Light-emitting device and display device

Abstract

A hole transport structure comprises a hole transport material and a cross-linked network formed by a cross-linking reaction of an ionic transition metal complex having a cross-linkable structure and a cross-linking agent, so that the hole transport structure is doped with the ionic transition metal complex, and the hole transport structure has a cross-linked structure; the hole concentration of the hole transport material can be improved so as to improve the hole injection and transport effects, thereby improving the mobility of holes, promoting the effective injection of holes, balancing the injection and transport of carriers in the light-emitting device, and further improving the light-emitting efficiency of the light-emitting device and prolonging the service life of the light-emitting device. Moreover, the doped ionic transition metal complex disclosed by the invention has a cross-linkable structure, and a cross-linking agent and the cross-linkable structure can be subjected to a cross-linking reaction under light or heat initiation, so that cations of the ionic transition metal complex are fixed in a hole transport structure; under the action of an electric field, the problems of reduction of device efficiency and service life caused by cation migration are solved.

Description

Technical Field

[0001] The present invention relates to the field of display technologies, and particularly to a light-emitting device and a display device. Background Art

[0002] Quantum Dots (QDs), also known as nanocrystals, are nanoparticles composed of II-VI or III-V elements. The particle size of quantum dots generally ranges from 1 to 20 nm. Due to the quantum confinement of electrons and holes, the continuous energy band structure becomes a discrete energy level structure, and fluorescence can be emitted after being excited.

[0003] With the in-depth development of quantum dot preparation technologies, the stability and luminous efficiency of quantum dots have been continuously improved, and the research on Quantum Light Emitting Diodes (QLEDs) has been continuously deepened, and the application prospects of QLEDs in the display field are becoming increasingly bright. Summary of the Invention

[0004] Embodiments of the present invention provide a light-emitting device and a display device for increasing the hole concentration to improve the hole transport and injection effects. The specific solutions are as follows:

[0005] A light-emitting device provided by an embodiment of the present invention includes an anode, a hole transport structure, a quantum dot light-emitting layer, and a cathode that are stacked. The hole transport structure includes a hole transport material and a crosslinked network, and the crosslinked network is formed by a crosslinking reaction between an ionic transition metal complex having a crosslinkable structure and a crosslinking agent.

[0006] Optionally, in the above light-emitting device provided by an embodiment of the present invention, the hole transport structure is a bilayer structure, and the hole transport structure includes: a hole transport layer located between the anode and the quantum dot light-emitting layer and made of the hole transport material, and the crosslinked network located between the hole transport layer and the quantum dot light-emitting layer.

[0007] Optionally, in the above light-emitting device provided by an embodiment of the present invention, the ratio of the thickness of the hole transport layer to the thickness of the film layer where the crosslinked network is located is 3:1.

[0008] Optionally, in the above light-emitting device provided by an embodiment of the present invention, the hole transport structure is a single-layer structure, and the hole transport structure includes the crosslinked network and the hole transport material mixed in the crosslinked network.

[0009] Optionally, in the above light-emitting device provided by an embodiment of the present invention, the mass ratio of the crosslinked network to the hole transport material is (1%:99%) to (20%:80%).

[0010] Optionally, in the above-mentioned light-emitting device provided by an embodiment of the present invention, the light-emitting device includes a first sub-pixel, a second sub-pixel, and a third sub-pixel with different light-emitting colors. The light-emitting color of the ionic transition metal complex corresponding to the first sub-pixel is the same as the light-emitting color of the first sub-pixel, the light-emitting color of the ionic transition metal complex corresponding to the second sub-pixel is the same as the light-emitting color of the second sub-pixel, and the light-emitting color of the ionic transition metal complex corresponding to the third sub-pixel is the same as the light-emitting color of the third sub-pixel.

[0011] Optionally, in the above-mentioned light-emitting device provided by an embodiment of the present invention, the ionic transition metal complex includes a cation and an anion counterion. The cation includes: a transition metal, a ligand coordinated with the transition metal, and the crosslinkable structure connected to the ligand.

[0012] Optionally, in the above-mentioned light-emitting device provided by an embodiment of the present invention, the crosslinkable structure includes: a dissolving group connected to the ligand, and an alkyl chain connected to the dissolving group; wherein,

[0013] the dissolving group includes -NH-, at least one of;

[0014] the carbon chain length of the alkyl chain is 4 to 20 carbon atoms.

