Light-emitting device, display panel, manufacturing method of display panel and display device

Abstract

The invention relates to a light-emitting device, the light-emitting device comprises a quantum dot light-emitting layer and an interface modification layer, the interface modification layer comprises an acetylacetone metal chelate, the quantum dot light-emitting layer comprises a quantum dot material and a cross-linking agent, and the cross-linking agent comprises a cross-linking group and carboxyl of a side chain. When the quantum dot light-emitting layer is formed on the interface modification layer, different quantum dot materials are cross-linked by using a cross-linking agent with a side chain containing carboxyl, carboxylic acid in the cross-linked quantum dot materials reacts with metal of acetylacetone metal chelate and is connected, and then the exposed quantum dot light-emitting layer is integrally anchored to the lower layer. The bonding property of the quantum dot light-emitting layer and the adjacent electron transport layer is greatly improved, so that the film forming quality of the quantum dot light-emitting layer is improved. The invention further provides a display panel comprising the light-emitting device, a manufacturing method of the display panel and a display device comprising the display panel.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to a light-emitting device, a display panel and a manufacturing method thereof, and a display apparatus. Background Art

[0002] In quantum dot light-emitting diode (QLED) display technology, a patterned quantum dot film layer is formed through spin coating, exposure, and development processes.

[0003] When forming a quantum dot light-emitting layer, the quantum dot light-emitting layer has poor bonding with its adjacent electron transport layer, which will affect the film-forming quality of the quantum dot light-emitting layer.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0005] The purpose of the present disclosure is to prevent the quantum dot film layer of the patterned sub-pixel area from being damaged during the manufacturing process of the light-emitting device, and to provide a light-emitting device, a display panel and a manufacturing method thereof, and a display device.

[0006] According to one aspect of the present disclosure, a light-emitting device is provided, comprising a cathode, an electron transport layer, an interface modification layer, a quantum dot light-emitting layer, a hole transport layer, a hole injection layer, and an anode stacked in sequence, wherein the interface modification layer comprises an acetylacetone metal chelate, the quantum dot light-emitting layer comprises a quantum dot material and a cross-linking agent, the cross-linking agent comprises a cross-linking group and a carboxyl group of a side chain, the quantum dot material is cross-linked together through the cross-linking group, and the carboxyl group in the cross-linking agent located at the interface between the interface modification layer and the quantum dot light-emitting layer is connected to the chelated metal in the acetylacetone metal chelate.

[0007] In one embodiment of the present disclosure, the acetylacetone metal chelate includes an acetylacetone coordination molecule, the chelated metal is chelated with the acetylacetone coordination molecule, and the chelated metal includes at least one of aluminum, hafnium, and zirconium.

[0008] In one embodiment of the present disclosure, the quantum dot material includes quantum dots and ligands on the surface of the quantum dots, and the ligands are bonded to cross-linking groups.

[0009] In one embodiment of the present disclosure, the quantum dots include at least one of CdS, CdSe, ZnSe, InP, PbS, CsPbCl3, CsPbBr3, CsPbI3, CdS and ZnS, CdSe and ZnS, ZnSe, InP and ZnS, PbS and ZnS, CsPbCl3 and ZnS, CsPbBr3 and ZnS, CsPbI3 and ZnS, the ligand includes a coordination unit, and a saturated or unsaturated hydrocarbon group and a heterohydrocarbon group, and the coordination unit includes at least one of an amine group, a thiol group, a hydroxyl group, and a phosphonic acid group.

[0010] In one embodiment of the present disclosure, the cross-linking agent includes a biazide cross-linking unit, a linking unit and a carboxyl group, wherein the linking unit includes at least one of a C1-C6 alkyl group, a cycloalkyl group and a C6-C12 aromatic group.

[0011] In one embodiment of the present disclosure, the metal on the acetylacetonate metal chelate is connected to the hydroxyl group on the electron transport layer.

[0012] In one embodiment of the present disclosure, the acetylacetone coordination molecules are arranged on the surface of the electron transport layer, and at least part of the acetylacetone coordination molecules are oriented outward and perpendicular to the electron transport layer.

[0013] In one embodiment of the present disclosure, the work function at the interface between the acetylacetone coordination molecule and the electron transport layer is between 3.6 and 3.3 eV.

[0014] In one embodiment of the present disclosure, the electron transport layer includes zinc oxide and doped zinc oxide, the doped zinc oxide includes zinc oxide and a doped metal, and the doped metal includes at least one of magnesium and tin.

[0015] According to another aspect of the present disclosure, a display panel is provided, comprising a base substrate, a pixel definition layer and at least three different colors of light-emitting devices provided in one aspect of the present disclosure, wherein the pixel definition layer is disposed on one side of the base substrate, and the pixel definition layer is provided with a plurality of pixel openings; and light-emitting devices of different colors are respectively disposed in the plurality of pixel openings.

