Display device

Abstract

A display device is provided. The display device includes: a light-emitting element layer including a plurality of light-emitting elements; and a light control layer located on the light-emitting element layer and overlapping the light-emitting element layer in a plane. At least one of the light-emitting element and the light control layer includes an amorphous carbon light emitter.

Description

[0001] This application claims priority and benefit of Korean Patent Application No. 10-2019-0018639, filed on Feb. 18, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0002] Embodiments of the present disclosure relate to a display device including quantum dot light emitters, and more particularly, to a display device including quantum dot light emitters formed of amorphous carbon. Background Art

[0003] Various display devices are being developed for multimedia devices such as televisions, mobile phones, tablet computers, navigation systems, and gaming consoles.

[0004] To improve color reproducibility and viewing angles of display devices, display devices including a light control layer containing quantum dot light emitters have been developed. In addition, to achieve long life and high color reproducibility, self-emitting display devices using quantum dot light-emitting materials as light-emitting materials have been developed.

[0005] However, in the case where the quantum dot light-emitting material includes cadmium, environmental protection is restricted. In addition, in the case where the quantum dot light-emitting material does not include cadmium, it is difficult to achieve blue light. Recently, research for improving display devices has been actively conducted. Summary of the Invention

[0006] Embodiments of the present disclosure provide a display device including an environmentally friendly amorphous carbon light emitter.

[0007] Embodiments of the present disclosure also provide a display device including an amorphous carbon light emitter capable of emitting blue light.

[0008] Embodiments of the present disclosure provide a display device including: a light-emitting element layer including a plurality of light-emitting elements; and a light control layer located on the light-emitting element layer and overlapping the light-emitting element layer in a plane, wherein at least one of the light-emitting element and the light control layer includes an amorphous carbon light emitter.

[0009] In an embodiment, each light-emitting element may include a light-emitting layer, and the light-emitting layer may include an amorphous carbon light emitter.

[0010] In an embodiment, each light-emitting element may include: a first electrode; a hole transport region located on the first electrode; a light-emitting layer located on the hole transport region; an electron transport region located on the light-emitting layer; and a second electrode located on the electron transport region, and the light-emitting layer may include an amorphous carbon light emitter.

[0011] In an embodiment, the light-emitting element may include a first light-emitting element that emits first-color light, a second light-emitting element that emits second-color light, and a third light-emitting element that emits third-color light.

[0012] In an embodiment, the first light-emitting element may include a first amorphous carbon light-emitting body having a size of 1.50 nm or more and 1.65 nm or less.

[0013] In an embodiment, the second light-emitting element may include a second amorphous carbon light-emitting body having a size of 1.66 nm or more and 2.00 nm or less, and the third light-emitting element may include a third amorphous carbon light-emitting body having a size of 2.10 nm or more and 3.00 nm or less.

[0014] In an embodiment, the first-color light may be blue light, the second-color light may be green light, and the third-color light may be red light.

[0015] In an embodiment, the light control layer may include a matrix resin and amorphous carbon light-emitting bodies dispersed in the matrix resin.

[0016] In an embodiment, the light-emitting element may emit first-color light, wherein the light control layer may include: a first light control part that transmits the first-color light; a second light control part that absorbs the first-color light and emits second-color light; and a third light control part that absorbs the first-color light and emits third-color light.

[0017] In an embodiment, the first light control part may include a matrix resin and a scatterer dispersed in the matrix resin, wherein the second light control part may include a second amorphous carbon light-emitting body that emits second-color light by changing the wavelength of the first-color light, and wherein the third light control part may include a third amorphous carbon light-emitting body that emits third-color light by changing the wavelength of the first-color light.

[0018] In an embodiment, each light-emitting element may include: a first electrode; a light-emitting layer disposed on the first electrode; and a second electrode disposed on the light-emitting layer, wherein the light-emitting layer may be a common layer for the light-emitting element.

[0019] In an embodiment, the display device may further include: a first color filter disposed on the first light control part and overlapping the first light control part in a plane; a second color filter disposed on the second light control part and overlapping the second light control part in a plane; and a third color filter disposed on the third light control part and overlapping the third light control part in a plane.

[0020] In an embodiment, each light-emitting element may include a light-emitting layer, wherein the light-emitting layer may include amorphous carbon light-emitting bodies, and wherein the light control layer may include a matrix resin and amorphous carbon light-emitting bodies dispersed in the matrix resin.

[0021] In an embodiment of the present disclosure, a display device includes a plurality of light-emitting elements, and each light-emitting element includes: a first electrode; a hole transport region located on the first electrode; a light-emitting layer located on the hole transport region; an electron transport region located on the light-emitting layer; and a second electrode located on the electron transport region, wherein at least one of the light-emitting elements includes an amorphous carbon light emitter in the light-emitting layer.

[0022] In an embodiment, the light-emitting elements may include a first light-emitting element that emits a first color light, a second light-emitting element that emits a second color light, and a third light-emitting element that emits a third color light.

[0023] In an embodiment, the first color light may be blue light, and the light-emitting layer of the first light-emitting element may include an amorphous carbon light emitter.

[0024] In an embodiment, the second color light may be green light, and the third color light may be red light, wherein the light-emitting layer of each of the second light-emitting element and the third light-emitting element may include an amorphous carbon light emitter.

[0025] In an embodiment of the present disclosure, a display device includes a display substrate, the display substrate includes a display area and a non-display area surrounding the display area, the display area includes a first color light-emitting area, a second color light-emitting area, and a third color light-emitting area, wherein the display substrate further includes a first light-emitting element, a second light-emitting element, and a third light-emitting element corresponding to the first color light-emitting area, the second color light-emitting area, and the third color light-emitting area respectively, and at least one of the first light-emitting element to the third light-emitting element includes a light-emitting layer containing an amorphous carbon light emitter.

[0026] In an embodiment, the first light-emitting element may include an amorphous carbon light emitter and emit blue light.

