WO2023093494A1 - Electroluminescent device and preparation method therefor, and photoelectric apparatus - Google Patents

Abstract

Disclosed in the present application are an electroluminescent device and a preparation method therefor, and a photoelectric apparatus. The electroluminescent device comprises: a first electrode, a second electrode, and functional layers, which are arranged between the first electrode and the second electrode, wherein there are at least two functional layers, one of the functional layers is a light-emitting layer, and the material of the at least two functional layers is doped with a photo-crosslinking agent; and the at least two functional layers are arranged adjacent to each other.

Description

Electroluminescence device and its preparation method, optoelectronic device

This application claims the priority of the Chinese patent application with the application number 202111402979.1 and the application title "Electroluminescence device and its preparation method, optoelectronic device" filed at the China Patent Office on November 24, 2021, the entire content of which is adopted References are incorporated in this application.

technical field

The present application relates to the field of photoelectric devices, in particular to an electroluminescence device, a preparation method thereof, and a photoelectric device.

Background technique

Electroluminescence, also known as electric field luminescence, is a physical phenomenon in which electrons excited by the electric field hit the luminescence center by applying a voltage to two electrodes to generate an electric field, which causes the transition, change, and recombination of electrons between energy levels to cause luminescence. QLED (Quantum Dots Light-Emitting Diode, Quantum Dot Light-Emitting Diode) is an emerging electroluminescent device based on inorganic semiconductor quantum dots.

The core technology of QLED is "Quantum Dot (quantum dot)". Quantum dots are composed of zinc, cadmium, selenium and sulfur atoms, and are particles with a particle diameter of less than 10nm. This substance has a very special property: when the quantum dot is stimulated by light, it will emit colored light, and the color is determined by the material making up the quantum dot and its size and shape. Because it has this property, it is able to change the color of the light emitted by the light source. The emission wavelength range of quantum dots is very narrow, and the color is relatively pure and can be adjusted. Therefore, the picture of quantum dot display will be clearer and brighter than that of liquid crystal display. It is expected to become the next generation of flat panel display with broad development prospects.

technical problem

There are still many problems in the research and development process of electroluminescent devices represented by QLED. For example, in the field of flexible panels, in order to cooperate with flexible substrates with low melting points, conductive films can only be deposited at low temperatures to form thin film resistors. High efficiency, poor transparency, poor adhesion with the functional layer, easy to break when bent, resulting in device failure.

technical solution

Therefore, the present application provides an electroluminescent device, a preparation method thereof, and a photoelectric device.

An embodiment of the present application provides an electroluminescent device, including: a first electrode, a second electrode, and a functional layer arranged between the first electrode and the second electrode, the functional layer has at least two layers, one of which is The functional layer is a light-emitting layer, and at least two layers of the functional layer are doped with a photocrosslinking agent and arranged adjacent to each other.

Optionally, in some embodiments of the present application, the photocrosslinking agent is selected from: coumarin, coumarin derivatives, hydroxyethyl methacrylate, hydroxypropyl methacrylate, divinylbenzene , one or more of N-methylolacrylamide or diacetone acrylamide, the photocrosslinking agent is combined with the material of the functional layer through a chemical bond, and a crosslinking structure is formed between the photocrosslinking agents .

Optionally, in some embodiments of the present application, when the photocrosslinking agent is selected from coumarins, the coumarins are crosslinked to form a four-membered ring.

Optionally, in some embodiments of the present application, in the functional layer doped with the photocrosslinking agent, the mass ratio of the photocrosslinking agent to the functional layer material is (1-3): 4.

Optionally, in some embodiments of the present application, the functional layer doped with the photocrosslinking agent is composed of a functional layer material and a photocrosslinking agent, and the photocrosslinking agent is mixed and dispersed in the functional layer material middle.

Optionally, in some embodiments of the present application, the material of each functional layer is doped with the photocrosslinking agent, each of the functional layers is composed of a functional layer material and the photocrosslinking agent, each In the functional layer, the photocrosslinking agent is mixed and dispersed in the corresponding material of the functional layer.

Optionally, in some embodiments of the present application, one of the functional layers includes a hole functional layer, and the hole functional layer is disposed between the light-emitting layer and the second electrode, and the phototransmitter The coupling agent is mixed and dispersed in the hole functional layer and the light-emitting layer.

Optionally, in some embodiments of the present application, one of the functional layers includes an electronic functional layer, and the electronic functional layer is disposed between the light-emitting layer and the first electrode, and the photocrosslinking agent mixed and dispersed in the light-emitting layer and the electronic functional layer.

Optionally, in some embodiments of the present application, one layer of the functional layer includes a first film layer away from the adjacent functional layer, and a second film layer and a third film layer close to the adjacent functional layer; wherein, The second film layer is close to the adjacent lower functional layer, the third film layer is close to the adjacent upper functional layer, and the photocrosslinking agent is mixed and dispersed in the second film layer and the third film layer.

Optionally, in some embodiments of the present application, the two functional layers are a hole functional layer and an electron functional layer, and the hole functional layer is disposed between the light-emitting layer and the second electrode , the electronic functional layer is arranged between the light-emitting layer and the first electrode; wherein, the side of the hole functional layer close to the light-emitting layer is doped with the photocrosslinking agent, and the light-emitting layer The photo-crosslinking agent is doped on the side close to the hole function; the photo-crosslinking agent is doped on the side of the electronic functional layer close to the light-emitting layer, and the light-emitting layer is close to the electronic functional layer One side is doped with the photocrosslinker.

Optionally, in some embodiments of the present application, the two functional layers are a hole functional layer and an electron functional layer, and the hole functional layer is disposed between the light-emitting layer and the second electrode , the electron functional layer is disposed between the light emitting layer and the first electrode, the functional layer further includes a hole functional layer and an electron functional layer, the hole functional layer includes a hole injection layer, the The electronic functional layer includes an electron injection layer, and the material of the hole injection layer is selected from: poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl)diphenylamine), polyvinylcarbazole , polymerized triarylamine, poly(N,N'bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine), poly(9,9-dioctylfluorene-co-bis- N,N-phenyl-1,4-phenylenediamine), 4,4',4"-tris(carbazol-9-yl)triphenylamine, 4,4'-bis(9-carbazole)biphenyl , N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine, 15N,N'-diphenyl- One or more of N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, graphene or _C60 ;

The material of the light-emitting layer is selected from one of direct bandgap compound semiconductors and perovskite semiconductors with luminescence ability, and the direct bandgap compound semiconductors with luminescence ability are selected from group II-VI compounds, III-V Group compound, II-V group compound, III-VI compound, IV-VI group compound, I-III-VI group compound, II-IV-VI group compound, IV group simple substance; Wherein, the II-VI compound is selected from One or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, PbS, PbSe or PbTe, and the III-V group compound is selected from one of GaP, GaAs, InP or InAs one or more; or, the perovskite semiconductor is selected from one or more of doped or non-doped inorganic perovskite semiconductors, and organic-inorganic hybrid perovskite semiconductors; wherein , the general structural formula of the inorganic perovskite semiconductor is AMX ₃ , A is a Cs ⁺ ion, M is a divalent metal cation, X is a halogen anion, and the divalent metal cation is selected from: Pb ²⁺ , Sn ^{2 +} , Cu ²⁺ , Ni ²⁺ , C ^d2+ , Cr ²⁺ , Mn ²⁺ , Co ²⁺ , Fe ²⁺ , Ge ²⁺ , Yb ²⁺ or Eu ²⁺ , the halogen anions are selected from Cl-, Br- or I-, the general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMX ₃ , wherein B is an organic amine cation, and the organic amine cation is selected from CH ₃ (CH ₂ ) _n-2 NH ³⁺ (n≥2) or NH ₃ (CH ₂ )nNH ₃ ²⁺ (n≥2);

