Quantum dot, light-emitting element, and display device

Abstract

The invention relates to a quantum dot. The quantum dot includes: a core including a first semiconductor nanocrystal; a first shell around (e.g., around) the core and comprising a second semiconductor nanocrystal different from the first semiconductor nanocrystal; and a second shell surrounding the first shell (e.g., around the first shell) and comprising a third semiconductor nanocrystal different from the first semiconductor nanocrystal and the second semiconductor nanocrystal, where the core has a band gap of about 1.5 eV to about 3.3 eV, the second shell having a band gap greater than the band gap of the core, and about 3.54 eV or less, and a band gap of the first shell is greater than the band gap of the core and less than the band gap of the second shell.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0130009, filed on September 27, 2023, which is hereby incorporated by reference in its entirety. Technical Field

[0003] Embodiments of the present disclosure relate to quantum dots, light-emitting elements, and display devices, and for example, relate to quantum dots, light-emitting elements including the quantum dots, and display devices including the quantum dots. Background Art

[0004] Various types of display devices are being developed for multimedia electronic devices such as televisions, mobile phones, tablet computers, navigation systems, and / or game consoles. Such display devices include so-called self-luminous light-emitting elements configured to achieve display (e.g., display of images) by emitting light from a light-emitting material of the light-emitting element.

[0005] Among light-emitting elements, quantum dot light-emitting elements including quantum dots in the emission layer can provide relatively high color purity, high luminous efficiency and multi-color luminescence compared with other similar display devices. In order to maintain such excellent or desired luminous quality, research is being conducted on the emission layer material of the emission layer. Summary of the invention

[0006] Aspects of one or more embodiments of the present disclosure are directed to quantum dots having satisfactory quantum yield characteristics and improved photostability and color reproducibility.

[0007] Aspects of one or more embodiments of the present disclosure are also directed to a light-emitting element having satisfactory quantum yield characteristics and improved light stability and color reproducibility, and thus exhibiting excellent or desired light-emitting characteristics.

[0008] Aspects of one or more embodiments of the present disclosure are also directed to a display device that includes quantum dots and thus has excellent or desired display quality characteristics.

[0009] Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the presented embodiments of the disclosure.

[0010] One or more embodiments of the present disclosure provide a quantum dot, including: a core including a first semiconductor nanocrystal; a first shell, around the core (e.g., surrounding the core) and including a second semiconductor nanocrystal different from the first semiconductor nanocrystal; and a second shell, around the first shell (e.g., surrounding the first shell) and including a third semiconductor nanocrystal different from the first semiconductor nanocrystal and the second semiconductor nanocrystal. The first semiconductor nanocrystal may include a I-III-VI group compound, the second semiconductor nanocrystal may include at least one of an I-III-VI group compound and a II-III-VI group compound, and the third semiconductor nanocrystal may include a II-VI group compound. The core may have a band gap of about 1.5 eV to about 3.3 eV, the band gap of the second shell may be greater than the band gap of the core, and may be about 3.54 eV or less, and the band gap of the first shell may be greater than the band gap of the core and less than the band gap of the second shell.

[0011] In one or more embodiments, the core may include copper, indium, gallium, and sulfur.

[0012] In one or more embodiments, the first shell may have the same crystal structure as that of the core.

[0013] In one or more embodiments, the first shell may satisfy Formula 1:

[0014] Formula 1

[0015]

[0016] In Formula 1 above, SH1 is the lattice constant of the first shell, and CO is the lattice constant of the core.

[0017] In one or more embodiments, the second semiconductor nanocrystal may include the I-III-VI compound and the II-III-VI compound, the I-III-VI compound of the first shell may be selected from a ternary compound and a quaternary compound, the ternary compound is selected from a group consisting of a compound containing Ag-In-S, a compound containing Ag-Ga-S, a compound containing Ag-Al-S, a compound containing Ag-In-Se, a compound containing Ag-Ga-Se, a compound containing Ag-Al-Se, a compound containing Cu-In-S, a compound containing Cu-Ga-S, a compound containing Cu-Al-S, a compound containing Cu-In-Se, a compound containing Cu-Ga-Se, a compound containing Cu-Al-Se and / or their (e.g., any suitable) mixtures; and the quaternary compound is selected from a group consisting of a compound containing Ag-In-Ga-S, a compound containing Ag-Ga-Se-S and / or their (e.g., any suitable) mixtures. The II-III-VI compound of the first shell can be selected from the group consisting of ternary compounds and quaternary compounds, the ternary compound is selected from the group consisting of compounds containing Zn-In-S, compounds containing Zn-Ga-S, compounds containing Zn-Al-S, compounds containing Zn-In-Se, compounds containing Zn-Ga-Se, compounds containing Zn-Al-Se, compounds containing Mg-In-S, compounds containing Mg-Ga-S, compounds containing Mg-Al-S, compounds containing Mg-In-Se, compounds containing Mg-Ga-Se, compounds containing Mg-Al-Se and / or their (e.g., any suitable) mixtures; and the quaternary compound is selected from the group including (e.g., consisting of) compounds containing Zn-In-Ga-S, compounds containing Zn-In-Se-S and / or their (e.g., any suitable) mixtures.

[0018] In one or more embodiments, the first shell may include the Group II-III-VI compound, and in the Group II-III-VI compound, gallium atoms may be included as a Group III element.

[0019] In one or more embodiments, the first shell may include zinc, gallium, and sulfur.

[0020] In one or more embodiments, the second shell may include at least one of MgO, MgS, MgSe, MgTe, ZnO, ZnS, ZnSe, and ZnTe.

[0021] In one or more embodiments, the second shell may include ZnS.

[0022] In one or more embodiments, the quantum dots may have a diameter of about 2 nm to about 10 nm.

[0023] In one or more embodiments, the quantum dots may have a full width at half maximum of about 65 nm or less.

[0024] In one or more embodiments, the quantum dots may have a central emission wavelength of about 380 nm to about 800 nm.

[0025] In one or more embodiments of the present disclosure, a light-emitting element includes: a first electrode, a second electrode facing the first electrode (opposite to the first electrode), an emission layer between the first electrode and the second electrode and including quantum dots, and a functional layer between the emission layer and the first electrode and / or between the emission layer and the second electrode. The quantum dots included in the emission layer may be the quantum dots in the above one or more embodiments.

[0026] In one or more embodiments, the functional layer may include a hole transport region below the emission layer, and an electron transport region above the emission layer.

[0027] In one or more embodiments of the present disclosure, a display device includes a circuit layer, and a display element layer on the circuit layer and including a light-emitting element and a pixel defining film that defines a pixel opening therein, and as the light-emitting element, the light-emitting element in one or more of the above embodiments can be used. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] 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 one or more embodiments of the present disclosure and together with the description are used to explain aspects, features and / or principles of the present disclosure. In the accompanying drawings:

[0029] Figure 1 is a perspective view of an electronic device according to one or more embodiments of the present disclosure;

[0030] Figure 2 is an exploded perspective view of an electronic device according to one or more embodiments of the present disclosure;

[0031] Figure 3 is a cross-sectional view of a display device taken along line II' according to one or more embodiments of the present disclosure;

[0032] Figure 4 is a plan view of a display device according to one or more embodiments of the present disclosure;

[0033] Figure 5 is a cross-sectional view of a display device taken along line II-II′ according to one or more embodiments of the present disclosure;

[0034] Fig. 6A is a cross-sectional view showing a light emitting element according to one or more embodiments of the present disclosure;

[0035] Figure 6B is a cross-sectional view showing a light emitting element according to one or more embodiments of the present disclosure;

[0036] Figure 7 is a view schematically showing the structure of a quantum dot according to one or more embodiments of the present disclosure;

[0037] Fig. 8A is a view showing a photoluminescence (PL) spectrum of a quantum dot of a comparative example;

[0038] Figure 8B is a diagram showing a photoluminescence (PL) spectrum of an exemplary quantum dot; and

[0039] Fig. 9 Results of evaluating the light stability of Examples and Comparative Examples are shown. DETAILED DESCRIPTION

[0040] The present disclosure can be modified in a variety of optional forms, and therefore specific embodiments will be shown in the drawings and described in more detail. However, it should be understood that this is not intended to limit the present disclosure to the specific form disclosed, but is intended to cover all modifications, equivalents and alternatives that fall within the spirit and scope of the present disclosure.

[0041] In addition, the embodiments included herein are provided as examples so that the present disclosure will be thorough and complete and will fully convey the aspects and features of the present disclosure to those skilled in the art. Therefore, processes, elements and techniques that are not necessary for a person of ordinary skill in the art to fully understand the various aspects and features of the present disclosure may not be described.

[0042] It should be understood that when an element (such as a region, layer, film, area, or portion) is referred to as being "on," "connected to," or "coupled to" another element, the element can be directly on, directly connected to, or coupled to the other element, or one or more intervening elements may be present. Additionally, it should be understood that when an element is referred to as being "between" two elements, the element can be the only element between the two elements, or one or more intervening elements may also be present.

[0043] Unless otherwise specified, the same numerals always refer to the same elements, and repeated descriptions thereof may not be provided. In addition, in the accompanying drawings, the thickness, ratio, and size of elements may be exaggerated for clarity and / or to effectively describe technical contents.

[0044] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0045] It should be understood that, although the terms "first", "second", "third", etc. may be used in this article to describe various elements, components, regions, layers and / or intervals, these elements, components, regions, layers and / or intervals should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or interval from another element, component, region, layer or interval. Therefore, without departing from the spirit and scope of the present disclosure, the first element, first component, first region, first layer or first interval described below may be referred to as the second element, second component, second region, second layer or second interval.

[0046] As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0047] As shown in the figures, for ease of explanation, spatially relative terms such as "on", "below", "lower", "below", "above", and "upper" may be used herein to describe the relationship of one element or feature to (multiple elements) another element or (multiple features) another feature. It will be understood that the spatially relative terms are intended to cover different orientations of the device in use or operation other than the orientation depicted in the accompanying drawings. For example, if the device in the figure is rotated, the element described as "below" or "below" or "below" other elements or features is then oriented to be "above" other elements or features. Therefore, the exemplary relative terms "below" or "below" may include both "above" and "below" orientations. In addition, the device may be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatially relative terms used herein should be interpreted accordingly.

[0048] It will be further understood that the terms “comprises, comprising,” “includes, including,” “have, having,” and “contain, containing,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0049] As used herein, "directly disposed on..." may mean that there are no additional layers, films, regions, plates, etc. between one part and another part (such as layers, films, regions, and / or plates, etc.). For example, "directly disposed on..." may mean that two layers or two components are disposed without using an additional component such as an adhesive component between them.

[0050] As used herein, the terms "use," "using," and "used" may be considered synonymous with the terms "utilize," "utilizing," and "utilized," respectively.

[0051] Unless it is obvious from the present disclosure, expressions such as “at least one of…”, “a plurality of…”, “one of…” and other prepositional phrases, when preceding / following a list of elements, should be understood to include a disjunctive meaning if they are written as a connected list, and vice versa. For example, the expressions “at least one of a, b, and c”, “one selected from the group consisting of a, b, and c”, “at least one selected from a, b, and c”, “at least one from a, b, and c”, “one from a, b, and c”, and “at least one from a to c” mean only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

[0052] As used herein, the term "Group" refers to a Group in the IUPAC Periodic Table of Elements.

[0053] As used herein, "Group I elements" may include Group IA elements and Group IB elements. For example, the Group I element may be copper (Cu), but is not limited thereto.

[0054] As used herein, "Group II elements" may include Group IIA elements and Group IIB elements. For example, the Group II element may be magnesium (Mg) or zinc (Zn), but is not limited thereto.

[0055] As used herein, "Group III elements" may include Group IIIA elements and Group IIIB elements. For example, the Group III element may be aluminum (Al), indium (In), or gallium (Ga), but is not limited thereto.

[0056] As used herein, "Group V elements" may include Group VA elements and Group VB elements. For example, the Group V element may be phosphorus (P), arsenic (As), or antimony (Sb), but is not limited thereto.

[0057] As used herein, "Group VI elements" may include Group VIA elements and Group VIB elements. For example, the Group VI element may be oxygen (O), sulfur (S), selenium (Se), or tellurium (Te), but is not limited thereto.

