Display device and method of manufacturing same

Abstract

The invention relates to a display device and a method of manufacturing the same. The display device includes an encapsulation layer. The encapsulation layer includes a first inorganic encapsulation film, an organic encapsulation film disposed on the first inorganic encapsulation film, and a second inorganic encapsulation film disposed on the organic encapsulation film. The second inorganic encapsulation film includes a first sub-inorganic encapsulation layer and a second sub-inorganic encapsulation layer, the second sub-inorganic encapsulation layer is disposed on the first sub-inorganic encapsulation layer and includes the same material as that of the first sub-inorganic encapsulation layer, and a density of the first sub-inorganic encapsulation layer and a density of the second sub-inorganic encapsulation layer are different from each other. The sum of the thickness of the first inorganic encapsulation film and the thickness of the second inorganic encapsulation film is 1 [mu] m or less.

Description

[0001] This application claims the priority of, and all benefits derived from, Korean Patent Application No. 10-2024-0008781, filed on January 19, 2024, the content of which is incorporated herein by reference in its entirety. Technical Field

[0002] Embodiments of the present disclosure described herein relate to a display device and a method of manufacturing a display device, and more particularly, to a display device including an inorganic encapsulation film and a method of manufacturing a display device. Background Art

[0003] Various types of display devices are used to provide image information, and emissive display devices using organic light-emitting materials or quantum dot light-emitting materials are being developed. The emissive display device includes a light-emitting element. The light-emitting element is vulnerable to an external environment such as oxygen and moisture, and thus various techniques for sealing the light-emitting element are desired. Among various techniques, a technique for blocking the penetration paths of air and moisture by providing an encapsulation layer on the light-emitting element is being developed. The encapsulation layer may include a structure in which an inorganic film including an inorganic material and an organic film including an organic material are alternately stacked. Summary of the Invention

[0004] Embodiments of the present disclosure provide a display device and a method of manufacturing a display device including an encapsulation layer having a relatively small thickness and a relatively low water vapor transmittance.

[0005] In an embodiment of the present disclosure, the display device includes a display panel. The display panel includes a display element layer and an encapsulation layer provided on the display element layer, and the display element layer includes a pixel defining layer defining a pixel opening therein and a light-emitting element. The encapsulation layer includes a first inorganic encapsulation film, an organic encapsulation film provided on the first inorganic encapsulation film, and a second inorganic encapsulation film provided on the organic encapsulation film, and the second inorganic encapsulation film includes a first sub-inorganic encapsulation layer and a second sub-inorganic encapsulation layer, the second sub-inorganic encapsulation layer being provided on the first sub-inorganic encapsulation layer and including the same material as the material of the first sub-inorganic encapsulation layer. The density of the first sub-inorganic encapsulation layer and the density of the second sub-inorganic encapsulation layer are different from each other, and the sum of the thickness of the first inorganic encapsulation film and the thickness of the second inorganic encapsulation film is 1 micrometer or less.

[0006] In an embodiment, the density of the second sub-inorganic encapsulation layer may be higher than the density of the first sub-inorganic encapsulation layer.

[0007] In an embodiment, the first sub-inorganic encapsulation layer and the second sub-inorganic encapsulation layer may include silicon nitride.

[0008] In an embodiment, the thickness of the second inorganic encapsulation film may be 0.5 micrometer or less.

[0009] In an embodiment, the thickness of the first inorganic encapsulation film may be 0.5 micrometers or less.

[0010] In an embodiment, the second inorganic encapsulation film may further include a third sub-inorganic encapsulation layer disposed on the second sub-inorganic encapsulation layer and a fourth sub-inorganic encapsulation layer disposed on the third sub-inorganic encapsulation layer. The material of each of the third sub-inorganic encapsulation layer and the fourth sub-inorganic encapsulation layer may be the same as the material of the first sub-inorganic encapsulation layer. The density of the second sub-inorganic encapsulation layer and the density of the third sub-inorganic encapsulation layer may be different from each other, and the density of the third sub-inorganic encapsulation layer and the density of the fourth sub-inorganic encapsulation layer may be different from each other.

[0011] In an embodiment, the first inorganic encapsulation film may include a first sub-inorganic encapsulation layer and a second sub-inorganic encapsulation layer, the second sub-inorganic encapsulation layer being disposed on the first sub-inorganic encapsulation layer of the first inorganic encapsulation film and including the same material as the first sub-inorganic encapsulation layer of the first inorganic encapsulation film. The density of the first sub-inorganic encapsulation layer of the first inorganic encapsulation film and the density of the second sub-inorganic encapsulation layer of the first inorganic encapsulation film may be different from each other.

[0012] In an embodiment, the encapsulation layer may have a water vapor transmittance of less than or equal to 1.5×10 -4 grams per square meter per 24 hours (g / m 2 ·day).

[0013] In an embodiment, the light-emitting element may include a first electrode, an emission layer disposed on the first electrode, and a second electrode disposed on the emission layer.

[0014] In an embodiment, the display device may further include an active area for displaying an image, and the active area may include a flat area and at least one curved area bent from the flat area.

[0015] In an embodiment, the display device may further include: a base layer disposed below the display element layer and including a silicon wafer; and a color filter layer disposed on the encapsulation layer.

[0016] In an embodiment, the light-emitting element may include: a first electrode; a light-emitting component including a first light-emitting stack disposed on the first electrode, a charge generation layer disposed on the first light-emitting stack, and a second light-emitting stack disposed on the charge generation layer; and a second electrode disposed on the light-emitting component.

[0017] In an embodiment, the display device may further include: a folding area folded around a virtual axis extending in one direction; and a first non-folding area and a second non-folding area with the folding area disposed therebetween.

[0018] In an embodiment of the present disclosure, a method of manufacturing a display device includes: forming a first inorganic encapsulation film on a display element layer including a pixel defining layer having a pixel opening defined therein and a light emitting element, forming an organic encapsulation film on the first inorganic encapsulation film, and forming a second inorganic encapsulation film on the organic encapsulation film. Forming the second inorganic encapsulation film includes depositing a first sub-inorganic encapsulation layer and depositing a second sub-inorganic encapsulation layer on the first sub-inorganic encapsulation layer. The material of the first sub-inorganic encapsulation layer and the material of the second sub-inorganic encapsulation layer are the same as each other, and the density of the first sub-inorganic encapsulation layer and the density of the second sub-inorganic encapsulation layer are different from each other, and the sum of the thickness of the first inorganic encapsulation film and the thickness of the second inorganic encapsulation film is 1 micrometer or less.

[0019] In an embodiment, depositing the first sub-inorganic encapsulation layer and depositing the second sub-inorganic encapsulation layer can be controlled with different process parameters.

[0020] In an embodiment, forming the second inorganic encapsulation film may further include depositing a third sub-inorganic encapsulation layer on the second sub-inorganic encapsulation layer and depositing a fourth sub-inorganic encapsulation layer on the third sub-inorganic encapsulation layer. The material of each of the third sub-inorganic encapsulation layer and the fourth sub-inorganic encapsulation layer may be the same as the material of the first sub-inorganic encapsulation layer. The density of the second sub-inorganic encapsulation layer and the density of the third sub-inorganic encapsulation layer may be different from each other, and the density of the third sub-inorganic encapsulation layer and the density of the fourth sub-inorganic encapsulation layer may be different from each other.

[0021] In an embodiment, forming the first inorganic encapsulation film may include depositing a first sub-inorganic encapsulation layer of the first inorganic encapsulation film on the display element layer and depositing a second sub-inorganic encapsulation layer of the first inorganic encapsulation film on the first sub-inorganic encapsulation layer of the first inorganic encapsulation film. The material of the first sub-inorganic encapsulation layer of the first inorganic encapsulation film and the material of the second sub-inorganic encapsulation layer of the first inorganic encapsulation film may be the same as each other, and the density of the first sub-inorganic encapsulation layer of the first inorganic encapsulation film and the density of the second sub-inorganic encapsulation layer of the first inorganic encapsulation film may be different from each other.

[0022] In an embodiment, the first sub-inorganic encapsulation layer and the second sub-inorganic encapsulation layer may include silicon nitride.

[0023] In an embodiment, the second inorganic encapsulation film may have a thickness of 0.5 micrometer or less.

[0024] In an embodiment, the density of the second sub-inorganic encapsulation layer of the second inorganic encapsulation film may be higher than the density of the first sub-inorganic encapsulation layer of the second inorganic encapsulation film. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other embodiments, advantages, and features of the present disclosure will become apparent by referring to the embodiments of the present disclosure described in detail with reference to the accompanying drawings.

[0026] Figure 1 Perspective view for explaining an embodiment of a display device according to the present disclosure.

[0027] Figure 2 For explaining corresponding to Figure 1 Cross-sectional view of an embodiment of a portion of line I-I'.

[0028] Figure 3 For explaining Figure 2 Enlarged cross-sectional view of region XX' in

[0029] Figure 4A Cross-sectional view of a portion of a display panel according to the present disclosure.

[0030] Figure 4B And Figure 4C Flowchart of an embodiment of a method for manufacturing a display device according to the present disclosure.

[0031] Figure 5A Cross-sectional view of a portion of a display panel according to the present disclosure.

[0032] Figure 5B Flowchart of an embodiment of a method for manufacturing a display device according to the present disclosure.

[0033] Figure 6A Cross-sectional view of a portion of a display panel according to the present disclosure.

[0034] Figure 6B Flowchart of an embodiment of a method for manufacturing a display device according to the present disclosure.

[0035] Figure 7 Cross-sectional view of a portion of a display panel according to the present disclosure.

[0036] Figure 8 Cross-sectional view of an embodiment of a display device according to the present disclosure.

[0037] Figure 9A And Figure 9B Enlarged cross-sectional view of a portion of a light-emitting element according to the present disclosure.

[0038] Figure 10 Perspective view for explaining an embodiment of a display device according to the present disclosure.

[0039] Figure 11 And Figure 12 Perspective view of an embodiment of a foldable display device according to the present disclosure. Detailed Description

[0040] In this specification, when a component (or region, layer, part, etc.) is referred to as being "on" another component (or region, layer, part, etc.), "connected to" or "coupled to" another component (or region, layer, part, etc.), this means that the component (or region, layer, part, etc.) can be directly on the other component (or region, layer, part, etc.), directly connected to or directly coupled to the other component (or region, layer, part, etc.), or a third component can be interposed therebetween.

[0041] Like reference numerals refer to like components. Additionally, in the drawings, for effective description, the scale and dimensions (e.g., thickness) of components are enlarged. As used herein, the term "and / or" includes all one or more combinations defined by the related components.

