Display device and method of manufacturing same

Abstract

A display apparatus and a method of manufacturing the same are provided. The display device includes: a pixel circuit including at least one thin film transistor; an organic light emitting diode electrically connected to the pixel circuit; and an insulating layer defining a pixel region for the organic light emitting diode. The organic light emitting diode includes: a pixel electrode electrically connected to a pixel circuit; an opposite electrode at least opposite to the pixel electrode; and an organic layer disposed at least between the pixel electrode and the opposite electrode, and including at least an emission layer. The pixel electrode includes: a first pixel electrode in contact with the organic layer; a reflective layer opposed to the first pixel electrode and reflecting light from the emission layer; and a protective layer disposed between the first pixel electrode and the reflective layer, and protecting the reflective layer.

Description

Technical Field

[0001] One or more embodiments relate to a display device and a method of manufacturing the display device. Background Technology

[0002] A flat panel display device, such as an organic light-emitting display or a liquid crystal display, is fabricated on a substrate in which at least one thin-film transistor (TFT), a capacitor, and a pattern including wiring connecting at least the TFT to the capacitor for driving are formed. The TFT includes an active layer and a gate electrode. The active layer includes a channel region, a source region, and a drain region. The gate electrode is electrically insulated from the active layer through a gate insulating layer.

[0003] Typically, the active layer of a TFT comprises a semiconductor material, such as amorphous silicon or polycrystalline silicon. When the active layer is amorphous silicon, the low mobility makes it difficult to implement high-speed driving circuits. When the active layer is polycrystalline silicon, the mobility is high, but the threshold voltage may be uneven, and separate compensation circuitry may be required. Furthermore, conventional TFT manufacturing methods using low-temperature polycrystalline silicon (LTPS) involve expensive processes such as laser thermal processing, resulting in high facility investment and management costs, and making them difficult to apply to large-area substrates. In this regard, recent research has focused on using oxide semiconductors as the active layer. Summary of the Invention

[0004] When external light penetrates into the active layer, the characteristics of a thin-film transistor (TFT) using oxide semiconductors may change. One method to block external light is to use a black pixel defining layer, or to use pixel electrodes that include a reflective layer.

[0005] For example, voids may appear in the reflective layer when unrefined material of the pixel definition layer penetrates into the reflective layer of the pixel electrode during the manufacturing process.

[0006] One or more embodiments may provide a display device and a method of manufacturing the display device, wherein damage to the reflective layer included in the pixel electrodes is minimized during the manufacturing process. However, these are merely examples, and the scope of this disclosure is not limited thereto.

[0007] According to one or more embodiments, a display device includes: a pixel circuit including at least one thin-film transistor; an organic light-emitting diode electrically connected to the pixel circuit; and an insulating layer defining a pixel region for the organic light-emitting diode, wherein the organic light-emitting diode includes: a pixel electrode electrically connected to the pixel circuit; a counter electrode at least opposite to the pixel electrode; and an organic layer at least disposed between the pixel electrode and the counter electrode, and including at least an emitting layer, and the pixel electrode includes: a first pixel electrode in contact with the organic layer; a reflective layer opposite to the first pixel electrode and reflecting light from the emitting layer; and a protective layer disposed between the first pixel electrode and the reflective layer and protecting the reflective layer.

[0008] The protective layer may include a transparent conductive layer.

[0009] Transparent conductive layers may include amorphous layers.

[0010] The transparent conductive layer may include a stack of a first protective layer and a second protective layer, wherein the first protective layer comprises the same material as the first pixel electrode, and the second protective layer is formed as an amorphous layer.

[0011] Each of the first pixel electrode and the protective layer may include a transparent conductive layer containing oxygen, and the amount of oxygen in the protective layer may be greater than the amount of oxygen in the first pixel electrode.

[0012] Each of the first pixel electrode and the protective layer may include a transparent conductive layer containing tin, and the amount of tin in the protective layer may be less than the amount of tin in the first pixel electrode.

[0013] The first pixel electrode and the protective layer can be stacked into multiple layers.

[0014] The display device may also include a second pixel electrode electrically connected to the pixel circuit to form an ohmic contact, wherein a reflective layer may be disposed between the second pixel electrode and a protective layer.

[0015] According to one or more embodiments, a method of manufacturing a display device includes: preparing a circuit substrate including a pixel circuit comprising at least one thin-film transistor; forming an organic light-emitting diode (OLED) electrically connected to the pixel circuit on the circuit substrate; and forming an insulating layer on the circuit substrate defining a pixel region for the OLED, wherein forming the OLED includes: forming a pixel electrode electrically connected to the pixel circuit; forming an organic layer including at least an emission layer on the pixel electrode; and forming a counter electrode on at least the organic layer, and forming the pixel electrode includes: forming a reflective layer reflecting light from the emission layer; forming a protective layer protecting the reflective layer on the reflective layer; and forming a first pixel electrode in contact with the organic layer on the protective layer.

[0016] Forming a protective layer may include forming a transparent conductive layer.

[0017] Transparent conductive layers may include amorphous layers.

[0018] The method may further include: forming a transparent conductive layer; forming a first protective layer comprising the same material as the first pixel electrode; and forming a second protective layer on the first protective layer as an amorphous layer.

[0019] Each of the first pixel electrode and the protective layer may include a transparent conductive layer containing oxygen, and forming the protective layer may include: forming the transparent conductive layer; and subjecting at least a portion of the transparent conductive layer to oxygen plasma treatment.

[0020] Each of the first pixel electrode and the protective layer may include a transparent conductive layer containing tin, and the protective layer may be formed such that the amount of tin in the protective layer may be less than the amount of tin in the first pixel electrode.

[0021] Forming a protective layer may include: forming a first-1 protective layer; and forming a first-2 protective layer, wherein forming a first pixel electrode may include: forming a first-1 pixel electrode between the first-1 protective layer and the first-2 protective layer; and forming a first-2 pixel electrode on the first-2 protective layer.

[0022] The method may further include: forming a second pixel electrode electrically connected to the pixel circuit to form an ohmic contact, wherein forming a reflective layer may include forming a reflective layer between the second pixel electrode and the protective layer.

[0023] According to one or more embodiments, an electronic device may include: a display device, including: a pixel circuit including at least one thin-film transistor; an organic light-emitting diode electrically connected to the pixel circuit; and an insulating layer defining a pixel region, wherein the organic light-emitting diode may include: a pixel electrode electrically connected to the pixel circuit; a counter electrode at least opposite to the pixel electrode; and an organic layer at least disposed between the pixel electrode and the counter electrode, and including at least an emitting layer, the pixel electrode may include: a first pixel electrode in contact with the organic layer; a reflective layer opposite to the first pixel electrode and reflecting light from the emitting layer; and a protective layer disposed between the first pixel electrode and the reflective layer and protecting the reflective layer.

