Display panel and electronic device comprising the same

Abstract

Disclosed are a display panel and an electronic device including the same. The display panel includes: a light emitting panel; and a color conversion panel having a surface opposite to a surface of the light emitting panel. The light emitting panel is configured to emit incident light including first light and second light. The color conversion panel includes a color conversion layer including two or more color conversion regions, the color conversion regions including a first region corresponding to a green color pixel, the first region including a first composite, the first composite including a matrix and a plurality of luminescent nanostructures dispersed within the matrix, and a spectral overlap between a UV-Vis absorption spectrum of the luminescent nanostructures, a maximum emission peak of the first light, and a maximum emission peak of the second light satisfies a following formula: B / A ≤ about 0.6, A and B as defined.

Description

[0001] This application claims priority and benefits derived therefrom to Korean Patent Application No. 10-2021-0029749, filed on March 5, 2021, with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0002] A display panel and an electronic device including the display panel are disclosed. Background Technology

[0003] Nanostructures can exhibit aspects, properties, or characteristics that differ from their corresponding bulk materials with substantially the same composition, for example, in terms of physical properties known as the inherent properties of bulk materials (band gap, melting point, etc.). Multiple luminescent nanostructures can be constructed to emit light upon energy excitation (e.g., by irradiation with light or application of a voltage). Luminescent nanostructures can find applicability in a variety of devices, such as display panels and electronic devices that include them. Summary of the Invention

[0004] The embodiment provides a display panel including a color conversion panel comprising (multiple) light-emitting nanostructures.

[0005] An embodiment provides an electronic device including the display panel.

[0006] In one embodiment, the display panel includes: a light-emitting panel; and a color conversion panel having a surface opposite to the surface of the light-emitting panel (e.g., facing the light-emitting panel).

[0007] The light-emitting panel is configured to emit incident light including a first light and a second light. The first light has a maximum emission peak wavelength greater than or equal to about 450 nm and less than or equal to about 480 nm, and the second light has a maximum emission peak wavelength greater than or equal to about 500 nm and less than or equal to about 580 nm.

[0008] The color conversion panel includes: a color conversion layer comprising color conversion areas (e.g., two or more color conversion areas); and optional partitions defining each area (or color conversion area) of the color conversion layer.

[0009] The color conversion area includes the first area corresponding to the green pixel.

[0010] The first region includes a first composite, which comprises a matrix and multiple luminescent nanostructures dispersed within the matrix, and

[0011] The spectral overlap between the UV-Vis absorption spectrum of the luminescent nanostructure, the maximum emission peak of the first light, and the maximum emission peak of the second light satisfies the following equation:

[0012] B / A ≤ approximately 0.6.

[0013] Here, the area of ​​overlap between the UV-Vis absorption spectrum of columinescent nanostructure A and the maximum emission peak of the first light in the wavelength range of less than or equal to about 500 nm corresponds to the area of ​​overlap between the UV-Vis absorption spectrum of columinescent nanostructure B and the maximum emission peak of the second light in the wavelength range of greater than or equal to about 500 nm.

[0014] Here, to determine A, the heights of the first absorption peak and the maximum emission peak of the first light in the UV-Vis absorption spectrum of the luminescent nanostructure are adjusted to be equal; to determine B, the heights of the first absorption peak and the maximum emission peak of the second light in the UV-Vis absorption spectrum of the luminescent nanostructure are adjusted to be equal.

[0015] Multiple luminescent nanostructures can be constructed to convert the emission spectrum of incident light.

[0016] The light-emitting panel may include a first electrode and a second electrode, as well as a light-emitting layer disposed between the first electrode and the second electrode.

[0017] The light-emitting layer may include organic compounds and dopants.

[0018] The light-emitting layer may include (multiple) first light-emitting layers and (multiple) second light-emitting layers disposed on the first light-emitting layers.

[0019] The first luminescent layer can be configured to emit the first light.

[0020] The second light-emitting layer can be configured to emit a second light.

[0021] The light-emitting layer may further include a first charge-generating layer disposed between the first light-emitting layer and the second light-emitting layer.

[0022] The light-emitting layer may further include a charge-assisted layer disposed between the first electrode and the first light-emitting layer, a charge-assisted layer disposed between the second electrode and the second light-emitting layer, or a charge-assisted layer disposed between the first electrode and the first light-emitting layer and between the second electrode and the second light-emitting layer.

[0023] Multiple charge-assisted layers may include hole-assisted layers, electron-assisted layers, or both.

[0024] The light-emitting layer may include a second light-emitting layer disposed between two or more first light-emitting layers.

[0025] The light-emitting layer may include a first light-emitting layer disposed between two or more second light-emitting layers.

[0026] The incident light may not include red light with a wavelength greater than or equal to about 600 nm and less than or equal to about 680 nm.

[0027] Incident light can include green light and blue light.

[0028] The maximum emission peak (wavelength) of the second light can be in the range of greater than or equal to about 515 nm and less than or equal to about 530 nm. The maximum emission peak (wavelength) of the first light can be in the range of greater than about 440 nm (e.g., greater than or equal to about 445 nm, greater than or equal to about 450 nm, or greater than or equal to about 455 nm) and less than or equal to about 465 nm.

[0029] The maximum photoluminescence peak wavelength of the luminescent nanostructure can be in the range of greater than or equal to about 520 nm and less than or equal to about 550 nm.

[0030] The difference between the wavelength of the first absorption peak of the luminescent nanostructure and the wavelength of the maximum photoluminescence peak of the luminescent nanostructure can be greater than or equal to about 45 nm and less than or equal to about 65 nm.

[0031] The first complex may exhibit an incident light (e.g., blue light) absorbance of about 89%, about 89.5%, about 90%, or about 90.5%.

[0032] The first complex can exhibit a light conversion efficiency of greater than or equal to about 45%, greater than or equal to about 46%, greater than or equal to about 47%, or greater than or equal to about 48%.

[0033] In the UV-Vis absorption spectrum of the luminescent nanostructure, the absorbance ratio (e.g., A450 / A350) of the first absorption peak wavelength or about 450 nm to the wavelength at about 350 nm can be greater than or equal to about 0.078:1, greater than or equal to about 0.09:1, greater than or equal to about 0.1:1, greater than or equal to about 0.12:1, greater than or equal to about 0.2:1, greater than or equal to about 0.23:1, greater than or equal to about 0.234:1, greater than or equal to about 0.24:1, or greater than or equal to about 0.243:1.

[0034] Luminescent nanostructures can exhibit UV-Vis absorption spectra with positive differential coefficients at approximately 450 nm.

[0035] The differential coefficient value can be greater than or equal to approximately 0.0001.

[0036] The luminescent nanostructure may include: a first semiconductor nanocrystal, including a group III-V compound; and a second semiconductor nanocrystal, including a zinc chalcogenide.

[0037] Group III-V compounds include indium, phosphorus, and optionally zinc.

[0038] Zinc sulfides include zinc, selenium, and sulfur, and

[0039] Luminescent nanostructures may be cadmium-free.

[0040] In luminescent nanostructures, the molar ratio of sulfur to selenium (S:Se) can be greater than or equal to about 0.3:1 or greater than or equal to about 0.5:1. In luminescent nanostructures, the molar ratio of sulfur to selenium can be greater than or equal to about 1.9:1, greater than or equal to about 2:1, greater than or equal to about 2.01:1, greater than or equal to about 2.1:1, greater than or equal to about 2.3:1, greater than or equal to about 2.4:1, greater than or equal to about 2.5:1, greater than or equal to about 2.6:1, greater than or equal to about 3:1, greater than or equal to about 3.5:1, or greater than or equal to about 4:1.

[0041] In luminescent nanostructures, the molar ratio of sulfur to selenium can be less than or equal to approximately 15:1, less than or equal to approximately 14.5:1, less than or equal to approximately 14:1, less than or equal to approximately 13:1, less than or equal to approximately 12:1, less than or equal to approximately 11:1, less than or equal to approximately 10:1, less than or equal to approximately 8:1, less than or equal to approximately 6:1, less than or equal to approximately 5.5:1, less than or equal to approximately 5:1, less than or equal to approximately 4.5:1, less than or equal to approximately 4:1, less than or equal to approximately 3.5:1, less than or equal to approximately 3:1, less than or equal to approximately 2.8:1, less than or equal to approximately 2.7:1, less than or equal to approximately 2.67:1, or less than or equal to approximately 2.66:1.

[0042] In luminescent nanostructures, the molar ratio of sulfur to indium can be greater than or equal to approximately 3:1, greater than or equal to approximately 5:1, greater than or equal to approximately 7:1, greater than or equal to approximately 9:1, or greater than or equal to approximately 9.4:1. In luminescent nanostructures, the molar ratio of sulfur to indium can be less than or equal to approximately 20:1, less than or equal to approximately 17:1, less than or equal to approximately 15:1, less than or equal to approximately 13:1, less than or equal to approximately 12:1, or less than or equal to approximately 11.5:1.

[0043] In luminescent nanostructures, the molar ratio of selenium to indium can be less than or equal to approximately 10:1, less than or equal to approximately 8:1, less than or equal to approximately 7:1, less than or equal to approximately 6:1, less than or equal to approximately 5:1, or less than or equal to approximately 4.8:1. The molar ratio of selenium to indium can be greater than or equal to approximately 1:1, greater than or equal to approximately 2:1, greater than or equal to approximately 2.5:1, greater than or equal to approximately 3:1, greater than or equal to approximately 3.5:1, greater than or equal to approximately 4:1, or greater than or equal to approximately 4.3:1.

