Display device and method of manufacturing same

Abstract

The invention discloses a display device and a method of manufacturing the same. The display device includes: a base substrate; a first pixel electrode disposed on the base substrate; a pixel defining layer disposed on the first pixel electrode and including an opening exposing the first pixel electrode; an organic light emitting unit disposed on the first pixel electrode; and a second pixel electrode disposed on the organic light emitting unit. The organic light emitting unit includes: a first functional layer disposed on the first pixel electrode and including a lower surface contacting the first pixel electrode and an upper surface opposite to the lower surface; a light emitting layer disposed on the first functional layer; and a third functional layer disposed on the light emitting layer and including a lower surface contacting the light emitting layer and an upper surface opposite the lower surface.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0074268 filed in the Korean Intellectual Property Office on June 9, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] Embodiments relate to a display device and a method of manufacturing the display device. Background Art

[0004] As the information society develops, the demand for display devices for displaying images has increased in various forms. For example, display devices are applied to various electronic devices such as smart phones, digital cameras, notebook computers, navigation devices, and smart TVs.

[0005] The display device includes a flat panel display device such as a liquid crystal display device, a field emission display device or a light emitting display device. The light emitting display device includes an organic light emitting display device including an organic light emitting element, an inorganic light emitting display device including an inorganic light emitting element including, for example, an inorganic semiconductor, and an ultra-small light emitting display device including an ultra-small light emitting element.

[0006] The organic light emitting display device includes an organic light emitting element including a hole injection electrode, an electron injection electrode, and an organic light emitting layer formed therebetween, and is a self-emitting display device in which light is generated as excitons generated by the recombination of holes injected from the hole injection electrode and electrons injected from the electron injection electrode in the organic light emitting layer drop from an excited state to a ground state. Since such an organic light emitting display device has a fast response speed and is driven with low power consumption, the organic light emitting display device is attracting attention as a next-generation display. Summary of the invention

[0007] The embodiment provides a display device which provides a shape of each of light generating layers forming an organic light emitting unit, the shape being capable of widening a region in which the thickness of the light generating layer is uniformly maintained.

[0008] The embodiment provides a display device capable of improving light emission efficiency by widening a region in which a thickness of a light generating layer forming an organic light emitting unit is uniformly maintained.

[0009] The embodiment provides a display device which provides a shape of each of light generating layers forming an organic light emitting unit for widening a region in which the thickness of the light generating layer is uniformly maintained.

[0010] The embodiment provides a method of manufacturing a display device.

[0011] However, the embodiments are not limited to those set forth herein.The above and other embodiments will become more apparent to those of ordinary skill in the art to which the present disclosure pertains by referring to the detailed description of the present disclosure given below.

[0012] According to aspects of the present invention, a display device may include: a base substrate; a first pixel electrode disposed on the base substrate; a pixel defining layer disposed on the first pixel electrode and including an opening exposing the first pixel electrode; an organic light-emitting unit disposed on the first pixel electrode; and a second pixel electrode disposed on the organic light-emitting unit. The organic light-emitting unit may include: a first functional layer disposed on the first pixel electrode and including a lower surface contacting the first pixel electrode and an upper surface opposite to the lower surface; a light-emitting layer disposed on the first functional layer; and a third functional layer disposed on the light-emitting layer and including a lower surface contacting the light-emitting layer and an upper surface opposite to the lower surface, the upper surface of the first functional layer may include a first concave portion and a first convex portion formed between the first concave portions, and the upper surface of the third functional layer may include a flat surface overlapping the first convex portion of the first functional layer in a plan view.

[0013] According to an embodiment, the upper surface of the third functional layer may further include an inclined surface, and the flat surface of the third functional layer may be disposed between the inclined surfaces of the third functional layer.

[0014] According to an embodiment, the display device may further include: a second functional layer, arranged between the first functional layer and the light-emitting layer and including a lower surface contacting the first functional layer and an upper surface contacting the light-emitting layer, and the upper surface of the second functional layer may include a second recess and a second protrusion formed between the second recesses.

[0015] According to an embodiment, a difference between a minimum height of the second concave portion and a maximum height of the second convex portion may be smaller than a difference between a minimum height of the first concave portion and a maximum height of the first convex portion.

[0016] According to an embodiment, a difference between a height of a lowest point of the second concave portion and a height of a highest point of the second convex portion may be equal to or less than about 10 nm.

[0017] According to an embodiment, the light-emitting layer may include a lower surface contacting an upper surface of the second functional layer and an upper surface contacting a lower surface of the third functional layer, the lower surface of the second functional layer may have a surface profile according to the upper surface of the first functional layer, and the lower surface of the light-emitting layer may have a surface profile according to the upper surface of the second functional layer.

[0018] According to an embodiment, the second convex portion may overlap the first convex portion in a plan view.

[0019] According to an embodiment, an upper surface of the first functional layer may include at least one first inflection point, an upper surface of the second functional layer may include at least one second inflection point, and the at least one first inflection point may be closer to the pixel defining layer than the at least one second inflection point.

[0020] According to an embodiment, at least one first inflection point may include a 1-1 inflection point and a 1-2 inflection point, at least one second inflection point may include a 2-1 inflection point and a 2-2 inflection point, the first convex portion may be formed between the 1-1 inflection point and the 1-2 inflection point, and the second convex portion may be formed between the 2-1 inflection point and the 2-2 inflection point.

[0021] According to an embodiment, the first functional layer may include a hole injection layer, the second functional layer may include a hole transport layer, and the third functional layer may include an electron transport layer.

[0022] According to an embodiment, an upper surface of the third functional layer may not include an inflection point.

[0023] According to an embodiment, a lower surface of the first functional layer may have a surface profile according to a surface shape of the first pixel electrode, and the lower surface of the first functional layer may have a flat surface profile.

[0024] According to an embodiment, the base substrate may include a protruding portion overlapping the first convex portion in a plan view and protruding in a thickness direction of the display device, and the first pixel electrode may be disposed on the base substrate and have a surface profile according to a shape of the protruding portion.

[0025] According to aspects of the present invention, a method for manufacturing a display device may include: forming a first pixel electrode on a base substrate; forming a pixel defining layer including an opening exposing the first pixel electrode on the first pixel electrode; forming a first functional layer by coating and drying a first organic material on the first pixel electrode, the first functional layer having an upper surface formed with a first recess and a first protrusion formed between the first recesses; forming a light-emitting layer on the first functional layer; forming a third functional layer by coating and drying a third organic material on the light-emitting layer, the third functional layer having an upper surface formed with a flat surface overlapping the first protrusion; and forming a second pixel electrode on the third functional layer.

[0026] According to an embodiment, drying the first organic material may include: forming the first concave portion by drying an edge region of the first organic material at a first intensity; and forming the first convex portion by drying a central region of the first organic material at a second intensity less than the first intensity.

[0027] According to an embodiment, drying the third organic material may include: forming an inclined surface by drying an edge area of ​​the third organic material at a third intensity between the first intensity and the second intensity; and forming a flat surface by drying a central area of ​​the third organic material at a fourth intensity greater than the third intensity and less than the first intensity.

[0028] According to an embodiment, the method may further include forming a second functional layer by coating and drying a second organic material on the first functional layer, the second functional layer having an upper surface formed with second concave portions and second convex portions formed between the second concave portions.

[0029] According to an embodiment, drying the second organic material may include: forming a second concave portion by drying an edge area of ​​the second organic material at a fifth intensity; and forming a second convex portion by drying a central area of ​​the second organic material at a sixth intensity, the fifth intensity may be less than the first intensity and greater than the fourth intensity, and the sixth intensity may be greater than the second intensity and less than the third intensity.

[0030] According to an embodiment, the first functional layer may include a hole injection layer, the second functional layer may include a hole transport layer, and the third functional layer may include an electron transport layer.

[0031] According to an embodiment, the method may further include forming a protruding portion in a region corresponding to the first convex portion by partially etching the base substrate, and the first pixel electrode may be formed on the protruding portion.

[0032] The display device and the method of manufacturing the display device according to the embodiment may secure a region in which the stack thickness of the light generating layers forming the organic light emitting unit is uniformly maintained, thereby improving light emitting efficiency.

[0033] However, the effects of the present disclosure are not limited to the above-described effects, and various extensions may be made without departing from the spirit and scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The above and other features of the present disclosure will become more apparent by describing embodiments of the present disclosure in more detail with reference to the accompanying drawings.

[0035] Figure 1 is a schematic plan view illustrating a display device according to an embodiment.

[0036] Figure 2 It is a graphic Figure 1 Schematic circuit diagram of a sub-pixel.

[0037] Figure 3A and Figure 3B It is a graphic Figure 2 Schematic cross-sectional view of an embodiment of a light-emitting element.

[0038] Figure 4 Yes Figure 3A and Figure 3B Schematic cross-sectional view of a display device having a light-emitting element.

[0039] Figure 5A is a schematic cross-sectional view illustrating a comparative example of a sub-pixel of a display device.

[0040] Figure 5B It is a graphic Figure 5A Schematic plan view of the emission area.

[0041] Fig. 6A It is a graphic Figure 4 Schematic cross-sectional view of an embodiment of a sub-pixel.

[0042] Figure 6B It is a graphic Fig. 6A Schematic plan view of the emission area.

[0043] Figure 7 is a schematic cross-sectional view illustrating an arrangement of a first functional layer and a method of forming the first functional layer according to an embodiment.

[0044] Figure 8 is a schematic cross-sectional view illustrating an arrangement of a second functional layer and a method of forming the second functional layer according to an embodiment.

[0045] Fig. 9 is a schematic cross-sectional view illustrating an arrangement of a light emitting layer and a method of forming the light emitting layer according to an embodiment.

[0046] Fig.10 is a schematic cross-sectional view illustrating an arrangement of a third functional layer and a method of forming the third functional layer according to an embodiment.

[0047] Fig.11 It is a graphic Figure 4 Schematic cross-sectional view of an embodiment of a sub-pixel. DETAILED DESCRIPTION

[0048] In the following description, for the purpose of illustration, many specific details are set forth in order to provide a thorough understanding of various embodiments or implementations of the present invention. As used herein, "embodiment" and "implementation" are interchangeable words, which are non-limiting examples of the device or method disclosed herein. However, it is apparent that various embodiments may be practiced without these specific details or with one or more equivalent arrangements. Here, various embodiments do not have to be exclusive, nor do they limit the present disclosure. For example, the specific shape, configuration, and characteristics of an embodiment may be used or implemented in another embodiment.

[0049] Unless otherwise specified, the illustrated embodiments should be understood to provide features of the present invention. Therefore, unless otherwise specified, the features, components, modules, layers, films, panels, regions and / or aspects of various embodiments, etc. (hereinafter, individually or collectively referred to as "elements") can be combined, separated, interchanged and / or rearranged in other ways without departing from the present invention.

