Indication device

Abstract

To provide a light-emitting element with improved efficiency and lifetime.SOLUTION: A light-emitting device includes: an upper display substrate including a first pixel region emitting first light, a second pixel region emitting second light, which is different from the first light, and a third pixel region emitting third light, which is different from the first light and the second light; and a lower display substrate including a first light-emitting element overlapping with the first pixel region, a second light-emitting element overlapping with the second pixel region, and a third light-emitting element overlapping with the third pixel region. The second light-emitting element includes one or more first stacks emitting the second light and including a plurality of organic layers. The third light-emitting element includes one or more second stacks emitting the third light and including a plurality of organic layers. The first stack includes a first hole transport region, a first light-emitting layer, and a first electron transport region. The second stack includes a second hole transport region, a second light-emitting layer, and a second electron transport region. The concentration of a conductive material included in the first electron transport region is higher than the concentration of a conductive material included in the second electron transport region.SELECTED DRAWING: Figure 3a

Description

[Technical Field]

[0001] The present invention relates to a display device, and more particularly to a display device including a light-emitting element with improved lifespan and luminous efficiency. [Background technology]

[0002] A variety of display devices are being developed for use in multimedia devices such as televisions, mobile phones, tablet computers, navigation systems, and game consoles. These display devices utilize so-called self-emissive display devices that achieve display by making light-emitting materials emit light.

[0003] In more detail, the light-emitting element generates excitons by recombining holes and electrons injected from the first and second electrodes in the light-emitting layer, and then drops the generated excitons to the bottom state to produce light.

[0004] When applying light-emitting elements to display devices, there is a need for improved luminescence efficiency and longer lifespan of the light-emitting elements, and there is a continuous demand for the development of light-emitting elements that can stably achieve these goals. [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The present invention aims to provide a light-emitting element with improved efficiency and lifespan.

[0006] Another object of the present invention is to provide a display panel including a light-emitting element with improved efficiency and lifespan. [Means for solving the problem]

[0007] A display device according to an embodiment of the present invention includes an upper display substrate including a first pixel region that emits first light, a second pixel region that emits second light different from the first light, and a third pixel region that emits third light different from the first light and the second light, a lower display substrate including a first light-emitting element that overlaps the first pixel region, a second light-emitting element that overlaps the second pixel region, and a third light-emitting element that overlaps the third pixel region, wherein the second light-emitting element includes one or more first stacks that emit the second light and include a plurality of organic layers, the third light-emitting element includes one or more second stacks that emit the third light and include a plurality of organic layers, the first stack includes a first hole transport region, a first light-emitting layer, and a first electron transport region, the second stack includes a second hole transport region, a second light-emitting layer, and a second electron transport region, and the concentration of a conductive substance included in the first electron transport region is higher than the concentration of the conductive substance included in the second electron transport region.

[0008] In one embodiment, the first electron transport region includes a first electron transport layer, the second electron transport region includes a second electron transport layer, and the concentration of a conductive substance included in the first electron transport layer is higher than the concentration of the conductive substance included in the second electron transport layer.

[0009] In one embodiment, the conductive substance is a p-type dopant.

[0010] In one embodiment, the conductive substance includes at least one of 4-[[2,3-bis[cyano-(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropylidene]-cyanomethyl]-2,3,5,6-tetrafluorobenzonitrile (NDP-9), dipyrazino[2,3-f:2’,3’-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN), 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), and tetracyanoquinodimethane (TCNQ).

[0011] In one embodiment, the first electron transport region includes a first electron transport layer, the second electron transport region includes a second electron transport layer, and the concentration of the insulating material contained in the first electron transport layer is lower than the concentration of the insulating material contained in the second electron transport layer.

[0012] In one embodiment, the insulating material contains at least one metal halide or an oxide having a dielectric constant of 5 or more.

[0013] In one embodiment, the lower display substrate further includes a bank disposed between the second light-emitting element and the third light-emitting element, and the bank is not disposed between the first light-emitting element and the second light-emitting element.

[0014] In one embodiment, the upper display substrate further includes non-pixel regions adjacent to the first to third pixel regions, the lower display substrate further includes a pixel definition film superimposed on the non-pixel regions, and the bank superimposed on the pixel definition film.

[0015] In one embodiment, the upper display substrate includes a first light control unit superimposed on the first pixel region and including a first quantum dot, a second light control unit superimposed on the second pixel region and transmitting the second light, and a third light control unit superimposed on the third pixel region and transmitting the third light, wherein the first quantum dot converts the second light or the third light into the first light.

[0016] In one embodiment, the second light-emitting element includes one or more first stacks and one or more second stacks, the second light control unit includes a second quantum dot, and the second quantum dot converts the third light into the second light.

[0017] In one embodiment, the second light-emitting element includes a plurality of only the first stacks.

[0018] In one embodiment, the first light-emitting element has the same structure as the second light-emitting element.

[0019] In one embodiment, the third light-emitting element includes multiple instances of only the second stack.

[0020] In one embodiment, the first light is red light, the second light is green light, and the third light is blue light.

[0021] In one embodiment, the first stack emits green phosphorescence, and the second stack emits blue fluorescence.

[0022] In one embodiment, the second light-emitting element includes a first electron transport layer, the third light-emitting element includes a second electron transport layer, and the concentration of the electron transport material contained in the second electron transport layer is equal to or greater than the concentration of the electron transport material contained in the first electron transport layer.

[0023] A display device according to one embodiment of the present invention includes a base layer including a first pixel region, a second pixel region, and a third pixel region; a first light-emitting element superimposed on the first pixel region disposed on the base layer; a second light-emitting element superimposed on the second pixel region disposed on the base layer; and a third light-emitting element superimposed on the third pixel region disposed on the base layer, wherein the second light-emitting element includes one or more first stacks that emit green light; the third light-emitting element includes one or more second stacks that emit blue light; the first stack includes a first hole transport layer, a first light-emitting layer that emits green light, and a first electron transport layer; the second stack includes a second hole transport layer, a second light-emitting layer that emits blue light, and a second electron transport layer, wherein the electron transport characteristics of the first electron transport layer are higher than those of the second electron transport layer.

[0024] In one embodiment, the concentration of the conductive material contained in the first electron transport layer is higher than the concentration of the conductive material contained in the second electron transport layer, and the conductive material includes at least one of NDP-9, HAT-CN, F4-TCNQ, and TCNQ.

[0025] In one embodiment, the concentration of the insulating material contained in the first electron transport layer is lower than the concentration of the insulating material contained in the second electron transport layer, and the insulating material contains at least one metal halide or an oxide with a dielectric constant of 5 or more.

[0026] In one embodiment, the system further includes a bank disposed on the base layer and positioned between the second light-emitting element and the third light-emitting element, wherein the bank is not positioned between the first light-emitting element and the second light-emitting element. [Effects of the Invention]

[0027] A display device according to one embodiment of the present invention has improved luminous efficiency and lifespan. [Brief explanation of the drawing]

[0028] [Figure 1] This is a plan view of a display device according to one embodiment. [Figure 2a] This is a cross-sectional view of a display device according to one embodiment. [Figure 2b] This is a cross-sectional view of a light-emitting element according to one embodiment. [Figure 3a] This is a schematic cross-sectional view showing a light-emitting element according to one embodiment. [Figure 3b] This is a schematic cross-sectional view showing a light-emitting element according to one embodiment. [Figure 4] This is a cross-sectional view of a display device according to one embodiment. [Modes for carrying out the invention]

[0029] Because the present invention can be modified in various ways and take on various forms, specific embodiments are illustrated in the drawings and described in detail in the text. However, this should be understood not as limiting the present invention to any particular form of disclosure, but rather as including all modifications, equivalents, or substitutions that fall within the spirit and technical scope of the present invention.

[0030] "and / or" includes all combinations of one or more of the related configurations.

[0031] Terms such as "first," "second," etc., are used to describe a variety of components, but the components are not limited to those defined by these terms. These terms are used solely for the purpose of distinguishing one structural element from other components. For example, within the scope of the present invention, the first component may be named the second component, and similarly, the second component may also be named the first component. A singular expression includes plural expressions unless the context clearly indicates otherwise.

[0032] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art in the field to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries should be interpreted as having the same meaning as in the context of the relevant art, and not as ideal or overly formal unless explicitly defined.

[0033] Terms such as "includes" or "has" indicate the presence of features, figures, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood not to pre-exist to exclude the presence or possibility of adding one or more other features, figures, steps, actions, components, parts, or combinations thereof.

[0034] A display module according to one embodiment of the present invention will be described below with reference to the drawings.

[0035] Figure 1 is a plan view showing one embodiment of the display device DD. Figure 2a is a cross-sectional view of the display device DD according to one embodiment. Figure 2a is a cross-sectional view showing the portion corresponding to the line I-I' in Figure 1.

[0036] Referring to Figure 1, the display device DD is defined as having a non-light-emitting region NPXA and light-emitting regions PXA-R, PXA-G, and PXA-B. The non-pixel region NPXA is a region that does not emit light, while the light-emitting regions PXA-R, PXA-G, and PXA-B are regions that emit light generated inside the display device DD. Each of the light-emitting regions PXA-R, PXA-G, and PXA-B is separated from each other on a plane.

[0037] Referring to Figure 2a, the display device DD includes a lower display board 100 and an upper display board 200 positioned on top of the lower display board 100. Although not shown, a filling layer is placed between the lower display board 100 and the upper display board 200. Hereafter, the lower display board 100 will be described as the display panel 100.

[0038] The display panel 100 may be any one of the following, but is not limited to: a liquid crystal display panel, an electrophoretic crystal display panel, a micro electro-mechanical system display panel, an electrowetting display panel, an organic light-emitting display panel, a micro LED display panel, a quantum dot display panel, or a quantum rod display panel.

[0039] The display panel 100 includes a base layer BS, a circuit layer DP-CL provided on the base layer BS, and a display element layer DP-ED. The display element layer DP-ED includes a pixel definition film PDL and light-emitting elements ED1, ED2, and ED3 arranged superimposed on an aperture OH provided in the pixel definition film PDL.

[0040] The pixel definition film (PDL) separates the light-emitting regions PXA-R, PXA-G, and PXA-B. The non-pixel region (NPXA) is the region between adjacent pixel regions PXA-R, PXA-G, and PXA-B, and corresponds to the region of the pixel definition film (PDL).

