Quantum dots, display panels, and electronic devices including the display panels.

Abstract

Quantum dots, quantum dot composites including the quantum dots, display panels including the quantum dot composites, and electronic devices including the display panels are provided, wherein the quantum dots include metals comprising indium and zinc and nonmetals comprising phosphorus and selenium, and do not include cadmium, and the quantum dots have an optical density (OD) per 1 mg for a wavelength of about 450 nm in the range of about 0.2 to about 0.3 and have an emission peak between about 500 nm and about 550 nm, or the quantum dots have an optical density per 1 mg for a wavelength of about 450 nm in the range of about 0.5 to about 0.7 and have an emission peak between about 610 nm and about 660 nm.

Description

[0001] This application claims priority and benefit to Korean Patent Application No. 10-2021-0096367, filed on July 22, 2021, with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0002] A quantum dot, a quantum dot composite, a display panel, and an electronic device are disclosed. Background Technology

[0003] Quantum dots are nanoscale semiconductor nanocrystal materials, and their optical properties (e.g., luminescence properties) can be controlled by, for example, changing their size and / or composition. The luminescence properties of quantum dots can be applied to electronic devices (e.g., display devices). When applied to electronic devices, quantum dots can be used in composite forms. There is a need to develop environmentally friendly quantum dots and quantum dot composites that exhibit improved physical properties when applied to electronic devices. Summary of the Invention

[0004] The embodiments provide (e.g., when applied to a device in the form of a composite) quantum dots that can exhibit improved luminescence properties and driving reliability, as well as quantum dot composites including the quantum dots.

[0005] Another embodiment provides a display panel that includes the quantum dot composite.

[0006] Another embodiment relates to an electronic device (e.g., a display device) that includes the display panel.

[0007] The quantum dots according to the embodiments include metals comprising indium and zinc and nonmetals comprising phosphorus and selenium, and do not include cadmium, wherein the quantum dots have an optical density (OD) per 1 mg for a wavelength of about 450 nm in the range of about 0.2 (e.g., greater than or equal to about 0.22 or greater than or equal to about 0.222) to about 0.27 (e.g., less than or equal to about 0.269) and have an emission peak between about 500 nm and about 550 nm, or the quantum dots have an optical density per 1 mg for a wavelength of about 450 nm in the range of about 0.5 to about 0.7 and have an emission peak between about 610 nm and about 660 nm.

[0008] In one embodiment, the display panel includes quantum dots (e.g., first quantum dots and second quantum dots) as described herein. In another embodiment, the display panel includes a quantum dot composite comprising a matrix and a plurality of (cadmium-free) quantum dots, wherein the plurality of quantum dots include metallic elements, non-metallic elements, the metallic elements including indium and zinc, the non-metallic elements including phosphorus and selenium, and optionally sulfur.

[0009] Among them, multiple quantum dots include (multiple) first quantum dots and (multiple) second quantum dots.

[0010] Among them, (multiple) first quantum dots have or exhibit an optical density (OD) per 1 mg at a wavelength of 450 nm in the range of about 0.2 (or greater than or equal to about 0.22 or about 0.222 or about 0.225 or greater) to about 0.27 (or less than or equal to about 0.269) and have or exhibit an emission peak between about 500 nm and about 550 nm.

[0011] Among them, (multiple) second quantum dots have or exhibit an optical density per 1 mg at a wavelength of about 450 nm in the range of about 0.5 to about 0.7 and have or exhibit an emission peak between about 610 nm and about 660 nm.

[0012] The display panel may or may not include a liquid crystal layer.

[0013] The first quantum dot and the second quantum dot are respectively included in a first color conversion region and a second color conversion region in the color conversion layer. The first quantum dot may be included in the first color conversion region, and the second quantum dot may be included in the second color conversion region. The first color conversion region and the second color conversion region may be separated from each other, for example, by a partition wall.

[0014] (First) Quantum dots may have an optical density per 1 mg for a wavelength of about 460 nm in the range of about 0.12 to about 0.35 and have an emission peak between about 500 nm (or about 530 nm) and about 550 nm (or about 540 nm).

[0015] (Second) The quantum dot may have an optical density per 1 mg for a wavelength of about 460 nm in the range of about 0.4 to about 0.5 and an emission peak between about 610 nm (or about 635 nm) and about 660 nm (or about 645 nm).

[0016] Quantum dots (e.g., first quantum dots and / or second quantum dots) may include a semiconductor nanocrystal core and a semiconductor nanocrystal shell, the semiconductor nanocrystal core comprising indium and phosphorus, and the semiconductor nanocrystal shell disposed on the semiconductor nanocrystal core and comprising zinc and selenium.

[0017] The shell of a semiconductor nanocrystal can also include sulfur.

[0018] The semiconductor nanocrystal shell may include a first semiconductor nanocrystal shell disposed on a semiconductor nanocrystal core and containing zinc and selenium, and may also include a second semiconductor nanocrystal shell disposed on the first semiconductor nanocrystal shell and containing zinc and sulfur.

[0019] In the quantum dot (or in the first quantum dot and / or the second quantum dot), the weight ratio of zinc to indium can be greater than or equal to about 10 and less than or equal to about 30, and the weight ratio of selenium to indium can be greater than or equal to about 2.9 and less than or equal to about 20.

[0020] The display panel according to an embodiment includes a color conversion layer comprising a plurality of quantum dot composites. The quantum dot composites include a matrix and a plurality of quantum dots dispersed in the matrix, and titanium dioxide (TiO2). The plurality of quantum dots include metals comprising indium and zinc, and nonmetals comprising phosphorus and selenium, and optionally sulfur.

[0021] The display panel has (e.g., in the color conversion layer) a weight ratio of indium (In) to titanium (Ti) greater than or equal to about 0.1 and less than or equal to about 0.7 and a weight ratio of phosphorus (P) to Ti greater than or equal to about 0.05 and less than or equal to about 0.2.

[0022] In an embodiment, the display panel may have a weight ratio of selenium (Se) to Ti of greater than or equal to about 0.5 and less than or equal to about 3 (e.g., in the color conversion layer or in the color conversion region and the light-transmitting region).

[0023] In an embodiment, the display panel may have an indium to titanium weight ratio (In / Ti) of less than or equal to about 0.5 (e.g., in the color conversion layer or in the color conversion region and the light-transmitting region).

[0024] In an embodiment, the display panel may have a phosphorus to titanium weight ratio (P / Ti) of less than or equal to about 0.15 (e.g., in the color conversion layer or in the color conversion region and the light-transmitting region).

[0025] The display panel may include a color conversion layer, which includes a plurality of regions containing color conversion areas, and a quantum dot composite may be disposed in the color conversion areas. In embodiments, the color conversion layer includes quantum dots or quantum dot composites as described herein.

[0026] The display panel may further include a light-emitting panel, which includes a light source configured to emit blue light, a light source configured to emit green light, or a combination thereof. The color conversion layer may include a first color conversion region, a second color conversion region, or a combination thereof. The first color conversion region is configured to convert blue light and / or green light emitted from the light-emitting panel into light of a first emission spectrum, and the second color conversion region is configured to convert blue light and / or green light emitted from the light-emitting panel into light of a second emission spectrum.

[0027] The color conversion layer may also include light-transmitting areas configured to transmit blue and / or green light emitted from the light-emitting panel.

[0028] The first emission spectrum may be a green emission spectrum having an emission peak wavelength between about 500 nm and about 550 nm, and in the first color conversion region, the weight ratio of selenium (Se) to titanium (Ti) may be greater than or equal to about 2 and less than or equal to about 12.

[0029] In the first color conversion region, the weight ratio of indium (In) to Ti can be greater than or equal to about 0.2 and less than or equal to about 1.8, and the weight ratio of phosphorus (P) to Ti can be greater than or equal to about 0.05 and less than or equal to about 0.4.

[0030] The second emission spectrum may be a red emission spectrum having an emission peak wavelength between about 610 nm and about 660 nm, and the weight ratio of Se to titanium (Ti) in the second color conversion region may be greater than or equal to about 1 and less than or equal to about 5.

[0031] In the second color conversion region, the weight ratio of In to titanium (Ti) can be greater than or equal to about 0.1 and less than or equal to about 0.5, and the weight ratio of P to titanium (Ti) can be greater than or equal to about 0.05 and less than or equal to about 0.3.

[0032] In the first color conversion region, the weight ratio of In to titanium (Ti) can be greater than or equal to about 0.2 and less than or equal to about 1.5, the weight ratio of P to titanium (Ti) can be greater than or equal to about 0.1 and less than or equal to about 0.3, and the weight ratio of Se to Ti can be greater than or equal to about 3 and less than or equal to about 10.

[0033] In the second color conversion region, the weight ratio of In to titanium (Ti) can be greater than or equal to about 0.2 and less than or equal to about 0.4, the weight ratio of P to titanium (Ti) can be greater than or equal to about 0.1 and less than or equal to about 0.3, and the weight ratio of Se to Ti can be greater than or equal to about 1.2 and less than or equal to about 3.

[0034] Multiple quantum dots include a semiconductor nanocrystal core and a semiconductor nanocrystal shell. The semiconductor nanocrystal core includes indium and phosphorus, and the semiconductor nanocrystal shell is disposed on the semiconductor nanocrystal core and includes zinc and selenium, as well as optional sulfur.

[0035] The matrix may include polymerizable monomers having carbon-carbon double bonds, organic solvents, polymers, thiols having at least one thiol group at the end, or combinations thereof.

[0036] The electronic device according to another embodiment includes a display panel.

[0037] According to an embodiment, a quantum dot is formed with a matrix comprising the quantum dot to exhibit improved optical properties, such as increased blue light absorption and improved green or red light conversion efficiency due to the increased blue light absorption. Therefore, the quantum dot composite according to the embodiment is desirablely applicable to various display devices, such as biolabels (e.g., biosensors or bioimaging), photodetectors, solar cells, hybrid composites, etc. Attached Figure Description

[0038] Figure 1A The diagram schematically illustrates a patterning process using a composition for manufacturing quantum dot composites according to an embodiment.

[0039] Figure 1B The diagram schematically illustrates a patterning process using an ink composition as a quantum dot complex according to an embodiment.

[0040] Figure 2 This is an exploded view of a display device according to an embodiment.

[0041] Figure 3 This is a perspective view showing an example of a display panel according to an embodiment.

[0042] Figure 4 yes Figure 3 A cross-sectional view of the display panel.

[0043] Figure 5 It shows Figure 3 A floor plan showing an example of the pixel arrangement of a display panel.

[0044] Figure 6A It is intercepted along line IV-IV. Figure 3 A cross-sectional view of the display panel.

[0045] Figure 6B This is a cross-sectional view of a display panel according to another embodiment.

[0046] Figure 7 This is a schematic cross-sectional view of a display device according to an embodiment.

[0047] Figure 8 The graph shows the optical density of the quantum dots prepared per 1 mg in Examples 1 and 2 for each wavelength. Detailed Implementation

[0048] The advantages and features of this disclosure and its implementation methods will become apparent from the following embodiments and the accompanying drawings. However, the embodiments should not be construed as limiting oneself to those set forth herein. Unless otherwise defined, all terms in this specification (including technical and scientific terms) may be defined as commonly understood by those skilled in the art. Terms defined in common dictionaries may not be interpreted in an idealized or exaggerated manner unless explicitly defined. Furthermore, unless explicitly stated otherwise, the word "comprising" and variations such as "including" or "containing" will be understood to mean including the stated elements, but not excluding any other elements.

[0049] In the accompanying drawings, the thickness of layers, films, panels, areas, etc., is exaggerated for clarity. Throughout the specification, the same reference numerals denote the same elements.

[0050] It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, the element may be directly on the other element, or an intermediary element may be present. Conversely, when an element is referred to as being "directly on" another element, no intermediary element is present.

[0051] Furthermore, unless otherwise stated, the singular includes the plural.

[0052] In the following text, as used herein, unless otherwise defined, “substituted” means that the hydrogen atoms of a compound are substituted by a substituent selected from C1 to C30 alkyl, C2 to C30 alkenyl, C2 to C30 alkynyl, C6 to C30 aryl, C7 to C30 alkylaryl, C1 to C30 alkoxy, C1 to C30 heteroalkyl, C3 to C30 heteroalkylaryl, C3 to C30 cycloalkyl, C3 to C15 cycloalkenyl, C6 to C30 cycloalkynyl, C2 to C30 heterocycloalkyl, halogen (-F, -Cl, -Br or -I), hydroxyl (-OH), nitro (-NO2), cyano (-CN), amino or amino (-NRR', where R and R' are both independently hydrogen or C1 to C6 alkyl), azide The following groups are used: α-N3, β-amidine (-C(=NH)NH2), hydrazine (-NHNH2), hydrazone (=N(NH2)), aldehyde (-C(=O)H), carbamoyl (-C(O)NH2), thiol (-SH), ester (-C(=O)OR, wherein R is a C1 to C6 alkyl or a C6 to C12 aryl), carboxylic acid (-COOH) or its salt (-C(=O)OM, wherein M is an organic or inorganic cation), sulfonic acid (-SO3H) or its salt (-SO3M, wherein M is an organic or inorganic cation), phosphate (-PO3H2) or its salt (-PO3MH or -PO3M2, wherein M is an organic or inorganic cation) or combinations thereof.

[0053] As used herein, “monovalent organic functional group” means C1 to C30 alkyl, C2 to C30 alkenyl, C2 to C30 alkynyl, C6 to C30 aryl, C7 to C30 alkylaryl, C1 to C30 alkoxy, C1 to C30 heteroalkyl, C3 to C30 heteroalkylaryl, C3 to C30 cycloalkyl, C3 to C15 cycloalkenyl, C6 to C30 cycloalkynyl or C2 to C30 heterocycloalkyl.

[0054] In addition, unless otherwise defined below, “heterogeneous” means a compound, group or substituent comprising one to three heteroatoms selected from N, O, S, Si or P.

[0055] As used herein, "alkylene" is a straight-chain or branched saturated aliphatic hydrocarbon group that optionally includes at least one substituent and has a valence of two or higher. As used herein, "arylene" can be a functional group that optionally includes at least one substituent and is formed by removing at least two hydrogens from at least one aromatic ring and has a valence of two or higher.

[0056] In addition, "aliphatic group" refers to a saturated or unsaturated straight-chain or branched C1 to C30 group composed of carbon and hydrogen, "aromatic organic group" includes C6 to C30 aryl or C2 to C30 heteroaryl, and "alicyclic group" refers to a saturated or unsaturated C3 to C30 cyclic group composed of carbon and hydrogen.

[0057] As used herein, the term "(meth)acrylate" refers to acrylates and / or methacrylates.

[0058] As used herein, “light conversion efficiency” is the ratio of the emission amount (G or R) of the quantum dot composite (denoted as A) to the amount of light absorbed (B-B') from the excitation light (e.g., blue light) (B) of the quantum dot composite. Similarly, “light conversion efficiency” is the ratio of the emission amount (G or R) of the quantum dot composite to the emission amount (B) of the excitation light. The total amount of excitation light (B) is obtained by integrating the PL spectrum. The PL spectrum of the quantum dot composite film is measured to obtain the amount of light emitted from the quantum dot composite film at green or red wavelengths (G or R) and the amount of excitation light (B'). The light conversion efficiency, light conversion efficiency, and blue light absorption rate are obtained using the following equations:

[0059] A / (B-B')×100=Light conversion efficiency (%)

[0060] A / B × 100 = Light conversion efficiency (%)

[0061] (B-B') / B×100=Blue light absorption rate of the membrane (%).

[0062] As used herein, “dispersion” means a dispersion in which the dispersed phase is a solid and the continuous phase includes a liquid. “Dispersion” can include colloidal dispersions in which the dispersed phase has a size greater than or equal to about 1 nm (e.g., greater than or equal to about 2 nm, greater than or equal to about 3 nm or greater than or equal to about 4 nm) and a few micrometers (μm) or smaller (e.g., about 2 μm or smaller or about 1 μm or smaller).