[0027] In an embodiment, the amorphous carbon light emitter may have a size of 1.50 nm or more and 1.65 nm or less. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings are included to provide a further understanding of the subject matter of the present disclosure, and the drawings are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, are used to explain the principles of the present disclosure. In the drawings:

[0029] Figure 1 is a perspective view of a display device according to an embodiment;

[0030] Figure 2 is a plan view of a first display substrate according to an embodiment;

[0031] Figure 3 is along Figure 2A cross-sectional view taken along line I-I';

[0032] Figure 4 is an image showing an amorphous carbon light-emitting body according to an embodiment;

[0033] Figure 5 and Figure 6 is a cross-sectional view of a first display substrate according to an embodiment; and

[0034] Figures 7 to 10 is a cross-sectional view of a display device according to an embodiment. DETAILED DESCRIPTION

[0035] In this specification, when a component (or region, layer, part, etc.) is referred to as being "on" another component, "connected to" or "coupled to" another component, this means that the component can be directly on the other component, directly connected to or directly coupled to the other component, or there can be a third component between them.

[0036] Like reference numerals denote like elements. Additionally, in the drawings, the thickness, ratios, and dimensions of components may be exaggerated for effective description.

[0037] "And / or" includes any one or more combinations defined by the related components.

[0038] It will be understood that the terms "first" and "second" are used herein to describe various components, but these components should not be limited by these terms. The above terms are only used to distinguish one component from another. For example, without departing from the spirit and scope of the present disclosure, a first component may be referred to as a second component, and vice versa. As used herein, unless the context clearly indicates otherwise, singular expressions include plural expressions.

[0039] Additionally, terms such as "below", "lower side", "on", and "upper side" are used to describe the relationship of the structures shown in the drawings. These terms are described as relative concepts based on the directions shown in the drawings.

[0040] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this disclosure pertains. Additionally, terms (such as those defined in a general dictionary) should be interpreted as having a meaning consistent with the meaning in the context of the relevant field, and should not be interpreted in an idealized or overly formal sense unless clearly defined herein.

[0041] In various embodiments of the present disclosure, the term "comprising" and its variants or "including" and its variants indicate the presence of properties, regions, fixed quantities, steps, processes, elements, and / or components, but do not exclude the presence of other properties, regions, fixed quantities, steps, processes, elements, and / or components.

[0042] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0043] Figure 1 is a perspective view of a display device DD according to an embodiment. Referring to Figure 1 , a display area DA and a non-display area NDA can be defined in the display device DD.

[0044] The display area DA can be an area for displaying an image. The non-display area NDA can be an area where no image is displayed. Pixels PX can be located in the display area DA, and pixels PX can not be located in the non-display area NDA. The pixels PX can represent effective pixels for providing an image.

[0045] The display area DA is parallel to (e.g., substantially parallel to) a plane defined by a first direction axis (first direction) DR1 and a second direction axis (second direction) DR2. The normal direction of the display area DA (e.g., the thickness direction of the display device DD) is indicated by a third direction DR3. The front surface (or upper surface) and the rear surface (or lower surface) of each member are divided by the third direction DR3. However, the directions indicated by the first direction DR1, the second direction DR2, and the third direction DR3 can be converted into other directions as relative concepts. Hereinafter, the terms "first direction", "second direction", and "third direction" respectively refer to the first direction DR1, the second direction DR2, and the third direction DR3.

[0046] In addition to large electronic devices (such as televisions, monitors, or external billboards), the display device DD can also be used in medium-sized electronic devices (such as personal computers, laptop computers, personal digital terminals, car navigation units, game consoles, portable electronic devices, and cameras). Additionally, these are briefly proposed as embodiments, and it should be apparent that, without departing from the spirit and scope of the present disclosure, they can be applied to other electronic devices.

[0047] The border area of the display device DD can be defined by the non-display area NDA. The non-display area NDA can be an area adjacent to the display area DA. The non-display area NDA can surround the display area DA. However, the present disclosure is not limited thereto, and the forms of the display area DA and the non-display area NDA can be designed relatively. In another embodiment of the present disclosure, the non-display area NDA can be omitted. The display device DD can include a first display substrate 100 and a second display substrate 200.

[0048] Figure 2 is a plan view of a first display substrate 100 according to an embodiment. Figure 3 is a cross-sectional view taken along line I-I' of Figure 2 . Figure 4 is an image showing an amorphous carbon light-emitting body CQD according to an embodiment.

[0049] Referring to Figure 2 and Figure 3 , the first display substrate 100 may include a non-light-emitting region NPXA and light-emitting regions PXA1, PXA2, and PXA3. Each of the light-emitting regions PXA1, PXA2, and PXA3 may be a region that emits the light generated in each of the light-emitting elements ELD1, ELD2, and ELD3. The area of each of the light-emitting regions PXA1, PXA2, and PXA3 may be different from each other, and the area may represent the area when viewed in the plan view. In the present specification, "on the plane" may refer to the display device DD viewed in the third direction DR3. The light-emitting regions PXA1, PXA2, and PXA3 may be divided into a plurality of groups according to the color of the light generated from the light-emitting elements ELD1, ELD2, and ELD3.

[0050] Three light-emitting regions PXA1, PXA2, and PXA3 for emitting first color light, second color light, and third color light are exemplarily shown in the first display substrate 100 of the embodiment shown in Figure 2 and Figure 3 . For example, the first display substrate 100 of the embodiment includes a first color light-emitting region PXA1, a second color light-emitting region PXA2, and a third color light-emitting region PXA3 that are separated from each other. The first light-emitting element ELD1 is positioned to correspond to the first color light-emitting region PXA1 and may be superimposed on the first color light-emitting region PXA1 on the plane. The second light-emitting element ELD2 is positioned to correspond to the second color light-emitting region PXA2 and may be superimposed on the second color light-emitting region PXA2 on the plane. The third light-emitting element ELD3 is positioned to correspond to the third color light-emitting region PXA3 and may be superimposed on the third color light-emitting region PXA3 on the plane.

