Light emitting element and display panel including same

Abstract

The invention relates to a light emitting element and a display panel including the same. The light-emitting element comprises a first electrode, a first light-emitting lamination layer arranged on the first electrode, a second light-emitting lamination layer arranged on the first light-emitting lamination layer, a third light-emitting lamination layer arranged on the second light-emitting lamination layer, a fourth light-emitting lamination layer arranged on the third light-emitting lamination layer and a fifth light-emitting lamination layer arranged on the fourth light-emitting lamination layer. A second electrode disposed on the fifth light emitting stack; and a charge generation layer disposed between adjacent stacks among the first to fifth light emitting stacks. Each of the first to fifth light emitting stacks includes at least one emission layer, and the first to fifth light emitting stacks include at least two blue emission layers, at least one green emission layer, and at least one red emission layer.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0094221 filed in the Korean Intellectual Property Office (KIPO) on July 20, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure herein relates to a light emitting element in which light emitting efficiency and element lifespan are improved, and a display panel including the same. Background Art

[0004] An organic light emitting element is a self-emitting element having a fast response speed and driven by a low voltage. Accordingly, an organic light emitting display device including an organic light emitting element can exclude a separate light source and thus can be thin and lightweight. An organic light emitting display device has many advantages, such as excellent brightness and viewing angle independence.

[0005] The organic light emitting element is a display element that includes an emission layer made of an organic material between an anode electrode and a cathode electrode. After holes provided from the anode electrode and electrons provided from the cathode electrode are recombined in the emission layer to form excitons, light corresponding to the energy between holes and electrons is generated by the excitons.

[0006] The organic light emitting elements connected in series may each have a structure including two or more stacked layers of a hole injection layer / emission layer / electron transport layer between an anode electrode and a cathode electrode. A charge generation layer that facilitates the generation and movement of charges may exist between each of these stacked layers. Summary of the invention

[0007] The present disclosure provides a light emitting element in which light emitting efficiency and element life are improved.

[0008] The present disclosure also provides a display panel with improved display efficiency.

[0009] In an embodiment of the present disclosure, a light-emitting element may include a first electrode, a first light-emitting stack disposed on the first electrode, a second light-emitting stack disposed on the first light-emitting stack, a third light-emitting stack disposed on the second light-emitting stack, a fourth light-emitting stack disposed on the third light-emitting stack, a fifth light-emitting stack disposed on the fourth light-emitting stack, a second electrode disposed on the fifth light-emitting stack, and a charge generation layer disposed between adjacent stacks in the first to fifth light-emitting stacks. Each of the first to fifth light-emitting stacks may include at least one emission layer, and the first to fifth light-emitting stacks may include at least two blue emission layers, at least one green emission layer, and at least one red emission layer.

[0010] In an embodiment, the first to fifth light emitting stacks may include three blue emission layers, one or two green emission layers, and one or two red emission layers.

[0011] In an embodiment, the first light emitting stack may include a first blue emission layer, the second light emitting stack may include a second blue emission layer, the third light emitting stack may include a red emission layer, the fourth light emitting stack may include a third blue emission layer, and the fifth light emitting stack may include a green emission layer.

[0012] In an embodiment, the first light-emitting stack may include a first blue emission layer, the second light-emitting stack may include a second blue emission layer, the third light-emitting stack may include a first composite emission layer, the fourth light-emitting stack may include a third blue emission layer, the fifth light-emitting stack may include a green emission layer, and the first composite emission layer may include a red sub-emission layer and a green sub-emission layer disposed on the first red sub-emission layer.

[0013] In an embodiment, the first light emitting stack may include a red emission layer, the second light emitting stack may include a first blue emission layer, the third light emitting stack may include a green emission layer, the fourth light emitting stack may include a second blue emission layer, and the fifth light emitting stack may include a third blue emission layer.

[0014] In an embodiment, the first light emitting stack may include a first composite emission layer, the second light emitting stack may include a first blue emission layer, the third light emitting stack may include a green emission layer, the fourth light emitting stack may include a second blue emission layer, the fifth light emitting stack may include a third blue emission layer, and the first composite emission layer may include a red sub-emission layer and a green sub-emission layer disposed on the red sub-emission layer.

[0015] In an embodiment, the first to fifth light-emitting stacks may include a first blue emission layer, a second blue emission layer, and a third blue emission layer, and the third blue emission layer may be disposed adjacent to the second electrode compared to the first and second blue emission layers, and a distance from a top surface of the first electrode to a center of the third blue emission layer may be an nth order resonance distance of the third blue emission layer. In an embodiment, n may be an integer greater than or equal to 3.

[0016] In an embodiment, the first to fifth light emitting stacks may include a red emission layer, and the distance from the top surface of the first electrode to the center of the first red emission layer may be the mth order resonance distance of the red emission layer. In an embodiment, m may be 1 or 2.

[0017] In an embodiment, at least one emission layer included in each of the first to fifth light-emitting stacks may have a thickness of about 100 nm. to about The thickness is within the range of .

[0018] In an embodiment, the charge generation layer may include a first charge generation layer disposed between a first light-emitting stack and a second light-emitting stack, a second charge generation layer disposed between the second light-emitting stack and a third light-emitting stack, a third charge generation layer disposed between the third light-emitting stack and a fourth light-emitting stack, and a fourth charge generation layer disposed between the fourth light-emitting stack and the fifth light-emitting stack.

[0019] In an embodiment, each of the charge generation layers may include a p-type charge generation layer doped with a p-dopant and an n-type charge generation layer doped with an n-dopant.

[0020] In an embodiment, each of the first to fifth light-emitting stacks may further include a hole transport region adjacent to the first electrode and an electron transport region spaced apart from the hole transport region, the emission layer is inserted between the electron transport region and the hole transport region, and the electron transport region may be adjacent to the second electrode.

[0021] In an embodiment, at least one of the electron transport regions of the first to fifth light emitting stacks may include an electron injection layer, and the electron injection layer may include at least two of Mg, Ag, Yb, and Al.

[0022] In an embodiment, at least one of the first to fifth light emitting stacks may include a phosphorescent emission layer, and at least another one of the first to fifth light emitting stacks may include a fluorescent emission layer.

[0023] In an embodiment, at least one of the first to fifth light emitting stacks may include a first host, a second host, and a dopant, and the first host and the second host may form an exciplex.

[0024] In an embodiment, the light emitting element may further include a capping layer disposed on the second electrode. The capping layer may have a refractive index greater than or equal to about 1.6.

[0025] In an embodiment of the present disclosure, a light-emitting element may include a first electrode, a first light-emitting stack disposed on the first electrode, a second light-emitting stack disposed on the first light-emitting stack, a third light-emitting stack disposed on the second light-emitting stack, a fourth light-emitting stack disposed on the third light-emitting stack, a fifth light-emitting stack disposed on the fourth light-emitting stack, and a second electrode disposed on the fifth light-emitting stack. Three of the first to fifth light-emitting stacks may include a blue emission layer, one of the first to fifth light-emitting stacks may include at least a green emission layer, and the remaining one of the first to fifth light-emitting stacks may include at least a red emission layer. Compared with one of the first to fifth light-emitting stacks including at least a green emission layer, the remaining one of the first to fifth light-emitting stacks including at least a red emission layer may be disposed adjacent to the first electrode.

[0026] In an embodiment of the present disclosure, a display panel may include: a light-emitting element that emits source light; and an optical structure layer that is disposed on the light-emitting element and transmits the source light or converts the source light into light with a different wavelength. The light-emitting element may include a first electrode, a first light-emitting stack disposed on the first electrode, a second light-emitting stack disposed on the first light-emitting stack, a third light-emitting stack disposed on the second light-emitting stack, a fourth light-emitting stack disposed on the third light-emitting stack, a fifth light-emitting stack disposed on the fourth light-emitting stack, a second electrode disposed on the fifth light-emitting stack, and a charge generation layer disposed between adjacent stacks in the first to fifth light-emitting stacks. Each of the first to fifth light-emitting stacks may include at least one emission layer, and the first to fifth light-emitting stacks may include at least two blue emission layers, at least one green emission layer, and at least one red emission layer.

[0027] In an embodiment, the optical structure layer may include a light control layer disposed on the light emitting element, and the light control layer may include a first light control pattern emitting light having a red wavelength, a second light control pattern emitting light having a blue wavelength, and a third light control pattern emitting light having a green wavelength.

[0028] In an embodiment, the first to fifth light emitting stacks may include three blue emission layers, one or two green emission layers, and one or two red emission layers. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate embodiments of the present disclosure and together with the description serve to explain the principles of the present disclosure. In the drawings:

[0030] Figure 1A is a perspective view of a display panel according to an embodiment of the present disclosure;

[0031] Figure 1B is a schematic cross-sectional view of a display panel according to an embodiment of the present disclosure;

[0032] Figure 1C is a plan view of a display panel according to an embodiment of the present disclosure;

[0033] Figure 2 is an enlarged plan view of a portion of a display panel according to an embodiment of the present disclosure;

[0034] Figure 3 is a schematic cross-sectional view of a display panel according to an embodiment of the present disclosure;

[0035] FIG. 4A to FIG. 4C is a schematic cross-sectional view of a display panel according to an embodiment of the present disclosure;

[0036] FIG. 5A to FIG. 5E A schematic cross-sectional view schematically illustrating a light emitting element according to an embodiment of the present disclosure; and

[0037] Figure 6 is a graph showing emission intensity according to an optical distance of each of red light, blue light, and green light. DETAILED DESCRIPTION

[0038] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0039] When an element or layer is referred to as being "on," "connected to," or "coupled to" another element or layer, it may be directly on, directly connected to, or directly coupled to another element or layer, or there may be intervening elements or layers. However, when an element or layer is referred to as being "directly on," "directly connected to," or "directly coupled to" another element or layer, there are no intervening elements or layers. For this purpose, the term "connected" may refer to a physical connection, an electrical connection, and / or a fluid connection with or without intervening elements. Furthermore, when an element is referred to as being "in contact" or "contacted," etc., with another element, the element may be "electrically in contact" or "physically in contact" with the other element; or "indirectly in contact" or "directly in contact" with the other element.

[0040] The same reference numerals refer to the same components throughout the text. Also, in the drawings, for the effective description of the technical contents, the proportions and sizes (eg, thickness) of the components are exaggerated.

[0041] In the specification and claims, the phrase "at least one of..." is intended to include the meaning of "at least one selected from the following groups" for the purpose of its meaning and interpretation. For example, "at least one of A and B" can be understood to mean "A, B, or A and B". In the specification and claims, the term "and / or" is intended to include any combination of the terms "and" and "or" for the purpose of its meaning and interpretation. For example, "A and / or B" can be understood to mean "A, B, or A and B". The terms "and" and "or" can be used in a conjunctive sense or a disjunctive sense and can be understood to be equivalent to "and / or".

[0042] It will be understood that although the terms "first", "second", etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component without departing from the scope of the present disclosure. Unless the context clearly indicates otherwise, a term in the singular may include a plural form.

[0043] Spatially relative terms, such as "below," "beneath," "below," "above," "upper," "above," "higher," and "side" (e.g., as in "sidewall"), etc., may be used herein for descriptive purposes, and therefore, to describe the relationship of one element to another element as illustrated in the accompanying drawings. Spatially relative terms are intended to encompass different orientations of the device in use, operation, and / or manufacture in addition to the orientation depicted in the accompanying drawings. For example, if the device in the drawings is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both orientations of above and below. Furthermore, the device may be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and, as such, the spatially relative descriptors used herein are interpreted accordingly.

[0044] The terms used in this article are for the purpose of describing specific embodiments and are not intended to be restrictive. As used in this article, unless the context clearly indicates otherwise, the singular forms "a", "an" and "said" are intended to also include plural forms. Moreover, the terms "comprises", "comprising", "include" and / or "including" when used in this specification indicate the presence of narrated features, integers, steps, operations, elements, components or groups thereof, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components or groups thereof. It should also be noted that, as used in this article, the terms "substantially", "about" and other similar terms are used as approximate terms and not as terms of degree, and, as such, are used to illustrate the inherent deviations in measured values, calculated values ​​or provided values ​​that will be recognized by those of ordinary skill in the art.

[0045] “Directly disposed on” herein means that there are no intervening layers, films, regions, or panels, etc., between a component (such as a layer, film, region, or panel) and another component (such as a layer, film, region, or panel). For example, “directly disposed on” may mean disposed between two layers or two members without using additional members (such as adhesive members).

[0046] Unless otherwise defined, all terms (including technical and scientific terms) used in this article have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. In addition, it will be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and will not be interpreted in an idealized or overly formal sense unless explicitly defined as such in this article.

[0047] Hereinafter, a display panel according to an embodiment of the present disclosure will be described with reference to the accompanying drawings.

[0048] Figure 1A is a perspective view of a display panel according to an embodiment of the present disclosure. Figure 1B is a schematic cross-sectional view of a display panel according to an embodiment of the present disclosure. Figure 1C is a plan view of a display panel according to an embodiment of the present disclosure.

[0049] like Figure 1AAs shown in , the display panel DP may display an image through a display surface DP-IS. The display surface DP-IS may be parallel to a plane defined by a first direction DR1 and a second direction DR2. The display surface DP-IS may include a display area DA and a non-display area NDA. The pixel PX may be disposed in the display area DA and the pixel PX may not be disposed in the non-display area NDA. The non-display area NDA may be defined along an edge of the display surface DP-IS. The non-display area NDA may surround the display area DA. However, the present disclosure is not limited thereto, and in an embodiment of the present disclosure, the non-display area NDA may be omitted or disposed only on one side of the display area DA.

[0050] The normal direction of the display surface DP-IS, for example, the thickness direction of the display panel DP may be the third direction DR3. The front surface (or upper surface) and the rear surface (or lower surface) of each of the layers or units described below are separated by the third direction DR3. However, the first to third directions DR1, DR2, and DR3 shown in the drawings are not limited thereto.

[0051] In the drawings, a display panel DP having a flat display surface DP-IS is illustrated, but the present disclosure is not limited thereto. The display panel DP may include a curved display surface or a three-dimensional display surface. The three-dimensional display surface may include a plurality of display areas facing different directions.

[0052] like Figure 1B As explained in the figure, the display panel DP may include a base substrate BS, a circuit element layer DP-CL, a display element layer DP-LED and an optical structure layer OSL. The base substrate BS may include a synthetic resin substrate or a glass substrate. The circuit element layer DP-CL may include at least one insulating layer and a circuit element. The circuit element may include a signal line, a pixel driving circuit, etc. The circuit element layer DP-CL may be formed by: a process of forming an insulating layer, a semiconductor layer and a conductive layer by coating, deposition, etc., and a process of patterning the insulating layer, the semiconductor layer and the conductive layer by a photoetching process. The display element layer DP-LED may include at least one display element. The optical structure layer OSL may convert the color of light provided from the display element. The optical structure layer OSL may include a structure for increasing the light control pattern and the light conversion efficiency.