[0042] Terms such as "first" and "second" may be used to describe various components, but the components should not be limited by these terms. These terms may be used only to distinguish one component from other components. For example, without departing from the scope of the present disclosure, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. Unless otherwise indicated, terms in the singular form may include the plural form.

[0043] Additionally, terms such as "below", "beneath", "above", and "on top of" are used to describe the relationships of components illustrated in the drawings. The terms are relative concepts and are described based on the directions illustrated in the drawings.

[0044] It should be understood that terms such as "comprise", "include", and "have" when used herein, indicate the presence of the recited features, quantities, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, steps, operations, components, parts, or combinations thereof.

[0045] Unless otherwise defined, all terms (including technical terms or scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Terms defined in commonly used dictionaries should be interpreted as having the same meaning as the context in the relevant technical field, and should not be interpreted as having an ideal or overly formal meaning, unless clearly defined as having such a meaning in this application.

[0046] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0047] Figure 1 A perspective view for illustrating an embodiment of a display device DD according to the present disclosure. Figure 2 For illustration corresponding to Figure 1Cross-sectional view of a portion of line I-I'. Additionally, Figure 2 It may be a cross-sectional view for explaining an embodiment of the display device DD.

[0048] The display device DD of the embodiment may be a device activated according to an electrical signal. In an embodiment, for example, the display device DD may be a mobile phone, a tablet computer, a car navigation unit, a game console, or a wearable device. However, the present disclosure is not limited thereto. Figure 1 An example of explaining that the display device DD is a mobile phone.

[0049] The display device DD may display an image IM through an active region AA-DD. The active region AA-DD may include a flat surface PA defined by a first direction axis DR1 and a second direction axis DR2. The active region AA-DD may further include a curved surface CA bent from at least one side of the flat surface PA defined by the first direction axis DR1 and the second direction axis DR2. In Figure 1 it, the display device DD of the embodiment is illustrated as including two curved surfaces CA bent from opposite sides of the flat surface PA defined by the first direction axis DR1 and the second direction axis DR2. However, this is illustrative, and the shape of the active region AA-DD is not limited thereto. In an embodiment, for example, the active region AA-DD may include only the flat surface PA. In an alternative embodiment, the active region AA-DD may further include at least two curved surfaces CA bent from at least two sides of the flat surface PA. For example, the active region AA-DD may further include four curved surfaces CA bent from four sides of the flat surface PA.

[0050] The outer peripheral region NAA-DD is adjacent to the active region AA-DD. The outer peripheral region NAA-DD may surround the active region AA-DD. Accordingly, the shape of the active region AA-DD may be substantially defined by the outer peripheral region NAA-DD. However, this is illustrative, and the outer peripheral region NAA-DD may be disposed adjacent to only one side of the active region AA-DD, or the outer peripheral region NAA-DD may be omitted. The display device DD in the embodiment may include an active region AA-DD having various shapes and is not limited to a specific embodiment.

[0051] Although in Figure 1The first to third direction axes DR1, DR2, and DR3 are illustrated in the following accompanying drawings. However, the directions indicated by the first to third direction axes DR1, DR2, and DR3 described in this specification may be relative concepts and may be changed to other directions. Additionally, the directions indicated by the first to third direction axes DR1, DR2, and DR3 may be described as the first to third directions, and the same reference numerals may be used to refer to the first to third directions. In this specification, the first direction axis DR1 and the second direction axis DR2 may be orthogonal to each other, and the third direction axis DR3 may correspond to the normal direction of the flat surface PA defined by the first direction axis DR1 and the second direction axis DR2.

[0052] The thickness direction of the display device DD may be a direction parallel to the third direction axis DR3, and the third direction axis DR3 is the normal direction of the flat surface PA defined by the first direction axis DR1 and the second direction axis DR2. In this specification, the front surface (or upper surface) and the rear surface (or lower surface) of the components constituting the display device DD may be defined based on the third direction axis DR3. In this specification, the upper side and the lower side may be defined based on the third direction axis DR3. The upper side means the direction close to the active area AA-DD on which the image IM is displayed, and the lower side means the direction away from the active area AA-DD on which the image IM is displayed.

[0053] In this specification, when a component is "directly disposed on / directly formed on" another component, this means that no third component is disposed therebetween. That is, when a component is "directly disposed on / directly formed on" another component, this means that the component "contacts" another component.

[0054] Reference Figure 2 , the display device DD of the embodiment may include a display panel DP and a protection member PF disposed on the display panel DP. Additionally, the display device DD may further include an input sensing layer ISP disposed between the display panel DP and the protection member PF.

[0055] The protection member PF may include an adhesive layer AP and a window WP. The window WP and the input sensing layer ISP may be bonded through the adhesive layer AP. The adhesive layer AP may include a conventional adhesive, such as a pressure-sensitive adhesive ("PSA"), an optically clear adhesive ("OCA"), or an optically clear resin ("OCR"), and is not limited to a specific embodiment. Different from Figure 2 , the adhesive layer AP may be omitted.

[0056] The window WP may include an optically transparent insulating material. The window WP may be a glass substrate or a polymer substrate. In an embodiment, for example, the window WP may be a tempered glass substrate. In an alternative embodiment, the window WP may include or be composed of the following: polyimide, polyacrylate, polymethyl methacrylate, polycarbonate, polyethylene naphthalate, polyvinylidene chloride, polyvinylidene fluoride, polystyrene, ethylene-vinyl alcohol copolymer, or any combination thereof. However, this is illustrative, and the materials included in the window WP are not limited thereto.

[0057] Although not illustrated, the protection member PF may further include at least one functional layer (not illustrated) provided on the window WP. In an embodiment, for example, the functional layer (not illustrated) may be a hard coat or an anti-fingerprint coat. However, the present disclosure is not limited thereto.

[0058] The input sensing layer ISP may be disposed on the display panel DP. The input sensing layer (also referred to as the input sensor layer) ISP may sense an external input applied from the outside. The external input may be a user input. The user input may include various types of external inputs, such as a part of the user's body, light, heat, a pen, or pressure.

[0059] The input sensing layer ISP may be formed on the display panel DP through a continuous process. In this case, the input sensing layer ISP may be directly disposed on the display panel DP. When the input sensing layer ISP is directly disposed on the display panel DP, it may mean that no third component is disposed between the input sensing layer ISP and the display panel DP. That is, no separate adhesive member may be disposed between the input sensing layer ISP and the display panel DP. In an alternative embodiment, the input sensing layer ISP may be coupled to the display panel DP through an adhesive member. The adhesive member may include a conventional adhesive or a viscous substance.

[0060] In addition, the display device DD may further include an optical layer RCL disposed between the input sensing layer ISP and the protection member PF. The optical layer RCL may be an anti-reflection layer that reduces the reflectance of external light. The optical layer RCL may be formed on the input sensing layer ISP through a continuous process. The optical layer RCL may include a polarizer or a color filter layer. When the optical layer RCL includes a color filter layer, the color filter layer may include a plurality of color filters disposed in a predetermined arrangement. In an embodiment, for example, the color filters may be arranged in consideration of the color of light emitted from the pixels included in the display panel DP. In addition, the optical layer RCL may further include a black matrix adjacent to the color filters. In an embodiment, the optical layer RCL may be omitted.

[0061] The display panel DP can be a component that basically generates an image. The display panel DP can be an emissive display panel. In an embodiment, for example, the display panel DP can be an organic light-emitting display panel, an inorganic light-emitting display panel, a quantum dot display panel, a micro light-emitting diode (“LED”) display panel, or a nano-LED display panel. The display panel DP can also be referred to as a display layer. The display panel DP can include a base layer BS, a circuit layer DP-CL, a display element layer DP-ED, and a packaging layer TFE.

[0062] The base layer BS can be a member that provides a base surface on which the circuit layer DP-CL is disposed. The base layer BS can be a rigid substrate or can be a flexible substrate capable of being bent, folded, or curled. The base layer BS can be a glass substrate, a metal substrate, or a polymer substrate. However, the present disclosure is not limited thereto, and the base layer BS can be an inorganic layer, an organic layer, or a composite layer.

[0063] The circuit layer DP-CL can be disposed on the base layer BS. The circuit layer DP-CL can include an insulating layer, a semiconductor pattern, a conductive pattern, and signal lines. The insulating layer, the semiconductor layer, and the conductive layer can be formed on the base layer BS by processes such as coating or deposition, and the insulating layer, the semiconductor layer, and the conductive layer can be selectively patterned by performing multiple photolithography processes. Thereafter, the semiconductor pattern, the conductive pattern, and the signal lines included in the circuit layer DP-CL can be formed.

[0064] The display element layer DP-ED can be disposed on the circuit layer DP-CL. The display element layer DP-ED can include a pixel definition layer PDL (refer to Figure 3 ) and first to third light-emitting elements ED-1, ED-2, and ED-3 (refer to Figure 3 ). In an embodiment, for example, the display element layer DP-ED can include an organic light-emitting material, an inorganic light-emitting material, an organic-inorganic light-emitting material, quantum dots, quantum rods, micro-LEDs, or nano-LEDs.

[0065] The packaging layer TFE can be disposed on the display element layer DP-ED. The packaging layer TFE can protect the display element layer DP-ED from moisture, oxygen, and external foreign substances (such as dust particles).

[0066] Figure 3 For illustration Figure 2 of the enlarged cross-sectional view of the region XX’ in Figure 3 It can be a cross-sectional view of the display panel DP specifically illustrating Figure 2

[0067] The base layer BS may include a single-layer structure or a multi-layer structure. In an embodiment, for example, the base layer BS may include a first synthetic resin layer, an intermediate layer having a multi-layer structure or a single-layer structure, and a second synthetic resin layer stacked in sequence. The intermediate layer may also be referred to as a base isolation layer. The intermediate layer may include a silicon oxide (SiO x ) layer and an amorphous silicon (a-Si) layer provided on the silicon oxide layer, but is not particularly limited thereto. In an embodiment, for example, the intermediate layer may include at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, and an amorphous silicon layer.

[0068] Each of the first synthetic resin layer and the second synthetic resin layer may include a polyimide-based resin. In an alternative embodiment, each of the first synthetic resin layer and the second synthetic resin layer may include at least one of an acrylate-based resin, a methacrylate-based resin, a polyisoprene-based resin, a vinyl-based resin, an epoxy-based resin, a urethane-based resin, a cellulose-based resin, a silicone-based resin, a polyamide-based resin, and a perylene-based resin. In the present disclosure, the "~~"-based resin used herein may refer to a resin including a "~~" functional group.

[0069] The circuit layer DP-CL may be provided on the base layer BS. The circuit layer DP-CL may include a plurality of transistors (not illustrated). Each transistor (not illustrated) may include a control electrode, an input electrode, and an output electrode. In an embodiment, for example, the circuit layer DP-CL may include switching transistors and driving transistors for driving light-emitting elements ED-1, ED-2, and ED-3 of the display element layer DP-ED.