[0051] In an embodiment, the first display substrate 100 may include a plurality of light-emitting elements ELD1, ELD2, and ELD3 that emit light in different wavelength regions. The plurality of light-emitting elements ELD1, ELD2, and ELD3 may emit light of different colors from each other. For example, in an embodiment, the first display substrate 100 includes a first light-emitting element ELD1 that emits blue light, a second light-emitting element ELD2 that emits green light, and a third light-emitting element ELD3 that emits red light. However, the embodiment is not limited thereto, and the first light-emitting element ELD1, the second light-emitting element ELD2, and the third light-emitting element ELD3 may emit light in the same (e.g., substantially the same) wavelength range, or at least one of them may emit light in a different wavelength range.

[0052] In Figure 2 and Figure 3 in the display device DD of the embodiment shown, the light-emitting regions PXA1, PXA2, and PXA3 may have different areas according to the colors of the light emitted from the light-emitting layers EML1, EML2, and EML3 of the light-emitting elements ELD1, ELD2, and ELD3. For example, referring to Figure 2 and Figure 3 , in the first display substrate 100 of the embodiment, the first-color light-emitting region PXA1 of the first light-emitting element ELD1 that emits first-color light may have the largest area, and the second-color light-emitting region PXA2 of the second light-emitting element ELD2 that emits second-color light may have the smallest area. However, the embodiment is not limited thereto, and the light-emitting regions PXA1, PXA2, and PXA3 may have the same (e.g., substantially the same) area, or the light-emitting regions PXA1, PXA2, and PXA3 may be set with an area ratio different from the area ratio shown in Figure 2 .

[0053] Each of the light-emitting regions PXA1, PXA2, and PXA3 may be a region defined by a pixel defining film PDL. The non-light-emitting region NPXA may be a region corresponding to the pixel defining film PDL as a region corresponding to the adjacent light-emitting regions PXA1, PXA2, and PXA3. On the other hand, each of the light-emitting regions PXA1, PXA2, and PXA3 in this specification may correspond to a pixel.

[0054] The first-color light-emitting region PXA1 and the third-color light-emitting region PXA3 may be alternately arranged along the second direction axis DR2 to form a first group PXG1. The second-color light-emitting region PXA2 may be arranged along the second direction axis DR2 to form a second group PXG2.

[0055] The first set of PXG1 can be spaced apart from the second set of PXG2 along the first direction axis DR1. Each of the first set of PXG1 and the second set of PXG2 can be provided in a plurality. The first set of PXG1 and the second set of PXG2 can be alternately arranged along the first direction axis DR1.

[0056] A second color light-emitting region PXA2 can be spaced apart from a first color light-emitting region PXA1 or a third color light-emitting region PXA3 along the fourth direction axis DR4. The fourth direction axis DR4 can be a direction between the first direction axis DR1 and the second direction axis DR2.

[0057] Figure 2 The arrangement structure of the light-emitting regions PXA1, PXA2, and PXA3 shown in can be referred to as a PenTile structure. However, the arrangement structure of the light-emitting regions PXA1, PXA2, and PXA3 in the display device DD according to the embodiment is not limited to Figure 2 the arrangement structure shown in. For example, in the embodiment, the light-emitting regions PXA1, PXA2, and PXA3 can have a stripe structure in which the first color light-emitting region PXA1, the second color light-emitting region PXA2, and the third color light-emitting region PXA3 are alternately arranged along the second direction axis DR2.

[0058] Referring to Figure 3 , the first display substrate 100 can include a first base layer BS1, a circuit layer CCL, and a light-emitting element layer EL. The circuit layer CCL can be located on the first base layer BS1. The circuit layer CCL can include a semiconductor layer, a plurality of insulating layers, and a plurality of conductive layers. The light-emitting element layer EL can be located on the circuit layer CCL.

[0059] The first base layer BS1 can be a silicon substrate, a plastic substrate, a glass substrate, an insulating film, or a stacked structure including a plurality of insulating layers.

[0060] The circuit layer CCL can include a first transistor TR1, a second transistor TR2, and a third transistor TR3, and a plurality of insulating layers IL1, IL2, IL3, and IL4. The plurality of insulating layers IL1, IL2, IL3, and IL4 include a first insulating layer IL1, a second insulating layer IL2, a third insulating layer IL3, and a fourth insulating layer IL4.

[0061] The first insulating layer IL1 may be located on the first base layer BS1, and the first transistor TR1, the second transistor TR2, and the third transistor TR3 may be located on the first insulating layer IL1. Since the first transistor TR1, the second transistor TR2, and the third transistor TR3 may have the same (e.g., substantially the same) structure, the content of the first transistor TR1 described below may be applied as it is. The first transistor TR1 may include a control electrode CE, an input electrode IE, an output electrode OE, and a semiconductor layer ACL.

[0062] The semiconductor layer ACL may be located on the first insulating layer IL1. The first insulating layer IL1 may be a buffer layer that provides an improved surface to the semiconductor layer ACL. In this case, the adhesion of the semiconductor layer ACL to the first insulating layer IL1 is higher than that to the first base layer BS1. Additionally, the first insulating layer IL1 may be a barrier layer for protecting the lower surface of the semiconductor layer ACL. In this case, the first insulating layer IL1 may prevent dirt, moisture, etc. from the first base layer BS1 itself or entering through the first base layer BS1 from penetrating into the semiconductor layer ACL. Optionally, the first insulating layer IL1 may be a light-blocking layer that blocks external light incident through the first base layer BS1 from entering the semiconductor layer ACL. In this case, the first insulating layer IL1 may further include a light-blocking material.

[0063] The semiconductor layer ACL may include polysilicon or amorphous silicon. Additionally, the semiconductor layer ACL may include a metal oxide semiconductor. The semiconductor layer ACL may include a first ion-doped region and a second ion-doped region, and a channel region located between the first ion-doped region and the second ion-doped region, where the channel region serves as a channel through which electrons or holes can travel.

[0064] The second insulating layer IL2 is located on the first insulating layer IL1 and may cover the semiconductor layer ACL. The second insulating layer IL2 may include an inorganic material. The inorganic material may include at least one of silicon nitride, silicon oxynitride, silicon oxide, titanium oxide, and aluminum oxide.

