Display device

Abstract

A display device is provided. The display device includes a light-emitting element layer that emits a first color light and a light control layer located on the light-emitting element layer. The light control layer includes: a first light control portion including a first light-emitting material that emits a second color light in a wavelength range shorter than the wavelength range of the first color light; a second light control portion that transmits the first color light; and a third light control portion including a second light-emitting material that emits a third color light in a wavelength range longer than the wavelength range of the first color light, so that a long life of the display device can be achieved.

Description

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2019-0052809 filed on May 7, 2019, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0002] An embodiment of the present disclosure relates to a display device. Background Art

[0003] A display device including a self-luminous element is being actively developed as an image display device. Unlike a liquid crystal display device, a display device including a self-luminous element is a display device in which holes and electrons injected from a first electrode and a second electrode, respectively, are recombined in an emission layer, and an organic material or an inorganic material contained in the emission layer is configured to emit light to produce an image. Various studies have been conducted to improve the life of the display device. Summary of the invention

[0004] One or more aspects of the embodiments of the present disclosure are directed to a display device having a long lifespan and / or high efficiency.

[0005] One or more exemplary embodiments of the present disclosure provide a display device, the display device including a light emitting element layer and a light control layer. The light emitting element layer may emit a first color light. The light control layer may be disposed on the light emitting element layer. The light control layer may include a first light control unit, a second light control unit, and a third light control unit. The first light control unit may include a first luminescent material that emits a second color light (light having a wavelength shorter than the wavelength of the first color light) in a wavelength range shorter than the wavelength range of the first color light. The second light control unit may transmit the first color light. The third light control unit may include a second luminescent material that emits a third color light (light having a wavelength longer than the wavelength of the first color light) in a wavelength range longer than the wavelength range of the first color light. The first to third light control units may be separated from each other in a plan view.

[0006] In an embodiment, the first color light may be green light having a central wavelength of 500nm to 580nm. The second color light may be blue light having a central wavelength of 420nm to 480nm. The third color light may be red light having a central wavelength of 600nm to 670nm.

[0007] In an embodiment, the first light-control part may further include a light-emitting auxiliary material, which may absorb the first color light to be excited and transfer energy to the first light-emitting material.

[0008] In an embodiment, the first lowest triplet energy level of the first light emitting material may be greater than 1.2 eV and less than the second lowest triplet energy level of the light emitting assisting material. The second lowest triplet energy level may be 2.5 eV or less.

[0009] In an embodiment, the lowest singlet energy level of the first light emitting material may be 2.5 eV to 3.1 eV.

[0010] In an embodiment, the first luminescent material may be a fluorescent material. The luminescent assisting material may be a phosphorescent material or a thermally activated delayed fluorescent material.

[0011] In an embodiment, the first luminescent material may be an anthracene derivative. The luminescent auxiliary material may be a porphyrin-metal complex.

[0012] In an embodiment, the first luminescent material may be quantum dots. The second luminescent material may be quantum dots.

[0013] In an embodiment, the display device may further include a color filter layer. The color filter layer may be disposed on the light control layer. The color filter layer may include a first color filter, a second color filter, and a third color filter. The first color filter may overlap with the first light control unit and transmit the second color light. The second color filter may overlap with the second light control unit and transmit the first color light. The third color filter may overlap with the third light control unit and transmit the third color light.

[0014] In an embodiment, the light-emitting element layer may include a light-emitting element. The light-emitting element may include a first electrode, a second electrode and at least one emission portion. The at least one emission portion may be disposed between the first electrode and the second electrode. The at least one emission portion may include a hole transport region, an emission layer and an electron transport region. The emission layer may be disposed on the hole transport region. The electron transport region may be disposed on the emission layer. The emission layer may include a host and a dopant. The dopant may include a phosphorescent dopant, a fluorescent dopant and / or a thermally activated delayed fluorescent dopant. The emission layer may emit phosphorescence.

[0015] In an embodiment, the at least one emission portion may include a plurality of emission portions stacked sequentially. The light emitting element may further include a charge generation layer. The charge generation layer may be disposed between the plurality of emission portions.

[0016] One or more exemplary embodiments of the present disclosure provide a display device, the display device including a display panel, the display panel including a display area and a non-display area. In the display area, a blue emission area, a green emission area, and a red emission area may be defined. The non-display area may be adjacent to the display area. The display panel may include a light-emitting element layer and a light control layer. The light-emitting element layer may emit green light. The light control layer may be disposed on the light-emitting element layer. The light control layer may include a first light control unit, a second light control unit, and a third light control unit. The first light control unit may overlap with the blue emission area, absorb green light and emit blue light. The second light control unit may overlap with the green emission area, and transmit green light. The third light control unit may overlap with the red emission area, absorb green light and emit red light.

[0017] In an embodiment, the first light-controlling part may include a first luminescent material and a luminescent auxiliary material. The first lowest triplet energy level of the first luminescent material may be greater than 1.2 eV and less than the second lowest triplet energy level of the luminescent auxiliary material. The second lowest triplet energy level of the luminescent auxiliary material may be 2.5 eV or less.

[0018] An embodiment of the present disclosure provides a display device, the display device comprising a light-emitting element layer and a light control layer. The light-emitting element layer may include a plurality of light-emitting elements. The light control layer may be disposed on the light-emitting element layer. Each light-emitting element may include a first electrode, a second electrode and at least one emission portion. The second electrode may be disposed on the first electrode. The at least one emission portion may be disposed between the first electrode and the second electrode.

[0019] In an embodiment, the at least one emission portion may include a hole transport region, an emission layer, and an electron transport region. The emission layer may be disposed on the hole transport region and emit green light. The electron transport region may be disposed on the emission layer. The light control layer may include a first light control portion, a second light control portion, and a third light control portion. The first light control portion may absorb green light and emit blue light. The second light control portion may transmit green light. The third light control portion may absorb green light and emit red light. The light emitting element layer may include a first emission portion, a second emission portion, and a charge generation layer. The second emission portion may be disposed on the first emission portion. The charge generation layer may be disposed between the first emission portion and the second emission portion.

[0020] In an embodiment, the first light-controlling part may include a first luminescent material and a luminescent auxiliary material. The first lowest triplet energy level of the first luminescent material may be greater than 1.2 eV. The second lowest triplet energy level of the luminescent auxiliary material may be greater than the first lowest triplet energy level of the first luminescent material and may be 2.5 eV or less.

[0021] In an embodiment, the first luminescent material may be represented by Formula 1:

[0022] Formula 1

[0023]

[0024] In formula 1, R 1 To R 10 Each of a and b may be 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 50 carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 50 ring carbon atoms, or may be bonded to an adjacent group to form a ring. a and b may be independently an integer of 0 to 5. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate example embodiments of the present disclosure and together with the description serve to explain the principles of the present disclosure. In the drawings:

[0026] Figure 1 is a perspective view of a display device according to an embodiment;

[0027] Figure 2 is an exploded perspective view of a display device according to an embodiment;

[0028] Figure 3 is a cross-sectional view of a display panel according to an embodiment;

[0029] Figure 4 is a plan view of a display panel according to an embodiment;

[0030] Figure 5 is along Figure 4 A cross-sectional view of the display panel taken along line II' in FIG.

[0031] Fig. 6A and Figure 6B are cross-sectional views of light emitting elements according to embodiments;

[0032] Fig. 7A and Figure 7B are respectively enlarged cross-sectional views in which a light control layer according to an embodiment is enlarged;

[0033] Fig. 8A and Figure 8B is a view schematically showing energy transfer between a first light-emitting material and a light-emitting auxiliary material included in a display device according to an embodiment;

[0034] Fig. 9 is a cross-sectional view of a display panel according to an embodiment;

[0035] Fig.10 is a cross-sectional view of a light emitting element according to an embodiment; and

[0036] Fig.11 and Fig.12 They are respectively cross-sectional views of display panels according to embodiments. DETAILED DESCRIPTION

[0037] It will be understood that when an element (or region, layer, section, etc.) is referred to as being “on,” “connected to” or “coupled to” another element, it can be directly on, directly connected to or directly coupled to the other element, or intervening elements may be present.