[0044] In luminescent nanostructures, the molar ratio of zinc to indium can be less than or equal to approximately 30:1, less than or equal to approximately 24:1, less than or equal to approximately 23:1, less than or equal to approximately 22:1, less than or equal to approximately 21:1, less than or equal to approximately 20:1, less than or equal to approximately 19:1, less than or equal to approximately 18:1, or less than or equal to approximately 17:1. The molar ratio of zinc to indium can be greater than or equal to approximately 5:1, greater than or equal to approximately 10:1, greater than or equal to approximately 15:1, or greater than or equal to approximately 17:1.

[0045] In luminescent nanostructures, the molar ratio of phosphorus to indium can be greater than or equal to approximately 0.7:1, greater than or equal to approximately 0.75:1, greater than or equal to approximately 0.8:1, greater than or equal to approximately 0.85:1, greater than or equal to approximately 0.88:1, greater than or equal to approximately 0.89:1, greater than or equal to approximately 0.9:1, greater than or equal to approximately 0.93:1, or greater than or equal to approximately 0.95:1. In luminescent nanostructures, the molar ratio of phosphorus to indium can be less than or equal to approximately 1.5:1, less than or equal to approximately 1.4:1, less than or equal to approximately 1.3:1, less than or equal to approximately 1.2:1, less than or equal to approximately 1.1:1, less than or equal to approximately 1.05:1, less than or equal to approximately 1:1, or less than or equal to approximately 0.95:1.

[0046] When confirmed by electron microscopy analysis, the luminescent nanostructures can have an average size of less than or equal to about 6 nm. As confirmed by electron microscopy analysis, the luminescent nanostructures can have a size distribution of less than or equal to about 30% of the average size.

[0047] In spectral overlap, B / A can be less than or equal to about 0.5 or less than or equal to about 0.45.

[0048] The first composite material or color conversion panel may have an incident light absorbance greater than or equal to approximately 89% as defined by the following formula:

[0049] Incident light absorbance (%) = [(B-B') / B] × 100 (%)

[0050] B: (For example, the amount of (blue) incident light with a wavelength less than or equal to about 500 nm)

[0051] B': The amount of (blue) incident light that has passed through the first complex (e.g., with a wavelength less than or equal to about 500 nm).

[0052] The first composite material or color conversion panel may have a light conversion efficiency greater than or equal to about 45% as defined by the following formula:

[0053] A / B (%) = Light Conversion Rate

[0054] A: The amount of green light emitted from the first complex (e.g., having a wavelength greater than about 500 nm).

[0055] B: (Blue) incident light with a wavelength less than or equal to about 500 nm.

[0056] The first complex can be in the form of a patterned film.

[0057] The color conversion area may also include a second area corresponding to the red pixel, a third area corresponding to the blue pixel, or a combination thereof.

[0058] In an embodiment, the electronic device (or display device) includes a color conversion panel or a display panel.

[0059] The display panel according to the embodiment can exhibit enhanced optical properties, thereby providing images of improved quality. The display panel of the embodiment can be applied to various electronic devices such as TVs, monitors, mobile devices, VR / AR, electric vehicle displays, etc. Attached Figure Description

[0060] Figure 1A This is a schematic cross-sectional view of a color conversion panel included in a display panel according to an embodiment.

[0061] Figure 1B The spectral overlap area between the UV-Vis absorption spectrum of the light-emitting nanostructure included in the display panel according to an embodiment and the emission peak of the first light is schematically shown.

[0062] Figure 1C The spectral overlap area between the UV-Vis absorption spectrum of the luminescent nanostructure included in the display panel according to an embodiment and the emission peak of the second light is schematically shown.

[0063] Figure 2 This is a perspective view showing an example of a display panel including a color conversion panel according to an embodiment.

[0064] Figure 3 yes Figure 2 A cross-sectional view of the display panel.

[0065] Figure 4 It is shown (for example, Figure 2 A plan view of an example of the pixel arrangement of a display panel.

[0066] Figure 5A yes Figure 4 A schematic cross-sectional view of the display panel taken along line IV-IV.

[0067] Figure 5BThis is a more detailed cross-sectional view of the light-emitting elements in the display panel according to an embodiment.

[0068] Figure 6A , Figure 6B , Figure 6C and Figure 6D These are cross-sectional views showing examples of light-emitting elements.

[0069] Figure 7A The relationship between the spectral overlap (A or B) of the UV-Vis absorption spectrum of the luminescent nanostructure under blue (or green) incident light and the first absorption peak wavelength (absorption peak position of QD) of the luminescent nanostructure (nm) is shown. This relationship was obtained by considering the results of UV-Vis absorption spectral analyses of the luminescent nanostructures prepared in the example and comparative examples. Figure 7A In the text, "QD-B_OLED" refers to spectral overlap A (au, any unit), and "QD-G_OLED" refers to spectral overlap B.

[0070] Figure 7B The relationship between the spectral overlap ratio (B / A) and the wavelength of the first absorption peak (the absorption peak position of QD, nm) is shown.

[0071] Figure 8 The results of measuring the light conversion efficiency and absorbance of the display panels in the example and comparative examples are shown.

[0072] Figure 9A The patterning process of the composition used in the examples is illustrated schematically.

[0073] Figure 9B The patterning process of the ink composition used in the embodiment is illustrated schematically. Detailed Implementation

[0074] The advantages and features of this disclosure and its implementation methods will become apparent from the following exemplary 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.

[0075] 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.

[0076] 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.

[0077] Furthermore, unless otherwise stated, the singular includes the plural.

[0078] Here, the description of excluding cadmium (or other toxic heavy metals) means that the concentration of cadmium (or the corresponding heavy metal) is less than or equal to about 100 ppm (by weight), less than or equal to about 50 ppm, less than or equal to about 10 ppm, less than or equal to about 1 ppm, less than or equal to about 0.1 ppm, less than or equal to about 0.01 ppm, or close to about 0. In the examples, cadmium (or the heavy metal thereof) is substantially absent, or if present, cadmium is present in amounts or at impurity levels below the detection limit of a given detection method.

[0079] 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), azido. (-N3), 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) and combinations thereof.

[0080] In addition, unless otherwise defined below, “heterogeneous” refers to a compound, group or substituent comprising one to three heteroatoms selected from N, O, S, Si or P.

[0081] As used herein, "alkylene" refers to a straight-chain or branched saturated aliphatic hydrocarbon group that optionally includes at least one substituent and has a valence of two or higher.

[0082] As used herein, "aryl" refers to a functional group having a valence of two or higher, which optionally includes at least one substituent and is formed by removing at least two hydrogens from at least one aromatic ring.

[0083] In addition, "aliphatic hydrocarbon group" refers to C1 to C30 straight-chain or branched alkyl, C2 to C30 straight-chain or branched alkenyl, or C2 to C30 straight-chain or branched alkynyl.

[0084] "Aromatic organic groups" refer to C6 to C30 aryl groups or C2 to C30 heteroaryl groups, and

[0085] "Alicyclic organic groups" refer to C3 to C30 cycloalkyl, C3 to C30 cycloalkenyl, and C3 to C30 cycloynyl groups.

[0086] As used herein, the term "(meth)acrylate" refers to acrylates and / or methacrylates.

[0087] As used here, "family" refers to the family of the periodic table.

[0088] As used herein, “Group II” refers to Group IIA and Group IIB, and examples of Group II metals may include, but are not limited to, Cd, Zn, Hg and Mg.

[0089] "Group III" refers to Group IIIA and Group IIIB, and examples of Group III metals can include, but are not limited to, Al, In, Ga and Tl.

[0090] As used herein, “group V” refers to group VA, and examples may include, but are not limited to, nitrogen, phosphorus, arsenic, antimony and bismuth.

[0091] As used herein, “VI group” refers to VIA group, and examples may include, but are not limited to, sulfur, selenium and tellurium.

[0092] In the following text, the term "combination" may include mixed and / or stacked structures.

[0093] Here, a nanostructure refers to at least one region having nanoscale dimensions or a structure having characteristic dimensions. In embodiments, the size of the nanostructure can be less than about 300 nm, less than about 250 nm, less than about 150 nm, less than about 100 nm, less than about 50 nm, or less than about 30 nm. These structures can have any shape. Nanostructures can have any shape such as nanowires, nanorods, nanotubes, multi-arm shapes with two or more arms, nanodots (or quantum dots), and are not particularly limited thereto. Nanostructures can be, for example, substantially crystalline, substantially single-crystal, polycrystalline, amorphous, or combinations thereof.

[0094] Quantum dot here refers to a nanocrystal that exhibits quantum confinement or exciton confinement (e.g., semiconductor-based) and is a luminescent nanostructure (e.g., capable of emitting light upon energy excitation). Unless otherwise defined, the shape of "quantum dot" is not limited herein.

[0095] Here, the term "dispersion" refers to a dispersion in which the dispersed phase is a solid and the continuous medium includes a liquid or solid that is different from the dispersed phase. Here, "dispersion" can be a colloidal dispersion 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., less than or equal to about 2 μm, less than or equal to about 1 μm, less than or equal to about 900 nm, less than or equal to about 800 nm, less than or equal to about 700 nm, less than or equal to about 600 nm, or less than or equal to about 500 nm).

[0096] Here, the mean can be either the median or the average. In this embodiment, the average value can be the mean.

[0097] Here, the quantum efficiency can be easily and reproducibly determined using commercially available equipment (e.g., equipment from Hitachi Co., Ltd. or Otsuka Co., Ltd.) and with reference to the instructions provided by, for example, the respective equipment manufacturer. The quantum efficiency (or quantum yield) can be measured in solution or in the solid state (in a complex). In embodiments, the quantum efficiency (or quantum yield) is the ratio of photons emitted to photons absorbed by a nanostructure or a population of nanostructures. In embodiments, the 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, the 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.

[0098] The full width at half maximum (FWHM) and the maximum photoluminescence (PL) peak wavelength can be measured, for example, by using the photoluminescence spectrum obtained by a spectrophotometer such as a fluorescence spectrophotometer.