[0065] The control electrode CE may be located on the second insulating layer IL2. The third insulating layer IL3 is located on the second insulating layer IL2 and may cover the control electrode CE. The third insulating layer IL3 may be composed of a single layer or multiple layers. For example, the single layer may include an inorganic layer. The multiple layers may be provided by stacking an organic layer and an inorganic layer.

[0066] The input electrode IE and the output electrode OE may be located on the third insulating layer IL3. Each of the input electrode IE and the output electrode OE may be connected to the semiconductor layer ACL through a via hole passing through the second insulating layer IL2 and the third insulating layer IL3.

[0067] The fourth insulating layer IL4 is located on the third insulating layer IL3 and may cover the input electrode IE and the output electrode OE. The fourth insulating layer IL4 may be composed of a single layer or multiple layers. For example, the single layer may include an organic layer. The multiple layers may be provided by stacking an organic layer and an inorganic layer. The fourth insulating layer IL4 may be a planarization layer that provides a flat surface on the upper part. The light-emitting element layer EL may be located on the fourth insulating layer IL4.

[0068] The light-emitting element layer EL may include a first light-emitting element ELD1, a second light-emitting element ELD2, a third light-emitting element ELD3, a pixel defining layer PDL, and a thin film encapsulation layer TFE located on the light-emitting element ELD. The thin film encapsulation layer TFE may encapsulate the light-emitting element ELD. In some embodiments, a cover layer covering the second electrode EL2 may be further located between the thin film encapsulation layer TFE and the second electrode EL2. In this case, the thin film encapsulation layer TFE may directly cover the cover layer. In an embodiment, the thin film encapsulation layer TFE may be omitted.

[0069] The first light-emitting element ELD1 may include a first electrode EL1, a hole transport region HTR located on the first electrode EL1, a first light-emitting layer EML1 located on the hole transport region HTR, an electron transport region ETR located on the first light-emitting layer EML1, and a second electrode EL2. Each of the second light-emitting element ELD2 and the third light-emitting element ELD3 may have a description substantially the same as that of the first light-emitting element ELD1, except that they respectively include a second light-emitting layer EML2 and a third light-emitting layer EML3.

[0070] The first electrode EL1 may be located on the fourth insulating layer IL4. The first electrode EL1 has conductivity. The first electrode EL1 may be formed of a metal alloy or a conductive compound. The first electrode EL1 may be an anode. Additionally, the first electrode EL1 may be a pixel electrode. The first electrode EL1 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. Each first electrode EL1 may be electrically connected to the first transistor TR1, the second transistor TR2, and the third transistor TR3 in a one-to-one correspondence through a via hole. For example, the first electrode EL1 of the first light-emitting element ELD1 may be electrically connected to the first transistor TR1. The first electrode EL1 of the second light-emitting element ELD2 may be electrically connected to the second transistor TR2. The first electrode EL1 of the third light-emitting element ELD3 may be electrically connected to the third transistor TR3.

[0071] The hole transport region HTR may include at least one of a hole injection layer, a hole transport layer, a hole buffer layer, and an electron blocking layer. The hole transport region HTR may have a single layer made of a single material, a single layer made of a plurality of different materials, or a multilayer structure having a plurality of layers made of a plurality of different materials. The material of the hole transport region HTR is not particularly limited and may include suitable materials available in the art.

[0072] The light emitting layers EML1, EML2, and EML3 may have a single layer of a single material, a single layer of a plurality of different materials, or a multilayer structure having a plurality of layers of a plurality of different materials.

[0073] The light emitting layers EML1, EML2, and EML3 may include amorphous carbon quantum dots CQD. Refer to Figure 4 , the amorphous carbon quantum dots CQD may include a core CR and a branch FG bonded to the surface of the core CR. The region where the branch FG is located may be defined as a branch region FGA. The branch region FGA may be defined as having a curved quasi-spherical shape on a virtual spherical surface or a spherical surface.

[0074] The core CR may be a light-emitting portion that emits light, and the branch FG may be a non-light-emitting portion that does not emit light.

[0075] The core CR may be spherical, or may have a curved quasi-spherical shape on the surface of a spherical surface. However, the embodiments are not limited thereto, and may have nanoparticles, nanotubes, nanowires, nanofibers, or nanoplate-like particles having shapes such as pyramids, multi-arms, or cubes. The amorphous carbon quantum dots CQD may be quantum dot light emitters having a size (e.g., diameter L1) of 1.50 nm or more and 1.65 nm or less. The size (e.g., diameter L1) of the amorphous carbon quantum dots CQD may be defined as the diameter of the core CR. If the core CR is not spherical, the diameter of the core CR may be a straight line passing through the center of gravity of the core CR, and may represent the average length of a segment connecting two points on the outer periphery of the core CR. As used herein, the term "size" may refer to the particle diameter of the core CR, such as the average particle diameter exemplified by D50, where D50 refers to such a diameter: at this diameter, half of the mass of the sample particles has a larger diameter, and the other half of the mass of the sample particles has a smaller diameter.

[0076] The core CR may include a hydrocarbon group. For example, the core CR may include a polymeric hydrocarbon polymer. In some embodiments, the core CR may include a hydrocarbon polymer composed of acrylamide compounds (such as polyacrylamide) or acrylate compounds (such as polymethyl methacrylate). In another example, the core CR may include an aromatic ring derivative. For example, the core CR may include phenyl derivatives such as diamine benzene, pyrene, phenanthroline, or trimethylbenzene. However, the embodiments are not limited thereto, and the core CR may include another hydrocarbon group and may also include heteroatoms.

[0077] The core CR may have an amorphous structure. For example, hydrocarbon groups and the like in the core CR may be irregularly bonded to each other to form an amorphous structure.