[0050] The use of cross hatching and / or shading in the drawings is generally provided to make the boundaries between adjacent elements clear. Therefore, unless otherwise specified, the presence or absence of cross hatching or shading does not express or indicate any preference or requirement for a particular material, material property, size, ratio, commonality between the illustrated elements and / or any other characteristics, attributes, properties, etc. of the elements. In addition, in the drawings, the size and relative size of the elements may be exaggerated for the purpose of clarity and / or description. When the embodiments can be implemented differently, the specific process sequence can be performed differently from the described sequence. For example, two processes described in succession can be performed substantially simultaneously or in an order opposite to the described order. Moreover, the same reference numerals represent the same elements.

[0051] When an element or layer is referred to as being "on" another element or layer, "connected to" or "coupled to" another element or layer, it may be directly on, connected to or coupled to the other element or layer, or there may be an intervening element or layer. However, when an element or layer is referred to as being "directly on" another element or layer, "directly connected to" or "directly coupled to" another element or layer, there is no intervening element or layer. For this reason, the term "connection" may refer to a physical, electrical and / or fluid connection with or without an intervening element. In addition, the first direction DR1, the second direction DR2 and the third direction DR3 are not limited to directions corresponding to the three axes of a rectangular coordinate system such as the X-axis, the Y-axis and the Z-axis, and may be interpreted in a broader sense. For example, the first direction DR1, the second direction DR2 and the third direction DR3 may be perpendicular to each other, or may represent different directions that are not perpendicular to each other. In addition, the X-axis, the Y-axis and the Z-axis are not limited to the three axes of a rectangular coordinate system such as the x-axis, the y-axis and the z-axis, and may be interpreted in a broader sense. For example, the X-axis, Y-axis, and Z-axis may be perpendicular to each other, or may represent different directions that are not perpendicular to each other. For the purposes of this disclosure, "at least one of A and B" may be interpreted as meaning only A, only B, or a combination of A and B. In addition, "at least one of X, Y, and Z" and "at least one selected from the group consisting of X, Y, and Z" may 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 associated listed items.

[0052] 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 element. Therefore, the first element discussed below can be referred to as the second element without departing from the teachings of the present disclosure.

[0053] Spatially relative terms such as "below," "below," "under," "down," "above," "up," "above," "higher," and "side" (e.g., as in "sidewall") may be used herein for descriptive purposes, and thereby describe the relationship of one element to another element(s) as shown in the drawings. In addition to the orientations depicted in the drawings, spatially relative terms are intended to include 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 being "below" or "below" other elements or features will then be oriented "above" the other elements or features. Thus, the term "below" can include both above and below orientations. In addition, the device can be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and therefore, the spatially relative descriptors used herein should be interpreted accordingly.

[0054] The terms used herein are used to describe the purpose of a particular embodiment and are not intended to limit. As used herein, the singular forms "one" and "the" are intended to also include plural forms unless the context clearly indicates otherwise. In addition, when used in this specification, the terms "include" and / or "comprise" and their variants indicate the presence of the features, integral bodies, steps, operations, elements, parts and / or its groups, but do not exclude the presence or addition of one or more other features, integral bodies, steps, operations, elements, parts and / or its groups. It should also be noted that, as used herein, the terms "substantially", "approximately" and other similar terms are used as approximate terms, rather than degree terms, and are therefore used to explain the inherent deviations of the measured values, calculated values ​​and / or values ​​provided that will be recognized by those of ordinary skill in the art.

[0055] Various embodiments are described herein with reference to cross-sectional illustrations and / or exploded illustrations, which are schematic illustrations of embodiments and / or intermediate structures. Therefore, variations in the shapes of the illustrations due to, for example, manufacturing techniques and / or tolerances may be expected. Therefore, the embodiments disclosed herein should not necessarily be interpreted as limited to the particular shapes of the illustrations of the regions, but rather include shape deviations caused by, for example, manufacturing. In this manner, the regions shown in the drawings may be schematic in nature, and the shapes of these regions may not reflect the actual shapes of the regions of the device, and therefore, are not necessarily intended to be limiting.

[0056] Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

[0057] Figure 1 is a schematic plan view illustrating a display device according to an embodiment.

[0058] refer to Figure 1 , structures of the display device DD and the display panel DP included in the display device DD are shown based on a display area DA displaying an image.

[0059] For convenience of description, the structure of the display device DD (eg, a display panel DP formed in the display device DD) is shown based on a display area DA displaying an image.

[0060] refer to Figure 1 The display panel DP (or display device DD) according to the embodiment may be formed in various shapes such as a rectangular plate shape having two pairs of sides parallel to each other, but the embodiment is not limited thereto. In the case where the display panel DP is formed in a rectangular plate shape, one of the two pairs of sides may be provided to be longer than the other pair of sides.

[0061] At least a portion of the display panel DP may have flexibility and may be folded at the portion having flexibility, but the embodiment is not limited thereto.

[0062] The display panel DP can display an image. As the display panel DP, a self-emitting display panel such as an organic light-emitting display panel (OLED panel) having an organic light-emitting diode as a light-emitting element, an ultra-small light-emitting diode display panel (micro-LED or nano-LED display panel) having an ultra-small light-emitting diode as a light-emitting element, and a quantum dot organic light-emitting display panel (QD OLED panel) having quantum dots and organic light-emitting diodes can be used. For example, as the display panel DP, a non-emissive display panel such as a liquid crystal display panel (LCD panel), an electrophoretic display panel (EPD panel), and an electrowetting display panel (EWD panel) can be used. In the case where a non-emissive display panel is used as the display panel DP, the display device DD may include a backlight unit that supplies light to the display panel DP.

[0063] The display panel DP may include a substrate SUB and pixels PXL disposed on the substrate SUB.

[0064] The substrate SUB may include a transparent insulating material to transmit light. The substrate SUB may be a rigid substrate or a flexible substrate.

[0065] The rigid substrate may be, for example, one of a glass substrate, a quartz substrate, a glass ceramic substrate, and a crystallized glass substrate.

[0066] The flexible substrate may be one of a film substrate and a plastic substrate including a polymerized organic material. For example, the flexible substrate may include at least one of polystyrene, polyvinyl alcohol, polymethyl methacrylate, polyether sulfone, polyacrylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyarylate, polyimide, polycarbonate, cellulose triacetate, and cellulose acetate propionate.

[0067] One area of ​​the substrate SUB may be provided as a display area DA and the pixels PXL may be disposed in the area, and the remaining area of ​​the substrate SUB may be provided as a non-display area NDA. For example, the substrate SUB may include a display area DA including a pixel area where each pixel PXL is disposed and a non-display area NDA disposed around the display area DA (or disposed adjacent to the display area DA).

[0068] The non-display area NDA may be positioned adjacent to the display area DA. The non-display area NDA may be disposed on at least one side of the display area DA. For example, the non-display area NDA may surround the periphery (or edge) of the display area DA. A line unit connected to each pixel PXL and a driver connected to the line unit and driving the pixel PXL may be formed in the non-display area NDA.

[0069] The pixel PXL may include sub-pixels. For example, the pixel PXL may include a first sub-pixel SPX1, a second sub-pixel SPX2, and a third sub-pixel SPX3. The first sub-pixel SPX1, the second sub-pixel SPX2, and the third sub-pixel SPX3 may be sequentially arranged in the second direction DR2. However, the embodiment is not limited thereto, and the first sub-pixel SPX1, the second sub-pixel SPX2, and the third sub-pixel SPX3 may be sequentially arranged in the first direction DR1 intersecting the second direction DR2.

[0070] The first sub-pixel SPX1, the second sub-pixel SPX2, and the third sub-pixel SPX3 may emit light of different colors. For example, the first sub-pixel SPX1 may be a red sub-pixel emitting red light, the second sub-pixel SPX2 may be a blue sub-pixel emitting blue light, and the third sub-pixel SPX3 may be a green sub-pixel emitting green light. However, the color, type, and / or number of sub-pixels forming the pixel PXL are not limited. For example, the color of light emitted from each of the sub-pixels SPX1, SPX2, and SPX3 may be variously changed.

[0071] According to an embodiment, the first sub-pixel SPX1, the second sub-pixel SPX2, and the third sub-pixel SPX3 may emit light of the same color. For example, all of the first sub-pixels SPX1, the second sub-pixels SPX2, and the third sub-pixel SPX3 may be sub-pixels that emit red light, green light, or blue light. For example, in order to realize a full-color pixel PXL, an optical layer such as a light conversion layer and / or a color filter for converting the color of light emitted from a corresponding unit pixel may be provided on at least a portion of the first sub-pixel SPX1, the second sub-pixel SPX2, and the third sub-pixel SPX3.

[0072] In the following embodiments, when the first sub-pixel SPX1 , the second sub-pixel SPX2 , and the third sub-pixel SPX3 are collectively referred to as sub-pixels SPX1 , the second sub-pixel SPX2 , and the third sub-pixel SPX3 , they are referred to as sub-pixels SPX.

[0073] The pixels PXL may be provided and arranged in a matrix form along rows extending in a first direction DR1 and columns extending in a second direction DR2 intersecting the first direction DR1. The arrangement form of the pixels PXL is not limited, and the pixels PXL may be arranged in various forms. According to an embodiment, in the case where the pixels PXL are provided, the pixels PXL may be provided to have different areas (or sizes). For example, in the case of pixels PXL having different colors of emitted light, the pixels PXL may be formed with different areas (or sizes) or different shapes for each color.

[0074] The driver may control driving of the pixels PXL by supplying a signal and power to each pixel PXL through a line unit.

[0075] Figure 2 It is a graphic Figure 1 Schematic circuit diagram of a sub-pixel.

[0076] exist Figure 2 , a sub-pixel SPX located in an i-th pixel row (or i-th horizontal line) and a j-th pixel column is shown (wherein i and j are natural numbers).

[0077] refer to Figure 1 and Figure 2 , the sub-pixel SPX may include a light emitting unit EMU generating light of brightness corresponding to the data signal. For example, the sub-pixel SPX may further include a pixel circuit PXC for driving the light emitting unit EMU.

[0078] The light emitting unit EMU may include a light emitting element LD connected between a first power line PL1 receiving a voltage of a first driving power source VDD (or a first power source) and a second power line PL2 receiving a voltage of a second driving power source VSS (or a second power source). For example, the light emitting unit EMU may include a light emitting element LD, the light emitting element LD including a first pixel electrode AE ​​connected to the first driving power source VDD via a pixel circuit PXC and a first power line PL1 and a second pixel electrode CE connected to the second driving power source VSS via a second power line PL2. The first pixel electrode AE ​​may be an anode, and the second pixel electrode CE may be a cathode. The first driving power source VDD and the second driving power source VSS may have different potentials. At this time, during the emission period of the sub-pixel SPX, the potential difference between the first driving power source VDD and the second driving power source VSS may be set to be higher than or equal to the threshold voltage of the light emitting element LD.

