Light-emitting devices, display panels and their manufacturing methods, display devices

Abstract

This disclosure relates to a light-emitting device comprising a quantum dot light-emitting layer and an interface modification layer. The interface modification layer comprises an acetylacetone metal chelate, and the quantum dot light-emitting layer comprises quantum dot material and a crosslinking agent. The crosslinking agent comprises crosslinking groups and carboxyl groups in its side chains. When forming the quantum dot light-emitting layer on the interface modification layer, different quantum dot materials are crosslinked using a crosslinking agent with carboxyl groups in its side chains. The carboxylic acid in the crosslinked quantum dot material reacts and connects with the metal in the acetylacetone metal chelate, thereby anchoring the exposed quantum dot light-emitting layer as a whole to the underlying layer. This significantly improves the bonding between the quantum dot light-emitting layer and its adjacent electron transport layer, thus improving the film quality of the quantum dot light-emitting layer. This disclosure also provides a display panel including the light-emitting device, a method for manufacturing the display panel, and a display device including the display panel.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and more specifically, to a light-emitting device, a display panel, a method for manufacturing the same, and a display apparatus. Background Technology

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

[0003] When forming a quantum dot luminescent layer, the poor bonding between the quantum dot luminescent layer and its adjacent electron transport layer can affect the film quality of the quantum dot luminescent layer.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this disclosure is to prevent damage to the quantum dot film layer of the patterned sub-pixel region during the fabrication of a light-emitting device, and to provide a light-emitting device, a display panel, a method for fabricating the same, and a display apparatus.

[0006] According to one aspect of this 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, which are stacked sequentially. The interface modification layer comprises an acetylacetone metal chelate, and the quantum dot light-emitting layer comprises quantum dot material and a crosslinking agent. The crosslinking agent comprises a crosslinking group and a carboxyl group on the side chain. The quantum dot material is crosslinked together by the crosslinking group. 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.

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

[0008] In one embodiment of this disclosure, the quantum dot material includes quantum dots and ligands on the surface of the quantum dots, the ligands being bonded together with crosslinking groups.

[0009] In one embodiment of this 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, and CsPbI3 and ZnS. The ligands include coordination units and saturated or unsaturated hydrocarbon and heterohydrocarbon groups. The coordination units include at least one of amino, mercapto, hydroxyl, and phosphonic acid groups.

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

[0011] In one embodiment of this disclosure, the metal on the acetylacetone metal chelate is linked to the hydroxyl group on the electron transport layer.

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

[0013] In one embodiment of this 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 this disclosure, the electron transport layer includes zinc oxide and doped zinc oxide, wherein 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 this disclosure, a display panel is provided, including a substrate, a pixel definition layer, and at least three different colors of light-emitting devices provided in one aspect of this disclosure. The pixel definition layer is disposed on one side of the substrate and has a plurality of pixel openings. The light-emitting devices of different colors are respectively disposed in the plurality of pixel openings.

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

[0017] A cathode is formed on one side of the substrate.

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

[0019] An interface modification layer is formed on the side of the electron transport layer away from the substrate. The interface modification layer includes an acetylacetone metal chelate.

[0020] A quantum dot light-emitting layer of at least three different colors is formed on the side of the interface modification layer away from the substrate.

[0021] A hole transport layer is formed on the side of the quantum dot light-emitting layer away from the substrate.

[0022] A hole injection layer is formed on the side of the hole transport layer away from the substrate.

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

[0024] In one embodiment of this disclosure, forming an electron transport layer exposing the pixel opening on the 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 the side of the electron transport layer away from the cathode, and the pixel definition layer has pixel openings that expose the electron transport layer.

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

[0028] A pixel definition layer with pixel openings is formed on the surface of the cathode;

[0029] An electron transport layer is formed on the portion of the cathode that exposes the pixel opening.

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

[0031] A quantum dot coating of a certain color containing a crosslinking agent is formed on the interface modification layer;

[0032] A mask is used to expose a quantum dot coating of one color, crosslinking different quantum dots, and allowing the carboxylic acid in the crosslinked quantum dots to react and connect with the metal of the acetylacetone metal chelate.

[0033] The exposed quantum dot coating of one color is developed. The unexposed areas of the quantum dot coating are removed during the development process, while the exposed areas of the quantum dot coating are retained, forming a quantum dot light-emitting layer for a light-emitting device of one color.

