Method of forming a hole injection layer and hole injection layer ink composition

Abstract

Methods of forming a hole injection layer and a hole injection layer ink composition are disclosed. The methods include the steps of forming a pixel electrode on a substrate; coating the pixel electrode with a composition to provide a pixel defining film on the pixel electrode; forming a patterned pixel defining film by photolithography, the patterned pixel defining film having an opening that exposes a portion of the pixel electrode; removing residue; and forming a hole injection layer on the pixel electrode that is exposed and from which the residue is removed.

Description

[0001] This application claims priority and all benefits derived therefrom to Korean Patent Application No. 10-2020-0159090, filed on November 24, 2020, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] The present invention relates to a method for forming a hole injection layer, a hole injection layer ink composition, and a light-emitting device manufactured using the hole injection layer ink composition. Background Technology

[0003] Among display devices, organic light-emitting diode (OLED) displays have attracted much attention as a next-generation display device due to their wide viewing angle, high contrast ratio, and relatively short response time. As an OLED, thin-film transistors and organic light-emitting devices (OLEDs) are formed on a substrate, and light is emitted from the OLED. OLEDs are sometimes used as display units in small products such as mobile phones, tablets, or laptops, or as display units in large products such as televisions or signage.

[0004] OLEDs consist of pixel electrodes, counter electrodes, and an organic emitting layer between the two electrodes. The organic emitting layer of an OLED can be formed by various methods such as chemical vapor deposition (CVD), inkjet printing, etc. Summary of the Invention

[0005] One or more embodiments include a method for forming a hole injection layer of a light-emitting device by using a hole injection layer ink composition with improved wettability on an electrode with removed residue, a hole injection layer ink composition for forming a hole injection layer, and a light-emitting device manufactured using said hole injection layer ink composition. Further aspects will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the disclosed embodiments given.

[0006] According to one or more embodiments, a method for forming a hole injection layer of a light-emitting device is provided, wherein the method may include the following steps:

[0007] Pixel electrodes are formed on the substrate;

[0008] The composition is coated onto the pixel electrode to provide a pixel-defining film on the pixel electrode;

[0009] A patterned pixel-defining film is formed by photolithography, the patterned pixel-defining film having an opening that can expose a portion of the pixel electrode;

[0010] Remove residue; and

[0011] A hole injection layer is formed on the exposed and descaled pixel electrode.

[0012] According to one or more embodiments, the hole injection layer ink composition may include a hole injection layer compound, a solvent, and a polymer compound comprising groups represented by Formula 1.

[0013] Formula 1

[0014]

[0015] In Equation 1,

[0016] X can be a single bond or a divalent organic linker.

[0017] R1 can be either unsubstituted or substituted with at least one R. 10a C1-C 10 Alkylene

[0018] R2 can be hydrogen, deuterium, hydroxyl, unsubstituted, or substituted with at least one R. 10a C1-C 60 Alkyl, unsubstituted or substituted with at least one R 10a C2-C 60 Alkenyl, unsubstituted or substituted with at least one R 10a C2-C 60 Alkyne group, unsubstituted or substituted with at least one R 10a C1-C 60 Alkyl groups and unsubstituted or substituted groups with at least one R 10a C1-C 60 Alkyl ether group,

[0019] n1 can be an integer from 2 to 100.

[0020] * indicates a connection site with an adjacent atom in the polymer compound, and

[0021] Each R 10a Independently: deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, or nitro;

[0022] All are independently unsubstituted or substituted with deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, C3-C 60 Carbocyclic group, C1-C 60 Heterocyclic group, C6-C 60 Aryloxy group, C6-C 60 Arylthio, -Si(Q) 11 (Q) 12 (Q) 13 -N(Q) 11 (Q) 12 -B(Q)11 (Q) 12 -C(=O)(Q) 11 -S(=O)2(Q) 11 -P(=O)(Q) 11 (Q) 12 C1-C or combinations thereof 60 Alkyl, C2-C 60 alkenyl, C2-C 60 Alkyne group or C1-C 60 Alkoxy;

[0023] All are independently unsubstituted or substituted with deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, C1-C 60 Alkyl, C2-C 60 alkenyl, C2-C 60 Alkyne group, C1-C 60 Alkoxy, C3-C 60 Carbocyclic group, C1-C 60 Heterocyclic group, C6-C 60 Aryloxy group, C6-C 60 Arylthio, -Si(Q) 21 (Q) 22 (Q) 23 -N(Q) 21 (Q) 22 -B(Q) 21 (Q) 22 -C(=O)(Q) 21 -S(=O)2(Q) 21 -P(=O)(Q) 21 (Q) 22 C3-C or combinations thereof 60 Carbocyclic group, C1-C 60 Heterocyclic group, C6-C 60 Aryloxy or C6-C 60 aryl thiols; or

[0024] -Si(Q 31 (Q) 32 (Q) 33 -N(Q) 31 (Q) 32 -B(Q) 31 (Q) 32 -C(=O)(Q) 31 -S(=O)2(Q) 31 ) or -P(=O)(Q 31 (Q) 32 ),

[0025] Among them, Q11 To Q 13 Q 21 To Q 23 and Q 31 To Q 33 Each of these groups is independently: hydrogen; deuterium; -F; -Cl; -Br; -I; hydroxyl; cyano; nitro; C1-C 60 Alkyl; C2-C 60 Alkenyl; C2-C 60 Alkyne group; C1-C 60 Alkyl groups; or all independently unsubstituted or substituted with deuterium, -F, cyano, C1-C. 60 Alkyl, C1-C 60 C3-C of alkoxy, phenyl, biphenyl, or combinations thereof 60 Carbocyclic or C1-C 60 Heterocyclic group.

[0026] According to one or more embodiments, the light-emitting device may include: a first electrode and a second electrode, each having surfaces opposite to each other; and an interlayer layer between the first electrode and the second electrode and including an emitting layer, wherein the interlayer layer may include a hole injection layer, and the hole injection layer may be manufactured using a hole injection layer ink composition.

[0027] According to one or more embodiments, the display device may include the light-emitting device.

[0028] Other aspects and features, in addition to those described above, will become apparent from the detailed description, the claims, and the accompanying drawings. Attached Figure Description

[0029] The above and other aspects, features, and advantages of certain embodiments disclosed will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0030] Figure 1 This is a schematic perspective view illustrating a display device according to an embodiment; and

[0031] Figure 2 This is a schematic cross-sectional view illustrating a display device according to an embodiment. Detailed Implementation

[0032] Referring now to embodiments, examples of which are shown in the accompanying drawings, wherein the same reference numerals always denote the same elements. In this respect, the embodiments given may take different forms and should not be construed as limited to the description set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Therefore, embodiments are described below only by reference to the accompanying drawings to explain aspects of this specification.

[0033] As used herein, unless the content expressly indicates otherwise, the singular forms “a,” “an,” and “the” are intended to include the plural forms containing “at least one.” “At least one” is not to be construed as limited to “a” or “an.” “Or” means “and / or.” As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. Throughout the disclosure, the expression “at least one of a, b, and c” means only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

[0034] Similarly, in this specification, "A and / or B" means A or B, or A and B. In this specification, "at least one of A and B" means A or B, or A and B.

[0035] It will also be understood that when the terms “comprising,” “including,” and / or “having,” and variations thereof are used in this specification or claims, it indicates the presence of the stated features, areas, integrals, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, areas, integrals, steps, operations, elements, components, and / or groups thereof.

[0036] It will be understood that when a layer, region, or component is referred to as being "on" or "to" another layer, region, or component, that layer, region, or component may be formed directly or indirectly on said other layer, region, or component. That is, for example, intermediate layers, regions, or components may exist. Conversely, when an element is referred to as being "directly on" another element, there is no intermediate element.

[0037] Furthermore, relative terms such as “below” or “bottom” and “above” or “top” may be used herein to describe the relationship between one element and another as shown in the accompanying drawings. It will be understood that these relative terms are intended to cover different orientations of the device beyond those depicted in the drawings. For example, if the device in one of the drawings is flipped, an element described as being “below” the other element will subsequently be oriented “above” the other element. Thus, the exemplary term “below” may include both “below” and “above” orientations depending on the specific orientation of the drawing. Similarly, if the device in one of the drawings is flipped, an element described as being “below” or “under” the other element will subsequently be oriented “above” the other element. Thus, the exemplary terms “below” or “under” may include both “above” and “below” orientations.

[0038] For ease of explanation, the dimensions of the components in the accompanying drawings may be exaggerated. In other words, since the dimensions and thicknesses of the components in the accompanying drawings are arbitrarily shown for ease of explanation, the following embodiments are not limited thereto.

[0039] When a particular example can be implemented differently, a particular process sequence can be performed in a manner different from that described. For example, two processes described consecutively can be performed substantially simultaneously, or the two processes described consecutively can be performed in the reverse order of being described.

[0040] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will also be understood that terms (such as those defined in a general dictionary) shall be interpreted as having the same meaning as they have in the relevant field and in the context of this disclosure, and shall not be interpreted in an idealized or overly formal sense unless expressly defined herein. It will be understood that when a layer, region, or component is referred to as being “connected to” another layer, region, or component, that layer, region, or component may be directly connected to said other layer, region, or component, or indirectly connected to said other layer, region, or component due to the presence of an intermediate layer, region, or component. For example, it will be understood that when a layer, region, or component is referred to as being “electrically connected to” another layer, region, or component, that layer, region, or component may be directly electrically connected to said other layer, region, or component, or indirectly electrically connected to said other layer, region, or component due to the presence of an intermediate layer, region, or component.

[0041] The x-axis, y-axis, and z-axis are not limited to three axes in an orthogonal coordinate system, and can be interpreted in a broad sense (including orthogonal coordinate systems). For example, the x-axis, y-axis, and z-axis can be orthogonal to each other, but they can also refer to different directions that are not orthogonal to each other.

[0042] The display device according to the embodiments can be described as an organic light-emitting display device. In some embodiments, the display device according to the embodiments may be a display device such as an inorganic light-emitting display device, an inorganic electroluminescent (EL) display device, or a quantum dot light-emitting display device. For example, a display device disposed in... Figure 1 The emitting layer in the display device 1 may include organic materials, quantum dots, or organic materials and quantum dots.

[0043] Figure 1 This is a schematic perspective view illustrating a display device according to an embodiment.

