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

Abstract

The embodiments of the present disclosure relates to the technical field of display, and is at least used for reducing the quenching of excitons. Provided are a light-emitting device and a manufacturing method therefor, and a display panel. The light-emitting device comprises an anode, a cathode, a light-emitting layer, and a first functional layer, wherein the anode and the cathode are disposed opposite to each other, the light-emitting layer is located between the anode and the cathode, and the first functional layer is located between the light-emitting layer and the cathode. The first functional layer is made of a first nano-material, which comprises a first metal oxide material and a first ligand material, wherein the first metal oxide material contains first metal elements, and the first ligand material contains first non-metal elements, the first non-metal elements being coordinatively bonded to the first metal elements. In the first nano-material, the mass ratio of the first metal elements to the first non-metal elements is greater than 3:1 and is less than or equal to 30:1. The light-emitting device is applied to a display apparatus.

Description

Light-emitting devices and their fabrication methods, display panels Technical Field

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

[0002] Quantum dots (QDs), as novel light-emitting materials, possess advantages such as high light purity, high quantum efficiency, tunable color emission, and long lifespan, making them a research hotspot for new LED (Light Emitting Diode) materials. Therefore, quantum dot light-emitting diodes (QLEDs) using quantum dot light-emitting materials as the emitting layer have found good applications in the display field. Summary of the Invention

[0003] On one hand, a light-emitting device is provided. The light-emitting device includes an anode, a cathode, a light-emitting layer, and a first functional layer. The anode and cathode are disposed opposite to each other. The light-emitting layer is located between the anode and the cathode. The first functional layer is located between the light-emitting layer and the cathode. The material of the first functional layer includes a first nanomaterial, which includes a first metal oxide material and a first ligand material. The first metal oxide material includes a first metal element, and the first ligand material includes a first non-metal element; the first non-metal element and the first metal element are capable of coordination linkage. In the first nanomaterial, the mass ratio of the first metal element to the first non-metal element is greater than 3:1 and less than or equal to 30:1.

[0004] In some embodiments, the first nonmetallic element includes nitrogen, and / or the first metallic element includes zinc.

[0005] In some embodiments, the first ligand material comprises a primary amine group and / or a secondary amine group.

[0006] In some embodiments, the first ligand material further includes a photosensitive group. The photosensitive group is configured to cause a cross-linking reaction between the first ligand materials under light irradiation conditions.

[0007] In some embodiments, the photosensitive group includes at least one of alkenyl, alkynyl, benzophenone, bisacridinyl, and azide.

[0008] In some embodiments, the first ligand material includes at least one selected from hydroxylamine compounds, secondary amine compounds, polyamine compounds, amino acid compounds, ethyleneimine compounds, amide compounds, alkenyl-containing amide compounds, and alkenyl-containing ethanolamine compounds.

[0009] In some embodiments, the first ligand material includes at least one of the structures shown in general formulas (I), (II), (III), (IV), (V), (VI), and (VII).

[0010] In this context, L1, L2, L3, and L4 may be the same or different, and are independently selected from substituted or unsubstituted C1-C5 straight-chain alkylene or branched alkylene. L5 and L6 may be the same or different, and are independently selected from single-bonded, substituted or unsubstituted C1-C5 straight-chain alkylene or branched alkylene. R1, R2, and R3 may be the same or different, and are independently selected from substituted or unsubstituted C1-C5 straight-chain alkyl or branched alkylene. n is a positive integer from 1 to 20.

[0011] In some embodiments, the light-emitting device further includes a second functional layer. The second functional layer is located between the first functional layer and the cathode. The material of the second functional layer includes a second nanomaterial. The material of the second nanomaterial includes a second metal oxide material.

[0012] In some embodiments, the thickness of the second functional layer is less than or equal to the thickness of the first functional layer.

[0013] In some embodiments, the first metal oxide material and the second metal oxide material comprise the same metal element.

[0014] In some embodiments, the light-emitting device further includes a third functional layer. The third functional layer is located between the first functional layer and the light-emitting layer. The material of the third functional layer includes a third nanomaterial, and the material of the third nanomaterial includes a third metal oxide material.

[0015] In some embodiments, the first metal oxide material and the third metal oxide material comprise the same metal element.

[0016] In some embodiments, the first metal oxide material further includes a first doped metal element; and / or, the light-emitting device further includes a second functional layer, the second metal oxide material including the first metal element and further including a second doped metal element; and / or, the light-emitting device further includes a third functional layer, the third metal oxide material including the first metal element and further including a third doped metal element. The first doped metal element, the second doped metal element, and the third doped metal element may be the same or different, and each independently includes at least one of magnesium, aluminum, tin, and manganese.

[0017] In some embodiments, the mass ratio of the first metal element to the doping metal element in the metal oxide material ranges from (20 to 30):1. The metal oxide material is any one of the first metal oxide material, the second metal oxide material, and the third metal oxide material. The doping metal element is one of the first doping metal element, the second doping metal element, and the third doping metal element included in the metal oxide material.

[0018] In some embodiments, the first nanomaterial further includes a second ligand material liganded to the first metal oxide material.

[0019] In some embodiments, the light-emitting device further includes a second functional layer, and the second nanomaterial further includes a second ligand material liganded to the second metal oxide material.

[0020] In some embodiments, the light-emitting device further includes a third functional layer, and the third nanomaterial further includes a second ligand material liganded in the third metal oxide material.

[0021] In some embodiments, the second ligand material includes at least one of hydroxyl and carboxyl groups.

[0022] On the other hand, a display panel is provided. The display panel includes: an encapsulation layer and a light-emitting device as described in any of the above embodiments. The encapsulation layer covers the light-emitting device. The material of the encapsulation layer includes an organic encapsulating adhesive.

[0023] In some embodiments, the organic encapsulant includes a neutral encapsulant, wherein the mass ratio of the first metal element to the first non-metal element is greater than 3:1 and less than or equal to 12:1.

[0024] In some embodiments, the organic encapsulant includes an acidic encapsulant; in the first nanomaterial, the mass ratio of the first metal element to the first non-metal element is greater than or equal to 10:1 and less than or equal to 30:1.

[0025] In another aspect, a method for fabricating a light-emitting device is provided. The method includes forming an anode, a cathode, a light-emitting layer, and a first functional layer. The anode and cathode are disposed opposite to each other. The light-emitting layer is located between the anode and the cathode. The first functional layer is located between the light-emitting layer and the cathode. The material of the first functional layer includes a first nanomaterial, which includes a first metal oxide material and a first ligand material. The first metal oxide material includes a first metal element, and the first ligand material includes a first non-metal element; the first non-metal element is coordinated with the first metal element. In the first nanomaterial, the mass ratio of the first metal element to the first non-metal element is greater than 3:1 and less than or equal to 30:1.

[0026] In some embodiments, after forming the anode, cathode, light-emitting layer, and first functional layer, the preparation method further includes: subjecting the first functional layer to ion treatment, wherein the ion treatment includes at least one of fluoride ion treatment, chloride ion treatment, and nitrogen ion treatment. In the first nanomaterial, the mass ratio of the first metal element to the first non-metal element is greater than or equal to 10:1 and less than or equal to 30:1. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in this disclosure, the accompanying drawings used in some embodiments of this disclosure will be briefly described below. Obviously, the drawings described below are only drawings of some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams and are not intended to limit the actual size of the product, the actual flow of the method, the actual timing of the signals, etc. involved in the embodiments of this disclosure.

[0028] Figure 1 is a structural diagram of a display panel according to some embodiments;

[0029] Figure 2 is a structural diagram of a display panel according to some other embodiments;

[0030] Figure 3 is a structural diagram of a display panel according to some other embodiments;

[0031] Figure 4 is a structural diagram of a display panel according to some other embodiments;

[0032] Figure 5 is a structural diagram of a display panel according to some other embodiments;

[0033] Figure 6 is a structural diagram of a display panel according to some other embodiments;

[0034] Figure 7 is a structural diagram of a display panel according to some other embodiments;

[0035] Figure 8 is a structural diagram of a display panel according to some other embodiments;

[0036] Figure 9 is a structural diagram of a display panel according to some other embodiments;

[0037] Figure 10 is a flowchart illustrating the fabrication process of a light-emitting device according to some embodiments;

[0038] Figure 11 is a step diagram of a method for fabricating a light-emitting device according to some embodiments;

[0039] Figure 12 is a step diagram of a method for fabricating a light-emitting device according to some embodiments;

[0040] Figure 13 is a structural diagram of a display panel according to some other embodiments;

[0041] Figure 14 is an absorption spectrum of the first nanomaterial in the first functional layer according to some embodiments;

[0042] Figure 15 is a graph showing the current density of a light-emitting device as a function of voltage according to some embodiments;

[0043] Figure 16 is a graph showing the change in brightness of a light-emitting device as a function of voltage according to some embodiments;

[0044] Figure 17 is a graph showing the external quantum efficiency of a light-emitting device as a function of voltage according to some embodiments;

[0045] Figure 18 is a graph showing the change in brightness of a light-emitting device as a function of voltage according to some other embodiments;

[0046] Figure 19 is a graph showing the external quantum efficiency of the light-emitting device according to some other embodiments as a function of voltage;

[0047] Figure 20 is a graph showing the current efficiency of a light-emitting device as a function of voltage according to some embodiments;

[0048] Figure 21 is a graph showing the external quantum efficiency of a light-emitting device according to some other embodiments as a function of voltage;

[0049] Figure 22 is a light-emitting morphology diagram of a light-emitting device according to some embodiments. Detailed Implementation

[0050] The technical solutions in some embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided in this disclosure are within the scope of protection of this disclosure.

[0051] Unless the context otherwise requires, throughout the specification and claims, the term "comprise" and its other forms, such as the third-person singular "comprises" and the present participle "comprising," are interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific example," or "some examples," etc., are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0052] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0053] "At least one of A, B and C" has the same meaning as "at least one of A, B or C", both including the following combinations of A, B and C: only A, only B, only C, combinations of A and B, combinations of A and C, combinations of B and C, and combinations of A, B and C.

[0054] "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0055] The use of “applies to” or “configured to” in this article implies an open and inclusive language that does not preclude applicability to or configuration to devices that perform additional tasks or steps.

[0056] As used herein, “about,” “approximately,” or “approximately” includes the stated value and the average value within an acceptable range of deviation from the given value, wherein the acceptable range of deviation is determined by a person skilled in the art taking into account the measurement under discussion and the error associated with the measurement of the given quantity (i.e., the limitations of the measurement system).

[0057] As used herein, “parallel,” “perpendicular,” and “equal” include the described situation and situations that are similar to the described situation, within an acceptable range of deviation, which is determined by those skilled in the art taking into account the measurement under discussion and the error associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, “parallel” includes absolute parallelism and approximate parallelism, where an acceptable range of deviation for approximate parallelism may be, for example, within 5°; “perpendicular” includes absolute perpendicularity and approximate perpendicularity, where an acceptable range of deviation for approximate perpendicularity may also be, for example, within 5°; “equal” includes absolute equality and approximate equality, where an acceptable range of deviation for approximate equality may be, for example, a difference between the two equals being less than or equal to 5% of either one.

[0058] It should be understood that when a layer or element is referred to as being on another layer or substrate, it can mean that the layer or element is directly on the other layer or substrate, or that there is an intermediate layer between the layer or element and the other layer or substrate.

