Light emitting device and display panel including the same

Abstract

A light-emitting device and a display panel including the light-emitting device are provided. The light-emitting device includes a first electrode, a first stack on the first electrode, a first charge-generating layer on the first stack, a second stack on the first charge-generating layer, and a second electrode on the second stack. The first stack includes a first light-emitting layer and a plurality of first organic layers, and the second stack includes a second light-emitting layer and a plurality of second organic layers. In the plurality of first organic layers and the plurality of second organic layers, at least one of the organic layers adjacent to the first light-emitting layer and the second light-emitting layer includes a light-emitting material.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2019-0084612, filed on July 12, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] In this document, one or more aspects of embodiments of the present disclosure relate to a light-emitting device and a display panel including the light-emitting device. More specifically, aspects of the present disclosure relate to a light-emitting device that has improved luminous efficiency and device life by preventing (or reducing) damage to the organic layer, and a display panel including the light-emitting device. Background Technology

[0004] Organic light-emitting devices are self-emissive devices with short response times and driven by low voltage. Therefore, organic light-emitting displays that include organic light-emitting devices may not require a separate light source, and thus can be manufactured to be lightweight and thin, offering numerous advantages such as excellent brightness and / or no viewing angle dependence.

[0005] Organic light-emitting devices may include a light-emitting layer made of organic matter (organic material) located between an anode and a cathode. Holes provided from the anode and electrons provided from the cathode combine in the light-emitting layer to form excitons, and when the excitons transition from an excited state to a ground state, light corresponding to the energy between the holes and electrons is generated from the excitons.

[0006] A tandem organic light-emitting device has a structure comprising two or more stacks (e.g., constituted therein) of a hole injection layer / hole transport layer / light emission layer / electron transport layer / electron injection layer located between an anode and a cathode, and a charge generation layer that facilitates the generation and movement of charge exists between each stack. Summary of the Invention

[0007] One or more aspects of embodiments of this disclosure relate to a light-emitting device that has improved luminous efficiency and device life by preventing (or reducing) damage to organic layers adjacent to the light-emitting layer.

[0008] This disclosure also relates to a display device that has improved light conversion efficiency and thus improved total light efficiency by including a light-emitting device with improved luminous efficiency.

[0009] Embodiments of the present disclosure provide a light emitting device including a first electrode, a first stack on the first electrode, a first charge generation layer on the first stack, a second stack on the first charge generation layer, and a second electrode on the second stack. In embodiments, the first stack can include a first light emitting layer and a plurality of first organic layers, and the second stack can include a second light emitting layer and a plurality of second organic layers. In embodiments, at least one of the organic layers adjacent to the first light emitting layer and the second light emitting layer among the plurality of first organic layers and the plurality of second organic layers can include a light emitting material.

[0010] In embodiments, the first stack can include a first hole transport region between the first electrode and the first light emitting layer, and a first electron transport region between the first light emitting layer and the first charge generation layer. In embodiments, the second stack can include a second hole transport region between the first charge generation layer and the second light emitting layer, and a second electron transport region between the second light emitting layer and the second electrode. In embodiments, each of the first hole transport region, the first electron transport region, the second hole transport region, and the second electron transport region can include at least one organic layer. In embodiments, the organic layer adjacent to the first light emitting layer among the organic layers of the first hole transport region and the first electron transport region can include a light emitting material; and the organic layer adjacent to the second light emitting layer among the organic layers of the second hole transport region and the second electron transport region can include a light emitting material.

[0011] In embodiments, each of the first hole transport region and the second hole transport region can include at least one selected from a hole injection layer and a hole transport layer. In embodiments, each of the first electron transport region and the second electron transport region can include at least one selected from an electron injection layer and an electron transport layer. In embodiments, at least one layer adjacent to the first light emitting layer or the second light emitting layer among the hole injection layer, the hole transport layer, the electron injection layer, and the electron transport layer can include a light emitting material.

[0012] In embodiments, the first hole transport region can include a first hole injection layer and a first hole transport layer between the first hole injection layer and the first light emitting layer. In embodiments, the first electron transport region can include a first electron injection layer and a first electron transport layer between the first electron injection layer and the first light emitting layer. In embodiments, the second hole transport region can include a second hole injection layer and a second hole transport layer between the second hole injection layer and the second light emitting layer. In embodiments, the second electron transport region can include a second electron injection layer and a second electron transport layer between the second electron injection layer and the second light emitting layer. In embodiments, at least one selected from the first hole transport layer, the first electron transport layer, the second hole transport layer, and the second electron transport layer can include a light emitting material.

[0013] In an embodiment, the first hole transport zone can include a first hole injection layer, a first hole transport layer positioned between the first hole injection layer and the first light emitting layer, and a first electron blocking layer positioned between the first hole transport layer and the first light emitting layer. In an embodiment, the first electron transport zone can include a first electron injection layer, a first electron transport layer positioned between the first electron injection layer and the first light emitting layer, and a first hole blocking layer positioned between the first electron transport layer and the first light emitting layer. In an embodiment, the second hole transport zone can include a second hole injection layer, a second hole transport layer positioned between the second hole injection layer and the second light emitting layer, and a second electron blocking layer positioned between the second hole transport layer and the second light emitting layer. In an embodiment, the second electron transport zone can include a second electron injection layer, a second electron transport layer positioned between the second electron injection layer and the second light emitting layer, and a second hole blocking layer positioned between the second electron transport layer and the second light emitting layer. In an embodiment, at least one selected from the first electron blocking layer, the first hole blocking layer, the second electron blocking layer, and the second hole blocking layer can include a light emitting material.

[0014] In an embodiment, each of the first electron blocking layer, the first hole blocking layer, the second electron blocking layer, and the second hole blocking layer can include a light emitting material.

[0015] In an embodiment, the light emitting device can further include a second charge generation layer positioned on the second stack, and a third stack positioned on the second charge generation layer.

[0016] In an embodiment, the first light emitting layer and the second light emitting layer can generate blue light.

[0017] In an embodiment, the light emitting material can be a material capable of generating green light, red light, and / or orange light.

[0018] In an embodiment, the organic layer including the light emitting material can include a base substance and the light emitting material doped in the base substance.

[0019] In an embodiment, the base substance can have a lowest triplet excited energy level higher than a lowest triplet excited energy level of the light emitting material.

[0020] In an embodiment, the light emitting material can be a phosphorescent light emitting material.

[0021] In an embodiment, the first electrode can be a reflective electrode, and the second electrode can be a transmissive electrode or a semi-transmissive and semi-reflective electrode.

[0022] In an embodiment, the light emitting device can further include a capping layer positioned on the second electrode.

[0023] In embodiments of the disclosure, a light emitting device includes a first electrode, a hole transport region including at least one organic layer on the first electrode, a light emitting layer including a first light emitting material on the hole transport region, an electron transport region including at least one organic layer on the light emitting layer, and a second electrode on the electron transport region. In embodiments, an organic layer of the at least one organic layer selected from the hole transport region and the electron transport region that is in contact with the light emitting layer can include a second light emitting material different from the first light emitting material.

[0024] In embodiments, the hole transport region can include a hole injection layer, a hole transport layer between the hole injection layer and the light emitting layer, and an electron blocking layer between the hole transport layer and the light emitting layer. In embodiments, the electron transport region can include an electron injection layer, an electron transport layer between the electron injection layer and the light emitting layer, and a hole blocking layer between the electron transport layer and the light emitting layer, and the electron blocking layer and the hole blocking layer can include the second light emitting material.

[0025] In embodiments, a wavelength of light generated by the second light emitting material can be greater than a wavelength of light generated by the first light emitting material.

[0026] In embodiments, the organic layer including the second light emitting material can be formed of a base substance doped with the second light emitting material.

[0027] In embodiments, a charge generation layer, a second hole transport region, a second light emitting layer, and a second electron transport region can be sequentially stacked between the electron transport region and the second electrode. In embodiments, the second hole transport region and the second electron transport region can include at least one organic layer. In embodiments, a layer adjacent to the second light emitting layer can include a third light emitting material different from the first light emitting material.

[0028] In embodiments, the third light emitting material can be the same material as the second light emitting material.

[0029] In embodiments of the disclosure, a display panel includes a base substrate having a pixel area and a peripheral area adjacent to the pixel area, and a plurality of display elements on the base substrate to overlap the pixel area in a plane. In embodiments, each of the plurality of display elements can include a first electrode, a first stack on the first electrode, a first charge generation layer on the first stack, a second stack on the first charge generation layer, and a second electrode on the second stack. In embodiments, the first stack can include a first light emitting layer and at least one first organic layer, and the second stack can include a second light emitting layer and at least one second organic layer, and at least one of the first organic layer and the second organic layer selected to be adjacent to the first light emitting layer and the second light emitting layer can include a light emitting material.

[0030] In an embodiment, the display panel can further include a light control layer on the plurality of display elements and overlapping the pixel area in the plane.

[0031] In an embodiment, the plurality of display elements can generate first light, and the light control layer can include first light control units that transmit the first light, second light control units that convert the first light into second light, and third light control units that convert the first light into third light.

[0032] In an embodiment, the first light can be light having a wavelength range of 410 nm to 480 nm, the second light can be light having a wavelength range of 500 nm to 570 nm, and the third light can be light having a wavelength range of 625 nm to 675 nm.

[0033] In an embodiment, the light control layer can include a base resin and a luminophore dispersed in the base resin. BRIEF DESCRIPTION OF DRAWINGS

[0034] The accompanying drawings, which are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the present disclosure and together with the description serve to explain the principles of the present disclosure. In the drawings:

[0035] FIG. 1 is a cross-sectional view schematically illustrating a light emitting device according to an embodiment of the present disclosure;

[0036] FIG. 2 is a cross-sectional view schematically illustrating a light emitting device according to an embodiment of the present disclosure;

[0037] FIG. 3 is a cross-sectional view schematically illustrating a light emitting device according to an embodiment of the present disclosure;

[0038] FIG. 4 is a cross-sectional view schematically illustrating a light emitting device according to an embodiment of the present disclosure;

[0039] FIG. 5 is a cross-sectional view schematically illustrating a light emitting device according to an embodiment of the present disclosure;

[0040] FIG. 6A is a perspective view of a display panel according to an embodiment of the present disclosure;

[0041] FIG. 6B is a cross-sectional view of a display panel according to an embodiment of the present disclosure;

[0042] FIG. 7 is a plan view of a display panel according to an embodiment of the present disclosure;

[0043] FIG. 8is a plan view of a pixel region of a display panel according to an embodiment of the present disclosure;

[0044] FIG. 9 is a cross-sectional view of one pixel region of a display panel according to an embodiment of the present disclosure;

[0045] FIG. 10 is a cross-sectional view of a display panel according to an embodiment of the present disclosure;

[0046] FIG. 11 is a graph showing current efficiency according to (with respect to) luminance for each of the example and comparative examples;

[0047] FIG. 12 is a graph showing luminous intensity according to (with respect to) wavelength for each of the example and comparative examples; and

[0048] FIG. 13 is a graph showing luminance efficiency over time for the example and comparative examples. DETAILED DESCRIPTION

[0049] Hereinafter, embodiments of the present disclosure will be described in greater detail with reference to the accompanying drawings. The present disclosure can be modified in many alternative forms, and thus, specific embodiments will be illustrated in the drawings and described in greater detail. It should be understood, however, that the present disclosure is not intended to be limited to the particular forms disclosed, but is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

[0050] In describing each drawing, like reference numerals are used to refer to like elements. In the drawings, the sizes of elements can be exaggerated for the sake of clarity in the present disclosure. It should be understood that, although the terms "first", "second", etc. can 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. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments of the present disclosure. The singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0051] In the present disclosure, it should be understood that the term "comprise" or "have" is intended to indicate that there is existence of the features, numbers, steps, operations, elements, parts, or combinations thereof stated in the present disclosure, but does not exclude the existence or addition of one or more other features, numbers, steps, operations, elements, parts, or combinations thereof.