[0038] The same mark always refers to the same element, and its redundant description may be omitted. In order to effectively describe the technical content, the thickness, proportion and size of the element may be exaggerated.

[0039] The term "and / or" includes any and all combinations of one or more of the associated listed items.

[0040] The terms "first" and "second" may be used to describe various elements, however, the elements should not be limited by these terms. These terms are only used for the purpose of distinguishing one element from another element. For example, without departing from the spirit or scope of the present disclosure, a first element may be designated as a second element, and similarly, a second element may also be designated as a first element. Unless otherwise indicated, the singular includes the plural.

[0041] In addition, for ease of description, the terms "under", "below", "on", "over", etc. may be used herein to describe the relationship of one element or feature to another (additional) element or feature as shown in the drawings. It will be understood that the terms are relative concepts and may be described based on the directions shown in the drawings.

[0042] Unless otherwise defined, all terms (including technical and scientific terms) used herein will have the meanings commonly understood by those skilled in the art. It will also be understood that terms commonly defined in dictionaries should be considered to have the contextual meaning of the prior art, unless explicitly defined herein as having a specific or non-standard meaning. As understood from the context, the terms "fluorescence", "phosphorescence" and "luminescence" may refer to the states of fluorescence, phosphorescence and luminescence, respectively.

[0043] In the description, it should be understood that the terms "including" or "having" indicate the presence of the stated features, numbers, steps, operations, elements, parts or combinations thereof, and do not exclude the possible presence or addition of other features, numbers, steps, operations, elements, parts or combinations thereof.

[0044] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0045] Figure 1 is a perspective view of a display device DD according to an embodiment. Figure 2 is an exploded perspective view of a display device DD according to an embodiment. Figure 3 is a cross-sectional view of a display panel DP according to an embodiment. Figure 4 is a plan view of a display panel DP according to an embodiment. Figure 5 is along Figure 4 4 is a cross-sectional view of the display panel DP taken along line II' in FIG. Fig. 6A and Figure 6B Each is a cross-sectional view of a light emitting element LD according to the embodiment.

[0046] Reference Figure 1 , a display area DA and a non-display area NDA may be defined in the display device DD. The display area DA may be an area in which an image IM is displayed. Figure 1 , a butterfly is shown as an example of an image IM. The non-display area NDA may be an area in which the image IM is not displayed. Pixels may be provided in the display area DA, and pixels may not be provided in the non-display area NDA (e.g., may not be included in the non-display area NDA). As used herein, the term "pixel" may refer to a pixel for effectively providing an image IM.

[0047] The display area DA is parallel to the plane defined by the first direction axis DR1 and the second direction axis DR2. The normal direction of the display area DA (e.g., the thickness direction of the display device DD) is represented by the third direction axis DR3 (e.g., parallel to the third direction axis DR3). The front surface (or upper surface) and the rear surface (or lower surface) of each component are separated on the third direction axis DR3. However, the directions represented by the first direction axis DR1, the second direction axis DR2, and the third direction axis DR3 are relative concepts and can be converted into different directions. In the following, the first direction, the second direction, and the third direction are represented by the same figure marks in the directions represented by the first direction axis DR1, the second direction axis DR2, and the third direction axis DR3, respectively.

[0048] The display device DD can be used in large electronic devices (such as televisions, monitors and / or outdoor billboards), and can also be used in small or medium-sized electronic devices (such as personal computers, notebook computers, personal digital terminals, car navigation units, game consoles, portable electronic devices and / or cameras). These embodiments are given as examples only, and it should be understood that the present disclosure can be implemented in other electronic devices without departing from the concept of the present disclosure.

[0049] The border area of ​​the display device DD may be defined by the non-display area NDA. The non-display area NDA may be an area adjacent to the display area DA. The non-display area NDA may surround the display area DA. However, the embodiment is not limited thereto, and the shape of the display area DA and the shape of the non-display area NDA may be designed relatively. In another embodiment of the present disclosure, the non-display area NDA may be omitted.

[0050] Reference Figure 2 , the display device DD may include a bottom cover BC, a display panel DP, and a top cover TC. The bottom cover BC may be disposed under the display panel DP to protect the display device DD from external impact or contaminants.

[0051] In another embodiment of the present disclosure, the top cover TC may be omitted. When the display device DD does not include the top cover TC, the non-display area NDA may be defined by a sealing member, a mold, or the like.

[0052] The top cover TC may protect the display panel DP, etc. from external impact and / or contaminants. The opening OP-TC of the top cover TC may define a display area DA by exposing a front surface of the display panel DP.

[0053] Reference Figure 2 and Figure 3 , the display panel DP may include a first display substrate 100 and a second display substrate 200. The second display substrate 200 may be disposed on the first display substrate 100. The first display substrate 100 may include a base film BF, a circuit layer CL, and a light emitting element layer LDL. The second display substrate 200 may include a light control layer WCL and a base substrate BS.

[0054] The base film BF may provide a base surface on which the circuit layer CL is disposed. The base film BF may be a silicon substrate, a plastic substrate, a glass substrate, a metal substrate, or a stacked structure including a plurality of insulating layers. However, the embodiment is not limited thereto, and the base film BF may be an inorganic layer, an organic layer, or a composite layer.

[0055] The circuit layer CL may be disposed on the base film BF. The circuit layer CL may include a plurality of transistors. The transistors may each include a control electrode, an input electrode, and an output electrode. For example, the circuit layer CL may include a switch transistor and a drive transistor for driving the light emitting element LD.

[0056] The light emitting element layer LDL may include a plurality of light emitting elements LD and a thin film encapsulation layer TFE. The thin film encapsulation layer TFE may cover the plurality of light emitting elements LD. The thin film encapsulation layer TFE may be directly disposed on the plurality of light emitting elements LD to seal the light emitting elements LD.

[0057] The light control layer WCL may be disposed on the thin film encapsulation layer TFE. An adhesive member may be disposed between the light control layer WCL and the thin film encapsulation layer TFE. The adhesive member may bond (attach) the light control layer WCL and the thin film encapsulation layer TFE. The adhesive member may be, for example, an optically transparent adhesive. The light control layer WCL may absorb light emitted from the light emitting element layer LDL and then emit light having a central wavelength in a wavelength range different from that of the absorbed light, or in some embodiments, may transmit light emitted from the light emitting element layer LDL. The base substrate BS may be used as a supporting substrate for supporting the light control layer WCL. The base substrate BS may be a glass substrate and / or a plastic substrate.

[0058] Reference Figure 4 and Figure 5 , the display panel DP may include a non-emitting area NPXA and emitting areas PXA1, PXA2, and PXA3. Each of the emitting areas PXA1, PXA2, and PXA3 may be an area in which light generated from each light emitting element LD is emitted. The areas of the respective emitting areas PXA1, PXA2, and PXA3 may be different from each other, and as used herein, each area may refer to a plane area viewed in a plan view. As used herein, a "plan view" may correspond to when the display device DD is viewed from above along a third directional axis DR3 (thickness direction). The emitting areas PXA1, PXA2, and PXA3 may be divided into a plurality of groups (in Figure 4 middle).

[0059] In accordance with Figure 4 and Figure 5 In the display panel DP of the embodiment shown in FIG, three emission areas PXA1, PXA2 and PXA3 that emit the second color light, the first color light and the third color light, respectively, are shown. For example, the display panel DP according to the embodiment may include the first emission area PXA1, the second emission area PXA2 and the third emission area PXA3 that are separated from each other.