[0024] The electronic device can be at least one of the following: smartwatch, mobile phone, smartphone, portable computer, tablet PC, watch phone, car display, smart glasses, portable multimedia player (PMP), navigation system, ultra-mobile computer (UMPC), head-mounted display (HMD) device, virtual reality (VR) device, mixed reality (MR) device, and augmented reality (AR) device. Attached Figure Description

[0025] Figure 1 This is a schematic perspective view of a display device according to an embodiment; Figure 2A and Figure 2B These are schematic cross-sectional views of the display device according to the embodiments; Figure 3A and Figure 3B These are schematic diagrams of the equivalent circuits of pixels according to the implementation method; Figure 4 This is a schematic cross-sectional view showing pixels according to an embodiment; Figure 5 This illustrates an embodiment. Figure 4 A schematic cross-sectional view of region A; Figure 6 This is a graph showing the X-ray diffraction (XRD) difference of indium tin oxide (ITO) with respect to oxygen plasma treatment time; Figure 7 This is a graph showing the XRD difference of ITO according to the concentration ratio of tin; Figure 8 This illustrates an embodiment according to another method. Figure 4 A schematic cross-sectional view of region A; Figure 9 This illustrates an embodiment according to another method. Figure 4 A schematic cross-sectional view of area A; and Figure 10 and Figure 11 This is a schematic perspective view illustrating an application example of an electronic device. Detailed Implementation

[0026] In the following description, numerous specific details are set forth for illustrative purposes in order to provide a thorough understanding of various embodiments or implementations of the invention. As used herein, “implementation” and “method” are interchangeable terms and are non-limiting examples of the apparatuses or methods disclosed herein. However, it will be apparent, however, that various embodiments may be practiced without these specific details or with one or more equivalent arrangements. These various embodiments are not necessarily exclusive, nor do they limit this disclosure. For example, a particular shape, configuration, and characteristic of an embodiment may be used or implemented in another embodiment.

[0027] Unless otherwise stated, the embodiments shown should be understood as providing features of the invention. Therefore, unless otherwise stated, features, components, modules, layers, films, panels, regions and / or aspects of various embodiments (hereinafter individually or collectively referred to as “elements”) may be combined, separated, interchanged and / or rearranged in other ways without departing from the scope of the invention.

[0028] The use of crosshairs and / or shading in the accompanying drawings is generally provided to clarify the boundaries between adjacent elements. Therefore, unless specified, the presence or absence of crosshairs or shading does not convey or indicate any preference or requirement for a particular material, material properties, size, scale, commonalities between the elements shown, and / or any other characteristics, properties, etc., of the elements. Furthermore, in the drawings, the dimensions and relative dimensions of elements may be exaggerated for clarity and / or descriptive purposes. When embodiments can be implemented differently, a particular process sequence may be performed differently than the sequence described. For example, two consecutively described processes may be performed substantially simultaneously, or in the reverse order of their description. Additionally, similar reference numerals denote similar elements.

[0029] When an element or layer is referred to as being "on," "connected to," or "linked to" another element or layer, it can be directly on, directly connected to, or directly linked to the other element or layer, or an intervening element or layer may be present. However, when an element or layer is referred to as being "directly on," "directly connected to," or "directly linked to" another element or layer, an intervening element or layer is not present. Therefore, the term "connection" can refer to a physical connection, electrical connection, and / or fluid connection, with or without an intervening element. Furthermore, the axis in the first direction X, the axis in the second direction Y, and the axis in the third direction Z are not limited to the three axes of a Cartesian coordinate system such as the X-axis, Y-axis, and Z-axis, and can be interpreted in a broader sense. For the purposes of this disclosure, "at least one of A and B" can be understood to mean only A, only B, or any combination of A and B. Furthermore, "at least one of X, Y, and Z" and "at least one selected from the group consisting of X, Y, and Z" can be interpreted as only X, only Y, only Z, or any combination of two or more of X, Y, and Z. As used herein, the term "and / or" includes any and all combinations of one or more of the related listed items.

[0030] Although the terms “first,” “second,” etc., may be used herein to describe various types of elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another. For example, without departing from the teachings of this disclosure, the first element discussed below may be referred to as the second element.

[0031] For descriptive purposes, spatial relative terms such as “below,” “under,” “below,” “down,” “above,” “above,” “higher,” and “side” (e.g., as in “sidewall”) may be used herein to describe the relationship between one element and another(s) as shown in the accompanying drawings. In addition to the orientations depicted in the drawings, spatial relative terms are intended to encompass different orientations of the device in use, operation, and / or manufacture. For example, if the device in the drawings is flipped, an element described as “below” or “under” other elements or features will be oriented “above” those elements or features. Thus, the term “below” can encompass both above and below orientations. Furthermore, the device may be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and therefore, the spatial relative descriptive terms used herein should be interpreted accordingly.

[0032] The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, the terms “comprises,” “comprising,” “includes,” and / or “including,” when used in this specification, designate the presence of stated features, integrals, steps, operations, elements, components, and / or groups thereof, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. It should also be noted that, as used herein, the terms “substantially,” “about,” and other similar terms are used as approximate terms and not as terms of degree, and therefore are used to explain the inherent biases of measured, calculated, and / or provided values ​​that would be recognized by those skilled in the art.

[0033] Various embodiments are described herein with reference to cross-sectional views and / or exploded views that serve as schematic diagrams of implementations and / or intermediate structures. Therefore, variations in the shape of the figures should be expected, for example, due to manufacturing techniques and / or tolerances. Consequently, the embodiments disclosed herein should not necessarily be construed as limited to the shapes of the specifically shown areas, but should include, for example, deviations in shape due to manufacturing processes. In this way, the areas shown in the figures may be schematic in nature, and the shapes of these areas may not reflect the actual shapes of the areas of the device, and are therefore not necessarily intended to be limiting.

[0034] As is customary in the art, some embodiments are described and illustrated in the accompanying drawings for the purpose of functional blocks, units, and / or modules. Those skilled in the art will appreciate that these blocks, units, and / or modules are physically implemented by electrical circuits (or optical circuits) such as logic circuits, discrete components, microprocessors, hardwired circuits, memory elements, wiring connectors, etc., which can be formed using semiconductor-based manufacturing techniques or other manufacturing techniques. Where blocks, units, and / or modules are implemented by microprocessors or other similar hardware, they can be programmed and controlled using software (e.g., microcode) to perform the various functions discussed herein, and can be selectively driven by firmware and / or software. It is also contemplated that each block, unit, and / or module can be implemented by dedicated hardware, or can be implemented as a combination of dedicated hardware for performing some functions and a processor (e.g., one or more programmable microprocessors and associated circuitry) for performing other functions. Furthermore, without departing from the scope of the invention, each block, unit, and / or module in some embodiments may be physically separated into two or more interactive and discrete blocks, units, and / or modules. Furthermore, without departing from the scope of the invention, some implementation blocks, units and / or modules can be physically combined into more complex blocks, units and / or modules.

[0035] Figure 1 This is a schematic perspective view of the display device 100 according to the embodiment.

[0036] refer to Figure 1 The display device 100 may include a display area DA and a non-display area NDA extending outward from the display area DA. The display device 100 may display an image in the display area DA. Examples of the display device 100 may include a liquid crystal display, an electrophoretic display, an organic light-emitting display, an inorganic light-emitting display, a quantum dot light-emitting display, a field emission display, a surface conduction electron emitter display, a plasma display, and a cathode ray display.

[0037] refer to Figure 1 The display device 100 may include pixels P disposed in a display area DA. Each pixel P may be electrically connected to a scan line SL extending in a first direction X, a data line DL extending in a second direction Y, and a drive voltage line PL extending in the second direction Y. A third direction Z may be perpendicular to the plane defined by the first direction X and the second direction Y.

[0038] Some of the pixels P may emit red, green, blue, or white light, and may include, for example, organic light-emitting diodes. In some embodiments, each of the pixels P may include pixel circuitry comprising a combination of elements such as TFTs and capacitors.

[0039] In the following description, an organic light-emitting display is used as an example of a display device 100 according to an embodiment. However, the display device disclosed herein is not limited to this, and other types of display devices may also be used.

[0040] Figure 2A and Figure 2B These are schematic cross-sectional views of display devices 200 and 200' according to the embodiments.

[0041] refer to Figure 2A The display device 200 may include a display element layer 220 on a first substrate 210 and an encapsulation component 230 covering the display element layer 220.

[0042] In other embodiments, the first substrate 210 may include glass.

[0043] In other embodiments, the first substrate 210 may include a polymeric resin, such as polyethersulfone, polyacrylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyarylate, polyimide, polycarbonate, or cellulose acetate propionate.