[0041] The light-emitting elements ED1, ED2, and ED3 are arranged superimposed on the pixel regions PXA-R, PXA-G, and PXA-B. Each of the pixel regions PXA-R, PXA-G, and PXA-B is a region from which light generated by the light-emitting elements ED1, ED2, and ED3 is emitted.

[0042] For example, pixel regions PXA-R, PXA-G, and PXA-B include a first pixel region PXA-R, a second pixel region PXA-G, and a third pixel region PXA-B, which are spaced apart from each other. Light-emitting elements ED1, ED2, and ED3 include a first light-emitting element ED1 superimposed on the first pixel region PXA-R, a second light-emitting element ED2 superimposed on the second pixel region PXA-G, and a first light-emitting element ED4 superimposed on the third pixel region PXA-B.

[0043] In one embodiment of the display device DD, the first light-emitting element ED1, the second light-emitting element ED2, and the third light-emitting element ED3 emit light in different wavelength regions. For example, the first light-emitting element ED1 may emit red light, the second light-emitting element ED2 may emit green light, and the third light-emitting element ED3 may emit blue light.

[0044] The first pixel region PXA-R is the red pixel region, the second pixel region PXA-G is the green pixel region, and the third pixel region PXA-B is the blue pixel region.

[0045] However, the embodiments are not limited to these, and the first to third light-emitting elements ED1, ED2, and ED3 may emit light in the same wavelength region, or at least one of them may emit light in a different wavelength region.

[0046] In one embodiment of the display device DD, the pixel regions PXA-R, PXA-G, and PXA-B are arranged in a striped pattern. Referring to Figure 1, multiple first pixel regions PXA-R, multiple second pixel regions PXA-G, and multiple third pixel regions PXA-B are aligned along the second directional axis DR2. Furthermore, the first pixel region PXA-R, the second pixel region PXA-G, and the third pixel region PXA-B are arranged alternately along the first direction DR1.

[0047] In Figures 1 and 2a, the areas of pixel regions PXA-R, PXA-G, and PXA-B are shown to be similar, but the examples are not limited to these, and the areas of pixel regions PXA-R, PXA-G, and PXA-B may differ from each other depending on the wavelength range of the emitted light. On the other hand, the areas of pixel regions PXA-R, PXA-G, and PXA-B refer to the area as viewed from the plane defined by the first direction DR1 and the second direction DR2.

[0048] On the other hand, the arrangement of pixel regions PXA-R, PXA-G, and PXA-B is not limited to that shown in Figure 1, and the order in which the first pixel region PXA-R, the second pixel region PXA-G, and the third pixel region PXA-B are arranged can be provided in various combinations depending on the display quality characteristics required by the display device DD. For example, the arrangement of pixel regions PXA-R, PXA-G, and PXA-B may be a pentile arrangement or a diamond arrangement.

[0049] The base layer BS is a component that provides the base surface on which the display element layer EP-ED is placed. The base layer BS can be a glass substrate, a metal substrate, a plastic substrate, etc. However, the examples are not limited to these, and the base layer BS may be an inorganic layer, an organic layer, or a composite material layer.

[0050] In one embodiment, the circuit layer DP-CL is located on the base layer BS, and the circuit layer DP-CL includes a plurality of transistors (not shown). Each transistor (not shown) includes a control electrode, an input electrode, and an output electrode. For example, the circuit layer DP-CL may include switching transistors and drive transistors for driving the first to third light-emitting elements ED1, ED2, and ED3.

[0051] A pixel definition film PDL is placed on the circuit layer DP-CL. The pixel definition film PDL is made of a polymer resin. For example, the pixel definition film PDL is formed by including a polyacrylate resin or a polyimide resin. In addition, the pixel definition film PDL may be formed by further including inorganic materials in addition to the polymer resin. On the other hand, the pixel definition film PDL is formed by including a light-absorbing material or by including a black pigment or black dye. A pixel definition film PDL formed by including a black pigment or black dye embodies a black pixel definition film. When forming the pixel definition film PDL, carbon black or the like may be used as the black pigment or black dye, but the examples are not limited to this.

[0052] Furthermore, the pixel definition film (PDL) is made of inorganic materials. For example, the pixel definition film (PDL) is made of silicon nitride (SiN x ), silicon dioxide (SiO₂) x ), silicon dioxide (SiO₂) x N y ) may be formed by including the following:

[0053] The first to third light-emitting elements ED1, ED2, and ED3 are distinguished by the pixel definition film PDL.

[0054] The first to third light-emitting elements ED1, ED2, and ED3 include a first electrode EL1 and a second electrode EL2 facing each other, and a plurality of stacks SF1, SF2, and SF3 stacked in a third direction DR3 positioned between the first electrode EL1 and the second electrode EL2. Each of the plurality of stacks SF1, SF2, and SF3 includes a hole transport region HTR, an emissive layer EML, and an electron transport region ETR. In other words, the display device DD of one embodiment is a light-emitting element with a tandem structure including a plurality of emissive layers.

[0055] In one embodiment, the structures of the first to third light-emitting elements ED1, ED2, and ED3 are all the same, at least one is different from the other two, or all three structures are different. For example, in the display device DD of one embodiment, the first light-emitting element ED1 and the second light-emitting element ED2 may have the same structure, while the third light-emitting element ED3 may have a different structure from the first and second light-emitting elements ED2. A bank BK is placed at the boundary with the third light-emitting element ED3. For example, a bank BK may be placed between the first light-emitting element ED1 and the third light-emitting element ED3. A bank BK is placed between the second light-emitting element ED2 and the third light-emitting element ED3. The bank BK separates the third light-emitting element ED3 from the first and second light-emitting elements ED1 and ED2.

[0056] In one embodiment, the bank BK is placed on top of the pixel definition film PDL and superimposed on the pixel definition film PDL. The hole transport region HTR, light-emitting layer EML, and electron transport region ETR are provided by patterning using an inkjet printing method, while the bank BK contains a liquid-repellent material. Alternatively, the bank BK contains the same material as the pixel definition film PDL and has a shape that is integrated with the pixel definition film PDL.

[0057] A sealing layer TFE is placed on the first to third light-emitting elements ED1, ED2, and ED3. The sealing layer TFE covers the first to third light-emitting elements ED1, ED2, and ED3. The sealing layer TFE seals the display element layer DP-ED. The sealing layer TFE is a thin film sealing layer. The sealing layer TFE consists of one or more layers stacked. The sealing layer TFE includes at least one insulating layer. In one embodiment, the sealing layer TFE includes at least one inorganic film (hereinafter referred to as the sealing inorganic film). In another embodiment, the sealing layer TFE includes at least one organic film (hereinafter referred to as the sealing organic film) and at least one sealing inorganic film.

[0058] The encapsulating inorganic film protects the display element layer DP-ED from moisture / oxygen, and the encapsulating organic film protects the display element layer DP-ED from foreign matter such as dust particles. The encapsulating inorganic film may, but is not limited to, silicon nitride, silicon oxynitride, silicon oxide, titanium oxide, or aluminum oxide. The encapsulating organic film may, but is not limited to, acrylic compounds or epoxy compounds. The encapsulating organic film may, but is not limited to, photopolymerizable organic substances.

[0059] The upper display substrate 200 is placed on top of the sealing layer TFE. The upper display substrate 200 includes a base substrate BL, a color filter layer CFL, and a light control layer CCL.

[0060] The optical control layer (CCL) is placed on top of the display panel 100. The optical control layer (CCL) contains photoconverters. These photoconverters are quantum dots or phosphors, etc. The photoconverters convert the wavelength of the light they receive and emit it. In other words, the optical control layer (CCL) is either a layer containing quantum dots or a layer containing phosphors.

[0061] The optical control layer CCL includes a plurality of optical control units CCP1, CCP2, and CCP3. The optical control units CCP1, CCP2, and CCP3 are spaced apart from each other. As shown in the figure, a segmentation pattern BMP is provided between the spaced-apart optical control units CCP1, CCP2, and CCP3, but the embodiment is not limited to this. The segmentation pattern BMP is shown not to overlap with the optical control units CCP1, CCP2, and CCP3, but the edges of the optical control units CCP1, CCP2, and CCP3 may overlap with the segmentation pattern BMP at least in part.

[0062] In one embodiment, the optical control layer CCL includes a first optical control unit CCP1, a second optical control unit CCP2, and a third optical control unit CCP3, which transmit or convert light provided from the display pad 100. For example, the first optical control unit CCP1 may include a first quantum dot QD1 that converts the second or third light into the first light. The second optical control unit CCP2 includes a second quantum dot QD3 that converts the third light into the second light. The third optical control unit CCP3 transmits the third light.

[0063] For example, a quantum dot may include group II-VI compounds, group III-VI compounds, group I-III-VI compounds, group III-V compounds, group III-II-V compounds, group IV-VI compounds, group IV elements, group IV compounds, and combinations thereof as a core.

[0064] Group II-VI compounds are binary compounds selected from the group consisting of CdSe, CdTe, CdS, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, and mixtures thereof, including CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHg A ternary compound selected from the group consisting of Te, HgZnS, HeZnSe, HeZnTe, MgZnSe, MgZnS, and mixtures thereof, and a quaternary compound selected from the group consisting of HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, and mixtures thereof.

[0065] Group III-VI compounds include dielemental compounds such as In2S3 and In2Se3, trielemental compounds such as InGaS3 and InGaSe3, or any combination thereof.

[0066] Group I-III-VI compounds are selected from the group consisting of AgInS, AgInS2, CuInS, CuInS2, AgGaS2, CuGaS2, CuGaO2, AgGaO2, AgAlO2, and mixtures thereof, or from tetra-element compounds such as AgInGaS2 and CuInGaS2.

[0067] The group III-V compounds are selected from the group consisting of binary compounds selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof; ternary compounds selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InAlP, InNP, InNAs, InNSb, InPAs, InPSb, and mixtures thereof; and quaternary compounds selected from the group consisting of GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and mixtures thereof. On the other hand, the group III-V compounds further contain group II metals. For example, InZnP, InGaZnP, and InAlZnP may be selected as the III-II-V group compound.