[0063] Herein, the term "quantum dot" refers to a nanostructure (such as semiconductor-based nanocrystals (particles)) that exhibits quantum confinement or exciton confinement, for example, a luminescent nanostructure (e.g., capable of emitting light by energy excitation). As used herein, unless otherwise defined, the term "quantum dot" is not limited in shape.

[0064] Here, "size (e.g., size, diameter, thickness, etc.)" can be an average size (e.g., size, diameter, thickness, etc.). Here, "average" can be the mean or median. Size can be a value obtained through electron microscopy analysis. Size can be a value calculated taking into account the composition and optical properties of the quantum dots (e.g., UV absorption wavelength).

[0065] Here, "quantum efficiency (or quantum yield)" can be measured in solution or in the solid state (in a complex). In embodiments, quantum efficiency (or quantum yield) is the ratio of photons emitted to photons absorbed by a nanostructure or a population of nanostructures. In embodiments, quantum efficiency can be measured by any method. For example, for fluorescence quantum yield or efficiency, there are two methods: absolute methods and relative methods. In the absolute method, quantum efficiency is obtained by detecting the fluorescence of all samples using an integrating sphere. In the relative method, the quantum efficiency of an unknown sample is calculated by comparing the fluorescence intensity of a standard dye (standard sample) with the fluorescence intensity of an unknown sample. Coumarin 153, coumarin 545, rhodamine 101 inner salt, anthracene, and rhodamine 6G can be used as standard dyes according to their PL wavelengths, but this disclosure is not limited thereto.

[0066] The quantum efficiency (or quantum yield) can be easily and reproducibly determined using commercially available equipment from Hitachi or Hamamatsu and by referring to the instruction manual provided by the respective equipment manufacturer.

[0067] The full width at half maximum (FWHM) and the peak wavelength of maximum emission (PL: photoluminescence) can be measured, for example, by using the emission spectrum obtained by a spectrophotometer such as a fluorescence spectrophotometer.

[0068] In this context, the description excluding cadmium (or other toxic heavy metals or given elements) means that the concentration of cadmium (or the corresponding toxic heavy metal or given element) is less than or equal to about 100 ppm, less than or equal to about 50 ppm, less than or equal to about 10 ppm, or close to 0. In the examples, cadmium (or other toxic heavy metals) is substantially absent, or if present, it is present in amounts below the detection limit of the given detection method or as an impurity level.

[0069] As used herein, the term "optical density" refers to the amount of light of a specific wavelength with a constant intensity passing through a solution layer and the intensity of the light emitted becomes constant. "Optical density" is a result of the Beer-Lambert law (which will be described later), or a value divided by the thickness of the solution layer through which the wavelength has passed. In this specification, the absorbance of a quantum dot solution contained in a cuvette with a 1 cm optical path at 450 nm is defined as optical density.

[0070] Semiconductor nanocrystals (also known as quantum dots) are crystalline semiconductor materials with nanoscale particle sizes. Quantum dots have a large surface area per unit volume, exhibit quantum confinement effects, and can display properties different from those of bulk materials with the same composition. Quantum dots absorb light from an excitation source to be excited and emit energy corresponding to their band gap.

[0071] Quantum dots can be used as luminescent materials in display devices. For example, a quantum dot composite (or quantum dot-polymer composite) comprising multiple quantum dots dispersed in a polymer matrix or the like can be used as a light conversion layer (e.g., a color conversion layer) in a display device, which converts light (e.g., blue light) from a light source (e.g., a backlight unit (BLU)) into light of a desired wavelength (e.g., green or red light). That is, unlike conventional absorptive color filters, a patterned film comprising a quantum dot composite can be used as an emissive color filter. Since the emissive color filter is positioned in front of the display device, for example, when linear excitation light arrives at the emissive color filter while passing through the liquid crystal layer, it scatters in all directions to achieve a wider viewing angle and avoids light loss caused by absorptive color filters. Display devices (e.g., liquid crystal displays) that include quantum dot-based emissive color filters can also include polarizers inside the panel (e.g., below the color filter). Depending on the option, the display device may also include a yellow recyclable film (YRF) configured to recycle light and an excitation light blocker (e.g., a blue light cutoff filter or a green light cutoff filter).

[0072] Quantum dots with properties currently applicable to electronic devices are primarily cadmium-based quantum dots. However, cadmium causes serious environmental and health problems and is therefore one of the restricted elements. Cadmium-free quantum dots can be, for example, based on group III-V nanocrystals. However, cadmium-free quantum dots suffer from low absorption per quantum dot, making it difficult for quantum dot color filters to adequately absorb blue light, and exhibiting relatively low light conversion efficiency and a wide full width at half maximum (FWHM) emission spectrum.

[0073] The absorption of blue light in quantum dot color filters is essentially based on the Beer-Lambert law, i.e., I = I0exp(-α), where I is the intensity of the absorbed blue light, I0 is the intensity of the blue light from the source, and α = εlc, where ε is the molar absorptivity of the quantum dot, l is the light travel distance, and c is the molar concentration of the quantum dot. Since quantum dots primarily absorb blue light, the absorptivity (ε) of the quantum dot itself becomes the primary variable for improving absorptivity. The light travel distance (l) is a component determined by considering the thickness of the color filter and the increased light path due to scattering. Typically, since quantum dots are added by weight to achieve color conversion pixels in the color filter, the concentration (c) of quantum dots per unit weight can also be an important variable in determining absorptivity. Therefore, increasing the light absorptivity of the quantum dots before the backscattering effect becomes significant, adding a large number of scattering particles or increasing the pixel thickness, and increasing the number of quantum dot particles per unit weight (i.e., increasing the concentration of quantum dots as much as possible) can be the basic directions for improving blue light absorptivity.

[0074] InP-based quantum dots are materials that do not contain heavy metals (such as cadmium (Cd) or lead (Pb)), exhibiting high quantum efficiencies of over 90% and can be mass-produced industrially. However, in the case of InP-based quantum dots, blue light absorption occurs only in the InP core and a portion of the ZnSe shell. When emission is limited to green light, the core size should also be fixed, making it virtually impossible to structurally increase the absorption coefficient of the quantum dot material itself. On the other hand, in methods that increase the density of the scatterer or the thickness of the color conversion pixel, when considering external light reflection or processability, the scatterer can be added in an amount of about 3 wt% to about 4 wt% based on the total weight of the pixel, and the thickness is almost always fixed at less than or equal to about 10 μm. Therefore, increasing the number of quantum dots per unit weight to increase the concentration of quantum dots inside the color conversion pixel could be a feasible and realistic development direction for increasing blue light absorption.

[0075] Therefore, the inventors have considered a method for minimizing the volume of the shell to reduce the weight of the quantum dots, thereby increasing the number of quantum dots per unit weight (i.e., the concentration of quantum dots in a pixel). This method plays an important role in increasing quantum efficiency but does not contribute to the absorption of excitation light in the quantum dots having a semiconductor nanocrystal core containing indium and phosphorus but excluding cadmium, and a semiconductor nanocrystal shell containing zinc and selenium and optionally sulfur. However, a thin shell should be achieved without degrading luminous efficiency. To achieve this, the inventors have demonstrated that when the quantum dots, for example, include a first semiconductor nanocrystal shell containing zinc and selenium and a second semiconductor nanocrystal shell containing zinc and sulfur, the thickness of each shell can be reduced to a degree that increases blue light absorption without significantly degrading light conversion efficiency, based on measurements of the light conversion efficiency and blue light absorption of the quantum dot composite after curing (POB) according to the thicknesses of the first and second semiconductor nanocrystal shells, thereby increasing the number of quantum dots per unit weight. In addition, another method has been shown to be that, compared with the quantum dots that include a first semiconductor nanocrystal shell containing zinc and selenium and a second semiconductor nanocrystal shell containing zinc and sulfur, when the quantum dots have a semiconductor nanocrystal core containing indium and phosphorus and a semiconductor nanocrystal shell disposed on the semiconductor nanocrystal core and including an alloy composition containing zinc, selenium and sulfur together, the shell thickness can be reduced while ensuring a similar level of energy barrier, thereby increasing the number of quantum dots per unit weight.

[0076] Furthermore, when using these two methods described above, the shell thickness is reduced, and thus the overall weight is reduced, thereby increasing the number of quantum dots per unit weight (i.e., the concentration of quantum dots). In an embodiment, the quantum dots capable of improving blue light absorption are green-emitting quantum dots and / or red-emitting quantum dots, thereby completing the present invention. The green-emitting quantum dots have an emission wavelength between about 500 nm and about 550 nm and an optical density (OD) per 1 mg in the range of about 0.2 to about 0.27 (0.22 to 0.269) for a wavelength of about 450 nm. The red-emitting quantum dots have an emission wavelength between about 610 nm and about 660 nm and an optical density (OD) per 1 mg in the range of about 0.5 to about 0.7 for a wavelength of about 450 nm.

[0077] Quantum dots can be dispersed (or set) in a matrix and can be provided as quantum dot composites. An example is a color conversion layer comprising the quantum dots described herein or a quantum dot composite containing the quantum dots.

[0078] According to embodiments, quantum dots include metals comprising indium and zinc and nonmetals comprising phosphorus and selenium but excluding cadmium. The quantum dots (e.g., a first quantum dot) have an optical density (OD) per 1 mg for a wavelength of about 450 nm in the range of about 0.2 to about 0.27 and have an emission peak between about 500 nm and about 550 nm, or the quantum dots (e.g., a second quantum dot) have an optical density (OD) per 1 mg for a wavelength of about 450 nm in the range of about 0.5 to about 0.7 and have an emission peak between about 610 nm and about 660 nm. In embodiments, a display device may include quantum dots such as the first quantum dot and / or the second quantum dot, or a quantum dot composite (color conversion layer) comprising quantum dots. The quantum dot composite may be included in the color conversion region of the color conversion layer.

[0079] In an embodiment, the display panel includes a quantum dot composite (color conversion layer) comprising a matrix and a plurality of quantum dots, wherein the plurality of quantum dots comprise metals and nonmetals, the metals comprising indium and zinc, the nonmetals comprising phosphorus and selenium, and optionally sulfur.

[0080] Among them, multiple quantum dots include (multiple) first quantum dots and (multiple) second quantum dots.

[0081] Among them, (a plurality of) first quantum dots have or exhibit an optical density (OD) per 1 mg at a wavelength of 450 nm in the range of about 0.2 to about 0.27 (e.g., greater than or equal to about 0.22 or 0.222 or 0.225 or greater and less than or equal to about 0.269) and have or exhibit an emission peak between about 500 nm and about 550 nm, and

[0082] The second quantum dots (multiple of them) have or exhibit an optical density per 1 mg at a wavelength of about 450 nm in the range of about 0.5 to about 0.7 and have or exhibit an emission peak between about 610 nm and about 660 nm. The optical density per unit weight of quantum dots can be readily measured using optical density measurement methods or instruments known in the art (e.g., based on UV-Vis spectroscopy). UV-Vis spectroscopy is based on absorbance. For example, quantum dots comprising metals including indium and zinc and nonmetals including phosphorus and selenium but excluding cadmium can be prepared by known or commercially available methods, dispersed in toluene, and then placed in a cuvette with an optical path of a specific length (e.g., about 1 cm), and the optical density of the dispersion is measured relative to the wavelength. Subsequently, after removing the solvent from the measured dispersion, the weight of the quantum dots in the measured dispersion is measured, and the measured optical density is converted to the optical density per 1 mg of quantum dots using the weight of the quantum dots, thus obtaining the optical density per unit weight of quantum dots.

[0083] In an embodiment, the quantum dots (e.g., the first quantum dots) may be quantum dots having an optical density per 1 mg for a wavelength of about 460 nm in the range of about 0.12 to about 0.35 and emitting green light with an emission peak between about 500 nm (or about 530 nm) and about 550 nm (or about 540 nm).

[0084] In another embodiment, the quantum dots (e.g., the second quantum dots) may be quantum dots emitting red light having an optical density per 1 mg for a wavelength of about 460 nm in the range of about 0.4 to about 0.5 and having an emission peak of about 610 nm (or about 635 nm) to about 660 nm (or about 645 nm).

[0085] Since quantum dots (e.g., first quantum dots, second quantum dots, or both, hereinafter simply referred to as "quantum dots") according to the embodiments can be dispersed in large quantities (i.e., at high concentrations) in various types of matrices known in the art to fabricate quantum dot color filters, the quantum dot composite prepared therefrom can absorb more excitation light from a light source configured to emit blue light. In other words, the quantum dot composite can exhibit increased blue light absorption. Therefore, this quantum dot composite can be advantageously applied to color conversion layers, etc., in various display devices.

[0086] As described above, in a quantum dot composed of a core and a shell, the shell can passivate surface defects in the semiconductor nanocrystal core and structurally stabilize the quantum dot, thereby improving luminous efficiency. Therefore, if increasing the blue light absorption rate by reducing the shell thickness adversely affects the effect of preventing surface defects, then although the blue light absorption rate increases, the luminous efficiency will deteriorate. The quantum dot according to the embodiment has the effect of improving the light conversion efficiency of quantum dot composites including the quantum dot (such as quantum dot color filters) when the blue light absorption rate increases or even slightly decreases.

[0087] When the emission peak of the quantum dot according to the embodiment is between about 500 nm and about 550 nm (i.e., when the quantum dot emits green light or in the case of the first quantum dot), the emission peak of the quantum dot may be greater than or equal to about 510 nm, greater than or equal to about 520 nm, greater than or equal to about 530 nm, or greater than or equal to about 535 nm and less than or equal to about 545 nm, less than or equal to about 540 nm, or less than or equal to about 535 nm.

[0088] When the emission peak of the quantum dot according to the embodiment is between about 600 nm and about 660 nm (i.e., when the quantum dot emits red light or in the case of a second quantum dot), the emission peak of the quantum dot may be greater than or equal to about 615 nm, greater than or equal to about 620 nm, or greater than or equal to about 625 nm and less than or equal to about 655 nm, less than or equal to about 650 nm, less than or equal to about 645 nm, less than or equal to about 640 nm, or less than or equal to about 630 nm.

[0089] As described above, the quantum dot (e.g., a first quantum dot and / or a second quantum dot) according to the embodiments may include a semiconductor nanocrystal core comprising indium and phosphorus and a semiconductor nanocrystal shell disposed on the semiconductor nanocrystal core and comprising zinc and selenium, the semiconductor nanocrystal shell may further comprise sulfur.

[0090] When the semiconductor nanocrystal shell further includes sulfur, the semiconductor nanocrystal shell may further include a first semiconductor nanocrystal shell disposed on the semiconductor nanocrystal core and containing zinc and selenium, and a second semiconductor nanocrystal shell disposed on the first semiconductor nanocrystal shell and containing zinc and sulfur. The first semiconductor nanocrystal shell may not include ZnSeS. The first semiconductor nanocrystal shell may be directly disposed on the semiconductor nanocrystal core.

[0091] The second semiconductor nanocrystal shell may include ZnS. The second semiconductor nanocrystal shell may not include selenium. The second semiconductor nanocrystal shell may be directly disposed on the first semiconductor nanocrystal shell. The second semiconductor nanocrystal shell may be the outermost layer of a quantum dot.

[0092] In the embodiments, the semiconductor nanocrystal core may further include zinc, or may not further include zinc.

[0093] In this embodiment, the semiconductor nanocrystal core may be InP or InZnP. The (average) size of the core may be greater than or equal to about 1 nm, greater than or equal to about 1.5 nm, greater than or equal to about 2 nm, greater than or equal to about 3 nm, or greater than or equal to about 3.3 nm. For example, the size of the core may be less than or equal to about 5 nm, less than or equal to about 4 nm, or less than or equal to about 3.8 nm.

[0094] In embodiments, the shell thickness of the quantum dots can be greater than or equal to about 1.5 nm, greater than or equal to about 1.6 nm, greater than or equal to about 1.7 nm, greater than or equal to about 1.8 nm, greater than or equal to about 1.9 nm, or greater than or equal to about 2 nm. For example, the shell thickness of the semiconductor nanocrystals can be less than or equal to about 2.5 nm, less than or equal to about 2.4 nm, less than or equal to about 2.3 nm, less than or equal to about 2.2 nm, or less than or equal to about 2.1 nm.

