Electronic device, hole injection layer ink, and display panel
Patent Information
- Application Number
- CN202610989976.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-03
- Publication Date
- 2026-11-03
AI Technical Summary
In inkjet printing, the doped material in the hole injection layer is prone to diffusion, which leads to a decrease in film quality and affects the brightness and uniformity of the light-emitting device.
A hole injection layer with a network structure is formed by cross-linked p-type doping units and cross-linked host units. The doping unit content is high on the side near the first electrode. The doping units are stably and concentratedly distributed by cross-linking groups, which reduces the diffusion probability.
This improves the hole injection capability of the hole injection layer, thereby enhancing the light emission uniformity and performance of electronic devices.
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Figure CN123035826A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of display technology, and more particularly to an electronic device, a hole injection layer ink, and a display panel. Background Technology
[0002] In organic light-emitting diodes (OLEDs) In OLED (Emitting Diode) light-emitting devices, the hole injection layer is a key functional layer between the anode and the hole transport layer. Its performance directly determines the injection efficiency of holes from the anode to the light-emitting layer and the uniformity of carrier transport, which in turn significantly affects the luminous brightness, luminous uniformity, lifespan and stability of the light-emitting device.
[0003] Currently, hole injection layers are often fabricated using solution processing techniques (such as inkjet printing). This process offers advantages such as low cost, high fabrication efficiency, and compatibility with large-area flexible devices, making it the mainstream fabrication method in the industry. To improve hole injection efficiency, existing technologies typically dope the host material of the hole injection layer with p-type dopants. Through charge transfer between the p-type dopant and the host material, the hole injection barrier is lowered, hole transport performance is improved, and thus the photoelectric performance of the light-emitting device is optimized.
[0004] However, during the solution processing of inkjet printing, the diffusion of doped materials can easily occur, leading to a decrease in the quality of the hole injection layer and ultimately causing uneven luminous brightness in the light-emitting device. Summary of the Invention
[0005] This application provides an electronic device, a hole injection layer ink, and a display panel, which enables the doped units to be stably and centrally distributed in the hole injection layer, thereby improving the light emission uniformity of the electronic device.
[0006] This application provides an electronic device, the electronic device comprising: First electrode; A hole injection layer is disposed on one side of the first electrode, and the hole injection layer includes a host unit and a doped unit; A light-emitting layer is disposed on the side of the hole injection layer away from the first electrode; The second electrode is disposed on the side of the light-emitting layer away from the hole injection layer; The content of the doped units in the hole injection layer on the side closer to the first electrode is greater than the content of the doped units in the hole injection layer on the side farther from the first electrode.
[0007] In one embodiment of this application, the doping unit is selected from cross-linked p-type doping units, and the host unit is selected from cross-linked host units.
[0008] In one embodiment of this application, the hole injection layer includes a network structure, the network structure including the host unit and the doped unit connected to each other.
[0009] In one embodiment of this application, the hole injection layer includes a first sub-section and a second sub-section, the first sub-section being located between the first electrode and the second sub-section, the content of the doped units in the first sub-section being greater than the content of the doped units in the second sub-section, and the ratio of the thickness of the first sub-section to the thickness of the hole injection layer being 0.5.
[0010] In one embodiment of this application, the content of the doped units in the first sub-section closer to the first electrode is greater than the content of the doped units in the first sub-section farther from the first electrode.
[0011] In one embodiment of this application, the ratio of the thickness of the first sub-part near the first electrode to the thickness of the hole injection layer is greater than or equal to 5% and less than or equal to 20%.
[0012] In one embodiment of this application, the doped units in the first sub-part, which is close to the first electrode and has a thickness of 1 nm to 2 nm, account for a mass ratio of greater than or equal to 10% and less than or equal to 70% of all the doped units in the hole injection layer.
[0013] In one embodiment of this application, the first sub-part is connected to the second sub-part, and there is no physical boundary between the first sub-part and the second sub-part.
[0014] In one embodiment of this application, the doped unit contains fluorine atoms, and the content of fluorine atoms in the hole injection layer on the side closer to the first electrode is greater than the content of fluorine atoms in the hole injection layer on the side farther from the first electrode.
[0015] In accordance with the above-mentioned objectives of this application, embodiments of this application also provide a hole injection layer ink, the hole injection layer ink comprising a host material and a dopant material, wherein the dopant material is selected from cross-linked p-type dopants.
[0016] In one embodiment of this application, the doped material contains fluorine atoms and crosslinking groups, wherein the crosslinking groups are selected from at least one of benzocyclobutenyl, styrene, oxocyclobutane, alkynyl, epoxy, and alkenyl.
[0017] In one embodiment of this application, the number of crosslinking groups in the doped material is greater than or equal to 3.
[0018] In one embodiment of this application, the host material is selected from cross-linked host materials.