The material of the electron injection layer is selected from one or more of ZnO, TiO ₂ , SnO ₂ , Ta ₂ O ₃ , ZrO ₂ , NiO, TiLiO, ZnAlO, ZnMgO, ZnSnO, ZnLiO or InSnO;

The second electrode material is selected from: metal or non-metallic materials, the metal or non-metallic materials are selected from nickel, platinum, gold, silver, iridium or carbon nanotubes; or selected from doped or undoped Metal oxides, the doped or undoped metal oxides are selected from the group consisting of indium tin oxide, indium zinc oxide, indium tin zinc oxide, indium copper oxide, tin oxide, indium oxide, cadmium:zinc oxide, fluorine : tin oxide, indium: zinc oxide, gallium: tin oxide or zinc: aluminum oxide;

The material of the first electrode is selected from one or more of metal materials, carbon materials, and metal oxides. Wherein, the metal material includes one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Mg, and the carbon material includes one or more of graphite, carbon nanotube, graphene, carbon fiber Various, the metal oxide is selected from doped/non-doped metal oxide, or a composite electrode with metal sandwiched between doped/non-doped transparent metal oxide, the doped/non-doped metal oxide The material includes one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, AMO, and the composite electrode includes AZO/Ag/AZO, AZO/Al/AZO, ITO/Ag/ITO, ITO/ Al/ITO, ZnO/Ag/ZnO, ZnO/Al/ZnO, TiO ₂ /Ag/TiO ₂ , TiO ₂ /Al/TiO ₂ , ZnS/Ag/ZnS, ZnS/Al/ZnS, TiO ₂ /Ag/TiO _2. One or more of TiO ₂ /Al/TiO ₂ .

Correspondingly, the embodiment of the present application also provides a method for manufacturing an electroluminescent device, the method comprising:

sequentially preparing at least two functional layers on the second electrode from bottom to top; and

preparing a first electrode on the functional layer to obtain the electroluminescent device;

One of the functional layers is a light-emitting layer, and at least two layers of the functional layer are doped with a photocrosslinking agent and arranged adjacent to each other.

Optionally, in some embodiments of the present application, the photocrosslinking agent is selected from: coumarin, coumarin derivatives, hydroxyethyl methacrylate, hydroxypropyl methacrylate, divinylbenzene , one or more of N-methylolacrylamide or diacetoneacrylamide.

Optionally, in some embodiments of the present application, when the photocrosslinking agent is selected from coumarins, the coumarins are crosslinked to form a four-membered ring.

Optionally, in some embodiments of the present application, the preparation method of the at least two functional layers includes:

mixing the crosslinking agent with the material solution of the functional layer and heating to obtain a mixed solution, and using the mixed solution to prepare the functional layer;

Carrying out the preparation of the next functional layer in sequence to obtain at least two functional layers; and

Each of the functional layers is subjected to ultraviolet light irradiation treatment.

Optionally, the preparation method of the at least two functional layers comprises:

Mix the crosslinking agent with the material solution of the functional layer and heat to obtain a mixed solution, use the material solution of the functional layer to prepare the first film layer, and use the mixed solution to prepare the second film layer and/or the third film layer , to obtain a functional layer; wherein, the second film layer is close to the adjacent lower functional layer, and the third film layer is close to the adjacent upper functional layer;

Carrying out the preparation of the next functional layer in sequence to obtain at least two functional layers; and

Each of the functional layers is subjected to ultraviolet light irradiation treatment.

Optionally, in some embodiments of the present application, in the mixed solution, the mass ratio of the photocrosslinking agent to the functional layer material is (1˜3):4.

Correspondingly, the embodiment of the present application also provides a photoelectric device, including the electroluminescent device as described above, or an electroluminescent device prepared by the manufacturing method as described above.

Beneficial effect

The present application mixes a photocrosslinking agent in the materials of at least two adjacent functional layers. On the one hand, the photocrosslinking agent can be combined with each functional layer material through a chemical bond. It can also form a cross-linked structure to make the bonding between adjacent functional layers more firm, avoiding the cracking of the film layer and the overall shedding of the film layer during the use of flexible devices, thereby improving the problem that the device is prone to failure .

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

Figure 1 is a schematic structural view of a positive-type electroluminescent device provided by an embodiment of the present application;

Fig. 2 is a schematic structural diagram of a positive-type electroluminescent device provided by another embodiment of the present application;

Fig. 3 is a schematic structural diagram of an electroluminescent device with an inverse structure provided by an embodiment of the present application;

Fig. 4 is a schematic flow chart of a method for preparing an electroluminescent device provided in an embodiment of the present application;

Fig. 5 is a schematic flow chart of a method for preparing a positive-type structure electroluminescent device provided in an embodiment of the present application;

Fig. 6 is a schematic flow chart of a method for preparing an electroluminescent device with an inverse structure provided in an embodiment of the present application;

Fig. 7 is a photogram of the topography of each electroluminescent device provided in the embodiment of the present application.

Embodiment of this application

The following will clearly and completely describe the technical solutions in the embodiments of the application with reference to the drawings in the embodiments of the application. Apparently, the described embodiments are only some of the embodiments of the application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts belong to the scope of protection of this application.

It should be noted that the description sequence of the following embodiments is not intended to limit the preferred sequence of the embodiments. In addition, in the description of the present application, the term "including" means "including but not limited to". Various embodiments of the present application may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be construed as a rigid limitation on the scope of the application; therefore, the described range should be regarded as The description has specifically disclosed all possible subranges as well as individual values within that range. For example, a description of a range from 1 to 6 should be considered to have specifically disclosed subranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and Single numbers within the stated ranges, eg 1, 2, 3, 4, 5 and 6, apply regardless of the range. Additionally, whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range.

In this application, "one or more" means one or more, and "multiple" means two or more. "One or more", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one item (unit) of a, b, or c", or "at least one item (unit) of a, b, and c" can mean: a, b, c, a-b( That is, a and b), a-c, b-c, or a-b-c, where a, b, and c can be single or multiple.

First, an embodiment of the present application provides an electroluminescent device, including: a first electrode, a second electrode, and a functional layer arranged between the first electrode and the second electrode, and the functional layer has at least two layers, One of them is a light-emitting layer, and the materials of at least two functional layers are doped with a photocrosslinking agent and arranged adjacently.

There are two or more functional layers, one of which is a light-emitting layer. Among the two or more functional layers, there are at least two adjacent functional layers, and the materials of these two functional layers are all doped with a photocrosslinking agent. It can be understood that the photo-crosslinking agent may be doped in both the light-emitting layer and its adjacent functional layers, or the cross-linking agent may be doped in other adjacent functional layers except the light-emitting layer.