[0095] In embodiments, the thickness of the first semiconductor nanocrystal shell can be about three monolayers (ML) or greater, for example, about 3.5 ML or greater, about 3.6 ML or greater, about 3.7 ML or greater, about 3.8 ML or greater, about 3.9 ML or greater, about 4 ML or greater, about 4.1 ML or greater, about 4.2 ML or greater, about 4.3 ML or greater, or about 4.4 ML or greater. The thickness of the first semiconductor nanocrystal shell can be about 7 ML or less, for example, about 6 ML or less, or about 5 ML or less. In embodiments, the thickness of the first semiconductor nanocrystal shell can be greater than or equal to about 0.9 nm, greater than or equal to about 1 nm, greater than or equal to about 1.1 nm, greater than or equal to about 1.2 nm, greater than or equal to about 1.3 nm, greater than or equal to about 1.4 nm, greater than or equal to about 1.43 nm, or greater than or equal to about 1.45 nm. In the embodiments, the thickness of the first semiconductor nanocrystal shell may be less than or equal to about 1.8 nm, less than or equal to about 1.75 nm, less than or equal to about 1.7 nm, less than or equal to about 1.6 nm, less than or equal to about 1.55 nm, or less than or equal to about 1.51 nm.

[0096] The (average) thickness of the second semiconductor nanocrystal shell can be less than or equal to about 0.65 nm, less than or equal to about 0.64 nm, less than or equal to about 0.63 nm, less than or equal to about 0.62 nm, less than or equal to about 0.61 nm, less than or equal to about 0.6 nm, or less than or equal to about 0.59 nm. The thickness of the second semiconductor nanocrystal shell can be greater than or equal to about 0.4 nm, greater than or equal to about 0.45 nm, greater than or equal to about 0.5 nm, greater than or equal to about 0.51 nm, greater than or equal to about 0.52 nm, greater than or equal to about 0.53 nm, or greater than or equal to about 0.54 nm.

[0097] Quantum dots can refer to a single particle (a single entity) or multiple particles, and can be free of harmful heavy metals (e.g., cadmium, lead, mercury, or combinations thereof).

[0098] In the (first and / or second) quantum dots of the embodiments, the weight ratio of zinc to indium (i.e., Zn / In) can be greater than or equal to about 10 and less than or equal to about 30, for example, greater than or equal to about 11 and less than or equal to about 29, greater than or equal to about 11.5 and less than or equal to about 27, greater than or equal to about 11.7 and less than or equal to about 26, but is not limited thereto. For example, the weight ratio of zinc to indium (i.e., Zn / In) can be greater than or equal to about 11.3, greater than or equal to about 11.5, greater than or equal to about 11.7, greater than or equal to about 11.75, greater than or equal to about 12, greater than or equal to about 13, greater than or equal to about 13.5, greater than or equal to about 14, greater than or equal to about 15, greater than or equal to about 16, greater than or equal to about 17, greater than or equal to about 18, greater than or equal to about 19, greater than or equal to about 20, greater than or equal to about 21, greater than or equal to about 22, greater than or equal to about 23, greater than or equal to about 24, or greater than or equal to about 25 and less than or equal to about 30, less than or equal to about 29, less than or equal to about 28, less than or equal to about 27.5, less than or equal to about 27, less than or equal to The following values ​​are included: approximately 26.5, less than or equal to approximately 26, less than or equal to approximately 25.8, less than or equal to approximately 25.7, less than or equal to approximately 25.5, less than or equal to approximately 25, less than or equal to approximately 24, less than or equal to approximately 23, less than or equal to approximately 22, less than or equal to approximately 21, less than or equal to approximately 20, less than or equal to approximately 19, less than or equal to approximately 18, less than or equal to approximately 17, less than or equal to approximately 16, less than or equal to approximately 15.5, less than or equal to approximately 15, less than or equal to approximately 14, less than or equal to approximately 13.5, less than or equal to approximately 13, less than or equal to approximately 12.5, less than or equal to approximately 12, less than or equal to approximately 11.75, less than or equal to approximately 11.5, less than or equal to approximately 11, or less than or equal to approximately 10.5, but not limited to these.

[0099] In the (first and / or second) quantum dots according to the embodiments, the weight ratio of selenium to indium (i.e., Se / In) can be greater than or equal to about 2.9 and less than or equal to about 20, for example, greater than or equal to about 3, greater than or equal to about 4, greater than or equal to about 5, greater than or equal to about 6, greater than or equal to about 7, greater than or equal to about 8, greater than or equal to about 9, greater than or equal to about 10, greater than or equal to about 11, greater than or equal to about 12, greater than or equal to about 13, greater than or equal to about 14, greater than or equal to about 15, greater than or equal to about 16, greater than or equal to about 17. , greater than or equal to about 18 or greater than or equal to about 19 and less than or equal to about 20, less than or equal to about 19, less than or equal to about 18, less than or equal to about 17, less than or equal to about 16, less than or equal to about 15, less than or equal to about 14, less than or equal to about 13, less than or equal to about 12, less than or equal to about 11, less than or equal to about 10.5, less than or equal to about 10, less than or equal to about 9, less than or equal to about 8, less than or equal to about 7, less than or equal to about 6, less than or equal to about 5, less than or equal to about 4 or less than or equal to about 3, but not limited thereto.

[0100] In the (first and / or second) quantum dots according to the embodiments, the weight ratio of sulfur to indium (i.e., S / In) can be greater than or equal to about 1 and less than or equal to about 10, for example, greater than or equal to about 1.2 and less than or equal to about 9, greater than or equal to about 1.25 and less than or equal to about 8.7, but is not limited thereto. For example, the ratio can be greater than or equal to about 1.2, greater than or equal to about 1.28, greater than or equal to about 1.3, greater than or equal to about 1.5, greater than or equal to about 2, greater than or equal to about 3, greater than or equal to about 4, greater than or equal to about 5, greater than or equal to about 6, greater than or equal to about 7, greater than or equal to about 8, or greater than or equal to about 9 and less than or equal to about 10, less than or equal to about 9.5, less than or equal to about 9, less than or equal to about 8.7, less than or equal to about 8.5, less than or equal to about 8, less than or equal to about 7, or less than or equal to about 6, but is not limited thereto. When considering the weight ratio of sulfur to indium in quantum dots, the sulfur content derived from ligands capable of binding to the surface of quantum dots, as described below, is not taken into account.

[0101] In the (first and / or second) quantum dots, the molar ratio of indium to the sum of sulfur and selenium (i.e., In / (S+Se)) can be greater than or equal to about 0.09, greater than or equal to about 0.095, greater than or equal to about 0.097, or greater than or equal to about 0.0975. In the quantum dots, the molar ratio of indium to the sum of sulfur and selenium (i.e., In / (S+Se)) can be less than or equal to about 0.12, less than or equal to about 0.115, less than or equal to about 0.113, less than or equal to about 0.111, less than or equal to about 0.11, or less than or equal to about 0.109.

[0102] In the (first and / or second) quantum dots, the molar ratio of the sum of sulfur and selenium to indium (i.e., (S+Se) / In) can be greater than or equal to about 8.96, greater than or equal to about 9.1, greater than or equal to about 9.2, greater than or equal to about 9.3, greater than or equal to about 9.4, greater than or equal to about 9.5, greater than or equal to about 9.6, greater than or equal to about 9.65, greater than or equal to about 9.7, greater than or equal to about 9.8, greater than or equal to about 9.9, greater than or equal to about 10, greater than or equal to about 10.1, or greater than or equal to about 10.2. In the quantum dots, the molar ratio of the sum of sulfur and selenium to indium (i.e., (S+Se) / In) can be less than or equal to about 10.5, less than or equal to about 10.3, or less than or equal to about 10.25.

[0103] The dimensions of the (first and / or second) quantum dots according to the embodiments may be greater than or equal to about 5 nm, greater than or equal to about 5.5 nm, greater than or equal to about 6 nm, greater than or equal to about 6.5 nm, greater than or equal to about 7.5 nm, greater than or equal to about 7.6 nm, or greater than or equal to about 7.7 nm. The dimensions of the (first and / or second) quantum dots may be less than or equal to about 8 nm, less than or equal to about 7.9 nm, less than or equal to about 7.8 nm, less than or equal to about 7.5 nm, less than or equal to about 7 nm, less than or equal to about 6.5 nm, less than or equal to about 6 nm, or less than or equal to about 5.5 nm.

[0104] The size or average size of the (first and / or second) quantum dots can be calculated by analyzing images using an electron microscope. In an embodiment, the size (or average size) can be the diameter or equivalent diameter (or its average value) determined by analysis of electron microscope images.

[0105] The shape of the (first and / or second) quantum dots is not particularly limited and may include, for example, spherical, polyhedral, pyramidal, multi-armed, cubic nanotubes, nanowires, nanofibers, nanosheets or combinations thereof, but is not limited thereto.

[0106] (First and / or second) Quantum dots may include organic ligands and / or organic solvents, which will be described later, on their surfaces. Organic ligands and / or organic solvents may be bound to the surface of the quantum dots.

[0107] In embodiments, the (first and / or second) quantum dots, in solution or in the solid state, may have a quantum efficiency greater than or equal to about 90%, greater than or equal to about 91%, greater than or equal to about 92%, greater than or equal to about 93%, greater than or equal to about 94%, or greater than or equal to about 95%. Additionally, the (first and / or second) quantum dots, in solution or in the solid state, may have a full width at half maximum (FWHM) less than or equal to about 40 nm (e.g., less than or equal to about 39 nm, less than or equal to about 37 nm, less than or equal to about 36 nm, or less than or equal to about 35 nm). The quantum dots may have an FWHM greater than or equal to about 5 nm (e.g., greater than or equal to about 10 nm, for example, greater than or equal to about 15 nm, or for example, greater than or equal to 20 nm).

[0108] The quantum dots according to the embodiments (first and / or second) can be prepared by a method comprising the steps of: preparing a core comprising a semiconductor nanocrystal containing indium and phosphorus; and reacting a precursor for forming a semiconductor nanocrystal shell with the core in a suitable solvent to form a semiconductor nanocrystal shell comprising zinc, selenium, and optionally sulfur on the core. Furthermore, the quantum dots according to the embodiments can be prepared by a method further comprising the steps of: introducing a precursor for forming an additional semiconductor nanocrystal shell onto particles in which the semiconductor nanocrystal shell is formed on the semiconductor nanocrystal core, and further using a precursor reaction for forming the additional semiconductor nanocrystal shell, said additional semiconductor nanocrystal shell comprising zinc and sulfur, and optionally selenium.

[0109] When forming the semiconductor nanocrystal shell and additional semiconductor nanocrystal shells, suitable organic ligands and / or surfactants may be included and reacted together, if necessary. Additionally, the step of preparing the semiconductor nanocrystal core may include preparing precursors of an indium compound and a phosphorus compound for preparing the semiconductor nanocrystal core and reacting them to prepare an in-situ semiconductor nanocrystal core, or using commercially available semiconductor nanocrystal cores. The quantum dot preparation method according to the embodiments described above can be readily performed using various quantum dot preparation methods known to those skilled in the art.

[0110] In each reaction step used to manufacture quantum dots, the contents of the zinc precursor, selenium precursor, and sulfur precursor relative to indium, as well as the total amount of each precursor, can be adjusted to achieve the composition of the quantum dots as described above. In each step, the desired reaction time can be adjusted to obtain the desired composition and / or structure (e.g., core / multilayer shell structure) of the final quantum dots.

[0111] There are no particular limitations on the zinc precursor, and it can be Zn metal powder, alkylated Zn compounds, alcoholic Zn, C2 to C10 carboxylic acid Zn, nitric acid Zn, perchloric acid Zn, sulfuric acid Zn, acetylacetone Zn, halogenated Zn, cyanide Zn, hydroxide Zn, oxide Zn, peroxide Zn, or combinations thereof. Examples of the first shell precursor may include dimethyl zinc, diethyl zinc, zinc acetate, zinc acetylacetone, zinc iodide, zinc bromide, zinc chloride, zinc fluoride, zinc carbonate, zinc cyanide, zinc nitrate, zinc oxide, zinc peroxide, zinc perchlorate, zinc sulfate, etc.

[0112] There are no particular restrictions on selenium-containing precursors, and they can be, for example, selenium, selenium-trioctylphosphine (Se-TOP), selenium-tributylphosphine (Se-TBP), selenium-triphenylphosphine (Se-TPP), or combinations thereof, but are not limited thereto.

[0113] There are no particular restrictions on sulfur-containing precursors, and they can be, for example, sulfur powder, hexamethylenetetramine, octanethiol, decanethiol, dodecanethiol, hexadecylthiol, mercaptopropylsilane, thio-trioctylphosphine (S-TOP), thio-tributylphosphine (S-TBP), thio-triphenylphosphine (S-TPP), thio-trioctylamine (S-TOA), trimethylsilyl sulfide, ammonium sulfide, sodium sulfide, or combinations thereof.

[0114] Organic ligands may include RCOOH, RNH2, R2NH, R3N, RSH, RH2PO, R2HPO, R3PO, RH2P, R2HP, R3P, ROH, RCOOR', RPO(OH)2, R2POOH (wherein R and R' are independently (e.g., C1 to C40 or C3 to C35 or C8 to C24) substituted or unsubstituted aliphatic hydrocarbon groups (e.g., alkyl, alkenyl, alkynyl) or (e.g., C6 to C40 or C6 to C24) substituted or unsubstituted aromatic hydrocarbon groups (e.g., aryl)) or combinations thereof.

[0115] Organic ligands coordinate with the surface of the prepared nanocrystals, enabling the nanocrystals to be well dispersed in the solution phase. Specific examples of organic ligands may include: methanethiol, ethanethiol, propanethiol, butanethiol, pentylenetetrazol, hexanethiol, octylthiol, dodecylthiol, hexadecylthiol, octadecylthiol, benzylthiol; methylamine, ethylamine, propylamine, butylamine, pentylemine, hexylamine, octylamine, dodecylamine, hexadecylamine, octadecylamine, dimethylamine, diethylamine, dipropylamine; formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, octanoic acid, dodecanoic acid, hexadecanoic acid, octadecanoic acid, oleic acid, benzoic acid; phosphine, such as substituted or unsubstituted methylphosphine (e.g., trimethylphosphine, methyldiphenylphosphine, etc.), substituted or unsubstituted ethylphosphine (e.g., triethylphosphine, ethyldiphenylphosphine, etc.), substituted or unsubstituted... Substituted propylphosphine, substituted or unsubstituted butylphosphine, substituted or unsubstituted pentylphosphine, substituted or unsubstituted octylphosphine (e.g., trioctylphosphine (TOP)), etc.; phosphine oxides, such as substituted or unsubstituted methylphosphine oxide (e.g., trimethylphosphine oxide, methyldiphenylphosphine oxide, etc.), substituted or unsubstituted ethylphosphine oxide (e.g., triethylphosphine oxide, ethyldiphenylphosphine oxide, etc.), substituted or unsubstituted propylphosphine oxide, substituted or unsubstituted butylphosphine oxide, substituted or unsubstituted octylphosphine oxide (e.g., trioctylphosphine oxide (TOPO)), etc.; diphenylphosphine, triphenylphosphine, or oxides thereof; phosphonic acids, etc., but not limited thereto. Organic ligands may be used alone or as a mixture of two or more.

[0116] (Organic) solvents may include: C6 to C22 primary amines, such as hexadecylamine; C6 to C22 secondary amines, such as dioctylamine; C6 to C40 tertiary amines, such as trioctylamine; nitrogen-containing heterocyclic compounds, such as pyridine; C6 to C40 aliphatic hydrocarbons (e.g., alkanes, alkenes, alkynes, etc.), such as hexadecane, octadecane, octadecene, and squalane; C6 to C30 aromatic hydrocarbons, such as phenyldodecane, phenyltetradecane, and phenylhexadecane; phosphine substituted with C6 to C22 alkyl groups, such as trioctylphosphine; phosphine oxide substituted with C6 to C22 alkyl groups, such as trioctylphosphine oxide; C12 to C22 aromatic ethers, such as phenyl ethers and benzyl ethers; and combinations thereof. The type and amount of solvent can be appropriately selected considering the type of precursor and organic ligand.