[0019] In accordance with the above objectives of this application, embodiments of this application also provide a display panel, the display panel including the electronic devices described above.
[0020] This application provides an electronic device, a hole injection layer ink, and a display panel, which can make the doped units stably and centrally distributed in the hole injection layer, reduce the probability of diffusion of the doped units, improve the hole injection capability of the hole injection layer, and improve the light emission uniformity of the electronic device.
[0021] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0022] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.
[0023] Figure 1 A schematic diagram of the structure of an electronic device provided in an embodiment of this application; Figure 2 A schematic diagram of a hole injection layer provided in an embodiment of this application; Figure 3 This is a partial structural schematic diagram of an electronic device provided in an embodiment of this application; Figure 4 Another partial structural schematic diagram of the electronic device provided in the embodiments of this application; Figure 5 This is a schematic diagram of the distribution of doped units in the embodiments provided in this application; Figure 6 An exposure test structure diagram of an electronic device provided in an embodiment of this application; Figure 7 This is a schematic diagram of a display panel provided in an embodiment of this application. Detailed Implementation
[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.
[0025] Please refer to Figure 1 This application provides an electronic device 10, which includes a first electrode 11, a hole injection layer 22, a light-emitting layer 21, and a second electrode 12.
[0026] The hole injection layer 22 is disposed on one side of the first electrode 11, and the hole injection layer 22 includes a main unit and a doped unit; the light-emitting layer 21 is disposed on the side of the hole injection layer 22 away from the first electrode 11; the second electrode 12 is disposed on the side of the light-emitting layer 21 away from the hole injection layer 22.
[0027] The content of the doped units in the hole injection layer 22 on the side closer to the first electrode 11 is greater than the content of the doped units in the hole injection layer 22 on the side farther from the first electrode 11.
[0028] In the implementation and application process, the electronic device 10 provided in this application embodiment can make the doped units stably and centrally distributed in the hole injection layer 22, reduce the probability of diffusion of the doped units, improve the hole injection capability of the hole injection layer 22, and improve the light emission uniformity of the electronic device 10.
[0029] Specifically, please refer to Figure 1 In some embodiments, the electronic device 10 includes a first electrode 11 and a second electrode 12 disposed opposite to each other, and a light-emitting functional layer disposed between the first electrode 11 and the second electrode 12.
[0030] In some embodiments, the materials of the first electrode 11 and the second electrode 12 may be selected from conductive materials; wherein, the material of the first electrode 11 may be selected from conductive materials with high work function to facilitate the injection of holes into the light-emitting functional layer, and the material of the first electrode 11 may be selected from at least one of Al, Cu, Au, Ag, Mg, Fe, Co, Ni, Mn, Pd, Pt, indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), indium zinc oxide (IZO), etc.; the second electrode 12 may be selected from conductive materials with low work function to facilitate the injection of electrons into the light-emitting functional layer, for example, the material of the second electrode 12 may be selected from at least one of Al, Au, Ag, Ca, Ba, Mg, LiF / Al, MgAg alloy, BaF2 / Al, Cu, Fe, Co, Ni, Mn, Pd, Pt, indium tin oxide (ITO), etc.
[0031] In some embodiments, the light-emitting functional layer may include a hole injection layer 22 disposed on the first electrode 11, a hole transport layer 23 disposed on the side of the hole injection layer 22 away from the first electrode 11, a light-emitting layer 21 disposed on the side of the hole transport layer 23 away from the first electrode 11, an electron transport layer 24 disposed on the side of the light-emitting layer 21 away from the hole transport layer 23, and an electron injection layer 25 disposed on the side of the electron transport layer 24 away from the light-emitting layer 21, wherein the second electrode 12 is disposed on the side of the electron injection layer 25 away from the electron transport layer 24.
[0032] In some embodiments, the material of the hole transport layer 23 may be independently selected from N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (NPB), 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC), m-MTDATA, N,N′-bis(3-methylphenyl)-N,N′-diphenylbenzidine (TPD), 4,4′,4″-tris(carbazole-9-yl)triphenylamine (TCTA), etc., but is not limited thereto.
[0033] In some embodiments, the material of the electron transport layer 24 may be selected from at least one of 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 4,7-diphenyl-1,10-phenanthroline, 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, and 1,3,5-tris[(3-pyridyl)-3-phenyl]benzene.
[0034] In some embodiments, the material of the electron injection layer 25 may be selected from at least one of lithium fluoride, lithium 8-hydroxyquinoline (Liq), cesium carbonate, magnesium, and lithium oxide / cesium oxide.
[0035] Furthermore, the material of the light-emitting layer 21 includes a light-emitting host material and a light-emitting object material.