[0099] Here, "first absorption peak wavelength" refers to the wavelength of the first main peak that appears in the lowest energy region of the UV-Vis absorption spectrum.

[0100] Luminescent nanostructures can be incorporated into a variety of electronic devices. The electrical and / or optical properties of nanostructures can vary depending on their physical properties (e.g., composition, size, and / or shape). For example, a luminescent nanostructure can be a semiconductor nanocrystal particle. Luminescent nanostructures (e.g., quantum dots) have a large surface area per unit volume and can therefore exhibit quantum confinement effects, and thus exhibit different physical or optical properties than their corresponding bulk materials with the same composition. For example, a luminescent nanostructure such as a quantum dot can absorb energy from an excitation source (e.g., light), become energetically excited, and release energy corresponding to its band gap energy.

[0101] Emitting nanostructures can be applied to color conversion panels (e.g., luminescent color filters) or display panels including such composites in the form of pixel-corresponding complexes (e.g., polymer complexes). For example, compared to liquid crystal displays that include white luminescent backlights and absorptive color filters, in display panels including quantum dot-based color conversion panels or luminescent color filters, luminescent material layers can be disposed opposite each other in front of the panel device, and the luminescent material layers can convert incident light supplied from a light source (or luminescent panel) into light of a desired emission spectrum (e.g., red or green light). Therefore, due to the forward scattering of light emitted from the luminescent material, such display panels can exhibit wide viewing angles and thus solve or address the problem of light loss caused by the use of absorptive color filters.

[0102] Color filters or color conversion panels based on luminescent nanostructures can be used with various light sources. However, the loss of luminous efficiency of a given light source and / or the relatively low light conversion rate of incident light in such devices will be significant technical obstacles that engineers may need to overcome in developing devices with color conversion panels. For example, when organic electroluminescent devices are used as light sources, the luminous efficiency of the electroluminescent device and the light conversion rate of the incident light emitted from it can have a certain impact on the display quality of the display panel. However, luminescent nanostructures disposed in the color conversion region or composites including such luminescent nanostructures (e.g., micro-LEDs, electroluminescent devices, etc.) remain of interest and are a subject of active research into achieving efficient absorption of incident light emitted from a given light source. For example, to improve absorbance, the composite may include a separate light scatterer and / or have increased thickness. In addition, the incident light absorbance of the luminescent nanostructures themselves present in the composite is also an important technical problem that needs to be solved.

[0103] Furthermore, luminescent nanostructures that achieve the desired absorbance or luminescence properties of incident light often include harmful heavy metals such as cadmium and lead. However, due to the serious environmental / health problems caused by cadmium and lead and their status as controlled elements, relatively eco-friendly luminescent nanostructures are needed to drive the development of next-generation display devices. Therefore, extensive research has been conducted on semiconductor nanocrystals based on group III-V compounds that achieve similar or even better optical properties compared to more harmful materials; however, this remains a significant and ongoing technological challenge. As demonstrated by the inventors, cadmium-free luminescent nanostructures based on group III-V compounds (e.g., indium phosphide) exhibit relatively inferior optical properties (e.g., luminous efficiency and / or incident light absorbance) compared to luminescent nanostructures that include harmful heavy metals. Therefore, it is desirable to develop a display that achieves improved optical properties without including harmful heavy metals such as cadmium and lead.

[0104] The display panel according to an embodiment may include a light-emitting panel that emits incident light of mixed colors (e.g., including a first light and a second light) to improve the overall properties of the device. The light-emitting panel can provide a device in which luminous efficiency is necessary to be increased and / or lifetime characteristics are improved. The light-emitting panel may have, for example, a series structure in which multiple light-emitting layers are stacked.

[0105] Without being bound by any theory, incident light can directly affect the efficiency of the corresponding display panel. For example, blue light (emitted from an organic electroluminescent device) can be fluorescent light with low intrinsic efficiency. The light-emitting panel in the display panel according to the embodiment can (e.g., by employing a tandem structure in which a green phosphor layer is disposed between two blue emitting layers) emit a mixture of green and blue light, thereby increasing the overall efficiency of the device.

[0106] In addition to a light-emitting panel that emits incident light of mixed colors, the display panel according to the embodiments may also include a color conversion panel comprising a light-emitting nanostructure having controlled optical properties (e.g., UV-Vis absorption curves and the ratio of absorbance at two or more predetermined wavelengths). When used with the light-emitting panel, the color conversion panel can exhibit improved optical properties (e.g., incident light absorbance, light conversion efficiency, etc.). For example, the green pixel in the display panel of the embodiments can be configured to extract green incident light with increased efficiency. In the display panel of the embodiments, because the absorption spectrum of the light-emitting nanostructure disposed in the green pixel is limited by spectral overlap with the maximum emission peak of the incident light (e.g., blue and green incident light), unnecessary color conversion of the incident light is minimized, and green light at the desired wavelength can be emitted.

[0107] The display panel according to an embodiment is described below with reference to the accompanying drawings. Figure 2 and Figure 3 The display panel 1000 according to an embodiment includes: a light-emitting panel 100; and a color conversion panel 200 having a surface opposite to the surface of the light-emitting panel (e.g., facing the light-emitting panel). The display panel 1000 according to an embodiment may further include a light-transmitting layer 300 disposed between the light-emitting panel 100 and the color conversion panel 200, an adhesive or bonding element 400 for adhering the light-emitting panel 100 to the color conversion panel 200, or a combination thereof.

[0108] In an embodiment, the light-emitting panel 100 and the color-converting panel 200 may face each other with the light-transmitting layer 300 located therebetween, and the color-converting panel 200 may be positioned such that light emitted from the light-emitting panel 100 is directed toward the color-converting panel 200. An adhesive or bonding element 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.

[0109] Reference Figure 4 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 in which a bonding element 400 may be positioned.

[0110] Display area 1000D may include multiple pixels PX arranged along rows (e.g., the x-direction) and / or columns (e.g., the y-direction), and 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, as a Bayer matrix, a PenTile matrix, and / or a diamond matrix, but are not limited to this.

[0111] Each of the sub-pixels PX1, PX2, and PX3 can be configured to display a color of the three primary colors or a combination of the three primary colors (e.g., red, green, blue, or a combination thereof (e.g., white light)). 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.

[0112] 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.

[0113] In the display panel according to the embodiment, the light-emitting panel 100 emits incident light (e.g., incident light of mixed colors) including a first light (e.g., blue light) and a second light (e.g., green light) and, for example, does not emit red light having a wavelength greater than or equal to about 600 nm and less than or equal to about 680 nm, in order to provide a light-emitting panel with improved luminous efficiency.

[0114] The maximum emission peak wavelength of the first light can be in the range of about 440 nm, about 445 nm, or about 450 nm (e.g., about 455 nm or about 460 nm). The maximum emission peak wavelength of the first light can be in the range of about 480 nm (e.g., about 475 nm, about 470 nm, or about 465 nm). The maximum emission peak wavelength of the second light can be in the range of about 500 nm, about 505 nm, about 510 nm, or about 515 nm. The maximum emission peak wavelength of the second light can be in the range of about 580 nm, about 575 nm, about 570 nm, about 565 nm, about 560 nm, about 550 nm, about 540 nm, about 535 nm, or about 530 nm.

[0115] In the following text, refer to Figure 1. Figure 5A and Figure 5B The display panel, including the light-emitting panel 100 and the color conversion panel 200, is described in more detail.

[0116] Reference Figure 5A The light-emitting panel 100 may include a light-emitting element configured to emit light within a predetermined wavelength region (spectrum) and circuitry for switching the light-emitting element on and / or driving the light-emitting element. (See reference...) Figure 5A The light-emitting panel 100 in this embodiment may include a lower substrate 110, a buffer layer 111, a thin-film transistor (TFT), a light-emitting element 180, and an optional encapsulation layer 190.

[0117] The lower substrate 110 can be an inorganic material substrate (e.g., a glass substrate) or an organic material substrate (e.g., a polymer substrate). In embodiments, the lower substrate can be a polymer substrate. The polymer substrate can include, but is not limited to, polyimide, polyamide, poly(amide-imide), polyethylene terephthalate, polyethylene naphthalate, polymethyl methacrylate, polycarbonate, copolymers thereof, or combinations thereof.

[0118] The buffer layer 111 may comprise organic, inorganic, or organic-inorganic materials. The buffer layer 111 may comprise, for example, oxides, nitrides, or oxynitrides, and may comprise, for example, silicon oxide, silicon nitride, silicon oxynitride, or combinations thereof, but is not limited thereto. The buffer layer 111 may be one, two, or more layers, and may cover a portion or the entire surface of the underlying substrate 110. The buffer layer 111 may be omitted.

[0119] The thin-film transistor (TFT) can be a three-terminal element for switching and / or driving the light-emitting element 180 (described later), and can include one, two, or more for each sub-pixel. The TFT can include a gate electrode 124, a semiconductor layer 154 stacked with the gate electrode 124, a gate insulating layer 140 between the gate electrode 124 and the semiconductor layer 154, and a source electrode 173 and a drain electrode 175 electrically connected to the semiconductor layer 154. In the figures, a coplanar top-gate structure is shown as an example, but the structure is not limited to this and various structures are possible.

[0120] The gate electrode 124 is electrically connected to the gate line (not shown) and may include, but is not limited to, a low-resistance metal, such as aluminum (Al), molybdenum (Mo), copper (Cu), titanium (Ti), silver (Ag), gold (Au), alloys thereof, or combinations thereof.