[0015] Optionally, in the above-mentioned light-emitting device provided by an embodiment of the present invention, the transition metal is selected from iridium, ruthenium, osmium or copper.

[0016] Optionally, in the above-mentioned light-emitting device provided by an embodiment of the present invention, the ligand includes one or more of phenylpyridine, pyridine derivatives, benzofused five-membered heterocyclic nitrogen-containing compounds, bipyridine, and derivatives of bipyridine.

[0017] Optionally, in the above-mentioned light-emitting device provided by an embodiment of the present invention, the ionic transition metal complex includes

[0018] Optionally, in the above-mentioned light-emitting device provided by an embodiment of the present invention, the crosslinking agent includes benzophenone compounds or azide compounds.

[0019] Optionally, in the above-mentioned light-emitting device provided by an embodiment of the present invention, it further includes: a hole injection layer located between the anode and the hole transport structure, and an electron transport layer located between the quantum dot light-emitting layer and the cathode.

[0020] Correspondingly, an embodiment of the present invention further provides a display device, including the above-mentioned light-emitting device provided by an embodiment of the present invention.

[0021] The beneficial effects of the embodiments of the present invention are as follows:

[0022] A light-emitting device and a display device provided by an embodiment of the present invention. Since the hole transport structure includes a hole transport material and a crosslinked network formed by a crosslinking reaction between an ionic transition metal complex having a crosslinkable structure and a crosslinking agent, the hole transport structure can increase the hole concentration of the hole transport material by doping with the ionic transition metal complex, so as to improve the hole injection and transport effects, thereby increasing the hole mobility, promoting the effective injection of holes, balancing the injection and transport of carriers in the light-emitting device, and further improving the light-emitting efficiency and device life of the light-emitting device; moreover, the doped ionic transition metal complex of the present disclosure has a crosslinkable structure, and a crosslinking agent can be used to carry out a crosslinking reaction with the crosslinkable structure under light or heat initiation, so that the cations of the ionic transition metal complex are fixed in the hole transport structure, and the problem of device efficiency and life reduction caused by cation migration will not occur under the action of an electric field. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of a light-emitting device provided by an embodiment of the present invention;

[0024] Figure 2 It is a schematic structural diagram of another light-emitting device provided by an embodiment of the present invention;

[0025] Figure 3 It is a schematic structural diagram of another light-emitting device provided by an embodiment of the present invention;

[0026] Figure 4 It is a schematic structural diagram of another light-emitting device provided by an embodiment of the present invention;

[0027] Figure 5 It is a schematic structural diagram of an ionic transition metal complex provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. And without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0029] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meanings as understood by those of ordinary skill in the art to which the present invention pertains. The words such as "comprising" or "including" used in the present invention mean that the elements or items appearing before this word cover the elements or items listed after this word and their equivalents, without excluding other elements or items. The words such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "inner", "outer", "upper", "lower", etc. are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0030] As used in the present invention, "about", "substantially" or "approximately" include the stated value and the average value within an acceptable deviation range of the specific value, where the acceptable deviation range is determined by those of ordinary skill in the art considering the measurement being discussed and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system).

[0031] As used in the present invention, "parallel", "perpendicular", "equal" include the stated situations and situations similar to the stated situations, and the range of the similar situations is within an acceptable deviation range, where the acceptable deviation range is determined by those of ordinary skill in the art considering the measurement being discussed and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallel and approximate parallel, where the acceptable deviation range of approximate parallel can be, for example, within 5° deviation; "perpendicular" includes absolute perpendicular and approximate perpendicular, where the acceptable deviation range of approximate perpendicular can also be, for example, within 5° deviation. "Equal" includes absolute equality and approximate equality, where the acceptable deviation range of approximate equality can be, for example, that the difference between the two equal ones is less than or equal to 10% of either one of them.

[0032] It should be understood that when a layer or element is said to be on another layer or substrate, it may be that the layer or element is directly on the other layer or substrate, or there may be an intermediate layer between the layer or element and the other layer or substrate.

[0033] The exemplary embodiments of the present invention are described with reference to cross-sectional views and / or plan views as idealized exemplary drawings. In the drawings, the thickness of layers and the area of regions are enlarged for clarity. Thus, variations in the shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances can be envisioned. Therefore, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but include shape deviations caused by, for example, manufacturing. For example, an etched region shown as rectangular will generally have curved features. Thus, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shape of the regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0034] In the present invention, shapes such as circles, triangles, rectangles, trapezoids, pentagons, or hexagons are not strictly defined and can be approximately circular, triangular, rectangular, trapezoidal, pentagonal, or hexagonal, etc. There can be some small deformations caused by tolerances, and there can be chamfers, arc edges, and deformations, etc.