[0036] In some embodiments, the electronic device 10 can be a blue light device, in which case the light-emitting host material can be a compound formed by combining thioxanthone as the core with strong electron-donating groups such as carbazole, dimethylacrimidine, and phenoxazine, for example, 2,8-bis(3,6-diphenyl-9H-carbazole-9-yl)thioxanthone, 9-(9-oxo-9H-thioxanthone-2-yl)-9′H-9,3′:6′,9″-triacrimidine, 2,4,6,8-tetra(9H-carbazole-9-yl)thioxanthone, etc. The light-emitting guest material can be selected from light-emitting materials with boron (B) and nitrogen (N) atoms as the core, which achieve narrow-spectrum emission and efficient TADF through the "multi-resonance" electronic effect, such as 5,9-dioxo-5,9-dihydro-10H-5λ. 4 ,9λ 4 -Diboronanthro[3,2,1-de]isoquinoline, boron-nitrogen-carbazole fusion materials, spirocyclic boron-nitrogen multi-resonance materials, etc.
[0037] In some embodiments, the electronic device 10 can be a green light device, and the light-emitting host material can include 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 1,3,5-tris[(3-pyridyl)-3-phenyl]benzene, 4,7-diphenyl-1,10-phenanthroline, 2,4,6-tris[3-(diphenylphosphino)phenyl]-1,3,5-triazine, 4,4′,4″-tris(carbazole-9-yl)triphenylamine, 1,3-bis(9H-carbazole-9-yl)benzene, 4,4′-bis(9H-carbazole-9-yl)biphenyl, N,N′-di(1-naphthyl)-N,N′-diphenylbiphenylamine, etc. The luminescent materials include 10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H-benzo[l]pyrano[6,7,8-ij]quinazine-11-one, tris(2-phenylpyridine)iridium, bis(2-phenylpyridine)(acetylacetone)iridium, 2,4,5,6-tetra(9H-carbazole-9-yl)isophthalonitrile, bis[4-(9,9-dimethyl-9,10-dihydroacrylidine)phenyl]sulfone, etc. The luminescent guest materials include derivatives of 2,8-bis(3,6-diphenyl-9H-carbazole-9-yl)thioxanthone, 10-phenyl-10H-phenoxazine-3-aldehyde, etc.
[0038] In some embodiments, the electronic device 10 can be a red light device, and the light-emitting host material can include 4,4′,4″-tris(carbazole-9-yl)triphenylamine, 4,4′-bis(9H-carbazole-9-yl)biphenyl, 1,3-bis(9H-carbazole-9-yl)benzene, N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine, etc. The light-emitting guest material can include bis(2-phenylquinoline)(acetylacetone)iridium, tris(1-phenylisoquinoline)iridium, bis(2-methyl-dibenzo[f,h]quinoxaline)(acetylacetone)iridium, octaethylporphyrin platinum, etc.
[0039] In some embodiments, the electronic device 10 further includes a light extraction layer 30 disposed on the side of the second electrode 12 away from the electron injection layer 25. The light extraction layer 30 is used to adjust the microcavity structure of the device, improve the light extraction efficiency, and improve the uniformity of light emission from the viewing angle.
[0040] In some embodiments, the material of the light extraction layer 30 is selected from 4,4',4'' Tricarbazole 9 Triphenylamine (TCTA, CAS: 139092) 78 9) N4,N4,N4',N4' Tetraphenyl [1,1' [Biphenyl] 4,4' Diamine (NPB, CAS: 123847) 85 8), 1, 3, 5 3(1) Phenyl 1H Benzo[d]imidazolium 2 Benzene (TPBi, CAS: 192198) 85 9), 4, 4' Double (N) (carbazolyl) 1,1' Biphenyl (CBP, CAS: 58328) 31 At least one of 7).
[0041] It should be noted that the materials of each film layer in the light-emitting functional layer described in the above embodiments are merely examples and not exhaustive, and are not limited to the materials mentioned above.
[0042] In the embodiments of this application, the hole injection layer, the hole transport layer, the light-emitting layer, the electron transport layer, and the electron injection layer can each be independently prepared using inkjet printing or vapor deposition. In the embodiments of this application, at least the hole injection layer, the hole transport layer, and the light-emitting layer can be prepared using inkjet printing.
[0043] In this embodiment, the hole injection layer 22 includes a host unit and a doped unit. The hole injection layer 22 includes a network structure, which includes the host unit and the doped unit connected together. In the electronic device 10 provided in this embodiment, the host unit and the doped unit in the hole injection layer 22 can be cross-linked to form the network structure, thereby making the doped unit stably and uniformly distributed in the hole injection layer 22, reducing the probability of diffusion of the doped unit, improving the hole injection capability of the hole injection layer 22, and improving the light emission uniformity of the electronic device 10.
[0044] In some embodiments, the doping unit is selected from cross-linked p-type doping units, and the host unit is selected from cross-linked host units; that is, the monomer of the doping unit is selected from cross-linked p-type dopant, and the monomer of the host unit is selected from cross-linked host material.