In the embodiment of the present application, by mixing a photocrosslinking agent in the materials of at least two adjacent functional layers, on the one hand, the photocrosslinking agent can be combined with each functional layer material through a chemical bond; on the other hand, the photocrosslinking agent A cross-linked structure can also be formed between them, so that the adjacent functional layers can be bonded more firmly, avoiding the cracking of the film layer and the overall shedding of the film layer during the use of the flexible device, thereby improving the ease of use of the device. failure problem.

In some embodiments, the first electrode is a cathode and the second electrode is an anode; in other embodiments, the first electrode is an anode and the second electrode is a cathode.

In some embodiments, the photocrosslinking agent is selected from: coumarin (2H-1-benzopyran-2-one), coumarin derivatives, hydroxyethyl methacrylate, hydroxyethyl methacrylate One or more of propyl ester, divinylbenzene, N-methylol acrylamide or diacetone acrylamide, the photocrosslinking agent is combined with the material of the functional layer through a chemical bond, and the photocrosslinking agent form a cross-linked structure between the agents.

When the photocrosslinking agent is selected from coumarin or its derivatives, the coumarins in each functional layer are crosslinked to form a four-membered ring. The chemical bonding mode of the material of each functional layer and coumarin or its derivatives is:

Taking the hole injection layer material carboxy-substituted polymeric triarylamine as an example, the cross-linking agent material is amino-substituted coumarin, carboxyl-substituted polymeric triarylamine and amino-substituted coumarin are combined through amide bonds to obtain reversible photoresponsive cross-linked holes Inject material.

Taking the light-emitting layer material ZnS quantum dots as an example, the cross-linking agent material is coumarin, and the carbonyl group of coumarin is combined with ZnS through a coordination bond to obtain a reversible light-responsive cross-linked QD material.

Taking the electron injection layer material ZnO as an example, the crosslinking agent material is coumarin, and the carbonyl group of coumarin is combined with ZnO through a coordination bond to obtain a reversible photoresponsive crosslinked electron injection layer material.

In some embodiments, in the functional layer doped with the photocrosslinking agent, the mass ratio of the photocrosslinking agent to the material of the functional layer is (1-3):4. If the content of the photocrosslinking agent is too high, the carrier mobility of the crosslinked layer will be reduced, and if the content is too low, the functional layers cannot be effectively crosslinked. It can be understood that the mass ratio of the photocrosslinking agent to the functional layer material is any value within the range of (1-3):4, such as 1:4, 1.5:4, 2:4, 2.5:4 , 3:4, etc., or other unlisted values within the range of (1～3):4.

It should be noted that the present application does not limit the distribution of the photocrosslinking agent in the functional layer. The photocrosslinking agent can be dispersed in the material of the functional layer, or can be dispersed in each functional layer. contact interface.

For example: in some embodiments, the functional layer doped with the photocrosslinking agent is composed of a functional layer material and a photocrosslinking agent, and the photocrosslinking agent is mixed and dispersed in the functional layer material. In some embodiments, the photocrosslinking agent is doped in the material of each functional layer, each functional layer is composed of functional layer material and the photocrosslinking agent, and the photocrosslinking agent is mixed and dispersed in the corresponding functional layer material. Under such structural conditions, a cross-linked structure can be formed between the functional layers, which greatly improves the physical deformation ability of each film layer in the flexible device and the resistance to water, oxygen or solvent. After the mechanical stress of the inventor's flexible device Test experiments have verified that the lifetime of devices with this structure can be significantly improved.

As an exemplary embodiment, as shown in FIG. 1, FIG. 1 shows an electroluminescent device, including a substrate 10, an anode 20 and a cathode 60, and a functional layer between the anode 20 and the cathode 60, so The functional layer includes a hole injection layer 30, a light-emitting layer 40, and an electron injection layer 50 stacked in sequence from bottom to top, wherein the photocrosslinking agent is mixed and dispersed in the hole injection layer 30, the light-emitting layer 40, and the electron injection layer 50 of the material.

Another example: in some embodiments, the functional layer includes a first film layer away from the adjacent functional layer, and a second film layer and a third film layer close to the adjacent functional layer; wherein, the second film layer Adjacent to the adjacent lower functional layer, the third film layer is adjacent to the adjacent upper functional layer, and the photocrosslinking agent is mixed and dispersed in the second film layer and the third film layer. During the preparation process of this structure, since the precursor solution of the functional layer material and the precursor solution of the cross-linking material are only different in ligands, the first film layer, the second film layer or the third film layer will appear to be miscible. , forming a relatively stable whole. Devices with this structure can not only form a cross-linked structure with other functional layers at the interface, but also retain their excellent electrical properties to the greatest extent.

When the adjacent functional layer is located above the functional layer, the functional layer may include a first film layer and a third film layer, the first film layer is located on a side of the functional layer away from the adjacent functional layer, The third film layer is located on a side of the functional layer close to the adjacent functional layer.

When the adjacent functional layer is located below the functional layer, the functional layer may include a first film layer and a second film layer, the first film layer is located on the side of the functional layer away from the adjacent functional layer , the second film layer is located on a side of the functional layer close to the adjacent functional layer.

When the adjacent functional layer is located below and above the functional layer, the functional layer may include a first film layer, a second film layer and a third film layer, and the second film layer is located close to the functional layer. One side of the adjacent functional layer below, the third film layer is located on the side of the functional layer close to the adjacent functional layer above, the first film layer is located between the second film layer and between the third layer.

As an exemplary embodiment, as shown in FIG. 2, FIG. 2 shows an electroluminescent device, including a substrate 10, an anode 20 and a cathode 60, and a functional layer between the anode 20 and the cathode 60, so The functional layer includes a hole injection layer 30 , a light emitting layer 40 and an electron injection layer 50 stacked in sequence from bottom to top.

Wherein, the hole injection layer 30 in FIG. 2 includes a first hole injection layer 31 away from the light-emitting layer 40, and a third hole injection layer 32 close to the light-emitting layer 40, and the first hole injection layer layer 31 as the first film layer, and the third hole injection layer 32 as the third film layer; the light emitting layer 40 includes a second light emitting layer 41 close to the hole injection layer 30, close to the electron injection layer 50 of the third light-emitting layer 43, and the first light-emitting layer 42 between the second light-emitting layer 41 and the third light-emitting layer 43, the first light-emitting layer 42 is used as the first film layer, and the second light-emitting layer 41 is used as the The second film layer, the third light-emitting layer 43 is used as the third film layer; the electron injection layer 50 includes a second electron injection layer 51 close to the light-emitting layer 40, and a first electron injection layer far away from the light-emitting layer 40 The injection layer 52, the first electron injection layer 52 is used as a first film layer, and the second electron injection layer 51 is used as a second film layer.

In some embodiments, the distribution of photocrosslinkers in a functional layer can be the same or different than that in an adjacent functional layer. For example: in some embodiments, the photocrosslinking agent in the functional layer and the adjacent functional layer is evenly distributed; in other embodiments, the functional layer is divided into the first film layer, the second film layer film layer and the third film layer, and the photocrosslinking agent in the adjacent functional layer is evenly distributed. Regardless of whether the distribution of the photocrosslinking agent in the functional layer can be the same as or different from that in the adjacent functional layer, the photocrosslinking agent can play a crosslinking effect, making the bonding between adjacent functional layers more perfect. firm.