[0052] In the present disclosure, if a portion of, for example, a layer, a film, a region, or a plate is referred to as being on or above another portion, it includes not only the case where the portion is directly on the other portion, but also the case where a further portion is disposed between the portion and the other portion. Similarly, when a portion of, for example, a layer, a film, a region, or a plate is referred to as being below or under another portion, it includes not only the case where the portion is directly below the other portion, but also the case where a further portion is disposed between the portion and the other portion. Furthermore, in the present disclosure, "disposed on" includes not only the case of being disposed above, but also the case of being disposed below.

[0053] On the other hand, in the present disclosure, "direct contact" (when used in connection with two or more elements) means that no layer, film, region, plate, or the like is added between the two or more elements. For example, "direct contact" can mean that two layers or two members are disposed without another member, such as an adhesive member, being disposed therebetween.

[0054] Hereinafter, a light-emitting device and a display panel according to an embodiment of the present disclosure will be described with reference to the accompanying drawings.

[0055] FIG. 1 is a cross-sectional view schematically showing a light-emitting device according to an embodiment of the present disclosure.

[0056] Referring to FIG. 1 A light-emitting device LED according to an embodiment of the present disclosure includes a first electrode EL1, a first stack ST1 disposed on the first electrode EL1, and a second electrode EL2 disposed on the first stack ST1. The light-emitting device LED can be disposed on a base substrate.

[0057] In the light-emitting device LED according to the embodiment of the present disclosure, the first electrode EL1 corresponds to a reflective electrode. The first electrode EL1 can be, for example, an anode. When the first electrode EL1 is an anode, the first electrode EL1 can be formed of a metal having a high work function such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or the like, or can include a mixture thereof. In some embodiments, the first electrode EL1 can be a metal single layer including a metal such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or the like, or a mixture thereof; or, the first electrode EL1 can have a multilayer structure of a metal layer including a metal such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or the like, or a mixture thereof, and a transparent conductive oxide layer including a transparent conductive oxide. The transparent conductive oxide can include, for example, indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), or the like. In an embodiment, the first electrode EL1 can have a three-layer structure of ITO / Ag / ITO. However, embodiments of the present disclosure are not limited thereto.

[0058] The first electrode EL1 can be, for example, a cathode. When the first electrode EL1 is a cathode, the first electrode EL1 can include a lanthanide metal or compound having a low work function such as Li, Ca, LiF / Ca, LiF / Al, Al, Mg, BaF, Ba, Ag, Yb, or the like, or a mixture thereof. In an embodiment, the first electrode EL1 can be Ag / Mg or Ag / Yb, but embodiments of the present disclosure are not limited thereto. The first electrode EL1 can be formed to be thick enough to reflect light.

[0059] In the light-emitting device LED according to the embodiment of the present disclosure, the second electrode EL2 can correspond to a transmissive electrode or a semi-transmissive and semi-reflective electrode. The second electrode EL2 can be, for example, a cathode. When the second electrode EL2 is a cathode, the second electrode EL2 can include a lanthanide metal or compound having a low work function such as Li, Ca, LiF / Ca, LiF / Al, Al, Mg, BaF, Ba, Ag, Yb, or the like, or a mixture thereof. In an embodiment, the second electrode EL2 can be Ag / Mg or Ag / Yb, but embodiments of the present disclosure are not limited thereto. The second electrode EL2 can be formed to be thin enough to transmit light.

[0060] The second electrode EL2 may, for example, be an anode. The second electrode EL2 can include a transparent conductive oxide having a high work function. For example, the second electrode EL2 can include indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), or the like. In an embodiment, the second electrode EL2 can have a three-layer structure of ITO / Ag / ITO. However, embodiments of the disclosure are not limited thereto.

[0061] The light emitting device LED according to an embodiment of the disclosure can be a top emission type light emitting device. In this case, the first electrode EL1 can be an anode, and the second electrode EL2 can be a cathode. The light emitting device LED according to another embodiment of the disclosure can be a bottom emission type light emitting device. In this case, the first electrode EL1 can be a cathode, and the second electrode EL2 can be an anode. In the light emitting device LED according to an embodiment of the disclosure, the first electrode EL1 can be a reflective electrode, and the second electrode EL2 can be a transmissive electrode or a semi-transmissive and semi-reflective electrode, such that the light emitting device LED emits light in a direction from the first electrode EL1 to the second electrode EL2. Hereinafter, a case in which the light emitting device LED is a top emission type light emitting device will be described.

[0062] The first stack ST1 can include a hole transport region HTR, a light emitting layer EML1 disposed (positioned) on the hole transport region HTR, and an electron transport region ETR disposed on the light emitting layer EML1. The hole transport region HTR can include at least one of organic layers HTR-OL1 and HTR-OL2. The hole transport region HTR can have a multi-layer structure having a plurality of layers each formed of a plurality of different materials. FIG. 1 The hole transport region HTR of the first stack ST1 is illustrated as including a plurality of organic layers HTR-OL1 and HTR-OL2, but embodiments of the disclosure are not limited thereto. The hole transport region HTR can include one organic layer.

[0063] The electron transport region ETR can include at least one of organic layers ETR-OL1 and ETR-OL2. The electron transport region ETR can have a multi-layer structure having a plurality of layers each formed of a plurality of different materials. FIG. 1 The electron transport region ETR of the first stack ST1 is illustrated as including a plurality of organic layers ETR-OL1 and ETR-OL2, but embodiments of the disclosure are not limited thereto. The electron transport region ETR can include one organic layer.

[0064] The light emitting layer EML1 can have a thickness of about 1 nm to about 50 nm. to about 50 nm. or about 50 nm. to about 50 nm. The thickness of the light-emitting layer EML1 can be determined based on the combination of the host material and the dopant material, the type of the quantum dot material, and the size of the core, etc. In an embodiment, the light-emitting layer EML1 can generate blue light, and the blue light can be light having a wavelength of 410 nm to 480 nm. The light emission spectrum of the blue light can have a maximum peak within 440 nm to 460 nm.

[0065] The color of light emitted from the light-emitting layer EML1 can be determined based on the combination of the host material and the dopant material, the type of the quantum dot material, and the size of the core, etc. In an embodiment, the light-emitting layer EML1 can generate blue light, and the blue light can be light having a wavelength of 410 nm to 480 nm. The light emission spectrum of the blue light can have a maximum peak within 440 nm to 460 nm.

[0066] As the host material of the light-emitting layer EML1, any suitable material can be used, and although not particularly limited, the host material can be selected from fluoranthene derivatives, pyrene derivatives, arylacetylene derivatives, anthracene derivatives, fluorene derivatives, perylene derivatives, cyclotriveratyl derivatives, etc. In some embodiments, a pyrene derivative, a perylene derivative, and / or an anthracene derivative can be selected.

[0067] As the dopant material of the light-emitting layer EML1, any suitable material can be used, and although not particularly limited, the dopant material can 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), and / or N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalen-2-yl)vinyl)phenyl)-N-phenylbenzenemethanamine (N-BDAVBi)), perylene and / or derivatives thereof (e.g., 2,5,8,8,11-tetra-tert-butylperylene (TBP)), pyrene and / or derivatives thereof (e.g., 1,1-dipyrene, 1,4-dipyrenylbenzene, 1,4-bis(N,N-diphenylamino)pyrene, and / or N1,N6-di(naphthalen-2-yl)-N1,N6-diphenylpyrene-1,6-diamine, etc.

[0068] At least one of the organic layers HTR-OL2 and ETR-OL2 adjacent to the light-emitting layer EML1 among the plurality of organic layers included in the hole transport zone HTR and the electron transport zone ETR includes a light-emitting material. In an embodiment, at least one of the adjacent organic layers HTR-OL2 and ETR-OL2 can be (e.g., can include) a host doped with a light-emitting dopant. The host can have a lowermost triplet excited energy level (T1) higher than that of the light-emitting material.

[0069] The light-emitting material included in the adjacent organic layer HTR-OL2 and / or ETR-OL2 can be a different material from the light-emitting dopant included in the light-emitting layer EML1. In an embodiment, the light-emitting layer EML1 includes a first light-emitting material, and the adjacent organic layer HTR-OL2 and / or ETR-OL2 can include a second light-emitting material. In an embodiment, the second light-emitting material can be a material that generates light of a longer wavelength when compared to the first light-emitting material. In an embodiment, the first light-emitting material can be a material that generates blue light, and the second light-emitting material can be a material that generates green light, red light, or orange light.

[0070] The light-emitting material included in the adjacent organic layer HTR-OL2 and / or ETR-OL2 can be a phosphorescent light-emitting dopant. The light-emitting material included in the adjacent organic layer HTR-OL2 and / or ETR-OL2 can be a phosphorescent light-emitting material that generates green light. For example, the light-emitting material can include an organometallic complex, such as iridium(ppy3) (tris[2-phenylpyridine]iridium(III)).

[0071] The light-emitting device according to an embodiment of the disclosure can include a light-emitting material in an organic layer adjacent to a light-emitting layer. For example, the light-emitting device according to an embodiment can include a light-emitting material in a light-emitting layer, and can further include a different light-emitting material in an organic layer formed in contact with the light-emitting layer. Accordingly, the host material of the organic layer is prevented (or protected) from being deteriorated and damaged due to the leakage of holes, electrons, etc. into the organic layer adjacent to the light-emitting layer, and instead of the host material being deteriorated, the leaked excitons can generate light through the light-emitting material of the adjacent organic layer. Accordingly, the durability of the light-emitting device including the organic layer can be improved, so that the device lifetime can be improved, and additional light emission due to the leakage current can be performed, so that the light-emitting efficiency can be improved.

[0072] FIG. 2 is a cross-sectional view schematically illustrating a light-emitting device according to an embodiment of the disclosure. Hereinafter, in describing the light-emitting device of the embodiment of FIG. 2 , the same reference numerals are given to the above-described components, and the description thereof is omitted.

[0073] Reference is made to FIG. 2The light emitting device LED according to an embodiment of the disclosure can include a first stack ST1 and a second stack ST2. Between the first stack ST1 and the second stack ST2, a first charge generation layer CGL1 can be disposed.

[0074] The first and second light emitting layers EML1 and EML2 can include, but are not limited to, the light emitting materials described above. Each of the first and second light emitting layers EML1 and EML2 can generate blue light, and the blue light can be light having a wavelength of 410 nm to 480 nm. The light emission spectrum of the blue light can have a maximum peak within 440 nm to 460 nm.