[0059] This document describes exemplary embodiments with reference to cross-sectional views and / or plan views, which are idealized exemplary drawings. In the drawings, the thickness of layers and the area of ​​regions are enlarged for clarity. Therefore, variations in shape relative to the drawings are contemplated due to, for example, manufacturing techniques and / or tolerances. Thus, exemplary embodiments should not be construed as being limited to the shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing processes. For example, etched areas shown as rectangular would typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of the areas of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0060] It should be noted that, for example, 11-1 in the accompanying drawings of this disclosure indicates that component 11 belongs to component 1; for example, 221-220 in Figure 2 indicates that pixel defining layer 221 belongs to light-emitting functional layer 220; other similar reference numerals in the drawings also follow the above description. For example, 1 / 2 in the accompanying drawings of this disclosure indicates that structure 1 and structure 2 can both refer to this structure; for example, 101 / 100 in Figure 2 indicates that the first light-emitting device 101 and the light-emitting device 100 can both be represented by this structure. Other similar reference numerals in the accompanying drawings also follow the above description.

[0061] As shown in FIG1, some embodiments of the present disclosure provide a display panel 200, which includes a light-emitting device 100.

[0062] The aforementioned display panel 200 can, for example, be a quantum dot light-emitting diode (QLED) display panel, in which case the light-emitting device 100 is a QLED light-emitting device. Based on the quantum confinement effect, quantum dots (QDs) can serve as the light-emitting material for novel light-emitting diodes (LEDs), possessing advantages such as high color purity, high quantum efficiency, tunable color emission, and long lifespan. Therefore, QLEDs using quantum dots as the light-emitting material have increasingly promising application prospects in the display field, and QLED light-emitting devices have received widespread attention.

[0063] The aforementioned display panel 200 can be applied to a display device. The display device can be any display device that displays either moving (e.g., video) or stationary (e.g., still images), and whether it displays text or images. More specifically, the display panel of the described embodiment is contemplated for implementation in or associated with a variety of electronic devices, such as (but not limited to) mobile phones, wireless devices, personal data assistants (PDAs), handheld or portable computers, GPS receivers / navigators, cameras, MP4 video players, camcorders, game consoles, watches, clocks, calculators, television monitors, flat panel displays, computer monitors, automotive displays (e.g., odometer displays, etc.), navigators, cockpit controllers and / or displays, displays of camera views (e.g., displays of rearview cameras in vehicles), electronic photographs, electronic billboards or signs, projectors, architectural structures, packaging and aesthetic structures (e.g., displays of images of a piece of jewelry), etc.

[0064] In some embodiments, as shown in FIG1, the display panel 200 includes a substrate 210 and a light-emitting functional layer 220 disposed on one side of the substrate 210, the light-emitting functional layer 220 including a plurality of light-emitting devices 100.

[0065] For example, a plurality of light-emitting devices 100 may be arranged along a second direction Y, which is, for example, a direction parallel to the plane where the substrate 210 is located.

[0066] For example, the material of the substrate 210 can be a rigid material, such as glass, to realize a rigid substrate display; or the material of the substrate 210 can also be a flexible material, such as polyimide (PI) or polyethylene terephthalate (PET), to realize a flexible substrate display.

[0067] In some embodiments, as shown in FIG1 and FIG2, the light-emitting functional layer 220 in the display panel 200 further includes a pixel defining layer 221, the pixel defining layer 221 having a plurality of openings Q, and a plurality of light-emitting devices 100 being configured one-to-one with the plurality of openings Q.

[0068] In some examples, as shown in FIG1, the display panel 200 further includes a driving circuit layer 230 disposed between the substrate 210 and the light-emitting functional layer 220, the driving circuit layer 230 including a plurality of pixel driving circuits 231.

[0069] For example, the pixel driving circuit 231 can generate a driving current. Each light-emitting device 100 can emit light under the driving action of the driving current generated by the corresponding pixel driving circuit 231. The light emitted by multiple light-emitting devices 100 cooperates with each other, thereby enabling the display panel 200 to perform the display function.

[0070] In some examples, the driving circuit layer 230 includes multiple pixel driving circuits 231 (e.g., multiple pixel driving circuits 231 arranged in an array), and each pixel driving circuit 231 includes multiple transistor TFTs. The pixel driving circuits 231 are electrically connected to the light-emitting device 100 and are used to drive the light-emitting device 100 to emit light. In this case, the pixel driving circuits 231 employ TFT technology, and the display panel 200 can be referred to as an active-drive display panel (e.g., an active-drive QLED display panel, an AMQLED display panel).

[0071] In some embodiments, as shown in FIG1, the display panel 200 further includes an encapsulation layer 240, which covers the light-emitting device 100.

[0072] For example, the driving circuit layer 230, the light-emitting functional layer 220 and the encapsulation layer 240 can be stacked on the substrate 210, and the driving circuit layer 230, the light-emitting functional layer 220 and the encapsulation layer 240 are arranged sequentially in a direction away from the substrate 210.

[0073] For example, the display panel 200 can be a QLED display panel 200. In this case, the encapsulation layer 240 covers the light-emitting device 100, which can prevent moisture and oxygen in the external environment from entering the display panel 200 and damaging the materials in the light-emitting device 100, thereby shortening the lifespan of the QLED display panel 200.

[0074] In some embodiments, the material of the encapsulation layer 240 includes an organic encapsulating adhesive.

[0075] Organic encapsulants have the characteristic of being able to level during the manufacturing process, which can achieve the planarization of the surface of the display panel 200. Moreover, organic encapsulants can encapsulate defects and particles that may occur during the process, thereby improving the encapsulation effect of the encapsulation layer 240.

[0076] In some examples, the encapsulation layer 240 employs thin-film encapsulation (TFE) technology. In this case, the encapsulation layer 240 can be a composite layer. For example, the encapsulation layer 240 may include a first sub-layer and a second sub-layer arranged sequentially in a direction away from the light-emitting device 100. The material of the first sub-layer includes the aforementioned organic encapsulant; the material of the second sub-layer includes an inorganic material. The inorganic material is, for example, silicon nitride.

[0077] For example, when the encapsulation layer 240 employs TFE technology, the encapsulation layer 240 may further include a third sublayer located between the first sublayer and the light-emitting device 100, the material of the third sublayer including an inorganic material. The inorganic material is, for example, silicon nitride.

[0078] For example, plasma-enhanced chemical vapor deposition (PECVD) can be used to coat inorganic materials on the side of the light-emitting device 100 away from the substrate 210 to form a second sublayer and / or a third sublayer.

[0079] When the encapsulation layer 240 also includes a second sublayer and / or a third sublayer, the second and / or third sublayers can form a passivation layer, and the organic encapsulant (i.e., the first sublayer) can relieve the stress of the passivation layer. Furthermore, when the encapsulation layer 240 includes a second sublayer, the inorganic material can form a protective layer on the outside of the organic encapsulant, and can also improve the water and oxygen barrier properties of the encapsulation layer 240.

[0080] In some other examples, as shown in Figure 13, the display panel 200 also includes a frame adhesive 260 (also referred to as Dam) surrounding the light-emitting device 100. In this case, the organic encapsulant of the encapsulation layer 240 can be filled inside the frame adhesive 260 so that the organic encapsulant can cover the light-emitting device 100.

[0081] For example, the material of the frame adhesive 260 includes at least one of epoxy resin and UV-curable adhesive.

[0082] In some examples, as shown in Figure 13, the organic encapsulant of the encapsulation layer 240 also fills the space between the frame adhesive 260 and the light-emitting device 100.

[0083] It should be noted that while Figure 13 shows only one light-emitting device 100 in the display panel 200, it should be understood that the display panel 200 may include multiple light-emitting devices 100, which are arranged within the space enclosed by the frame adhesive 260. The encapsulation layer 240 covers the multiple light-emitting devices 100.

[0084] In some examples, the display panel 200 also includes a drying sheet (not shown) located on the side of the encapsulation layer 240 and / or the frame adhesive 260 away from the substrate 210. The drying sheet can function as a barrier against water and oxygen, preventing the materials of the encapsulation layer 240 and / or the frame adhesive 260 from being degraded by the water and oxygen environment.

[0085] As exemplarily shown in FIG13, the display panel 200 further includes a cover plate 250 disposed on the side of the encapsulation layer 240 away from the light-emitting device 100. The cover plate 250 provides support and protection for the display panel 200 and enables the display panel 200 to maintain good performance even when subjected to impact or scratches.

[0086] For example, cover plate 250 may include one or any combination of glass cover plate, ceramic cover plate, plastic cover plate and optical composite material cover plate.

[0087] For example, as shown in FIG13, when the display panel 200 also includes a frame adhesive 260, the cover plate 250 can be attached to the frame adhesive 260.

[0088] For example, if the display panel 200 also includes a drying sheet, the drying sheet may be attached to the surface of the cover plate 250 near the substrate 210.

[0089] In some embodiments, as shown in Figures 2 and 3, the plurality of light-emitting devices 100 of the display panel 200 include at least one first light-emitting device 101, at least one second light-emitting device 102, and at least one third light-emitting device 103. Under the action of a driving voltage, the first light-emitting device 101 is configured to emit a first color light (e.g., blue light), the second light-emitting device 102 is configured to emit a second color light (e.g., green light), and the third light-emitting device 103 is configured to emit a third color light (e.g., red light). Thus, the brightness (grayscale) of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 can be adjusted respectively, and multiple colors can be displayed through color combination and superposition, thereby achieving full-color display of the display panel 200.

[0090] In some embodiments, as shown in Figures 1 to 3, the light-emitting device 100 includes an anode 110 and a cathode 120 disposed opposite to each other, and a light-emitting layer 130 located between the anode 110 and the cathode 120.

[0091] It should be understood that, as shown in Figures 2 and 3, when the multiple light-emitting devices 100 of the display panel 200 include at least one first light-emitting device 101, at least one second light-emitting device 102 and at least one third light-emitting device 103, the materials of the light-emitting layer 131 of the first light-emitting device 101, the light-emitting layer 132 of the second light-emitting device 102 and the light-emitting layer 133 of the third light-emitting device 103 are different, so as to achieve the purpose of emitting different colors of light.

[0092] For example, the anode 110 and the cathode 120 may be arranged opposite each other along a first direction X, which intersects (e.g., is perpendicular to) a second direction Y.

[0093] In some examples, as shown in Figure 2, the anode 110 can be located on the side of the light-emitting layer 130 closer to the substrate 210, and the cathode 120 can be located on the side of the light-emitting layer 130 away from the substrate 210. In this case, the light-emitting device 100 can be referred to as a positive light-emitting device.

[0094] In other examples, as shown in Figure 3, the cathode 120 may be located on the side of the light-emitting layer 130 closer to the substrate 210, and the anode 110 may be located on the side of the light-emitting layer 130 away from the substrate 210. In this case, the light-emitting device 100 may be referred to as an inverted light-emitting device.

[0095] For example, the materials of the anode 110 and the cathode 120 may be the same or different, and can be independently selected from at least one of conductive metal oxide materials (e.g., transparent conductive metal oxide materials), conductive glass, conductive polymers (e.g., transparent conductive polymers), and metallic materials (e.g., opaque metallic materials). The conductive metal oxide materials are, for example, indium tin oxide (ITO), fluorine-doped tin oxide (FTO), or indium zinc oxide (IZO), and the metallic materials are, for example, aluminum (Al), silver (Ag), or magnesium-silver alloy (Mg:Ag). The conductive polymers are, for example, polyaniline (PANI), polycarbazole (PZ), polythiophene (PTh), or polypropylene (PPy).

[0096] In some embodiments, as shown in Figures 2 and 3, when the plurality of light-emitting devices 100 include a first light-emitting device 101, a second light-emitting device 102 and a third light-emitting device 103, the anode 110 and the cathode 120 that are farther from the substrate 210 can be a structure that is connected in one layer, that is, the anode 110 and the cathode 120 that are farther from the substrate 210 can be a common electrode shared by the plurality of light-emitting devices 100.

[0097] For example, as shown in Figures 2 and 3, when the anode 110 and cathode 120 that are farther from the substrate 210 can be a common electrode shared by multiple light-emitting devices 100, the anode 110 and cathode 120 that are farther from the substrate 210 are also formed on the side of the pixel defining layer 221 that is farther from the substrate 210.