[0034] Quantum dot coatings of other colors are repeatedly formed. A mask is used to expose the quantum dot coating of that color, and the exposed quantum dot coating is developed to form the quantum dot light-emitting layer of the light-emitting device of other colors.

[0035] According to another aspect of this disclosure, a display device is provided, the display device including a display panel provided in another aspect of this disclosure.

[0036] The light-emitting device disclosed herein includes a quantum dot light-emitting layer and an interface modification layer. The interface modification layer includes an acetylacetone metal chelate, and the quantum dot light-emitting layer includes quantum dot materials and a crosslinking agent. The crosslinking agent includes crosslinking groups and carboxyl groups in its side chains. When forming the quantum dot light-emitting layer on the interface modification layer, different quantum dot materials are crosslinked using a crosslinking agent with carboxyl groups in its side chains. The carboxylic acid in the crosslinked quantum dot materials reacts and connects with the metal in the acetylacetone metal chelate, thereby anchoring the exposed quantum dot light-emitting layer as a whole to the underlying layer. This significantly improves the bonding between the quantum dot light-emitting layer and its adjacent electron transport layer, thus improving the film quality of the quantum dot light-emitting layer.

[0037] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0038] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0039] Figure 1 This is a cross-sectional schematic diagram of the light-emitting device involved in the embodiments of this disclosure.

[0040] Figure 2 This is a cross-sectional schematic diagram of a display panel according to an embodiment of this disclosure.

[0041] Figure 3 This is a flowchart illustrating a method for manufacturing a display panel according to an embodiment of this disclosure.

[0042] Figure 4 This is a cross-sectional schematic diagram of a display panel according to an embodiment of this disclosure.

[0043] Figure 5 This is a cross-sectional schematic diagram of another display panel according to an embodiment of this disclosure.

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

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

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

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

[0048] Figure 10 This is a cross-sectional schematic diagram of a substrate after a red quantum dot coating has been formed on one side of the substrate according to an embodiment of this disclosure.

[0049] Figure 11 This is a cross-sectional schematic diagram of a red quantum dot light-emitting layer formed on one side of a substrate according to an embodiment of this disclosure.

[0050] Figure 12 This is a cross-sectional schematic diagram of a substrate after a green quantum dot coating has been formed on one side of the substrate according to an embodiment of this disclosure.

[0051] Figure 13 This is a cross-sectional schematic diagram of a green quantum dot light-emitting layer formed on one side of a substrate according to an embodiment of this disclosure.

[0052] Figure 14 This is a cross-sectional schematic diagram of a substrate after a blue quantum dot coating has been formed on one side of the substrate according to an embodiment of this disclosure.

[0053] Figure 15 This is a cross-sectional schematic diagram of a blue quantum dot light-emitting layer formed on one side of a substrate according to an embodiment of this disclosure.

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

[0055] Figure 17 This is a flowchart illustrating a quantum dot light-emitting layer for a light-emitting device of at least three different colors formed on the side of the interface modification layer away from the substrate, according to an embodiment of this disclosure.

[0056] Figure 18 This is a schematic diagram illustrating the reaction process of the quantum dot coating with the acetylacetone metal chelate during exposure, as described in an embodiment of this disclosure.

[0057] In the diagram: 1. Substrate; 2. Driving circuit layer; 3. Pixel layer; 31. Pixel definition layer; 311. Pixel aperture; 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 Implementation

[0058] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.

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

[0060] The terms “a,” “one,” “the,” “the,” 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 indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first,” “second,” and “third,” etc., are used only as markers and are not a limitation on the number of objects.

[0061] Quantum dots (QDs) are excellent nanomaterials for emitting light, possessing advantages such as high quantum yield, narrow emission peaks, tunable emission spectra, and high photochemical stability. Therefore, quantum dot light-emitting diodes (QLEDs) with quantum dots as the emitting layer have attracted widespread attention due to their self-emissive nature, low power consumption, and wide color gamut.

[0062] In current quantum dot light-emitting diode (QLED) display technology, patterning is a crucial process step, and photolithography patterning is one high-resolution patterning method. The photolithography patterning process requires repeating the spin-coating, exposure, and development processes 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, forming multiple red sub-pixels, multiple green sub-pixels, and multiple blue sub-pixels. These red, green, and blue sub-pixels constitute a pixel unit.

[0063] To ensure the color purity of each sub-pixel, the development process must guarantee that the quantum dot emitting layers 3223 of each color dot ...

