Organic light-emitting diode and method for manufacturing the organic light-emitting diode

Abstract

An organic light-emitting diode (OLED) and a method of manufacturing the OLED are provided. The OLED includes: a first electrode and a second electrode facing each other; an organic emitting layer between the first electrode and the second electrode; and a hole injection layer between the first electrode and the organic emitting layer, wherein the hole injection layer includes a second metal compound layer and a second metal layer, the second metal compound layer being between the first electrode and the organic emitting layer, and the second metal layer being between the second metal compound layer and the organic emitting layer.

Description

[0001] This application claims priority and benefit to Korean Patent Application No. 10-2020-0105531, filed on August 21, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0002] One or more embodiments relate to an organic light-emitting diode (OLED) and a method of manufacturing the OLED, and more specifically, to an OLED with improved luminous efficiency and a method of manufacturing the OLED. Background Technology

[0003] Among display devices, organic light-emitting diode (OLED) displays have the advantages of wide viewing angle, excellent contrast ratio and fast response speed, and are therefore attracting attention as the next generation of display devices.

[0004] Organic light-emitting displays (OLEDs) are self-emissive and do not require a separate light source, thus allowing them to be driven with low voltage. Furthermore, OLEDs can be constructed with lightweight and thin profiles and possess high-quality characteristics such as wide viewing angles, high contrast, and fast response times, making them a promising next-generation display technology.

[0005] Organic light-emitting display devices include organic light-emitting diodes (OLEDs), which include hole injection electrodes, electron injection electrodes, and an organic emitting layer between them. Organic light-emitting display devices are self-emissive display devices that emit light when excitons descend from an excited state to a ground state. Excitons are generated when holes injected from the hole injection electrode and electrons injected from the electron injection electrode recombine in the organic emitting layer. Summary of the Invention

[0006] One or more aspects of embodiments of this disclosure relate to organic light-emitting diodes (OLEDs) with improved luminous efficiency and advantages in terms of process, as well as methods of manufacturing organic light-emitting diodes. However, such aspects are exemplary, and this disclosure is not limited thereto.

[0007] Other aspects will be set forth in part in the description which follows, and in part will be apparent from the description, or may be learned by practice of the disclosed embodiments.

[0008] According to one or more embodiments, an organic light-emitting diode includes: a first electrode and a second electrode facing each other; an organic emitting layer between the first electrode and the second electrode; and a hole injection layer between the first electrode and the organic emitting layer, wherein the hole injection layer includes a second metal compound layer and a second metal layer, the second metal compound layer being between the first electrode and the organic emitting layer, and the second metal layer being between the second metal compound layer and the organic emitting layer.

[0009] The second metal compound layer may include (for example, is) a dipolar material, which includes (for example, is) a first metal and a halogen element, wherein the first metal is the same as the metal of the first electrode.

[0010] The hole injection layer may also include a residual layer of the first metal compound layer, which is located between the second metal layer and the organic emission layer.

[0011] The first metal compound layer may include (e.g., is) a certain material, which includes (e.g., is) a second metal and a halogen element of the second metal layer (e.g., the second metal and the halogen element of the second metal layer may be combined with each other).

[0012] The second metal compound layer may include (for example, is) a dipolar material, which includes (for example, is) a first metal and a halogen element, wherein the first metal is the same as the metal of the first electrode.

[0013] According to one or more embodiments, a method of manufacturing an organic light-emitting diode includes the following steps: forming a first electrode on a substrate, the first electrode including (e.g., a first metal); forming a first metal layer on the first electrode, the first metal layer including (e.g., a first metal); forming a hole injection layer by forming a first metal compound layer on the first metal layer, the hole injection layer including a second metal compound layer and a second metal layer, the second metal layer being on the second metal compound layer; forming the second metal compound layer by oxidizing the first metal compound layer via the first metal compound layer; and forming the second metal layer by reducing the first metal compound layer via the first metal layer; forming an organic emission layer on the hole injection layer; and forming a second electrode on the organic emission layer.

[0014] The second metal compound layer may include (e.g., is) a dipolar material, which includes (e.g., is) a first metal of the first metal layer and a halogen element of the first metal compound layer (e.g., the first metal of the first metal layer and the halogen element of the first metal compound layer may be bonded to each other).

[0015] According to one or more embodiments, a method of manufacturing an organic light-emitting diode includes: forming a first electrode on a substrate, the first electrode including (e.g., a first metal); forming a first metal layer on the first electrode, the first metal layer including (e.g., a first metal); forming a hole injection layer by forming a first metal compound layer on the first metal layer, the hole injection layer including a second metal compound layer, a second metal layer and a residual layer of the first metal compound layer, the second metal layer being on the second metal compound layer; forming the second metal compound layer by oxidizing the first metal compound layer via the first metal compound layer; and forming the second metal layer by reducing the first metal compound layer via the first metal layer; forming an organic emission layer on the hole injection layer; and forming a second electrode on the organic emission layer.

[0016] The first metal compound of the first metal compound layer may include (for example, is) a certain material, said certain material including (for example, is) a second metal and a halogen element of the second metal layer.

[0017] The second metal compound layer may include (for example, is) a dipolar material, which includes (for example, is) a first metal of the first metal layer and a halogen element of the first metal compound (the first metal and the halogen element are bonded to each other).

[0018] These and / or other aspects will become apparent and more readily understood from the following description of some embodiments, the accompanying drawings, and the claims.

[0019] These general specific aspects can be achieved by utilizing systems, methods, computer programs, or a combination of specific systems, methods, and computer programs. Attached Figure Description

[0020] The above and other aspects and features of the disclosed embodiments will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0021] Figure 1 This is a perspective view of a portion of a display device according to an embodiment;

[0022] Figure 2 yes Figure 1 A cross-sectional view of a portion of the display device;

[0023] Figure 3 This is a view of the stacked structure of organic light-emitting diodes according to an embodiment;

[0024] Figure 4 This is a view of a stacked structure of organic light-emitting diodes according to another embodiment;

[0025] Figure 5 This is a view of a stacked structure of organic light-emitting diodes according to another embodiment;

[0026] Figure 6 yes Figure 5 Energy diagram of each layer of an organic light-emitting diode;

[0027] Figure 7 This is a flowchart illustrating a portion of a method for manufacturing an organic light-emitting diode according to an embodiment;

[0028] Figure 8 This is a view showing the redox reaction before and after according to an embodiment;

[0029] Figure 9 This is a view showing the redox reaction before and after according to another embodiment; and

[0030] Figure 10A and Figure 10B This is an atomic force microscope (AFM) image of the surface of the first electrode according to an embodiment. Detailed Implementation

[0031] Referring now to embodiments in more detail, examples of which are shown in the accompanying drawings, in which the same reference numerals throughout denote the same elements. In this regard, the embodiments may take different suitable forms and should not be construed as limited to the description set forth herein. Therefore, the embodiments are described below only by reference to the accompanying drawings to explain aspects of this specification. 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 or variations thereof. As used herein, the use of the term “may” when describing embodiments of the present disclosure indicates “one or more embodiments of the present disclosure.” As used herein, the terms “substantially,” “about,” and “approximately,” and similar terms, are used as approximate terms rather than terms of degree and are intended to account for inherent deviations in measurements or calculations that will be recognized by one of ordinary skill in the art.