[0035] Quantum dot light-emitting diodes have great potential application value in the future display and lighting fields. Currently, one of the main problems in quantum dot display applications is the carrier injection balance problem of the device. Carriers are divided into electrons and holes. For most quantum dot devices, currently, materials such as zinc oxide are used as electron injection and transport materials, which can meet the electron injection of the device. However, for the hole terminal in quantum dot devices, the injection and transport of holes are problems that need to be solved. Currently, there are relatively few hole transport and injection materials, and even fewer hole materials that meet the requirements of quantum dot devices. Specifically, the hole concentration and hole mobility of hole transport materials are low. Currently, TFB and its derivatives are used more frequently as hole transport materials, and their hole mobility is lower than that of electron transport materials, resulting in an imbalance in the injection and transport of electrons and holes in the device and affecting the efficiency of the device. Therefore, increasing the hole concentration of the device and enhancing the injection and transport ability of holes are important methods to improve the performance of QLED devices.

[0036] In related technologies, in order to increase the hole concentration of hole transport materials, generally, an ionic transition metal complex is added to the solution-type hole transport material to increase the hole concentration. This method can increase the hole concentration of the hole transport material to a certain extent. However, considering the migration problem of cations in the ionic transition metal complex under the action of an electric field, for example, after cation doping, the hole mobility of the hole transport material increases, but the cations will also migrate under the action of an electric field and enter the adjacent film layer, ultimately affecting the efficiency and lifespan of the device.

[0037] In view of this, in order to increase the hole concentration of hole transport materials and improve the efficiency and lifespan of the device, the embodiments of the present invention provide a light-emitting device, such as Figures 1 - 4As shown, it includes an anode 1, a hole transport structure 2, a quantum dot light-emitting layer 3, and a cathode 4 which are stacked. The hole transport structure 2 includes a hole transport material 21 and a crosslinked network 22. The crosslinked network 22 is formed by a crosslinking reaction between an ionic transition metal complex having a crosslinkable structure and a crosslinking agent.

[0038] In the above light-emitting device provided by the embodiment of the present invention, since the hole transport structure includes a hole transport material and a crosslinked network formed by a crosslinking reaction between an ionic transition metal complex having a crosslinkable structure and a crosslinking agent, in this way, through the doping of the ionic transition metal complex, the hole concentration of the hole transport material can be increased to improve the hole injection and transport effects, thereby improving the hole mobility, promoting the effective injection of holes, balancing the injection and transport of carriers in the light-emitting device, and further improving the light-emitting efficiency and device life of the light-emitting device; moreover, the doped ionic transition metal complex of the present disclosure has a crosslinkable structure, and a crosslinking agent can be used to carry out a crosslinking reaction with the crosslinkable structure under light or heat initiation, so that the cation of the ionic transition metal complex is fixed in the hole transport structure, and the problem of reduction in device efficiency and life caused by cation migration will not occur under the action of an electric field.

[0039] In a possible implementation manner, in the above light-emitting device provided by the embodiment of the present disclosure, as Figure 1 and Figure 3 shown, the hole transport structure 2 can be a bilayer structure. The hole transport structure 2 includes: a hole transport layer (still denoted by the reference numeral 21) located between the anode 1 and the quantum dot light-emitting layer 3 and made of the hole transport material 21, and a crosslinked network 22 located between the hole transport layer 21 and the quantum dot light-emitting layer 3. In this embodiment, a crosslinked network 22 formed by a crosslinking reaction between an ionic transition metal complex having a crosslinkable structure and a crosslinking agent is formed between the hole transport layer 21 and the quantum dot light-emitting layer 3. Since the crosslinked network 22 has an ionic transition metal complex, the hole concentration of the hole transport material can be increased to balance the injection and transport of carriers in the light-emitting device; moreover, the crosslinked network 22 can block the multi-electron transmission to the hole transport layer 21, avoid the light emission of the hole transport layer 21, and reduce the influence on the color purity of the light emission of the device due to the light emission of the hole transport layer 21; in addition, since the ionic transition metal complex forms the crosslinked network 22, the cation of the ionic transition metal complex can be fixed between the hole transport layer 21 and the quantum dot light-emitting layer 3, and the problem of reduction in device efficiency and life caused by cation migration will not occur under the action of an electric field.