[0075] The first stack ST1 can include a first light emitting layer EML1 for emitting light, a first hole transport region HTR1 for transporting a hole provided from a first electrode EL1 to the first light emitting layer EML1, and a first electron transport region ETR1 for transporting an electron generated from a first charge generation layer CGL1 to the first light emitting layer EML1. FIG. 2 The first hole transport region HTR1 is illustrated as including a first hole injection layer HIL1 and a first hole transport layer HTL1, but embodiments of the disclosure are not limited thereto. Any one of the first hole transport layer HTL1 and the first hole injection layer HIL1 can be omitted. In an embodiment, the first hole transport region HTR1 can include only the first hole injection layer HIL1, and the first hole injection layer HIL1 can be in contact with the first light emitting layer EML1. The first electron transport region ETR1 is illustrated as including a first electron injection layer EIL1 and a first electron transport layer ETL1, but embodiments of the disclosure are not limited thereto. Any one of the first electron injection layer EIL1 and the first electron transport layer ETL1 can be omitted. In an embodiment, the first electron transport region ETR1 can include only the first electron transport layer ETL1, and the first electron transport layer ETL1 can be in contact with the first light emitting layer EML1 and the first charge generation layer CGL1. The first electron transport layer ETL1 can be provided as a plurality.

[0076] The second stack ST2 can include a second light emitting layer EML2 for emitting light, a second hole transport region HTR2 for transporting a hole provided from the first charge generation layer CGL1 to the second light emitting layer EML2, and a second electron transport region ETR2 for transporting an electron generated from a second electrode EL2 to the second light emitting layer EML2. FIG. 2A second hole transport zone HTR2 is shown to include a second hole injection layer HIL2 and a second hole transport layer HTL2, but embodiments of the present disclosure are not limited thereto. Either of the second hole transport layer HTL2 and the second hole injection layer HIL2 can be omitted. In embodiments, the second hole transport zone HTR2 can include only the second hole injection layer HIL2, and the second hole injection layer HIL2 can be in contact with the second emission layer EML2. A second electron transport zone ETR2 is shown to include a second electron injection layer EIL2 and a second electron transport layer ETL2, but embodiments of the present disclosure are not limited thereto. Either of the second electron injection layer EIL2 and the second electron transport layer ETL2 can be omitted. In embodiments, the second electron transport zone ETR2 can include only the second electron transport layer ETL2, and the second electron transport layer ETL2 can be in contact with the second emission layer EML2. The second electron transport layer ETL2 can be provided as a plurality.

[0077] Each layer of the first hole transport zone HTR1 and the second hole transport zone HTR2 can be formed using any suitable method. For example, the first hole transport zone HTR1 and the second hole transport zone HTR2 can be formed by one or more suitable methods, such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) method, inkjet printing, laser printing, and / or laser induced thermal imaging (LITI) method.

[0078] The first hole injection layer HIL1 and the second hole injection layer HIL2 can include a hole injection material. The hole injection material can include a phthalocyanine compound (e.g., copper phthalocyanine), N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolylamino)-phenyl]-biphenyl-4,4'-diamine (DNTPD), 4,4',4"-[tris(3-methylphenyl)phenylamino]triphenylamine (m-MTDATA), 4,4',4"-tris(N,N-diphenylamino)triphenylamine (TDATA), 4,4',4"-tris{N-(2-naphthyl)-N-phenylamino}-triphenylamine (2-TNATA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / dodecylbenzenesulfonic acid (PANI / DBSA), polyaniline / camphorsulfonic acid (PANI / CSA), polyaniline / poly(4-styrenesulfonate) (PANI / PSS), N,N'-di(naphthalen-1-yl)-N,N'-diphenylbenzidine (NPB), N,N'-di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (NPD), triphenylamine-containing polyether ketone (TPAPEK), 4-isopropyl-4'-methyl diphenyl iodide [tetrakis(pentafluorophenyl)borate], bisquinoxaline[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexanitrile (HAT-CN), or the like.

[0079] The first hole transport layer HTL1 and the second hole transport layer HTL2 can each independently include a hole transport material. The hole transport material can include carbazolyl derivatives (e.g., N-phenylcarbazole and / or polyvinylcarbazole), fluorenyl derivatives, triphenylamine-based derivatives (e.g., N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD) and / or 4,4',4"-tris(N-carbazolyl)triphenylamine (TCTA)), N,N'-di(naphthalen-1-yl)-N,N'-dibenzylidene-aniline (NPB), 4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl)benzenamine] (TAPC), 4,4'-bis[N,N'-(3-methylphenyl)amino]-3,3'-dimethylbiphenyl (HMTPD), 1,3-bis(N-carbazolyl)benzene (mCP), 9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole (CzSi), or the like.

[0080] The thickness of each of the first hole transport region HTR1 and the second hole transport region HTR2 can be about 1 nm to about 100 nm, about 1 nm to about 50 nm, about 1 nm to about 20 nm, about 1 nm to about 10 nm, about 1 nm to about 5 nm, about 1 nm to about 2 nm, about 2 nm to about 100 nm, about 2 nm to about 50 nm, about 2 nm to about 20 nm, about 2 nm to about 10 nm, about 2 nm to about 5 nm, about 5 nm to about 100 nm, about 5 nm to about 50 nm, about 5 nm to about 20 nm, about 5 nm to about 10 nm, about 10 nm to about 100 nm, about 10 nm to about 50 nm, about 10 nm to about 20 nm, about 20 nm to about 100 nm, about 20 nm to about 50 nm, about 50 nm to about 100 nm, about 100 nm, or the like. about 100 nm, about 10 nm to about 100 nm, about 10 nm to about 50 nm, about 10 nm to about 20 nm, about 20 nm to about 100 nm, about 20 nm to about 50 nm, about 50 nm to about 100 nm, about 100 nm, or the like. about 100 nm, about 10 nm to about 100 nm, about 10 nm to about 50 nm, about 10 nm to about 20 nm, about 20 nm to about 100 nm, about 20 nm to about 50 nm, about 50 nm to about 100 nm, about 100 nm, or the like. about 100 nm, about 10 nm to about 100 nm, about 10 nm to about 50 nm, about 10 nm to about 20 nm, about 20 nm to about 100 nm, about 20 nm to about 50 nm, about 50 nm to about 100 nm, about 100 nm, or the like. The thickness of the hole injection layers HIL1 and HIL2 may, for example, be about 1 nm to about 100 nm, about 1 nm to about 50 nm, about 1 nm to about 20 nm, about 1 nm to about 10 nm, about 1 nm to about 5 nm, about 1 nm to about 2 nm, about 2 nm to about 100 nm, about 2 nm to about 50 nm, about 2 nm to about 20 nm, about 2 nm to about 10 nm, about 2 nm to about 5 nm, about 5 nm to about 100 nm, about 5 nm to about 50 nm, about 5 nm to about 20 nm, about 5 nm to about 10 nm, about 10 nm to about 100 nm, about 10 nm to about 50 nm, about 10 nm to about 20 nm, about 20 nm to about 100 nm, about 20 nm to about 50 nm, about 50 nm to about 100 nm, about 100 nm, or the like. to about and the thicknesses of the hole transport layers HTL1 and HTL2 can be about to about When the thicknesses of the hole transport region HTR, the hole injection layers HIL1 and HIL2, and the hole transport layers HTL1 and HTL2 satisfy any one of the above ranges, satisfactory (or suitable) hole transport characteristics can be obtained without a significant increase in driving voltage.

[0081] In addition to the above-described materials, the first hole transport region HTR1 and the second hole transport region HTR2 can further include a charge generation material to improve conductivity. The charge generation material can be uniformly or non-uniformly dispersed in the first hole transport region HTR1 and the second hole transport region HTR2. The charge generation material can be, for example, a p-type dopant. The p-type dopant can be one of a quinone derivative, a metal oxide, and a compound containing a cyano group, but embodiments of the present disclosure are not limited thereto. Non-limiting examples of the p-type dopant can include a quinone derivative (e.g., tetracyanoquinodimethane (TCNQ) and / or 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinodimethane (F4-TCNQ)), a metal oxide (e.g., tungsten oxide and / or molybdenum oxide), etc., but embodiments of the present disclosure are not limited thereto.

[0082] Each layer of the first electron transport region ETR1 and the second electron transport region ETR2 can be formed using any suitable method. For example, the first electron transport region ETR1 and the second electron transport region ETR2 can each independently be formed by one or more suitable methods, such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) method, inkjet printing, laser printing, and / or laser-induced thermal imaging (LITI) method.

[0083] The first electron injection layer EIL1 and the second electron injection layer EIL2 can include an electron injection material. A halogenated metal (e.g., LiF, NaCl, CsF, RbCl, RbI, and / or Cul), a lanthanide metal (e.g., Yb), a metal oxide (e.g., Li2O and / or BaO), lithium quinolinolate (LiQ), etc. can be used as the electron injection material, but embodiments of the present disclosure are not limited thereto. The first electron injection layer EIL1 and the second electron injection layer EIL2 can each independently consist of a mixture of the electron injection material and an insulating organic metal salt. The organic metal salt can be a material having an energy band gap of about 4 eV or more. For example, the organic metal salt can include a metal acetate, a metal benzoate, a metal acetoacetate, a metal acetylacetoneate, and / or a metal stearate. The thickness of each of the first electron injection layer EIL1 and the second electron injection layer EIL2 can be about to about or about to approximately When the thicknesses of the first electron injection layer EIL1 and the second electron injection layer EIL2 meet any of the above ranges, satisfactory (or suitable) electron injection characteristics can be obtained without significantly increasing the driving voltage.

[0084] The first electron transport layer ETL1 and the second electron transport layer ETL2 may each independently include an electron transport material. The electron transport material may include anthracene-based compounds. However, the embodiments disclosed herein are not limited thereto. Electron transport materials can be, for example, tris(8-hydroxyquinoline)aluminum (Alq3), 1,3,5-tris[(3-pyridyl)-phenyl-3-yl]benzene, 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzimidazol-1-ylphenyl)-9,10-dinaphthylanthracene, 1,3,5-tris(1-phenyl-1H-benzimidazol-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-(naphthyl-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (tBu-PBD), bis(2-methyl-8-quinolinyl-N1,O8)-(1,1'-biphenyl-4-olyl)aluminum (BAlq), beryllium (benzoquinoline-10-ol) (BeBq2), 9,10-di(naphthyl-2-yl)anthracene (ADN), diphenyl(4-(triphenylsilyl)phenyl)phosphine oxide (TSPO1), and any mixture thereof. The thickness of each of the first electron transport layer ETL1 and the second electron transport layer ETL2 can be approximately to approximately For example, about to approximately When the thicknesses of the first electron transport layer ETL1 and the second electron transport layer ETL2 meet any of the above ranges, satisfactory (or suitable) electron injection characteristics can be obtained without significantly increasing the driving voltage.

[0085] In the light emitting device LED according to the embodiments, a layer adjacent to each of the first and second light emitting layers EML1 and EML2 can include a light emitting material. In some embodiments, at least one of the first hole transport layer HTL1, the first electron transport layer ETL1, the second hole transport layer HTL2, and the second electron transport layer ETL2 adjacent to either of the first and second light emitting layers EML1 and EML2 can include a light emitting material. In embodiments, all of the first hole transport layer HTL1, the first electron transport layer ETL1, the second hole transport layer HTL2, and the second electron transport layer ETL2 adjacent to either of the first and second light emitting layers EML1 and EML2 can include a light emitting material. The light emitting material included in the first hole transport layer HTL1, the first electron transport layer ETL1, the second hole transport layer HTL2, and the second electron transport layer ETL2 can all be the same material.