[0058] In the present disclosure, when the particles are spherical, "diameter" means the particle diameter or the average particle diameter, and when the particles are non-spherical, "diameter" means the major axis length or the average major axis length. The diameter of the particles can be measured using a scanning electron microscope or a particle size analyzer. As a particle size analyzer, for example, HORIBA's LA-950 laser particle size analyzer can be used. When the size of the particles is measured using a particle size analyzer, the average particle diameter (or size) is referred to as D50. D50 refers to the average diameter of the particles whose cumulative volume corresponds to 50 vol% in a particle size distribution (e.g., cumulative distribution), and refers to the value of the particle size corresponding to 50% starting from the smallest particle when the total number of particles is 100% in a distribution curve accumulated in the order of the smallest particle size to the largest particle size.

[0059] 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 the present disclosure belongs. It is further understood that, unless explicitly defined herein, terms (such as those defined in general dictionaries) should be interpreted as having a meaning consistent with their context in the relevant art and / or the meaning of this specification, and should not be interpreted as an idealized or overly formal meaning.

[0060] Hereinafter, a quantum dot, a light emitting element including the quantum dot, and a display device including the quantum dot according to an embodiment of the present disclosure will be described with reference to the accompanying drawings.

[0061] Figure 1 is a perspective view showing an electronic device EA according to one or more embodiments of the present disclosure. Figure 2 is an exploded perspective view of an electronic device EA according to one or more embodiments of the present disclosure.

[0062] In one or more embodiments, the electronic device EA may be a large electronic device, such as a television, a monitor, or an outdoor billboard. In one or more embodiments, the electronic device EA may be a small or medium-sized electronic device, such as a personal computer (e.g., a notebook computer, a tablet computer), a personal digital terminal, a car navigation unit, a game console, a smart phone, and / or a camera. These devices are provided only as examples, and other electronic devices may be employed as long as they do not depart from the spirit and scope of the present disclosure. Figure 1 , as an example, a smart phone is shown as the electronic device EA.

[0063] In one or more embodiments, the electronic device EA may include a foldable display device having a folding area and a non-folding area, or a curved display device having at least one curved portion.

[0064] The front surface FS in the electronic device EA may correspond to the front surface of the display device DD and may correspond to the front surface of the window WP. Therefore, reference numeral FS will be used throughout for the front surface of the electronic device EA, the front surface of the display device DD, and the front surface of the window WP.

[0065] The user may observe the provided image IM through the transmission area TA corresponding to the front surface FS of the electronic device EA. The image IM may include a static image as well as a dynamic image. Figure 1 The front surface FS is shown to be parallel to a plane defined by a first direction DR1 and a second direction DR2 crossing the first direction DR1. However, this is merely an example, and the front surface FS of the electronic device EA may have a curved shape in one or more embodiments.

[0066] Herein, the term "plane" refers to a plane defined by the first direction DR1 and the second direction DR2, and the term "cross-section" refers to a plane that is orthogonal (e.g., vertical) to the plane defined by the first direction DR1 and the second direction DR2 and parallel to the third direction DR3. The thickness direction of the electronic device EA may be parallel to the third direction DR3, which is a normal direction relative to the plane defined by the first direction DR1 and the second direction DR2. Among the thickness directions of the electronic device EA, the direction in which the image IM is displayed is represented by the third direction DR3. The front surface (or upper surface) and the rear surface (or lower surface) of each component may be defined by the third direction DR3.

[0067] The fourth direction DR4 (see for example Figure 4) may be a direction between the first direction DR1 and the second direction DR2. The fifth direction DR5 may cross the fourth direction DR4 and may be inclined with respect to the second direction DR2. The fourth direction DR4 and the fifth direction DR5 may be located on a plane parallel to a plane defined by the first direction DR1 and the second direction DR2. The directions represented by the first direction DR1, the second direction DR2, the third direction DR3, the fourth direction DR4, and the fifth direction DR5 are relative concepts and may be changed to other directions accordingly.

[0068] In this document, when a component is “directly disposed / directly arranged / directly formed” on another component, it means that a third component is not disposed between the component and the other component. That is, when a component is “directly placed / directly arranged / directly formed” on another component, it means that the component is “in contact” with the other component.

[0069] Reference Figure 1 and Figure 2 , the electronic device EA may include a window WP, a display device DD, and a housing HAU. The window WP may be arranged above the display device DD. The housing HAU may be arranged below the display device DD. The display device DD may be arranged between the window WP and the housing HAU.

[0070] The window WP may include an optically transparent insulating material. The front surface FS of the window WP may include a transmission area TA and a bezel area BZA. The front surface FS of the window WP including the transmission area TA and the bezel area BZA corresponds to the front surface FS of the electronic device EA.

[0071] The transmission area TA may be an optically transparent area. Figure 1 and Figure 2 , the transmission area TA is shown as a rectangular shape with rounded corners in a plan view. However, this is presented as an example, and the transmission area TA may have one or more suitable shapes in a plan view and is not limited to any one embodiment.

[0072] The border area BZA may be an area having a relatively lower light transmittance than the transmission area TA. The border area BZA may have a set or predetermined color. The border area BZA may be adjacent to the transmission area TA and may be around the transmission area TA (e.g., surrounding the transmission area TA). The border area BZA may define the shape of the transmission area TA. However, the present disclosure is not limited to the shape shown, and the border area BZA may be arranged adjacent to only one side of the transmission area TA, and may not provide a portion thereof.

[0073] In one or more embodiments, the display device DD may be substantially configured to generate the image IM. The display device DD may be arranged below the window WP. As used herein, "below" may mean a direction opposite to a direction in which the display device DD provides the image IM.

[0074] The display device DD may display an image IM through a display surface IS. The display surface IS may be parallel to a plane defined by the first direction DR1 and the second direction DR2. The display surface IS may include a display area DA and a non-display area NDA.

[0075] The display area DA may be an area activated according to an electrical signal. The non-display area NDA may be an area covered by the bezel area BZA. The non-display area NDA may be adjacent to the display area DA. The non-display area NDA may be around the display area DA (e.g., surrounding the display area DA). However, the present disclosure is not limited thereto, and the non-display area NDA may not be provided, or the non-display area NDA may be arranged only on one or more sides of the display area DA.

[0076] The housing HAU may house the display device DD. The housing HAU may be arranged to cover the display device DD while exposing the display surface IS as the top surface of the display device DD. The housing HAU may cover the side surface and the bottom surface of the display device DD and expose the entire top surface. However, the present disclosure is not limited thereto, and the housing HAU may cover the top surface and a portion of the side surface and the bottom surface of the display device DD.

[0077] Figure 3 is a cross-sectional view of a display device DD according to one or more embodiments of the present disclosure. Figure 3 It may be along the lines of one or more embodiments of the present disclosure Figure 2 2 is a cross-sectional view of the display device DD taken along line II'.

[0078] Reference Figure 3 , the display device DD may include a display panel DP and a light control layer PP arranged on the display panel DP. The display panel DP may include a base substrate BS, a circuit layer DP-CL and a display element layer DP-EL. In one or more embodiments, the display panel DP may include an encapsulation layer TFE arranged on the display element layer DP-EL.

[0079] In the display device DD of one or more embodiments, the display panel DP may be a light-emitting display panel. For example, the display panel DP may be a quantum dot light-emitting display panel including quantum dot light-emitting elements. However, the present disclosure is not limited thereto.

[0080] The display panel DP may include a base substrate BS, a circuit layer DP-CL disposed on the base substrate BS, and a display element layer DP-EL disposed on the circuit layer DP-CL. The display element layer DP-EL may include a light emitting element ED (see, for example, Figure 5 ). The encapsulation layer TFE may be directly disposed on the display element layer DP-EL, or may be bonded to the display element layer DP-EL through a separate member.

[0081] The light control layer PP may be arranged on the display panel DP to control the light reflected in the display panel DP due to external light. The light control layer PP may be a reflection reducing layer that reduces the reflection of external light. For example, the light control layer PP may include: a polarizing film (or polarizing layer) including a phase retarder and / or a polarizer, a multilayer reflective layer that induces destructive interference of reflected light, or a color filter arranged corresponding to the pixel arrangement and luminous color of the display panel DP. When the light control layer PP includes a color filter, the color filter may be arranged in consideration of the luminous color of the pixels included in the display panel DP. In one or more embodiments, the light control layer PP may not be provided.

[0082] Figure 4 is a plan view of a display device DD according to one or more embodiments of the present disclosure. Figure 5 is a cross-sectional view showing a display device DD according to one or more embodiments of the present disclosure. Figure 5 According to one or more embodiments of the present disclosure, Figure 4 2 is a cross-sectional view of the display device DD taken along line II-II'.

[0083] Reference Figure 4 and Figure 5 The display device DD may include a display area DA (see for example Figure 2) are a plurality of light-emitting areas PXA-B, PXA-G, and PXA-R that are repeatedly arranged (with each other). The display device DD of one or more embodiments may include a first light-emitting area PXA-B, a second light-emitting area PXA-G, and a third light-emitting area PXA-R that are different from each other. In one or more embodiments, the display device DD may have a peripheral area NPXA arranged around the first light-emitting area PXA-B, the second light-emitting area PXA-G, and the third light-emitting area PXA-R (for example, around each of the first light-emitting area PXA-B, the second light-emitting area PXA-G, and the third light-emitting area PXA-R). The peripheral area NPXA is set at a boundary between the first light-emitting area PXA-B, the second light-emitting area PXA-G, and the third light-emitting area PXA-R. The peripheral area NPXA may be around the first light-emitting area PXA-B, the second light-emitting area PXA-G, and the third light-emitting area PXA-R (for example, surrounding the first light-emitting area PXA-B, the second light-emitting area PXA-G, and the third light-emitting area PXA-R). A structure to prevent color mixing among the first light emitting area PXA-B, the second light emitting area PXA-G, and the third light emitting area PXA-R, such as a pixel defining film PDL, may be disposed in the peripheral area NPXA.

[0084] The pixel defining film PDL may define the light emitting regions PXA-B, PXA-G, and PXA-R. The light emitting regions PXA-B, PXA-G, and PXA-R and the peripheral region NPXA may be partitioned by the pixel defining film PDL.

[0085] The display panel DP according to one or more embodiments may include a plurality of light emitting elements ED-1, ED-2, and ED-3 that emit light in different wavelength ranges. The plurality of light emitting elements ED-1, ED-2, and ED-3 may emit light of different colors. For example, the display panel DP may include a first light emitting element ED-1 that emits blue light, a second light emitting element ED-2 that emits green light, and a third light emitting element ED-3 that emits red light. However, the present disclosure is not limited thereto, and the first light emitting element ED-1, the second light emitting element ED-2, and the third light emitting element ED-3 may emit light in substantially the same wavelength range, or at least one of the three may emit light in different wavelength ranges.

[0086] The light emitting regions PXA-B, PXA-G, and PXA-R may each be a region that emits light generated from one of the light emitting elements ED-1, ED-2, and ED-3. Figure 4 and Figure 5The first light emitting region PXA-B, the second light emitting region PXA-G, and the third light emitting region PXA-R that emit blue light, green light, and red light, respectively, are shown. For example, the display device DD of one or more embodiments may include a first light emitting region PXA-B that emits blue light, a second light emitting region PXA-G that emits green light, and a third light emitting region PXA-R that emits red light that are separated.

[0087] exist Figure 4 and Figure 5 In the display device DD of one or more embodiments shown in , the light-emitting regions PXA-B, PXA-G, and PXA-R may have different sizes (e.g., areas) according to the colors emitted from the emission layers EML-B, EML-G, and EML-R of the light-emitting elements ED-1, ED-2, and ED-3. Figure 4 The first light emitting region PXA-B, the second light emitting region PXA-G, and the third light emitting region PXA-R having different plane areas are illustrated as an example, but the present disclosure is not limited thereto.

[0088] The first light-emitting region PXA-B corresponding to the first light-emitting element ED-1 emitting blue light may have the largest area, and the second light-emitting region PXA-G corresponding to the second light-emitting element ED-2 emitting green light may have the smallest area. However, the present disclosure is not limited thereto, and the first light-emitting region PXA-B, the second light-emitting region PXA-G, and the third light-emitting region PXA-R may emit light of other colors in addition to blue light, green light, and red light. In one or more embodiments, the first light-emitting region PXA-B, the second light-emitting region PXA-G, and the third light-emitting region PXA-R may have the same area, or may provide a region having the same area as the first light-emitting region PXA-B. Figure 4 The area ratios shown in the figure are different from the area ratios shown in the figure. The areas of the first light-emitting region PXA-B, the second light-emitting region PXA-G, and the third light-emitting region PXA-R may be set according to the color of the emitted light. In this case, the area may be the area when viewed on a plane (e.g., in a plan view).