[0040] In a possible implementation manner, in the above light-emitting device provided by the embodiment of the present disclosure, as Figure 1 and Figure 3As shown, if the thickness of the film layer where the crosslinked network 22 is located is too thin, the effect of blocking electrons is poor; if the thickness of the film layer where the crosslinked network 22 is located is too thick, although electrons can be blocked, the transport of holes will be affected. Therefore, the ratio of the thickness of the hole transport layer 21 to the thickness of the film layer where the crosslinked network 22 is located can be 3:1.

[0041] Optionally, the thickness of the hole transport layer 21 can be 20 nm to 30 nm, and the thickness of the film layer where the crosslinked network 22 is located can be less than or equal to 10 nm.

[0042] In a possible implementation, in the above-mentioned light-emitting device provided by the embodiments of the present disclosure, as Figure 2 and Figure 4 shown, the hole transport structure 2 can be a single-layer structure. The hole transport structure 2 includes a crosslinked network 22 and a hole transport material 21 mixed in the crosslinked network 22. In this embodiment, the hole transport material, the ionic transition metal complex with a crosslinkable structure, and the crosslinking agent can be mixed, and the crosslinkable structure of the ionic transition metal complex and the crosslinking agent can be caused to undergo a crosslinking reaction under light or heat initiation to form the crosslinked network 22. Since the ionic transition metal complex is doped in the hole transport material, the hole concentration of the hole transport material can be increased, and the injection and transport of carriers in the light-emitting device can be balanced; and when multiple electrons are transported into the single-layer hole transport structure 2, the electrons preferentially recombine with the cations of the ionic transition metal complex to emit light, avoiding the light emission of the hole transport material 21, so that the recombination in the hole transport structure 2 occurs on the cations of the ionic transition metal complex, reducing the influence on the color purity of the device light emission; in addition, since the ionic transition metal complex forms the crosslinked network 22, the cations of the ionic transition metal complex can be fixed in the hole transport material 21, and the problem of reduction in device efficiency and lifetime caused by cation migration will not occur under the action of an electric field.

[0043] In a possible implementation, in the above-mentioned light-emitting device provided by the embodiments of the present disclosure, as Figure 2 and Figure 4 shown, if the mass percentage of the crosslinked network is too low, the injection of holes will be affected; if the mass percentage of the crosslinked network is too high, although the injection of holes can be ensured, the transport of holes will be affected. Therefore, the mass ratio of the crosslinked network to the hole transport material can be (1%:99%) to (20%:80%), thereby ensuring the injection and transport of holes.

[0044] Optionally, the hole transport material can be at least one of poly(9,9-dioctylfluorene-co-N-(4-butylphenyl)diphenylamine) (TFB), poly-N-vinylcarbazole (PVK), and poly[bis(4-phenyl)(4-butylphenyl)amine] (Poly-TPD).

[0045] In a possible implementation, in the above-mentioned light-emitting device provided in the embodiment of the present disclosure, as Figures 1 - 4 As shown, the light emitting device may include a first sub-pixel (eg, a red sub-pixel R), a second sub-pixel (eg, a green sub-pixel R), and a third sub-pixel (eg, a blue sub-pixel R) with different luminous colors. Figures 1 - 4 Only one sub-pixel is shown, and the luminescent color of the ionic transition metal complex corresponding to the first sub-pixel can be the same as the luminescent color of the first sub-pixel, the luminescent color of the ionic transition metal complex corresponding to the second sub-pixel can be the same as the luminescent color of the second sub-pixel, and the luminescent color of the ionic transition metal complex corresponding to the third sub-pixel can be the same as the luminescent color of the third sub-pixel. In this way, when selecting an ionic transition metal complex to prepare a hole transport structure 2 corresponding to sub-pixels of different luminescent colors, an ionic transition metal complex with the same luminescent color as the corresponding sub-pixel can be selected. The luminescent color of the ionic transition metal complex is mainly related to its ligand. By changing the molecular weight of the ligand, the effect of red shift of the luminescent color can be achieved. For example, the change of the ligand of the ionic transition metal complex from benzene ring to naphthalene ring and then to phenanthrene ring is adjusted, which increases the π conjugation of the complex and reduces the energy level difference, thereby adjusting the change of the luminescent color from blue light to red light.