[0044] In other embodiments, the first substrate 210 may include a flexible metallic material.

[0045] In other embodiments, the first substrate 210 may have a single-layer or multi-layer structure of the above-described material. The first substrate 210 may also include an inorganic layer and / or an organic layer.

[0046] In other embodiments, the first substrate 210 may be flexible, rollable, or bendable.

[0047] Display element layer 220 may include pixels P. Each pixel P may include an organic light-emitting diode and pixel circuitry electrically connected to the organic light-emitting diode. The pixel circuitry may include a thin-film transistor (TFT), a storage capacitor, wires connected to the TFT and the storage capacitor, etc., and may include an insulating layer.

[0048] The encapsulation member 230 can protect the display element layer 220 from external foreign matter such as moisture. The encapsulation member 230 can be a thin-film encapsulation layer comprising at least one inorganic encapsulation layer and / or at least one organic encapsulation layer. The at least one inorganic encapsulation layer may include a silicon oxide layer, a silicon nitride layer, and / or a silicon nitride layer, a titanium oxide layer, an aluminum oxide layer, etc., but this disclosure is not limited thereto. The at least one organic encapsulation layer may include an acrylic-based organic material, but this disclosure is not limited thereto.

[0049] Figure 2AThe encapsulation component 230 may include an inorganic encapsulation layer and an organic encapsulation layer disposed between the inorganic encapsulation layers. The stacking order of the inorganic and organic encapsulation layers can be varied. Although Figure 2A The encapsulation component 230 is shown to be a thin-film encapsulation layer, but this disclosure is not limited thereto.

[0050] refer to Figure 2B The display device 200' may include an encapsulation component 230', which includes a sealing portion 240 and a second substrate 250. Figure 2B The first substrate 210 may include the aforementioned polymer resin, or may include glass or metal.

[0051] The second substrate 250 may be disposed facing the first substrate 210, and the sealing portion 240 may be disposed between the first substrate 210 and the second substrate 250. The sealing portion 240 may surround the display area DA. The internal space defined by the first substrate 210, the second substrate 250, and the sealing portion 240 may be separated from the outside and may prevent the penetration of moisture or impurities. The second substrate 250 may include the aforementioned polymer resin, metal, or glass, and the sealing portion 240 may use glass frit or epoxy resin.

[0052] Figure 3A and Figure 3B These are schematic diagrams of the equivalent circuit of pixel P according to the implementation method.

[0053] refer to Figure 3A Each pixel P may include a pixel circuit PC connected to a scan line SL, a data line DL, and a drive voltage line PL, as well as an organic light-emitting diode (OLED) connected to the pixel circuit PC. The pixel circuit PC may include a driving TFT T1, a switching TFT T2, and a storage capacitor Cst.

[0054] Switch TFT T2 can respond to the scan signal S input through scan line SL. n The data signal D input through the data line DL m Transmitted to the driving TFT T1.

[0055] The storage capacitor Cst can be connected to the switch TFT T2 and the drive voltage line PL, and can store the voltage corresponding to the difference between the voltage received from the switch TFT T2 and the first power supply voltage (or drive voltage) ELVDD provided to the drive voltage line PL.

[0056] The driving TFT T1 can be connected to the driving voltage line PL and the storage capacitor Cst, and the driving current flowing from the driving voltage line PL to the organic light-emitting diode (OLED) can be controlled according to the voltage value stored in the storage capacitor Cst. The OLED can emit light with a specific brightness according to the driving current.

[0057] although Figure 3A The pixel circuit PC shown includes two TFTs and a storage capacitor, but this disclosure is not limited thereto. Although Figure 3A The TFT shown is a p-type TFT, but this disclosure is not necessarily limited to this, and at least one TFT may be an n-type TFT. In other embodiments, the switching TFT T2 may be designed as an n-type TFT, and the driving TFT T1 may be designed as a p-type TFT.

[0058] refer to Figure 3B The pixel circuit PC may include a driving TFT T1, a switching TFT T2, a compensation TFT T3, a first initialization TFT T4, a first emission control TFT T5, a second emission control TFT T6, and a second initialization TFT T7.

[0059] although Figure 3B It shows that a signal line SL is provided for each pixel P. n SL n-1 This disclosure covers the cases of EL and DL, the initialization voltage line VL, and the drive voltage line PL, but is not limited thereto. In other embodiments, the initialization voltage line VL and / or signal line SL... n SL n-1 At least one of EL and DL can be shared by adjacent pixels.

[0060] The electrode of driving TFT T1 can be electrically connected to an organic light-emitting diode (OLED) via a second emission control TFT T6. Driving TFT T1 can receive data signal D according to the switching operation of switching TFT T2. m It also provides driving current to organic light-emitting diodes (OLEDs).

[0061] The gate electrode of the switching TFT T2 can be connected to the first scan line SL. n Furthermore, the first electrode of the switching TFT T2 can be connected to the data line DL. The second electrode of the switching TFT T2 can be connected to the first electrode of the driving TFT T1 and connected to the driving voltage line PL via the first emission control TFT T5.

[0062] Switch TFT T2 can respond to the first scan line SL n The first scan signal S received nAnd conduction, and perform a switching operation to transmit the data signal D m Data is transmitted from the data line DL to the first electrode of the driving TFT T1.

[0063] The gate electrode of the compensation TFT T3 can be connected to the first scan line SL. n The first electrode of the compensation TFT T3 can be connected to the second electrode of the driving TFT T1, and is connected to the pixel electrode of the organic light-emitting diode OLED via the second emission control TFT T6. The second electrode of the compensation TFT T3 can be connected to the electrode of the storage capacitor Cst, the first electrode of the first initialization TFT T4, and the gate electrode of the driving TFT T1. The compensation TFT T3 can respond to the first scan line SL. n The first scan signal S received n The circuit is turned on, and the gate electrode of the driving TFT T1 is connected to the second electrode of the driving TFT T1, so that the driving TFT T1 can be diode connected.

[0064] The gate electrode of the first initialization TFT T4 can be connected to the second scan line (e.g., the previous scan line) SL. n-1 The second electrode of the first initialization TFT T4 can be connected to the initialization voltage line VL. The first electrode of the first initialization TFT T4 can be connected to the electrode of the storage capacitor Cst, the second electrode of the compensation TFT T3, and the gate electrode of the driving TFT T1. The first initialization TFT T4 can respond to the second scan line SL. n-1 Received second scan signal S n-1 It is then turned on and performs an initialization operation to transfer the initialization voltage VINT to the gate electrode of the driving TFT T1 in order to initialize the voltage of the gate electrode of the driving TFT T1.

[0065] The gate electrode of the first emission control TFT T5 can be connected to the emission control line EL. The first electrode of the first emission control TFT T5 can be connected to the drive voltage line PL. The second electrode of the first emission control TFT T5 can be connected to the first electrode of the driving TFT T1 and the second electrode of the switching TFT T2.

[0066] The gate electrode of the second emission control TFT T6 can be connected to the emission control line EL. The first electrode of the second emission control TFT T6 can be connected to the second electrode of the driving TFT T1 and the first electrode of the compensation TFT T3. The second electrode of the second emission control TFT T6 can be electrically connected to the pixel electrode of the organic light-emitting diode (OLED). The first emission control TFT T5 and the second emission control TFT T6 can respond to the emission control signal E received through the emission control line EL. nSimultaneously, the circuit is turned on, allowing the first power supply voltage ELVDD to be transmitted to the organic light-emitting diode (OLED), and the driving current to flow to the OLED.