[0089] The first light emitting regions PXA-B and the third light emitting regions PXA-R may be alternately arranged in the first direction DR1 to form a first group PXG1. The second light emitting regions PXA-G may be arranged in the first direction DR1 to form a second group PXG2. The first group PXG1 may be spaced and / or separated (e.g., spaced or separated) from the second group PXG2 in the second direction DR2. The first group PXG1 and the second group PXG2 may each be provided in plurality. The first group PXG1 and the second group PXG2 may be alternately arranged in the second direction DR2.

[0090] One third light emitting region PXA-R may be spaced and / or separated (e.g., spaced apart or separated) from one second light emitting region PXA-G in the fourth direction DR4. One first light emitting region PXA-B may be spaced and / or separated (e.g., spaced apart or separated) from one second light emitting region PXA-G in the fifth direction DR5.

[0091] In one or more embodiments, the arrangement structure of the light emitting regions PXA-B, PXA-G, and PXA-R is not limited to Figure 4 For example, among the light-emitting regions PXA-B, PXA-G, and PXA-R, the first light-emitting region PXA-B, the second light-emitting region PXA-G, and the third light-emitting region PXA-R may be sequentially and alternately arranged along the first direction DR1. In one or more embodiments, the shapes of the light-emitting regions PXA-B, PXA-G, and PXA-R when viewed on a plane (e.g., in a plan view) are not limited to the shapes shown, and may be defined as shapes different from the shapes shown.

[0092] Reference Figure 5 , the display device DD may include a display panel DP and a light control layer PP, which are stacked in the third direction DR3. The display panel DP may include a base substrate BS, a circuit layer DP-CL provided on the base substrate BS, a display element layer DP-EL, and an encapsulation layer TFE. The display element layer DP-EL may include a light emitting element ED arranged between or on the pixel defining films PDL. The encapsulation layer TFE may be arranged on the display element layer DP-EL and may thus cover the light emitting element ED.

[0093] The base substrate BS may be a member that provides a base surface on which the display element layer DP-EL is arranged. The base substrate BS may be a glass substrate, a metal substrate, and / or a plastic substrate, etc. However, the present disclosure is not limited thereto, and the base substrate BS may be an inorganic layer, an organic layer, or a composite material layer.

[0094] The base substrate BS may include a single-layer structure or a multi-layer structure. For example, the base substrate BS may include a first synthetic resin layer, a multi-layer or single-layer intermediate layer, and a second synthetic resin layer stacked sequentially. The intermediate layer may be referred to as a base barrier layer. The intermediate layer may include silicon oxide (SiO x ) layer and an amorphous silicon (a-Si) layer arranged on the silicon oxide layer, but the present disclosure is not particularly limited thereto. For example, the intermediate layer may include at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, and an amorphous silicon layer. The base substrate BS may be a flexible substrate that can be easily bent or folded.

[0095] The first synthetic resin layer and the second synthetic resin layer may each include a polyimide-based resin. In one or more embodiments, the first synthetic resin layer and the second synthetic resin layer may each include at least one selected from acrylic acid-based resins, methacrylate-based resins, polyisoprene-based resins, vinyl resins, epoxy-based resins, polyurethane-based resins, cellulose-based resins, siloxane-based resins, polyamide-based resins, and perylene-based resins. As used herein, "~~-based" resins may be considered as including a functional group of "~~".

[0096] In one or more embodiments, the circuit layer DP-CL may be arranged on the base substrate BS, and the circuit layer DP-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 DP-CL may include a switch transistor and a driving transistor for driving the light emitting element ED of the display element layer DP-EL.

[0097] The display element layer DP-EL may be arranged on the circuit layer DP-CL. The display element layer DP-EL may include a pixel defining film PDL and a first light emitting element ED-1, a second light emitting element ED-2, and a third light emitting element ED-3 divided (separated) by the pixel defining film PDL. The light emitting elements ED-1, ED-2, and ED-3 of the display element layer DP-EL may be electrically connected to the driving element of the circuit layer DP-CL, and may therefore generate light to display an image according to a signal provided by the driving element.

[0098] The encapsulation layer TFE may be arranged on the display element layer DP-EL. The encapsulation layer TFE may be used to protect the light emitting element layer DP-EL from moisture, oxygen and / or foreign matter such as dust particles. The encapsulation layer TFE may seal the light emitting element ED of the display element layer DP-EL. The encapsulation layer TFE may include at least one film for improving the optical efficiency of the display element layer DP-EL or protecting the display element layer DP-EL. The encapsulation layer TFE may include at least one inorganic layer. The encapsulation layer TFE may include a stacked structure in which an inorganic layer, an organic layer and an inorganic layer are sequentially stacked.

[0099] 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-based resin or a polyimide-based resin. In one or more embodiments, the pixel defining film PDL may be formed by including an inorganic material in addition to the polymer resin. In one or more embodiments, the pixel defining film PDL may be formed to include a light absorbing material, or may be formed to include a black pigment and / or a black dye. A pixel defining film PDL formed to include a black pigment and / or a black dye may implement a black pixel defining film. When forming the pixel defining film PDL, carbon black may be used as the black pigment and / or the black dye, but the present disclosure is not limited thereto.

[0100] In one or more embodiments, the pixel definition film PDL may be formed of an inorganic material. For example, the pixel definition film PDL may be formed of an inorganic material (such as, for example, Si 3 N 4 Silicon nitride (Si x N y ), such as SiO 2 Silicon oxide (SiO x ) and / or silicon oxynitride (SiO x N y ))form.

[0101] The pixel definition film PDL may have a pixel opening OH (e.g., a plurality of pixel openings OH) defined therein. A portion of the first electrode EL1 may be exposed in the pixel opening OH. A portion corresponding to the first electrode EL1 exposed in the pixel opening OH may be defined as light emitting regions PXA-B, PXA-G, and PXA-R. However, the present disclosure is not limited thereto.

[0102] The pixel definition film PDL may separate the first light emitting element ED-1, the second light emitting element ED-2, and the third light emitting element ED-3. The emission layers EML-B, EML-G, and EML-R of the light emitting elements ED-1, ED-2, and ED-3 may be arranged and separated in the pixel opening OH defined by the pixel definition film PDL.

[0103] The first light-emitting element ED-1, the second light-emitting element ED-2, and the third light-emitting element ED-3 may each include a first electrode EL1, a second electrode EL2 facing the first electrode EL1 (opposite to the first electrode EL1), one of the emission layers EML-B, EML-G, and EML-R arranged between the first electrode EL1 and the second electrode EL2, and a functional layer FL arranged between the first electrode EL1 and the second electrode EL2. The functional layer FL may be arranged between the first electrode EL1 and the emission layers EML-B, EML-G, and EML-R, or between the emission layers EML-B, EML-G, and EML-R and the second electrode EL2, or both between the first electrode EL1 and the emission layers EML-B, EML-G, and EML-R and between the emission layers EML-B, EML-G, and EML-R and the second electrode EL2. For example, the first light emitting element ED-1, the second light emitting element ED-2, and the third light emitting element ED-3 may each include a first electrode EL1, a first functional layer FL-B, one of emission layers EML-B, EML-G, and EML-R, a second functional layer FL-T, and a second electrode EL2 sequentially stacked in the third direction DR3.

[0104] The first electrode EL1 may be exposed in the pixel opening OH of the pixel definition film PDL. The first electrode EL1 has conductivity (eg, is a conductor). The first electrode EL1 may be formed of a metal material, a metal alloy, or a conductive compound. The first electrode EL1 may be an anode or a cathode. However, the present disclosure is not limited thereto.

[0105] In one or more embodiments, the first electrode EL1 may be a pixel electrode. The first electrode EL1 may be a transmissive electrode, a semi-transmissive semi-reflective electrode, or a reflective electrode. The first electrode EL1 may include at least one selected from Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, W, In, Sn, and Zn, a compound selected from two or more thereof, a mixture selected from two or more thereof, or an oxide thereof.

[0106] When the first electrode EL1 is a transmissive electrode, the first electrode EL1 may include a transparent metal oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and indium tin zinc oxide (ITZO). When the first electrode EL1 is a semi-transmissive and semi-reflective electrode or a reflective electrode, the first electrode EL1 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, W, their compounds and / or their (e.g., any suitable) mixture (e.g., a mixture of Ag and Mg), or a material having a multilayer structure such as LiF / Ca or LiF / Al. In one or more embodiments, the first electrode EL1 may have a multilayer structure including a reflective film or a semi-transmissive and semi-reflective film formed of the above materials and a transparent conductive film formed of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and / or indium tin zinc oxide (ITZO), etc. For example, the first electrode EL1 may have a three-layer structure of ITO / Ag / ITO, but the present disclosure is not limited thereto. In one or more embodiments, the first electrode EL1 may include the above-mentioned metal material, a combination of two or more metal materials selected from the above-mentioned metal materials, or an oxide of the above-mentioned metal material; however, the present disclosure is not limited thereto. The first electrode EL1 may have a thickness of about 700 angstroms. To about For example, the first electrode EL1 may have a thickness of To about Thickness.

[0107] The second electrode EL2 may be arranged on the first electrode EL1. The second electrode EL2 may be a cathode or an anode. In one or more embodiments, if the first electrode EL1 is an anode (e.g., when the first electrode EL1 is an anode), the second electrode EL2 may be a cathode, and if the first electrode EL1 is a cathode (e.g., when the first electrode EL1 is a cathode), the second electrode EL2 may be an anode. The second electrode EL2 may be a common electrode. However, the present disclosure is not limited thereto.

[0108] The second electrode EL2 may include at least one selected from Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, W, In, Sn and Zn, a compound of two or more selected therefrom, a mixture of two or more selected therefrom, or an oxide thereof.

[0109] The second electrode EL2 may be a transmissive electrode, a semi-transmissive and semi-reflective 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, such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO) and / or indium tin zinc oxide (ITZO).

[0110] When the second electrode EL2 is a semi-transmissive and semi-reflective electrode or a reflective electrode, the second electrode EL2 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, Yb, W, their compounds (e.g., AgMg, AgYb or MgYb) and / or their (e.g., any suitable) mixture, or a material having a multilayer structure such as LiF / Ca or LiF / Al. In one or more embodiments, the second electrode EL2 may have a multilayer structure including a reflective film or a semi-transmissive and semi-reflective film formed of the above materials and / or a transparent conductive film formed of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO) and / or indium tin zinc oxide (ITZO), etc. For example, the second electrode EL2 may include the above-mentioned metal material, a combination of two or more metal materials selected from the above-mentioned metal materials, or one or more oxides of the above-mentioned metal materials.

[0111] In one or more 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.

[0112] The emission layers EML-B, EML-G and EML-R may be arranged between the first electrode EL1 and the second electrode EL2. The light-emitting element ED of one or more embodiments may include quantum dots QD1, QD2 and QD3 in the emission layers EML-B, EML-G and EML-R. In one or more embodiments, the display device DD may include a first light-emitting element ED-1, a second light-emitting element ED-2 and a third light-emitting element ED-3, and the first light-emitting element ED-1, the second light-emitting element ED-2 or the third light-emitting element ED-3 may include one of the emission layers EML-B, EML-G and EML-R, and the emission layers EML-B, EML-G and EML-R include quantum dots QD1, QD2 and QD3 according to one or more embodiments.

[0113] The quantum dots QD1, QD2 and QD3 of one or more embodiments may each include a core and a shell around the core (e.g., surrounding the core). Therefore, the quantum dots QD1, QD2 and QD3 may each have a core-shell structure. For example, quantum dots QD1, QD2 and QD3 may include a core and two shells around the core (e.g., surrounding the core). The quantum dots QD1, QD2 and QD3 of one or more embodiments include two shells containing different semiconductor nanocrystals, in which the shell adjacent to the core has a crystal structure identical to the crystal structure of the core, and a lattice constant substantially similar to the lattice constant of the core, thereby maintaining a narrow half-maximum full width of the core, and exhibiting high quantum yield, excellent or suitable stability and high absorption characteristics. Therefore, the light-emitting element ED of one or more embodiments may exhibit excellent or suitable element characteristics and reliability.

[0114] In one or more embodiments, a display device DD including a plurality of light emitting elements ED including quantum dots QD1, QD2, and QD3 according to one or more embodiments may exhibit excellent or suitable display quality and reliability due to the improved surface properties of the quantum dots QD1, QD2, and QD3.

[0115] The emission layers EML-B, EML-G, and EML-R may include a plurality of quantum dots QD1, QD2, and QD3, respectively. In one or more embodiments, the emission layers EML-B, EML-G, and EML-R may emit light having fluorescence. For example, the quantum dots QD1, QD2, and QD3 may be used as fluorescent doping materials.