[0046] In a possible implementation, in the above-mentioned light-emitting device provided in the embodiment of the present disclosure, as Figure 5 As shown, the ionic transition metal complex includes a cation and an anion counter ion. The anion counter ion is mainly used to make the solution of the ionic transition metal complex electrically neutral. The anion counter ion can be a hexafluorophosphate ion (PF6 - ).

[0047] In a possible implementation, in the above-mentioned light-emitting device provided in the embodiment of the present disclosure, as Figure 5 As shown, cations may include:

[0048] A transition metal, which may be selected from iridium, ruthenium, osmium or copper. In this embodiment, the transition metal is iridium (Ir) as an example;

[0049] The ligands coordinated with the transition metal (Ir) include, but are not limited to, one or more of phenylpyridines, pyridine derivatives, benzo-nitrogen-containing five-membered heterocyclics, bipyridine, and bipyridine derivatives. In this embodiment, the ligands include phenylpyridine and bipyridine For example;

[0050] A cross-linkable structure connected to a ligand, the cross-linkable structure comprising: a solubilizing group connected to the ligand, and an alkyl chain connected to the solubilizing group; the solubilizing group may include but is not limited to -NH-, at least one of; since too long an alkyl chain will lead to non-radiative transitions and too short an alkyl chain will affect the cross-linking reaction, the carbon chain length of the alkyl chain can be 4 to 20 carbon atoms; in this embodiment, C4H9NH- is connected to the phenylpyridine ligand and is taken as an example.

[0051] Specifically, by introducing a suitable ligand around the transition metal, the luminescence color of the cation of the ionic transition metal complex is made close to the luminescence color of the quantum dot light-emitting layer. In this way, when multiple electrons are transported into the hole transport structure, the electrons preferentially recombine with the cation of the ionic transition metal complex to emit light, rather than the hole transport material emitting light, thereby improving the color purity of the device.

[0052] In one possible implementation, in the above-mentioned light-emitting device provided by the embodiments of the present disclosure, as Figure 5 shown, the structure of the ionic transition metal complex can be but is not limited to For the ionic transition metal complex with this structure provided by the embodiments of the present disclosure, compared with the traditional ionic transition metal complex, a cross-linkable structure is modified on the ligand of the ionic transition metal complex of the present disclosure. This cross-linkable structure can undergo a cross-linking reaction with a cross-linking agent under photoinitiation, so that the cation of the ionic transition metal complex is restricted between the hole transport layer and the quantum dot light-emitting layer or is restricted in the hole transport layer. Therefore, the cation will not migrate under the action of an electric field, thereby improving the efficiency and lifespan of the device.

[0053] In one possible implementation, in the above-mentioned light-emitting device provided by the embodiments of the present disclosure, the cross-linking agent can include but is not limited to benzophenone-based or azide-based compounds. These two types of cross-linking agents can both undergo a cross-linking reaction with the C chain on the alkyl chain under photoinitiation.

[0054] It should be noted that when benzophenone undergoes a cross-linking reaction with to form a cross-linked network, any one or a combination of the following reactions can occur: the carbonyl group of benzophenone undergoes an H abstraction reaction with one CH2 in C4H9NH-, the carbonyl group of benzophenone undergoes an H abstraction reaction with one CH2 in , and the carbonyl group in undergoes an H abstraction reaction with C4H9NH- in the remaining ionic transition metal complexes or one CH2 in .

[0055] Specifically, when an azide-based compound undergoes a cross-linking reaction with to form a cross-linked network, any one or a combination of the following reactions can occur: after the azide loses N2, it undergoes an H abstraction reaction with one CH2 in C4H9NH-, after the azide loses N2, it undergoes an H abstraction reaction with one CH2 in , The carbonyl group in it undergoes an H abstraction reaction with C4H9NH- in the remaining ionic transition metal complexes or one of the CH2 groups in

[0056] It should be noted that the embodiments of the present disclosure Figure 5 merely schematically illustrate one structure of the ionic transition metal complex, and of course, it is not limited thereto. Appropriate ligands can be selected according to the requirements of the sub-pixel emission color.

[0057] In a possible implementation manner, in the above-mentioned light-emitting device provided by the embodiments of the present disclosure, as Figures 1 - 4 shown, it further includes: a hole injection layer 5 located between the anode 1 and the hole transport structure 2, and an electron transport layer 6 located between the quantum dot light-emitting layer 3 and the cathode 4; wherein, the hole injection layer 5 functions to inject holes, and the electron transport layer 6 functions to inject electrons.