[0121] Semiconductor layer 154 may be: an inorganic semiconductor, such as amorphous silicon, polycrystalline silicon, or oxide semiconductor; an organic semiconductor; an organic-inorganic semiconductor; or a combination thereof. For example, semiconductor layer 154 may include an oxide semiconductor comprising at least one of indium (In), zinc (Zn), tin (Sn), and gallium (Ga), and the oxide semiconductor may include, for example, indium gallium zinc oxide, zinc tin oxide, or a combination thereof, but is not limited thereto. Semiconductor layer 154 may include a channel region and doped regions disposed on both sides of the channel region, and electrically connected to source electrode 173 and drain electrode 175, respectively.

[0122] The gate insulating layer 140 may comprise organic, inorganic, or organic-inorganic materials, and may include, for example, oxides, nitrides, or oxynitrides, and may include, for example, silicon oxide, silicon nitride, silicon oxynitride, or combinations thereof, but is not limited thereto. The accompanying drawings show an example in which the gate insulating layer 140 is formed over the entire surface of the lower substrate 110, but this disclosure is not limited thereto and may optionally be formed between the gate electrode 124 and the semiconductor layer 154. The gate insulating layer 140 may be formed of one, two, or more layers.

[0123] The source electrode 173 and drain electrode 175 may comprise, but are not limited to, low-resistance metals such as aluminum (Al), molybdenum (Mo), copper (Cu), titanium (Ti), silver (Ag), gold (Au), alloys thereof, or combinations thereof. The source electrode 173 and drain electrode 175 may be electrically connected to doped regions of the semiconductor layer 154, respectively. The source electrode 173 is electrically connected to a data line (not shown), and the drain electrode 175 is electrically connected to the light-emitting element 180, which will be described later.

[0124] An interlayer insulating layer 145 is additionally formed between the gate electrode 124 and the source electrode 173 / drain electrode 175. The interlayer insulating layer 145 may include, but is not limited to, organic materials, inorganic materials, or organic-inorganic materials (e.g., oxides, nitrides, or oxynitrides, such as silicon oxide, silicon nitride, silicon oxynitride, or combinations thereof). The interlayer insulating layer 145 may be formed of one, two, or more layers.

[0125] A protective layer 160 is formed on a thin-film transistor (TFT). The protective layer 160 may be, for example, a passivation layer. The protective layer 160 may include, but is not limited to, organic, inorganic, or organic-inorganic materials (e.g., polyacrylic acid, polyimide, polyamide, poly(amide-imide), or combinations thereof). The protective layer 160 may be formed of one, two, three, or more layers.

[0126] In the light-emitting panel of this embodiment, a light-emitting element 180 can be provided for each sub-pixel PX1, PX2, and PX3. The light-emitting element 180 provided in each sub-pixel PX1, PX2, and PX3 can be driven independently. The light-emitting element 180 can be, for example, a light-emitting diode (LED). The light-emitting element 180 can be an electroluminescent element. The light-emitting element 180 can be a micro LED. The light-emitting element 180 may include a pair of electrodes and a light-emitting layer between the pair of electrodes.

[0127] The light-emitting layer may include a light emitter that emits light in a predetermined wavelength region, for example, it may include a light emitter that emits light belonging to a first emission spectrum of the visible wavelength spectrum. The light emitter may include an organic light emitter, an inorganic light emitter, an organic-inorganic light emitter, or a combination thereof, and may be one type or two or more types.

[0128] The light-emitting element 180 can be, for example, an organic light-emitting diode (OLED), an inorganic light-emitting diode, or a combination thereof. Inorganic light-emitting diodes can be, for example, quantum dot light-emitting diodes, perovskite light-emitting diodes, micro-light-emitting diodes, inorganic nano-light-emitting diodes, or combinations thereof, but are not limited thereto.

[0129] The display panel according to an embodiment is shown schematically with reference to the diagram. Figure 5B In the light-emitting panel, oxide-based TFTs are disposed on a substrate, and light-emitting elements having a series structure are disposed on the TFTs. The light-emitting elements may include a blue light-emitting layer, a green light-emitting layer, and another blue light-emitting layer disposed between a first electrode and a second electrode facing each other. Furthermore, a charge-generating layer CGL may be disposed between each of the light-emitting layers. Although in Figure 5B In the diagram, the first and second electrodes are shown in an unpatterned form, but the electrodes can be patterned into multiple electrode elements to correspond to pixels. The first electrode can be an anode or a cathode. The second electrode can be a cathode or an anode.

[0130] Figures 6A to 6C This is a cross-sectional view showing an example of a light-emitting element.

[0131] Reference Figure 6A In an embodiment, the light-emitting element 180 may include: a first electrode 181 and a second electrode 182 facing each other; a light-emitting layer 183 disposed between the first electrode 181 and the second electrode 182; and optional auxiliary layers 184 and 185, respectively between the first electrode 181 and the light-emitting layer 183 and between the second electrode 182 and the light-emitting layer 183.

[0132] Both the first electrode 181 and the second electrode 182 may have surfaces facing each other (i.e., arranged to face each other along the thickness direction (e.g., the z-direction), and either the first electrode 181 or the second electrode 182 may be an anode, and the other may be a cathode. The first electrode 181 may be a light-transmitting electrode, a semi-transparent electrode, or a reflective electrode, and the second electrode 182 may be a light-transmitting electrode or a light-transmitting / reflective electrode. The light-transmitting electrode or the semi-transparent electrode may be made, for example, of a single layer or multiple layers of a metal thin film, including conductive oxides (such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), tin oxide (SnO), aluminum tin oxide (AlTO), and fluorine-doped tin oxide (FTO)) or silver (Ag), copper (Cu), aluminum (Al), magnesium (Mg), magnesium-silver (Mg-Ag), magnesium-aluminum (Mg-Al), or combinations thereof. The reflective electrode may include, but is not limited to, metals, metal nitrides, or combinations thereof (e.g., silver (Ag), copper (Cu), aluminum (Al), gold (Au), titanium (Ti), chromium (Cr), nickel (Ni), alloys thereof, nitrides thereof (e.g., TiN), or combinations thereof).

[0133] The light-emitting layer 183 may include a first light emitter capable of emitting light with a first emission spectrum and a second light emitter capable of emitting light with a second emission spectrum. The first emission spectrum may be a blue emission spectrum. The second emission spectrum may be a green emission spectrum.

[0134] The maximum emission wavelength of the blue emission spectrum can fall within a wavelength region greater than or equal to about 400 nm and less than about 500 nm. Within this region, it can fall within the wavelength ranges of about 410 nm to about 490 nm, about 420 nm to about 480 nm, about 430 nm to about 470 nm, about 440 nm to about 465 nm, about 445 nm to about 460 nm, about 450 nm to about 458 nm, or any range derived from the stated wavelengths. The light of the blue emission spectrum can have a maximum emission peak wavelength within the aforementioned range. In an embodiment, the light of the blue emission spectrum can have a maximum emission peak wavelength within the wavelength range of greater than or equal to about 400 nm and less than about 500 nm, about 410 nm to about 490 nm, about 420 nm to about 480 nm, about 430 nm to about 475 nm, about 440 nm to about 460 nm, about 445 nm to about 458 nm, about 450 nm to about 455 nm, or any range derived from the stated wavelengths.

[0135] The maximum emission wavelength of the green emission spectrum may fall within the wavelength region greater than or equal to about 500 nm and less than about 590 nm, within which ranges are about 510 nm to about 580 nm, about 515 nm to about 570 nm, about 520 nm to about 560 nm, about 525 nm to about 555 nm, about 530 nm to about 550 nm, about 535 nm to about 545 nm, or any range derived from the stated wavelengths.

[0136] The light emitting a green emission spectrum can have a maximum emission peak wavelength within the range described above. In an embodiment, the light emitting a green emission spectrum can have a maximum emission peak wavelength in a wavelength region greater than or equal to about 500 nm and less than or equal to about 580 nm, about 510 nm to about 570 nm, about 515 nm to about 565 nm, about 520 nm to about 560 nm, about 525 nm to about 550 nm, about 530 nm to about 545 nm, about 535 nm to about 540 nm, or derived from any of the stated wavelength ranges.

[0137] The first luminescent material (e.g., a blue luminescent material) can be a single material or compound, or a mixture of at least two materials or compounds. The second luminescent material (e.g., a green luminescent material) can be a single material or compound, or a mixture of at least two materials or compounds.

[0138] For example, the light-emitting layer 183, the first light emitter, the second light emitter, or a combination thereof (hereinafter referred to as the light-emitting layer) may include (a plurality of) host compounds (e.g., electron transport compounds or hole transport compounds) and (a plurality of) dopant compounds.

[0139] For example, the luminescent layer 183 may include phosphorescent materials, fluorescent materials, or combinations thereof. The first luminescent material may include fluorescent materials, phosphorescent materials, or combinations thereof. The second luminescent material may include phosphorescent materials, fluorescent materials, or combinations thereof. For example, the luminescent material may include an organic luminescent material, and the organic luminescent material may be a low molecular weight compound, a polymer compound, or a combination thereof. There are no particular limitations on the specific types of phosphorescent and fluorescent materials, and they may be suitably selected from known materials.

[0140] The first and / or second light emitter may include a phosphorescent dopant. The dopant may be an organometallic compound comprising a metal M. The metal M may include iridium (Ir), platinum (Pt), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), thulium (Tm), rhodium (Rh), ruthenium (Ru), rhenium (Re), beryllium (Be), magnesium (Mg), aluminum (Al), calcium (Ca), manganese (Mn), cobalt (Co), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), rhodium (Rh), palladium (Pd), silver (Ag), gold (Au), or combinations thereof.