[0053] Figure 1C The planar arrangement of the signal lines GL1 to GLn and DL1 to DLm and the pixels PX11 to PXnm is schematically illustrated. The signal lines GL1 to GLn and DL1 to DLm may include a plurality of gate lines GL1 to GLn and a plurality of data lines DL1 to DLm.

[0054] Each of the pixels PX11 to PXnm may be connected to a corresponding gate line among the gate lines GL1 to GLn and a corresponding data line among the data lines DL1 to DLm. Each of the pixels PX11 to PXnm may include a pixel driving circuit and a display element. According to the configuration of the pixel driving circuit of the pixels PX11 to PXnm, more types of signal lines may be provided in the display panel DP.

[0055] The pixels PX11 to PXnm in a matrix form are schematically illustrated, but the present disclosure is not limited thereto. The pixels PX11 to PXnm may be arranged in a matrix. For example, the points where the pixels PX11 to PXnm are arranged may correspond to the vertices of the rhombus. The gate driving circuit GDC may be integrated in the display panel DP by an oxide silicon gate driving circuit (OSG) or an amorphous silicon gate driving circuit (ASG) process.

[0056] Figure 2 is an enlarged plan view of a portion of a display panel according to an embodiment of the present disclosure. Figure 2 The display panel DP (see FIG. Figure 1A ), the plane including three pixel regions PXA-R, PXA-B and PXA-G and the bank well region BWA adjacent thereto. In the embodiment of the present disclosure, Figure 2 The three types of pixel regions PXA-R, PXA-B and PXA-G explained in the above description may be arranged in the entire display area DA (see Figure 1A ) are set repeatedly.

[0057] The peripheral area NPXA may be disposed adjacent to the first to third pixel areas PXA-R, PXA-B, and PXA-G. The peripheral area NPXA may define boundaries of the first to third pixel areas PXA-R, PXA-B, and PXA-G. The peripheral area NPXA may surround the first to third pixel areas PXA-R, PXA-B, and PXA-G. In the peripheral area NPXA, a structure for preventing color mixing between the first to third pixel areas PXA-R, PXA-B, and PXA-G may be disposed, for example, a pixel definition film PDL (see Figure 3 ) or dike BMP (see Figure 3 )wait.

[0058] although Figure 2The first to third pixel regions PXA-R, PXA-B, and PXA-G having the same planar shape and different planar areas are explained, but the present disclosure is not limited thereto. The areas of at least two of the first to third pixel regions PXA-R, PXA-B, and PXA-G may be the same. The areas of the first to third pixel regions PXA-R, PXA-B, and PXA-G may be set according to the luminous color. Among these primary colors, the area of ​​the pixel region emitting red light may be the largest, and the area of ​​the pixel region emitting blue light may be the smallest.

[0059] although Figure 2 The first to third pixel regions PXA-R, PXA-B, and PXA-G are explained as being rectangular in a plan view, but the present disclosure is not limited thereto. In a plan view, the first to third pixel regions PXA-R, PXA-B, and PXA-G may have other polygonal shapes (substantially polygonal shapes), such as a rhombus or a pentagon. In an embodiment, the first to third pixel regions PXA-R, PXA-B, and PXA-G may have a rectangular shape (substantially rectangular shape) whose corners are rounded in a plan view.

[0060] although Figure 2 It is explained that the third pixel region PXA-G is disposed in the first row and the first pixel region PXA-R and the second pixel region PXA-B are disposed in the second row, but the arrangement of the first to third pixel regions PXA-R, PXA-B, and PXA-G is not limited thereto and may be variously changed. For example, the first to third pixel regions PXA-R, PXA-B, and PXA-G may be disposed in the same row.

[0061] One of the first to third pixel regions PXA-R, PXA-B, and PXA-G may provide red light, another may provide blue light, and the remaining one may provide green light. In an embodiment, the first pixel region PXA-R may provide red light, the second pixel region PXA-B may provide blue light, and the third pixel region PXA-G may provide green light. The first pixel region PXA-R may emit light having an emission wavelength in the range of about 620 nm to about 700 nm, the second pixel region PXA-B may emit light having an emission wavelength in the range of about 410 nm to about 480 nm, and the third pixel region PXA-G may emit light having an emission wavelength in the range of about 520 nm to about 600 nm.

[0062] The well area BWA may be defined in the display area DA (see Figure 1A The bank well area BWA may be a region in which a bank well is formed in order to prevent the light control layer CCL (see Figure 4A ) includes a plurality of light control patterns CCP-R, CCP-B and CCP-G (see Figure 4A) is patterned by the process of patterning. For example, the well bank area BWA may be a well bank area defined by removing the bank BMP (see Figure 4A ) is a region of a dam well formed by a portion of the dam.

[0063] although Figure 2 It is illustrated that two bank well areas BWA are defined adjacent to the third pixel area PXA-G, but the present disclosure is not limited thereto, and the shapes and arrangements of the bank well areas BWA may be variously changed.

[0064] Figure 3 is a schematic cross-sectional view of a display panel according to an embodiment of the present disclosure. Figure 4A is a schematic cross-sectional view of a display panel according to an embodiment of the present disclosure. Figure 3 is a schematic cross-sectional view of a light emitting element included in a display panel according to an embodiment of the present disclosure. Figure 3 Schematic illustration of the Figure 2 A cross section taken along the cutting line II' shown in FIG. Figure 4A Schematic illustration of the Figure 2 A cross section taken along the cutting line II-II' shown in FIG.

[0065] refer to Figure 3 The display panel DP of the embodiment may include a base substrate BS, a circuit element layer DP-CL disposed on the base substrate BS, and a display element layer DP-LED disposed on the circuit element layer DP-CL. In this specification, the base substrate BS, the circuit element layer DP-CL, and the display element layer DP-LED may be collectively referred to as a lower panel.

[0066] The base substrate BS may be a member providing a base surface on which the configuration included in the circuit element layer DP-CL is disposed. In an embodiment, the base substrate BS may be a glass substrate, a metal substrate, a polymer substrate, etc. However, the present disclosure is not limited thereto, and the base substrate BS may be an inorganic layer, a functional layer, or a composite material layer.

[0067] The base substrate BS may have a multilayer structure. For example, the base substrate BS may have a three-layer structure including a polymer resin layer, an adhesive layer and a polymer resin layer. For example, the polymer resin layer may include a polyimide resin. For example, the polymer resin layer may include at least one of an acrylate resin (e.g., a methacrylate resin), a polyisoprene resin, a vinyl resin, an epoxy resin, a urethane resin, a cellulose resin, a siloxane resin, a polyamide resin and a perylene resin. In this specification, the term "a-type" resin means a resin including an "a" functional group.

[0068] The circuit element layer DP-CL may be disposed on the base substrate BS. The circuit element layer DP-CL may include a transistor TD as a circuit element. The configuration of the circuit element layer DP-CL may vary with the pixel PX (see Figure 1A ) varies depending on the design of the drive circuit, and Figure 3 One transistor TD according to an embodiment is explained. Arrangement of an active portion AD, a source SD, a drain DD, and a gate GD constituting the transistor TD is explained according to an embodiment. The active portion AD, the source SD, and the drain DD may be regions divided according to doping concentration or conductivity of a semiconductor pattern.

[0069] The circuit element layer DP-CL may include a lower buffer layer BRL, a first insulating layer 10, a second insulating layer 20, and a third insulating layer 30 disposed on the base substrate BS. For example, the lower buffer layer BRL, the first insulating layer 10, and the second insulating layer 20 may be inorganic layers, and the third insulating layer 30 may be an organic layer.

[0070] The display element layer DP-LED may include a light emitting element ED as a display element. The light emitting element ED may generate source light. In an embodiment, the source light may be white light or blue light. In an embodiment, the display element layer DP-LED may include an organic light emitting diode as the light emitting element ED. For example, the emission layer included in the light emitting element ED may include an organic light emitting material as the light emitting material.

[0071] The light emitting element ED may include a first electrode EL1, a second electrode EL2, and at least one light emitting stack ST1, ST2, ST3, ST4, and ST5 disposed between the first electrode EL1 and the second electrode EL2. In an embodiment, the light emitting element ED may include a first electrode EL1, a second electrode EL2, and five light emitting stacks ST1, ST2, ST3, ST4, and ST5 disposed between the first electrode EL1 and the second electrode EL2. The light emitting stacks ST1, ST2, ST3, ST4, and ST5 included in the light emitting element ED will be described below.

[0072] The first electrode EL1 may be disposed on the third insulating layer 30. The first electrode EL1 may be directly or indirectly connected to the transistor TD, and Figure 3 The connection structure of the first electrode EL1 and the transistor TD is not illustrated.

[0073] The display element layer DP-LED may include a pixel defining film PDL. For example, the pixel defining film PDL may be an organic layer. A light emitting opening OH may be defined in the pixel defining film PDL. The light emitting opening OH of the pixel defining film PDL may expose at least a portion of the first electrode EL1. In an embodiment, the first light emitting area EA1 may be defined by the light emitting opening OH.

[0074] Each of the five light emitting stacks ST1, ST2, ST3, ST4, and ST5 may overlap at least the pixel region PXA-R in a plan view and may include an emission layer. Each of the five light emitting stacks ST1, ST2, ST3, ST4, and ST5 may be commonly disposed in the first to third pixel regions PXA-R, PXA-B, and PXA-G (see FIG. Figure 4A ) in the first to third pixel regions PXA-R, PXA-B and PXA-G (see Figure 4A Each of the five light emitting stacks ST1, ST2, ST3, ST4, and ST5 overlapped with each other may have an integral shape. However, the present disclosure is not limited thereto, and at least one of the five light emitting stacks ST1, ST2, ST3, ST4, and ST5 may be separately formed in the first to third pixel regions PXA-R, PXA-B, and PXA-G (see Figure 4A In an embodiment, at least one of the five light emitting stacks ST1, ST2, ST3, ST4, and ST5 may be patterned in the light emitting opening OH and may be separately formed in the first to third pixel regions PXA-R, PXA-B, and PXA-G (see Figure 4A ) in each of them.

[0075] The second electrode EL2 may be disposed to face the first electrode EL1 with five light emitting stacks ST1 , ST2 , ST3 , ST4 , and ST5 interposed therebetween.

[0076] The display element layer DP-LED may include a thin film encapsulation layer TFE that protects the second electrode EL2. The thin film encapsulation layer TFE may include an organic material or an inorganic material. The thin film encapsulation layer TFE may have a multilayer structure in which inorganic layers / organic layers are alternately stacked with each other. In an embodiment, the thin film encapsulation layer TFE may include a first inorganic encapsulation layer IOL1 / organic encapsulation layer OL / second inorganic encapsulation layer IOL2. The first inorganic encapsulation layer IOL and the second inorganic encapsulation layer IOL2 may protect the light emitting element ED from external moisture, and the organic encapsulation layer OL may prevent pit defects of the light emitting element ED caused by the introduction of foreign matter during the manufacturing process. Although not explained, the display panel DP may further include a refractive index control layer for improving light output efficiency.

[0077] like Figure 3 As explained in the specification, the optical structure layer OSL may be disposed on the thin film encapsulation layer TFE. The optical structure layer OSL may include a light control layer CCL, a low refractive index layer LR, a color filter layer CFL and a base layer BL. In the specification, the optical structure layer OSL may be referred to as an upper panel.

[0078] The light control layer CCL may be disposed on the display element layer DP-LED including the light emitting element ED. The light control layer CCL may include a bank BMP, light control patterns CCP-R, CCP-G (see Figure 4A ) and CCP-B, and the first barrier layer CAP1.

[0079] The bank BMP may include a base resin and an additive. The base resin may be formed of various resin compositions that may be generally referred to as a binder. The additive may include a coupling agent and / or a photoinitiator. The additive may further include a dispersant.

[0080] The bank BMP may include a black colorant for shielding light. The bank BMP may include a black pigment and / or a black dye mixed in a base resin. In an embodiment, the black colorant may include carbon black, or may include a metal such as chromium or an oxide thereof.

[0081] The bank BMP may include a bank opening BW-OH corresponding to the light emitting opening OH. In a plan view, the bank opening BW-OH may overlap with the light emitting opening OH and may have an area larger than that of the light emitting opening OH. For example, the bank opening BW-OH may have an area larger than that of the light emitting area EA1 defined by the light emitting opening OH. In the specification, "corresponding" means that two configurations overlap each other in the thickness direction (i.e., the third direction DR3) of the display panel DP and are not limited to the same area.

[0082] Light control pattern CCP-R, CCP-G (see Figure 4A ) and CCP-B may be disposed inside the bank opening BW-OH. The light control patterns CCP-R, CCP-G (see Figure 4A ) and at least a portion of CCP-B may change the optical properties of the source light. In an embodiment, the first light-controlling pattern CCP-R may change the optical properties of the source light.

[0083] The first light-controlling pattern CCP-R may include quantum dots for changing the optical characteristics of the source light. The first light-controlling pattern CCP-R may include quantum dots for converting the source light into light having a different wavelength. In the first light-controlling pattern CCP-R overlapping the first pixel area PXA-R in a plan view, the quantum dots may convert the source light into red light.

[0084] In the specification, quantum dots refer to crystals of semiconductor compounds. Depending on the size of the crystals, quantum dots can emit light with various emission wavelengths. By adjusting the ratio of elements in the quantum dot compound, quantum dots can emit light with various emission wavelengths.

[0085] The quantum dots may have a diameter in a range of, for example, about 1 nm to about 10 nm.

[0086] Quantum dots can be synthesized by wet chemical process, metal organic chemical vapor deposition process, molecular beam epitaxy process or similar processes.

[0087] The wet chemical process is a method in which a precursor material is mixed with an organic solvent to grow a quantum dot particle crystal. When the quantum dot particle crystal grows, the organic solvent naturally acts as a dispersant coordinated on the surface of the quantum dot particle crystal and controls the growth of the quantum dot particle crystal. Therefore, the wet chemical process can control the growth of quantum dot particle crystals by a process that is easier to perform and at a low cost than a vapor deposition method such as metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE).

[0088] The core of the quantum dot may include a Group II-VI compound, a Group III-V compound, a Group III-VI compound, a Group I-III-VI compound, a Group IV-VI compound, a Group II-IV-V compound, a Group IV element, a Group IV compound, or any combination thereof.