[0045] It should be noted that the doping unit (crosslinked p-type doping unit) is the group structure formed by the crosslinking group in the crosslinked p-type dopant after the crosslinking polymerization is opened; similarly, the host unit (crosslinked host unit) is the group structure formed by the crosslinking group in the crosslinked host unit after the crosslinking polymerization is opened.
[0046] In some embodiments, the doping unit and the host unit are crosslinked and copolymerized to form the network structure, wherein the network structure includes the doping unit and the host unit connected together.
[0047] In some embodiments, the network structure includes the doped units, the host units are cross-linked to form a host network structure, and the network structure and the host network structure are connected to form a composite network structure.
[0048] In some embodiments, the crosslinking group is selected from at least one of benzocyclobutenyl, styrene, oxetane, alkynyl, epoxy, and alkenyl, and the doping unit (crosslinked p-type doping unit) is a group structure formed by the crosslinking polymerization of at least one of benzocyclobutenyl, styrene, oxetane, alkynyl, epoxy, and alkenyl after the unsaturated bonds are opened.
[0049] For example, when the alkenyl group in an alkenyl or styryl group is opened, the resulting group is -CH2-CH2-.
[0050] It should be noted that the network structure is formed by cross-linking and copolymerizing the main unit and the doping unit, and the doping unit is connected to the network structure by covalent bonding; thereby, the doping unit can be stably and uniformly distributed in the network structure, and the probability of the doping unit diffusing in the hole injection layer is reduced.
[0051] Further, please refer to Figure 1 and Figure 2 The hole injection layer 22 includes a first sub-part 221 and a second sub-part 222. The first sub-part 221 is located between the first electrode 11 and the second sub-part 222. The content of the doped units in the first sub-part 221 is greater than the content of the doped units in the second sub-part 222. The ratio of the thickness of the first sub-part 221 to the thickness of the hole injection layer 22 is 0.5. In addition, the ratio of the thickness of the second sub-part 222 to the thickness of the hole injection layer 22 is 0.5, that is, the thickness of the first sub-part 221 is equal to the thickness of the second sub-part 222.
[0052] It should be noted that the crosslinking groups promote greater stability and concentration of the crosslinked p-type dopant during film formation, ensuring its uniform deposition at the interface between the hole injection layer 22 and the first electrode 11. Figure 3 As shown, this can improve the hole injection capability of the hole injection layer 22 and make the light emission of the electronic device 10 more uniform and the light emission performance better.
[0053] Understandable Figure 3 The diagram also shows a pixel definition layer 40, which can be used to space multiple electronic devices 10 in the display panel when the electronic device 10 is applied in the display panel.
[0054] In some embodiments, the content of the doped units in the first sub-section 221 on the side closer to the first electrode 11 is greater than the content of the doped units in the first sub-section 221 on the side farther from the first electrode 11.
[0055] Furthermore, the ratio of the thickness of the first sub-part 221 near the first electrode 11 to the thickness of the hole injection layer 22 is greater than or equal to 5% and less than or equal to 20%; that is, in this embodiment, by selecting the cross-linked p-type dopant as the doping material in the hole injection layer 22, the doped units can be uniformly and concentratedly distributed on the side of the hole injection layer 22 near the first electrode 11, and the doped units are prevented from being distributed in a concentrated manner. Figure 4It diffuses during the process.
[0056] For example, the ratio of the thickness of the first sub-part 221 near the first electrode 11 to the thickness of the hole injection layer 22 can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%.
[0057] In some embodiments, the proportion of the mass content of the doped units in the first sub-part 221, which is close to the first electrode 11 and has a thickness of 1nm to 2nm (inclusive), to all the doped units in the hole injection layer 22 can be greater than or equal to 10% and less than or equal to 70%, for example, it can be 10%, 20%, 30%, 40%, 50%, 60% or 70%.
[0058] It is understood that the doped units can be concentrated in an extremely thin region near the first electrode 11, forming a highly doped thin layer at the interface between the first electrode 11 and the hole injection layer 22, which strongly changes the interface energy level and significantly reduces the potential barrier for hole injection from the first electrode 11; holes can be rapidly injected into the hole injection layer 22, improving the current efficiency and brightness of the electronic device 10; in addition, the doped units are concentrated in a thin layer near the first electrode 11, keeping them away from the hole transport layer 23 and the light-emitting layer 21, so even if a small amount diffuses, it will not reach the light-emitting region, which can significantly improve the efficiency and lifetime of the electronic device 10.
[0059] It is understood that the first sub-part 221 is connected to the second sub-part 222, and there is no physical boundary between the first sub-part 221 and the second sub-part 222; that is, the first sub-part 221 and the second sub-part 222 are both parts of the hole injection layer 22, and the first sub-part 221 and the second sub-part 222 are a whole.