[0141] In embodiments, the phosphorescent dopant may include an organometallic compound containing iridium (Ir), an organometallic compound containing platinum (Pt), or an organometallic compound containing osmium (Os). In embodiments, the dopant may include an organometallic compound having a square planar coordination structure including (e.g., as described above) a metal M. The dopant may include substituted or unsubstituted C5 to C30 carbocyclic groups, substituted or unsubstituted C1 to C30 heterocyclic groups, acyclic groups, or combinations thereof. The C5 to C30 carbocyclic groups or C1 to C30 heterocyclic groups may be selected from 6-membered rings, condensation rings in which two or more 6-membered rings are condensed together, and condensation rings in which one or more 6-membered rings are condensed with one or more 5-membered rings. The 6-membered ring may include a cyclohexyl group, a cyclohexene group, an adamantyl group, a norbornel group, a norbornene group, a phenyl group, a pyridinium group, a pyrazine group, a pyridazine group, a triazine group, or combinations thereof. The 5-membered ring may include cyclopentyl groups, cyclopentenyl groups, cyclopentadienyl groups, furan groups, thiophene groups, thiophene groups, pyrrole groups, pyrazole groups, imidazole groups, triazole groups, oxazole groups, isoxazole groups, thiazole groups, isothiazole groups, oxadiazole groups, thiadiazole groups, or combinations thereof.

[0142] The dopant may include (e.g., as described above) a metal M and an organic ligand, wherein the metal M and the organic ligand may form one, two, or three metallized rings. The dopant may include a metal M and a tetracoordinate organic ligand capable of forming three or four (e.g., three) metallized rings. The tetracoordinate organic ligand may include, for example, a benzimidazole group, a phenyl group, a pyridinium group, an imidazole group, or a combination thereof, but is not limited thereto. The organic ligand may include one or more hydrogen atoms selectively substituted with deuterium. When the light emitter includes an organic light emitter, the light-emitting element 180 may be an organic light-emitting diode (OLED).

[0143] For example, the light emitter may include an inorganic light emitter, and the inorganic light emitter may be an inorganic semiconductor, quantum dot, perovskite, or a combination thereof. Inorganic semiconductors may include metal nitrides, metal oxides, or a combination thereof. Metal nitrides, metal oxides, or a combination thereof may include group III metals (such as aluminum, gallium, indium, and thallium), group IV metals (such as silicon, germanium, or tin), or a combination thereof. When the light emitter includes an inorganic light emitter, the light-emitting element 180 may be a quantum dot light-emitting diode, a perovskite light-emitting diode, or a micro-light-emitting diode (micro-LED). Materials that can be used as inorganic light emitters are known.

[0144] In an embodiment, the light-emitting element 180 may further include auxiliary layers 184 and 185. Auxiliary layers 184 and 185 may be disposed between the first electrode 181 and the light-emitting layer 183, or between the second electrode 182 and the light-emitting layer 183, respectively. Auxiliary layers 184 and 185 may be charge-assisted layers controlling the injection and / or migration of charge carriers (electrons or holes). Each of auxiliary layers 184 and 185 may be one, two, or more layers, and may be, for example, a hole injection layer, a hole transport layer, an electron blocking layer, an electron injection layer, an electron transport layer, a hole blocking layer, or a combination thereof. At least one of auxiliary layers 184 and 185 may be omitted. The material used for each auxiliary layer may be suitably selected from known materials used in organic electroluminescent elements, etc.

[0145] The light-emitting elements 180 disposed in each of sub-pixels PX1, PX2, and PX3 can be the same or different from each other. The light-emitting elements 180 disposed in each of sub-pixels PX1, PX2, and PX3 can emit light with the same or different emission spectra. The light-emitting elements 180 disposed in each of sub-pixels PX1, PX2, and PX3 can emit light, for example, light with a blue emission spectrum, light with a green emission spectrum, or a combination thereof. The light-emitting elements 180 disposed in each of sub-pixels PX1, PX2, and PX3 can be separated by a pixel-defining layer.

[0146] In an embodiment, the light-emitting element 180 may be a light-emitting element having a series (or stacked) structure. In an embodiment, the light-emitting element or the light-emitting layer included therein may include a first light-emitting layer and a second light-emitting layer disposed on the first light-emitting layer. The first light-emitting layer may emit a first light, and the second light-emitting layer may emit a second light. A first charge-generating layer may be disposed between the first light-emitting layer and the second light-emitting layer. Optionally, a charge-assisted layer may be disposed between the first electrode and the first light-emitting layer, and a charge-assisted layer may be disposed between the second electrode and the second light-emitting layer; or the same or different charge-assisted layers may be disposed between the first electrode and the first light-emitting layer and between the second electrode and the second light-emitting layer.

[0147] In an embodiment, the light-emitting layer may include a second light-emitting layer disposed between two or more first light-emitting layers, a first light-emitting layer disposed between two or more second light-emitting layers, or a combination thereof. The first light-emitting layer may be configured to emit first light. The second light-emitting layer may be configured to emit second light.

[0148] Reference Figure 6B The light-emitting element 180 may have a series structure and includes: a first electrode 181 and a second electrode 182 facing each other; a first light-emitting layer 183a and a second light-emitting layer 183b disposed between the first electrode 181 and the second electrode 182; a charge-generating layer 186 disposed between the first light-emitting layer 183a and the second light-emitting layer 183b; and optional auxiliary layers 184 and 185 disposed between the first electrode 181 and the first light-emitting layer 183a and / or between the second electrode 182 and the second light-emitting layer 183b.

[0149] The first electrode 181, the second electrode 182, and the auxiliary layers 184 and 185 are as described above.

[0150] The first light-emitting layer 183a and the second light-emitting layer 183b can emit light with different emission spectra or different maximum emission wavelengths. In one embodiment, the first light-emitting layer 183a can emit light with a blue emission spectrum. In another embodiment, the second light-emitting layer 183b can emit light with a green emission spectrum. The detailed description is the same as that for the light-emitting layer 183 described above.

[0151] The charge generation layer 186 can be configured to inject charge into the first light-emitting layer 183a and / or the second light-emitting layer 183b, and can be configured to control the charge balance between the first light-emitting layer 183a and the second light-emitting layer 183b. The charge generation layer 186 may include, for example, n-type and p-type layers, and may include, for example, electron transport materials and / or hole transport materials containing n-type dopants and / or p-type dopants. The charge generation layer 186 can be one, two, or more layers.

[0152] Reference Figure 6C The light-emitting element (e.g., having a series structure) may include: a first electrode 181 and a second electrode 182 facing each other; a first light-emitting layer 183a, a second light-emitting layer 183b and a third light-emitting layer 183c disposed between the first electrode 181 and the second electrode 182; a first charge-generating layer 186a disposed between the first light-emitting layer 183a and the second light-emitting layer 183b; a second charge-generating layer 186b disposed between the second light-emitting layer 183b and the third light-emitting layer 183c; and optional auxiliary layers 184 and 185 disposed between the first electrode 181 and the first light-emitting layer 183a and / or between the second electrode 182 and the third light-emitting layer 183c.

[0153] The first electrode 181, the second electrode 182, and the auxiliary layers 184 and 185 are as described above.

[0154] The first light-emitting layer 183a, the second light-emitting layer 183b, and the third light-emitting layer 183c can emit light with the same or different emission spectra. In one embodiment, the first light-emitting layer 183a and the third light-emitting layer 183c can emit light with a blue emission spectrum, and the second light-emitting layer 183b can emit light with a green emission spectrum. In another embodiment, the first light-emitting layer 183a and the third light-emitting layer 183c can emit light with a green emission spectrum, and the second light-emitting layer 183b can emit light with a blue emission spectrum. The detailed description is the same as that described above regarding the light-emitting layers.

[0155] The first charge generating layer 186a can inject charge into the first light-emitting layer 183a and / or the second light-emitting layer 183b, and can control the charge balance between the first light-emitting layer 183a and the second light-emitting layer 183b. The second charge generating layer 186a can inject charge into the second light-emitting layer 183b and / or the third light-emitting layer 183c, and can control the charge balance between the second light-emitting layer 183b and the third light-emitting layer 183c. Each of the first charge generating layer 186a and the second charge generating layer 186b can be one, two, or more layers.

[0156] Reference Figure 6D The light-emitting element 180 includes a first electrode 181, a second electrode 182, and a light-emitting layer 183 including multiple nanostructures 187.

[0157] One of the first electrode 181 and the second electrode 182 can be an anode, and the other can be a cathode. The first electrode 181 and the second electrode 182 can be electrodes patterned according to the arrangement direction of a plurality of nanostructures 187, and can include, for example, conductive oxides (such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), tin oxide (SnO), aluminum tin oxide (AlTO), and fluorine-doped tin oxide (FTO)); silver (Ag), copper (Cu), aluminum (Al), gold (Au), titanium (Ti), chromium (Cr), nickel (Ni), their alloys, their nitrides (e.g., TiN); or combinations thereof, but are not limited thereto.

[0158] The light-emitting layer 183 may include a plurality of nanostructures 187, and each of the sub-pixels PX1, PX2, and PX3 may include a plurality of nanostructures 187. The plurality of nanostructures 187 may be arranged along one direction, but this disclosure is not limited thereto. The nanostructures 187 may be compound semiconductors configured to emit light of a predetermined wavelength when an electric current is applied, and may be, for example, linear nanostructures (such as nanorods or nanoneedles). The diameter or long diameter of the nanostructures 187 may be, for example, from a few nanometers to several hundred nanometers, and the aspect ratio of the nanostructures 187 may be greater than about 1, greater than or equal to about 1.5, greater than or equal to about 2.0, greater than or equal to about 3.0, greater than or equal to about 4.0, greater than or equal to about 4.5, greater than or equal to about 5.0, about 1 to about 20, about 1.5 to about 20, about 2.0 to about 20, about 3.0 to about 20, about 4.0 to about 20, about 4.5 to about 20, or about 5.0 to about 20.

[0159] The nanostructure 187 may include a p-type region 187p, an n-type region 187n, and a multi-quantum-well region 187i, and may emit light from the multi-quantum-well region 187i. The nanostructure 187 may include, for example, gallium nitride (GaN), indium gallium nitride (InGaN), aluminum gallium nitride (AlGaN), or combinations thereof, and may have, for example, a core-shell structure.