[0060] In an embodiment, the display panel DP may include: a plurality of light emitting elements LD, emitting a first color light; and light control parts WCL1, WCL2, and WCL3, transmitting the first color light or absorbing the first color light and then emitting light having a different wavelength range from each other. Each of the light control parts WCL1, WCL2, and WCL3 may transmit the first color light or absorb the first color light to subsequently emit light of a different color. For example, in an embodiment, the first light control part WCL1 may absorb the first color light to emit the second color light, the second light control part WCL2 may transmit the first color light, and the third light control part WCL3 may absorb the first color light to emit the third color light. The first color light may be light in a wavelength range longer than the wavelength range of the second color light (light having a wavelength longer than the wavelength of the second color light) and light in a wavelength range shorter than the wavelength range of the third color light (light having a wavelength shorter than the wavelength of the third color light). The embodiment is not limited thereto, and in some embodiments, for example, the first color light may be green light, the second color light may be blue light, and the third color light may be red light. For example, the first color light may be green light having a central wavelength of about 500 nm to about 580 nm, the second color light may be blue light having a central wavelength of about 420 nm to about 480 nm, and the third color light may be red light having a central wavelength of about 600 nm to about 670 nm. For example, the first color light may be green light having a central wavelength of about 515 nm to about 545 nm.

[0061] When viewed in a plan view, the light control parts WCL1, WCL2, and WCL3 may be disposed to correspond to the first emission region PXA1, the second emission region PXA2, and the third emission region PXA3, respectively, and may overlap the first emission region PXA1, the second emission region PXA2, and the third emission region PXA3, respectively. For example, the first emission region PXA1 may be a blue emission region (e.g., a region emitting blue light), the second emission region PXA2 may be a green emission region (e.g., a region emitting green light), and the third emission region PXA3 may be a red emission region (e.g., a region emitting red light).

[0062] In accordance with Figure 4 and Figure 5 In the display panel DP of the embodiment shown in FIG. 1 , the emission regions PXA1, PXA2, and PXA3 may have different areas (eg, plane area sizes) according to the colors of the light emitted from the light control parts WCL1, WCL2, and WCL3 of the light control layer WCL. Figure 4 and Figure 5, the first emission region PXA1 of the first light control part WCL1 (which emits the second color light) may have the largest area, and the second emission region PXA2 of the second light control part WCL2 may have the smallest area. However, the embodiment is not limited thereto, and in some embodiments, the emission regions PXA1, PXA2, and PXA3 may have the same area, or may be arranged in the same manner as Figure 4 and Figure 5 The area ratios (relative plane dimensions) shown in the figure are set according to different area ratios (relative plane dimensions).

[0063] Each of the emission regions PXA1, PXA2, and PXA3 may be separated by a pixel defining layer PDL. The non-emission region NPXA may be located between adjacent emission regions PXA1, PXA2, and PXA3 and may correspond to the pixel defining layer PDL. In the present specification, each of the emission regions PXA1, PXA2, and PXA3 may correspond to a pixel.

[0064] The pixel defining layer PDL may be formed of a polymer resin. For example, the pixel defining layer PDL may be formed by including a polyacrylate resin and / or a polyimide resin. In addition, in addition to the polymer resin, the pixel defining layer PDL may be formed by further including an inorganic material. On the other hand, the pixel defining layer PDL may be formed by including a light absorbing material and / or by including a black pigment and / or a black dye. A black pixel defining layer may be realized by forming a pixel defining layer PDL including a black pigment and / or a black dye. During the formation of the pixel defining layer PDL, carbon black or the like may be used as a black pigment and / or a black dye, but the embodiment is not limited thereto.

[0065] For example, the pixel defining layer PDL may be formed of an inorganic material. In some embodiments, the pixel defining layer PDL may be formed of an inorganic material. x ), silicon oxide (SiO x ), silicon oxynitride (SiO x N y ) etc. The pixel defining layer PDL may define emission regions PXA1, PXA2, and PXA3. The emission regions PXA1, PXA2, and PXA3 and the non-emission region NPXA may be distinguished from each other by the pixel defining layer PDL.

[0066] The first and third emission regions PXA1 and PXA3 may be alternately disposed (arranged) along the first direction axis DR1 to constitute a first group PXG1. The second emission regions PXA2 may be arranged (aligned) along the first direction axis DR1 (eg, along parallel lines) to constitute a second group PXG2.

[0067] The first group PXG1 may be disposed separately (separated) from the second group PXG2 along the second direction axis DR2. Each of the first group PXG1 and the second group PXG2 may be disposed in plural (eg, multiple). The first group PXG1 and the second group PXG2 may be alternately arranged along the second direction axis DR2.

[0068] One second emission region PXA2 may be disposed separately from one first emission region PXA1 or one third emission region PXA3 in the direction of the fourth direction axis DR4. The direction of the fourth direction axis DR4 may be an oblique direction between the direction of the first direction axis DR1 and the direction of the second direction axis DR2 (e.g., an intermediate angle less than 90 degrees (e.g., 45 degrees each) with the first direction axis DR1 and the second direction axis DR2 in a plane formed by the first direction axis DR1 and the second direction axis DR2 in the first Cartesian quadrant (or, in some embodiments, the second quadrant)).

[0069] Figure 4 The arrangement structure of the emission regions PXA1, PXA2, and PXA3 shown in FIG. 1 may be referred to as a pentile structure. However, the arrangement structure of the emission regions PXA1, PXA2, and PXA3 in the display device DD according to the embodiment is not limited to the pentile structure. Figure 4 For example, in an embodiment, the emission regions PXA1, PXA2, and PXA3 may have a stripe structure along the first direction axis DR1, wherein the first emission region PXA1, the second emission region PXA2, and the third emission region PXA3 may be alternately arranged.

[0070] Reference Figure 5 , the light emitting element layer LDL may include a plurality of light emitting elements LD. The light emitting element LD may include a first electrode EL1, a second electrode EL2, and at least one emission portion EM. The first electrode EL1 may be disposed on the circuit layer CL. The first electrode EL1 may be electrically connected to the driving transistor to receive a driving signal. The first electrode EL1 may be separately disposed by a plurality of pixel defining layers PDL (e.g., separated by a plurality of pixel defining layers PDL). The second electrode EL2 may be disposed on or above the first electrode EL1. At least one emission portion EM may be disposed between the first electrode EL1 and the second electrode EL2. At least one emission portion EM may include a hole transport region HTR, an emission layer EML, and an electron transport region ETR.

[0071] Fig. 6A and Figure 6B is a cross-sectional view showing a light emitting element LD included in a light emitting element layer LDL according to an embodiment including an electron transport region ETR between a second electrode EL2 and an emission layer EML and a hole transport region HTR between a first electrode EL1 and an emission layer EML. Fig. 6A compared to, Figure 6B is a cross-sectional view of a light emitting element LD according to an embodiment, wherein the hole transport region HTR includes a hole injection layer HIL and a hole transport layer HTL, and the electron transport region ETR includes an electron injection layer EIL and an electron transport layer ETL.

[0072] The first electrode EL1 constituting the light emitting element LD has conductivity (for example, may be conductive). The first electrode EL1 may be formed of a metal alloy or a conductive compound. The first electrode EL1 may be an anode. The first electrode EL1 may be a pixel electrode. In the light emitting element LD according to the embodiment, the first electrode EL1 may be a reflective electrode. However, the embodiment is not limited thereto. For example, the first electrode EL1 may be a transmissive electrode or a transflective electrode. When the first electrode EL1 is a transflective electrode or a reflective electrode, the first electrode EL1 may include silver (Ag), magnesium (Mg), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), LiF / Ca, LiF / Al, molybdenum (Mo), titanium (Ti) and / or a compound or mixture thereof (for example, a mixture of Ag and Mg). For example, the first electrode EL1 may have a structure including a plurality of layers including: a reflective layer or a transflective layer formed of any described material; and a transparent conductive layer formed of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), etc. For example, the first electrode EL1 may be a multilayer metal film, or may be a structure in which a metal film of ITO / Ag / ITO is stacked.