In some specific embodiments, in addition to the light-emitting layer, the functional layer further includes a hole functional layer and an electron functional layer, and the hole functional layer is disposed between the light-emitting layer and the second electrode , the electronic functional layer is disposed between the light-emitting layer and the first electrode, and the photocrosslinking agent is mixed and dispersed in the electronic functional layer, hole functional layer and the light-emitting layer.

In other specific embodiments, in addition to the light emitting layer, the functional layer further includes a hole functional layer and an electron functional layer, and the hole functional layer is disposed between the light emitting layer and the second electrode Between, the electronic functional layer is arranged between the light-emitting layer and the first electrode, the side of the hole functional layer close to the light-emitting layer is doped with the photocrosslinking agent, and the light-emitting layer is close to The side of the hole function is doped with the photocrosslinking agent, and/or, the side of the electronic functional layer close to the light-emitting layer is doped with the photocrosslinker, and the light-emitting layer is close to the light-emitting layer. One side of the electronic functional layer is doped with the photocrosslinking agent.

The electroluminescent device described in the embodiment of the present application may be of a positive type structure or an inverse type structure. In the electroluminescent device, the side of the first electrode or the second electrode away from the light-emitting layer also includes a substrate, the second electrode is arranged on the substrate in the positive structure, and the first electrode is arranged on the substrate in the inverse structure on the substrate. Whether it is a positive structure or an inverse structure, hole functional layers such as a hole transport layer and an electron blocking layer can also be provided between the second electrode and the light-emitting layer, and between the first electrode and the Electronic functional layers such as hole blocking layers can also be arranged between the light emitting layers. For example: in some embodiments, the functional layer further includes a hole functional layer and an electron functional layer, the hole functional layer includes a hole injection layer, and the electron functional layer includes an electron injection layer.

Figure 1 shows a schematic diagram of a positive structure of the electroluminescent device described in the embodiment of the present application. As shown in Figure 1, the positive structure quantum dot device includes a substrate 10, and The anode 20, the hole injection layer 30 arranged on the surface of the anode 20, the light emitting layer 40 arranged on the surface of the hole injection layer 30, the electron injection layer 50 arranged on the surface of the light emitting layer 40, and the The cathode 60 on the surface of the electron injection layer 50, wherein the hole injection layer 30, the light emitting layer 40 and the electron injection layer 50 are all doped with a photocrosslinking agent.

Fig. 3 shows a schematic diagram of an inverse structure of the quantum dot device described in the embodiment of the present application. As shown in Fig. The cathode 60, the electron injection layer 50 disposed on the surface of the cathode 60, the light emitting layer 40 disposed on the surface of the electron injection layer 50, the hole injection layer 30 disposed on the surface of the light emitting layer 40, and the anode 20, wherein, A photocrosslinking agent is doped in the hole injection layer 30 , the light emitting layer 40 and the electron injection layer 50 .

In some embodiments, the electronic light emitting device is an electroluminescent device (QLED).

In each embodiment of the present application, the material of each functional layer may be the following materials, for example:

The substrate can be a rigid substrate or a flexible substrate. Specific materials may include one of glass, silicon wafer, polycarbonate, polymethylmethacrylate, polyethylene terephthalate, polyethylene naphthalate, polyamide, polyethersulfone or more.

The second electrode material may be composed of nickel (Ni), platinum (Pt), gold (Au), silver (Ag), iridium (Ir) or carbon nanotube (CNT) metal or non-metal material. Can also include doped or undoped metal oxides such as indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), indium copper oxide (ICO), tin oxide (SnO ₂ ), indium oxide (In ₂ O ₃ ), cadmium: zinc oxide (Cd: ZnO), fluorine: tin oxide (F: SnO ₂ ), indium: zinc oxide (In: SnO ₂ ), gallium: tin oxide (Ga : SnO ₂ ) or zinc: aluminum oxide (Al: ZnO; AZO).

The material of the hole injection layer is selected from: poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl) diphenylamine), polyvinylcarbazole, polymeric triarylamine, poly(N , N'bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine), poly(9,9-dioctylfluorene-co-bis-N,N-phenyl-1 ,4-phenylenediamine), 4,4',4"-tris(carbazol-9-yl)triphenylamine, 4,4'-bis(9-carbazole)biphenyl, N,N'-diphenyl Base-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine, 15N,N'-diphenyl-N,N'-(1- One or more of naphthyl)-1,1'-biphenyl-4,4'-diamine, graphene or _C60 .

The material of the light-emitting layer is selected from: direct bandgap compound semiconductors with light-emitting ability, including but not limited to II-VI compounds, III-V compounds, II-V compounds, III-VI compounds, IV-VI compounds One or more of compound, I-III-VI compound, II-IV-VI compound or IV element. In some embodiments, the semiconductor materials used in the light-emitting layer include but are not limited to nanocrystals of II-VI semiconductors, such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, PbS, PbSe, PbTe and other binary, ternary, and quaternary II-VI compounds; nanocrystals of III-V semiconductors, such as GaP, GaAs, InP, InAs, and other binary, ternary, and quaternary III-V compounds; The materials used for the light-emitting layer are not limited to II-V compounds, III-VI compounds, IV-VI compounds, I-III-VI compounds, II-IV-VI compounds, IV simple substances, etc. Wherein, the light-emitting layer material can also be one or more of doped or non-doped inorganic perovskite semiconductors and organic-inorganic hybrid perovskite semiconductors; specifically, the inorganic The general structural formula of perovskite semiconductor is AMX ₃ , where A is Cs ⁺ ion, M is a divalent metal cation, including but not limited to Pb ²⁺ , Sn ²⁺ , Cu ²⁺ , Ni ²⁺ , Cd ²⁺ , Cr ²⁺ , Mn ²⁺ , Co ²⁺ , Fe ²⁺ , Ge ²⁺ , Yb ²⁺ , Eu ²⁺ , X is a halogen anion, including but not limited to Cl ^- , Br ^- , I ^- ; The general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMX ₃ , where B is an organic amine cation, including but not limited to

CH ₃ (CH ₂ ) _n-2 NH ³⁺ (n≥2) or NH ₃ (CH ₂ ) _n NH ₃ ²⁺ (n≥2). When n=2, the inorganic metal halide octahedron MX ₆₄ ^- is connected by a common top, the metal cation M is located at the body center of the halogen octahedron, and the organic amine cation B fills the gap between the octahedrons, forming an infinitely extending Three-dimensional structure; when n>2, the inorganic metal halide octahedron ^MX ₆₄ connected in a common top-extends in the two-dimensional direction to form a layered structure, and an organic amine cationic bilayer (protonated monoamine) is inserted between the layers Or organic amine cation monolayer (protonated diamine), the organic layer and the inorganic layer overlap each other to form a stable two-dimensional layered structure; M is a divalent metal cation, including but not limited to Pb ²⁺ , Sn ²⁺ , Cu ²⁺ , Ni ²⁺ , Cd ²⁺ , Cr ²⁺ , Mn ²⁺ , Co ²⁺ , ^Fe2+ , Ge ²⁺ , Yb ²⁺ , Eu ²⁺ ; X is a halogen anion, including but not limited to Cl ^- , Br ^- , I.