[0044] like Figure 1As shown, the display device 1 may include a display area DA where an image can be displayed and a non-display area NDA where an image can not be displayed. The display device 1 can provide an image by utilizing light emitted from a plurality of pixels P within the display area DA.

[0045] exist Figure 1 In the embodiment, the display area DA in display device 1 is shown in a rectangular form, but the embodiment is not limited to this. The shape of the display area DA can be circular, elliptical, or a polygonal shape such as a triangle or pentagon. Furthermore, although... Figure 1 The display device 1 shown is illustrated as a flat panel display device in a planar form; however, it is evident that the display device 1 can be implemented in various forms, such as partially flexible or foldable display devices.

[0046] Figure 2 This is a schematic cross-sectional view illustrating a display device according to an embodiment. Figure 2 As shown, a display device 1 according to one or more embodiments may include: a substrate 100; a pixel electrode 180 on the substrate 100; and a pixel defining film 191 on the pixel electrode 180, the pixel defining film 191 having an opening that can expose a portion (optionally, a central portion) of the pixel electrode 180.

[0047] The substrate 100 may comprise glass or a polymeric resin. The polymeric resin may comprise polyethersulfone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyallylate, polyimide (PI), polycarbonate (PC), or cellulose acetate propionate (CAP). The substrate 100 comprising the polymeric resin may possess flexible, rollable, or bendable properties. The substrate 100 may have a multilayer structure comprising a layer containing the polymeric resin and an inorganic layer (not shown).

[0048] A buffer layer 110 may be disposed on a substrate 100 to planarize the upper surface of the substrate 100 and to prevent impurities from entering from the substrate 100. The buffer layer 110 may include silicon oxide (SiO2). X ), silicon nitride (SiN) X ) and silicon oxynitride (SiO) X N Y At least one of the following.

[0049] The active layer 120 may be on the buffer layer 110. The active layer 120 may include oxide semiconductors and / or silicon semiconductors. When the active layer 120 is formed of an oxide semiconductor, the active layer 120 may include at least one oxide selected from indium (In), gallium (Ga), tin (Sn), zirconium (Zr), vanadium (V), hafnium (Hf), cadmium (Cd), germanium (Ge), chromium (Cr), titanium (Ti), and zinc (Zn). For example, the active layer 120 may be an ITZO (InSnZnO) active layer or an IGZO (InGaZnO) active layer. When the active layer 120 is formed of a silicon semiconductor, the active layer 120 may include, for example, amorphous silicon (a-Si) or low-temperature polycrystalline silicon (LTPS).

[0050] The gate electrode 140 may be located on the active layer 120, and the first insulating layer 130 may be located between the gate electrode 140 and the active layer 120. The gate electrode 140 may be formed as a single layer or multiple layers of at least one metal selected from aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), nickel (Ni), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten (W), and copper (Cu). The gate electrode 140 may be connected to a gate line (not shown) to which an electrical signal is applied.

[0051] The source electrode 160 and / or drain electrode 161 may be on the gate electrode 140, and the second insulating layer 150 may be between the source electrode 160 and / or drain electrode 161 and the gate electrode 140. The source electrode 160 and / or drain electrode 161 may be electrically connected to the active layer 120 through contact holes formed in the second insulating layer 150 and the first insulating layer 130.

[0052] like Figure 2 As shown, the third insulating layer 170 may be on the second insulating layer 150. Figure 2 In the diagram, the third insulating layer 170 is shown as a single layer; however, the third insulating layer 170 can be formed as multiple layers. The third insulating layer 170 can planarize the upper surface of the pixel circuit (PC), thereby planarizing the surface in which the organic light-emitting device (OLED) is positioned.

[0053] The third insulating layer 170 may include, for example, general-purpose polymers (such as benzocyclobutene (BCB), polyimide, hexamethyldisiloxane (HMDSO), polymethyl methacrylate (PMMA), or polystyrene (PS)), polymer derivatives having phenolic groups, acrylic polymers, imide polymers, aryl ether polymers, amide polymers, fluorinated polymers, p-xylene polymers, vinyl alcohol polymers, and mixtures thereof. As another example, the third insulating layer 170 may contain organic and inorganic materials.

[0054] Pixel electrode 180 may be located on third insulating layer 170. Pixel electrode 180 may be a (semi-)transmissive electrode or a reflective electrode. Pixel electrode 180 may be electrically connected to PC via contact holes formed in third insulating layer 170.

[0055] In some embodiments, the pixel electrode 180 may include a reflective film formed of Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or their respective compounds or mixtures (e.g., alloys), and a transparent electrode layer or a semi-transparent electrode layer on the reflective film. The transparent electrode layer or semi-transparent electrode layer may include at least one of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In2O3), indium gallium oxide (IGO), and zinc aluminum oxide (AZO). For example, the pixel electrode 180 may include a stacked structure of ITO / Ag / ITO.

[0056] Pixel defining film 191 may be located on pixel electrode 180. Since pixel defining film 191 may have an opening that exposes a portion (optionally, the central portion) of pixel electrode 180, pixel defining film 191 may define the emission region AA of pixel P. In addition, since pixel defining film 191 may increase the distance between the edge portion of pixel electrode 180 and the counter electrode 210 on pixel electrode 180, pixel defining film 191 may prevent arcing or the like from occurring at the edge portion of pixel electrode 180.

[0057] The pixel-defining film 191 can be formed by curing a conventional composition used for the pixel-defining film, and the composition used for the pixel-defining film may include a photoinitiator, an alkali-soluble resin, a liquid repellent (or "liquid repellent"), a developer protectant, and a solvent.

[0058] During the inkjet process, the upper layer of the pixel-defining film 191 can have liquid repulsion (liquid repellency) properties, so that luminescent materials and the like do not need to be applied to the non-emissive area NAA.

[0059] Interlayer 200 may be on pixel electrode 180 exposed by pixel defining film 191. Interlayer 200 may include hole injection layer. Interlayer 200 may include organic emission layer, and optionally, may also include functional layers such as hole transport layer, electron transport layer and electron injection layer on and under organic emission layer.

[0060] The organic emitting layer may include organic materials, including fluorescent or phosphorescent materials that can emit red, green, blue, or white light. The organic emitting layer can be formed from low-molecular-weight or high-molecular-weight organic materials.

[0061] Pixel electrodes 180 may be configured as a plurality of pixel electrodes, and interlayer layer 200 may be arranged to correspond to each of the plurality of pixel electrodes 180. However, embodiments are not limited thereto. Interlayer layer 200 may be modified in various ways, such as including an interlayer layer 200 comprising an integral layer covering the plurality of pixel electrodes 180. In some embodiments, organic emitting layers may be uniformly arranged to correspond to each of the plurality of pixel electrodes 180, and functional layers other than organic emitting layers may be integrally formed covering the plurality of pixel electrodes 180.

[0062] Counter electrode 210 may be disposed on interlayer 200. Counter electrode 210 may be a transmissive electrode or a reflective electrode. In some embodiments, counter electrode 210 may be a transparent electrode or a translucent electrode, and counter electrode 210 may be formed of a metal thin film having a low work function and comprising Li, Ca, LiF, Al, Ag, Mg or compounds or mixtures thereof (e.g., alloys) or a material having a multilayer structure such as LiF / Ca or LiF / Al.

[0063] As an optional example, a transparent conductive oxide (TCO) film (such as ITO, IZO, ZnO, or In2O3) may be further disposed on the counter electrode 210. The counter electrode 210 may be disposed throughout the display area DA and the non-display area NDA, and the counter electrode 210 may be disposed on the interlayer layer 200 and the pixel defining film 191. The counter electrode 210 may be integrally formed in multiple organic light-emitting devices (OLEDs) to correspond to multiple pixel electrodes 180.

[0064] When the pixel electrode 180 is set as a reflective electrode and the counter electrode 210 is set as a transmissive electrode, light emitted from the interlayer layer 200 can be emitted toward the counter electrode 210, so that the display device 1 can be a top-emitting type.

[0065] In some embodiments, when the pixel electrode 180 is configured as a transparent electrode or a semi-transparent electrode, and the counter electrode 210 is configured as a reflective electrode, light emitted from the interlayer layer 200 can be emitted toward the substrate 100, making the display device 1 a bottom-emitting type. However, the embodiments are not limited to this, and the display device 1 of this embodiment can be a light-emitting type that can emit light in both the top and bottom directions.

[0066] According to an embodiment, the counter electrode 210 can be formed as a low-reflection layer. Since the counter electrode 210 can be disposed not only in the non-emissive region NAA but also in the emissive region AA, the light reflectivity in the emissive region AA can be reduced, thereby reducing the light reflectivity of the entire display device 1.

[0067] A thin-film encapsulation layer (not shown) may be formed on the counter electrode 210. The thin-film encapsulation layer may include at least one organic layer and at least one inorganic layer. In a top-emitting display device 1 according to one or more embodiments, the thin-film encapsulation layer may be on the OLED, and light emitted from the OLED may pass through the thin-film encapsulation layer to the outside.

[0068] A method for forming a hole injection layer of a light-emitting device according to one or more embodiments may include the steps of: forming a pixel electrode on a substrate; coating the pixel electrode with a composition to provide a pixel defining film on the pixel electrode; forming a patterned pixel defining film by photolithography, the patterned pixel defining film having an opening that can expose a portion (e.g., a central portion) of the pixel electrode; removing decum (or "sludge removal"); and forming a hole injection layer on the exposed and decumbed pixel electrode.

[0069] The step of forming a pixel-defining film on the pixel electrode can be performed using a common photolithography method known to those skilled in the art, therefore more detailed information about the photolithography step is omitted.

[0070] When forming the pixel defining film, residual films or residues of components of the composition used for the pixel defining film may form on the upper surface of the pixel electrode. Since the presence of residual films or residues on the pixel electrode can affect the luminous efficiency and lifetime of the light-emitting device, these residual films or residues can be removed by descaling. After forming the hole injection layer, a hole transport layer, an emission layer, an electron transport layer, and a counter electrode are formed to fabricate the light-emitting device.

[0071] The steps for removing residues may include plasma treatment, UV treatment, and / or O3 treatment.

[0072] In some embodiments, the residue removal step may include plasma treatment.

[0073] In some embodiments, the step of removing residue may include plasma treatment with a fluorine-containing gas.

