Light-emitting element, ink composition, and display device including light-emitting element

Abstract

The invention relates to a light-emitting element, an ink composition, and a display device including the light-emitting element. A light-emitting element according to an embodiment of the present invention comprises: a first electrode; a functional layer disposed on the first electrode; and a second electrode disposed on the functional layer, in which the functional layer includes a nanoparticle including a core including at least one of a first core compound represented by the following Chemical Formula 1, a second core compound represented by the following Chemical Formula 2, and a third core compound represented by the following Chemical Formula 3, and a ligand, the ligand including at least one of the first core compound represented by the following Chemical Formula 1, the second core compound represented by the following Chemical Formula 2, and the third core compound represented by the following Chemical Formula 3, therefore, the service life and efficiency of the light-emitting element are improved. [Chemical Formula 1] Sn < 4 + 1-x > Sn < 2 + x > O < 2-x > [Chemical Formula 2] Sn < 4 + 1-y > Cu < + 2 > y O < 2-y > [Chemical Formula 3] Sn < 4 + 1-z > Ni < 2 + z > O < 2-z >.

Description

Technical Field

[0001] The present invention relates to a light-emitting element, an ink composition, and a display device including the light-emitting element, and more particularly, to a light-emitting element having improved luminous efficiency and element life, and a display device including the light-emitting element. Background Art

[0002] Recently, the development of organic electroluminescence display devices as image display devices has been actively carried out. Organic electroluminescence display devices are different from liquid crystal display devices and are so-called self-luminous display devices as follows: holes and electrons injected from the first electrode and the second electrode are recombined in the light-emitting layer, and the light-emitting material including organic compounds in the light-emitting layer emits light to achieve display.

[0003] When an organic electroluminescent element is applied to a display device, high luminous efficiency and long life are required, and there is a continuous demand for the development of a material for a light-emitting element that can stably achieve high luminous efficiency and long life.

[0004] In particular, in order to realize a light-emitting element with high luminous efficiency and long life, development of materials for an electron transport region having excellent electron transport properties and stability is in progress. Summary of the invention

[0005] An object of the present invention is to provide a light-emitting element with improved luminous efficiency and element life.

[0006] Another object of the present invention is to provide an ink composition capable of improving the light emitting characteristics and device life of a light emitting device.

[0007] Another object of the present invention is to provide a display device including a light-emitting element with improved luminous efficiency and element life.

[0008] According to one embodiment of the present invention, a light-emitting element includes: a first electrode; a functional layer arranged on the first electrode; and a second electrode arranged on the functional layer, wherein the functional layer includes nanoparticles, the nanoparticles include a core and a ligand, and the core includes at least one of a first core compound represented by the following chemical formula 1, a second core compound represented by the following chemical formula 2, and a third core compound represented by the following chemical formula 3.

[0009] [Chemical formula 1]

[0010] Sn 4+ 1-x Sn 2+ x O 2-x

[0011] In the chemical formula 1,

[0012] x is greater than 0 and less than or equal to 0.3,

[0013] [Chemical formula 2]

[0014] Sn 4+ 1-y Cu + 2y O 2-y

[0015] In the chemical formula 2,

[0016] y is greater than 0 and less than or equal to 0.3,

[0017] [Chemical formula 3]

[0018] Sn 4+ 1-z Ni 2+ z O 2-z

[0019] In the chemical formula 3,

[0020] z is greater than 0 and less than or equal to 0.3.

[0021] In one embodiment, the nanoparticle may be formed using the core and the ligand, and the core may be formed using the first core compound.

[0022] In one embodiment, the relative Sn content of the nanoparticles is measured by X-ray photoelectron spectroscopy (XPS). 4+ 3 d 5 / 2 Sn 2+ 3 d 5 / 2 The ratio of the peak intensities of can be greater than 0 and less than or equal to 0.6.

[0023] In one embodiment, the absolute quantum yield of the nanoparticles may be greater than 0% and less than or equal to 5%.

[0024] In one embodiment, the nanoparticle may be formed using the core and the ligand, and the core may be formed using at least one of the first core compound, the second core compound, and the third core compound.

[0025] In one embodiment, the ligand may include oleic acid or oleylamine.

[0026] In one embodiment, the ligand may be chemically bound to the core.

[0027] In one embodiment, the nanoparticles may be doped with metal atoms.

[0028] In one embodiment, the metal atoms may include at least one of Zn, Mg, Li and Na.

[0029] In one embodiment, the functional layer may include: a hole transport region arranged on the first electrode; a light-emitting layer arranged on the hole transport region; and an electron transport region arranged between the light-emitting layer and the second electrode, wherein the electron transport region may include the nanoparticles.

[0030] In one embodiment, the electron transport region may include: an electron transport layer arranged on the light emitting layer; and an electron injection layer arranged on the electron transport layer, wherein at least one of the electron transport layer and the electron injection layer may include the nanoparticles.

[0031] In one embodiment, the light emitting layer may include quantum dots.

[0032] According to an embodiment of the present invention, an ink composition includes nanoparticles and a solvent, wherein the nanoparticles include a core and a ligand, and the core includes at least one of a first core compound represented by Chemical Formula 1, a second core compound represented by Chemical Formula 2, and a third core compound represented by Chemical Formula 3.

[0033] In one embodiment, the solvent may be a hydrophobic solvent.

[0034] In one embodiment, the nanoparticle may be formed using the core and the ligand, and the core may be formed using the first core compound.

[0035] In one embodiment, the nanoparticle may be formed using the core and the ligand, and the core may be formed using the second core compound or the third core compound.

[0036] According to one embodiment of the present invention, a display device includes: a base layer; a circuit layer arranged on the base layer; and a display element layer arranged on the circuit layer and including a light-emitting element, wherein the light-emitting element includes: a first electrode; a second electrode arranged on the first electrode; and an electron transport region arranged between the first electrode and the second electrode and including nanoparticles, wherein the nanoparticles include a core and a ligand, and the core includes at least one of a first core compound represented by the chemical formula 1, a second core compound represented by the chemical formula 2, and a third core compound represented by the chemical formula 3.

[0037] In one embodiment, the light emitting element may further include: a hole transport region disposed on the first electrode; and a light emitting layer disposed between the hole transport region and the electron transport region.

[0038] In one embodiment, the light emitting layer may include quantum dots.

[0039] In one embodiment, the electron transport region may include: an electron transport layer arranged on the light emitting layer; and an electron injection layer arranged on the electron transport layer, wherein at least one of the electron transport layer and the electron injection layer may include the nanoparticles.

[0040] The light-emitting element of one embodiment can exhibit improved element characteristics of high light-emitting efficiency and long life.

[0041] The ink composition of one embodiment can contribute to improving the light emission efficiency and extending the life of a light emitting element.

[0042] A display device according to an embodiment may include a light-emitting element having excellent light-emitting efficiency and lifespan. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is a perspective view showing a display device according to an embodiment.

[0044] Figure 2 is shown corresponding to Figure 1 A cross-sectional view of a portion taken along line I-I'.

[0045] Figure 3 is a plan view showing a display device according to an embodiment.

[0046] Figure 4 is shown corresponding to Figure 3 A cross-sectional view of a portion taken along line II-II'.

[0047] Figure 5 is a cross-sectional view showing a light emitting element according to an embodiment.

[0048] Figure 6 is a diagram showing a portion of an ink composition according to an embodiment.

[0049] Description of Reference Numerals

[0050] DD: Display Device

[0051] ED: Light-emitting element EL1: First electrode

[0052] EL2: Second electrode HTR: Hole transport region

[0053] EML: Emitting Layer ETR: Electron Transport Region

[0054] NP: nanoparticle LD: ligand

[0055] CO: core SL: solvent DETAILED DESCRIPTION

[0056] The present invention can be subjected to various changes and can have multiple forms, and specific embodiments are exemplarily shown in the drawings and described in detail in the text. However, this does not limit the present invention to a specific disclosed form, and it should be understood that it includes all changes, equivalents and substitutes included in the concept and technical scope of the present invention.

[0057] In this specification, when a certain component (or region, layer, part, etc.) is mentioned as being "on" another component, "connected to" another component, or "combined with" another component, it means that it can be directly arranged on the other component or directly connected / combined with the other component, or a third component may be arranged between them.

[0058] The same reference numerals refer to the same components. In addition, in the drawings, the thickness, ratio and size of the components are exaggerated in order to effectively illustrate the technical content. "And / or" includes all combinations of more than one that can be defined for the relevant components.

[0059] The terms "first", "second" and the like may be used to describe various constituent elements, but the constituent elements shall not be limited by the terms. The terms are used only for the purpose of distinguishing one constituent element from other constituent elements. For example, without departing from the scope of the present invention, the first constituent element may be named as the second constituent element, and similarly, the second constituent element may be named as the first constituent element. Singular expressions include plural expressions if they do not clearly indicate different meanings in the context.

[0060] Furthermore, terms such as “below”, “lower side”, “above”, and “upper side” are used to describe the relationship between components shown in the drawings. These terms are relative concepts and are described based on the directions shown in the drawings.

[0061] The terms "including" or "having" should be understood to indicate the existence of the features, numbers, steps, operations, constituent elements, parts or their combinations recorded in the specification, rather than excluding the existence or additional possibility of one or more other features, numbers, steps, operations, constituent elements, parts or their combinations in advance.

[0062] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this specification have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. Furthermore, terms that are the same as those defined in commonly used dictionaries should be interpreted as having the same meanings as those in the context of the relevant technology, and herein, unless explicitly defined, should not be interpreted as having overly ideal or overly formal meanings.

[0063] Hereinafter, a light emitting element and a display device including the light emitting element according to an embodiment of the present invention will be described with reference to the accompanying drawings. Figure 1 is a perspective view showing a display device according to an embodiment.

[0064] Reference Figure 1 The display device DD of an embodiment may be a device activated according to an electrical signal. For example, the display device DD may be a large device such as a television, a monitor, or an external billboard. Also, the display device DD may be a small or medium-sized electronic device such as a personal computer, a notebook computer, a personal digital terminal, a car navigation unit, a game console, a smart phone, a tablet computer, and a camera. Moreover, these are only proposed as embodiments, and other display devices may also be used as long as they do not depart from the concept of the present invention.