[0070] The display element layer DP-ED may include a pixel defining layer PDL and first to third light-emitting elements ED-1, ED-2, and ED-3. A pixel opening OH may be defined in the pixel defining layer PDL. In an embodiment, for example, the pixel defining layer PDL may include an organic light-blocking material or an inorganic light-blocking material containing a black pigment and / or a black dye.

[0071] The display panel DP may be divided into a non-emitting region NPXA and emitting regions PXA-R, PXA-G, and PXA-B. The emitting regions PXA-R, PXA-G, and PXA-B may be regions that emit light generated by the first to third light-emitting elements ED-1, ED-2, and ED-3, respectively. When viewed from above the plane, the emitting regions PXA-R, PXA-G, and PXA-B may be spaced apart from each other.

[0072] The emission regions PXA-R, PXA-G, and PXA-B may be regions separated from each other by the pixel defining layer PDL. The non-emission region NPXA may be a region between adjacent emission regions PXA-R, PXA-G, and PXA-B and may be a region corresponding to the pixel defining layer PDL. In the present specification, the emission regions PXA-R, PXA-G, and PXA-B may respectively correspond to pixels. The pixel defining layer PDL may separate the first light-emitting element to the third light-emitting element ED-1, ED-2, and ED-3 from each other. The emission layers EML-R, EML-G, and EML-B of the first light-emitting element to the third light-emitting element ED-1, ED-2, and ED-3 may be disposed in the pixel openings OH defined in the pixel defining layer PDL and may be separated from each other.

[0073] According to the colors of the light generated by the first light-emitting element to the third light-emitting element ED-1, ED-2, and ED-3, the emission regions PXA-R, PXA-G, and PXA-B may be divided into a plurality of groups. In Figure 3 the display panel DP of the embodiment illustrated in, three emission regions PXA-R, PXA-G, and PXA-B that respectively emit red light, green light, and blue light are illustrated. In an embodiment, for example, the display device DD of the embodiment may include an emission region PXA-R that emits red light, an emission region PXA-G that emits green light, and an emission region PXA-B that emits blue light, which are separated from each other.

[0074] The first light-emitting element to the third light-emitting element ED-1, ED-2, and ED-3 may be spaced apart from each other in a direction (for example, the first direction axis (also referred to as the first direction) DR1) perpendicular to the third direction axis (also referred to as the thickness direction) DR3. The first light-emitting element to the third light-emitting element ED-1, ED-2, and ED-3 may emit light in different wavelength ranges. In an embodiment, the first light-emitting element ED-1 may emit red light, the second light-emitting element ED-2 may emit green light, and the third light-emitting element ED-3 may emit blue light. For example, the emission region PXA-R that emits red light, the emission region PXA-G that emits green light, and the emission region PXA-B that emits blue light may respectively correspond to the first light-emitting element ED-1, the second light-emitting element ED-2, and the third light-emitting element ED-3.

[0075] However, the present disclosure is not limited thereto, and the first light-emitting element to the third light-emitting element ED-1, ED-2, and ED-3 may emit light in the same wavelength range, or at least one of the first light-emitting element to the third light-emitting element ED-1, ED-2, and ED-3 may emit light in different wavelength ranges. In an embodiment, for example, the first light-emitting element to the third light-emitting element ED-1, ED-2, and ED-3 may all emit blue light.

[0076] Each of the light-emitting elements ED-1, ED-2, and ED-3 may include a first electrode EL1, a second electrode EL2 provided over the first electrode EL1, and an emission layer EML-R, EML-G, or EML-B provided between the first electrode EL1 and the second electrode EL2. The first electrode EL1 may be exposed through a pixel opening OH of a pixel defining layer PDL.

[0077] In addition, each of the light-emitting elements ED-1, ED-2, and ED-3 may further include a hole transport region HTR and an electron transport region ETR. The hole transport region HTR may be provided between the first electrode EL1 and the emission layer EML-R, EML-G, or EML-B. The electron transport region ETR may be provided between the emission layer EML-R, EML-G, or EML-B and the second electrode EL2.

[0078] Figure 3 An embodiment is illustrated as follows: in which the emission layers EML-R, EML-G, and EML-B of the first to third light-emitting elements ED-1, ED-2, and ED-3 are provided in a pixel opening OH defined in a pixel defining layer PDL, and the hole transport region HTR, the electron transport region ETR, and the second electrode EL2 are provided as a common layer in the light-emitting elements ED-1, ED-2, and ED-3. However, the present disclosure is not limited thereto, and different from those Figure 3 illustrated therein, in an embodiment, the hole transport region HTR and the electron transport region ETR may be patterned and provided in the pixel opening OH defined in the pixel defining layer PDL. In an embodiment, for example, the hole transport regions HTR, the emission layers EML-R, EML-G, and EML-B, and the electron transport regions ETR of the light-emitting elements ED-1, ED-2, and ED-3 may be patterned by an inkjet printing method.

[0079] The first electrode EL1 may be an anode or a cathode. However, the present disclosure is not limited thereto. In addition, the first electrode EL1 may be a pixel electrode. The first electrode EL1 may be a transmissive electrode, a transflective electrode, or a reflective electrode. The first electrode EL1 may include at least one selected from the group consisting of Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, W, In, Sn, and Zn, a compound of two or more elements selected from the group, a combination of two or more elements selected from the group, or an oxide thereof.

[0080] When the first electrode EL1 is a transmissive electrode, the first electrode EL1 may include a transparent metal oxide, for example, indium tin oxide (“ITO”), indium zinc oxide (“IZO”), zinc oxide (ZnO), or indium tin zinc oxide (“ITZO”). When the first electrode EL1 is a transmissive-reflective electrode or a reflective electrode, the first electrode EL1 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, W, or a compound thereof, or any combination thereof (for example, a combination of Ag and Mg), or a multilayer structural material such as LiF / Ca (a stacked structure of LiF and Ca) or LiF / Al (a stacked structure of LiF and Al). In an alternative embodiment, the first electrode EL1 may have a multilayer structure including a reflective film or a transmissive-reflective film and a transparent conductive film, the reflective film or the transmissive-reflective film including or consisting of the aforementioned materials, and the transparent conductive film including or consisting of ITO, IZO, zinc oxide (ZnO), or ITZO. In an embodiment, for example, the first electrode EL1 may have a three-layer structure of ITO / Ag / ITO, but is not limited thereto. In addition, the first electrode EL1 may include the aforementioned metal materials, a combination of two or more metal materials selected from the aforementioned metal materials, or an oxide of the aforementioned metal materials, and the present disclosure is not limited thereto.

[0081] The hole transport region HTR may have: a single-layer structure including or consisting of a single material; a single-layer structure including or consisting of a plurality of different materials; or a multilayer structure including or consisting of a plurality of materials different from each other. The hole transport region HTR may include a hole injection layer (not illustrated) and a hole transport layer (not illustrated). And the hole transport layer (not illustrated) further includes at least one of a hole buffer layer (not illustrated) and an electron blocking layer (not illustrated). Additionally, the hole transport region HTR may further include a light emission assisting layer (not illustrated) for compensating for the resonance distance according to the wavelength of light emitted from the emission layer EML-R, EML-G, or EML-B.

[0082] The hole transport region HTR may include a phthalocyanine compound (such as copper phthalocyanine), DNTPD (N 1 ,N 1 '-([1,1'-biphenyl]-4,4'-diyl)bis(N 1 -phenyl-N 4 ,N 4-m-MTDATA (4,4',4"-[tris(3-methylphenyl)phenylamino]triphenylamine), TDATA (4,4',4"-tris(N,N-diphenylamino)triphenylamine), 2-TNATA (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), PANI / PSS (polyaniline / poly(4-styrenesulfonate)), NPB (N,N'-bis(naphthalen-1-yl)-N,N'-diphenyl-benzidine), polyetherketone containing triphenylamine (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium [tetrakis(pentafluorophenyl)borate], or HAT-CN (dipyrazino[2,3-f;2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile), etc.

[0083] In addition, the hole transport region HTR may include carbazole derivatives (such as N-phenylcarbazole or polyvinylcarbazole), fluorene derivatives, triphenylamine derivatives (such as TPD (N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine), TCTA (4,4',4”-tris(carbazol-9-yl)triphenylamine), TAPC (4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl)aniline]), HMTPD (4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl), and mCP (1,3-bis(N-carbazolyl)benzene)), CzSi (9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole), CCP (9-phenyl-9H-3,9'-bicarbazole), or mDCP (1,3-bis(1,8-dimethyl-9H-carbazol-9-yl)benzene).

[0084] The emission layer EML-R, EML-G, or EML-B may have: a single-layer structure including or consisting of a single material; a single-layer structure including or consisting of a plurality of different materials; or a multi-layer structure including or consisting of a plurality of materials different from each other. The emission layer EML-R, EML-G, or EML-B may include anthracene derivatives, pyrene derivatives, fluoranthene derivatives, 1,2-benzophenanthrene derivatives, dihydrobenzanthracene derivatives, or triphenylene derivatives.

[0085] In an embodiment, for example, the emission layer EML-R, EML-G, or EML-B may include one host and one dopant. In an alternative embodiment, the emission layer EML-R, EML-G, or EML-B may include two or more hosts and two or more dopants.

[0086] The emission layer EML-B of the third light-emitting element ED-3 that emits blue light may emit thermally activated delayed fluorescence (TADF) or phosphorescence. The emission layer EML-B of the third light-emitting element ED-3 may include a thermally activated delayed fluorescence material and / or a phosphorescent material. The third light-emitting element ED-3 including a thermally activated delayed fluorescence material and / or a phosphorescent material may exhibit excellent luminous efficiency.

[0087] The emission layer EML-R, EML-G, or EML-B may include styryl derivatives (e.g., 1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene (BCzVB), 4-(di-p-tolylamino)-4'-[(di-p-tolylamino)styryl]stilbene (DPAVB), N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalen-2-yl)vinyl)phenyl)-N-phenylaniline (N-BDAVBi), and 4,4'-bis[2-(4-(N,N-diphenylamino)phenyl)vinyl]biphenyl (DPAVBi)), perylene and its derivatives (e.g., 2,5,8,11-tetra-tert-butylperylene (TBP)), or pyrene and its derivatives (e.g., 1,1'-dipyrene, 1,4-dipyrenylbenzene, 1,4-bis(N,N-diphenylamino)pyrene) as well-known dopant materials.