[0116] In one or more embodiments, the first light-emitting element ED-1 may include a first emission layer EML-B including a first quantum dot QD1, the second light-emitting element ED-2 may include a second emission layer EML-G including a second quantum dot QD2, and the third light-emitting element ED-3 may include a third emission layer EML-R including a third quantum dot QD3. In one or more embodiments, the first quantum dot QD1 may emit blue light, the second quantum dot QD2 may emit green light, and the third quantum dot QD3 may emit red light. However, the present disclosure is not limited thereto, and the first quantum dot QD1, the second quantum dot QD2, and the third quantum dot QD3 may emit light in a wavelength range other than blue, green, and red.

[0117] The quantum dots QD1, QD2, and QD3 respectively included in the emission layers EML-B, EML-G, and EML-R may be stacked to form a layer. Figure 5In the embodiment, each of the quantum dots QD1, QD2 and QD3 having a circular cross-section is arranged to form two layers, but the present disclosure is not limited thereto. For example, the arrangement of the quantum dots QD1, QD2 and QD3 may vary according to the thickness of the emission layers EML-B, EML-G and EML-R, the shapes of the quantum dots QD1, QD2 and QD3 included in the emission layers EML-B, EML-G and EML-R, and / or the average diameter of the quantum dots QD1, QD2 and QD3, etc. For example, in the emission layers EML-B, EML-G and EML-R, the quantum dots QD1, QD2 and QD3 may be aligned adjacent to each other to form a single layer, or may be aligned to form multiple layers (such as two or three layers). In one or more embodiments, the emission layers EML-B, EML-G and EML-R may include a luminescent material in addition to the quantum dots QD1, QD2 and QD3. In one or more embodiments, the emission layers EML-B, EML-G, EML-R may further include a fluorescent or phosphorescent doping material, or may further include a host material.

[0118] In one or more embodiments, the first quantum dot QD1, the second quantum dot QD2, and the third quantum dot QD3 included in the light-emitting elements ED-1, ED-2, and ED-3 may be formed of different core materials. In one or more embodiments, the first quantum dot QD1, the second quantum dot QD2, and the third quantum dot QD3 may be formed of the same core material, or two quantum dots selected from the first quantum dot QD1, the second quantum dot QD2, and the third quantum dot QD3 may be formed of the same core material, and the remaining quantum dots may be formed of different core materials.

[0119] In one or more embodiments, the first quantum dot QD1, the second quantum dot QD2, and the third quantum dot QD3 may have different diameters. For example, the first quantum dot QD1 used in the first light-emitting element ED-1 that emits light in a relatively short wavelength range may have a relatively small average diameter compared to the second quantum dot QD2 of the second light-emitting element ED-2 and the third quantum dot QD3 of the third light-emitting element ED-3, each of which emits light in a relatively long wavelength range. In this article, the average diameter refers to the arithmetic mean of the diameters of multiple quantum dot particles. In this article, the diameter of the quantum dot particles may be the average value of the width of the quantum dot particles when observed in a cross-sectional view.

[0120] The relationship between the average diameters of the first quantum dot QD1, the second quantum dot QD2, and the third quantum dot QD3 is not limited to the above limitations. For example, Figure 5It is shown that the sizes of the first quantum dot QD1, the second quantum dot QD2 and the third quantum dot QD3 are substantially similar to each other, but the sizes of the first quantum dot QD1, the second quantum dot QD2 and the third quantum dot QD3 included in the light emitting elements ED-1, ED-2 and ED-3 may be different.

[0121] Will refer to later Figure 7 The physical or chemical properties (such as structure and material) of the quantum dots QD1, QD2, and QD3 according to one or more embodiments are described in more detail.

[0122] In the display device DD according to one or more embodiments, as shown in FIG. Figure 5 As shown in , although the thicknesses of the emission layers EML-B, EML-G, and EML-R of the first light-emitting element ED-1, the second light-emitting element ED-2, and the third light-emitting element ED-3 are shown to be substantially similar to each other, the present disclosure is not limited thereto. For example, in one or more embodiments, the thicknesses of the emission layers EML-B, EML-G, and EML-R of the first light-emitting element ED-1, the second light-emitting element ED-2, and the third light-emitting element ED-3 may be different from each other.

[0123] Either one of the first functional layer FL-B arranged between the first electrode EL1 and the emission layers EML-B, EML-G and EML-R and the second functional layer FL-T arranged between the emission layers EML-B, EML-G and EML-R and the second electrode EL2 may be a hole transport region, and the other may be an electron transport region.

[0124] Fig. 6A and Figure 6B 1 are views each showing a light emitting element ED-a and ED-b according to one or more embodiments of the present disclosure. Fig. 6A and Figure 6B The structures of the light emitting elements ED-a and ED-b described above can be applied to Figure 5 At least one of the first light emitting element ED-1, the second light emitting element ED-2 and the third light emitting element ED-3 shown in FIG.

[0125] exist Fig. 6A In the light emitting element ED-a of one or more embodiments, the first electrode EL1, the hole transport region HTR, the emission layer EML, the electron transport region ETR, and the second electrode EL2 sequentially stacked along the third direction DR3 may be included. In the light emitting element ED-a of one or more embodiments, the first electrode EL1 may be an anode, and the second electrode EL2 may be a cathode.

[0126] In one or more embodiments, referring to Figure 6BThe light emitting element ED-b of one or more embodiments may include a first electrode EL1, an electron transport region ETR, an emission layer EML, a hole transport region HTR, and a second electrode EL2 sequentially stacked along a third direction DR3. In the light emitting element ED-b of one or more embodiments, the first electrode EL1 may be a cathode, and the second electrode EL2 may be an anode.

[0127] For example, Figure 5 The first light emitting element ED-1, the second light emitting element ED-2, and the third light emitting element ED-3 shown in FIG. Fig. 6A or Figure 6B Therefore, in the first light-emitting element ED-1, the second light-emitting element ED-2, and the third light-emitting element ED-3, if the first functional layer FL-B is the hole transport region HTR (for example, when the first functional layer FL-B is the hole transport region HTR), the second functional layer FL-T may be the electron transport region ETR, and in the first light-emitting element ED-1, the second light-emitting element ED-2, and the third light-emitting element ED-3, if the first functional layer FL-B is the electron transport region ETR (for example, when the first functional layer FL-B is the electron transport region ETR), the second functional layer FL-T may be the hole transport region HTR.

[0128] exist Fig. 6A and Figure 6B In the light-emitting elements ED-a and ED-b according to one or more embodiments shown in , the hole transport region HTR may include a hole injection layer and a hole transport layer. The hole transport region HTR may have a single-layer structure formed of a single material, a single-layer structure formed of a plurality of different materials, or a multi-layer structure having a plurality of layers formed of a plurality of different materials.

[0129] The hole transport region HTR may be formed using one or more suitable methods such as a vacuum deposition method, a spin coating method, a casting method, a Langmuir-Blodgett (LB) method, an inkjet printing method, a laser printing method, and / or a laser induced thermal imaging (LITI) method.

[0130] The hole transport region HTR may include one or more suitable hole injection materials and / or one or more suitable hole transport materials. For example, the hole transport region HTR may include a phthalocyanine compound (such as copper phthalocyanine), N 1 ,N 1 '-([1,1'-biphenyl]-4,4'-diyl)bis(N 1 -phenyl-N 4 ,N 4-di-m-tolylbenzene-1,4-diamine)(DNTPD), 4,4',4"-[tri(3-methylphenyl)phenylamino]triphenylamine (m-MTDATA), 4,4',4"-tri(N,N-diphenylamino)triphenylamine (TDATA), 4,4',4"-tri[N(2-naphthyl)-N-phenylamino]-triphenylamine (2-TNATA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / dodecylbenzenesulfonic acid (P ANI / DBSA), polyaniline / camphorsulfonic acid (PANI / CSA), polyaniline / poly(4-styrenesulfonate) (PANI / PSS), N,N'-di(naphthalene-1-yl)-N,N'-diphenylbenzidine (NPB), triphenylamine-containing polyether ketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate and / or dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexanitrile (HATCN), etc.

[0131] In one or more embodiments, the hole transport region HTR may include a carbazole-based derivative (such as N-phenylcarbazole and polyvinylcarbazole), a fluorene-based derivative, N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine (TPD), a triphenylamine-based derivative (such as 4,4',4"-tri(N-carbazolyl)triphenylamine (TCTA), N,N'-di(1-naphthalene-1-yl)-N,N'-diphenylbenzidine (NPB), 4,4'-cyclohexylbis(1-hydroxyphenyl)-N,N'-diphenylamine (1,1-biphenyl)-4,4'-diamine (TPD), a triphenylamine-based derivative (such as 4,4',4"-tri(N-carbazole-1-yl ... [N,N-bis(4-methylphenyl)aniline] (TAPC), 4,4'-bis[N,N'-(3-methylphenyl)amino]-3,3'-dimethylbiphenyl (HMTPD)), 9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole (CzSi), 9-phenyl-9H-3,9'-bicarbazole (CCP), 1,3-bis(N-carbazolyl)benzene (mCP) and / or 1,3-bis(1,8-dimethyl-9H-carbazole-9-yl)benzene (mDCP), etc.

[0132] The hole transport region HTR may have a thickness of about 5 nm to about 1,500 nm, for example, about 10 nm to about 500 nm. When the thickness of the hole transport region HTR satisfies the above range, satisfactory hole transport performance may be obtained without significantly increasing the driving voltage.

[0133] In the light emitting elements ED-a and ED-b according to one or more embodiments, the electron transport region ETR may include at least one of an electron transport layer and an electron injection layer, but the present disclosure is not limited thereto.

[0134] The electron transport region ETR may have a single-layer structure formed of a single material, a single-layer structure 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 electron transport region ETR may have a single-layer structure of an electron injection layer or an electron transport layer, and may have a single-layer structure formed of an electron injection material and an electron transport material. The electron transport region ETR may have a thickness of, for example, about 20 nm to about 150 nm.

[0135] The electron transport region ETR may be formed using one or more suitable methods such as a vacuum deposition method, a spin coating method, a casting method, a Langmuir-Blodgett (LB) method, an inkjet printing method, a laser printing method, and / or a laser induced thermal imaging (LITI) method.

[0136] The electron transport region ETR may include one or more suitable electron injection materials and / or one or more suitable electron transport materials. For example, the electron transport region ETR may include an anthracene-based compound. In one or more embodiments, the electron transport region ETR may include, for example, tris(8-hydroxyquinoline)aluminum (Alq 3 ), 1,3,5-tris[(3-pyridyl)-phenyl-3-yl]benzene, 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzimidazol-1-ylphenyl)-9,10-dinaphthylanthracene, 1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bp hen), 3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), 4-(naphthalene-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (tBu-PBD), bis(2-methyl-8-quinolinol-N1,O8)-(1,1`-biphenyl-4-quinolinol)aluminum (BAlq), bis(benzoquinolinol-10-ol)beryllium (Bebq 2 ), 9,10-di(naphthalene-2-yl)anthracene (ADN), 1,3-bis[3,5-di(pyridin-3-yl)phenyl]benzene (BmPyPhB) and / or their (e.g., any suitable) mixtures. In one or more embodiments, the electron transport region ETR may include 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), diphenyl(4-(triphenylsilyl)phenyl)phosphine oxide (TSPO1), and / or 4,7-diphenyl-1,10-phenanthroline (Bphen), etc.

[0137] Reference Figure 5 , the first functional layer FL-B and the second functional layer FL-T may be provided as a common layer throughout the light emitting areas PXA-B, PXA-G, and PXA-R. In one or more embodiments, the functional layer FL may overlap both the emission layers EML-B, EML-G, and EML-R and the pixel defining film PDL. However, the present disclosure is not limited thereto, and at least one of the first functional layer FL-B and the second functional layer FL-T may overlap one of the emission layers EML-B, EML-G, and EML-R, and may be patterned and provided to be arranged in the pixel opening OH.

[0138] Reference Figure 5 , the display device DD of one or more embodiments includes a light control layer PP disposed on the display panel DP. The light control layer PP may include a base layer BL and a color filter layer CFL.

[0139] The base layer BL may be a member providing a base surface on which the color filter layer CFL is arranged. The base layer BL may be a glass substrate, a metal substrate, and / or a plastic substrate, etc. However, the present disclosure is not limited thereto, and the base layer BL may be an inorganic layer, an organic layer, or a composite material layer.