[0079] When the subpixel SPX is located in the i-th pixel row and the j-th pixel column in the display area DA, the pixel circuit PXC of the subpixel SPX can be electrically connected to the i-th scan line Si and the j-th data line Dj. For example, the pixel circuit PXC can be further electrically connected to the i-th control line CLi and the j-th sensing line SENj.

[0080] The pixel circuit PXC may include first, second and third transistors T1, T2 and T3 and a storage capacitor Cst.

[0081] The first transistor T1 may be a driving transistor for controlling a driving current applied to the light emitting element LD, and may be electrically connected between the first driving power source VDD and the light emitting element LD. For example, the second terminal of the first transistor T1 may be electrically connected to the first driving power source VDD through the first power line PL1, the first terminal of the first transistor T1 may be electrically connected to the second node N2, and the gate electrode of the first transistor T1 may be electrically connected to the first node N1. The first transistor T1 may control the amount of driving current applied to the light emitting element LD from the first driving power source VDD through the second node N2 according to the voltage applied to the first node N1. In an embodiment, the first terminal of the first transistor T1 may be a drain electrode and the second terminal of the first transistor T1 may be a source electrode, but the embodiment is not limited thereto. According to an embodiment, the first terminal may be a source electrode, and the second terminal may be a drain electrode.

[0082] The second transistor T2 may be a switching transistor that selects the sub-pixel SPX in response to the scan signal and activates the sub-pixel SPX, and may be electrically connected between the data line Dj (e.g., the j-th data line) and the first node N1. The first terminal of the second transistor T2 may be electrically connected to the data line Dj, the second terminal of the second transistor T2 may be connected to the first node N1 (or the gate electrode of the first transistor T1), and the gate electrode of the second transistor T2 may be electrically connected to the scan line Si (or the i-th scan line). The first terminal and the second terminal of the second transistor T2 may be different terminals, and for example, in the case where the first terminal is a drain electrode, the second terminal may be a source electrode.

[0083] In the case where a scan signal of a gate-on voltage (e.g., a high level voltage) is supplied from the scan line Si, the second transistor T2 may be turned on to electrically connect the data line Dj and the first node N1. The first node N1 may be a point at which the second terminal of the second transistor T2 and the gate electrode of the first transistor T1 are connected, and the second transistor T2 may transmit a data signal to the gate electrode of the first transistor T1.

[0084] The third transistor T3 can receive a sensing signal through the sensing line SENj by electrically connecting the first transistor T1 to the sensing line SENj (e.g., the jth sensing line), and detect the characteristics of the sub-pixel SPX including the threshold voltage of the first transistor T1 by using the sensing signal. Information about the characteristics of the sub-pixel SPX can be used to convert image data so that the characteristic deviation between the sub-pixels SPX can be compensated. The second terminal of the third transistor T3 can be electrically connected to the first terminal of the first transistor T1, the first terminal of the third transistor T3 can be electrically connected to the sensing line SENj, and the gate electrode of the third transistor T3 can be electrically connected to the control line CLi (e.g., the i-th control line). The first terminal of the third transistor T3 can be a drain electrode, and the second terminal of the third transistor T3 can be a source electrode.

[0085] The third transistor T3 may be an initialization transistor capable of initializing the second node N2 and may be turned on when a sensing control signal is supplied from the control line CLi to transmit the voltage of the initialization power source to the second node N2. Accordingly, the storage capacitor Cst electrically connected to the second node N2 may be initialized.

[0086] The storage capacitor Cst may include a lower electrode LE (or a first storage electrode) and an upper electrode UE (or a second storage electrode). The lower electrode LE may be electrically connected to the first node N1, and the upper electrode UE may be electrically connected to the second node N2. The storage capacitor Cst may be charged with a data voltage corresponding to a data signal supplied to the first node N1 during a frame period. Accordingly, the storage capacitor Cst may store a voltage corresponding to a difference between a voltage of the gate electrode of the first transistor T1 and a voltage of the second node N2.

[0087] exist Figure 2 , an embodiment in which the first transistor T1, the second transistor T2, and the third transistor T3 are all N-type transistors is disclosed, but the embodiment is not limited thereto. For example, at least one of the first transistor T1, the second transistor T2, and the third transistor T3 may be changed (or modified) to a P-type transistor. The structure of the pixel circuit PXC may be variously modified and implemented in various ways.

[0088] In the following embodiments, for the convenience of description, the width direction on the plane (e.g., the X-axis direction or the horizontal direction) is indicated as the first direction DR1, the height direction on the plane (e.g., the Y-axis direction or the vertical direction) is indicated as the second direction DR2, and the vertical direction on the cross section is indicated as the third direction DR3 (or the thickness direction of the display device).

[0089] Figure 3A and Figure 3B It is a graphic Figure 2 Schematic cross-sectional view of an embodiment of a light-emitting element.

[0090] refer to Figure 3A , the light emitting element LD may include a first pixel electrode AE, an organic light emitting unit EL, and a second pixel electrode CE stacked in sequence.

[0091] In an embodiment, the organic light emitting unit EL may be disposed on the first pixel electrode AE. The organic light emitting unit EL may have a multi-layer thin film structure including a light generating layer. The organic light emitting unit EL may include a hole injection layer HIL, a hole transport layer HTL, a light emitting layer EML, an electron transport layer ETL, and an electron injection layer EIL stacked in sequence.

[0092] The hole injection layer HIL may be an organic layer disposed between the first pixel electrode AE ​​and the hole transport layer HTL to facilitate injection of holes from the first pixel electrode AE ​​into the emission layer EML. The hole transport layer HTL may be disposed between the hole injection layer HIL and the emission layer EML to receive holes from the first pixel electrode AE ​​and transport the holes to the emission layer EML.

[0093] The electron injection layer EIL may be disposed between the electron transport layer ETL and the second pixel electrode CE. The electron transport layer ETL may be disposed on the light emitting layer EML to receive electrons from the second pixel electrode CE and to transfer the electrons to the light emitting layer EML.

[0094] The light emitting layer EML may be a region in which light is generated by recombination of holes and electrons supplied from the first pixel electrode AE ​​and the second pixel electrode CE, respectively. The light emitting layer EML may include an organic light emitting material such as a high molecular organic material or a low molecular organic material that emits color light. For example, the light emitting layer EML may include an organic material that emits blue light. However, the embodiment is not limited thereto. In an example, the light emitting layer EML may include an organic material that emits red light or green light, or may include an inorganic material or a quantum dot.

[0095] In an embodiment, the second pixel electrode CE may be integrally formed. The second pixel electrode CE may be disposed on the organic light emitting unit EL. The second pixel electrode CE may be integrally formed in a plurality of light emitting elements LD.

[0096] refer to Figure 3B , the light emitting element LD may include a first pixel electrode AE, an organic light emitting unit EL and a second pixel electrode CE.

[0097] The organic light emitting unit EL may include a light generating layer. In an example, the organic light emitting unit EL may include a first organic light emitting unit ELa, a charge generating layer CGL, and a second organic light emitting unit ELb. The first pixel electrode AE, the first organic light emitting unit ELa, the charge generating layer CGL, the second organic light emitting unit ELb, and the second pixel electrode CE may be sequentially stacked.

[0098] The first organic light-emitting unit ELa may be formed in a structure in which a hole injection layer HIL, a first hole transport layer HTLa, a first organic light-emitting layer EMLa, and a first electron transport layer ETLa are sequentially stacked. The second organic light-emitting unit ELb may be formed in a structure in which a second hole transport layer HTLb, a second organic light-emitting layer EMLb, a second electron transport layer ETLb, and an electron injection layer EIL are sequentially stacked.

[0099] In an embodiment, a buffer layer may be disposed on the first organic light emitting layer EMLa and the second organic light emitting layer EMLb. The buffer layer may include an electron transport compound.

[0100] The charge generation layer CGL may play a role of supplying charges to the first organic light emitting unit ELa and the second organic light emitting unit ELb. The charge generation layer CGL may be provided by including an n-type charge generation layer n-CGL for supplying charges to the first organic light emitting unit ELa and a p-type charge generation layer p-CGL for supplying holes to the second organic light emitting unit ELb. At this time, the n-type charge generation layer n-CGL may be provided by including a metal material as a dopant.

[0101] exist Figure 3B In the embodiment, two organic light emitting units ELa and ELb of the light emitting element LD may be stacked, but the embodiment is not limited thereto. For example, three or four or more organic light emitting units may be stacked in the light emitting element LD.

[0102] Figure 4 Yes Figure 3A and Figure 3B Schematic cross-sectional view of a display device having a light-emitting element.

[0103] refer to Figure 4 , the stacked structure of the sub-pixel SPX is shown in a simplified manner, for example, each electrode is shown as a single-layer electrode and each insulating layer is shown as a single-layer insulating layer, but the embodiment is not limited thereto.

[0104] Figure 4 The sub-pixel SPX shown in FIG. Figure 1 The present invention is one of the first sub-pixel SPX1, the second sub-pixel SPX2, and the third sub-pixel SPX3 shown in FIG. 1 , and may also be applied to other pixels.

[0105] The sub-pixel SPX may be disposed in the display area DA. The sub-pixel SPX may include an emission area EMA and a non-emission area NEA. The sub-pixel SPX may include a substrate SUB, a pixel circuit layer PCL, a display element layer DPL, and an encapsulation layer TFE.

[0106] The substrate SUB may include a transparent insulating material to transmit light. The substrate SUB may be a rigid substrate or a flexible substrate.

[0107] Circuit elements (e.g. Figure 2 A first transistor T1, a second transistor T2, and a third transistor T3) and a signal line electrically connected to the circuit elements may be provided in the pixel circuit layer PCL. A light emitting element LD electrically connected to each of the circuit elements may be provided in the display element layer DPL.

[0108] The pixel circuit layer PCL may be disposed on the substrate SUB. The pixel circuit layer PCL may include a lower auxiliary electrode BML, a buffer layer BFL, a first transistor T1, an interlayer insulating layer ILD, a protective layer PVX, and a via layer VIA. Figure 4 In the figure, for the convenience of description, only the first transistor T1 among the circuit elements is shown.

[0109] The lower auxiliary electrode BML may be disposed on the substrate SUB. The lower auxiliary electrode BML may function as a path through which an electrical signal is transmitted. In an example, the lower auxiliary electrode BML may overlap the first transistor T1.

[0110] The buffer layer BFL may be disposed on the substrate SUB. The buffer layer BFL may cover the lower auxiliary electrode BML. The buffer layer BFL may prevent impurities from diffusing from the outside. The buffer layer BFL may prevent impurities from diffusing into the first transistor T1 disposed on the substrate SUB and improve the flatness of the substrate SUB. The buffer layer BFL may be formed as a single layer or may be formed as a plurality of layers. The buffer layer BFL may be an inorganic insulating layer including an inorganic material. The inorganic insulating layer may include, for example, silicon nitride (SiN x ), silicon oxide (SiO x ), silicon oxynitride (SiO x N y ) and such as aluminum oxide (AlO x ) is at least one of metal oxides of . In the case where the buffer layer BFL is formed as a plurality of layers, each layer may be formed of the same material or different materials. In another example, the buffer layer BFL may be omitted in some cases.