[0098] In some examples, the light-emitting layer 130 is a quantum dot light-emitting layer. During operation, voltages are applied to the anode 110 and the cathode 120 respectively, generating an electric field between them. This field drives the holes in the anode 110 and the electrons in the cathode 120 to recombine in the quantum dot light-emitting layer 130, generating excitons (i.e., electron-hole pairs). The excitons then undergo radiative transitions back to the ground state, emitting photons and thus emitting light.

[0099] For example, the materials forming the quantum dot luminescent layer include a quantum dot luminescent material and a photosensitive material; wherein the quantum dot luminescent material includes a quantum dot matrix and a ligand material coordinated to the quantum dot matrix. The photosensitive material is configured to undergo a cross-linking reaction with the ligand material under light radiation conditions to generate a cross-linked quantum dot luminescent material. With the above configuration, a quantum dot luminescent layer can be formed by photolithography. Specifically, by utilizing photochemical reactions such as the decomposition or cross-linking of photosensitive groups, the colloidal stability of the quantum dots changes before and after the photochemical reaction, and selective patterning is achieved through development.

[0100] In some examples, the quantum dot body may include any one or more of the following: group II-VI quantum dots, group III-V quantum dots, group IV-VI quantum dots, group IV quantum dots, group I-III-VI quantum dots, group I-II-IV-VI quantum dots, core-shell quantum dots, and ABX3 type perovskite quantum dots, or any combination thereof.

[0101] Among them, group II-VI quantum dots can be selected from one or more of the following: binary compounds such as CdS, CdSe, CdTe, ZnS, ZnO, ZnSe, ZnTe, HgSe, HgTe, and HgS; ternary compounds such as Hg x Cd 1-x Te, Hg x Cd 1-x S, Hg x Cd 1-x Se, Hg x Zn 1-x Te, Cd x Zn 1-x Se、Cd x Zn 1-x One or more of S and ZnTeSe, where 0 < x < 1, but not limited thereto.

[0102] III-V group quantum dots can be selected from: InP, InAs, InSb, GaAs, GaP, GaN, GaSb, GaNk, InN, AlP, AlN, AlAs, InGaAs, InGaN, or mixtures thereof; but are not limited thereto.

[0103] Group IV-VI quantum dots can be selected from: PbS, PbSe, PbTe, or mixtures thereof; but are not limited to these.

[0104] Core-shell quantum dots refer to quantum dots where one material forms the core and the other forms the shell. For example, a CdS@ZnS quantum dot means that the core is made of CdS and the shell is made of ZnS. Core-shell quantum dots can be selected from: CdS@ZnS, CdSe@CdS, InP@ZnS, CdTe@CdSe, CdSe@ZnTe, CdSe@ZnS, PdS@ZnS, ZnTe@CdSe, ZnSe@CdS, and Cd... 1-x Zn x One or more of S@ZnS, where 0 < x < 1, but not limited thereto.

[0105] In ABX3 type perovskite quantum dots, A can be CH3NH3. + (methylamine), NH2CH=NH2 (formamidinium) and Cs + One or more of them, B can be Pb 2+ and Sn 2+ One or two of them, X can be Cl - ,Br - and I - One or more of the following can be used: ABX3 type perovskite quantum dots can include, but are not limited to, CH3NH3PbBr3, CH3NH3PbCl3, CH3NH3PbI3, CsPbBr3, CsPbCl3 and CsPbI3.

[0106] When multiple quantum dots are combined, the quantum dot body can be one of CsPbCl3 / ZnS, CsPbBr3 / ZnS, CsPbI3 / ZnS, CdS / ZnSeS / ZnS, CdSe / ZnSeS / ZnS, ZnSe / ZnSeS / ZnS, and ZnSeTe / ZnSeS / ZnS.

[0107] In other examples, the quantum dot bulk can be other nanoscale materials, such as nanorods, nanosheets, etc. The composition of other nanoscale materials may include, but is not limited to, at least one of CuInS2, CuInSe2, AgInS2, etc.

[0108] For example, the shape of the quantum dot body can be any geometric shape such as sphere, ellipsoid, polyhedron, rod, cross, ring, etc.

[0109] In some examples, the ligand material may be selected from any one or a combination of organic acids, organic amines, organophosphorus compounds, and organothiols. For example, the ligand material may be oleic acid, oleylamine, or dodecyl mercaptan.

[0110] In some embodiments, as shown in Figures 2 and 3, to improve luminous efficiency, the light-emitting device 100 further includes an electron transport unit 140 located on the side of the light-emitting layer 130 near the cathode 120 and in contact with the light-emitting layer 130. The electron transport unit 140 includes, for example, at least one of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (EBL).

[0111] In some embodiments, as shown in Figures 2 and 3, to improve luminous efficiency, the light-emitting device 100 further includes a hole transport unit 150 located on the side of the light-emitting layer 130 near the anode 110 and in contact with the light-emitting layer 130. The hole transport unit 150 includes, for example, at least one of a hole injection layer (HIL) 151, a hole transport layer (HTL) 152, and an electron blocking layer (EBL).

[0112] By setting up film layers such as hole transport unit 150 and electron transport unit 140, it is equivalent to setting transition steps between anode 110 and light-emitting layer 130, and between cathode 150 and light-emitting layer 130, which reduces the potential barrier height that carrier transitions need to overcome, resulting in higher luminous efficiency.

[0113] Exemplarily, the material of the hole injection layer 151 may include organic and / or inorganic materials. Organic materials may include, for example, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene (HAT-CN), polyethylene dioxythiophene (PEDOT), or polyethylene dioxythiophene-polystyrene sulfonate (PEDOT:PSS); inorganic materials may include, for example, molybdenum oxide (MoO). x Examples of fluorides include lithium fluoride (LiF), sodium fluoride (NaF), and magnesium fluoride (MgF2). For example, x is 3.

[0114] For example, the material of the hole transport layer 152 includes organic and / or inorganic materials. Organic materials include, for example, poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4′-(N-(4-sec-butylphenyl)diphenylamine)] (TFB), N,N′-diphenyl-N,N′-(1-naphthyl)-1,1′-biphenyl-4,4′-diamine (NPB), 4,4',4”-tris(carbazole-9-yl)triphenylamine (TCTA), N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), poly(4-butyltriphenylamine) (Poly-TPD), 4,4'-di(9-carbazole)biphenyl (CBP), poly(p-phenylacetylene) (PPV), or poly(N-vinylcarbazole) (PVK), etc.; inorganic materials include, for example, nickel oxide (NiO). y ), tungsten oxide (WO) z Or cuprous thiocyanate (CuSCN), etc. Where y is, for example, 1, and z is, for example, 3.

[0115] As shown in Figure 2, when the light-emitting device 100 is an upright light-emitting device, the structure of the light-emitting device 100 includes, for example, an anode 110, a hole transport unit 150, a light-emitting layer 130, an electron transport unit 140, and a cathode 120 arranged sequentially in a direction away from the substrate 210.

[0116] As shown in Figure 3, when the light-emitting device 100 is an inverted light-emitting device, the structure of the light-emitting device 100 includes, for example, a cathode 120, an electron transport unit 140, a light-emitting layer 130, a hole transport unit 150, and an anode 110 arranged sequentially in a direction away from the substrate 210.

[0117] It should be noted that Figures 2 to 9, 11 and 12 are schematic diagrams of the display panel 200 after omitting the driving circuit layer 230.

[0118] As mentioned above, during operation, the light-emitting layer 130 emits light through exciton transitions. In some implementations, the material of the electron transport unit 140 may cause exciton quenching, leading to a decrease in the performance of the light-emitting device 100. For example, if the material of the electron transport unit 140 includes zinc oxide nanoparticles (ZnO NPs), defects on the surface of the ZnO NPs may trap electrons or holes, causing exciton quenching. As another example, if the material of the electron transport unit 140 (e.g., including zinc oxide) is in direct contact with the quantum dot material, contact quenching may occur, leading to exciton quenching.

[0119] In some implementations, the electron mobility of the electron transport unit 140 is high, resulting in more electrons than holes injected into the light-emitting layer 130. This leads to a charge imbalance within the light-emitting device 100, which may cause electrons to accumulate in the functional layer and / or the light-emitting layer 130, resulting in the failure of the functional layer material and / or the light-emitting layer material. It may also cause the local current of the light-emitting device 100 to be too large. All these factors can lead to poor stability of the light-emitting morphology. For example, in short-term or long-term tests, bright spots / dark spots, bright spots / dark spots or black holes are likely to appear, and phenomena such as incomplete light-emitting areas and large leakage current may occur.

[0120] Based on this, some embodiments of this disclosure provide a light-emitting device 100. As shown in Figures 4 and 5, the light-emitting device includes a first functional layer 141. The first functional layer 141 is located between the light-emitting layer 130 and the cathode 120. The material of the first functional layer 141 includes a first nanomaterial, which includes a first metal oxide material and a first ligand material. The first metal oxide material includes a first metal element, and the first ligand material includes a first non-metal element; the first non-metal element and the first metal element are capable of coordination connection.

[0121] It should be understood that when the first functional layer 141 is located between the light-emitting layer 130 and the cathode 120, the first functional layer 141 forms at least a portion of the electron transport unit 140.

[0122] In some examples, the first functional layer 141 may be at least one of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (EBL). For an understanding of the electron injection layer (EIL), electron transport layer (ETL), and hole blocking layer (EBL), please refer to the foregoing exemplary descriptions of the electron injection layer (EIL), electron transport layer (ETL), and hole blocking layer (EBL), which will not be repeated here.

[0123] In some examples, the first functional layer 141 may be an electronic transport layer (ETL).

[0124] In some examples, when the display panel 200 includes a first light-emitting device 101, a second light-emitting device 102 and a third light-emitting device 103, the first functional layer 141 can be a structure that is fully connected, that is, the first functional layer 141 can be a common film layer shared by multiple light-emitting devices 100.

[0125] The aforementioned first nanomaterial includes a first metal oxide material. As a semiconductor material, the first metal oxide material exhibits n-type conductivity in electrical terms, giving the first nanomaterial superior photoelectric properties and enabling it to perform electron transport functions.

[0126] It should be understood that when the first non-metallic element and the first metallic element can coordinate and connect, the first ligand material can coordinate with the surface of the first metal oxide material through the first non-metallic element to form the first nanomaterial. In this case, the first metal oxide material forms the core of the first nanomaterial, and the first ligand material forms the shell of the first nanomaterial.

[0127] Understandably, through the above configuration, firstly, the surface of the first metal oxide material can be modified using the first ligand material to passivate surface defects, thereby reducing the defect density of the first metal oxide material and thus reducing the trapping of electrons or holes by surface defects, and minimizing exciton quenching. Here, surface defects of the first metal oxide material include, for example, point defects and / or surface defects generated during growth, and may also include exposed dangling bonds (when the specific surface area of ​​the first metal oxide material is large, there are more exposed dangling bonds). Secondly, direct contact between the first metal oxide material and the material of the light-emitting layer 130 can be avoided, reducing contact quenching caused by direct contact, and thus minimizing exciton quenching. Thirdly, when the first ligand material is located on the surface of the first metal oxide material, it can slow down the electron transport rate of the electron transport unit 140 to a certain extent. Firstly, it can reduce the accumulation of electrons on the functional layer (e.g., at least part of the hole transport unit 150) and / or the light-emitting layer 130, thereby protecting the functional layer and / or the light-emitting layer 130 and improving the performance of the light-emitting device 100 (performance includes but is not limited to lifetime). Secondly, it can improve the current of the light-emitting device 100, reduce the power consumption of the light-emitting device 100, and improve the stability of the light-emitting morphology, so that the light-emitting morphology can be better maintained.

[0128] In some embodiments, in the first nanomaterial, the mass ratio of the first metallic element to the first non-metallic element is greater than 3:1 and less than or equal to 30:1.