[0140] The color filter layer CFL may include filters CF-B, CF-G, and CF-R. The color filter layer CFL may include a first filter CF-B, a second filter CF-G, and a third filter CF-R. The first filter CF-B, the second filter CF-G, and the third filter CF-R may be arranged to correspond to the first light-emitting element ED-1, the second light-emitting element ED-2, and the third light-emitting element ED-3, respectively. For example, the first filter CF-B may be a blue filter, the second filter CF-G may be a green filter, and the third filter CF-R may be a red filter. The first filter CF-B, the second filter CF-G, and the third filter CF-R may each be arranged to correspond to one of the first light-emitting area PXA-B, the second light-emitting area PXA-G, and the third light-emitting area PXA-R.

[0141] In one or more embodiments, a plurality of filters CF-B, CF-G, and CF-R that transmit different light may be arranged to overlap in an area corresponding to the peripheral area NPXA arranged between the light-emitting areas PXA-B, PXA-G, and PXA-R. A plurality of filters CF-B, CF-G, and CF-R may be arranged to overlap in a third direction DR3 (as a thickness direction) to separate the boundaries between adjacent light-emitting areas PXA-B, PXA-G, and PXA-R. Therefore, the effect of blocking external light is increased to play a role substantially the same as that of a black matrix. The overlapping structure of a plurality of filters CF-B, CF-G, and CF-R may be used to prevent or reduce color mixing.

[0142] The first filter CF-B, the second filter CF-G and the third filter CF-R may each include a polymer photosensitive resin and a pigment and / or a dye. The first filter CF-B may include a blue pigment and / or a blue dye, the second filter CF-G may include a green pigment and / or a green dye, and the third filter CF-R may include a red pigment and / or a red dye. However, the present disclosure is not limited thereto, and the first filter CF-B may not include (e.g., may exclude) a pigment and / or a dye. The first filter CF-B may include a polymer photosensitive resin, but does not include a pigment and / or a dye. The first filter CF-B may be transparent. The first filter CF-B may be formed of a transparent photosensitive resin.

[0143] The color filter layer CFL may further include a buffer layer BFL. For example, the buffer layer BFL may be a protective layer for protecting the first filter CF-B, the second filter CF-G, and the third filter CF-R. The buffer layer BFL may be arranged between the display panel DP and the filters CF-B, CF-G, and CF-R. The buffer layer BFL may be arranged between the encapsulation layer TFE and the filters CF-B, CF-G, and CF-R. The buffer layer BFL may be an inorganic material layer including at least one inorganic material among silicon nitride, silicon oxide, and silicon oxynitride. The buffer layer BFL may be formed of a single layer or a multilayer.

[0144] In one or more embodiments, the second filter CF-G and the third filter CF-R may be yellow filters. The second filter CF-G and the third filter CF-R may not be separated from each other and may be provided as a single body.

[0145] In one or more embodiments, the color filter layer CFL may further include a light blocking unit. The light blocking unit may be a black matrix. The light blocking unit may be formed to include an organic light blocking material and / or an inorganic light blocking material, and both or either of the organic light blocking material and the inorganic light blocking material may include a black pigment and / or a black dye. The light blocking unit may prevent or reduce light leakage and separate the boundaries between adjacent filters CF-B, CF-G, and CF-R.

[0146] In one or more embodiments, the light control layer PP of the display device DD of one or more embodiments may not include (eg, may exclude) the color filter layer CFL. The display device DD of one or more embodiments may include a polarizing layer instead of the color filter layer CFL of the light control layer PP.

[0147] Reference Figures 5 to 6B The emission layers EML-B, EML-G, EML-R, and EML of the light emitting elements ED, ED-a, and ED-b described according to one or more embodiments may include quantum dots according to one or more embodiments of the present disclosure.

[0148] Figure 7 Schematically illustrates the structure of a quantum dot QD according to one or more embodiments of the present disclosure. Figure 7 The structure of quantum dots QD described can be applied to Figure 5 One or more of the first quantum dot QD1, the second quantum dot QD2 and the third quantum dot QD3 shown in .

[0149] Quantum dot QD refers to a crystal of a semiconductor compound and may include any material that can emit light of one or more suitable emission wavelengths depending on the size of the crystal or the adjusted element ratio in the quantum dot QD compound. Quantum dot QD may include semiconductor nanocrystals.

[0150] In one or more embodiments, the quantum dot QD may have a core-shell structure including a core CO and a shell SH. The quantum dot QD having a core-shell structure according to one or more embodiments may include: a core CO, the core CO comprising semiconductor nanocrystals; and a shell SH, the shell SH being around the core CO (e.g., surrounding the core CO) and comprising semiconductor nanocrystals different from the semiconductor nanocrystals of the core CO. The shell SH of the quantum dot QD may be used as a protective layer to prevent or reduce chemical deformation of the core CO to maintain the semiconductor properties of the quantum dot QD, and / or as a charging layer to give the quantum dot QD electrophoretic properties.

[0151] In one or more embodiments, the quantum dot QD may have an average diameter of about 2 nm to about 10 nm. When the diameter of the quantum dot QD satisfies the above range, the characteristic behavior of the quantum dot QD and excellent or suitable dispersibility can also be achieved. In one or more embodiments, if the average particle diameter of the quantum dot QD is selected differently within the above range (for example, when the average particle diameter of the quantum dot QD is selected differently within the above range), the emission wavelength of the quantum dot QD and / or the semiconductor properties of the quantum dot QD can be changed differently.

[0152] Reference Figure 7 , the quantum dot QD may include a core CO and a shell SH around (eg, surrounding) the core CO. The shell SH may include a first shell SH1 and a second shell SH2.

[0153] The core CO may include a first semiconductor nanocrystal. The core CO is a first semiconductor nanocrystal and may include a group I-III-VI semiconductor compound. The core CO may be a group I-III-VI quaternary CuInGaS compound. For example, the core CO may include copper (Cu), indium (In), gallium (Ga), and sulfur (S). The core CO may be formed of copper, indium, gallium, and sulfur. The core CO may be CuInGaS 2 . The quantum dot QD of one or more embodiments includes a core CO comprising a group I-III-VI semiconductor compound, and may therefore have a high blue light absorptivity. In one or more embodiments, the quantum dot QD may be a non-Cd-based quantum dot. For example, the core CO of the quantum dot QD may not include (e.g., may exclude) cadmium (Cd).

[0154] For example, the core CO may include 1 wt% to 30 wt% of copper, 1 wt% to 80 wt% of gallium, 1 wt% to 80 wt% of indium, and 15 wt% to 50 wt% of sulfur relative to 100 wt% of the total mass of the quantum dot QD. The molar ratio of the group VI element relative to the total molar number of the group I-III-VI semiconductor compound constituting the core CO may be about 0.3 to about 0.7, but the present disclosure is not limited thereto.

[0155] When the amount of copper, indium, gallium and sulfur included in the core CO is adjusted within the above range, the quantum dot QD of one or more embodiments may have improved color reproducibility and light absorption characteristics. The quantum dot QD includes an element included in the core CO, the amount of the element included in the core CO is within the above range, and can therefore emit light having a desired or suitable maximum emission wavelength. As the amount of copper, indium, gallium and sulfur included in the core CO changes within the above range, it is possible to adjust the quantum dot QD to a desired or suitable emission wavelength. In one or more embodiments, if the amount of the element included in the core CO is adjusted within the above range (for example, when the amount of the element included in the core CO is adjusted within the above range), the quantum dot QD may emit light having an emission wavelength of about 380nm to about 800nm. Therefore, the quantum dot QD may emit, for example, blue light, green light or red light.

[0156] In one or more embodiments, the core CO may have a diameter of about 1.5 nm to about 8 nm. The large diameter of the core CO contributes to excellent or suitable light absorption characteristics and high quantum efficiency. When the average diameter of the core CO is selected differently within the above range, the emission wavelength of the quantum dot QD and / or the semiconductor properties of the quantum dot may be changed differently.

[0157] The core CO including copper, indium, gallium and sulfur may have an absorption wavelength of about 350 nm to about 530 nm. The core CO may absorb blue light in the above wavelength range to emit blue light, green light or red light. The emission wavelength of light emitted from the quantum dot QD may be controlled or selected by adjusting the size of the core CO and / or the thickness of the first shell SH1 and the second shell SH2, etc.

[0158] In one or more embodiments, the core CO may have a band gap of about 1.5 eV to about 3.3 eV. For example, the core CO may have a band gap of about 2.0 eV. The band gap may be the energy difference between the conduction band, where there is no electron at the lowest energy level, and the valence band, where there is an electron at the highest energy level. The quantum dot QD includes a core CO having a band gap of about 1.5 eV to about 3.3 eV, and may therefore emit blue, green, and / or red light having an emission wavelength of about 380 nm to about 800 nm.

[0159] The band gap of the core CO can be adjusted by adjusting the size of the core CO or adjusting the ratio of elements of the first semiconductor nanocrystals constituting the core CO. For example, the larger the diameter of the core CO, the smaller the band gap can be, and the smaller the diameter of the core CO, the larger the band gap can be. When the band gap decreases, the core CO can emit light of a relatively long wavelength. In one or more embodiments, when the band gap increases, the core CO can emit light of a relatively short wavelength. By adjusting the size of the core CO or the ratio of elements of the first semiconductor nanocrystals, the quantum dot QD in one or more embodiments can adjust the band gap of the core CO within a range of about 1.5 eV to about 3.3 eV, and can therefore selectively emit blue light, green light and / or red light. In one or more embodiments, by combining one or more suitable colors of light, the quantum dot QD can be configured to emit white light.

[0160] In one or more embodiments, the core CO may have a narrow full width at half maximum. For example, the core CO may have a full width at half maximum (FWHM) of the emission wavelength spectrum of about 65 nm or less. In one or more embodiments, the core CO may have a full width at half maximum (FWHM) of the emission wavelength spectrum of about 60 nm or less. For example, the core CO may have a full width at half maximum of the emission wavelength spectrum of about 62 nm.

[0161] The crystal structure of the core CO containing copper, indium, gallium and sulfur may be a tetragonal structure. In one or more embodiments, the core CO may have a crystal structure of approximately The lattice constant of , but the present disclosure is not limited thereto.

[0162] In one or more embodiments, the shell SH may be around the core CO (e.g., surrounding the core CO). The shell SH may have a multilayer structure formed by a variety of different materials. The shell SH may include a first shell SH1 and a second shell SH2. The first shell SH1 may be or completely around the core CO (e.g., surrounding the core CO), and the second shell SH2 may be or completely around the first shell SH1 (e.g., surrounding the first shell SH1). Therefore, the surface of the quantum dot QD may be defined by the outer surface of the second shell SH2. The first shell SH1 may be covered by the second shell SH2 and may therefore not be exposed to the outside of the quantum dot QD. When the quantum dot QD of one or more embodiments includes a first shell SH1 and a second shell SH2, the passivation effect on the core CO may be excellent or suitable. Therefore, the quantum dot QD of one or more embodiments may exhibit high quantum yield characteristics.

[0163] The shell SH may be around the core CO (e.g., surround the core CO) and grow to have a set or predetermined thickness. The thickness of the first shell SH1 and the second shell SH2 is not particularly limited, and the first shell SH1 and the second shell SH2 may each be stacked on the core CO to a set or predetermined thickness so that the quantum dot QD has a diameter of about 2 nm to about 10 nm. Figure 7 As shown in FIG, the first shell SH1 and the second shell SH2 may have substantially the same thickness. In one or more embodiments, different from the thickness shown, the first shell SH1 and the second shell SH2 may have different thicknesses.

[0164] The first shell SH1 and the second shell SH2 may include semiconductor nanocrystals different from the semiconductor nanocrystals included in the core CO. In one or more embodiments, the first shell SH1 and the second shell SH2 may include different semiconductor nanocrystals. The first shell SH1 may include a second semiconductor nanocrystal, and the second shell SH2 may include a third semiconductor nanocrystal. The second semiconductor nanocrystal may be different from the first semiconductor nanocrystal, and the third semiconductor nanocrystal may be different from the first semiconductor nanocrystal and the second semiconductor nanocrystal.

[0165] The first shell SH1 may include at least one of a I-III-VI group compound and a II-III-VI group compound. The first shell SH1 may include a material corresponding to a I-III-VI group compound, a II-III-VI group compound, and / or a combination thereof (e.g., any suitable). For example, the second semiconductor nanocrystal included in the first shell SH1 may be selected from a I-III-VI group compound, a II-III-VI group compound, and a combination thereof (e.g., any suitable). The second semiconductor nanocrystal included in the first shell SH1 may have a band gap larger than the band gap of the first semiconductor nanocrystal included in the core CO.