[0117] Semiconductor nanocrystal particles comprising indium and phosphorus can be the core as described above. The semiconductor nanocrystal particles (hereinafter referred to as the "core") are commercially available or can be synthesized using known methods for preparing indium phosphide-based cores. The cores of the embodiments can be prepared by a hot-injection method, in which a solution comprising a metal precursor (such as an indium precursor, for example) and optionally a ligand is heated to a high temperature (e.g., about 200°C or higher) and a phosphorus precursor is injected.

[0118] When a non-solvent is added to the final reaction solution, the nanocrystals coordinated to the organic ligands can be separated (e.g., precipitated). The non-solvent can be a polar solvent miscible with the solvent used in the reaction but unable to disperse the nanocrystals. The non-solvent can be selected based on the solvent used in the reaction and can be, for example, acetone, ethanol, butanol, isopropanol, ethylene glycol, water, tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), diethyl ether, formaldehyde, acetaldehyde, solvents having a solubility parameter similar to the solvents mentioned above, or combinations thereof. Separation can be performed by centrifugation, precipitation, chromatography, or distillation. If necessary, the separated nanocrystals can be washed with a washing solvent. There are no particular limitations on the washing solvent, and it can have a solubility parameter similar to that of the ligand, and can include, for example, hexane, heptane, octane, chloroform, toluene, benzene, etc.

[0119] According to another embodiment, the display panel includes a quantum dot composite (color conversion layer), the quantum dot composite including a matrix and a plurality of quantum dots dispersed in the matrix and titanium dioxide (TiO2), wherein the plurality of quantum dots in the quantum dot composite include metals including indium and zinc and nonmetals including phosphorus and selenium, in the display panel (or in the color conversion layer or in the color conversion region and the light-transmitting region), the weight ratio of indium (In) to titanium (Ti) is greater than or equal to about 0.1 and less than or equal to about 0.7 or less than or equal to about 0.5, and the weight ratio of phosphorus (P) to Ti is greater than or equal to about 0.05 and less than or equal to about 0.12 or less than or equal to about 0.15.

[0120] In an embodiment, in the display panel (or in the color conversion layer or in the color conversion area and the light-transmitting area), the weight ratio of selenium (Se) to Ti is greater than or equal to about 0.5 and less than or equal to about 5 or greater than or equal to about 0.5 and less than or equal to about 3.

[0121] As described above, since the blue light absorption rate is increased by appropriately reducing the shell thickness without reducing the luminous efficiency, the quantum dots, according to the embodiment, can be included in a large quantity in the pixels constituting the quantum dot color filter when prepared as a quantum dot composite for forming quantum dot color filters, etc. Furthermore, the quantum dot composite includes quantum dots with shells of a predetermined thickness, thereby including elements within a specific content range. Therefore, the display panel including the quantum dot composite can also have each element within a specific content range in the color conversion area including the quantum dot composite. Moreover, the display panel according to the embodiment includes a quantum dot composite comprising a plurality of quantum dots according to the embodiment and a plurality of titanium dioxide particles in a matrix. Therefore, throughout the entire display panel according to the embodiment, the ratio of the content (e.g., weight or molar number) of each element constituting the quantum dots included in the quantum dot composite (e.g., the content of indium, phosphorus, and selenium (e.g., weight or molar number)) to the content (e.g., weight or molar number) of titanium derived from titanium dioxide can exist within a specific range. The content ratios between these elements may differ from the weight or molar ratios of corresponding elements in conventional quantum dot composites or display panels that include conventional quantum dots constituting the same elements and titanium dioxide.

[0122] In embodiments, the weight ratio of indium (In) to titanium (Ti) in the display panel (or in the color conversion layer or in the color conversion region and the light-transmitting region) can be greater than or equal to about 0.15 and less than or equal to about 0.7, less than or equal to about 0.5, or less than or equal to about 0.4, for example, greater than or equal to about 0.16 and less than or equal to about 0.36. For example, when the content of titanium dioxide in the display panel or the color conversion layer is about 5 wt% to about 10 wt%, as the content of titanium dioxide increases, the weight ratio of In to Ti can have a lower value within the above range, and as the content of titanium dioxide decreases within the above range, the weight ratio of In to Ti can have a higher value within the above range. For example, when titanium dioxide is present at about 10 wt%, the weight ratio of In to Ti can be about 0.16 to about 0.26, and when the content of titanium dioxide is about 5 wt%, the weight ratio of In to Ti can be about 0.22 to about 0.36.

[0123] Furthermore, the weight ratio of phosphorus (P) to titanium (Ti) in the display panel (e.g., in the color conversion layer or in the color conversion area and the light-transmitting area) can be greater than or equal to about 0.06 and less than or equal to about 0.2, less than or equal to about 0.15, or less than or equal to about 0.13. For example, greater than or equal to about 0.06 and less than or equal to about 0.12. When the content of titanium dioxide in the display panel (e.g., in the color conversion layer or in the color conversion area and the light-transmitting area) is about 5 wt% to about 10 wt%, as the content of titanium dioxide increases, the weight ratio of P to Ti can have a lower value within the above range, and as the content of titanium dioxide decreases within the above range, the weight ratio of P to Ti can have a higher value within the above range. For example, when titanium dioxide is present at about 10 wt%, the weight ratio of P to Ti can be about 0.06 to about 0.08, and when the content of titanium dioxide is about 5 wt%, the weight ratio of P to Ti can be about 0.08 to about 0.12.

[0124] Furthermore, the weight ratio of selenium (Se) to titanium (Ti) in the display panel (e.g., in the color conversion layer or in the color conversion area and the light-transmitting area) can be greater than or equal to about 0.8 and less than or equal to about 2.7, for example, greater than or equal to about 0.9 and less than or equal to about 2.66. When the titanium dioxide content in the display panel is about 5 wt% to about 10 wt%, as the titanium dioxide content increases, the weight ratio of Se to Ti can have a lower value within the above range, and as the titanium dioxide content decreases within the above range, the weight ratio of Se to Ti can have a higher value within the above range. For example, when titanium dioxide is present at about 10 wt%, the weight ratio of Se to Ti can be about 0.95 to about 1.95, and when the titanium dioxide content is about 5 wt%, the weight ratio of Se to Ti can be about 1.3 to about 2.66.

[0125] The content of each element in the display panel (e.g., in the color conversion layer or in the color conversion area and the light-transmitting area) and the content of Ti can be converted into the molar number of each atom. For example, the ratio of the molar number of indium (In) to the molar number of titanium (Ti) in the display panel (e.g., in the color conversion layer or in the color conversion area and the light-transmitting area) can be greater than or equal to about 0.05 and less than or equal to about 0.2, the ratio of the molar number of phosphorus (P) to the molar number of titanium (Ti) can be greater than or equal to about 0.05 and less than or equal to about 0.2, and the ratio of the molar number of selenium (Se) to the molar number of titanium (Ti) can be greater than or equal to about 1 and less than or equal to about 4.

[0126] In an embodiment, when a quantum dot composite comprising quantum dots and titanium dioxide according to an embodiment is applied to a display panel, the content (e.g., molar or weight) ratio between the elements mentioned herein (i.e., the ratio of the weight or molar number of indium, phosphorus, and selenium included in the display panel (e.g., in the color conversion layer or in the color conversion region and the light-transmitting region) to the weight or molar number of titanium (Ti) derived from titanium dioxide) can be obtained by taking into account (e.g., comparing) the weight or molar number of each of indium, phosphorus, and selenium (in the display panel or in the color conversion layer or in the color conversion region and the light-transmitting region) with the weight or molar number of titanium.

[0127] Meanwhile, quantum dot composites can be manufactured by a composition comprising (a plurality of) quantum dots according to the embodiments (e.g., in a solid state by polymerization, etc.).

[0128] The quantum dot composition may include: (e.g., multiple) the quantum dots described above; optional monomers, dispersants, or combinations thereof; and (organic) solvents and / or liquid carriers. The dispersant can disperse the quantum dots. The dispersant may include a compound (monomer or polymer) containing a carboxylic acid group. The composition may also include a (photo)polymerizable monomer containing a carbon-carbon double bond and optional (thermal or photo) initiator. The composition may be a photosensitizing composition.

[0129] Since the details of the quantum dots in the composition are the same as those of the quantum dots according to the above embodiments, their detailed description will be omitted.

[0130] The content of quantum dots in the composition can be appropriately adjusted with consideration for the end use (e.g., color conversion layer or color conversion panel such as an emissive color filter). In the composition (or complex), based on the total weight or total solids content of the composition or complex, the content of (a plurality of) quantum dots can be greater than or equal to about 1 wt%, for example, greater than or equal to about 2 wt%, greater than or equal to about 3 wt%, greater than or equal to about 4 wt%, greater than or equal to about 5 wt%, greater than or equal to about 6 wt%, greater than or equal to about 7 wt%, greater than or equal to about 8 wt%, greater than or equal to about 9 wt%, greater than or equal to about 10 wt%, greater than or equal to about 15 wt%, greater than or equal to about 20 wt%, greater than or equal to about 25 wt%, greater than or equal to about 30 wt%, greater than or equal to about 35 wt%, or greater than or equal to about 40 wt%. Based on the total weight or total solids content of the composition or complex, the quantum dot content may be less than or equal to about 70 wt%, less than or equal to about 65 wt%, less than or equal to about 60 wt%, less than or equal to about 55 wt%, less than or equal to about 50 wt%, less than or equal to about 45 wt%, less than or equal to about 40 wt%, or less than or equal to about 30 wt%.

[0131] Here, (for example, when the quantum dot composition includes an organic solvent), the total solids content in the composition can correspond to the content of the corresponding component in the quantum dot composite. For example, when the quantum dot composition is a solvent-free system (excluding organic solvents), the content range in the composition can correspond to the content range in the composite.

[0132] In the compositions according to the embodiments, the dispersant can help ensure the dispersibility of quantum dots and / or titanium dioxide. In the embodiments, the dispersant may include (e.g., an organic compound containing a carboxylic acid group) (e.g., a monomer or polymer) (e.g., an adhesive polymer). The dispersant or adhesive polymer may be an insulating polymer.

[0133] Organic compounds containing a carboxylic acid group may include:

[0134] Combinations of monomers or copolymers of monomers, wherein the monomers include a first monomer, a second monomer and an optional third monomer, the first monomer having a carboxylic acid group and a carbon-carbon double bond, the second monomer having a carbon-carbon double bond and a hydrophobic portion but not having a carboxylic acid group, and the optional third monomer having a carbon-carbon double bond and a hydrophilic portion but not having a carboxylic acid group;

[0135] Polymers containing multiple aromatic rings (hereinafter, cardo adhesives) having a backbone in which two aromatic rings in the main chain are bonded to a quaternary carbon atom and have a carboxylic acid group (-COOH), the quaternary carbon atom being a constituent atom of the other ring moieties; or

[0136] Their combination.

[0137] The dispersant may include the first monomer, the second monomer, and optionally the third monomer.

[0138] Based on the total weight or total solids content of the composition or composite, the content of the dispersant (or binder polymer) in the composition may be greater than or equal to about 0.5 wt%, for example, greater than or equal to about 1 wt%, greater than or equal to about 5 wt%, greater than or equal to about 10 wt%, greater than or equal to about 15 wt%, greater than or equal to about 20 wt%, greater than or equal to about 30 wt%, greater than or equal to about 40 wt%, or greater than or equal to about 50 wt%, but is not limited thereto. Based on the total weight or total solids content of the composition or composite, the content of the dispersant (or binder polymer) may be less than or equal to about 60 wt%, less than or equal to about 50 wt%, less than or equal to about 40 wt%, less than or equal to about 35 wt%, less than or equal to about 33 wt%, less than or equal to about 30 wt%, less than or equal to about 20 wt%, or less than or equal to about 10 wt%. Based on the total weight or total solids content of the composition or composite, the content of the dispersant (or binder polymer) may be from about 0.5 wt% to about 55 wt%.

[0139] The composition may include polymerizable (e.g., photopolymerizable) monomers containing carbon-carbon double bonds. Monomers may include (e.g., photopolymerizable) (meth)acrylic acid monomers. Monomers may be precursors for insulating polymers.

[0140] Based on the total weight or total solids content of the composition or complex, the monomer content may be greater than or equal to about 0.5 wt%, for example, greater than or equal to about 1 wt%, greater than or equal to about 2 wt%, greater than or equal to about 5 wt%, greater than or equal to about 10 wt%, greater than or equal to about 15 wt%, greater than or equal to about 20 wt%, greater than or equal to about 25 wt%, or greater than or equal to about 30 wt%. Based on the total weight or total solids content of the composition or complex, the content of (photo)polymerizable monomers may be less than or equal to about 60 wt%, less than or equal to about 50 wt%, less than or equal to about 40 wt%, less than or equal to about 30 wt%, less than or equal to about 28 wt%, less than or equal to about 25 wt%, less than or equal to about 23 wt%, less than or equal to about 20 wt%, less than or equal to about 18 wt%, less than or equal to about 17 wt%, less than or equal to about 16 wt%, or less than or equal to about 15 wt%.

[0141] The (photo)initiator included in the composition can be used for the (photo)polymerization of the aforementioned monomers. An initiator is a compound that promotes a free radical reaction (e.g., free radical polymerization of monomers) by generating free radical chemicals under mild conditions (e.g., by heat or light). The initiator can be a thermal initiator or a photoinitiator. There are no particular limitations on the initiator, and it can be appropriately selected.

[0142] In the composition, the initiator content can be appropriately adjusted by considering the type and amount of polymerizable monomers. In the examples, based on the total weight of the composition (or the total weight of the solid content), the initiator content can be greater than or equal to about 0.01 wt% (e.g., greater than or equal to about 1 wt%, greater than or equal to about 5 wt%, or greater than or equal to about 10 wt%) and, for example, less than or equal to about 9 wt%, less than or equal to about 8 wt%, less than or equal to about 7 wt%, less than or equal to about 6 wt%, or less than or equal to about 5 wt%, but is not limited thereto.

[0143] The composition may also include a thiol compound (polyfunctional or monofunctional) or a combination thereof having at least one thiol group at the end.

[0144] In the embodiments, based on the total weight (or solid weight) of the composite, the content of titanium dioxide (TiO2) in the composite may be greater than or equal to about 1 wt%, greater than or equal to about 5 wt%, greater than or equal to about 10 wt%, greater than or equal to about 15 wt%, greater than or equal to about 20 wt%, greater than or equal to about 25 wt%, greater than or equal to about 30 wt%, or greater than or equal to about 35 wt% and / or less than or equal to about 60 wt%, less than or equal to about 50 wt%, less than or equal to about 40 wt%, less than or equal to about 30 wt%, less than or equal to about 25 wt%, less than or equal to about 20 wt%, less than or equal to about 15 wt%, less than or equal to about 10 wt%, or less than or equal to about 5 wt%, for example, from about 5 wt% to about 10 wt%.

[0145] Titanium dioxide (TiO2) exists in the matrix in the form of particles, and the diameter of the particles is not particularly limited and can be appropriately selected. The diameter of titanium dioxide (TiO2) can be greater than or equal to about 100 nm (e.g., greater than or equal to about 150 nm or greater than or equal to about 200 nm) and less than or equal to about 1000 nm, less than or equal to about 800 nm, less than or equal to about 500 nm, less than or equal to about 400 nm, or less than or equal to about 300 nm.