[0078] The branch FG may be composed of functional groups. The branch FG may be a hydrocarbon derivative including an alkyl group, an alkenyl group, an alkynyl group, an amine group (or amino group), a thiol group, a hydroxyl group, an ether group, an ester group, a hydrazine group, a carboxyl group, an amide group, or a carbonyl group. For example, the branch FG may be composed of the above-mentioned functional groups or a combination of the above-mentioned functional groups or one or more functional groups bonded to the main chain of a hydrocarbon.

[0079] However, the embodiments are not limited thereto, and the branch FG may include other functional groups.

[0080] Referring again to Figure 2 and Figure 3 , the first light-emitting layer EML1 may include a first amorphous carbon light-emitting body CQD1. The second light-emitting layer EML2 may include a second amorphous carbon light-emitting body CQD2. The third light-emitting layer EML3 may include a third amorphous carbon light-emitting body CQD3.

[0081] The diameter of the first amorphous carbon light-emitting body CQD1 may be smaller than the diameter of the second amorphous carbon light-emitting body CQD2, and the diameter of the second amorphous carbon light-emitting body CQD2 may be smaller than the diameter of the third amorphous carbon light-emitting body CQD3.

[0082] The emission wavelengths of the first to third amorphous carbon light-emitting bodies CQD may be determined by the diameters of the first to third amorphous carbon light-emitting bodies CQD.

[0083] For example, the first amorphous carbon light-emitting body CQD1 emits blue light and may have a diameter of 1.50 nm or more and 1.65 nm or less. The second amorphous carbon light-emitting body CQD2 emits green light and may have a diameter of 1.66 nm or more and 2.00 nm or less. The third amorphous carbon light-emitting body CQD3 emits red light and may have a diameter of 2.10 nm or more and 3.00 nm or less. However, the emission wavelengths of the first to third amorphous carbon light-emitting bodies CQD are not limited only by the diameters of the first to third amorphous carbon light-emitting bodies CQD.

[0084] In an embodiment, the emission wavelength can be additionally adjusted by adjusting the type (or kind) of functional groups included in the branch FG of the first amorphous carbon emitter to the third amorphous carbon emitter CQD. For example, the emission wavelength can be changed according to the type (or kind) of functional groups included in the branch FG of the first amorphous carbon emitter to the third amorphous carbon emitter CQD. In some embodiments, when the branch FG has oxygen-containing groups (such as hydroxyl, ether, carboxyl, carbonyl, or ester groups), the emission wavelength can be changed. In an embodiment, the emission wavelength of the first amorphous carbon emitter to the third amorphous carbon emitter CQD can be adjusted by adjusting the roughness of the surface of the first amorphous carbon emitter to the third amorphous carbon emitter CQD. For example, the emission wavelength can be changed by adjusting the roughness of the surface of the first amorphous carbon emitter to the third amorphous carbon emitter CQD, a planarization process, etc.

[0085] The amorphous carbon emitter CQD can be synthesized in various ways. For example, the amorphous carbon emitter CQD can be synthesized by the following method.

[0086] (Synthesis of Amorphous Carbon Emitter CQD)

[0087] Aqueous polyacrylamide solution (1 mL, 90 wt% in water) and nitric acid (0.5 M, 1 mL) are mixed with oleylamine (10 mL), and stirred for 30 minutes under an argon atmosphere to form an emulsion. The formed emulsion is heated to 250 °C for 2 hours under an argon (Ar) atmosphere, and then cooled to room temperature. The resulting solution is precipitated in methanol and centrifuged at 3000 rpm for 10 minutes to obtain a precipitate.

[0088] The obtained precipitate is dispersed in hexane, precipitated in methanol, and separated by centrifugation. To remove impurities, this process is repeated three times to obtain the final product.

[0089] Amorphous carbon emitters CQD with various suitable sizes can be synthesized using various suitable hydrocarbon compounds by changing the type, molecular weight, and concentration of the polymer and changing the reaction conditions.

[0090] In addition to the above synthesis method, amorphous carbon emitters CQD can be fabricated by treating an amorphous carbon substrate with physicochemical methods such as chemical ablation, laser ablation, or microwave irradiation.

[0091] In Figure 3 , the first emission layer EML1, the second emission layer EML2, and the third emission layer EML3 are shown to include amorphous carbon emitters CQD, but the embodiments are not limited thereto, and further details thereof will be described below.

[0092] The electron transport region ETR is disposed on the light emitting layers EML1, EML2, and EML3. The electron transport region ETR may include at least one of a hole blocking layer, an electron transport layer, and an electron injection layer, but the embodiment is not limited thereto. The electron transport region ETR may have a single layer made of a single material, a single layer made of a plurality of different materials, or a multilayer structure having a plurality of layers made of a plurality of different materials. The material of the electron transport region ETR is not particularly limited and may include any suitable material available in the art.

[0093] 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 a transmissive electrode, a semi-transmissive electrode or a reflective electrode.

[0094] The pixel defining film PDL may be located between the light emitting elements ELD and expose at least a portion of each first electrode EL1. The pixel defining film PDL may be formed of a polymer resin. For example, the pixel defining film PDL may be formed to include a polyacrylate resin or a polyimide resin. In addition, the pixel defining film PDL may be formed to include an inorganic material in addition to the polymer resin. On the other hand, the pixel defining film PDL may be formed to include a light absorbing material, or may be formed to include a black pigment or a black dye. The pixel defining film PDL formed of a black pigment or a black dye may realize a black pixel defining film. When forming the pixel defining film PDL, carbon black may be used as a black pigment or a black dye, but the embodiment is not limited thereto.

[0095] In addition, the pixel definition layer PDL may be formed of an inorganic material. For example, the pixel definition layer PDL may be formed of silicon nitride (SiN x ), silicon oxide (SiO x ) or silicon oxynitride (SiO x N y ) and so on.

[0096] Figure 5 and Figure 6 1 is a cross-sectional view of first display substrates 100 - 1 and 100 - 2 according to an embodiment. Figure 5 and Figure 6 The cross-sectional view can be compared with the Figure 2 The cross-sectional view taken along the line II' shown in FIG. Figure 5 and Figure 6 They respectively include a light emitting element layer EL-1 and a light emitting element layer EL-2.