[0166] In the quantum dots QD of one or more embodiments, the group III elements (e.g., gallium elements) included in the core CO are also included in the first shell SH, and the group III elements of the first shell SH are distributed around the interface between the core CO and the first shell SH1 to prevent or reduce the group VI elements (e.g., zinc elements) in the first shell SH1 and the second shell SH2 from diffusing into the core CO, and thus the change in the half-maximum full width can be reduced.

[0167] The I-III-VI group compound included in the first shell SH1 may have a band gap larger than that of the I-III-VI group compound included in the core CO. The I-III-VI group compound included in the first shell SH1 may be selected from the group consisting of a ternary compound and a quaternary compound. x S y(x and y are real numbers greater than 0), AgGa x S y (x and y are real numbers greater than 0), AgAl x S y (x and y are real numbers greater than 0), AgIn x Se y (x and y are real numbers greater than 0), AgGa x Se y (x and y are real numbers greater than 0), AgAl x Se y (x and y are real numbers greater than 0), CuIn x S y (x and y are real numbers greater than 0), CuGa x S y (x and y are real numbers greater than 0), CuAl x S y (x and y are real numbers greater than 0), CuIn x Se y (x and y are real numbers greater than 0), CuGa x Se y (x and y are real numbers greater than 0), CuAl x Se y (x and y are real numbers greater than 0) and their (eg, any suitable) mixtures; and the quaternary compound is selected from the group consisting of AgIn x Ga y S z (x, y and z are real numbers greater than 0), AgGa x Se y S z (x, y and z are real numbers greater than 0) and (e.g., any suitable) mixtures thereof.

[0168] In one or more embodiments, the I-III-VI group compound included in the first shell SH1 may be selected from the group consisting of a ternary compound and a quaternary compound, the ternary compound being selected from the group consisting of a compound containing Ag-In-S, a compound containing Ag-Ga-S, a compound containing Ag-Al-S, a compound containing Ag-In-Se, a compound containing Ag-Ga-Se, a compound containing Ag-Al-Se, a compound containing Cu-In-S, a compound containing Cu-Ga-S, a compound containing Cu-Al-S, a compound containing Cu-In-Se, a compound containing Cu-Ga-Se, a compound containing Cu-Al-Se, and (e.g., any suitable) mixtures thereof; and the quaternary compound being selected from the group consisting of a compound containing Ag-In-Ga-S, a compound containing Ag-Ga-Se-S, and (e.g., any suitable) mixtures thereof. In the above-mentioned I-III-VI group compounds, the molar ratios of the corresponding groups are not specified and may be changed. For example, a compound containing Ag-In-S is a compound containing Ag, In, and S, and the molar ratio of Ag, In, and S is not specified and may be changed. In one or more embodiments, in the ternary compound and / or quaternary compound, the molar ratio of elements of each group constituting each compound is not specified and may be changed.

[0169] For example, the I-III-VI group compound included in the first shell SH1 can be selected from the group consisting of a ternary compound and a quaternary compound, the ternary compound being selected from the group consisting of AgInS 2 、AgGaS 2 、AgAlS 2 、AgInSe 2 、AgGaSe 2 、AgAlSe 2 、CuInS 2 、CuGaS 2 、CuAlS 2 、CuInSe 2 、CuGaSe 2 、CuAlSe 2 and (eg, any suitable) mixtures thereof; and the quaternary compound is selected from the group consisting of AgInGaS 2 However, this is presented as an example, and the first shell SH1 may include a group I-III-VI compound of a different type or kind from the above compounds, depending on the molar ratio of elements of the corresponding group.

[0170] In the I-III-VI group compound, each element included in the multi-element compound (such as a ternary compound and / or a quaternary compound) may be present in the particle in a substantially uniform concentration or a non-uniform (substantially non-uniform) concentration. For example, the above chemical formula represents the type (species) of elements included in the I-III-VI group compound, and the ratio of elements in the compound may be the same or different. For example, as in AgIn x Ga 1-x S 2 As shown in (x is a real number greater than 0 and less than 1), the proportions of elements in Group III may be the same or different. In one or more embodiments, as in AgGaSe 2-x S x As shown in (x is a real number greater than 0 and less than 2), the ratio of elements of Group VI may be the same or different. This is due to the fact that compounds of different molar ratios can be produced, which is a characteristic of multi-component compounds.

[0171] The II-III-VI group compound included in the first shell SH1 can be selected from the group consisting of a ternary compound and a quaternary compound, wherein the ternary compound is selected from the group consisting of ZnIn x S y (x and y are real numbers greater than 0), ZnGa x S y (x and y are real numbers greater than 0), ZnAl x S y (x and y are real numbers greater than 0), ZnIn x Se y (x and y are real numbers greater than 0), ZnGa x Se y (x and y are real numbers greater than 0), ZnAl x Se y (x and y are real numbers greater than 0), MgIn x S y (x and y are real numbers greater than 0), MgGa x S y (x and y are real numbers greater than 0), MgAl x S y (x and y are real numbers greater than 0), MgIn x Se y (x and y are real numbers greater than 0), MgGa x Se y (x and y are real numbers greater than 0), MgAl x Se y (x and y are real numbers greater than 0) and their (eg, any suitable) mixtures; and the quaternary compound is selected from the group consisting of ZnIn xGa y S z (x, y and z are real numbers greater than 0), ZnIn x Se y S z (x, y and z are real numbers greater than 0) and (e.g., any suitable) mixtures thereof.

[0172] In one or more embodiments, the II-III-VI group compound included in the first shell SH1 may be selected from the group consisting of a ternary compound and a quaternary compound, the ternary compound being selected from the group consisting of a compound containing Zn-In-S, a compound containing Zn-Ga-S, a compound containing Zn-Al-S, a compound containing Zn-In-Se, a compound containing Zn-Ga-Se, a compound containing Zn-Al-Se, a compound containing Mg-In-S, a compound containing Mg-Ga-S, a compound containing Mg-Al-S, a compound containing Mg-In-Se, a compound containing Mg-Ga-Se, a compound containing Mg-Al-Se, and (e.g., any suitable) mixtures thereof; and the quaternary compound being selected from the group consisting of a compound containing Zn-In-Ga-S, a compound containing Zn-In-Se-S, and (e.g., any suitable) mixtures thereof. In the above II-III-VI group compounds, the molar ratios of the corresponding groups are not specified and may be changed. For example, a compound containing Zn-Ga-S is a compound containing Zn, Ga, and S, and the molar ratio of Zn, Ga, and S is not specified and may be changed. In one or more embodiments, in the ternary compound and the quaternary compound, the molar ratio of the elements of each group constituting each compound is not specified and may be changed.

[0173] For example, the II-III-VI group compound included in the first shell SH1 can be selected from the group consisting of a ternary compound and a quaternary compound, wherein the ternary compound is selected from the group consisting of ZnIn 2 S 4 、ZnGaS、ZnGa 2 S 4 、ZnAl 2 S 4 、ZnIn 2 Se 4 、ZnGa 2 Se 4 、ZnAl 2 Se 4 MgIn 2 S 4 MgGa 2 S 4 MgAl2 S 4 MgIn 2 Se 4 MgGa 2 Se 4 MgAl 2 Se 4 and (eg, any suitable) mixtures thereof; and the quaternary compound is selected from the group consisting of ZnInGaS 4 、ZnIn 2 However, this is presented as an example, and the first shell SH1 may include a II-III-VI group compound of a different type or kind from the above compounds, depending on the molar ratio of elements of the corresponding group.

[0174] In the II-III-VI group compound, each element included in the multi-element compound (such as a ternary compound and a quaternary compound) may be present in the particle in a substantially uniform concentration or a non-uniform (substantially non-uniform) concentration. For example, the above chemical formula represents the type (species) of elements included in the II-III-VI group compound, and the ratio of elements in the compound may be the same or different. For example, as in ZnIn x Ga 2-x S 4 As shown in (x is a real number between 0 and 2), the proportions of the elements of Group III may be the same or different, and ZnIn x Ga 2-x S 4 Can include ZnInGaS 4 In one or more embodiments, such as in ZnIn 2 Se 4-x S x As shown in (x is a real number between 0 and 4), the proportions of the elements of Group VI may be the same or different, and ZnIn 2 Se 4-x S x Can include ZnIn 2 SeS et al.

[0175] For example, the first shell SH1 may include a II-III-VI semiconductor compound. The first shell SH1 may include zinc (Zn), gallium (Ga), and sulfur (S). The molar numbers of zinc, gallium, and sulfur in the first shell SH1 may be the same or different. For example, the first shell SH1 may include ZnGaS or ZnGaS. 2 S 4 II-III-VI semiconductor compounds.

[0176] In one or more embodiments, the first shell SH1 may have a band gap larger than the band gap of the core CO. The band gap of the first shell SH1 may be larger than the band gap of the core CO, and may be smaller than the band gap of the second shell SH2. The band gap of the first shell SH1 may have a value between the band gap of the core CO and the band gap of the second shell SH2. The band gap of the first shell SH1 may be adjusted by adjusting the type or kind of elements of the second semiconductor nanocrystals included in the first shell SH1 and / or the element ratio of the second semiconductor nanocrystals, but the present disclosure is not limited thereto.

[0177] The first shell SH1 may have a band gap of about 1.6 eV to about 3.5 eV. For example, if the first shell SH1 includes zinc, gallium, and sulfur (when the first shell SH1 includes zinc, gallium, and sulfur), the band gap of the first shell SH1 may be about 3.18 eV, but the present disclosure is not limited thereto. In the quantum dot QD of one or more embodiments, when the first shell SH1 having a band gap larger than that of the core CO surrounds the core CO, the luminous efficiency and stability may be improved.

[0178] In one or more embodiments, the first shell SH1 may have the same crystal structure as the core CO. For example, the first shell SH1 may include zinc, gallium, and sulfur, and may have the same crystal structure as the core CO including copper, indium, gallium, and sulfur. The crystal structure of the first shell SH1 including zinc, gallium, and sulfur may be a tetragonal structure.

[0179] In one or more embodiments, the first shell SH1 may have a level of a lattice constant substantially similar to that of the core CO. For example, the lattice constant of the first shell SH1 may have a level of a lattice constant substantially similar to that of the core CO. For example, with respect to an absolute value, the lattice constant of the first shell SH1 may have a level of about The lattice constant of the first shell SH1 may satisfy Formula 1. The first shell SH1 satisfying Formula 1 may have a level of a lattice constant substantially similar to that of the core CO.

[0180] Formula 1

[0181]

[0182] In Formula 1, SH1 is the lattice constant of the first shell SH1, and CO is the lattice constant of the core CO.

[0183] For example, the first shell SH1 including zinc, gallium and sulfur may have a size of about lattice constant. The first shell SH1 has a crystal structure identical to that of the core CO, and has a lattice constant substantially similar to that of the core CO, and can therefore be stacked on the core CO while maintaining the narrow half-maximum full width of the core CO. For example, a core CO including copper, indium, gallium, and sulfur may have a half-maximum full width of approximately 63 nm, and if the first shell SH1 including zinc, gallium, and sulfur is around the core CO (e.g., surrounding the core CO) (e.g., when the first shell SH1 including zinc, gallium, and sulfur is around the core CO (e.g., surrounding the core CO)), the quantum dot QD of one or more embodiments may have a half-maximum full width of approximately 65 nm or less. Therefore, if the first shell SH1 is introduced into the core CO (e.g., when the first shell SH1 is introduced into the core CO), the quantum dot QD of one or more embodiments may achieve excellent or suitable color reproducibility due to a small change in the half-maximum full width.

[0184] The second shell SH2 may include a third semiconductor nanocrystal. The second shell SH2 may include a material corresponding to a II-VI group compound and / or their (e.g., any suitable) combination. The third semiconductor nanocrystal may be selected from a II-VI group compound and / or their (e.g., any suitable) combination. The third semiconductor nanocrystal included in the second shell SH2 may have a band gap larger than the band gap of the first semiconductor nanocrystal and the second semiconductor nanocrystal.