[0068] Group IV-VI compounds are selected from the group consisting of binary compounds selected from the group consisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe, and mixtures thereof; ternary compounds selected from the group consisting of SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and mixtures thereof; and quaternary compounds selected from the group consisting of SnPbSSe, SnPbSeTe, SnPbSTe, and mixtures thereof. Group IV elements are selected from the group consisting of Si, Ge, and mixtures thereof. Group IV compounds are binary compounds selected from the group consisting of SiC, SiGe, and mixtures thereof.

[0069] In this case, the binary, ternary, or quaternary compounds either exist within the particle at a uniform concentration or are separated into states with partially different concentration distributions within the same particle. Alternatively, one quantum dot may have a core / shell structure surrounding other quantum dots. In this core / shell structure, there is a concentration gradient where the concentration of elements in the shell decreases as you move towards the core.

[0070] The shell of the quantum dot serves as a protective layer to prevent chemical degradation of the core and maintain its semiconductor properties, and / or as a charging layer to impart electrophoretic properties to the quantum dot. The shell can be a single layer or multiple layers. Examples of the quantum dot shell include metallic or nonmetallic oxides, semiconductor compounds, or combinations thereof.

[0071] For example, the metal or nonmetal oxides include dielemental compounds such as SiO2, Al2O3, TiO2, ZnO, MnO, Mn2O3, Mn3O4, CuO, FeO, Fe2O3, Fe3O4, CoO, Co3O4, and NiO, or trielemental compounds such as MgAl2O4, CoFe2O4, NiFe2O4, and CoMn2O4, but the present invention is not limited to these.

[0072] Furthermore, examples of the semiconductor compound include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, and the like, but the present invention is not limited to these.

[0073] Quantum dots have an emission wavelength spectrum with a full width at half maximum (FWHM) of approximately 45 nm or less, preferably approximately 40 nm or less, and more preferably approximately 30 nm or less. Within this range, color purity and color reproducibility can be improved. Furthermore, since the light emitted through such quantum dots is emitted in all directions, the optical viewing angle is improved.

[0074] Furthermore, the form of the quantum dots is not limited to those commonly used in this field, but more specifically, spherical, pyramidal, multi-arm, or cubic nanoparticles, nanotubes, nanowires, nanofibers, or nanoplate-like particles may be used.

[0075] Quantum dots adjust the hue of the light they emit depending on the size of the particle, resulting in dots having a variety of emission colors such as red, green, and blue.

[0076] For example, the first quantum dot QD1 included in the first optical control unit CCP1 may be a red quantum dot, and the second quantum dot QD2 included in the second optical control unit CCP2 may be a green quantum dot. However, the embodiments of the optical control layer CCL are not limited to this, and the third optical control unit CCP3 may also include quantum dots.

[0077] On the other hand, the optical control layer CCL includes a scatterer SP. The first optical control unit CCP1 includes a first quantum dot QD1 and at least one of the scatterer SPs, the second optical control unit CCP2 includes a second quantum dot QD2 and at least one of the scatterer SPs, and the third optical control unit CCP3 includes a scatterer SP.

[0078] The scatterer SP is an inorganic particle. For example, the scatterer SP may contain at least one of TiO2, ZnO, Al2O3, SiO2, and hollow silica. The scatterer SP contains at least one of TiO2, ZnO, Al2O3, SiO2, and hollow silica, or it is a mixture of two or more substances selected from TiO2, ZnO, Al2O3, SiO2, and hollow silica.

[0079] Each of the first optical control unit CCP1, the second optical control unit CCP2, and the third optical control unit CCP3 includes base resins BR1, BR2, and BR3 for dispersing quantum dots QD1 and QD2 and scatterers SP. In one embodiment, the first optical control unit CCP1 includes first quantum dots QD1 and scatterers SP dispersed in the first base resin BR1, the second optical control unit CCP2 includes second quantum dots QD2 and scatterers SP dispersed in the second base resin BR2, and the third optical control unit CCP1 includes scatterers SP dispersed in the third base resin BR3.

[0080] The base resins BR1, BR2, and BR3 are media in which quantum points QD1, QD2 and scatterers SP are dispersed, and consist of various resin compositions generally referred to as binders. For example, the base resins BR1, BR2, and BR3 are acrylic resins, urethane resins, silicone resins, epoxy resins, etc. The base resins BR1, BR2, and BR3 are transparent resins. In one embodiment, the first base resin BR1, the second base resin BR2, and the third base resin BR3 are either the same as or different from each other.

[0081] The optical control layer CCL includes a barrier layer BFL1. The barrier layer BFL1 prevents the penetration of moisture and / or oxygen (hereinafter referred to as "moisture / oxygen"). The barrier layer BFL1 is placed on top of the optical control units CCP1, CCP2, and CCP3 to block them from being exposed to moisture / oxygen. On the other hand, the barrier layer BFL1 covers the optical control units CCP1, CCP2, and CCP3. In addition, a barrier layer BLF2 may be provided between the optical control units CCP1, CCP2, and CCP3 and the first to third color filters CF1, CF2, and CF3.

[0082] The barrier layers BFL1 and BFL2 include at least one inorganic layer. In other words, the barrier layers BFL1 and BFL2 are formed by including inorganic materials. For example, the barrier layers BFL1 and BFL2 are formed by including silicon nitride, aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride, silicon oxide, aluminum oxide, titanium oxide, tin oxide, cerium oxide, and silicon oxynitride, or a metal thin film with sufficient light transmittance. On the other hand, the barrier layers BFL1 and BFL2 further include an organic film. The barrier layers BFL1 and BFL2 consist of a single layer or multiple layers.

[0083] In one embodiment of the display device DD, the color filter layer CFL is placed on top of the color control layer CCL. For example, the color filter layer CFL may be placed directly on top of the color control layer CCL. In this case, the barrier layer BFL2 may be omitted.

[0084] The color filter layer CFL includes a light-shielding section BM and color filter sections CF1, CF2, and CF3. More specifically, the color filter CFL includes a first filter CF1 that transmits first light, a second filter CF2 that transmits second light, and a third filter CF3 that transmits third light. For example, the first filter CF1 may be a red filter, the second filter CF2 a green filter, and the third filter CF3 a blue filter. Each of the first to third color filters CF1, CF2, and CF3 contains a polymer photosensitive resin and a pigment or dye. The first color filter CF1 contains a red pigment or dye, the second color filter CF2 contains a green pigment or dye, and the third color filter CF3 contains a blue pigment or dye. However, the examples are not limited to this. For example, the third color filter CF3 does not have to contain a pigment or dye. The third color filter CF3 may contain a polymer photosensitive resin or may not contain a pigment or dye.

[0085] The light-shielding section BM is a black matrix. The light-shielding section BM is formed by including an organic or inorganic light-shielding material containing a black pigment or black dye. The light-shielding section BM prevents light leakage and demarcates the boundaries between adjacent color filters CF1, CF2, and CF3. In one embodiment, the light-shielding section BM is formed from a blue filter.

[0086] The first to third color filters CF1, CF2, and CF3 are arranged to correspond to the first pixel area PXA-R, the second pixel area PXA-G, and the third pixel area PXA-B, respectively.

[0087] The base substrate BL provides a base surface on which the color filter layer CFL and the light control layer CCL are arranged. The base substrate BL can be a glass substrate, a metal substrate, a plastic substrate, etc. However, the embodiments are not limited to these, and the base substrate BL may be an inorganic layer, an organic layer, or a composite material layer. Also, contrary to the figures, the base substrate BL may be omitted in one embodiment. If the base substrate BL is omitted, the light control layer CCL and the color filter layer CFL are laminated on the display panel 100 in that order.

[0088] On the other hand, the configuration of the upper display substrate 200 is not limited to this. For example, the upper display substrate 200 may further include a polarizing layer, or the color filter layer CFL may be omitted. The polarizing layer blocks external light that is incident on the display device DD from the outside. For example, the polarizing layer may function to block reflected light that is incident on the display panel 100 and then emitted after light incident on the display device DD from the outside.

[0089] Figure 2b is a cross-sectional view of a light-emitting element ED according to one embodiment.

[0090] Referring to Figure 2b, each of the first to third light-emitting elements ED1, ED2, and ED3 in one embodiment has the structure of the light-emitting element ED shown in the figure.

[0091] The light-emitting element ED includes a first electrode EL1, a second electrode EL2, and a plurality of stacks SF1, SF2, and SF3 stacked between the first electrode EL1 and the second electrode EL2. In one embodiment, the plurality of stacks is provided by two or more stacks. Figure 2b shows a light-emitting element ED provided by three stacks. Specifically, the light-emitting element ED includes a first electrode EL1, a first layer stack SF1, a second layer stack SF2, a third layer stack SF3, and a third electrode EL2. However, the embodiment is not limited to this, and the light-emitting element ED may include two stacks or four or more stacks.

[0092] Each of the first to third stacks SF1, SF2, and SF3 includes a hole transport region (HTR), an emission layer (EML), and an electron transport region (ETR). A charge generation layer (CGL) is placed between adjacent stacks of the first to third stacks SF1, SF2, and SF3. The charge generation layer CGL includes a p-type charge generation layer and / or an n-type charge generation layer. The charge generation layer CGL facilitates the movement of holes and / or charges.

[0093] The first electrode EL1 is conductive. The first electrode EL1 is made of a metallic material, a metal alloy, or a conductive compound. The first electrode EL1 is either an anode or a cathode. However, the examples are not limited to these. The first electrode EL1 is also a pixel electrode. The first electrode EL1 is a transmissive electrode, a semitransmissive electrode, or a reflective electrode. If the first electrode EL1 is a transmissive electrode, it includes transparent metal oxides, such as ITO (indium tin oxide), IZO (indium zinc oxide), ZnO (zinc oxide), ITZO (indium tin zinc oxide), etc. If the first electrode EL1 is a semi-transparent or reflective electrode, the first electrode EL1 contains Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, W, or compounds or mixtures thereof (e.g., a mixture of Ag and Mg). Alternatively, the first electrode EL1 is a multi-layer structure including a reflective or semi-transparent film made of the above-mentioned material, and a transparent conductive film made of ITO, IZO, ZnO, ITZO, etc. For example, the first electrode EL1 may have a three-layer structure of ITO / Ag / ITO, but is not limited to this. Furthermore, the examples are not limited to these, and the first electrode EL1 may contain the above-mentioned metal materials, a combination of two or more metal materials selected from the above-mentioned metal materials, or oxides of the above-mentioned metal materials. The thickness of the first electrode EL1 is approximately 700 Å or more and approximately 10000 Å or less. For example, the thickness of the first electrode EL1 may be approximately 1000 Å or more and approximately 3000 Å or less.