[0086] Each of the first hole transport layer HTL1, the first electron transport layer ETL1, the second hole transport layer HTL2, and the second electron transport layer ETL2 can include a hole transport material or an electron transport material as a base substance, and can be doped with a light emitting material. For example, each of the first hole transport layer HTL1, the first electron transport layer ETL1, the second hole transport layer HTL2, and the second electron transport layer ETL2 can include a hole transport material or an electron transport material as a base substance, and can be doped with a phosphorescent light emitting dopant. The light emitting material included in each of the first hole transport layer HTL1, the first electron transport layer ETL1, the second hole transport layer HTL2, and the second electron transport layer ETL2 can be doped to less than 10% of the total mass of each layer. The light emitting material doped in each of the first hole transport layer HTL1, the first electron transport layer ETL1, the second hole transport layer HTL2, and the second electron transport layer ETL2 can be a material having a lowermost triplet excitation energy level (T1) lower than that of the hole transport material or the electron transport material of the base substance forming the corresponding layer.

[0087] Between the first and second stacks ST1 and ST2, a first charge generation layer CGL1 can be provided. When a voltage is applied, the first charge generation layer CGL1 can generate charges (electrons and holes) by forming a complex through an oxidation-reduction reaction. Then, the first charge generation layer CGL1 can provide the generated charges to each of the adjacent stacks ST1 and ST2. The first charge generation layer CGL1 can double the efficiency of the current generated in one stack ST1 or ST2, and can be used to control the charge balance between the first and second stacks ST1 and ST2.

[0088] The first charge generation layer CGL1 can have a layered structure in which the first sub charge generation layer CGL1-1 and the second sub charge generation layer CGL1-2 are combined with each other. As an example, the first sub charge generation layer CGL1-1 can be an n-type charge generation layer, which can provide electrons to the first stack ST1 by being disposed adjacent to the first stack ST1. The second sub charge generation layer CGL1-2 can be a p-type charge generation layer, which can provide holes to the second stack ST2 by being disposed adjacent to the second stack ST2. Between the first sub charge generation layer CGL1-1 and the second sub charge generation layer CGL1-2, a buffer layer can be further disposed.

[0089] FIG. 3 is a cross-sectional view schematically illustrating a light emitting device according to an embodiment of the disclosure. Hereinafter, in describing the light emitting device of the embodiment, the same reference numerals are given to the above-described components, and a repeated description thereof will not be provided. FIG. 3

[0090] Referring to FIG. 3 , the light emitting device LED-1 according to the embodiment of the disclosure can further include a third stack ST3 disposed on the first stack ST1 and the second stack ST2. Between the second stack ST2 and the third stack ST3, a second charge generation layer CGL2 can be disposed. The third stack ST3 can be disposed between the second charge generation layer CGL2 and the second electrode EL2.

[0091] The third stack ST3 can have a stack structure similar to the first stack ST1 and the second stack ST2. For example, the third stack ST3 can be a stack in which a third hole transport region HTR3, a third light emitting layer EML3, and a third electron transport region ETR3 are sequentially stacked.

[0092] The third light emitting layer EML3 can include the above-described light emitting material, but is not limited thereto. The third light emitting layer EML3 can generate blue light, and the blue light can be light having a wavelength of 410 nm to 480 nm. The light emission spectrum of the blue light can have a maximum peak within 440 nm to 460 nm.

[0093] The third hole transport region HTR3 can include a third hole injection layer HIL3 and a third hole transport layer HTL3. The third electron transport region ETR3 can include a third electron injection layer EIL3 and a third electron transport layer ETL3. The third hole transport region HTR3 can include the above-described hole injection material and hole transport material. The third electron transport region ETR3 can include the above-described electron injection material and electron transport material.

[0094] FIG. 3 ​A third hole transport region HTR3 including a third hole injection layer HIL3 and a third hole transport layer HTL3 is illustrated, but embodiments of the present disclosure are not limited thereto. Any one of the third hole transport layer HTL3 and the third hole injection layer HIL3 can be omitted. In an embodiment, the third hole transport region HTR3 can include only the third hole injection layer HIL3, and the third hole injection layer HIL3 can be a layer adjacent to the third emission layer EML3.

[0095] FIG. 3 A third electron transport region ETR3 including a third electron injection layer EIL3 and a third electron transport layer ETL3 is illustrated, but embodiments of the present disclosure are not limited thereto. Any one of the third electron injection layer EIL3 and the third electron transport layer ETL3 can be omitted. In an embodiment, the third electron transport region ETR3 can include only the third electron transport layer ETL3, and the third electron transport layer ETL3 can be a layer adjacent to the third emission layer EML3. The third electron transport layer ETL3 can be provided as a plurality.

[0096] In the light emitting device LED-1 according to an embodiment, a layer adjacent to the third emission layer EML3 can include an emission material. For example, in the third hole transport region HTR3 and the third electron transport region ETR3, a layer adjacent to the third emission layer EML3 can include an emission material. In an embodiment, at least one of the third hole transport layer HTL3 and the third electron transport layer ETL3 adjacent to the third emission layer EML3 can include an emission material. In an embodiment, each of the third hole transport layer HTL3 and the third electron transport layer ETL3 can include an emission material. In an embodiment, all of the first hole transport layer HTL1, the first electron transport layer ETL1, the second hole transport layer HTL2, the second electron transport layer ETL2, the third hole transport layer HTL3, and the third electron transport layer ETL3 can include an emission material. The emission material included in each of the third hole transport layer HTL3 and the third electron transport layer ETL3 can be the same material. The emission material included in each of the third hole transport layer HTL3 and the third electron transport layer ETL3 can be different from the emission material included in the third emission layer EML3.

[0097] Each of the third hole transport layer HTL3 and the third electron transport layer ETL3 can include a hole transport material or an electron transport material as a base substance, respectively, and can be doped with a light emitting material. For example, each of the third hole transport layer HTL3 and the third electron transport layer ETL3 can include a hole transport material or an electron transport material as a base substance, respectively, and can be doped with a phosphorescent light emitting dopant. The light emitting material included in each of the third hole transport layer HTL3 and the third electron transport layer ETL3 can be doped to less than 10% of the total mass of each layer. The light emitting material doped in each of the third hole transport layer HTL3 and the third electron transport layer ETL3 can be a material having a lowermost triplet excitation energy level (T1) lower than that of the hole transport material or the electron transport material of the base substance forming the corresponding layer.

[0098] Between the second stack ST2 and the third stack ST3, a second charge generation layer CGL2 can be provided. When a voltage is applied, the second charge generation layer CGL2 can generate charges (electrons and holes) by forming a complex through an oxidation-reduction reaction. Then, the second charge generation layer CGL2 can provide the generated charges to each of the adjacent stacks ST2 and ST3. The second charge generation layer CGL2 can double the efficiency of generating a current in one stack ST2 or ST3, and can be used to control the charge balance between the second stack ST2 and the third stack ST3.

[0099] The second charge generation layer CGL2 can have a layered structure in which a first sub charge generation layer CGL2-1 and a second sub charge generation layer CGL2-2 are combined with each other. As an example, the first sub charge generation layer CGL2-1 can be an n-type charge generation layer that provides electrons to the second stack ST2 by being disposed adjacent to the second stack ST2. The second sub charge generation layer CGL2-2 can be a p-type charge generation layer that provides holes to the third stack ST3 by being disposed adjacent to the third stack ST3. Between the first sub charge generation layer CGL2-1 and the second sub charge generation layer CGL2-2, a buffer layer can be further disposed.

[0100] FIG. 4 is a cross-sectional view schematically illustrating a light emitting device according to an embodiment of the disclosure. Hereinafter, in describing the light emitting device of the embodiment, the same reference numerals are given to the above-described components, and a repetitive description thereof will not be provided. FIG. 4 In describing the light emitting device of the embodiment, the same reference numerals are given to the above-described components, and a repetitive description thereof will not be provided.

[0101] Referring to FIG. 4In the light emitting device LED-2 according to the embodiment, the first hole transport region HTR1 can further include a first electron blocking layer EBL1 disposed between the first light emitting layer EML1 and the first hole transport layer HTL1. The first electron transport region ETR1 can further include a first hole blocking layer HBL1 disposed between the first light emitting layer EML1 and the first electron transport layer ETL1. The second hole transport region HTR2 can further include a second electron blocking layer EBL2 disposed between the second light emitting layer EML2 and the second hole transport layer HTL2. The second electron transport region ETR2 can further include a second hole blocking layer HBL2 disposed between the second light emitting layer EML2 and the second electron transport layer ETL2. The third hole transport region HTR3 can further include a third electron blocking layer EBL3 disposed between the third light emitting layer EML3 and the third hole transport layer HTL3. The third electron transport region ETR3 can further include a third hole blocking layer HBL3 disposed between the third light emitting layer EML3 and the third electron transport layer ETL3.

[0102] The electron blocking layer is a layer for preventing or reducing leakage of electrons from the electron transport region to the hole transport region. The thickness of the electron blocking layer can be about 1 nm to about 10 nm, but embodiments of the present disclosure are not limited thereto. to about 10 nm The electron blocking layer can include, for example, carbazolyl derivatives (e.g., N-phenylcarbazole and / or polyvinylcarbazole), fluorenyl derivatives, triphenylamine-based derivatives (e.g., N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine (TPD) and / or 4,4',4"-tris(N-carbazolyl)triphenylamine (TCTA)), N,N'-di(naphthalen-1-yl)-N,N'-dimalenyl-biphenylamine (NPD), 4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl)benzenamine] (TAPC), 4,4'-bis[N,N'-(3-methylphenyl)amino]-3,3'-dimethylbiphenyl (HMTPD), mCP, etc.

[0103] The hole blocking layer is a layer for preventing or reducing leakage of holes from the hole transport region to the electron transport region. The thickness of the hole blocking layer can be about 1 nm to about 10 nm, but embodiments of the present disclosure are not limited thereto. to about 10 nm The hole blocking layer can include, for example, at least one of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), and 2,4,6-tris([1,1'-biphenyl]-3-yl)-1,3,5-triazine (T2T), but embodiments of the present disclosure are not limited thereto.

[0104] In the light-emitting device LED-2 according to the embodiment, the layers adjacent to the first to third light-emitting layers EML1, EML2, and EML3 are the first to third electron-blocking layers EBL1, EBL2, and EBL3 and the first to third hole-blocking layers HBL1, HBL2, and HBL3, and at least one of the first to third electron-blocking layers EBL1, EBL2, and EBL3 and the first to third hole-blocking layers HBL1, HBL2, and HBL3 can include a light-emitting material. In the embodiment, each of the first to third electron-blocking layers EBL1, EBL2, and EBL3 and the first to third hole-blocking layers HBL1, HBL2, and HBL3 can include a light-emitting material. The light-emitting material included in each of the first to third electron-blocking layers EBL1, EBL2, and EBL3 and the first to third hole-blocking layers HBL1, HBL2, and HBL3 can be the same material. The light-emitting material included in each of the first to third electron-blocking layers EBL1, EBL2, and EBL3 and the first to third hole-blocking layers HBL1, HBL2, and HBL3 can be different from the light-emitting material included in the first to third light-emitting layers EML1, EML2, and EML3.

[0105] FIG. 5 is a cross-sectional view schematically illustrating a light-emitting device according to an embodiment of the disclosure. Hereinafter, in describing the light-emitting device of the embodiment, the same reference numerals are given to the above-described components, and a repeated description thereof will not be provided. FIG. 5 is a cross-sectional view schematically illustrating a light-emitting device according to an embodiment of the disclosure. Hereinafter, in describing the light-emitting device of the embodiment, the same reference numerals are given to the above-described components, and a repeated description thereof will not be provided.