[0058] Optionally, the material of the hole injection layer may be, but is not limited to, PEDOT:PSS.

[0059] Optionally, the material of the electron transport layer may be, but is not limited to, ZnO.

[0060] In the quantum dot material of the embodiments of the present application, the quantum dot body and the coordination group in the quantum dot ligand are connected by chemical bonds.

[0061] Optionally, the quantum dot body includes any one of IIB-VIA group quantum dots, IIIA-VA group quantum dots, ⅣA-VIA group quantum dots, quantum dots with a core-shell structure, and ABX3 type perovskite quantum dots. In the ABX3 type perovskite quantum dots, A is CH3NH3 + (methylamine), NH2CH=NH2 (formamidine), and Cs + one or more of them, B is Pb 2+ and Sn 2+ one or two of them, X is Cl - , Br - and I - one or more of them, and the ABX3 type perovskite quantum dots include CH3NH3PbBr3, CH3NH3PbCl3, CH3NH3PbI3, CsPbBr3, CsPbCl3, and CsPbI3.

[0062] Exemplarily, the IIB-VIA group quantum dots are selected from: one or more of binary compounds such as CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, and MgS; ternary compounds such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, or mixtures thereof; and quaternary compounds such as HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, or mixtures thereof, but not limited thereto.

[0063] The IIIA-VA group quantum dots are selected from: one or more of binary compounds such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, or mixtures thereof; ternary compounds such as GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, or mixtures thereof; and quaternary compounds such as GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, or mixtures thereof, but not limited thereto.

[0064] The IVA-VIA group quantum dots are selected from: one or more of binary compounds such as SnS, SnSe, SnTe, PbS, PbSe, PbTe, or mixtures thereof; ternary compounds such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, or mixtures thereof; and quaternary compounds such as SnPbSSe, SnPbSeTe, SnPbSTe, or mixtures thereof, but not limited thereto. The IVA-VIA group quantum dots are, for example, selected from: elemental (mono-) semiconductors such as Si, Ge, or mixtures thereof; and binary semiconductor compounds such as SiC, SiGe, and mixtures thereof, but not limited thereto.

[0065] A core-shell structured quantum dot refers to a quantum dot in which one material serves as the core material and the other as the shell material. For example, a quantum dot of CdS / ZnS means that the core material of the quantum dot is CdS and the shell material is ZnS.

[0066] In some other embodiments, the quantum dot body can be other nano-scale materials, such as nanorods, nanosheets, etc. The composition of other nano-scale materials can include at least one of materials such as CdS, CdSe, CdTe, ZnSe, InP, PbS, CuInS2, ZnO, CsPbCl3, CsPbBr3, CsPhI3, CdS / ZnS, CdSe / ZnS, ZnSe, InP / ZnS, PbS / ZnS, InAs, InGaAs, InGaN, GaNk, ZnTe, Si, Ge, and C.

[0067] For example, the quantum dot body can include cadmium-free (Cd) quantum dots. Cadmium-free quantum dots are quantum dots that do not include cadmium (Cd). Cadmium (Cd) can cause serious environmental / health problems, so non-cadmium-based quantum dots can be effectively used.

[0068] The shape of the quantum dot material includes, but is not limited to, quantum dot materials with any geometric shape such as spherical, spherical-like, ellipsoidal, polyhedral, rod-shaped, cross-shaped, annular, etc.

[0069] Optionally, the light-emitting device provided by the present invention can be a quantum dot light-emitting diode, a photodetector, a photovoltaic solar cell, etc., but is not limited thereto.

[0070] Optionally, the quantum dot light-emitting device provided by the present invention can be a quantum dot light-emitting diode, as Figures 1 - 4 shown. Optionally, the structure of the quantum dot light-emitting diode provided by the embodiments of the present invention can be Figure 1 and Figure 2 the shown normal structure, where the normal structure is to sequentially fabricate an anode 1, a hole injection layer 5, a hole transport structure 2, a quantum dot light-emitting layer 3, an electron transport layer 6, and a cathode 4 on a substrate 7; the structure of the quantum dot light-emitting diode provided by the embodiments of the present invention can also be Figure 3 and Figure 4 the shown inverted structure, where the inverted structure is to sequentially fabricate a cathode 4, an electron transport layer 6, a quantum dot light-emitting layer 3, a hole transport structure 2, a hole injection layer 5, and an anode 1 on a substrate 7.

[0071] Optionally, the light-emitting type of the quantum dot light-emitting diode can be a top-emitting structure, a bottom-emitting structure, or a double-sided emitting structure.