[0185] In one or more embodiments, the II-VI compound included in the second shell SH2 may have a band gap larger than the band gap of the second semiconductor nanocrystal included in the first shell SH1. The II-VI compound included in the second shell SH2 may be selected from the group consisting of binary compounds, and the binary compound is selected from the group consisting of MgO, MgS, MgSe, MgTe, ZnO, ZnS, ZnSe, ZnTe and their (e.g., any suitable) mixtures. For example, the second shell SH2 may include at least one of MgO, MgS, MgSe, MgTe, ZnO, ZnS, ZnSe and ZnTe. In one or more embodiments, the second shell SH2 may include zinc (Zn) and sulfur (S). The second shell SH2 may include ZnS, but the present disclosure is not limited thereto.

[0186] In the II-VI group compound, each element included in the multi-element compound (such as a binary compound) may be present in the particle in a substantially uniform concentration or a non-uniform (substantially non-uniform) concentration. For example, the chemical formula above represents the type (species) of elements included in the II-VI group compound, and the ratio of elements in the compound may be the same or different.

[0187] In one or more embodiments, the second shell SH2 may have a band gap larger than the band gap of the core CO. For example, the second shell SH2 may have a band gap larger than the band gap of the core CO, and the core CO has a band gap of about 1.5eV to about 3.3eV. In one or more embodiments, the second shell SH2 may have a band gap larger than the band gap of the first shell SH1. For example, the band gap of the second shell SH2 may be larger than the band gap of the core CO and may be about 3.54eV or less. The quantum dots QD of one or more embodiments include a second shell SH2 having a band gap adjusted to the above range, and therefore, quantum efficiency and stability can be improved. The band gap of the second shell SH2 can be adjusted by adjusting the type or kind of elements of the third semiconductor nanocrystal included in the second shell SH2, the element ratio of the third semiconductor nanocrystal and / or the thickness of the second shell SH2, but the present disclosure is not limited thereto.

[0188] The band gap of the second shell SH2 may be greater than the band gap of the core CO and the first shell SH1, and may be about 3.54 eV or less. For example, if the second shell SH2 includes ZnS (e.g., when the second shell SH2 includes ZnS), the band gap of the second shell SH2 may be about 3.54 eV, but the present disclosure is not limited thereto. When the second shell SH2 having a band gap greater than the band gap of the core CO and the first shell SH1 is around the core CO and the first shell SH1 (e.g., surrounding the core CO and the first shell SH1), the quantum dot QD of one or more embodiments has improved quantum efficiency and stability.

[0189] In one or more embodiments, the second shell SH2 may have a crystal structure substantially similar to those of the core CO and the first shell SH1. For example, the second shell SH2 may include ZnS, and the crystal structure of the second shell SH2 may be a cubic structure.

[0190] In one or more embodiments, the second shell SH2 may have a level of lattice constant substantially similar to that of the first shell SH1. For example, the lattice constant of the second shell SH2 may have a level of lattice constant substantially similar to that of the first shell SH1 in terms of absolute value. The lattice constant of the second shell SH2 may satisfy Formula 2. The second shell SH2 satisfying Formula 2 may have a level of a lattice constant substantially similar to that of the first shell SH1.

[0191] Formula 2

[0192]

[0193] In Formula 2, SH2 is the lattice constant of the second shell SH2, and SH1 is the lattice constant of the first shell SH1.

[0194] For example, the second shell SH2 including ZnS may have a thickness of about The second shell SH2 has a crystal structure and a lattice constant substantially similar to those of the first shell SH1, respectively, and can therefore be formed to have a sufficient thickness to surround the core CO and the first shell SH1 (surround the core CO and the first shell SH1) while maintaining a narrow half-maximum full width of the core CO.

[0195] The quantum dot QD of one or more embodiments may have a full width at half maximum (FWHM) of an emission wavelength spectrum of about 60 nm or less. For example, the quantum dot QD may have a full width at half maximum (FWHM) of an emission wavelength spectrum of about 25 nm to about 65 nm.

[0196] In the quantum dot QD of one or more embodiments, the first shell SH1 includes a structure in which the first shell SH1 is introduced between the core CO and the second shell SH2, so that the first shell SH1 is around the core CO (e.g., surrounding the core CO), and the second shell SH2 is around the first shell SH1 (e.g., surrounding the first shell SH1), and the increase in the half-maximum full width of the core CO can be minimized or reduced. In one or more embodiments, in the quantum dot QD of one or more embodiments, the core CO is surrounded (e.g., covered or encapsulated) by the first shell SH1 and the second shell SH2, and therefore, the quantum dot QD can have greatly increased photostability and chemical stability. Light emitted by the quantum dot QD is emitted in all directions, and therefore the wide viewing angle can be improved.

[0197] In one or more embodiments, the form of quantum dots QD is not particularly limited, as long as it is a form commonly used in the art, for example, quantum dots in the form of spherical nanoparticles, pyramidal nanoparticles, multi-arm nanoparticles or cubic nanoparticles, nanotubes, nanowires, nanofibers, and / or nanosheets can be used. In one or more embodiments, the quantum dots QD may be spherical.

[0198] In one or more embodiments, the quantum dot QD may also include a ligand chemically bonded to the surface. The ligand may be chemically bonded to the surface of the quantum dot QD to passivate the quantum dot QD. For example, the quantum dot QD may also include a ligand chemically bonded to the second shell SH2. In one or more embodiments, the ligand may include an organic ligand or a metal halide.

[0199] Quantum dot QD can be synthesized by wet chemical process, metal organic chemical vapor deposition process, molecular beam epitaxy process or a process substantially similar thereto. The wet chemical process is a method of mixing an organic solvent and a precursor material, and then growing particle crystals of quantum dot QD. When the crystal grows, the organic solvent naturally acts as a dispersant that coordinates with the surface of the crystal of quantum dot QD, and the growth of the crystal can be controlled. Therefore, the wet chemical process is simpler than a vapor deposition method (such as metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE)), and the growth of quantum dot QD particles can be controlled by a low-cost process.

[0200] Hereinafter, a method for manufacturing quantum dots according to one or more embodiments will be described. However, this is presented as an example, and the method for manufacturing quantum dots according to the present disclosure is not limited thereto. The description of the above quantum dots QD may also be applied to the method for manufacturing quantum dots of one or more embodiments, which will be described in more detail later.

[0201] For example, a method for manufacturing a quantum dot according to one or more embodiments may include synthesizing a core CO, synthesizing a first shell SH1 , and synthesizing a second shell SH2 .

[0202] The synthesis of the core CO may include providing a first mixture, the first mixture including a first precursor including copper atoms, a second precursor including indium atoms, and a third precursor including gallium atoms. Thereafter, a first solvent and a second solvent may be added to the first mixture to form a second mixture. The first solvent may be trioctylphosphine oxide, and the second solvent may be trioctylamine, but the present disclosure is not limited thereto. The first solvent and the second solvent may dissolve the first precursor, the second precursor, and the third precursor, and help control the concentration and reaction rate of the materials in the second mixture.

[0203] The second mixture may include a first precursor including copper atoms, a second precursor including indium atoms, and a third precursor including gallium atoms in a certain ratio. In the second mixture, the mole number of the second precursor and the third precursor relative to the mole number of the first precursor may be included in a ratio (e.g., amount) of about 1 to about 10, but the present disclosure is not limited thereto.

[0204] In one or more embodiments, the synthesis of the core CO may include adding a fourth precursor including sulfur atoms to the second mixture, and then reacting the mixture at a high temperature of 230° C. In forming the core CO, the high temperature reaction of 230° C. or higher may last for about 2 hours, and then the core CO may be formed through a cooling and purification process.

[0205] The synthesis of the first shell SH1 may include mixing the first element precursor and the second element precursor with trioctylamine and vacuum treating the mixture at 120° C. to form a third mixture. Thereafter, in the synthesis of the first shell SH1, the core CO and the third element precursor for synthesizing the core CO may be injected into the third mixture and reacted at a high temperature of 250° C. or higher. This high temperature reaction may be maintained at 250° C. or higher for approximately 40 minutes to form the first shell SH1 around the core CO (e.g., surrounding the core CO).

[0206] In the synthesis of the first shell SH1, the first element precursor may include a Group II element. For example, the first element precursor may include a zinc atom or a magnesium atom. The second element precursor may include a Group III element. For example, the second element precursor may include at least one of an aluminum atom, a gallium atom, and an indium atom. The third element precursor may include a Group VI element. For example, the third element precursor may include at least one of a sulfur atom and a selenium atom. In one or more embodiments, the first element precursor may include a zinc atom, the second element precursor may include a gallium atom, and the third element precursor may include a sulfur atom, but the present disclosure is not limited thereto.

[0207] The synthesis of the second shell SH2 may further include adding a fourth element precursor and a fifth element precursor to the first particle including the core CO and the first shell SH1 after forming the first shell SH1 to form the second shell SH2 around (eg, surrounding) the first shell SH1 .

[0208] In the formation of the second shell SH2, the fourth element precursor may include a Group II element. For example, the fourth element precursor may include at least one of a zinc atom and a magnesium atom. The fifth element precursor may include a Group VI element. For example, the fifth element precursor may include at least one of a selenium atom, a sulfur atom, a tellurium atom, and an oxygen atom. In one or more embodiments, the fourth element precursor may include a zinc atom, and the fifth element precursor may include a sulfur atom.

[0209] In the formation of the second shell SH2, the fourth element precursor and the fifth element precursor may be injected into the first particle, the temperature may be raised to 280° C., and then the reaction may be maintained for 30 minutes. Thereafter, a quantum dot QD including a first shell SH1 around the core CO (e.g., surrounding the core CO) and a second shell SH2 around the first shell SH1 (e.g., surrounding the first shell SH1) of one or more embodiments may be manufactured through a cooling and purification process.

[0210] Table 1 shows the crystal structure, lattice constant and band gap of the quantum dot of Example 1. In Table 1, Example 1 includes a core including copper, indium, gallium and sulfur, a first shell around the core (e.g., surrounding the core) and including zinc, gallium and sulfur, and a second shell around the first shell (e.g., surrounding the first shell) and including ZnS. That is, the quantum dot of Example 1 has a structure of CuInGaS-ZnGaS-ZnS (core-first shell-second shell).

[0211] Table 1

[0212]

[0213] Referring to Table 1, it was determined that, in the quantum dots of Example 1, the band gap of the first shell had a value between the band gap of the core and the band gap of the second shell. In addition, it was determined that, in the quantum dots of Example 1, the first shell had the same crystal structure as that of the core, and had a lattice constant substantially similar to that of the core.

[0214] Table 2 shows the evaluation of the luminescent properties and quantum yield (QY) of the quantum dots of Example 1 and Comparative Example 1. Table 2 shows the results of measuring the full width at half maximum (FWHM) and quantum yield of the quantum dots of Example 1 and Comparative Example 1. In Table 2, the quantum yield is obtained from the results of measuring the quantum dots of Example 1 and Comparative Example 1 using a QE-2100 device in a solution state.

[0215] Fig. 8A and Figure 8B Each is a view showing the results of evaluating light emission characteristics of Comparative Example 1 and Example 1. Fig. 8A is a view showing a photoluminescence (PL) spectrum of the quantum dots of Comparative Example 1. Figure 8B is a view showing the photoluminescence (PL) spectrum of the quantum dots of Example 1. Fig. 8A and Figure 8B In Table 2, the "core" shown by the dotted line shows the photoluminescence spectrum result of the core only, and the "shell" shown by the solid line shows the photoluminescence spectrum result of the quantum dots with the shell wrapped on the outside of the core. In addition, in Table 2, the half-maximum full width of the core shows the result of measuring the half-maximum full width of the core, and the half-maximum full width of the shell shows the result of measuring the half-maximum full width of the quantum dots with the shell wrapped on the outside of the core.

[0216] In Table 2 and Fig. 8A , Comparative Example 1 includes a core including copper, indium, gallium, and sulfur and a second shell around the core (e.g., surrounding the core) and including ZnS. That is, compared with the quantum dots of Example 1, the quantum dots of Comparative Example 1 have a structure of CuInGaS-ZnS (core-second shell), and therefore do not include a first shell. In Tables 2 and Figure 8B, the quantum dot of Example 1 corresponds to the same quantum dot as Example 1 in Table 1, and has a structure of CuInGaS-ZnGaS-ZnS (core-first shell-second shell).