[0074] In some embodiments, the residue removal step may include plasma treatment with CF4, NF3, SF6, C3F8, C4F8, or a combination thereof.

[0075] In some embodiments, the residue removal step may include: plasma treatment with O2, N2, or a combination thereof; and plasma treatment with CF4, NF3, SF6, C3F8, C4F8, or a combination thereof.

[0076] When an interlayer is formed using a solution process (e.g., inkjet printing), the surface of the film surrounding the emission region (e.g., a pixel-defining film) exhibits liquid repellency. After the pixel-defining film is formed, residues present on the upper surface of the pixel electrode can be removed by plasma treatment (e.g., by O2, N2, or a combination thereof). Plasma treatment can be performed non-selectively, or on both the pixel electrode and the pixel-defining film.

[0077] For example, plasma treatment can be performed using O2 plasma. O2 plasma refers to plasma primarily derived from oxygen, with other gases besides oxygen (e.g., N2) mixed together as plasma gas feedstock. For instance, O2 and N2 can be used as reactant and carrier gases, respectively. By adjusting variables such as gas flow ratio, power, pressure, and reaction time, the conditions for plasma treatment of the pixel-defining film can be optimized. Because pixel electrodes and pixel-defining films subjected to plasma treatment with O2, N2, or combinations thereof can both be water-soluble, liquid repellency can be imparted to the pixel-defining film by additional plasma treatment with a fluorine-containing gas.

[0078] Fluorine-containing gases may include, for example, CF4, NF3, SF6, C3F8, C4F8, or combinations thereof. For example, the residue removal step may include plasma treatment with a fluorine-containing gas, instead of plasma treatment with O2, N2, or combinations thereof. Furthermore, because plasma treatment with a fluorine-containing gas can be performed non-selectively, both the pixel electrode and the pixel-defining film treated with a fluorine-containing gas can be liquid-repellent.

[0079] The upper portion of the surface of a pixel-defining film with liquid repellency can have a contact angle of 55° or greater. For example, the contact angle of the upper portion of the surface of the pixel-defining film can be in the range of approximately 55° to approximately 110°.

[0080] In some embodiments, the step of forming a hole injection layer on the pixel electrode can be performed using a solution process (e.g., an inkjet process).

[0081] When forming a hole injection layer on a liquid-repellent pixel electrode using a solution process (e.g., inkjet printing), prior art hole injection layer ink compositions may exhibit problems due to insufficient wettability. To address this lack of wettability, hole injection layer ink compositions sprayed onto the pixel electrode via inkjet printing (e.g., in the form of a spray or aerosol) can have high viscosity. However, if the viscosity is too high when spraying the hole injection layer ink composition via inkjet printing, spraying problems may occur.

[0082] In some embodiments, in the method of forming a hole injection layer of a light-emitting device, the step of forming a hole injection layer on a pixel electrode can be performed by using a hole injection layer ink composition, wherein the hole injection layer ink composition may include a hole injection layer compound, a solvent and a polymer compound, and the polymer compound and the solvent may form a reversible network structure (or "mesh structure") through hydrogen bonds.

[0083] "Forming a reversible network structure" means that when an external shear force is applied to the composition, the viscosity of the composition can be relatively lower than when a smaller external shear force is applied or no external shear force is applied. "Forming a reversible network structure" refers to the situation where, at approximately 0.05 reciprocating seconds (s), the viscosity of the composition can be significantly lower than when a smaller external shear force is applied or no external shear force is applied. -1 (to approximately 0.15s) -1 At shear rates within the specified range, the viscosity of the composition can range from about 12 centipoise (cP) to about 1,000 cP, and in about 70 s... -1 up to 130s -1 At shear rates within a certain range, the viscosity can range from approximately 2.5 cP to approximately 13 cP. For example, "forming a reversible network structure" refers to a situation where the composition can exhibit a viscosity within 0.1 s⁻¹. -1 Viscosities in the range of approximately 12 cP to approximately 1,000 cP at shear rates, and at 100 s... -1 Viscosity in the range of approximately 2.5 cP to approximately 13 cP at shear rates.

[0084] Theoretically, the point where no external force is applied to the composition will correspond to 0s. -1 The shear rate, however, cannot be measured in principle at 0s. -1 The viscosity at which the viscosity is measured. Therefore, in this specification, 0.1s... -1 The viscosity is defined as the viscosity value when no external shear force is applied to the composition.

[0085] In addition, 100s -1 The shear rate can be defined as the shear rate in a solution process (e.g., inkjet process). In the case of inkjet, the application state in the solution process represents the inkjet ejection state. For example, the shear rate in the ejection state can be determined by the ejection pressure. It will be apparent to those skilled in the art that the shear rate in the application state in a solution process can vary depending on the process conditions. However, in this specification, 100s -1 The viscosity is defined as the value of the viscosity in the application state or spray state of the solution process.

[0086] In some embodiments, the hole injection layer ink composition may include a hole injection layer compound, a solvent, and an organic thickener as a polymer compound, and

[0087] The polymer compound may include at least one group represented by Formula 1:

[0088] Formula 1

[0089]

[0090] In Equation 1,

[0091] X can be a single bond or a divalent organic linker.

[0092] R1 can be either unsubstituted or substituted with at least one R. 10a C1-C 10 Alkylene

[0093] R2 can be selected from hydrogen, deuterium, hydroxyl, unsubstituted or substituted with at least one R. 10a C1-C 60 Alkyl, unsubstituted or substituted with at least one R 10a C2-C 60 Alkenyl, unsubstituted or substituted with at least one R 10a C2-C 60 Alkyne group, unsubstituted or substituted with at least one R 10a C1-C 60 Alkyl groups and unsubstituted or substituted groups with at least one R 10a C1-C 60 Alkyl ether group,

[0094] n1 can be an integer from 2 to 100.

[0095] * indicates a connection site with an adjacent atom of the polymer compound, and

[0096] Each R 10a It can be independently: deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, or nitro;

[0097] All are independently unsubstituted or substituted with deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, C3-C 60 Carbocyclic group, C1-C 60 Heterocyclic group, C6-C 60 Aryloxy group, C6-C 60 Arylthio, -Si(Q) 11 (Q) 12 (Q) 13 -N(Q) 11 (Q) 12 -B(Q)11 (Q) 12 -C(=O)(Q) 11 -S(=O)2(Q) 11 -P(=O)(Q) 11 (Q) 12 C1-C or combinations thereof 60 Alkyl, C2-C 60 alkenyl, C2-C 60 Alkyne group or C1-C 60 Alkoxy;

[0098] All are independently unsubstituted or substituted with deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, C1-C 60 Alkyl, C2-C 60 alkenyl, C2-C 60 Alkyne group, C1-C 60 Alkoxy, C3-C 60 Carbocyclic group, C1-C 60 Heterocyclic group, C6-C 60 Aryloxy group, C6-C 60 Arylthio, -Si(Q) 21 (Q) 22 (Q) 23 -N(Q) 21 (Q) 22 -B(Q) 21 (Q) 22 -C(=O)(Q) 21 -S(=O)2(Q) 21 -P(=O)(Q) 21 (Q) 22 C3-C or combinations thereof 60 Carbocyclic group, C1-C 60 Heterocyclic group, C6-C 60 Aryloxy or C6-C 60 aryl thiols; or

[0099] -Si(Q 31 (Q) 32 (Q) 33 -N(Q) 31 (Q) 32 -B(Q) 31 (Q) 32 -C(=O)(Q) 31 -S(=O)2(Q) 31 ) or -P(=O)(Q 31 (Q) 32 ),

[0100] Among them, Q11 To Q 13 Q 21 To Q 23 and Q 31 To Q 33 Each of these can be independently: hydrogen; deuterium; -F; -Cl; -Br; -I; hydroxyl; cyano; nitro; C1-C 60 Alkyl; C2-C 60 Alkenyl; C2-C 60 Alkyne group; C1-C 60 Alkyl groups; or all independently unsubstituted or substituted with deuterium, -F, cyano, C1-C. 60 Alkyl, C1-C 60 C3-C of alkoxy, phenyl, biphenyl, or any combination thereof 60 Carbocyclic or C1-C 60 Heterocyclic group.

[0101] In some embodiments, X can be a single key.

[0102] In the embodiments, when X is a divalent organic linker, X can be selected from: unsubstituted or substituted with at least one R. 10a C1-C 20 Alkylene; unsubstituted or substituted with at least one R 10a C1-C 20 Alkylene, wherein at least one methylene group (-CH2-) is represented by a sulfonyl group (-SO2-), a carbonyl group (-C(=O)-), an ether group (-O-), a thioether group (-S-), a sulfoxide group (-SO-), an ester group (-C(=O)O-), or an amide group (-C(=O)NR-) (wherein, R can be hydrogen or C1-C). 10 Alkyl groups or combinations thereof are substituted; the substituted or substituted groups have at least one R group. 10a C2-C 20 alkenyl; unsubstituted or substituted with at least one R 10a C3-C 10 Cycloalkylene; unsubstituted or substituted with at least one R 10a C1-C 10 Heterocyclic alkyl; unsubstituted or substituted with at least one R 10a C3-C 10 Cycloalkenyl; unsubstituted or substituted with at least one R 10a C1-C 10 Heterocyclic alkenyl; unsubstituted or substituted with at least one R 10a C6-C 60 Aromatic; unsubstituted or substituted with at least one R 10a C1-C 60 heteroaryl; unsubstituted or substituted with at least one R10a A divalent non-aromatic condensed polycyclic group; and an unsubstituted or substituted group having at least one R 10a The divalent non-aromatic condensed heterocyclic group.

[0103] In Equation 1, n1 can be the number of repeating units represented by -[O-R1]-, and at least two -[O-R1]- can be the same or different from each other.

[0104] For example, R2 can be a C1-C substituted with a hydroxyl group. 20 Alkyl or substituted C1-C 20 Alkyl ether group. For example, R2 can be a C1-C group with a hydroxyl group substituted at the end. 20 Alkyl groups or C1-C groups with hydroxyl groups substituted at the terminal. 20 Alkyl ether group.

[0105] Hole injection layer compounds refer to compounds that may be included in the hole transport region of the interlayer 200 described herein.

[0106] In some embodiments, the polymer compound includes at least one group represented by Formula 1 in at least one side chain or at at least one end of the polymer compound. In some embodiments, the polymer compound may include at least one group represented by Formula 1 at the end of the polymer compound.