[0088] The emission layer EML-R, EML-G, or EML-B may include well-known phosphorescent dopant materials. In an embodiment, for example, metal complexes including iridium (Ir), platinum (Pt), osmium (Os), gold (Au), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), or thulium (Tm) may be used as phosphorescent dopants. Specifically, FIrpic (bis(4,6-difluorophenylpyridinato-N,C2')iridium(III) picolinate), FIr6 (bis(2,4-difluorophenylpyridinato)-tetrakis(1-pyrazolyl)boratoiridium(III)), or PtOEP (platinum octaethylporphyrin) may be used as phosphorescent dopants. However, the present disclosure is not limited thereto.

[0089] The electron transport region ETR may include at least one of a hole blocking layer (not illustrated), an electron transport layer (not illustrated), and an electron injection layer (not illustrated). The electron transport region ETR may have: a single-layer structure including a single material or composed of a single material; a single-layer structure including a plurality of different materials or composed of a plurality of different materials; or a multilayer structure including a plurality of materials different from each other or composed of a plurality of materials different from each other.

[0090] The electron transport region ETR may include anthracene compounds. However, but not limited thereto, the electron transport region ETR may include, for example, Alq3 (aluminum tris(8-hydroxyquinoline)), 1,3,5-tris[(3-pyridinyl)-benzen-3-yl]benzene, 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzimidazol-1-yl)phenyl)-9,10-dinaphthylanthracene, 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-biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole), NTAZ (4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole), t Bu-PBD (2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), BAlq (bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-ol)aluminum), Bebq2 (bis(benzoquinoline-10-ol)beryllium), ADN (9,10-di(naphthalen-2-yl)anthracene), BmPyPhB (1,3-bis[3,5-bis(pyridin-3-yl)phenyl]benzene) or any combination thereof.

[0091] In addition, the electron transport region ETR may include metal halides (such as LiF, NaCl, CsF, RbCl, RbI, CuI or KI), lanthanide metals (such as Yb) or co-deposited materials of metal halides and lanthanide metals. In an embodiment, the electron transport region ETR may include KI:Yb, RbI:Yb or LiF:Yb as co-deposited materials. Metal oxides (such as Li2O or BaO) or Liq (lithium 8-hydroxyquinoline) etc. may be used in the electron transport region ETR, but the present disclosure is not limited thereto. The electron transport region ETR may include a combination of an electron transport material and an insulating organometallic salt or be composed of a combination of an electron transport material and an insulating organometallic salt. The insulating organometallic salt may be a material having a band gap of about 4 electron volts (eV) or greater. Specifically, for example, the insulating organometallic salt may include metal acetates, metal benzoates, metal acetoacetates, metal acetylacetonates or metal stearates.

[0092] The second electrode EL2 may be a common electrode. The second electrode EL2 may be a cathode or an anode, but the present disclosure is not limited thereto. In an embodiment, for example, when the first electrode EL1 is an anode, the second electrode EL2 may be a cathode, and when the first electrode EL1 is a cathode, the second electrode EL2 may be an anode. The second electrode EL2 may include at least one selected from the group consisting of Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, W, In, Sn, and Zn, a compound of two or more elements selected from the group, a combination of two or more elements selected from the group, or an oxide thereof.

[0093] The light-emitting elements ED-1, ED-2, and ED-3 may further include a capping layer CPL disposed on the second electrode EL2. The capping layer CPL may be an organic layer or an inorganic layer. In an embodiment, for example, when the capping layer CPL includes an inorganic material, the inorganic material may include an alkali metal compound (e.g., LiF), an alkaline earth metal compound (e.g., MgF2), SiON, SiN x or SiO y and the like. In an embodiment, for example, when the capping layer CPL includes an organic material, the organic material may include N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-2,2'-dimethylbenzidine (α-NPD), NPB, TPD, m-MTDATA, Alq3, CuPc, TPD15 (N4,N4,N4',N4'-tetrakis(biphenyl-4-yl)biphenyl-4,4'-diamine), or TCTA (4,4',4"-tris(carbazol-9-yl)triphenylamine), or may include an epoxy resin or an acrylate (such as a methacrylate).

[0094] In an embodiment, the encapsulation layer TFE may cover the display element layer DP-ED. The encapsulation layer TFE may be a thin-film encapsulation layer. The encapsulation layer TFE will be described in detail below with reference to Figure 4A The encapsulation layer TFE will be described in detail below with reference to

[0095] Figure 4A To illustrate a cross-sectional view of an embodiment of a portion of a display panel DP (refer to Figure 3 ) according to the present disclosure. Figure 4A To illustrate a cross-sectional view of the encapsulation layer TFE.

[0096] With reference to Figure 3 and Figure 4A , the encapsulation layer TFE in the embodiment may include a first inorganic encapsulation film IL1, an organic encapsulation film OL disposed on the first inorganic encapsulation film IL1, and a second inorganic encapsulation film IL2 disposed on the organic encapsulation film OL.

[0097] Each of the first inorganic encapsulation film IL1 and the second inorganic encapsulation film IL2 can protect the display element layer DP-ED from moisture and / or oxygen. Each of the first inorganic encapsulation film IL1 and the second inorganic encapsulation film IL2 can include at least one of silicon nitride, silicon oxynitride, silicon oxide, titanium oxide, and aluminum oxide.

[0098] In the present embodiment, the sum of the thickness TH1 of the first inorganic encapsulation film IL1 and the thickness TH2 of the second inorganic encapsulation film IL2 can be 1 micrometer or less. In the present embodiment, the thickness TH2 of the second inorganic encapsulation film IL2 can be 0.5 micrometer or less.

[0099] In the present embodiment, the second inorganic encapsulation film IL2 can include a first sub-inorganic encapsulation layer IL2-1 and a second sub-inorganic encapsulation layer IL2-2 stacked in sequence. The first sub-inorganic encapsulation layer IL2-1 and the second sub-inorganic encapsulation layer IL2-2 can have different densities from each other. The second sub-inorganic encapsulation layer IL2-2 can have a density higher than that of the first sub-inorganic encapsulation layer IL2-1. In the present embodiment, the first sub-inorganic encapsulation layer IL2-1 can also be referred to as a low-density layer, and the second sub-inorganic encapsulation layer IL2-2 can also be referred to as a high-density layer.

[0100] The first sub-inorganic encapsulation layer IL2-1 and the second sub-inorganic encapsulation layer IL2-2 include the same material as each other. In an embodiment, for example, both the first sub-inorganic encapsulation layer IL2-1 and the second sub-inorganic encapsulation layer IL2-2 can include silicon nitride (SiN x ).

[0101] In the present embodiment, the thickness TH2 of the second inorganic encapsulation film IL2 can correspond to the sum of the thickness TH2-1 of the first sub-inorganic encapsulation layer IL2-1 and the thickness TH2-2 of the second sub-inorganic encapsulation layer IL2-2.

[0102] In the present embodiment, the first sub-inorganic encapsulation layer IL2-1 can contact the organic encapsulation film OL. The first sub-inorganic encapsulation layer IL2-1 (i.e., the low-density layer) can cover the particles remaining on the organic encapsulation film OL. Accordingly, a relatively flat upper surface can be provided for the components (such as the second sub-inorganic encapsulation layer IL2-2) disposed on the first sub-inorganic encapsulation layer IL2-1. The second sub-inorganic encapsulation layer IL2-2 can be disposed at the outermost position of the encapsulation layer TFE. The second sub-inorganic encapsulation layer IL2-2 (i.e., the high-density layer) can reduce the water vapor transmission rate (“WVTR”) of the encapsulation layer TFE.

[0103] In an embodiment, the thickness TH1 of the first inorganic encapsulation film IL1 may also be 0.5 micrometers or less. That is, both the thickness TH1 of the first inorganic encapsulation film IL1 and the thickness TH2 of the second inorganic encapsulation film IL2 may be 0.5 micrometers or less. However, the thickness TH1 of the first inorganic encapsulation film IL1 is not limited thereto, as long as the sum of the thickness TH1 of the first inorganic encapsulation film IL1 and the thickness TH2 of the second inorganic encapsulation film IL2 is 1 micrometer or less.

[0104] The organic encapsulation film OL can protect the display element layer DP-ED from external foreign matters such as dust particles. The organic encapsulation film OL may include an acrylic compound or an epoxy compound, etc. The organic encapsulation film OL may include an organic material capable of photopolymerization, but is not particularly limited. In an embodiment, the organic encapsulation film OL may have a thickness TH3 of 5 micrometers to 10 micrometers.

[0105] In an embodiment, the encapsulation layer TFE may have 1.5×10 -4 grams per square meter per 24 hours (g / m 2 ·day) or less WVTR. Preferably, the encapsulation layer TFE may have a WVTR of 10 -5 g / m 2 ·day to 10 -4 g / m 2 ·day.

[0106] Hereinafter, the characteristic evaluation results of the display panel in the embodiments of the present disclosure will be described with reference to the above Figure 3 and Figure 4A as well as the following embodiments and comparative examples. In addition, the following embodiments are for better understanding of the present disclosure, and the scope of the present disclosure is not limited thereto.

[0107] In the display panel of Comparative Example 1, the first inorganic encapsulation film is a single inorganic film with a thickness of 0.8 micrometers, the second inorganic encapsulation film is a single inorganic film with a thickness of 0.7 micrometers, and the organic encapsulation film is an organic film with a thickness of 8 micrometers. In the display panel of Embodiment 1, the first inorganic encapsulation film is a single inorganic film with a thickness of 0.6 micrometers, the second inorganic encapsulation film has a thickness of 0.4 micrometers and includes a low-density layer and a high-density layer stacked in sequence, and the organic encapsulation film is an organic film with a thickness of 8 micrometers. The high-density layer of Embodiment 1 has a higher density than the single inorganic film of the second inorganic encapsulation film of Comparative Example 1. The display panels of Comparative Example 1 and Embodiment 1 have the structure of the display panel DP with the above reference Figure 3 described above.

[0108] Table 1 below shows the measured light efficiency and WVTR of the display panels of Comparative Example 1 and Embodiment 1. In terms of light efficiency, the evaluation results when white light is provided from the front and when white light is provided at an angle of 45° with respect to the front are shown. In addition, in terms of light efficiency, the luminance according to the current (measured in candela per square meter (cd / m 2 )) is measured, and the luminance value in Embodiment 1 represents a relative value based on the luminance value in Comparative Example 1, where the luminance value in Comparative Example 1 is set to 100%.

[0109] [Table 1]

[0110]

[0111] Referring to Table 1, it can be seen that since the encapsulation layer of Embodiment 1 has a smaller thickness than the encapsulation layer of Comparative Example 1, the display panel of Embodiment 1 exhibits excellent light efficiency when compared with the display panel of Comparative Example 1.