[0146] (Multi)thiol compounds can be dithiols, trithiols, tetrathiols, or combinations thereof. For example, thiols can be ethylene glycol di-3-mercaptopropionate, ethylene glycol dimercaptoacetate, trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetra(3-mercaptopropionate), pentaerythritol tetra(2-mercaptoacetate), 1,6-hexanedithiol, 1,3-propanedithiol, 1,2-ethylenedithiol, polyethylene glycol dithiols comprising one to ten ethylene glycol repeating units, or combinations thereof.

[0147] Based on the total weight of the composition (or the total weight of solids), the content of the (poly)thiol compound may be less than or equal to about 60 wt%, less than or equal to about 50 wt%, less than or equal to about 40 wt%, less than or equal to about 30 wt%, less than or equal to about 20 wt%, less than or equal to about 10 wt%, less than or equal to about 9 wt%, less than or equal to about 8 wt%, less than or equal to about 7 wt%, less than or equal to about 6 wt%, or less than or equal to about 5 wt%. Based on the total weight of the composition (or the total weight of solids), the content of the thiol compound may be greater than or equal to about 0.1 wt%, for example, greater than or equal to about 0.5 wt%, greater than or equal to about 1 wt%, greater than or equal to about 5 wt%, greater than or equal to about 10 wt%, greater than or equal to about 15 wt%, greater than or equal to about 20 wt%, or greater than or equal to about 25 wt%.

[0148] The composition may also include an organic solvent (or liquid carrier, referred to below as solvent). There are no particular limitations on the types of solvents that may be used. Non-limiting examples of solvents or liquid carriers may include: ethyl 3-ethoxypropionate; ethylene glycol systems, such as ethylene glycol, diethylene glycol, polyethylene glycol, etc.; ethylene glycol ether systems, such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, etc.; ethylene glycol ether acetate systems, such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, etc.; propylene glycol systems, such as propylene glycol, etc.; propylene glycol ether systems, such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol dimethyl ether, dipropylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol diethyl ether, dipropylene glycol diethyl ether, etc.; propylene glycol ether acetate systems, such as propylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether, dipropylene glycol monoethyl ether, etc. Diethyl ether acetate, etc.; amides, such as N-methylpyrrolidone, dimethylformamide, dimethylacetamide, etc.; ketones, such as methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), cyclohexanone, etc.; petroleum-based hydrocarbons, such as solvent naphtha, etc.; esters, such as ethyl acetate, butyl acetate, ethyl lactate, etc.; ethers, such as tetrahydrofuran, diethyl ether, dipropyl ether, dibutyl ether, etc.; chloroform; C1 to C40 aliphatic hydrocarbons (e.g., alkanes, alkenes, or alkynes); halogen (e.g., chlorine)-substituted C1 to C40 aliphatic hydrocarbons (e.g., dichloroethane, chloroform, etc.); C6 to C40 aromatic hydrocarbons (e.g., toluene, xylene, etc.); halogen (e.g., chlorine)-substituted C6 to C40 aromatic hydrocarbons; dimethyl sulfoxide; or combinations thereof, but not limited thereto.

[0149] The type and amount of organic solvent can be appropriately determined by taking into account the main components mentioned above (i.e., quantum dots, dispersants, polymerizable monomers, initiators, and, if used, thiols) and the type and amount of additives described later. The composition may include the remaining amount of solvent in addition to the desired amount of (non-volatile) solids.

[0150] The composition (e.g., an ink composition) may have a viscosity at 25°C greater than or equal to about 4 cPs, greater than or equal to about 5 cPs, greater than or equal to about 5.5 cPs, greater than or equal to about 6.0 cPs, or greater than or equal to about 7.0 cPs. The composition may have a viscosity at 25°C less than or equal to about 12 cPs, less than or equal to about 10 cPs, or less than or equal to about 9 cPs.

[0151] When used for inkjet printing, the composition can be discharged onto a substrate at room temperature and can be heated, for example, to form a quantum dot-polymer composite film or a pattern of a quantum dot-polymer composite film. While having the above-mentioned viscosity, the ink composition may have a surface tension at about 23°C that is greater than or equal to about 21 mN / m, greater than or equal to about 22 mN / m, greater than or equal to about 23 mN / m, greater than or equal to about 24 mN / m, greater than or equal to about 25 mN / m, greater than or equal to about 26 mN / m, greater than or equal to about 27 mN / m, greater than or equal to about 28 mN / m, greater than or equal to about 29 mN / m, greater than or equal to about 30 mN / m, or greater than or equal to about 31 mN / m and less than or equal to about 40 mN / m, less than or equal to about 39 mN / m, less than or equal to about 38 mN / m, less than or equal to about 36 mN / m, less than or equal to about 35 mN / m, less than or equal to about 34 mN / m, less than or equal to about 33 mN / m, or less than or equal to about 32 mN / m. The ink composition may have a surface tension of less than or equal to about 31 mN / m, less than or equal to about 30 mN / m, less than or equal to about 29 mN / m, or less than or equal to about 28 mN / m.

[0152] In embodiments, the composition may further include, for example, additives included in compositions for use as photoresists or ink compositions. Additives may include light diffusing agents, leveling agents, coupling agents, etc. For specific details, see, for example, the description in US-2017-0052444-A1.

[0153] The composition can be prepared by a method comprising the following steps: preparing a quantum dot dispersion comprising the above-described quantum dots, a dispersant, and a solvent; and mixing an initiator; a polymerizable monomer (e.g., an acrylic monomer); and optionally a thiol compound; titanium dioxide (TiO2); and optionally the above-described additives into the quantum dot dispersion. Each of the above components may be mixed sequentially or simultaneously, and the order is not particularly limited.

[0154] The composition can be used to provide patterning for quantum dot composites (e.g., quantum dot-polymer composites). The composition can provide quantum dot-polymer composites via (e.g., free radical) polymerization. The composition for preparing the quantum dot composite according to the embodiments can be a photoresist composition containing quantum dots suitable for photolithography. The composition according to the embodiments can be an ink composition capable of providing patterning via printing methods (e.g., droplet emission methods such as inkjet printing).

[0155] In the embodiments, the quantum dot composite includes, for example, a polymer matrix and the aforementioned quantum dots(s) and titanium dioxide (TiO2) dispersed in the matrix. In the composite, titanium dioxide (TiO2) acts as a light diffuser, such that light absorbed from the excitation light remains in the quantum dot composite for a longer time and can be absorbed more by the quantum dots.

[0156] The (polymer) matrix may include cross-linked polymers and / or linear polymers. Cross-linked polymers may include thiolene resins, cross-linked poly(meth)acrylates, cross-linked polyurethanes, cross-linked epoxy resins, cross-linked vinyl polymers, cross-linked silicone resins, or combinations thereof. Linear polymers may include repeating units containing carboxylic acids.

[0157] The content of quantum dots and titanium dioxide (TiO2) in the quantum dot composite is the same as described above. The matrix content in the quantum dot composite can be greater than or equal to about 10%, greater than or equal to about 20%, greater than or equal to about 30%, greater than or equal to about 40%, greater than or equal to about 50%, or greater than or equal to about 60%. The matrix content in the quantum dot composite can be less than or equal to about 90%, less than or equal to about 80%, less than or equal to about 70%, less than or equal to about 60%, less than or equal to about 50%, or less than or equal to about 40%. The total content of quantum dots and titanium dioxide (TiO2) in the quantum dot composite can be greater than or equal to about 10%, greater than or equal to about 20%, greater than or equal to about 30%, greater than or equal to about 40%, greater than or equal to about 50%, or greater than or equal to about 60%. The matrix content in the quantum dot composite can be less than or equal to about 90%, less than or equal to about 80%, less than or equal to about 70%, less than or equal to about 60%, less than or equal to about 50%, or less than or equal to about 40%.

[0158] The matrix may include the dispersant described above (e.g., a carboxyl-containing monomer or polymer), a polymeric product (such as an insulating polymer) containing at least one (e.g., two or more, three or more, four or more, or five or more) carbon-carbon double bonds of a polymerizable monomer, and optionally a polymeric product between a polymerizable monomer and a thiol compound having at least one (e.g., two or more) thiol groups at the end.

[0159] In embodiments, the polymer matrix may include crosslinked polymers, linear polymers, or combinations thereof. Crosslinked polymers may include thiolene resins, crosslinked poly(meth)acrylates, or combinations thereof. In embodiments, the crosslinked polymer may be a polymer of the polymerizable monomers described above and optionally (poly)thiol compounds. Details regarding the description of quantum dots, dispersants, polymerizable monomers, and (poly)thiol compounds are the same as described above.

[0160] When the quantum dot composite according to the embodiments is applied to a display device having a light-emitting panel (the light-emitting panel comprising blue light having an emission peak of about 430 nm to about 470 nm as a light source), the light conversion efficiency of absorbing blue light and converting it into green or red light can be greater than or equal to about 25%, for example, greater than or equal to about 30%, for example, greater than or equal to about 35%, for example, greater than or equal to about 36%, for example, greater than or equal to about 38%, for example, greater than or equal to about 38.3%. As can be seen from the examples and comparative examples described later, the light conversion efficiency has been significantly increased compared to quantum dot composites comprising quantum dots having a thinner shell and thus having an increased blue light absorption rate or quantum dots having a thicker shell and thus having a more stable structure. This is an unexpectedly surprising effect achieved by including quantum dot composites comprising quantum dots having a shell of a certain thickness and / or compositions adjusted to have a specific optical density per unit weight.

[0161] In other words, the quantum dot composite according to the embodiments comprises quantum dots having an InP core and a ZnSe or ZnSeS shell disposed on the core (in which the thickness of the ZnSe or ZnSeS shell can not only be reduced to reduce its non-contribution to blue light absorption, but the thickness can also be kept beyond a minimum range within an appropriate thickness range that passivates and stabilizes defects on the surface of the quantum dots), and therefore can have excellent blue light absorption (e.g., greater than or equal to about 80% (e.g., greater than or equal to about 83%, e.g., greater than or equal to about 84%, e.g., greater than or equal to about 85%, e.g., greater than or equal to about 90%)) while having significantly improved light conversion efficiency. Therefore, the quantum dot composite according to the embodiments can be advantageously applied to display panels of display devices, etc.

[0162] The display panel may include a color conversion layer, which includes multiple regions containing color conversion areas. A quantum dot composite may be disposed in the color conversion layer within the color conversion regions. In an embodiment, the color conversion layer may further include partition walls defining the multiple regions.

[0163] In embodiments, the display panel may further include a light-emitting panel, comprising a light source configured to emit blue light, a light source configured to emit green light, or a combination thereof, and a color conversion layer capable of converting the emission spectrum of the excitation light emitted from the light-emitting panel. For example, the color conversion layer may absorb blue light and convert it into green or red light. In this case, the light conversion efficiency may be greater than or equal to about 30%, for example, greater than or equal to about 35%, for example, greater than or equal to about 36%, for example, greater than or equal to about 37%, for example, greater than or equal to about 38%, for example, greater than or equal to about 39%, and the blue light absorption rate may also be greater than or equal to about 80%. Additionally, the display device including the display panel, described later, may have a BT2020 reference color gamut greater than or equal to about 90%.

[0164] In this embodiment, the color conversion layer may be in the form of a patterned film.

[0165] In an embodiment, the color conversion region of the color conversion layer includes at least one first color conversion region (hereinafter also referred to as a first region or first partition) configured to emit a first light upon irradiation with excitation light, the first color conversion region comprising a quantum dot composite. The color conversion layer may be a patterned film of the quantum dot composite.

[0166] The color conversion region may include a second color conversion region (also referred to below as a second region or second partition) configured to emit a second light different from the first light (e.g., by illumination with excitation light), and the second color conversion region may include a quantum dot complex according to an embodiment.

[0167] The quantum dot complex in the second color conversion region may include quantum dots that emit light at a different wavelength (e.g., a different color) than the quantum dot complex in the first color conversion region.

[0168] The first or second light can be red light having an emission peak wavelength of about 610 nm to about 660 nm (e.g., about 620 nm to about 650 nm), or green light having an emission peak wavelength of about 500 nm to about 550 nm (e.g., about 510 nm to about 540 nm). The color conversion layer may also include at least one third region (hereinafter also referred to as the third partition) that emits a third light (e.g., blue light) different from the first and second light, or allows the third light (e.g., blue light) different from the first and second light to pass through. The third light may include excitation light. The third light may include blue and / or green light having an emission peak wavelength in the range of about 430 nm to about 470 nm.

[0169] In an embodiment, the first emission spectrum may be a green emission spectrum having an emission peak wavelength between about 500 nm and about 550 nm, and the weight ratio of selenium (Se) to titanium (Ti) in the first color conversion region may be greater than or equal to about 2 and less than or equal to about 12. For example, the weight ratio of selenium (Se) to titanium (Ti) in the first color conversion region may be greater than or equal to about 2 and less than or equal to about 10 (e.g., greater than or equal to about 3 and less than or equal to about 10), but is not limited thereto.

[0170] In an embodiment, in the first color conversion region, the weight ratio of indium (In) to titanium (Ti) can be greater than or equal to about 0.2 and less than or equal to about 1.8, and the weight ratio of phosphorus (P) to Ti can be greater than or equal to about 0.05 and less than or equal to about 0.4. For example, in the first color conversion region, the weight ratio of indium (In) to titanium (Ti) can be greater than or equal to about 0.2 and less than or equal to about 1.7 (e.g., greater than or equal to about 0.2 and less than or equal to about 1.5), and the weight ratio of phosphorus (P) to Ti can be greater than or equal to about 0.1 and less than or equal to about 0.4 (e.g., greater than or equal to about 0.1 and less than or equal to about 0.3).

[0171] In an embodiment, the second emission spectrum may be a red emission spectrum having an emission peak wavelength between about 610 nm and about 660 nm, and the weight ratio of Se to titanium (Ti) in the second color conversion region may be greater than or equal to about 1 and less than or equal to about 5. For example, the weight ratio of Se to Ti in the second color conversion region may be greater than or equal to about 1 and less than or equal to about 4 (e.g., greater than or equal to about 1.2 and less than or equal to about 3), but is not limited thereto.

[0172] In an embodiment, in the second color conversion region, the weight ratio of In to titanium (Ti) can be greater than or equal to about 0.1 and less than or equal to about 0.5, and the weight ratio of P to titanium (Ti) can be greater than or equal to about 0.05 and less than or equal to about 0.3. For example, in the second color conversion region, the weight ratio of In to titanium (Ti) can be greater than or equal to about 0.1 and less than or equal to about 0.4 (e.g., greater than or equal to about 0.1 and less than or equal to about 0.3, e.g., greater than or equal to about 0.1 and less than or equal to about 0.2, e.g., greater than or equal to about 0.2 and less than or equal to about 0.4), and the weight ratio of P to titanium (Ti) can be greater than or equal to about 0.1 and less than or equal to about 0.3 (e.g., greater than or equal to about 0.1 and less than or equal to about 0.2), but is not limited thereto.

[0173] The content ratio of each element in each color conversion region can be measured, for example, by the following steps: physically scraping a solid of a predetermined area (basically, a predetermined volume) of each color conversion region containing quantum dots from the display panel; forming it into a powder; dissolving the powder in various types of acids (e.g., nitric acid, bromic acid, hydrofluoric acid, etc.) to prepare a solution; and performing ICP analysis on the solution. Here, the polymer constituting the polymer matrix forming the quantum dot composite included in each color conversion region, the light diffusing agent (such as titanium dioxide, etc.) dispersed in the polymer matrix along with the quantum dots, and various other components can be detected from the solution. In this case, although titanium may be derived solely from the light diffusing agent, other elements such as indium, phosphorus, selenium, etc., are derived solely from the quantum dots in the color conversion regions. Therefore, the content ratio of indium, phosphorus, or selenium to Ti is independent of the presence of other components included in each color conversion region besides quantum dots and light diffusing agents. Therefore, the content or content ratio of the elements included in the color conversion regions can be quantitatively analyzed. As described above, since the display panel according to the embodiment includes a quantum dot composite containing quantum dots according to the embodiment, and the quantum dot composite exhibits an element content ratio that is different from that of a quantum dot composite that does not contain quantum dots according to the embodiment, the content ratio of each element in each color conversion region of the display panel according to the embodiment may be an inherent characteristic of the display panel according to the embodiment.