[0107] In some embodiments, the polymer compound may include polyurethane units, polyamide units, polyurea units, or any combination thereof. For example, the polymer compound may include polyurethane-polyurea or polyamide-polyurea.

[0108] For example, the polymer compound can be an end-modified polyurethane, an end-modified polyamide, or an end-modified polyurea, all having an end structure represented by Formula 1.

[0109] In some embodiments, the polymer compound may be a urea-modified polyurethane or a urea-modified polyamide, both of which include groups represented by Formula 1 at their ends.

[0110] In some embodiments, in Formula 1, R2 can be a group represented by Formula 2:

[0111] Formula 2

[0112]

[0113] In Equation 2,

[0114] R 21 It can be either unsubstituted or substituted with at least one R 10a C1-C 10 Alkylene

[0115] m1 can be an integer from 1 to 10.

[0116] * indicates the connection bit with R1, and R in Equation 2 10a By referring to R in Equation 1 10a To understand this, we need to refer to the description.

[0117] In some embodiments, the polymer compound includes at least one group represented by Formula 3:

[0118] Formula 3

[0119]

[0120] In Equation 3,

[0121] X can be a single bond or a divalent organic linker.

[0122] R1 and R 21 Each can be independently unsubstituted or substituted with at least one R 10a C1-C 10 Alkylene

[0123] n1 can be an integer from 2 to 100, and m1 can be an integer from 1 to 10.

[0124] * indicates a connection site with an adjacent atom in the polymer compound, and R in Equation 3 10a By referring to R in Equation 1 10a To understand this, we need to refer to the description.

[0125] In the embodiments, the number-average molecular weight (Mn) of the polymer compound can be in the range of about 100 to about 100,000 g / mol, and the weight-average molecular weight (Mw) of the polymer compound can be in the range of about 1,500 to about 1,000,000 g / mol.

[0126] In the embodiments, the polymer compound and solvent can form a reversible network structure via hydrogen bonding. This "reversible network structure" can be understood by referring to the description of "reversible network structure" provided herein.

[0127] In the embodiments, the solvent may include functional groups capable of hydrogen bonding with the polymer compound.

[0128] Solvents may include functional groups capable of hydrogen bonding with polymer compounds, allowing the polymer compound and solvent to form a reversible network structure. For example, solvents may include hydroxyl, carbonyl, amino, carboxyl, alkoxy, ether, ester, or combinations thereof.

[0129] In embodiments, the solvent may include at least one selected from: alkylene glycol alkyl ethers, such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and propylene glycol methyl ethyl ether; diethylene glycol dialkyl ethers, such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, and diethylene glycol dibutyl ether; triethylene glycol monoalkyl ethers, such as triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, and triethylene glycol monobutyl ether; triethylene glycol dialkyl ethers, such as triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol dipropyl ether, and triethylene glycol dibutyl ether; aromatic... Ethers, such as ethylene glycol monophenyl ether and diethylene glycol monophenyl ether; alkylene glycol alkyl ether acetates, such as methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate and propylene glycol monopropyl ether acetate; alkoxyalkyl acetates, such as methoxybutyl acetate and methoxypentyl acetate; ketones, such as methyl ethyl ketone, acetone, methyl pentyl ketone, methyl isobutyl ketone and cyclohexanone; alcohols, such as ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol and glycerol; esters, such as ethyl 3-ethoxypropionate and methyl 3-methoxypropionate; and cyclic esters, such as γ-butyrolactone.

[0130] For example, the solvent can be diethylene glycol monophenyl ether.

[0131] Solvents can be used alone or in combination of at least two or more solvents.

[0132] When the hole-injection layer ink composition includes, for example, an end-modified polyamide having an end structure represented by Formula 1 as the polymer compound and an alkylene glycol alkyl ether solvent as the solvent, the polymer compounds can interact with each other through hydrogen bonds between the -NH groups and carbonyl groups in the side chains of the polymer compounds. Furthermore, since the polymer compound and solvent also form hydrogen bonds, the polymer compound and solvent molecules can form a three-dimensional reversible network structure in the hole-injection layer ink composition through hydrogen bonds with each other.

[0133] When no external force (e.g., no external shear force) is applied to the hole-injected ink composition, the three-dimensional network structure of the composition can be maintained. However, when an external force is applied to the composition, the hydrogen bonds between molecules may break, thus disrupting the three-dimensional network structure. Therefore, the hole-injected ink composition can exhibit thixotropic properties.

[0134] In the embodiments, the content of polymer compounds in the hole-injection layer ink composition may be in the range of about 0.05 wt% to about 1 wt%, or for example, in the range of about 0.1 wt% to about 0.5 wt%, based on the total weight of the hole-injection layer ink composition.

[0135] When the number-average molecular weight (Mn), weight-average molecular weight (Mw), and content of the polymer compound are within these ranges, the hole-injection layer ink composition can have high viscosity without the application of external force, and the hole-injection layer ink composition can have relatively low viscosity when external force is applied.

[0136] Examples of polymer compounds include RHEOBYK-100, RHEOBYK-405, RHEOBYK-410, RHEOBYK-411, RHEOBYK-415, RHEOBYK-420, RHEOBYK-425, RHEOBYK-428, RHEOBYK-430, RHEOBYK-431, RHEOBYK-440, RHEOBYK-7405, RHEOBYK-7410ET, RHEOBYK-7411ES, RHEOBYK-7420ES, RHEOBYK-7590, RHEOBYK-7594, RHEOBYK-7600, RHEOBYK-7610, RHEOBYK-D 410, RHEOBYK-D 420, and RHEOBYK-H, all available from BYK (Germany). RHEOBYK-H 400, RHEOBYK-H 600, RHEOBYK-H 3300VF, RHEOBYK-H 6500VF, RHEOBYK-H 7500VF, RHEOBYK-H 7625VF, RHEOBYK-HV 80, RHEOBYK-L100, RHEOBYK-L 1400VF, RHEOBYK-M 2600VF, RHEOBYK-R 605, RHEOBYK-R 606, RHEOBYK-R607, RHEOBYK-T 1000VF, RHEOBYK-T 1010VF, and RHEOBYK-TVS VF, but the embodiments are not limited to these.

[0137] Examples of polymer compounds include Rheovis-PU 1190, Rheovis-PU1191, Rheovis-PU 1291, Rheovis-PU 1214, Rheovis-PU 125, Rheovis-PU 1331, Rheovis-PU 1330, Rheovis-1331, Rheovis-HS 1162, Rheovis-HS 1152, Rheovis-HS 1169, Rheovis-HS 1212, Rheovis-HS 1332, Rheovis-AS 1130, and Rheovis-AS 1125, which are available from BASF (Germany), but the examples are not limited thereto.

[0138] Hole transport region in interlayer layer 200

[0139] The hole transport region included in the interlayer layer 200 may have: i) a single-layer structure consisting of a single layer made of a single material; ii) a single-layer structure consisting of a single layer comprising multiple different materials; or iii) a multilayer structure having multiple identical or different layers comprising multiple different materials. The hole transport region may include a hole injection layer (HIL), a hole transport layer (HTL), an emission assist layer, an electron blocking layer (EBL), or a combination thereof.

[0140] For example, the hole transport region can have a multilayer structure, such as a hole injection layer / hole transport layer structure, a hole injection layer / hole transport layer / emission auxiliary layer structure, a hole injection layer / emission auxiliary layer structure, a hole transport layer / emission auxiliary layer structure, or a hole injection layer / hole transport layer / electron blocking layer structure, wherein the layers of each structure are stacked sequentially in the order stated therein, such as... Figure 2 On the pixel electrode 180 shown.

[0141] The hole transport region may include the compound represented by Formula 201, the compound represented by Formula 202, or a combination thereof:

[0142] Formula 201

[0143]

[0144] Formula 202

[0145]

[0146] Among them, in equations 201 and 202,

[0147] L 201 To L 204 Each can be independently unsubstituted or substituted with at least one R 10a C3-C 60 The carbocyclic group is either unsubstituted or substituted with at least one R. 10a C1-C 60 Heterocyclic group,

[0148] L 205 It can be *-O-*', *-S-*', or *-N(Q) 201 )-*', unsubstituted or substituted with at least one R 10a C1-C 20 Alkylene, unsubstituted or substituted with at least one R 10a C2-C 20 alkenyl, unsubstituted or substituted with at least one R10a C3-C 60 The carbocyclic group is either unsubstituted or substituted with at least one R. 10a C1-C 60 Heterocyclic group,

[0149] xa1 to xa4 can each be an independent integer from 0 to 5.

[0150] xa5 can be an integer from 1 to 10.

[0151] R 201 To R 204 and Q 201 Each can be independently unsubstituted or substituted with at least one R 10a C3-C 60 The carbocyclic group is either unsubstituted or substituted with at least one R. 10a C1-C 60 Heterocyclic group,

[0152] R 201 and R 202 It can optionally be via a single bond, unsubstituted or substituted with at least one R 10a C1-C5 alkylene groups or unsubstituted or substituted groups having at least one R 10a The C2-C5 alkenyl groups combine with each other to form unsubstituted or substituted groups with at least one R group. 10a C8-C 60 Polycyclic groups (e.g., carbazolyl, etc.) (e.g., compound HT16 described herein),

[0153] R 203 and R 204 It can optionally be via a single bond, unsubstituted or substituted with at least one R 10a C1-C5 alkylene groups or unsubstituted or substituted groups having at least one R 10a The C2-C5 alkenyl groups combine with each other to form unsubstituted or substituted groups with at least one R group. 10a C8-C 60 Polycyclic groups, and

[0154] na1 can be an integer from 1 to 4.

[0155] In some embodiments, both Formula 201 and Formula 202 may include at least one of the groups represented by Formulas CY201 to CY217:

[0156]

[0157] In formulas CY201 to CY217, R 10b and R 10c All can be referenced through R10a To understand from the description, CY 201 To CY 204 Each can be independently C3-C 20 carbonyl group or C1-C 20 Heterocyclic group, and at least one hydrogen in formulas CY201 to CY217 may be unsubstituted or substituted with R. 10a .

[0158] In some embodiments, in formulas CY201 to CY217, the ring CY 201 To CY 204 Each group can be independently a phenyl group, a naphthol group, a phenanthrene group, or anthracene group.