[0067] The gate electrode of the second initialization TFT T7 can be connected to the second scan line SL. n-1 The first electrode of the second initialization TFT T7 can be connected to the pixel electrode of the organic light-emitting diode (OLED). The second electrode of the second initialization TFT T7 can be connected to the initialization voltage line VL. The second initialization TFT T7 can respond to the second scan line SL. n-1 Received second scan signal S n-1 This enables the conduction of light and initializes the pixel electrodes of the organic light-emitting diode (OLED).

[0068] although Figure 3B The first initialization TFT T4 and the second initialization TFT T7 are shown connected to the second scan line SL. n-1 However, this disclosure is not limited thereto. In other embodiments, the first initialization TFT T4 may be connected to a second scan line SL, which serves as the previous scan line. n-1 And in response to the second scan signal S n-1 The second initialization TFT T7 is driven, and can be connected to a separate signal line (e.g., the next scan line) and driven in response to a signal transmitted to the corresponding scan line.

[0069] The other electrode of the storage capacitor Cst can be connected to the drive voltage line PL. The electrode of the storage capacitor Cst can be connected to the gate electrode of the drive TFT T1, the second electrode of the compensation TFT T3, and the first electrode of the first initialization TFT T4.

[0070] The opposite electrode (e.g., cathode) of an organic light-emitting diode (OLED) can receive a second power supply voltage (e.g., common power supply voltage) ELVSS. The OLED can receive a driving current from the driving TFT T1 and emit light externally.

[0071] although Figure 3B The TFT shown is a p-type TFT, but this disclosure is not necessarily limited to this, and at least one TFT may be an n-type TFT.

[0072] In other embodiments, the current leakage-sensitive switching TFTs T3 and T4 can be designed as n-type TFTs, and the remaining TFTs T1, T2, and T5 through T7 can be designed as p-type TFTs. In other embodiments, the n-type TFT can be a TFT using an oxide active layer capable of reducing current leakage in the off state, and the p-type TFT can be a TFT using a polysilicon-based active layer with good drive speed and stable bias stress.

[0073] Pixel circuit PC is not limited to reference Figure 3A and Figure 3B The number of TFTs and storage capacitors and the circuit design are described, and the number of TFTs and storage capacitors and the circuit design can be modified in various ways.

[0074] Figure 4 This is a schematic cross-sectional view showing the pixels of the display device described above according to an embodiment.

[0075] refer to Figure 4 The pixel circuit PC, including the TFT 320, can be formed on the first substrate 310. An insulating layer (also known as a planarization layer) 315 can be formed to cover the pixel circuit PC. An organic light-emitting diode (OLED) electrically connected to the pixel circuit PC can be formed on the insulating layer 315. Figure 4 TFT 320 in the reference can correspond to the reference. Figure 3A Described driving TFT T1 or reference Figure 3B The second emission control TFT T6 is described.

[0076] A buffer layer 311, which is provided (or formed) as an insulating layer, may be formed on the first substrate 310. The active layer 321 of the TFT 320 may be formed on the buffer layer 311.

[0077] The TFT 320 may include a semiconductor active layer 321, a gate electrode 322, a first electrode 323, and a second electrode 324. The gate electrode 322 may overlap with the channel region, and a gate insulating layer 312 may be interposed between them. The gate insulating layer 312 may be disposed between the gate electrode 322 and at least the channel region of the active layer 321. The first electrode 323 and the second electrode 324 may be connected to the source region and drain region of the active layer 321, respectively.

[0078] The active layer 321 may include polycrystalline silicon or amorphous silicon.

[0079] In other embodiments, the active layer 321 may comprise an oxide of at least one material 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 321 may comprise an oxide semiconductor such as indium gallium zinc oxide (IGZO), zinc tin oxide (ZTO), or zinc indium oxide (ZIO). In other embodiments, the active layer 321 may comprise IGZO. When the active layer 321 comprises an oxide semiconductor, current leakage in the off-state can be reduced.

[0080] The gate insulating layer 312 may include silicon oxide (SiO2). x ) or silicon nitride (SiN) x The gate electrode 322 may be a single layer or multiple layers comprising 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), lithium (Li), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten (W), and copper (Cu).

[0081] When the active layer 321 comprises a silicon-based material, each of the source and / or drain regions may be doped with impurities. In other embodiments, when the active layer 321 comprises an oxide semiconductor, the source and drain regions may be made conductive by means of plasma or the like to improve conductivity.

[0082] After the gate electrode 322 is formed, it can be used as a self-aligned mask to dope impurities into the portion of the active layer 321 that does not overlap with the gate electrode 322, or to perform plasma treatment on the portion of the active layer 321 that does not overlap with the gate electrode 322. Therefore, the conductivity of the source and drain regions can be improved.

[0083] An interlayer insulating layer 313 can be formed on the buffer layer 311 to cover the active layer 321, the gate electrode 322, and the gate insulating layer 312. Holes exposing the source and drain regions of the active layer 321 can be formed by an etching process. The interlayer insulating layer 313 can be made of materials such as silicon oxide (SiO2). x ), silicon nitride (SiN) x Single or multiple layers of inorganic materials, such as alumina (Al2O3) and / or aluminum oxide (Al2O3).

[0084] The first electrode 323 and the second electrode 324 can be formed on the interlayer insulating layer 313. The first electrode 323 and the second electrode 324 can be electrically connected to the source region and the drain region of the active layer 321, respectively, through holes formed in the interlayer insulating layer 313.

[0085] Passivation layer 314 can be formed on interlayer insulating layer 313. Planarization layer 315 can be formed on passivation layer 314. Passivation layer 314 can be composed of materials such as silicon oxide (SiO2). x ), silicon nitride (SiN) x The planarization layer 315 may comprise a single or multiple layers of inorganic materials such as poly(methyl methacrylate) (PMMA) or polystyrene (PS), polymer derivatives having phenolic groups, acrylic acid-based polymers, imide-based polymers, aryl ether-based polymers, amide-based polymers, fluorine-based polymers, p-xylene-based polymers, vinyl alcohol-based polymers, and any blends thereof, but this disclosure is not limited thereto. In embodiments, a stacked structure in which passivation layer 314 and planarization layer 315 are sequentially formed on interlayer insulating layer 313 is shown, but this disclosure is not necessarily limited thereto, and only one of passivation layer 314 and planarization layer 315 may be used. In the following embodiments, a stacked structure in which passivation layer 314 and planarization layer 315 are sequentially formed is described.

[0086] The hole exposing the second electrode 324 can be formed in the passivation layer 314 and the planarization layer 315 by an etching process.

[0087] Organic light-emitting diodes (OLEDs) can be formed on the planarization layer 315.

[0088] An organic light-emitting diode (OLED) may include a pixel electrode 331, an organic layer 333, and a counter electrode 332. The pixel electrode 331 may be disposed on a planarization layer 315, electrically connected to a TFT 320, and exposed to the outside while its edge portions are covered by a pixel defining layer 316. The organic layer 333 may be configured to correspond to (or overlap with) the pixel electrode 331 exposed through the pixel defining layer 316. The counter electrode 332 may be formed on the organic layer 333 as a common electrode covering both the organic layer 333 and the pixel defining layer 316.

[0089] A pixel defining layer 316 may be disposed on the pixel electrode 331. The pixel defining layer 316 may define a pixel region by having an opening corresponding to (or overlapping with) each of the pixels P (e.g., an opening exposing a portion of the pixel electrode 331). For example, the pixel defining layer 316 may prevent arcing or the like between the edge portion of the pixel electrode 331 and the opposite electrode 332 by increasing the distance between them.

[0090] The pixel-defining layer 316 may include organic insulating materials and inorganic insulating materials, or it may include only organic insulating materials or only inorganic insulating materials.

[0091] During the manufacturing process or due to material limitations, the pixel defining layer 316 may include impurity components, such as reactive components. According to an embodiment, the reactive component may include unrefined chlorine (Cl).