[0065] The display device DD may display an image (or video) through a display surface DD-IS. The display surface DD-IS may be parallel to a plane defined by the first direction axis DR1 and the second direction axis DR2. The display surface DD-IS may include a display area DA and a non-display area NDA.

[0066] Pixels PX may be arranged in the display area DA, and pixels PX may not be arranged in the non-display area NDA. The non-display area NDA may be defined along the edge of the display surface DD-1S. The non-display area NDA may surround the display area DA. However, the embodiment is not limited thereto, and the non-display area NDA may be omitted, or the non-display area NDA may be arranged only on one side of the display area DA.

[0067] exist Figure 1 , a display device DD equipped with a flat display surface DD-IS is shown, but the embodiment is not limited thereto. The display device DD may also include a curved display surface or a stereoscopic display surface. The stereoscopic display surface may also include a plurality of display areas indicating different directions from each other.

[0068] exist Figure 1 The first direction axis DR1, the second direction axis DR2 and the third direction axis DR3 are shown in the following drawings, but the directions indicated by the first direction axis DR1, the second direction axis DR2 and the third direction axis DR3 described in this specification are relative concepts and can be converted into other directions. In addition, the directions indicated by the first direction axis DR1, the second direction axis DR2 and the third direction axis DR3 can describe the first direction, the second direction and the third direction, and the same reference numerals can be used. In this specification, the first direction axis DR1 and the second direction axis DR2 can be orthogonal to each other, and the third direction axis DR3 can be a normal direction to the plane defined by the first direction axis DR1 and the second direction axis DR2. In this specification, "plane" means a plane defined by the first direction axis DR1 and the second direction axis DR2, and "section" means a surface perpendicular to the plane defined by the first direction axis DR1 and the second direction axis DR2 and parallel to the third direction axis DR3. The thickness direction of the display device DD can be a direction parallel to the third direction axis DR3 as the normal direction to the plane defined by the first direction axis DR1 and the second direction axis DR2.

[0069] In the present specification, the upper surface (or front surface) and the lower surface (or rear surface) of the components constituting the display device DD may be defined with reference to the third direction DR3. More specifically, in one component, the surface relatively adjacent to the display surface DD-IS of the two surfaces facing each other with reference to the third direction DR3 may be defined as the front surface (or upper surface), and the surface relatively separated from the display surface DD-IS may be defined as the rear surface (or lower surface). Furthermore, in the present specification, the upper portion (or upper side) and the lower portion (or lower side) may be defined with reference to the third direction DR3, and the upper portion (or upper side) may be defined as the direction close to the display surface DD-IS, and the lower portion (or lower side) may be defined as the direction away from the display surface DD-IS.

[0070] In this specification, when a certain component is “directly arranged / directly formed” on another component, it means that no third component is arranged between the certain component and the other component. In other words, when a certain component is “directly arranged / directly formed” on another component, it means that the certain component and the other component are “in contact”.

[0071] Figure 2 is shown corresponding to Figure 1A cross-sectional view of a portion taken along line I-I'. Figure 2 It may be a cross-sectional view of a display device according to an embodiment.

[0072] The display device DD may include a display panel DP and an optical layer PP arranged on the display panel DP. The display panel DP may include a base layer BS, a circuit layer DP-CL arranged on the base layer BS, a display element layer DP-EL arranged on the circuit layer DP-CL, and an encapsulation layer TFE arranged on the display element layer DP-EL.

[0073] The display panel DP may be a structure that substantially generates an image. 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.

[0074] The base layer BS may be a component that provides a base surface on which the circuit layer DP-CL is arranged. The base layer BS may be a rigid substrate or a flexible substrate that can be bent, folded, rolled, etc. The base layer BS may be a glass substrate, a metal substrate, a polymer substrate, etc. However, the embodiment is not limited thereto, and the base layer BS may be an inorganic layer, an organic layer, or a composite material layer.

[0075] The circuit layer DP-CL may be arranged on the base layer BS. The circuit layer DP-CL may include an insulating layer, a semiconductor pattern, a conductive pattern, and a signal line. After the insulating layer, the semiconductor layer, and the conductive layer are formed on the base layer BS by coating, deposition, etc., the insulating layer, the semiconductor layer, and the conductive layer may be selectively patterned by multiple photolithography processes. Thereafter, the semiconductor pattern, the conductive pattern, and the signal line included in the circuit layer DP-CL may be formed.

[0076] The display element layer DP-EL may be disposed on the circuit layer DP-CL. The display element layer DP-EL may include a pixel definition film PDL (see Figure 4 ) and the first light emitting element ED-1, the second light emitting element ED-2 and the third light emitting element ED-3 (refer to Figure 4 ). For example, the display element layer DP-EL may include an organic light-emitting substance, an inorganic light-emitting substance, an organic-inorganic light-emitting substance, a quantum dot, a quantum rod, a micro-LED or a nano-LED. More specifically, the display element layer DP-EL may include a quantum dot as a light-emitting substance.

[0077] The encapsulation layer TFE can protect the display element layer DP-EL from foreign matter such as moisture, oxygen and dust particles. The encapsulation layer TFE may include at least one inorganic layer. The encapsulation layer TFE may include a structure in which an inorganic layer, an organic layer and an organic layer are sequentially stacked.

[0078] The optical layer PP may be disposed on the display panel DP to control reflected light from the display panel DP caused by external light. For example, the optical layer PP may include a polarizing layer (not shown), or may include a color filter layer CFL (refer to Figure 4 ). In addition, unlike what is shown in the drawings, the optical layer PP may also be omitted.

[0079] Figure 3 is a plan view showing a display device according to an embodiment. Figure 4 is shown corresponding to Figure 3 A cross-sectional view of a portion taken along line II-II'. Figure 4 This may be a cross-sectional view showing a display device according to an embodiment.

[0080] Reference Figure 3 and Figure 4 , the display device DD may include a peripheral area NPXA and light-emitting areas PXA-R, PXA-G, and PXA-B. Each of the light-emitting areas PXA-R, PXA-G, and PXA-B may be an area where light generated from each of the light-emitting elements ED-1, ED-2, and ED-3 is emitted. The area of ​​each of the light-emitting areas PXA-R, PXA-G, and PXA-B may be different from each other, and in this case, the area may represent an area on a plane.

[0081] The light emitting regions PXA-R, PXA-G, and PXA-B may be divided into a plurality of groups according to the colors of the lights generated from the light emitting elements ED-1, ED-2, and ED-3. Figure 3 and Figure 4 , three light emitting regions PXA-R, PXA-G, and PXA-B emitting red light, green light, and blue light are exemplarily shown. For example, a display device DD of an embodiment may include a red light emitting region PXA-R, a green light emitting region PXA-G, and a blue light emitting region PXA-B that are distinguished from each other.

[0082] The display panel DP may include a plurality of light emitting elements ED-1, ED-2, ED-3 that emit light of different wavelength regions from each other. The light emitting element ED may include a plurality of light emitting elements. The light emitting element ED may include a first light emitting element ED-1, a second light emitting element ED-2, and a third light emitting element ED-3. The plurality of light emitting elements ED-1, ED-2, ED-3 may emit light of different colors from each other. 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 embodiment 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 of the same wavelength region, or at least one may emit light of a different wavelength region.

[0083] exist Figure 3 and Figure 4 In the display device DD of an embodiment shown, the light-emitting regions PXA-R, PXA-G, and PXA-B may have different areas according to the colors of the light emitted from the light-emitting layers EML-B, EML-G, and EML-R of the light-emitting elements ED-1, ED-2, and ED-3. The blue light-emitting region PXA-B of the first light-emitting element ED-1 that emits blue light may have the largest area, and the green light-emitting region PXA-G of the second light-emitting element ED-2 that emits green light may have the smallest area. However, the embodiments are not limited thereto, and the light-emitting regions PXA-R, PXA-G, and PXA-B may also emit light of other colors in addition to red light, green light, and blue light. Alternatively, the light-emitting regions PXA-R, PXA-G, and PXA-B may have the same area, or may be arranged in different areas as shown in FIG. Figure 3 The different area ratios shown provide light emitting regions PXA-R, PXA-G, PXA-B.

[0084] Each of the light-emitting regions PXA-R, PXA-G, and PXA-B may be a region divided by a pixel definition film PDL. The peripheral region NPXA is a region between adjacent light-emitting regions PXA-R, PXA-G, and PXA-B, and may be a region corresponding to the pixel definition film PDL. Each of the light-emitting regions PXA-R, PXA-G, and PXA-B may correspond to a pixel.

[0085] The pixel definition film PDL may define the light emitting regions PXA-R, PXA-G, and PXA-B. The light emitting regions PXA-R, PXA-G, and PXA-B and the peripheral region NPXA may be divided by the pixel definition film PDL.

[0086] The blue light emitting regions PXA-B and the red light emitting regions PXA-R may be alternately arranged along the first direction axis DR1 to constitute a first group PXG1. The green light emitting regions PXA-G may be arranged along the first direction axis DR1 to constitute a second group PXG2. The first group PXG1 may be arranged spaced relative to the second group PXG2 in the direction of the second direction axis DR2. The first group PXG1 and the second group PXG2 may be provided in plural, respectively. The first group PXG1 and the second group PXG2 may be alternately arranged with each other along the second direction axis DR2.

[0087] One red light emitting region PXA-R may be arranged in a direction of the fourth direction axis DR4, spaced from one green light emitting region PXA-G. One blue light emitting region PXA-B may be arranged in a direction of the fifth direction axis DR5, spaced from one green light emitting region PXA-G. The fourth direction axis DR4 may be a direction between the first direction axis DR1 and the second direction axis DR2. The fifth direction axis DR5 may intersect with the fourth direction axis DR4, and may be a direction inclined relative to the second direction axis DR2.

[0088] In addition, the arrangement structure of the light emitting regions PXA-R, PXA-G, and PXA-B is not limited to Figure 3 For example, in the light-emitting regions PXA-R, PXA-G, and PXA-B, the red light-emitting regions PXA-R, the green light-emitting regions PXA-G, and the blue light-emitting regions PXA-B may also be alternately arranged in sequence along the first direction axis DR1. Moreover, on a plane, the shapes of the light-emitting regions PXA-R, PXA-G, and PXA-B are not limited to the shapes shown in the figure, and may be defined as shapes different from the shapes shown in the figure.