[0089] The II-VI Group compounds may be selected from the group consisting of: binary compounds selected from the group consisting of CdSe, CdTe, CdS, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS and mixtures thereof, and binary compounds selected from the group consisting of CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, Cd ZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS and mixtures thereof, and ternary compounds selected from the group consisting of CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe and mixtures thereof. The II-VI Group compounds may further include Group I metals and / or Group IV elements. The I-II-VI Group compounds may include CuSnS or CuZnS, etc. and the II-IV-VI Group compounds may include ZnSnS, etc. The I-II-IV-VI Group compounds may include CuSnS or CuZnS, etc. 2 ZnSnS 2 , Cu 2 ZnSnS 4 , Cu 2 ZnSnSe 4 、Ag 2 ZnSnS 2 and mixtures thereof.

[0090] Group III-VI compounds may include binary compounds (such as In 2 S 3 or In 2 Se 3 ), ternary compounds (such as InGaS 3 or InGaSe 3 ) or any combination thereof.

[0091] The Group I-III-VI compound may include a compound selected from AgInS, AgInS 2 、CuInS、CuInS 2 、AgGaS 2 、CuGaS 2 CuGaO 2 、AgGaO 2 、AgAlO 2 and mixtures thereof, or ternary compounds (such as AgInGaS 2 or CuInGaS 2 ).

[0092] The III-V compound may be selected from the group consisting of: a binary compound selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof, a ternary compound selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InAlP, InNP, InNAs, InNSb, InPAs, InPSb, and mixtures thereof, and a quaternary compound selected from the group consisting of GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and mixtures thereof. The III-V compound may further include a Group II metal. For example, InZnP or the like may be selected as the Group III-II-V compound.

[0093] The Group IV-VI compounds may be selected from the group consisting of: binary compounds selected from the group consisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe and mixtures thereof, ternary compounds selected from the group consisting of SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe and mixtures thereof, and quaternary compounds selected from the group consisting of SnPbSSe, SnPbSeTe, SnPbSTe and mixtures thereof.

[0094] Examples of Group II-IV-V compounds may include compounds selected from ZnSnP, ZnSnP 2 、ZnSnAs 2 、ZnGeP 2 、ZnGeAs 2 、CdSnP 2 、CdGeP 2 and mixtures thereof.

[0095] The Group IV element may be selected from the group consisting of Si, Ge, and mixtures thereof. The Group IV compound may be a binary compound selected from the group consisting of SiC, SiGe, and mixtures thereof.

[0096] Each element included in a multi-component compound (such as a binary compound, a ternary compound, or a quaternary compound) may be present in a particle in a uniform or non-uniform concentration distribution. For example, the formula indicates the type of element included in the compound, and the ratio of the elements in the compound may vary. For example, AgInGaS 2 Can mean AgIn x Ga 1-x S 2 (0 <x<1)。

[0097] The binary, ternary or quaternary compound may be present in the particle with a uniform concentration distribution, or may be present in the particle with a partially different concentration distribution. The quantum dot may have a core-shell structure in which one quantum dot surrounds another quantum dot. The core-shell structure may have a concentration gradient in which the concentration of the element present in the shell decreases toward the core.

[0098] In an embodiment, the quantum dot may have a core-shell structure, which includes a core containing nanocrystals and a shell surrounding the core. The shell of the quantum dot can be used as a protective layer to prevent chemical denaturation of the core to maintain semiconductor properties, and / or as a charging layer to give the quantum dot electrophoretic properties. The shell can be a single layer or multiple layers. The shell of the quantum dot can include a metal oxide or a non-metal oxide, a semiconductor compound, or any combination thereof.

[0099] For example, the metal oxide or non-metal oxide may be a binary compound (such as SiO 2 、Al 2 O 3 、TiO 2 、ZnO、MnO、Mn 2 O 3 , Mn 3 O 4 , CuO, FeO, Fe 2 O 3 , Fe 3 O 4 , CoO, Co 3 O 4 or NiO) or ternary compounds (such as MgAl 2 O 4 、CoFe 2 O 4 、NiFe 2 O 4 or CoMn 2 O 4 ), but the present disclosure is not limited thereto.

[0100] The semiconductor compound may be, for example, CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, etc., but the present disclosure is not limited thereto.

[0101] The quantum dot may have a half-maximum full width (FWHM) of an emission wavelength spectrum less than or equal to about 45 nm. For example, the quantum dot may have a half-maximum full width (FWHM) of an emission wavelength spectrum less than or equal to about 40 nm. For example, the quantum dot may have a half-maximum full width (FWHM) of an emission wavelength spectrum less than or equal to about 30 nm. Within the above range, color purity or color reproducibility can be improved. Light emitted by such quantum dots can be emitted in all directions, and thus a wide viewing angle can be improved.

[0102] Although the form of quantum dots is not particularly limited to the forms commonly used in the art, quantum dots in the form of, for example, spherical nanoparticles, pyramidal nanoparticles, multi-arm nanoparticles, cubic nanoparticles, nanotubes, nanowires, nanofibers, nanoplates, etc. can be used.

[0103] Because the size of the quantum dot is adjusted or the ratio of elements in the quantum dot compound is adjusted, the energy band gap of the quantum dot can be controlled, and thus light in various wavelength ranges can be obtained in the quantum dot. Therefore, quantum dots as described above can be used (quantum dots of different sizes or quantum dots of different element ratios in quantum dot compounds), and thus a light-emitting element emitting light of various wavelengths can be realized. For example, the size of the quantum dot or the ratio of elements in the quantum dot compound can be selected to emit red light, green light and / or blue light. The quantum dot can be configured to emit white light by combining light of various colors.

[0104] In an embodiment, the quantum dots included in the first light control pattern CCP-R overlapping the first pixel region PXA-R may have a red light emitting color. The smaller the particle size of the quantum dots becomes, the shorter the wavelength of the emitted light. For example, in quantum dots having the same core, the particle size of quantum dots emitting green light may be smaller than the particle size of quantum dots emitting red light. In quantum dots having the same core, the particle size of quantum dots emitting blue light may be smaller than the particle size of quantum dots emitting green light. However, the present disclosure is not limited thereto, and even in quantum dots having the same core, the particle size may be adjusted according to the forming material and thickness of the shell.

[0105] In the case where quantum dots have various luminescent colors such as blue, red, and green, quantum dots having different luminescent colors may have different core materials.

[0106] The first light-controlling pattern CCP-R may further include a scatterer. The first light-controlling pattern CCP-R may include quantum dots that convert blue light into red light and a scatterer that scatters light.

[0107] The scatterers may be inorganic particles. For example, the scatterers may include TiO 2 、ZnO、Al 2 O 3 、SiO 2 and hollow spherical silica. The scatterer may include TiO 2 、ZnO、Al 2 O 3 、SiO 2 and hollow spherical silica, or TiO 2 、ZnO、Al 2 O 3 、SiO 2 and a mixture of at least two of hollow spherical silica.

[0108] The first light-controlling pattern CCP-R may include a base resin in which quantum dots and scatterers are dispersed. The base resin may be a medium in which quantum dots and scatterers are dispersed, and may be composed of various resin compositions that may be generally referred to as a binder. For example, the base resin may be an acrylic resin, a urethane resin, a silicone resin, an epoxy resin, etc. The base resin may be a transparent resin.

[0109] In an embodiment, the first light-controlling pattern CCP-R may be formed by an inkjet process. A liquid composition may be provided in the bank opening BW-OH. The composition polymerized by a thermal curing process or a photocuring process may be reduced in volume after curing.

[0110] A height difference may occur between the bottom surface of the bank BMP and the bottom surface of the first light-controlling pattern CCP-R. For example, the bottom surface of the bank BMP may be higher than the bottom surface of the first light-controlling pattern CCP-R. The height difference between the bottom surface of the bank BMP and the bottom surface of the light-controlling pattern CCP-R may be, for example, in the range of about 2 μm to about 3 μm.

[0111] The light control layer CCL may include a first barrier layer CAP1 disposed on the surface of the first light control pattern CCP-R. The first barrier layer CAP1 may be used to prevent the penetration of moisture and / or oxygen (hereinafter, referred to as "moisture / oxygen") and adjust the refractive index, thereby improving the optical properties of the optical structure layer OSL. The first barrier layer CAP1 may be disposed on the surface of the upper portion or the lower portion of the first light control pattern CCP-R to prevent the first light control pattern CCP-R from being exposed to moisture / oxygen, for example, the quantum dots included in the first light control pattern CCP-R may be prevented from being exposed to moisture / oxygen. The first barrier layer CAP1 may also protect the first light control pattern CCP-R from external impacts.

[0112] In an embodiment, the first barrier layer CAP1 may be spaced apart from the display element layer DP-LED, and the first light control pattern CCP-R may be inserted between the first barrier layer CAP1 and the display element layer DP-LED. For example, the first barrier layer CAP1 may be disposed on the top surface of the first light control pattern CCP-R. In an embodiment, the light control layer CCL may include a second barrier layer CAP2 disposed between the first light control pattern CCP-R and the display element layer DP-LED. The first barrier layer CAP1 may cover the top surface of the first light control pattern CCP-R adjacent to the low refractive index layer LR, and the second barrier layer CAP2 may cover the bottom surface of the first light control pattern CCP-R adjacent to the display element layer DP-LED. In the specification, the "top surface" may be a surface located at the upper part based on the third direction DR3, and the "bottom surface" may be a surface located at the lower part based on the third direction DR3.

[0113] The first barrier layer CAP1 and the second barrier layer CAP2 may cover the bank BMP and surfaces of the first light-controlling patterns CCP-R.

[0114] The first barrier layer CAP1 may cover the surface of the bank BMP and the first light control pattern CCP-R adjacent to the low refractive index layer LR. The first barrier layer CAP1 may be disposed (e.g., directly disposed) on the lower portion of the low refractive index layer LR. The second barrier layer CAP2 may be disposed to follow the height difference between the bank BMP and the first light control pattern CCP-R. The second barrier layer CAP2 may be disposed (e.g., directly disposed) on the upper portion of the filling layer FML.

[0115] The first barrier layer CAP1 and the second barrier layer CAP2 may include an inorganic material. In the display panel DP of the embodiment, the first barrier layer CAP1 may include silicon oxynitride (SiON). Both the first barrier layer CAP1 and the second barrier layer CAP2 may include silicon oxynitride. However, the present disclosure is not limited thereto, and the first barrier layer CAP1 disposed on the upper portion of the first light-controlling pattern CCP-R may include silicon oxynitride, and the second barrier layer CAP2 disposed on the lower portion of the first light-controlling pattern CCP-R may include silicon oxide (SiO x ).

[0116] The color filter layer CFL may be disposed on the light control layer CCL. The color filter layer CFL may include at least one color filter. The color filter may transmit light having a specific wavelength range and block light other than the light having the specific wavelength range. The first color filter CF1 of the first pixel area PXA-R may transmit red light and block green light and blue light.

[0117] The first color filter CF1 may include a base resin, and a dye and / or pigment dispersed in the base resin. The base resin may be a medium in which the dye and / or pigment is dispersed, and may be composed of various resin compositions that may be generally referred to as a binder.

[0118] The first color filter CF1 may have a uniform thickness in the first pixel region PXA-R. Light converted from source light as blue light into red light by the first light-controlling pattern CCP-R may be provided to the outside with uniform brightness in the first pixel region PXA-R.

[0119] The optical structure layer OSL may include a low refractive index layer LR. The low refractive index layer LR may be disposed between the light control layer CCL and the color filter layer CFL. The low refractive index layer LR may be disposed on an upper portion of the light control layer CCL and block the light control pattern CCP-R from being exposed to moisture / oxygen. The low refractive index layer LR may be disposed between the light control pattern CCP-R and the first color filter CF1 to perform the function of an optical functional layer, for example, to increase light extraction efficiency or prevent reflected light from being incident on the light control layer CCL. The low refractive index layer LR may have a refractive index lower than that of an adjacent layer.

[0120] The low refractive index layer LR may include at least one inorganic layer. For example, the low refractive index layer LR may include silicon nitride, aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride, silicon oxide, aluminum oxide, titanium oxide, tin oxide, cerium oxide or silicon oxynitride, or a thin metal film to ensure transmittance. However, the present disclosure is not limited thereto, and the low refractive index layer LR may include an organic film. The low refractive index layer LR may have a structure in which, for example, a plurality of hollow particles are dispersed in an organic polymer resin. The low refractive index layer LR may be formed by a single layer or a plurality of layers.

[0121] In an embodiment, the display panel DP may further include a base layer BL disposed on the color filter layer CFL. The base layer BL may be a member providing a reference surface on which the color filter layer CFL, the low refractive index layer LR, the light control layer CCL, etc. are disposed. The base layer BL may be a glass substrate, a metal substrate, a plastic substrate, etc. However, the present disclosure is not limited thereto, and the base layer BL may be an inorganic layer, an organic layer, or a composite material layer. Unlike the illustrated configuration, in an embodiment, the base layer BL may be omitted.

[0122] Although not illustrated, an anti-reflection layer may be provided on the base layer BL. The anti-reflection layer may be a layer that reduces the reflectivity of external light incident from the outside. The anti-reflection layer may be a layer that selectively transmits light emitted from the display panel DP. In an embodiment, the anti-reflection layer may be a single layer including a dye and / or a pigment dispersed in a base resin. The anti-reflection layer may be provided to be aligned with the first to third pixel areas PXA-R, PXA-B, and PXA-G (see FIG. 1 ) in a plan view. Figure 4A ) Completely overlapping consecutive layers.

[0123] The anti-reflection layer may not include a polarization layer. Accordingly, light passing through the anti-reflection layer and incident on the display element layer DP-LED may be non-polarized light. The display element layer DP-LED may receive non-polarized light from an upper portion of the anti-reflection layer.

[0124] The display panel DP of the embodiment may include a lower panel including a display element layer DP-LED and an upper panel (optical structure layer OSL) including a color filter layer CFL, and in an embodiment, a filling layer FML may be disposed between the lower panel and the upper panel (optical structure layer OSL). In an embodiment, the filling layer FML may fill the space between the display element layer DP-LED and the light control layer CCL. The filling layer FML may be disposed (e.g., directly disposed) on the thin film encapsulation layer TFE, and the second barrier layer CAP2 may be disposed (e.g., directly disposed) on the filling layer FML. The bottom surface of the filling layer FML may be in contact with the top surface of the thin film encapsulation layer TFE, and the top surface of the filling layer FML may be in contact with the bottom surface of the second barrier layer CAP2.