[0094] The hole transport region (HTR) is provided on the first electrode EL1. The hole transport region (HTR) includes at least one of a hole transport layer (HTL) and an electron blocking layer (EBL). However, the examples are not limited to this, and the hole transport region (HTR) may further include a hole injection layer (not shown), a buffer layer (not shown), or a light emission auxiliary layer (not shown). The thickness of the hole transport region (HTR) may be, for example, about 50 Å or more and about 15,000 Å or less.

[0095] The hole transport region (HTR) has a multilayer structure consisting of a single layer made of a single material, a single layer made of multiple different materials, or multiple layers made of multiple different materials.

[0096] For example, the hole transport region HTR may have a single-layer structure consisting of a hole injection layer or a hole transport layer, or a single-layer structure consisting of a hole injection material and a hole transport material. Furthermore, the hole transport region HTR may have a single-layer structure consisting of multiple different materials, or a structure consisting of a hole injection layer / hole transport layer, a hole injection layer / hole transport layer / buffer layer, a hole injection layer / buffer layer, a hole injection layer / buffer layer, a hole transport layer / buffer layer, or a hole injection layer / hole transport layer / electron blocking layer stacked sequentially from the first electrode EL1, but the examples are not limited to these.

[0097] Hole transport regions (HTRs) are formed using a variety of methods, including vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) method, inkjet printing, laser printing, and laser-induced thermal imaging (LITI).

[0098] The hole transport region (HTR) includes compounds represented by the chemical formula H-1 shown below.

[0099] [Chemical formula H-1] [ka]

[0100] In chemical formula H-1, L1 and L2 are independently directly bonded, substituted, or unsubstituted arylene groups with 6 to 30 ring-forming carbon atoms, or substituted or unsubstituted heteroarylene groups with 2 to 30 ring-forming carbon atoms. a and b are independently integers between 0 and 10. On the other hand, if a or b is an integer of 2 or more, then multiple L1 and L2 are independently substituted or unsubstituted arylene groups with 6 to 30 ring-forming carbon atoms, or substituted or unsubstituted heteroarylene groups with 2 to 30 ring-forming carbon atoms.

[0101] In chemical formula H-1, Ar1 to Ar2 are each independently substituted or unsubstituted aryl groups with 6 to 30 ring-forming carbon atoms, or substituted or unsubstituted heteroaryl groups with 2 to 30 ring-forming carbon atoms. Furthermore, in chemical formula H-1, Ar3 is a substituted or unsubstituted aryl group with 6 to 30 ring-forming carbon atoms.

[0102] The compound represented by the chemical formula H-1 is a monoamine compound. Alternatively, the compound represented by the chemical formula H-1 is Ar -1 The compound is a diamine compound in which at least one of Ar1 to Ar2 contains an amine group as a substituent. Alternatively, the compound represented by the chemical formula H-1 is a carbazole compound in which at least one of Ar1 to Ar2 contains a substituted or unsubstituted carbazole group, or a cafluorene compound in which at least one of Ar1 to Ar2 contains a substituted or unsubstituted fluorene group.

[0103] A compound represented by the chemical formula H-1 is represented by any one of the compounds in compound group H below. However, the compounds listed in compound group H below are illustrative examples, and the compound represented by the chemical formula H-1 is not limited to those shown in compound group H below.

[0104] [Compound group H] [ka] [ka] [Chemistry] [Chemistry] [Chemistry]

[0105] The hole transport region HTR may contain phthalocyanine compounds such as copper phthalocyanine, DNTPD (N 1 ,N 1’ -([1,1'-biphenyl]-4,4'-diyl)bis(N 1 -phenyl-N 4 ,N 4 -di-m-tolylbenzene-1,4-diamine)), m-MTDATA (4,4',4''-[tris(3-methylphenyl)phenylamino)triphenylamino], TDATA (4,4',4''-tris(N,N-diphenylamino)triphenylamine), 2-TNATA (4,4',4''-tris[N-(2-naphthyl)-N-phenylamino]-triphenylamine), PEDOT / PSS (poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate), PANI / DBSA (polyaniline / dodecylbenzenesulfonic acid), PANI / CSA (polyaniline / camphorsulfonic acid), PANI / PSS ((polyaniline) / poly(4-styrenesulfonate)), NPB (N,N'-di(naphthalen-1-yl)-N,N'-diphenyl-benzidine), polyether ketone containing triphenylamine (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate, HAT-CN (dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile), etc.

[0106] The hole transport region HTR may include, for example, carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole, fluorene derivatives, triphenylamine derivatives such as TPD (N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine) and TCTA (4,4',4"-tris(N-carbazolyl)triphenylamine), NPB (N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine), TAPC (4,4'-cyclohexylidenebis[N,N'-bis(4-methylphenyl)benzeneamine]), and HMTPD (4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl).

[0107] Furthermore, the hole transport region (HTR) includes CzSi(9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-(carbazole), CCP(9-phenyl-9H-3,9'-bicarbazole), or mDCP(1,3-bis(1,8-dimethyl-9H-carbazole-9-yl)benzene).

[0108] The hole transport region HTR comprises the hole transport region compound described above, and includes at least one of the hole injection layer, hole transport layer, and electron blocking layer.

[0109] The thickness of the hole transport region (HTR) may be between approximately 100 Å and approximately 10,000 Å, for example, between approximately 100 Å and approximately 5,000 Å. If the hole transport region (HTR) includes a hole injection layer, the thickness of the hole injection layer is, for example, between approximately 30 Å and approximately 1,000 Å.

[0110] If the hole transport region (HTR) includes a hole transport layer, the thickness of the hole transport layer is approximately 30 Å to approximately 1000 Å. For example, if the hole transport region (HTR) includes a hole blocking layer, the thickness of the hole blocking layer is, for example, approximately 10 Å to approximately 1000 Å. If the thicknesses of the hole transport region (HTR), hole injection layer, hole transport layer, and electron blocking layer satisfy the above-described ranges, satisfactory hole transport characteristics can be obtained without a substantial increase in driving voltage.

[0111] The hole transport region further includes charge-generating materials in addition to the materials described above to improve conductivity. The charge-generating materials are uniformly or non-uniformly dispersed within the hole transport region (HTR). The charge-generating materials are, for example, p-type dopants. The p-type dopant may, but is not limited to, include at least one of metal halide compounds, quinone derivatives, metal oxides, and cyano group-containing compounds. For example, p-type dopants include metal halide compounds such as CuI and RBI, quinone derivatives such as TCNQ (tetracyanoquinodimethane) and F4-TCNQ (2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane), metal oxides such as tungsten oxide and molybdenum oxide, and cyano group-containing compounds such as HAT-CN (dipyradino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonnitrile) and NDP-9 (4-[[2,3-bis[cyano-(4-cyano-2,3,5,6-tetrafluorophenyl)methylidene]cyclopropylidene]-cyanomethyl]-2,3,5,6-tetrafluorobenzonitrile), but the examples are not limited to these.

[0112] As described above, the hole transport region (HTR) includes at least one of a buffer layer and an electron blocking layer, in addition to the hole transport layer and the hole injection layer. The buffer layer compensates for the resonance distance due to the wavelength of light emitted from the light emission layer (EML) and increases the light emission efficiency. The material included in the buffer layer is a material that can be included in the hole transport region (HTR). The electron blocking layer prevents the injection of electrons from the electron transport region (ETR) into the hole transport region (HTR).

[0113] The luminescent layer EML is provided on top of the hole transport region HTR. The luminescent layer EML has a thickness of, for example, about 100 Å to about 1000 Å, or about 100 Å to about 300 Å. The luminescent layer EML has a multilayer structure having a single layer made of a single material, a single layer made of multiple different materials, or multiple layers made of multiple different materials.

[0114] In one embodiment of the light-emitting element ED, the light-emitting layer EML contains an anthracene derivative, a pyrene derivative, a fluorantene derivative, a chrysene derivative, a dihydrobenzanthracene derivative, or a triphenylene derivative. More specifically, the light-emitting layer EML may contain an anthracene derivative or a pyrene derivative.

[0115] In one embodiment of the light-emitting element ED, the light-emitting layer EML contains a host and a dopant, but the light-emitting layer EML contains a compound represented by the following chemical formula E-1. The compound represented by the following chemical formula E-1 is used as a fluorescent host material.

[0116] [Chemical formula E-1] [ka]

[0117] In chemical formula E-1, R 31 ~R 40 Each of these is independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted silyl group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms that form a ring, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms that form a ring by bonding with an adjacent group. On the other hand, R 31 ~R 40 These groups bond with adjacent groups to form saturated or unsaturated hydrocarbon rings.

[0118] In chemical formula E-1, c and d are each independent integers between 0 and 5 (inclusive).

[0119] Chemical formula E-1 is represented by one of the following compounds E1 through E19.

[0120] [ka] [ka]

[0121] In one embodiment, the light-emitting layer EML contains a compound represented by the following chemical formula E-2a or chemical formula E-2b. The compound represented by the following chemical formula E-2a or chemical formula E-2b is used as a phosphorescent host material.

[0122] [Chemical formula E-2a] [ka]

[0123] In chemical formula E-2a, a is an integer between 0 and 10, and L a is a directly bonded, substituted, or unsubstituted ring-forming allylene group with 6 to 30 carbon atoms, or a substituted or unsubstituted ring-forming heteroalylene group with 2 to 30 carbon atoms. On the other hand, if a is an integer of 2 or more, L a Each of these is independently a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms.

[0124] In chemical formula E-2a, A1 to A5 are each independently N or CR. i That is. R a ~R i Each of these groups is independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted amine group, a substituted or unsubstituted thio group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted ring-forming aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted ring-forming heteroaryl group having 2 to 30 carbon atoms, or is bonded to an adjacent group to form a ring. a ~R i These groups bond with adjacent groups to form a hydrocarbon ring or a heterocycle containing N, O, S, etc., as ring-forming atoms.