[0016] According to another aspect of the present disclosure, a method for manufacturing the display panel provided in another aspect of the present disclosure is provided, the method comprising:

[0017] forming a cathode on one side of the substrate;

[0018] An electron transport layer exposing a pixel opening is formed on a side of the cathode away from the substrate;

[0019] forming an interface modification layer on a side of the electron transport layer away from the substrate, wherein the interface modification layer comprises an acetylacetone metal chelate;

[0020] Forming quantum dot light-emitting layers of light-emitting devices of at least three different colors on a side of the interface modification layer away from the substrate;

[0021] Forming a hole transport layer on a side of the quantum dot light-emitting layer away from the substrate;

[0022] forming a hole injection layer on a side of the hole transport layer away from the substrate;

[0023] An anode is formed on a side of the hole injection layer away from the substrate.

[0024] In one embodiment of the present disclosure, forming an electron transport layer exposing a pixel opening on a side of the cathode away from the substrate includes:

[0025] An electron transport layer is formed on the entire surface of the cathode;

[0026] A pixel definition layer is formed on a side of the electron transport layer away from the cathode, and the pixel definition layer has a pixel opening exposing the electron transport layer.

[0027] In one embodiment of the present disclosure, forming an electron transport layer exposing a pixel opening on a side of the cathode away from the substrate includes:

[0028] forming a pixel definition layer having a pixel opening on a surface of the cathode;

[0029] Electron transport layers are formed on portions of the cathodes where the pixel openings are exposed.

[0030] In one embodiment of the present disclosure, forming a quantum dot light-emitting layer of a light-emitting device of at least three different colors on a surface of the interface modification layer away from the cathode comprises:

[0031] forming a quantum dot coating of one color containing a cross-linking agent on the interface modification layer;

[0032] A mask is used to expose a quantum dot coating of one color, so that different quantum dots are cross-linked, and the carboxylic acid in the cross-linked quantum dots reacts with and connects to the metal of the acetylacetone metal chelate;

[0033] Developing the quantum dot coating of one color after exposure, wherein the unexposed area of ​​the quantum dot coating is removed during the development process, and the exposed area of ​​the quantum dot coating is retained to form a quantum dot light-emitting layer of a light-emitting device of one color;

[0034] Repeat the process to form quantum dot coatings of other colors, use a mask to expose the quantum dot coating of the color, and develop the exposed quantum dot coating to form quantum dot light-emitting layers of light-emitting devices of other colors.

[0035] According to still another aspect of the present disclosure, a display device is provided. The display device includes the display panel provided by another aspect of the present disclosure.

[0036] The light-emitting device disclosed in the present invention comprises a quantum dot light-emitting layer and an interface modification layer, wherein the interface modification layer comprises an acetylacetone metal chelate, and the quantum dot light-emitting layer comprises a quantum dot material and a cross-linking agent, wherein the cross-linking agent comprises a cross-linking group and a carboxyl group of a side chain. When forming the quantum dot light-emitting layer on the interface modification layer, different quantum dot materials are cross-linked by using a cross-linking agent containing a carboxyl group in a side chain, and the carboxylic acid in the cross-linked quantum dot material reacts and connects with the metal of the acetylacetone metal chelate, thereby anchoring the quantum dot light-emitting layer after exposure as a whole in the lower layer, greatly improving the binding property between the quantum dot light-emitting layer and the adjacent electron transport layer, thereby improving the film-forming quality of the quantum dot light-emitting layer.

[0037] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0039] Figure 1 It is a cross-sectional schematic diagram of the light-emitting device involved in the embodiment of the present disclosure.

[0040] Figure 2 It is a cross-sectional schematic diagram of a display panel involved in an embodiment of the present disclosure.

[0041] Figure 3 The present invention is a flowchart of a method for manufacturing a display panel according to an embodiment of the present disclosure.

[0042] Figure 4 It is a cross-sectional schematic diagram of a display panel involved in an embodiment of the present disclosure.

[0043] Figure 5 It is a cross-sectional schematic diagram of another display panel involved in an embodiment of the present disclosure.

[0044] Figure 6 It is a cross-sectional schematic diagram after a cathode is formed on one side of a substrate according to an embodiment of the present disclosure.

[0045] Figure 7 It is a cross-sectional schematic diagram after a pixel definition layer is formed on one side of a substrate according to an embodiment of the present disclosure.

[0046] Figure 8It is a cross-sectional schematic diagram after an electron transport layer is formed on one side of a substrate according to an embodiment of the present disclosure.

[0047] Fig. 9 It is a cross-sectional schematic diagram after an interface modification layer is formed on one side of a substrate according to an embodiment of the present disclosure.

[0048] Fig.10 It is a cross-sectional schematic diagram after a red quantum dot coating is formed on one side of a substrate according to an embodiment of the present disclosure.

[0049] Fig.11 It is a cross-sectional schematic diagram after a red quantum dot light-emitting layer is formed on one side of the base substrate according to an embodiment of the present disclosure.