[0032] Because this description allows for various suitable variations and numerous embodiments, some embodiments will be shown in the accompanying drawings and described in the written description. The disclosed aspects and features, as well as methods of implementing them, will become clear from the following more detailed description of the embodiments with reference to the accompanying drawings. However, the disclosure is not limited to the following embodiments and can be implemented in various suitable forms.

[0033] In the following description, embodiments will be described with reference to the accompanying drawings, wherein the same reference numerals always denote the same elements and may not be described repeatedly.

[0034] While terms such as "first" and "second" can be used to describe various components, these components are not limited to the terms mentioned above. The terms above are used to distinguish one component from another.

[0035] Unless the context clearly indicates otherwise, the singular forms “a (kind)” and “the” as used herein are also intended to include the plural forms.

[0036] It will be understood that the terms “comprising,” “including,” and variations thereof, as used herein, indicate the presence of the stated features and / or components, but do not preclude the presence or addition of one or more other features and / or components.

[0037] It will also be understood that when a layer, region, or component is referred to as being "on" another layer, region, or component, that layer, region, or component may be directly or indirectly on the other layer, region, or component. For example, one or more intermediate layers, regions, and / or components may exist.

[0038] For ease of interpretation, the dimensions of elements in the accompanying drawings may be exaggerated or reduced. For example, the dimensions and thickness of elements in the accompanying drawings may be exaggerated for ease of interpretation, but the disclosure is not limited thereto.

[0039] When embodiments can be implemented differently, a particular process sequence may be performed in a manner different from that described. For example, two consecutively described processes may be performed substantially simultaneously or in a sequence reversed from that described (e.g., two processes described as being performed consecutively).

[0040] In this specification, "A and / or B" means A or B, or A and B. In this specification, "at least one (species / being) selected from A and B" means A or B, or A and B.

[0041] It will also be understood that when layers, regions, and / or components are referred to as being connected to each other, they may be directly connected to each other, or they may be indirectly connected to each other with one or more intermediate layers, regions, and / or components between them. For example, when layers, regions, and / or components are referred to as being electrically coupled (e.g., connected) to each other, they may be directly electrically coupled (e.g., connected) to each other, or they may be indirectly electrically coupled (e.g., connected) to each other with one or more intermediate layers, regions, and / or components between them.

[0042] The x-axis, y-axis, and z-axis are not limited to the three axes of a Cartesian coordinate system and can be interpreted in a broader sense. For example, the x-axis, y-axis, and z-axis can be perpendicular to each other, or they can represent different directions that are not perpendicular to each other.

[0043] In the following description, embodiments are described in more detail with reference to the accompanying drawings.

[0044] Figure 1 This is a plan view of a portion of a display device according to an embodiment.

[0045] The display device according to embodiments may include means for displaying moving images and / or still images, and can be used as a display screen for a variety of suitable products (including televisions, laptop computers, monitors, billboards, Internet of Things (IoT) devices) and portable electronic devices (including mobile phones, smartphones, tablet PCs, mobile communication terminals, electronic managers (electronic notebooks), e-books, portable multimedia players (PMPs), navigation devices, and ultra-mobile personal computers (UMPCs)). Additionally, the display device according to embodiments can be used in wearable devices (including smartwatches, watch phones, glasses-type displays (e.g., displays integrated into or with glasses), and head-mounted displays (HMDs)). However, this disclosure is not limited thereto.

[0046] Despite Figure 1 The diagram illustrates a flat panel display device having a flat shape; however, the display device can be, for example, a flexible display device, and therefore easily bendable (e.g., flexible), foldable, and / or rollable. As examples, the display device may include a foldable display device that can be folded and / or unfolded, a curved display device whose display surface is bent (e.g., bent), a flexible display device whose area other than the display surface can be bent (e.g., bent), a rollable display device that can be rolled and / or unfolded, and a stretchable display device.

[0047] like Figure 1 As shown, the display device according to an embodiment includes a light-emitting display area DA and a non-light-emitting peripheral area PA. The peripheral area PA may partially or completely surround the display area DA. The substrate may include a first area and a second area, the first area corresponding to the display area DA and the second area corresponding to the peripheral area PA. Pixel circuitry and display elements may be arranged in the first area of ​​the substrate, with the display elements electrically coupled (e.g., connected) to the pixel circuitry. Additionally, the peripheral area PA may include a pad (or "soldering pad") area on at least one side therein.

[0048] Figure 1 A display device is shown in a plan view, including a display area DA with a rectangular shape. For example... Figure 1As shown, the display area DA can have a rectangular planar shape, which has a short side in a first direction and a long side in a second direction. The corner where the short side in the first direction and the long side in the second direction intersect can have a rounded corner or a right angle with a set or preset curvature. The planar shape of the display area DA is not limited to the above example, and can be other suitable polygonal shapes, elliptical shapes, or amorphous shapes.

[0049] In an embodiment, the display device may include components disposed on one side of the display panel. The components may include electronic elements that utilize light and / or sound. The electronic elements may include sensors such as infrared sensors that emit and / or receive light, cameras that receive light to capture images, sensors that output and sense light and / or sound to measure distance or identify objects (e.g., fingerprints), small lamps that output light, and / or speakers that output sound.

[0050] Figure 2 yes Figure 1 A cross-sectional view of a portion of the display device.

[0051] The substrate 100 may include (e.g., is) glass, metal, and / or polymeric resin. Where the substrate 100 is suitably flexible and / or bendable, it may include (e.g., is) polymeric resins such as polyethersulfone, polyacrylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyarylate, polyimide, polycarbonate, and / or cellulose acetate propionate. The substrate 100 may have a multilayer structure comprising two layers and a barrier layer, each of the two layers comprising a polymeric resin, the barrier layer disposed between the two layers and comprising (e.g., is) an inorganic material (such as silicon oxide, silicon nitride, and / or silicon oxynitride). However, various suitable modifications may be made.

[0052] A buffer layer 101 may be disposed on the substrate 100. The buffer layer 101 may include (e.g., be) an inorganic material such as silicon oxide, silicon nitride, and / or silicon oxynitride, and may have a single-layer or multi-layer structure. Additionally, the buffer layer 101 may extend to the display area DA and non-display areas (e.g., the peripheral area PA). The buffer layer 101 may increase the flatness of the top surface of the substrate 100 and / or prevent or reduce the penetration of impurities and / or moisture from the outside of the substrate 100 into the active layer.