[0112] In addition, it can be seen that the display panel of Embodiment 1 has a similar level of WVTR when compared with the display panel of Comparative Example 1. As the thickness of the second inorganic encapsulation film increases, the WVTR may decrease. However, since the second inorganic encapsulation film of Embodiment 1 includes a high-density layer, the display panel of Embodiment 1 has a relatively low level of WVTR even though the second inorganic encapsulation film is relatively thin. To provide a thick inorganic encapsulation film, a longer tact time period may be required, and the production efficiency may be reduced. In contrast, according to the present disclosure, a thin inorganic encapsulation film can be provided, and thus an encapsulation layer having relatively high barrier properties while improving the batch productivity and reducing the cost can be provided, and a display device including the encapsulation layer can be provided.

[0113] Figure 4B and Figure 4C is a flowchart for explaining an embodiment of a method for manufacturing a display device according to the present disclosure.

[0114] Referring to Figure 3 、 Figure 4A and Figure 4B , the method for manufacturing a display device in an embodiment of the present disclosure may include an operation S100 of forming a first inorganic encapsulation film IL1 on a display element layer DP-ED, an operation S200 of forming an organic encapsulation film OL on the first inorganic encapsulation film IL1, and an operation S300 of forming a second inorganic encapsulation film IL2 on the organic encapsulation film OL. Accordingly, an encapsulation layer TFE for sealing the display element layer DP-ED can be formed.

[0115] The operation S100 of forming the first inorganic encapsulation film IL1 and the operation S300 of forming the second inorganic encapsulation film IL2 can be carried out by chemical vapor deposition (“CVD”). In an embodiment, for example, the operation S100 of forming the first inorganic encapsulation film IL1 and the operation S300 of forming the second inorganic encapsulation film IL2 can be carried out by plasma enhanced CVD (“PECVD”). The operation S200 of forming the organic encapsulation film OL can be carried out by an inkjet process.

[0116] Reference Figure 3 and Figures 4A to 4C , in an embodiment of the present disclosure, the operation S300 of forming the second inorganic encapsulation film IL2 may include an operation S310 of depositing a first sub-inorganic encapsulation layer IL2-1 on the organic encapsulation film OL and an operation S320 of depositing a second sub-inorganic encapsulation layer IL2-2 on the first sub-inorganic encapsulation layer IL2-1. The operation S310 of depositing the first sub-inorganic encapsulation layer IL2-1 and the operation S320 of depositing the second sub-inorganic encapsulation layer IL2-2 can each be carried out by CVD.

[0117] In the operation S310 of depositing the first sub-inorganic encapsulation layer IL2-1 and the operation S320 of depositing the second sub-inorganic encapsulation layer IL2-2, the same material can be deposited. In an embodiment, in the operation S310 of depositing the first sub-inorganic encapsulation layer IL2-1 and the operation S320 of depositing the second sub-inorganic encapsulation layer IL2-2, silicon nitride (SiN x ) can be deposited. The operation S310 of depositing the first sub-inorganic encapsulation layer IL2-1 and the operation S320 of depositing the second sub-inorganic encapsulation layer IL2-2 can be carried out in the same chamber.

[0118] The operation S310 of depositing the first sub-inorganic encapsulation layer IL2-1 and the operation S320 of depositing the second sub-inorganic encapsulation layer IL2-2 can be controlled and carried out with different process parameters. More specifically, the process parameters in each step can be controlled such that the second sub-inorganic encapsulation layer IL2-2 has a higher density than the density of the first sub-inorganic encapsulation layer IL2-1. In an embodiment, for example, the deposition rate in the operation S310 of depositing the first sub-inorganic encapsulation layer IL2-1 and the deposition rate in the operation S320 of depositing the second sub-inorganic encapsulation layer IL2-2 can be set to be different from each other.

[0119] Figure 5A To illustrate a cross-sectional view of an embodiment of a part of a display panel DP (reference Figure 3 ) according to the present disclosure. Figure 5A To illustrate a cross-sectional view of the encapsulation layer TFEa. The encapsulation layer TFEa may include a first inorganic encapsulation film IL1, an organic encapsulation film OL, and a second inorganic encapsulation film IL2. As with reference Figures 4A to 4CComponents identical or similar to the described components will be assigned identical or similar reference numerals, and repeated descriptions will be omitted.

[0120] Reference Figure 5A , in the embodiment, the second inorganic encapsulation film IL2 may include a first sub-inorganic encapsulation layer IL2-1, a second sub-inorganic encapsulation layer IL2-2, a third sub-inorganic encapsulation layer IL2-3, and a fourth sub-inorganic encapsulation layer IL2-4 stacked in sequence. Among the first sub-inorganic encapsulation layer to the fourth sub-inorganic encapsulation layer IL2-1, IL2-2, IL2-3, and IL2-4, the sub-inorganic encapsulation layers in contact with each other may have different densities from each other. In the present embodiment, the first sub-inorganic encapsulation layer IL2-1 may also be referred to as the first low-density layer, the second sub-inorganic encapsulation layer IL2-2 may also be referred to as the first high-density layer, the third sub-inorganic encapsulation layer IL2-3 may also be referred to as the second low-density layer, and the fourth sub-inorganic encapsulation layer IL2-4 may also be referred to as the second high-density layer. That is, in the present embodiment, the second inorganic encapsulation film IL2 may have a structure in which low-density layers and high-density layers are alternately stacked. Although FIG. 5 illustrates an example in which the low-density layer and the high-density layer are repeated twice, the number of repetitions of the low-density layer and the high-density layer is not limited thereto.

[0121] In the present embodiment, the first sub-inorganic encapsulation layer IL2-1 (i.e., the first low-density layer) may be in contact with the organic encapsulation film OL, and the fourth sub-inorganic encapsulation layer IL2-4 (i.e., the second high-density layer) may be disposed at the outermost position of the encapsulation layer TFEa. That is, the second inorganic encapsulation film IL2 may be provided such that the low-density layer is in contact with the organic encapsulation film OL, and the high-density layer is disposed at the outermost position of the encapsulation layer TFEa.

[0122] The first sub-inorganic encapsulation layer to the fourth sub-inorganic encapsulation layer IL2-1, IL2-2, IL2-3, and IL2-4 may include the same material as each other. In an embodiment, for example, the first sub-inorganic encapsulation layer to the fourth sub-inorganic encapsulation layer IL2-1, IL2-2, IL2-3, and IL2-4 may all include silicon nitride SiN x .

[0123] The sum of the thickness TH1 of the first inorganic encapsulation film IL1 and the thickness TH2 of the second inorganic encapsulation film IL2 may be 1 micrometer or less. In the present embodiment, the thickness TH2 of the second inorganic encapsulation film IL2 may be 0.5 micrometer or less. The thickness TH2 of the second inorganic encapsulation film IL2 may correspond to the sum of the thickness of the first sub-inorganic encapsulation layer IL2-1, the thickness of the second sub-inorganic encapsulation layer IL2-2, the thickness of the third sub-inorganic encapsulation layer IL2-3, and the thickness of the fourth sub-inorganic encapsulation layer IL2-4.

[0124] Figure 5B A flowchart for explaining an embodiment of a method for manufacturing a display device according to the present disclosure.

[0125] Reference Figure 3 、 Figure 4B 、 Figure 5A and Figure 5B In the embodiments of the present disclosure, the operation S300 of forming the second inorganic encapsulation film IL2 may include an operation S310a of depositing a first sub-inorganic encapsulation layer IL2-1 on the organic encapsulation film OL, an operation S320a of depositing a second sub-inorganic encapsulation layer IL2-2 on the first sub-inorganic encapsulation layer IL2-1, an operation S330a of depositing a third sub-inorganic encapsulation layer IL2-3 on the second sub-inorganic encapsulation layer IL2-2, and an operation S340a of depositing a fourth sub-inorganic encapsulation layer IL2-4 on the third sub-inorganic encapsulation layer IL2-3. The operation S310a of depositing the first sub-inorganic encapsulation layer IL2-1, the operation S320a of depositing the second sub-inorganic encapsulation layer IL2-2, the operation S330a of depositing the third sub-inorganic encapsulation layer IL2-3, and the operation S340a of depositing the fourth sub-inorganic encapsulation layer IL2-4 may each be performed by CVD.

[0126] In the operation S310a of depositing the first sub-inorganic encapsulation layer IL2-1, the operation S320a of depositing the second sub-inorganic encapsulation layer IL2-2, the operation S330a of depositing the third sub-inorganic encapsulation layer IL2-3, and the operation S340a of depositing the fourth sub-inorganic encapsulation layer IL2-4, the same material (e.g., silicon nitride (SiN x )) may be deposited. The operation S310a of depositing the first sub-inorganic encapsulation layer IL2-1, the operation S320a of depositing the second sub-inorganic encapsulation layer IL2-2, the operation S330a of depositing the third sub-inorganic encapsulation layer IL2-3, and the operation S340a of depositing the fourth sub-inorganic encapsulation layer IL2-4 may be performed in the same chamber.

[0127] The operation S310a of depositing the first sub-inorganic encapsulation layer IL2-1 and the operation S320a of depositing the second sub-inorganic encapsulation layer IL2-2 may be controlled and performed with different process parameters. The operation S320a of depositing the second sub-inorganic encapsulation layer IL2-2 and the operation S330a of depositing the third sub-inorganic encapsulation layer IL2-3 may be controlled and performed with different process parameters. The operation S330a of depositing the third sub-inorganic encapsulation layer IL2-3 and the operation S340a of depositing the fourth sub-inorganic encapsulation layer IL2-4 may be controlled and performed with different process parameters. Accordingly, the second sub-inorganic encapsulation layer IL2-2 may have a density higher than the density of the first sub-inorganic encapsulation layer IL2-1 and the density of the third sub-inorganic encapsulation layer IL2-3. The fourth sub-inorganic encapsulation layer IL2-4 may have a density higher than the density of the third sub-inorganic encapsulation layer IL2-3.

[0128] Figure 6ATo illustrate a cross-sectional view of an embodiment that is part of a display panel DP according to the present disclosure (refer to Figure 3 ). Figure 6A To illustrate a cross-sectional view of an encapsulation layer TFEb. The encapsulation layer TFEb may include a first inorganic encapsulation film IL1, an organic encapsulation film OL, and a second inorganic encapsulation film IL2. Components that are the same as or similar to the components described in reference Figures 4A to 5B will be assigned the same or similar reference numerals, and repeated descriptions will be omitted.