[0106] The light-emitting device LED-3 according to the embodiment can further include a capping layer CPL disposed on the second electrode EL2. The capping layer CPL can include, for example, α-NPD, NPB, TPD, m-MTDATA, Alq3, CuPc, N4,N4,N4',N4'-Tetrakis(3-phenyl-4-yl)phenyl-4,4'-diamine (TPD15), 4,4',4"-tris(N-carbazolyl)triphenylamine, N,N'-bis(naphthalen-1-yl) (TCTA), or the like. The capping layer CPL serves to help light emitted from the light-emitting layers EML1 and EML2 of the light-emitting device LED-3 to be efficiently (or properly) emitted to the outside of the light-emitting device LED-3. When the light-emitting device LED-3 of the embodiment further includes a thin film encapsulation layer, the capping layer CPL can be disposed between the second electrode EL2 and the thin film encapsulation layer.

[0107] FIG. 6A is a perspective view of a display panel according to an embodiment of the present invention. FIG. 6B is a cross-sectional view of a display panel according to an embodiment of the present invention. FIG. 7 is a plan view of a display panel according to an embodiment of the present disclosure.

[0108] Referring to FIGS. 6A-7The display panel DP can be any of the following: liquid crystal display panel, electrophoretic display panel, microelectromechanical system display panel (MEMS), electrowetting display panel, organic light-emitting display panel, micro LED display panel, quantum dot display panel, and quantum rod display panel, but the embodiments disclosed herein are not limited thereto.

[0109] The display panel DP may also include housing components and / or molded components, and may also include a backlight unit depending on the type (variety) of the display panel DP.

[0110] The display panel DP may include a lower display substrate 100 (or a first display substrate) and an upper display substrate 200 (or a second display substrate) facing and spaced apart from the lower display substrate 100. A filler layer BFL may be filled between the lower display substrate 100 and the upper display substrate 200. Furthermore, in the display panel DP according to the embodiment, the filler layer BFL may be omitted, and a predetermined or defined cell gap may be defined between the lower display substrate 100 and the upper display substrate 200.

[0111] In the display panel DP according to an embodiment, the non-display area NDA may include a sealant SLM that bonds the lower display substrate 100 and the upper display substrate 200. The sealant SLM may include organic adhesive components and / or inorganic adhesive components. For example, the sealant SLM may include glass frit.

[0112] like FIG. 6A As shown, the display panel DP can display an image through the display surface DP-IS. The display surface DP-IS is parallel to the plane defined by the first direction DR1 and the second direction DR2. The display surface DP-IS may include a display area DA and a non-display area NDA. Pixels PX are provided in the display area DA. The non-display area NDA is defined along the edge of the display surface DP-IS. The display area DA may be surrounded by the non-display area NDA.

[0113] The normal direction of the display surface DP-IS (i.e., the thickness direction of the display panel DP) is represented by the third direction DR3. The front (or upper) and rear (or lower) surfaces of each layer or unit described below are positioned along the third direction DR3 and are separated by the third direction DR3. However, the first to third directions DR1, DR2, and DR3 shown in this embodiment are merely exemplary (examples).

[0114] In embodiments of this disclosure, a display panel DP with a flat display surface DP-IS is shown; however, embodiments of this disclosure are not limited thereto. The display panel DP may include a curved display surface and / or a three-dimensional display surface. The three-dimensional display surface may include multiple display areas indicating different orientations.

[0115] FIG. 7 The planar arrangement relationship of the signal lines GL1 to GLn and DL1 to DLm and the pixels PX11 to PXnm is shown. The signal lines GL1 to GLn and DL1 to DLm can include a plurality of gate lines GL1 to GLn and a plurality of data lines DL1 to DLm.

[0116] Each of the pixels PX11 to PXnm is connected to a corresponding gate line of the plurality of gate lines GL1 to GLn and a corresponding data line of the plurality of data lines DL1 to DLm. Each of the pixels PX11 to PXnm can include a pixel driving circuit and a light emitting device. Depending on the configuration of the pixel driving circuit, more types (or kinds) of signal lines can be provided in the display panel DP.

[0117] The pixels PX11 to PXnm can be arranged in a matrix form, but embodiments of the present disclosure are not limited thereto. For example, the pixels PX11 to PXnm can be arranged in a Pentile form. In some embodiments, the pixels PX11 to PXnm can be arranged in a diamond form.

[0118] The gate driving circuit GDC can be arranged in the non-display area NDA. The gate driving circuit GDC can be integrated into the display panel DP by a silicon oxide gate driving circuit (OSG) process and / or an amorphous silicon gate driving circuit (ASG) process.

[0119] FIG. 8 is a plan view of a pixel region of a display panel according to an embodiment of the present disclosure. FIG. 9 is a cross-sectional view of one pixel region of a display panel according to an embodiment of the present disclosure. FIG. 9 is a cross-sectional view of line I-I' corresponding to FIG. 8 in FIG. 1.

[0120] FIG. 8 is an enlarged view of a portion of the display region DA shown in FIG. 6A FIG. 8 Mainly three pixel regions Pxa-B, Pxa-G, and Pxa-R are shown. FIG. 8 The three pixel regions Pxa-B, Pxa-G, and Pxa-R shown in FIG. 2 can be repeatedly arranged throughout the display region DA.

[0121] FIG. 8 A stripe structure in which the pixel regions Pxa-B, Pxa-G, and Pxa-R are sequentially and alternately arranged along the same line is shown. However, the arrangement structure of the pixel regions Pxa-B, Pxa-G, and Pxa-R is not limited thereto, and various arrangement forms can exist. In embodiments, the pixel regions Pxa-B, Pxa-G, and Pxa-R can have a diamond arrangement structure or a Pentile type arrangement structure.​

[0122] Referring to FIG. 8 The peripheral area NPxa is provided to surround the first to third pixel areas Pxa-B, Pxa-G, and Pxa-R. The peripheral area NPxa sets a boundary of the first to third pixel areas Pxa-B, Pxa-G, and Pxa-R to prevent (or reduce) color mixing between the first to third pixel areas Pxa-B, Pxa-G, and Pxa-R. In addition, the peripheral area NPxa blocks (or reduces) the source light so that the source light is not provided to the user.

[0123] In the present embodiment, the first to third pixel areas Pxa-B, Pxa-G, and Pxa-R are shown to have the same planar area, but embodiments of the present disclosure are not limited thereto. The first to third pixel areas Pxa-B, Pxa-G, and Pxa-R can have different areas, or areas of at least two of them can be different from each other. The first to third pixel areas Pxa-B, Pxa-G, and Pxa-R are shown to have a rectangular shape with a planar rounded corner area, but embodiments of the present disclosure are not limited thereto. The first to third pixel areas Pxa-B, Pxa-G, and Pxa-R can have another polygonal shape when viewed on a plane (e.g., in a plan view), and / or can have a regular polygonal shape with a rounded corner area.

[0124] One of the first to third pixel areas Pxa-B, Pxa-G, and Pxa-R can provide the first light to the user, another can provide the second light different from the first light, and the remaining one can provide the third light different from the first and second lights. In an embodiment, the first pixel area Pxa-B can provide blue light, the second pixel area Pxa-G can provide green light, and the third pixel area Pxa-R can provide red light. In the present embodiment, the source light can be the blue light as the first light. The source light can be generated from the same light source as the light source of the backlight unit, or can be generated from a display device such as a light emitting device.

[0125] FIG. 9 A cross section corresponding to the second pixel area Pxa-G of the display panel DP is shown. FIG. 9 A cross section corresponding to the driving transistor T-D and the light emitting device LED is shown. In FIG. 9 In the present embodiment, the upper display substrate 200 is simply (schematically) shown.

[0126] As shown in FIG. 9 The display panel DP can include a first base substrate BS1, a circuit element layer CL provided on the first base substrate BS1, and a display device layer provided on the circuit element layer CL, as shown in

[0127] The first base substrate BS1 can include a synthetic resin substrate and / or a glass substrate. The circuit element layer CL includes at least one insulating layer and one circuit element. The circuit element includes a signal line and a driving circuit of a pixel, etc. The circuit element layer CL can be formed via a formation process of an insulating layer, a semiconductor layer, and / or a conductive layer by coating, deposition, etc. and / or a patterning process of an insulating layer, a semiconductor layer, and / or a conductive layer by a photolithography process.

[0128] In the present embodiment, the circuit element layer CL can include a buffer film BL, a first insulating layer 10, a second insulating layer 20, and a third insulating layer 30. The first insulating layer 10 and the second insulating layer 20 can each be an inorganic film, and the third insulating layer 30 can be an organic film. The third insulating layer 30 can include polyimide (PI).

[0129] FIG. 9 The arrangement relationship of the semiconductor pattern OSP, the control electrode GE, the input electrode DE, and the output electrode SE constituting the driving transistor T-D is shown. The first via CH1, the second via CH2, and the third via CH3 are also shown.

[0130] The display device layer includes a plurality of light emitting devices LED. For the light emitting device LED according to the embodiment included in the display device layer, reference can be made to FIGS. 1-5 The description of the light emitting device according to the embodiment is provided. The light emitting device LED can generate the source light described above. The source light generated by the light emitting device LED can be blue light. The light emitting device LED includes a first electrode EL1, a second electrode EL2, and a light emitting layer disposed therebetween. In the present embodiment, the light emitting device LED can include an organic light emitting device. However, the embodiments of the present disclosure are not limited thereto. The light emitting device LED included in the display device layer can be a light emitting device including various suitable display devices, such as LCD, LED, micro-LED, nano-LED, quantum dot, and / or quantum rod, which are non-limiting examples.

[0131] The display device layer includes a pixel defining film PDL. The pixel defining film PDL has an opening OP corresponding to the second pixel area Pxa-G. The pixel defining film PDL can have a plurality of openings corresponding to the first to third pixel areas Pxa-B, Pxa-G, and Pxa-R, respectively.

[0132] The pixel defining film PDL can include a light-blocking (or light-reducing) material. In an embodiment, the pixel defining film PDL can include a black material. The pixel defining film PDL can include a black organic dye / pigment, such as carbon black and / or aniline black. The pixel defining film PDL can also include a liquid-repellent organic substance.

[0133] In the display panel DP according to the embodiment, the first electrode EL1 can be disposed on the third insulating layer 30. The first electrode EL1 can be connected to the output electrode SE through the third via hole CH3 that passes through the third insulating layer 30. FIG. 9 The first electrode EL1 is shown as being disposed on the third insulating layer 30, but embodiments of the present disclosure are not limited thereto. The first electrode EL1 can be embedded within the third insulating layer 30 and disposed so as to expose an upper surface thereof. In this case, the upper surface of the first electrode EL1 and the upper surface of the third insulating layer 30 can constitute the same plane.

[0134] The opening OP of the pixel definition film PDL exposes at least a portion of the first electrode EL1. In plan view, the pixel definition film PDL can overlap at least a portion of the first electrode EL1. For example, the pixel definition film PDL can overlap an outer portion of the first electrode EL1 in plan view.