[0050] Fig.12 It is a cross-sectional schematic diagram after a green quantum dot coating is formed on one side of a substrate according to an embodiment of the present disclosure.

[0051] Fig.13 It is a cross-sectional schematic diagram after a green quantum dot light-emitting layer is formed on one side of a base substrate according to an embodiment of the present disclosure.

[0052] Fig.14 It is a cross-sectional schematic diagram after a blue quantum dot coating is formed on one side of a substrate according to an embodiment of the present disclosure.

[0053] Fig.15 It is a cross-sectional schematic diagram after a blue quantum dot light-emitting layer is formed on one side of a base substrate according to an embodiment of the present disclosure.

[0054] Fig.16 It is a cross-sectional schematic diagram after an anode is formed on one side of a substrate according to an embodiment of the present disclosure.

[0055] Fig.17 The present invention is a flow chart of forming a quantum dot light-emitting layer of a light-emitting device of at least three different colors on a side of the interface modification layer away from the base substrate according to an embodiment of the present disclosure.

[0056] Fig.18 FIG. 4 is a schematic diagram of the process of the quantum dot coating reacting with the acetylacetone metal chelate during exposure according to an embodiment of the present disclosure.

[0057] In the figure: 1. substrate, 2. driving circuit layer, 3. pixel layer, 31. pixel definition layer, 311. pixel opening, 32. light-emitting device, 321. cathode, 322. light-emitting layer group, 3221. electron transport layer, 3222. interface modification layer, 3223. quantum dot light-emitting layer, 3224. hole transport layer, 3225. hole injection layer, 3226. red quantum dot light-emitting layer, 3227. green quantum dot light-emitting layer, 3228. blue quantum dot light-emitting layer, 323. anode, 324. red quantum dot coating, 325. green quantum dot coating, 326. blue quantum dot coating, 4. encapsulation layer. DETAILED DESCRIPTION

[0058] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0059] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of the illustration to another component, these terms are used in this specification only for convenience, such as according to the orientation of the examples described in the drawings. It is understood that if the device of the illustration is turned upside down, the component described as "upper" will become the component "lower". When a structure is "on" other structures, it may mean that the structure is formed integrally on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.

[0060] 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 "including" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used merely as labels and are not intended to limit the quantity of their objects.

[0061] Quantum dots (QD) are excellent nano-luminescent materials with advantages such as high quantum yield, narrow luminescence peak, adjustable luminescence spectrum, and high photochemical stability. Therefore, quantum dot light-emitting diodes (QLEDs) with quantum dots as the light-emitting layer have the advantages of self-luminescence, low power consumption, and high color gamut, and have received widespread attention.

[0062] In the current quantum dot light-emitting diode (QLED) display technology, patterning process is a key process step, and photolithography patterning is one of the high-resolution patterning process methods. The photolithography patterning process requires repeating the spin coating, exposure, and development process of quantum dots multiple times to pattern the red quantum dot light-emitting layer 3226, the green quantum dot light-emitting layer 3227, and the blue quantum dot light-emitting layer 3228, respectively, to form multiple red sub-pixels, multiple green sub-pixels, and multiple blue sub-pixels, which constitute pixel units.

[0063] In order to ensure the color purity of each sub-pixel, the development process needs to ensure that each color quantum dot light-emitting layer 3223 does not enter the other two sub-pixel areas and is only retained in the exposure area. If a strong development process is used, the quantum dot light-emitting layer 3223 in the patterned sub-pixel area may be damaged, so it is necessary to select appropriate development conditions to minimize the impact on other sub-pixels while ensuring no residue.

[0064] Secondly, the display panel uses a pixel definition layer 31 to separate each sub-pixel. The material of the pixel definition layer 31 is usually an inorganic oxygen silicon material, such as SiO. The quantum dot solvent is usually an organic solvent. In the pixel opening 311 of the pixel definition layer 31, the quantum dot solution has poor wettability, which will affect the quality of the quantum dot light-emitting layer 3223 deposited by the solution spin coating method.

[0065] In addition, in most of the existing high-efficiency quantum dot light-emitting diodes, the electron transport layer 3221 material is ZnO and its doped materials, and the hole transport layer 3224 is an organic material. The electron mobility of metal oxides is higher than the hole mobility of organic materials, which usually leads to an imbalance in carrier injection in the device, thereby reducing the efficiency and life of the device.

[0066] To solve this problem, the structure of quantum dot light-emitting diodes can be adjusted, such as inserting an insulating layer, which can be polymethyl methacrylate (PMMA), using Mg-doped ZnO and other methods to reduce the electron transfer rate or increase the injection barrier to achieve the effect of inhibiting electron injection. During the solution processing, the film thickness accuracy of the insulating layer is extremely high. An overly thick insulating layer will cause the conductivity of the quantum dot light-emitting diode to decrease, and the reliability of the deposition process of a few nanometers of thin film cannot be guaranteed. Metal oxides will lead to an increase in defective interfaces.