[0053] Pixel circuitry can be arranged on buffer layer 101 within the display area DA. In an embodiment, the pixel circuitry of each pixel arranged in the display area DA may include multiple thin-film transistors and a storage capacitor Cst. The number of thin-film transistors per pixel is not limited. For example, two to seven thin-film transistors may be provided. However, various suitable modifications can be made. Additionally, each pixel may also include a capacitor.

[0054] Each thin-film transistor may include a semiconductor layer, a gate electrode, a source electrode, and a drain electrode. In an embodiment, such as... Figure 2 As shown, the first thin-film transistor T1 may include a first semiconductor layer A1, a first gate electrode G1, a first source electrode S1, and a first drain electrode D1. The second thin-film transistor T2 may include a second semiconductor layer A2, a second gate electrode G2, a second source electrode S2, and a second drain electrode D2. In this case, the first thin-film transistor T1 may be combined (e.g., connected) to the organic light-emitting diode 200 to serve as a driving thin-film transistor for driving the organic light-emitting diode 200. The second thin-film transistor T2 may be combined (e.g., connected) to a data line to serve as a switching thin-film transistor. Here, a more detailed construction of the display device according to an embodiment is described. These can also be applied to at least one of the plurality of thin-film transistors in the display device (e.g., the first thin-film transistor T1 and the second thin-film transistor T2).

[0055] A semiconductor layer may be disposed on buffer layer 101 and may comprise (e.g.,) amorphous silicon and / or polycrystalline silicon. In embodiments, the semiconductor layer may comprise (e.g.,) an oxide selected from at least one of indium (In), gallium (Ga), tin (Sn), zirconium (Zr), vanadium (V), hafnium (Hf), cadmium (Cd), germanium (Ge), chromium (Cr), titanium (Ti), aluminum (Al), cesium (Cs), and zinc (Zn). Additionally, the semiconductor layer may comprise (e.g.,) one or more Zn oxide-based materials. For example, the semiconductor layer may comprise (e.g.,) Zn oxide, In-Zn oxide, and / or Ga-In-Zn oxide. In some embodiments, the semiconductor layer may comprise (e.g.,) In-Ga-Zn-O (IGZO), In-Sn-Zn-O (ITZO), and / or In-Ga-Sn-Zn-O (IGTZO) semiconductors comprising metals such as indium (In), gallium (Ga), and tin (Sn) in ZnO. The semiconductor layer may include impurity-doped source and drain regions on two opposite sides of the channel region. For example, at least one of the source, drain, and channel regions of the semiconductor layer may be doped with impurities.

[0056] A gate electrode is disposed on a semiconductor layer to be superimposed on at least a portion of the semiconductor layer. For example, the gate electrode may be superimposed on a channel region of the semiconductor layer. The gate electrode may include, for example, various suitable conductive materials comprising, for example, aluminum (Al), copper (Cu), and / or titanium (Ti), and may have various suitable layered structures. As an example, the gate electrode may include a molybdenum (Mo) layer and / or an Al layer, or the gate electrode may have a Mo / Al / Mo multilayer structure. In some embodiments, the gate electrode may have a multilayer structure including, for example, an indium tin oxide (ITO) layer covering a metallic material.

[0057] The source and drain electrodes may include (e.g., are) various suitable conductive materials comprising (e.g., are) molybdenum (Mo), aluminum (Al), copper (Cu), and / or titanium (Ti), and may have various suitable layered structures. As an example, the source and / or drain electrodes may include Ti layers and / or Al layers, or may have a Ti / Al / Ti multilayer structure. The source and drain electrodes may be coupled (e.g., connected) to the source and drain regions of the semiconductor layer respectively through contact holes (e.g., through corresponding contact holes). In some embodiments, the source and / or drain electrodes may have a multilayer structure including an ITO layer covering a metallic material.

[0058] To ensure insulation between the semiconductor layer and the gate electrode, a first inorganic insulating layer 103 may be disposed between the semiconductor layer and the gate electrode. For example, the first inorganic insulating layer 103 may be disposed on the substrate 100, below the gate electrode, and may cover the semiconductor layer. The first inorganic insulating layer 103 may include an insulating layer comprising (e.g., is) an inorganic material (such as silicon oxide, silicon nitride, and / or silicon oxynitride).

[0059] The second inorganic insulating layer 105 may be disposed on the first inorganic insulating layer 103 and may cover the gate electrode. The second inorganic insulating layer 105 may include an insulating layer containing (e.g., is) inorganic materials (such as silicon oxide, silicon nitride, and / or silicon oxynitride).

[0060] The storage capacitor Cst may include a bottom electrode CE1 and a top electrode CE2.

[0061] The bottom electrode CE1 can be coupled (e.g., connected) to the first gate electrode G1 of the first thin-film transistor T1. In some embodiments, the first gate electrode G1, or a portion thereof, can be the bottom electrode CE1. The top electrode CE2 can be coupled (e.g., connected) to the drive voltage line. In this case, the bottom electrode CE1 and the first gate electrode G1 can be integrated. For example, the first gate electrode G1 can serve not only as the control electrode of the first thin-film transistor T1, but also as the bottom electrode CE1 of the storage capacitor Cst. The storage capacitor Cst can maintain the voltage applied to the first gate electrode G1 by storing and holding a voltage corresponding to the voltage difference between the drive voltage line and the first gate electrode G1.

[0062] The top electrode CE2 is stacked with the bottom electrode CE1, and a second inorganic insulating layer 105 is disposed between them. In this case, the second inorganic insulating layer 105 can serve as the dielectric layer of the storage capacitor Cst. The top electrode CE2 may include (e.g., is) a conductive material comprising (e.g., is) molybdenum (Mo), aluminum (Al), copper (Cu), and / or titanium (Ti), and may include (e.g., is) a single-layer structure or a multilayer structure comprising the above materials. As an example, the top electrode CE2 may include a single layer of Mo or a multilayer of Mo / Al / Mo. In some embodiments, the source electrode and the drain electrode may have a multilayer structure including an ITO layer covering a metallic material.

[0063] A third inorganic insulating layer 107 may be disposed on the second inorganic insulating layer 105 and may cover the top electrode CE2 of the storage capacitor Cst. For example, the top electrode CE2 may be disposed between the second inorganic insulating layer 105 and the third inorganic insulating layer 107. Additionally, the source electrode and drain electrode may be disposed on the third inorganic insulating layer 107. The third inorganic insulating layer 107 may include an insulating layer comprising (e.g., is) an inorganic material (such as silicon oxide, silicon nitride, and / or silicon oxynitride).

[0064] The protective layer may be disposed on the third inorganic insulating layer 107 and may cover the source electrode and the drain electrode. The protective layer may include an insulating layer containing (e.g., is) inorganic materials such as silicon oxide, silicon nitride and / or silicon oxynitride.