[0089] exist Figure 4 In the embodiment, the base layer BS may include a single layer or a multi-layer structure. For example, the base layer BS may include a first synthetic resin layer, an intermediate layer of a multi-layer or single-layer structure, and a second synthetic resin layer stacked in sequence. 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 disposed on the silicon oxide layer, but 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.

[0090] Each of the first synthetic resin layer and the second synthetic resin layer may include a polyimide resin. Furthermore, each of the first synthetic resin layer and the second synthetic resin layer may include at least one of an acrylate resin, a methacrylate resin, a polyisoprene resin, a vinyl resin, an epoxy resin, a urethane resin, a cellulose resin, a siloxane resin, a polyamide resin, and a perylene resin. In this specification, a "~~" type resin means including a "~~" type functional group.

[0091] The circuit layer DP-CL may be arranged on the base layer BS, and the circuit layer DP-CL may include a plurality of transistors (not shown). The transistors (not shown) may include control electrodes, input electrodes, and output electrodes, respectively. For example, the circuit layer DP-CL may include a switching transistor and a driving transistor for driving the light-emitting elements ED-1, ED-2, and ED-3 of the display element layer DP-EL.

[0092] The display element layer DP-EL may include a pixel definition 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. The pixel definition film PDL may define a pixel opening portion OH. The pixel definition film PDL may divide the first light emitting element ED-1, the second light emitting element ED-2, and the third light emitting element ED-3. The light emitting 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 arranged in the pixel opening portion OH defined by the pixel definition film PDL and divided.

[0093] The pixel definition film PDL can be formed of a polymer resin. For example, the pixel definition film PDL can be formed to include a polyacrylate resin or a polyimide resin. In addition, the pixel definition film PDL can also include inorganic substances other than the polymer resin. In addition, the pixel definition film PDL can be formed to include a light absorbing substance, or can be formed to include a black pigment or a black dye. The pixel definition film PDL formed to include a black pigment or a black dye can realize a black pixel definition film. When forming the pixel definition film PDL, carbon black or the like can be used as a black pigment or a black dye, but the embodiment is not limited to this.

[0094] Furthermore, the pixel definition film PDL may be formed of an inorganic material. For example, the pixel definition film PDL may be formed of silicon nitride (SiN x ), silicon oxide (SiO x ), silicon oxynitride (SiO x N y ) and other inorganic substances.

[0095] The light emitting element ED may include a plurality of light emitting elements. The light emitting element ED may include a first light emitting element ED-1, a second light emitting element ED-2, and a third light emitting element ED-3. Each of the light emitting elements ED-1, ED-2, and ED-3 may include a first electrode EL1, a hole transport region HTR-1, HTR-2, and HTR-3 arranged on the first electrode EL1, a light emitting layer EML-B, EML-G, and EML-R arranged on the hole transport region HTR-1, HTR-2, and HTR-3, an electron transport region ETR-1, ETR-2, and ETR-3 arranged on the light emitting layer EML-B, EML-G, and EML-R, and a second electrode EL2 arranged on the electron transport region ETR-1, ETR-2, and ETR-3. The light emitting layer EML-B, EML-G, and EML-R may include a first light emitting layer EML-B, a second light emitting layer EML-G, and a third light emitting layer EML-R. The hole transport region HTR may include a first hole transport region HTR-1, a second hole transport region HTR-2, and a third hole transport region HTR-3. The electron transport region ETR may include a first electron transport region ETR-1, a second electron transport region ETR-2, and a third electron transport region ETR-3.

[0096] The first electrode EL1 may be exposed from the pixel opening OH of the pixel definition film PDL. The first electrode EL1 has conductivity. The first electrode EL1 may be formed of a metal material, a metal alloy, or a conductive compound. The first electrode EL1 may be a cathode or an anode. However, the embodiment is not limited thereto. Furthermore, the first electrode EL1 may be a pixel electrode. The first electrode EL1 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. 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.

[0097] When the first electrode EL1 is a transmissive electrode, the first electrode EL1 may include a transparent metal oxide (e.g., indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO)). When the first electrode EL1 is a semi-transmissive 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, or a compound or mixture thereof (e.g., a mixture of Ag and Mg) or a material having a multilayer structure including two or more selected therefrom (e.g., LiF / Ca (a stacked structure of LiF and Ca) or LiF / Al (a stacked structure of LiF and Al)). Alternatively, the first electrode EL1 may be a multilayer structure including a reflective film or a semi-transmissive film formed of the above-mentioned substances and a transparent conductive film formed using indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), etc. For example, the first electrode EL1 may have a three-layer structure of ITO / Ag / ITO, but is not limited thereto. Furthermore, 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, etc., but the embodiment is not limited thereto. The thickness of the first electrode EL1 may be about 1000 Å. to about For example, the thickness of the first electrode EL1 may be about to about

[0098] The second electrode EL2 may be a common electrode. The second electrode EL2 may be an anode or a cathode, but the embodiment is not limited thereto. For example, when the first electrode EL1 is an anode, the second electrode EL2 may be a cathode, and when the first electrode EL1 is a cathode, the second electrode EL2 may be an anode. 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 selected from two or more thereof, a mixture selected from two or more thereof, or an oxide thereof.

[0099] The second electrode EL2 may be a transmissive electrode, a semi-transmissive electrode or a reflective electrode. When the second electrode EL2 is a transmissive electrode, the second electrode EL2 may be formed using a transparent metal oxide (e.g., indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO)) or the like.

[0100] In the case where the second electrode EL2 is a semi-transmissive 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, or a compound or mixture thereof (e.g., AgMg, AgYb, or MgYb) or a material having a multilayer structure including two or more selected therefrom (e.g., LiF / Ca (a stacked structure of LiF and Ca) or LiF / Al (a stacked structure of LiF and Al)). Alternatively, the second electrode EL2 may be a multilayer structure including a reflective film or a semi-transmissive film formed of the above-mentioned substances and a transparent conductive film formed using indium tin oxide (ITO: indium tin oxide), indium zinc oxide (IZO: indium zinc oxide), zinc oxide (ZnO: zinc oxide), indium tin zinc oxide (ITZO: indium tin zinc oxide), or the like. 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 an oxide of the above-mentioned metal material.

[0101] Although not shown, the second electrode EL2 may be connected to the auxiliary electrode. If the second electrode EL2 is connected to the auxiliary electrode, the resistance of the second electrode EL2 may be reduced.

[0102] Light-emitting layers EML-B, EML-G, and EML-R may be arranged between the first electrode EL1 and the second electrode EL2. The first light-emitting element ED-1 may include a first light-emitting layer EML-B, the second light-emitting element ED-2 may include a second light-emitting layer EML-G, and the third light-emitting element ED-3 may include a third light-emitting layer EML-R. The first light-emitting layer EML-B may include a first quantum dot QD-C1. The second light-emitting layer EML-G may include a second quantum dot QD-C2. The third light-emitting layer EML-R may include a third quantum dot QD-C3.

[0103] The quantum dots QD-C1, QD-C2, and QD-C3 included in the light-emitting layers EML-B, EML-G, and EML-R may be stacked to form a layer. Figure 4 In the figure, the case where the quantum dots QD-C1, QD-C2, and QD-C3 having a circular cross-section are arranged to roughly form two layers is exemplified, but the embodiment is not limited thereto. For example, the arrangement of the quantum dots QD-C1, QD-C2, and QD-C3 may be different depending on the thickness of the light-emitting layers EML-B, EML-G, and EML-R, the shapes of the quantum dots QD-C1, QD-C2, and QD-C3 included in the light-emitting layers EML-B, EML-G, and EML-R, and the average diameter of the quantum dots QD-C1, QD-C2, and QD-C3. Specifically, in the light-emitting layers EML-B, EML-G, and EML-R, the quantum dots QD-C1, QD-C2, and QD-C3 may be aligned in a manner adjacent to each other to form one layer, or may be aligned in a manner to form multiple layers such as two layers, three layers, and the like.

[0104] The first quantum dot QD-C1 of the first light-emitting element ED-1 can emit blue light. The second quantum dot QD-C2 of the second light-emitting element ED-2 can emit green light. The third quantum dot QD-C3 of the third light-emitting element ED-3 can emit red light. Quantum dots QD-C1, QD-C2, and QD-C3 can respectively include a core (not shown) and a shell (not shown) surrounding the core. Accordingly, quantum dots QD-C1, QD-C2, and QD-C3 can respectively include a core-shell structure. The cores of quantum dots QD-C1, QD-C2, and QD-C3 may include substances different from each other. In contrast, the cores of quantum dots QD-C1, QD-C2, and QD-C3 may include the same substance. Alternatively, two cores selected from the cores of quantum dots QD-C1, QD-C2, and QD-C3 may include the same substance, and the remaining core may include a different substance.

[0105] exist Figure 4 In the figure, the diameters of each of the first quantum dot QD-C1, the second quantum dot QD-C2, and the third quantum dot QD-C3 are shown to be similar to each other, but the embodiment is not limited thereto. The diameters of each of the first quantum dot QD-C1, the second quantum dot QD-C2, and the third quantum dot QD-C3 may be different from each other. For example, the average diameter of the first quantum dot QD-C1 of the first light-emitting element ED-1 that emits light in a relatively short wavelength region may be relatively small compared to the second quantum dot QD-C2 of the second light-emitting element ED-2 that emits light in a relatively long wavelength region and the third quantum dot QD-C3 of the third light-emitting element ED-3. The average diameter is equivalent to the arithmetic mean of the particle diameters of multiple quantum dots. The particle diameter of the quantum dot may be the average of the widths of the quantum dot particles on the cross section.

[0106] In one embodiment, the electron transport regions ETR-1, ETR-2, and ETR-3 may include nanoparticles NP described below (see Figure 6 ). In the following text, nanoparticles NP (refer to Figure 6 ) for a more detailed description.