[0073] The hole transport region HTR may have a structure as follows: a single layer formed of a single material; a single layer formed of a plurality of different materials; or a multilayer structure having a plurality of layers formed of a plurality of different materials. For example, the hole transport region HTR may have a structure of a single layer formed of a plurality of different materials, or may have a structure of a hole injection layer HIL / hole transport layer HTL, a hole injection layer HIL / hole transport layer HTL / buffer layer, a hole injection layer HIL / buffer layer, a hole transport layer HTL / buffer layer, or a hole injection layer HIL / hole transport layer HTL / electron blocking layer, wherein the elements of each structure are sequentially stacked from the first electrode EL1 in each stated order, but the embodiment is not limited thereto.

[0074] For example, the hole transport region HTR may include a hole injection layer HIL and a hole transport layer HTL, and any suitable hole injection material and hole transport material may be used for the hole injection layer HIL and the hole transport layer HTL, respectively.

[0075] The emission layer EML is disposed on the hole transport region HTR. The emission layer EML may have a structure of a single layer formed of a single material, a single layer formed of a plurality of different materials, or a multilayer having a plurality of layers formed of a plurality of different materials.

[0076] The emission layer EML may emit a first color light. For example, the emission layer EML may be formed of an organic material configured to emit green light, and may include a fluorescent material and / or a phosphorescent material. For example, the emission layer EML may include a host and a dopant. The dopant may include a phosphorescent dopant, a fluorescent dopant and / or a thermally activated delayed fluorescent dopant. For example, the emission layer EML may include any one of a phosphorescent dopant, a fluorescent dopant and a thermally activated delayed fluorescent dopant as a dopant, or may include a thermally activated delayed fluorescent dopant as a first dopant and a fluorescent dopant as a second dopant. For example, the emission layer EML may include a phosphorescent dopant. For example, the emission layer EML may emit phosphorescence.

[0077] When the emission layer EML emits green light, the emission layer EML may further include, for example, tris(8-hydroxyquinoline)aluminum (Alq 3 When the emission layer EML emits green light, the dopant included in the emission layer EML may be selected from, for example, a metal complex or an organic metal complex (such as, for example, face-tris(2-phenylpyridine)iridium (Ir(ppy) 3 ), coumarin and its derivatives). The metal used to form the metal complex or the organic metal complex may be selected from the group consisting of iridium (Ir), platinum (Pt), osmium (Os), gold (Au), copper (Cu), rhenium (Re) and ruthenium (Ru). For example, the dopant included in the emission layer EML may include bis (2-phenylquinolyl-N, C2') acetylacetonate iridium (III) (PQIr), face-tris (2-phenylpyridine) iridium (Ir(ppy) 3 ) and at least one selected from the compounds of compound group 1:

[0078] Compound Group 1

[0079]

[0080] However, the embodiments are only examples, and the emission layer EML may include any suitable green phosphorescent material available in the art without limitation.

[0081] exist Fig. 6A and Figure 6BIn the description of the light emitting element LD shown in FIG, the emission layer EML includes an organic material, but the embodiment is not limited thereto, and the emission layer EML may be a quantum dot emission layer including quantum dots as a light emitting material. When the emission layer EML includes quantum dots as a light emitting material, the quantum dots may be substantially the same as the quantum dots QD2 to be described later.

[0082] The electron transport region ETR is disposed on the emission layer EML. The electron transport region ETR may include at least one selected from a hole blocking layer, an electron transport layer ETL, and an electron injection layer EIL, but the embodiment is not limited thereto.

[0083] When the electron transport region ETR includes the electron injection layer EIL and the electron transport layer ETL, any suitable electron injection material and electron transport material may be used for the electron injection layer EIL and the electron transport layer ETL, respectively.

[0084] The second electrode EL2 is disposed on the electron transport region ETR. The second electrode EL2 may be a common electrode or a cathode. The second electrode EL2 may be formed of a metal alloy or a conductive compound. The second electrode EL2 may be a transmissive electrode, a transflective electrode or a reflective electrode. When the second electrode EL2 is a transmissive electrode, the second electrode EL2 may be formed of a transparent metal oxide (e.g., indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), etc.).

[0085] When the second electrode EL2 is a transflective electrode or a reflective electrode, the second electrode EL2 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti and / or a compound or mixture thereof (e.g., a mixture of Ag and Mg). For example, the second electrode EL2 may have a structure including a plurality of layers, the plurality of layers including: a reflective layer or a transflective layer formed of the described materials; and a transparent conductive layer formed of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), etc.

[0086] In some embodiments, the second electrode EL2 may be connected to the auxiliary electrode. When the second electrode EL2 is connected to the auxiliary electrode, the resistance of the second electrode EL2 may be reduced.

[0087] Among the first electrode EL1 and the second electrode EL2 facing each other in the display panel DP according to the embodiment, the first electrode EL1 may be a reflective electrode and the second electrode EL2 may be a transmissive electrode. In the embodiment, the light emitting element LD may be front surface emitting (for example, light may be emitted through the front surface or the upper surface). However, the embodiment is not limited thereto.

[0088] In some embodiments, a capping layer may be further disposed on the second electrode EL2. The capping layer may be a layer for adjusting a resonance distance of light emitted from the emission layer EML or for adjusting optical characteristics such as a refractive index of the light emitting element LD.

[0089] Refer again Figure 5 , each of the hole transport region HTR, the emission layer EML, and the electron transport region ETR constituting the emission part EM (included in the emission part EM) may be provided as a common layer in all of the plurality of adjacent light emitting elements LD. Unlike the case where the first electrode EL1 is patterned and provided on the circuit layer CL in a state of being separated from each other, each of the hole transport region HTR, the emission layer EML, and the electron transport region ETR may not be patterned and may be positioned to extend throughout the entire light emitting element layer LDL.

[0090] The thin film encapsulation layer TFE may be disposed on the second electrode EL2. In some embodiments, the thin film encapsulation layer TFE may be directly disposed on the second electrode EL2. When the light emitting element LD further includes a cap layer, the thin film encapsulation layer TFE may be directly disposed on the cap layer.

[0091] The light control layer WCL may be disposed on the thin film encapsulation layer TFE. The light control layer WCL may include a first light control part WCL1, a second light control part WCL2, a third light control part WCL3 and a partition wall part BK (e.g., a plurality of partition wall parts BK). The partition wall parts BK may be disposed separately from each other on the base substrate BS. The partition wall parts BK may be disposed in a one-to-one correspondence with the arrangement position of the pixel defining layer PDL. The partition wall part BK may be disposed between the first light control part WCL1, the second light control part WCL2 and the third light control part WCL3 to prevent or reduce the light emitted from the first light control part WCL1, the second light control part WCL2 and the third light control part WCL3 from being mixed.

[0092] The first light-control part WCL1 , the second light-control part WCL2 , and the third light-control part WCL3 may be disposed apart from each other in a plan view.

[0093] The light control layer WCL may further include a protective layer CAP. The protective layer CAP may be disposed on the first light control part WCL1, the second light control part WCL2, and the third light control part WCL3 and the partition wall part BK. The protective layer CAP may be used to prevent or reduce the penetration of moisture and / or oxygen (hereinafter referred to as "moisture / oxygen"). The protective layer CAP may be disposed on the first light control part WCL1, the second light control part WCL2, and the third light control part WCL3 to block the first light control part WCL1, the second light control part WCL2, and the third light control part WCL3 from being exposed to moisture / oxygen. The protective layer CAP may include at least one inorganic layer. For example, the protective layer CAP may be formed by including an inorganic material. For example, the protective layer CAP may be 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, silicon oxynitride, and / or a metal film having a guaranteed light transmittance. On the other hand, the protective layer CAP may also include an organic film. The protection layer CAP may consist of a single layer or multiple layers.

[0094] Fig. 7A and Figure 7B 2 and 3 are enlarged cross-sectional views in which light control layers WCL and WCL- 1 according to embodiments are enlarged, respectively. Fig. 8A and Figure 8B is a view schematically illustrating energy transfer between a first light emitting material RM and a light emitting auxiliary material included in the display device DD according to the embodiment.