[0125] On the other hand, in chemical formula E-2a, two or three selected from A1 to A5 are N and the rest are CR. i That is the case.

[0126] [Chemical formula E-2b] [ka]

[0127] In the chemical formula E-2b, Cbz1 and Cbz2 are each independently a carbazole group or a carbazole group substituted with an aryl group having 6 to 30 ring-forming carbon atoms. b is a directly bonded, substituted, or unsubstituted ring-forming arylene group with 6 to 30 carbon atoms, or a substituted or unsubstituted ring-forming heteroarylene group with 2 to 30 carbon atoms. On the other hand, b is an integer between 0 and 10, and if b is an integer of 2 or more, then multiple L b Each of these is independently a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms.

[0128] The compound represented by chemical formula E-2a and the compound represented by E-2b are each represented by one of the compounds in compound group E-2 below. However, the compounds listed in compound group E-2 below are illustrative examples, and the compounds represented by chemical formula E-2a or chemical formula E-2b are not limited to those shown in compound group E-2 below.

[0129] [Compound group E-2] [ka] [ka]

[0130] The luminescent layer EML may further contain common materials known in the relevant art as host materials. For example, the luminescent layer EML may contain DPEPO (bis[2-(diphenylphosphino)phenyl] ether oxide), CBP (4,4-bis(carbazole-9-yl)biphenyl), mCP (1,3-bis(carbazole-9-yl)benzene), PPF (2,8-bis(diphenylphosphoryl)dibenzo[b,d]furan), TCTA (4,4',4”-tris(carbazole-9-yl)-triphenyl It may contain at least one of the following: methyl )Anthracene), TCTA (4,4',4"-Tris(carbazole-9-yl)-triphenylamine), TPBi (1,3,5-Tris(N-phenylbenzimidazole-2-yl)benzene), TBADN (2-tert-butyl-9,10-di(naphtho-2-yl)anthracene), DSA (distyryl allylene), CDBP (4,4'-bis(9-carbazolyl)-2,2'-dimethylbiphenyl), MA DN (2-methyl-9,10-bis(naphthalene-2-yl)anthracene), CP1 (hexaphenylcyclotriphosphazene), UGH2 (1,4-bis(triphenylsilyl)benzene), DPSiO3 (hexaphenylcyclotrisiloxane), DPSiO4 (octaphenylcyclotetrasiloxane), PPF (2,8-bis(diphenylphospholyl)dizenzofuran), etc. may be used as host materials.

[0131] In one embodiment, the light-emitting layer EML contains a compound represented by the following chemical formula Ma or chemical formula Mb. The compound represented by the following chemical formula Ma or chemical formula Mb is used as a phosphorescent dopant material.

[0132] [Chemical formula Ma] [ka]

[0133] In the chemical formula Ma, Y1 to Y4 and Z1 to Z4 are each independently CR1 or N, and R1 to R4 are each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted amine group, a substituted or unsubstituted thio group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted ring-forming aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted ring-forming heteroaryl group having 2 to 30 carbon atoms, or are bonded to adjacent groups to form a ring. In the chemical formula Ma, m is 0 or 1, and n is 2 or 3. In the chemical formula Ma, if m is 0, then n is 3, and if m is 1, then n is 2.

[0134] Compounds represented by the chemical formula Ma are used as red phosphorescent dopants or green phosphorescent dopants.

[0135] A compound represented by the chemical formula Ma can be any one of the compounds in the following group of compounds M-a1 to M-a19. However, the compounds M-a1 to M-a19 are illustrative examples, and the compound represented by the chemical formula Ma is not limited to those represented by the compounds M-a1 to M-a19.

[0136] [ka] [ka] [ka] [ka]

[0137] Compounds M-a1 and M-a2 are used as red dopant materials, and compounds M-a3 through M-a5 are used as green dopant materials.

[0138] [Chemical formula Mb] [ka]

[0139] In chemical formula Mb, Q1 and Q4 are independently C or N, and C1 to C4 are independently substituted or unsubstituted hydrocarbon rings with 5 to 30 carbon atoms, or substituted or unsubstituted heterocycles with 2 to 30 carbon atoms.

[0140] L 21 ~L 24 Each is independently and directly connected. JPEG0007833275000020.jpg72139 The group is a substituted or unsubstituted divalent alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms, where e1 to e4 are each independently 0 or 1.

[0141] R 31 ~R 39 Each of these groups is independently a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms that form a ring, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms that form a ring by bonding with adjacent groups, and each of d1 to d4 is independently an integer between 0 and 4.

[0142] The compound represented by the chemical formula Mb is used as a blue phosphorescent dopant or a green phosphorescent dopant.

[0143] A compound represented by the chemical formula Mb is one of the following compounds. However, the following compounds are illustrative examples, and the compound represented by the chemical formula Mb is not limited to those listed below.

[0144] [ka]

[0145] In chemical compounds, R, R 38 , and R 39 Each of these is independently a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms.

[0146] The EML (Emitting Layer) contains a compound represented by any one of the following chemical formulas: Fa to Fc. These compounds are used as fluorescent dopant materials.

[0147] [Chemical formula Fa] [ka]

[0148] In the aforementioned chemical formula Fa, R a ~R j The two selected from among them are independent of each other. JPEG0007833275000023.jpg837 It is replaced by R. a ~R j among JPEG0007833275000024.jpg837 The remaining unsubstituted atoms are, independently, a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. JPEG0007833275000025.jpg838 In this example, Ar1 and Ar2 are each independently substituted or unsubstituted aryl groups with 6 to 30 ring-forming carbon atoms, or substituted or unsubstituted heteroaryl groups with 2 to 30 ring-forming carbon atoms. For example, at least one of Ar1 and Ar2 is a heteroaryl group containing O or S as a ring-forming atom.

[0149] [Chemical formula Fb] [ka]

[0150] In the chemical formula Fb, R a and R b Each of these groups is independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted ring-forming alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted ring-forming aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted ring-forming heteroaryl group having 2 to 30 carbon atoms, or is bonded to an adjacent group to form a ring.

[0151] In the chemical formula Fb, U and V are independently substituted or unsubstituted hydrocarbon rings with 5 to 30 carbon atoms, or substituted or unsubstituted heterocycles with 2 to 30 carbon atoms.

[0152] In chemical formula Fb, the number of rings represented by U and V is either 0 or 1, independently of each other. For example, in chemical formula Fb, if the number of U or V is 1, it means that one ring constitutes a fused ring in the part represented by U or V, and if the number of U or V is 0, it means that there are no rings represented by U or V. More specifically, if the number of U is 0 and the number of V is 1, or if the number of U is 1 and the number of V is 0, the fused ring with a fluorene core in chemical formula Fb is a tetracyclic compound. Also, if the number of both U and V is 0, the fused ring with a fluorene core in chemical formula Fb is a tricyclic compound. Furthermore, if the number of both U and V is 1, the fused ring with a fluorene core in chemical formula Fb is a quintic cyclic compound.

[0153] [Chemical formula Fc] [ka]

[0154] In the chemical formula Fc, A1 and A2 are independently O, S, Se, or NR, respectively. m And R m R1 to R 11 Each of these groups is independently a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted amine group, a substituted or unsubstituted boryl group, a substituted or unsubstituted oxy group, a substituted or unsubstituted thio group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, or is bonded to an adjacent group to form a ring.

[0155] In the chemical formula Fc, A1 and A2 independently bond to substituents on adjacent rings to form fused rings. For example, A1 and A2 independently bond to NR mIn that case, A1 will bond with R4 or R5 to form a ring. Also, A2 will bond with R7 or R8 to form a ring.

[0156] In one embodiment, the luminescent layer EML is a known dopant material, and is a styryl derivative (e.g., 1,4-bis[2-(3-N-ethylcarbazol)vinyl]benzene (BCzVB), 4-(di-p-tolylamino)-4'-[(di-p-tolylamino)styryl]stilbene (DPAVB), N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalen-2-yl)vinyl)phenyl This includes )-N-phenylbenzeneamine (N-BDAVBi), 4,4'-bis[2-(4-(N,N-diphenylamino)phenyl)vinyl]biphenyl (DPAVBi), perylene and its derivatives (e.g., 2,5,8,11-tetra-t-butylperylene (TBP)), pyrene and its derivatives (e.g., 1,1'-dipylene, 1,4-dipyrenylbenzene, 1,4-bis(N,N-diphenylamino)pyrene, etc.).

[0157] The luminescent layer EML contains known phosphorescent dopant materials. For example, metal complexes containing iridium (Ir), platinum (Pt), osmium (Os), gold (Au), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), or thulium (Tm) may be used as phosphorescent dopants. Specifically, Flrpic (iridium(III)bis(4,6-difluorophenylpyridinate-N,C2')picolinate), Fir6 (bis(2,4-difluorophenylpyridinate)-tetrakis(1-pyrazolyl)borate-iridium(III)) or PtOEP (platinum-octaethylporphyrin) may be used as phosphorescent dopants. However, the examples are not limited to these.

[0158] The light-emitting layers (EMLs) contained in each of the first to third layers SF1, SF2, and SF3 emit different light from each other. For example, one of the light-emitting layers (EMLs) contained in the first to third layers SF1, SF2, and SF3 may emit light different from the other two. However, the embodiment is not limited to this, and the light-emitting layers (EMLs) contained in each of the first to third layers SF1, SF2, and SF3 may all emit the same light.

[0159] An electron transport region (ETR) is positioned above the light-emitting layer (EML).

[0160] The hole transport region (HTR) includes at least one of the electron transport layer (ETL) and the hole blocking layer (HBL). However, the examples are not limited to this, and the electron transport region (ETR) may further include an electron injection layer, a buffer layer (not shown), or an emissive layer (not shown).

[0161] The electron transport region (ETR) has a multilayer structure consisting of a single layer made of a single material, a single layer made of multiple different materials, or multiple layers made of multiple different materials.

[0162] For example, the electron transport region (ETR) may have a single-layer structure consisting of an electron injection layer or an electron transport layer ETL, or a single-layer structure consisting of an electron injection material and an electron transport material. Furthermore, the electron transport region (ETR) may have a single-layer structure consisting of multiple different materials, or a structure in which electron transport layers / electron injection layers, hole element layers / electron transport layers / electron injection layers are stacked in order from the light-emitting layer (EML), but is not limited to these.