[0125] The filling layer FML may be used as a buffer between the display element layer DP-LED and the light control layer CCL. In an embodiment, the filling layer FML may absorb shock and increase the strength of the display panel DP. The filling layer FML may be formed of a filling resin including a polymer. For example, the filling layer FML may be formed of a filling resin such as an acrylic resin or an epoxy resin.

[0126] refer to Figure 4A , the display panel DP may include a base substrate BS, a circuit element layer DP-CL disposed on the base substrate BS. The circuit element layer DP-CL may be disposed on the base substrate BS. The circuit element layer DP-CL may include an insulating layer, a semiconductor pattern, a conductive pattern, a signal line, and the like. The insulating layer, the semiconductor layer, and the conductive layer may be formed on the base substrate BS by coating or vapor deposition, and the insulating layer, the semiconductor layer, and the conductive layer may be optionally patterned by a plurality of photoetching processes. Thereafter, the semiconductor pattern, the conductive pattern, and the signal line included in the circuit element layer DP-CL may be formed. In an embodiment, the circuit element layer DP-CL may include a transistor, a buffer layer, and a plurality of insulating layers.

[0127] The light emitting elements ED according to the embodiment may each include a first electrode EL1, a second electrode EL2 facing the first electrode EL1, and five light emitting stacks ST1, ST2, ST3, ST4, and ST5 disposed between the first electrode EL1 and the second electrode EL2. Each of the five light emitting stacks ST1, ST2, ST3, ST4, and ST5 included in the light emitting element ED may include an organic light emitting material as a light emitting material. Each of the five light emitting stacks ST1, ST2, ST3, ST4, and ST5 included in the light emitting element ED may include a hole transport region, an emission layer, and an electron transport region. The light emitting element ED may further include a capping layer CPL (see FIG. 1 ) disposed on an upper portion of the second electrode EL2. Figure 5A ).

[0128] The pixel defining film PDL may be disposed on the circuit element layer DP-CL and may cover a portion of the first electrode EL1. A light emitting opening OH may be defined in the pixel defining film PDL. The light emitting opening OH of the pixel defining film PDL may expose at least a portion of the first electrode EL1. In an embodiment, the light emitting areas EA1, EA2, and EA3 may correspond to a portion of the first electrode EL1 exposed by the light emitting opening OH.

[0129] The display element layer DP-LED may include a first light emitting area EA1, a second light emitting area EA2, and a third light emitting area EA3. The first light emitting area EA1, the second light emitting area EA2, and the third light emitting area EA3 may be areas divided by a pixel definition film PDL. The first light emitting area EA1, the second light emitting area EA2, and the third light emitting area EA3 may correspond to the first pixel area PXA-R, the second pixel area PXA-B, and the third pixel area PXA-G, respectively.

[0130] In a plan view, the emission areas EA1, EA2, and EA3 may overlap with the pixel areas PXA-R, PXA-B, and PXA-G and may not overlap with the bank well area BWA. In a plan view, the areas of the pixel areas PXA-R, PXA-B, and PXA-G divided by the bank BMP may be larger than the areas of the emission areas EA1, EA2, and EA3 divided by the pixel definition film PDL.

[0131] In the light emitting element ED, the first electrode EL1 may be disposed on the circuit element layer DP-CL. The first electrode EL1 may be an anode or a cathode. 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.

[0132] In the display panel DP of the embodiment, five light emitting stacks ST1 , ST2 , ST3 , ST4 , and ST5 may be disposed between the first electrode EL1 and the second electrode EL2 of the light emitting element ED.

[0133] Each of the five light emitting stacks ST1, ST2, ST3, ST4, and ST5 may be disposed in common in the first to third pixel regions PXA-R, PXA-B, and PXA-G. Each of the five light emitting stacks ST1, ST2, ST3, ST4, and ST5 overlapping the first to third pixel regions PXA-R, PXA-B, and PXA-G may have an integral shape. However, the present disclosure is not limited thereto, and at least one of the five light emitting stacks ST1, ST2, ST3, ST4, and ST5 may be formed separately in each of the first to third pixel regions PXA-R, PXA-B, and PXA-G. In an embodiment, at least one of the five light emitting stacks ST1, ST2, ST3, ST4, and ST5 may be patterned in the light emitting opening OH and may be formed separately in each of the first to third pixel regions PXA-R, PXA-B, and PXA-G. The light emitting stacks ST1 , ST2 , ST3 , ST4 , and ST5 included in the light emitting element ED will be described in detail below.

[0134] The second electrode EL2 may be provided on the five light emitting stacks ST1, ST2, ST3, ST4 and ST5. 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. 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 be a transmissive electrode, a transflective electrode or a reflective electrode.

[0135] The thin film encapsulation layer TFE may be disposed on the light emitting element ED. For example, the thin film encapsulation layer TFE of the embodiment may be disposed on the second electrode EL2. Figure 5A ), the thin film encapsulation layer TFE may be disposed on the capping layer CPL. As described above, the thin film encapsulation layer TFE may include at least one organic film and at least one inorganic film, and the inorganic film and the organic film may be alternately stacked.

[0136] The display panel DP of the embodiment may include an optical structure layer OSL disposed on the display element layer DP-LED. The optical structure layer OSL may include a light control layer CCL, a color filter layer CFL, and a base layer BL.

[0137] The light control layer CCL may include a light converter. The light converter may be a quantum dot or a phosphor, etc. The light converter may emit the provided light by converting the wavelength of the light. For example, the light control layer CCL may be a layer containing quantum dots or a layer containing phosphors in at least a portion of the light control layer CCL.

[0138] The light control layer CCL may include a plurality of light control patterns CCP-R, CCP-B, and CCP-G. The light control patterns CCP-R, CCP-B, and CCP-G may be spaced apart from each other. The light control patterns CCP-R, CCP-B, and CCP-G may be spaced apart from each other by the dam BMP. The light control patterns CCP-R, CCP-B, and CCP-G may be disposed in the dam opening BW-OH defined in the dam BMP. However, the present disclosure is not limited thereto. Although Figure 4A It is explained that the bank BMP has a rectangular shape in a cross-sectional view and does not overlap with the light-controlling patterns CCP-R, CCP-B, and CCP-G in a plan view, but the present disclosure is not limited thereto, and the edges of the light-controlling patterns CCP-R, CCP-B, and CCP-G may at least partially overlap with the bank BMP in a plan view. The bank BMP may have a trapezoidal shape in a cross-sectional view. The bank BMP may have a shape in a cross-sectional view in which a width increases as the bank BMP is adjacent to the display element layer DP-LED.

[0139] The light control patterns CCP-R, CCP-B, and CCP-G may be portions that convert the wavelength of light provided from the display element layer DP-LED or transmit the provided light. The light control patterns CCP-R, CCP-B, and CCP-G may be formed by an inkjet process. A liquid ink composition may be provided in the bank opening BW-OH, and the provided ink composition may be polymerized by a thermal curing process or a photocuring process to form the light control patterns CCP-R, CCP-B, and CCP-G.

[0140] The light control layer CCL may include a first light control pattern CCP-R that transmits red light as a first light, a second light control pattern CCP-B that transmits blue light as a second light, and a third light control pattern CCP-G that transmits green light as a third light. The light control layer CCL may include a first light control pattern CCP-R that converts source light provided from the light emitting element ED into the first light, a second light control pattern CCP-B that converts the source light into the second light, and a third light control pattern CCP-G that converts the source light into the third light. Each of the light control patterns CCP-R, CCP-B, and CCP-G may include a quantum dot that converts the source light into light having a specific wavelength.

[0141] The light control layer CCL may further include a scatterer. The first light control pattern CCP-R may include first quantum dots and a scatterer, the third light control pattern CCP-G may include second quantum dots and a scatterer, and the second light control pattern CCP-B may not include quantum dots and may include a scatterer.

[0142] Each of the first light-controlling pattern CCP-R, the second light-controlling pattern CCP-B, and the third light-controlling pattern CCP-G may include a base resin that disperses quantum dots and scatterers.

[0143] The light control layer CCL may include a first barrier layer CAP1 disposed on the surfaces of the light control patterns CCP-R, CCP-B, and CCP-G. The light control layer CCL may include: the first barrier layer CAP1 spaced apart from the display element layer DP-LED, the light control pattern CCP-R inserted between the first barrier layer CAP1 and the display element layer DP-LED; and a second barrier layer CAP2 adjacent to the display element layer DP-LED.

[0144] In the display panel DP, the optical structure layer OSL may include a color filter layer CFL disposed on the light control layer CCL. The color filter layer CFL may include color filters CF1, CF2, and CF3. The color filter layer CFL may include a first color filter CF1 that transmits a first light, a second color filter CF2 that transmits a source light, and a third color filter CF3 that transmits a second light. In an embodiment, the first color filter CF1 may be a red filter, the second color filter CF2 may be a blue filter, and the third color filter CF3 may be a green filter.

[0145] Each of the color filters CF1, CF2, and CF3 may include a polymerized photosensitive resin and a colorant. The first color filter CF1 may include a red colorant, the second color filter CF2 may include a blue colorant, and the third color filter CF3 may include a green colorant. The first color filter CF1 may include a red pigment and / or a red dye, the second color filter CF2 may include a blue pigment and / or a blue dye, and the third color filter CF3 may include a green pigment and / or a green dye.

[0146] The first to third color filters CF1, CF2 and CF3 may be disposed to correspond to the first to third pixel areas PXA-R, PXA-B and PXA-G, respectively. The first to third color filters CF1, CF2 and CF3 may be disposed to correspond to the first to third light-controlling patterns CCP-R, CCP-B and CCP-G, respectively.

[0147] A plurality of color filters CF1, CF2, and CF3 transmitting different lights may be disposed to overlap with the peripheral area NPXA, which is disposed between the pixel areas PXA-R, PXA-B, and PXA-G. The color filters CF1, CF2, and CF3 may overlap with each other in a third direction DR3, which is a thickness direction, so that the boundaries between the adjacent pixel areas PXA-R, PXA-B, and PXA-G may be distinguished. Different from the illustrated configuration, the color filter layer CFL may include a light shielding member (not shown) defining the boundaries between the adjacent color filters CF1, CF2, and CF3. The light shielding member (not shown) may be formed of a blue filter or may include an organic light shielding material or an inorganic light shielding material including a black pigment and / or a black dye.

[0148] The optical structure layer OSL may include a low refractive index layer LR disposed between the light control layer CCL and the color filter layer CFL. The low refractive index layer LR may be disposed between the light control patterns CCP-R, CCP-B and CCP-G and the color filters CF1, CF2 and CF3. The low refractive index layer LR may be disposed on the upper portion of the light control layer CCL and prevent the light control patterns CCP-R, CCP-B and CCP-G from being exposed to moisture / oxygen. The low refractive index layer LR may be disposed between the light control patterns CCP-R, CCP-B and CCP-G and the color filters CF1, CF2 and CF3 or may be used as an optical functional layer, for example, to increase light extraction efficiency or prevent reflected light from being incident on the light control layer CCL. The low refractive index layer LR may be a layer having a small refractive index compared to an adjacent layer.

[0149] In an embodiment, the optical structure layer OSL may further include a base layer BL disposed on the color filter layer CFL. The base layer BL may be a member configured to provide a base surface on which the color filter layer CFL and the light control layer CCL are disposed. The base layer BL may be a glass substrate, a metal substrate, a plastic substrate, etc. However, the present disclosure is not limited thereto, and the base layer BL may be an inorganic layer, an organic layer, or a composite material layer. Different from the illustrated configuration, in an embodiment, the base layer BL may be omitted.

[0150] Figure 4B and Figure 4C Each is a schematic cross-sectional view of a display panel according to an embodiment of the present disclosure. Figure 4B and Figure 4C Each schematically illustrates the Figure 4A The display panel DP of the embodiment explained in the embodiment is different from the display panels DP_1 and DP_2.

[0151] refer to Figure 4B , the display panel DP_1 according to the embodiment may include: a lower panel including a base substrate BS, a circuit element layer DP-CL disposed on the base substrate BS, and a display element layer DP-LED disposed on the circuit element layer DP-CL; and an optical structure layer OSL-1 disposed on the lower panel. The optical structure layer OSL-1 in the display panel DP_1 according to the embodiment may include a light control layer CCL-1, a low refractive index layer LR-1, a color filter layer CFL-1, and a base layer BL-1 sequentially disposed on the thin film encapsulation layer TFE. The optical structure layer OSL-1 may include a first barrier layer CAP1 and a second barrier layer CAP2 disposed on the upper surface and the lower surface of the light control layer CCL-1, respectively.

[0152] The light control layer CCL-1 may be disposed on the thin film encapsulation layer TFE of the display element layer DP-LED, and the second barrier layer CAP2 is inserted between the light control layer CCL-1 and the thin film encapsulation layer TFE. The light control layer CCL-1 may include a plurality of dams BMP and light control patterns CCP-B, CCP-G, and CCP-R disposed between the dams BMP. The low refractive index layer LR-1 may be disposed on the light control layer CCL-1.

[0153] The color filter layer CFL-1 may include a plurality of color filters CF1, CF2, and CF3 and a light blocking member BM.

[0154] and Figure 4A Compared with the display panel DP explained in Figure 4B The display panel DP_1 of the embodiment illustrated in the embodiment is an embodiment in which the light control layer CCL-1, the low refractive index layer LR-1 and the color filter layer CFL-1 are arranged on the top surface of the thin film encapsulation layer TFE as the substrate surface. For example, the light control patterns CCP-B, CCP-G and CCP-R of the light control layer CCL-1 can be formed on the thin film encapsulation layer TFE by a continuous process, and the color filters CF1, CF2 and CF3 of the color filter layer CFL-1 can be sequentially formed on the light control layer CCL-1 by a continuous process. The light control layer CCL-1 can be formed by using the top surface of the second barrier layer CAP2 arranged on the thin film encapsulation layer TFE as the substrate surface, and can have the same Figure 4A For example, each of the bank BMP and the light-controlling patterns CCP-B, CCP-G, and CCP-R may have a shape similar to that of the light-controlling layer CCL. Figure 4A The color filter layer CFL-1 may be formed by using the top surface of the light control layer CCL-1 as a base surface, and may have the same Figure 4A Shapes illustrated in different shapes.

[0155] In the color filter layer CFL-1 of the embodiment, the light shielding member BM may be a black matrix. The light shielding member BM may include an organic light shielding material or an inorganic light shielding material containing a black pigment and / or a black dye. The light shielding member BM may prevent light leakage and may define a boundary between adjacent color filters CF-B, CF-G, and CF-R.