[0159] In one or more embodiments, both Formula 201 and Formula 202 may include at least one of the groups represented by Formula CY201 to Formula CY203.

[0160] In one or more embodiments, Formula 201 may include at least one of the groups represented by Formulas CY201 to CY203 and at least one of the groups represented by Formulas CY204 to CY217.

[0161] In one or more embodiments, in Equation 201, xa1 can be 1, R 201 It can be any group represented by formula CY201 to CY203, xa2 can be 0, and R 202 It can be any group represented by formula CY204 to CY207.

[0162] In one or more embodiments, formulas 201 and 202 may not include groups represented by formulas CY201 to CY203.

[0163] In one or more embodiments, Formula 201 and Formula 202 may each exclude groups represented by Formulas CY201 to CY203, and may each include at least one of groups represented by Formulas CY204 to CY217.

[0164] In one or more embodiments, formulas 201 and 202 may both exclude groups represented by formulas CY204 to CY217.

[0165] In some embodiments, the hole transport region may include one or any combination of compounds HT1 to HT46, m-MTDATA, TDATA, 2-TNATA, NPB (NPD), β-NPB, TPD, spiro-TPD, spiro-NPB, methylated NPB, TAPC, HMTPD, 4,4',4"-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline / dodecylbenzenesulfonic acid (PANI / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (PANI / CSA), and polyaniline / poly(4-styrenesulfonate) (PANI / PSS):

[0166]

[0167]

[0168]

[0169]

[0170] The thickness of the hole transport region can be approximately 50 angstroms. up to approximately (for example, approximately) up to approximately Within the range of ), when the hole transport region includes a hole injection layer, a hole transport layer, and any combination thereof, the thickness of the hole injection layer can be approximately up to approximately (for example, approximately) up to approximately Within the range of ), the thickness of the hole transport layer can be approximately up to approximately (for example, approximately) up to approximately Within the range of ), excellent hole transport characteristics can be obtained without significantly increasing the driving voltage when the thickness of the hole transport region, hole injection layer, and hole transport layer are all within these ranges.

[0171] The emission assist layer can improve luminous efficiency by compensating for the optical resonant distance according to the wavelength of the light emitted by the emission layer. The electron blocking layer can reduce or eliminate the flow of electrons from the electron transport region. The emission assist layer and the electron blocking layer can include the materials described above.

[0172] dispersant

[0173] The hole injection layer ink composition may also include a dispersant to improve the dispersion of the hole injection layer compound. The dispersant may be a resin-type dispersant such as a phosphate ester dispersant, a urethane dispersant, or an acrylic dispersant. Specifically, commercially available dispersants may include DISPER BYK-103, DISPER BYK-110, DISPER BYK-111, DISPER BYK-2000, DISPER BYK-2001, DISPER BYK-2011, DISPER BYK-2070, DISPER BYK-2150, DISPER BYK-160, DISPER BYK-161, DISPER BYK-162, DISPER BYK-163, DISPER BYK-164, and DISPER BYK-166, all available from BYK-Chemie GmbH.

[0174] Based on 100 parts by weight of the hole injection layer ink composition, the content of the dispersant can be in the range of about 10 parts by weight to about 50 parts by weight, or for example, about 15 parts by weight to about 30 parts by weight.

[0175] In addition, the hole injection layer ink composition may also include an adhesion promoter for enhancing adhesion to the substrate, a leveling agent for improving coating performance, an antioxidant, an ultraviolet absorber, or a combination thereof.

[0176] Adhesion promoters can be added to enhance adhesion to the substrate. Examples of adhesion promoters may include silane coupling agents having reactive substituents selected from carboxyl, methacryloyl, isocyanate, epoxy, and combinations thereof, but the examples are not limited thereto. For example, the silane coupling agent may be trimethoxysilylbenzoate, γ-methacryloyloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatepropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, or any combination thereof.

[0177] Examples of leveling agents include silicone compounds, fluorinated compounds, siloxane compounds, nonionic surfactants, ionic surfactants, and titanate coupling agents, but the embodiments are not limited thereto. For example, the leveling agent may be a silicone compound and / or a fluorinated compound.

[0178] Examples of silicon-based compounds include dimethylsilane, methylsilane, phenylsilane, methylphenylsilane, alkyl-modified silicon, alkoxy-modified silicon, and polyether-modified silicon, but the embodiments are not limited thereto. For example, the silicon-based compound may be dimethylsilane or methylphenylsilane.

[0179] Examples of fluorinated compounds include polytetrafluoroethylene, polyvinylidene fluoride, fluoroalkyl methacrylates, perfluoropolyethers, and perfluoroalkylethylene oxide, but the examples are not limited thereto. For example, a fluorinated compound may be polytetrafluoroethylene.

[0180] Examples of siloxane compounds include dimethylsiloxane compounds (available from Shinetsu Silicone with product numbers KF96L-1, KF96L-5, KF96L-10 or KF96L-100), but the examples are not limited thereto.

[0181] Leveling agents can be used alone or in combination of two or more types.

[0182] The leveling agent content can vary depending on the desired performance, and based on the total weight of the hole-injection layer ink composition, the content can range from about 0.001 wt% to about 5 wt%, or for example, from about 0.001 wt% to about 1 wt%. When the leveling agent content is within this range, the flowability and uniformity of the film in the hole-injection layer ink composition can be improved.

[0183] Because hole injection layer ink compositions can have excellent inkjet stability, for example, hole injection layer ink compositions can be ink compositions for inkjet printing, but the embodiments are not limited thereto.

[0184] Solution Process

[0185] Hole-injected ink compositions can be used to manufacture light-emitting devices through solution processing.

[0186] A hole-injection layer ink composition can be provided on a substrate including an emission region in which a first electrode and a second electrode can be disposed, via a solution process.

[0187] Solution coating can be performed by spin coating, slot coating, drop casting, casting, gravure coating, bar coating, roller coating, dip coating, spraying, screen coating, flexographic printing, offset printing, inkjet printing, or nozzle printing, but the examples are not limited to these.

[0188] For example, solution processes can be performed by spin coating, slot coating, or inkjet printing, but the embodiments are not limited to these.

[0189] For example, the hole-injection layer ink composition can be provided in the form of a film on a substrate on which a first electrode and a second electrode may be disposed by spin coating, or the hole-injection layer ink composition can be provided in the form of microdroplets by inkjet printing.

[0190] Because hole-injection layer ink compositions exhibit excellent inkjet stability, they are suitable for inkjet printing.

[0191] Inkjet printing can be done using an inkjet printer with an inkjet head equipped with a piezoelectric nozzle that applies pressure based on voltage.

[0192] In some embodiments, the hole-injection layer ink composition can be ejected from the nozzle of the inkjet head onto the substrate. The ejection volume of the hole-injection layer ink composition can range from about 1 picoliter per ejection (pL / ejection) to about 50 pL / ejection (e.g., about 1 pL / ejection to about 30 pL / ejection, or, for example, 1 pL / ejection to 20 pL / ejection).

[0193] The orifice size of the inkjet head can be from about 5 micrometers (μm) to about 50 μm (e.g., from about 10 μm to about 30 μm) to reduce nozzle clogging and improve jetting accuracy, but the embodiments are not limited thereto.

[0194] Based on the shear rate, the ejection pressure of the inkjet head can be 1,000 s. -1 Up to 10,000s -1 However, the embodiments are not limited to this.

[0195] There is no particular limitation on the temperature during the formation of the coating film, but from the perspective of suppressing the crystallization of the materials contained in the hole injection layer ink composition, the temperature can be in the range of about 10°C to about 50°C, about 15°C to about 40°C, about 15°C to about 30°C, or, for example, about 20°C to about 25°C.

[0196] General definition of terminology

[0197] As used herein, the term "C3-C" 60 "Carbocyclic group" refers to a cyclic group consisting only of carbon atoms and having 3 to 60 carbon atoms. For example, the term "C1-C" as used herein... 60 A "heterocyclic group" refers to a cyclic group having 1 to 60 carbon atoms in addition to the ring heteroatoms other than carbon atoms. (C3-C) 60 Carbocyclic groups and C1-C 60 Heterocyclic groups can be monocyclic groups consisting entirely of one ring or polycyclic groups in which at least two rings are condensed. For example, C1-C 60 The number of cyclic atoms in a heterocyclic group can range from 3 to 61.

[0198] As used herein, the term "cycloid" can include C3-C 60 Carbocyclic groups and C1-C 60 Heterocyclic group.

[0199] The term "π-electron-rich C3-C" 60"Cyclic group" refers to a cyclic group having 3 to 60 carbon atoms and excluding *-N=*' as the cyclic moiety. For example, the term "π-electron-poor nitrogen-containing C1-C" is used herein. 60 "Cyclic group" refers to a heterocyclic group having 1 to 60 carbon atoms and *-N=*' as the cyclic part.

[0200] In some embodiments, C3-C 60 The carbocyclic group can be: i) a T1 group; or ii) a group formed by the condensation of at least two T1 groups (e.g., cyclopentadienyl group, adamantyl group, norbornel group, phenyl group, cyclopentadienyl group, naphthyl group, chamomile ring group, indane group, acenaphthene group, phenatene group, anthracene group, fluoranthene group, benzo[9,10]phenanthrene group, pyrene group, Groups, perylene groups, pentanene groups, heptadiene groups, tetraphenyl groups, fentanyl groups, hexaphenyl groups, pentaphenyl groups, rutin groups, fentanyl groups, ovoid groups, indole groups, fluorene groups, spiro-difluorene groups, benzo[a]fluorene groups, indole[a]phenanthrene groups, or indole[a]anthracene groups),

[0201] C1-C 60 The heterocyclic group can be: i) a T2 group; ii) a group in which at least two T2 groups are condensed; or iii) a group in which at least one T2 group is condensed with at least one T1 group (e.g., pyrrole group, thiophene group, furan group, indole group, benzoindole group, naphthoindole group, isoindole group, benzoisoindole group, naphthoisoindole group, benzothiophene group, benzofuran group, carbazole group, dibenzothiophene group, dibenzothiophene group, dibenzofuran group, indolecarbazole group, indolecarbazole group, benzofuran-carbazole group, benzothiophenecarbazole group, benzothiophenecarbazole group, benzoindolecarbazole group, benzocarbazole group, benzonaphthiophene group, benzonaphthiophene group, benzofuran-dibenzofuran group, benzofuran-dibenzothiophene group, benzene Benzethion, dibenzothiophene group, pyrazole group, imidazole group, triazole group, oxazole group, isoxazole group, oxadiazole group, thiazole group, isothiazole group, thiaazole group, thiadiazole group, benzopyrazole group, benzimidazole group, benzoxazole group, benziisoxazole group, benzothiazole group, benziisothiazole group, pyridine group, pyrimidine group, pyrazine group, pyridazine group, triazine group, quinoline group, isoquinoline group, benzoquinoline Groups, including benzo[i]isoquinoline group, quinoxaloline group, benzo[i]quinoxaloline group, quinazoline group, benzo[i]quinazoline group, phenanthrene group, cyclophosphine group, phthalazine group, naphthidine group, imidazo[i]pyridine group, imidazo[i]pyrimidine group, imidazo[i]triazine group, imidazo[i]pyrazine group, imidazo[i]pyridazine group, azacarbazole group, azafluorene group, azadibenzothiophene group, azadibenzo[i]thiophene group, azadibenzofuran group, etc.