[0129] Reference Figure 6A , the second inorganic encapsulation film IL2 in the embodiment may include a first sub-inorganic encapsulation layer IL2-1 and a second sub-inorganic encapsulation layer IL2-2 stacked in sequence. The second sub-inorganic encapsulation layer IL2-2 may have a higher density than the first sub-inorganic encapsulation layer IL2-1. In this embodiment, the first sub-inorganic encapsulation layer IL2-1 may also be referred to as a first low-density layer, and the second sub-inorganic encapsulation layer IL2-2 may also be referred to as a first high-density layer.

[0130] The first inorganic encapsulation film IL1 in the embodiment may include a first sub-inorganic encapsulation layer IL1-1 and a second sub-inorganic encapsulation layer IL1-2 stacked in sequence. The first sub-inorganic encapsulation layer IL1-1 and the second sub-inorganic encapsulation layer IL1-2 include the same material as each other. The first sub-inorganic encapsulation layer IL1-1 and the second sub-inorganic encapsulation layer IL1-2 may have different densities from each other. In the embodiment, the second sub-inorganic encapsulation layer IL1-2 may have a higher density than the first sub-inorganic encapsulation layer IL1-1. In this case, for example, the first sub-inorganic encapsulation layer IL1-1 may also be referred to as a second low-density layer, and the second sub-inorganic encapsulation layer IL1-2 may also be referred to as a second high-density layer.

[0131] However, the present disclosure is not limited thereto, and the first sub-inorganic encapsulation layer IL1-1 may have a higher density than the second sub-inorganic encapsulation layer IL1-2. In this case, the first sub-inorganic encapsulation layer IL1-1 may also be referred to as a second high-density layer, and the second sub-inorganic encapsulation layer IL1-2 may also be referred to as a second low-density layer.

[0132] The sum of the thickness TH1 of the first inorganic encapsulation film IL1 and the thickness TH2 of the second inorganic encapsulation film IL2 may be 1 micron or less. In the present embodiment, the thickness TH2 of the second inorganic encapsulation film IL2 may be 0.5 micron or less. The thickness TH2 of the second inorganic encapsulation film IL2 may correspond to the sum of the thickness TH2-1 of the first sub-inorganic encapsulation layer IL2-1 and the thickness TH2-2 of the second sub-inorganic encapsulation layer IL2-2. In an embodiment, the thickness TH1 of the first inorganic encapsulation film IL1 may be 0.5 micron or less. The thickness TH1 of the first inorganic encapsulation film IL1 may correspond to the sum of the thickness TH1-1 of the first sub-inorganic encapsulation layer IL1-1 and the thickness TH1-2 of the second sub-inorganic encapsulation layer IL1-2.

[0133] Figure 6B A flowchart for explaining an embodiment of a method of manufacturing a display device according to the present disclosure.

[0134] Reference Figure 3 、 Figure 4B 、 Figure 6A and Figure 6B ,In an embodiment of the present disclosure, the operation S100 of forming the first inorganic encapsulation film IL1 may include the operation S110 of depositing the first sub-inorganic encapsulation layer IL1-1 on the display element layer DP-ED and the operation S120 of depositing the second sub-inorganic encapsulation layer IL1-2 on the first sub-inorganic encapsulation layer IL1-1. The operation S110 of depositing the first sub-inorganic encapsulation layer IL1-1 and the operation S120 of depositing the second sub-inorganic encapsulation layer IL1-2 may each be performed by CVD.

[0135] In the operation S110 of depositing the first sub-inorganic encapsulation layer IL1-1 and the operation S120 of depositing the second sub-inorganic encapsulation layer IL1-2, the same material may be deposited. In an embodiment, in the operation S110 of depositing the first sub-inorganic encapsulation layer IL1-1 and the operation S120 of depositing the second sub-inorganic encapsulation layer IL1-2, silicon nitride (SiN x ) may be deposited. The operation S110 of depositing the first sub-inorganic encapsulation layer IL1-1 and the operation S120 of depositing the second sub-inorganic encapsulation layer IL1-2 may be performed in the same chamber.

[0136] The operation S110 of depositing the first sub-inorganic encapsulation layer IL1-1 and the operation S120 of depositing the second sub-inorganic encapsulation layer IL1-2 may be controlled and performed with different process parameters. More specifically, the process parameters in each step may be controlled such that the first sub-inorganic encapsulation layer IL1-1 and the second sub-inorganic encapsulation layer IL1-2 have different densities from each other. In an embodiment, for example, the deposition rate in the operation S110 of depositing the first sub-inorganic encapsulation layer IL1-1 and the deposition rate in the operation S120 of depositing the second sub-inorganic encapsulation layer IL1-2 may be set to be different from each other.

[0137] Figure 7 To illustrate a cross-sectional view of an embodiment that is part of a display panel DP (refer to Figure 3 ). Figure 7 To illustrate a cross-sectional view of the encapsulation layer TFEc. The encapsulation layer TFEc may include a first inorganic encapsulation film IL1, an organic encapsulation film OL, and a second inorganic encapsulation film IL2. Components that are the same as or similar to the components described in the reference Figures 4A to 6B will be assigned the same or similar reference numerals, and repeated descriptions will be omitted.

[0138] Reference Figure 7 , the second inorganic encapsulation film IL2 in the embodiment may include a first sub-inorganic encapsulation layer IL2-1, a second sub-inorganic encapsulation layer IL2-2, a third sub-inorganic encapsulation layer IL2-3, and a fourth sub-inorganic encapsulation layer IL2-4 stacked in sequence. Among the first sub-inorganic encapsulation layer to the fourth sub-inorganic encapsulation layer IL2-1, IL2-2, IL2-3, and IL2-4, the sub-inorganic encapsulation layers in contact with each other may have different densities from each other. In this embodiment, the first sub-inorganic encapsulation layer to the fourth sub-inorganic encapsulation layer IL2-1, IL2-2, IL2-3, and IL2-4 may also be referred to as the first-first low-density layer, the first-first high-density layer, the first-second low-density layer, and the first-second high-density layer, respectively.

[0139] The first inorganic encapsulation film IL1 in the embodiment may include a first sub-inorganic encapsulation layer IL1-1 and a second sub-inorganic encapsulation layer IL1-2 stacked in sequence. The first sub-inorganic encapsulation layer IL1-1 and the second sub-inorganic encapsulation layer IL1-2 may have different densities from each other. In the embodiment, for example, the first sub-inorganic encapsulation layer IL1-1 and the second sub-inorganic encapsulation layer IL1-2 may also be referred to as the second low-density layer and the second high-density layer, respectively. In an alternative embodiment, the first sub-inorganic encapsulation layer IL1-1 and the second sub-inorganic encapsulation layer IL1-2 may also be referred to as the second high-density layer and the second low-density layer, respectively.

[0140] The sum of the thickness TH1 of the first inorganic encapsulation film IL1 and the thickness TH2 of the second inorganic encapsulation film IL2 may be 1 micrometer or less. In this embodiment, the thickness TH2 of the second inorganic encapsulation film IL2 may be 0.5 micrometer or less. The thickness TH2 of the second inorganic encapsulation film IL2 may correspond to the sum of the thicknesses of the first sub-inorganic encapsulation layer IL2-1, the second sub-inorganic encapsulation layer IL2-2, the third sub-inorganic encapsulation layer IL2-3, and the fourth sub-inorganic encapsulation layer IL2-4.

[0141] In an embodiment of the present disclosure, the thickness TH1 of the first inorganic encapsulation film IL1 may be 0.5 micrometers or less. The thickness TH1 of the first inorganic encapsulation film IL1 may correspond to the sum of the thickness of the first sub-inorganic encapsulation layer IL1-1 and the thickness of the second sub-inorganic encapsulation layer IL1-2. However, the thickness TH1 of the first inorganic encapsulation film IL1 is not limited thereto, as long as the sum of the thickness TH1 of the first inorganic encapsulation film IL1 and the thickness TH2 of the second inorganic encapsulation film IL2 is 1 micrometer or less.

[0142] Figure 8 A cross-sectional view illustrating an embodiment of a display device DD-1 according to the present disclosure. Figure 9A and Figure 9B An enlarged cross-sectional view of an embodiment of a part of the light-emitting elements EDa and EDb according to the present disclosure.

[0143] Reference Figures 8 to 9B , the display device DD-1 may include a display panel DP-1, and the display panel DP-1 may include a base layer BS, a circuit layer DP-CL provided on the base layer BS, a display element layer DP-ED provided on the circuit layer DP-CL, and an encapsulation layer TFE provided on the display element layer DP-ED. Additionally, the display device DD-1 in the embodiment may further include a color filter layer CFL and a planarization layer OC provided on the encapsulation layer TFE. The color filter layer CFL may be a component corresponding to Figure 2 the optical layer RCL in

[0144] In an embodiment, the base layer BS may be a silicon wafer. The circuit layer DP-CL may be formed by performing a CMOS process on the silicon wafer. In this case, the circuit layer DP-CL may include a miniaturized semiconductor pattern and a conductive pattern, and may provide a display panel DP-1 that can easily achieve a relatively high resolution.

[0145] Each of the light-emitting elements ED-1, ED-2, and ED-3 according to the present embodiment may include a first electrode EL1, a second electrode EL2 provided above the first electrode EL1, and a light-emitting component EP1, EP2, or EP3 provided between the first electrode EL1 and the second electrode EL2. The first to third light-emitting elements ED-1, ED-2, and ED-3 may include the first to third light-emitting components EP1, EP2, and EP3, respectively. Figure 9A The light-emitting element EDa of Figure 9B and Figure 8 the light-emitting element EDb of Figure 9A Each of the light-emitting components EPa of Figure 9B and Figure 8One of the first to third light-emitting components EP1, EP2, and EP3.

[0146] Reference Figure 9A , the light-emitting component EPa in the embodiments of the present disclosure may include a first light-emitting stack ST1, a charge generation layer CGL, and a second light-emitting stack ST2 that are sequentially stacked on the third-direction axis (also referred to as the third direction) DR3. The light-emitting element EDa may be a light-emitting element having a series structure including a plurality of light-emitting stacks ST1 and ST2.

[0147] The first light-emitting stack ST1 may include a first emission layer EML1, a first hole control layer HTR1, and a first electron control layer ETR1 disposed therebetween with the first emission layer EML1.

[0148] The first hole control layer HTR1 may include at least one of a first hole injection layer HIL1 and a first hole transport layer HTL1. The first hole transport layer HTL1 may include at least one of a first hole buffer layer and a first electron blocking layer.

[0149] The first electron control layer ETR1 may include at least one of a first electron injection layer EIL1 and a first electron transport layer ETL1. The first electron control layer ETR1 may further include a first hole blocking layer.

[0150] The second light-emitting stack ST2 may include a second emission layer EML2, a second hole control layer HTR2, and a second electron control layer ETR2 disposed therebetween with the second emission layer EML2.