[0129] Here, there are no restrictions on how the mass ratio of the first metallic element to the first non-metallic element in the first nanomaterial is obtained.

[0130] As one possible method of obtaining this information, a combination of scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), or an elemental detection device such as inductively coupled plasma atomic emission spectrometry (ICP-AES) can be used to measure the material of the first functional layer 141 to obtain the mass ratio of the first metallic element to the first non-metallic element in the first nanomaterial.

[0131] As another possible method, a focused ion beam (FIB) and / or a transmission electron microscope (TEM) can be used to locate the test site on the first functional layer 141 of the light-emitting device 100 and measure the composition of the first functional layer 141 to obtain the mass ratio of the first metal element to the first non-metal element in the first nanomaterial.

[0132] Understandably, when the mass proportion of the first ligand material in the first nanomaterial is high (e.g., the mass ratio of the first metal element to the first non-metal element is less than 3:1), the first ligand material may affect the bulk properties of the first metal oxide and the electron transport function of the first functional layer 141, potentially causing the light-emitting device 100 to fail to light up. Conversely, when the mass proportion of the first ligand material in the first nanomaterial is low (e.g., the mass ratio of the first metal element to the first non-metal element is greater than 30:1), it may affect the first ligand material's functions in reducing exciton quenching, protecting the light-emitting layer and functional layer materials, and improving the luminescent morphology. Therefore, by setting the mass ratio of the first metal element to the first non-metal element to be greater than 3:1 and less than or equal to 30:1, the mass proportion of the first ligand material in the first nanomaterial can be kept within a suitable range. This ensures the electron transport function of the first functional layer 141, optimizes the efficiency, brightness, lifetime, power consumption, and luminescent morphology of the light-emitting device 100, and avoids the phenomenon of the light-emitting device 100 failing to light up.

[0133] In some examples, the mass ratio of the first metallic element to the first non-metallic element in the first nanomaterial is greater than 3:1 and less than or equal to 30:1. For example, the mass ratio of the first metallic element to the first non-metallic element in the first nanomaterial can be 3.01:1, 4:1, 5:1, 6:1, 9:1, 10:1, 15:1, 20:1, 24:1, 26:1, 27:1, 28:1, 29:1, or 30:1, etc.

[0134] In some examples, the mass ratio of the first metallic element to the first non-metallic element in the first nanomaterial ranges from 6:1 to 25:1. For example, the mass ratio of the first metallic element to the first non-metallic element in the first nanomaterial can be 6:1, 8:1, 11:1, 14:1, 17:1, 19:1, 21:1, 22:1, 23:1, 24:1, or 25:1, etc.

[0135] In some examples, the mass ratio of the first metallic element to the first non-metallic element in the first nanomaterial ranges from 8:1 to 20:1. For example, the mass ratio of the first metallic element to the first non-metallic element in the first nanomaterial can be 8:1, 9:1, 11:1, 12:1, 13:1, 15:1, 16:1, 17.5:1, 18:1, 19.5:1, or 20:1, etc.

[0136] In some examples, the mass ratio of the first metallic element to the first non-metallic element in the first nanomaterial ranges from 9:1 to 15:1. For example, the mass ratio of the first metallic element to the first non-metallic element in the first nanomaterial can be 9:1, 9.5:1, 10:1, 10.5:1, 10.5:1, 11:1, 11.5:1, 12:1, 12.5:1, 13:1, 13.5:1, 14:1, 14.5:1, or 15:1, etc.

[0137] In some examples, the mass ratio of the first metallic element to the first non-metallic element in the first nanomaterial ranges from 7:1 to 11:1. For example, the mass ratio of the first metallic element to the first non-metallic element in the first nanomaterial can be 7:1, 7.3:1, 7.6:1, 7.9:1, 8.2:1, 8.5:1, 8.7:1, 9.0:1, 9.4:1, 9.7:1, 10.1:1, 10.4:1, 10.7:1, or 11:1, etc.

[0138] In some examples, the mass ratio of the first metallic element to the first non-metallic element in the first nanomaterial ranges from 13:1 to 17:1. For example, the mass ratio of the first metallic element to the first non-metallic element in the first nanomaterial can be 13:1, 13.3:1, 13.6:1, 13.9:1, 14.2:1, 14.5:1, 14.7:1, 15.0:1, 15.4:1, 15.7:1, 16.1:1, 16.4:1, 16.7:1, or 17:1, etc.

[0139] In some embodiments, the light-emitting device 100 undergoes positive aging. Specifically, after treatment in a certain manner, the efficiency of the light-emitting device 100 shows a significant increase, sometimes accompanied by a significant decrease in the turn-on voltage. This phenomenon can improve the efficiency of the light-emitting device 100 to a certain extent. As a possible reason, the positive aging of the light-emitting device 100 is because the electron transport material (e.g., ZnO or ZnMgO) used in the electron transport unit 140 has a large number of active sites (e.g., oxygen vacancy defects) on its surface. When these active sites are occupied by active elements in the environment (e.g., hydrogen), the performance of the light-emitting device 100 can be improved. Here, the improved performance includes at least one of efficiency, conductivity, luminous morphology, and operating lifetime. Moreover, when the active element occupying the active sites is hydrogen, hydrogen can act as a shallow donor in the electron transport unit 140, which can increase the carrier concentration of the electron transport unit 140 and improve the conductivity of the electron transport unit 140.

[0140] During the forward aging process of the light-emitting device 100, where the device includes a first functional layer 141 and the first ligand material has a high mass proportion in the first nanomaterial, the coating effect (or protective effect) of the first ligand material on the first metal oxide is strong, which may affect the forward aging process. Therefore, depending on whether the light-emitting device 100 undergoes forward aging, the content of the first ligand material in the first nanomaterial will be set differently; that is, the mass ratio of the first metal element to the first non-metal element in the first nanomaterial will be set differently. An example will be given below.

[0141] In some embodiments, as shown in FIG1, the organic encapsulant in the encapsulation layer 240 of the display panel 200 includes an acidic encapsulant; in the first nanomaterial, the mass ratio of the first metal element to the first non-metal element is greater than or equal to 10:1 and less than or equal to 30:1.

[0142] For example, acidic encapsulants include acrylic encapsulants, such as acrylate encapsulants.

[0143] For example, the organic encapsulant includes an acidic encapsulant; in the first nanomaterial, the mass ratio of the first metal element to the first non-metal element can be 10:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 20:1, 21:1, 23:1, 25:1, 27:1 or 30:1, etc.

[0144] By incorporating an acidic encapsulant into the organic encapsulant, the acidic encapsulant releases hydrogen, causing a positive aging process in the light-emitting device 100 to improve its performance and enhance the conductivity of the electron transport unit 140. In this case, by setting the mass ratio of the first metal element to the first non-metal element to be greater than or equal to 10:1, the functions of the first ligand material, such as reducing exciton quenching and protecting the light-emitting layer 130 material, can be maintained, while ensuring that the content of the first ligand material in the first nanomaterial is relatively low. This avoids the influence of the first ligand material on the positive aging process of the light-emitting device 100.

[0145] In some embodiments, as shown in FIG1, the organic encapsulant in the encapsulation layer 240 of the display panel 200 includes a neutral encapsulant; in the first nanomaterial, the mass ratio of the first metal element to the first non-metal element is greater than 3:1 and less than or equal to 12:1.

[0146] In some examples, the organic encapsulant includes a neutral encapsulant, and the light-emitting device 100 does not undergo positive aging.

[0147] For example, the organic encapsulant includes a neutral encapsulant. In the first nanomaterial, the mass ratio of the first metallic element to the first non-metallic element is greater than 3:1 and less than or equal to 12:1. For example, in the first nanomaterial, the mass ratio of the first metallic element to the first non-metallic element can be 3.01:1, 5:1, 7:1, 7.5:1, 8:1, 8.5:1, 9:1, 9.5:1, 10:1, 10.5:1, 11:1, 11.5:1, or 12:1, etc.

[0148] In some examples, the first metallic element may include a Group IIB metallic element.

[0149] In some embodiments, the first metallic element includes zinc.

[0150] When the first metallic element includes zinc, the first metal oxide includes zinc oxide. Zinc oxide possesses excellent optical and electronic properties, making it suitable as a semiconductor optoelectronic material, and it offers the advantage of low-temperature processing. Furthermore, zinc oxide is a wide-bandgap group II-VI compound with a direct bandgap of 3.37 eV at room temperature, causing it to exhibit n-type conductivity electrically. Under certain conditions, the resistivity of zinc oxide can be as low as 10⁻⁶. -4 Ω / cm.

[0151] In some examples, the first nonmetallic element may include a group V element.

[0152] In some embodiments, the first nonmetallic element includes nitrogen.

[0153] Nitrogen has the property of coordinating with metallic elements. When the first non-metallic element includes nitrogen, the first ligand material can coordinate with the first metal oxide (e.g., zinc oxide) through nitrogen. As mentioned above, this has two advantages: First, it can passivate surface defects of the first metal oxide and reduce contact quenching, thereby reducing exciton quenching and improving the efficiency of the light-emitting device 100. Second, it can slow down the electron transport rate of the electron transport unit 140, which can improve the lifetime of the light-emitting device 100, reduce the power consumption of the light-emitting device 100, and improve the stability of the light-emitting morphology.

[0154] In some embodiments, the first metal oxide material further includes a first doped metal element; the first doped metal element includes at least one of magnesium, aluminum, tin and manganese.

[0155] For example, the first doped metal element includes one metal element, such as magnesium. Alternatively, the first doped metal element may include at least two metal elements, such as magnesium and aluminum.

[0156] The above settings can improve the electron transport efficiency of the first functional layer 141 and enhance the efficiency of the light-emitting device 100.

[0157] Here, no limit is set on the range of the mass ratio of the first metal element to the first doped metal element in the first metal oxide material. For example, the mass ratio of the first metal element to the first doped metal element is greater than 1:1.

[0158] In some embodiments, the mass ratio of the first metal element to the first doped metal element in the first metal oxide material is in the range of (20-30):1.

[0159] For example, in the first metal oxide material, the mass ratio of the first metal element to the first doped metal element can be 20:1, 22:1, 24:1, 25:1, 26:1, 28:1 or 30:1, etc.

[0160] For example, a first metal oxide material containing a first doped metal element can be synthesized by a solution method.

[0161] Understandably, when the mass ratio of the first metal element to the first doped metal element in the first metal oxide material is small (e.g., less than 20:1), the mass proportion of the first doped metal element in the first metal oxide is relatively high, which may increase the difficulty of synthesizing the first metal oxide. Conversely, when the mass ratio of the first metal element to the first doped metal element in the first metal oxide material is large (e.g., greater than 30:1), the mass proportion of the first doped metal element in the first metal oxide is relatively low, which will affect the effect of the first doped metal element in improving electron transport efficiency. Therefore, by setting the mass ratio of the first metal element to the first doped metal element in the first metal oxide material to be in the range of (20-30:1), the difficulty of synthesizing the first metal oxide can be reduced, and the effect of the first doped metal element in improving electron transport efficiency can be enhanced.

[0162] In some examples, the first ligand material includes a tertiary amine group and / or a quaternary amine group. Thus, the first ligand material can utilize the nitrogen element in the tertiary amine group and / or the quaternary amine group to coordinate on the surface of the first metal oxide material.

[0163] In some examples, the particle size of the first metal oxide material is small, and the surface space of the first metal oxide material is relatively narrow.

[0164] Therefore, in some embodiments, the first ligand material includes a primary amine group and / or a secondary amine group.