[0160] Multiple nanostructures 187 can emit light with the same or different emission spectra. In an embodiment, the first nanostructure among the multiple nanostructures 187 can emit light with a blue emission spectrum (e.g., light with a blue emission spectrum having a maximum emission wavelength in the wavelength region of about 400 nm and less than about 500 nm, about 410 nm to about 490 nm, or about 420 nm to about 480 nm).

[0161] The display panel according to an embodiment includes a color conversion panel 200. The color conversion panel 200 can receive incident light of a mixed color from a light-emitting panel 100 and convert the spectrum of the incident light into an emission spectrum different from the emission spectrum of the incident light (mixed light). The emitted light from the color conversion panel 200 can then be directed from the device toward a viewer (not shown). The color conversion panel includes a color conversion layer comprising a color conversion region, wherein the color conversion region includes a first region corresponding to a green pixel, wherein the first region includes a first composite, and the first composite includes a matrix and a plurality of light-emitting nanostructures dispersed in the matrix and configured to convert the emission spectrum of the incident light.

[0162] The spectral overlap between the UV-Vis absorption spectrum of the luminescent nanostructure, the maximum emission peak of the first light, and the maximum emission peak of the second light is constructed to satisfy the following equation (e.g., the inequality):

[0163] B / A≤0.60.

[0164] Here, A is the area of ​​overlap between the maximum emission peak of the UV-Vis absorption spectrum of the luminescent nanostructure and the maximum emission peak of the first light (e.g., blue incident light) in a wavelength range of less than or equal to about 500 nm, and B is the area of ​​overlap between the maximum emission peak of the UV-Vis absorption spectrum of the luminescent nanostructure and the maximum emission peak of the second light (e.g., green incident light) in a wavelength range of greater than (or equal to) about 500 nm.

[0165] Here, to determine A, the heights of the first absorption peak and the maximum emission peak of the first light in the UV-Vis absorption spectrum of the luminescent nanostructure are adjusted to be equal; to determine B, the heights of the first absorption peak and the maximum emission peak of the second light in the UV-Vis absorption spectrum of the luminescent nanostructure are adjusted to be equal.

[0166] Reference Figure 1B and Figure 1C The exemplary or represented overlapping areas A and B are depicted and can be determined by a person skilled in the art, for example, using equipment typically used with optical measurement devices or commercially available graphic tools (such as images from the NIH). Origin or from It is a well-known analysis software provided along with "Paint".

[0167] The B / A value of spectral overlap (ratio) can be less than or equal to 0.62, less than or equal to about 0.61, less than or equal to about 0.6, less than or equal to about 0.59, less than or equal to about 0.58, less than or equal to about 0.57, less than or equal to about 0.56, less than or equal to about 0.55, less than or equal to about 0.54, less than or equal to about 0.53, less than or equal to about 0.52, less than or equal to about 0.51, less than or equal to about 0.5, less than or equal to about 0.49, less than or equal to about 0.48, and less than or equal to... Approximately 0.47, less than or equal to approximately 0.46, less than or equal to approximately 0.45, less than or equal to approximately 0.44, less than or equal to approximately 0.43, less than or equal to approximately 0.42, less than or equal to approximately 0.41, less than or equal to approximately 0.4, less than or equal to approximately 0.39, less than or equal to approximately 0.38, less than or equal to approximately 0.37, less than or equal to approximately 0.36, less than or equal to approximately 0.35, less than or equal to approximately 0.34, less than or equal to approximately 0.33, less than or equal to approximately 0.32, or less than or equal to approximately 0.31.

[0168] The B / A values ​​for spectral overlap can be in the range of about 0.01 to about 0.60, about 0.02 to about 0.48, about 0.03 to about 0.31, about 0.07 to about 0.31, about 0.12 to about 0.20, or any range derived from the stated B / A values.

[0169] In display panels where the light-emitting panel is configured to provide incident light including a mixture of green light, it is advantageous to emit the green light of the incident light from the screen as efficiently as possible, especially in the case of green pixels. However, according to research conducted by the inventors, there are portions where the absorption spectrum of the light-emitting nanostructure overlaps with the absorption spectrum of the green light of the incident light. In this case, the green incident light unnecessarily undergoes color conversion by the light-emitting nanostructure, which leads to a reduction in the efficiency of the entire device.

[0170] Specifically, the inventors have discovered that the center wavelength of the maximum emission peak of green incident light can be in the range of approximately 515 nm to approximately 530 nm. In this case, most of the absorption peaks of the green-emitting nanostructure (e.g., the first absorption peak greater than or equal to approximately 510 nm) can have significant overlap, thus allowing most of the green incident light to be reabsorbed by the luminescent nanostructure. Therefore, this can lead to a decrease in the overall efficiency of the display device. For example, when the quantum efficiency of the luminescent nanostructure is approximately 75% and approximately 30% of the green incident light is reabsorbed, approximately 8% of the incident light is lost due to reabsorption.

[0171] The inventors have discovered that the absorption peak (e.g., the first absorption peak) of a luminescent nanostructure can be in the range of (e.g., greater than or equal to about 450 nm or greater than or equal to about 460 nm) less than or equal to about 500 nm or less than or equal to about 490 nm. In this case, since the center wavelength of the blue incident light falls on the absorption spectral region of the green-emitting nanostructure in which the absorbance increases with increasing wavelength, the absorbance of the blue incident light can be improved. In this regard, it is conceivable to blue-shift the absorption spectrum of the green-emitting nanostructure to prevent it from overlapping with the green incident light. However, the inventors have discovered that this blue-shift also affects the emission spectrum of the luminescent nanostructure. In a color conversion panel, it is desirable that the maximum emission peak (or the maximum photoluminescence peak wavelength) or its center wavelength of the green-emitting nanostructure exists in the range of about 520 nm to about 550 nm, and that the difference between the wavelength of the first absorption peak of the luminescent nanostructure and the wavelength of the maximum photoluminescence peak is greater than or equal to 45 nm and less than or equal to 65 nm, to achieve an improved color gamut. Surprisingly, the inventors have discovered that by controlling the overlap between the absorption spectrum of the luminescent nanostructure and the emission spectrum of a first light having a predetermined wavelength range and the emission spectrum of a second light having a predetermined wavelength range, unwanted color conversion of green incident light can be suppressed. Therefore, the green pixel can emit light of the desired wavelength with improved efficiency.

[0172] The inventors have also discovered that luminescent nanostructures included in a color conversion panel may require increased absorbance per unit weight. They have further found that absorbance at 350 nm reflects the weighting factor of the luminescent nanostructure, and therefore, adjusting the ratio of absorbance at 450 nm to absorbance at 350 nm (e.g., to provide a ratio greater than or equal to about 0.2) can further contribute to improving the luminous efficiency of the device.

[0173] Referring to the accompanying drawings, a color conversion panel is further described. Referring to FIG1, the color conversion panel 200 according to an embodiment further includes partition walls (e.g., black matrix (BM), embankments, or both) to define each region of the color conversion layer 270. The color conversion layer may be a patterned film comprising a composite including luminescent nanostructures. The color conversion region includes a first region 270b configured to (e.g., receive incident light and) convert the emission spectrum of the incident light into a green spectrum. The first region 270b may correspond to a green pixel. The first region 270b includes a first (luminescent) composite. In an embodiment, the first composite includes a matrix (e.g., a polymer matrix) 273b and a plurality of luminescent nanostructures (hereinafter also referred to as nanostructures) 271b dispersed in the matrix 273b. The term "nanostructure" refers to (a plurality of) luminescent nanostructures. The first composite (or the first region) is configured to emit green light.

[0174] The maximum emission peak wavelength of green light (or multiple luminescent nanostructures) can be greater than or equal to about 500 nm, greater than or equal to about 501 nm, greater than or equal to about 504 nm, greater than or equal to about 505 nm, greater than or equal to about 510 nm, greater than or equal to about 515 nm, or greater than or equal to about 520 nm. The maximum emission peak wavelength of green light (or multiple luminescent nanostructures) can be 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 530 nm, less than or equal to about 525 nm, less than or equal to about 520 nm, less than or equal to about 515 nm, or less than or equal to about 510 nm. The difference between the wavelength of the first absorption peak of the (multiple) luminescent nanostructures and the wavelength of the maximum photoluminescence peak of the (multiple) luminescent nanostructures is greater than or equal to 45 nm, greater than or equal to 50 nm, greater than or equal to 55 nm and less than or equal to 65 nm, less than or equal to about 60 nm, or less than or equal to about 56 nm.

[0175] The color conversion region includes (e.g., one or more) second regions 270a, which are configured (e.g., by illumination with incident light) to emit light of a different color than green light (e.g., red light), and the second regions 270a may include a second composite. The second composite includes a matrix (e.g., a polymer matrix) 273a and a plurality of luminescent nanostructures 271a dispersed in the matrix 273a. The luminescent nanostructure composite of the second region may include luminescent nanostructures that emit light of a different wavelength (e.g., a different color or red) than the luminescent nanostructure composite of the first region.

[0176] The color conversion panel may also include one or more third regions 270c through which incident blue light is emitted or passed. The third region 270c may include a third composite comprising a matrix (e.g., a polymer matrix) 273c with a luminescent nanostructure, or the third composite comprising a matrix (e.g., a polymer matrix) 273c without a luminescent nanostructure. The maximum peak wavelength of the blue light may include blue light in the range of greater than or equal to about 380 nm (e.g., greater than or equal to about 440 nm, greater than or equal to about 445 nm, greater than or equal to about 450 nm, or greater than or equal to about 455 nm) and less than or equal to about 480 nm (less than or equal to about 475 nm, less than or equal to about 470 nm, less than or equal to about 465 nm, or less than or equal to about 460 nm).