[0060] In some embodiments, the doped unit contains fluorine atoms; thus, the high electronegativity and strong CF bond of fluorine atoms can be utilized to primarily function in photoelectric modulation, improving carrier balance through molecular interactions; furthermore, it can reduce molecular aggregation, resulting in a more uniform distribution of the doped units, reducing concentration quenching, making the hole injection layer 22 film smoother with fewer defects, and achieving a higher photoluminescence quantum yield / photoluminescence quantum efficiency (PLQY); additionally, fluorine can modify the film surface to reduce the surface energy of the hole injection layer 22, improve interfacial contact, and further facilitate carrier transport.
[0061] In some embodiments, the distribution of the doped units can be characterized by the distribution of fluorine atoms.
[0062] In some embodiments, the content of fluorine atoms in the hole injection layer 22 on the side closer to the first electrode 11 is greater than the content of fluorine atoms in the hole injection layer 22 on the side farther from the first electrode 11.
[0063] Furthermore, in some embodiments, the content of fluorine atoms in the first sub-section 221 on the side closer to the first electrode 11 is greater than the content of fluorine atoms in the first sub-section 221 on the side farther from the first electrode 11.
[0064] It is understood that the content of the doped unit in the above embodiments can be regarded as any one of the mass content or molar content of the doped unit; and the content of fluorine atoms in the above embodiments can be regarded as any one of the atomic percentage, mass content or molar content of fluorine atoms.
[0065] As described above, in the electronic device 10 provided in this application embodiment, the hole injection layer 22 can form the network structure, and the network structure includes the doped units, thereby enabling the doped units to be stably and uniformly distributed in the hole injection layer 22, reducing the probability of diffusion of the doped units, improving the hole injection capability of the hole injection layer 22, and improving the light emission uniformity of the electronic device 10.
[0066] In addition, this application embodiment also provides a hole injection layer ink, which includes a host material and a dopant material, wherein the dopant material is selected from cross-linked p-type dopants.
[0067] In some embodiments, the doped material contains fluorine atoms and crosslinking groups, wherein the crosslinking groups are selected from at least one of benzocyclobutenyl, styryl, oxocyclobutane, alkynyl, epoxy, and alkenyl.
[0068] In some embodiments, the number of crosslinking groups in the doped material is greater than or equal to 3.
[0069] In some embodiments, the host material is selected from cross-linked host materials.
[0070] In some embodiments, the host material is selected from vinyl-modified polytriphenylamine (V-PolyTPD), vinyl-modified polyfluorene triphenylamine copolymer (V-TFB), vinyl-modified polyvinylcarbazole (V-PVK), vinyl-modified indolocarbazole conjugated polymer (V-PICA), benzocyclobutene-grafted polytriphenylamine (BCB-PolyTPD), benzocyclobutene-grafted polyfluorene triphenylamine copolymer (BCB-TFB), oxacyclobutane side-chain polytriphenylamine (Ox-PolyTPD), oxacyclobutane side-chain polyvinylcarbazole (Ox-PVK), ethynyl-modified polytriphenylamine (E-PolyTPD), ethynyl-modified polycarbazole (E-PCz), furan side-chain polyfluorene triphenylamine (Diesel-Alder crosslinking system) (Furan-PTFB), vinyl-modified brominated polyfluorene quaternary ammonium salt (V-PFN-Br), vinyl-substituted biphenyl diamine (Vp-TPD), vinyl-modified N,N'- At least one of the following: diphenylbiphenyl diamine (V-NPB), vinyl-modified 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline] (V-TAPC), ethynyl-modified triphenylamine small molecule (E-TPD), ethynyl-modified 4,4'-bis(9-carbazolyl)biphenyl (E-CBP), and ethynyl-modified spiromethoxytriphenylamine (E-spiro-OMeTAD).
[0071] In some embodiments, the dopant material is selected from vinyl-modified tetrafluorotetracyanobenzoquinone dimethane (Vinyl-F4-TCNQ), benzocyclobutene-modified hexafluorotetracyanonaphthoquinone dimethane (BCB-F6-TCNNQ), ethynyl-HAT-CN-F, acrylate-perfluoroquinone, vinyl-perfluorinated sulfonic ionomer (V-PFI), epoxy-perfluoroaryl borate salt, and vinyl-imidazolium tetrafluoroborate. At least one of the following: tetrafluoroborate, vinyl-pyridinium hexafluorophosphate, vinylsilane-PMA-F, epoxysilane-PWA-F, azide-perfluorotrifluorobenzene derivative, and UV-crosslinked perfluorotriflateiron.
[0072] In some embodiments, the mass percentage of the host material in the hole injection layer ink ranges from 1.0 wt% to 7.5 wt%; and the mass percentage of the dopant material in the hole injection layer ink ranges from 0.02 wt% to 0.8 wt%.