[0072] Taking Figure 1Taking the green light-emitting device with the normal structure shown as an example, the structure of the light-emitting device is ITO / PEDOT:PSS / TFB / crosslinked network / GQD / ZnO / / Al, and the specific manufacturing process is as follows:

[0073] (1) After ultrasonically cleaning the glass substrate with ITO (anode) in deionized water and acetone for 10 minutes each, place the cleaned glass substrate in a vacuum oven and dry it at 135 °C, and then irradiate the glass substrate with ultraviolet light for 10 minutes to increase the surface work function of ITO;

[0074] (2) Spin-coat the PEDOT:PSS solution on the surface of ITO (rotation speed: 3000 rpm, duration: 40 s), and then anneal it at 120 °C for 20 minutes to improve the surface morphology and form a hole injection layer;

[0075] (3) Spin-coat the hole transport material (TFB, concentration: 4 - 8 g / L) on the surface of the hole injection layer, and then anneal it at 120 °C for 15 minutes to remove the solvent and form a hole transport layer;

[0076] (4) Dissolve the ionic transition metal complex and crosslinking agent (benzophenone or azide compound) shown Figure 5 in a solvent (acetone, chloroform, acetonitrile, tetrahydrofuran) to obtain a mixed solution. Spin-coat this mixed solution on the hole transport layer, and under ultraviolet light irradiation, the crosslinkable structure of the ionic transition metal complex and the crosslinking agent undergo a photocrosslinking reaction to form a crosslinked network;

[0077] (5) Spin-coat and deposit the solution of the green quantum dot material on the crosslinked network film layer. A green quantum dot pattern can be formed by photolithography and annealed at 100 °C for 15 minutes to form a green quantum dot layer;

[0078] (6) Static spin-coat the ethanol solution of ZnO nanoparticles on the green quantum dot layer and anneal it at 80 °C for 15 minutes to form an electron transport layer;

[0079] (7) Form a cathode on the electron transport layer.

[0080] Taking Figure 2 the green light-emitting device with the normal structure shown as an example, the structure of the light-emitting device is ITO / PEDOT:PSS / TFB / hole transport material + crosslinked network / GQD / ZnO / / Al, and the specific manufacturing process is as follows:

[0081] (1) After ultrasonically cleaning the glass substrate with ITO (anode) in deionized water and acetone for 10 minutes each, place the cleaned glass substrate in a vacuum oven and dry it at 135 °C, and then irradiate the glass substrate with ultraviolet light for 10 minutes to increase the surface work function of ITO;

[0082] (2) Spin coating the PEDOT:PSS solution on the surface of ITO (rotation speed of 3000 rpm, duration of 40 s), and then annealing at 120 °C for 20 min to improve the surface morphology and form a hole injection layer;

[0083] (3) hole transport material (TFB), Figure 5 The ionic transition metal complex shown in the figure and the cross-linking agent (benzophenone or azide compound) are mixed to obtain a mixed solution, the solvent of the mixed solution can be acetone, chloroform, acetonitrile, tetrahydrofuran, toluene, etc., and toluene is used in this embodiment; the mixed solution is spin-coated on the hole injection layer, and the cross-linkable structure of the ionic transition metal complex and the cross-linking agent undergo a photo-cross-linking reaction under ultraviolet light to form a cross-linked network, and then annealed at 120° C. for 15 minutes to remove the solvent to form a single-layer hole transport structure including a hole transport material and a cross-linked network;

[0084] (4) spin coating a solution of green quantum dot material on the hole transport structure, forming a green quantum dot pattern by photolithography, and annealing at 100° C. for 15 min to form a green quantum dot layer;

[0085] (5) statically spin-coating an ethanol solution of ZnO nanoparticles on the green quantum dot layer and annealing at 80°C for 15 min to form an electron transport layer;

[0086] (6) A cathode is formed on the electron transport layer.

[0087] It should be noted that Figure 3 and Figure 4 The manufacturing method of the inverted structure light emitting device is similar to the manufacturing method of the upright structure light emitting device, the only difference is the film layer manufacturing sequence, and the manufacturing method of the inverted structure light emitting device is not described in detail here.