[0065] In some embodiments, the inorganic insulating layer (e.g., the first inorganic insulating layer 103, the second inorganic insulating layer 105, and the third inorganic insulating layer 107) and the protective layer comprising (e.g., is) the corresponding inorganic material can be formed by chemical vapor deposition (CVD) and / or atomic layer deposition (ALD), but this disclosure is not limited thereto.

[0066] Organic insulating layer 109 may be disposed on the source electrode and the drain electrode. Organic insulating layer 109 may be disposed on the substrate 100, extending over the display area DA and extending over the peripheral area PA outside the display area DA (e.g., surrounding the display area DA). Organic insulating layer 109 may have a flat top surface, such that the first electrode 210 is formed flat. Organic insulating layer 109 may include a single layer or multiple layers comprising (e.g., is) an organic material. Organic insulating layer 109 may include (e.g., is) a general polymer (such as benzocyclobutene (BCB), polyimide, hexamethyldisiloxane (HMDSO), polymethyl methacrylate (PMMA) and / or polystyrene (PS)), polymer derivatives having phenolic groups, acryloyl polymers, imide polymers, aryl ether polymers, amide polymers, fluorinated polymers, p-xylene polymers, vinyl alcohol polymers, or blends thereof.

[0067] In the display area DA of the substrate 100, an organic light-emitting diode 200 is disposed on an organic insulating layer 109. The organic light-emitting diode 200 may include a first electrode 210, a second electrode 240, and an intermediate layer 230 therebetween, the intermediate layer 230 including an emissive layer EML.

[0068] In an embodiment, the first electrode 210 may be a pixel electrode. In this case, the first electrode 210 is electrically coupled (e.g., connected) to a thin-film transistor by contacting one of the source electrode and the drain electrode through a contact hole formed in an organic insulating layer 109, etc. The first electrode 210 may be a (semi-)transparent electrode or a reflective electrode. In an embodiment, the first electrode 210 may include a reflective layer and a transparent electrode layer or a semi-transparent electrode layer on the reflective layer, the reflective layer including (e.g., is) at least one selected from silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), and compounds or mixtures thereof. The transparent electrode layer or the semi-transparent electrode layer may include (e.g., is) at least one selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In2O3), indium gallium oxide (IGO), and zinc aluminum oxide (AZO). Additionally, the first electrode 210 may have a stacked structure of an ITO layer and a metal layer between the ITO layers. As an example, the first electrode 210 may have an ITO / Ag / ITO stacked structure.

[0069] The pixel defining layer 110 may be disposed on the organic insulating layer 109, extending over the display area DA and the peripheral area PA. The pixel defining layer 110 may define a pixel (or emission area) by including an opening corresponding to each pixel. In this case, the opening is formed to expose at least a portion of the central portion of the first electrode 210. For example, the pixel defining layer 110 may cover a portion of the first electrode 210 (e.g., the edge) and may expose another portion of the first electrode 210 (e.g., the central portion).

[0070] Additionally, the pixel defining layer 110 can prevent or suppress arcing at the edge of the first electrode 210 by increasing the distance between the edge of the first electrode 210 and the second electrode 240 above the first electrode 210. The pixel defining layer 110 may include (for example, is) one or more organic insulating materials selected from the group consisting of polyamides, polyimides, acrylic resins, BCBs, and phenolic resins, and can be formed by methods such as spin coating. However, this disclosure is not limited thereto.

[0071] The intermediate layer 230 of the organic light-emitting diode 200 may include an emission layer EML (see...) Figure 3 The emission layer EML may include (e.g., is) an organic material containing (e.g., is) a fluorescent material and / or a phosphorescent material to emit red, green, blue, or white light. The emission layer EML may be an organic emission layer comprising (e.g., is) a low molecular weight organic material and / or a polymeric organic material. As an example, the emission layer EML is an organic emission layer and may include (e.g., is) copper phthalocyanine (CuPc), aluminum tri-8-hydroxyquinoline (Alq3) materials, and / or polyfluorene materials. Although the organic emission layer can be formed by vacuum deposition, screen printing, inkjet printing, and / or laser-induced thermal imaging (LITI), this disclosure is not limited thereto.

[0072] Functional layers may be optionally further arranged below and on the emitter layer EML, and the functional layers include a hole injection layer (HIL) 220, a hole transport layer (HTL), an electron transport layer (ETL), and / or an electron injection layer (EIL). For example, the intermediate layer 230 may include an organic emitter layer and / or at least one functional layer, and may have a stacked structure with a single or composite structure.

[0073] Although the intermediate layer 230 can be formed by screen printing, inkjet printing, deposition and / or laser-induced thermal imaging (LITI), this disclosure is not limited thereto.

[0074] like Figure 2As shown, although the intermediate layer 230 may include layers patterned to correspond to the respective pixels, this disclosure is not limited thereto. In some embodiments, the intermediate layer 230 may include a layer that is uniformly distributed across a plurality of pixels. However, various suitable modifications may be made.

[0075] The second electrode 240 is arranged to extend across the display area DA. In an embodiment, the second electrode 240 may be a counter electrode. In an embodiment, the second electrode 240 may include a layer formed integrally to cover the entire surface of the display area DA, and may be arranged to extend across the display area DA. For example, the second electrode 240 may be formed integrally across multiple pixels to correspond to a plurality of first electrodes 210 respectively. In this case, the second electrode 240 may cover the display area DA and may extend (e.g., to or into) a portion of a peripheral area PA outside the display area DA (e.g., surrounding the display area DA). In an embodiment, the second electrode 240 may be patterned to correspond to a plurality of first electrodes 210 respectively.

[0076] The second electrode 240 may be a transparent electrode or a reflective electrode. In embodiments, the second electrode 240 may be a transparent electrode or a semi-transparent electrode, and may include a metal thin film having a small work function and comprising (e.g., is) at least one material selected from Li, Ca, LiF, Al, Ag, Mg, their compounds or mixtures, and having a multilayer structure such as LiF / Ca or LiF / Al. In addition to the metal thin film, a transparent conductive oxide (TCO) film, such as ITO, IZO, ZnO, or In2O3, may also be included.

[0077] Because the organic light-emitting diode 200 may be easily damaged by external moisture and / or oxygen, the encapsulation layer 300 can cover and protect the organic light-emitting diode 200. The encapsulation layer 300 can cover the display area DA and can extend beyond the display area DA. Figure 2 As shown, the encapsulation layer 300 may include a first inorganic encapsulation layer 310, an organic encapsulation layer 320, and a second inorganic encapsulation layer 330.

[0078] The first inorganic encapsulation layer 310 may cover the second electrode 240 and may include (e.g., silicon oxide, silicon nitride, and / or silicon oxynitride). Other layers, such as a capping layer, may be disposed between the first inorganic encapsulation layer 310 and the second electrode 240. Because the first inorganic encapsulation layer 310 is formed along the underlying structure, the top surface of the first inorganic encapsulation layer 310 is not flat.