The material of the electron injection layer is selected from one or more of ZnO, TiO ₂ , SnO ₂ , Ta ₂ O ₃ , ZrO ₂ , NiO, TiLiO, ZnAlO, ZnMgO, ZnSnO, ZnLiO or InSnO.

The material of the first electrode is selected from one or more of metal materials, carbon materials, and metal oxides. Wherein, the metal material includes one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Mg, and the carbon material includes one or more of graphite, carbon nanotube, graphene, carbon fiber Various, the metal oxide is selected from doped/non-doped metal oxide, or a composite electrode with metal sandwiched between doped/non-doped transparent metal oxide, the doped/non-doped metal oxide The material includes one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, AMO, and the composite electrode includes AZO/Ag/AZO, AZO/Al/AZO, ITO/Ag/ITO, ITO/ Al/ITO, ZnO/Ag/ZnO, ZnO/Al/ZnO, TiO ₂ /Ag/TiO ₂ , TiO ₂ /Al/TiO ₂ , ZnS/Ag/ZnS, ZnS/Al/ZnS, TiO ₂ /Ag/TiO _2. One or more of TiO ₂ /Al/TiO ₂ .

Correspondingly, the present application also provides a method for preparing an electroluminescence device. Referring to Fig. 4, the preparation method of described electroluminescence device comprises the following steps:

S1. Prepare at least two functional layers sequentially from bottom to top on the second electrode; and

S2. preparing a first electrode on the functional layer to obtain the electroluminescent device;

One of the functional layers is a light-emitting layer, and at least two layers of the functional layer are doped with a photocrosslinking agent and arranged adjacent to each other.

In some embodiments, the electroluminescent device is a positive structure, correspondingly, the first electrode is a cathode, and the second electrode is an anode; in other embodiments, the electroluminescent device is Negative structure, correspondingly, the first electrode is an anode, and the second electrode is a cathode.

As an exemplary embodiment, Fig. 5 shows a method for preparing a positive structure of the electroluminescent device described in the embodiment of the present application. As shown in Fig. 5, the method for preparing the electroluminescent device of the positive structure includes the following step:

S10. Prepare at least two functional layers on the anode sequentially from bottom to top; and

S20. Prepare a cathode on the functional layer to obtain the electroluminescent device.

One of the functional layers is a light-emitting layer, and the materials of at least two functional layers are doped with a photocrosslinking agent and arranged adjacent to each other.

As an exemplary embodiment, FIG. 6 shows a method for preparing an inverse structure of the electroluminescent device described in the embodiment of the present application. As shown in FIG. 6, the method for preparing an electroluminescent device with an inverse structure includes the following step:

S100. sequentially prepare at least two functional layers on the cathode from bottom to top; and

S200. Prepare an anode on the functional layer to obtain the electroluminescent device.

One of the functional layers is a light-emitting layer, and the materials of at least two functional layers are doped with a photocrosslinking agent and arranged adjacent to each other.

In the embodiment of the present application, the formation method of each functional layer can be realized by methods known in the art. As an exemplary embodiment, each functional layer is prepared by a solution method, and the production cost can be greatly reduced by using this method. For mass production, solution methods include spin coating, printing, inkjet printing, blade coating, printing, dipping, soaking, spraying, roll coating, casting, slot coating method, strip coating method.

In some embodiments, the preparation method of at least two functional layers in the step S1, S10 or S200 includes:

(1) mixing and heating the crosslinking agent and the material solution of the functional layer to obtain a mixed solution, and using the mixed solution to prepare the functional layer;

(2) performing the preparation of the next functional layer in sequence to obtain at least two functional layers; and

(3) Subjecting each of the functional layers to ultraviolet light irradiation treatment.

In other embodiments, the preparation method of the two or more functional layers includes:

(10) mixing and heating the crosslinking agent and the material solution of the functional layer to obtain a mixed solution, using the material solution of the functional layer to prepare a first film layer, and using the mixed solution to prepare a second film layer, and/or , the third film layer to obtain a functional layer; wherein, the second film layer is close to the adjacent lower functional layer, and the third film layer is close to the adjacent upper functional layer;

(20) Carrying out the preparation of the next functional layer in sequence to obtain at least two functional layers; and

(30) Subjecting each of the functional layers to ultraviolet light irradiation treatment.

In some embodiments, in the mixed solution, the mass ratio of the photocrosslinking agent to the functional layer material is (1˜3):4.

In some embodiments, the photocrosslinking agent is selected from: coumarin, coumarin derivatives, hydroxyethyl methacrylate, hydroxypropyl methacrylate, divinylbenzene, N-methylolpropylene One or more of amide or diacetone acrylamide.

When the photocrosslinking agent is selected from coumarin or its derivatives, the double bonds in coumarin can undergo chemical crosslinking to form a four-membered ring under the irradiation of 365nm ultraviolet light. The way in which each functional layer is mixed with coumarin or its derivatives is:

Taking the hole injection material carboxyl-substituted polymeric triarylamine as an example, the cross-linking agent material is amino-substituted coumarin, the two are mixed and then heated to cause amidation reaction of the two materials, as shown in formula 1, to obtain Backlight Responsive Crosslinked Hole Injection Materials.

Taking the light-emitting layer material ZnS quantum dots as an example, the cross-linking agent material is coumarin, the two are mixed and heated, and the carbonyl group of coumarin forms a coordination bond with ZnS to obtain a reversible light-responsive cross-linked QD material.

Taking the electron injection material ZnO as an example, the crosslinking agent material is coumarin, and the two are mixed and then heated. The carbonyl group of coumarin forms a coordination bond with ZnO to obtain a reversible photoresponsive crosslinked electron injection material.

Wherein, the cross-linked structure of the hole injection material and the light-emitting layer is shown in Formula 1, and the cross-linked structure of the electron injection material and the light-emitting layer material is shown in Formula 2. (Zn in Formula 1 represents ZnS quantum dots of the light-emitting layer material, and Zn in Formula 2 represents the electron injection material ZnO)

From Formula 1 and Formula 2, it can be seen that the photocrosslinking agent can be combined with the materials of each functional layer through chemical bonds, and the double bond in coumarin can also undergo chemical crosslinking to form four layers under the irradiation of 365nm ultraviolet light. This structure can make the bonding between adjacent functional layers more firm, avoiding the cracking of the film layer and the overall shedding of the film layer during the use of flexible devices, thereby improving the problem that the device is prone to failure .

Correspondingly, the present application also provides a photoelectric device, including the electroluminescent device described in any one of the above, or an electroluminescent device prepared by the preparation method described in any of the above, its structure, realization principle and effect similar and will not be repeated here. In a specific embodiment, the optoelectronic device is a QLED.

Optionally, the optoelectronic device may be: a lighting fixture and a backlight, or any product or component with a display function such as a mobile phone, a tablet computer, a television, a monitor, a notebook computer, a digital photo frame, and a navigator.

It should be noted that the drawings of the embodiments of the present application only refer to the structures involved in the embodiments of the present application, and other structures may refer to common designs.

The present application will be described in detail below through examples.