[0095] Reference Fig. 7A The first light control part WCL1 may include a first luminescent material RM. The first luminescent material RM may emit a second color light in a wavelength range shorter than that of the first color light. The first luminescent material RM may be an organic compound or a quantum dot. The first light control part WCL1 may further include a luminescent auxiliary material.

[0096] When the first luminescent material RM is an organic compound, the first light control part WCL1 may further include a luminescence auxiliary material that absorbs the first color light and is excited (eg, raised to an excited state), and then may transfer energy to the first luminescent material RM.

[0097] Reference Fig. 8A , the first luminescent material RM and the luminescent auxiliary material exchange energy with each other through a Dexter energy transfer method.

[0098] In this manual, S 0 R refers to the energy level of the bottom state (e.g., ground state) of the luminescence-assisting material, S 0 BRefers to the energy level of the bottom state (eg, ground state) of the first luminescent material RM. 1 R Refers to the lowest triplet energy level of the luminescent auxiliary material, T 1 B Refers to the lowest triplet energy level of the first luminescent material RM. 1 B Refers to the lowest excited singlet energy level of the first luminescent material RM. In this specification, the lowest triplet energy level (T 1 B ) can be referred to as the first lowest triplet energy level (eg, in the entire system), and the lowest triplet energy level (T 1 R ) can be referred to as the second-lowest triplet energy level (e.g., in the entire system).

[0099] The light-emitting auxiliary material receives the first color light emitted from the light-emitting element LD and from S 0 R The electrons are excited to T 1 R After that, the light-emitting auxiliary material is in T 1 R The electrons are transferred to the first luminescent material RM 1 B , and S from the first luminescent material RM 0 B The electrons are transferred to the S of the luminescent auxiliary material 0 R .

[0100] Reference Figure 8B , triplet-triplet annihilation (hereinafter, referred to as TTA) occurs in the first luminescent material RM and can generate an S 1 B Electrons in S 1 B The electron in the S state drops to 0 B The ground state can emit second color light (light having a wavelength shorter than the wavelength of the first color light) in a wavelength range shorter than that of the first color light. For example, blue light having a wavelength shorter than that of green light can be emitted.

[0101] The lowest triplet energy level (T 1 B ) can be greater than 1.2 eV and less than the lowest triplet energy level (T 1 R The lowest singlet energy level (S 1B ) may be about 2.5 eV to about 3.1 eV. For example, the first light emitting material RM may be a blue fluorescent material.

[0102] The lowest triplet energy level (T 1 R ) can be 2.5 eV or less. When the lowest triplet energy level (T 1 R ) is 2.5 eV or less, electrons in the ground state can be excited to the lowest triplet energy level (T 1 R ) or the lowest singlet energy level.

[0103] When the lowest triplet energy level (T 1 B ) is less than (lower than) the lowest triplet energy level (T 1 R ) when the light-emitting auxiliary material is in T 1 R The electrons can move to the first light emitting material RM 1 B .

[0104] When the lowest triplet energy level (T 1 B ) is greater than 1.42 eV, TTA may occur and a singlet state having an energy level of 2.7 eV to 3.0 eV may be generated. Therefore, blue light emission may be possible.

[0105] The first light control part WCL1 may include a first light emitting material RM and a light emitting auxiliary material in a state dispersed in the matrix part MX. For example, the first light control part WCL1 may include a first light emitting material RM and a light emitting auxiliary material in the form of a film mixed with a polymer resin such as poly(methyl methacrylate) (PMMA). However, the embodiment is not limited thereto, and the matrix part MX may be an organic compound instead of a polymer resin. For example, the first light control part WCL1 may include a first light emitting material RM and a light emitting auxiliary material mixed with an organic compound such as 1,2-dichloroethane provided in a gel form or state.

[0106] When the matrix part MX is a polymer resin, substantially the same description as the base resin BR in the first to third light control parts WCL1 to WCL3 (described below) may be applied.

[0107] Relative to the total weight (100wt%) of the first luminescent material RM and the luminescent auxiliary material, the first luminescent material RM may have a ratio (amount) of about 70wt% or more and 99wt% or less, and the luminescent auxiliary material may have a ratio (amount) of about 1wt% or more and 30wt% or less. When the ratio (relative amount) of the first luminescent material RM and the luminescent auxiliary material satisfies the described range, the first light control unit WCL1 can achieve satisfactory light conversion efficiency.

[0108] In some embodiments, the first luminescent material RM may be a blue fluorescent material. For example, the first luminescent material RM may be an anthracene derivative, a pyrene derivative, a fluoranthene derivative, derivatives, dihydrobenzanthracene derivatives or benzo[9,10]phenanthrene derivatives.

[0109] When the first light emitting material RM is an anthracene derivative, for example, the anthracene derivative may be represented by Formula 1:

[0110] Formula 1

[0111]

[0112] In formula 1, R 1 To R 10 Each may independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted silyl group, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 50 ring-forming carbon atoms, or may be bonded to an adjacent group to form a ring.

[0113] In this specification, the term "substituted or unsubstituted" corresponds to: substituted with at least one substituent selected from the group consisting of a deuterium atom, a halogen atom, a cyano group, a nitro group, an amino group, a silyl group, a boron group, a phosphine oxide group, a phosphine sulfide group, an alkyl group, an alkenyl group, an aryl group, and a heterocyclic group; or unsubstituted. In addition, each of the substituents exemplified above may be substituted or unsubstituted. For example, a biphenyl group may be interpreted as an aryl group or a phenyl group substituted with a phenyl group.

[0114] In the present specification, the alkyl group may be linear, branched or cyclic (eg, linear, branched or cyclic alkyl group). The carbon number of the alkyl group may be 1 to 50, 1 to 30, 1 to 20, 1 to 10 or 1 to 6. Examples of the alkyl group may include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, 2-ethylbutyl, 3,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, cyclopentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 2-butylhexyl, cyclohexyl, 4-methylcyclohexyl, 4-tert-butylcyclohexyl, n-heptyl, 1-methylheptyl, 2,2-dimethylheptyl, 2-ethylheptyl, 2-butylheptyl, n-octyl, tert-octyl, 2-ethyloctyl, 2-butyloctyl, 2-hexyloctyl, 3,7-dimethyloctyl, cyclooctyl, n-nonyl, n-decyl, adamantyl, 2-ethyldecyl, 2-butyldecyl, 2 -hexyldecyl, 2-octyldecyl, n-undecyl, n-dodecyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, 2-ethylhexadecyl, 2-butylhexadecyl, 2-hexylhexadecyl, 2-octylhexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl, 2-ethyleicosyl, 2-butyleicosyl, 2-hexyleicosyl, 2-octyleicosyl, n-heneicosyl, n-docosyl, n-tricosyl, n-tetracosyl, n-pentacosyl, n-hexacosyl, n-heptacosyl, n-octacosyl, n-nonacosyl, n-triacontyl, and the like, but the present disclosure is not limited thereto.

[0115] In this specification, the term "aryl" means an optional functional group or substituent derived from an aromatic hydrocarbon ring. The aryl group may be a monocyclic aryl group or a polycyclic aryl group. The number of ring carbon atoms in the aryl group may be 6 to 36, 6 to 30, 6 to 20, or 6 to 15. Examples of aryl groups may include phenyl, naphthyl, fluorenyl, anthracenyl, phenanthrenyl, biphenyl, terphenyl, quaterphenyl, pentaphenyl, hexaphenyl, benzo[9,10]phenanthrenyl, pyrenyl, benzofluoranthenyl, Base, etc., but the present disclosure is not limited thereto.