[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 silicon oxide material, such as SiO. However, the quantum dot solvent is usually an organic solvent. Within the pixel opening 311 of the pixel definition layer 31, the wettability of the quantum dot solution is poor, which will affect the quality of the quantum dot light-emitting layer 3223 deposited by solution spin coating.

[0065] Furthermore, in most existing high-efficiency quantum dot light-emitting diodes, the electron transport layer 3221 is made of ZnO or its doped materials, while the hole transport layer 3224 is made of organic materials. Metal oxides have higher electron mobility than organic materials, which typically leads to an imbalance in carrier injection within the device, resulting in reduced device efficiency and lifetime.

[0066] To address this issue, the structure of quantum dot LEDs can be modified, such as by inserting an insulating layer. This insulating layer could be made of polymethyl methacrylate (PMMA), or Mg-doped ZnO, to reduce the electron transport rate or increase the injection barrier, thereby suppressing electron injection. During solution processing, the thickness of the insulating layer requires extremely high precision. An excessively thick insulating layer will reduce the conductivity of the quantum dot LED, and the reliability of the deposition process for thin films of a few nanometers cannot be guaranteed. Furthermore, metal oxides can lead to an increase in defect interfaces.

[0067] Based on this, the present disclosure provides a light-emitting device 32. For example... 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 sequentially. The interface modification layer 3222 includes an acetylacetone metal chelate. The quantum dot light-emitting layer 3223 includes quantum dot material and a crosslinking agent. The crosslinking agent includes crosslinking groups and carboxyl groups on the side chains. The quantum dot materials are crosslinked together through the crosslinking groups. The carboxyl groups in the crosslinking agent located at the interface between the interface modification layer 3222 and the quantum dot light-emitting layer 3223 are 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 crosslinked by using a crosslinking agent with carboxyl groups in the side chain. The carboxylic acid in the crosslinked quantum dot material reacts and connects with the metal of the acetylacetone metal chelate, thereby anchoring the exposed quantum dot light-emitting layer 3223 as a whole to the lower layer. This greatly improves the bonding between the quantum dot light-emitting layer 3223 and its adjacent electron transport layer 3221, thereby improving the film formation quality of the quantum dot light-emitting layer 3223.

[0069] The light-emitting device 32 according to the embodiments of this disclosure will now be described in detail.

[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 disposed between the anode 323 and the cathode 321. An electron transport layer 3221 is provided on one side of the cathode 321. An interface modification layer 3222 is provided on the side of the electron transport layer 3221 away from the cathode 321. A quantum dot light-emitting layer 3223 is provided on the side of the interface modification layer 3222 away from the cathode 321. A hole transport layer 3224 is provided on the side of the quantum dot light-emitting layer 3223 away from the cathode 321. A hole injection layer 3225 is provided on the side of the hole transport layer 3224 away from the cathode 321. An anode 323 is provided 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 coordinating molecule (acac-) and a chelating metal M. The specific molecular structure of the acetylacetone metal chelate may be M(acac)x. The chelating metal M may include at least one of aluminum, hafnium, and zirconium. It should be noted that the chelating metal includes, but is not limited to, aluminum, hafnium, and zirconium, and may also be other metals that can coordinate with the acetylacetone coordinating molecule.

[0073] The quantum dot luminescent layer 3223 comprises quantum dot material, which includes quantum dots and ligand R2 on the surface of the quantum dots, specifically as shown in the molecular structure of equation (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, and CsPbI3 and ZnS. The ligands are organic ligands, possessing a coordination unit and saturated or unsaturated hydrocarbon and heteroalkyl groups (R2). The coordination unit includes, but is not limited to, amino groups, mercapto groups, hydroxyl groups, and phosphonic acids, such as oleic acid, oleylamine, isooctyl mercaptan, and trioctylphosphine, which can provide the groups included in the coordination unit.

[0076] The quantum dot light-emitting layer 3223 includes a crosslinking agent, which comprises a bis(azide) crosslinking unit, a linking unit R1, and a carboxyl group, specifically as shown in the molecular structure of formula (2):

[0077]

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

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

[0080] 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'-di(9-carbazole)biphenyl (CBP), NiOx, and V2O5.