[0079] The organic encapsulation layer 320 may cover the first inorganic encapsulation layer 310. Unlike the first inorganic encapsulation layer 310, the top surface of the organic encapsulation layer 320 may be approximately or substantially flat. In an embodiment, the portion of the top surface of the organic encapsulation layer 320 corresponding to the display area DA may be approximately flat. The organic encapsulation layer 320 may include (for example, is) at least one selected from polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, and hexamethyldisiloxane.

[0080] The second inorganic encapsulation layer 330 may cover the organic encapsulation layer 320 and may include (e.g., silicon oxide, silicon nitride, and / or silicon oxynitride). The second inorganic encapsulation layer 330 may prevent or reduce the exposure of the organic encapsulation layer 320 to the outside by contacting the first inorganic encapsulation layer 310 at its edge outside the display area DA. For example, the first and second inorganic encapsulation layers 310 and 330 may extend beyond the organic encapsulation layer 320 in a plan view and may contact each other to encapsulate the organic encapsulation layer 320.

[0081] Because the encapsulation layer 300 includes a first inorganic encapsulation layer 310, an organic encapsulation layer 320, and a second inorganic encapsulation layer 330, even if a crack occurs inside the encapsulation layer 300, the crack can be prevented from bonding (e.g., connecting) between the first inorganic encapsulation layer 310 and the organic encapsulation layer 320, or from bonding (e.g., connecting) between the organic encapsulation layer 320 and the second inorganic encapsulation layer 330, through the aforementioned multi-layer structure. This construction can prevent, minimize, or reduce the formation of pathways through which external moisture and / or oxygen permeate into the display area DA.

[0082] Various suitable functional layers, such as a touchscreen layer and a polarizing film, can be further disposed on the encapsulation layer 300. A cover layer configured to improve light efficiency can be further disposed between the second electrode 240 and the encapsulation layer 300.

[0083] Figure 3 This is a view of the stacked structure of the organic light-emitting diodes 200 according to an embodiment. Figure 4 This is a view of the stacked structure of an organic light-emitting diode 200 according to another embodiment.

[0084] like Figure 3 and Figure 4 As shown, in the organic light-emitting diode 200 according to the embodiment, a first electrode 210, an intermediate layer 230, and a second electrode 240 are stacked sequentially. Additionally, the intermediate layer 230 may include an emitter layer EML and a high-level emitter layer 220.

[0085] The first electrode 210 can be used as an anode electrode and may include (e.g., is) a material with a large work function to rapidly inject holes into the emitter layer (EML). The first electrode 210 may be a reflective electrode, a semi-transparent electrode, or a transmissive electrode. When the first electrode 210 includes a transmissive electrode, it may include (e.g., is) at least one selected from indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), zinc oxide (ZnO), and indium oxide (In2O3). When the first electrode 210 includes a reflective electrode, it may include a reflective layer and a transparent layer. The reflective layer includes (e.g., is) silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), or compounds or mixtures thereof, and the transparent layer includes (e.g., is) ITO, IZO, ZnO, and / or In2O3. In the embodiments, the first electrode 210 may have a single-layer structure or a multi-layer structure with two or more layers. As an example, the first electrode 210 may have a two-layer structure of ITO / Ag or a three-layer structure of ITO / Ag / ITO. In this case, the work function of ITO can be adjusted by plasma treatment.

[0086] The intermediate layer 230 may include HIL 220 and the emitter layer EML.

[0087] HIL 220 is disposed between the first electrode 210 and the emitter layer EML. HIL 220 may include (e.g., is) a material having a work function greater than that of the material of the first electrode 210. Therefore, holes injected from the first electrode 210 can be easily injected into the emitter layer EML. As an example, in the case where the first electrode 210 has a multilayer structure, HIL 220 may include (e.g., is) a material having a work function greater than that of the material of the uppermost layer of the first electrode 210 (the layer directly in contact with HIL 220).

[0088] HIL 220 can have a multilayer structure of inorganic materials.

[0089] In an embodiment, such as Figure 3As shown, HIL 220 can have a two-layer structure. In an embodiment, HIL 220 may include a second metal compound layer 225 and a second metal layer 227, with the second metal compound layer 225 on the first electrode 210 and the second metal layer 227 on the second metal compound layer 225. For example, HIL 220 may include a second metal compound layer 225 and a second metal layer 227, with the second metal compound layer 225 between the first electrode 210 and the emitter layer EML, and the second metal layer 227 between the second metal compound layer 225 and the emitter layer EML. For example, in some embodiments, the first electrode 210, the second metal compound layer 225, the second metal layer 227, and the emitter layer EML may be stacked sequentially.

[0090] The second metal compound layer 225 and the second metal layer 227 of HIL 220 may include (e.g., are) a material with a high work function to rapidly inject holes into the emitter layer EML. For example, the work function of the second metal compound layer 225 and the work function of the second metal layer 227 may both be greater than the work function of the first electrode 210. In some embodiments, the work function of the second metal layer 227 may be greater than the work function of the second metal compound layer 225.

[0091] The second metal compound layer 225 and the second metal layer 227 may not be directly deposited on the first electrode 210. For example, in some embodiments, the second metal compound layer 225 and the second metal layer 227 may be formed indirectly through a redox reaction. In an embodiment, the second metal compound layer 225 and the second metal layer 227 are formed through the first metal layer 221 (see...). Figure 8 ) and the first metal compound layer 223 (see Figure 8 HIL 220 is formed by a redox reaction. HIL 220 can have a stacked structure of a second metal compound layer 225 and a second metal layer 227. The second metal compound layer 225 is formed by oxidizing the first metal layer 221 using the first metal compound layer 223, and the second metal layer 227 is formed by reducing the first metal compound layer 223 using the first metal layer 221. (See below for reference.) Figure 8 The method of forming the second metal compound layer 225 and the second metal layer 227 is described in more detail.

[0092] The second metal compound layer 225 may be a dipolar material comprising (e.g., is) a first metal and a halogen element bonded together, wherein the first metal is the same metal as that of the first electrode 210. In an embodiment, the second metal compound is a material comprising (e.g., is) a first metal and a halogen element bonded together. The second metal compound is a dipolar material having a dipole moment, in which electrons shared by the nuclei of the first metal and the halogen element are deflected toward the halogen element, which has higher electronegativity.

[0093] In this case, the first metal is the same metal as the metal of the first electrode 210, and can be one of Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, and Cr. Because the second metal compound layer 225, which is the bottom layer of HIL 220, includes (e.g., is) the same metal as the metal of the first electrode 210, defects such as short circuits and black spots caused by metal particles of the first electrode 210 can be prevented or reduced. As an example, when the first electrode 210 has an ITO / Ag / ITO stacked structure, the second metal compound layer 225 can be a dipolar material including (e.g., is) Ag and halogen elements bonded together, where Ag is the same metal as the metal of the first electrode 210.