Example 1:

This embodiment provides an electroluminescent device with a positive top emission structure, and the preparation process of the device includes:

(1) Preparation of materials for the cross-linked hole injection layer: Mix amino-substituted coumarin powder (5 mg/mL) into carboxyl-substituted polymeric triarylamine (8 mg/mL), and heat at 120 ° C for 10 min in an inert gas environment to obtain a cross-linked hole injection layer. Bi-polymeric triarylamines.

(2) Preparation of materials for the cross-linked luminescent layer: mix amino-substituted coumarin powder (8 mg/mL) into the ZnS quantum dot material (20 mg/mL), and heat at 80 ° C for 10 min in an inert gas environment to obtain cross-linked QDs.

(3) Preparation of materials for the cross-linked electron injection layer: use ZnO precursor solution (30 mg/mL) mixed with coumarin powder (10 mg/mL), and heat at 120 °C for 10 min in an inert gas environment to obtain cross-linked-ZnO.

(4) On the ITO substrate, the material solution (8 mg/mL) of the cross-linked hole injection layer was spin-coated at 3000 rpm for 30 seconds, then heated at 80° C. for 10 minutes, and left to cool for 5 minutes.

(5) Spin-coat the material (20 mg/mL) of the cross-linked light-emitting layer at a rotation speed of 2000 rpm for 30 seconds, then heat at 80° C. for 10 minutes, and stand to cool for 5 minutes.

(6) Spin-coat the material of the cross-linked electron injection layer at a rotational speed of 2000 rpm for 30 seconds, then heat at 80° C. for 20 minutes, and stand for cooling for 5 minutes.

(7) Ultraviolet light is used for irradiation, the wavelength is 365nm, the pulse width of the ultraviolet laser is 22ns, the power is 5W, the frequency is 1.2Hz, and the time is 90s.

(8) By thermal evaporation, the vacuum degree is not higher than 3 × 10 ^-4 Pa, and Ag is evaporated at a speed of 1 angstrom/second, for 200 seconds, and a thickness of 20nm, to obtain a top-emitting positive electroluminescent device, and to The device is packaged.

Example 2:

This embodiment provides an electroluminescent device with a positive top emission structure, and the preparation process of the device includes:

(1) Preparation of materials for the cross-linked hole injection layer: use carboxy-substituted polymeric triarylamine (8 mg/mL) mixed with amino-substituted coumarin powder (5 mg/mL), and heat at 120 ° C for 10 min in an inert gas environment to obtain cross-linking - Polymerized triarylamines.

(2) Preparation of materials for the cross-linked light-emitting layer: use ZnS quantum dot material (20 mg/mL) mixed with amino-substituted coumarin powder (8 mg/mL), and heat at 80°C for 10 min in an inert gas environment to obtain cross-linked-QD.

(3) Preparation of materials for the cross-linked electron injection layer: use ZnO precursor solution (30 mg/mL) mixed with coumarin powder (10 mg/mL), and heat at 120 °C for 10 min in an inert gas environment to obtain cross-linked-ZnO.

(4) On the ITO substrate, spin-coat polymerized triarylamine (8 mg/mL) at 4500 rpm for 30 seconds, then heat at 80° C. for 10 minutes, and let it cool for 5 minutes.

(5) On the ITO substrate, spin-coat the material (8 mg/mL) of the cross-linked hole injection layer at a rotation speed of 5000 rpm for 30 seconds, then heat at 80° C. for 10 minutes, and stand for cooling for 5 minutes.

(6) Spin-coat the material (20 mg/mL) of the cross-linked light-emitting layer at a rotation speed of 5000 rpm for 30 seconds, then heat at 80° C. for 10 minutes, and stand to cool for 5 minutes.

(7) Spin-coat the quantum dot material (20 mg/mL) at a rotational speed of 3000 rpm for 30 seconds, then heat at 80° C. for 10 minutes, and stand for cooling for 5 minutes.

(8) Spin-coat the material (20 mg/mL) of the cross-linked light-emitting layer at a rotation speed of 5000 rpm for 30 seconds, then heat at 80° C. for 10 minutes, and stand to cool for 5 minutes.

(9) Spin-coat the material of the cross-linked electron injection layer at a rotational speed of 5000 rpm for 30 seconds, then heat at 80° C. for 20 minutes, and stand for cooling for 5 minutes.

(10) Spin-coat ZnO at a speed of 3000 rpm for 30 seconds, then heat at 80°C for 20 minutes, and let it cool for 5 minutes;

(11) Use ultraviolet light for irradiation, the wavelength is 365nm, the pulse width of the ultraviolet laser is 22ns, the power is 5W, the frequency is 1.2Hz, and the time is 90s.

(12) By thermal evaporation, the vacuum degree is not higher than 3×10 ^-4 Pa, and Ag is evaporated at a speed of 1 angstrom/second for 200 seconds and a thickness of 20 nm to obtain a top-emitting positive-type electroluminescent device, and Package the device.

Example 3:

This example is roughly the same as Example 1, except that the concentration of coumarin in the crosslinked hole transport layer is 2 mg/mL; the concentration of coumarin in the crosslinked light-emitting layer is 5 mg/mL; Soybean concentration is 8mg/mL.

Example 4:

This example is roughly the same as Example 1, except that the concentration of coumarin in the crosslinked hole transport layer is 6 mg/mL; the concentration of coumarin in the crosslinked light-emitting layer is 15 mg/mL; Soybean concentration is 20mg/mL.

Example 5:

This example is roughly the same as Example 1, except that the concentration of coumarin in the crosslinked hole transport layer is 0.2 mg/mL; the concentration of coumarin in the crosslinked light-emitting layer is 1 mg/mL; The concentration of coumarin was 1 mg/mL.

Embodiment 6:

This example is roughly the same as Example 1, except that the concentration of coumarin in the crosslinked hole transport layer is 12 mg/mL; the concentration of coumarin in the crosslinked light-emitting layer is 30 mg/mL; Soybean concentration is 50mg/mL.

Embodiment 7:

This example is roughly the same as Example 2, except that the concentration of coumarin in the crosslinked hole transport layer is 2 mg/mL; the concentration of coumarin in the crosslinked light-emitting layer is 5 mg/mL; Soybean concentration is 8mg/mL.

Embodiment 8:

This example is roughly the same as Example 2, except that the concentration of coumarin in the crosslinked hole transport layer is 6 mg/mL; the concentration of coumarin in the crosslinked light-emitting layer is 15 mg/mL; Soybean concentration is 20mg/mL.

Embodiment 9:

This example is roughly the same as Example 2, except that the concentration of coumarin in the crosslinked hole transport layer is 0.2 mg/mL; the concentration of coumarin in the crosslinked light-emitting layer is 1 mg/mL; The concentration of coumarin was 1 mg/mL.

Example 10:

This example is roughly the same as Example 2, except that the concentration of coumarin in the crosslinked hole transport layer is 12 mg/mL; the concentration of coumarin in the crosslinked light-emitting layer is 30 mg/mL; Soybean concentration is 50mg/mL.

Comparative example 1:

This embodiment provides an electroluminescent device with a positive top emission structure, and the preparation process of the device includes:

(1) Spin-coat PEDOT:PSS on an ITO substrate at a rotational speed of 5000 rpm for 30 seconds, then heat at 150° C. for 15 minutes, and stand for cooling for 5 minutes.