[0067] Based on this, the embodiment of the present disclosure provides a light emitting device 32. Figure 1 As shown, the light-emitting device 32 includes a cathode 321, an electron transport layer 3221, an interface modification layer 3222, a quantum dot light-emitting layer 3223, a hole transport layer 3224, a hole injection layer 3225, and an anode 323 stacked in sequence, the interface modification layer 3222 includes an acetylacetone metal chelate, the quantum dot light-emitting layer 3223 includes a quantum dot material and a cross-linking agent, the cross-linking agent includes a cross-linking group and a carboxyl group of a side chain, the quantum dot material is cross-linked together through the cross-linking group, and the carboxyl group in the cross-linking agent located at the interface between the interface modification layer 3222 and the quantum dot light-emitting layer 3223 is connected to the chelated metal in the acetylacetone metal chelate.

[0068] When forming the quantum dot light-emitting layer 3223 on the interface modification layer 3222, different quantum dot materials are cross-linked by using a cross-linking agent containing a carboxyl group in the side chain. The carboxylic acid in the cross-linked quantum dot material reacts with and connects with the metal of the acetylacetone metal chelate, thereby anchoring the entire exposed quantum dot light-emitting layer 3223 to the lower layer, greatly improving the bonding between the quantum dot light-emitting layer 3223 and its adjacent electron transport layer 3221, thereby improving the film-forming quality of the quantum dot light-emitting layer 3223.

[0069] The light emitting device 32 according to the embodiment of the present disclosure will be described in detail below.

[0070] like Figure 1 As shown, the light-emitting device 32 includes a cathode 321, a light-emitting layer group 322 and an anode 323. The light-emitting layer group 322 is arranged between the anode 323 and the cathode 321. An electron transport layer 3221 is arranged on one side of the cathode 321. An interface modification layer 3222 is arranged on the side of the electron transport layer 3221 away from the cathode 321. A quantum dot light-emitting layer 3223 is arranged on the side of the interface modification layer 3222 away from the cathode 321. A hole transport layer 3224 is arranged on the side of the quantum dot light-emitting layer 3223 away from the cathode 321. A hole injection layer 3225 is arranged on the side of the hole injection layer 3225 away from the cathode 321.

[0071] The electron transport layer 3221 may include zinc oxide and doped zinc oxide. The doped zinc oxide may include a doped metal and zinc oxide. The doped metal may include one of magnesium and tin, or may include both magnesium and tin.

[0072] The interface modification layer 3222 may include an acetylacetone metal chelate, which may include an acetylacetone coordination molecule (acac-) and a chelated metal M. The specific molecular structure of the acetylacetone metal chelate may be: M(acac)x. The chelated metal M may include at least one of aluminum, hafnium, and zirconium. It should be noted that the chelated metal includes but is not limited to aluminum, hafnium, and zirconium, and other metals that can coordinate with the acetylacetone coordination molecule may also be used.

[0073] The quantum dot light-emitting layer 3223 includes quantum dot materials, which include quantum dots and ligands R2 on the surface of the quantum dots. Specifically, the molecular structure may be as shown in the following formula (1):

[0074]

[0075] Quantum dots include but are not limited to at least one of CdS, CdSe, ZnSe, InP, PbS, CsPbCl3, CsPbBr3, CsPbI3, CdS and ZnS, CdSe and ZnS, ZnSe, InP and ZnS, PbS and ZnS, CsPbCl3 and ZnS, CsPbBr3 and ZnS, CsPbI3 and ZnS. The ligand is an organic ligand, and the ligand has a coordination unit and a saturated or unsaturated hydrocarbon group and heteroalkyl group R2. The coordination unit includes but is not limited to an amine group, a thiol group, a hydroxyl group, a phosphonic acid, etc. For example, oleic acid, oleylamine, isooctylmercaptan, and trioctylphosphine can provide the groups included in the coordination unit.

[0076] The quantum dot light-emitting layer 3223 includes a cross-linking agent, which includes a diazide cross-linking unit, a connecting unit R1 and a carboxyl group, and specifically can be a molecular structure shown in the following formula (2):

[0077]

[0078] The linking unit R1 includes at least one of a C1-C6 alkyl group, a cycloalkyl group, and a C6-C12 aromatic group. The molecular structure of the crosslinking agent can be as follows:

[0079] 3,5-Diazidobenzoic acid, cis-syn-3,4-diazidocyclopentanecarboxylic acid, 3-azido-2-(azidomethyl)propanoic acid methyl ester, etc.

[0080] The hole transport layer 3224 includes, but is not limited to, poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine)] (TFB), poly[bis(4-phenyl)(4-butylphenyl)amine] (Poly-TPD), N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), 4,4'-bis(9-carbazole)biphenyl (CBP), NiOx, V 2 O 5 .

[0081] The hole injection layer 3225 includes, but is not limited to, poly (3,4-ethylenedioxythiophene:polystyrene sulfonate) (PEDOT:PSS) and molybdenum trioxide (MoO3).