[0094] Halogens are elements in Group 17 of the periodic table, and are nonmetallic elements that readily gain electrons and thus exhibit oxidizing properties. Examples of halogens include fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).

[0095] According to this embodiment, because a second metal compound layer 225, including (for example, a second metal compound), is disposed between the first electrode 210 and the second metal layer 227, the adhesion between the top surface of the first electrode 210 and the HIL 220 can be improved. Furthermore, because the second metal compound layer 225 is disposed to cover the top surface of the first electrode 210, surface defects on the top surface of the first electrode 210 can be mitigated or reduced. For example, the smoothness and coverage of the top surface of the first electrode 210 can be improved. Referring below... Figure 10A and Figure 10B To describe it in more detail.

[0096] The second metal layer 227 comprises (e.g., is) a second metal with a high work function. Because the second metal layer 227 comprises (e.g., is) a metal with a high work function, holes are rapidly injected into the emitter layer EML, thus improving the luminous efficiency of the organic light-emitting diode 200. In this case, the second metal can be a transition metal in Group 10 (e.g., nickel (Ni), palladium (Pd), platinum (Pt), etc.), and is not limited thereto. For example, the second metal can be any suitable metal with a high work function. Furthermore, the work function of the second metal layer 227 can be greater than that of the first electrode 210, and can be greater than that of the second metal compound layer 225.

[0097] In another embodiment, such as Figure 4As shown, HIL 220 can have a three-layer structure. More specifically, HIL 220 may include a second metal compound layer 225, a second metal layer 227, and a residual layer 229 of the first metal compound layer, with the second metal compound layer 225 on the first electrode 210, the second metal layer 227 on the second metal compound layer 225, and the residual layer 229 on the second metal layer 227. For example, HIL 220 may include a second metal compound layer 225, a second metal layer 227, and a residual layer 229 of the first metal compound layer, with the second metal compound layer 225 between the first electrode 210 and the emitter layer EML, the second metal layer 227 between the second metal compound layer 225 and the emitter layer EML, and the residual layer 229 between the second metal layer 227 and the emitter layer EML. In some embodiments, the first electrode 210, the second metal compound layer 225, the second metal layer 227, the residual layer 229, and the emitter layer EML are stacked sequentially.

[0098] The description of the second metal compound layer 225 and the second metal layer 227 according to the previous embodiment also applies to the second metal compound layer 225 and the second metal layer 227 according to this embodiment. In the following description, a repetition of the description is not required, and the residual layer 229 of the first metal compound layer, which is a different element, will be described primarily.

[0099] The second metal compound layer 225, the second metal layer 227, and the residual layer 229 of the first metal compound layer included in HIL 220 may include (e.g., be) a material with a high work function, allowing holes to be rapidly injected into the emitter layer EML. For example, the work function of the second metal compound layer 225, the second metal layer 227, and the residual layer 229 of the first metal compound layer may be greater than the work function of the first electrode 210. In some embodiments, the work function of the second metal layer 227 may be greater than that of the second metal compound layer 225 and greater than that of the residual layer 229 of the first metal compound layer.

[0100] The residual layer 229 of the first metal compound layer is a residual layer formed during the process of forming HIL 220 when the first metal compound layer 223 did not fully react during the redox reaction and was partially retained. In an embodiment, the second metal compound layer 225 and the second metal layer 227 are connected through the first metal layer 221 (see...). Figure 9 ) and the first metal compound layer 223 (see Figure 9The redox reaction forms the first metal compound layer 223. When the first metal compound layer 223 is formed to be thicker than the first metal layer 221 (e.g., thicker or relatively thicker), even if the first metal layer 221 reacts completely, a portion of the first metal compound layer 223 does not react and remains to form a residual layer 229 of the first metal compound layer. In this case, the HIL 220 can have a structure in which the second metal compound layer 225, the second metal layer 227, and the residual layer 229 of the first metal compound layer are sequentially stacked, the second metal compound layer 225 is formed by oxidizing the first metal layer 221 using the first metal compound layer 223, the second metal layer 227 is formed by reducing the first metal compound layer 223 using the first metal layer 221, and the residual layer 229 is formed by not reacting during the redox reaction (e.g., by the unreacted portion of the first metal compound layer 223) and remaining. (Refer to below) Figure 9 The method for forming the second metal compound layer 225, the second metal layer 227 and the residual layer 229 of the first metal compound layer is described in more detail.

[0101] Because the residual layer 229 of the first metal compound layer is the first metal compound layer 223 (see...) Figure 9 As part of the first metal compound layer, the residual layer 229 of the first metal compound layer includes (for example, is) the first metal compound of the first metal compound layer 223.

[0102] The second electrode 240 can be disposed on the emitter layer EML. The second electrode 240 can be a cathode serving as an electron injection electrode. In this case, the second electrode 240 can include (e.g., a material with a small work function) to facilitate electron injection. In embodiments, the second electrode 240 can be implemented as a reflective electrode, a semi-transparent electrode, or a transmissive electrode by forming a thin film comprising (e.g.,) Li, Mg, Al, Ag, Al-Li, Ca, Mg-In, Mg-Ag, LiF / Al, and / or Li2O / Al. To obtain a front-emitting display device, the second electrode 240 can be implemented as a transmissive electrode comprising (e.g.,) ITO, IZO, ZnO, and / or In2O3. However, various suitable modifications can be made.

[0103] Figure 5 This is a view of the stacked structure of an organic light-emitting diode 200 according to another embodiment. Figure 6 yes Figure 5 Energy level diagram of each layer of an organic light-emitting diode 200.

[0104] In the accompanying drawings, since the same reference numerals denote the same elements, their repeated descriptions are not required.

[0105] like Figure 5 and Figure 6As shown, the organic light-emitting diode 200 may include a first electrode 210, a second electrode 240, and an intermediate layer 230 therebetween, with the first electrode 210 and the second electrode 240 facing each other. For example, the first electrode 210 and the second electrode 240 may be stacked on top of each other in a planar view.

[0106] According to this embodiment, the intermediate layer 230 may have a structure in which HIL 220, HTL, EML, ETL, and EIL are stacked sequentially. However, this disclosure is not limited thereto, and some or all of HIL 220, HTL, ETL, and EIL may be omitted. For example, in some embodiments, the intermediate layer 230 may include HIL 220, HTL, EML, ETL, and / or EIL.

[0107] exist Figure 6 In the energy level diagram, the bottom line represents the highest energy level of the valence band, denoted by the highest occupied molecular orbital (HOMO), and the top line represents the lowest energy level of the conduction band, denoted by the lowest unoccupied molecular orbital (LUMO). The difference between the HOMO and LUMO energy levels is the band gap.

[0108] HIL 220, HTL, ETL, and EIL can be layers introduced to lower the energy walls between layers, allowing holes or electrons to easily reach the emitter layer EML.