[0107] The hole transport regions HTR-1, HTR-2, and HTR-3 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 arranged at the pixel opening OH and divided. The first light-emitting element ED-1 may include a first hole transport region HTR-1, the second light-emitting element ED-2 may include a second hole transport region HTR-2, and the third light-emitting element ED-3 may include a third hole transport region HTR-3.

[0108] Each of the hole transport regions HTR-1, HTR-2, and HTR-3 may have a single-layer structure formed of a single substance, a single-layer structure formed of a plurality of substances different from each other, or a multi-layer structure having a plurality of layers formed of a plurality of substances different from each other. For example, the thickness of each of the first hole transport region HTR-1, the second hole transport region HTR-2, and the third hole transport region HTR-3 may be about to about The thickness of each of the first hole transport region HTR-1, the second hole transport region HTR-2, and the third hole transport region HTR-3 may be about 100 Å. to about For example, it can be about to about

[0109] The first hole transport region HTR-1, the second hole transport region HTR-2, and the third hole transport region HTR-3 may also include a known hole injection material and / or a known hole transport material. For example, the first hole transport region HTR-1, the second hole transport region HTR-2, and the third hole transport region HTR-3 may include a phthalocyanine compound such as copperphthalocyanine, 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: N 1 ,N 1 '-([1,1'-biphenyl]-4,4'-diyl)bis(N 1-phenyl-N 4 ,N 4 '-di-m-tolylbenzene-1,4-diam ine)), 4,4',4"-[tris(3-methylphenyl)phenylamino]triphenylamine (m-MTDATA: 4,4',4"-[tris(3-methylphenyl)phenylamino]triphenylamine), 4,4',4"-tris(N,N-diphenylamino)triphenylamine (TDATA: 4,4'4"-Tris(N,N-diphenylamino)triphenylamine), 4,4',4"-tris[N-(2-naphthyl)-N-phenylamino]-triphenylamine (2-TNAT A: 4,4',4"-tris[N-(2-naphthyl)-N-phenylamino]-triphenylamine), PEDOT / PSS: Poly(3,4-ethylenedioxythiophene) / Poly(4-styrenesulfonate)), PANI / DBSA: Polyaniline / Dodecylbenzenesulfonic acid), polyaniline / camphorsulfonic acid (PANI / CSA: Polyaniline / Camphorsulfonicacid), polyaniline / poly(4-styrenesulfonate) (PANI / PSS: Polyaniline / Poly(4-styrenesulfonate)), N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPB: N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine), triphenylamine-containing polyetherketone (TPAPEK) , 4-Isopropyl-4'-methyldiphenyliodonium[Tetrakis(pentafluorophenyl)borate], dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HATCN: dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile), etc.

[0110] Furthermore, the first hole transport region HTR-1, the second hole transport region HTR-2, and the third hole transport region HTR-3 may include carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole, fluorene derivatives, such as N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD: N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine), 4,4' Triphenylamine derivatives such as 4,4',4"-tris(N-carbazolyl)triphenylamine (TCTA: 4,4',4"-tris(N-carbazolyl)triphenylamine), N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPB: N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine), 4,4'-cyclohexylenebis[N,N-bis(4-methylphenyl)aniline] (TAPC: 4,4'-Cyclohexylidene bis[N,N-bis(4-methylphenyl)benzenamine]), 4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl (HMTPD: 4,4'-Bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl), 9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole (CzSi: 9-(4-tert-Butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole phenylsilyl)-9H-carbazole), 9-phenyl-9H-3,9'-bicarbazole (CCP: 9-phenyl-9H-3,9'-bicarbazole), 1,3-bis(N-carbazolyl)benzene (mCP: 1,3-Bis(N-carbazolyl)benzene) or 1,3-bis(1,8-dimethyl-9H-carbazol-9-yl)benzene (mDCP: 1,3-bis(1,8-dimethyl-9H-carbazol-9-yl)benzene), etc.

[0111] The electron transport regions ETR-1, ETR-2, and ETR-3 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 arranged at the pixel opening OH and divided. The first light-emitting element ED-1 may include a first electron transport region ETR-1, the second light-emitting element ED-2 may include a second electron transport region ETR-2, and the third light-emitting element ED-3 may include a third electron transport region ETR-3.

[0112] Each of the first electron transport region ETR-1, the second electron transport region ETR-2, and the third electron transport region ETR-3 may have a single-layer structure formed of a single substance, a single-layer structure formed of a plurality of substances different from each other, or a multi-layer structure having a plurality of layers formed of a plurality of substances different from each other. For example, the thickness of each of the first electron transport region ETR-1, the second electron transport region ETR-2, and the third electron transport region ETR-3 may be about to about

[0113] The first electron transport region ETR-1, the second electron transport region ETR-2 and the third electron transport region ETR-3 may further include the nanoparticles NP (see Figure 6 ) and / or known electron injection materials other than ). For example, the electron transport region ETR may include an anthracene compound. Or, for example, the first electron transport region ETR-1, the second electron transport region ETR-2, and the third electron transport region ETR-3 may include tris(8-hydroxyquinoline)aluminum (Alq 3:Tris(8-hydroxyquinolinato)aluminum、1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene、2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine、2-(4-(N-phenylbenzimidazol-1-yl)phenyl)-9,10-dinaphthylanthracene(2- (4-(N-phenylbenzoimidazol-1-yl)phenyl)-9,10-dinaphthylanthracene), 1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi: 1,3,5-Tri(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP: 2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline), 4,7 -Diphenyl-1,10-phenanthroline (Bphen: 4,7-Diphenyl-1,10-phenanthroline), 3-(4-biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ: 3-(4-Biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole), 4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triaz ole), 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (tBu-PBD: 2-(4-Biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), bis(2-methyl-8-hydroxyquinolinolato-N1,O8)-(1,1'-biphenyl-4-olato)aluminum (BAlq: Bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-Biphenyl-4-olato)aluminum), bis(benzoquinolinolato-10-hydroxy)beryllium (Bebq 2:berylliumbis(benzoquinolin-10-olate))、9,10-di(naphthalene-2-yl)anthracene(AND:9,10-di(naphthalene-2-yl)anthracene)、1,3-bis[3,5-di(pyridin-3-yl)phenyl]benzene(BmPyPhB:1,3-Bis[3,5-di(pyridin-3-yl)phenyl]benzene)and mixtures thereof. Alternatively, the electron transport region ETR may include 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP: 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), diphenyl(4-(triphenylsilyl)phenyl)phosphine oxide (TSPO1: diphenyl(4-(triphenylsilyl)phenyl)phosphine oxide), and 4,7-diphenyl-1,10-phenanthroline (Bphen: 4,7-diphenyl-1,10-phenanthroline), etc.

[0114] The encapsulation layer TFE may include at least one inorganic film (hereinafter, referred to as an encapsulation inorganic film). Also, the encapsulation layer TFE may include at least one organic film (hereinafter, referred to as an encapsulation organic film) and at least one encapsulation inorganic film.

[0115] The encapsulated inorganic film can protect the display element layer DP-EL from moisture / oxygen, and the encapsulated organic film can protect the display element layer DP-EL from foreign matter such as dust particles. The encapsulated inorganic film may include silicon nitride, silicon nitride oxide, silicon oxide, titanium oxide or aluminum oxide, etc., but is not particularly limited. The encapsulated organic film may include acrylic compounds, epoxy compounds, etc. The encapsulated organic film may include an organic substance capable of photopolymerization, and is not particularly limited.

[0116] The optical layer PP may include a base substrate BL and a color filter layer CFL. The base substrate BL may be a component providing a base surface on which the color filter layer CFL is arranged. The base substrate BL may be a glass substrate, a metal substrate, a plastic substrate, etc. However, the embodiment is not limited thereto, and the base substrate BL may be an inorganic layer, an organic layer, or a composite material layer.

[0117] The color filter layer CFL may include a first color filter CF-B, a second color filter CF-G, and a third color filter CF-R. The first color filter CF-B, the second color filter CF-G, and the third color 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 color filter CF-B may be a blue color filter, the second color filter CF-G may be a green color filter, and the third color filter CF-R may be a red color filter. The first color filter CF-B, the second color filter CF-G, and the third color filter CF-R may be arranged to correspond to the blue light emitting area PXA-B, the green light emitting area PXA-G, and the red light emitting area PXA-R, respectively.

[0118] Each of the first color filter CF-B, the second color filter CF-G, and the third color filter CF-R may include a polymer photosensitive resin and a pigment or dye. The first color filter CF-B may include a blue pigment or a blue dye, the second color filter CF-G may include a green pigment or a green dye, and the third color filter CF-R may include a red pigment or a red dye. However, the embodiment is not limited thereto, and the first color filter CF-B may not include a pigment or a dye. The first color filter CF-B may include a polymer photosensitive resin without including a pigment or a dye. The first color filter CF-B may be transparent. The first color filter CF-B may be formed of a transparent photosensitive resin.

[0119] 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 color filter CF-B, the second color filter CF-G, and the third color filter CF-R. The buffer layer BFL may be an inorganic layer including at least one of silicon nitride, silicon oxide, and silicon oxynitride. The buffer layer BFL may be formed of a single layer or multiple layers.

[0120] Also, the second color filter CF-G and the third color filter CF-R may be yellow color filters. The second color filter CF-G and the third color filter CF-R may also be integrally provided without being distinguished from each other.

[0121] Although not shown, the color filter layer CFL may further include a light shielding portion (not shown). The light shielding portion may be a black matrix. The light shielding portion may be formed to include an organic light shielding material or an inorganic light shielding material including a black pigment or a black dye. The light shielding portion may prevent light leakage and may demarcate the boundaries between adjacent color filters CF-B, CF-G, and CF-R.

[0122] Figure 5 1 is a cross-sectional view showing a light emitting element ED according to an embodiment. Figure 5 The light emitting element ED described above can be similarly applied to Figure 4At 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.