[0088] Based on the same inventive concept, an embodiment of the present invention further provides a display device, including the above-mentioned light-emitting device provided in an embodiment of the present invention. The principle of solving the problem of the display device is similar to that of the above-mentioned light-emitting device, so the implementation of the display device can refer to the implementation of the above-mentioned light-emitting device, and the repeated parts will not be repeated here. The display device can be any product or component with a display function, such as a mobile phone, a tablet computer, a television, a display, a laptop computer, a digital photo frame, a navigator, etc. The other essential components of the display device should be understood by ordinary technicians in the field, and will not be repeated here, nor should they be used as limitations on the present invention.

[0089] An illuminating device and a display device provided by an embodiment of the present invention. Since the hole transport structure includes a hole transport material and a crosslinked network formed by a crosslinking reaction between an ionic transition metal complex having a crosslinkable structure and a crosslinking agent, the hole concentration of the hole transport material can be increased by doping the ionic transition metal complex in the hole transport structure, so as to improve the injection and transport effects of holes, thereby increasing the hole mobility, promoting the effective injection of holes, balancing the injection and transport of carriers in the illuminating device, and further improving the luminous efficiency and device life of the illuminating device. Moreover, the doped ionic transition metal complex of the present disclosure has a crosslinkable structure, and a crosslinking agent can be used to react with the crosslinkable structure under light or heat initiation, so that the cations of the ionic transition metal complex are fixed in the hole transport structure, and the problem of reduction in device efficiency and life caused by cation migration will not occur under the action of an electric field.

[0090] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims

1. A light-emitting device, characterized in that, It includes an anode, a hole transport structure, a quantum dot light-emitting layer, and a cathode which are stacked. The hole transport structure includes a hole transport material and a crosslinked network, and the crosslinked network is formed by a crosslinking reaction between an ionic transition metal complex having a crosslinkable structure and a crosslinking agent.

2. The light-emitting device according to claim 1, characterized in that, The hole transport structure is a bilayer structure, and the hole transport structure includes: a hole transport layer located between the anode and the quantum dot light-emitting layer and made of the hole transport material, and the crosslinked network located between the hole transport layer and the quantum dot light-emitting layer.

3. The light-emitting device according to claim 2, wherein, The ratio of the thickness of the hole transport layer to the thickness of the film layer where the crosslinked network is located is 3:

1.

4. The light-emitting device according to claim 1, characterized in that, The hole transport structure is a monolayer structure, and the hole transport structure includes the crosslinked network and the hole transport material mixed in the crosslinked network.

5. The light-emitting device according to claim 4, wherein, The mass ratio of the crosslinked network to the hole transport material is (1%:99%) to (20%:80%).

6. The light-emitting device according to any one of claims 1-5, characterized in that, The light-emitting device includes a first sub-pixel, a second sub-pixel, and a third sub-pixel with different light-emitting colors. The light-emitting color of the ionic transition metal complex corresponding to the first sub-pixel is the same as the light-emitting color of the first sub-pixel, the light-emitting color of the ionic transition metal complex corresponding to the second sub-pixel is the same as the light-emitting color of the second sub-pixel, and the light-emitting color of the ionic transition metal complex corresponding to the third sub-pixel is the same as the light-emitting color of the third sub-pixel.

7. The light-emitting device according to claim 6, wherein, The ionic transition metal complex includes a cation and an anion counterion. The cation includes: a transition metal, a ligand coordinated with the transition metal, and the crosslinkable structure connected to the ligand.

8. The light-emitting device according to claim 7, characterized in that, The crosslinkable structure includes: a solubilizing group connected to the ligand, and an alkyl chain connected to the solubilizing group; wherein, The dissolution group includes -NH- and at least one of them; The carbon chain length of the alkyl chain is 4 to 20 carbon atoms.

9. The light-emitting device according to claim 8, wherein, The transition metal is selected from iridium, ruthenium, osmium, or copper.

10. The light-emitting device according to claim 9, characterized in that, The ligand includes one or more of phenylpyridine-based, pyridine derivatives, benzo-fused five-membered nitrogen heterocyclic-based, bipyridine, and derivatives of bipyridine.

11. The light-emitting device according to claim 10, wherein, The ionic transition metal complex includes 12. The light-emitting device according to any one of claims 1-5, 7-11, characterized in that, The crosslinking agent includes benzophenone-based or azide-based compounds.

13. The light-emitting device according to any one of claims 1-5, 7-11, characterized in that, It further includes: a hole injection layer located between the anode and the hole transport structure, and an electron transport layer located between the quantum dot light-emitting layer and the cathode.

14. A display device, characterized in that, It includes the light-emitting device according to any one of claims 1-13.

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