[0092] In other embodiments, the active layer of one of the TFTs included in the pixel circuit PC may include an oxide semiconductor, such as IGZO. Therefore, current leakage in the off-state can be reduced.

[0093] However, oxide semiconductors may be sensitive to external light, which alters the characteristics of display devices.

[0094] As one method of blocking external light, the pixel defining layer 316 can be made of an opaque material. For example, the pixel defining layer 316 can use a material including black pigment. When using a black pixel defining layer 316 including black pigment, the reliability of the display device can be improved. For example, the threshold voltage (Vth) fluctuation range can be reduced.

[0095] In the case where the active layer is a silicon-based semiconductor, a black pixel defining layer 316 comprising black pigment can be applied. The use of the black pixel defining layer 316 can further increase the contrast of the pixels.

[0096] The black pixel-defining layer 316, including black pigment, may require a chlorine (Cl) component for the synthesis of the binder. When using a cardo-type binder, a Cl component is necessary. For the epoxy reaction of carbon-based binders, the presence of Cl- may be unavoidable.

[0097] However, the purification effect is limited when the Cl component is purified by an adsorption filter. Table 1 below shows the change in Cl- ions (unit: ppm) in the Cado-type binder according to the number of purifications, and indicates that the purification effect does not improve after two or more purifications.

[0098] [Table 1]

[0099] As described above, impurities such as Cl in the pixel defining layer 316 may damage the pixel electrode 331. According to an embodiment, the impurities may react with the metallic components of the pixel electrode 331, thereby forming voids in the pixel electrode 331.

[0100] To address the above issues, the pixel electrode 331 may include a protective layer.

[0101] Figure 5 yes Figure 4 An enlarged schematic cross-sectional view of region A is shown, and a specific cross-section of the organic light-emitting diode according to the embodiment is also shown.

[0102] Pixel electrode 331 can be formed on planarization layer 315. Pixel defining layer 316 can be formed to cover pixel electrode 331. Openings can be drilled in pixel defining layer 316 to expose pixel electrode 331.

[0103] Organic layer 333 and relative electrode 332 can be stacked on top of exposed pixel electrode 331.

[0104] The organic layer 333 may include an emitting layer 3333. The emitting layer 3333 may include an organic light-emitting material that emits red, green, blue, or white light for each pixel. The organic light-emitting material may include low-molecular-weight organic materials or high-molecular-weight organic materials.

[0105] The emitter layer 3333 can include various organic materials, such as copper phthalocyanine, N,N'-di(naphthyl-1-yl)-N,N'-diphenylbenzidine, and tri-8-hydroxyquinoline aluminum (Alq3). These layers can be formed by vacuum deposition.

[0106] The organic light-emitting diode (OLED) may further include a functional layer disposed adjacent to the emitter layer 3333. For example, a first intermediate layer 3331 may be disposed between the pixel electrode 331 and the emitter layer 3333, and a second intermediate layer 3332 may be disposed between the emitter layer 3333 and the opposing electrode 332. The first intermediate layer 3331 may include a hole injection layer (HIL) and / or a hole transport layer (HTL), and the second intermediate layer 3332 may include an electron transport layer (ETL) and / or an electron injection layer (EIL). The first intermediate layer 3331 and the second intermediate layer 3332 may be configured to correspond to (or overlap with) the pixel electrode 331, and may extend along the planar direction to correspond to (or overlap with) the pixel defining layer 316.

[0107] When the organic layer 333 comprises a polymer material, the organic layer 333 may typically have a structure including an HTL and an emission layer. For example, the HTL may comprise poly(3,4-ethylenedioxythiophene) (PEDOT), and the emission layer may comprise polymer materials such as polyphenylene vinylidene (PPV) and polyfluorene.

[0108] The structure of the organic layer 333 is not limited to those described above, and the organic layer 333 may have other structures. For example, at least one of the layers constituting the organic layer 333 may be integrally formed across the pixel electrode 331. For example, the organic layer 333 may include layers patterned to correspond to (or overlap with) each of the pixel electrodes 331.

[0109] The relative electrode 332 can be disposed above the display area DA and can cover the display area DA. For example, the relative electrode 332 can be integrally formed to cover the pixel P.

[0110] According to an embodiment, a top-emitting structure can be achieved because light from the emitting layer 3333 is emitted toward the opposing electrode 332. Therefore, the opposing electrode 332 can be provided (or formed) as a transparent conductive layer or a semi-transparent conductive layer. According to an embodiment, the opposing electrode 332 may include a metal thin film having a low work function and comprising Li, Ca, LiF / Ca, LiF / Al, Al, Ag, Mg, and any of their compounds. In some embodiments, a transparent conductive oxide (TCO) layer such as ITO, indium zinc oxide (IZO), zinc oxide (ZnO), or indium oxide (In2O3) may be further disposed on the metal thin film.

[0111] The relative electrode 332 can extend not only to the display area DA, but also to... Figure 1 The non-display area NDA is shown outside the display area DA.

[0112] Because the relative electrode 332 is formed to cover the entire display area DA, its resistance may be relatively high compared to other wiring or electrodes. When the resistance of the relative electrode 332 is too high, IR drop and brightness deviation may occur. Therefore, by further providing auxiliary electrodes electrically connected to the relative electrode 332 in the non-display area NDA and / or the display area DA, the IR drop of the relative electrode 332 can be reduced.

[0113] The pixel electrode 331 formed on the planarization layer 315 may include a first pixel electrode 3311, a reflective layer 3313, and a protective layer 3314.

[0114] The first pixel electrode 3311 may be provided (or formed) as a transparent conductive layer or a semi-transparent conductive layer, and may include at least one selected from, for example, ITO, IZO, ZnO, In2O3, indium gallium oxide (IGO) and aluminum zinc oxide (AZO).

[0115] According to the embodiment, the first pixel electrode 3311 may be in contact with the organic layer 333, and ITO may be used. When using ITO, the work function gap between the organic layer 333 (e.g., the first intermediate layer 3331, e.g., HTL) and the first pixel electrode 3311 can be appropriately matched to prevent an increase in the driving voltage.

[0116] The reflective layer 3313 can be disposed from the first pixel electrode 3311 in a direction away from the organic layer 333.

[0117] The reflective layer 3313 may include a reflective material, including Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or any compound thereof. According to other embodiments, the reflective layer 3313 may include Ag or an Ag compound.

[0118] The reflective layer 3313 can reflect light from the emission layer 3333 of the organic layer 333 toward the opposite electrode 332, and thus, top emission can be achieved.

[0119] According to an embodiment, the protective layer 3314 protecting the reflective layer 3313 may be further included between the first pixel electrode 3311 and the reflective layer 3313.

[0120] As described above, the protective layer 3314 can protect the reflective layer 3313 from the effects of unrefined impurity elements included in the pixel defining layer 316, and can also protect the reflective layer 3313 from the penetration of external gases.

[0121] As described above, when the pixel defining layer 316 includes unrefined chlorine (Cl) element, crystallization occurs on the first pixel electrode 3311 during the process of curing the pixel defining layer 316. Therefore, the chlorine (Cl) component included in the pixel defining layer 316 may permeate into the reflective layer 3313 between the crystal pinholes. For example, the metallic material of the reflective layer 3313 may react with Cl- ions to form compounds such as AgCl. This may result in defects in the form of voids within the reflective layer 3313.

[0122] The protective layer 3314 can prevent pixel defects by protecting the reflective layer 3313 from external influences (e.g., external elements penetrating into the reflective layer 3313 from the pixel defining layer 316). The protective layer 3314 can also prevent the metallic components of the reflective layer 3313 from being oxidized due to the penetration of external oxygen or moisture.