[0123] Reference Figure 5 , the light emitting element ED includes a first electrode EL1, a functional layer FCL and a second electrode EL2 stacked in sequence. The functional layer FCL may include a hole transport region HTR, a light emitting layer EML and an electron transport region ETR. The hole transport region HTR may include a hole injection layer HIL and a hole transport layer HTL. The hole injection layer HIL may be arranged on the first electrode EL1, and the hole transport layer HTL may be arranged on the hole injection layer HIL. The electron transport region ETR may include an electron transport layer ETL and an electron injection layer EIL. The electron injection layer EIL may be arranged on the electron transport layer ETL, and the second electrode EL2 may be arranged on the electron injection layer EIL. In the light emitting element ED, the functional layer FCL includes nanoparticles NP of an embodiment. In the light emitting element ED, the electron transport region ETR may include nanoparticles NP of an embodiment. At least one of the electron transport layer ETL and the electron injection layer EIL may include nanoparticles NP of an embodiment. Specifically, as Figure 5 As shown, the electron transport layer ETL may include the nanoparticles NP of an embodiment. Alternatively, each of the electron transport layer ETL and the electron injection layer EIL may include the nanoparticles NP of an embodiment. The electron transport region ETR including the nanoparticles NP of an embodiment may improve the difference between the speed of electron injection and transfer and the speed of hole injection and transfer, thereby contributing to improving the luminous efficiency of the light-emitting element ED.

[0124] The light emitting layer EML may include quantum dots QD-C. Hereinafter, the description of the quantum dots QD-C may be applied to the same Figure 4 The first quantum dot QD-C1, the second quantum dot QD-C2 and the third quantum dot QD-C3 are shown.

[0125] In this specification, quantum dot QD-C refers to a crystal of a semiconductor compound. The quantum dot QD-C can emit light of various luminescent wavelengths depending on the size of the crystal. For example, the diameter of the quantum dot QD-C can be about 1nm to 10nm.

[0126] Quantum dot QD-C can be synthesized by wet chemical process, metal organic chemical deposition process, molecular beam epitaxy process or similar process. The wet chemical process is a method of growing quantum dot QD-C particle crystals after mixing an organic solvent and a precursor substance. When the crystal grows, the organic solvent naturally acts as a dispersant coordinated on the surface of the quantum dot QD-C crystal, and the growth of the crystal can be controlled. Therefore, the wet chemical process is easier than vapor deposition methods such as metal organic chemical vapor deposition (MOCVD: Metal Organic Chemical Vapor Deposition) or molecular beam epitaxy (MBE: Molecular Beam Epitaxy), and the growth of quantum dot QD-C particles can be controlled by a low-cost process.

[0127] The quantum dots may include II-VI semiconductor compounds, I-II-VI semiconductor compounds, II-IV-VI semiconductor compounds, I-II-IV-VI semiconductor compounds, III-V semiconductor compounds, III-VI semiconductor compounds, I-III-VI semiconductor compounds, IV-VI semiconductor compounds, II-IV-V semiconductor compounds, IV elements or compounds, or any combination thereof. In this specification, "Group" refers to a group of the IUPAC periodic table.

[0128] Examples of the II-VI semiconductor compounds may include binary compounds such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, etc., binary compounds such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, Ternary compounds of CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, etc., quaternary compounds such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, etc., or any combination thereof. In addition, the II-VI semiconductor compound may also include a Group I metal and / or a Group IV element. The I-II-VI semiconductor compound may be selected from CuSnS or CuZnS, and the II-IV-VI semiconductor compound may be selected from ZnSnS, etc. The I-II-IV-VI semiconductor compound may be selected from Cu 2 ZnSnS 2 , Cu 2 ZnSnS4 , Cu 2 ZnSnSe 4 、Ag 2 ZnSnS 2 and mixtures thereof.

[0129] Examples of the III-V semiconductor compounds may include binary compounds such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, etc., ternary compounds such as GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP, InNAs, InNSb, InPAs, InPSb, etc., quaternary compounds such as GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, etc., or any combination thereof. In addition, the III-V semiconductor compounds may also include Group II elements. Examples of the Group III-V semiconductor compound also including the Group II element may include InZnP, InGaZnP, InAlZnP, and the like.

[0130] Examples of the III-VI semiconductor compounds may include GaS, Ga 2 S 3 ,GaSe,Ga 2 Se 3 、GaTe、InS、InSe、In 2 Se 3 , InTe, etc., binary compounds such as InGaS 3 、InGaSe 3 or any combination thereof.

[0131] Examples of the I-III-VI group semiconductor compounds may include AgInS, AgInS 2 、AgInSe 2 、AgGaS、AgGaS 2 、AgGaSe 2 、CuInS、CuInS 2 、CuInSe 2 、CuGaS 2 、CuGaSe 2 、CuGaO2 、AgGaO 2 、AgAlO 2 Ternary compounds such as AgInGaS 2 、AgInGaSe 2 A quaternary compound or any combination thereof.

[0132] Examples of the IV-VI group semiconductor compounds may include binary compounds such as SnS, SnSe, SnTe, PbS, PbSe, PbTe, etc., ternary compounds such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, etc., quaternary compounds such as SnPbSSe, SnPbSeTe, SnPbSTe, etc., or any combination thereof.

[0133] Examples of the II-IV-V semiconductor compound may be selected from ZnSnP, ZnSnP 2 、ZnSnAs 2 、ZnGeP 2 、ZnGeAs 2 、CdSnP 2 、CdGeP 2 and ternary compounds in the group consisting of mixtures thereof.

[0134] The Group IV element or compound may include a single element compound such as Si, Ge, etc., a double element compound such as SiC, SiGe, etc., or any combination thereof.

[0135] Each element included in the multi-component compound such as the binary compound, the ternary compound, and the quaternary compound may exist in the particle at a uniform concentration or a non-uniform concentration. That is, the above chemical formula may represent the types of elements included in the compound, and the element ratios in the compound may be different. For example, AgInGaS 2 Can represent AgIn x Ga 1-x S 2 (x is a real number between 0 and 1).

[0136] In addition, the quantum dot QD-C may have a single structure or a core-shell dual structure in which the concentration of each element included in the corresponding quantum dot QD-C is uniform. For example, a substance included in the core and a substance included in the shell may be different.

[0137] The shell of the quantum dot QD-C may act as a protective layer for maintaining semiconductor properties by preventing chemical modification of the core and / or as a charging layer for imparting electrophoretic properties to the quantum dot. The shell may be a single layer or multiple layers. The interface between the core and the shell may have a concentration gradient in which the concentration of the element present in the shell is lower as it approaches the core.

[0138] Examples of the shell of the quantum dot QD-C may include metal or non-metal oxides, semiconductor compounds, or combinations thereof. Examples of the metal or non-metal oxides may include SiO 2 、Al 2 O 3 、TiO 2 、ZnO、MnO、Mn 2 O 3 , Mn 3 O 4 , CuO, FeO, Fe 2 O 3 , Fe 3 O 4 , CoO, Co 3 O 4 , NiO and other binary compounds, such as MgAl 2 O 4 、CoFe 2 O 4 、NiFe 2 O 4 、CoMn 2 O 4 Examples of the semiconductor compound may include III-VI semiconductor compounds, II-VI semiconductor compounds, III-V semiconductor compounds, I-III-VI semiconductor compounds, IV-VI semiconductor compounds, or any combination thereof as described in this specification. For example, the semiconductor compound may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaS, GaSe, AgGaS, AgGaS 2 , GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb or any combination thereof.

[0139] Each element included in the multi-component compound such as the binary compound, the ternary compound, etc. may exist in the particle at a uniform concentration or a non-uniform concentration. That is, the chemical formula may represent the types of elements included in the compound, and the element ratio in the compound may be different.

[0140] The quantum dots may have a full width at half maximum (FWHM) of the emission wavelength spectrum of about 45 nm or less, preferably about 40 nm or less, and more preferably about 30 nm or less, in which range the color purity or color reproducibility may be improved. Furthermore, since the light emitted by these quantum dots may be emitted in all directions, the wide viewing angle may be improved.

[0141] Furthermore, the quantum dots may be in the form of commonly used forms in the art, and more specifically may be in the form of spherical, pyramidal, multi-arm or cubic nanoparticles, nanotubes, nanowires, nanofibers, nanoplates, etc., although there is no particular limitation.

[0142] By adjusting the size of the quantum dots or adjusting the element ratio in the quantum dot compound, the energy band gap can be adjusted, so that light of multiple wavelength bands can be obtained in the quantum dot light-emitting layer. Therefore, a light-emitting element that emits light of multiple wavelengths can be realized by using quantum dots as described above (using quantum dots of different sizes from each other or making the element ratios in the quantum dot compound different). Specifically, the size of the quantum dots or the adjustment of the element ratio in the quantum dot compound can be selected in a manner to emit red light, green light and / or blue light. In addition, the quantum dots can be configured to combine multiple colors of light to emit white light.

[0143] Figure 6 is a diagram showing a portion of an ink composition according to an embodiment.

[0144] Figure 6 The ink composition IC shown can be used to form Figure 5 The material of the electron transport region ETR of the light emitting element ED shown. The method of forming the electron transport region ETR includes the steps of: bonding the ligand LD to the surface of the core CO dispersed in the solvent SL to form nanoparticles NP; providing the ink composition IC formed with the nanoparticles NP on the light emitting layer EML; and drying the solvent SL.

[0145] Refer to Figure 5 and Figure 6 , an ink composition IC of an embodiment includes nanoparticles NP and a solvent SL.

[0146] The nanoparticle NP includes a core CO and a ligand LD. The nanoparticle NP can be formed using the core CO and the ligand LD. The nanoparticle NP can be included in the electron transport region ETR and the speed of electron transport and transfer can be appropriately adjusted. If the difference between the speed of electron transfer and the speed of hole transfer is reduced by appropriately adjusting the speed of electron transport and transfer in the light-emitting element ED, the imbalance of charge in the element can be improved, thereby improving the efficiency and life of the element.

[0147] The nanoparticles NP may be doped with metal atoms. If the nanoparticles NP are doped with metal atoms, the electrons that can be transferred from the outside to the core CO of the nanoparticles NP can be blocked, thereby improving the stability of the nanoparticles NP. The metal atoms may include at least one of Zn, Mg, Li and Na. For example, the metal atom may be Mg.

[0148] The solvent SL is a substance that can disperse the nanoparticles NP. The solvent SL can play the role of a medium that can stably deposit the nanoparticles NP during the deposition process. The solvent SL can be hydrophobic. For example, the solvent SL can include hexane, cyclohexylbenzene (CHB: Cyclohexylbenzene) or hexadecane.