[0165] With this configuration, the first ligand material can utilize the nitrogen element in the primary amine group and / or secondary amine group to coordinate on the surface of the first metal oxide material. Moreover, compared to the case where the first ligand material includes tertiary amine groups and / or quaternary amine groups, the structure of the first ligand material can be simpler, reducing the coordination difficulty when the first ligand material is coordinated on the surface of the first metal oxide material. This allows the coordination ratio of the first metal oxide material and the first ligand material to reach a preset ratio, thereby enhancing the effect of the first ligand material in reducing exciton quenching and regulating electron transport rate.

[0166] In some embodiments, the first ligand material further includes a photosensitive group. The photosensitive group is configured to cause a cross-linking reaction between the first ligand materials under light irradiation conditions.

[0167] In some examples, the light irradiation conditions are ultraviolet light irradiation conditions. Here, the wavelength of ultraviolet light can be selected according to the type of photosensitive group.

[0168] Here, there are no restrictions on the type of reaction that occurs between the first ligand materials, as long as cross-linking between the first ligand materials can be achieved. For example, cross-linking between the first ligand materials can be achieved through addition reactions or hydrocarbon insertion reactions.

[0169] When the first ligand material also includes a photosensitive group, an in-situ cross-linking reaction can occur between the first ligand materials under light irradiation conditions. In this way, the first ligand material contained in one first nanoparticle and the first ligand material contained in another first nanoparticle can be connected to achieve the connection between the first nanoparticles. This allows the material of the first functional layer 141 to form a denser film, thereby improving the tolerance of the first functional layer 141. Firstly, it can improve the stability of the light emission morphology; secondly, it can enable the first functional layer 141 and the entire light-emitting device 100 to resist the damage of the atmosphere and possible acidic adhesives, thus improving the lifespan of the light-emitting device 100.

[0170] Here, there are no restrictions on the type of photosensitive group, as long as it meets the requirement of undergoing a chemical reaction under light irradiation to cause a cross-linking reaction between the first ligand materials.

[0171] In some embodiments, the photosensitive group includes at least one of alkenyl, alkynyl, benzophenone, bisacridinyl, and azide.

[0172] In some examples, the photosensitive groups include alkenyl and / or alkynyl groups, causing the first ligand material to include unsaturated bonds (carbon-carbon double bonds and / or carbon-carbon double bonds). In this case, under light irradiation conditions, cross-linking can be achieved between the first ligand materials through an addition reaction.

[0173] In some examples, the photosensitive group includes a benzophenone group. In this case, the principle of the cross-linking reaction between the first ligand materials can be described as follows: the benzophenone group, under light irradiation conditions (hv), photolyzes to generate a triplet ketone intermediate, with the structure shown in the following formula, where C in the triplet ketone intermediate... ● -O ● It will attack nearby CH bonds (e.g., CH bonds in the first ligand material), causing a hydrocarbon insertion reaction and cross-linking between the first ligand materials.

[0174] In some examples, the photosensitive group includes an azide group. In this case, the principle of the cross-linking reaction between the first ligand materials can be described as follows: under light irradiation, the azide group photodecomposes to generate the active intermediate free radical nitrogen carbene. Nitrogen carbene attacks nearby CH bonds (e.g., CH bonds in the first ligand material), causing a hydrocarbon insertion reaction and cross-linking between the first ligand materials.

[0175] In some embodiments, the photosensitive group includes a diaziridine group. In this case, the principle of the cross-linking reaction between the first ligand materials can be described as follows: under light irradiation, the bisacrididine group photodecomposes to generate the active intermediate free radical carbene. Carbene attacks nearby CH bonds (e.g., CH bonds in the first ligand material), causing hydrocarbon insertion reactions and cross-linking reactions between the first ligand materials.

[0176] Based on the aforementioned properties of alkenyl, alkynyl, benzophenone, bisacridinyl, and azide, when the photosensitive group includes at least one of alkenyl, alkynyl, benzophenone, and azide, the first ligand materials can undergo a cross-linking reaction under light irradiation conditions. Thus, as mentioned above, the stability of the luminescent morphology can be improved, and the lifetime of the light-emitting device 100 can be extended.

[0177] In some embodiments, the first ligand material includes at least one selected from hydroxylamine compounds, secondary amine compounds, polyamine compounds, amino acid compounds, ethyleneimine compounds, amide compounds, alkenyl-containing amide compounds, and alkenyl-containing ethanolamine compounds.

[0178] In some examples, the polyamine compound can be a diamine compound.

[0179] Among the aforementioned materials, the molecular structures of hydroxylamine compounds, secondary amine compounds, polyamine compounds, amino acid compounds, ethyleneimine compounds, and amide compounds include at least one primary or secondary amine group. The molecular structures of alkenyl-containing amide compounds include one secondary amine group and also an alkenyl group. The molecular structures of alkenyl-containing ethanolamine compounds include one primary amine group and also an alkenyl group.

[0180] The aforementioned materials contain primary or secondary amine groups, enabling the first ligand material to coordinate with the first metal oxide material and reducing the coordination difficulty when the first ligand material is coordinated with the surface of the first metal oxide material. Furthermore, the aforementioned materials are readily available and compatible with conventional solvents, which can reduce the material and process costs of fabricating the light-emitting device 100 to some extent.

[0181] Furthermore, when the first ligand material includes at least one of an alkenyl-containing amide compound and an alkenyl-containing ethanolamine compound, the first ligand material contains an alkenyl group, which can react under light irradiation conditions to crosslink the first ligand material. This can improve the stability of the light emission morphology and extend the lifetime of the light emission device 100.

[0182] In some embodiments, the first ligand material includes at least one of the structures shown in general formulas (I), (II), (III), (IV), (V), (VI), and (VII).

[0183] Among them, L1, L2, L3 and L4 may be the same or different, and are independently selected from substituted or unsubstituted C1 to C5 straight-chain alkylene or branched alkylene.

[0184] L5 and L6 may be the same or different, and are independently selected from single-bonded, substituted or unsubstituted C1 to C5 straight-chain alkylene or branched alkylene.

[0185] R1, R2, and R3 may be the same or different, and are independently selected from substituted or unsubstituted C1 to C5 straight-chain alkyl or branched-chain alkyl groups.

[0186] n is a positive integer from 1 to 20.

[0187] Here, straight-chain alkyl refers to the group remaining after removing one hydrogen atom from a straight-chain alkane, and straight-chain alkylene refers to the group remaining after removing two hydrogen atoms from a straight-chain alkane. For the understanding of branched-chain alkyl and branched-chain alkylene, please refer to the above content, which will not be repeated here. A Cx straight-chain alkyl refers to a straight-chain alkyl group with x carbon (C) atoms, where x is a positive integer. For the understanding of Cx branched-chain alkyl, Cx straight-chain alkylene, and Cx branched-chain alkylene, please refer to the above content, which will not be repeated here.

[0188] L5 can be a single bond, meaning that the carboxyl group and alkenyl group in general formula (VI) can be directly connected by a single bond. L6 can be a single bond, meaning that the secondary amine group and alkenyl group in general formula (VII) can be directly connected by a single bond.

[0189] For example, the C1 to C5 straight-chain alkyl or branched alkyl may include any one of methyl, ethyl, n-propyl, isopropyl, butylene, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, and neopentyl.

[0190] For example, the straight-chain alkylene or branched alkylene of C1 to C5 may include any one of methylene, ethylene, n-propylene, isopropylene, n-butylene, sec-butylene, isobutylene, tert-butylene, n-pentylene, isopentylene, and neopentylene.

[0191] For example, if any one of L1 to L6 is selected from substituted C1 to C5 straight-chain alkylene or branched alkylene, and / or R1, R2 or R3 is selected from substituted C1 to C5 straight-chain alkyl or branched alkyl, the number of substituents is, for example, 1 to 2 or 1 to 3; the type of substituent is, for example, C1 to C3 straight-chain alkyl or branched alkyl, or C1 to C5 straight-chain alkyl or branched alkyl.

[0192] In some examples, the structure shown in general formula (I) can be ethanolamine, with the structure shown in formula (I-1).

[0193] In some examples, the structure shown in general formula (II) can be shown in formula (II-1) below.

[0194] In some examples, the structure shown in general formula (III) can be shown in formula (III-1) below.

[0195] In some examples, the structure shown in general formula (IV) can be shown as in formula (IV-1) or (IV-2).

[0196] In some examples, the structure shown in general formula (V) can be represented as shown in formula (V-1).

[0197] In some examples, the structure shown in general formula (VI) can be shown as in formula (VI-1) or (VI-2).

[0198] In some examples, the structure shown in general formula (VII) can be Boc-ethanolamine (N-Boc type), with the structure shown in formula (VII-1) below.

[0199] The structure shown in general formula (I) belongs to the hydroxyamine class of compounds; the structure shown in general formula (II) belongs to the secondary amine class of compounds; the structure shown in general formula (III) belongs to the diamine class of compounds; the structure shown in general formula (IV) belongs to the amino acid class of compounds; the structure shown in general formula (V) belongs to the ethyleneimine class of compounds; the structure shown in general formula (VI) belongs to the alkenyl-containing amide class of compounds; and the structure shown in general formula (VII) belongs to the alkenyl-containing ethanolamine class of compounds.

[0200] Therefore, when the first ligand material includes at least one of the structures shown in general formulas (I) to (VII), the first ligand material includes at least one of hydroxylamine compounds, secondary amine compounds, polyamine compounds, amino acid compounds, ethyleneimine compounds, alkenyl-containing amide compounds, and alkenyl-containing ethanolamine compounds. Moreover, the structures shown in general formulas (I) to (VII) have the advantage of simpler molecular structures, which can further reduce the coordination difficulty when the first ligand material is coordinated to the surface of the first metal oxide material, and can reduce the material cost of preparing the light-emitting device 100.

[0201] In some embodiments, the first nanomaterial further includes a second ligand material liganded to the first metal oxide material.

[0202] For example, the second ligand material may be generated during the synthesis of the first metal oxide material, in which case the second ligand material may also be referred to as the original ligand material.

[0203] It should be understood that when the first nanomaterial includes the second ligand material, the first ligand material can be directly coordinated with the first metal oxide material, or it can undergo a ligand exchange reaction with the second ligand material to achieve coordination connection between the first ligand material and the first metal oxide material.

[0204] Understandably, on the one hand, the second ligand material can improve the stability of the first nanomaterial and prevent the aggregation of particles in the first nanomaterial. On the other hand, when the first nanomaterial includes both the first ligand material and the second ligand material, the polarity of the first nanomaterial can be adjusted by utilizing the difference in polarity between the first ligand material and the second ligand material. In this way, the types of solvents that can dissolve the first nanomaterial can be increased, and the first nanomaterial can be dissolved in a preset solvent, which can broaden the scope of the film formation process of the first functional layer 141.

[0205] For example, the second ligand material (e.g., a ligand material containing carboxyl or hydroxyl groups) has a higher polarity, while the first ligand material (e.g., ethanolamine) has a relatively lower polarity. When the first ligand material has a lower mass proportion in the first nanomaterial, the first nanomaterial can be dissolved in a polar solvent (e.g., a low-boiling-point polar alcohol solvent, such as formaldehyde, ethanol, etc.). When the first ligand material has a higher mass proportion in the first nanomaterial, the first nanomaterial can be dissolved in a solvent with relatively low polarity (e.g., propylene glycol methyl ether acetate, PMA). This allows the selectable film-forming process of the first functional layer 141 to include spin coating, blade coating, and inkjet printing, thus broadening the range of film-forming processes for the first functional layer 141.

[0206] In some embodiments, the second ligand material includes at least one of hydroxyl and carboxyl groups.

[0207] Hydroxyl and carboxyl groups are primary coordination groups that are easily generated during the synthesis of the first metal oxide material (e.g., ZnO or ZnMgO). When the second ligand material includes at least one of hydroxyl and carboxyl groups, the second ligand material can be generated during the synthesis of the first metal oxide material. In this way, the second ligand material can improve the stability of the synthesized first nanomaterial and prevent the aggregation of particles in the first nanomaterial.