[0156] refer to Figure 4C ,and Figure 4A Compared with the display panel DP explained in the above, in addition to the pixel areas PXA-R, PXA-B, PXA-G, the display panel DP can be Figure 4CThe display panel DP_2 of the embodiment illustrated in further includes a white pixel area PXA-W. In the display panel DP_2 of the embodiment, the light emitting element ED may generate white light, and the white pixel area PXA-W may be an area through which the light generated by the light emitting element ED is transmitted without being converted. Figure 4C It is explained that the areas of the pixel areas PXA-R, PXA-B, PXA-G, and PXA-W in the plan view are the same, but the present disclosure is not limited thereto, and the white pixel area PXA-W may have an area different from that of each of the other pixel areas PXA-R, PXA-B, and PXA-G. The white light emitted from the white pixel area PXA-W may be a mixture of light of various wavelengths. The display element layer DP-LED may include a fourth light emitting area EA4 corresponding to the white pixel area PXA-W.

[0157] In addition to the first light control pattern CCP-R, the second light control pattern CCP-B and the third light control pattern CCP-G, the light control layer CCL-2 of the display panel DP_2 according to the embodiment may further include a fourth light control pattern CCP-T. The fourth light control pattern CCP-T may overlap with the white pixel area PXA-W in a plan view. The dike BMP may be provided between the fourth light control pattern CCP-T and the adjacent light control pattern. The fourth light control pattern CCP-T may not include a light emitter (such as a quantum dot). The fourth light control pattern CCP-T may be a transmissive component that transmits the incident light without converting the wavelength of the incident light. The fourth light control pattern CCP-T may include only scatterers dispersed in the base resin. The same description as described above can be applied to the description of the base resin and the scatterer.

[0158] In the color filter layer CFL-2 of the display panel DP_2 according to the embodiment, an opening T-OP overlapping with the white pixel area PXA-W in a plan view may be defined. The color filters CF1, CF2, and CF3 included in the color filter layer CFL-2 may not overlap with the white pixel area PXA-W in a plan view. For example, an opening T-OP corresponding to the white pixel area PXA-W may be defined in the second color filter CF2, and accordingly, the color filters CF1, CF2, and CF3 may not overlap with the white pixel area PXA-W. However, the present disclosure is not limited thereto, and the second color filter CF2 may overlap with the white pixel area PXA-W in a plan view, and the second color filter CF2 may be formed of a transparent photosensitive resin.

[0159] FIG. 5A to FIG. 5E Schematic cross-sectional view of a light emitting element according to an embodiment of the present disclosure is schematically illustrated. FIG. 5A to FIG. 5E Light emitting elements ED, ED-1, ED-2, and ED-3 according to an embodiment of the present disclosure are described.

[0160] refer to Figure 5A , the light emitting element ED of the embodiment may include a first electrode EL1, a second electrode EL2 facing the first electrode EL1, and a plurality of light emitting stacks ST1, ST2, ST3, ST4, and ST5 disposed between the first electrode EL1 and the second electrode EL2. The light emitting stacks ST1, ST2, ST3, ST4, and ST5 may include a first light emitting stack ST1, a second light emitting stack ST2, a third light emitting stack ST3, a fourth light emitting stack ST4, and a fifth light emitting stack ST5. Each of the first light emitting stack ST1, the second light emitting stack ST2, the third light emitting stack ST3, the fourth light emitting stack ST4, and the fifth light emitting stack ST5 may include an emission layer. Although Figure 5A It is schematically illustrated that the light emitting element ED includes five light emitting stacks ST1 , ST2 , ST3 , ST4 , and ST5 , but the present disclosure is not limited thereto, and the light emitting element ED may include more than five light emitting stacks.

[0161] The light emitting element ED according to the embodiment may include charge generation layers CGL1, CGL2, CGL3 and CGL4 respectively disposed between sequential pairs of light emitting stacks ST1, ST2, ST3, ST4 and ST5. The light emitting element ED according to the embodiment may include a first charge generation layer CGL1 disposed between the first light emitting stack ST1 and the second light emitting stack ST2, a second charge generation layer CGL2 disposed between the second light emitting stack ST2 and the third light emitting stack ST3, a third charge generation layer CGL3 disposed between the third light emitting stack ST3 and the fourth light emitting stack ST4, and a fourth charge generation layer CGL4 disposed between the fourth light emitting stack ST4 and the fifth light emitting stack ST5.

[0162] When a voltage is applied to the light emitting element ED, the charge generation layers CGL1, CGL2, CGL3, and CGL4 may generate charges (electrons and holes) by forming a complex using an oxidation-reduction reaction. The charge generation layers CGL1, CGL2, CGL3, and CGL4 may provide the generated charges to each of the adjacent light emitting stacks ST1, ST2, ST3, ST4, and ST5. The charge generation layers CGL1, CGL2, CGL3, and CGL4 may double the efficiency of the current generated in each of the adjacent light emitting stacks ST1, ST2, ST3, ST4, and ST5, and may be used to adjust the balance of charges between the adjacent light emitting stacks ST1, ST2, ST3, ST4, and ST5.

[0163] The charge generation layers CGL1, CGL2, CGL3 and CGL4 may each have a layer structure in which n-type charge generation layers n-CGL1, n-CGL2, n-CGL3 and n-CGL4 are adjacent to p-type charge generation layers p-CGL1, p-CGL2, p-CGL3 and p-CGL4, respectively. The first charge generation layer CGL1 may have a layer structure in which the first n-type charge generation layer n-CGL1 is adjacent to the first p-type charge generation layer p-CGL1. The second charge generation layer CGL2 may have a layer structure in which the second n-type charge generation layer n-CGL2 is adjacent to the second p-type charge generation layer p-CGL2. The third charge generation layer CGL3 may have a layer structure in which the third n-type charge generation layer n-CGL3 is adjacent to the third p-type charge generation layer p-CGL3. The fourth charge generation layer CGL4 may have a layer structure in which the fourth n-type charge generation layer n-CGL4 is adjacent to the fourth p-type charge generation layer p-CGL4.

[0164] The n-type charge generation layers n-CGL1, n-CGL2, n-CGL3 and n-CGL4 may be charge generation layers that provide electrons to adjacent light-emitting stacks. The n-type charge generation layers n-CGL1, n-CGL2, n-CGL3 and n-CGL4 may be layers in which n-dopants are doped in a base material. The p-type charge generation layers p-CGL1, p-CGL2, p-CGL3 and p-CGL4 may be charge generation layers that provide holes to adjacent light-emitting stacks. Although not illustrated, buffer layers may be further disposed between sequential pairs of the n-type charge generation layers n-CGL1, n-CGL2, n-CGL3 and n-CGL4 and the p-type charge generation layers p-CGL1, p-CGL2, p-CGL3 and p-CGL4, respectively.

[0165] The charge generation layers CGL1, CGL2, CGL3 and CGL4 may each include an n-type aromatic amine material or a p-type metal oxide. For example, the charge generation layers CGL1, CGL2, CGL3 and CGL4 may each include a charge generation compound formed of an aromatic amine organic compound, a metal, an oxide, carbide or fluoride of a metal, or a mixture thereof.

[0166] For example, the aromatic amine organic compound may be N'-bis(naphthalene-1-yl)-N,N'-di(phenyl)-2,2'-dimethylbenzidine (α-NPD), 2-TNATA, TDATA, MTDATA, 2,2',7,7'-tetrakis(N,N-diphenylamino)-2,7-diamino-9,9-spirobifluorene (spiro-TAD) or N,N'-bis(naphthalene-1-yl)-N,N'-di(phenyl)-2,7-diamino-9,9-spirobifluorene (spiro-NPB). For example, the metal may be cesium (Cs), molybdenum (Mo), vanadium (V), titanium (Ti), tungsten (W), barium (Ba) or lithium (Li). And, for example, the oxide, carbide or fluoride of the metal may be Re 2 O 7 、MoO 3 、V 2 O 5 , WO 3 、TiO 2 , Cs 2 CO 3 , BaF 2 , LiF or CsF.

[0167] Each of the first light emitting stack ST1, the second light emitting stack ST2, the third light emitting stack ST3, the fourth light emitting stack ST4 and the fifth light emitting stack ST5 may include an emission layer. The first light emitting stack ST1, the second light emitting stack ST2, the third light emitting stack ST3, the fourth light emitting stack ST4 and the fifth light emitting stack ST5 may include at least two blue emission layers, at least one green emission layer and at least one red emission layer. At least two of the first light emitting stack ST1, the second light emitting stack ST2, the third light emitting stack ST3, the fourth light emitting stack ST4 and the fifth light emitting stack ST5 may include a blue emission layer, at least one of the first light emitting stack ST1, the second light emitting stack ST2, the third light emitting stack ST3, the fourth light emitting stack ST4 and the fifth light emitting stack ST5 may include a green emission layer, and at least one of the first light emitting stack ST1, the second light emitting stack ST2, the third light emitting stack ST3, the fourth light emitting stack ST4 and the fifth light emitting stack ST5 may include a red emission layer.

[0168] The first light-emitting stack ST1, the second light-emitting stack ST2, the third light-emitting stack ST3, the fourth light-emitting stack ST4, and the fifth light-emitting stack ST5 may include three blue emission layers, one or two green emission layers, and one or two red emission layers. Three of the first light-emitting stack ST1, the second light-emitting stack ST2, the third light-emitting stack ST3, the fourth light-emitting stack ST4, and the fifth light-emitting stack ST5 may include a blue emission layer. The remaining two of the first light-emitting stack ST1, the second light-emitting stack ST2, the third light-emitting stack ST3, the fourth light-emitting stack ST4, and the fifth light-emitting stack ST5 may include at least one green emission layer or at least one red emission layer. One of the remaining two light-emitting stacks may include at least a green emission layer, and the other of the remaining two light-emitting stacks may include at least a red emission layer.

[0169] In the first light emitting stack ST1, the second light emitting stack ST2, the third light emitting stack ST3, the fourth light emitting stack ST4 and the fifth light emitting stack ST5, the light emitting stack including the red emission layer may be disposed adjacent to the first electrode EL1 compared to the light emitting stack including the green emission layer. For example, the light emitting stack including the red emission layer may be Figure 5A The light-emitting stack in the light-emitting element ED illustrated in FIG. 1 is arranged below the light-emitting stack including the green emission layer.

[0170] At least one of the red emission layers included in the first light emitting stack ST1, the second light emitting stack ST2, the third light emitting stack ST3, the fourth light emitting stack ST4, and the fifth light emitting stack ST5 may include a green emission layer at the same time. At least one of the green emission layers included in the first light emitting stack ST1, the second light emitting stack ST2, the third light emitting stack ST3, the fourth light emitting stack ST4, and the fifth light emitting stack ST5 may include a red emission layer at the same time.

[0171] FIG. 5B to FIG. 5E Each schematically illustrates a layer included in light emitting stacks ST1 , ST2 , ST3 , ST4 , and ST5 included in a light emitting element according to an embodiment of the present disclosure.

[0172] refer to Figure 5B The first light emitting stack ST1 may include a first blue emission layer BEML1, the second light emitting stack ST2 may include a second blue emission layer BEML2, the third light emitting stack ST3 may include a first red emission layer REML, the fourth light emitting stack ST4 may include a third blue emission layer BEML3, and the fifth light emitting stack ST5 may include a first green emission layer GEML.

[0173] In the light emitting element ED according to the embodiment, each of the blue emission layers BEML1, BEML2 and BEML3 may emit light having a first wavelength. The light having the first wavelength may be light in a blue wavelength region. In an embodiment, the first wavelength may be in a range of about 410 nm to about 480 nm. The blue emission layers BEML1, BEML2 and BEML3 may include an organic material that emits light having a wavelength in a range of about 410 nm to about 480 nm. The blue emission layers BEML1, BEML2 and BEML3 may include, for example, a host and a dopant.

[0174] The blue emission layers BEML1, BEML2, and BEML3 may have a single-layer structure. Each of the first blue emission layer BEML1, the second blue emission layer BEML2, and the third blue emission layer BEML3 may have a single-layer structure. The blue emission layers BEML1, BEML2, and BEML3 having a single-layer structure may have a thickness of about 100 nm. to about The thickness is within the range of Figure 5B Unlike the configuration explained in , at least some of the blue emission layers BEML1, BEML2, and BEML3 may have a double-layer structure. The double-layer structure of at least some of the blue emission layers BEML1, BEML2, and BEML3 may include different host materials, but the present disclosure is not limited thereto.

[0175] The blue emission layers BEML1, BEML2, and BEML3 may include a host and a dopant. In an embodiment, the blue emission layers BEML1, BEML2, and BEML3 may include a host and a first dopant that emits light having a first wavelength. The host included in each of the blue emission layers BEML1, BEML2, and BEML3 may be a blue fluorescent host, and the first dopant may be a blue fluorescent dopant.

[0176] In the light emitting element ED according to the embodiment, the host included in the blue emission layers BEML1, BEML2, and BEML3 may include one of the materials H1-1 to H1-20 listed below. The host material included in each of the blue emission layers BEML1, BEML2, and BEML3 may include one of the materials H1-1 to H1-20 listed below. However, the host material included in the blue emission layers BEML1, BEML2, and BEML3 is not limited to the materials H1-1 to H1-20 described below.

[0177]

[0178]

[0179] In an embodiment, materials H1-1 to H1-20 may each independently substitute a deuterium atom for any one of the hydrogen atoms. For example, the above material H1-1 may be represented by the following material H1-1D.

[0180]

[0181] In the light emitting element ED according to the embodiment, the first dopant included in the blue emission layers BEML1, BEML2, and BEML3 may include one of the materials FD1 to FD44 listed below. In the embodiment, the first dopant included in each of the blue emission layers BEML1, BEML2, and BEML3 may include one of the materials FD1 to FD44 listed below. However, the first dopant material included in the blue emission layers BEML1, BEML2, and BEML3 is not limited to the materials FD1 to FD44 described below.

[0182]

[0183]

[0184]

[0185]

[0186] In the light emitting element ED according to the embodiment, the first green emission layer GEML may emit light having a second wavelength. The light having the second wavelength may be light in a green wavelength region. In an embodiment, the second wavelength may be in a range of about 520nm to about 600nm. The first green emission layer GEML may include an organic material that emits light having a wavelength in a range of about 520nm to about 600nm.

[0187] The first green emission layer GEML may have a single-layer structure. The first green emission layer GEML having a single-layer structure may have a layer in which two different host materials are mixed in one layer. In an embodiment, the first green emission layer GEML may have a structure in which a hole transport host material and an electron transport host material are mixed in one layer. In the specification, the hole transport host may be described as a "first host" and the electron transport host may be described as a "second host". The hole transport host material and the electron transport host material may form an excited complex. The first green emission layer GEML having a single-layer structure may have a thickness of about 100 nm. to about In another embodiment, the thickness of Figure 5BDifferent from the configuration explained in , the first green emission layer GEML may have a double-layer structure. In the case where the first green emission layer GEML has a double-layer structure, the double-layer structure may include different host materials, but the present disclosure is not limited thereto.