[0097] Reference Figure 5, the first light-emitting layer EML1 of the first light-emitting element ELD1 may include a first amorphous carbon quantum dot CQD1 and may emit first-color light. The first-color light may be blue light. Existing cadmium (Cd)-based quantum dot light-emitting materials are harmful to the human body and have limited use due to the environmental pollution they cause. Quantum dot light-emitting materials of other inorganic substances are difficult to synthesize into light-emitting materials that emit light with a blue wavelength. The amorphous carbon quantum dot CQD of the embodiment can be easily synthesized into a blue quantum dot light-emitting material that is environmentally friendly and emits light with a blue wavelength. In addition, due to the low material cost, the manufacturing cost of the display device can be reduced.

[0098] The first light-emitting layer EML1 may only include the first amorphous carbon quantum dot CQD1. However, the embodiment is not limited thereto, and the first light-emitting layer EML1 may further include another material. For example, the first light-emitting layer EML1 may further include a matrix resin.

[0099] In the embodiment, the second light-emitting layer EML2 of the second light-emitting element ELD2 may emit second-color light, and the third light-emitting layer EML3 of the third light-emitting element ELD3 may emit third-color light. The second-color light may be green light, and the third-color light may be red light.

[0100] In the display device of the embodiment, the first light-emitting layer EML1 that emits blue light includes an amorphous carbon quantum dot CQD. The second light-emitting layer EML2 and the third light-emitting layer EML3 may include quantum dot light-emitting materials other than the amorphous carbon quantum dot CQD, and the quantum dot light-emitting materials include materials selected from II-VI group compounds, III-V group compounds, IV-VI group compounds, group IV elements, or group IV compounds.

[0101] The II-VI group compounds may be selected from binary compounds, ternary compounds, and quaternary compounds. The binary compounds are selected from the group consisting of ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, and mixtures thereof. The ternary compounds are selected from the group consisting of AgInS, CuInS, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, and mixtures thereof. The quaternary compounds are selected from the group consisting of HgZnTeS, HgZnSeS, HgZnSeTe, HgZnSTe, and mixtures thereof.

[0102] The III-V compounds can be selected from binary compounds, ternary compounds, and quaternary compounds. The binary compounds are selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof. The ternary compounds are selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InNAs, InNSb, InPAs, InPSb, and mixtures thereof. The quaternary compounds are selected from the group consisting of GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, GaAlNP, and mixtures thereof. The IV-VI compounds can be selected from binary compounds, ternary compounds, and quaternary compounds. The binary compounds are selected from the group consisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe, and mixtures thereof. The ternary compounds are selected from the group consisting of SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and mixtures thereof. The quaternary compounds are selected from the group consisting of SnPbSSe, SnPbSeTe, SnPbSTe, and mixtures thereof. The Group-IV elements can be selected from the group consisting of Si, Ge, and mixtures thereof. The Group-IV compounds can be binary compounds, and the binary compounds are selected from the group consisting of SiC, SiGe, and mixtures thereof.

[0103] At this time, the binary compound, ternary compound, or quaternary compound can be present in the particles at a uniform (e.g., substantially uniform) concentration, or can be present in the same particles in a partially different concentration distribution state.

[0104] The quantum dot light emitter can be a core-shell structure including a core and a shell surrounding the core. In addition, a single quantum dot light emitter can have a core / shell structure surrounding another quantum dot light emitter. The interface between the core and the shell can have a concentration gradient in which the concentration of the elements in the shell decreases as it approaches the core.

[0105] The shell of the quantum dot light emitter can be used as a protective layer for preventing or reducing chemical modification of the core to maintain semiconductor characteristics and / or can be used as a charge layer for providing electrophoretic characteristics to the quantum dot light emitter. The shell can be a single layer or multiple layers. The interface between the core and the shell can have a concentration gradient in which the concentration of the elements in the shell decreases as it approaches the core. Examples of the shell of the quantum dot light emitter can include oxides of metals or non-metals, semiconductor compounds, or combinations thereof.

[0106] For example, the oxides of metals or non-metals can include binary compounds (such as SiO2, Al2O3, TiO2, ZnO, MnO, Mn2O3, Mn3O4, CuO, FeO, Fe2O3, Fe3O4, CoO, Co3O4, and NiO, etc.) or ternary compounds (such as MgAl2O4, CoFe2O4, NiFe2O4, and CoMn2O4, etc.), but the present disclosure is not limited thereto.

[0107] In addition, the semiconductor compounds can include ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, but the present disclosure is not limited thereto.

[0108] The quantum dot light emitter can be particles having a nanoscale size. The quantum dot light emitter can have a full width at half maximum (FWHM) of the emission wavelength spectrum of about 45 nm or less, about 40 nm or less, or for example about 30 nm or less, and within this range, color purity and color reproducibility can be improved. In addition, since the light emitted by the quantum dot light emitter is emitted in all directions, a wide viewing angle can be improved.

[0109] The shape of the quantum dot light emitter is not particularly limited and can have any suitable form commonly used in the art. For example, the quantum dot light emitter can be nanoparticles, nanotubes, nanowires, nanofibers, and / or nanoplatelet particles in the form of spheres, pyramids, multi-arms, or cubes, etc.

[0110] Referring to Figure 6 , instead of the amorphous carbon light emitter CQD, the first light-emitting element ELD1 can include a quantum dot light emitter in the first light-emitting layer EML1, and the quantum dot light emitter includes materials selected from group II-VI compounds, group III-V compounds, group IV-VI compounds, group IV elements, group IV compounds, and combinations thereof. The second light-emitting element ELD2 and the third light-emitting element ELD3 can include the amorphous carbon light emitter CQD. The second light-emitting element ELD2 can include a second amorphous carbon light emitter CQD2 that emits green light, and the third light-emitting element ELD3 can include a third amorphous carbon light emitter CQD3 that emits red light.