[0174] A photoresist composition can be used to fabricate a color conversion layer (or a patterned film of a quantum dot composite). The method may include the following steps: forming a film of the above composition on a substrate (S1); pre-baking the film according to selection (S2); exposing selected areas of the film to light (e.g., having a wavelength less than or equal to about 400 nm) (S3); and developing the exposed film with an alkaline developing solution to obtain a pattern of the quantum dot-polymer composite (S4).

[0175] Reference Figure 1A The above composition is applied to a substrate to a predetermined thickness using a suitable method such as spin coating or slot coating to form a film (S1). Optionally, the formed film may be pre-baked (PRB) (S2). Pre-baking can be performed by selecting appropriate conditions from known conditions such as temperature, time, atmosphere, etc.

[0176] Under a mask with a predetermined pattern, the formed (or optionally pre-baked) film is exposed to light with a predetermined wavelength (S3). The wavelength and intensity of the light can be selected by considering factors such as the type and amount of photoinitiator, the type and amount of quantum dots, etc.

[0177] The exposed film is treated with an alkaline developing solution (e.g., immersion or spraying) to dissolve the unexposed areas and obtain the desired pattern (S4). Optionally, the obtained pattern can be post-baked (POB) at a temperature of, for example, about 150°C to about 230°C for a predetermined time (e.g., greater than or equal to about 10 minutes or greater than or equal to about 20 minutes) (S5) to improve the crack resistance and solvent resistance of the pattern.

[0178] When the color conversion panel or patterned film of the quantum dot composite has multiple repeating zones (i.e., color conversion regions), each repeating zone can be formed (S6) as follows: Prepare multiple compositions comprising quantum dots (e.g., red-emitting quantum dots, green-emitting quantum dots, or optionally blue-emitting quantum dots) having desired luminescent properties (emission peak wavelength, etc.); and for each composition, repeat the above patterning process multiple times (e.g., two or more times, or three or more times) as needed, resulting in a quantum dot-polymer composite with a desired pattern. For example, the quantum dot-polymer composite may have a pattern with at least two repeating color zones (e.g., RGB color zones). This quantum dot-polymer composite pattern can be used as a photoluminescent color filter in a display device.

[0179] Ink compositions can be used to manufacture patterned films of color conversion panels or quantum dot composites, the ink compositions being configured to form patterns via inkjet printing. (See reference...) Figure 1B This method may include the following steps: preparing an ink composition according to an embodiment (S1); providing a substrate (S2) having pixel regions patterned by electrodes and optional dikes, etc.; depositing the ink composition on the substrate (or pixel regions) to form, for example, a first quantum dot layer (or a first region) (S3); and depositing the ink composition on the substrate (or pixel regions) to form, for example, a second quantum dot layer (or a second region) (S4). The formation of the first quantum dot layer and the second quantum dot layer are performed simultaneously or sequentially.

[0180] The deposition of the ink composition can be performed using a suitable droplet ejector (e.g., an inkjet or nozzle printing system with an ink reservoir and at least one printhead). The deposited ink composition can be removed by solvent and polymerized via heating to provide a first or second quantum dot layer. This method can provide highly precise quantum dot-polymer composite films or patterned films in a short time using a simple approach.

[0181] The aforementioned quantum dots or quantum dot composites (patterns) can be included in electronic devices. Such electronic devices may include, but are not limited to, display devices, light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), quantum dot LEDs, sensors, solar cells, imaging sensors, photodetectors, or liquid crystal displays. The aforementioned quantum dots can also be included in electronic devices. Such electronic devices may include, but are not limited to, portable terminal devices, monitors, laptops, televisions, electronic signal boards, cameras, automobiles, etc. Electronic devices may be portable terminal devices, monitors, laptops, or televisions that include a display device (or light-emitting device) containing quantum dots. Electronic devices may be cameras or mobile terminal devices that include image sensors containing quantum dots. Electronic devices may be cameras or vehicles that include photodetectors containing quantum dots.

[0182] In embodiments, the electronic device or display device (e.g., a display panel) may further include a color conversion panel and an optional light source. In embodiments, the display panel may include a light-emitting panel (or light source), a color conversion panel, and a light-transmitting layer between the light-emitting panel and the color conversion panel. The color conversion panel may include a substrate, and the color conversion layer may be disposed on the substrate.

[0183] A light source or light-emitting panel (if present) may be configured to provide incident light to the light-emitting element. The incident light may have an emission peak wavelength in the range of greater than or equal to about 430 nm (e.g., greater than or equal to about 440 nm or greater than or equal to about 450 nm) and less than or equal to about 470 nm (e.g., less than or equal to about 460 nm).

[0184] In one embodiment, the color conversion panel or device (e.g., a photoluminescent device) may include a sheet of quantum dot composite. See reference. Figure 2 The device includes a backlight unit and a liquid crystal panel (LC). The backlight unit may include a quantum dot-polymer composite sheet (QD sheet). Specifically, the backlight unit may have a structure in which reflectors, light guide plates (LGP), light sources (such as blue LEDs), quantum dot-polymer composite sheets (QD sheets), and optical films (such as prisms and dual brightness enhancement films (DBEF)) are stacked. The liquid crystal panel (LC) is disposed on the backlight unit and may have a structure including liquid crystals and color filters between two polarizers (Pol). The quantum dot-polymer composite sheet (QD sheet) may include quantum dots that emit red light by absorbing light from the light source and quantum dots that emit green light. Blue light from the light source can be combined with the red and green light emitted from the quantum dots and converted into white light by passing through the quantum dot-polymer composite sheet. The white light can be separated into blue, green, and red light by the color filters in the liquid crystal panel and can be emitted to the outside in each pixel.

[0185] The color conversion panel can include a base, and the color conversion layer can be set on the base.

[0186] The color conversion layer or color conversion panel may include a patterned film of a quantum dot composite. The patterned film includes repeating sections configured to emit desired light. The repeating sections may include a first section. The second section may include a green-emitting section. The third section may be a section that emits or transmits blue light. The details of the first, second, and third sections are the same as described above.

[0187] The light-emitting panel or light source can be an element that emits excitation light. The excitation light can include blue light and / or green light. The light source can include an LED. The light source can include an organic LED (OLED). On the front surfaces (light-emitting surfaces) of the first and second partitions, optical elements (e.g., a blue light (and optional green light) blocking layer or a first filter, which will be described later, can be disposed. When the light source includes an organic light-emitting diode that emits blue light and an organic light-emitting diode that emits green light, a green light removal filter can be further disposed on a third partition through which blue light transmits.

[0188] The light-emitting panel or light source may include a plurality of light-emitting units corresponding to a first partition and a second partition, respectively. Each light-emitting unit may include a first electrode and a second electrode facing each other, and an (organic) electroluminescent layer between the first and second electrodes. The electroluminescent layer may include an organic light-emitting material. For example, each light-emitting unit of the light source may include an electroluminescent device (e.g., an organic light-emitting diode) configured to emit light of a predetermined wavelength (e.g., blue light, green light, or a combination thereof). The structure and materials of the electroluminescent device and the organic light-emitting diode are known and are not particularly limited.

[0189] The display panel and color conversion panel will be described in more detail below with reference to the accompanying drawings.

[0190] Reference Figure 3 and Figure 4 The display panel 1000 according to an embodiment includes a light-emitting panel 100, a color conversion panel 200, a light-transmitting layer 300 disposed between the light-emitting panel 100 and the color conversion panel 200, and an adhesive (hereinafter also referred to as a bonding element) 400 for bonding the light-emitting panel 100 and the color conversion panel 200.

[0191] The light-emitting panel 100 and the color-converting panel 200 may face each other, and the light-transmitting layer 300 is located between the light-emitting panel 100 and the color-converting panel 200. The color-converting panel 200 may be positioned in the direction along which light is emitted from the light-emitting panel 100. The adhesive 400 may be disposed along the edges of the light-emitting panel 100 and the color-converting panel 200, and may be, for example, a sealant.

[0192] exist Figure 3 and Figure 4 In this configuration, a light-transmitting layer 300 is disposed between the light-emitting panel 100 and the color-conversion panel 200, and an adhesive 400 is disposed along the edges of the light-emitting panel 100 and the color-conversion panel 200. However, the light-transmitting layer 300 and the adhesive 400 can be omitted and are not necessary. That is, the light-emitting panel 100 and the color-conversion panel 200 can be directly bonded together without the light-transmitting layer 300.

[0193] Reference Figure 5 According to an embodiment, the display panel 1000 includes a display area 1000D for displaying images and a non-display area 1000P disposed around the display area 1000D and wherein a bonding element 400 is disposed.

[0194] Display area 1000D may include multiple pixels PX arranged along rows (e.g., the x-direction) and / or columns (e.g., the y-direction), each pixel PX may include multiple sub-pixels PX1, PX2, and PX3 displaying different colors. Here, as an example, a construction is shown in which three sub-pixels PX1, PX2, and PX3 constitute one pixel PX, but the construction is not limited to this. Additional sub-pixels, such as white sub-pixels, may also be included, and one or more sub-pixels displaying the same color may be included. The multiple pixels PX may be arranged, for example, in a Bayer matrix, a PenTile matrix, and / or a diamond matrix, but are not limited to this.

[0195] Each of the sub-pixels PX1, PX2, and PX3 can be configured to display the colors of the three primary colors or combinations of the three primary colors (e.g., red, green, blue, or combinations thereof). For example, the first sub-pixel PX1 can be configured to display red, the second sub-pixel PX2 can be configured to display green, and the third sub-pixel PX3 can be configured to display blue.

[0196] The accompanying drawings show an example where all subpixels have the same size, but this disclosure is not limited thereto. At least one subpixel may be larger or smaller than the other subpixels. The accompanying drawings also show an example where all subpixels have the same shape, but this disclosure is not limited thereto. At least one subpixel may have a different shape than the other subpixels.

[0197] Figure 6A and Figure 6B This is a schematic cross-sectional view of the device (or display panel) according to an embodiment. (Refer to...) Figure 6A and Figure 6BThe light source (or light-emitting panel) includes an organic light-emitting diode (OLED) that emits blue light (and optionally green light). An OLED may include at least two pixel electrodes formed on a substrate, a pixel-defining layer formed between adjacent pixel electrodes, an organic light-emitting layer formed on each pixel electrode, and a common electrode layer formed on the organic light-emitting layer. Thin-film transistors and a substrate may be disposed beneath the OLED. The pixel regions of the OLED may be configured to correspond to a first, second, and third partition, which will be described later.

[0198] A stacked structure comprising a quantum dot composite pattern (e.g., a first partition comprising red quantum dots and a second partition comprising green quantum dots) and a substrate can be disposed on a light source. Blue light emitted from the light source enters the first and second partitions, emitting red and green light respectively. The blue light emitted from the light source can pass through a third partition. If necessary, an element configured to block the excitation light (a first filter or excitation light blocking layer) can be disposed between the quantum dot composite layers R and G and the substrate. When the excitation light comprises both blue and green light, a green light blocking filter can be added to the third partition. The first filter or excitation light blocking layer will be described in more detail later.

[0199] Such a device can be manufactured by separately fabricating the aforementioned color conversion panel and (e.g., emitting blue light and optionally green light) LEDs or OLEDs and then combining them. Alternatively, the device can be manufactured by directly forming a quantum dot composite pattern on the LED or OLED.

[0200] The substrate can be a substrate comprising an insulating material. The substrate may include: glass; various polymers such as polyesters, polycarbonates, and polyacrylates, including polyethylene terephthalate (PET), polyethylene naphthalate (PEN); polysiloxanes (e.g., PDMS); inorganic materials such as Al₂O₃ or ZnO; or combinations thereof, but not limited thereto. The thickness of the substrate can be suitably selected considering the substrate material, but there are no particular limitations. The substrate can be flexible. For light emitted from quantum dots, the substrate can have a transmittance greater than or equal to about 50%, greater than or equal to about 60%, greater than or equal to about 70%, greater than or equal to about 80%, or greater than or equal to about 90%.

[0201] A wiring layer, including thin-film transistors, is formed on the substrate. The wiring layer may further include gate lines, sustaining voltage lines, a gate insulating layer, data lines, source electrodes, drain electrodes, semiconductors, a protective layer, etc. The detailed structure of the wiring layer can vary depending on the embodiment. The gate lines and sustaining voltage lines are electrically separated from each other, and the data lines are insulated from and cross the gate lines and sustaining voltage lines. The gate electrode, source electrode, and drain electrode form the control terminal, input terminal, and output terminal of the thin-film transistor, respectively. The drain electrode is electrically connected to the pixel electrode, which will be described later.

[0202] Pixel electrodes can be used as electrodes (e.g., anodes) in display devices. Pixel electrodes can be formed from transparent conductive materials such as indium tin oxide (ITO) or indium zinc oxide (IZO). Pixel electrodes can also be formed from light-blocking materials such as gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), or titanium (Ti). Pixel electrodes can have a bilayer structure in which transparent conductive materials and light-blocking materials are sequentially stacked.

[0203] Between two adjacent pixel electrodes, a pixel defining layer (PDL) is stacked at the end of the pixel electrode to divide the pixel electrode into pixel units. The pixel defining layer is an insulating layer that can electrically block at least two pixel electrodes.

[0204] A pixel defining layer covers a portion of the upper surface of the pixel electrode, and the remaining area of ​​the pixel electrode not covered by the pixel defining layer can provide an opening. An organic light-emitting layer, which will be described later, can be formed in the area defined by the opening.

[0205] The organic light-emitting layer defines each pixel region through the aforementioned pixel electrode and pixel defining layer. In other words, a pixel region can be defined as a region having an organic light-emitting unit layer, which is in contact with a pixel electrode defined by the pixel defining layer. In the display device according to the embodiment, the organic light-emitting layer can be defined as a first pixel region, a second pixel region, and a third pixel region, each pixel region being separated from each other by a predetermined interval through the pixel defining layer.

[0206] In embodiments, the organic light-emitting layer can emit a third light belonging to either the visible light region or the UV region. Each of the first to third pixel regions of the organic light-emitting layer can emit the third light. In embodiments, the third light can be light with the highest energy in the visible light region, for example, it can be blue light (and optionally green light). When all pixel regions of the organic light-emitting layer are designed to emit the same type of light, each pixel region of the organic light-emitting layer can be entirely formed of the same or similar materials, or can exhibit the same or similar properties. Therefore, the process difficulty of forming the organic light-emitting layer can be greatly reduced, and thus, the display device can be easily applied to large-scale / large-area processing. However, the organic light-emitting layer according to the embodiments is not limited to this, but the organic light-emitting layer can be designed to emit at least two different types of light.

[0207] The organic light-emitting layer includes an organic light-emitting unit layer in each pixel region. In addition to the light-emitting layer, each organic light-emitting unit layer may also include auxiliary layers (e.g., hole injection layer, hole transport layer, electron transport layer, etc.).

[0208] The common electrode can be used as the cathode of a display device. The common electrode can be formed from a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). The common electrode can be formed on and integrated with the organic light-emitting layer.

[0209] A planarization layer or passivation layer (not shown) may be formed on the common electrode. The planarization layer may include an insulating material (e.g., transparent) to ensure electrical insulation from the common electrode.

[0210] In this embodiment, the display device may further include a lower substrate, a polarizing plate disposed below the lower substrate, and a liquid crystal layer disposed between the stacked structure and the lower substrate. In the stacked structure, the light-emitting layer may be configured to face the liquid crystal layer. The display device may also include a polarizing plate between the liquid crystal layer and the light-emitting layer. The light source may also include an LED, and if necessary, a light guide plate.

[0211] The accompanying drawings illustrate a non-limiting example of a display device (e.g., a liquid crystal display device) according to an embodiment. Figure 7 This is a schematic cross-sectional view showing a liquid crystal display according to an embodiment. (Refer to...) Figure 7 The display device of the embodiment includes a liquid crystal panel 200, a polarizing plate 300 disposed below the liquid crystal panel 200, and a backlight unit (BLU) disposed below the polarizing plate 300.