[0073] In some embodiments, the hole injection layer ink further includes a solvent and additives; wherein the solvent may include a main solvent and a co-solvent, and the additives may include a viscosity modifier, a surfactant, and an antioxidant.
[0074] In some embodiments, the solvent in the hole injection layer ink has a mass percentage range of 91.4 to 98.965 wt%, wherein the main solvent in the hole injection layer ink has a mass percentage range of 88 wt% to 98 wt%, and the co-solvent in the hole injection layer ink has a mass percentage range of 0.5 wt% to 4 wt%.
[0075] In some embodiments, the viscosity modifier in the hole injection layer ink has a mass percentage range of 0.1 wt% to 1 wt%; the surfactant in the hole injection layer ink has a mass percentage range of 0.05 wt% to 0.5 wt%; and the antioxidant in the hole injection layer ink has a mass percentage range of 0.01 wt% to 0.2 wt%.
[0076] In some embodiments, in the total solid components of the hole injection layer ink, the mass content of the host material ranges from 80 wt% to 99 wt%, and the mass content of the dopant material ranges from 0.1 wt% to 30 wt%.
[0077] In some embodiments, the main solvent can be used to dissolve the host material, the dopant material and other additives, and can be used to adjust the ink viscosity and surface tension so that the hole injection layer ink is adapted to the inkjet printing process, thereby avoiding the occurrence of nozzle clogging and ink splatter.
[0078] In some embodiments, the main solvent may be selected from one or more combinations of diphenyl ether, trimethylbenzene, tetrahydronaphthalene, 1,2,4-trimethylbenzene, cyclohexylbenzene, and p-xylene.
[0079] In some embodiments, the co-solvent can be used to adjust the surface tension (e.g., controlled at 20–35 mN / m) and viscosity (e.g., controlled at 5–20 mPa·s) of the ink to improve the wettability of the hole injection layer ink on the substrate and avoid the occurrence of edge shrinkage and pinholes.
[0080] In some embodiments, the cosolvent may be selected from one or more combinations of ethanol, isopropanol, ethylene glycol monomethyl ether, diethylene glycol dimethyl ether, and N-methylpyrrolidone (NMP).
[0081] In some embodiments, the viscosity modifier can be used to fine-tune the ink viscosity so that the cavity injection layer ink is adapted to the jetting performance of inkjet printing, ensuring uniform droplet size, stable jetting, and avoiding nozzle clogging.
[0082] In some embodiments, the viscosity modifier may be selected from one or more combinations of polyethylene glycol (PEG-2000), polypropylene glycol, hydroxypropyl cellulose, and polyvinylpyrrolidone (PVP-K30).
[0083] In some embodiments, the surfactant is used to reduce the surface tension of the ink, improve the compatibility and wettability of the ink with the substrate, avoid surface defects such as edge shrinkage, pinholes, and orange peel texture after printing, and ensure that the hole injection layer forms a dense and uniform film.
[0084] In some embodiments, the surfactant may be selected from one or more of sodium perfluorooctyl sulfonate, polyoxyethylene octylphenyl ether (OP-10), sodium dodecylbenzene sulfonate, and fluorocarbon surfactant (FC-4430).
[0085] In some embodiments, the antioxidant is used to prevent the cross-linked host material and cross-linked p-type dopant from being oxidized during the storage, transportation and printing of the ink composition, thereby ensuring the stability of the ink, avoiding the degradation of hole injection layer performance due to component oxidation, and thus ensuring the reliability and service life of the light-emitting device.
[0086] In some embodiments, the antioxidant may be selected from one or more of 2,6-di-tert-butyl-p-cresol (BHT), ascorbate palmitate, hindered phenolic antioxidants (1010), and phosphite antioxidants (168).
[0087] In addition, this application provides Example 1 to verify the distribution of the doped material in the hole injection layer 22 of the electronic device 10.
[0088] Specifically, in the electronic device 10 of Embodiment 1, IZO represents the first electrode 11, HIL represents the hole injection layer 22, HTL represents the hole transport layer 23, EML represents the light-emitting layer 21, ETL represents the electron transport layer 24, Yb / Ag represents the stacked structure of the electron injection layer 25 and the second electrode 12, and CPL represents the light extraction layer 30.
[0089] In Example 1, the host material can be a cross-linked host material, specifically vinyl-modified polyvinylcarbazole; the dopant material is selected from cross-linked p-type dopants, specifically vinylimidazolium tetrafluoroborate.
[0090] By detecting the F element in the electronic device 10 of Example 1 using TOF-SIMS, the distribution of the doped material in the hole injection layer 22 of Example 1 can be clearly determined, and the results are as follows: Figure 5 As shown.