[0123] In other embodiments, the protective layer 3314 may be provided (or formed) as a transparent conductive layer or a semi-transparent conductive layer. Because the protective layer 3314 is provided (or formed) as a transparent conductive layer or a semi-transparent conductive layer, the reduction of the reflectivity of the reflective layer 3313 to the protective layer 3314 can be prevented.

[0124] In other embodiments, the protective layer 3314 may be provided (or formed) as a transparent or semi-transparent conductive layer having amorphous properties stronger than those of the material forming the first pixel electrode 3311. For example, when ITO is used as the first pixel electrode 3311, the protective layer 3314 may use IGZO, indium tin gallium zinc oxide (ITGZO), and / or ZIO, which have amorphous properties stronger than those of ITO. For example, the protective layer 3314 may mitigate crystallization of the first pixel electrode 3311. In the event of crystallization of the first pixel electrode 3311, the protective layer 3314 may act as an amorphous layer, serving as a partition to prevent external air penetration, thereby protecting the reflective layer 3313 disposed beneath the protective layer 3314.

[0125] In other embodiments, the second pixel electrode 3312 may be further disposed below the reflective layer 3313. The second pixel electrode 3312 may be a portion directly connected or electrically connected to the pixel circuit PC, and may comprise a transparent conductive metal oxide or a semi-transparent conductive metal oxide. The second pixel electrode 3312 may comprise at least one selected from ITO, IZO, ZnO, In2O3, IGO, and AZO, and the second pixel electrode 3312 and the first pixel electrode 3311 may comprise the same material to simplify the process.

[0126] According to an embodiment, the second pixel electrode 3312 may contact the second electrode 324 of the TFT 320 of the pixel circuit PC. The second pixel electrode 3312 may include ITO and may have an ohmic contact with the second electrode 324.

[0127] The second pixel electrode 3312 can be used in the implementation method.

[0128] According to other embodiments, the protective layer 3314 may include a transparent conductive metal oxide or a semi-transparent conductive metal oxide. For example, the amount of oxygen in the protective layer 3314 may be greater than the amount of oxygen in the first pixel electrode 3311.

[0129] For example, the protective layer 3314 may include ITO, and oxygen plasma may be applied to the protective layer 3314 after the ITO layer is formed. Therefore, the amount of oxygen in the protective layer 3314 can be increased. After the protective layer 3314 is formed, the first pixel electrode 3311 can be formed again on the protective layer 3314 using ITO. The protective layer 3314, comprising the same transparent or semi-transparent conductive metal oxide as the first pixel electrode 3311, can act as (or be used as) a pixel electrode that overcomes the work function difference with the organic layer 333, together with the first pixel electrode 3311.

[0130] Figure 6This is an embodiment in which ITO is used as a protective layer 3314, and the protective layer 3314 is shown as a graph of the X-ray diffraction (XRD) difference according to the oxygen plasma treatment time.

[0131] Crystallinity increases with increasing intensity of the (222) peak corresponding to the main crystal plane of ITO. However, from Figure 6 It can be confirmed that the intensity of the (222) peak in ITO subjected to oxygen plasma treatment for 300 seconds is lower than that in ITO without oxygen plasma treatment, and therefore, the crystallinity can be low. Thus, the protective layer 3314 can adequately protect the reflective layer 3313.

[0132] According to other embodiments, the protective layer 3314 may include a transparent conductive metal oxide or a semi-transparent conductive metal oxide containing tin (Sn). The first pixel electrode 3311 may also include a transparent conductive metal oxide or a semi-transparent conductive metal oxide containing tin (Sn). According to embodiments, each of the first pixel electrode 3311 and the protective layer 3314 may include ITO. For example, the amount of Sn in the protective layer 3314 may be less than the amount of Sn in the first pixel electrode 3311.

[0133] For example, the protective layer 3314 may include ITO. The ITO layer may be formed with a small amount of Sn content. After forming the protective layer 3314, the first pixel electrode 3311 may be formed again on the protective layer 3314 using ITO. For example, the amount of Sn content in the first pixel electrode 3311 may be greater than the amount of Sn content in the protective layer 3314. The protective layer 3314, which includes the same transparent conductive metal oxide or semi-transparent conductive metal oxide as the first pixel electrode 3311, may act together with the first pixel electrode 3311 as (or be used as) a pixel electrode that overcomes the difference in work function with the organic layer 333.

[0134] Figure 7 This is a graph showing the XRD difference of the protective layer 3314 according to the concentration ratio of tin (Sn) in an embodiment where ITO is used as the protective layer 3314.

[0135] As mentioned above, crystallinity increases with increasing intensity of the (222) peak corresponding to the main crystal plane of ITO. However, from Figure 7 It can be confirmed that when the concentration of tin (Sn) is about 30 wt%, the intensity of peak (222) is high, and therefore, the crystallinity increases. Therefore, it is desirable to have the concentration of tin (Sn) in the protective layer 3314 as low as possible. Thus, for example, the protective layer 3314 can adequately protect the reflective layer 3313.

[0136] Figure 8This illustrates an embodiment according to another method. Figure 4 A schematic cross-sectional view of region A.

[0137] exist Figure 8 In the embodiment shown, the protective layer 3314 may include a first protective layer 33141 and a second protective layer 33142.

[0138] The first protective layer 33141 can be formed on the reflective layer 3313 using the same material as the first pixel electrode 3311, and the second protective layer 33142 can be formed as an amorphous layer between the first protective layer 33141 and the first pixel electrode 3311. The amorphous properties of the second protective layer 33142 can be relatively higher than those of the first protective layer 33141. In the above embodiments, the second protective layer 33142 and the protective layer 3314 can include the same material.

[0139] In other embodiments, similar to the first pixel electrode 3311, the first protective layer 33141 may include ITO. For example, the second protective layer 33142 may use IGZO, ITGZO, and / or ZIO, which have stronger amorphous properties than ITO.

[0140] In other embodiments, the second protective layer 33142 may be a transparent or semi-transparent conductive metal oxide having more oxygen than the first protective layer 33141 and / or the first pixel electrode 3311, for example, ITO on which an oxygen plasma treatment for a set time is performed.

[0141] In other embodiments, the second protective layer 33142 may be a transparent or semi-transparent conductive metal oxide having less tin (Sn) than the first protective layer 33141 and / or the first pixel electrode 3311, for example, ITO having even less Sn.

[0142] When using a stacked structure of the first protective layer 33141 and the second protective layer 33142, the reflectivity of the reflective layer 3313 can be kept from being significantly reduced by controlling the thickness of the stacked structure.

[0143] For example, in a comparative example where Ag is formed to a thickness of approximately 800 Å as the reflective layer 3313 and ITO is formed to a thickness of approximately 115 Å as the first pixel electrode 3311, and in an example where Ag is formed to a thickness of approximately 800 Å as the reflective layer 3313, ITO is formed to a thickness of approximately 50 Å as the first protective layer 33141, ITGZO is formed to a thickness of approximately 50 Å as the second protective layer 33142, and ITO is formed to a thickness of approximately 65 Å as the first pixel electrode 3311, reflectivities of approximately 95.8% and approximately 95.4% are observed, respectively, even after a curing process is performed on the pixel defining layer 316. Therefore, it can be confirmed that almost identical reflectivities are observed.

[0144] In other embodiments, the stacking of the first pixel electrode 3311 and the protective layer 3314 described above can have a structure in which multiple layers are stacked by repeatedly applying the process. For example, the reflectivity of the reflective layer 3313 can be slightly reduced, but the reflective layer 3313 can be reliably protected from the effects of external air and / or external impurity elements. Therefore, the reliability of the organic light-emitting diode OLED can be improved.