[0212] The liquid crystal panel 200 includes a lower substrate 210, a stacked structure, and a liquid crystal layer 220 disposed between the stacked structure and the lower substrate. The stacked structure includes a transparent substrate 240 and a photoluminescent layer 230, the photoluminescent layer 230 including a pattern of quantum dot-polymer composite.

[0213] The lower substrate 210, referred to as the array substrate, may be a transparent insulating material substrate. The substrate is the same as described above. A wiring board 211 is disposed on the upper surface of the lower substrate 210. The wiring board 211 may include, but is not limited to, multiple gate lines (not shown) and data lines (not shown) defining pixel regions, thin-film transistors positioned adjacent to the intersection regions of the gate lines and data lines, and pixel electrodes for each pixel region. Details of such a wiring board are known and not particularly limited.

[0214] A liquid crystal layer 220 is disposed on a wiring board 211. A liquid crystal panel 200 may include an alignment layer 221 on and beneath the liquid crystal layer 220 to initially align the liquid crystal material contained therein. Details of the liquid crystal layer and alignment layer (e.g., liquid crystal material, alignment layer material, method of forming the liquid crystal layer, thickness of the liquid crystal layer, etc.) are known and not particularly limited.

[0215] A polarizer 300 is disposed below the lower substrate. The material and structure of the polarizer 300 are known and not particularly limited. (For example, a backlight unit emitting blue light) can be disposed below the polarizer 300. The upper optical element or polarizer 300 can be disposed between the liquid crystal layer 220 and the transparent substrate 240, but is not limited thereto. For example, the polarizer can be disposed between the liquid crystal layer 220 and the photoluminescent layer 230. The polarizer can be any polarizer that can be used in a liquid crystal display device. The polarizer can be TAC (triacetyl cellulose) with a thickness of less than or equal to about 200 μm, but is not limited thereto. In another embodiment, the upper optical element can be a coating that controls the refractive index but does not have a polarization function.

[0216] The backlight unit includes a light source 110. The light source can emit blue light or white light. The light source can include, but is not limited to, blue LEDs, white LEDs, white OLEDs, or combinations thereof.

[0217] The backlight unit may also include a light guide plate 120. In embodiments, the backlight unit may be edge-mounted. For example, the backlight unit may include a reflector (not shown), a light guide plate (not shown) disposed on the reflector and providing a planar light source to the liquid crystal panel 200, and / or at least one optical sheet (e.g., a diffuser, prism sheet, etc.) (not shown) on the light guide plate, but is not limited thereto. The backlight unit may not include a light guide plate. In embodiments, the backlight unit may be directly illuminated. For example, the backlight unit may have a reflector (not shown) and may have a plurality of fluorescent lamps disposed at regular intervals on the reflector, or may have an LED operating substrate on which a plurality of light-emitting diodes may be disposed, a diffuser on the LED operating substrate, and optionally at least one optical sheet. The details of such a backlight unit (e.g., each component among the light-emitting diodes, fluorescent lamps, light guide plate, various optical sheets, and reflector) are known and not particularly limited.

[0218] A black matrix 241 is disposed beneath a transparent substrate 240 and has openings, concealing gate lines, data lines, and thin-film transistors of a wiring board on the lower substrate. For example, the black matrix 241 may have a grid shape. A color conversion layer is disposed within the openings of the black matrix 241 and has a photoluminescent layer 230 with a quantum dot-polymer composite pattern comprising a first partition R configured to emit a first light (e.g., red light), a second partition G configured to emit a second light (e.g., green light), and a third partition B configured to emit / transmit, for example, blue light. If desired, the photoluminescent layer may further include at least one fourth partition. The fourth partition may include quantum dots that emit light of a different color (e.g., cyan, magenta, and yellow light) than the light emitted from the first to the third partitions.

[0219] In the photoluminescent layer 230, the patterned partitions can be repeated correspondingly to the pixel regions formed on the lower substrate. A transparent common electrode 231 can be disposed on the photoluminescent layer 230.

[0220] The third section B, configured to emit / transmit blue light, can be a transparent color filter that does not alter the emission spectrum of the light source. In this case, blue light emitted from the backlight unit can enter in a polarized state and pass through the polarizer and liquid crystal layer as is. If desired, the third section can include quantum dots that emit blue light.

[0221] As described above, if desired, the display device or light-emitting device according to the embodiment may further include an excitation light blocking layer or a first optical filter layer (hereinafter referred to as the first filter layer). The first filter layer may be disposed between the bottom surface of the first partition R and the second partition G and the substrate (e.g., transparent substrate 240) or disposed on the upper surface of the transparent substrate 240. The first filter layer may be a sheet having an opening in the portion corresponding to the blue pixel area (third partition), and thus may be formed in the portions corresponding to the first partition and the second partition. That is, the first filter layer may be as follows Figure 6A , Figure 6B and Figure 7 The first filter layers are integrally formed in portions other than those superimposed on the third zone, but are not limited thereto. Two or more first filter layers may be separated from each other in locations superimposed on the first and second zones and optionally the third zone. When the light source includes a green light-emitting element, a green light blocking layer may be disposed on the third zone.

[0222] The first filter layer can block light with a predetermined wavelength region, such as the visible light region, and can transmit light in other wavelength regions. For example, the first filter layer can block blue light (or green light) and can transmit light other than blue light (or green light). The first filter layer can transmit, for example, green light, red light, and / or yellow light as a mixture of green and red light. The first filter layer can transmit blue light and block green light, and can be disposed on a blue light emitting pixel.

[0223] The first filter layer can essentially block the excitation light and transmit light in the desired wavelength region. For light within the desired wavelength range, the transmittance of the first filter layer can be greater than or equal to about 70%, greater than or equal to about 80%, greater than or equal to about 90%, or even about 100%.

[0224] A first filter layer configured to selectively transmit red light can be disposed at a position superimposed on the red light emitting zone, and a first filter layer configured to selectively transmit green light can be disposed at a position superimposed on the green light emitting zone. The first filter layer may include at least one of a first region and a second region. The first region blocks (e.g., absorbs) blue and red light and selectively transmits light within a predetermined range (e.g., greater than or equal to about 500 nm, greater than or equal to about 510 nm, or greater than or equal to about 515 nm and less than or equal to about 550 nm, less than or equal to about 545 nm, less than or equal to about 540 nm, less than or equal to about 535 nm, less than or equal to about 530 nm, less than or equal to about 525 nm, or less than or equal to about 520 nm). The second region blocks (e.g., absorbs) blue and green light and selectively transmits light within a predetermined range (e.g., greater than or equal to about 600 nm, greater than or equal to about 610 nm, or greater than or equal to about 615 nm and less than or equal to about 650 nm, less than or equal to about 645 nm, less than or equal to about 640 nm, less than or equal to about 635 nm, less than or equal to about 630 nm, less than or equal to about 625 nm, or less than or equal to about 620 nm). When the light source emits a mixture of blue and green light, the first filter layer may also include a third region that selectively transmits blue light and blocks green light.

[0225] The first area can be positioned overlapping the green light emitting zone. The second area can be positioned overlapping the red light emitting zone. The third area can be positioned overlapping the blue light emitting zone.

[0226] The first region, the second region, and the optional third region can be optically isolated. This first filter layer can help improve the color purity of the display device.

[0227] The display device may further include a second filter layer (e.g., a red / green or yellow light recycling layer) disposed between the photoluminescent layer and the liquid crystal layer (e.g., between the photoluminescent layer and a polarizer), transmitting at least a portion of the third light (excitation light) and reflecting at least a portion of the first light and / or the second light. The first light may be red light, the second light may be green light, and the third light may be blue light. The second filter layer may transmit only the third light (B) in the blue light wavelength region having a wavelength region less than or equal to about 500 nm, while light in the wavelength region greater than about 500 nm (which is green light (G), yellow light, red light (R), etc.) may not pass through the second filter layer 140 and may be reflected. The reflected green and red light may pass through the first and second partitions and be emitted to the outside of the display device.

[0228] The second filter layer or the first filter layer can be formed as an integrated layer with a relatively flat surface.

[0229] The first filter layer may include a polymer film comprising a dye and / or pigment that absorbs light at wavelengths to be blocked. The second and first filter layers may comprise a single layer having a low refractive index and may be, for example, a transparent film having a refractive index of less than or equal to about 1.4, less than or equal to about 1.3, or less than or equal to about 1.2. The second or first filter layer having a low refractive index may be, for example, porous silica, a porous organic material, a porous organic-inorganic composite, or a combination thereof.

[0230] The first or second filter layer may comprise multiple layers with different refractive indices. It can be formed by stacking two layers with different refractive indices. For example, the first / second filter layer can be formed by alternately stacking a material with a high refractive index and a material with a low refractive index.

[0231] In the following description, embodiments are illustrated in more detail with reference to examples. However, these are exemplary examples of this disclosure, and the disclosure is not limited thereto.

[0232] [Example]

[0233] Analytical methods

[0234] [1] UV-Vis spectrum

[0235] UV-visible absorption spectra were obtained by using an Agilent Cary 5000 spectrometer.

[0236] [2] Photoluminescence analysis

[0237] The photoluminescence (PL) spectrum of the manufactured quantum dots at an excitation wavelength of 450 nm was obtained using a Hitachi F-7000 spectrometer.

[0238] [3] ICP analysis

[0239] Inductively coupled plasma atomic emission spectroscopy (ICP-AES) was performed using a Shimadzu ICPS-8100.

[0240] [4] Regarding the blue light absorption rate and light conversion efficiency of the composite

[0241] The amount of blue excitation light (B) was measured using an integrating sphere. Then, the quantum dot polymer composite was placed in the integrating sphere and illuminated with blue excitation light to measure the amount of red light (A) and blue light (B') emitted from the composite.

[0242] Based on the measured values, the blue light absorption rate and light conversion efficiency are obtained through the following equations.

[0243] Blue light absorption rate (%) = (B - B') / B × 100

[0244] Light conversion efficiency (%) = A / B × 100

[0245] [5] Transmission electron microscopy analysis

[0246] TEM analysis was performed using a UT F30 Tecnai electron microscope.

[0247] [6] Measurement of optical density

[0248] 10 μL of coarse quantum dots were diluted in 990 μL of toluene and placed in a 1 mL cuvette with a 1 cm optical path. The optical density for each wavelength in the region from 300 nm to 700 nm was then measured using a UV-Vis absorption spectroscopy (Shimadzu UV-2600).

[0249] Synthesis Example 1: Preparation of InP Cores

[0250] InP semiconductor nanocrystal particles (hereinafter also referred to as cores) are prepared in the following manner.

[0251] In a 200 mL reaction flask, indium acetate and palmitic acid were dissolved in 1-octadecene and then heated under vacuum at 120 °C. The molar ratio of indium to palmitic acid was approximately 1:3. After 1 hour, the atmosphere in the reaction flask was converted to nitrogen. After heating the reaction flask to 280 °C, a mixed solution of tris(trimethylsilyl)phosphine (TMS3P) and trioctylphosphine was rapidly injected, and the reaction was allowed to proceed for 20 minutes. Acetone was added to the reaction solution, which had been cooled to room temperature, and the precipitate from centrifugation was then redispersed in toluene. TMS3P was used at a rate of 0.5 mol per mol of indium. The size of the obtained InP core was approximately 2 nm.

[0252] Synthesis Example 2: Preparation of InP Cores

[0253] InP semiconductor nanocrystal particles (hereinafter also referred to as cores) are prepared in the following manner.

[0254] In a 200 mL reaction flask, indium acetate and palmitic acid were dissolved in 1-octadecene and then heated under vacuum at 120 °C. The molar ratio of indium to palmitic acid was approximately 1:3. After 1 hour, the atmosphere in the reaction flask was converted to nitrogen. After heating the reaction flask to 280 °C, a mixed solution of tris(trimethylsilyl)phosphine (TMS3P) and trioctylphosphine was rapidly injected, and the reaction was allowed to proceed for 20 minutes. Acetone was added to the reaction solution, which had been cooled to room temperature, and the precipitate from centrifugation was then redispersed in toluene. TMS3P was used at a rate of 0.75 mol per mol of indium. The size of the obtained InP core was approximately 3.6 nm.

[0255] Example 1: Fabrication and characterization of green quantum dots (InP / ZnSe / ZnS) and quantum dot composites

[0256] [1] Synthesis of quantum dots and measurement of optical density

[0257] (1) Selenium was dispersed in trioctylphosphine to prepare a Se / TOP stock solution, and sulfur was dispersed in trioctylphosphine to prepare a S / TOP stock solution.

[0258] In a 200 mL reaction flask, 24 mmol of zinc acetate and oleic acid were dissolved in trioctylamine, and the mixture was then vacuum-treated at 120 °C for 10 min. After purging the inside of the reaction flask with N2, a toluene dispersion of the InP core synthesized in Synthesis Example 1 was injected, while the temperature of the resulting solution was raised to 320 °C, and the prepared Se / TOP stock solution was injected several times. The reaction was carried out to obtain a reaction solution comprising particles having a ZnSe shell set on the core. The total reaction time was approximately 100 min, and the total amount of Se used per mole of indium was approximately 23 moles.

[0259] Then, at the reaction temperature, the S / TOP stock solution was injected into the reaction solution. The reaction was carried out to obtain a reaction solution containing particles in which the ZnS shell was set on the ZnSe shell. The total reaction time was 60 minutes, and the total content of S used for 1 mole of indium was approximately 13 moles. Afterward, the solution was cooled to room temperature, excess ethanol was added and centrifuged, the supernatant was discarded, and the precipitate was dried and dispersed in toluene to obtain an InP / ZnSe / ZnS quantum dot solution.

[0260] (2) The quantum dot solution prepared in (1) was placed in a cuvette with a 1 cm optical path length in a UV-Vis absorption spectroscopy apparatus (UV-2600, Shimadzu Corp.), and the optical density (OD) of the obtained quantum dots (QD) per unit weight was measured. The results are shown in... Figure 8 And in Table 1.

[0261] [2] Fabrication of quantum dot-polymer composites and their patterns

[0262] (1) Preparation of quantum dot-binder dispersion

[0263] The quantum dot-toluene dispersion prepared in [1] was mixed with a binder (a quaternary copolymer of methacrylic acid, benzyl methacrylate, hydroxyethyl methacrylate and styrene, acid value: 130 mg KOH / g, molecular weight: 8000) solution (binder concentration: 30 wt%, in propylene glycol monomethyl ether acetate) to prepare a quantum dot-binder dispersion.

[0264] (2) Preparation of photosensitizing composition

[0265] A quantum dot binder dispersion was mixed with a hexaacrylate (as a photopolymerizable monomer), ethylene glycol di-3-mercaptopropionate (hereinafter, 2T), an oxime ester compound (as an initiator), TiO2 (as a light diffuser), and PGMEA to prepare a composition.

[0266]

[0267] Based on the solid weight of the composition, the prepared composition comprises 42 wt% quantum dots, 17.5 wt% binder polymer, 3 wt% TiO2, 25 wt% 2T, 12 wt% photopolymerizable monomer and 0.5 wt% initiator, with a total solids content (TSC) of 25 wt%.

[0268] (3) Preparation and property analysis of quantum dot-polymer composite patterns

[0269] The photosensitive composition obtained in (2) was spin-coated onto a glass substrate at 150 rpm for 5 seconds to obtain a film. The obtained film was pre-baked (PRB) at 100 °C for 2 minutes. The pre-baked film was irradiated with light (wavelength: 365 nm, intensity: 100 mJ) for 1 second under a mask with a predetermined pattern (e.g., dot or stripe pattern) and then post-baked (POB) at 180 °C for 30 minutes. The film was then developed with an aqueous solution of potassium hydroxide (concentration: 0.043%) for 50 seconds to obtain a patterned quantum dot-polymer composite film (e.g., QD C / F film) with a thickness of about 10 μm.