[0091] in, Figure 5 The diagram shows the distribution of the doped material in the hole injection layer 22 described in Example 1. It can be seen that in this embodiment, a cross-linked p-type dopant is used as the doped material in the hole injection layer 22. The cross-linking groups make the doped material more stable in the hole injection layer 22 and allow it to be uniformly deposited at the interface between the hole injection layer 22 and the first electrode 11, thereby improving hole injection. Furthermore, this results in more uniform light emission and better light emission performance for the electronic device 10.
[0092] Furthermore, this application provides Comparative Example 1, Comparative Example 2, and Example 2 to perform exposure testing on the electronic device 10 and obtain the results shown in the example. Figure 6 The results are shown.
[0093] In Examples 2, 1, and 2, the electronic devices 10 are identical except for the doping materials; all other films and materials are the same.
[0094] In Example 2, the doping material is selected from cross-linked p-type dopants, specifically vinylimidazolium tetrafluoroborate.
[0095] In Comparative Example 1, the doped material can be selected from non-crosslinked p-type dopants, specifically 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-p-benzoquinone dimethyl ether (F4-TCNQ).
[0096] In Comparative Example 2, the doping material can be selected from non-crosslinked p-type dopants, specifically hexafluorotetracyanonaphthoquinone dimethyl ether (F6-TCNNQ).
[0097] As can be seen, under the same camera exposure conditions of ISO 400, the electronic device 10 using cross-linked p-type dopant in this embodiment of the application only requires an exposure time of 50 μs to achieve 100% luminescence uniformity; while the electronic device using non-cross-linked p-type dopant requires an exposure time of up to 1000 μs to achieve the same 100% luminescence uniformity. This indicates that the cross-linked p-type dopant, by being fixed in the network structure, will not migrate, aggregate, or precipitate locally, resulting in a uniform doping concentration distribution within the hole injection layer 22. The hole injection barrier at the interface between the hole injection layer 22 and the first electrode 11 is consistent, and the hole injection is uniform. Therefore, a completely uniform luminescence effect can be exhibited under extremely short exposure times, effectively improving the luminescence uniformity of the electronic device 10.
[0098] In addition, this application embodiment also provides a display panel, please refer to Figure 1 and Figure 7 The display panel includes the electronic device 10 as described in the above embodiments.
[0099] In some embodiments, the display panel includes an array substrate 50 and a plurality of electronic devices 10 disposed on the array substrate 50.
[0100] In some embodiments, the array substrate 50 includes a substrate and a thin-film transistor layer disposed on the substrate.
[0101] In some embodiments, the substrate may be a rigid substrate, such as a glass substrate; or the substrate may be a flexible substrate, such as a substrate formed of polyimide. When the substrate is a flexible substrate, the substrate may be formed of multiple sub-substrates of the same material, such as polyimide, and adjacent sub-substrates may be bonded together by adhesive sub-layers.
[0102] In some embodiments, the thin-film transistor layer includes a thin-film transistor comprising a semiconductor located on the substrate, the semiconductor being formed of polycrystalline silicon or a metal oxide (such as indium gallium zinc oxide). The semiconductor is divided into a channel region and source and drain regions formed on either side of the channel region. The thin-film transistor layer further includes a first gate insulating layer covering the semiconductor. The thin-film transistor also includes a first gate formed on the first gate insulating layer, the first gate overlapping the channel region. The first gate may be formed as multiple layers or a single layer comprising a low-resistance material such as Al, Ti, Mo, Cu, Ni, or alloys thereof, or a material with high corrosion resistance. The thin-film transistor layer further includes a second gate insulating layer covering the first gate. The thin-film transistor also includes a second gate located on the second gate insulating layer, the second gate overlapping the first gate, the second gate being formed as multiple layers or a single layer comprising a low-resistance material such as Al, Ti, Mo, Cu, Ni, or alloys thereof, or a material with high corrosion resistance. The thin-film transistor layer further includes a first interlayer insulating layer formed on the second gate. The first interlayer insulating layer, the first gate insulating layer, and the second gate insulating layer include source contact holes and drain contact holes, and the source region and the drain region are exposed through the source contact holes and the drain contact holes, respectively.
[0103] The thin-film transistor further includes a source and a drain disposed on the same layer. Both the source and the drain are formed on the first interlayer insulating layer. The source is connected to the source region through a source contact hole, and the drain is connected to the drain region through a drain contact hole. The source and the drain can be multiple layers or a single layer formed of low-resistance materials such as Al, Ti, Mo, Cu, Ni, or their alloys, or materials with high corrosion resistance. For example, the source and the drain can be a triple layer of Ti / Cu / Ti, Ti / Ag / Ti, Ti / Al / Ti, or Mo / Al / Mo, or other single-layer or multi-layer structures.
[0104] In some embodiments, the thin-film transistor layer further includes a planarization layer located on the side of the first interlayer insulating layer away from the substrate, the planarization layer covering the source and the drain.