[0145] Figure 9 This illustrates other embodiments. Figure 4 A schematic cross-sectional view of region A.

[0146] refer to Figure 9 The first-1 protective layer 3314-1 can be formed on the reflective layer 3313, and the first-1 pixel electrode 3311-1 can be formed on the first-1 protective layer 3314-1. The first-2 protective layer 3314-2 can be formed on the first-1 pixel electrode 3311-1, and the first-2 pixel electrode 3311-2 can be formed on the first-2 protective layer 3314-2.

[0147] The first-1 pixel electrode 3311-1 and the first-2 pixel electrode 3311-2 may contain the same material as the first pixel electrode 3311 in the above embodiment, and the first-1 protective layer 3314-1 and the first-2 protective layer 3314-2 may contain the same material as the protective layer 3314 described above.

[0148] By simply repeating the stacking process, the manufacturing process can be further simplified, and the level of protection for the reflective layer 3313 can be further increased.

[0149] The display device according to the above embodiments can minimize defects in a structure capable of implementing (or constructing) a top-emitting structure by protecting the reflective layer from the influence of external air or impurity elements. When using a black pixel-defining layer, void defects in the reflective layer can be minimized because unrefined chlorine (Cl) components can penetrate into the pinholes through the grain boundary barrier of the crystalline first pixel electrode and react with the reflective layer. Therefore, this can be a more useful structure in structures using a black pixel-defining layer to minimize the influence of external light.

[0150] A method for manufacturing a display device having the aforementioned structure is described.

[0151] refer to Figure 4 A circuit substrate comprising a pixel circuit PC including at least one TFT 320 can be fabricated. As described above, the pixel circuit PC may include TFTs using silicon-based semiconductors and / or oxide-based semiconductors.

[0152] In other embodiments, the active layer of one of the TFTs included in the pixel circuit PC may include an oxide semiconductor, such as IGZO. Therefore, current leakage in the off-state can be reduced.

[0153] Pixel electrodes 331 electrically connected to the pixel circuit PC can be formed on the planarization layer 315 of the circuit substrate.

[0154] A pixel defining layer 316 can be formed on the planarization layer 315 to cover the pixel electrode 331. An opening exposing a portion of the pixel electrode 331 can be formed by an etching process.

[0155] The pixel-defining layer 316 may include organic insulating materials and inorganic insulating materials, or it may include only organic insulating materials or only inorganic insulating materials.

[0156] In other embodiments, the pixel defining layer 316 may include a material containing black pigment to block (or absorb) external light. The black pixel defining layer 316 containing black pigment may require a chlorine (Cl) component for the synthesis of the binder. A Cl component may be required when using a Cado-type binder. For epoxy reactions with carbon-based binders, the inclusion of Cl- may be unavoidable.

[0157] An organic layer 333 and a counter electrode 332 can be stacked on top of the exposed pixel electrode 331.

[0158] In the implementation method, such as Figure 5 As shown, a first intermediate layer 3331, an emissive layer 3333, and a second intermediate layer 3332 can be stacked on the pixel electrode 331 to form an organic layer 333.

[0159] A counter electrode 332 may be formed to cover the organic layer 333. The counter electrode 332 may be provided (or formed) as a transparent conductive layer or a semi-transparent conductive layer. According to embodiments, the counter electrode 332 may comprise a metal thin film having a low work function, and includes Li, Ca, LiF / Ca, LiF / Al, Al, Ag, Mg, and any compounds thereof. In some embodiments, a transparent conductive oxide (TCO) layer such as ITO, IZO, ZnO, or In2O3 may be further disposed on the metal thin film.

[0160] In some embodiments, the pixel electrodes 331 can be stacked to include a first pixel electrode 3311, a reflective layer 3313, and a protective layer 3314.

[0161] According to the embodiment, a second pixel electrode 3312 can be formed on the planarization layer 315 for ohmic contact with the pixel circuit PC, and a reflective layer 3313 can be formed on the second pixel electrode 3312. A protective layer 3314 can be formed to cover the reflective layer 3313, and a first pixel electrode 3311 can be formed to cover the protective layer 3314. An organic layer 333 can be deposited on the first pixel electrode 3311.

[0162] The second pixel electrode 3312 may be a portion directly connected or electrically connected to the pixel circuit PC, and may include a transparent conductive metal oxide or a semi-transparent conductive metal oxide. The second pixel electrode 3312 may include at least one selected from ITO, IZO, ZnO, In2O3, IGO, and AZO, and the second pixel electrode 3312 and the first pixel electrode 3311 may include the same material to simplify the process.

[0163] The reflective layer 3313 may include a reflective material, including Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or any compound thereof. According to other embodiments, the reflective layer 3313 may include Ag or an Ag compound.

[0164] The first pixel electrode 3311 may be provided (or formed) as a transparent conductive layer or a semi-transparent conductive layer, and may include at least one selected from, for example, ITO, IZO, ZnO, In2O3, IGO, and AZO. According to embodiments, the first pixel electrode 3311 may be in contact with the organic layer 333, and ITO may be used. When using ITO, the work function gap between the organic layer 333 (e.g., the first intermediate layer 3331, e.g., HTL) and the first pixel electrode 3311 can be appropriately matched to prevent an increase in driving voltage.

[0165] In other embodiments, the protective layer 3314 may be provided (or formed) as a transparent or semi-transparent conductive layer having amorphous properties stronger than those of the material forming the first pixel electrode 3311. For example, when ITO is used as the first pixel electrode 3311, the protective layer 3314 may use IGZO, ITGZO, and / or ZIO having amorphous properties stronger than those of ITO.

[0166] According to other embodiments, the protective layer 3314 may include a transparent conductive metal oxide or a semi-transparent conductive metal oxide. For example, the amount of oxygen in the protective layer 3314 may be greater than the amount of oxygen in the first pixel electrode.

[0167] For example, the protective layer 3314 may include ITO, and oxygen plasma may be applied to the protective layer 3314 after the ITO layer is formed. Therefore, the amount of oxygen in the protective layer 3314 can be increased. After forming the protective layer 3314, the first pixel electrode 3311 can be formed again on the protective layer 3314 using ITO. The protective layer 3314, comprising the same transparent or semi-transparent conductive metal oxide as the first pixel electrode 3311, can function together with the first pixel electrode 3311 as a pixel electrode that overcomes the work function difference with the organic layer 333.

[0168] According to other embodiments, the protective layer 3314 may include a transparent conductive metal oxide or a semi-transparent conductive metal oxide containing tin (Sn). The first pixel electrode 3311 may also include a transparent conductive metal oxide or a semi-transparent conductive metal oxide containing tin (Sn). According to embodiments, each of the first pixel electrode 3311 and the protective layer 3314 may include ITO. For example, the amount of Sn in the protective layer 3314 may be less than the amount of Sn in the first pixel electrode 3311. For example, the protective layer 3314 may include ITO. The ITO layer can be formed with a small amount of Sn. After forming the protective layer 3314, the first pixel electrode 3311 can be formed again on the protective layer 3314 using ITO. For example, the amount of Sn in the first pixel electrode 3311 may be greater than the amount of Sn in the protective layer 3314.

[0169] In other embodiments, such as Figure 8As shown, the protective layer 3314 may include a first protective layer 33141 and a second protective layer 33142. The first protective layer 33141 can be formed on the reflective layer 3313 using the same material as the first pixel electrode 3311, and the second protective layer 33142 can be formed between the first protective layer 33141 and the first pixel electrode 3311 as an amorphous layer. The amorphous properties of the second protective layer 33142 may be relatively higher than those of the first protective layer 33141. In the above embodiments, the second protective layer 33142 and the protective layer 3314 may include the same material.