[0082] After the quantum dot coating is exposed through a mask, the biazide crosslinking unit in the crosslinker reacts with the hydrocarbons in the ligands on the surface of the quantum dots to crosslink different quantum dot materials. At the interface between the quantum dot light-emitting layer 3223 and the interface modification layer 3222, the biazide crosslinking unit of the crosslinker connected to the interface modification layer 3222 also participates in the crosslinking of the quantum dot material, bonding the crosslinked quantum dot material to the chelated metal in the metal chelate, thereby anchoring the entire exposed quantum dot light-emitting layer 3223 on the interface modification layer 3222. The acetylacetone metal chelate can fix the crosslinked quantum dot light-emitting layer 3223 through an in-situ chemical reaction rather than physical affinity, and can withstand a strong development process. Using a strong development process can improve the residue problem while reducing the impact on the exposed area.

[0083] Acetylacetone metal chelate is deposited on the electron transport layer 3221 . The chelated metal on the acetylacetone metal chelate can be connected to the hydroxyl group on SiO . The reaction product is an organic molecule that has good affinity with the acetylacetone coordination molecule. The quantum dot solution has good affinity with the acetylacetone coordination molecule, which improves the wettability of the quantum dot solution in the electron transport layer 3221 .

[0084] After the chelated metal on the acetylacetone metal chelate contacts the electron transport layer 3221, the chelated metal can connect with the hydroxyl group on the electron transport layer 3221, and the remaining acetylacetone coordination molecules form an outward orientation and are arranged on the surface of the electron transport layer 3221, thereby deepening the work function at the interface between the acetylacetone coordination molecules and the electron transport layer 3221, increasing the electron injection barrier, and balancing the carrier injection. It should be noted that the work function at the interface between the acetylacetone coordination molecules and the electron transport layer 3221 is between 3.6 and 3.3 eV.

[0085] Hydroxyl groups usually provide channels for non-radiative recombination of carriers. Acetylacetone metal chelates are a type of interface layer material. While improving the bonding strength between the quantum dot light-emitting layer 3223 and the electron transport layer 3221, they can connect with the hydroxyl groups on the ZnO, remove the hydroxyl groups at the interface of the electron transport layer 3221, and inhibit the non-radiative recombination at the interface between the quantum dot material and the electron transport layer 3221, so that more carriers can undergo radiative recombination, thereby improving the efficiency of the light-emitting device 32.

[0086] Several specific embodiments are given below to illustrate the light emitting device 32 .

[0087] Example 1

[0088] The light emitting device 32 includes a cathode 321, an electron transport layer 3221, an interface modification layer 3222, a quantum dot light emitting layer 3223, a hole transport layer 3224, a hole injection layer 3225, and an anode 323 stacked in sequence, wherein the electron transport layer 3221 includes zinc oxide and doped zinc oxide, and the doped zinc oxide includes zinc oxide and a doped metal, and the doped metal includes magnesium. The acetylacetone metal chelate includes an acetylacetone coordination molecule and a chelated metal, and the chelated metal includes aluminum. The quantum dot light emitting layer 3223 includes a quantum dot material and a crosslinker, and the quantum dot material includes quantum dots and ligands on the surface of the quantum dots. The quantum dots include CdS, and the ligands include coordination units, as well as saturated or unsaturated hydrocarbon groups and heterohydrocarbon groups, and the coordination units include amine groups, thiol groups, hydroxyl groups, and phosphonic acids. The crosslinker includes a diazide crosslinking unit, a connecting unit R1, and a carboxyl group, wherein the crosslinker can be 3,5-Diazidobenzoic acid. The hole transport layer 3224 is poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine)]. The hole injection layer 3225 is poly-3,4-ethylenedioxythiophene:polystyrene sulfonate. The cathode 321 and the anode 323 can be made of metal.

[0089] Example 2

[0090] The light emitting device 32 includes a cathode 321, an electron transport layer 3221, an interface modification layer 3222, a quantum dot light emitting layer 3223, a hole transport layer 3224, a hole injection layer 3225, and an anode 323 stacked in sequence, wherein the electron transport layer 3221 includes zinc oxide and doped zinc oxide, and the doped zinc oxide includes zinc oxide and a doped metal, and the doped metal includes magnesium. The acetylacetone metal chelate includes an acetylacetone coordination molecule and a chelated metal, and the chelated metal includes hafnium. The quantum dot light emitting layer 3223 includes a quantum dot material and a crosslinker, and the quantum dot material includes quantum dots and ligands on the surface of the quantum dots. The quantum dots include CdS and ZnS, and the ligands include coordination units, as well as saturated or unsaturated hydrocarbon groups and heterohydrocarbon groups, and the coordination units include amine groups. The crosslinker includes a diazide crosslinking unit, a connecting unit R1, and a carboxyl group, wherein the crosslinker can be cis-syn-3,4-diazidocyclopentanecarboxylicacid. The hole transport layer 3224 is poly[bis(4-phenyl)(4-butylphenyl)amine]. The hole injection layer 3225 is poly-3,4-ethylenedioxythiophene:polystyrene sulfonate. The cathode 321 and the anode 323 can be made of metal.