[0208] The above is an exemplary description of the first ligand material and the first functional layer 141. The other films in the light-emitting device 100 will be described exemplary below.

[0209] In some embodiments, as shown in Figures 6 and 7, the light-emitting device 100 further includes a second functional layer 142. The second functional layer 142 is located between the first functional layer 141 and the cathode 120. The material of the second functional layer 142 includes a second nanomaterial. The material of the second nanomaterial includes a second metal oxide material.

[0210] In some examples, where the display panel 200 includes a first light-emitting device 101, a second light-emitting device 102, and a third light-emitting device 103, the second functional layer 142 can be a structure that is fully connected, that is, the second functional layer 142 can be a common film layer shared by multiple light-emitting devices 100.

[0211] In some examples, the second metal oxide material does not include any other ligand materials besides the original ligand materials generated during the synthesis process; that is, the second nanomaterial only includes the original ligand materials generated during the synthesis of the second metal oxide material.

[0212] When the light-emitting device 100 further includes a second functional layer 142, and the material of the second nanomaterial includes a second metal oxide material, on the one hand, compared with the first nanomaterial, the mass ratio of the second metal oxide material in the second nanomaterial is relatively high, so that the second functional layer 142 has a relatively high electron transport rate, which can promote electron injection; on the other hand, the second functional layer 142 is located between the cathode 120 and the first functional layer 141, and an interface for achieving positive aging can be constructed between the cathode 120 and the first functional layer 141, so that the positive aging degree of the light-emitting device 100 is high, which can improve the efficiency of the light-emitting device 100.

[0213] Moreover, the second functional layer 142 is closer to the cathode 120 than the first functional layer 141. Since the cathode 120 can generate electrons, the second functional layer 142 can perform electron transport function at a position closer to the cathode 120, which can further enhance the effect of the second functional layer 142 in increasing the electron transport rate.

[0214] Here, no restrictions are set regarding the relative size relationship between the thickness of the second functional layer 142 and the thickness of the first functional layer 141.

[0215] In some examples, the thickness D2 of the second functional layer 142 is greater than the thickness D1 of the first functional layer 141.

[0216] In some embodiments, as shown in Figures 6 and 7, the thickness D2 of the second functional layer 142 is less than or equal to the thickness D1 of the first functional layer 141.

[0217] By setting the thickness D2 of the second functional layer 142 to be less than or equal to the thickness D1 of the first functional layer 141, the thickness D1 of the first functional layer 141 can be relatively thick to match its function of reducing exciton quenching and protecting the material of the light-emitting layer 130, and the thickness D2 of the second functional layer 142 can be relatively thin to match its function of promoting electron injection and constructing an interface for achieving positive aging.

[0218] In some embodiments, as shown in Figures 6 and 7, the first metal oxide material and the second metal oxide material comprise the same metal element.

[0219] For example, both the first metal oxide material and the second metal oxide material include zinc, that is, both the first metal oxide material and the second metal oxide material are zinc oxide (ZnO); or for example, both the first metal oxide material and the second metal oxide material include zinc and magnesium, that is, both the first metal oxide material and the second metal oxide material are zinc magnesium oxide (ZnMgO).

[0220] For example, the first metal oxide material and the second metal oxide material are the same metal oxide material. The interface between the first functional layer 141 and the second functional layer 142 can be determined by the content of the first ligand material. For example, the first functional layer 141 contains the first ligand material, and the second functional layer 142 does not contain the first ligand material.

[0221] With the above configuration, the energy levels of the first metal oxide material and the second metal oxide material are closer, which is beneficial for the transmission of electrons between the first metal oxide material and the second metal oxide material, and can improve the electron transmission effect between the first functional layer 141 and the second functional layer 142.

[0222] In some embodiments, the second metal oxide material includes a first metal element and a second doped metal element; the first doped metal element and the second doped metal element may be the same or different, and each independently includes at least one of magnesium, aluminum, tin and manganese.

[0223] For example, the second doped metal element includes one metal element, such as magnesium. Also for example, the second doped metal element includes at least two metal elements, such as magnesium and aluminum.

[0224] Similarly, through the above-described configuration, the electron transport efficiency of the second functional layer 142 can be increased, thereby improving the efficiency of the light-emitting device 100. Furthermore, both the first metal oxide material and the second metal oxide material include the first metal element, which can enhance the electron transport effect between the first functional layer 141 and the second functional layer 142.

[0225] Here, no limit is set on the range of the mass ratio of the first metal element to the second doped metal element in the second metal oxide material. For example, the mass ratio of the first metal element to the second doped metal element is greater than 1:1.

[0226] In some embodiments, the mass ratio of the first metal element to the second doped metal element in the second metal oxide material ranges from (20 to 30):1.

[0227] For example, in the second metal oxide material, the mass ratio of the first metal element to the second doped metal element can be 20:1, 21:1, 23:1, 25:1, 26:1, 28:1 or 30:1, etc.

[0228] Similarly, the above settings can reduce the difficulty of synthesizing the second metal oxide and enhance the effect of the second doped metal element in improving electron transport efficiency.

[0229] In some embodiments, the second nanomaterial further includes a second ligand material liganded to the second metal oxide material.

[0230] Similarly, this design achieves two goals: first, it improves the stability of the second nanomaterial and prevents particle aggregation; second, it allows for the adjustment of the polarity of the second nanomaterial, thus broadening the range of film-forming processes for the second functional layer 142.

[0231] For an understanding of the groups contained in the second ligand material and the film-forming process of broadening the second functional layer 142 using the second ligand material, please refer to the description of the corresponding part of the first functional layer 141 in the foregoing section, which will not be repeated here.

[0232] In some embodiments, as shown in Figures 8 and 9, the light-emitting device 100 further includes a third functional layer 143. The third functional layer is located between the first functional layer 141 and the light-emitting layer 130. The material of the third functional layer 143 includes a third nanomaterial, and the material of the third nanomaterial includes a third metal oxide material.

[0233] In some examples, when the display panel 200 includes a first light-emitting device 101, a second light-emitting device 102 and a third light-emitting device 103, the third functional layer 143 can be a structure that is fully connected, that is, the third functional layer 143 can be a common film layer shared by multiple light-emitting devices 100.

[0234] In some examples, the third metal oxide material does not include other ligand materials besides the original ligand material generated during the synthesis process; that is, the third nanomaterial only includes the third metal oxide material and the original ligand material generated during the synthesis process.

[0235] In some examples, the light-emitting device 100 includes a first functional layer 141 and a third functional layer 143, but does not include a second functional layer 142. In still other examples, the light-emitting device 100 includes a first functional layer 141, a second functional layer 142, and a third functional layer 143.

[0236] In the case where the light-emitting device 100 further includes a third functional layer 143, and the material of the third nanomaterial includes a third metal oxide material, the third functional layer 143 is located between the light-emitting layer 130 and the first functional layer 141. An interface for achieving positive aging can be constructed between the light-emitting layer 130 and the first functional layer 141, thereby further improving the positive aging degree of the light-emitting device 100 and increasing its efficiency. Moreover, with this configuration, the first functional layer 141 can protect the light-emitting layer 130, for example, by reducing the impact of the environment and vapor deposition on the material of the light-emitting layer 130.

[0237] Here, no restrictions are set regarding the relative size relationship between the thickness D3 of the third functional layer 143 and the thickness D1 of the first functional layer 141.

[0238] In some examples, the thickness D3 of the third functional layer 143 is greater than the thickness D1 of the first functional layer 141. In still other examples, the thickness D3 of the third functional layer 143 is equal to the thickness D1 of the first functional layer 141. In yet other examples, the thickness D3 of the third functional layer 143 is less than the thickness D1 of the first functional layer 141.

[0239] In some embodiments, as shown in Figures 8 and 9, the first metal oxide material and the third metal oxide material comprise the same metal element.

[0240] For example, both the first metal oxide material and the third metal oxide material include zinc, that is, both the first metal oxide material and the third metal oxide material are zinc oxide (ZnO); or for example, both the first metal oxide material and the third metal oxide material include zinc and magnesium, that is, both the first metal oxide material and the third metal oxide material are zinc magnesium oxide (ZnMgO).

[0241] In some examples, the first metal oxide material and the third metal oxide material are the same metal oxide material. The interface between the first functional layer 141 and the third functional layer 143 can be determined by the content of the first ligand material. For example, the first functional layer 141 contains the first ligand material, while the third functional layer 143 does not contain the first ligand material.

[0242] Similarly, through the above arrangement, the energy levels of the first metal oxide material and the third metal oxide material are closer, which can improve the electron transport effect between the first functional layer 141 and the third functional layer 143.

[0243] In some embodiments, the third metal oxide material includes a first metal element and a third doped metal element; the first doped metal element, the second doped metal element, and the third doped metal element may be the same or different, and each independently includes at least one of magnesium, aluminum, tin, and manganese.

[0244] For example, the third doped metal element includes one metal element, such as magnesium. Alternatively, the third doped metal element may include at least two metal elements, such as magnesium and aluminum.

[0245] Similarly, through the above-mentioned configuration, the electron transport efficiency of the third functional layer 143 can be increased, thereby improving the efficiency of the light-emitting device 100. Furthermore, both the first metal oxide material and the third metal oxide material include the first metal element, which can enhance the electron transport effect between the first functional layer 141 and the third functional layer 143.

[0246] Here, no limit is set on the range of the mass ratio of the first metal element to the third doped metal element in the third metal oxide material. For example, the mass ratio of the first metal element to the third doped metal element is greater than 1:1.

[0247] In some embodiments, the mass ratio of the first metal element to the third doped metal element in the third metal oxide material is in the range of (20-30):1.

[0248] For example, in the third metal oxide material, the mass ratio of the first metal element to the third doped metal element can be 20:1, 21:1, 23:1, 25:1, 26:1, 28:1 or 30:1, etc.

[0249] Similarly, the above settings can reduce the difficulty of synthesizing the third metal oxide and enhance the effect of the third doped metal element in improving electron transport efficiency.

[0250] In some embodiments, the third nanomaterial further includes a second ligand material liganded to the third metal oxide material.

[0251] Similarly, this design achieves two goals: first, it improves the stability of the third nanomaterial and prevents particle aggregation; second, it allows for the adjustment of the polarity of the third nanomaterial, thus broadening the range of film-forming processes for the third functional layer 143.

[0252] For an understanding of the groups contained in the second ligand material and the film-forming process of using the second ligand material to broaden the third functional layer 143, please refer to the description of the corresponding part of the first functional layer 141 in the foregoing section, which will not be repeated here.

[0253] Some embodiments of this disclosure also provide a method for fabricating a light-emitting device 100. As shown in FIG10, the method for fabricating the light-emitting device 100 includes S1.

[0254] S1: An anode 110 (see Figure 4), a cathode 120, a light-emitting layer 130, and a first functional layer 141 are formed. The anode 110 and cathode 120 are disposed opposite to each other. The light-emitting layer 130 is located between the anode 110 and cathode 120. The first functional layer 141 is located between the light-emitting layer 130 and cathode 120. The material of the first functional layer 141 includes a first nanomaterial, which includes a first metal oxide material and a first ligand material. The first metal oxide material includes a first metal element, and the first ligand material includes a first non-metal element; the first non-metal element is coordinated with the first metal element. In the first nanomaterial, the mass ratio of the first metal element to the first non-metal element is greater than 3:1 and less than or equal to 30:1.

[0255] For an understanding of the first functional layer 141, the first nanomaterial, the first metal oxide material, the first ligand material, and the mass ratio of the first metal element to the first non-metal element, please refer to the foregoing exemplary description of the first functional layer 141, the first nanomaterial, the first metal oxide material, the first ligand material, and the mass ratio of the first metal element to the first non-metal element, etc., which will not be repeated here.