[0135] On the first electrode EL1, the first stack ST1, the first charge generation layer CGL1, the second stack ST2, the second charge generation layer CGL2, the third stack ST3, and the second electrode EL2 can be sequentially disposed. The first stack ST1, the first charge generation layer CGL1, the second stack ST2, the second charge generation layer CGL2, the third stack ST3, and the second electrode EL2 can be collectively disposed on the first electrode EL1 and the pixel definition film PDL. The first stack ST1, the first charge generation layer CGL1, the second stack ST2, the second charge generation layer CGL2, the third stack ST3, and the second electrode EL2 can be collectively disposed above the first to third pixel regions Pxa-B, Pxa-G, and Pxa-R. However, embodiments of the present disclosure are not limited thereto. The first stack ST1, the first charge generation layer CGL1, the second stack ST2, the second charge generation layer CGL2, the third stack ST3, and the second electrode EL2 can be patterned and disposed only in the opening OP of the pixel definition film PDL. As a detailed description regarding the first electrode EL1, the first stack ST1, the first charge generation layer CGL1, the second stack ST2, the second charge generation layer CGL2, the third stack ST3, and the second electrode EL2, reference can be made to the detailed description regarding the first electrode EL1, the first stack ST1, the first charge generation layer CGL1, the second stack ST2, the second charge generation layer CGL2, the third stack ST3, and the second electrode EL2 of the display panel DP according to the embodiment. FIGS. 1-5 A description is provided of the light emitting device according to the embodiment. Although FIG. 9 The display panel DP is shown as including the light emitting device LED having the three stacks ST1, ST2, and ST3, but embodiments of the present disclosure are not limited thereto. The display panel DP can include a light emitting device having a single stack without a series structure, or can include a light emitting device including two stacks.

[0136] In some embodiments, the second electrode EL2 can be connected to the auxiliary electrode. When the second electrode EL2 is connected to the auxiliary electrode, the resistance of the second electrode EL2 can be reduced.

[0137] The encapsulation member TFE can be disposed on the display device layer and can encapsulate the light emitting device LED. The encapsulation member TFE can include an inorganic film disposed on the outermost circumference thereof. The encapsulation member TFE can further include an organic film, and / or can have a structure in which the inorganic film and the organic film are alternately repeated. The encapsulation member TFE protects the light emitting device LED from moisture / oxygen, and can be used to protect the light emitting device LED from foreign substances.

[0138] In an embodiment, the inorganic film can include any suitable material without any particular limitation, as long as it is a material capable of protecting the lower light emitting device LED, and can include, for example, silicon nitride (SiN x ), silicon oxynitride (SiO y N x ), silicon oxide (SiO i O y ), titanium oxide (TiO y ), aluminum oxide (AlO y ), etc.

[0139] The organic film can include any suitable material without any particular limitation, as long as it is a material capable of planarizing the upper portion of the light emitting device LED, and can include, for example, acrylate-based organic material. The inorganic film can be formed by a deposition method or the like, and the organic film can be formed by a deposition method, a coating method, or the like.

[0140] On the encapsulation member TFE, a filling layer BFL can be disposed. The filling layer BFL is disposed between the lower display substrate 100 and the upper display substrate 200 to prevent (or protect) a component included in the upper display substrate 200, for example, a light control layer, from contacting the encapsulation member TFE of the lower display substrate 100, and can improve the light extraction efficiency of the display panel DP. The filling layer BFL can cover the upper surface of the encapsulation member TFE.

[0141] FIG. 9 The filling layer BFL filled between the lower display substrate 100 and the upper display substrate 200 is illustrated, but embodiments of the present disclosure are not limited thereto. In the display panel DP according to embodiments of the present disclosure, the filling layer BFL can be omitted. In this case, between the lower display substrate 100 and the upper display substrate 200, a predetermined (or set) cell gap can be defined.

[0142] FIG. 10 is a cross-sectional view of a display panel according to an embodiment of the present disclosure. FIG. 10 is a cross-sectional view corresponding to line II-II' of FIG. 8 .

[0143] Referring to FIG. 10 , the display panel DP of the embodiment includes a circuit element layer CL disposed on a first base substrate BS1, a display device layer disposed on the circuit element layer CL, a packaging member TFE disposed on the display device layer, and a filling layer BFL disposed on the packaging member TFE. The upper display substrate 200 (see FIG. 9 ) of the display panel DP can include a second base substrate BS2, a color filter layer CFL disposed below the second base substrate BS2, and a light control layer CCL disposed below the color filter layer CFL.

[0144] In the embodiment, the display panel DP can include a first light emitting device LED overlapping the first pixel region Pxa-B, a second light emitting device LED overlapping the second pixel region Pxa-G, and a third light emitting device LED overlapping the third pixel region Pxa-R. For each light emitting device LED, the description provided with reference to FIGS. 1-5 to the light emitting device according to the embodiment can be applied.

[0145] The packaging member TFE can be disposed on the light emitting device LED and can encapsulate the light emitting device LED. The packaging member TFE can include an inorganic film IL disposed on the outermost periphery thereof. The packaging member TFE can further include an organic film OL, or can have a structure in which the inorganic film IL and the organic film OL are alternately repeated. The packaging member TFE protects the light emitting device LED from moisture / oxygen, and can be used to protect the light emitting device LED from a contaminant such as a dust particle.

[0146] In the embodiment, the inorganic film IL can include any suitable material without any particular limitation, as long as it is a material capable of protecting the underlying light emitting device LED, and can include, for example, silicon nitride (SiN x ), silicon oxynitride (SiO y N x ), silicon oxide (SiO y ), titanium oxide (TiO y ), aluminum oxide (AlO y ), etc.

[0147] The organic film OL can include an acrylate-based organic material, but the embodiment of the present disclosure is not particularly limited thereto. The inorganic film IL can be formed by a deposition method or the like, and the organic film OL can be formed by a deposition method, a coating method, or the like.

[0148] The display panel DP according to the embodiment can include a light control layer CCL. The light control layer CCL can be disposed on the display device layer. The light control layer CCL can be disposed on the plurality of light emitting devices LED and can be spaced apart from the encapsulation member TFE by the filler layer BFL disposed therebetween.

[0149] The light control layer CCL can include a first light control unit CCP1 that transmits first light, a second light control unit CCP2 that converts the first light into second light, and a third light control unit CCP3 that converts the first light into third light. For example, the second light can be green light, and the green light can be light corresponding to light having a wavelength range of 500 nm to 570 nm. The third light can be red light, and can be light corresponding to light having a wavelength range of 625 nm to 675 nm.

[0150] The second light control unit CCP2 and the third light control unit CCP3 can each independently include a luminescent body. The luminescent body can be a particle capable of changing the wavelength of light. In an embodiment, the luminescent body included in the second light control unit CCP2 and the third light control unit CCP3 can each be a quantum dot.

[0151] A quantum dot is a material having a crystal structure of several nanometers in size, and is composed of several hundred to several thousand atoms. Due to its small size, a quantum dot exhibits a quantum confinement effect in which the energy band gap increases. When light having a wavelength higher than the band gap is incident on the quantum dot, the quantum dot is excited by absorbing the light, and falls into a ground state by emitting light of a specific wavelength. The emitted light of the specific wavelength has a value corresponding to the band gap. When the size and composition of the quantum dot are controlled, the light emission characteristics caused by the quantum confinement effect can be controlled.

[0152] The core of the quantum dot can be selected from a group II-VI compound, a group III-V compound, a group IV-VI compound, a group IV element, a group IV compound, and combinations thereof.

[0153] The II-VI compounds can be selected from binary compounds (selected from CdSe, CdTe, Cds, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, and mixtures thereof), ternary compounds (selected from AgInS, CuInS, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, and mixtures thereof), and quaternary compounds (selected from HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, and mixtures thereof).

[0154] The III-V compounds can be selected from binary compounds (selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof), ternary compounds (selected from GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InAlP, InNP, InNAs, InNSb, InPAs, InPSb, and mixtures thereof), and quaternary compounds (selected from GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and mixtures thereof).

[0155] The IV-VI compounds can be selected from binary compounds (selected from SnS, SnSe, SnTe, PbS, PbSe, PbTe, and mixtures thereof), ternary compounds (selected from SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and mixtures thereof), and quaternary compounds (selected from SnPbSSe, SnPbSeTe, SnPbSTe, and mixtures thereof). The IV element can be selected from Si, Ge, and mixtures thereof. The IV compound can be a binary compound selected from SiC, SiGe, and mixtures thereof.

[0156] In some embodiments, the binary compound, the ternary compound, and / or the quaternary compound can exist in a uniform concentration distribution in the particle, or can exist in a partially different concentration in the same particle. In some embodiments, the quantum dot can have a core-shell structure in which one quantum dot surrounds another quantum dot. The interface between the core and the shell can have a concentration gradient in which the concentration of the element existing in the shell becomes lower toward the center.

[0157] In some embodiments, the quantum dot can have a core-shell structure including a core having the above-described nanocrystal and a shell surrounding the core. The shell of the quantum dot having the core-shell structure can serve as a protective layer for preventing (or reducing) chemical deformation of the core to maintain a semiconductor property and / or as a charging layer for imparting an electrophoretic property to the quantum dot. The shell can be a single layer or multiple layers. The interface between the core and the shell can have a concentration gradient in which the concentration of the element existing in the shell becomes lower toward the center. Non-limiting examples of the shell of the quantum dot having the core-shell structure can include a metal oxide, a non-metal oxide, a semiconductor compound, and combinations thereof.

[0158] For example, the metal oxide or the non-metal oxide can be a binary compound (e.g., SiO2, Al2O3, TiO2, ZnO, MnO, Mn2O3, Mn3O4, CuO, FeO, Fe2O3, Fe3O4, CoO, Co3O4, and / or NiO) and / or a ternary compound (e.g., MgAl2O4, CoFe2O4, NiFe2O4, and / or CoMn2O4). However, embodiments of the present disclosure are not limited thereto.

[0159] Further, the semiconductor compound may, for example, be CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, etc. However, embodiments of the present disclosure are not limited thereto.

[0160] The quantum dot can have a full width at half maximum (FWHM) of a light emission wavelength spectrum of about 45 nm or less, for example, about 40 nm or less, or about 30 nm or less, and color purity or color reproducibility can be improved within the above-described range. Light emitted by such a quantum dot can be emitted in all directions, so that light viewing angle can be improved.

[0161] Although the form of the quantum dot is not particularly limited, as long as it is a suitable form for the intended purpose, the quantum dot can be used in, for example, a spherical, pyramidal, multi-armed, and / or cubic nanoparticle, nanotube, nanowire, nanofiber, nanoparticle, etc. form.

[0162] Quantum dots can control the color of emitted light according to the size of the quantum dots. Thus, quantum dots can have various light emission colors, such as blue, red, green, etc. The smaller the size of the quantum dots, the shorter the wavelength range of light that can be emitted. For example, the size of quantum dots that emit green light can be smaller than the size of quantum dots that emit red light. For example, the size of quantum dots that emit blue light can be smaller than the size of quantum dots that emit green light.

[0163] For example, the size of quantum dots included in the second light control unit CCP2 can be smaller than the size of quantum dots included in the third light control unit CCP3. Here, the quantum dots included in the second light control unit CCP2 can emit light having a shorter wavelength than the wavelength of the quantum dots included in the third light control unit CCP3.

[0164] In an embodiment, the light control layer CCL can include a base resin. The light control layer CCL can further include scattering particles. The light emitter and the scattering particles can be included only in a portion of the light control layer CCL. In an embodiment, the first light control unit CCP1 can include only the scattering particles, without the light emitter. The second light control unit CCP2 and the third light control unit CCP3 can each independently include both the light emitter and the scattering particles.

[0165] The base resin is a medium in which the light emitter is dispersed, and can be formed of one or more suitable resin compositions, which can be generally referred to as an adhesive. However, embodiments of the present disclosure are not limited thereto. In the present specification, any medium can be referred to as a base resin regardless of its name, additional functions, constituent materials, etc., as long as the medium can disperse and arrange the light emitter. The base resin can be a polymer resin. For example, the base resin can be an acrylic resin, a urethane-based resin, a silicone-based resin, an epoxy resin, etc. The base resin can be a transparent resin.