[0111] The first transistor T1 may include a semiconductor pattern layer SCP, a gate electrode GE, a first terminal TE1, and a second terminal TE2. The first terminal TE1 may be any one of a source electrode and a drain electrode, and the second terminal TE2 may be another electrode. For example, when the first terminal TE1 is a drain electrode, the second terminal TE2 may be a source electrode.

[0112] The semiconductor pattern layer SCP may be provided and / or formed on the buffer layer BFL. The semiconductor pattern layer SCP may include a first contact region contacting the first terminal TE1, a second contact region contacting the second terminal TE2, and a channel region between the first contact region and the second contact region. The channel region may overlap with the gate electrode GE of the first transistor T1. The semiconductor pattern layer SCP may be a semiconductor pattern layer formed of amorphous silicon, polycrystalline silicon (e.g., low temperature polycrystalline silicon), an oxide semiconductor, or an organic semiconductor. The channel region may be, for example, a semiconductor pattern layer not doped with impurities, and may be an intrinsic semiconductor. The first contact region and the second contact region may be semiconductor pattern layers doped with impurities. In the example, the first terminal TE1 may be electrically connected to the light emitting element LD by a separate connection device such as a bridge electrode.

[0113] An interlayer insulating layer ILD may be provided and / or formed on the semiconductor pattern layer SCP. The interlayer insulating layer ILD may be an inorganic insulating layer including an inorganic material. The interlayer insulating layer ILD and the buffer layer BFL may include the same material. The interlayer insulating layer ILD may include one or more materials selected from materials such as the construction material of the buffer layer BFL. In an example, the interlayer insulating layer ILD may be formed as an organic insulating layer including an organic material. The interlayer insulating layer ILD may be formed as a single layer, but may be formed as a plurality of layers of at least two layers.

[0114] The gate electrode GE may be provided and / or formed on the interlayer insulating layer ILD to correspond to (or overlap) the channel region of the semiconductor pattern layer SCP. The gate electrode GE may be disposed on the interlayer insulating layer ILD and overlap the channel region of the semiconductor pattern layer SCP. The gate electrode GE may be formed as a single layer of a material selected from the group consisting of copper (Cu), molybdenum (Mo), tungsten (W), titanium (Ti), aluminum (Al), silver (Ag) and alloys thereof (e.g., aluminum neodymium (AlNd)) alone or a mixture thereof, or may be formed as a double-layer or multi-layer structure of molybdenum (Mo), titanium (Ti), copper (Cu), aluminum (Al) or silver (Ag) which is a low resistance material to reduce line resistance.

[0115] The second terminal TE2 may be provided and / or formed on the interlayer insulating layer ILD to contact the second contact region of the semiconductor pattern layer SCP through a contact hole passing through the interlayer insulating layer ILD. The second terminal TE2 may contact the lower auxiliary electrode BML through a contact hole passing through the interlayer insulating layer ILD and the buffer layer BFL. The first terminal TE1 and the second terminal TE2 may include the same material as that of the gate electrode GE, or may include one or more materials selected from materials such as the construction material of the gate electrode GE.

[0116] In the above-described embodiment, the first terminal TE1 of the first transistor T1 may be disposed in a region adjacent to the channel region of the semiconductor pattern layer SCP and the second terminal TE2 may be a separate electrode connected (e.g., electrically connected) to the semiconductor pattern layer SCP through a contact hole passing through the interlayer insulating layer ILD, but the embodiment is not limited thereto. According to an embodiment, the first terminal TE1 may be connected (e.g., electrically connected) to the semiconductor pattern layer SCP through a contact hole passing through the interlayer insulating layer ILD, and the second terminal TE2 may be disposed in a region adjacent to the channel region of the semiconductor pattern layer SCP.

[0117] A protective layer PVX may be provided and / or formed on the first transistor T1. The protective layer PVX may be formed in the form of an insulating layer disposed on an organic insulating layer or an organic insulating layer disposed on an inorganic insulating layer. The inorganic insulating layer may include, for example, silicon oxide (SiO x), Silicon Nitride (SiN x ), silicon oxynitride (SiO x N y ) and such as aluminum oxide (AlO x The organic insulating layer may include, for example, at least one of an acrylic resin (eg, a polyacrylate resin), an epoxy resin, a phenolic resin, a polyamide resin, a polyimide resin, an unsaturated polyester resin, a polyphenylene ether resin, a polyphenylene sulfide resin, and a benzocyclobutene resin.

[0118] The via layer VIA may be provided and / or formed on the protection layer PVX (eg, completely provided and / or formed on the protection layer PVX). The via layer VIA may be an inorganic insulating layer including an inorganic material or an organic insulating layer including an organic material.

[0119] Each of the interlayer insulating layer ILD, the protection layer PVX, and the via layer VIA may be partially opened to include a contact portion CNT (or a contact hole). The first terminal TE1 may be connected (eg, electrically connected) to the light emitting element LD through the contact portion CNT.

[0120] The display element layer DPL may be provided and / or formed on the via layer VIA. The display element layer DPL may include a light emitting element LD and a pixel defining layer PDL.

[0121] The light emitting element LD may include a first pixel electrode AE, an organic light emitting unit EL, and a second pixel electrode CE. The light emitting element LD may be connected (eg, electrically connected) to a pixel circuit (eg, Figure 2 Pixel circuit PXC).

[0122] The first pixel electrode AE ​​may be provided and / or formed on the via layer VIA of the corresponding sub-pixel SPX. The first pixel electrode AE ​​may be an anode electrode of the light emitting element LD.

[0123] The first pixel electrode AE ​​may be connected (eg, electrically connected) to the first terminal TE1 through the corresponding contact portion CNT.

[0124] Each of the first pixel electrodes AE may be formed of a conductive material (or substance). The conductive material may include an opaque metal. The opaque metal may include, for example, metals such as silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), titanium (Ti) and alloys thereof. However, the material of each of the first pixel electrodes AE is not limited to the above-described embodiments. According to an embodiment, the first pixel electrode AE ​​may include a transparent conductive material (or substance). The transparent conductive material (or substance) may include conductive oxides such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium gallium zinc oxide (IGZO), indium tin zinc oxide (ITZO) and conductive polymers such as poly (3,4-ethylenedioxythiophene) (PEDOT), etc. In the case where the first pixel electrode AE ​​includes a transparent conductive material (or substance), a conductive layer for displaying the first pixel electrode AE ​​in a display device (e.g., Figure 1 A separate conductive layer formed of an opaque metal that reflects light emitted from the organic light emitting unit EL in an image display direction of the display device DD (or toward the encapsulation layer TFE). The first pixel electrode AE ​​may be located in the emission area EMA.

[0125] The pixel defining layer PDL may define (or separate) the emission area EMA. The pixel defining layer PDL may be an organic insulating layer formed of an organic material. In an embodiment, the pixel defining layer PDL may include a light absorbing material or may be coated with a light absorbing material to absorb light introduced (or transmitted) from the outside. For example, the pixel defining layer PDL may include a carbon-based black pigment. However, the embodiment is not limited thereto.

[0126] The pixel defining layer PDL may be partially opened to include an opening exposing a region of the first pixel electrode AE, and may protrude from the through hole layer VIA in the third direction DR3 along the periphery of the emission region EMA. The pixel defining layer PDL may be disposed on the through hole layer VIA to define a region where the organic light emitting unit EL contacts the first pixel electrode AE. The organic light emitting unit EL may be disposed on the first pixel electrode AE ​​exposed by the opening of the pixel defining layer PDL.

[0127] The organic light emitting unit EL may be located above the pixel defining layer PDL and above the first pixel electrode AE ​​in the opening of the pixel defining layer PDL, but the embodiment is not limited thereto, and the organic light emitting unit EL may be located only above the first pixel electrode AE ​​in the opening of the pixel defining layer PDL.

[0128] The organic light emitting unit EL may have a multilayer thin film structure including a light generating layer that generates light. The organic light emitting unit EL may emit one of red light, green light, and blue light, but the embodiment is not limited thereto. The organic light emitting unit EL may have a multilayer thin film structure including a light generating layer. The organic light emitting unit EL may include a hole injection layer for injecting holes, a hole transport layer having excellent hole transport properties and increasing the chance of recombination of holes and electrons by suppressing the movement of electrons that are not recombined in the light generating layer, a light generating layer for emitting light by recombination of injected electrons and holes, a hole blocking layer for suppressing the movement of holes that are not recombined in the light generating layer, an electron transport layer for smoothly transporting electrons to the light generating layer, and an electron injection layer for injecting electrons. The organic light emitting unit EL may emit light based on an electrical signal provided from the first pixel electrode AE ​​and the second pixel electrode CE.

[0129] The second pixel electrode CE may be disposed on the organic light emitting unit EL and the pixel defining layer PDL. The second pixel electrode CE may be formed in a plate shape throughout the entire area of ​​the display area DA.

[0130] The second pixel electrode CE may be a thin film metal layer having a thickness sufficient to transmit the light emitted from each organic light emitting unit EL. The second pixel electrode CE may be formed of a metal material or a transparent conductive material to have a relatively thin thickness. The second pixel electrode CE may include at least one of various transparent conductive materials including indium tin oxide, indium zinc oxide, indium tin zinc oxide, aluminum zinc oxide, gallium zinc oxide, zinc tin oxide, or gallium tin oxide, and may be implemented as substantially transparent or translucent to satisfy the transmittance. Accordingly, the light emitted from the light emitting layer EML located under the second pixel electrode CE may pass through the second pixel electrode CE and may be emitted in the upward direction of the encapsulation layer TFE.

[0131] An encapsulation layer TFE may be provided and / or formed on the entire second pixel electrode CE.

[0132] The encapsulation layer TFE may include a first insulating layer INS1, an organic insulating layer OINS, and a second insulating layer INS2 sequentially disposed on the second pixel electrode CE. The first insulating layer INS1 may be located on the display element layer DPL (or the second pixel electrode CE) and may be disposed in the display area DA (eg, completely disposed in the display area DA).

[0133] Each of the first and second insulating layers INS1 and INS2 may be formed of an inorganic layer including an inorganic material, and the organic insulating layer OINS may be formed of an organic layer including an organic material.

[0134] Figure 5A is a schematic cross-sectional view illustrating a comparative example of a sub-pixel of a display device. Figure 5BIt is a graphic Figure 5A Schematic plan view of the emission area.

[0135] refer to Figure 5A , the comparison sub-pixel SPX_ref may include a pixel circuit layer PCL and a display element layer DPL disposed on the pixel circuit layer PCL. The pixel circuit layer PCL may include a transistor and a signal line connected to the transistor. The display element layer DPL may be disposed on a base substrate BSL (or a through-hole layer) of the pixel circuit layer PCL.