[0081] 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 via a mask, the diazid crosslinking units in the crosslinking agent react with the hydrocarbons in the ligands on the quantum dot surface, crosslinking different quantum dot materials. At the interface between the quantum dot luminescent layer 3223 and the interface modification layer 3222, the diazid crosslinking units of the crosslinking agent connected to the interface modification layer 3222 also participate in the crosslinking of the quantum dot materials, bonding the crosslinked quantum dot materials together with the chelated metal in the metal chelate, thereby anchoring the exposed quantum dot luminescent layer 3223 onto the interface modification layer 3222. The acetylacetone metal chelate fixes the crosslinked quantum dot luminescent layer 3223 through in-situ chemical reaction, rather than physical affinity, and can withstand strong development processes. Using a strong development process improves the residue problem while reducing the impact on the exposed area.

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

[0084] When the chelated metal on the acetylacetone metal chelate comes into contact with the electron transport layer 3221, the chelated metal can connect with the hydroxyl groups on the electron transport layer 3221. The remaining acetylacetone coordination molecules then form an outward orientation and arrange themselves on the surface of the electron transport layer 3221, 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 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 typically provide channels for nonradiative recombination of charge carriers. Acetylacetone metal chelates are a type of interface layer material that, while improving the bonding strength between the quantum dot emitting layer 3223 and the electron transport layer 3221, can connect with hydroxyl groups on ZnO, remove hydroxyl groups present at the interface of the electron transport layer 3221, suppress nonradiative recombination between the quantum dot material and the electron transport layer 3221, and allow more charge carriers to undergo radiative recombination, thereby improving the efficiency of the light-emitting device 32.

[0086] The following are several specific embodiments 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 sequentially. The electron transport layer 3221 includes zinc oxide and doped zinc oxide. The doped zinc oxide includes zinc oxide and a doped metal, including magnesium. The acetylacetone metal chelate includes acetylacetone coordination molecules and a chelated metal, including aluminum. The quantum dot light-emitting layer 3223 includes quantum dot material and a crosslinking agent. The quantum dot material includes quantum dots and ligands on the surface of the quantum dots. The quantum dots include CdS. The ligands include coordination units and saturated or unsaturated hydrocarbon and heterohydrocarbon groups. The coordination units include amino groups, mercapto groups, hydroxyl groups, and phosphonic acids. The crosslinking agent includes a diazid crosslinking unit, a linking unit R1, and a carboxyl group, wherein the crosslinking agent can be 3,5-Diazidobenzoic acid. Hole transport layer 3224 is poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine)]. Hole injection layer 3225 is poly3,4-ethylenedioxythiophene:polystyrene sulfonate. Cathode 321 and 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 sequentially. The electron transport layer 3221 includes zinc oxide and doped zinc oxide. The doped zinc oxide includes zinc oxide and a doped metal, including magnesium. The acetylacetone metal chelate includes acetylacetone coordination molecules and a chelated metal, including hafnium. The quantum dot light-emitting layer 3223 includes quantum dot material and a crosslinking agent. The quantum dot material includes quantum dots and ligands on the surface of the quantum dots. The quantum dots include CdS and ZnS. The ligands include coordination units and saturated or unsaturated hydrocarbon and heterohydrocarbon groups. The coordination units include amine groups. The crosslinking agent includes a diazido crosslinking unit, a linking unit R1, and a carboxyl group, wherein the crosslinking agent can be cis-syn-3,4-diazidocyclopentanecarboxylicacid. Hole transport layer 3224 is poly[bis(4-phenyl)(4-butylphenyl)amine]. Hole injection layer 3225 is poly(3,4-ethylenedioxythiophene):polystyrene sulfonate. Cathode 321 and 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 sequentially. The electron transport layer 3221 includes zinc oxide and doped zinc oxide. The doped zinc oxide includes zinc oxide and a doped metal, including tin. The acetylacetone metal chelate includes acetylacetone coordination molecules and a chelated metal, including zirconium. The quantum dot light-emitting layer 3223 includes quantum dot material and a crosslinking agent. The quantum dot material includes quantum dots and ligands on the surface of the quantum dots. The quantum dots include CdSe. The ligands include coordination units and saturated or unsaturated hydrocarbon and heterohydrocarbon groups. The coordination units include amino groups and thiol groups. The crosslinking agent includes a diazidide crosslinking unit, a linking unit R1, and a carboxyl group, wherein the crosslinking agent 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 anode 323 can be made of metal.

[0093] It should be noted that, in addition to the cases involved in Examples 1 to 3, the components included in each layer can also be freely combined to form new light-emitting devices 32, which will not be listed here.