[0111] Except for Figure 5 and Figure 6 those shown in, it is obvious that any one or two of the first light-emitting element ELD1, the second light-emitting element ELD2, and the third light-emitting element ELD3 may include an amorphous carbon light-emitting body CQD.

[0112] Figure 7 and Figure 8 are cross-sectional views of the display devices DD-1 and DD-2 according to the embodiments. Referring to Figure 7 , in the display device DD-1 of the embodiment, the second display substrate 200 may be located on the first display substrate 100-3 including the light-emitting element layer EL-3. The second display substrate 200 may include an adhesive member ADH, a light control layer WCL, and a second substrate layer BS2.

[0113] For the first display substrate 100-3 according to the embodiment, except that each of the light-emitting layers EML1, EML2, and EML3 may emit first-color light, the same content as that described with reference to Figure 3 , Figure 5 and Figure 6 may be applied. For example, each of the light-emitting layers EML1, EML2, and EML3 may include a first amorphous carbon light-emitting body CQD1 and emit blue light.

[0114] However, the embodiment is not limited thereto. Referring to Figure 8 , in the display device DD-2 of the embodiment, the light-emitting element ELD of the first display substrate 100-4 may be an organic electroluminescent element including an organic material other than the light-emitting element ELD including a quantum dot light-emitting body. The display device DD-2 includes a light-emitting element layer EL-4.

[0115] In some embodiments, the first display substrate may emit ultraviolet light, and in this case, the first display substrate may include a backlight and a liquid crystal layer.

[0116] The adhesive member ADH may be a member for attaching the first display substrate (for example, Figure 7 the first display substrate 100-3 of Figure 8 or the first display substrate 100-4 of

[0117] and the second display substrate 200 together. The adhesive member ADH may be an optically transparent adhesive.

[0118] The light control layer WCL may be located between the adhesive member ADH and the second substrate layer BS2. The light control layer WCL may include a first light control portion WCL1, a second light control portion WCL2, and a third light control portion WCL3. The light control layer WCL may transmit the first color light emitted from the light-emitting element layer (e.g., Figure 7 the light-emitting element layer EL-3 of Figure 8 or the light-emitting element layer EL-4), or may emit the second color light by absorbing the first color light, or may emit the third color light by absorbing the first color light. For example, the first light control portion WCL1 may transmit the first color light. The second light control portion WCL2 may absorb the first color light and emit the second color light. The third light control portion WCL3 may absorb the first color light and emit the third color light. The first color light may be blue light, the second color light may be green light, and the third color light may be red light.

[0119] The first light control portion WCL1 may be superimposed on the first color light-emitting region PXA1 in a plane and may be partially superimposed on the non-light-emitting region NPXA. The second light control portion WCL2 may be superimposed on the second color light-emitting region PXA2 in a plane and may be partially superimposed on the non-light-emitting region NPXA. The third light control portion WCL3 may be superimposed on the third color light-emitting region PXA3 in a plane and may be partially superimposed on the non-light-emitting region NPXA.

[0120] The first light control portion WCL1 may include a matrix resin RS and a scatterer (e.g., scattering particles SC) dispersed in the matrix resin RS. The scattering particles SC may be TiO2 or silica-based nanoparticles. The scattering particles SC may scatter light. Since the first light control portion WCL1 does not include a light emitter, the amount of scattering particles SC per unit area included in the first light control portion WCL1 may be greater than the amount of scattering particles SC per unit area included in each of the second light control portion WCL2 and the third light control portion WCL3. However, the embodiments are not limited thereto. When ultraviolet light is emitted from the first display substrate, the first light control portion WCL1 may include a first amorphous carbon light emitter CQD1. In this case, the first amorphous carbon light emitter CQD1 may absorb ultraviolet light and emit blue light.

[0121] The second light control portion WCL2 may include a matrix resin RS, scattering particles SC dispersed in the matrix resin RS, and a second amorphous carbon light emitter CQD2. The second amorphous carbon light emitter CQD2 may absorb the first color light and emit the second color light.

[0122] The third light control portion WCL3 may include a matrix resin RS, scattering particles SC dispersed in the matrix resin RS, and a third amorphous carbon light emitter CQD3. The third amorphous carbon light emitter CQD3 may absorb the first color light and emit the third color light.

[0123] In an embodiment, although it is described that all of the first light control unit WCL1, the second light control unit WCL2, and the third light control unit WCL3, or the second light control unit WCL2 and the third light control unit WCL3 include amorphous carbon quantum dots CQD, the embodiment is not limited thereto. Any one or two of the first light control unit WCL1, the second light control unit WCL2, and the third light control unit WCL3 may include amorphous carbon quantum dots CQD. In this case, the remaining light control units may include quantum dot light emitters, and the quantum dot light emitters include materials selected from II-VI group compounds, III-V group compounds, IV-VI group compounds, group IV elements, group IV compounds, and mixtures thereof.

[0124] Figure 9 is a cross-sectional view of a display device DD-3 including a first display substrate 100-5 according to an embodiment. Referring to Figure 9 , the light emitting layer EML-1 in the light emitting element ELD-1 of the light emitting element layer EL-5 may be a common layer among the light emitting elements ELD1-1, ELD2-1, and ELD3-1. In this case, since a separate mask for depositing the light emitting layer EML-1 is not required, the manufacturing process of the display device DD-3 can be simplified.

[0125] The light emitting layer EML-1 of the embodiment may include quantum dot light emitters. For example, the light emitting layer EML-1 of the embodiment may include a first amorphous carbon quantum dot CQD1. However, the embodiment is not limited thereto, and the light emitting layer EML-1 may include an organic material as a light emitting material.

[0126] Figure 10 is a cross-sectional view of a display device DD-4 according to an embodiment. Referring to Figure 10 , the display device DD-4 may include a first color filter CF1, a second color filter CF2, and a third color filter CF3. The first color filter CF1 may be located on the first light control unit WCL1 and may be superimposed on the first light control unit WCL1 in a plane. The second color filter CF2 may be located on the second light control unit WCL2 and may be superimposed on the second light control unit WCL2 in a plane. The third color filter CF3 may be located on the third light control unit WCL3 and may be superimposed on the third light control unit WCL3 in a plane.