[0116] In the present specification, the heteroaryl group may be a heteroaryl group including one or more of O, N, P, Si or S as a heteroatom. The number of ring carbon atoms in the heteroaryl group may be 2 to 30 or 2 to 20. The heteroaryl group may be a monocyclic heteroaryl group or a polycyclic heteroaryl group. The polycyclic heteroaryl group may have, for example, a bicyclic structure or a tricyclic structure. Examples of heteroaryl groups may include thienyl, furanyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, oxadiazolyl, triazolyl, pyridyl, bipyridyl, pyrimidyl, triazinyl, acridinyl, pyridazinyl, pyrazinyl, quinolyl, quinazolinyl, quinoxalinyl, phenoxazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, isoquinolyl, indolyl, carbazolyl, N-arylcarbazolyl, N-heteroarylcarbazolyl, N-alkylcarbazolyl, benzoxazolyl, benzimidazolyl, benzothiazolyl, benzocarbazolyl, benzothienyl, dibenzothienyl, thienothiphenyl, benzofuranyl, phenanthrolinyl, isoxazolyl, thiadiazolyl, phenothiazinyl, dibenzosilolyl, dibenzofuranyl, and the like, but the present disclosure is not limited thereto.

[0117] In the specification, the expression "bonded to an adjacent group to form a ring" may refer to a state of bonding to an adjacent group to form a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocyclic ring. Hydrocarbon rings include aliphatic hydrocarbon rings and aromatic hydrocarbon rings. Heterocyclic rings include aliphatic heterocyclic rings and aromatic heterocyclic rings. Hydrocarbon rings and heterocyclic rings may be monocyclic or polycyclic. In some embodiments, the ring formed by bonding to an adjacent group may be connected to another ring to form a spiro structure.

[0118] The substituted or unsubstituted alkyl group having 1 to 50 carbon atoms may include a urethane group, an amide group, an alkoxy group, and the like.

[0119] In Formula 1, a and b may each independently be an integer of 0 to 5. When a and b are 2 or more, R 9 and R 10 Each may independently bond to an adjacent group to form a ring.

[0120] When the first light emitting material RM is a pyrene derivative, for example, the pyrene derivative can be represented by Formula 2:

[0121] Formula 2

[0122]

[0123] In formula 2, R 20 It may be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted silyl group, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 50 ring-forming carbon atoms, or may bond to an adjacent group to form a ring.

[0124] c can be 1 to 10. When c is 2 or more, R 20 can be the same as or different from each other. 20 At least one of R may not be (eg, is not) hydrogen. 20 It may include an amine group, for example, an aromatic amine group. 20 The arylene group may be substituted or unsubstituted.

[0125] In one embodiment, the luminescence assisting material may be at least one selected from a fluorescent material, a phosphorescent material, and a thermally activated delayed fluorescence (TADF) material.

[0126] For example, the luminescence assisting material may be a phosphorescent material or a thermally activated delayed fluorescent material. When the luminescence assisting material is a phosphorescent material or a thermally activated delayed fluorescent (TADF) material, an electron excited to the lowest excited singlet energy level may be transferred to the lowest triplet energy level (T 1 R ) inter-system crossing. Therefore, all excited electrons can be used to transfer energy to the first luminescent material RM, thereby achieving high-efficiency luminescence.

[0127] For example, the luminescence auxiliary material can be an organic metal complex configured to emit red light. The metal forming the organic metal complex can be selected from the group consisting of Ir, Pt, Os, Au, Cu, Re and Ru. For example, the luminescence auxiliary material can be a porphyrin derivative. For example, the luminescence auxiliary material can be a porphyrin-metal complex.

[0128] Reference Figure 7B In the display device DD according to the embodiment, the first light control part WCL1a may include quantum dots QD1 as the first light emitting material RM. The core of the quantum dots may be selected from II-VI group compounds, III-V group compounds, IV-VI group compounds, IV group elements, IV group compounds and combinations thereof.

[0129] The II-VI compound can be selected from the group consisting of: a two-element compound selected from the group consisting of CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS and a combination thereof; a three-element compound selected from the group consisting of AgInS, CuInS, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS and combinations thereof; and a four-element compound selected from the group consisting of HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe and combinations thereof.

[0130] The III-V compounds can be selected from the group consisting of: two-element compounds selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb and combinations thereof; three-element compounds selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InNAs, InNSb, InPAs, InPSb and combinations thereof; and four-element compounds selected from the group consisting of GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, GaAlNP and combinations thereof.

[0131] The IV-VI Group compounds can be selected from the group consisting of: two-element compounds selected from the group consisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe and combinations thereof; three-element compounds selected from the group consisting of SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe and combinations thereof; and four-element compounds selected from the group consisting of SnPbSSe, SnPbSeTe, SnPbSTe and combinations thereof.

[0132] The Group IV element may be selected from the group consisting of Si, Ge, and combinations thereof.

[0133] The Group IV compound may be a binary compound selected from the group consisting of SiC, SiGe, and combinations thereof.

[0134] Here, the two-element compound, the three-element compound, or the four-element compound may be present in the particle at a substantially uniform concentration, or may be present in the same particle in a state where the concentration distribution is partially different (e.g., non-uniform distribution). For example, a core-shell structure in which one quantum dot QD1 surrounds another quantum dot QD1 (e.g., a first quantum dot material forms a shell around a second quantum dot material) may be possible. The interface between the core and the shell may have a concentration gradient in which the concentration of the element present in the shell decreases toward the core.

[0135] In some embodiments, the quantum dot QD1 may have a core-shell structure comprising a core comprising the described nanocrystals and a shell surrounding the core. The shell of the quantum dot QD1 may be used as a protective layer for maintaining semiconductor properties by preventing or reducing chemical denaturation of the core and / or as a charged layer for imparting electrophoretic properties to the quantum dot QD1. The shell may have a single layer or multiple layers. The interface between the core and the shell may have a concentration gradient in which the concentration of certain elements present in the core decreases toward the core. The shell of the quantum dot QD1 may be, for example, a metal oxide or a non-metal oxide, a semiconductor compound, or a combination thereof.

[0136] The metal oxide or non-metal oxide may be, for example, a binary compound (such as SiO 2 、Al 2 O 3 、TiO 2 、ZnO、MnO、Mn 2 O 3 , Mn 3 O 4 , CuO, FeO, Fe 2 O 3 , Fe 3 O 4 , CoO, Co 3 O 4 and / or NiO) or ternary compounds (such as MgAl 2 O 4 、CoFe 2 O 4 、NiFe 2 O 4 and / or CoMn 2 O 4 ), but the embodiments of the present disclosure are not limited thereto.

[0137] In some embodiments, the semiconductor compound may be, for example, CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, or AlSb, but the present disclosure is not limited thereto.

[0138] The quantum dot QD1 may have a full width at half maximum (FWHM) of an emission wavelength spectrum of about 45 nm or less, about 40 nm or less, or about 30 nm or less, and may improve color purity or color reproducibility within the described range. For example, light emitted from such a quantum dot QD1 is emitted omnidirectionally, thereby improving the viewing angle of the light.

[0139] In addition, the shape of the quantum dot QD1 is not specifically limited to the shape commonly used in the art, for example, nanoparticles, nanotubes, nanowires, nanofibers, nanoplanar particles, etc. in spherical, pyramidal, multi-armed or cubic forms can be used. For example, the quantum dot QD1 can be a rod-shaped quantum rod. The color of the light generated by the quantum dot QD1 can be adjusted according to the particle size of the quantum dot QD1, and therefore, the quantum dot QD1 can have various emission colors such as blue, red and green. The quantum dot QD1 can absorb light in a first wavelength range, and then emit light in a shorter wavelength range according to the material and shape of the quantum dot QD1.

[0140] For example, when the core of the quantum dot QD1 includes a plurality of different compounds, the parts including different compounds in the core of the quantum dot QD1 may all have different band gap energies (the difference between the lowest conduction band energy level and the highest valence band energy level). For example, the quantum dot QD1 may include a first part consisting of a first compound having a first band gap and a second part consisting of a second compound having a second band gap. Excitons excited to the lowest conduction band of the first band gap may drop to the highest valence band of the second band gap, and the second band gap has a highest valence band energy lower than the highest valence band energy of the first band gap. Therefore, the quantum dot QD1 in the embodiment may be configured to absorb light within a first wavelength range and subsequently emit light within a shorter wavelength range (compared to the light within the first wavelength range).