[0188] In an embodiment, the first green emission layer GEML may have a first hole transport host, a first electron transport host, and a second dopant. The first green emission layer GEML may be a layer in which the first hole transport host and the first electron transport host are mixed, and the layer is doped with a second dopant that emits light having a second wavelength. In an embodiment, the first hole transport host and the first electron transport host included in the first green emission layer GEML may be a material different from the host material included in the blue emission layers BEML1, BEML2, and BEML3. The second dopant may be a phosphorescent dopant. The second dopant may be a green phosphorescent dopant.

[0189] In the light emitting element ED according to the embodiment, the first hole transport host included in the first green emission layer GEML may include one of the materials H4-1 to H4-11 listed below. However, the first hole transport host included in the first green emission layer GEML is not limited to the materials H4-1 to H4-11 described below.

[0190]

[0191] In the light emitting element ED according to the embodiment, the first electron transport host included in the first green emission layer GEML may include one of the materials H3-1 to H3-23 listed below. However, the first electron transport host included in the first green emission layer GEML is not limited to the materials H3-1 to H3-23 described below.

[0192]

[0193] In the light emitting element ED according to the embodiment, the second dopant included in the first green emission layer GEML may include one of the materials PD1 to PD33 listed below. However, the second dopant material included in the first green emission layer GEML is not limited to the materials PD1 to PD33 described below.

[0194]

[0195]

[0196] In the light emitting element ED according to the embodiment, the first red emission layer REML may emit light having a third wavelength. The light having the third wavelength may be light in a red wavelength region. In an embodiment, the third wavelength may be in a range of about 620nm to about 700nm. The first red emission layer REML may include an organic material that emits light having a wavelength in a range of about 620nm to about 700nm.

[0197] The first red emission layer REML may have a single-layer structure. The first red emission layer REML having a single-layer structure may have a layer in which two different host materials are mixed in one layer. In an embodiment, the first red emission layer REML may have a structure in which a hole transport host material and an electron transport host material are mixed in one layer. The first red emission layer REML having a single-layer structure may have a thickness of about 100 nm. to about In another embodiment, the thickness of Figure 5B Different from the configuration explained in , the first red emission layer REML may have a double-layer structure. In the case where the first red emission layer REML has a double-layer structure, the double-layer structure may include different host materials, but the present disclosure is not limited thereto.

[0198] In an embodiment, the first red emission layer REML may have a second hole transport host, a second electron transport host, and a third dopant. The first red emission layer REML may be a layer in which the second hole transport host and the second electron transport host are mixed, and the layer is doped with a third dopant that emits light having a third wavelength. In an embodiment, the second hole transport host and the second electron transport host included in the first red emission layer REML may be a material different from the host material included in the blue emission layers BEML1, BEML2, and BEML3 and the first green emission layer GEML. The third dopant may be a phosphorescent dopant. The third dopant may be a red phosphorescent dopant.

[0199] In the light emitting element ED according to the embodiment, the second hole transport host included in the first red emission layer REML may be, for example, the following material H5. The second electron transport host included in the first red emission layer REML may be, for example, the following material H6. However, the second hole transport host and the second electron transport host included in the first red emission layer REML are not limited to the following materials H5 and H6.

[0200]

[0201] In the light emitting element ED according to the embodiment, the third dopant included in the first red emission layer REML may include one of the materials PR1 to PR35 listed below. However, the third dopant material included in the first red emission layer REML is not limited to the materials PR1 to PR35 described below.

[0202]

[0203]

[0204]

[0205]

[0206] At least one of the emission layers included in each of the light emitting stacks ST1, ST2, ST3, ST4, and ST5 may be an emission layer that emits light with at least a third order resonance. For example, the emission layer included in the fifth light emitting stack ST5 disposed on the top among the light emitting stacks ST1, ST2, ST3, ST4, and ST5 included in the light emitting element ED of the embodiment may be an emission layer that emits light with at least a third order resonance.

[0207] In the specification, the "optical distance" may be defined as a distance from the top surface of the first electrode EL1 to the center of the corresponding emission layer. In an embodiment, each of the emission layers included in the light emitting stacks ST1, ST2, ST3, ST4, and ST5 may be disposed at a distance at which light emitted from the emission layer resonates in the xth order. x may be a natural number greater than or equal to 1.

[0208] The blue emission layers BEML1, BEML2 and BEML3 may be included in three of the light emitting stacks ST1, ST2, ST3, ST4 and ST5, and the uppermost blue emission layer among the blue emission layers BEML1, BEML2 and BEML3 may be an emission layer that emits light in at least a third order resonance. The uppermost blue emission layer may mean a blue emission layer that is disposed closest to the second electrode EL2. The uppermost blue emission layer may be disposed to have an optical distance at which blue light resonates in the nth order, and n may be an integer greater than or equal to 3. Figure 5B In the light emitting element ED illustrated in FIG. 4 , the third blue emission layer BEML3 included in the fourth light emitting stack ST4 may be an emission layer that emits light with a third-order resonance or a fourth-order resonance.

[0209] The first red emission layer REML may be included in one of the light emitting stacks ST1, ST2, ST3, ST4, and ST5, and may be an emission layer that emits light in a first-order resonance or a second-order resonance. The first red emission layer REML may be arranged to have an optical distance at which red light resonates in the mth order, and m may be 1 or 2. Figure 5B In the light emitting element ED illustrated in FIG. 1 , the first red emission layer REML included in the third light emitting stack ST3 may be an emission layer that emits light in a second-order resonance.

[0210] exist Figure 5B In the light emitting element ED explained in FIG. 1 , the first green emission layer GEML included in the fifth light emitting stack ST5 may be an emission layer that emits light in a third order resonance. In another embodiment, the first green emission layer GEML may be disposed at a resonance distance of green light in a fourth order or higher.

[0211] Figure 6 is a graph showing the emission intensity according to the optical distance of each of red light, blue light and green light. Figure 6 The unit of optical distance is angstrom. And the emission intensity indicates the relative emission intensity in the case where the emission intensity of each light at the position of the first-order resonance distance is "1".

[0212] Also refer to Figure 5B and Figure 6 , the uppermost blue emission layer may be the third blue emission layer BEML3 included in the fourth light emitting stack ST4, and the third blue emission layer BEML3 may have a first optical distance OD-B. The first optical distance OD-B may be the third order resonance distance of blue light. The first optical distance OD-B may be, for example, about

[0213] The first red emission layer REML included in the third light emitting stack ST3 may have a second optical distance OD-R. The second optical distance OD-R may be a second order resonance distance of red light. The second optical distance OD-R may be, for example, about

[0214] The first green emission layer GEML included in the fifth light emitting stack ST5 may have a third optical distance OD-G. The third optical distance OD-G may be a third order resonance distance of green light. The third optical distance OD-G may be, for example, about

[0215] refer to Figure 5CIn the light emitting element ED-1 of the embodiment, the first light emitting stack ST1 may include a first red emission layer REML, the second light emitting stack ST2 may include a first blue emission layer BEML1, the third light emitting stack ST3 may include a first green emission layer GEML, the fourth light emitting stack ST4 may include a second blue emission layer BEML2, and the fifth light emitting stack ST5 may include a third blue emission layer BEML3. The above description may be applied to the respective thicknesses and materials of the blue emission layers BEML1, BEML2 and BEML3, the first green emission layer GEML and the first red emission layer REML.

[0216] The blue emission layers BEML1, BEML2 and BEML3 may be included in three of the light emitting stacks ST1, ST2, ST3, ST4 and ST5, and the uppermost blue emission layer among the blue emission layers BEML1, BEML2 and BEML3 may be an emission layer that emits light in at least a third order resonance. The uppermost blue emission layer may mean a blue emission layer that is disposed closest to the second electrode EL2. The uppermost blue emission layer may be disposed to have an optical distance at which blue light resonates in the nth order, and n may be an integer greater than or equal to 3. Figure 5C In the light emitting element ED-1 illustrated in FIG. 4 , the third blue emission layer BEML3 included in the fifth light emitting stack ST5 may be an emission layer that emits light with fourth-order resonance.

[0217] The first red emission layer REML may be included in one of the light emitting stacks ST1, ST2, ST3, ST4, and ST5, and may be an emission layer that emits light in a first-order resonance or a second-order resonance. The first red emission layer REML may be arranged to have an optical distance at which red light resonates in the mth order, and m may be 1 or 2. Figure 5C In the light emitting element ED-1 illustrated in FIG. 2 , the first red emission layer REML included in the first light emitting stack ST1 may be an emission layer that emits light in a first-order resonance.

[0218] exist Figure 5C In the light emitting element ED-1 illustrated in FIG. 2 , the first green emission layer GEML included in the third light emitting stack ST3 may be an emission layer that emits light in a second-order resonance.

[0219] Also refer to Figure 5C and Figure 6 , the blue emission layer disposed on the top may be the third blue emission layer BEML3 included in the fifth light emitting stack ST5, and the third blue emission layer BEML3 may have a first optical distance OD-B. The first optical distance OD-B may be the fourth order resonance distance of blue light. The first optical distance OD-B may be, for example, about

[0220] The first red emission layer REML included in the first light emitting stack ST1 may have a second optical distance OD-R. The second optical distance OD-R may be a first order resonance distance of red light. The second optical distance OD-R may be, for example, about

[0221] The first green emission layer GEML included in the third light emitting stack ST3 may have a third optical distance OD-G. The third optical distance OD-G may be a second order resonance distance of green light. The third optical distance OD-G may be, for example, about

[0222] refer to Figure 5D and Figure 5E , the light emitting element ED-2 and the light emitting element ED-3 of the embodiment may each include a first composite emission layer HEML1 and a first composite emission layer HEML. Figure 5B and Figure 5C Compared with the light emitting element ED and the light emitting element ED-1 explained in the embodiment, Figure 5D and Figure 5E The light emitting element ED-2 and the light emitting element ED-3 illustrated in FIG. 1 can be formed by replacing the first red emission layer REML with the first composite emission layer HEML1. In an embodiment, Figure 5D The light emitting element ED-2 illustrated in FIG. 1 may include a first composite emission layer HEML1 included in the third light emitting stack ST3. Figure 5E The light emitting element ED-3 illustrated in FIG. 1 may include a first composite emission layer HEML included in the first light emitting stack ST1.

[0223] The first composite emission layer HEML1 may include a first red sub-emission layer S-REML1 and a first green sub-emission layer S-GEML1 disposed on the first red sub-emission layer S-REML1. The first red sub-emission layer S-REML1 and the first green sub-emission layer S-GEML1 may be in contact with each other. The first red sub-emission layer S-REML1 may be disposed adjacent to the first electrode EL1 compared to the first green sub-emission layer S-GEML1, and the first green sub-emission layer S-GEML1 may be disposed adjacent to the second electrode EL2 compared to the first red sub-emission layer S-REML1. In the light-emitting element ED-2 and the light-emitting element ED-3 of the embodiment, since the first red sub-emission layer S-REML1 is disposed adjacent to the first electrode EL1 compared to the first green sub-emission layer S-GEML1, more red light emission may be generated in the first composite emission layer HEML1 and the first composite emission layer HEML, and thus the white light emission efficiency of the light-emitting element ED-2 and the light-emitting element ED-3 may be improved.

[0224] The first red sub-emission layer S-REML1 may emit light having a third wavelength. The light having the third wavelength may be light in a red wavelength region. In an embodiment, the third wavelength may be in a range of about 620nm to about 700nm. The first red sub-emission layer S-REML1 may include an organic material that emits light having a wavelength in a range of about 620nm to about 700nm.

[0225] The first red sub-emission layer S-REML1 may have a single-layer structure. The first red sub-emission layer S-REML1 having a single-layer structure may have a layer in which two different host materials are mixed in one layer. In an embodiment, the first red sub-emission layer S-REML1 may have a structure in which a hole transport host material and an electron transport host material are mixed in one layer. The first red sub-emission layer S-REML1 having a single-layer structure may have a thickness of about 100 nm. to about In another embodiment, the thickness of Figure 5D and Figure 5E Different from the configuration explained in , the first red sub emission layer S-REML1 may have a double-layer structure. In the case where the first red sub emission layer S-REML1 has a double-layer structure, the double-layer structure may include different host materials, but the present disclosure is not limited thereto.

[0226] In an embodiment, the first red sub-emission layer S-REML1 may have a second hole transport host, a second electron transport host, and a third dopant. The first red sub-emission layer S-REML1 may be a layer in which the second hole transport host and the second electron transport host are mixed, and the layer is doped with a third dopant that emits light having a third wavelength. In an embodiment, the second hole transport host and the second electron transport host included in the first red sub-emission layer S-REML1 may be a material different from the host material included in the blue emission layers BEML1, BEML2, and BEML3 and the first green emission layer GEML. The third dopant may be a phosphorescent dopant. The third dopant may be a red phosphorescent dopant.

[0227] The first green sub-emission layer S-GEML1 may emit light having a second wavelength. The light having the second wavelength may be light in a green wavelength region. In an embodiment, the second wavelength may be in a range of about 520nm to about 600nm. The first green sub-emission layer S-GEML1 may include an organic material that emits light having a wavelength in a range of about 520nm to about 600nm.

[0228] The first green sub-emission layer S-GEML1 may have a single-layer structure. The first green sub-emission layer S-GEML1 having a single-layer structure may have a layer in which two different host materials are mixed in one layer. In an embodiment, the first green sub-emission layer S-GEML1 may have a structure in which a hole transport host material and an electron transport host material are mixed in one layer. The first green sub-emission layer S-GEML1 having a single-layer structure may have a thickness of about 100 nm. to about In another embodiment, the thickness of Figure 5D and Figure 5E Different from the configuration explained in , the first green sub-emission layer S-GEML1 may have a double-layer structure. In the case where the first green sub-emission layer S-GEML1 has a double-layer structure, the double-layer structure may include different host materials, but the present disclosure is not limited thereto.

[0229] In an embodiment, the first green sub-emission layer S-GEML1 may have a first hole transport host, a first electron transport host, and a second dopant. The first green sub-emission layer S-GEML1 may be a layer in which the first hole transport host and the first electron transport host are mixed, and the layer is doped with a second dopant that emits light having a second wavelength. The second dopant may be a phosphorescent dopant. The second dopant may be a green phosphorescent dopant.