[0091] Example 3

[0092] The light emitting device 32 includes a cathode 321, an electron transport layer 3221, an interface modification layer 3222, a quantum dot light emitting layer 3223, a hole transport layer 3224, a hole injection layer 3225, and an anode 323 stacked in sequence, wherein the electron transport layer 3221 includes zinc oxide and doped zinc oxide, and the doped zinc oxide includes zinc oxide and a doped metal, and the doped metal includes tin. The acetylacetone metal chelate includes an acetylacetone coordination molecule and a chelated metal, and the chelated metal includes zirconium. The quantum dot light emitting layer 3223 includes a quantum dot material and a crosslinker, and the quantum dot material includes quantum dots and ligands on the surface of the quantum dots. The quantum dots include CdSe, and the ligands include coordination units, as well as saturated or unsaturated hydrocarbon groups and heterohydrocarbon groups, and the coordination units include amine groups and thiol groups. The crosslinker includes a diazide crosslinking unit, a connecting unit R1, and a carboxyl group, wherein the crosslinker can be 3-azido-2-(azidomethyl)propanoic acidmethyl ester. The hole transport layer 3224 is N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine. The hole injection layer 3225 is molybdenum trioxide (MoO3). The cathode 321 and the anode 323 can be made of metal.

[0093] It should be noted that, in addition to the several situations involved in Embodiments 1 to 3, the components included in each layer can also be freely combined to form a new light-emitting device 32, which will not be listed one by one here.

[0094] The present disclosure provides a display panel. Figure 2 As shown, the display panel includes a base substrate 1, a pixel definition layer 31, and at least three different colors of light-emitting devices 32 proposed in any one of the above items, the pixel definition layer 31 is arranged on one side of the base substrate 1, the pixel definition layer 31 is provided with a plurality of pixel openings 311, and the light-emitting devices 32 of different colors are respectively arranged in the plurality of pixel openings 311, and each light-emitting device 32 and the pixel definition layer 31 form a pixel layer 3. The structure and beneficial effects of the display panel are similar to those of the light-emitting device 32, and the structure and beneficial effects of the display panel can refer to the light-emitting device 32, and will not be repeated here.

[0095] It should be noted that the light emitting device 32 included in the display panel can adopt the structure and material of the light emitting device 32 mentioned in any one of the above embodiments 1 to 3. In addition to the several situations involved in embodiments 1 to 3, a new light emitting device 32 formed by combining other optional materials in each layer is also adopted.

[0096] The present disclosure also provides a method for manufacturing a display panel. Figures 3 to 17 As shown, the method includes:

[0097] Step S10 , forming a cathode 321 on one side of the base substrate 1 .

[0098] In step S20 , an electron transport layer 3221 exposing the pixel opening 311 is formed on a side of the cathode 321 away from the base substrate 1 .

[0099] Step S30 , forming an interface modification layer 3222 on a side of the electron transport layer 3221 away from the base substrate 1 , wherein the interface modification layer 3222 includes acetylacetone metal chelate.

[0100] Step S40 , forming a quantum dot light-emitting layer 3223 of at least three different colors of the light-emitting device 32 on a side of the interface modification layer 3222 away from the base substrate 1 .

[0101] Step S50 , forming a hole transport layer 3224 on a side of the quantum dot light-emitting layer 3223 away from the base substrate 1 .

[0102] In step S60 , a hole injection layer 3225 is formed on a side of the hole transport layer 3224 away from the base substrate 1 .

[0103] In step S70 , an anode 323 is formed on a side of the hole injection layer 3225 away from the base substrate 1 .

[0104] Among them, the cathode 321 can be formed on the driving circuit layer 2 on one side of the base substrate 1 by vacuum evaporation. The electron transport layer 3221 can be formed on the surface of the cathode 321 by solution spin coating. The electron transport layer 3221 can be equal to the width of the pixel opening 311, and the width of the electron transport layer 3221 is formed in the pixel opening 311; the electron transport layer 3221 can also be greater than the width of the pixel opening 311, and the electron transport layer 3221 is arranged between the cathode 321 and the pixel definition layer 31, and the pixel opening 311 is exposed. The interface modification layer 3222 can be formed by spin coating acetylacetone metal chelate on the surface of the electron transport layer 3221. The quantum dot light-emitting layer 3223 can be formed on the surface of the interface modification layer 3222 by solution spin coating. The hole transport layer 3224 can be deposited on the quantum dot light-emitting layer 3223. The hole injection layer 3225 can be deposited on the hole transport layer 3224. The cathode 321 can be formed on the hole transport layer 3224 by vacuum evaporation.

[0105] like Figure 4 As shown, in step S20, forming an electron transport layer 3221 exposing the pixel opening 311 on the side of the cathode 321 away from the base substrate 1 may include:

[0106] An electron transport layer 3221 is formed on the surface of the cathode 321.