(2) Spin-coat TFB (8 mg/mL) at a rotational speed of 3000 rpm for 30 seconds, then heat at 80° C. for 10 minutes, and stand for cooling for 5 minutes.

(3) Spin-coat quantum dots (20 mg/mL) at a rotational speed of 2000 rpm for 30 seconds, then heat at 80° C. for 10 minutes, and stand to cool for 5 minutes.

(4) Spin-coat ZnO (30 mg/mL) at 1500 rpm for 30 seconds, then heat at 80° C. for 20 minutes, and stand for cooling for 5 minutes.

(5) By thermal evaporation, the vacuum degree is not higher than 3 × 10 ^-4 Pa, and Ag is evaporated at a speed of 1 angstroms/second, for 200 seconds, and a thickness of 20nm, to obtain a top-emitting positive electroluminescent device, and to The device is packaged.

In order to illustrate the influence of crosslinking agent doped in the material of the device functional layer in the embodiment of the present application on the electrical properties and life of the device, the JVL data of each embodiment and comparative example were tested respectively to determine the electrical properties of the device and test the working life data of the device. Using a constant current drive of 2mA, determine the working life of the device, the results of electrical performance and life are shown in Table 1. The electroluminescent topography (EL) of the devices in Example 1, Example 2 and Comparative Example 1 were photographed using an optical microscope, and the results are shown in FIG. 7 .

Table 1

Remarks: The data in the table is the working life test data of the flexible QLED device after the mechanical stress test. Due to the cracking of the device film prepared by the process of Comparative Example 1, there is no test data. Among them: L represents the brightness of the device. Under the same current, the higher the brightness of the device, the better the efficiency of the device; T95 represents the time it takes for the brightness of the device to decay from 100% to 95%. Under the same current, the longer the T95 time of the device, it means the performance of the device The better the stability, the better the stability; T95-1K means when the device is under 1000nit brightness, the time it takes for the brightness to decay from 100% to 95%. This value is calculated from the value of L and T95; C.E indicates the current efficiency of the device. Under the premise that the area of the light emitting area and the driving current are consistent, the higher the C.E, the better the performance of the device; C.E-1000nit indicates the current of the device at a brightness of 1000nit Efficiency, under the premise that the area of the light-emitting area and the driving current are consistent, the higher the C.E-1000nit, the better the performance of the device.

Comparing the morphology and performance of Example 1, Example 2 and Comparative Example 1, it can be seen from Figure 7 that the morphology of Embodiment 1 and Example 2 is obviously better than that of Comparative Example, and in Table 1, Comparative Example The device of 1 failed due to cracking of the film layer, indicating that doping a crosslinking agent in the material of the functional layer of the device can avoid cracking of the functional layer, improve the yield of the device, and improve the problem of device failure. This is due to the formation of a cross-linking structure between the photo-crosslinking agents, which makes the bonding between adjacent functional layers more firm, and prevents the cracking of the film layer and the overall shedding of the film layer during the use of the flexible device.

Embodiment 1, embodiment 3 to embodiment 6 are respectively compared with embodiment 2, embodiment 7 to embodiment 10 correspondingly, as can be seen from table 1, the device performance of embodiment 2, embodiment 7 to embodiment 10 and life are significantly better than the corresponding examples 1, 3 to 6, indicating that a cross-linked structure is formed at the interface where each functional layer contacts, and the excellent electrical properties of the device itself are preserved to the greatest extent.

In addition, in each embodiment in which the cross-linking agent is uniformly dispersed in each film layer, compare embodiment 1, embodiment 3, embodiment 4 with embodiment 5, embodiment 6, embodiment 1, embodiment 3, embodiment The performance of example 4 is obviously better than other examples 5 and 6, indicating that when the mass ratio of the crosslinking agent to the functional layer material is (1～3):4, the performance of the device is better, and when the mass ratio of the crosslinking agent When the content is too low, as in Example 5, the device is still prone to failure. When the content of the crosslinking agent is too high, as in Example 6, the performance of the device is not significantly improved.

In each embodiment in which the cross-linking agent forms a cross-linked structure at the interface of each film layer contact, it can be seen that embodiment 2, embodiment 7, embodiment 8 are compared with embodiment 9, embodiment 10, embodiment 2 , Example 7, and Example 8 are significantly better than other examples, indicating that when the mass ratio of the crosslinking agent to the functional layer material is (1～3):4, the performance of the device is better, and when the crosslinking agent When the content of the crosslinking agent is too low, as in Example 9, the device is still prone to failure; when the content of the crosslinking agent is too high, as in Example 10, the performance of the device is not significantly improved.

A kind of electroluminescent device provided by the embodiment of the present application, its preparation method, and photoelectric device have been introduced in detail above. In this paper, specific examples have been used to illustrate the principle and implementation of the present application. The description of the above embodiment is only It is used to help understand the technical solution and its core idea of the present application; those skilled in the art should understand that it can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and These modifications or replacements do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims (18)

1. An electroluminescent device, including: a first electrode, a second electrode, and a functional layer arranged between the first electrode and the second electrode, the functional layer has at least two layers, one of which is the The functional layer is a light-emitting layer, and at least two layers of the functional layer are doped with a photocrosslinking agent and arranged adjacent to each other.
2. The electroluminescent device according to claim 1, wherein the photocrosslinking agent is selected from the group consisting of: coumarin, coumarin derivatives, hydroxyethyl methacrylate, hydroxypropyl methacrylate, divinyl One or more of benzene, N-methylolacrylamide or diacetone acrylamide, the photocrosslinking agent is combined with the material of the functional layer through a chemical bond, and crosslinking is formed between the photocrosslinking agents structure.
3. The electroluminescent device according to claim 2, wherein when the photocrosslinking agent is selected from coumarins, the coumarins are crosslinked to form a four-membered ring.
4. The electroluminescent device according to any one of claims 1 to 3, wherein, in the functional layer doped with the photocrosslinking agent, the mass ratio of the photocrosslinking agent to the material of the functional layer For (1～3):4.
5. The electroluminescent device according to any one of claims 1 to 4, wherein the functional layer doped with the photocrosslinking agent is composed of functional layer material and the photocrosslinking agent, and the photocrosslinking agent The agent is mixed and dispersed in the functional layer material.
6. The electroluminescent device according to any one of claims 1 to 5, wherein the material of each of the functional layers is doped with the photocrosslinking agent, and each of the functional layers is composed of a functional layer material and the photo-crosslinking agent. The composition of the crosslinking agent is that in each functional layer, the photocrosslinking agent is mixed and dispersed in the corresponding functional layer material.
7. The electroluminescent device according to any one of claims 1 to 6, wherein one of the functional layers comprises a hole functional layer, and the hole functional layer is disposed between the light emitting layer and the second electrode During this period, the photocrosslinking agent is mixed and dispersed in the hole functional layer and the light emitting layer.
8. The electroluminescent device according to any one of claims 1 to 7, wherein one of the functional layers comprises an electronic functional layer, and the electronic functional layer is arranged between the light-emitting layer and the first electrode, The photo-crosslinking agent is mixed and dispersed in the light-emitting layer and the electronic functional layer.
9. The electroluminescent device according to any one of claims 1 to 8, wherein one layer of said functional layer comprises a first film layer far away from an adjacent functional layer, and a second film layer and a first film layer close to an adjacent functional layer. Three membrane layers; where,