[0136] The first pixel electrode AE ​​of the comparison subpixel SPX_ref may be disposed on the base substrate BSL. The comparison subpixel SPX_ref may include a light generating layer disposed on the first pixel electrode AE ​​in the third direction DR3. The comparison subpixel SPX_ref may include a first functional layer IGL1, a second functional layer IGL2, a light emitting layer EML, and a third functional layer IGL3 sequentially disposed on the first pixel electrode AE ​​in the third direction DR3.

[0137] The first functional layer IGL1 , the second functional layer IGL2 , the light emitting layer EML, and the third functional layer IGL3 of the comparison sub-pixel SPX_ref may be sequentially deposited on the first pixel electrode AE.

[0138] The first functional layer IGL1 may be deposited on the pixel defining layer PDL and the first pixel electrode AE ​​to cover the side surface of the pixel defining layer PDL and the first pixel electrode AE. The first functional layer IGL1 may include an inner surface (or lower surface) contacting the first pixel electrode AE ​​and the pixel defining layer PDL and an outer surface (or upper surface) facing the opposite direction. The outer surface (or upper surface) of the first functional layer IGL1 may include a first inclined surface inclined along the side surface of the pixel defining layer PDL and a first flat surface S1 connected to the first inclined surface. The first functional layer IGL1 may be a hole injection layer HIL of a light emitting element.

[0139] The second functional layer IGL2 may be disposed on the first functional layer IGL1 and deposited to cover the first functional layer IGL1. The second functional layer IGL2 may include an inner surface (or lower surface) contacting the first functional layer IGL1 and an outer surface (or upper surface) facing the opposite direction. The outer surface (or upper surface) may be opposite to the inner surface (or lower surface). The inner surface (or lower surface) of the second functional layer IGL2 may have a profile (or surface profile) according to the outer surface (or upper surface) of the first functional layer IGL1. The outer surface (or upper surface) of the second functional layer IGL2 may include a second inclined surface inclined along the first inclined surface of the first functional layer IGL1 and a second flat surface S2 connected to the second inclined surface. The width of the second flat surface S2 of the second functional layer IGL2 may be smaller than the width of the first flat surface S1 of the first functional layer IGL1 by the thickness of the second functional layer IGL2. The second functional layer IGL2 may be a hole transport layer HTL of a light emitting element.

[0140] The light-emitting layer EML may be disposed on the second functional layer IGL2 and deposited to cover the second functional layer IGL2. The light-emitting layer EML may include an inner surface (or lower surface) contacting the second functional layer IGL2 and an outer surface (or upper surface) facing the opposite direction. The inner surface (or lower surface) of the light-emitting layer EML may have a profile according to the outer surface (or upper surface) of the second functional layer IGL2. The outer surface (or upper surface) of the light-emitting layer EML may include a third inclined surface inclined along the second inclined surface of the second functional layer IGL2 and a third flat surface S3 connected to the third inclined surface. The width of the third flat surface S3 of the light-emitting layer EML may be smaller than the width of the second flat surface S2 of the second functional layer IGL2 by the thickness of the light-emitting layer EML. The light-emitting layer EML may be a region in which light is generated by the recombination of electrons and holes.

[0141] The third functional layer IGL3 may be disposed on the light emitting layer EML and deposited to cover the light emitting layer EML. The third functional layer IGL3 may include an inner surface (or lower surface) contacting the light emitting layer EML and an outer surface (or upper surface) facing the opposite direction. The inner surface (or lower surface) of the third functional layer IGL3 may have a profile according to the outer surface (or upper surface) of the light emitting layer EML. The outer surface (or upper surface) of the third functional layer IGL3 may include a fourth inclined surface inclined along the third inclined surface of the light emitting layer EML and a fourth flat surface S4 connected to the fourth inclined surface and disposed on the third flat surface S3 of the light emitting layer EML. The width of the fourth flat surface S4 of the third functional layer IGL3 may be smaller than the width of the third flat surface S3 of the light emitting layer EML by the thickness of the third functional layer IGL3. The third functional layer IGL3 may be an electron transport layer ETL of a light emitting element.

[0142] In order to improve the light emission efficiency of the display device, it may be necessary to ensure a region where holes and electrons are balanced, and the region where holes and electrons are balanced may be a region where the thickness of a light generating layer forming an organic light emitting unit is kept constant.

[0143] refer to Figure 5A and Figure 5B A region where the stacked thicknesses of the first functional layer IGL1 , the second functional layer IGL2 , and the third functional layer IGL3 and the light emitting layer EML of the comparison subpixel SPX_ref remain constant corresponds to the fourth flat surface S4 .

[0144] The resonance satisfaction area RSA_ref may be an area of ​​the light-emitting layer EML corresponding to the fourth flat surface S4, and may include an area in which holes and electrons are balanced. The resonance non-satisfaction area NRSA_ref may be an area excluding the resonance satisfaction area RSA_ref from the emission area EMA, and may be an area that does not emit light normally due to constructive interference of light emitted from the light-emitting layer EML. Through the stacking structure of the first functional layer IGL1, the second functional layer IGL2, and the third functional layer IGL3 and the light-emitting layer EML, the resonance satisfaction area RSA_ref is limited to an area corresponding to the area of ​​the fourth flat surface S4 of the third functional layer IGL3. Accordingly, the size of the resonance satisfaction area RSA_ref may be smaller than the size of the resonance non-satisfaction area NRSA_ref. Therefore, in order to improve the light-emitting efficiency, the display device may need to ensure an area in which holes and electrons are balanced. For example, the display device may need to ensure that the organic light-emitting unit (e.g., Figure 4 A region in which the stacking thickness of the light generating layers in the organic light emitting unit EL) is kept constant.

[0145] Fig. 6A It is a graphic Figure 4 Schematic cross-sectional view of an embodiment of a sub-pixel. Figure 6B It is a graphic Fig. 6A Schematic plan view of the emission area.

[0146] refer to Fig. 6A The sub-pixel SPX may include a pixel circuit layer PCL and a display element layer DPL disposed on the pixel circuit layer PCL. The pixel circuit layer PCL may include transistors and signal lines connected to the transistors. The display element layer DPL may be disposed on a base substrate BSL (e.g., Figure 4 On the through hole layer VIA).

[0147] In an embodiment, the first pixel electrode AE ​​may be disposed on the base substrate BSL. In the sub-pixel SPX, an organic light emitting unit (eg, Figure 4The light generating layer of the organic light emitting unit EL) may be sequentially disposed on the first pixel electrode AE ​​in the third direction DR3. In an example, the first functional layer IGL1, the second functional layer IGL2, the light emitting layer EML, and the third functional layer IGL3 forming the organic light emitting unit may be sequentially disposed on the first pixel electrode AE ​​in the third direction DR3.

[0148] In an embodiment, a first functional layer IGL1 , a second functional layer IGL2 , a light emitting layer EML, and a third functional layer IGL3 may be sequentially deposited on the first pixel electrode AE.

[0149] In an embodiment, the first functional layer IGL1 may be disposed on the pixel defining layer PDL and the first pixel electrode AE ​​and may be deposited to cover the side surface of the pixel defining layer PDL and the first pixel electrode AE. The first functional layer IGL1 may be disposed between the first pixel electrode AE ​​and the second functional layer IGL2 and may be an organic layer that facilitates hole injection from the first pixel electrode AE ​​into the light emitting layer EML. The first functional layer IGL1 may be a hole injection layer HIL.

[0150] In an embodiment, the first functional layer IGL1 may include an inner surface (or lower surface) contacting the first pixel electrode AE ​​and the pixel defining layer PDL and an outer surface (or upper surface) facing the opposite direction. For example, the outer surface (or upper surface) may be opposite to the inner surface (or lower surface).

[0151] In an embodiment, the inner surface (or lower surface) of the first functional layer IGL1 may have a contour according to the shapes of the pixel defining layer PDL and the first pixel electrode AE. In an example, the inner surface (or lower surface) of the first functional layer IGL1 contacting the first pixel electrode AE ​​may have a flat surface.

[0152] In an embodiment, the outer surface (or upper surface) of the first functional layer IGL1 may include an inclined surface inclined according to the shape of the side surface of the pixel defining layer PDL and a first curved surface WS1 connected to the inclined surface. In an example, the first curved surface WS1 may include at least one convex portion. The at least one convex portion may correspond to the central area of ​​the emission area EMA. In an example, the first curved surface WS1 may include a first concave portion (e.g., Figure 7 and a first convex portion (eg, Figure 7 In the example, for each position along the direction intersecting the third direction DR3, the stacking thickness of the first functional layer IGL1 according to the first curved surface WS1 may not be constant. Figure 7 The arrangement and design process of the first functional layer IGL1 is described.

[0153] In an embodiment, the second functional layer IGL2 may be disposed on the first functional layer IGL1 and deposited to cover the first functional layer IGL1. The second functional layer IGL2 may be disposed between the first functional layer IGL1 and the light emitting layer EML to receive holes from the first pixel electrode AE ​​and transfer the holes to the light emitting layer EML. In an example, the second functional layer IGL2 may be a hole transport layer HTL.

[0154] In an embodiment, the second functional layer IGL2 may include an inner surface (or lower surface) contacting the first functional layer IGL1 and an outer surface (or upper surface) facing the opposite direction. The outer surface (or upper surface) may be opposite to the inner surface (or lower surface).

[0155] In an embodiment, the inner surface (or lower surface) of the second functional layer IGL2 may have a contour according to the shape of the outer surface (or upper surface) of the first functional layer IGL1. In an example, the inner surface (or lower surface) of the second functional layer IGL2 may correspond to the first curved surface WS1 of the first functional layer IGL1.

[0156] In an embodiment, the outer surface (or upper surface) of the second functional layer IGL2 may include an inclined surface inclined along the inclined surface of the first functional layer IGL1 and a second curved surface WS2 connected to the inclined surface. The second curved surface WS2 may include at least one convex portion. The at least one convex portion may correspond to the central area of ​​the emission area EMA. In an example, the second curved surface WS2 may include a second concave portion (e.g., Figure 8 and a second convex portion (eg, Figure 8 In an example, in a cross-sectional view, the second convex portion CXA2 may overlap with the first convex portion CXA1.

[0157] In an embodiment, the second curved surface WS2 of the second functional layer IGL2 may be set in consideration of the shape of the first curved surface WS1 of the first functional layer IGL1. In an example, the difference between the lowest height of the second concave portion and the highest height of the second convex portion may be smaller than the difference between the lowest height of the first concave portion and the highest height of the first convex portion of the first functional layer IGL1, but the embodiment is not limited thereto.