[0270] For this film, the emission spectrum (photoluminescence: PL) at an excitation wavelength of 450 nm was measured using a Hitachi F-7000 spectrometer, from which the emission peak wavelength and full width at half maximum (FWHM) were measured. Additionally, the blue light absorptivity and light conversion efficiency of the film were measured using an Otsuka QE-2100 quantum efficiency measurement system (manufacturer: Otsuka Electronics Co., Ltd.). The measurement results are shown in Table 1.

[0271] In addition, to measure the content of each element in the quantum dot-polymer composite film, the film was dissolved in nitric acid, bromic acid, or hydrofluoric acid to obtain a solution, and ICP analysis was performed. As a result of the ICP analysis, the weight of each element in the composite was calculated based on the weight ratio of titanium, using the content of each element. The results are shown in Table 2.

[0272] Example 2: Fabrication and Characterization of Green Quantum Dots (InP / ZnSeS) and Quantum Dot Composites

[0273] [1] Synthesis of quantum dots and measurement of optical density

[0274] (1) Selenium was dispersed in trioctylphosphine to prepare a Se / TOP stock solution, and sulfur was dispersed in trioctylphosphine to prepare a S / TOP stock solution.

[0275] In a 200 mL reaction flask, 24 mmol of zinc acetate and oleic acid were dissolved in trioctylamine, and the mixture was then vacuum-treated at 120 °C for 10 min. After purging the inside of the reaction flask with N2, a toluene dispersion of the InP core synthesized in Synthesis Example 1 was injected into the flask while the temperature of the solution was raised to 280 °C. Se / TOP and dodecyl mercaptan were then injected into the reaction flask several times while the temperature of the flask was maintained at 280 °C, and the reaction was carried out to obtain a reaction solution comprising particles having a ZnSeS shell set on the core. The total reaction time was approximately 30 min, and the total amount of Se used per mole of indium was 7 moles, and the total amount of dodecyl mercaptan (DDT) was 2 moles.

[0276] Subsequently, the solution was cooled to room temperature, excess ethanol was added and centrifuged, the supernatant was discarded, and the precipitate was dried and dispersed in toluene to obtain an InP / ZnSeS quantum dot solution.

[0277] (2) The OD was measured using the prepared quantum dot solution in the same manner as in Example 1, and the results are shown in Figure 8 And in Table 1.

[0278] [2] Fabrication of quantum dot-polymer composites and their patterns

[0279] The quantum dots prepared in [1] were used to fabricate a patterned film of the quantum dot-polymer composite in the same manner as in Example 1 [2]. The patterned film was measured relative to the emission peak wavelength, full width at half maximum (FWHM), blue light absorptivity, and light conversion efficiency, and the results are shown in Table 1. In addition, the weight of each element in the film was measured in the same manner as in Example 1, and then used to calculate the weight ratio of each element in the film based on the weight of titanium, and the results are shown in Table 2.

[0280] Example 3: Fabrication and characterization of red quantum dots (InP / ZnSe / ZnS) and quantum dot composites

[0281] Except that the InP core of Synthesis Example 2 was used instead of the InP core of Synthesis Example 1, quantum dots were prepared in a manner similar to that in Example 1, such that the quantum dots could emit red light instead of green light. The optical density of the quantum dots was measured in the same manner as in Example 1, and the results are shown in Table 1.

[0282] Additionally, quantum dots were used in the same manner as described in Example 1 [2] to form a patterned film of quantum dot-polymer composite. The film was measured relative to the emission peak wavelength, full width at half maximum (FWHM), blue light absorptivity, and light conversion efficiency, and the results are shown in Table 1. Furthermore, the weight of each element in the film was measured relative to Example 1 and then used to calculate the weight ratio of each element in the film based on the weight of titanium, and the results are shown in Table 2.

[0283] Comparative Example 1: Fabrication and Characterization of Green Quantum Dots (InP / ZnSe / ZnS) and Quantum Dot Composites with Reduced ZnSe Shell Thickness

[0284] Except for reducing the ZnSe shell thickness to increase the optical density per unit weight (OD), green quantum dots were prepared in the same manner as in Example 1, and the optical density per unit weight is shown in Table 1.

[0285] Additionally, quantum dots were used in the same manner as described in Example 1 [2] to form a patterned film of quantum dot-polymer composite. The film was measured relative to the emission peak wavelength, full width at half maximum (FWHM), blue light absorptivity, and light conversion efficiency, and the results are shown in Table 1. Furthermore, the weight of each element in the film was measured in the same manner as in Example 1, and then used to calculate the weight ratio of each element in the film based on the weight of titanium, and the results are shown in Table 2.

[0286] Comparative Example 2: Fabrication and Characterization of Green Quantum Dots (InP / ZnSe / ZnS) and Quantum Dot Composites with Reduced ZnS Shell Thickness

[0287] Except for reducing the thickness of the ZnS shell to increase the optical density (OD) per unit weight, green quantum dots were prepared in the same manner as in Example 1, and the results are shown in Table 1.

[0288] Additionally, quantum dots were used in the same manner as described in Example 1 [2] to form a patterned film of the quantum dot-polymer composite. The patterned film of the quantum dot-polymer composite was measured relative to the emission peak wavelength, full width at half maximum (FWHM), blue light absorptivity, and light conversion efficiency. The results are shown in Table 1. Furthermore, the weight of each element in the film was measured in the same manner as in Example 1, and then used to calculate the weight ratio of each element based on the weight of titanium. The results are shown in Table 2.

[0289] Comparative Example 3: Fabrication and Characterization of Green Quantum Dots (InP / ZnSeS) and Quantum Dot Composites with Increased ZnSeS Shell Thickness

[0290] Except for increasing the ZnSeS shell thickness to reduce the optical density per unit weight (OD), green quantum dots were prepared using the same method as in Example 2, and then the optical density per unit weight was measured, with the results shown in Table 1.

[0291] Additionally, quantum dots were used in the same manner as described in Example 1 [2] to form a patterned film of quantum dot-polymer composite. The film was measured relative to the emission peak wavelength, full width at half maximum (FWHM), blue light absorptivity, and light conversion efficiency, and the results are shown in Table 1. Furthermore, the weight of each element was measured in the same manner as in Example 1, and then used to calculate the weight ratio of each element in the film based on the weight of titanium, and the results are shown in Table 2.

[0292] (Table 1)

[0293]

[0294] As shown in Table 1, compared with the quantum dot composites of Comparative Examples 1 to 3 (which comprise a core and shell having the same composition as the examples, and have a blue light absorption rate greater than or equal to 80%, a light conversion efficiency less than 35%, and an OD outside the ranges stated), the quantum dot composites of Examples 1 to 3 exhibit significantly superior light conversion efficiency even with a slight decrease in blue light absorption rate. The quantum dot composites of Examples 1 to 3 comprise quantum dots having an OD per 1 mg of quantum dots for a wavelength of 450 nm in the range of 0.2 to 0.3 and an emission peak wavelength of about 500 nm to about 550 nm, or quantum dots having an OD per 1 mg of quantum dots for a wavelength of 450 nm in the range of 0.5 to 0.7 and an emission peak wavelength of about 610 nm to about 660 nm.

[0295] In other words, the light conversion efficiency of quantum dot composites does not increase simply by reducing the shell thickness, but rather there exists a specific range of shell thicknesses where the light conversion efficiency increases, while the blue light absorption remains at a predetermined level or higher. Not intended to be bound by a particular theory, this specific range of shell thicknesses can be satisfied by limiting the optical density per unit weight of quantum dots to a specific range.

[0296] (Table 2)

[0297]

[0298]

[0299] Referring to Table 2, the quantum dot composites according to Examples 1 to 3 have a weight ratio of each element included therein (specifically, based on the weight of titanium derived from titanium dioxide), which differs from the weight ratio of the quantum dot composites according to Comparative Examples 1 to 3. Therefore, quantum dots satisfying a specific optical density range according to the embodiments can be included in the quantum dot composite at a concentration different from that included with conventional quantum dots. Consequently, the light conversion efficiency of the quantum dot composite can be improved due to the difference in quantum dot concentration within the composite.

[0300] Fabrication Example: Manufacturing of a Display Panel Including a Color Conversion Layer

[0301] Quantum dot composites prepared in Examples 1 and 2, respectively, and a red quantum dot composite prepared in Example 3, comprising green quantum dots, were applied to green and red pixels in a color conversion panel (or color conversion layer), respectively. A film comprising components other than quantum dots was applied to a light-transmitting layer that transmits blue light as excitation light to manufacture a display panel. Here, the display panel was manufactured by varying the content of titanium dioxide included in the blue light-transmitting layer at 5 wt% or 10 wt%. Furthermore, the areas of the green pixels, red pixels, and the light-transmitting layer were varied, as described in Tables 3 and 4, respectively, to manufacture various types of display panels including a color conversion layer. The structures of the display panels manufactured in this way by varying the area ratio of each pixel to the light-transmitting layer and the content of titanium dioxide in the light-transmitting layer are shown in Tables 3 and 4, respectively. In these display panels (or these color conversion layers), the weight ratio of indium, phosphorus, zinc, selenium, or sulfur included in each display panel to the weight of titanium was calculated and provided in Tables 3 and 4. In addition, the weight ratio of each element to the weight of Ti element in each display panel provided in Tables 3 and 4 respectively is converted into the molar ratio of each element, which is provided in Tables 5 and 6 respectively.

[0302] (Table 3)

[0303]

[0304]

[0305] (Table 4)

[0306]

[0307]

[0308] (Table 5)

[0309]

[0310]

[0311] (Table 6)

[0312]

[0313]

[0314] Referring to Tables 3 to 6, since the quantum dot composites according to Examples 1 to 3 have a weight or molar number of each element included therein (specifically, each element forming the quantum dots) within a specific range relative to the weight or molar number of titanium derived from titanium dioxide, the weight or molar number ratio of the elements is also within a specific range throughout the entire display panel manufactured therefrom. Therefore, when a quantum dot composite containing quantum dots satisfying this specific range or a display panel containing the quantum dot composite is included, the absorption rate of blue light is increased and the light conversion efficiency is improved, thereby manufacturing a display device with excellent luminous efficiency.

[0315] On the other hand, the method for measuring the content of each element in each display panel, as described in Tables 3 to 6, is performed by the following steps: physically scraping off a portion of solid corresponding to a predetermined area (basically, a predetermined volume) comprising red pixels, green pixels, and a light-transmitting layer from each display panel; pulverizing the solid; dissolving the powder in various types of acids (e.g., nitric acid, bromic acid, or hydrofluoric acid) to prepare a solution; and performing ICP analysis on the solution. The pixels and light-transmitting layer include various components such as quantum dots, titanium dioxide, polymers forming the polymer matrix, polymers forming the light-transmitting layer, and materials forming the barrier ribs (i.e., the black matrix). However, since among these components, titanium is derived from titanium dioxide, while indium, phosphorus, selenium, sulfur, and zinc are derived from quantum dots, the presence of other components included in each pixel and light-transmitting layer that are not derived from quantum dots or titanium dioxide is completely independent of the weight or molar ratio of each element listed in Tables 3 to 6 to the weight or molar ratio of Ti. Therefore, the content of indium, phosphorus, zinc, selenium and sulfur elements derived from quantum dots and the content of Ti element in the entire display panel according to the embodiment can be quantitatively analyzed.

[0316] While this disclosure has been described in conjunction with embodiments now considered practical, it will be understood that the invention is not limited to the disclosed embodiments. Rather, it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A display panel, the display panel comprising: Color conversion layer, including color conversion areas; as well as The light-emitting panel includes a light source configured to emit blue light, a light source configured to emit green light, or a combination thereof; The color conversion area includes a first color conversion area and a second color conversion area. The first color conversion region is configured to convert blue light, green light, or a combination thereof emitted from the light source into green light of a first emission spectrum of 500nm to 550nm, and The second color conversion region is configured to convert blue light, green light, or a combination thereof emitted from the light source into red light of a second emission spectrum ranging from 610 nm to 660 nm. The first color conversion region includes a first quantum dot composite, which comprises a first matrix and a plurality of green emitting quantum dots and titanium dioxide dispersed in the first matrix. The plurality of green emitting quantum dots include metals and non-metals, with the metals including indium and zinc, and the non-metals including phosphorus and selenium. The second color conversion region includes a second quantum dot composite, which comprises a second matrix and multiple red emitting quantum dots and titanium dioxide dispersed within the second matrix. The plurality of red emitting quantum dots include metals and non-metals; the metals include indium and zinc, and the non-metals include phosphorus and selenium. The display panel has a weight ratio of indium greater than or equal to 0.1 and less than or equal to 0.7 to titanium, and a weight ratio of phosphorus greater than or equal to 0.05 and less than or equal to 0.2 to titanium. The first color conversion region has a weight ratio of selenium to titanium that is greater than or equal to 2 and less than or equal to 12.

2. The display panel according to claim 1, wherein, The color conversion layer also includes light-transmitting areas configured to transmit blue light, green light, or a combination thereof emitted from the light source.

3. The display panel according to claim 2, wherein, In the first color conversion region, the weight ratio of indium to titanium is greater than or equal to 0.2 and less than or equal to 1.8, and the weight ratio of phosphorus to titanium is greater than or equal to 0.05 and less than or equal to 0.

4.

4. The display panel according to claim 1, wherein, In the second color conversion region, the weight ratio of selenium to titanium is greater than or equal to 1 and less than or equal to 5.

5. The display panel according to claim 4, wherein, In the second color conversion region, the weight ratio of indium to titanium is greater than or equal to 0.1 and less than or equal to 0.5, and the weight ratio of phosphorus to titanium is greater than or equal to 0.05 and less than or equal to 0.

3.

6. The display panel according to claim 1, wherein, In the first color conversion region, the weight ratio of indium to titanium is greater than or equal to 0.2 and less than or equal to 1.5, the weight ratio of phosphorus to titanium is greater than or equal to 0.1 and less than or equal to 0.3, and the weight ratio of selenium to titanium is greater than or equal to 3 and less than or equal to 10.

7. The display panel according to claim 1, wherein, In the second color conversion region, the weight ratio of indium to titanium is greater than or equal to 0.2 and less than or equal to 0.4, the weight ratio of phosphorus to titanium is greater than or equal to 0.1 and less than or equal to 0.3, and the weight ratio of selenium to titanium is greater than or equal to 1.2 and less than or equal to 3.

8. The display panel according to claim 1, wherein, Each of the plurality of green emitting quantum dots and the plurality of red emitting quantum dots includes a semiconductor nanocrystal core and a semiconductor nanocrystal shell, the semiconductor nanocrystal core comprising indium and phosphorus, and the semiconductor nanocrystal shell disposed on the semiconductor nanocrystal core and comprising zinc and selenium, and optionally sulfur.

9. The display panel according to claim 1, wherein, Each of the first and second matrices comprises a polymerizable monomer having a carbon-carbon double bond, an organic solvent, a polymer, a thiol compound having at least one thiol group, or a combination thereof.

10. The display panel according to claim 1, wherein, The display panel has a weight ratio of selenium greater than or equal to 0.5 and less than or equal to 5 to the weight of titanium.

11. The display panel according to claim 1, wherein, The display panel has a weight ratio of selenium greater than or equal to 0.5 and less than or equal to 3 to the weight of titanium.

12. The display panel according to claim 1, wherein, The first and second color conversion regions exhibit light conversion efficiency greater than 35% and blue light absorption rate greater than 83%.

13. The display panel according to claim 1, wherein, The plurality of green emitting quantum dots have an optical density of 0.12 to 0.35 per 1 mg for a wavelength of 460 nm and / or have an emission peak of 530 nm to 540 nm.

14. The display panel according to claim 1, wherein, The plurality of red emitting quantum dots have an optical density of 0.4 to 0.5 per 1 mg for a wavelength of 460 nm and / or have an emission peak of 635 nm to 645 nm.

15. The display panel according to claim 1, wherein, Each of the first quantum dot composite and the second quantum dot composite comprises 1 wt% to 10 wt% titanium dioxide.

16. An electronic device comprising a display panel according to any one of claims 1 to 15.

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