals. Among them, the germyl radicals can initiate the opening of the double bond on the aminoacrylamide on the surface of the quantum dots, resulting in an intermolecular crosslinking reaction. Finally, through the development process, the quantum dots in the exposed area are left, and the quantum dots in the non-exposed area are removed, obtaining patterned quantum dots.

[0130]

[0131] Similarly, for crosslinked quantum dots 3, side reactions similar to those in the formation of crosslinked quantum dots 2 also occur during crosslinking, and the side reaction products can be removed in the subsequent development process without affecting the crosslinked quantum dots cured in the exposed area.

[0132] It should be noted that the above crosslinked quantum dots only show schematic diagrams of the binding of quantum dot coordination groups to the surface of the quantum dots. For example, for crosslinked quantum dots 1, after coordination, the structural formula can be as follows, that is, the quantum dot coordination group is connected to the surface of the quantum dots through a chemical structure.

[0133]

[0134] Similarly, crosslinked quantum dots 2 and crosslinked quantum dots 3 also only give schematic diagrams of the binding of quantum dot coordination groups to the surface of the quantum dots, which will not be elaborated here.

[0135] In summary, due to the adoption of the aforementioned composition, this quantum dot light-emitting diode can meet various different resolution requirements of QLED, making the product forms of display devices with this quantum dot light-emitting diode diverse.

[0136] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present application.

[0137] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims

1. A quantum dot composition, characterized in that, it comprises quantum dots, ligands and crosslinking agents, wherein one of the ligands and the crosslinking agents comprises an acrylate compound, and the other of the ligands and the crosslinking agents comprises a metal-organic compound, and the metal-organic compound is configured to generate free radicals under light irradiation conditions and undergo a crosslinking reaction with the acrylate compound.

2. The quantum dot composition according to claim 1, characterized in that, the ligand has a quantum dot coordination group and a photosensitive group, the quantum dot coordination group and the photosensitive group are connected, the photosensitive group comprises a double bond group in the acrylate compound or a free radical generating group in the metal-organic compound, the quantum dot coordination group comprises at least one of a mercapto group, an amino group, a carboxyl group, a sulfonic acid group, a phosphoric acid group and a phosphoxy group.

3. The quantum dot composition according to claim 2, characterized in that, the metal-organic compound has a structure satisfying the following formula: wherein M is a metal capable of generating free radicals under light irradiation conditions; Rn and Rm are each independently at least one of an alkyl group, an ester group, an aryl group, a mercapto group, a carboxyl group and an amino group; p and q are both integers greater than or equal to 1 and q + p ≤ 4.

4. The quantum dot composition according to claim 3, characterized in that, the metal-organic compound satisfies: M is Ge or Ir; when at least one of q and p is greater than 1, the plurality of Rn are the same or different, and the plurality of Rm are the same or different; when Rn contains an acyl group, the number of q is not greater than 2.

5. The quantum dot composition according to claim 4, characterized in that, the metal-organic compound comprises: and at least one of; Among them, L 1 ~L 8 are respectively selected from a single bond, O, a substituted or unsubstituted C1-11 alkylene group, a substituted or unsubstituted C1-8 alkoxy group, a substituted or unsubstituted C2-6 alkenylene group, a substituted or unsubstituted C2-6 alkenyloxy group, a substituted or unsubstituted C2-6 alkynylene group, a substituted or unsubstituted C2-6 alkynyloxy group, a substituted or unsubstituted C3-8 cycloalkylene group, a substituted or unsubstituted C3-8 epoxyalkylene group, a substituted or unsubstituted C6-12 arylene group, or a substituted or unsubstituted C6-12 heteroarylene group; R 1 ~R 8 are each independently selected from H, a substituted or unsubstituted C1-11 alkyl group, a substituted or unsubstituted C1-8 alkoxy group, a substituted or unsubstituted C2-6 alkenyl group, a substituted or unsubstituted C2-6 alkenyloxy group, a substituted or unsubstituted C2-6 alkynyl group, a substituted or unsubstituted C2-6 alkynyloxy group, a substituted or unsubstituted C3-8 cycloalkyl group, a substituted or unsubstituted C3-8 epoxyalkyl group, a substituted or unsubstituted C6-12 aryl group, a substituted or unsubstituted C6-12 heteroaryl group, or a quantum dot coordination group; and, R 1 ~R 4 at least one of them is the quantum dot coordination group.

6. The quantum dot composition according to claim 5, characterized in that, the metal-organic compound is: and at least one of Among them, L 9 ~L 12 are respectively selected from C1-11 alkylene groups; L 9 to L 12 、R 9 to R 16 are each independently selected from C1-11 alkyl groups; A 1 is a sulfhydryl group, an amino group or a carboxyl group, A 2 ~A 4 At least one of them is a mercapto group, an amino group or a carboxyl group.

7. The quantum dot composition according to claim 6, characterized in that, The metal organic compound is and at least one of them.

8. The quantum dot composition according to claim 2, characterized in that, the acrylate compound is as shown in formula III: wherein, L 13 is selected from a single bond or a C1-11 alkylene group; R 17 selected from H, C1-11 alkyl, or the quantum dot coordination group.

9. The quantum dot composition according to claim 8, characterized in that, The acrylate compound is selected from at least one of methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, and the like.

10. A method for patterning a quantum dot light-emitting layer, characterized in that, it comprises: preparing a quantum dot initial film by using a film-forming solution, wherein the film-forming solution contains the quantum dot composition according to any one of claims 1-9; performing light irradiation treatment on a predetermined area of the quantum dot initial film; performing a developing treatment on the quantum dot initial film after the light irradiation treatment to remove the quantum dot initial film in the non-predetermined area.

11. A display device, characterized in that, it comprises a substrate and a quantum dot light-emitting diode located on the substrate, and the material for forming the quantum dot light-emitting diode comprises the quantum dot composition according to any one of claims 1-9.

12. The display device according to claim 11, characterized in that, the light-emitting layer of the quantum dot light-emitting diode comprises at least one of the following structures: wherein, QD is the quantum dot, and each group in formulas IV-VI is as described in any one of claims 1-9.

13. The display device according to claim 12, characterized in that, The light-emitting layer includes at least one of the following compounds: and

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