[0141] In addition to the quantum dots QD1, the first light control part WCL1a may further include a matrix resin BR and scattering particles SC. The quantum dots QD1 and the scattering particles SC may be substantially uniformly or non-uniformly dispersed in the matrix resin BR. The scattering particles SC may scatter light emitted from the quantum dots QD1 to improve the viewing angle of the light.

[0142] The matrix resin BR is a medium in which quantum dots QD1 and QD2 and / or scattering particles SC are dispersed, and can be formed of various resin compositions that are generally referred to as adhesives. The polymer resin composition forming the matrix resin BR may include, for example, acrylic resins, urethane resins, silicone resins, epoxy resins, etc. The polymer resin composition may be transparent.

[0143] The scattering particles SC may be inorganic particles. For example, the scattering particles SC may include TiO 2 、ZnO、Al 2 O 3 、SiO 2 and hollow silica. The scattering particles SC may include TiO 2 、ZnO、Al 2 O 3 、SiO 2 and hollow silica or any one of TiO 2 、ZnO、Al 2 O 3 、SiO 2 and a mixture of two or more materials selected from hollow silica.

[0144] The second light control part WCL2 may transmit the first color light emitted from the light emitting element LD. For example, the second light control part WCL2 may transmit the green light emitted from the light emitting element LD. The second light control part WCL2 may include a base resin BR and scattering particles SC. The second light control part WCL2 may not include a separate (additional) luminescent material. Therefore, the density of the scattering particles SC in the second light control part WCL2 may be higher than the density of the scattering particles SC in the first light control part WCL1a and the third light control part WCL3.

[0145] The third light control unit WCL3 may include a second luminescent material to emit a third color light. The second luminescent material may absorb the first color light emitted from the light emitting element LD, and then emit a third color light having a wavelength longer than the wavelength of the first color light. For example, the second luminescent material may absorb the green light emitted from the light emitting element LD, and then emit red light. The second luminescent material may be, for example, a quantum dot QD2. When the second luminescent material is a quantum dot QD2, the quantum dot QD2 may have a description or content substantially the same as the description or content of the quantum dot QD1 described in the first luminescent material RM, except that the quantum dot QD2 may absorb light having a short (shorter) wavelength and emit light having a long (longer) wavelength.

[0146] In the display device DD according to the embodiment, in addition to the organic compound or quantum dot, the first light control part WCL1 (or WCL1a) may include a nanocrystalline compound. The nanocrystalline compound may be a perovskite. The first light control part WCL1 (or WCL1a), the second light control part WCL2, and the third light control part WCL3 may absorb the first color light to emit light having a wavelength shorter than that of the first color light. For example, the first light control part WCL1 (or WCL1a) may absorb the first color light to emit blue light, the second light control part WCL2 may absorb the first color light to emit green light, and the third light control part WCL3 may absorb the first color light to emit red light. The first color light may be infrared light. However, the embodiment is not limited to the description.

[0147] Fig. 9 is a cross-sectional view of a display panel DP-1 according to an embodiment. Fig. 9 In the embodiment, the first display substrate 100-1 includes a light emitting element layer LDL-1 including a light emitting element LD-1. Fig.10 is a cross-sectional view of a light emitting element LD-1 according to an embodiment. Fig. 9 and Fig.10 Each light emitting element LD-1 may include a plurality of emitting parts EM1, EM2, and EM3. The plurality of emitting parts EM1, EM2, and EM3 may be stacked and arranged sequentially. For the emitting parts EM1, EM2, and EM3, the same Figure 5 The contents of the emission part EM described in etc. are substantially the same. When the plurality of emission parts EM1, EM2, and EM3 are included, higher brightness and longer life can be achieved compared with the case where one emission part EM is included.

[0148] Reference Fig. 9 According to the embodiment, the display panel DP-1 includes three stacked emission parts EM1, EM2 and EM3, but the embodiment is not limited thereto. For example, two emission parts may be stacked, or four or more emission parts may be stacked. For example, three or four emission parts may be stacked. When five or more emission parts are stacked, the driving voltage of the light emitting element LD-1 may be increased.

[0149] A charge generation layer CGL (e.g., a plurality of charge generation layers CGL) may be disposed between the emission parts EM1, EM2, and EM3. When a voltage is applied to the charge generation layer CGL, charges are generated. The charge generation layer CGL is disposed between adjacent emission parts EM1, EM2, and EM3 to control the charge balance between the emission parts EM1, EM2, and EM3. For example, the charge generation layer CGL between the emission parts EM1 and EM2 may be used to help inject electrons into the first emission part EM1 and help inject holes into the second emission part EM2.

[0150] The charge generation layer CGL may consist of a layer in which an electron injection material and a hole injection material are mixed. In some embodiments, the charge generation layer CGL may consist of two or more layers. For example, the charge generation layer CGL may include an n-type charge generation layer doped with an n-type dopant and a p-type charge generation layer doped with a p-type dopant. The n-type charge generation layer may be disposed adjacent to the electron transport region ETR to facilitate electron injection, and the p-type charge generation layer may be disposed adjacent to the bottom of the hole transport region HTR to facilitate hole injection.

[0151] The material of the charge generation layer CGL is not particularly limited, and any suitable material available in the art may be used without limitation. On the other hand, in an embodiment, the charge generation layer CGL may be omitted.

[0152] Fig.11 and Fig.12 are cross-sectional views of display panels DP-2 and DP-3 according to the embodiments. Fig.11 , the display panel DP-2 may further include a color filter layer CFL located in the second display substrate 200-1. The color filter layer CFL may be disposed on the light control layer WCL. The color filter layer CFL may include a first color filter CF1, a second color filter CF2, and a third color filter CF3. The first color filter CF1, the second color filter CF2, and the third color filter CF3 may be disposed separately from each other. The light blocking layer BM may be disposed between the first color filter CF1, the second color filter CF2, and the third color filter CF3. The light blocking layer BM may be disposed directly below the second base layer BS2. The light blocking layer BM may overlap with the non-emitting area NPXA on a plane. The light blocking layer BM may include carbon black particles. The light blocking layer BM may prevent or reduce mixing of light emitted from adjacent emission areas. In an embodiment, the light blocking layer BM may be omitted.

[0153] The first color filter CF1 may overlap with the first light control part WCL1, the second color filter CF2 may overlap with the second light control part WCL2, and the third color filter CF3 may overlap with the third light control part WCL3. Each of the first color filter CF1, the second color filter CF2, and the third color filter CF3 may transmit light of different wavelengths. For example, the first color filter CF1 may transmit the second color light and absorb the rest of the light, the second color filter CF2 may transmit the first color light and absorb the rest of the light, and the third color filter CF3 may transmit the third color light and absorb the rest of the light.

[0154] The first color filter CF1, the second color filter CF2, and the third color filter CF3 can transmit light emitted from the first light control part WCL1, the second light control part WCL2, and the third light control part WCL3, respectively, and absorb the remaining light (for example, light having a wavelength or color different from the wavelength or color expected to be emitted from the light control part). The first color filter CF1 can be a blue color filter that transmits blue light, the second color filter CF2 can be a green color filter that transmits green light, and the third color filter CF3 can be a red color filter that transmits red light.

[0155] The first color filter CF1, the second color filter CF2, and the third color filter CF3 may each independently include a matrix resin, and may each independently include at least one dye or pigment dispersed in the matrix resin. The first color filter CF1, the second color filter CF2, and the third color filter CF3 may include different types of dyes and pigments. For example, the first color filter CF1 may include at least one blue dye or blue pigment, the second color filter CF2 may include at least one green dye or green pigment, and the third color filter CF3 may include at least one red dye or red pigment.

[0156] The first color filter CF1, the second color filter CF2, and the third color filter CF3 are included in the above-mentioned positions so that only light within the target wavelength range is emitted from those positions, and the color reproducibility of the display panel DP-2 can be improved. For example, because when the first color filter CF1, the second color filter CF2, and the third color filter CF3 absorb light incident from the outside, the reflection of the external light can be reduced, so the visibility of the display panel DP-2 can be improved.