[0107] A pixel definition layer 31 is formed on a side of the electron transport layer 3221 away from the cathode 321 . The pixel definition layer 31 has a pixel opening 311 exposing the electron transport layer 3221 .

[0108] like Figure 5 As shown, in step S20, forming an electron transport layer 3221 exposing the pixel opening 311 on the side of the cathode 321 away from the base substrate 1 may also include:

[0109] A pixel definition layer 31 having a pixel opening 311 is formed on the surface of the cathode 321;

[0110] Electron transport layers 3221 are formed on portions of the cathode 321 that are exposed from the pixel opening 311 .

[0111] like Figures 6 to 16 As shown, the three light emitting devices 32 of different colors include a red light emitting device 32, a green light emitting device 32 and a blue light emitting device 32. Fig.17 As shown, in step S40, forming a quantum dot light-emitting layer 3223 of at least three different colors of the light-emitting device 32 on a side of the interface modification layer 3222 away from the base substrate 1 may include:

[0112] Step S401 , forming a red quantum dot coating 324 containing a crosslinking agent on the interface modification layer 3222 , exposing the red quantum dot coating 324 using a mask, and developing the exposed red quantum dot coating 324 to form a red quantum dot light-emitting layer 3226 of the red light-emitting device 32 .

[0113] like Fig.18 As shown, after mask exposure, the biazide crosslinking unit in the crosslinking agent reacts with the hydrocarbon in the ligand on the surface of the quantum dot under ultraviolet light irradiation, and crosslinks different quantum dots, and makes the carboxylic acid in the crosslinked red quantum dot coating 324 react and connect with the metal of the acetylacetone metal chelate;

[0114] The cross-linking agent connected to the acetylacetone metal chelate at the interface of the red quantum dot coating, whose biazide cross-linking unit also participates in the quantum dot cross-linking, adheres the cross-linked red quantum dot coating 324 to the interface modification layer 3222 through chemical action.

[0115] The exposed red quantum dot coating 324 is developed, and the unexposed areas of the red quantum dot coating 324 are removed during the development process, while the exposed areas of the red quantum dot coating 324 are retained, thereby achieving patterning of the red quantum dot coating 324 and forming a red quantum dot light-emitting layer 3226 of each red light-emitting device 32.

[0116] In step S402, a green quantum dot coating 325 is formed on the side of the red quantum dot light-emitting layer 3226 and the interface modification layer 3222 away from the base substrate 1, the green quantum dot coating 325 is exposed using a mask, and the exposed green quantum dot coating 325 is developed. The unexposed area of ​​the green quantum dot coating 325 is removed during the development process, and the exposed area of ​​the green quantum dot coating 325 is retained to form a green quantum dot light-emitting layer 3227 of the green light-emitting device 32.

[0117] In step S403, a blue quantum dot coating 326 is formed on the side of the red quantum dot light-emitting layer 3226, the green quantum dot light-emitting layer 3227 and the interface modification layer 3222 away from the substrate 1, the blue quantum dot coating 326 is exposed using a mask, and the exposed blue quantum dot coating 326 is developed. The unexposed area of ​​the blue quantum dot coating 326 is removed during the development process, and the exposed area of ​​the blue quantum dot coating 326 is retained to form a blue quantum dot light-emitting layer 3228 of the blue light-emitting device 32.

[0118] In the process of forming the quantum dot light-emitting layer 3223, acetylacetone is formed. Therefore, step S40 may also include:

[0119] Step S404, drying to remove the quantum dot solvent and the acetylacetone remaining after the reaction.

[0120] The method may further include: forming an encapsulation layer 4 on a side of the light emitting devices 32 of various colors away from the base substrate 1 .

[0121] The embodiment of the present disclosure also provides a display device. The display device may include the display panel provided by any one of the above embodiments of the present disclosure. The specific structure of the display panel, the materials of each layer and the beneficial effects have been described in detail above, so they will not be repeated here.

[0122] It should be noted that, in addition to the display panel, the display device also includes other necessary components and components, such as circuit boards, power lines, etc. Those skilled in the art may make corresponding supplements according to the specific usage requirements of the display device, which will not be elaborated here.

[0123] The display device can be a traditional electronic device, such as a mobile phone, a computer, a television, a projector, and a camcorder, or it can be an emerging wearable device, such as a VR wearable device, which are not listed here one by one. When the display device is a VR wearable device, the optical path adjustment lens 400 is a VR lens.

[0124] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A light emitting device, characterized in that: The invention comprises a cathode, an electron transport layer, an interface modification layer, a quantum dot light-emitting layer, a hole transport layer, a hole injection layer and an anode which are stacked in sequence, wherein the interface modification layer comprises an acetylacetone metal chelate, the quantum dot light-emitting layer comprises a quantum dot material and a crosslinking agent, the crosslinking agent comprises a crosslinking group and a carboxyl group of a side chain, the quantum dot material is crosslinked together through the crosslinking group, and the carboxyl group in the crosslinking agent located at the interface between the interface modification layer and the quantum dot light-emitting layer is connected to the chelated metal in the acetylacetone metal chelate.