[0230] refer to FIG. 5A to FIG. 5E In the embodiment, the light emitting elements ED, ED-1, ED-2 and ED-3 may emit light in a direction from the first electrode EL1 to the second electrode EL2. In the light emitting elements ED, ED-1, ED-2 and ED-3 of the embodiment, each of the light emitting stacks ST1, ST2, ST3, ST4 and ST5 may include hole transport regions HTR1, HTR2, HTR3, HTR4 and HTR5 and electron transport regions ETR1, ETR2, ETR3, ETR4 and ETR5. The hole transport regions HTR1, HTR2, HTR3, HTR4 and HTR5 may transport holes provided from the first electrode EL1 or the charge generation layers CGL1, CGL2, CGL3 and CGL4 to the emission layer. The electron transport regions ETR1, ETR2, ETR3, ETR4 and ETR5 may transport electrons provided from the second electrode EL2 or the charge generation layers CGL1, CGL2, CGL3 and CGL4 to the emission layer.

[0231] In the light-emitting elements ED, ED-1, ED-2 and ED-3 of the embodiments, a structure in which hole transport regions HTR1, HTR2, HTR3, HTR4 and HTR5 are arranged below respective emission layers included in the light-emitting stacks ST1, ST2, ST3, ST4 and ST5 and electron transport regions ETR1, ETR2, ETR3, ETR4 and ETR5 are arranged above respective emission layers included in the light-emitting stacks ST1, ST2, ST3, ST4 and ST5 is explained based on the direction of emitted light. For example, the light-emitting elements ED, ED-1, ED-2 and ED-3 of the embodiment may have a forward element structure, but the present disclosure is not limited thereto, and based on the direction of emitted light, the light-emitting elements ED, ED-1, ED-2 and ED-3 may have an inverted element structure in which electron transport regions ETR1, ETR2, ETR3, ETR4 and ETR5 are arranged below the respective emission layers included in the light-emitting stacks ST1, ST2, ST3, ST4 and ST5 and hole transport regions HTR1, HTR2, HTR3, HTR4 and HTR5 are arranged above the respective emission layers included in the light-emitting stacks ST1, ST2, ST3, ST4 and ST5.

[0232] The hole transport regions HTR1, HTR2, HTR3, HTR4 and HTR5 may include hole injection layers HIL1, HIL2, HIL3, HIL4 and HIL5, respectively, and hole transport layers HTL1, HTL2, HTL3, HTL4 and HTL5, respectively, disposed on the hole injection layers HIL1, HIL2, HIL3, HIL4 and HIL5. The hole transport layers HTL1, HTL2, HTL3, HTL4 and HTL5 may each contact the bottom surface of the emission layer. However, the present disclosure is not limited thereto, and the hole transport regions HTR1, HTR2, HTR3, HTR4 and HTR5 may further include hole side additional layers disposed on the hole transport layers HTL1, HTL2, HTL3, HTL4 and HTL5, respectively. The hole side additional layers may include at least one of a hole buffer layer, an emission auxiliary layer and an electron blocking layer. The hole buffer layer may compensate for the resonance distance according to the wavelength of light emitted from the emission layer, thereby increasing the luminous efficiency. The electron blocking layer may serve to prevent electrons from the electron transport regions ETR1 , ETR2 , ETR3 , ETR4 , and ETR5 from being injected into the hole transport regions HTR1 , HTR2 , HTR3 , HTR4 , and HTR5 .

[0233] The electron transport regions ETR1, ETR2, ETR3, ETR4 and ETR5 may include electron transport layers ETL1, ETL2, ETL3, ETL4 and ETL5, respectively. The electron transport regions ETR1, ETR2, ETR3, ETR4 and ETR5 may further include electron injection layers disposed on the electron transport layers ETL1, ETL2, ETL3, ETL4 and ETL5, respectively. For example, the fifth electron transport region ETR5 included in the fifth light-emitting stack ST5 may further include a fifth electron injection layer EIL5 disposed on the fifth electron transport layer ETL5. The electron transport regions ETR1, ETR2, ETR3, ETR4 and ETR5 may each further include an electron side additional layer disposed between the electron transport layer ETL (ETL1, ETL2, ETL3, ETL4 or ETL5 are collectively referred to as "ETL") and the emission layer. The electron side additional layer may include at least one of an electron buffer layer and a hole blocking layer.

[0234] In the light emitting elements ED, ED-1, ED-2 and ED-3 according to the embodiments, the first electrode EL1 may be a reflective electrode. For example, the first electrode EL1 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, W, In, Zn, Sn and compounds or mixtures thereof (e.g., mixtures of Ag and Mg) having high reflectivity, or a material having a multilayer structure such as LiF / Ca or LiF / Al. For example, the first electrode EL1 may have a multilayer structure including a reflective film formed of the above materials and a transparent conductive film formed of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), etc. For example, the first electrode EL1 may have a two-layer structure of ITO / Ag or a three-layer structure of ITO / Ag / ITO. However, the present disclosure is not limited thereto, and the first electrode EL1 may include the above metal materials, a combination of at least two of the above metal materials, or an oxide of the above metal materials, etc. The first electrode EL1 may have a thickness in the range of about 70 nm to about 1,000 nm. For example, the first electrode EL1 may have a thickness in the range of about 100 nm to about 300 nm.

[0235] In the light emitting elements ED, ED-1, ED-2 and ED-3 according to the embodiments, the hole transport regions HTR1, HTR2, HTR3, HTR4 and HTR5 may each have a single-layer structure formed of a single material, a single-layer structure formed of different materials, or a multilayer structure including a plurality of layers formed of a plurality of different materials.

[0236] The hole transport regions HTR1, HTR2, HTR3, HTR4 and HTR5 may each be formed using various methods such as vacuum deposition, spin coating, casting, Langmuir-Brokett (LB), inkjet printing, laser printing, laser induced thermal imaging (LITI), etc.

[0237] The hole transport regions HTR1, HTR2, HTR3, HTR4, and HTR5 may each include a phthalocyanine compound (eg, copper phthalocyanine); N 1 ,N 1 '-([1,1'-biphenyl]-4,4'-diyl)bis(N 1 -phenyl-N 4 ,N 4 -Di-m-tolylbenzene-1,4-diamine) (DNTPD), 4,4',4"-[tri(3-methylphenyl)phenylamino]triphenylamine (m-MTDATA), 4,4',4"-tri(N,N-diphenylamino)triphenylamine (TDATA), 4,4',4"-tri[N-(2-naphthyl)-N-phenylamino]triphenylamine (2-TNATA), poly(3,4-ethylenedioxydioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / dodecylbenzenesulfonic acid (PANI / DB SA), polyaniline / camphorsulfonic acid (PANI / CSA), polyaniline / poly(4-styrenesulfonate) (PANI / PSS), N,N'-di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (NPB), triphenylamine-containing polyetherketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium [tetrakis(pentafluorophenyl)borate], dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN), etc.

[0238] The hole transport regions HTR1, HTR2, HTR3, HTR4 and HTR5 may each include a carbazole derivative (such as N-phenylcarbazole or polyvinylcarbazole), a fluorene derivative, a triphenylamine derivative (such as N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD), 4,4',4"-tri(carbazole-9-yl)triphenylamine (TCT A), N,N'-di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (NPB), 4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl)aniline] (TAPC), 4,4'-bis[N,N'-(3-methylphenyl)amino]-3,3'-dimethylbiphenyl (HMTPD) or 1,3-bis(carbazol-9-yl)benzene (mCP)).

[0239] The hole transport regions HTR1, HTR2, HTR3, HTR4 and HTR5 may each include 9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole (CzSi), 9-phenyl-9H-3,9'-bicarbazole (CCP), 1,3-bis(1,8-dimethyl-9H-carbazole-9-yl)benzene (mDCP), or the like.

[0240] The hole transport regions HTR1, HTR2, HTR3, HTR4 and HTR5 may each include the above-mentioned compound of the hole transport region in at least one of the hole injection layer HIL1, HIL2, HIL3, HIL4 or HIL5 (collectively referred to as HIL), the hole transport layer HTL1, HTL2, HTL3, HTL4 or HTL5 (collectively referred to as HTL) and the hole side additional layer.

[0241] The hole transport regions HTR1, HTR2, HTR3, HTR4 and HTR5 may each have a thickness in the range of about 10 nm to about 1,000 nm (e.g., in the range of about 10 nm to about 500 nm). The hole injection layer HIL may each have a thickness in the range of, for example, about 5 nm to about 100 nm. The hole transport layer HTL may each have a thickness in the range of about 5 nm to about 100 nm. In the case where the hole transport regions HTR1, HTR2, HTR3, HTR4 and HTR5 each include a hole side additional layer, the hole side additional layer may have a thickness in the range of about 1 nm to about 10 nm. In the case where the thickness of the hole transport regions HTR1, HTR2, HTR3, HTR4 and HTR5 and the layers included therein meet the above range, satisfactory hole transport characteristics may be obtained without significantly increasing the driving voltage.

[0242] In addition to the above materials, the hole transport regions HTR1, HTR2, HTR3, HTR4, and HTR5 may each further include a charge generation material to increase conductivity. The charge generation material may be uniformly or non-uniformly dispersed in the hole transport regions HTR1, HTR2, HTR3, HTR4, and HTR5. The charge generation material may be, for example, a p-type dopant. The p-type dopant may include at least one of a metal halide, a quinone derivative, a metal oxide, and a cyano compound, but the present disclosure is not limited thereto. For example, the p-type dopant may include metal halides (such as CuI and RbI), quinone derivatives (such as tetracyanoquinodimethane (TCNQ) and 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinodimethane (F4-TCNQ)), metal oxides (such as tungsten oxide and molybdenum oxide), cyano compounds (such as dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN) and 4-[[2,3-bis[cyano-(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropylidene]-cyanomethyl]-2,3,5,6-tetrafluorobenzonitrile (NDP9)), etc., but the present disclosure is not limited thereto.

[0243] Each of the blue emission layers BEML1, BEML2 and BEML3, the first green emission layer GEML and the first red emission layer REML may include the above-mentioned host material and dopant material. The blue emission layers BEML1, BEML2 and BEML3, the first green emission layer GEML and the first red emission layer REML may include a material including a carbazole derivative portion or an amine derivative portion as a hole transport host material. Each of the blue emission layers BEML1, BEML2 and BEML3, the first green emission layer GEML and the first red emission layer REML may include a material including a nitrogen-containing aromatic ring structure (such as a pyridine derivative portion, a pyridazine derivative portion, a pyrimidine derivative portion, a pyrazine derivative portion or a triazine derivative portion) as an electron transport host material.

[0244] Each of the blue emission layers BEML1, BEML2 and BEML3, the first green emission layer GEML and the first red emission layer REML may include an anthracene derivative, a pyrene derivative, a fluoranthene derivative, a 1,2-benzophenanthrene derivative, a dihydrobenzanthracene derivative or a triphenylene derivative, etc. as a host material. Each of the blue emission layers BEML1, BEML2 and BEML3, the first green emission layer GEML and the first red emission layer REML may further include a general host material as a host material. For example, each of the blue emission layers BEML1, BEML2, and BEML3, the first green emission layer GEML, and the first red emission layer REML may include at least one of bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO), 4,4'-bis(carbazole-9-yl)biphenyl (CBP), 1,3-bis(carbazole-9-yl)benzene (mCP), 2,8-bis(diphenylphosphino)dibenzo[b,d]furan (PPF), 4,4',4"-tri(carbazole-9-yl)triphenylamine (TCTA), and 1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi) as a host material. However, the present disclosure is not limited thereto, and for example, tris(8-hydroxyquinoline)aluminum (Alq 3 ), poly(N-vinylcarbazole) (PVK), 9,10-di(naphthalene-2-yl)anthracene (ADN), 3-tert-butyl-9,10-di(naphthalene-2-yl)anthracene (TBADN), distyrylarene (DSA), 4,4′-bis(9-carbazolyl)-2,2′-dimethyl-biphenyl (CDBP), 2-methyl-9,10-bis(naphthalene-2-yl)anthracene (MADN), hexaphenylcyclotriphosphazene (CP1), 1,4-bis(triphenylsilyl)benzene (UGH2), hexaphenylcyclotrisiloxane (DPSiO 3 ), octaphenylcyclotetrasiloxane (DPSiO 4 ) etc. can be used as the main material.

[0245] In an embodiment, the blue emission layers BEML1, BEML2, and BEML3 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)phenyl)phenyl)) as fluorescent dopant materials.

[0063] Examples of the invention include bis(2-(4-(N,N-diphenylamino)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)), pyrene and its derivatives (e.g., 1,1'-dipyrene, 1,4-dipyrenylbenzene, 1,4-bis(N,N-diphenylamino)pyrene), and the like.

[0246] The first green emission layer GEML and the first red emission layer REML may include a phosphorescent dopant material. For example, a metal complex 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 a phosphorescent dopant. For example, bis(4,6-difluorophenylpyridyl-N,C2') picolinyl iridium (III) (FIrpic), bis(2,4-difluorophenylpyridyl)-tetra(1-pyrazolyl) borate iridium (III) (FIr6) or octaethylporphyrin platinum (PtOEP) may be used as a phosphorescent dopant.

[0247] The electron transport regions ETR1, ETR2, ETR3, ETR4, and ETR5 may each have a single-layer structure formed of a single material, a single-layer structure formed of different materials, or a multi-layer structure having a plurality of layers formed of a plurality of different materials.

[0248] The electron transport regions ETR1, ETR2, ETR3, ETR4 and ETR5 may each be formed using various methods such as vacuum deposition, spin coating, casting, Langmuir-Brokett (LB) method, inkjet printing, laser printing, laser induced thermal imaging (LITI), etc.

[0249] The electron transport regions ETR1, ETR2, ETR3, ETR4, and ETR5 may each include an anthracene-based compound. However, the present disclosure is not limited thereto, and the electron transport layers ETL may each include, for example, tris(8-hydroxyquinoline)aluminum (Alq 3)、1,3,5-tris[(3-pyridyl)-phenyl-3-yl]benzene、2,4,6-tris([1,1'-biphenyl]-3-yl)-1,3,5-triazine (T2T), 2,4,6-tris(3-(pyrimidin-5-yl)phenyl)-1,3,5-triazine (TPM-TAZ), 2-(4-(N-phenylbenzimidazol-1-yl)phenyl)-9,10-dinaphthylanthracene, 1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), 3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), 4-(naphthalene-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole ( t Bu-PBD), bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq), bis(benzoquinoline-10-hydroxy)beryllium (Bebq 2 ), 9,10-di(naphthalene-2-yl)anthracene (ADN), 1,3-bis[3,5-di(pyridin-3-yl)phenyl]benzene (BmPyPhB) or a mixture thereof.