[0151] The second hole control layer HTR2 may include at least one of a second hole injection layer HIL2 and a second hole transport layer HTL2. The second electron control layer ETR2 may include at least one of a second electron injection layer EIL2 and a second electron transport layer ETL2. The descriptions of the first hole control layer HTR1 and the first electron control layer ETR1 may equally apply to the descriptions of the second hole control layer HTR2 and the second electron control layer ETR2.

[0152] In an embodiment, the light emitted from the light-emitting stacks ST1 and ST2 may be light within the same wavelength range. In an embodiment, for example, the light emitted from the light-emitting stacks ST1 and ST2 may be blue light. However, the present disclosure is not limited thereto, and the light-emitting stacks ST1 and ST2 may emit light within different wavelength ranges. In an embodiment, for example, at least one of the light-emitting stacks ST1 and ST2 may emit blue light, and the remaining light-emitting stacks may emit green light. The light-emitting element EDa including the light-emitting stacks ST1 and ST2 that emit light within different wavelength ranges may emit white light.

[0153] The charge generation layer CGL may be disposed between the first light-emitting stack ST1 and the second light-emitting stack ST2. When a voltage is applied, the charge generation layer CGL may generate charges (electrons and holes) by forming a complex using a redox reaction. The charge generation layer CGL may supply the generated charges to the light-emitting stacks ST1 and ST2. The charge generation layer CGL may double the current efficiency generated in the light-emitting stacks ST1 and ST2 and may be used to balance the charges between the first light-emitting stack ST1 and the second light-emitting stack ST2.

[0154] More specifically, the charge generation layer CGL may have a layer structure in which the lower charge generation layer CGL-1 and the upper charge generation layer CGL-2 are combined with each other. The lower charge generation layer CGL-1 may be an n-type charge generation layer disposed adjacent to the first light-emitting stack ST1 and supplying electrons to the first light-emitting stack ST1. The lower charge generation layer CGL-1 may include an arylamine-based organic compound.

[0155] The upper charge generation layer CGL-2 may be a p-type charge generation layer disposed adjacent to the second light-emitting stack ST2 and supplying holes to the second light-emitting stack ST2. The upper charge generation layer CGL-2 may include a charge generation compound including or consisting of the following: a metal; an oxide of a metal, a carbide of a metal, or a fluoride of a metal; or any combination thereof.

[0156] A buffer layer may be additionally disposed between the lower charge generation layer CGL-1 and the upper charge generation layer CGL-2.

[0157] According to the present embodiment, the first light-emitting stack ST1, the charge generation layer CGL, and the second light-emitting stack ST2 may be commonly formed in a plurality of pixels using an aperture mask. However, the present invention is not limited thereto, and at least one of the first hole control layer HTR1 and the second hole control layer HTR2, the first emission layer EML1 and the second emission layer EML2, and the first electron control layer ETR1 and the second electron control layer ETR2 may be patterned and formed through a mask. In an embodiment, for example, the first emission layer EML1 and the second emission layer EML2 may be disposed in a region corresponding to the pixel opening OH (refer to Figure 8 ). That is, the first emission layer EML1 and the second emission layer EML2 may be separately formed in the pixels.

[0158] Refer to Figure 9B, the light-emitting component EPb in the embodiments of the present disclosure may include a first light-emitting stack ST1, a first charge generation layer CGL1, a second light-emitting stack ST2, a second charge generation layer CGL2, and a third light-emitting stack ST3. That is, in this embodiment, the light-emitting component EPb may include three light-emitting stacks ST1, ST2, and ST3 and two charge generation layers CGL1 and CGL2 disposed between adjacent light-emitting stacks ST1, ST2, and ST3. Components identical or similar to the components described with reference to Figure 9A will be assigned the same or similar reference numerals, and repeated descriptions will be omitted.

[0159] The third light-emitting stack ST3 may have a structure similar to that of the first light-emitting stack ST1 and the second light-emitting stack ST2 of the above reference Figure 9A . The third light-emitting stack ST3 may include a third hole control layer, a third emission layer, and a third electron control layer stacked in sequence on the second charge generation layer CGL2 in a third direction DR3.

[0160] In addition, each of the first charge generation layer CGL1 and the second charge generation layer CGL2 may have a structure similar to that of the charge generation layer CGL of the above reference Figure 9A . The first charge generation layer CGL1 may have a layer structure in which a first lower charge generation layer CGL-1 and a first upper charge generation layer CGL-2 are bonded to each other, and the second charge generation layer CGL2 may have a layer structure in which a second lower charge generation layer CGL-3 and a second upper charge generation layer CGL-4 are bonded to each other.

[0161] The number of the light-emitting stacks ST1, ST2, and ST3 and the number of the charge generation layers CGL1 and CGL2 are not limited to Figure 9A and Figure 9B illustrated, and may include four or more light-emitting stacks and three or more charge generation layers disposed therebetween.

[0162] Return to reference Figure 8 , reference Figures 4A to 7The descriptions of the encapsulation layers TFE, TFEa, TFEb, and TFEc can be equally applied to the encapsulation layer TFE. The color filter layer CFL can be disposed on the encapsulation layer TFE. The color filter layer CFL can include a first color filter CF1 corresponding to an emission region (also referred to as a first pixel region) PXA-R that emits red light, a second color filter CF2 corresponding to an emission region (also referred to as a second pixel region) PXA-G that emits green light, and a third color filter CF3 corresponding to an emission region (also referred to as a third pixel region) PXA-B that emits blue light. The color filter layer CFL can further include a light-blocking member BM. The light-blocking member BM can be disposed in a non-emission region (also referred to as a non-pixel region) NPXA to have a width narrower than the width of the non-pixel region NPXA. However, it is not limited thereto, and the light-blocking member BM can be disposed corresponding to the non-pixel region NPXA. The light-blocking member BM can be a black matrix. The light-blocking member BM can include or be composed of the following: an organic light-blocking material or an inorganic light-blocking material, and the organic light-blocking material or the inorganic light-blocking material includes a black pigment and / or a black dye or is composed of a black pigment and / or a black dye. The light-blocking member BM can prevent light leakage and can separate the color filters CF1, CF2, and CF3 from each other. In the present disclosure, the expression "one region / part corresponds to another region / part" used herein means that these regions / parts overlap each other and are not limited to having the same area.

[0163] Each of the first to third color filters CF1, CF2, and CF3 can include a photosensitive polymer resin and a colorant. In the present specification, the colorant includes a pigment and / or a dye. The red colorant can include a red pigment and / or a red dye, the green colorant can include a green pigment and / or a green dye, and the blue colorant can include a blue pigment and / or a blue dye.

[0164] In an embodiment, for example, the first color filter CF1 can include a red pigment or a red dye, the second color filter CF2 can include a green pigment or a green dye, and the third color filter CF3 can include a blue pigment or a blue dye. The light provided from the light-emitting component EP1 and passing through the first color filter CF1 can provide red light outside the display panel DP-1, the light provided from the light-emitting component EP2 and passing through the second color filter CF2 can provide green light outside the display panel DP-1, and the light provided from the light-emitting component EP3 and passing through the third color filter CF3 can provide blue light outside the display panel DP-1.

[0165] The planarization layer OC can be disposed on the color filter layer CFL. The planarization layer OC can cover the first to third color filters CF1, CF2, and CF3. The planarization layer OC can include an organic material. The organic material can be transparent and can include, for example, an acrylic resin. The planarization layer OC can provide a flat upper surface. In another embodiment, the planarization layer OC can be omitted.

[0166] Reference Figure 4A and Figure 8 , Table 2 below shows the measured light efficiency of the display panels of Comparative Example 2 and Embodiment 2. In the display panel of Comparative Example 2, the first inorganic encapsulation film is a single inorganic film with a thickness of 0.8 micrometers, the second inorganic encapsulation film is a single inorganic film with a thickness of 0.7 micrometers, and the organic encapsulation film is an organic film with a thickness of 8 micrometers. In the display panel of Embodiment 2, the first inorganic encapsulation film is a single inorganic film with a thickness of 0.6 micrometers, the second inorganic encapsulation film has a thickness of 0.4 micrometers and includes a low-density layer and a high-density layer stacked in sequence, and the organic encapsulation film is an organic film with a thickness of 8 micrometers. The high-density layer of Embodiment 2 has a higher density than the single inorganic film of the second inorganic encapsulation film of Comparative Example 2. The display panels of Comparative Example 2 and Embodiment 2 have the structure of the display panel DP-1 of the above reference Figure 8 .

[0167] In terms of light efficiency, the evaluation results when white light is provided from the front are shown. In addition, in terms of light efficiency, the luminance according to the current (cd / m 2 ) is measured, and the luminance value in Embodiment 2 represents a relative value based on the luminance value in Comparative Example 2, where the luminance value in Comparative Example 2 is set to 100%.

[0168] [Table 2]

[0169] Luminous efficiency (%, white light, front surface) Comparative Example 2 100 Embodiment 2 106.2

[0170] Referring to Table 2, it can be seen that since the encapsulation layer of Embodiment 2 has a smaller thickness than the encapsulation layer of Comparative Example 2, the display panel of Embodiment 2 exhibits excellent light efficiency when compared with the display panel of Comparative Example 2. The distance d between the display element layer DP-ED and the color filter layer CFL in the display panel of Embodiment 2 can be shorter than the distance between the display element layer DP-ED and the color filter layer CFL in the display panel of Comparative Example 2. Accordingly, the display panel of Embodiment 2 can prevent and / or reduce light from reaching adjacent emission regions. Therefore, color mixing can be prevented, and thus the light efficiency can be improved.

[0171] Figure 10 A perspective view for explaining an embodiment of the display device DD-2 according to the present disclosure. Components that are the same as or similar to the components described with reference to Figure 1 will be assigned the same or similar reference numerals, and repeated descriptions will be omitted.

[0172] Reference Figure 10, the display device DD-2 according to the present embodiment may include a folding region FA and a plurality of non-folding regions NFA1 and NFA2. The non-folding regions NFA1 and NFA2 may include a first non-folding region NFA1 and a second non-folding region NFA2. The folding region FA may be provided between the first non-folding region NFA1 and the second non-folding region NFA2. The first non-folding region NFA1, the folding region FA, and the second non-folding region NFA2 may be arranged on a second direction axis (also referred to as the second direction) DR2. The folding region FA may also be referred to as a foldable region, and the first non-folding region NFA1 and the second non-folding region NFA2 may also be referred to as a first non-foldable region and a second non-foldable region.

[0173] Although one folding region FA and two non-folding regions NFA1 and NFA2 are illustrated in the embodiment, the number of the folding region FA and the number of the non-folding regions NFA1 and NFA2 are not limited thereto. In the embodiment, for example, the display device DD-2 may include more than two non-folding regions and a plurality of folding regions provided between the non-folding regions.