[0202] C3-C rich in π electrons 60 The cycloid can be: i) a T1 group; ii) a condensation group in which at least two T1 groups are condensed; iii) a T3 group; iv) a condensation group in which at least two T3 groups are condensed; or v) a condensation group in which at least one T3 group is condensed with at least one T1 group (e.g., C3-C). 60 Carbocyclic groups, pyrrole groups, thiophene groups, furan groups, indole groups, benzoindole groups, naphthoindole groups, isoindole groups, benzoisoindole groups, naphthoisoindole groups, benzothiophene groups, benzofuran groups, carbazole groups, dibenzothiophene groups, dibenzofuran groups, indole-carbazole groups, indole-carbazole groups, benzofuran-carbazole groups, benzothiophene-carbazole groups, benzothiophene-carbazole groups, benzoindole-carbazole groups, benzocarbazole groups, benzonaphthofuran groups, benzonaphthophene groups, benzonaphthothiophene groups, benzofuran-dibenzofuran groups, benzofuran-dibenzothiophene groups, benzothiophene-dibenzothiophene groups, etc.), and

[0203] Nitrogen-containing C1-C cells with depleted π electrons 60 The cycloid can be: i) a T4 group; ii) a group in which at least two T4 groups are condensed; iii) a group in which at least one T4 group is condensed with at least one T1 group; iv) a group in which at least one T4 group is condensed with at least one T3 group; or v) a group in which at least one T4 group, at least one T1 group, and at least one T3 group are condensed (e.g., pyrazole group, imidazole group, triazole group, oxazole group, isoxazole group, oxadiazole group, thiazole group, isothiazole group, thiazolid group, benzopyrazole group, benzimazole group, benzoxazole group, benzisopyrazole group, benzisopyrazole group, benzimazole group, benzoxazole group, benzisopyrazole group). Oxazole group, benzothiazole group, benzoisothiazole group, pyridine group, pyrimidine group, pyrazine group, pyridazine group, triazine group, quinoline group, isoquinoline group, benzoquinoline group, benzoisoquinoline group, quinoxaline group, benzoquinoxaline group, quinazoline group, benzoquinazoline group, phenanthrene group, cinnamyl group, phthalazine group, naphthidine group, imidazopyridine group, imidazopyrimidine group, imidazotriazine group, imidazopyrazine group, imidazopyridazine group, azacarbazole group, azafluorene group, azadibenzothiophene group, azadibenzothiophene group, azadibenzofuran, etc.

[0204] Wherein, the T1 group can be a cyclopropane group, a cyclobutane group, a cyclopentane group, a cyclohexane group, a cycloheptane group, a cyclooctane group, a cyclobutene group, a cyclopentene group, a cyclopentadiene group, a cyclohexene group, a cyclohexadiene group, a cycloheptene group, adamantane group, norbornane (or bicyclo[2.2.1]heptane) group, a norbornene group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, a bicyclo[2.2.2]octane group, or a phenyl group.

[0205] The T2 group can be a furan group, thiophene group, 1H-pyrrole group, thiorrole group, borocyclopentadienyl group, 2H-pyrrole group, 3H-pyrrole group, imidazole group, pyrazole group, triazole group, tetraazole group, oxazole group, isoxazole group, oxadiazole group, thiazole group, isothiazole group, thiadiazole group, azathirrole group, azaboracyclopentadienyl group, pyridine group, pyrimidine group, pyrazine group, pyridazine group, triazine group, or tetraazine group.

[0206] The T3 group can be a furan group, a thiophene group, a 1H-pyrrole group, a thiophene group, or a borocyclopentadiene group, and

[0207] The T4 group can be a 2H-pyrrole group, a 3H-pyrrole group, an imidazole group, a pyrazole group, a triazole group, a tetraazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, an azathiazole group, an azaboranecyclopentadiene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, or a tetraazine group.

[0208] As used herein, the terms "cyclogroup" and "C3-C" are similar. 60 "Carbocyclic group", "C1-C" 60 Heterocyclic groups, π-electron-rich C3-C 60 "Cyclonal group" or "π-electron-poor nitrogen-containing C1-C" 60 "Cycloyl group" can be a group formed by the condensation of the structure of a formula according to the applied term with any suitable cycloyl group, monovalent group, or polyvalent group (e.g., divalent group, trivalent group, tetravalent group, etc.). For example, "phenyl group" can be a benzo[a] group, phenyl, phenylene, etc., as understood by those skilled in the art based on the structure of a formula including "phenyl group".

[0209] Unit price C3-C 60 Carbocyclic groups and monovalent C1-C 60 Examples of heterocyclic groups can include C3-C 10 cycloalkyl, C1-C 10 Heterocyclic alkyl, C3-C 10 Cycloalkenyl, C1-C 10 Heterocyclic alkenyl, C6-C 60Aryl, C1-C 60 Heteroaryl, monovalent non-aromatic condensed polycyclic, and monovalent non-aromatic condensed heterocyclic. Divalent C3-C 60 Carbocyclic groups and divalent C1-C 60 Examples of heterocyclic groups can include C3-C 10 Cycloalkylene, C1-C 10 Heterocyclic alkyl, C3-C 10 Cycloalkylene, C1-C 10 Heterocyclic alkenyl, C6-C 60 aryl, C1-C 60 Hybrid aryl, divalent non-aromatic condensed polycyclic and divalent non-aromatic condensed heterocyclic.

[0210] As used herein, the term "C1-C" 60 "Alkyl" refers to a straight-chain or branched monovalent group of an aliphatic saturated hydrocarbon having 1 to 60 carbon atoms, and examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, tert-pentyl, neopentyl, isopentyl, sec-pentyl, 3-pentyl, sec-isopentyl, n-hexyl, isohexyl, sec-hexyl, tert-hexyl, n-heptyl, isoheptyl, sec-heptyl, tert-heptyl, n-octyl, isooctyl, sec-octyl, tert-octyl, n-nonyl, isononyl, sec-nonyl, tert-nonyl, n-decyl, isodel, sec-decyl, and tert-decyl. The term "C1-C" as used herein... 60 "alkylene" refers to C1-C 60 Alkyl groups have the same structure as divalent groups.

[0211] As used herein, the term "C2-C" 60 "Alkenyl" refers to the group formed at C2-C. 60 A monovalent hydrocarbon group having at least one carbon-carbon double bond at the middle or end of an alkyl group. Examples include vinyl, propenyl, and butenyl groups. As used herein, the term "C2-C" is used in conjunction with this. 60 "Alkenyl" refers to C2-C 60 Alkenes have divalent groups with the same structure.

[0212] As used herein, the term "C2-C" 60 "Alkyne group" refers to the group at C2-C 60 An alkyl group having at least one carbon-carbon triple bond at its middle or end. Examples include ethynyl and propynyl groups. As used herein, the term "C2-C" is used in conjunction with this terminology. 60 "Immyneyl" refers to C2-C 60 The alkynyl group is a divalent group with the same structure.

[0213] As used herein, the term "C1-C" 60 "Alkoxy" refers to the compound formed by -OA 101 (where A) 101It is C1-C 60 Alkyl groups are monovalent groups. Examples include methoxy, ethoxy, and isopropoxy.

[0214] As used herein, the term "C3-C" 10 "Cycloalkyl" refers to a monocyclic cycloalkanes of monovalent saturated hydrocarbons comprising 3 to 10 carbon atoms. For example, C3-C... 10 Examples of cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, adamantyl, norbornene (bicyclo[2.2.1]heptyl), bicyclo[1.1.1]pentyl, bicyclo[2.1.1]hexyl, or bicyclo[2.2.2]octyl. As used herein, the term "C3-C" is used in conjunction with these other terms. 10 "Cycloalkylene" refers to C3-C 10 Cycloalkyl groups have divalent groups with the same structure.

[0215] As used herein, the term "C1-C" 10 "Heterocyclic alkyl" refers to a monovalent cyclic group having 1 to 10 carbon atoms, comprising at least one heteroatom other than a carbon atom as a cyclic atom. Examples include 1,2,3,4-oxatriazolyl, tetrahydrofuranyl, and tetrahydrothiophenyl. As used herein, the term "C1-C..." 10 "Heterocyclic alkyl" refers to C1-C 10 Heterocyclic alkyl groups have divalent groups with the same structure.

[0216] As used herein, the term "C3-C" 10 "Cycloalkenyl" refers to a monovalent cycloalkenyl group having 3 to 10 carbon atoms and at least one carbon-carbon double bond in its ring and being non-aromatic. Examples include cyclopentenyl, cyclohexenyl, and cycloheptenyl. As used herein, the term "C3-C" is also relevant. 10 "Biopylene" refers to C3-C 10 Cycloalkenyl groups are divalent groups with the same structure.

[0217] As used herein, the term "C1-C" 10 "Heterocyclic alkenyl" refers to a monovalent cyclic group that includes at least one heteroatom other than a carbon atom as a cyclic atom, 1 to 10 carbon atoms, and at least one double bond in its ring. C1-C 10 Examples of heterocyclic alkenyl groups include 4,5-dihydro-1,2,3,4-oxarizolyl, 2,3-dihydrofuranyl, and 2,3-dihydrothiophenyl. As used herein, the term "C1-C..." 10 "Heterocyclic alkenyl" refers to C1-C 10 Heterocyclic alkenyl groups are divalent groups with the same structure.