[0157] Reference Fig.12 , the display panel DP-3 according to the embodiment may further include a polarization layer POL located in the second display substrate 200-2. The polarization layer POL may block or reduce some external light. The polarization layer POL may perform an anti-reflection function to minimize or reduce the reflection of external light. Therefore, the visibility of the display panel DP-3 may be improved. The polarization layer POL may include a circular polarizer or a linear polarizer and a λ / 4 phase retarder.

[0158] The display device DD according to the embodiment may include a light emitting element layer LDL emitting a first color light and a light control layer WCL disposed on the light emitting element layer LDL. The light control layer WCL may include a first light control unit WCL1 emitting a second color light in a wavelength range shorter than the wavelength range of the first color light, a second light control unit WCL2 transmitting the first color light, and a third light control unit WCL3 emitting a third color light in a wavelength range longer than the wavelength range of the first color light. For example, the display device DD according to the embodiment may include (e.g., simultaneously include) both a first light control unit WCL1 (which is up-converted into a shorter wavelength light compared to the light provided by the light source) and a third light control unit WCL3 (which is down-converted into a longer wavelength light compared to the light provided by the light source) on the light emitting element layer LDL used as a light source. Therefore, the display device DD according to the embodiment can effectively convert the light provided by the light source and exhibit improved life characteristics and luminous efficiency characteristics. Therefore, the display device DD according to the embodiment can achieve long life and high efficiency.

[0159] The display device according to the embodiment of the present disclosure may achieve long life and high efficiency.

[0160] Although example embodiments of the present disclosure have been described, it is understood that the present disclosure should not be limited to these example embodiments, but a person skilled in the art may make various changes and modifications within the spirit and scope of the present disclosure as claimed above and its equivalents.

Claims

1. A display device, comprising: a light emitting element layer; as well as a light control layer, located on the light emitting element layer, The light control layer includes: a first light control unit including a first luminescent material emitting a second color light in a wavelength range shorter than the wavelength range of the first color light; a second light control unit transmitting the first color light; and a third light control unit including a second luminescent material emitting a third color light in a wavelength range longer than the wavelength range of the first color light. The first to third light control parts are spaced apart from each other in a plan view, Wherein, the first light control unit further includes at least one luminescence auxiliary material selected from fluorescent materials, phosphorescent materials and thermally activated delayed fluorescent materials, Wherein, the first luminescent material is a pyrene derivative, a fluoranthene derivative, a chrysene derivative, a dihydrobenzanthracene derivative or a benzo[9,10]phenanthrene derivative, wherein the first lowest triplet energy level of the first luminescent material is greater than 1.2 eV and less than the second lowest triplet energy level of the luminescent auxiliary material, the second lowest triplet energy level is 2.5 eV or less, the lowest singlet energy level of the first luminescent material is 2.5 eV to 3.1 eV, and Among them, relative to the total weight of the first luminescent material and the luminescent auxiliary material, the first luminescent material has a proportion of 70wt% or more and 99wt% or less, and the luminescent auxiliary material has a proportion of 1wt% or more and 30wt% or less.

2. The display device according to claim 1, wherein: The first color light is green light having a central wavelength of 500 nm to 580 nm, The second color light is blue light having a central wavelength of 420 nm to 480 nm, and The third color light is red light having a central wavelength of 600 nm to 670 nm.

3. The display device according to claim 1, wherein: The luminescence auxiliary material absorbs the first color light to be excited and transfers energy to the first luminescent material.

4. The display device according to claim 1, wherein: The second luminescent material is quantum dots.

5. The display device according to claim 1, further comprising a color filter layer located on the light control layer, wherein: The color filter layer comprises: a first color filter, overlapping the first light control part to transmit the second color light; a second color filter overlapped with the second light control part to transmit the first color light; and A third color filter is overlapped with the third light control part to transmit the third color light.

6. The display device according to claim 1, wherein: The light emitting element layer includes light emitting elements, The light emitting element includes a first electrode, a second electrode, and at least one emitting portion located between the first electrode and the second electrode, and The at least one emission portion includes: a hole transport region; an emission layer located on the hole transport region; and an electron transport region located on the emission layer.

7. The display device according to claim 6, wherein: The emission layer includes a host and a dopant, and The dopant includes at least one selected from a phosphorescent dopant, a fluorescent dopant, and a thermally activated delayed fluorescent dopant.

8. The display device according to claim 6, wherein: The emitting layer emits phosphorescence.

9. The display device according to claim 6, in, The at least one transmitting portion includes a plurality of transmitting portions stacked sequentially, and The light emitting element further includes a charge generation layer located between the plurality of emission portions.

10. A display device, comprising a display panel, the display panel comprising a display area in which a blue emission area, a green emission area and a red emission area are defined, and a non-display area adjacent to the display area, in, The display panel includes: a light emitting element layer emitting green light; and a light control layer located on the light emitting element layer, and The light control layer includes: a first light control portion overlapping the blue emission region to absorb the green light and emit blue light; a second light control portion overlapping the green emission region to transmit the green light; and a third light control portion overlapping the red emission region to absorb the green light and emit red light. The first light control unit includes a first luminescent material and at least one luminescent auxiliary material selected from a fluorescent material, a phosphorescent material, and a thermally activated delayed fluorescent material. Wherein, the first luminescent material is a pyrene derivative, a fluoranthene derivative, a chrysene derivative, a dihydrobenzanthracene derivative or a benzo[9,10]phenanthrene derivative, wherein the first lowest triplet energy level of the first luminescent material is greater than 1.2 eV and less than the second lowest triplet energy level of the luminescent auxiliary material, the second lowest triplet energy level is 2.5 eV or less, the lowest singlet energy level of the first luminescent material is 2.5 eV to 3.1 eV, and Among them, relative to the total weight of the first luminescent material and the luminescent auxiliary material, the first luminescent material has a proportion of 70wt% or more and 99wt% or less, and the luminescent auxiliary material has a proportion of 1wt% or more and 30wt% or less.

11. A display device, comprising: a light emitting element layer, comprising a plurality of light emitting elements; as well as a light control layer, located on the light emitting element layer, Each of the plurality of light emitting elements includes a first electrode, a second electrode located on the first electrode, and at least one emission portion located between the first electrode and the second electrode. The at least one emission portion includes: a hole transport region; an emission layer located on the hole transport region to emit green light; and an electron transport region located on the emission layer, The light control layer includes: a first light control part that absorbs the green light and emits blue light; a second light control part that transmits the green light; and a third light control part that absorbs the green light and emits red light. The first light control unit includes a first luminescent material and at least one luminescent auxiliary material selected from a fluorescent material, a phosphorescent material, and a thermally activated delayed fluorescent material. Wherein, the first luminescent material is a pyrene derivative, a fluoranthene derivative, a chrysene derivative, a dihydrobenzanthracene derivative or a benzo[9,10]phenanthrene derivative, wherein the first lowest triplet energy level of the first luminescent material is greater than 1.2 eV and less than the second lowest triplet energy level of the luminescent auxiliary material, the second lowest triplet energy level is 2.5 eV or less, the lowest singlet energy level of the first luminescent material is 2.5 eV to 3.1 eV, and Among them, relative to the total weight of the first luminescent material and the luminescent auxiliary material, the first luminescent material has a proportion of 70wt% or more and 99wt% or less, and the luminescent auxiliary material has a proportion of 1wt% or more and 30wt% or less.

12. The display device according to claim 11, wherein: The plurality of light emitting elements include: The first launch unit; A second emitting portion, located on the first emitting portion; and The charge generation layer is located between the first emission portion and the second emission portion.

13. The display device according to claim 11, wherein: The first luminescent material is represented by Formula 2: Formula 2 ， Among them, in formula 2, R 20 is a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted silyl group, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 50 ring carbon atoms, or is bonded to an adjacent group to form a ring, c is an integer from 1 to 10, When c is 2 or greater, R 20 are the same as or different from each other, and R 20 At least one of is not hydrogen.

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