[0109] The material of HIL 220 is one that can effectively receive holes from the first electrode 210. The HOMO of the material of HIL 220 can be between the Fermi level that determines the work function of the material of HIL 220 and the HOMO of the adjacent organic layer. For example, the HOMO of the hole injection material (e.g., the material of HIL 220) can be formed at a level lower than the Fermi level that determines the work function of HIL 220.

[0110] HIL 220 may include (for example) metalloporphyrins, oligothiophenes, arylamine organic materials, hexanitrile hexaazabenzophenanthrene, quinacridone organic materials, perylene organic materials, anthraquinone conductive polymers, polyaniline conductive polymers and / or polythiophene conductive polymers, but HIL 220 is not limited thereto.

[0111] Similarly, HTL includes (for example, is) a material that can well receive holes from HIL 220. The HOMO of HTL can be lower than that of the material of HIL 220.

[0112] The material of the EIL is one that can readily accept electrons from the second electrode 240 at low voltages. The LUMO of the EIL material lies between the Fermi level, which determines the work function of the second electrode 240, and the LUMO of the adjacent organic layer.

[0113] Similarly, ETL materials are materials that readily accept electrons from EIL. The LUMO of ETL materials is higher than that of EIL materials.

[0114] In the embodiments, the ETL may include (for example) PBP (4-phenylbenzophenone), t-Bu-PBD (2-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), 3TPYMB (tris-[3-(3-pyridyl)trimethylyl]borane) and / or B3PYMPM (bis-4,6-(3,5-di-3-pyridylphenyl)-2-methylpyrimidine).

[0115] Because the organic light-emitting diode 200 according to this embodiment includes not only HIL220 but also various suitable functional layers, holes and electrons can be easily transferred to the emission layer EML, thus further improving the luminous efficiency.

[0116] Figure 7 This is a flowchart illustrating a portion of a method for manufacturing an organic light-emitting diode according to an embodiment. Figure 8 This is a view showing the redox reaction before and after according to an embodiment. Figure 9 This is a view showing the redox reaction before and after according to another embodiment.

[0117] like Figure 7 As shown, the method for manufacturing an organic light-emitting diode according to an embodiment may include operations such as forming a first electrode (s10), forming a HIL (high-intensity layer), forming an HTL (high-intensity layer), forming an EML (emitter layer), forming an ETL (emitter layer), forming an EIL (emitter layer), forming an EIL (emitter layer), forming an EIL (emitter layer), forming a second electrode, and forming a second electrode (s70).

[0118] As described above, in some embodiments, one or more of HIL 220, HTL, ETL, and EIL can be omitted. Therefore, some or all of operations S20, S30, S50, and S60 can be omitted.

[0119] Operation S10 is the operation of forming a first electrode 210 comprising (for example, a first metal).

[0120] Operation S20 is the operation of forming HIL 220 on the first electrode 210.

[0121] In the case where HIL 220 includes a second metal compound layer 225 and a second metal layer 227, operation S20 includes forming a first metal layer 221 on the first electrode 210 and forming a first metal compound layer 223 on the first metal layer 221. Operation S20 may include (for example, may also include) forming HIL 220 comprising the second metal compound layer 225 and the second metal layer 227, wherein the second metal layer 227 is formed on the second metal compound layer 225 by oxidizing the first metal compound layer 221 using the first metal compound layer 223, and the second metal layer 227 is formed by reducing the first metal compound layer 223 using the first metal layer 221. For example, the second metal compound layer 225 and the second metal layer 227 may be formed by a redox reaction between the first metal layer 221 and the first metal compound layer 223.

[0122] For example, when a first metal layer 221 and a first metal compound layer 223 on the first metal layer 221 are formed sequentially, the first metal layer 221 and the first metal compound layer 223 undergo a redox reaction to form a second metal compound layer 225 and a second metal layer 227 on the second metal compound layer 225. As described above, according to the embodiment, the layers constituting HIL 220 (e.g., the second metal compound layer 225 and the second metal layer 227, or the second metal compound layer 225, the second metal layer 227, and the residual layer 229) can be formed indirectly by a redox reaction without directly depositing them (e.g., not directly forming the second metal compound layer 225 on the first electrode 210 and not directly forming the second metal compound layer 227 on the second metal compound layer 225). Therefore, materials with large work function that are difficult to apply to processes due to their very high melting points can be utilized more conveniently and economically.

[0123] The first metal layer 221 includes (for example, is) a first metal, which is the same metal as that of the first electrode 210. The first metal compound of the first metal compound layer 223 may be a material comprising (for example, is) a second metal bonded to each other with a second metal layer 227 and a halogen element.

[0124] In an embodiment, such as Figure 8 As shown, the first electrode 210 may include (e.g., is) a stacked structure of ITO / Ag / ITO, the first metal layer 221 may include (e.g., is) Ag as the first metal, and the first metal compound layer 223 may include (e.g., is) PtI2 containing Pt and I bonded together, where Pt is the second metal of the second metal layer 227 and I is a halogen element. When the first metal layer 221 is formed on the first electrode 210 and the first metal compound layer 223 is formed on the first metal layer 221, a redox reaction as shown in Reaction Formula 1 occurs.

[0125] Reaction 1

[0126] PtI₂ + 2Ag → Pt + 2AgI

[0127] According to reaction formula 1, Ag is oxidized by PtI2 to form AgI, and PtI2 is reduced by Ag to form Pt. For example, a first metal layer 221 comprising (e.g., is) Ag is oxidized by a first metal compound layer 223 comprising (e.g., is) PtI2 to form a second metal compound layer 225 comprising (e.g., is) AgI. The first metal compound layer 223 comprising (e.g., is) PtI2 is reduced by the first metal layer 221 comprising (e.g., is) Ag to form a second metal layer 227 comprising (e.g., is) Pt.

[0128] In this case, where the ratio of the first metal compound to the first metal is the ratio at which the first metal compound and the first metal react completely with each other, the first metal compound and the first metal leave no residue after the redox reaction. For example, during the redox reaction, the first metal layer 221 may be substantially or completely oxidized, and the first metal compound layer 223 may be substantially or completely reduced.

[0129] In contrast, when the ratio of the first metal compound to the first metal, as reactants, is such that only the first metal reacts completely and only a portion of the first metal compound reacts, a portion of the first metal compound remains after the redox reaction, thus forming a residual layer 229 of the first metal compound layer. For example, during the redox reaction, the first metal layer 221 may be substantially or completely oxidized, and the first metal compound layer 223 may be partially reduced, such that after the redox reaction ends, a portion (e.g., the uppermost portion) of the first metal compound layer 223 may remain (e.g., may not be reduced).