[0218] As used here, the term "C6-C" 60"Aryl" refers to a monovalent group having a carbocyclic aromatic system with 6 to 60 carbon atoms. For example, the term "C6-C" as used herein... 60 "Aryl" refers to a divalent group that has a carbocyclic aromatic system with 6 to 60 carbon atoms. (C6-C) 60 Examples of aryl groups include phenyl, cyclopentadienyl, naphthyl, chamomilecycloyl, indarabinyl, acenaphthel, phenanthyl, anthracene, fluoranthyl, benzo[9,10]phenanthyl, pyrene, alkyl, peryl, pentylenyl, hepta-alkenyl, tetraphenyl, framylinyl, hexaphenyl, pentaphenyl, rubidyl, benzoyl, and ovoxyl. When C6-C 60 Aryl and C6-C 60 When each aryl group independently comprises two or more rings, the corresponding rings can fused together.

[0219] As used herein, the term "C1-C" 60 "Heteroaryl" refers to a monovalent group having a heterocyclic aromatic system, which includes at least one heteroatom as a cyclizing atom in addition to a carbon atom, and 1 to 60 carbon atoms. As used herein, the term "C1-C" is also relevant. 60 "Hypo-heteroaryl" refers to a divalent group possessing a heterocyclic aromatic system. This system includes, in addition to carbon atoms, at least one heteroatom as a cyclic atom and 1 to 60 carbon atoms. (C1-C) 60 Examples of heteroaryl groups include pyridinyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, quinolinyl, benzo[a]quinolinyl, isoquinolinyl, benzo[a]isoquinolinyl, quinoxalinyl, benzo[a]quinoxalinyl, quinazolinyl, benzo[a]quinazolinyl, cyclolinyl, phenanthrolinel, phthalazinyl, and naphthidyl. When C1-C 60 heteroaryl and C1-C 60 When each heteroaryl group independently comprises two or more rings, the corresponding rings can fused together.

[0220] As used herein, the term "monovalent nonaromatic condensation polycyclic group" refers to a monovalent group having two or more condensation rings and with only carbon atoms (e.g., 8 to 60 carbon atoms) as cyclic atoms, wherein the molecular structure is nonaromatic when considered as a whole. Examples of monovalent nonaromatic condensation polycyclic groups include indenyl, fluorenyl, spiro-difluorenyl, benzo[a]fluorenyl, indeno[a]phenanthryl, and indeno[a]anthrayl. As used herein, the term "divalent nonaromatic condensation polycyclic group" refers to a divalent group having substantially the same structure as a monovalent nonaromatic condensation polycyclic group.

[0221] As used herein, the term "monovalent non-aromatic condensed heterocyclic group" refers to a monovalent group having two or more condensed rings and at least one heteroatom other than carbon atoms (e.g., 1 to 60 carbon atoms) as a cyclic atom, wherein the molecular structure is non-aromatic when considered as a whole. Examples of monovalent non-aromatic condensed heterocyclic groups include pyrrole, thiophene, furanyl, indole, benzoindole, naphthoindole, isoindole, benzoisoindole, naphthoisoindole, benzothiophene, benzofuranyl, carbazole, dibenzothiophene, dibenzofuranyl, azacarbazole, azafluorenyl, azadibenzothiophene, azadibenzofuranyl, pyrazolyl, imidazolyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, isothiazolyl, oxadiazolyl, thiazolyl. Benzopyrazolyl, benzoimidazolyl, benzooxazolyl, benzothiazolyl, benzooxadiazolyl, benzothiadiazolyl, imidazopyridyl, imidazopyrimidinyl, imidazotriazinyl, imidazopyrazinyl, imidazopyridazinyl, indolecarbazolyl, indolocarbazolyl, benzofuranocarbazolyl, benzothiophenocarbazolyl, benzothiophenocarbazolyl, benzoindolocarbazolyl, benzocarbazolyl, benzonaphthiophenyl, benzonaphthiophenyl, benzofuranodibenzofuranyl, benzofuranodibenzothiophenyl, and benzothiophenodibenzothiophenyl. As used herein, the term "divalent nonaromatic condensation heteropolycyclic group" refers to a divalent group having substantially the same structure as a monovalent nonaromatic condensation heteropolycyclic group.

[0222] As used here, the term "C6-C" 60 "Aryloxy group" indicates the group consisting of -OA 102 (where A) 102 For C6-C 60 Aryl) indicates. As used herein, the term "C6-C" is used in conjunction with other compounds. 60 "Arylthio" indicates that it is composed of -SA 103 (where A) 103 For C6-C 60 (Aromatic) indicates.

[0223] As used herein, the term "R" 10a "Can be:

[0224] Deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano or nitro;

[0225] All are independently unsubstituted or substituted with deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, C3-C 60 Carbocyclic group, C1-C 60 Heterocyclic group, C6-C 60 Aryloxy group, C6-C 60 Arylthioyl, -Si(Q) 11(Q) 12 (Q) 13 -N(Q) 11 (Q) 12 -B(Q) 11 (Q) 12 -C(=O)(Q) 11 -S(=O)2(Q) 11 -P(=O)(Q) 11 (Q) 12 C1-C or combinations thereof 60 Alkyl, C2-C 60 alkenyl, C2-C 60 Alkyne group or C1-C 60 Alkoxy;

[0226] All are independently unsubstituted or substituted with deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, C1-C 60 Alkyl, C2-C 60 alkenyl, C2-C 60 alkynyl group, C1-C 60 Alkoxy, C3-C 60 Carbocyclic group, C1-C 60 Heterocyclic group, C6-C 60 Aryloxy group, C6-C 60 Arylthioyl, -Si(Q) 21 (Q) 22 (Q) 23 -N(Q) 21 (Q) 22 -B(Q) 21 (Q) 22 -C(=O)(Q) 21 -S(=O)2(Q) 21 -P(=O)(Q) 21 (Q) 22 C3-C or combinations thereof 60 Carbocyclic group, C1-C 60 Heterocyclic group, C6-C 60 aryloxy or C6-C 60 aryl thiols; or

[0227] -Si(Q 31 (Q) 32 (Q) 33 -N(Q) 31 (Q) 32 -B(Q) 31 (Q) 32 -C(=O)(Q) 31 -S(=O)2(Q) 31) or -P(=O)(Q 31 (Q) 32 ),

[0228] Among them, Q 11 To Q 13 Q 21 To Q 23 and Q 31 To Q 33 Each of these can be independently: hydrogen; deuterium; -F; -Cl; -Br; -I; hydroxyl; cyano; nitro; C1-C 60 Alkyl; C2-C 60 Alkenyl; C2-C 60 Alkyne group; C1-C 60 Alkyl groups; or all independently unsubstituted or substituted with deuterium, -F, cyano, C1-C. 60 Alkyl, C1-C 60 C3-C of alkoxy, phenyl, biphenyl, or combinations thereof 60 carbonyl group or C1-C 60 Heterocyclic group.

[0229] As used herein, the term "heteroatom" refers to any atom other than a carbon atom. Examples of heteroatoms may include O, S, N, P, Si, B, Ge, Se, or any combination thereof.

[0230] The term "Ph" as used herein represents phenyl, "Me" as used herein represents methyl, "Et" as used herein represents ethyl, and "tert-Bu" or "Bu" as used herein represent ethyl. t "" indicates tert-butyl, and "OMe" used here indicates methoxy.

[0231] As used herein, the term "biphenyl" refers to a phenyl group that has at least one substituted phenyl group. "Biphenyl" belongs to the group with a C6-C... 60 "Aryl" is "substituted phenyl" as a substituent.

[0232] As used herein, the term "terphenyl" refers to a phenyl group substituted with at least one biphenyl group. "Terphenyl" belongs to the class of phenyl groups having "substituted C6-C..." 60 C6-C of aryl 60 "Aryl" is "substituted phenyl" as a substituent.

[0233] Unless otherwise defined, the symbols * and *' used herein refer to the connection point with the adjacent atom in the corresponding expression (e.g., the adjacent atom in a polymer compound).

[0234] Example

[0235] Preparation of Hole Injection Layer Graphite Composition

[0236] Example 1

[0237] A first mixture solution was prepared by mixing the hole injection layer compound 2-TNATA (0.1 wt%), DISPER BYK-161 (0.01 wt%) as a dispersant, and diethylene glycol monophenyl ether (99.89 wt%) as a solvent. The dispersant was added to the mixture as a solution of 1.0 wt% DISPER BYK-161 in the solvent. The first mixture solution was then sonicated in a bath for 20 minutes to provide a first dispersion liquid.

[0238] RHEOBYK-430 (available from BYK) as a polymer compound (in a 1.0 wt% solution in solvent) was added to a first dispersion, such that the concentration of RHEOBYK-430 in the second mixture solution was 0.2 wt%. The second mixture solution was sonicated in a bath for 20 minutes, and then vigorously stirred at 70°C for 120 minutes. Thereafter, the temperature was lowered to room temperature and vigorously stirred for an additional 30 minutes to provide a cavity-injection layer ink composition.

[0239] Comparison Example 1

[0240] Except for the use of polystyrene (0.2 wt%) as a polymer compound in the preparation of the hole-injection layer ink composition, the hole-injection layer ink composition was prepared in essentially the same manner as in Example 1.

[0241] Manufacturing of organic light-emitting devices

[0242] Example 2

[0243] ITO / Ag / ITO The glass substrate (anode) was cut to a size of 50 mm × 50 mm × 0.7 mm, ultrasonically cleaned with isopropanol (5 minutes), then ultrasonically cleaned with pure water (5 minutes), and irradiated with UV light for 30 minutes. The glass substrate was then exposed to ozone and loaded into a vacuum deposition apparatus.

[0244] Pixel-defining films are formed on a glass substrate using photolithography, which exposes the electrodes.

[0245] The glass substrate was treated with O2 plasma (O2:N2 = 5:95 100W) for 50 seconds to remove residues on the electrodes, and then treated with CF4 plasma for 60 seconds.

[0246] By using an inkjet process, a hole-injection layer ink composition of Example 1 is used to form a layer with a thickness of [thickness value missing] on the exposed electrode. The hole injection layer was then formed. Subsequently, hole transport material 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (hereinafter referred to as "NPB") was vacuum deposited onto the hole injection layer using an inkjet process. The thickness is sufficient to form a hole transport layer.