[0149] The core CO includes a metal oxide and is included in the electron transport region ETR to play a role in transporting electrons. The core CO includes at least one of a first core compound represented by the following chemical formula 1, a second core compound represented by the following chemical formula 2, and a third core compound represented by the following chemical formula 3. The core CO may be composed of at least one of the first core compound, the second core compound, and the third core compound. For example, the core CO may be composed of the first core compound. Alternatively, the core CO may be composed of the second core compound, or may be composed of the third core compound. The first core compound includes Sn forming a tetravalent cation, Sn forming a divalent cation, and an oxygen atom. The second core compound includes Sn forming a tetravalent cation, Cu forming a monovalent cation, and an oxygen atom. The third core compound includes Sn forming a tetravalent cation, Ni forming a divalent cation, and an oxygen atom.

[0150] [Chemical formula 1]

[0151] Sn 4+ 1-x Sn 2+ x O 2-x

[0152] In Chemical Formula 1, x is greater than 0 and less than or equal to 0.3.

[0153] Sn, which forms a tetravalent cation, is an n-type material that can quickly transfer electrons. Figure 4 ), if the electron transfer speed is faster than the hole transfer speed, charge imbalance occurs, and the efficiency and life of the element are reduced. Sn forming divalent cations is a p-type material whose electron transfer speed is slower than that of Sn forming tetravalent cations. Figure 4 ) is applied to Sn forming tetravalent cations and an oxide of Sn forming divalent cations doped therein, since the speed of electron transfer is slowed down, the difference between the speed of electron transfer and the speed of hole transfer can be reduced. As a result, the problem of the difference between the speed of electron transfer and the speed of hole transfer in the light emitting element ED (see Figure 4 ) can increase the efficiency and life of the component.

[0154] [Chemical formula 2]

[0155] Sn 4+ 1-y Cu + 2y O 2-y

[0156] In Chemical Formula 2, y is greater than 0 and less than or equal to 0.3. Cu forming a monovalent cation is a p-type substance whose electron transfer rate is slower than Sn forming a tetravalent cation. Figure 4 ) is applied to Sn forming tetravalent cations and Cu forming monovalent cations, since the speed of electron transfer is slowed down, the difference between the speed of electron transfer and the speed of hole transfer can be reduced. As a result, the light emitting element ED (refer to Figure 4 ) can increase the efficiency and life of the component.

[0157] [Chemical formula 3]

[0158] Sn 4+ 1-z Ni 2+ z O 2-z

[0159] In Chemical Formula 3, z is greater than 0 and less than or equal to 0.3. Ni forming a divalent cation is a p-type substance whose electron transfer rate is slower than Sn forming a tetravalent cation. Figure 4) is applied to Sn forming tetravalent cations and Ni forming divalent cations, since the speed of electron transfer is slowed down, the difference between the speed of electron transfer and the speed of hole transfer can be reduced. As a result, the light emitting element ED (refer to Figure 4 ) can increase the efficiency and life of the component.

[0160] When the nanoparticles NP are composed of the first core compound, the Sn content measured by X-ray photoelectron spectroscopy (XPS) is 4+ 3 d 5 / 2 The peak position of Sn can be above 485.0eV and below 489.0eV. 2+ 3 d 5 / 2 The peak position of can be above 483.0eV and below 487.0eV. 4+ 3 d 5 / 2 Sn 2+ 3 d 5 / 2 The ratio of the peak intensity of the nanoparticles NP to the peak intensity of the nanoparticles NP may be greater than 0 and less than or equal to 0.6. The absolute quantum yield of the nanoparticles NP may be greater than 0% and less than or equal to 5%. The absolute quantum yield indicates the number of emitted photons relative to the number of absorbed photons, so for an organic electroluminescent element, the absolute quantum yield is proportional to the luminous efficiency of the element.

[0161] The ligand LD can be combined with the core CO to improve the stability of the core CO, thereby preventing reverse reactions caused by oxygen, moisture, etc., and improving the aggregation phenomenon between particles by increasing the average distance between the core CO and the core CO, thereby improving the spitting characteristics of the ink composition IC. The ligand LD can impart hydrophobicity to the surface of the nanoparticle NP. The ligand LD can be chemically bound to the core CO. The ligand LD can be jointly bound to the surface of the core CO. Multiple ligands LD can be bound to one core CO. The number of ligands LD can be greater than the number of core CO. The ligand LD can include oleic acid (Oleicacid) or oleylamine (Oleylamine). The ligand LD can be composed of oleic acid or oleylamine. For example, the ligand LD can be composed of oleic acid.

[0162] Hereinafter, the nanoparticles according to one embodiment of the present invention and the light emitting element according to one embodiment are described in detail with reference to the examples and comparative examples. In addition, the examples shown below are examples for helping to understand the present invention, and the scope of the present invention is not limited thereto.

[0163] [Example]

[0164] 1. Manufacturing and evaluation of light-emitting elements

[0165] (1) Manufacturing of Light-Emitting Element of One Embodiment

[0166] A light-emitting element of an embodiment including nanoparticles of an embodiment in an electron transport region is manufactured by the following method.

[0167] (Production of Nanoparticles in Example 1)

[0168] To synthesize Sn 4+ 0.98 Sn 2+ 0.02 O 1.98 Nanoparticles, 0.98mmol tin(IV) acetate, 0.02mmol tin(II) acetate, 3.3ml oleic acid, 3.3ml oleylamine and 30ml xylene were placed in a reactor and then stirred for 30 minutes under vacuum atmosphere. 2 After the reaction was completed, the temperature was raised to 100°C and the reactor was maintained for 30 minutes. 1 ml of deionized water (DI water) was quickly injected into the stabilized mixture and the reaction was maintained for 5 hours. After the temperature of the mixture after the reaction was completed was lowered to room temperature, an excess of ethanol was injected to stabilize the synthesized SnO 2 After precipitation, it is dispersed in hexane to synthesize Sn 4+ 0.98 Sn 2+ 0.02 O 1.98 Seed (seed).

[0169] In order to make Sn 4+ 0.98 Sn 2+ 0.02 O 1.98For further growth, 0.98 mmol of tin(IV) acetate, 0.02 mmol of tin(II) acetate, 3.3 ml of oleic acid and 10 ml of trioctylamine were placed in the reactor, the temperature was raised to 120°C, and then stirred for 30 minutes under vacuum. 2 After the atmosphere, Sn is injected 4+ 0.98 Sn 2+ 0.02 O 1.98 The reaction was then continued for 1 hour. 4+ 0.98 Sn 2+ 0.02 O 1.98 After the temperature of the nanoparticle solution was lowered to room temperature, it was purified twice using hexane and ethanol, and then dispersed in cyclohexylbenzene.

[0170] (Production of Nanoparticles of Example 2)

[0171] To synthesize Sn 4+ 0.95 Sn 2+ 0.05 O 1.95 Nanoparticles, 0.95mmol tin(IV) acetate, 0.05mmol tin(II) acetate, 3.3ml oleic acid, 3.3ml oleylamine and 30ml xylene were placed in a reactor and then stirred for 30 minutes under vacuum. 2 After the reaction was completed, the temperature was raised to 100°C and the reactor was maintained for 30 minutes. 1 ml of deionized water (DI water) was quickly injected into the stabilized mixture and the reaction was maintained for 5 hours. After the temperature of the mixture after the reaction was completed was lowered to room temperature, an excess of ethanol was injected to stabilize the synthesized SnO 2 After precipitation, it is dispersed in hexane to synthesize Sn 4+ 0.95 Sn 2+ 0.05 O 1.95 Seed (seed).

[0172] In order to make Sn 4+ 0.95 Sn 2+ 0.05 O1.95 For further growth, 0.95 mmol of tin(IV) acetate, 0.05 mmol of tin(II) acetate, 3.3 ml of oleic acid and 10 ml of trioctylamine were placed in the reactor, the temperature was raised to 120°C, and then stirred for 30 minutes under vacuum. 2 After the atmosphere, inject Sn 4+ 0.95 Sn 2+ 0.05 O 1.95 The reaction was then continued for 1 hour. 4+ 0.95 Sn 2+ 0.05 O 1.95 After the temperature of the nanoparticle solution was lowered to room temperature, it was purified twice using hexane and ethanol, and then dispersed in cyclohexylbenzene.

[0173] (Production of Nanoparticles of Example 3)

[0174] To synthesize Sn 4+ 0.9 Sn 2+ 0.1 O 1.9 Nanoparticles, 0.9mmol tin(IV) acetate, 0.1mmol tin(II) acetate, 3.3ml oleic acid, 3.3ml oleylamine and 30ml xylene were placed in a reactor and then stirred for 30 minutes under vacuum. 2 After the reaction was completed, the temperature was raised to 100°C and the reactor was maintained for 30 minutes. 1 ml of deionized water (DI water) was quickly injected into the stabilized mixture and the reaction was maintained for 5 hours. After the temperature of the mixture after the reaction was completed was lowered to room temperature, an excess of ethanol was injected to stabilize the synthesized SnO 2 After precipitation, it is dispersed in hexane to synthesize Sn 4+ 0.9 Sn 2+ 0.1 O 1.9 Seed (seed).

[0175] In order to make Sn 4+0.9 Sn 2+ 0.1 O 1.9 For further growth, 0.9 mmol of tin(IV) acetate, 0.1 mmol of tin(II) acetate, 3.3 ml of oleic acid and 10 ml of trioctylamine were placed in the reactor, the temperature was raised to 120°C, and then stirred for 30 minutes under vacuum. 2 After the atmosphere, Sn is injected 4+ 0.9 Sn 2+ 0.1 O 1.9 The reaction was then continued for 1 hour. 4 + 0.9 Sn 2+ 0.1 O 1.9 After the temperature of the nanoparticle solution was lowered to room temperature, it was purified twice using hexane and ethanol, and then dispersed in cyclohexylbenzene.