[0127] 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 first color light and absorb the remaining light. The second color filter CF2 may transmit second color light and absorb the remaining light. The third color filter CF3 may transmit third color light and absorb the remaining light.

[0128] Each of the first color filter CF1, the second color filter CF2, and the third color filter CF3 may transmit color light corresponding to the light emitted from the first light control unit WCL1, the second light control unit WCL2, and the third light control unit WCL3, and absorb the remaining light. The first color filter CF1 may be a blue color filter that transmits blue light. The second color filter CF2 may be a green color filter that transmits green light. The third color filter CF3 may be a red color filter that transmits red light.

[0129] The first color filter CF1, the second color filter CF2, and the third color filter CF3 include a base resin, and may include at least one dye or pigment dispersed in the base resin. The first color filter CF1, the second color filter CF2, and the third color filter CF3 may include different types of dyes or 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. The third color filter CF3 may include at least one red dye or red pigment.

[0130] Due to the inclusion of the first color filter CF1, the second color filter CF2, and the third color filter CF3, since only light in the target wavelength region is emitted, the color reproducibility of the display device DD-4 can be improved. In addition, since external light reflection can be reduced by absorbing the light incident from the outside, the visibility of the display device DD-4 can be improved.

[0131] The second display substrate 200-1 includes a light-blocking layer BM that may be located between each of the first color filter CF1, the second color filter CF2, and the third color filter CF3. The light-blocking layer BM may be directly located on the lower portion of the second base layer BS2. The light-blocking layer BM may overlap with the non-light-emitting region NPXA in a plane. The light-blocking layer BM may include carbon black particles. Due to the inclusion of the light-blocking layer BM, the phenomenon of light emitted from adjacent light-emitting regions being mixed can be prevented or reduced. In an embodiment, the light-blocking layer BM may be omitted.

[0132] A display device according to an embodiment may include a light-emitting element layer and a light control layer located on the light-emitting element layer. At least one of the light-emitting element layer and the light control layer may include an amorphous carbon light emitter.

[0133] A display device according to an embodiment may include a light-emitting element. The light-emitting element may include a light-emitting layer, and the light-emitting layer may include an amorphous carbon light emitter.

[0134] According to an embodiment of the present disclosure, a display device including an environmentally friendly amorphous carbon light emitter may be provided.

[0135] According to an embodiment of the present disclosure, a display device including an amorphous carbon light emitter capable of emitting blue light may be provided.

[0136] As used herein, the terms "substantially", "about", and similar terms are used as approximate terms and not as terms of degree, and are intended to account for the inherent deviations of measured or calculated values that would be recognized by a person of ordinary skill in the art. In addition, when describing embodiments of the present disclosure, the use of "may" refers to "one or more embodiments of the present disclosure". As used herein, the terms "use" and its variations may be considered synonymous with "utilize" and its variations, respectively. In addition, the term "exemplary" is intended to indicate an example or instance.

[0137] In addition, any numerical range stated herein is intended to include all sub-ranges of the same numerical precision that are included within the stated range. For example, a range of "1.0 to 10.0" is intended to include all sub-ranges between the stated minimum value of 1.0 and the stated maximum value of 10.0 (including the stated minimum value of 1.0 and the stated maximum value of 10.0), i.e., having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, by way of example, 2.4 to 7.6. Any maximum numerical limit stated herein is intended to include all lesser numerical limits contained therein, and any minimum numerical limit stated in this specification is intended to include all greater numerical limits contained therein. Accordingly, the applicant reserves the right to amend this specification (including the claims) to expressly recite any sub-ranges that are included within the ranges expressly stated herein.

[0138] Although exemplary embodiments of the present disclosure have been described, it is understood that the present disclosure should not be limited to these exemplary embodiments, but rather various changes and modifications can be made by a person of ordinary skill in the art within the spirit and scope of the appended claims and their equivalents.

Claims

1. A display device, the display device comprising: A light-emitting element layer including a plurality of light-emitting elements; And A light control layer located on the light-emitting element layer and overlapping the light-emitting element layer in a plane, Wherein at least one of the plurality of light-emitting elements and the light control layer includes an amorphous carbon light emitter, Wherein the plurality of light-emitting elements include a first light-emitting element that emits first-color light, a second light-emitting element that emits second-color light, and a third light-emitting element that emits third-color light, and Wherein the light-emitting layer of the first light-emitting element includes an amorphous carbon light emitter, and each of the light-emitting layers of the second light-emitting element and the third light-emitting element includes quantum dots.

2. The display device according to claim 1, wherein, Each light-emitting element among the plurality of light-emitting elements further includes: A first electrode; A hole transport region located on the first electrode; An electron transport region located on the light-emitting layer; and A second electrode located on the electron transport region, Wherein the light-emitting layer is located on the hole transport region.

3. The display device according to claim 1, Among them, The first-color light is blue light, the second-color light is green light, and the third-color light is red light.

4. The display device according to claim 1, wherein The first light-emitting element includes a first amorphous carbon light emitter having a size of 1.50 nm or more and 1.65 nm or less.

5. The display device according to claim 1, Among them, The light control layer includes: A first light control portion that transmits the first-color light; A second light control portion that absorbs the first-color light and emits the second-color light; and A third light control portion that absorbs the first-color light and emits the third-color light.

6. The display device according to claim 5, wherein, The first light control portion includes a matrix resin and a scatterer dispersed in the matrix resin, Wherein the second light control portion includes a second amorphous carbon light emitter for emitting the second-color light by changing the wavelength of the first-color light, and Wherein the third light control portion includes a third amorphous carbon light emitter for emitting the third-color light by changing the wavelength of the first-color light.

7. The display device according to claim 6, the display device further comprising: A first color filter located on the first light control portion and overlapping the first light control portion in a plane; A second color filter located on the second light control portion and overlapping the second light control portion in a plane; And A third color filter located on the third light control portion and overlapping the third light control portion in a plane.

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