[0158] In an embodiment, the stacking thickness of the first functional layer IGL1 and the second functional layer IGL2 may not be constant depending on the position along the direction intersecting the third direction DR3. In an example, the difference in the stacking thickness of the first functional layer IGL1 and the second functional layer IGL2 at each position may be smaller than the thickness difference of the first functional layer IGL1 at each position, but the embodiment is not limited thereto. For example, the difference in the stacking thickness of the first functional layer IGL1 and the second functional layer IGL2 at each position may be greater than the thickness difference of the first functional layer IGL1 at each position. Refer to Figure 8 The arrangement and design process of the second functional layer IGL2 is described.

[0159] In an embodiment, the light emitting layer EML may be disposed on the second functional layer IGL2 and deposited to cover the second functional layer IGL2. The light emitting layer EML may be disposed between the second functional layer IGL2 and the third functional layer IGL3, and may be formed by respectively emitting light from the first pixel electrode AE ​​and the second pixel electrode (eg, Figure 4 A region where light is generated by the recombination of holes and electrons supplied by the second pixel electrode CE).

[0160] In embodiments, the light emitting layer EML may include an inner surface (or lower surface) contacting the second functional layer IGL2 and an outer surface (or upper surface) facing an opposite direction.

[0161] In an embodiment, the inner surface (or lower surface) of the light emitting layer EML may have a contour according to the shape of the outer surface (or upper surface) of the second functional layer IGL2. In an example, the inner surface (or lower surface) of the light emitting layer EML may correspond to the second curved surface WS2 of the second functional layer IGL2.

[0162] In an embodiment, the outer surface (or upper surface) of the light emitting layer EML may include an inclined surface inclined along the inclined surface of the second functional layer IGL2 and a third curved surface WS3 connected to the inclined surface. The third curved surface WS3 may include at least one convex portion. The at least one convex portion may correspond to the central area of ​​the emission area EMA. In an example, the third curved surface WS3 may include a third concave portion (e.g., Fig. 9 The third concave portion CDA3) and the third convex portion (for example, Fig. 9 In an example, in a cross-sectional view, the third convex portion CXA3 may be aligned with the first convex portion of the first functional layer IGL1 (eg, Figure 7 The first convex portion CXA1 of the second functional layer IGL2 (eg, Figure 8 overlaps with the second protrusion CXA2).

[0163] In an embodiment, the third curved surface WS3 of the light emitting layer EML may be formed considering the shape of the second curved surface WS2 of the second functional layer IGL2. In an example, the difference between the lowest height of the third concave portion and the highest height of the third convex portion may be smaller than the difference between the lowest height of the second concave portion and the highest height of the second convex portion of the second functional layer IGL2.

[0164] In an embodiment, the stacking thickness of the first functional layer IGL1 and the second functional layer IGL2 and the light-emitting layer EML may not be constant depending on the position along the direction intersecting the third direction DR3. The difference in the stacking thickness of the first functional layer IGL1 and the second functional layer IGL2 and the light-emitting layer EML at each position may be smaller than the difference in the stacking thickness of the first functional layer IGL1 and the second functional layer IGL2 at each position. The light-emitting layer EML may be set to allow the difference in the stacking thickness of the first functional layer IGL1 and the second functional layer IGL2 and the light-emitting layer EML at each position to be smaller than the difference in the stacking thickness of the first functional layer IGL1 and the second functional layer IGL2 at each position. Refer to the following later. Fig. 9 The arrangement and design process of the light emitting layer EML is described.

[0165] In an embodiment, the third functional layer IGL3 may be disposed on the light emitting layer EML and deposited to cover the light emitting layer EML. The third functional layer IGL3 may be disposed between the light emitting layer EML and the second pixel electrode (eg, Figure 4 The third functional layer IGL3 may be an electron transport layer ETL.

[0166] In an embodiment, the third functional layer IGL3 may include an inner surface (or lower surface) contacting the light emitting layer EML and an outer surface (or upper surface) facing the opposite direction. The outer surface (or upper surface) may be opposite to the inner surface (or lower surface).

[0167] In an embodiment, the inner surface (or lower surface) of the third functional layer IGL3 may have a contour according to the shape of the outer surface (or upper surface) of the light emitting layer EML. In an example, the inner surface (or lower surface) of the third functional layer IGL3 may correspond to the third curved surface WS3 of the light emitting layer EML.

[0168] In an embodiment, the outer surface (or upper surface) of the third functional layer IGL3 may include an inclined surface inclined along the inclined surface of the light emitting layer EML and a flat surface FS connected to the inclined surface. The flat surface FS may be a region where the thickness of the stacked structure of the first functional layer IGL1, the second functional layer IGL2, and the third functional layer IGL3 and the light emitting layer EML remains constant.

[0169] In an embodiment, the stacking thickness of the first functional layer IGL1, the second functional layer IGL2, the third functional layer IGL3, and the light emitting layer EML may be kept constant on the flat surface FS. A third functional layer IGL3 that allows the stacking thickness of the first functional layer IGL1, the second functional layer IGL2, the third functional layer IGL3, and the light emitting layer EML to be kept constant may be provided. Fig.10 The arrangement and design process of the third functional layer IGL3 are described. The resonance satisfied area RSA may be an emission area EMA corresponding to the flat surface FS, and may be an area in which holes and electrons are balanced. The resonance unsatisfied area NRSA may be an area excluding the resonance satisfied area RSA from the emission area EMA, and may be an area in which light is not normally emitted due to constructive interference of light emitted from the light emitting layer EML.

[0170] refer to Figure 6B , the resonance satisfaction area RSA can occupy most of the emission area EMA.

[0171] The display device according to the embodiment can ensure a region (e.g., a flat surface FS) in which the stacking thickness of the first functional layer IGL1, the second functional layer IGL2, the third functional layer IGL3, and the light-emitting layer EML can be ensured to remain constant according to the individual shape of each of the first functional layer IGL1, the second functional layer IGL2, the third functional layer IGL3, and the light-emitting layer EML.

[0172] In the following, reference Figure 7 , Figure 8 , Fig. 9 and Fig.10 Arrangements (or shapes) of the first, second, and third functional layers IGL1, IGL2, and IGL3 and the light emitting layer EML and a method of manufacturing the same are described.

[0173] Figure 7 is a schematic cross-sectional view illustrating an arrangement of a first functional layer and a method of forming the first functional layer according to an embodiment. Figure 8 is a schematic cross-sectional view illustrating an arrangement of a second functional layer and a method of forming the second functional layer according to an embodiment. Fig. 9 is a schematic cross-sectional view illustrating an arrangement of a light emitting layer and a method of forming the light emitting layer according to an embodiment. Fig.10 is a schematic cross-sectional view illustrating an arrangement of a third functional layer and a method of forming the third functional layer according to an embodiment.

[0174] refer to Figure 7 , Figure 8 , Fig. 9 and Fig.10, the method of manufacturing a display device according to an embodiment may include: forming a first pixel electrode AE ​​on a base substrate BSL, and forming a pixel defining layer PDL including an opening exposing the first pixel electrode AE ​​on the first pixel electrode AE; forming a first functional layer IGL1 by coating a first organic material on the first pixel electrode AE ​​and drying the first organic material, the first functional layer IGL1 having an outer surface (or upper surface) on which a first concave portion CDA1 and a first convex portion CXA1 formed between the first concave portions CDA1 are formed (refer to Figure 7 ); forming a light-emitting layer EML on the first functional layer IGL1 (reference Fig. 9 ); a third functional layer IGL3 is formed by coating a third organic material on the light-emitting layer EML and drying the third organic material, the third functional layer IGL3 having an outer surface (or upper surface) on which a flat surface FS overlapping the first convex portion CXA1 is formed (reference Fig.10 ); and forming a second pixel electrode (eg, Figure 4 The method of manufacturing a display device may further include forming a second functional layer IGL2 having an outer surface (or upper surface) on which second concave portions CDA2 and second convex portions CXA2 formed between the second concave portions CDA2 are formed (refer to Figure 8 ).

[0175] refer to Figure 7 The first pixel electrode AE ​​may be disposed and / or formed on the base substrate BSL. A pixel defining layer PDL including an opening exposing the first pixel electrode AE ​​may be disposed and / or formed on the first pixel electrode AE. The first functional layer IGL1 may be disposed and / or formed on the first pixel electrode AE.

[0176] In an embodiment, the first functional layer IGL1 may be formed by coating and drying (or curing) a first organic material on the first pixel electrode AE.

[0177] In an embodiment, the first organic material may include a phthalocyanine compound such as copper phthalocyanine, DNTPD (N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4'-diamine), m-MTDATA (4,4',4"-tris(3-methylphenylphenylamino)triphenylamine), TDATA (4,4'4"-tris(N,N-diphenylamino)triphenylamine), 2TNATA (4,4',4"-tris{N-(2-naphthyl)-N-phenylamino}-triphenylamine), PEDOT / PSS (poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate)), PANI / DBSA (polyaniline / dodecylbenzenesulfonic acid), PANI / CSA (polyaniline / camphorsulfonic acid), and PANI / PSS (polyaniline / poly(4-styrenesulfonate)), but the embodiment is not limited thereto.

[0178] In an embodiment, the inner surface (or lower surface) of the first functional layer IGL1 may have a contour according to the shapes of the pixel defining layer PDL and the first pixel electrode AE, but the surface shape of the outer surface (or upper surface) of the first functional layer IGL1 may be controlled according to the degree of dryness of the first organic material.

[0179] In an embodiment, the first organic material coated on the first pixel electrode AE ​​may be dried by a vacuum drying device. For example, the surface shape of the first organic material may be controlled by changing the drying degree (eg, drying intensity and / or drying speed) of each position of the first organic material.

[0180] In an embodiment, the degree of drying may be controlled according to heat and vapor pressure of the organic material, etc. As the drying intensity increases (or the drying speed increases), the solvent may evaporate quickly, and thus the surface of the organic material may be formed to sink toward the base substrate BSL. As the drying intensity decreases (or the drying speed decreases), the surface of the organic material may be formed to bulge.

[0181] In an embodiment, the first concave portion CDA1 of the first functional layer IGL1 may be formed by drying an edge region of the first organic material at a first intensity. The edge region of the first organic material may be a region adjacent to the pixel defining layer PDL. In an example, the first convex portion CXA1 of the first functional layer IGL1 may be formed by drying a central region of the first organic material at a second intensity less than the first intensity. The central region of the first organic material may be a region surrounded by an edge region of the first organic material. The first convex portion CXA1 may be formed in a central region of the emission region EMA, and may be disposed and / or formed between the first concave portions CDA1.

[0182] In an embodiment, a drying speed of an edge region of the first organic material may be relatively fast, and thus a first concave portion CDA1 may be formed. A drying speed of a central region of the first organic material may be relatively slow, and thus a first convex portion CXA1 may be formed.