[0176] (Production of Nanoparticles of Example 4)

[0177] To synthesize Sn 4+ 0.8 Sn 2+ 0.2 O 1.8 Nanoparticles, 0.8mmol tin(IV) acetate, 0.2mmol tin(II) acetate, 3.3ml oleic acid, 3.3ml oleylamine and 30ml xylene were placed in a reactor and then stirred for 30 minutes under vacuum atmosphere. 2 After the reaction was completed, the temperature was raised to 100°C and the reactor was maintained for 30 minutes. 1 ml of deionized water (DI water) was quickly injected into the stabilized mixture and the reaction was maintained for 5 hours. After the temperature of the mixture after the reaction was completed was lowered to room temperature, an excess of ethanol was injected to stabilize the synthesized SnO 2 After precipitation, it is dispersed in hexane to synthesize Sn 4+ 0.8 Sn 2+ 0.2 O 1.8Seed (seed).

[0178] In order to make Sn 4+ 0.8 Sn 2+ 0.2 O 1.8 For further growth, 0.8 mmol of tin(IV) acetate, 0.2 mmol of tin(II) acetate, 3.3 ml of oleic acid and 10 ml of trioctylamine were placed in the reactor, the temperature was raised to 120°C, and then stirred for 30 minutes under vacuum. 2 After the atmosphere, Sn is injected 4+ 0.8 Sn 2+ 0.2 O 1.8 The reaction was then continued for 1 hour. 4 + 0.8 Sn 2+ 0.2 O 1.8 After the temperature of the nanoparticle solution was lowered to room temperature, it was purified twice using hexane and ethanol, and then dispersed in cyclohexylbenzene.

[0179] (Production of Nanoparticles of Example 5)

[0180] To synthesize Sn 4+ 0.7 Sn 2+ 0.3 O 1.7 Nanoparticles, 0.7mmol tin(IV) acetate, 0.3mmol tin(II) acetate, 3.3ml oleic acid, 3.3ml oleylamine and 30ml xylene were placed in a reactor and then stirred for 30 minutes under vacuum atmosphere. 2 After the reaction was completed, the temperature was raised to 100°C and the reactor was maintained for 30 minutes. 1 ml of deionized water (DI water) was quickly injected into the stabilized mixture and the reaction was maintained for 5 hours. After the temperature of the mixture after the reaction was completed was lowered to room temperature, an excess of ethanol was injected to stabilize the synthesized SnO 2 After precipitation, it is dispersed in hexane to synthesize Sn 4+0.7 Sn 2+ 0.3 O 1.7 Seed (seed).

[0181] In order to make Sn 4+ 0.7 Sn 2+ 0.3 O 1.7 For further growth, 0.7 mmol of tin(IV) acetate, 0.3 mmol of tin(II) acetate, 3.3 ml of oleic acid and 10 ml of trioctylamine were placed in the reactor, the temperature was raised to 120°C, and then stirred for 30 minutes under vacuum. 2 After the atmosphere, inject Sn 4+ 0.7 Sn 2+ 0.3 O 1.7 The reaction was then continued for 1 hour. 4 + 0.7 Sn 2+ 0.3 O 1.7 After the temperature of the nanoparticle solution was lowered to room temperature, it was purified twice using hexane and ethanol, and then dispersed in cyclohexylbenzene.

[0182] The nanoparticles of the comparative example were formed by the following method.

[0183] (Production of Nanoparticles in Comparative Example 1)

[0184] In order to synthesize ZnMgO nanoparticles, 65.2mmol of zinc acetate dihydrate, 14.8mmol of magnesium acetate tetrahydrate and 320ml of dimethyl sulfoxide were injected into the reactor and stirred for 120 minutes. Then, after the temperature of the reactor was lowered to 4°C, 80ml of a mixed solution of 1M tetramethylammonium hydroxide pentahydrate (TMAH) and ethanol was injected for 20 minutes. After the injection of the TMAH solution, the reaction was maintained for 1 hour and 20 minutes, and the synthesized ZnMgO nanoparticles were precipitated using acetone and hexane. The finally precipitated nanoparticles were dispersed in ethanol.

[0185] (Production of Nanoparticles in Comparative Example 2)

[0186] In order to synthesize SnO 2 Nanoparticles, 1mmol of tin(IV) acetate, 3.3ml of oleic acid, 3.3ml of oleylamine and 30ml of xylene were placed in a reactor and then stirred for 30 minutes under vacuum. 2 After the reaction was completed, the temperature was raised to 100°C and the reactor was maintained for 30 minutes. 1 ml of deionized water (DI water) was quickly injected into the stabilized mixture and the reaction was maintained for 5 hours. After the temperature of the mixture after the reaction was completed was lowered to room temperature, an excess of ethanol was injected to stabilize the synthesized SnO 2 After precipitation, it was dispersed in hexane to synthesize SnO 2 Seed (seed).

[0187] In order to make SnO 2 For further growth, 1 mmol of tin(IV) acetate, 3.3 ml of oleic acid and 10 ml of trioctylamine were placed in the reactor, the temperature was raised to 120°C, and then stirred for 30 minutes under vacuum. 2 After the atmosphere is injected SnO 2 The reaction was continued for 1 hour. 2After the temperature of the nanoparticle solution was lowered to room temperature, it was purified twice using hexane and ethanol, and then dispersed in cyclohexylbenzene.

[0188] (Production of Nanoparticles in Comparative Example 3)

[0189] To synthesize Sn 4+ 0.6 Sn 2+ 0.4 O 1.6 Nanoparticles, 0.6mmol tin(IV) acetate, 0.4mmol tin(II) acetate, 3.3ml oleic acid, 3.3ml oleylamine and 30ml xylene were placed in a reactor and then stirred for 30 minutes under vacuum. 2 After the reaction was completed, the temperature was raised to 100°C and the reactor was maintained for 30 minutes. 1 ml of deionized water (DI water) was quickly injected into the stabilized mixture and the reaction was maintained for 5 hours. After the temperature of the mixture after the reaction was completed was lowered to room temperature, an excess of ethanol was injected to stabilize the synthesized SnO 2 After precipitation, it is dispersed in hexane to synthesize Sn 4+ 0.6 Sn 2+ 0.4 O 1.6 Seed (seed).

[0190] In order to make Sn 4+ 0.6 Sn 2+ 0.4 O 1.6 For further growth, 0.6 mmol of tin(IV) acetate, 0.4 mmol of tin(II) acetate, 3.3 ml of oleic acid and 10 ml of trioctylamine were placed in the reactor, the temperature was raised to 120°C, and then stirred for 30 minutes under vacuum. 2 After the atmosphere, inject Sn 4+ 0.6 Sn 2+ 0.4 O 1.6 The reaction was then continued for 1 hour. 4 +0.6 Sn 2+ 0.4 O 1.6 After the temperature of the nanoparticle solution was lowered to room temperature, it was purified twice using hexane and ethanol, and then dispersed in cyclohexylbenzene.

[0191] (Manufacturing of Light Emitting Element of Example 1)

[0192] An ITO glass substrate (50 x 50 mm, 15 Ω / cm 2 ) was subjected to ultrasonic cleaning, and then UV ozone cleaning was performed for 30 minutes. Poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) (Clevios TM HIL8) was spin-coated onto a washed glass substrate with a transparent electrode line attached to form a film with a thickness of 60nm, and then baked at 120°C for 10 minutes to form a hole injection layer. Compound 101 was spin-coated onto the hole injection layer to form a film with a thickness of 20nm, and then baked at 120°C for 10 minutes to form a hole transport layer. Green indium phosphide quantum dots (Green InP QD) dispersed in octane were spin-coated on the hole transport layer to form a film with a thickness of 20nm, and then baked at 100°C for 10 minutes to form a green (Green) light-emitting layer. Inorganic nanoparticles were spin-coated on the green (Green) light-emitting layer to form a film with a thickness of 30nm, and then baked at 120°C for 10 minutes to form an electron transport layer. The glass substrate was mounted on a substrate holder of a vacuum deposition device, and Al was then deposited on the electron transport layer to form an anode with a thickness of 100nm, thereby manufacturing a quantum dot light-emitting element. The quantum dot light-emitting elements were deposited using a Suicel plus 200 deposition machine from Sunic System.

[0193] (Substances used in manufacturing light-emitting devices)

[0194] (PEDOT:PSS)

[0195]

[0196] (Compound 101)

[0197]

[0198] (Manufacturing of Light Emitting Element of Example 2)

[0199] A light-emitting element was manufactured by the same method as the light-emitting element of Example 1, except that the substance included in the electron transport region was the nanoparticles of Example 2.

[0200] (Manufacturing of Light Emitting Element of Example 3)

[0201] A light-emitting element was manufactured by the same method as the light-emitting element of Example 1, except that the substance included in the electron-transporting region was the nanoparticles of Example 3.

[0202] (Manufacturing of Light Emitting Element of Example 4)

[0203] A light-emitting element was manufactured by the same method as the light-emitting element of Example 1, except that the substance included in the electron transport region was the nanoparticles of Example 4.

[0204] (Manufacturing of Light Emitting Element of Example 5)

[0205] A light-emitting element was manufactured by the same method as the light-emitting element of Example 1, except that the substance included in the electron-transporting region was the nanoparticles of Example 5.

[0206] (Manufacturing of Light Emitting Element of Comparative Example 1)

[0207] A light-emitting element was manufactured by the same method as the light-emitting element of Example 1, except that the substance included in the electron transport region was the nanoparticles of Comparative Example 1.

[0208] (Manufacturing of Light Emitting Element of Comparative Example 2)

[0209] A light-emitting element was manufactured by the same method as the light-emitting element of Example 1, except that the substance included in the electron transport region was the nanoparticles of Comparative Example 2.

[0210] (Manufacturing of Light Emitting Element of Comparative Example 3)

[0211] A light-emitting element was manufactured by the same method as the light-emitting element of Example 1, except that the substance included in the electron transport region was the nanoparticles of Comparative Example 3.