[0166] The scattering particles can be TiO2 and / or silica-based nanoparticles. The scattering particles can scatter light. In another embodiment of the present disclosure, the scattering particles can be omitted.

[0167] The light control layer CCL can include a plurality of light control units CCP1, CCP2, and CCP3. In an embodiment, each of the first light control unit CCP1, the second light control unit CCP2, and the third light control unit CCP3 can be disposed apart from each other in a plane. Each of the first light control unit CCP1, the second light control unit CCP2, and the third light control unit CCP3 can be arranged to be spaced apart from each other in a plane defined by an axis of the first direction DR1 and an axis of the third direction DR3.

[0168] The first light control unit CCP1 can be disposed corresponding to the first pixel region Pxa-B, the second light control unit CCP2 can be disposed corresponding to the second pixel region Pxa-G, and the third light control unit CCP3 can be disposed corresponding to the third pixel region Pxa-R.

[0169] In FIG. 10 , the first light control unit CCP1, the second light control unit CCP2, and the third light control unit CCP3 are illustrated as having substantially the same area and / or the same thickness. However, embodiments of the present disclosure are not limited thereto. The first light control unit CCP1, the second light control unit CCP2, and the third light control unit CCP3 can have different areas and / or different thicknesses. For example, the third light control unit CCP3 can have a larger area than the areas of the first light control unit CCP1 and the second light control unit CCP2. The area of the first light control unit CCP1 can be smaller than the areas of the second light control unit CCP2 and the third light control unit CCP3.

[0170] Between the first light control unit CCP1 and the second light control unit CCP2 spaced apart from each other and between the second light control unit CCP2 and the third light control unit CCP3, a partition wall portion BP can be disposed. The partition wall portion BP overlaps the peripheral region NPxa in a planar view. The partition wall portion BP can prevent (or reduce) a light leakage phenomenon and can distinguish a boundary between adjacent light control units CCP1, CCP2, and CCP3. The partition wall portion BP can include an organic light blocking material containing a black pigment and / or a black dye. The partition wall portion BP can include an organic material having a hydrophobic property. In an embodiment, the partition wall portion BP can be omitted.

[0171] In an embodiment, the display panel DP can include a color filter layer CFL. The color filter layer CFL is disposed on the light control layer CCL and can include first to third color filter units CF-B, CF-G, and CF-R and a light blocking member BM.

[0172] In an embodiment, the first to third color filter units CF-B, CF-G, and CF-R can be disposed to be spaced apart from each other in a planar view. Referring to FIG. 10 , the first to third color filter units CF-B, CF-G, and CF-R can be arranged to be spaced apart from each other along the first direction DR1.

[0173] The first to third color filter units CF-B, CF-G, and CF-R can transmit light having different wavelengths. The first color filter unit CF-B can be disposed in correspondence with the first light control unit CCP1, and can transmit the first light. The second color filter unit CF-G can be disposed in correspondence with the second light control unit CCP2, and can block (or reduce) the first light and transmit the second light. The third color filter unit CF-R can be disposed in correspondence with the third light control unit CCP3, and can block (or reduce) the first light and transmit the third light. By including the color filter layer CFL in the display panel DP, external light reflection can be effectively reduced, and color mixing can be prevented (or reduced).

[0174] The light blocking member BM is disposed in correspondence with the peripheral area NPxa. The light blocking member BM can be formed by including an organic light blocking material and / or an inorganic light blocking material, both of which include a black pigment and / or a black dye. The light blocking member BM can prevent (or reduce) a light leakage phenomenon, and can distinguish a boundary between adjacent color filter units. At least a portion of the light blocking member BM can be disposed to overlap with an adjacent color filter unit. For example, in a plane defined by an axis of the first direction DR1 and an axis of the third direction DR3, the light blocking member BM can be disposed such that at least a portion thereof overlaps with an adjacent color filter unit in a thickness direction (third direction DR3). In FIG. 10 In the embodiment, the light blocking member BM is shown to completely overlap with the color filter unit in the thickness direction, such that the thickness of the light blocking member BM is the same as the thickness of the entire color filter layer CFL. However, embodiments of the present disclosure are not limited thereto. The thickness of the light blocking member BM can be smaller than the thickness of the entire color filter layer CFL. In embodiments of the present disclosure, the light blocking member BM is shown to be included in the color filter layer CFL. However, embodiments of the present disclosure are not limited thereto. The light blocking member BM can be omitted.

[0175] In an embodiment, the filling layer BFL can fill a space between the packaging member TFE and the light control layer CCL. Filling a space between the packaging member TFE and the light control layer CCL can mean that the space between the packaging member TFE and the light control layer CCL is filled with the filling layer BFL such that there is no internal space between the packaging member TFE and the light control layer CCL, and such that the filling layer BFL completely covers the partition wall portion BP and contacts a portion of each of the upper surface of the packaging member TFE and the lower surface of the light control layer CCL.

[0176] The filling layer BFL can prevent (or reduce) the luminescent body, scattering particles, etc. included in the light control layer CCL from being oxidized by internal air, and thus, can maintain the light extraction efficiency of the display panel DP without being significantly (substantially) changed.

[0177] In an embodiment, the filler layer BFL can be directly disposed on the inorganic film IL on the outermost periphery of the encapsulation member TFE. The filler layer BFL may include inorganic adhesives, organic adhesives, and / or liquid crystal compounds, but the embodiments of this disclosure are not particularly limited thereto.

[0178] A display panel according to an embodiment of the present disclosure includes light-emitting devices in which a plurality of stacked bodies are stacked. The light-emitting devices according to an embodiment of the present disclosure may include a light-emitting material in an organic layer adjacent to the light-emitting layer. For example, the light-emitting device according to the embodiment may include a light-emitting material in the light-emitting layer, and may also include different light-emitting materials in the organic layer formed in contact with the light-emitting layer. Therefore, the luminous efficiency of the light-emitting device can be improved, and the wavelength of the light emitted by the light-emitting device can be reduced. For example, the light-emitting layer of the light-emitting device may emit blue light, and because the organic layer formed in contact with the light-emitting layer includes different light-emitting materials, the light generated by the light-emitting device may be blue light. Therefore, the light conversion efficiency of a light-emitting element, such as a quantum dot, included in the light control layer of the display panel can be improved, and the overall luminous efficiency of the display panel can be improved.

[0179] The present disclosure will be described in more detail below with reference to examples and comparative examples. The following examples are for illustrative purposes only to facilitate an understanding of the present disclosure, and therefore the scope of the present disclosure is not limited thereto.

[0180] Stacked structure of the device

[0181] A first electrode, a first stack, a first charge-generating layer, a second stack, a second charge-generating layer, a third stack, a second electrode, and a capping layer are sequentially stacked to manufacture a light-emitting device according to an embodiment. The first electrode is formed as follows: The thickness. The first stack is manufactured having wherein sequentially stacked... Hole injection layer Hole transport layer Electron blocking layer The light-emitting layer Hole blocking layer and The structure of the electron transport layer. The first charge generation layer is fabricated to have the following structure: n-type charge generation layer and The structure consists of p-type charge-generating layers that are sequentially stacked. A second stack is fabricated having... Hole transport layer electron blocking layer The light-emitting layer Hole blocking layer and The electron transport layers are stacked sequentially. The second charge generation layer is fabricated having a structure in which the electron transport layers are stacked sequentially. n-type charge generation layer and The structure of the p-type charge generation layer. The third stack was fabricated to have a structure in which the hole transport layer, the electron blocking layer, the light emitting layer, the hole blocking layer, the electron transport layer, and the electron injection layer were sequentially stacked. The second electrode was formed to have a thickness of The capping layer was formed to have a thickness of The materials used to form each layer are as follows.

[0182]

[0183] The first electrode was formed by stacking ITO / Ag / ITO to have a thickness of The hole injection layer and the p-type charge generation layer were each formed by (from) bispyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexanitrile (HAT-CN). The hole transport layer was formed by (from) N,N'-di(naphthalen-1-yl)-N,N'-diphenylbenzidine (NPB). The electron blocking layer was formed by (from) 4,4',4"-tris(N-carbazolyl)triphenylamine (TCTA). The light emitting layer was formed by doping 4-(10-phenylanthracen-9-yl)dibenzo[b,d]furan with 3% of a blue dopant (N1,N6-di(naphthalen-2-yl)-N1,N6-diphenylpy-1,6-diamine). The hole blocking layer was formed by (from) 2,4,6-tris([1,1'-biphenyl]-3-yl)-1,3,5-triazine (T2T). The electron transport layer was formed by mixing TPM-TAZ (2,4,6-tris(3-(pyrimidin-5-yl)phenyl)-1,3,5-triazine) and Liq in a ratio of 5:5. The n-type charge generation layer was formed by doping ((1,3,5-triazin-2,4,6-triyl)tris(phen-3,1-diyl))tris(diphenylphosphine oxide) (PO-T2T) with 1% of Yb. The electron injection layer was formed by (from) Yb. The second electrode was formed by mixing Ag and Mg in a ratio of 10:1. The capping layer was formed by (from) N4,N4'-diphenyl-N4,N4'-bis(9-phenyl-9H-carbazol-3-yl)-[1,1'-biphenyl]-4,4'-diamine.

[0184] Example 1

[0185] When forming the electron blocking layer of each stack in the above-described device stack structure, a green dopant Ir(ppy3) (tris[2-phenylpyridine]iridium(III)) was doped at 5%.

[0186] Example 2

[0187] When forming the hole blocking layer of each stack in the above device stack structure, the green dopant Ir(ppy3) (tris[2-phenylpyridine]iridium(III)) was doped at 5%.

[0188] Example 3

[0189] When forming the hole blocking layer and the electron blocking layer of each stack in the above device stack structure, the green dopant Ir(ppy3) (tris[2-phenylpyridine]iridium(III)) was doped at 5%.

[0190] Comparative Example 1

[0191] The hole blocking layer and the electron blocking layer of each stack were formed according to the above device stack structure, except that the green dopant was excluded.

[0192] Experimental Example 1

[0193] The driving voltage, current efficiency, and luminance lifetime of the light emitting devices according to each of Examples 1 to 3 and the light emitting device according to Comparative Example 1 were measured, and the results are shown in Table 1. The current efficiency was measured at 1500 nit luminance. The luminance lifetime represents the time taken to show 95% of the initial luminous intensity, i.e., the 95% lifetime time (T95) of the light emitting device.

[0194] Table 1

[0195] Drive voltage (V) Current efficiency (Cd / A) Luminance lifetime (T95, hr) Example 1 10.2 26.8 460 Example 2 10.2 27.8 540 Example 3 10.2 30.4 620 Comparative Example 1 10.2 23.1 260

[0196] Referring to Table 1, in the three-stack tandem device including the blue dopant, the light emitting devices of each of Examples 1 to 3 showed increased current efficiency and luminance lifetime while maintaining the same driving voltage. Without being bound by any particular theory, it is believed that this beneficial effect is due at least in part to the hole blocking layer and / or the electron blocking layer of the present embodiments being adjacent to the light emitting layer and doped with the green dopant. In particular, the current efficiency and luminance lifetime of Example 3, in which both the hole blocking layer and the electron blocking layer adjacent to the light emitting layer are doped with the green dopant, were greatly improved compared to the rest of the examples and the comparative example. The current efficiency as a function of luminance of the light emitting devices according to each of Examples 1 to 3 and the light emitting device according to Comparative Example 1 were measured, and are shown in the graph of FIG. 1. FIG. 11 Referring to the results of FIG. 1, in the three-stack tandem device including the blue dopant, the current efficiency increased when the hole blocking layer and / or the electron blocking layer adjacent to the light emitting layer was doped with the green dopant. FIG. 11

[0197] ​The wavelength-dependent light emission intensity of the light emitting devices according to each of Examples 1 to 3 and the light emitting device according to Comparative Example 1 was measured, and is shown in a graph of FIG. 10. Referring to the results of FIG. 10, it can be seen that the light emission intensity of the light emitting device increases when the hole blocking layer and / or the electron blocking layer adjacent to the light emitting layer is doped with a light emitting dopant. FIG. 12 FIG. 12 Referring to the results of FIG. 11, it can be seen that the degree of decrease in the luminance efficiency of the device decreases over time when the hole blocking layer and / or the electron blocking layer adjacent to the light emitting layer is doped with a light emitting dopant.