[0177] In addition, light scatterers 272a, 272b and 272c may be included in the respective complexes to scatter the incident light.

[0178] Reference Figure 5A and Figure 5BThe color conversion panel 200 (e.g., color conversion layer 270) includes multiple surfaces opposite to the surfaces of the light-emitting panel, i.e., the color conversion panel 200 of the embodiment faces the light-emitting element 180 of the light-emitting panel 100. The color conversion panel 200 (e.g., color conversion layer 270) of the embodiment may include at least one color conversion region for converting the emission spectrum of light supplied from the light-emitting panel 100 into light with a different emission spectrum. The color conversion region may, for example, convert light in the emission spectrum supplied from the light-emitting panel 100 into light in the emission spectrum of the color displayed by each of the sub-pixels PX1, PX2, and PX3. The color conversion panel 200 of the embodiment may also include an upper substrate 210, a light-blocking pattern or black matrix 220, a color filter layer or first optics 230, a planarization layer 240, partition walls 250 (250a and 250b), color conversion layers 270 (270a, 270b, and 270c), an encapsulation layer 290, or combinations thereof.

[0179] In an embodiment, the luminescent nanostructure included in the first composite comprises a first semiconductor nanocrystal comprising a group III-V compound and a second semiconductor nanocrystal comprising a zinc chalcogenide. The nanostructure may have a core-shell structure comprising a core and a shell disposed on the core. The first semiconductor nanocrystal may be included in the core. The second semiconductor nanocrystal may be included in the shell. The luminescent nanostructure does not contain cadmium. The luminescent nanostructure may not contain cadmium, lead, mercury, or combinations thereof.

[0180] Group III-V compounds include: indium; phosphorus; and optionally zinc. Group III-V compounds may also include gallium. Group III-V compounds may include indium phosphide, indium gallium phosphide, indium zinc phosphide, indium zinc gallium phosphide, or combinations thereof.

[0181] The first semiconductor nanocrystal or core can be the emission center of the light-emitting nanostructure. The size (e.g., average size) of the first semiconductor nanocrystal or core can be appropriately selected by considering the photoluminescence wavelength. For example, the size (e.g., average size) of the first semiconductor nanocrystal or core can be greater than or equal to about 1 nm, greater than or equal to about 1.5 nm, greater than or equal to about 1.8 nm, or greater than or equal to about 2 nm. For example, the size (e.g., average size) of the core can be less than or equal to about 5 nm, less than or equal to about 4 nm, less than or equal to about 3 nm, or less than or equal to about 2.5 nm.

[0182] In embodiments, the nanostructure further includes a second semiconductor nanocrystal or shell comprising a zinc chalcogenide. The outermost surface of the nanostructure may include zinc, selenium, and sulfur. In other words, at least a portion of the surface of the luminescent nanostructure may include the second semiconductor nanocrystal (e.g., a zinc chalcogenide comprising zinc, selenium, and sulfur). According to embodiments, the portion of the second semiconductor nanocrystal adjacent to the first semiconductor nanocrystal comprises a ZnSeS alloy containing ZnS, thus effectively confining electrons in the first semiconductor nanocrystal and reducing lattice mismatch due to its wider band gap than ZnSe. According to embodiments, improved high-temperature stability can be achieved by having an increased sulfur content in the second semiconductor nanocrystal (e.g., on the surface facing the luminescent nanostructure).

[0183] The zinc sulfide included in the second semiconductor nanocrystal may include ZnSe, ZnSeS, ZnS, or combinations thereof. The second semiconductor nanocrystal or zinc sulfide may include ZnSeS. The second semiconductor nanocrystal may include a combination of a first zinc sulfide containing ZnSe and a second zinc sulfide containing ZnS.

[0184] The thickness of the second semiconductor nanocrystal or (monolayer) shell can be about 6 mL or less, about 5.5 mL or less, about 5 mL or less, about 4.5 mL or less, about 4 mL or less, about 3.5 mL or less, about 3 mL or less, or about 2.5 mL or less. The thickness of the second semiconductor nanocrystal (or shell) can be about 2 mL or more, about 2.5 mL or more, about 3 mL or more, or about 3.5 mL or more.

[0185] The thickness of the second semiconductor nanocrystal (or shell) 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, less than or equal to about 2.1 nm, less than or equal to about 2 nm, less than or equal to about 1.9 nm, less than or equal to about 1.8 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, less than or equal to about 1.5 nm, less than or equal to about 1.45 nm, less than or equal to about 1.4 nm, or less than or equal to about 1.35 nm. The thickness of the second semiconductor nanocrystal (or shell) can be greater than or equal to about 0.5 nm, greater than or equal to about 0.6 nm, greater than or equal to about 0.7 nm, greater than or equal to about 0.8 nm, greater than or equal to about 0.9 nm, or greater than or equal to about 1 nm.

[0186] In one embodiment, the shell may comprise a monolayer containing a second semiconductor nanocrystal. The monolayer may have a composition that varies in the thickness direction. Within the monolayer, the concentration of sulfur may exhibit a gradient that increases toward the surface of the luminescent nanostructure.

[0187] In embodiments, the shell may be a multilayer shell comprising two or more layers, wherein adjacent layers have different compositions. The multilayer shell may include a first layer disposed on a semiconductor nanocrystal core and comprising zinc, selenium, and optionally sulfur, and a second layer disposed on the first layer and comprising zinc, sulfur, and optionally selenium. The second layer may include sulfur with increased content compared to the first layer. The first or second layer may include ZnSe, ZnS, ZnSeS, or combinations thereof. The first layer may be disposed on (or directly on) the semiconductor nanocrystal core. The second layer may be disposed on the first layer (e.g., directly on the first layer). The second shell may be the outermost layer of the quantum dot.

[0188] When the shell is a multi-layered shell, the thickness of the first layer can be less than or equal to about 1 nm, less than or equal to about 0.9 nm, less than or equal to about 0.8 nm, less than or equal to about 0.7 nm, or less than or equal to about 0.6 nm. The thickness of the first layer can be greater than or equal to about 0.3 nm, greater than or equal to about 0.4 nm, or greater than or equal to about 0.5 nm. The thickness of the second layer can be less than or equal to about 1 nm, less than or equal to about 0.9 nm, less than or equal to about 0.8 nm, less than or equal to about 0.7 nm, or less than or equal to about 0.6 nm. The thickness of the second layer can be greater than or equal to about 0.3 nm, greater than or equal to about 0.4 nm, or greater than or equal to about 0.5 nm.

[0189] When confirmed by structural compositional analysis (e.g., inductively coupled plasma atomic emission analysis, etc.), the thickness of the ZnSe or the first layer in the luminescent nanostructure or shell of the embodiments may be about 4 monolayers (ML) or less, about 3.5 ML or less, about 3 ML or less, about 2.5 ML or less, about 2.3 ML or less, or about 2 ML or less. In the embodiments, the thickness of the ZnSe or the first layer in the luminescent nanostructure (or shell) may be about 0.5 ML or more, about 1 ML or more, about 1.5 ML or more, about 2 ML or more, or about 2.3 ML or more. When confirmed by compositional ratio, the thickness of the ZnSe or the first layer in the luminescent nanostructure (or shell) of the embodiments may be less than or equal to about 1.2 nm, less than or equal to about 1 nm, less than or equal to about 0.9 nm, less than or equal to about 0.8 nm, or less than or equal to about 0.7 nm and / or greater than or equal to about 0.3 nm, greater than or equal to about 0.5 nm, or greater than or equal to about 0.55 nm.

[0190] When confirmed by structural compositional analysis (e.g., inductively coupled plasma atomic emission analysis, etc.), the thickness of the ZnS or second layer in the luminescent nanostructure or shell of the embodiments can be less than or equal to about 1 nm, for example, less than or equal to about 0.9 nm, less than or equal to about 0.8 nm, less than or equal to about 0.7 nm, or less than or equal to about 0.6 nm. As confirmed by compositional analysis, the thickness of the ZnS or second layer in the luminescent nanostructure (or shell) of the embodiments can be greater than or equal to about 0.3 nm, greater than or equal to about 0.4 nm, or greater than or equal to about 0.5 nm. The thickness of the ZnS or second layer can be about 0.5 mL or more, about 1 mL or more, about 1.5 mL or more, about 2 mL or more, or about 2.5 mL or more and about 5 mL or less, about 4 mL or less, about 3 mL or less, about 2.5 mL or less, about 2 mL or less, or about 1.5 mL or less.

[0191] In the luminescent nanostructures of the embodiments, the molar ratio of sulfur to selenium (S:Se) is greater than or equal to about 2:1. The molar ratio of sulfur to selenium can be greater than about 2:1, greater than or equal to about 2.1:1, greater than or equal to about 2.2:1, greater than or equal to about 2.3:1, greater than or equal to about 2.4:1, greater than or equal to about 2.5:1, greater than or equal to about 2.52:1, greater than or equal to about 2.55:1, greater than or equal to about 2.6:1, greater than or equal to about 2.62:1, greater than or equal to about 2.65:1, or greater than or equal to about 2.7:1. In the nanostructures of the embodiments, the molar ratio of sulfur to selenium can be less than or equal to about 10:1, less than or equal to about 8:1, less than or equal to about 6:1, less than or equal to about 5.5:1, less than or equal to about 5:1, less than or equal to about 4.5:1, less than or equal to about 4:1, less than or equal to about 3.7:1, less than or equal to about 3.5:1, less than or equal to about 3.4:1, less than or equal to about 3.3:1, less than or equal to about 3.2:1, less than or equal to about 3.1:1, less than or equal to about 3:1, less than or equal to about 2.9:1, less than or equal to about 2.8:1, less than or equal to about 2.7:1, less than or equal to about 2.6:1, less than or equal to about 2.5:1, less than or equal to about 2.4:1, less than or equal to about 2.3:1, less than or equal to about 2.2:1, or less than or equal to about 2.1:1.