[0183] In an embodiment, the outer surface (or upper surface) of the first functional layer IGL1 may include a first inflection point P1. In an example, the first inflection point P1 may include a 1-1 inflection point and a 1-2 inflection point. The outer surface (or upper surface) of the first functional layer IGL1 may continuously change from the first concave portion CDA1 to the first convex portion CXA1 based on the 1-1 inflection point of the first inflection point P1, and may continuously change from the first convex portion CXA1 to the first concave portion CDA1 based on the 1-2 inflection point. In an example, the outer surface (or upper surface) of the first functional layer IGL1 may have a first curved surface (for example, a curved surface) that changes from a concave shape to a convex shape based on the first inflection point P1 and continuously changes from a convex shape to a concave shape. Fig. 6A The first curved surface WS1).

[0184] In an embodiment, the lowest height IGL1_min of the first concave portion CDA1 and the highest height IGL1_max of the first convex portion CXA1 may be about 10 nm or more. In an example, the lowest height IGL1_min of the first concave portion CDA1 may be the height of the lowest point of the first concave portion CDA1 based on the surface of the first pixel electrode AE ​​(or the base substrate BSL). The highest height IGL1_max of the first convex portion CXA1 may be the height of the highest point of the first convex portion CXA1 based on the surface of the first pixel electrode AE ​​(or the base substrate BSL).

[0185] refer to Figure 8 , the second functional layer IGL2 may be disposed and / or formed on the first functional layer IGL1.

[0186] In an embodiment, the second functional layer IGL2 may be formed by coating a second organic material on the first functional layer IGL1 and drying the second organic material.

[0187] In an embodiment, the second organic material may include a carbazole derivative such as N-phenylcarbazole or polyvinylcarbazole, a fluorene derivative, a triphenylamine derivative such as TPD (N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine) and TCTA (4,4',4"-tri(N-carbazolyl)triphenylamine), NPB (N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine) and TAPC (4,4'-cyclohexylenebis[N,N-bis(4-methylphenyl)aniline]), etc., but the embodiment is not limited thereto.

[0188] In an embodiment, the inner surface (or lower surface) of the second functional layer IGL2 may have a contour according to the shape of the outer surface (or upper surface) of the first functional layer IGL1, but the surface shape of the outer surface (or upper surface) of the second functional layer IGL2 may be controlled according to the degree of dryness of the second organic material.

[0189] In an embodiment, the second organic material coated on the first functional layer IGL1 may be dried by a vacuum drying device. For example, the surface shape of the second organic material may be controlled by changing the drying degree (eg, drying intensity and / or drying speed) of each position of the second organic material.

[0190] In an embodiment, the second concave portion CDA2 of the second functional layer IGL2 may be formed by drying an edge region of the second organic material at a fifth intensity. The edge region of the second organic material may be a region adjacent to the pixel defining layer PDL.

[0191] In an embodiment, the second convex portion CXA2 of the second functional layer IGL2 may be formed by drying the central area of ​​the second organic material at a sixth intensity less than the fifth intensity. The central area of ​​the second organic material may be an area surrounded by an edge area of ​​the second organic material. The second convex portion CXA2 may be formed in the central area of ​​the emission area EMA and may be disposed and / or formed between the second concave portions CDA2.

[0192] In an embodiment, the second concave portion CDA2 may be formed by relatively quickly drying an edge region of the second organic material, and the second convex portion CXA2 may be formed by relatively slowly drying a central region of the second organic material.

[0193] In an embodiment, the fifth strength may be less than the first strength (eg, dry strength for forming the first concave portion CDA1 of the first functional layer IGL1 ). The sixth strength may be greater than the second strength (eg, dry strength for forming the first convex portion CXA1 of the first functional layer IGL1 ).

[0194] In an embodiment, a difference between the drying strength for forming the first concave portion CDA1 and the drying strength for forming the first convex portion CXA1 may be greater than a difference between the drying strength for forming the second concave portion CDA2 and the drying strength for forming the second convex portion CXA2.

[0195] In an embodiment, the outer surface (or upper surface) of the second functional layer IGL2 may include a second inflection point P2. The second inflection point P2 may include a 2-1 inflection point and a 2-2 inflection point. The outer surface (or upper surface) of the second functional layer IGL2 may continuously change from the second concave portion CDA2 to the second convex portion CXA2 based on the 2-1 inflection point of the second inflection point P2, and continuously change from the second convex portion CXA2 to the second concave portion CDA2 based on the 2-2 inflection point of the second inflection point P2. In an example, the outer surface (or upper surface) of the second functional layer IGL2 may have a second curved surface (for example, Fig. 6A The first inflection point P1 may be closer to the pixel defining layer PDL than the second inflection point P2.

[0196] In an embodiment, the difference between the lowest height EL1_min of the first stacked structure and the highest height EL1_max of the first stacked structure may be equal to or less than about 10 nm. In an example, the lowest height EL1_min of the first stacked structure may be the height of the lowest point of the second concave portion CDA2 formed by disposing the second functional layer IGL2 on the first functional layer IGL1. The highest height EL1_max of the first stacked structure may be the height of the highest point of the second convex portion CXA2 formed by disposing the second functional layer IGL2 on the first functional layer IGL1.

[0197] In another example, in the case where the second organic material is coated on the base substrate BSL (the second organic material is on a flat surface) and the edge area of ​​the second organic material is dried at a fifth intensity, a concave portion may be formed in an area corresponding to the second concave portion CDA2, and the height of the concave portion may be the lowest height IGL2_min of the second functional layer IGL2. In the case where the second organic material is coated on the base substrate BSL (the second organic material is on a flat surface) and the central area of ​​the second organic material is dried at a sixth intensity less than the fifth intensity, a convex portion may be formed in an area corresponding to the second convex portion CXA2, and the height of the convex portion may be the highest height IGL2_max of the second functional layer IGL2. In an example, in the case where the second functional layer IGL2 is formed on the base substrate BSL (the second functional layer IGL2 is on a flat surface), the lowest height IGL2_min of the second functional layer IGL2 may be the distance at which the concave portion is separated from the surface of the first pixel electrode AE ​​(or the base substrate BSL) in the third direction DR3. When the second functional layer IGL2 is formed on the base substrate BSL (the second functional layer IGL2 is on a flat surface), the maximum height IGL2_max of the second functional layer IGL2 may be a distance separating the convex portion from the surface of the first pixel electrode AE ​​(or the base substrate BSL) in the third direction DR3.

[0198] refer to Figure 7 and Figure 8 , a difference between a maximum height IGL1_max of the first functional layer IGL1 and a minimum height IGL1_min of the first functional layer IGL1 may be greater than a difference between a maximum height IGL2_max of the second functional layer IGL2 and a minimum height IGL2_min of the second functional layer IGL2. However, the embodiment is not limited thereto, and a difference between a maximum height IGL1_max of the first functional layer IGL1 and a minimum height IGL1_min of the first functional layer IGL1 may be less than a difference between a maximum height IGL2_max of the second functional layer IGL2 and a minimum height IGL2_min of the second functional layer IGL2.

[0199] refer to Fig. 9 , the light emitting layer EML may be disposed and / or formed on the second functional layer IGL2 .

[0200] In an embodiment, the light emitting layer EML may be formed by coating a light emitting material on the second functional layer IGL2 and drying the light emitting material. For example, the light emitting layer EML may be formed by inkjet printing or spin coating.

[0201] In an embodiment, the light emitting material may include a low molecular weight organic material or a high molecular weight organic material. The low molecular weight organic material may include copper phthalocyanine (CuPc), N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (NPB) and tris(8-hydroxyquinoline)aluminum (Alq 3 ), etc. The polymer organic material may include poly(3,4-ethylenedioxythiophene (PEDOT), polyaniline (PANI), poly(p-phenylene vinylene) (PPV), soluble PPV, cyano PPV, and polyfluorene, etc.

[0202] In an embodiment, the inner surface (or lower surface) of the light-emitting layer EML may have a contour according to the shape of the outer surface (or upper surface) of the second functional layer IGL2, but the surface shape of the outer surface (or upper surface) of the light-emitting layer EML may change according to the degree of dryness of the light-emitting material.

[0203] In an embodiment, the light emitting material coated on the second functional layer IGL2 may be dried by a vacuum drying device. For example, the surface shape of the light emitting material may be controlled by changing the drying degree (eg, drying intensity and / or drying speed) of each position of the light emitting material.

[0204] In an embodiment, the outer surface (or upper surface) of the light emitting layer EML may include a third inflection point P3. The third inflection point P3 may include a 3-1 inflection point and a 3-2 inflection point. The outer surface (or upper surface) of the light emitting layer EML may continuously change from the third concave portion CDA3 to the third convex portion CXA3 based on the 3-1 inflection point of the third inflection point P3, and continuously change from the third convex portion CXA3 to the third concave portion CDA3 based on the 3-2 inflection point of the third inflection point P3. In an example, the outer surface (or upper surface) of the light emitting layer EML may have a third curved surface (for example, Fig. 6A The third curved surface WS3).

[0205] In an embodiment, the difference between the lowest height EL2_min of the second stacked structure and the highest height EL2_max of the second stacked structure may be less than the difference between the lowest height EL1_min of the first stacked structure and the highest height EL1_max of the first stacked structure. The lowest height EL2_min of the second stacked structure may be the lowest height of the stacked structure of the first functional layer IGL1 and the second functional layer IGL2 and the light-emitting layer EML. For example, the lowest height EL2_min of the second stacked structure may be the height of the lowest point of the third concave portion CDA3 formed by disposing the light-emitting layer EML on the second functional layer IGL2. In an example, the highest height EL2_max of the second stacked structure may be the highest height of the stacked structure of the first functional layer IGL1 and the second functional layer IGL2 and the light-emitting layer EML. For example, the highest height EL2_max of the second stacked structure may be the height of the highest point of the third convex portion CXA3 formed by disposing the light-emitting layer EML on the second functional layer IGL2.

[0206] In an embodiment, when the light emitting material is disposed on the second functional layer IGL2 and dried, the light emitting material may be formed in a surface shape for compensating for a degree of curvature formed on an outer surface (or upper surface) of the second functional layer IGL2 .

[0207] In another example, when the light-emitting material is coated on the base substrate BSL (the light-emitting material is on a flat surface) and the edge area and the center area of ​​the light-emitting material are dried, the drying intensity of the center area of ​​the light-emitting material may be greater than the drying intensity of the edge area of ​​the light-emitting material. For example, the outer surface (or upper surface) of the light-emitting layer EML may be formed as a first concave surface CXAa. For example, when the light-emitting layer EML is formed on the second functional layer IGL2, the outer surface (or upper surface) of the light-emitting layer EML may be formed so as to form a third curved surface that changes from a concave shape to a convex shape and continuously changes from a convex shape to a concave shape.

[0208] refer to Fig.10, the third functional layer IGL3 may be disposed and / or formed on the light emitting layer EML.

[0209] In an embodiment, the third functional layer IGL3 may be formed by coating a third organic material on the light emitting layer EML and drying the third organic material.