[0212] 2. Physical properties of nanoparticles and characteristics of light-emitting elements

[0213] (Evaluation of the physical properties of nanoparticles)

[0214] In the following Table 1, the changes in the photoluminescence quantum yield defect emission (PL QY defect emission) (%), Rel. PL decrease ratio, surface organic content, and dynamic light scattering (DLS) average particle size (nm) of the nanoparticles of the above-mentioned embodiments and comparative examples are evaluated. The photoluminescence quantum yield defect emission (PLQY defect emission) (%) was measured by the following method: The absolute quantum efficiency (PL QY) in the visible light wavelength region generated by the surface defects of the metal nanoparticles was measured from the liquid metal nanoparticles using the QE-2100 equipment of Otsuka Corporation. The Rel. PL decrease ratio was measured by the following method: The green indium phosphide quantum dots (Green InP QD) dispersed in octane (Octane) solvent was spin-coated with The film was coated on glass with a thickness of 1000 nm, and then heated at 140° C. for 10 minutes, and the solvent was dried to form a light-emitting layer, and the luminescence intensity was measured using a FluoroMax Plus device. Thereafter, a metal nanoparticle solution was spin-coated thereon in the same manner as described above to form a film with a thickness of 1000 nm. The surface organic content was measured by thermogravimetric analysis, and the inorganic nanoparticles were dried and measured using a TGA 5500 device from TA Instrumnents. The ink composition including the nanoparticles of each embodiment and comparative example was placed at room temperature and its particle size was measured after 21 days. The particle size was measured using a DLS device (Nano-ZS90 from Malvern).

[0215] The larger the PL QY defect emission (%) value, the more surface defects there are. The smaller the absolute values ​​of the PL QY defect emission (%) and the Rel.PL decrease ratio, the less the luminescence reduction caused by the defect, which indicates excellent luminescence efficiency. The surface organic content is an indicator of the degree to which organic matter is contained in the nanoparticles. The higher the surface organic content, the more organic matter is contained in the nanoparticles. Since the ligands are organic substances, they contain a lot of ligands, which is interpreted as excellent stability of the substance. The DLS average particle size is an indicator of the average size of the nanoparticles. The changes in the size of the nanoparticles measured on the 0th day as the first measurement period and the size of the nanoparticles measured on the 21st day after 21 days from the 0th day are observed. If the difference in size change is large, there is agglomeration of the nanoparticles, which is interpreted as reduced ink ejection characteristics.

[0216] [Table 1]

[0217]

[0218] Referring to Table 1, since the nanoparticles of Examples 1 to 5 have lower absolute values ​​of photoluminescence quantum yield defect emission (PL QY defect emission) (%) and Rel.PL decrease ratio than the nanoparticles of Comparative Examples 1 and 2, the degree of luminescence reduction caused by defects is less, which is interpreted as excellent luminous efficiency. Since the organic content of the nanoparticles of Examples 1 to 5 is higher than that of the nanoparticles of Comparative Examples 1 and 2, more organic substances are included in the surface, and since the core of the nanoparticles is protected by more ligands and the average spacing between the nanoparticles is larger, the agglomeration phenomenon between the nanoparticles is improved, which is interpreted as excellent ink ejection characteristics. Since the change in the average particle size of the nanoparticles of Examples 1 to 5 is not large compared with the nanoparticles of Comparative Examples 1 and 2, the reverse reaction caused by oxygen, moisture, etc. or the agglomeration phenomenon between the nanoparticles is improved, which is interpreted as excellent ink ejection characteristics.

[0219] (Evaluation of characteristics of light-emitting elements)

[0220] The driving voltage (V), element efficiency (Cd / A) and element life (@T 90) were evaluated. Table 1 shows the evaluation results of the light-emitting elements of Examples 1 to 5 and Comparative Examples 1 to 3. In order to evaluate the characteristics of the light-emitting elements manufactured in Examples 1 to 5 and Comparative Examples 1 to 3, the brightness of the light-emitting elements was measured by using Keithley SMU 236 and luminance meter PR650 at a brightness of 1280 cd / m 2 The absolute time required for the brightness to reach 90% of the initial brightness is taken as the lifespan (@T 90 , h) and measurements were carried out.

[0221] [Table 2]

[0222] Efficiency (Cd / A) Driving voltage(V) <![CDATA[Life (@T 90 , h)]]> Example 1 74.0 6.2 180 Example 2 120.4 6.4 213 Example 3 118.2 6.5 218 Example 4 90.0 7.0 190 Example 5 65.2 7.3 101 Comparative Example 1 62.2 5.2 14 Comparative Example 2 55.2 4.6 18 Comparative Example 3 30.1 8.2 15

[0223] Referring to the results in Table 2, it can be seen that the light-emitting element of the embodiment using the nanoparticles according to one embodiment of the present invention as the material of the electron transport layer shows relatively high luminous efficiency and relatively long element life compared with the light-emitting element of the comparative example. In particular, in Chemical Formula 1, when x is greater than 0.3, it is observed that the efficiency and life of the light-emitting element are sharply reduced.

[0224] In the nanoparticles included in the light-emitting element of the embodiment, since the electron transfer and injection speed of Sn forming divalent cations are slower than those of Sn forming tetravalent cations, if the ratio of Sn forming divalent cations is increased, the electron transfer and injection speed in the light-emitting element can be controlled. In the nanoparticles of Examples 1 to 5, the difference between the speed of electron transfer and the speed of hole transfer is reduced by adjusting the ratio of Sn forming tetravalent cations to Sn forming divalent cations from 98:2 to 70:30, thereby improving the imbalance of charge in the light-emitting layer, and thus improving the luminous efficiency and life of the light-emitting element.

[0225] In addition, as shown in Table 1, the nanoparticles of Comparative Example 3 have the absolute values ​​of the photoluminescence quantum yield defect emission (PLQY defect emission) (%) and the Rel.PL decrease ratio (decrease ratio) at similar levels to those of the nanoparticles of the embodiment, but in the nanoparticles of Comparative Example 3, the ratio of Sn forming tetravalent cations to Sn forming divalent cations exceeds the above-mentioned range of 98:2 to 70:30, so when applied to a light-emitting element, it can be confirmed that the efficiency and life of the light-emitting element are reduced. As shown in the nanoparticles of Comparative Example 3, if the ratio of divalent cation Sn exceeds the range proposed in the present invention and becomes excessively large, the speed of electron transfer becomes slower than the speed of hole transfer, thereby causing charge imbalance in the light-emitting layer, so when applied to an element, the efficiency and life of the light-emitting element are reduced.

[0226] Although the above description is made with reference to the preferred embodiments of the present invention, any skilled technician in the technical field or a person with ordinary knowledge in the technical field will understand that various modifications and changes can be made to the present invention without departing from the scope of the concept and technical field of the present invention recorded in the claims.

[0227] Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be determined by the claims.

Claims

1. A light emitting element, comprising: a first electrode; A functional layer is arranged on the first electrode; as well as a second electrode disposed on the functional layer, Wherein, the functional layer comprises nanoparticles, The nanoparticles include a core and a ligand, The core includes at least one of a first core compound represented by the following Chemical Formula 1, a second core compound represented by the following Chemical Formula 2, and a third core compound represented by the following Chemical Formula 3: [Chemical formula 1] Sn 4+ 1-x Sn 2+ x O 2-x , In the chemical formula 1, x is greater than 0 and less than or equal to 0.3, [Chemical formula 2] Sn 4+ 1-y With + 2y A 2-y , In the chemical formula 2, y is greater than 0 and less than or equal to 0.3, [Chemical formula 3] Sn 4+ 1-z In 2+ z SHE 2-z , In the chemical formula 3, z is greater than 0 and less than or equal to 0.

3.

2. The light emitting element according to claim 1, wherein The nanoparticle is composed of the core and the ligand. The core is formed using the first core compound.

3. The light emitting element according to claim 2, wherein: Relative to Sn measured by X-ray photoelectron spectroscopy 4+ 3d 5 / 2 Sn 2+ 3d 5 / 2 The ratio of the peak intensities is greater than 0 and less than or equal to 0.

6.

4. The light emitting element according to claim 2, wherein The absolute quantum efficiency of the nanoparticles is greater than 0% and less than or equal to 5%.

5. The light emitting element according to claim 1, wherein The nanoparticle is composed of the core and the ligand. The core is formed using at least one of the first core compound, the second core compound, and the third core compound.

6. The light emitting element according to claim 1, wherein The ligand includes oleic acid or oleylamine.

7. The light emitting element according to claim 1, wherein The ligand is chemically bound to the core.

8. The light emitting element according to claim 1, wherein The nanoparticles are doped with metal atoms.

9. The light emitting element according to claim 8, wherein The metal atoms include at least one of Zn, Mg, Li and Na.

10. The light emitting element according to claim 1, wherein The functional layer comprises: a hole transport region, arranged on the first electrode; a light-emitting layer disposed on the hole transport region; and an electron transport region, arranged between the light-emitting layer and the second electrode, Wherein, the electron transport region includes the nanoparticles.

11. The light emitting element according to claim 10, wherein The electron transport region comprises: an electron transport layer disposed on the light-emitting layer; and an electron injection layer, disposed on the electron transport layer, Wherein, at least one of the electron transport layer and the electron injection layer includes the nanoparticles.

12. The light emitting element according to claim 10, wherein The light emitting layer includes quantum dots.

13. An ink composition comprising: Nanoparticles; as well as Solvents, Wherein, the nanoparticles include a core and a ligand, The core includes at least one of a first core compound represented by the following Chemical Formula 1, a second core compound represented by the following Chemical Formula 2, and a third core compound represented by the following Chemical Formula 3: [Chemical formula 1] Sn 4+ 1-x Sn 2+ x O 2-x , In the chemical formula 1, x is greater than 0 and less than or equal to 0.3, [Chemical formula 2] Sn 4+ 1-y With + 2y A 2-y , In the chemical formula 2, y is greater than 0 and less than or equal to 0.3, [Chemical formula 3] Sn 4+ 1-z In 2+ z SHE 2-z , In the chemical formula 3, z is greater than 0 and less than or equal to 0.

3.

14. The ink composition according to claim 13, wherein The solvent is a hydrophobic solvent.

15. The ink composition according to claim 13, wherein The nanoparticle is composed of the core and the ligand. The core is formed using the first core compound.

16. The ink composition according to claim 13, wherein The nanoparticle is composed of the core and the ligand. The core is formed using the second core compound or the third core compound.

17. A display device, comprising: Base layer; A circuit layer, arranged on the base layer; as well as A display element layer is arranged on the circuit layer and includes a light emitting element, The light-emitting element is a light-emitting element according to any one of claims 1 to 12.

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