[0163] The electron transport region (ETR) is formed using a variety of methods, including vacuum deposition, spin coating, Langmuir-Blodgett (LB) method, inkjet printing, laser printing, and laser-induced thermal imaging (LITI).

[0164] In one embodiment, the electron transport layer (ETL) further includes a conductive material to improve conductivity. The conductive material is uniformly or non-uniformly dispersed within the electron transport layer (ETL). The conductive material is a conductor or semiconductor. For example, the conductive material has an electrical conductivity of 10 -4 Ω -1 m -1 The above 10 7 Ω -1 m -1 The following are also acceptable:

[0165] For example, the conductive material is a p-type dopant. More specifically, the electron transport layer contains at least one of the following: metal halide compounds such as CuI and RbI, quinone derivatives such as TCNQ and F4-TCNQ, metal oxides such as tungsten oxide and molybdenum oxide, and cyano group-containing compounds such as HAT-CN and NDP-9.

[0166] In addition, the electron transport region (ETR) includes known electron transport materials. For example, the electron transport region (ETR) includes compounds represented by the following chemical formula ET-1.

[0167] [Chemical ET-1] [ka]

[0168] In the chemical formula ET-1, at least one of X1 to X3 is N and the rest are CR. a That is. R a Each of the following is a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and each of Ar1 to Ar3 is independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms.

[0169] In chemical formula ET-1, a to c are each independently integers between 0 and 10. In chemical formula ET-1, L1 and L3 are each independently arylene groups with 6 to 30 ring-forming carbon atoms, either directly bonded, substituted, or unsubstituted, or heteroarylene groups with 2 to 30 ring-forming carbon atoms, either directly bonded, substituted, or unsubstituted. On the other hand, if a to c are integers of 2 or more, then multiple L1 and L3 are each independently substituted or unsubstituted arylene groups with 6 to 30 ring-forming carbon atoms, or heteroarylene groups with 2 to 30 ring-forming carbon atoms, either substituted or unsubstituted.

[0170] The electron transport region (ETR) includes anthracene compounds. However, it is not limited to these; electron transport region ETRs include, for example, Alq3 (tris(8-hydroxyquinolinato)aluminum), 1,3,5-tri[(3-pyridyl)phen-3-yl]benzene, 2,4,6-tris(3'-pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzimidazole-1-yl)phenyl)-9,10-dinaphthylanthracene, TPBi (1,3,5-tri(1-phenyl-1H-benzo[d]imidazole-2-yl)benzene), BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), Bphen (4,7-diphenyl-1,10-phenanthroline), TAZ (3-(4-biphenyl The following may be included: (4-(naphthalene-1-yl)-3,5-diphenyl-4H-1,2,4-triazole), NTAZ (4-(naphthalene-1-yl)-3,5-diphenyl-4H-1,2,4-triazole), tBu-PBD (2-(4-biphenylyl)-5-(4-tertobutylphenyl)-1,3,4-oxadiazole), BAlq (bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-biphenyl-4-orato)aluminum), Bebq2 (beryllium bis(benzoquinoline-10-orato), ADN (9,10-di(naphthalene-2-yl)anthracene), BmPyPhB (1,3-bis[3,5-di(pyridine-3-yl)phenyl]benzene), and mixtures thereof.

[0171] The electron transport region (ETR) includes at least one of the following compounds ET1 to ET36.

[0172] [ka] [ka] [ka] [ka] [ka] [ka]

[0173] Furthermore, the electron transport region (ETR) includes metal halides such as LiF, NaCl, CsF, RbCl, Rbl, Cul, and Kl, lanthanum group metals such as Yb, or co-deposited materials of the aforementioned metal halides and lanthanum group metals. For example, the electron transport region (ETR) may include Kl:Yb, Rbl:Yb, etc., as co-deposited materials. On the other hand, the electron transport region (ETR) may also use metal oxides such as Li2O and BaO, or Liq (8-hydroxylithium quinolate), but the examples are not limited to these. The electron transport region (ETR) also consists of a mixture of an electron transport material and an insulating organometallic salt. The organometallic salt is a material with an energy band gap of approximately 4 eV or more. For more details, organometallic salts include, for example, metal acetate, metal benzoate, metal acetoacetate, metal acetylacetonate, or metal stearate.

[0174] The electron transport region (ETR) may, but is not limited to, further contain at least one of BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) and Bphen (4,7-diphenyl-1,10-phenanthroline) in addition to the materials described above.

[0175] The electron transport region ETR comprises the aforementioned electron transport region compound, at least one of the electron injection layer EIL, electron transport layer ETL, and hole blocking layer HBL.

[0176] If the electron transport region (ETR) includes an electron transport layer (ETL), the thickness of the electron transport layer (ETL) may be between approximately 100 Å and approximately 1000 Å, for example, between approximately 150 Å and approximately 500 Å. If the thickness of the electron transport layer (HTL) satisfies the above-mentioned range, satisfactory electron transport characteristics can be obtained without a substantial increase in the driving voltage. If the electron transport region (ETR) includes an electron injection layer (EIL), the thickness of the electron injection layer (EIL) may be between approximately 1 Å and approximately 100 Å, or between approximately 3 Å and 90 Å. If the thickness of the electron injection layer (EIL) satisfies the above-mentioned range, satisfactory electron injection characteristics can be obtained without a substantial increase in the driving voltage.

[0177] In one embodiment, the light-emitting element ED includes an electron injection layer EIL below the second electrode EL2. However, the embodiment is not limited to this, and the electron injection layer may be placed in the electron transport region ETR included in the first to third layers SF1, SF2, and SF3, respectively.

[0178] The electron injection layer (EIL) contains a lanthanum group metal such as Yb. However, the examples are not limited to this, and the electron injection layer (EIL) may also be a metal halide such as LiF, NaCl, CsF, RbCl, RbI, a metal oxide such as Li2O, BaO, or Liq (lithium quinolate). Furthermore, the electron injection layer (EIL) consists of a mixture of an electron transport material and an insulating organometallic salt. The organometallic salt is a substance with an energy band gap of approximately 4 eV or higher. Specifically, for example, organometallic salts include metal acetate, metal benzoate, metal acetoacetate, metal acetylacetonate, or metal stearate.

[0179] The second electrode EL2 is provided on the electron transport region ETR. The second electrode EL2 is a common electrode. The second electrode EL2 may be a cathode or an anode, but the embodiment is not limited to this. For example, if the first electrode EL1 is an anode, the second electrode may be a cathode, and if the first electrode EL1 is a cathode, the second electrode may be an anode.

[0180] The second electrode EL2 is a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. If the second electrode EL2 is a transmissive electrode, it is made of a transparent metal oxide, such as ITO (indium tin oxide), IZO (indium zinc oxide), ZnO (zinc oxide), or ITZO (indium tin zinc oxide).

[0181] If the second electrode EL2 is a semi-transparent or reflective electrode, the second electrode EL2 contains Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, Yb, W, or compounds or mixtures containing these (e.g., Al-Li, Mg-In, AgMg, AgYb, or MgAg). Alternatively, the second electrode EL2 is a multi-layer structure including a reflective or semi-transparent film made of the above-mentioned material, and a transparent conductive film made of ITO, IZO, ZnO, ITZO, etc. For example, the second electrode EL2 may contain the above-mentioned metallic material, a combination of two or more metallic materials selected from the above-mentioned metallic materials, or an oxide of the above-mentioned metallic material.

[0182] The first to third light-emitting elements ED1, ED2, and ED3 each independently contain the aforementioned material in their hole transport region (HTR), light-emitting layer (EML), and electron transport region (ETR).

[0183] Figures 3a and 3b are schematic cross-sectional views showing a light-emitting element according to one embodiment. Figures 3a and 3b show the first to third light-emitting elements ED1, ED2, and ED3 included in the display device DD of Figure 2a, respectively. Figures 3a and 3b show that a capping layer CPL is further arranged on the first to third light-emitting elements ED1, ED2, and ED3 of Figure 2a. The capping layer CPL can be multilayer or monolayer. In one embodiment, the capping layer CPL is an organic layer or an inorganic layer. For example, if the capping layer CPL contains an inorganic material, the inorganic material may include alkali metal compounds such as LiF, alkaline earth compounds such as MgF2, SiON, SiNx, SiOy, etc.

[0184] For example, if the capping layer CPL contains organic matter, the organic matter may include α-NPD, NPB, TPD, m-MTDATA, Alq3, CuPc, TPD15 (N4,N4,N4',N4'-tetra(biphenyl-4-yl)biphenyl-4,4'-diamine), TCTA (4,4',4”-tris(carbazolesol-9-yl)triphenylamine), or epoxy resin, or acrylates such as methacrylate. However, the examples are not limited to these, and the capping layer CPL may contain at least one of the compounds P1 to P5 described below.

[0185] [ka] [ka] [ka] [ka] [ka]

[0186] However, the examples are not limited to these, and the capping layer (CPL) may be omitted.

[0187] Referring to Figure 3a, in one embodiment, each of the first to third light-emitting elements ED1, ED2, and ED3 is shown to include three stacks. More specifically, each of the first to third light-emitting elements ED1, ED2, and ED3 is shown to include three stacks corresponding to the first to third layer stacks SF1, SF2, and SF3 described in Figure 2b. However, the embodiment is not limited to this, and each of the first to third light-emitting elements ED1, ED2, and ED3 may include two stacks, or four or more stacks.

[0188] In one embodiment, the first light-emitting element ED1 includes a first stack ST-G as the first layer stack SF1 as described in Figures 2a and 2b, a first stack ST-G as the second layer stack SF2, and a first stack ST-B as the third layer stack SF3. In other words, the first light-emitting element ED1 includes two first stacks ST-G and one second stack ST-B. However, the stacking order of the first stacks ST-G and the second stacks ST-B is not limited to this. For example, the second stack ST-B may be the first layer stack SF1 or the second layer stack SF2. Furthermore, the configuration of the first light-emitting element ED1 is not limited to this. For example, the first light-emitting element ED1 may include four stacks, or it may include, for example, three second stacks ST-B and one first stack ST-G.