[0198] The wavelength-dependent light emission intensity of the light emitting devices according to each of Examples 1 to 3 and the light emitting device according to Comparative Example 1 was measured, and is shown in a graph of FIG. 10. Referring to the results of FIG. 10, it can be seen that the light emission intensity of the light emitting device increases when the hole blocking layer and / or the electron blocking layer adjacent to the light emitting layer is doped with a light emitting dopant. FIG. 13 FIG. 13 Referring to the results of FIG. 11, it can be seen that the degree of decrease in the luminance efficiency of the device decreases over time when the hole blocking layer and / or the electron blocking layer adjacent to the light emitting layer is doped with a light emitting dopant.

[0199] In the three-stack tandem device including a blue dopant, because the hole blocking layer and / or the electron blocking layer adjacent to the light emitting layer is doped with a green dopant to prevent (or protect) the materials of the adjacent layers (e.g., the hole blocking layer and the electron blocking layer adjacent to the light emitting layer) from being deteriorated due to the leakage of holes and / or electrons into the adjacent layers, the light emitting device of each of the examples can have an increased device lifetime. In addition, the light emission efficiency of the device can be improved by generating light from the dopant included in the adjacent layer (e.g., the light emitting layer).

[0200] According to embodiments of the present disclosure, the organic layer adjacent to the light emitting layer of the light emitting device includes a light emitting material, and thus damage to the organic layer due to the current leaked from the light emitting layer can be prevented (or reduced). Accordingly, the light emission efficiency and the device lifetime of the light emitting device can be improved.

[0201] When used before / after a list of elements, e.g., "at least one of," "one or more of," and "at least one selected from the group of," the expression modifies the entire list of elements and does not modify the individual elements of the list.

[0202] As used herein, the terms "use," "using," and "used" can be considered synonymous with the terms "utilize," "utilizing," and "utilized," respectively.

[0203] ​​Furthermore, the terms“substantially,”“about,” and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent deviations in measured or computed values that would be recognized by those of ordinary skill in the art.

[0204] Furthermore, any numerical range recited herein is intended to include all sub-ranges of the same numerical precision, encompassed within the recited range. For example, a range of“1.0 to 10.0” is intended to include all sub-ranges, for example, 2.4 to 7.6, 3.1 to 6.9, etc., within the same precision used to recite the original range. Any maximum numerical limitation recited herein is intended to include all lower numerical limitations subsumed therein and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, Applicant reserves the right to amend this specification, including the claims, to expressly recite any sub-range including any minimum or maximum numerical limitation recited herein.

[0205] While example embodiments of the present application have been described herein, it should be understood that the present application is not limited to these example embodiments, but rather, various changes and modifications can be made by those skilled in the art which fall within the spirit and scope of the present application as defined by the following claims and their equivalents.

[0206] While the present disclosure has been described with reference to example embodiments thereof, it is to be understood that various other changes can be made and equivalents employed herein without departing from the scope of the present disclosure.

[0207] Accordingly, the technical scope of the present disclosure is not intended to be limited to what is set forth in the specific embodiments described in the specification, but rather intended to be defined by the claims and their equivalents.

Claims

1. A light-emitting device, comprising: First electrode; A first stack is located on the first electrode; A first charge generation layer is located on the first stack body; The second stack is located on the first charge generation layer; as well as The second electrode is located on the second stack body. in, The first stack includes a first light-emitting layer and multiple first organic layers. The second stack includes a second light-emitting layer and multiple second organic layers. In the plurality of first organic layers, each organic layer adjacent to the first light-emitting layer includes a light-emitting material, and in the plurality of second organic layers, each organic layer adjacent to the second light-emitting layer includes a light-emitting material. The luminescent material is a material that produces green, red, and / or orange light with a wavelength longer than the light produced by the first and second luminescent layers.

2. The light-emitting device as claimed in claim 1, wherein, The first stack includes a first hole transport region located between the first electrode and the first light-emitting layer, and a first electron transport region located between the first light-emitting layer and the first charge-generating layer. The second stack includes a second hole transport region located between the first charge generation layer and the second light-emitting layer, and a second electron transport region located between the second light-emitting layer and the second electrode. Each of the first hole transport region, the first electron transport region, the second hole transport region, and the second electron transport region includes at least one organic layer, and Each of the organic layers selected from the organic layers of the first hole transport region and the first electron transport region, and each of the organic layers adjacent to the first light-emitting layer, includes the light-emitting material; and each of the organic layers selected from the organic layers of the second hole transport region and the second electron transport region, and each of the organic layers adjacent to the second light-emitting layer, includes the light-emitting material.

3. The light-emitting device as described in claim 2, wherein, Each of the first hole transport region and the second hole transport region includes at least one selected from a hole injection layer and a hole transport layer. Each of the first electron transport region and the second electron transport region includes at least one selected from the electron injection layer and the electron transport layer, and The light-emitting material is included in the layers selected from the hole injection layer, the hole transport layer, the electron injection layer, and the electron transport layer that are adjacent to the first light-emitting layer or the second light-emitting layer.

4. The light-emitting device as described in claim 2, wherein, The first hole transport region includes a first hole injection layer and a first hole transport layer located between the first hole injection layer and the first light-emitting layer. The first electron transport region includes a first electron injection layer and a first electron transport layer located between the first electron injection layer and the first light-emitting layer. The second hole transport region includes a second hole injection layer and a second hole transport layer located between the second hole injection layer and the second light-emitting layer. The second electron transport region includes a second electron injection layer and a second electron transport layer located between the second electron injection layer and the second light-emitting layer, and Each of the first hole transport layer, the first electron transport layer, the second hole transport layer, and the second electron transport layer includes the luminescent material.

5. The light-emitting device as claimed in claim 2, wherein, The first hole transport region includes a first hole injection layer, a first hole transport layer located between the first hole injection layer and the first light-emitting layer, and a first electron blocking layer located between the first hole transport layer and the first light-emitting layer. The first electron transport region includes a first electron injection layer, a first electron transport layer located between the first electron injection layer and the first light-emitting layer, and a first hole blocking layer located between the first electron transport layer and the first light-emitting layer. The second hole transport region includes a second hole injection layer, a second hole transport layer located between the second hole injection layer and the second light-emitting layer, and a second electron blocking layer located between the second hole transport layer and the second light-emitting layer. The second electron transport region includes a second electron injection layer, a second electron transport layer located between the second electron injection layer and the second light-emitting layer, and a second hole blocking layer located between the second electron transport layer and the second light-emitting layer. Each of the first electron blocking layer, the first hole blocking layer, the second electron blocking layer, and the second hole blocking layer includes the luminescent material.

6. The light-emitting device as claimed in claim 1, further comprising: A second charge generation layer is located on the second stack body; as well as The third stack is located on the second charge generation layer.

7. The light-emitting device as claimed in claim 1, wherein, The first and second light-emitting layers produce blue light.

8. The light-emitting device as claimed in claim 1, wherein, The organic layer comprising the luminescent material includes a base material and the luminescent material doped in the base material.

9. The light-emitting device as claimed in claim 8, wherein, The base material has a lower triplet excitation energy level that is higher than that of the luminescent material.

10. The light-emitting device as claimed in claim 1, wherein, The luminescent material is a phosphorescent material.

11. The light-emitting device as claimed in claim 1, wherein, The first electrode is a reflective electrode, and the second electrode is a transmissive electrode or a semi-transmissive and semi-reflective electrode.

12. The light-emitting device as claimed in claim 1, further comprising: A capping layer is located on the second electrode.

13. A light-emitting device, comprising: First electrode; A hole transport region is located on the first electrode and includes at least one organic layer; A light-emitting layer is located on the hole transport region and includes a first light-emitting material; An electron transport region is located on the light-emitting layer and includes at least one organic layer; as well as The second electrode is located on the electron transport region. Wherein, each of the organic layers selected from the organic layers of the hole transport region and the electron transport region, and in contact with the light-emitting layer, includes a second light-emitting material different from the first light-emitting material, and The second luminescent material is a material that produces green, red, and / or orange light with a wavelength longer than that produced by the first luminescent material.

14. The light-emitting device as claimed in claim 13, wherein, The hole transport region includes a hole injection layer, a hole transport layer located between the hole injection layer and the light-emitting layer, and an electron blocking layer located between the hole transport layer and the light-emitting layer. The electron transport region includes an electron injection layer, an electron transport layer located between the electron injection layer and the light-emitting layer, and a hole blocking layer located between the electron transport layer and the light-emitting layer. The electron blocking layer and the hole blocking layer comprise the second luminescent material.

15. The light-emitting device as claimed in claim 13, wherein, The organic layer, including the second luminescent material, is formed from a base material doped with the second luminescent material.

16. The light-emitting device as claimed in claim 13, wherein, A charge generation layer, a second hole transport region, a second light-emitting layer, and a second electron transport region are sequentially stacked between the electron transport region and the second electrode. The second hole transport region and the second electron transport region include at least one organic layer, and The layer adjacent to the second luminescent layer includes a third luminescent material that is different from the first luminescent material.

17. The light-emitting device as claimed in claim 16, wherein, The third luminescent material is the same material as the second luminescent material.

18. A display panel, including: The base substrate includes a pixel region and a peripheral region adjacent to the pixel region; as well as Multiple display elements are located on the base substrate to overlap the pixel region in a plane. in, Each of the plurality of display elements includes: First electrode; A first stack is located on the first electrode; A first charge generation layer is located on the first stack body; A second stack is located on the first charge-generating layer; and The second electrode is located on the second stack body. in, The first stack includes a first light-emitting layer and multiple first organic layers. The second stack includes a second light-emitting layer and multiple second organic layers. Each of the layers selected from the first organic layer and adjacent to the first light-emitting layer includes a light-emitting material, and each of the layers selected from the second organic layer and adjacent to the second light-emitting layer includes a light-emitting material, and The luminescent material is a material that produces green, red, and / or orange light with a wavelength longer than the light produced by the first and second luminescent layers.

19. The display panel of claim 18, further comprising: A light control layer is located on the plurality of display elements and overlaps with the pixel area in a plane.

20. The display panel as claimed in claim 19, wherein, The plurality of display elements generate a first light, and The optical control layer includes: The first optical control unit transmits the first light. The second optical control unit converts the first light into the second light, and The third light control unit converts the first light into the third light.

21. The display panel as claimed in claim 20, wherein, The first light has a wavelength range of 410 nm to 480 nm, the second light has a wavelength range of 500 nm to 570 nm, and the third light has a wavelength range of 625 nm to 675 nm.

22. The display panel as claimed in claim 19, wherein, The light control layer comprises a base resin and a light emitter dispersed in the base resin.

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