2. The light emitting device according to claim 1, characterized in that: The acetylacetone metal chelate includes acetylacetone coordination molecules, the chelated metal is chelated with the acetylacetone coordination molecules, and the chelated metal includes at least one of aluminum, hafnium and zirconium.

3. The light emitting device according to claim 1, characterized in that: The quantum dot material includes quantum dots and ligands on the surface of the quantum dots, and the ligands are bonded to the cross-linking groups.

4. The light emitting device according to claim 3, characterized in that: The quantum dots include at least one of CdS, CdSe, ZnSe, InP, PbS, CsPbCl3, CsPbBr3, CsPbI3, CdS and ZnS, CdSe and ZnS, ZnSe, InP and ZnS, PbS and ZnS, CsPbCl3 and ZnS, CsPbBr3 and ZnS, CsPbI3 and ZnS; the ligand includes a coordination unit, and a saturated or unsaturated hydrocarbon group and a heterohydrocarbon group; the coordination unit includes at least one of an amine group, a thiol group, a hydroxyl group, and a phosphonic acid group.

5. The light emitting device according to claim 1, characterized in that: The cross-linking agent comprises a biazide cross-linking unit, a linking unit and a carboxyl group, wherein the linking unit comprises at least one of a C1-C6 alkyl group, a cycloalkyl group and a C6-C12 aromatic group.

6. The light emitting device according to claim 2, characterized in that: The metal on the acetylacetonate metal chelate is connected to the hydroxyl group on the electron transport layer.

7. The light emitting device according to claim 6, characterized in that: The acetylacetone coordination molecules are arranged on the surface of the electron transport layer, and at least part of the acetylacetone coordination molecules are oriented outwards and perpendicular to the electron transport layer.

8. The light emitting device according to claim 7, characterized in that: The work function at the interface between the acetylacetone coordination molecule and the electron transport layer is between 3.6 and 3.3 eV.

9. The light emitting device according to claim 1, characterized in that: The electron transport layer includes zinc oxide and doped zinc oxide. The doped zinc oxide includes zinc oxide and a doped metal. The doped metal includes at least one of magnesium and tin.

10. A display panel, characterized in that: include: substrate substrate; A pixel definition layer is disposed on one side of the base substrate, and the pixel definition layer is provided with a plurality of pixel openings; At least three different colors of the light emitting devices according to claim 1, the light emitting devices of different colors are respectively arranged in the plurality of pixel openings.

11. A method for manufacturing a display panel according to claim 10, characterized in that: The method comprises: forming a cathode on one side of the substrate; An electron transport layer exposing a pixel opening is formed on a side of the cathode away from the substrate; forming an interface modification layer on a side of the electron transport layer away from the substrate, wherein the interface modification layer comprises an acetylacetone metal chelate; Forming quantum dot light-emitting layers of light-emitting devices of at least three different colors on a side of the interface modification layer away from the base substrate; Forming a hole transport layer on a side of the quantum dot light-emitting layer away from the substrate; forming a hole injection layer on a side of the hole transport layer away from the substrate; An anode is formed on a side of the hole injection layer away from the base substrate.

12. The method for manufacturing a display panel according to claim 11, characterized in that: Forming an electron transport layer exposing a pixel opening on a side of the cathode away from the substrate includes: forming an entire electron transport layer on the surface of the cathode; A pixel definition layer is formed on a side of the electron transport layer away from the cathode, and the pixel definition layer has a pixel opening exposing the electron transport layer.

13. The method for manufacturing a display panel according to claim 11, characterized in that: Forming an electron transport layer exposing a pixel opening on a side of the cathode away from the substrate includes: forming a pixel definition layer having a pixel opening on a surface of the cathode; Electron transport layers are respectively formed on portions of the cathodes that are exposed from the pixel openings.

14. The method for manufacturing a display panel according to claim 11, characterized in that: The quantum dot light-emitting layer of the light-emitting device of at least three different colors is formed on the surface of the interface modification layer away from the cathode, comprising: forming a quantum dot coating of one color containing a cross-linking agent on the interface modification layer; A mask is used to expose a quantum dot coating of one color, so that different quantum dots are cross-linked, and the carboxylic acid in the cross-linked quantum dot coating reacts with and connects to the metal of the acetylacetone metal chelate; Developing the quantum dot coating of one color after exposure, wherein the unexposed area of ​​the quantum dot coating is removed during the development process, and the exposed area of ​​the quantum dot coating is retained to form a quantum dot light-emitting layer of a light-emitting device of one color; Repeat the process to form quantum dot coatings of other colors, use a mask to expose the quantum dot coating of the color, and develop the exposed quantum dot coating to form quantum dot light-emitting layers of light-emitting devices of other colors.

15. A display device, characterized in that: Comprising the display panel according to claim 10.

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