[0130] In the case where HIL 220 includes (for example) a second metal compound layer 225, a second metal layer 227, and a residual layer 229 of the first metal compound layer, operation S20 includes the operation of forming a first metal layer 221 on the first electrode 210 and the operation of forming HIL 220. The operation of forming HIL 220 includes forming a first metal compound layer 223 on the first metal layer 221 to include the second metal compound layer 225, the second metal layer 227 on the second metal compound layer 225, and the residual layer 229 of the first metal compound layer, wherein the second metal compound layer 225 is formed by oxidizing the first metal layer 221 using the first metal compound layer 223, and the second metal layer 227 is formed by reducing the first metal compound layer 223 using the first metal layer 221. For example, the operation of forming HIL 220 may include forming a first metal compound layer 223 on the first metal layer 221, the amount of which is greater than the amount required for the first metal layer 221 to be substantially or completely oxidized during the redox reaction between the first metal layer 221 and the first metal compound layer 223, such that a portion of the first metal compound layer 223 (e.g., the uppermost portion) remains (e.g., is not reduced) after the first metal layer 221 has been substantially or completely oxidized. The portion of the first metal compound layer 223 that remains after the first metal layer 221 has been substantially or completely oxidized may be a residual layer 229.

[0131] For example, when the first metal layer 221 on the first electrode 210 and the first metal compound layer 223 on the first metal layer 221 are formed sequentially, the first metal layer 221 and the first metal compound layer 223 perform a redox reaction, thereby forming a second metal compound layer 225, a second metal layer 227 on the second metal compound layer 225 and a residual layer 229 of the first metal compound layer on the second metal layer 227.

[0132] Operation S30 is the operation of forming an HTL on HIL 220, operation S40 is the operation of forming an emitter layer EML on HTL, operation S50 is the operation of forming an ETL on emitter layer EML, operation S60 is the operation of forming an EIL on ETL, and operation S70 is the operation of forming a second electrode 240 on EIL. Since a more detailed description of operations S30 to S70 is the same as those described above, this description is not required.

[0133] Figure 10A and Figure 10B This is an atomic force microscope (AFM) image of the surface of the first electrode 210 according to an embodiment.

[0134] In an embodiment, Figure 10AThis is an AFM image of the surface of the first electrode 210 before the metal compound layer is formed on the first electrode 210 having an uppermost layer including (e.g., ITO). Figure 10B This is an AFM image of the surface of the first electrode 210 after a metal compound layer has been formed on the first electrode 210 having an uppermost layer including (e.g., ITO).

[0135] Reference Figure 10A and Figure 10B Before the metal compound layer is formed on the first electrode 210, the surface of the first electrode 210 is rough and uneven due to surface defects. Conversely, after the metal compound layer is formed on the first electrode 210, the surface of the first electrode 210 becomes smoother and flatter because the surface defects are reduced.

[0136] This means that, compared to the case where a metal layer including (for example,) a metal with a high work function is directly formed on the first electrode 210, the adhesion between the first electrode 210 and the HIL 220 can be improved when a metal compound layer is disposed between the metal layer and the first electrode 210. Furthermore, because the metal compound layer covers the surface of the first electrode 210, defects caused by metal particles in the first electrode 210 can be prevented or reduced.

[0137] While the organic light-emitting diode (OLED) and methods for manufacturing the OLED have been described primarily above, this disclosure is not limited thereto. As an example, display devices including OLEDs and methods for manufacturing the display devices also fall within the scope of this disclosure.

[0138] According to the embodiments, an organic light-emitting diode (OLED) with improved luminous efficiency and a process advantage can be achieved, as well as a method for manufacturing the OLED. However, this disclosure is not limited to such effects.

[0139] It will be understood that the embodiments described herein should be considered in a descriptive sense only and not for limiting purposes. The descriptions of features and / or aspects within each embodiment should generally be considered applicable to other similar features and / or aspects in other embodiments. While 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 suitable changes in form and detail may be made therein without departing from the spirit and scope of this disclosure as defined by the claims and their equivalents.

Claims

1. A method for manufacturing an organic light-emitting diode, the method comprising the following steps: A first electrode is formed on a substrate, the first electrode comprising a first metal; A first metal layer is formed on the first electrode, the first metal layer comprising the first metal; A hole injection layer is formed by forming a first metal compound layer on the first metal layer. The hole injection layer includes a second metal compound layer and a second metal layer, the second metal layer being on the second metal compound layer. The second metal compound layer is formed by oxidizing the first metal compound layer via the first metal compound layer, and by reducing the first metal compound layer via the first metal layer. An organic emission layer is formed on the hole injection layer; as well as A second electrode is formed on the organic emission layer.

2. The method according to claim 1, wherein, The second metal compound of the second metal compound layer includes a dipolar material, which includes the first metal of the first metal layer and the halogen element of the first metal compound of the first metal compound layer.

3. A method for manufacturing an organic light-emitting diode, the method comprising the following steps: A first electrode is formed on a substrate, the first electrode comprising a first metal; A first metal layer is formed on the first electrode, the first metal layer comprising the first metal; A hole injection layer is formed by forming a first metal compound layer on the first metal layer. The hole injection layer includes a second metal compound layer, a second metal layer, and a residual layer of the first metal compound layer. The second metal layer is on the second metal compound layer. The second metal compound layer is formed by oxidizing the first metal layer via the first metal compound layer and by reducing the first metal compound layer via the first metal layer. An organic emission layer is formed on the hole injection layer; as well as A second electrode is formed on the organic emission layer.

4. The method according to claim 3, wherein, The first metal compound layer comprises a certain material, and the certain material comprises a second metal and a halogen element of the second metal layer.

5. The method according to claim 4, wherein, The second metal compound of the second metal compound layer includes a dipolar material, which includes the first metal of the first metal layer and the halogen element of the first metal compound.

6. An organic light-emitting diode manufactured according to the method of claim 1, the organic light-emitting diode comprising: The first and second electrodes face each other. An organic emission layer is located between the first electrode and the second electrode; as well as A hole injection layer is located between the first electrode and the organic emitter layer. The second metal compound layer is located between the first electrode and the organic emission layer, and the second metal layer is located between the second metal compound layer and the organic emission layer.

7. The organic light-emitting diode according to claim 6, wherein, The second metal compound layer comprises a dipolar material, which includes a first metal and a halogen element, wherein the first metal is the same as the metal of the first electrode.

8. An organic light-emitting diode manufactured according to the method of claim 3, the organic light-emitting diode comprising: The first and second electrodes face each other. An organic emission layer is located between the first electrode and the second electrode; as well as A hole injection layer is located between the first electrode and the organic emitter layer. Wherein, the second metal compound layer is between the first electrode and the organic emission layer, the second metal layer is between the second metal compound layer and the organic emission layer, and the residual layer is between the second metal layer and the organic emission layer.

9. The organic light-emitting diode according to claim 8, wherein, The first metal compound layer comprises a certain material, and the certain material comprises a second metal and a halogen element of the second metal layer.

10. The organic light-emitting diode according to claim 9, wherein, The second metal compound layer comprises a dipolar material, which includes a first metal and a halogen element, wherein the first metal is the same as the metal of the first electrode.

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