[0174] The sensor region ED-SA may be defined in the active region AA-DD of the display device DD-2. Although one sensor region ED-SA is illustrated as an example in Figure 10 , the number of the sensor regions ED-SA is not limited thereto. The sensor region ED-SA may be a part of the active region AA-DD. The display device DD-2 may display an image through the sensor region ED-SA. However, the present disclosure is not limited thereto. In the embodiment, for example, a portion of the display panel corresponding to the sensor region ED-SA may be removed, and the sensor region ED-SA may not display an image.

[0175] The electronic module may be provided in a region overlapping with the sensor region ED-SA. The electronic module may receive an external input transmitted through the sensor region ED-SA, or may provide an output through the sensor region ED-SA. In the embodiment, for example, the electronic module may be a camera module, a sensor for measuring a distance (e.g., a proximity sensor), a sensor for recognizing a part of a user's body (e.g., a fingerprint, an iris, or a face), or a relatively small lamp that outputs light, but is not particularly limited thereto. Hereinafter, an example in which the electronic module overlapping with the sensor region ED-SA is a camera module will be given.

[0176] Figure 11 and Figure 12 are perspective views of an embodiment of the foldable display device DD-2 according to the present disclosure. In Figure 11 and Figure 12 , the folding state of the display device DD-2 illustrated in Figure 10 is illustrated.

[0177] Reference Figure 11 and Figure 12 , the display device DD-2 can be a foldable display device DD-2 that can be folded or unfolded. In an embodiment, for example, the folding region FA can be bent around a virtual folding axis FX parallel to the first direction DR1, and the display device DD-2 can be folded accordingly. The folding axis FX can be defined as the major axis parallel to the long side of the display device DD-2.

[0178] When the display device DD-2 is folded, the first non-folding region NFA1 and the second non-folding region NFA2 can face each other, and the display device DD-2 can be folded in an inward folding manner such that the display surface is not exposed to the outside. However, the embodiments of the present disclosure are not limited thereto. In an embodiment, for example, the display device DD-2 can be folded around the folding axis FX in an outward folding manner such that the display surface is exposed to the outside.

[0179] The folding region FA can be bent to have a radius of curvature R1. As Figure 11 explained, the distance between the first non-folding region NFA1 and the second non-folding region NFA2 can be substantially equal to twice the radius of curvature R1 (e.g., diameter). In this case, the display device DD-2 can be folded into a "U" shape.

[0180] However, it is not limited thereto. As Figure 12 explained, the distance between the first non-folding region NFA1 and the second non-folding region NFA2 can be less than twice the radius of curvature R1. In this case, the display device DD-2 can be folded into a dumbbell shape.

[0181] The display device DD-2 of the present embodiment can include one of the encapsulation layers TFE, TFEa, TFEb, and TFEc of the above-mentioned reference Figure 4A , Figure 5A , Figure 6A and Figure 7 . According to the present embodiment, since the foldable display device DD-2 includes one of the thinner encapsulation layers TFE, TFEa, TFEb, and TFEc (reference Figure 4A , Figure 5A , Figure 6A and Figure 7 ), the bending characteristics can be improved, and thus the folding reliability can be improved. At the same time, the display device can include an encapsulation layer with a relatively low WVTR, while improving the mass productivity and reducing the cost, and can provide a display device with improved light efficiency.

[0182] According to the present disclosure, the display device can include an encapsulation layer with a relatively small thickness and a relatively low WVTR. Accordingly, the display device can have high isolation characteristics while improving the mass productivity and reducing the cost.

[0183] According to the present disclosure, since the encapsulation layer has a relatively small thickness, a display device with improved light efficiency can be provided. When implementing a high-resolution display device, color mixing can be prevented due to the reduced distance between the display element layer and the color filter layer. Accordingly, the light efficiency can be improved. When implementing a foldable display device, the bending characteristics can be improved, and thus the folding reliability can be improved.

[0184] Although the present disclosure has been described with reference to its embodiments, it will be apparent to those of ordinary skill in the art that various changes and modifications can be made thereto without departing from the spirit and scope of the disclosure as set forth in the claims.

Claims

1. A display device, comprising: A display panel, comprising: A display element layer, comprising: A pixel defining layer in which pixel openings are defined; and Light-emitting elements; and A encapsulation layer disposed on the display element layer, the encapsulation layer comprising: A first inorganic encapsulation film; An organic encapsulation film disposed on the first inorganic encapsulation film; and A second inorganic encapsulation film disposed on the organic encapsulation film, the second inorganic encapsulation film comprising: A first sub-inorganic encapsulation layer; and A second sub-inorganic encapsulation layer disposed on the first sub-inorganic encapsulation layer, the second sub-inorganic encapsulation layer comprising the same material as that of the first sub-inorganic encapsulation layer, wherein the density of the first sub-inorganic encapsulation layer and the density of the second sub-inorganic encapsulation layer are different from each other, and wherein the sum of the thickness of the first inorganic encapsulation film and the thickness of the second inorganic encapsulation film is 1 micrometer or less.

2. The display device according to claim 1, wherein the density of the second sub-inorganic encapsulation layer is higher than the density of the first sub-inorganic encapsulation layer.

3. The display device according to claim 1, wherein the first sub-inorganic encapsulation layer and the second sub-inorganic encapsulation layer comprise silicon nitride.

4. The display device according to claim 1, wherein the thickness of the second inorganic encapsulation film is 0.5 micrometer or less.

5. The display device according to claim 1, wherein the thickness of the first inorganic encapsulation film is 0.5 micrometer or less.

6. The display device according to claim 1, wherein the second inorganic encapsulation film further comprises: A third sub-inorganic encapsulation layer disposed on the second sub-inorganic encapsulation layer; and A fourth sub-inorganic encapsulation layer disposed on the third sub-inorganic encapsulation layer, wherein the material of each of the third sub-inorganic encapsulation layer and the fourth sub-inorganic encapsulation layer is the same as the material of the first sub-inorganic encapsulation layer, wherein the density of the second sub-inorganic encapsulation layer and the density of the third sub-inorganic encapsulation layer are different from each other, and wherein the density of the third sub-inorganic encapsulation layer and the density of the fourth sub-inorganic encapsulation layer are different from each other.

7. The display device according to claim 1, wherein the first inorganic encapsulation film comprises: A first sub-inorganic encapsulation layer; and A second sub-inorganic encapsulation layer disposed on the first sub-inorganic encapsulation layer of the first inorganic encapsulation film, wherein the second sub-inorganic encapsulation layer of the first inorganic encapsulation film comprises the same material as the first sub-inorganic encapsulation layer of the first inorganic encapsulation film, and wherein the density of the first sub-inorganic encapsulation layer of the first inorganic encapsulation film and the density of the second sub-inorganic encapsulation layer of the first inorganic encapsulation film are different from each other.

8. The display device according to claim 1, wherein the encapsulation layer has a water vapor transmission rate of less than or equal to 1.5×10 -4 grams per square meter per 24 hours.

9. The display device according to claim 1, wherein the light-emitting element comprises: A first electrode; An emission layer disposed on the first electrode; and A second electrode disposed on the emission layer.

10. The display device according to claim 1, further comprising an active area configured to display an image, and wherein the active area comprises a flat area and at least one curved area bent from the flat area.

11. The display device according to claim 1, further comprising: a base layer disposed below the display element layer and including a silicon wafer; and a color filter layer disposed on the encapsulation layer.

12. The display device according to claim 11, wherein the light-emitting element includes: a first electrode; a light-emitting component including a first light-emitting stack disposed on the first electrode, a charge generation layer disposed on the first light-emitting stack, and a second light-emitting stack disposed on the charge generation layer; and a second electrode disposed on the light-emitting component.

13. The display device according to claim 1, further comprising: A folding region folded around a virtual axis extending in one direction, and a first non-folding region and a second non-folding region with the folding region disposed therebetween.

14. A method of manufacturing a display device, the method comprising: forming a first inorganic encapsulation film on a display element layer including a pixel defining layer having a pixel opening defined therein and a light-emitting element; forming an organic encapsulation film on the first inorganic encapsulation film; and forming a second inorganic encapsulation film on the organic encapsulation film, forming the second inorganic encapsulation film including: depositing a first sub-inorganic encapsulation layer; and depositing a second sub-inorganic encapsulation layer on the first sub-inorganic encapsulation layer, wherein the material of the first sub-inorganic encapsulation layer and the material of the second sub-inorganic encapsulation layer are the same as each other, wherein the density of the first sub-inorganic encapsulation layer and the density of the second sub-inorganic encapsulation layer are different from each other, and wherein the sum of the thickness of the first inorganic encapsulation film and the thickness of the second inorganic encapsulation film is 1 micrometer or less.

15. The method according to claim 14, wherein depositing the first sub-inorganic encapsulation layer and depositing the second sub-inorganic encapsulation layer are controlled by different process parameters.

16. The method according to claim 14, wherein forming the second inorganic encapsulation film further includes: depositing a third sub-inorganic encapsulation layer on the second sub-inorganic encapsulation layer; and depositing a fourth sub-inorganic encapsulation layer on the third sub-inorganic encapsulation layer, wherein the material of each of the third sub-inorganic encapsulation layer and the fourth sub-inorganic encapsulation layer is the same as the material of the first sub-inorganic encapsulation layer, wherein the density of the second sub-inorganic encapsulation layer and the density of the third sub-inorganic encapsulation layer are different from each other, and wherein the density of the third sub-inorganic encapsulation layer and the density of the fourth sub-inorganic encapsulation layer are different from each other.

17. The method according to claim 14, wherein forming the first inorganic encapsulation film includes: depositing a first sub-inorganic encapsulation layer of the first inorganic encapsulation film on the display element layer; and depositing a second sub-inorganic encapsulation layer of the first inorganic encapsulation film on the first sub-inorganic encapsulation layer of the first inorganic encapsulation film, and wherein the material of the first sub-inorganic encapsulation layer of the first inorganic encapsulation film and the material of the second sub-inorganic encapsulation layer of the first inorganic encapsulation film are the same as each other, and wherein the density of the first sub-inorganic encapsulation layer of the first inorganic encapsulation film and the density of the second sub-inorganic encapsulation layer of the first inorganic encapsulation film are different from each other.

18. The method according to claim 14, wherein the first sub-inorganic encapsulation layer and the second sub-inorganic encapsulation layer comprise silicon nitride.

19. The method according to claim 14, wherein the second inorganic encapsulation film has a thickness of 0.5 micrometers or less.

20. The method according to claim 14, wherein the density of the second sub-inorganic encapsulation layer is higher than the density of the first sub-inorganic encapsulation layer.

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