[0217] Table 2

[0218] Nuclear full width at half maximum (nm) Shell half maximum width (nm) Quantum efficiency (%) Example 1 62 65 85 Comparative Example 1 60 105 85

[0219] Refer to Table 2 and Fig. 8A and Figure 8B , it is seen that the quantum dots of Example 1 and Comparative Example 1 each have a core having an emission wavelength of about 550 nm to about 680 nm and a full width at half maximum of 65 nm or less. In addition, it is seen that Example 1, which includes the core, the first shell, and the second shell according to one or more embodiments together, exhibits a high quantum yield of 85%. It is determined that Comparative Example 1 also exhibits a quantum yield at the same level as the quantum yield of Example 1. Therefore, it is seen that the quantum dots of Example 1 show excellent or suitable quantum yields compared to Comparative Example 1 even when multiple shells are included (when multiple shells are included).

[0220] In addition, the quantum dots of Example 1 have a first shell of ZnGaS introduced between the core and the second shell, and are shown to have a half-maximum full width of 65nm, and the half-maximum full width of the quantum dots of Example 1 is increased by 3nm compared to the core with a half-maximum full width of 62nm. That is, it can be seen that even if multiple shells are introduced on the outer surface of the core, the increase in the half-maximum full width of the quantum dots of Example 1 is minimized or reduced. Therefore, the color reproducibility can be improved using the quantum dots of Example 1. In the quantum dots of Example 1, it is determined that the gallium component contained in the core is also included in the first shell, and the gallium component of the first shell is distributed on the outside of the core, that is, around the interface between the core and the first shell, to prevent or reduce the zinc component of the first shell and the second shell from diffusing into the core, resulting in a small change in the amount of half-maximum full width.

[0221] However, it is seen that the quantum dots of Comparative Example 1 have a structure in which the first shell is not introduced between the core and the second shell and the second shell directly surrounds the core, and therefore has a half-maximum full width increased by 45nm compared to the core. Therefore, it is seen that the quantum dots of Comparative Example 1 in which the first shell ZnGaS is not introduced between the core and the second shell, have a greatly increased half-maximum full width compared to the core, resulting in deterioration in color reproducibility. In the quantum dots of Comparative Example 1, it is determined that the zinc component of the second shell diffuses into the core, resulting in a large change in the amount in the half-maximum full width.

[0222] In addition, refer to Fig. 8A and Figure 8B, it can be seen that the quantum dots of Example 1 show little change in emission wavelength even when a shell is formed on the core, while the quantum dots of Comparative Example 1 show a large change in emission wavelength when a shell is formed on the core. Therefore, it is determined that the quantum dots of Example 1 sufficiently obtain shell stability compared to the quantum dots of Comparative Example 1, and thus the core characteristics are well maintained.

[0223] Table 3 and Fig. 9 The results of evaluating the light stability of Example 1 and Comparative Examples 1 and 2 are shown respectively. Fig. 9 In the photostability evaluation, the power conversion efficiency (PCE) is measured over time. Fig. 9 In the example 1, the comparative example 1 and the comparative example 2 are shown by adding quantum dots in an amount of 8 wt % to the sample and exposing the mixture to 100,000 nits of blue light, and then measuring the light retention over time. Fig. 9 , the quantum dots of Example 1 and Comparative Example 1 correspond to the quantum dots of Example 1 and Comparative Example 1 in Table 2 above. Comparative Example 2 includes a core including silver, indium, gallium, and sulfur, and a shell around the core (e.g., surrounding the core) and including GaS. That is, compared to the quantum dots of Example 1, the quantum dots of Comparative Example 2 have a structure of AgInGaS-GaS and include a shell.

[0224] Table 3

[0225] 0 24(hr) 53(hr) 96(hr) 192(hr) 384(hr) Example 1 100％ 85％ 78％ 63％ 56％ 40％ Comparative Example 1 100％ 90％ 81％ 67％ 55％ 43％ Comparative Example 2 100％ 78％ 63％ 39％ 23％ 21％

[0226] Refer to Table 3 and Fig. 9 , Comparative Example 1 and Example 1 show substantially similar values ​​in the photostability evaluation. That is, over time, it can be seen that the quantum dots of Example 1 exhibit a quantum yield substantially similar to that of Comparative Example 1. For example, it is considered that even if the first shell is introduced between the core and the second shell to include a plurality of shells, the luminescence characteristics of the quantum dots are maintained at a level substantially similar to the luminescence characteristics of typical quantum dots in which the first shell is not introduced.

[0227] In addition, Comparative Example 2 shows significantly reduced photostability results compared to Example 1, indicating that quantum dots without the first shell and the second shell according to one or more embodiments have insufficient light emitting performance.

[0228] Consider Tables 1 to 3 and FIG. 8A to FIG. 9It can be seen that, according to the introduction of the first shell, the light stability of the quantum dots of the example shows a level substantially similar to or significantly improved than the light stability of the quantum dots of the comparative example, and the increase in the half-width can be minimized or reduced. For example, for one or more embodiments including a first shell, the first shell has a band gap between the core and the second shell and has a crystal structure that is the same as the crystal structure of the core and a lattice constant that is substantially similar to the lattice constant of the core. Since the first shell is introduced between the core and the second shell, the light emission wavelength characteristics and light emission efficiency of the light emitting element according to one or more embodiments can be expected to be maintained at a satisfactory level or improved. In addition, the display device including quantum dots according to one or more embodiments can also be expected to exhibit excellent or suitable display quality in terms of light emission characteristics and display efficiency.

[0229] The quantum dots of one or more embodiments include different semiconductor nanocrystals and include a core and multiple shells having specific bandgap characteristics, and can therefore maintain the full width at half maximum of the core, thereby exhibiting improved color reproducibility and stability and satisfactory quantum efficiency.

[0230] The light-emitting element of one or more embodiments includes the above-described quantum dots in an emission layer, and can therefore exhibit satisfactory light-emitting characteristics and excellent or appropriate element quality.

[0231] The display device of one or more embodiments includes a light-emitting element including the above-described quantum dots in an emission layer, and can therefore exhibit excellent or appropriate display quality.

[0232] As used herein, the terms "substantially," "approximately," and similar terms are used as terms of approximation rather than terms of degree, and are intended to account for the inherent deviations in measured or calculated values ​​that one of ordinary skill in the art would recognize. As used herein, "substantially" includes the stated value, and includes methods within the acceptable range of deviation for a particular value as determined by one of ordinary skill in the art, taking into account the measurement in question and the errors associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "substantially" can mean within one or more standard deviations, or within ±30%, ±20%, ±10%, or ±5% of the stated value.

[0233] In addition, any numerical range recorded herein is intended to include all sub-ranges with the same numerical precision contained in the recorded range. For example, the range of "1.0 to 10.0" is intended to include all sub-ranges between the minimum value of 1.0 recorded and the maximum value of 10.0 recorded (and including the minimum value of 1.0 and the maximum value of 10.0), that is, with a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limit recorded herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit recorded in this specification is intended to include all higher numerical limits contained therein. Therefore, the applicant reserves the right to modify this specification (including claims) to explicitly record any sub-range contained in the range explicitly recorded herein.

[0234] Furthermore, when describing embodiments of the present disclosure, the use of “may” refers to “one or more embodiments of the present disclosure.”

[0235] According to the light-emitting device, electronic device or any other related device or component of the embodiment of the present disclosure described herein can be implemented using any suitable hardware, firmware (e.g., application specific integrated circuit), software or a combination of software, firmware and hardware. For example, the various components of the device can be formed in an integrated circuit (IC) chip or in a separate IC chip. In addition, the various components of the device can be implemented on a flexible printed circuit film, a tape carrier package (TCP), a printed circuit board (PCB), or formed on a substrate. In addition, the various components of the device can be processes or threads running on one or more processors in one or more computing devices, executing computer program instructions and interacting with other system components to perform the various functions described herein. Computer program instructions are stored in a memory, which can be implemented in a computing device using a standard memory device (such as, for example, a random access memory (RAM)). Computer program instructions can also be stored in other non-temporary computer-readable media (such as, for example, a CD-ROM, or a flash drive, etc.). In addition, it should be appreciated by those skilled in the art that, without departing from the scope of the embodiments of the present disclosure, the functions of various computing devices can be combined or integrated into a single computing device, or the functions of a specific computing device can be distributed across one or more other computing devices.

[0236] Although embodiments of the present disclosure have been described, it should be understood that the present disclosure should not be limited to these embodiments, but a person skilled in the art may make one or more appropriate changes and modifications within the spirit and scope of the present disclosure as defined by the appended claims and their equivalents.

Claims

1. A quantum dot, comprising: A core comprising a first semiconductor nanocrystal; a first shell surrounding the core and comprising a second semiconductor nanocrystal different from the first semiconductor nanocrystal; as well as a second shell surrounding the first shell and including a third semiconductor nanocrystal different from the first semiconductor nanocrystal and the second semiconductor nanocrystal, wherein the first semiconductor nanocrystal comprises a Group I-III-VI compound, The second semiconductor nanocrystal includes at least one of a Group I-III-VI compound and a Group II-III-VI compound, The third semiconductor nanocrystal includes a II-VI group compound, The core has a band gap of 1.5 eV to 3.3 eV, The band gap of the second shell is larger than the band gap of the core and is 3.54 eV or less, and The band gap of the first shell is larger than the band gap of the core and smaller than the band gap of the second shell.

2. The quantum dot according to claim 1, wherein The core includes copper, indium, gallium and sulfur.

3. The quantum dot according to claim 1, wherein The first shell has the same crystal structure as that of the core.

4. The quantum dot according to claim 3, wherein The first shell satisfies Formula 1: Formula 1 Wherein, in Formula 1, SH1 is the lattice constant of the first shell, and CO is the lattice constant of the core.

5. The quantum dot according to claim 1, wherein The second semiconductor nanocrystal includes the Group I-III-VI compound and the Group II-III-VI compound, Wherein, the Group I-III-VI compound of the first shell is selected from the group consisting of: a ternary compound selected from the group consisting of a compound comprising Ag-In-S, a compound comprising Ag-Ga-S, a compound comprising Ag-Al-S, a compound comprising Ag-In-Se, a compound comprising Ag-Ga-Se, a compound comprising Ag-Al-Se, a compound comprising Cu-In-S, a compound comprising Cu-Ga-S, a compound comprising Cu-Al-S, a compound comprising Cu-In-Se, a compound comprising Cu-Ga-Se, a compound comprising Cu-Al-Se, and a mixture thereof; and a quaternary compound selected from the group consisting of a compound comprising Ag-In-Ga-S, a compound comprising Ag-Ga-Se-S, and a mixture thereof, and Wherein, the II-III-VI group compound of the first shell is selected from the group consisting of: a ternary compound selected from the group consisting of a compound containing Zn-In-S, a compound containing Zn-Ga-S, a compound containing Zn-Al-S, a compound containing Zn-In-Se, a compound containing Zn-Ga-Se, a compound containing Zn-Al-Se, a compound containing Mg-In-S, a compound containing Mg-Ga-S, a compound containing Mg-Al-S, a compound containing Mg-In-Se, a compound containing Mg-Ga-Se, a compound containing Mg-Al-Se, and a mixture thereof; and The quaternary compound is selected from the group consisting of a compound containing Zn-In-Ga-S, a compound containing Zn-In-Se-S, and a mixture thereof.

6. The quantum dot according to claim 1, wherein The first shell includes the Group II-III-VI compound, and In the Group II-III-VI compound, gallium atoms are included as Group III elements.

7. The quantum dot according to claim 1, wherein The first shell includes zinc, gallium, and sulfur.

8. The quantum dot according to claim 1, wherein The second shell includes at least one of MgO, MgS, MgSe, MgTe, ZnO, ZnS, ZnSe, and ZnTe.

9. The quantum dot according to claim 8, wherein The second shell includes ZnS.

10. The quantum dot according to claim 1, wherein The quantum dots have a diameter of 2 nm to 10 nm.

11. The quantum dot according to claim 1, wherein The quantum dots have a full width at half maximum of 65 nm or less.

12. The quantum dot according to claim 1, wherein The quantum dots have a central emission wavelength of 380 nm to 800 nm.

13. A light emitting element, comprising: a first electrode; a second electrode opposite to the first electrode; an emission layer between the first electrode and the second electrode and comprising quantum dots according to any one of claims 1 to 12; as well as A functional layer is between the emission layer and the first electrode and / or between the emission layer and the second electrode.

14. A display device, comprising: Circuit layer; as well as A display element layer, which is on the circuit layer and includes a light-emitting element and a pixel-defining film, wherein a pixel opening is defined in the pixel-defining film; Wherein, the light emitting element comprises: a first electrode; a second electrode facing the first electrode; an emission layer between the first electrode and the second electrode and comprising quantum dots according to any one of claims 1 to 12; and A functional layer is between the emission layer and the first electrode and / or between the emission layer and the second electrode.

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