[0256] The beneficial effects of the above-described method for preparing the light-emitting device 100 are the same as those of the light-emitting device 100 described in some of the above embodiments, and will not be repeated here.

[0257] In some examples, the light-emitting device 100 is a positively positioned light-emitting device. In this case, as shown in Figure 11, the fabrication method of the light-emitting device 100 may include R1 to R4. It should be noted that Figure 11 illustrates a fabrication process of a light-emitting device 100. In actual applications, during the fabrication of this light-emitting device 100, other light-emitting devices 100 in the display panel 200 can also be formed. The same applies to Figure 12, which is described in detail below.

[0258] R1: An anode 110 is formed on a substrate 210.

[0259] For example, the process for forming the anode 110 can be a sputtering process or a photolithography process, etc.

[0260] R2: A light-emitting layer 130 is formed on the side of the anode 110 away from the substrate 210.

[0261] For example, the process of forming the light-emitting layer 130 can be a spin coating process, a coating process, a printing process (e.g., inkjet printing process) or a printing process.

[0262] For example, the materials forming the light-emitting layer 130 include quantum dot light-emitting materials and photosensitive materials. In this case, the method for preparing the light-emitting layer 130 may include: coating the material forming the light-emitting layer 130, exposing the area where the target opening is located, and developing the material of the light-emitting layer 130 except for the exposed area. Here, the target opening refers to the opening among a plurality of openings that corresponds to the prepared light-emitting device 100.

[0263] Through the above exposure process, the quantum dot luminescent material and the photosensitive material can be cross-linked within the target opening (which can also be understood as the target pixel area), thus achieving selective patterning after development.

[0264] In some examples, R1A to R1B are included after R1 and before R2.

[0265] R1A: A hole injection layer 151 is formed on the side of the anode 110 away from the substrate 210.

[0266] For example, the process of forming the hole injection layer 151 is, for example, a spin coating process, a printing process, a coating process, or a vapor deposition process.

[0267] For examples of the material of the hole injection layer 151, please refer to the preceding section, which will not be repeated here.

[0268] R1B: A hole transport layer 152 is formed on the side of the hole injection layer 151 away from the anode 110.

[0269] For example, the process of forming the hole transport layer 152 is, for example, a spin coating process, a printing process, a coating process, a sputtering process, or a vapor deposition process.

[0270] For examples of the materials of the hole transport layer 152, please refer to the preceding sections, which will not be repeated here.

[0271] It should be understood that when the fabrication method of the light-emitting device 100 includes R1A to R1B, in R2, the light-emitting layer 130 may be formed on the side of the hole transport layer 152 away from the hole injection layer 151.

[0272] R3: A first functional layer 141 is formed on the side of the light-emitting layer 130 away from the anode 110.

[0273] For example, the process of forming the first functional layer 141 is, for example, a spin coating process, a blade coating process, or a printing process.

[0274] For example, when the first metal oxide material includes a first doped metal element, the method for preparing the first nanomaterial includes: firstly, doping the first doped metal element into the oxide material of the first metal element; then, adding a first ligand material to the mixture including the first doped metal element and the oxide material of the first metal element by solution method, stirring, and purifying.

[0275] In some embodiments, R3A is also included before R3 and after R2.

[0276] R3A: A third functional layer 143 is formed on the side of the light-emitting layer 130 away from the anode 110.

[0277] For example, the process of forming the third functional layer 143 is, for example, a spin coating process, a blade coating process, or a printing process.

[0278] When the fabrication method of the light-emitting device 100 includes R3A, an interface for achieving positive aging can be constructed between the light-emitting layer 130 and the first functional layer 141. In this way, the positive aging degree of the light-emitting device 100 can be improved, thereby improving the efficiency of the light-emitting device 100.

[0279] R4: A cathode 120 is formed on the side of the first functional layer 141 away from the light-emitting layer 130.

[0280] For example, the cathode 120 is formed by depositing material using a sputtering process or a vapor deposition process.

[0281] In some embodiments, R3B is included after R3 and before R2.

[0282] R3B: A second functional layer 142 is formed on the side of the first functional layer 141 away from the light-emitting layer 130.

[0283] For example, the process of forming the second functional layer 142 is, for example, a spin coating process, a blade coating process, or a printing process.

[0284] When the fabrication method of the light-emitting device 100 includes R3B, electron injection can be promoted, and an interface for achieving positive aging can be constructed between the cathode 120 and the first functional layer 141, thereby improving the efficiency of the light-emitting device 100.

[0285] In some other examples, the light-emitting device 100 is an inverted light-emitting device. In this case, as shown in Figure 12, the method for preparing the light-emitting device 100 may include N1 to N4.

[0286] N1: A cathode 120 is formed on a substrate 210.

[0287] For example, the process for forming the cathode 120 can be a sputtering process or a photolithography process, etc.

[0288] N2: A first functional layer 141 is formed on the side of the cathode 120 away from the substrate 210.

[0289] For a description of the formation of the first functional layer 141, please refer to the foregoing exemplary description of R3, which will not be repeated here.

[0290] N3: A light-emitting layer 130 is formed on the side of the first functional layer 141 away from the cathode 120.

[0291] For a description of the formation of the light-emitting layer 130, please refer to the foregoing exemplary description of R2, which will not be repeated here.

[0292] N4: An anode 110 is formed on the side of the light-emitting layer 130 away from the first functional layer 141.

[0293] For example, the material of the anode 110 is deposited using a sputtering process or a vapor deposition process to form the anode 110.

[0294] In some examples, N3A and N3B are included after N3 and before N4.

[0295] N3A: A hole transport layer 152 is formed on the side of the light-emitting layer 130 away from the first functional layer 141.

[0296] N3B: A hole injection layer 151 is formed on the side of the hole transport layer 152 away from the light-emitting layer 130.

[0297] For an understanding of N3A and N3B, please refer to the aforementioned description of R1B and R1A, which will not be repeated here.

[0298] In some examples, N2A is included after N1 and before N2.

[0299] N2A: A second functional layer 142 is formed on the side of the cathode 120 away from the substrate 210.

[0300] In some examples, N2B is included after N2 and before N3.

[0301] N2B: A third functional layer 143 is formed on the side of the first functional layer 141 away from the cathode 120.

[0302] For an understanding of N2A and N2B, please refer to the aforementioned description of R3B and R3A, which will not be repeated here.

[0303] In some embodiments, after forming the anode 110, cathode 120, light-emitting layer 130 and first functional layer 141 (i.e., S1), the fabrication method further includes S2.

[0304] S2: The first functional layer 141 (see Figure 4) undergoes ion treatment, including fluoride ion (F) treatment. - Treatment, chloride ions (Cl) - Treatment and nitrogen (N) - At least one of the following in ion treatment. In the first nanomaterial, the mass ratio of the first metallic element to the first non-metallic element is greater than or equal to 10:1 and less than or equal to 30:1.

[0305] In some examples, the above-mentioned ion treatment includes one of fluoride ion treatment, chloride ion treatment and nitrogen ion treatment, for example, fluoride ion treatment; in still other examples, the above-mentioned ion treatment includes at least two of fluoride ion treatment, chloride ion treatment and nitrogen ion treatment, for example, fluoride ion treatment and chloride ion treatment performed sequentially.

[0306] For example, when the preparation method includes S2, the mass ratio of the first metal element to the first non-metal element in the first nanomaterial can be 10:1, 11:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 20:1, 22:1, 24:1, 26:1, 28:1 or 30:1, etc.

[0307] By ionizing the first functional layer 141, a positive aging process can be initiated in the light-emitting device 100, thereby improving its performance and enhancing the conductivity of the electron transport unit 140. In this case, by setting the mass ratio of the first metal element to the first non-metal element to be greater than or equal to 10:1, the functions of the first ligand material, such as reducing exciton quenching and protecting the light-emitting layer 130, can be guaranteed, while ensuring that the content of the first ligand material in the first nanomaterial is relatively low. This avoids the influence of the first ligand material on the positive aging process of the light-emitting device 100.

[0308] The technical solutions provided in this disclosure will be described in detail and by way of example through the following experimental examples and comparative examples. Based on the evaluation purpose of the experimental examples, the following experimental examples and comparative examples are divided into a first group of experimental examples, a second group of experimental examples, and a third group of experimental examples.

[0309] [First Group of Test Cases]

[0310] The following Examples 1-5 and Comparative Example 1 prepared light-emitting devices 100 with different contents of the first ligand material included in the first functional layer 141. In Examples 1-5, the structure of the light-emitting device 100 is the same as that of the light-emitting device 100 in FIG. 13. In Comparative Example 1, the structure of the light-emitting device 100 is similar to that of the light-emitting device 100 in FIG. 13, the only difference being that the first functional layer 141 is replaced with a comparative electron transport layer. In FIG. 13, K represents a TFT substrate including an anode.

[0311] In Examples 1 to 5 and Comparative Example 1, the method for preparing the light-emitting device 100 includes R1 to R4 as described above, and the light-emitting device 100 is encapsulated with epoxy resin encapsulant.

[0312] In Examples 1-5 and Comparative Example 1, the thickness and material of all films except the first functional layer 141 are the same. Specifically, in Examples 1-5 and Comparative Example 1, the hole injection layer 151 is made of PEDOT and has a thickness of 20 nm; the hole transport layer 152 is made of TFB and has a thickness of 20 nm; the light-emitting layer 130 is made of red quantum dot material and has a thickness of 20 nm; and the cathode 120 is made of aluminum and has a thickness of [missing information - likely a specific thickness].

[0313] The thickness of the first functional layer 141 in Examples 1 to 5 is 40 nm. The thickness of the comparative electron transport layer in Comparative Example 1 is 40 nm.

[0314] In Examples 1 to 5, the material of the first functional layer 141 is a first nanomaterial, which is composed of a first metal oxide material, zinc magnesium oxide (ZnMgO), and a first ligand material, ethanolamine. In the zinc magnesium oxide (ZnMgO), the mass ratio of Zn to Mg is in the range of (20-30):1. Specifically, the mass ratios of zinc to nitrogen in Examples 1 to 5 are 30:1, 15:1, 12:1, 9:1, and 3:1, respectively. In Comparative Example 1, the material of the comparative electron transport layer only includes the first metal oxide material, zinc magnesium oxide (ZnMgO).

[0315] In this set of experimental examples, the absorption spectra of the materials of the first functional layer 141 in Examples 1 to 5 were tested, and the results are shown in Figure 14. As can be seen from Figure 14, the absorption peaks of the absorption spectra of the materials of the first functional layer 141 in Examples 1 to 5 appear at the same wavelength.

[0316] In this set of test examples, the current density of the light-emitting device 100 in Examples 1 to 4 as a function of voltage was also tested, and the results are shown in Figure 15.

[0317] As shown in Figure 15, under the same voltage conditions, the current density of the light-emitting device 100, from largest to smallest, is as follows: Example 1, Example 2, Example 3, and Example 4. This indicates that as the content of the first ligand material in the first functional layer 141 (see Figure 13) increases, the current density of the light-emitting device 100 gradually increases. It is evident that when the first functional layer 141 includes the first ligand material, the driving voltage of the light-emitting device 100 can be reduced, and the power consumption of the light-emitting device 100 can be improved.

[0318] In this set of experiments, the brightness and external quantum efficiency (EQE) of the light-emitting device 100 in Examples 1-4 and Comparative Example 1 were also tested as a function of voltage. The brightness as a function of voltage curves for Examples 2-4 and Comparative Example 1 are shown in Figure 16. The EQE as a function of voltage curves for Examples 2-4 and Comparative Example 1 are shown in Figure 17. The brightness as a function of voltage curves for Examples 1, 2, and Comparative Example 1 are shown in Figure 18. The EQE as a function of voltage curves for Examples 1, 2, and Comparative Example 1 are shown in Figure 19. The light-emitting device 100 prepared in Example 5 could not be lit (possibly due to the excessive amount of the first ligand material affecting the bulk properties of the first metal oxide material), therefore, the brightness and EQE curves for the light-emitting device 100 of Example 5 are not included.