[0250] The electron transport regions ETR1, ETR2, ETR3, ETR4, and ETR5 may each include a metal halide (such as LiF, NaCl, CsF, RbCl, RbI, CuI, and KI), a lanthanide metal (such as Yb), or a co-deposited material of a metal halide and a lanthanide metal. For example, the electron transport regions ETR1, ETR2, ETR3, ETR4, and ETR5 may include KI:Yb, RbI:Yb, etc. as co-deposited materials. The electron transport regions ETR1, ETR2, ETR3, ETR4, and ETR5 may include at least two of Mg, Ag, Yb, and Al. For example, the electron transport regions ETR1, ETR2, ETR3, ETR4, and ETR5 may include Mg and Yb.

[0251] Electron transport regions ETR1, ETR2, ETR3, ETR4 and ETR5 may be formed of metal oxides (e.g., Li 2O or BaO) or 8-hydroxyquinoline lithium (Liq), etc., but the present disclosure is not limited thereto. Each of the electron transport regions ETR1, ETR2, ETR3, ETR4, and ETR5 may be formed of a mixed material of an electron transport material and an insulating organic metal salt. The insulating organic metal salt may be a material having an energy band gap greater than or equal to about 4 eV. For example, the insulating organic metal salt may include, for example, a metal acetate, a metal benzoate, a metal acetoacetate, a metal acetylacetonate, or a metal stearate.

[0252] In addition to the above materials, the electron transport regions ETR1, ETR2, ETR3, ETR4, and ETR5 may each further include at least one of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and 4,7-diphenyl-1,10-phenanthroline (Bphen), but the present disclosure is not limited thereto.

[0253] The electron transport regions ETR1, ETR2, ETR3, ETR4, and ETR5 may include the above-mentioned compounds of the electron transport region in the electron injection layer EIL5 or the electron transport layers ETL1, ETL2, ETL3, ETL4, and ETL5. In the case where the electron transport regions ETR1, ETR2, ETR3, ETR4, and ETR5 each include an electron side additional layer, the above-mentioned materials may be included in the electron side additional layer. In an embodiment, the electron injection layer EIL5 may be formed of at least two of Mg, Ag, Yb, and Al. The electron injection layer EIL5 may be formed of, for example, a mixture of Mg and Yb.

[0254] The electron transport regions ETR1, ETR2, ETR3, ETR4, and ETR5 may each have, for example, a thickness in the range of about 10 nm to about 150 nm. The electron transport layer ETL may have a thickness in the range of about 0.1 nm to about 100 nm (for example, in the range of about 0.3 nm to about 50 nm). When the thickness of the electron transport layer ETL satisfies the aforementioned range, satisfactory electron transport characteristics may be obtained without significantly increasing the driving voltage.

[0255] The second electrode EL2 may be provided on the plurality of light emitting stacks ST1, ST2, ST3, ST4 and ST5. 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. 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.

[0256] The second electrode EL2 may be a transflective electrode, a transmissive electrode or a reflective electrode. In the case where the second electrode EL2 is a transmissive electrode, the second electrode EL2 may be formed of, for example, ITO, IZO, ZnO, ITZO, etc.

[0257] In the case where the second electrode EL2 is a transflective electrode or a reflective electrode, the second electrode EL2 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, Yb, W, In, Zn, Sn or a compound or mixture thereof (e.g., AgMg, AgYb or MgYb), or a material having a multilayer structure such as LiF / Ca or LiF / Al. In an embodiment, the second electrode EL2 may have a multilayer structure including a reflective film or a transflective film formed of the above materials and a transparent conductive film formed of ITO, IZO, ZnO, ITZO, etc. For example, the second electrode EL2 may include the above metal materials, a combination of at least two of the above metal materials, or an oxide of the above metal materials, etc.

[0258] Although not shown, the second electrode EL2 may be connected to the auxiliary electrode. In the case where the second electrode EL2 is connected to the auxiliary electrode, the resistance of the second electrode EL2 may be reduced.

[0259] A capping layer CPL may be further disposed on the second electrode EL2 of each of the light emitting elements ED, ED-1, ED-2, and ED-3 of the embodiment. The capping layer CPL may include a plurality of layers or a single layer.

[0260] In an embodiment, the capping layer CPL may be an organic layer or an inorganic layer. For example, in the case where the capping layer CPL contains an inorganic material, the inorganic material may include an alkali metal compound (eg, LiF), an alkaline earth metal compound (eg, MgF 2 )、SiON、SiN x 、SiO y wait.

[0261] For example, in the case where the capping layer CPL includes an organic material, the organic material may include α-NPD, NPB, TPD, m-MTDATA, Alq 3 , CuPc, N4,N4,N4',N4'-tetrakis(biphenyl-4-yl)biphenyl-4,4'-diamine (TPD15), 4,4',4"-tris(carbazole-9-yl)triphenylamine (TCTA), etc., or may include epoxy resin or acrylate (such as methacrylate). However, the present disclosure is not limited thereto, and the capping layer CPL may include at least one of the following compounds P1 to P7:

[0262]

[0263]

[0264] The refractive index of the capping layer CPL may be greater than or equal to about 1.6. For example, for light in a wavelength range of about 550 nm to about 660 nm, the refractive index of the capping layer CPL may be greater than or equal to about 1.6.

[0265] The light emitting elements ED, ED-1, ED-2 and ED-3 included in the display panel DP of the embodiment may have a structure including a plurality of blue emission layers BEML1, BEML2 and BEML3, at least one first green emission layer GEML and at least one first red emission layer REML, and therefore, light emission at a plurality of resonance distances may be used, thereby maximizing the light emission efficiency. The light emitting elements ED, ED-1, ED-2 and ED-3 according to the embodiment may include at least five light emitting stacks, and three of the five light emitting stacks may include a blue emission layer, one light emitting stack may include at least a green emission layer, and one light emitting stack may include at least a red emission layer, thereby maximizing the efficiency of the x-th order resonance region of each of the blue light, the green light and the red light, thereby maximizing the light emission efficiency of the light emitting element.

[0266] Hereinafter, with reference to Examples and Comparative Examples, characteristic evaluation results of light emitting elements according to embodiments of the present disclosure will be described. The Examples described below are merely illustrative to facilitate understanding of the present disclosure, and the scope of the present disclosure is not limited thereto.

[0267] (Manufacturing of Light Emitting Devices)

[0268] In the embodiment and the comparative example, after forming the first electrode on the glass substrate, five light-emitting stacks are formed on the first electrode, and the second electrode and the capping layer are formed to manufacture a light-emitting element connected in series. An n-type charge generation layer in which 2,4,6-tris(3-(pyrimidin-5-yl)phenyl)-1,3,5-triazine (TPM-TAZ) is doped with Liq and a p-type charge generation layer in which 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) is doped with Li is arranged between the sequential pairs of light-emitting stacks. ITO / Ag / ITO was used as the first electrode, AgMg was used as the second electrode, dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN) was used as a hole injection layer material, and N,N'-di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (NPB) was used as a hole transport layer material. In the first to fourth light-emitting stacks, 2,4,6-tris([1,1'-biphenyl]-3-yl)-1,3,5-triazine (T2T) was used as an electron transport layer material, and in the top fifth light-emitting stack, TPM-TAZ doped with Liq was used as an electron transport layer material, and Mg and Yb were used as electron injection layer materials. In the light-emitting stack including the blue emission layer, an electron blocking layer disposed between the hole transport layer and the emission layer was formed, and 4,4',4"-tri(carbazole-9-yl)triphenylamine (TCTA) was used as the electron blocking layer material. Each layer was formed by a deposition method under vacuum conditions. A film having a thickness of about 100 nm was formed on the second electrode using the above-mentioned compound P4. The thickness of the capping layer.

[0269] In the embodiments and comparative examples, the above-mentioned material H1-1 is used as the main body included in the blue emission layer. The above-mentioned material FD35 is used as the dopant included in the blue emission layer. The above-mentioned materials H4-3 and the above-mentioned H3-23 that form an excited complex structure in a ratio of 1:1 are used as the main body included in the green emission layer. The above-mentioned material PD28 is used as the dopant included in the green emission layer. The above-mentioned materials H5 and material H6 of the excited complex structure formed in a ratio of 1:1 are used as the main body included in the red emission layer. The above-mentioned material PR32 is used as the dopant included in the red emission layer.

[0270] (Evaluation of Characteristics of Examples 1 to 4 and Comparative Examples 1 and 2)

[0271] In the light emitting elements of Examples 1 to 4, as shown in reference FIG. 5A to FIG. 5EAs described above, three of the first to fifth light-emitting stacks include a blue emission layer, one light-emitting stack includes at least a green emission layer, and one light-emitting stack includes at least a red emission layer. Unlike the embodiment, the light-emitting elements of Comparative Examples 1 and 2 do not include a light-emitting stack including a red emission layer.

[0272] The evaluation results of Examples 1 to 4 and Comparative Examples 1 and 2 are shown in Table 1 below. In the evaluation of the light-emitting element of Table 1, the driving voltage and the luminous efficiency indicate the voltage value and the luminous efficiency value corresponding to the brightness of 3,500 nits. The element service life is determined by measuring the time taken for the brightness of the light-emitting element to decrease to 97% of the initial brightness. The driving voltage, the luminous efficiency, and the element service life show relative comparison values ​​based on the driving voltage, the luminous efficiency, and the element service life of Comparative Example 2 being 100%.

[0273] [Table 1]

[0274]

[0275] Referring to the results of Table 1, it can be seen that the light-emitting elements of Examples 1 to 4 show similar or low driving voltages and similar or excellent luminous efficiency and element life characteristics compared to the light-emitting elements of Comparative Examples 1 and 2.

[0276] The light-emitting element of the embodiment may include a plurality of blue emission layers, at least one green emission layer and at least one red emission layer, and, for example, compared with the light-emitting stack including the green emission layer, the light-emitting stack including the red emission layer may be disposed adjacent to the first electrode so as to optimize the efficiency of forming white light, thereby improving the luminous efficiency and the service life of the element. Compared with the light-emitting elements of Comparative Examples 1 and 2 that include only blue emission layers and green emission layers in five stacks, the light-emitting element of the embodiment may include a red emission layer so as to uniformly emit red light, green light and blue light. Therefore, compared with the light-emitting elements of Comparative Examples 1 and 2, the luminous efficiency and the service life of the light-emitting elements of Examples 1 to 4 may be improved.

[0277] According to an embodiment of the present disclosure, in a light-emitting element including a plurality of light-emitting stacks connected in series, the luminous efficiency can be maximized by a plurality of blue emission layers, at least one green emission layer and at least one red emission layer, and thus the luminous efficiency and service life of the light-emitting element can be improved.

[0278] The above description is an example of the technical features of the present disclosure, and those skilled in the art to which the present disclosure belongs will be able to make various modifications and variations.Therefore, the embodiments of the present disclosure described above can be implemented individually or in combination with each other.

[0279] Therefore, the embodiments disclosed in the present disclosure are not intended to limit the technical spirit of the present disclosure, but to describe the technical spirit of the present disclosure, and the scope of the technical spirit of the present disclosure is not limited by these embodiments. The protection scope of the present disclosure should be interpreted by the claims, and should be interpreted as all technical spirits within the equivalent scope are included in the scope of the present disclosure.

Claims

1. A light emitting element, comprising: a first electrode; A first light emitting stack disposed on the first electrode; A second light-emitting stack disposed on the first light-emitting stack; a third light-emitting stack disposed on the second light-emitting stack; a fourth light-emitting stack disposed on the third light-emitting stack; A fifth light-emitting stack disposed on the fourth light-emitting stack; A second electrode disposed on the fifth light-emitting stack; and A charge generation layer is provided between adjacent stacks in the first to fifth light-emitting stacks, wherein Each of the first to fifth light-emitting stacks includes at least one emission layer, and The first to fifth light-emitting stacks include at least two blue emission layers, at least one green emission layer, and at least one red emission layer. 2 . The light-emitting element according to claim 1 , wherein the first to fifth light-emitting stacks include three blue emission layers, one or two green emission layers, and one or two red emission layers.

3. The light-emitting element according to claim 1, wherein The first light emitting stack comprises a first blue emitting layer, The second light emitting stack includes a second blue emitting layer, The third light emitting stack comprises a red emitting layer, The fourth light emitting stack includes a third blue emitting layer, and The fifth light emitting stack includes a green emission layer.

4. The light-emitting element according to claim 1, wherein The first light emitting stack comprises a first blue emitting layer, The second light emitting stack includes a second blue emitting layer, The third light emitting stack includes a first composite emission layer, The fourth light emitting stack includes a third blue emitting layer, The fifth light emitting stack includes a green emitting layer, and The first composite emission layer includes a red sub-emission layer and a green sub-emission layer disposed on the red sub-emission layer.

5. The light-emitting element according to claim 1, wherein The first light emitting stack includes a red emitting layer, The second light emitting stack comprises a first blue emitting layer, The third light emitting stack comprises a green emitting layer, The fourth light emitting stack includes a second blue emitting layer, and The fifth light emitting stack includes a third blue emission layer.

6. The light-emitting element according to claim 1, wherein The first light emitting stack comprises a first composite emission layer, The second light emitting stack comprises a first blue emitting layer, The third light emitting stack comprises a green emitting layer, The fourth light emitting stack includes a second blue emitting layer, The fifth light emitting stack includes a third blue emitting layer, and The first composite emission layer includes a red sub-emission layer and a green sub-emission layer disposed on the red sub-emission layer.

7. The light-emitting element according to claim 1, wherein The first to fifth light-emitting stacks include a first blue emission layer, a second blue emission layer and a third blue emission layer, Compared with the first blue emission layer and the second blue emission layer, the third blue emission layer is disposed adjacent to the second electrode. The distance from the top surface of the first electrode to the center of the third blue emission layer is the nth order resonance distance of the third blue emission layer, and n is an integer greater than or equal to 3.

8. The light-emitting element according to claim 1, wherein The first to fifth light-emitting stacks include a red emission layer, The distance from the top surface of the first electrode to the center of the red emission layer is the m-th order resonance distance of the red emission layer, and m is 1 or 2.

9. The light-emitting element according to claim 1, wherein At least one of the first to fifth light-emitting stacks includes a phosphorescent emission layer, and At least another one of the first to fifth light-emitting stacks includes a fluorescent emission layer.

10. A display panel, comprising: A light-emitting element, which is a light-emitting element according to any one of claims 1 to 9, wherein the light-emitting element emits source light; and The optical structure layer is disposed on the light emitting element and transmits the source light or converts the source light into light with a different wavelength.

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