[0170] In other embodiments, similar to the first pixel electrode 3311, the first protective layer 33141 may include ITO. For example, the second protective layer 33142 may use IGZO, ITGZO, and / or ZIO, which have stronger amorphous properties than ITO.

[0171] In other embodiments, the second protective layer 33142 may be a transparent or semi-transparent conductive metal oxide having more oxygen than the first protective layer 33141 and / or the first pixel electrode 3311, for example, ITO on which an oxygen plasma treatment for a set time is performed.

[0172] In other embodiments, the second protective layer 33142 may be a transparent or semi-transparent conductive metal oxide having less tin (Sn) than the first protective layer 33141 and / or the first pixel electrode 3311, for example, ITO having even less Sn.

[0173] In other embodiments, the stacking of the first pixel electrode 3311 and the protective layer 3314 in the above embodiments may have a structure in which multiple layers are stacked by repeatedly applying the process.

[0174] For example, refer to Figure 9 A first-1 protective layer 3314-1 can be formed on the reflective layer 3313, and a first-1 pixel electrode 3311-1 can be formed on the first-1 protective layer 3314-1. A first-2 protective layer 3314-2 can be formed on the first-1 pixel electrode 3311-1, and a first-2 pixel electrode 3311-2 can be formed on the first-2 protective layer 3314-2.

[0175] The first-1 pixel electrode 3311-1, the first-2 pixel electrode 3311-2, and the first pixel electrode 3311 in the above embodiments may include the same material, and the first-1 protective layer 3314-1, the first-2 protective layer 3314-2, and the protective layer 3314 may include the same material.

[0176] refer to Figure 10 The display device can be applied to electronic devices including a smartwatch 1000, which includes a display portion 1100 and a strip portion 1200.

[0177] The smartwatch 1000 can be a wearable electronic device. For example, the smartwatch 1000 may have a structure in which the strap portion 1200 is mounted on the user's wrist. A display device may be applied to the display portion 1100 so that image data including time information can be provided to the user.

[0178] refer to Figure 11 Electronic devices may include head-mounted display devices 2000.

[0179] The head-mounted display device 2000 can be a wearable electronic device that is worn on a user's head. For example, the head-mounted display device 2000 can be a wearable device for virtual reality (VR) or mixed reality (MR). The head-mounted display device 2000 may include a headband 2100 and a display housing 2200. The headband 2100 may be connected to the display housing 2200. The headband 2100 may include a horizontal strap and / or a vertical strap for securing the head-mounted display device 2000 to the user's head. The horizontal strap may be configured to surround the side portion of the user's head, and the vertical strap may be configured to surround the upper portion of the user's head. However, the implementation is not limited thereto. For example, within the spirit and scope of this disclosure, the headband 2100 may be implemented in the form of an eyeglass frame, a helmet, etc.

[0180] For example, the electronic device can be at least one of a smartwatch, mobile phone, smartphone, portable computer, tablet PC, watch phone, car display, smart glasses, portable multimedia player (PMP), navigation system, ultra-mobile computer (UMPC), head-mounted display (HMD) device, virtual reality (VR) device, mixed reality (MR) device, and augmented reality (AR) device.

[0181] By simply repeating the stacking process, the manufacturing process can be further simplified, and the level of protection for the reflective layer 3313 can be further increased.

[0182] According to the implementation, in structures capable of realizing (or implementing) a top-emitting structure, defects can be minimized by protecting the reflective layer from external air or impurity elements. In the case of using a black pixel-defining layer, void defects in the reflective layer can be minimized because unrefined chlorine (Cl) components can penetrate into the pinholes through the grain boundary barrier of the crystalline first pixel electrode and react with the reflective layer. Therefore, this can be a more useful structure in applications such as oxide semiconductors that use a black pixel-defining layer to minimize the influence of external light.

[0183] Each of the above embodiments can be implemented independently, but obviously, the structure of each of the embodiments can be combined and applied to other embodiments.

[0184] This disclosure has been described with reference to embodiments shown in the accompanying drawings, but these are merely examples. It will be understood by those skilled in the art that various modifications and equivalents can be made therein. Therefore, the true scope of protection of this disclosure should be defined by the technical spirit of the appended claims.

[0185] The specific implementations described in the embodiments are implementation methods, which do not limit the scope of the implementation methods in any way. Where no specific references are made to terms such as "essential" or "important," they may not be essential components for the application of this disclosure.

[0186] In concluding this detailed description, those skilled in the art will appreciate that many variations and modifications can be made to the embodiments without substantially departing from the principles, spirit, and scope of this disclosure. Therefore, the disclosed embodiments are used in a general and descriptive sense only and are not intended to be limiting.

Claims

1. A display device, comprising: Pixel circuitry, including at least one thin-film transistor; Organic light-emitting diodes are electrically connected to the pixel circuit; as well as Insulating layer, defining the pixel area. The organic light-emitting diode includes: Pixel electrodes are electrically connected to the pixel circuit. The opposing electrode is at least opposite to the pixel electrode; and An organic layer is disposed at least between the pixel electrode and the opposing electrode, and includes at least an emissive layer. The pixel electrode includes: The first pixel electrode is in contact with the organic layer; A reflective layer, opposite to the first pixel electrode, reflects light from the emitting layer; and A protective layer is disposed between the first pixel electrode and the reflective layer, and protects the reflective layer.

2. The display device according to claim 1, wherein, The protective layer includes a transparent conductive layer.

3. The display device according to claim 2, wherein, The transparent conductive layer includes an amorphous layer.

4. The display device according to claim 2, wherein, The transparent conductive layer comprises a stack of a first protective layer and a second protective layer, wherein the first protective layer comprises the same material as the first pixel electrode, and the second protective layer is formed as an amorphous layer.

5. The display device according to claim 1, wherein, Each of the first pixel electrode and the protective layer includes a transparent conductive layer containing oxygen, and The amount of oxygen in the protective layer is greater than the amount of oxygen in the first pixel electrode.

6. The display device according to claim 1, wherein, Each of the first pixel electrode and the protective layer includes a transparent conductive layer containing tin, and The amount of tin in the protective layer is less than the amount of tin in the first pixel electrode.

7. A method for manufacturing a display device, the method comprising: Fabrication of a circuit substrate comprising a pixel circuit containing at least one thin-film transistor; An organic light-emitting diode electrically connected to the pixel circuit is formed on the circuit substrate; as well as An insulating layer defining a pixel region is formed on the circuit substrate. The organic light-emitting diode (OLED) comprises: Forming pixel electrodes electrically connected to the pixel circuit; An organic layer comprising at least an emissive layer is formed on the pixel electrode; and At least on the organic layer, a counter electrode is formed. Forming the pixel electrode includes: A reflective layer is formed to reflect light from the emitting layer; A protective layer is formed on the reflective layer to protect the reflective layer; and A first pixel electrode is formed on the protective layer to contact the organic layer.

8. The method according to claim 7, wherein, Forming the protective layer includes forming a transparent conductive layer.

9. The method according to claim 8, wherein, The transparent conductive layer includes an amorphous layer.

10. The method according to claim 8, wherein, Forming the transparent conductive layer includes: Forming a first protective layer comprising the same material as the first pixel electrode; and A second protective layer is formed on the first protective layer, and the second protective layer is formed as an amorphous layer.

11. The method according to claim 7, wherein, Each of the first pixel electrode and the protective layer includes a transparent conductive layer containing oxygen, and Forming the protective layer includes: Forming the transparent conductive layer; and At least a portion of the transparent conductive layer is subjected to oxygen plasma treatment.

12. The method according to claim 7, wherein, Each of the first pixel electrode and the protective layer includes a transparent conductive layer containing tin, and The protective layer is formed such that the amount of tin in the protective layer is less than the amount of tin in the first pixel electrode.

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