[0319] As shown in Figures 17 and 19, under the same voltage conditions, the external quantum efficiency of the light-emitting device 100 in Examples 1 to 4 is higher than that of the light-emitting device 100 in Comparative Example 1. Moreover, the external quantum efficiency of the light-emitting device 100 in Examples 1 to 4 is similar, indicating that as the content of the first ligand material in the first functional layer 141 (see Figure 13) increases, the efficiency improvement ratio of the light-emitting device 100 is similar.

[0320] As shown in Figures 16 and 18, under the same voltage conditions, the brightness of the light-emitting devices in Examples 1 to 4 is lower than that of the light-emitting device 100 in Comparative Example 1, and the order of brightness from highest to lowest for the light-emitting devices 100 in Examples 1 to 4 is: Example 4, Example 3, Example 2. This indicates that the brightness of the light-emitting device 100 gradually increases with the increase of the content of the first ligand material in the first functional layer 141 (see Figure 13). Therefore, considering both efficiency and brightness, the content of the first ligand material in Example 4 is preferred, that is, the mass ratio of the first metallic element zinc to the first non-metallic element nitrogen is preferably 9:1.

[0321] [Second Group of Test Examples]

[0322] Examples 6 to 10 below describe the preparation of light-emitting devices 100 with different contents of the first ligand material included in the first functional layer 141. In Examples 6 to 10, the structure of the light-emitting device 100 is the same as that of the light-emitting device 100 in FIG. 13.

[0323] In Examples 6 to 10, the method for preparing the light-emitting device 100 includes R1 to R4 as described above, and the light-emitting device 100 is encapsulated using an acidic encapsulating adhesive.

[0324] In Examples 6 to 10, the thickness and material of all films except the first functional layer 141 are the same. Specifically, in Examples 6 to 10, the hole injection layer 151 is made of PEDOT and has a thickness of 20 nm; the hole transport layer 152 is made of TFB and has a thickness of 20 nm; the light-emitting layer 130 is made of red quantum dot material and has a thickness of 20 nm; and the cathode 120 is made of aluminum and has a thickness of [missing information - likely a thickness value].

[0325] The thickness of the first functional layer 141 in Examples 6 to 10 is 40 nm.

[0326] In Examples 6 to 10, the material of the first functional layer 141 is a first nanomaterial, which is composed of a first metal oxide material, zinc magnesium oxide (ZnMgO), and a first ligand material, ethanolamine. In the zinc magnesium oxide (ZnMgO), the mass ratio of Zn to Mg is in the range of (20-30):1. Specifically, the mass ratios of zinc to nitrogen in Examples 6 to 10 are 30:1, 15:1, 12:1, 9:1, and 3:1, respectively.

[0327] In this set of experiments, the brightness and external quantum efficiency (EQE) of the light-emitting devices 100 in Examples 6 to 10 were tested as a function of voltage. The current efficiency (cd / A) as a function of voltage for Examples 7 and 9 is shown in Figure 20. The external quantum efficiency (EQE) as a function of voltage for Examples 7 and 9 is shown in Figure 21.

[0328] As shown in Figures 20 and 21, under the same voltage conditions, the current efficiency of the light-emitting device 100 in Example 7 is higher than that of the light-emitting device 10 in Example 9, and the external quantum efficiency of the light-emitting device 100 in Example 7 is higher than that of the light-emitting device 10 in Example 9. This indicates that when the content of the first ligand material in the first functional layer 141 is high, the coating effect of the first ligand material on the first metal oxide is stronger, which may affect the forward aging process and result in lower efficiency of the light-emitting device 100. Therefore, when the material of the encapsulation layer 240 includes an acidic encapsulating adhesive, the content of the first ligand material in Example 7 is preferred, that is, the mass ratio of the first metallic element zinc to the first non-metallic element nitrogen is preferably 15:1.

[0329] [Third Group of Test Examples]

[0330] The following Example 11 describes the fabrication of a light-emitting device 100 including a first functional layer 141. The structure of the light-emitting device 100 is shown in Figure 13. The fabrication method of the light-emitting device 100 includes M1 to M8.

[0331] M1: A hole injection layer 151 is formed on a glass substrate with a pre-patterned ITO using a spin coating process or a vapor deposition process.

[0332] M2: A hole transport layer 152 is formed on the side of the hole injection layer 151 away from the anode 110 by means of spin coating, vapor deposition or sputtering.

[0333] M3: A spin coating process is used to form a light-emitting layer 130 on the side of the hole transport layer 152 away from the hole injection layer 151, and then the layer is baked after spin coating.

[0334] M4: A first initial functional layer is formed on the side of the light-emitting layer 130 away from the hole transport layer 152 using a spin-coating or blade-coating process. The material of the first initial functional layer includes a first metal oxide material and a first ligand material, and the first ligand material includes a photosensitive group. Then, the first initial functional layer is irradiated with ultraviolet light to cause the first ligand material to undergo a photoreaction, forming the first functional layer 141.

[0335] M5: A cathode 120 is formed on the side of the first functional layer 141 away from the light-emitting layer 130 to form a light-emitting device 100.

[0336] M6: Apply UV-curable adhesive to the outside of the light-emitting device 100, and place a drying sheet on the outside of the UV-curable adhesive for encapsulation.

[0337] The observed luminescence morphology of multiple light-emitting devices 100 in Example 11 is shown in Figure 22, where the luminescence color is red. As can be seen from Figure 22, when the light-emitting device 100 includes the first functional layer 141, the luminescence morphology can be maintained for a longer period of time, thus improving the stability of the luminescence morphology.

[0338] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A light-emitting device, comprising: Anode and cathode arranged opposite each other; A light-emitting layer is located between the anode and the cathode; A first functional layer is located between the light-emitting layer and the cathode; the material of the first functional layer includes a first nanomaterial, which includes a first metal oxide material and a first ligand material. Wherein, the first metal oxide material includes a first metal element, and the first ligand material includes a first non-metal element; the first non-metal element and the first metal element can coordinate and connect; in the first nanomaterial, the mass ratio of the first metal element to the first non-metal element is greater than 3:1 and less than or equal to 30:

1.

2. The light-emitting device according to claim 1, wherein, The first non-metallic element includes nitrogen, and / or the first metallic element includes zinc.

3. The light-emitting device according to claim 1 or 2, wherein, The first ligand material includes primary amine groups and / or secondary amine groups.

4. The light-emitting device according to any one of claims 1 to 3, wherein, The first ligand material further includes: A photosensitive group; the photosensitive group is configured to cause a cross-linking reaction between the first ligand materials under light irradiation conditions.

5. The light-emitting device according to claim 4, wherein, The photosensitive group includes at least one of alkenyl, alkynyl, benzophenone, bisacridinyl, and azide.

6. The light-emitting device according to any one of claims 1 to 5, wherein, The first ligand material includes at least one of hydroxylamine compounds, secondary amine compounds, polyamine compounds, amino acid compounds, ethyleneimine compounds, amide compounds, alkenyl-containing amide compounds, and alkenyl-containing ethanolamine compounds.

7. The light-emitting device according to any one of claims 1 to 6, wherein, The first ligand material includes at least one of the structures shown in general formula (I), general formula (II), general formula (III), general formula (IV), general formula (V), general formula (VI) and general formula (VII); Among them, L1, L2, L3 and L4 may be the same or different, and are independently selected from substituted or unsubstituted C1 to C5 straight-chain alkylene or branched alkylene. L5 and L6 may be the same or different, and are independently selected from single-bonded, substituted or unsubstituted C1 to C5 straight-chain alkylene or branched alkylene; R1, R2, and R3 may be the same or different, and are independently selected from substituted or unsubstituted C1-C5 straight-chain alkyl or branched-chain alkyl groups. n is a positive integer from 1 to 20.

8. The light-emitting device according to any one of claims 1 to 7, wherein, The light-emitting device further includes: A second functional layer is located between the first functional layer and the cathode; the material of the second functional layer includes a second nanomaterial, and the material of the second nanomaterial includes a second metal oxide material.

9. The light-emitting device according to claim 8, wherein, The thickness of the second functional layer is less than or equal to the thickness of the first functional layer.

10. The light-emitting device according to claim 8 or 9, wherein, The first metal oxide material and the second metal oxide material contain the same metal elements.

11. The light-emitting device according to any one of claims 8 to 10, wherein, The light-emitting device further includes: A third functional layer is located between the first functional layer and the light-emitting layer; the material of the third functional layer includes a third nanomaterial, and the material of the third nanomaterial includes a third metal oxide material.

12. The light-emitting device according to claim 11, wherein, The first metal oxide material and the third metal oxide material contain the same metal elements.

13. The light-emitting device according to any one of claims 1 to 12, wherein, The first metal oxide material further includes a first doped metal element; and / or, The light-emitting device further includes a second functional layer, wherein the second metal oxide material comprises the first metal element and also includes a second doped metal element; and / or, The light-emitting device further includes a third functional layer, and the third metal oxide material includes the first metal element and a third doped metal element; The first doped metal element, the second doped metal element, and the third doped metal element may be the same or different, and each independently includes at least one of magnesium, aluminum, tin, and manganese.

14. The light-emitting device according to claim 13, wherein, In metal oxide materials, the mass ratio of the first metal element to the doped metal element is in the range of (20-30):1; Wherein, the metal oxide material is any one of the first metal oxide material, the second metal oxide material, and the third metal oxide material; the doping metal element is one of the first doping metal element, the second doping metal element, and the third doping metal element included in the metal oxide material.

15. The light-emitting device according to any one of claims 1 to 14, wherein, The first nanomaterial further includes: a second ligand material liganded to the first metal oxide material; and / or, The light-emitting device further includes a second functional layer, and the second nanomaterial further includes: a second ligand material configured to be disposed on the second metal oxide material; and / or The light-emitting device further includes a third functional layer, and the third nanomaterial further includes a second ligand material liganded in the third metal oxide material.

16. The light-emitting device according to claim 15, wherein, The second ligand material includes at least one of hydroxyl and carboxyl groups.

17. A display panel, comprising: The light-emitting device as described in any one of claims 1 to 16; An encapsulation layer is applied to the light-emitting device; the material of the encapsulation layer includes an organic encapsulating adhesive.

18. The display panel according to claim 17, wherein, The organic encapsulant includes a neutral encapsulant, wherein the mass ratio of the first metal element to the first non-metal element is greater than 3:1 and less than or equal to 12:1; or, The organic encapsulant includes an acidic encapsulant; in the first nanomaterial, the mass ratio of the first metal element to the first non-metal element is greater than or equal to 10:1 and less than or equal to 30:

1.

19. A method for fabricating a light-emitting device, comprising: An anode, a cathode, a light-emitting layer, and a first functional layer are formed; the anode and the cathode are disposed opposite to each other; the light-emitting layer is located between the anode and the cathode; the first functional layer is located between the light-emitting layer and the cathode; the material of the first functional layer includes a first nanomaterial, which includes a first metal oxide material and a first ligand material; Wherein, the first metal oxide material includes a first metal element, the first ligand material includes a first non-metal element; the first non-metal element is coordinated with the first metal element; in the first nanomaterial, the mass ratio of the first metal element to the first non-metal element is greater than 3:1 and less than or equal to 30:

1.

20. The method for fabricating a light-emitting device according to claim 19, wherein, After forming the anode, cathode, light-emitting layer, and first functional layer, the fabrication method further includes: The first functional layer is subjected to ion treatment, the ion treatment including at least one of fluoride ion treatment, chloride ion treatment and nitrogen ion treatment; In the first nanomaterial, the mass ratio of the first metallic element to the first non-metallic element is greater than or equal to 10:1 and less than or equal to 30:1.

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