[0105] In some embodiments, a plurality of electronic devices 10 are disposed on the array substrate 50, and a first electrode 11 of the electronic device 10 is located on the side of the electronic device 10 closer to the array substrate 50. The first electrode 11 can be connected to the source or drain in the array substrate 50 to realize signal transmission.
[0106] In some embodiments, the display panel further includes an encapsulation layer, which is disposed on the side of the plurality of electronic devices 10 away from the array substrate 50, and covers the plurality of electronic devices 10.
[0107] In some embodiments, the encapsulation layer is disposed on the second electrode 12, and the encapsulation layer includes a first inorganic encapsulation layer, an organic layer, and a second inorganic encapsulation layer stacked together; wherein, the first inorganic encapsulation layer and the second inorganic encapsulation layer can be prepared using inorganic materials, such as silicon nitride, silicon oxynitride, aluminum oxide, etc., which can play a role in blocking water and oxygen; while the organic layer can be prepared using organic resin materials, such as acrylic resin, epoxy resin, etc., which can play a role in improving flatness and buffering stress.
[0108] In summary, in the electronic device 10 provided in this application embodiment, the network structure can be formed in the hole injection layer 22, and the network structure includes the main unit and the doped unit connected to each other. This allows the doped unit to be stably, centrally and uniformly distributed in the hole injection layer 22, reducing the probability of diffusion of the doped unit, improving the hole injection capability of the hole injection layer 22, and improving the light emission uniformity of the electronic device 10.
[0109] In addition, this application embodiment also provides a display device, which includes the display panel as described above.
[0110] It is understood that the display device has the same display panel as in the above embodiments, and therefore has the same beneficial effects as in the above embodiments, which will not be repeated here.
[0111] In some embodiments, the display device may include a mobile phone, computer, tablet, wearable device, or virtual reality display device, etc.
[0112] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0113] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.
[0114] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.
[0115] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.
Claims
1. An electronic device, characterized in that, include: First electrode; A hole injection layer is disposed on one side of the first electrode, and the hole injection layer includes a host unit and a doped unit; A light-emitting layer is disposed on the side of the hole injection layer away from the first electrode; The second electrode is disposed on the side of the light-emitting layer away from the hole injection layer; The content of the doped units in the hole injection layer on the side closer to the first electrode is greater than the content of the doped units in the hole injection layer on the side farther from the first electrode.
2. The electronic device according to claim 1, characterized in that, The doping unit is selected from cross-linked p-type doping units, and the host unit is selected from cross-linked host units.
3. The electronic device according to claim 1, characterized in that, The hole injection layer includes a network structure, which includes the host unit and the doped unit connected together.
4. The electronic device according to any one of claims 1 to 3, characterized in that, The hole injection layer includes a first sub-section and a second sub-section. The first sub-section is located between the first electrode and the second sub-section. The content of the doped units in the first sub-section is greater than the content of the doped units in the second sub-section, and the ratio of the thickness of the first sub-section to the thickness of the hole injection layer is 0.
5.
5. The electronic device according to claim 4, characterized in that, The content of the doped units in the first sub-section closer to the first electrode is greater than the content of the doped units in the first sub-section farther from the first electrode.
6. The electronic device according to claim 5, characterized in that, The ratio of the thickness of the first sub-part near the first electrode to the thickness of the hole injection layer is greater than or equal to 5% and less than or equal to 20%.
7. The electronic device according to claim 4, characterized in that, The doped units in the first sub-part, which are close to the first electrode and have a thickness of 1 nm to 2 nm, account for a mass ratio of greater than or equal to 10% and less than or equal to 70% of all the doped units in the hole injection layer.
8. The electronic device according to claim 4, characterized in that, The first sub-part is connected to the second sub-part, and there is no physical boundary between the first sub-part and the second sub-part.
9. The electronic device according to any one of claims 1 to 3, characterized in that, The doped unit contains fluorine atoms, and the content of fluorine atoms in the hole injection layer on the side closer to the first electrode is greater than the content of fluorine atoms in the hole injection layer on the side farther from the first electrode.
10. A hole-injection layer ink, characterized in that, The hole injection layer ink includes a host material and a dopant material, wherein the dopant material is selected from cross-linked p-type dopants.
11. The hole injection layer ink according to claim 10, characterized in that, The doped material contains fluorine atoms and crosslinking groups, wherein the crosslinking groups are selected from at least one of benzocyclobutenyl, styryl, oxocyclobutane, alkynyl, epoxy, and alkenyl.
12. The hole injection layer ink according to claim 11, characterized in that, The number of crosslinking groups in the doped material is greater than or equal to 3.
13. The hole injection layer ink according to claim 10, characterized in that, The host material is selected from cross-linked host materials.
14. A display panel, characterized in that, The display panel includes the electronic device as described in any one of claims 1 to 9.