[0094] This disclosure provides a display panel. For example... Figure 2 As shown, the display panel includes a substrate 1, a pixel definition layer 31, and at least three different colored light-emitting devices 32 as described above. The pixel definition layer 31 is disposed on one side of the substrate 1 and has multiple pixel openings 311. The light-emitting devices 32 of different colors are respectively disposed within the multiple pixel openings 311. 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 be referred to the light-emitting device 32, which 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 materials of the light-emitting device 32 mentioned in any of Embodiments 1 to 3 above. In addition to the several cases involved in Embodiments 1 to 3, new light-emitting devices 32 formed by other optional material combinations of each layer are also used.

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

[0097] In step S10, a cathode 321 is formed on one side of the substrate 1.

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

[0099] In step S30, an interface modification layer 3222 is formed on the side of the electron transport layer 3221 away from the substrate 1. The interface modification layer 3222 includes an acetylacetone metal chelate.

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

[0101] In step S50, a hole transport layer 3224 is formed on the side of the quantum dot light-emitting layer 3223 away from the substrate 1.

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

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

[0104] The cathode 321 can be formed on the driving circuit layer 2 on one side of the substrate 1 using vacuum evaporation. An 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, with its width formed within the pixel opening 311; alternatively, the electron transport layer 3221 can be larger than the width of the pixel opening 311, positioned between the cathode 321 and the pixel definition layer 31, exposing the pixel opening 311. An interface modification layer 3222 can be formed by spin coating an acetylacetone metal chelate onto the surface of the electron transport layer 3221. A quantum dot light-emitting layer 3223 can be formed on the surface of the interface modification layer 3222 by solution spin coating. A hole transport layer 3224 can be deposited on the quantum dot light-emitting layer 3223. A 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 substrate 1 may include:

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

[0107] A pixel definition layer 31 is formed on the side of the electron transport layer 3221 away from the cathode 321, and the pixel definition layer 31 has a pixel opening 311 that exposes 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 substrate 1 may further include:

[0109] A pixel definition layer 31 with pixel openings 311 is formed on the surface of the cathode 321;

[0110] An electron transport layer 3221 is formed on the portion of the cathode 321 that exposes the pixel opening 311.

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

[0112] In step S401, a red quantum dot coating 324 containing a crosslinking agent is formed on the interface modification layer 3222. The red quantum dot coating 324 is exposed using a mask, and the exposed red quantum dot coating 324 is developed to form the red quantum dot light-emitting layer 3226 of the red light-emitting device 32.

[0113] like Figure 18 As shown, after exposure by masking, the bisazide crosslinking unit in the crosslinking agent reacts with the hydrocarbons in the ligands on the surface of the quantum dots under ultraviolet light irradiation, crosslinking different quantum dots, and causing the carboxylic acid in the crosslinked red quantum dot coating 324 to react and connect with the metal of the acetylacetone metal chelate.

[0114] The crosslinking agent at the interface of the red quantum dot coating is connected to the acetylacetone metal chelate. Its bisazide crosslinking unit also participates in the crosslinking of quantum dots, and the crosslinked red quantum dot coating 324 is chemically adhered to the interface modification layer 3222.

[0115] The exposed red quantum dot coating 324 is developed. 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 the patterning of the red quantum dot coating 324 and forming the 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 substrate 1. The green quantum dot coating 325 is exposed using a mask and then developed. The unexposed areas of the green quantum dot coating 325 are removed during the development process, while the exposed areas of the green quantum dot coating 325 are retained, forming the 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 then developed. The unexposed areas of the blue quantum dot coating 326 are removed during the development process, while the exposed areas of the blue quantum dot coating 326 are retained, forming the blue quantum dot light-emitting layer 3228 of the blue light-emitting device 32.

[0118] During the formation of the quantum dot light-emitting layer 3223, acetylacetone is formed. Therefore, step S40 may further include:

[0119] Step S404: Drying removes the quantum dot solvent and residual acetylacetone after the reaction.

[0120] The method may also include forming an encapsulation layer 4 on the side of the light-emitting device 32 of various colors away from the substrate 1.

[0121] This disclosure also provides a display device. This display device may include the display panel provided in any of the embodiments described above. The specific structure, materials of each layer, and beneficial effects of the display panel have been described in detail above, and therefore 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 parts, such as circuit boards, power cords, etc. Those skilled in the art can make corresponding additions 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, computer, television, projector, and camcorder, or an emerging wearable device, such as a VR wearable device, which will not be listed here. When the display device is a VR wearable device, the optical path adjustment lens 400 is a VR lens.