[0247] 9,10-bis(naphthyl-2-yl)anthracene (hereinafter referred to as "ADN"), serving as the blue fluorescent host, and 4,4'-bis[2-(4-(N,N-diphenylamino)phenyl)vinyl]biphenyl (hereinafter referred to as "DPAVBi"), serving as the blue fluorescent dopant, were vacuum-deposited on the hole transport layer using an inkjet process at a weight ratio of approximately 98:2 to form a layer with… The thickness of the emission layer.

[0248] Alq3 was vacuum deposited onto the emitter layer to form a structure with... An electron transport layer of a certain thickness is formed. Then, alkali halide metal LiF is vacuum-deposited onto the electron transport layer to form an electron transport layer with... An electron-injected layer of a certain thickness was then formed. Finally, Al was vacuum-deposited onto the electron-injected layer to form a layer with [missing information]. A cathode of a certain thickness is formed to create a LiF / Al electrode to provide an organic light-emitting device.

[0249] After plasma treatment, methyl benzoate was dropped onto the pixel-defining film, and the contact angle was measured. A contact angle greater than 55° was found, thus confirming liquid repulsion.

[0250] Comparison Example 2

[0251] The organic light-emitting device is fabricated in essentially the same manner as in Example 2, except that no plasma processing is performed after the pixel-defining film is formed.

[0252] Compare Example 3

[0253] The organic light-emitting device was fabricated in a manner substantially the same as that in Example 2, except that the hole injection layer ink composition of Comparative Example 1 was used in forming the hole injection layer.

[0254] Viscosity measurement

[0255] For the hole-injected layer ink compositions prepared in Example 1 and Comparative Example 1, the rotational viscosity at 0.1 s⁻¹ was measured using rotational viscosity measurement methods known to those skilled in the art. -1 Up to 1,000s -1 Viscosity at the shear rate. A rotational viscometer, DV-IPrime Brookfield rheometer, was used as the measuring device, and the average values ​​after five repeated measurements are listed in Table 1.

[0256] Table 1

[0257]

[0258] According to the results in Table 1, the viscosity of the hole-injected ink layer composition in Example 1 varies significantly with shear rate. Specifically, the hole-injected ink layer composition of Example 1 exhibits lower viscosity at higher shear rates. Due to the lower viscosity, the hole-injected ink layer composition of Example 1 is deposited with less difficulty in the inkjet process. Furthermore, the hole-injected ink layer composition of Example 1 exhibits high viscosity at low shear rates. Therefore, in the absence of external shear forces, the hole-injected ink layer composition ejected in the inkjet process can maintain high viscosity on the electrode, thus resulting in improved wettability of the hole-injected ink layer composition.

[0259] The luminous efficacy of the organic light-emitting devices of Example 2, Comparative Example 2, and Comparative Example 3 was measured at 700 nits using a PR650 luminance meter. The results are shown in Table 2.

[0260] Table 2

[0261]

[0262] Referring to the results in Table 2, compared with the organic light-emitting devices of Comparative Example 2 and Comparative Example 3, it was found that the organic light-emitting device of Example 2 has improved characteristics.

[0263] Specifically, when the organic light-emitting device of Comparative Example 2 is manufactured without removing residues (e.g., using a plasma process), the performance of the organic light-emitting device is degraded due to residues on the electrodes.

[0264] Specifically, since the hole injection layer ink composition ejected by inkjet has low viscosity on the electrode without external force, the organic light-emitting device of Comparative Example 3 exhibits poor device performance due to poor wettability.

[0265] Based on the foregoing description, it is evident that, compared to existing light-emitting devices that include a hole injection layer, light-emitting devices comprising a hole injection layer prepared according to the method for forming a light-emitting device exhibit superior luminous efficiency and lifetime.

[0266] It should be understood that the embodiments described herein are to be considered in a descriptive sense only and not for limiting purposes. The description of features or aspects within each embodiment should generally be considered applicable to other similar features or aspects in other embodiments. Although one or more embodiments have been described with reference to the accompanying drawings, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope as defined by the claims.

Claims

1. A method for forming a hole injection layer in a light-emitting device, the method comprising the following steps: Pixel electrodes are formed on the substrate; The pixel electrode is coated with the composition to provide a pixel-defining film on the pixel electrode; A patterned pixel-defining film is formed by photolithography, the patterned pixel-defining film having an opening that exposes a portion of the pixel electrode; Remove residue; as well as A hole injection layer ink composition is deposited on the exposed and residue-free pixel electrode to form the hole injection layer. The hole injection layer ink composition includes a hole injection layer compound, a solvent, and a polymer compound. The polymer compound includes polyurethane units, polyamide units, polyurea units, or any combination thereof, and The polymer compound and the solvent form a reversible network structure through hydrogen bonds.

2. The method according to claim 1, wherein, The step of removing residue includes plasma treatment with fluorine-containing gas.

3. The method according to claim 2, wherein, The fluorine-containing gas includes CF4, NF3, SF6, C3F8, C4F8, or combinations thereof.

4. A hole injection layer ink composition, said hole injection layer ink composition comprising a hole injection layer compound, a solvent, and a polymer compound comprising groups represented by Formula 1: Formula 1 in, In Equation 1, X is a single bond or a divalent organic linker. R1 is either unsubstituted or substituted with at least one R. 10a C1-C 10 Alkylene R2 is hydrogen, deuterium, hydroxyl, unsubstituted, or substituted with at least one R. 10a C1-C 60 Alkyl, unsubstituted or substituted with at least one R 10a C2-C 60 Alkenyl, unsubstituted or substituted with at least one R 10a C2-C 60 Alkyne group, unsubstituted or substituted with at least one R 10a C1-C 60 Alkyl groups, either unsubstituted or substituted with at least one R group. 10a C1-C 60 Alkyl ether group, n1 is an integer from 2 to 100. This indicates the connection site with the adjacent atoms of the polymer compound, and Each R 10a Independently: deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, or nitro; All are independently unsubstituted or substituted with deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, C3-C 60 carbonyl group, C1-C 60 Heterocyclic group, C6-C 60 Aryloxy group, C6-C 60 Arylthioyl, -Si(Q) 11 (Q) 12 (Q) 13 -N(Q) 11 (Q) 12 -B(Q) 11 (Q) 12 -C(=O)(Q) 11 -S(=O)2(Q) 11 -P(=O)(Q) 11 (Q) 12 C1-C or combinations thereof 60 Alkyl, C2-C 60 alkenyl, C2-C 60 alkynyl or C1-C 60 Alkoxy; All are independently unsubstituted or substituted with deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, C1-C 60 Alkyl, C2-C 60 alkenyl, C2-C 60 alkynyl group, C1-C 60 Alkoxy, C3-C 60 carbonyl group, C1-C 60 Heterocyclic group, C6-C 60 Aryloxy group, C6-C 60 Arylthioyl, -Si(Q) 21 (Q) 22 (Q) 23 -N(Q) 21 (Q) 22 -B(Q) 21 (Q) 22 -C(=O)(Q) 21 -S(=O)2(Q) 21 -P(=O)(Q) 21 (Q) 22 C3-C or combinations thereof 60 carbonyl group, C1-C 60 Heterocyclic group, C6-C 60 aryloxy or C6-C 60 aryl thiols; or -Si(Q 31 )(Q 32 )(Q 33 ), -N(Q 31 )(Q 32 ), -B(Q 31 )(Q 32 ), -C(=O)(Q 31 ), -S(=O)2(Q 31 ) or -P(=O)(Q 31 )(Q 32 ), Among them, Q 11 To Q 13 Q 21 To Q 23 and Q 31 To Q 33 Each of these groups is independently: hydrogen; deuterium; -F; -Cl; -Br; -I; hydroxyl; cyano; nitro; C1-C 60 Alkyl; C2-C 60 Alkenyl; C2-C 60 Alkyne group; C1-C 60 Alkyl groups; or all independently unsubstituted or substituted with deuterium, -F, cyano, C1-C. 60 Alkyl, C1-C 60 C3-C of alkoxy, phenyl, biphenyl, or combinations thereof 60 Carbocyclic or C1-C 60 Heterocyclic group, The polymer compound includes polyurethane units, polyamide units, polyurea units, or any combination thereof, and The polymer compound and the solvent form a reversible network structure through hydrogen bonding.

5. The hole-injection layer ink composition according to claim 4, wherein, In Equation 1, R2 is a group represented by Equation 2: Formula 2 In Equation 2, R 21 For being unsubstituted or substituted, there is at least one R 10a C1-C 10 Alkylene m1 is an integer from 1 to 10. This indicates the connection bit with R1, and R in Equation 2 10a R is defined as Equation 1 10a .

6. The hole-injection layer ink composition according to claim 4, wherein, The polymer compound includes at least one group represented by Formula 3: Formula 3 In Equation 3, X is a single bond or a divalent organic linker. R1 and R 21 Each is independently unsubstituted or substituted with at least one R 10a C1-C 10 Alkylene n1 is an integer from 2 to 100. m1 is an integer from 1 to 10. This indicates the connection site with the adjacent atoms of the polymer compound, and R in Equation 3 10a R is defined as Equation 1 10a .

7. The hole-injection layer ink composition according to claim 4, wherein, The number-average molecular weight of the polymer compound is in the range of 100 g / mol to 100,000 g / mol, and the weight-average molecular weight of the polymer compound is in the range of 1,500 g / mol to 1,000,000 g / mol.

8. The hole-injection layer ink composition according to claim 4, wherein, The content of the polymer compound in the hole injection layer ink composition is in the range of 0.05 wt% to 1 wt%.

9. The hole-injection layer ink composition according to claim 4, wherein, The solvent includes alkylene glycol alkyl ethers, diethylene glycol dialkyl ethers, triethylene glycol monoalkyl ethers, triethylene glycol dialkyl ethers, aromatic ethers, alkylene glycol alkyl ether acetates, alkoxyalkyl acetates, ketones, alcohols, cyclic esters, or combinations thereof.

10. The hole-injection layer ink composition according to claim 4, wherein the hole-injection layer ink composition is in the range of 0.05 s -1 up to 0.15s -1 It exhibits a viscosity ranging from 12 centipoise to 1,000 centipoise at shear rates within a certain range, and at 70 s... -1 up to 130s -1 It has a viscosity ranging from 2.5 centipoise to 13 centipoise at shear rates within the specified range.

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