[0189] A charge generation layer is placed between stacks ST-G and ST-B. More specifically, a p-type charge generation layer P-CGL and an n-type charge generation layer N-CGL are stacked and placed between stacks ST-G and ST-B. The p-type charge generation layer P-CGL and the n-type charge generation layer N-CGL facilitate the movement of holes and / or charges between stacks ST-G and ST-B.

[0190] The first stack, ST-G, emits the second light, and the second stack, ST-B, emits the third light. For example, the first stack, ST-G, may emit green light, and the second stack, ST-B, may emit blue light.

[0191] The first stack ST-G and the second stack ST-B each include the hole transport region, light-emitting layer, and electron transport region described above. In Figure 3a, the electron transport region is simply shown to include an electron transport layer, and the hole transport region is simply shown to include a hole transport layer. For example, the first stack ST-G may include a first hole transport HTL1, a first light-emitting layer EML-G, and a first electron transport layer ETL1. The first light-emitting layer EML-G emits second light.

[0192] For example, the second stack ST-B may include a second hole transport HTL2, a second light-emitting layer EML-B, and a second electron transport layer ETL2. The second light-emitting layer EML-B emits a third light.

[0193] However, the examples are not limited to these, and the first stack ST-G and the second stack ST-B may each further include an electron injection layer, a hole blocking layer, a hole transport layer, an electron blocking layer, a buffer layer, and so on.

[0194] The first light-emitting element ED1 includes both the first stack ST-G and one second stack ST-B, and emits second and third light. The first light control unit CCP1 superimposed on the first light-emitting element ED1 includes the first quantum dot QD1, and converts the second and third light into first light.

[0195] In one embodiment, the second light-emitting element ED2 has the same structure as the first light-emitting element ED1. For example, the second light-emitting element ED2 may include two first stacks ST-G and one second stack ST-B.

[0196] The second light-emitting element ED2 includes the first stack ST-G as the first layer stack SF1 as described in Figures 2a and 2b, the first stack ST-G as the second layer stack SF2, and the first stack ST-B as the third layer stack SF3. However, the stacking order of the first stack ST-G and the second stack ST-B is not limited to this, and the configuration of the second light-emitting element ED2 is not limited to this. The second light-emitting element ED2 has the same stacking structure as the first light-emitting element ED1, but the stacking structures of stacks ST-G and ST-B are diverse.

[0197] In one embodiment, the second light-emitting element ED2 includes both the first stack ST-G and one second stack ST-B, and emits second and third light. The second light control unit CCP2 superimposed on the second light-emitting element ED2 includes a second quantum dot QD2, which transmits the second light, or converts the third light into the second light and transmits the second light.

[0198] The third light-emitting element ED3 of one embodiment has a different structure from the first light-emitting element ED1 and the second light-emitting element ED2. For example, the third light-emitting element ED3 may include three second stacks ST-B. Specifically, in the third light-emitting element ED3, the first to third stacks SF1, SF2, and SF3 are all third stacks ST-B.

[0199] On the other hand, in the light-emitting elements ED1, ED2, and ED3 of one embodiment shown in Figure 3a, the third stack SF3 (see Figure 2a) of the first to third light-emitting elements ED1, ED2, and ED3 is all the second stack ST-B, so the third stack SF3 (see Figure 2a) of the first to third light-emitting elements ED1, ED2, and ED3 have a single shape. The bank BK, which is placed on the pixel definition film PDL, is superimposed on the first direction DR1 with the first layer stack SF1 (see Figure 2a) and the second layer stack SF3 (see Figure 2a) of the third light-emitting element ED3, but not with the third layer stack SF3 (see Figure 2a). However, the embodiment is not limited to this.

[0200] The first hole transport layer HTL1 and the second hole transport layer HTL2 are simplified representations of the first hole transport region HTR1 and the second hole transport region HTR2, respectively. The first electron transport layer ETL1 and the second electron transport layer ETL2 are simplified representations of the first electron transport region ETR1 and the second electron transport region ETR2, respectively.

[0201] In one embodiment, the first light-emitting layer EML-G of the first stack ST-G emits second light. For example, the first light-emitting layer EML-G may emit green light, or more specifically, it may emit green phosphorescence.

[0202] In one embodiment, the second light-emitting layer EML-B of the second stack ST-B emits the third light. For example, the second light-emitting layer EML-B may emit blue light, and specifically, it may emit blue phosphorescent light.

[0203] The display device DD of the present invention emits green phosphorescent light and blue phosphorescent light from the first light-emitting layer EML-G and the second light-emitting layer EML-B, respectively, thereby improving the luminous efficiency of the display device DD.

[0204] Specifically, compared with a display device in which the light-emitting layer emits only blue light, in the display device of the present invention, since the light-emitting layer emits both green light and blue light, the light conversion rate of green light in the light control layer CCL is improved. As a result, compared with a display device in which the light-emitting layer emits only blue light, the light amount of light having a central wavelength of 500 nm or more and 550 nm or less in the display device of the present invention increases by 60% or more.

[0205] In addition, the first light-emitting layer EML-G emits phosphorescent light, and the second light-emitting layer EML-B emits fluorescent light, thereby increasing the luminous efficiency of the display device of the present invention. The internal quantum efficiency of fluorescent emission is theoretically 25% or more and 62.5%, and the internal quantum efficiency of phosphorescent emission is at most 100%. The display device of one embodiment emits both phosphorescent light and fluorescent light in the light-emitting layer, thereby further improving the luminous efficiency compared with a display device in which the light-emitting layer emits only fluorescent light.

[0206] The first electron transport layer ETL is disposed on the first light-emitting layer EML-G. The second electron transport layer ETL2 is disposed on the second light-emitting layer EML-B. Since the first light-emitting layer EML-G and the second light-emitting layer EML-B emit different lights, the electron mobilities of the first electron transport layer ETL1 and the second electron transport layer ETR2 are adjusted to be different from each other.

[0207] For example, the electron mobility of the first electron transport layer ETL1 may be higher than the electron mobility of the second electron transport layer ETL2. Specifically, the concentration of the conductive substance contained in the first electron transport layer ETL1 is higher than the concentration of the conductive substance contained in the second electron transport layer ETL2.

[0208] For example, the conductive material may contain a p-type dopant. Specifically, the conductive material contains at least one of NDP-9, HAT-CN, F4-TCNQ, and TCNQ.

[0209] For example, the concentration of NDP-9 contained in the first electron transport layer ETL1 is higher than the concentration of NDP-9 contained in the second electron transport layer ETL2, whereby the electron mobility of the first electron transport layer ETL1 is higher than the electron mobility of the second electron transport layer ETL2.

[0210] Also, the concentration of the insulating material contained in the first electron transport layer ETL1 is lower than the concentration of the insulating material contained in the second electron transport layer ETL2. The insulating material has an electrical conductivity of 10 -4 Ω -1 m -1 or less.

[0211] For example, the insulating material may contain a metal halide or an oxide having a dielectric constant of 5 or more.

[0212] Specifically, the insulating material contains at least one of an alkali halide and a lanthanum halide. For example, the insulating material may contain any one of Li, Na, K, Rb, Cs, and Fr which are alkali metals and any one of F, Cl, Br, I, At, and Ts which are halogen elements. Or it may contain any one of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu which are lanthanide metals and any one of F, Cl, Br, I, At, and Ts which are halogen elements.

[0213] Specifically, the insulating material is an oxide having a dielectric constant of 5 or more, and is hafnium oxide (HfO x ), zirconium oxide (ZrO x ), lanthanum oxide (LaO x ), tantalum oxide (TaO x ), aluminum oxide (Al x O y ), silicon oxide (SiO x), strontium oxide (SrO), yttrium oxide (Y2O3), calcium oxide (CaO), barium oxide (BaO), magnesium oxide (MgO), titanium oxide (TiO2), zirconium-silicon oxide (ZrSiO4), hafnium-silicon oxide (HfSiO4), barium-zirconium oxide (BaZrO), and lanthanum-aluminum oxide (LaAlO x ) includes at least one of the following.

[0214] Figure 3 shows the electron injection layer EIL superimposed on the first to third pixel regions PXA-R, PXA-G, and PXA-B, forming a single, integrated shape. However, the embodiment is not limited to this, and the electron injection layer EIL may contain different materials for each pixel region, or the concentration of the materials may be adjusted to differ depending on the underlying pixel region to which it is superimposed. Specifically, as mentioned above, the electron injection layer EIL further contains LiF and Liq in addition to lanthanum group metals such as Yb. For example, the concentrations of LiF and Liq in the electron injection layer superimposed on the first pixel region PXA-R and the second pixel region PXA-G may be adjusted to be lower than the concentrations of LiF and Liq in the electron injection layer superimposed on the third pixel region PXA-B. This adjusts the balance of the first to third light-emitting elements ED1, ED2, and ED3 in the display device DD, thereby improving its lifespan.

[0215] Referring to Figure 3b, in one embodiment, each of the first light-emitting element ED1 and the second light-emitting element ED2 includes three first stacks ST-G. More specifically, in each of the first light-emitting element ED3 and the second light-emitting element ED2, the first to third stacks SF1, SF2, and SF3 (see Figure 2b) are all first stacks ST-G. As a result, each of the first light-emitting element ED1 and the second light-emitting element ED2 emits second light. For example, each of the first light-emitting element ED1 and the second light-emitting element ED2 may emit green light.

[0216] The third light-emitting element ED3 of one embodiment has a different structure from the first light-emitting element ED1 and the second light-emitting element ED2. For example, the third light-emitting element ED3 may include three second stacks ST-B. Specifically, in the third light-emitting element ED3, the first to third stacks SF1, SF2, and SF3 (see Figure 2b) are all third stacks ST-B. As a result, the third light-emitting element ED3 emits a third light. For example, the third light-emitting element ED3 may emit blue light.

[0217] The third light-emitting element ED3 does not have to have the same shape as the first light-emitting element ED1 and the second light-emitting element ED2. For example, the third light-emitting element ED3 may be separated from the first light-emitting element ED1 and the second light-emitting element ED2 by a pixel definition film PDL and a bank BK. In the drawings, the pixel definition film PDL and the bank BK are shown to have separate shapes, but this is not limited to this, and the pixel definition film PDL and the bank BK may have a single shape. For example, the pixel definition film PDL and the bank BK may contain different materials from each other.