[0124] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A light-emitting device, characterized in that, The device comprises, in sequence, a cathode, an electron transport layer, an interface modification layer, a quantum dot luminescent layer, a hole transport layer, a hole injection layer, and an anode. The interface modification layer includes an acetylacetone metal chelate. The quantum dot luminescent layer includes quantum dot material and a crosslinking agent. The crosslinking agent includes crosslinking groups and carboxyl groups on the side chains. The quantum dot material is crosslinked together by the crosslinking groups. The carboxyl groups in the crosslinking agent located at the interface between the interface modification layer and the quantum dot luminescent layer are connected to the chelated metal in the acetylacetone metal chelate. The metal on the acetylacetone metal chelate is connected to the hydroxyl groups on the electron transport layer. The acetylacetone coordination molecules are arranged on the surface of the electron transport layer, with at least a portion of the acetylacetone coordination molecules oriented outwards and perpendicular to the electron transport layer.

2. The light-emitting device according to claim 1, characterized in that, The acetylacetone metal chelate comprises an acetylacetone coordination molecule, wherein the chelating metal is chelated together with the acetylacetone coordination molecule, and the chelating metal comprises 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, wherein the ligands are bonded together with the crosslinking 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, and CsPbI3 and ZnS. The ligands include coordination units and saturated or unsaturated hydrocarbon and heterohydrocarbon groups. The coordination units include at least one of amino, mercapto, hydroxyl, and phosphonic acid groups.

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

6. The light-emitting device according to claim 4, 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.

7. The light-emitting device according to claim 1, characterized in that, The electron transport layer comprises zinc oxide and doped zinc oxide, wherein the doped zinc oxide comprises zinc oxide and a doped metal, and the doped metal comprises at least one of magnesium and tin.

8. A display panel, characterized in that, include: Substrate; A pixel definition layer is disposed on one side of the substrate, and the pixel definition layer has multiple pixel openings; The light-emitting device of claim 1 has at least three different colors, and the light-emitting devices of different colors are respectively disposed in the plurality of pixel openings.

9. A method for manufacturing a display panel as described in claim 8, characterized in that, The method includes: A cathode is formed on one side of the substrate. An electron transport layer exposing the pixel opening is formed on the side of the cathode away from the substrate. An interface modification layer is formed on the side of the electron transport layer away from the substrate, the interface modification layer comprising an acetylacetone metal chelate; A quantum dot light-emitting layer of at least three different colors of light-emitting devices is formed on the side of the interface modification layer away from the substrate. A hole transport layer is formed on the side of the quantum dot light-emitting layer away from the substrate. A hole injection layer is formed on the side of the hole transport layer away from the substrate. An anode is formed on the side of the hole injection layer away from the substrate.

10. The method for manufacturing a display panel according to claim 9, characterized in that, An electron transport layer exposing a pixel opening is formed on the side of the cathode away from the substrate, comprising: An electron transport layer is formed on the entire surface of the cathode; A pixel definition layer is formed on the side of the electron transport layer away from the cathode, and the pixel definition layer has pixel openings that expose the electron transport layer.

11. The method for manufacturing a display panel according to claim 9, characterized in that, An electron transport layer exposing a pixel opening is formed on the side of the cathode away from the substrate, comprising: A pixel definition layer with pixel openings is formed on the surface of the cathode; An electron transport layer is formed on the portion of the cathode that exposes the pixel opening.

12. The method for manufacturing a display panel according to claim 9, characterized in that, The quantum dot light-emitting layer of the light-emitting device, which forms at least three different colors on the surface of the interface modification layer away from the cathode, includes: A quantum dot coating of a certain color containing a crosslinking agent is formed on the interface modification layer; A mask is used to expose a quantum dot coating of one color, crosslinking different quantum dots, and causing the carboxylic acid in the crosslinked quantum dot coating to react and connect with the metal of the acetylacetone metal chelate. A quantum dot coating of one color is developed after exposure, wherein the unexposed areas of the quantum dot coating are removed during the development process, and the exposed areas of the quantum dot coating are retained, forming a quantum dot light-emitting layer for a light-emitting device of one color. Quantum dot coatings of other colors are repeatedly formed. A mask is used to expose the quantum dot coating of that color, and the exposed quantum dot coating is developed to form the quantum dot light-emitting layer of the light-emitting device of other colors.

13. A display device, characterized in that, Includes the display panel as described in claim 8.

Images