   The second film layer is close to the adjacent lower functional layer, the third film layer is close to the adjacent upper functional layer, and the photocrosslinking agent is mixed and dispersed in the second film layer and the third film layer.
10. The electroluminescent device according to claim 9, wherein two of the functional layers are a hole functional layer and an electron functional layer, and the hole functional layer is arranged between the light emitting layer and the second electrode Between, the electronic functional layer is disposed between the light-emitting layer and the first electrode; wherein,

    The side of the hole function layer close to the light-emitting layer is doped with the photo-crosslinking agent, and the side of the light-emitting layer close to the hole function is doped with the photo-crosslinker;

    The side of the electronic functional layer close to the light emitting layer is doped with the photocrosslinking agent, and the side of the light emitting layer close to the electronic functional layer is doped with the photocrosslinking agent.
11. The electroluminescent device according to any one of claims 1 to 10, wherein two of the functional layers comprise a hole functional layer and an electron functional layer, and the hole functional layer is arranged between the light-emitting layer and the Between the second electrodes, the electronic functional layer is disposed between the light-emitting layer and the first electrode, the hole functional layer includes a hole injection layer, and the electronic functional layer includes an electron injection layer;

    The material of the hole injection layer is selected from: poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl) diphenylamine), polyvinylcarbazole, polymeric triarylamine, poly(N , N'bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine), poly(9,9-dioctylfluorene-co-bis-N,N-phenyl-1 ,4-phenylenediamine), 4,4',4"-tris(carbazol-9-yl)triphenylamine, 4,4'-bis(9-carbazole)biphenyl, N,N'-diphenyl Base-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine, 15 N,N'-diphenyl-N,N'-(1 One or more of -naphthyl)-1,1'-biphenyl-4,4'-diamine, graphene or _C60 ;

    The material of the light-emitting layer is selected from one of direct bandgap compound semiconductors and perovskite semiconductors with luminescence ability, and the direct bandgap compound semiconductors with luminescence ability are selected from group II-VI compounds, III-V One or more of group compounds, II-V group compounds, III-VI compounds, IV-VI group compounds, I-III-VI group compounds, II-IV-VI group compounds, and IV group simple substances; The II-VI compound is selected from one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, PbS, PbSe or PbTe, and the III-V group compound is selected from GaP, GaAs One or more of , InP or InAs; the perovskite semiconductor is selected from one of doped or non-doped inorganic perovskite semiconductors, and organic-inorganic hybrid perovskite semiconductors or more; wherein, the general structural formula of the inorganic perovskite semiconductor is AMX ₃ , A is a Cs ⁺ ion, M is a divalent metal cation, X is a halogen anion, and the divalent metal cation is selected from: Pb ²⁺ , Sn ²⁺ , Cu ²⁺ , Ni ²⁺ , C ^d2+ , Cr ²⁺ , Mn ²⁺ , Co ²⁺ , Fe ²⁺ , Ge ²⁺ , Yb ²⁺ or Eu ²⁺ , the halogen anion Selected from Cl-, Br- or I-, the general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMX ₃ , wherein B is an organic amine cation, and the organic amine cation is selected from CH ₃ (CH ₂ ) _n-2 NH ³⁺ (n≥2) or NH ₃ (CH ₂ )nNH ₃ ²⁺ (n≥2);

    The material of the electron injection layer is selected from one or more of ZnO, TiO ₂ , SnO ₂ , Ta ₂ O ₃ , ZrO ₂ , NiO, TiLiO, ZnAlO, ZnMgO, ZnSnO, ZnLiO or InSnO;

    The second electrode material is selected from: metal or non-metallic materials, the metal or non-metallic materials are selected from nickel, platinum, gold, silver, iridium or carbon nanotubes; or selected from doped or undoped Metal oxides, the doped or undoped metal oxides are selected from the group consisting of indium tin oxide, indium zinc oxide, indium tin zinc oxide, indium copper oxide, tin oxide, indium oxide, cadmium:zinc oxide, fluorine : tin oxide, indium: zinc oxide, gallium: tin oxide or zinc: aluminum oxide;

    The material of the first electrode is selected from one or more of metal materials, carbon materials, and metal oxides; wherein, the metal materials include Al, Ag, Cu, Mo, Au, Ba, Ca, Mg One or more, the carbon material includes one or more of graphite, carbon nanotubes, graphene, carbon fiber, the metal oxide is selected from doped/non-doped metal oxides, or doped/ A composite electrode with metal sandwiched between non-doped transparent metal oxides, the doped/non-doped metal oxides include one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, AMO , the composite electrode includes AZO/Ag/AZO, AZO/Al/AZO, ITO/Ag/ITO, ITO/Al/ITO, ZnO/Ag/ZnO, ZnO/Al/ZnO, TiO ₂ /Ag/TiO ₂ , One or more of TiO ₂ /Al/TiO ₂ , ZnS/Ag/ZnS, ZnS/Al/ZnS, TiO ₂ /Ag/TiO ₂ , TiO ₂ /Al/TiO ₂ .
12. A method for preparing an electroluminescent device, wherein the method comprises:

    sequentially preparing at least two functional layers on the second electrode from bottom to top; and

    preparing a first electrode on the functional layer to obtain the electroluminescent device;

    One of the functional layers is a light-emitting layer, and at least two layers of the functional layer are doped with a photocrosslinking agent and arranged adjacent to each other.
13. The preparation method according to claim 12, wherein the photocrosslinking agent is selected from the group consisting of: coumarin, coumarin derivatives, hydroxyethyl methacrylate, hydroxypropyl methacrylate, divinylbenzene, One or more of N-methylolacrylamide or diacetoneacrylamide.
14. The preparation method according to claim 13, wherein, when the photocrosslinking agent is selected from coumarins, the coumarins are crosslinked to form four-membered rings.
15. The preparation method according to any one of claims 12 to 14, wherein the preparation method of the at least two functional layers comprises:

    mixing the crosslinking agent with the material solution of the functional layer and heating to obtain a mixed solution, and using the mixed solution to prepare the functional layer;

    Carrying out the preparation of the next functional layer in sequence to obtain at least two functional layers; and

    Each of the functional layers is subjected to ultraviolet light irradiation treatment.
16. The preparation method according to any one of claims 12 to 14, wherein the preparation method of the at least two functional layers comprises:

    Mixing the crosslinking agent with the material solution of the functional layer and heating to obtain a mixed solution, using the material solution of the functional layer to prepare a first film layer, using the mixed solution to prepare a second film layer and a third film layer, and obtaining A functional layer; wherein, the second film layer is close to the adjacent lower functional layer, and the third film layer is close to the adjacent upper functional layer;

    Carrying out the preparation of the next functional layer in sequence to obtain at least two functional layers; and

    Each of the functional layers is subjected to ultraviolet light irradiation treatment.
17. The preparation method according to claim 15 or 16, wherein, in the mixed solution, the mass ratio of the photocrosslinking agent to the functional layer material is (1-3):4.
18. A photoelectric device, comprising the electroluminescent device according to any one of claims 1 to 11, or comprising the electroluminescent device prepared by the preparation method according to any one of claims 12 to 17.

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