[0210] In an embodiment, the third organic material may include Alq 3 (Tris(8-hydroxyquinoline)aluminum), TPBi(1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene), BCP(2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), Bphen(4,7-diphenyl-1,10-phenanthroline), TAZ(3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole), NTAZ(4-(naphthalene-1-yl)-3,5-diphenyl-4H-1,2,4-triazole), tBu-PBD(2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), BAlq(bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum), Bebq 2 (bis(10-hydroxybenzoquinolinolato)beryllium) and ADN(9,10-di(naphthalene-2-yl)anthracene), etc., but the embodiment is not limited thereto.

[0211] In an embodiment, the inner surface (or lower surface) of the third functional layer IGL3 may have a contour corresponding to the shape of the outer surface (or upper surface) of the light-emitting layer EML, but the surface shape of the outer surface (or upper surface) of the third functional layer IGL3 may change according to the degree of dryness of the third organic material.

[0212] In an embodiment, the third organic material coated on the light emitting layer EML may be dried by a vacuum drying device. For example, the surface shape of the third organic material may be controlled by changing the drying degree (eg, drying intensity and / or drying speed) of each position of the third organic material.

[0213] In an embodiment, the outer surface (or upper surface) of the third functional layer IGL3 may not include an inflection point. The edge area of ​​the third organic material may be an inclined surface, and the central area of ​​the third organic material may be a flat surface FS. The flat surface FS may be an area surrounded by the inclined surface. The flat surface FS may be an area in which the height EL3_con of the stacked structure of the first functional layer IGL1, the second functional layer IGL2, and the third functional layer IGL3 and the light-emitting layer EML is kept constant. In the case where the third organic material is disposed on the light-emitting layer EML and is dried, the third organic material may be used to compensate for the third curved surface (for example, Fig. 6AThe surface shape of the third curved surface WS3) is formed.

[0214] In an embodiment, the inclined portion of the third functional layer IGL3 (or a region corresponding to the resonance non-satisfied area NRSA) may be formed by drying an edge region of the third organic material at a third intensity.

[0215] In an embodiment, the flat surface FS of the third functional layer IGL3 (or a region corresponding to the resonance satisfying area RSA) may be formed by drying a central region of the third organic material at a fourth intensity greater than the third intensity.

[0216] In an embodiment, the flat surface FS of the third functional layer IGL3 may be formed by relatively quickly drying the central area of ​​the third organic material, and the inclined portion of the third functional layer IGL3 may be formed by relatively slowly drying the edge area of ​​the third organic material. In an example, the emission area EMA corresponding to the flat surface FS of the third functional layer IGL3 may be a resonance satisfied area RSA. The emission area EMA corresponding to the inclined portion of the third functional layer IGL3 may be a resonance unsatisfied area NRSA.

[0217] In an embodiment, the third strength may be greater than the sixth strength (eg, a dry strength for forming the second convex portion CXA2 of the second functional layer IGL2).

[0218] In embodiments, the fourth strength may be less than the fifth strength (eg, a dry strength for forming the second concave portion CDA2 of the second functional layer IGL2 ).

[0219] In another example, the third organic material may be coated on the base substrate BSL (the third organic material is on a flat surface), the edge region of the third organic material may be dried at a third intensity, and the center region of the third organic material may be dried at a fourth intensity greater than the third intensity. For example, the outer surface (or upper surface) of the third functional layer IGL3 may be formed as a second concave surface CXAb.

[0220] The display device and the method of manufacturing the display device according to the embodiment can ensure the resonance satisfaction area RSA by combining the shapes of the outer surfaces (or upper surfaces) of each of the first functional layer IGL1, the second functional layer IGL2 and the third functional layer IGL3 and the light emitting layer EML of the organic light emitting unit forming the light emitting element, thereby improving the light emitting efficiency.

[0221] Fig.11 It is a graphic Figure 4 Schematic cross-sectional view of another embodiment of a sub-pixel.

[0222] refer to Fig.11 , components other than the base substrate BSL' and the first pixel electrode AE' may be Fig. 6A The components shown in FIG. 1 are the same or correspond to each other.

[0223] refer to Fig.11 , the base substrate BSL' may include a protruding portion PRU in a region overlapping the resonance satisfying area RSA. In an example, the protruding portion PRU may be formed by partially etching the base substrate BSL'. The protruding portion PRU may be formed by removing a surface of the base substrate BSL' corresponding to a remaining region other than the resonance satisfying area RSA.

[0224] In an embodiment, the first pixel electrode AE' may be disposed and / or formed on a base substrate BSL' including a protruding portion PRU. The first pixel electrode AE' may include an inner surface (or lower surface) contacting the base substrate BSL' and an outer surface (or upper surface) contacting the first functional layer IGL1. The inner surface (or lower surface) and the outer surface (or upper surface) of the first pixel electrode AE' may have a surface profile corresponding to the shape of the protruding portion PRU. Accordingly, the inner surface (or lower surface) of the first functional layer IGL1 disposed on the first pixel electrode AE' may include a protruding surface according to the shape of the outer surface (or upper surface) of the first pixel electrode AE'.

[0225] The display device according to the embodiment can ensure that the stacking thickness of the first functional layer IGL1, the second functional layer IGL2, the third functional layer IGL3 and the light-emitting layer EML maintains a constant area (e.g., a flat surface FS) according to the individual shape of each of the first functional layer IGL1, the second functional layer IGL2, the third functional layer IGL3 and the light-emitting layer EML.

[0226] At the end of the detailed description, those skilled in the art will appreciate that many changes and modifications may be made to the embodiments without substantially departing from the principles, spirit and scope of the present disclosure. Therefore, the disclosed embodiments are used only in a general and descriptive sense and not for the purpose of limitation.

Claims

1. A display device, include: base substrate; A first pixel electrode is disposed on the base substrate; a pixel defining layer disposed on the first pixel electrode and comprising an opening exposing the first pixel electrode; An organic light-emitting unit, disposed on the first pixel electrode; as well as The second pixel electrode is arranged on the organic light emitting unit, wherein: The organic light emitting unit comprises: a first functional layer disposed on the first pixel electrode and comprising a lower surface contacting the first pixel electrode and an upper surface opposite to the lower surface; a light-emitting layer, disposed on the first functional layer; and a third functional layer disposed on the light-emitting layer and including a lower surface contacting the light-emitting layer and an upper surface opposite to the lower surface, The upper surface of the first functional layer includes first concave portions and first convex portions formed between the first concave portions, and The upper surface of the third functional layer includes a flat surface overlapping the first convex portion of the first functional layer in a plan view.

2. The display device according to claim 1, in, The upper surface of the third functional layer further includes an inclined surface, and The flat surface of the third functional layer is disposed between the inclined surfaces of the third functional layer.

3. The display device according to claim 1, further comprising: include: a second functional layer disposed between the first functional layer and the light-emitting layer and including a lower surface contacting the first functional layer and an upper surface contacting the light-emitting layer, The upper surface of the second functional layer includes second concave portions and second convex portions formed between the second concave portions.

4. The display device according to claim 3, in, A difference between a minimum height of the second recess and a maximum height of the second projection is smaller than a difference between a minimum height of the first recess and a maximum height of the first projection.

5. The display device according to claim 3, in, A difference between a height of a lowest point of the second concave portion and a height of a highest point of the second convex portion is equal to or less than 10 nm.

6. The display device according to claim 3, in, The light emitting layer includes a lower surface contacting the upper surface of the second functional layer and an upper surface contacting the lower surface of the third functional layer, The lower surface of the second functional layer has a surface profile according to the upper surface of the first functional layer, and The lower surface of the light emitting layer has a surface profile according to the upper surface of the second functional layer.

7. The display device according to claim 3, in, In the plan view, the second convex portion overlaps with the first convex portion.

8. The display device according to claim 3, in, The upper surface of the first functional layer includes at least one first inflection point, The upper surface of the second functional layer includes at least one second inflection point, and The at least one first inflection point is closer to the pixel defining layer than the at least one second inflection point.

9. The display device according to claim 8, in, The at least one first inflection point includes a 1-1 inflection point and a 1-2 inflection point, The at least one second inflection point includes a 2-1 inflection point and a 2-2 inflection point, The first convex portion is formed between the 1-1 inflection point and the 1-2 inflection point, and The second convex portion is formed between the 2-1 inflection point and the 2-2 inflection point.

10. The display device according to claim 3, in, The first functional layer comprises a hole injection layer, The second functional layer includes a hole transport layer, and The third functional layer includes an electron transport layer.

11. The display device according to any one of claims 1 to 10, in, The upper surface of the third functional layer does not include an inflection point.

12. The display device according to claim 1, in, The lower surface of the first functional layer has a surface profile according to the surface shape of the first pixel electrode, and The lower surface of the first functional layer has a flat surface profile.

13. The display device according to claim 1, in, The base substrate includes a protruding portion overlapping the first convex portion in the plan view and protruding in the thickness direction of the display device, and The first pixel electrode is disposed on the base substrate and has a surface profile according to a shape of the protruding portion.

14. A method for manufacturing a display device, the method include: forming a first pixel electrode on a base substrate; forming a pixel defining layer including an opening exposing the first pixel electrode on the first pixel electrode; forming a first functional layer by coating and drying a first organic material on the first pixel electrode, the first functional layer having an upper surface formed with first concave portions and first convex portions formed between the first concave portions; forming a light-emitting layer on the first functional layer; forming a third functional layer by coating and drying a third organic material on the light emitting layer, the third functional layer having an upper surface formed with a flat surface overlapping the first convex portion; as well as A second pixel electrode is formed on the third functional layer.

15. The method according to claim 14, in, The drying of the first organic material comprises: forming the first recess by drying an edge region of the first organic material at a first intensity; and The first convex portion is formed by drying a central area of ​​the first organic material at a second intensity that is less than the first intensity.

16. The method according to claim 15, in, The drying of the third organic material comprises: forming an inclined surface by drying an edge region of the third organic material at a third intensity between the first intensity and the second intensity; and The flat surface is formed by drying a central region of the third organic material at a fourth intensity that is greater than the third intensity and less than the first intensity.

17. The method according to claim 16, further comprising: include: A second functional layer is formed by coating and drying a second organic material on the first functional layer, the second functional layer having an upper surface formed with second concave portions and second convex portions formed between the second concave portions.

18. The method according to claim 17, in, The drying of the second organic material comprises: forming the second recess by drying an edge region of the second organic material at a fifth intensity; and forming the second convex portion by drying a central area of ​​the second organic material at a sixth intensity, The fifth strength is less than the first strength and greater than the fourth strength, and The sixth strength is greater than the second strength and less than the third strength.

19. The method according to claim 18, in, The first functional layer comprises a hole injection layer, The second functional layer includes a hole transport layer, and The third functional layer includes an electron transport layer.

20. The method according to any one of claims 14 to 19, further comprising: include: forming a protruding portion in a region corresponding to the first convex portion by partially etching the base substrate, Wherein, the first pixel electrode is formed on the protruding portion.

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