[0218] Figure 4 is a cross-sectional view of a display device DD-1 according to one embodiment.

[0219] Referring to Figure 4, the configuration of the first to third light control units CCP1, CCP2, and CCP3 is varied depending on the light emitted from the first to third light-emitting elements ED1, ED2, and ED3.

[0220] For example, in the display device DD-1 of one embodiment, the first light-emitting element ED1 and the second light-emitting element DE2 may emit second light, and the third light-emitting element ED3 may emit third light. More specifically, the first light-emitting element ED1 and the second light-emitting element ED2 may emit green phosphorescence, and the third light-emitting element ED3 may emit blue phosphorescence.

[0221] In one embodiment, the first optical control unit CCP1 includes a first quantum dot QD1, a first base resin BR1, and a scatterer SP. The first optical control unit CCP1 converts the second light emitted from the first light-emitting element ED1 into first light using the first quantum dot QD1.

[0222] The second light control unit CCP2 of an embodiment includes a second base resin BR2 and a scatterer SP. For example, the second light control unit CCP2 may not include the second quantum dot QD2. The second light control unit CCP2 transmits the second light emitted from the second light emitting element ED2.

[0223] The third light control unit CCP3 of an embodiment includes a third base resin BR2 and a scatterer SP. The third light control unit CCP3 transmits the third light emitted from the third light emitting element ED3.

[0224] Hereinafter, the characteristic evaluation of the light emitting element of the present invention will be described with reference to specific examples. However, the present invention is not limited to the following examples.

[0225] (Example - Fabrication and Evaluation of Light Emitting Element) Table 1 shows the dopants and doping concentrations of the first electron transport layer and the second electron transport layer included in each of the light emitting elements of Examples 1 to 9 and Comparative Example 1.

[0226] The first electron transport layer is an electron transport layer that overlaps with the red pixel region and the green pixel region, and the second electron transport layer is an electron transport layer that overlaps with the blue pixel region.

[0227] In Examples 1 to 9 and Comparative Example 1, the first electron transport layer was fabricated by doping the following compound ET1 with Liq or NDP-9. In Examples 1 to 9 and Comparative Example 1, the second electron transport layer was fabricated by doping the compound ET1 with Liq, SmF3, or YbF3.

[0228] According to the above, NDP-9 has higher conductivity than SmF3 and YbF3, and SmF3 and YbF3 have higher insulation than NDP-9. Also, Liq was used as a material with strong insulation.

[0229] [Chemical formula] [Chemical formula]

[0230] [Table 1]

[0231] Referring to Table 1, in the light-emitting element of Example 1, the doping concentration of Liq in the first electron transport layer was lower than that of Liq in the second electron transport layer. In the light-emitting elements of Examples 2 to 9, the first electron transport layer is compound ET1 doped with the conductive material NDP-9, and the second electron transport layer is compound ET1 doped with the insulating materials SmF3 and YbF3.

[0232] In Comparative Example 1, the doping concentration of Liq in the first electron transport layer was the same as the doping concentration of Liq in the second electron transport layer.

[0233] In other words, in the light-emitting devices of Examples 1 to 9, the electron mobility of the first electron transport layer is manufactured to be higher than that of the second electron transport layer. In the light-emitting device of Comparative Example 1, the electron mobility of the first electron transport layer and the electron mobility of the second electron transport layer are manufactured to be the same.

[0234] Table 2 compares the drive voltage, efficiency, and lifetime of the light-emitting elements fabricated in Table 1. The drive voltages shown in Table 2 are measured with a current of 10 mA. Lifetime is the time it takes for the brightness of the light-emitting element to drop to 97% of its initial value.

[0235] In Table 2, efficiency and device lifespan are shown as relative values ​​based on Comparative Example 1. In other words, efficiency and lifespan represent relative percentages when the efficiency and lifespan of Comparative Example 1 are set to 100%.

[0236] [Table 2]

[0237] Referring to Table 2, the average drive voltage of the light-emitting elements in Examples 1 to 9 was lower than that of the light-emitting element in Comparative Example 1. Furthermore, the efficiency and lifespan of the light-emitting elements in Examples 1 to 9 were improved compared to the light-emitting element in Comparative Example 1. This confirms that in one embodiment of the present invention, the electron mobility of the first electron transport layer is adjusted to be higher than that of the second electron transport layer, resulting in a lower drive voltage during element drive and improved efficiency and lifespan.

[0238] In other words, the first electron transport layer superimposed on the red and green pixel regions has a higher electron mobility than the second electron transport layer superimposed on the blue pixel region, thereby improving the efficiency and lifespan of the device.

[0239] The present invention allows for balancing the electron mobilities of the first stack ST-G and the second stack ST-B by increasing the electron mobility of the first electron transport layer ETL1 and decreasing the electron mobility of the second electron transport layer ETL2. This improves the lifespan of the display device DD, which includes the first stack ST-G and the second stack ST-B that emit different colors.

[0240] Although preferred embodiments of the present invention have been described so far with reference, a person skilled in the art or with ordinary knowledge in the art will understand that the present invention can be modified and altered in various ways without departing from the spirit and art domain of the invention as described in the claims below.

[0241] Therefore, the technical scope of the present invention is not limited to what is described in the detailed description of the specification, but should be determined by the claims. [Explanation of Symbols]

[0242] EL1: First electrode EL2: 2nd electrode ED1, ED2, ED3: First to third light-emitting elements ST-G: 1st Stack ST-B: Second Stack SF1, SF2, SF3: Layer 1 to Layer 3 stacks

Claims

1. An upper display substrate including a first pixel region that emits a first light, a second pixel region that emits a second light different from the first light, and a third pixel region that emits a third light different from the first and second lights, A lower display substrate including a first light-emitting element superimposed on the first pixel region, a second light-emitting element superimposed on the second pixel region, and a third light-emitting element superimposed on the third pixel region, The second light-emitting element includes one or more first stacks that emit the second light and contain a plurality of organic layers, The third light-emitting element includes one or more second stacks that emit the third light and include a plurality of organic layers, The first stack includes a first hole transport region, a first light-emitting layer, and a first electron transport region. The second stack includes a second hole transport region, a second light-emitting layer, and a second electron transport region. The electron transport characteristics of the first electron transport region are higher than those of the second electron transport region. The lower display board further includes a bank disposed between the second light-emitting element and the third light-emitting element, The bank is not located between the first light-emitting element and the second light-emitting element. Display device.

2. The first electron transport region includes the first electron transport layer, The aforementioned second electron transport region includes a second electron transport layer, The display device according to claim 1, wherein the electron transport characteristics of the first electron transport layer are higher than those of the second electron transport layer.

3. The first electron transport region includes a conductive material, The device according to claim 1, wherein the conductive material is a p-type dopant.

4. The first electron transport region includes a conductive material, The display device according to claim 1, wherein the conductive substance comprises at least one of 4-[[2,3-bis[cyano-(4-cyano-2,3,5,6-tetrafluorophenyl)methylidene]cyclopropylidene]-cyanomethyl]-2,3,5,6-tetrafluorobenzonitrile (NDP-9), dipyradino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitride (HAT-CN), 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), and tetracyanoquinodimethane (TCNQ).

5. The first electron transport region includes the first electron transport layer, The aforementioned second electron transport region includes a second electron transport layer, The electron transport characteristics of the first electron transport layer are higher than those of the second electron transport layer. The second electron transport layer contains an insulating material. The display device according to claim 1.

6. The display device according to claim 5, wherein the insulating material includes at least one metal halide, or an oxide having a dielectric constant of 5 or more.

7. The upper display substrate further includes non-pixel regions adjacent to the first to third pixel regions, The lower display substrate further includes a pixel definition film superimposed on the non-pixel region, The display device according to claim 1, wherein the bank is superimposed on the pixel definition film.

8. The aforementioned upper display board is A first optical control unit, which includes a first quantum dot, is superimposed on the first pixel region. A second light control unit superimposed on the second pixel region and transmitting the second light, The system includes a third light control unit that is superimposed on the third pixel region and transmits the third light, The display device according to claim 1, wherein the first quantum dot converts the second light or the third light into the first light.

9. The second light-emitting element includes one or more of the first stacks and one or more of the second stacks, The second optical control unit includes a second quantum dot, The display device according to claim 8, wherein the second quantum dot converts the third light into the second light.

10. The display device according to claim 1, wherein the second light-emitting element comprises a plurality of the first stacks only.

11. The display device according to claim 1, wherein the first light-emitting element has the same structure as the second light-emitting element.

12. The display device according to claim 1, wherein the third light-emitting element comprises a plurality of the second stacks only.

13. The first light is red light, The second light is green light, The display device according to claim 1, wherein the third light is blue light.

14. The display device according to claim 1, wherein the first stack emits green phosphorescence and the second stack emits blue fluorescence.

15. The second light-emitting element includes a first electron transport layer, The third light-emitting element includes a second electron transport layer, The display device according to claim 1, wherein the concentration of the electron transport material contained in the second electron transport layer is equal to or greater than the concentration of the electron transport material contained in the first electron transport layer.

16. A base layer including a first pixel region, a second pixel region, and a third pixel region, A first light-emitting element superimposed on the first pixel region arranged on the base layer, A second light-emitting element superimposed on the second pixel region, which is arranged on the base layer, A third light-emitting element superimposed on the third pixel region arranged on the base layer, The second light-emitting element includes one or more first stacks that emit green light, The third light-emitting element includes one or more second stacks that emit blue light, The first stack includes a first hole transport layer, a first light-emitting layer that emits green light, and a first electron transport layer. The second stack includes a second hole transport layer, a second light-emitting layer that emits the blue light, and a second electron transport layer. The electron transport characteristics of the first electron transport layer are higher than those of the second electron transport layer. The bank is disposed on the base layer and is positioned between the second light-emitting element and the third light-emitting element, The bank is not located between the first light-emitting element and the second light-emitting element. The display device according to claim 1.

17. The first electron transport layer contains a conductive material, The display device according to claim 16, wherein the conductive material comprises at least one of NDP-9, HAT-CN, F4-TCNQ, and TCNQ.

18. The second electron transport layer comprises an insulating material, The display device according to claim 16, wherein the insulating material includes at least one metal halide or an oxide having a dielectric constant of 5 or more.

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