[0192] In luminescent nanostructures, the molar ratio of sulfur to indium (S:In) can be greater than or equal to about 3:1, greater than or equal to about 3.5:1, greater than or equal to about 4:1, greater than or equal to about 4.5:1, greater than or equal to about 5:1, greater than or equal to about 5.5:1, greater than or equal to about 6:1, greater than or equal to about 6.5:1, greater than or equal to about 7:1, greater than or equal to about 7.5:1, greater than or equal to about 8:1, greater than or equal to about 8.5:1, greater than or equal to about 9:1, greater than or equal to about 9.5:1, greater than or equal to about 10:1, greater than or equal to about 10.5:1, or greater than or equal to about 11:1. In luminescent nanostructures, the molar ratio of sulfur to indium can be less than or equal to about 20:1, less than or equal to about 19:1, less than or equal to about 18:1, less than or equal to about 17:1, less than or equal to about 16:1, less than or equal to about 15:1, less than or equal to about 14.5:1, less than or equal to about 14:1, less than or equal to about 13.5:1, less than or equal to about 13:1, less than or equal to about 12.5:1, less than or equal to about 12:1, or less than or equal to about 11.5:1.

[0193] In luminescent nanostructures, the molar ratio of selenium to indium (Se:In) can be less than or equal to approximately 10:1, less than or equal to approximately 9:1, less than or equal to approximately 8:1, less than or equal to approximately 7:1, less than or equal to approximately 6.5:1, less than or equal to approximately 6:1, less than or equal to approximately 5.5:1, less than or equal to approximately 5:1, less than or equal to approximately 4.8:1, or less than or equal to approximately 4.5:1. The molar ratio of selenium to indium (Se:In) can be greater than or equal to approximately 1:1, greater than or equal to approximately 1.5:1, greater than or equal to approximately 2:1, greater than or equal to approximately 2.5:1, greater than or equal to approximately 3:1, greater than or equal to approximately 3.5:1, greater than or equal to approximately 3.8:1, or greater than or equal to approximately 4:1.

[0194] In the nanostructures of the embodiments, the molar ratio of zinc to indium (Zn:In) can be less than or equal to about 30:1, less than or equal to about 29:1, less than or equal to about 28:1, less than or equal to about 27:1, less than or equal to about 26:1, less than or equal to about 25:1, less than or equal to about 24:1, less than or equal to about 23:1, less than or equal to about 22:1, less than or equal to about 21:1, less than or equal to about 20:1, less than or equal to about 19:1, less than or equal to about 18:1, less than or equal to about 17:1, less than or equal to about 16:1, less than or equal to about 15:1, or less than or equal to about 14:1. In the nanostructures of the embodiments, the molar ratio of zinc to indium (Zn:In) can be greater than or equal to about 3:1, greater than or equal to about 4:1, greater than or equal to about 5:1, greater than or equal to about 6:1, greater than or equal to about 7:1, greater than or equal to about 8:1, greater than or equal to about 9:1, greater than or equal to about 10:1, greater than or equal to about 11:1, greater than or equal to about 12:1, greater than or equal to about 13:1, greater than or equal to about 14:1, greater than or equal to about 15:1, greater than or equal to about 16:1, greater than or equal to about 17:1, greater than or equal to about 18:1, greater than or equal to about 19:1, or greater than or equal to about 19.5:1.

[0195] In luminescent nanostructures, the molar ratio of phosphorus to indium (P:In) can be greater than or equal to approximately 0.7:1, greater than or equal to approximately 0.75:1, greater than or equal to approximately 0.8:1, greater than or equal to approximately 0.85:1, greater than or equal to approximately 0.88:1, greater than or equal to approximately 0.89:1, greater than or equal to approximately 0.9:1, greater than or equal to approximately 0.93:1, or greater than or equal to approximately 0.95:1. The molar ratio of phosphorus to indium (P:In) can be less than or equal to approximately 1.5:1, less than or equal to approximately 1.4:1, less than or equal to approximately 1.3:1, less than or equal to approximately 1.2:1, less than or equal to approximately 1.05:1, less than or equal to approximately 1.03:1, less than or equal to approximately 1:1, less than or equal to approximately 0.98:1, less than or equal to approximately 0.97:1, less than or equal to approximately 0.96:1, or less than or equal to approximately 0.95:1.

[0196] In the nanostructures of the embodiments, the molar ratio of indium to chalcogenides (e.g., the sum of S and Se) (In:(S+Se)) can be greater than or equal to about 0.05:1, greater than or equal to about 0.06:1, greater than or equal to about 0.062:1, or greater than or equal to about 0.065:1. In the nanostructures of the embodiments, the molar ratio of indium to chalcogenides (e.g., the sum of S and Se) (In:(S+Se)) can be less than or equal to about 0.15:1, less than or equal to about 0.14:1, less than or equal to about 0.13:1, less than or equal to about 0.12:1, less than or equal to about 0.11:1, less than or equal to about 0.105:1, less than or equal to about 0.1:1, less than or equal to about 0.095:1, less than or equal to about 0.09:1, less than or equal to about 0.085:1, less than or equal to about 0.08:1, or less than or equal to about 0.075:1.

[0197] In the nanostructures of the embodiments, the molar ratio of zinc to chalcogenides (e.g., the sum of S and Se) (Zn:(S+Se)) can be greater than or equal to about 1:1, greater than or equal to about 1.05:1, greater than or equal to about 1.1:1, greater than or equal to about 1.15:1, greater than or equal to about 1.2:1, greater than or equal to about 1.25:1, or greater than or equal to about 1.3:1. In the nanostructures of the embodiments, the molar ratio of zinc to chalcogenides (e.g., the sum of S and Se) can be less than or equal to about 2:1, less than or equal to about 1.9:1, less than or equal to about 1.8:1, less than or equal to about 1.7:1, less than or equal to about 1.6:1, less than or equal to about 1.5:1, less than or equal to about 1.45:1, or less than or equal to about 1.4:1.

[0198] As used herein, the presence and abundance (ratio) of elements (e.g., metals, nonmetals, and halogens) included in the luminescent nanostructures can be readily and reproducibly determined by appropriate analytical methods (e.g., X-ray photoelectron spectroscopy (XPS), inductively coupled plasma atomic emission spectroscopy (ICP-AES), ion chromatography, Rutherford backscattering spectroscopy (RBS), time-of-flight secondary ion mass spectrometry (TOFSIMS), or combinations thereof).

[0199] In this embodiment, the method for fabricating luminescent nanostructures includes the following steps:

[0200] The process involves preparing a first semiconductor nanocrystal (or a core particle comprising the first semiconductor nanocrystal) comprising indium (In) and phosphorus (P) and optionally zinc; and, in the presence of the first semiconductor nanocrystal (or a core particle comprising the first semiconductor nanocrystal) and an organic ligand, reacting a zinc precursor simultaneously or sequentially with at least one of a selenium precursor and a sulfur precursor (e.g., in an organic solvent) to form a second semiconductor nanocrystal (or a shell comprising the second semiconductor nanocrystal, hereinafter also referred to as the second semiconductor nanocrystal); wherein, during the formation of the second semiconductor nanocrystal, the selenium precursor and the sulfur precursor are implanted such that at least a portion of the surface of the final luminescent nanostructure comprises all of sulfur, selenium, and zinc. In embodiments, during the formation of the second semiconductor nanocrystal, the selenium precursor and the sulfur precursor may be implanted such that the portion adjacent to the core may comprise both selenium and sulfur.

[0201] In this method, selenium precursors and sulfur precursors can be implanted such that in the final luminescent nanostructure, the thickness of the second semiconductor nanocrystal can be about 5 mL or less (or less than or equal to about 2 nm or less than or equal to about 1.5 nm) and / or the molar ratio of sulfur to selenium can be greater than about 2.

[0202] In embodiments, the preparation of a first semiconductor nanocrystal (or a core particle comprising the first semiconductor nanocrystal) may include the following steps: heating an indium compound in the presence of a second organic ligand and an organic solvent to prepare an indium precursor solution; and injecting a phosphorus precursor into the indium precursor solution, followed by heating the resulting mixture. The method may also include first obtaining a zinc precursor prior to the preparation of the indium precursor solution, wherein the preparation of the indium precursor solution is carried out in the presence of the zinc precursor. Depending on the type, the zinc precursor may be obtained by heating the zinc compound and the organic ligand in an organic solvent at a high temperature (e.g., greater than or equal to about 100°C and less than or equal to about 200°C). In nucleosynthesis, the molar ratio of zinc to indium may be greater than or equal to about 1:1, greater than or equal to about 1.1:1, or greater than or equal to about 1.2:1 and less than or equal to about 3:1, less than or equal to about 2.5:1, or less than or equal to about 2:1. In embodiments, the zinc precursor and the indium precursor may include a carboxylic acid ester portion. In the zinc precursor (or indium precursor), the number of moles of the organic ligand containing a carboxylic acid relative to 1 mole of metal can be greater than or equal to about 1 mole, greater than or equal to about 1.5 moles, greater than or equal to about 2 moles and less than or equal to about 5 moles, less than or equal to about 4 moles, or less than or equal to about 3 moles.

[0203] In an embodiment, the reaction system for forming the second semiconductor nanocrystal may simultaneously include a sulfur precursor and a selenium precursor. In the formation of the second semiconductor nanocrystal, a mixture comprising a zinc precursor, a first organic ligand, and an organic solvent may be heated to a predetermined temperature (e.g., a temperature range greater than or equal to about 100°C, greater than or equal to about 120°C, greater than or equal to about 130°C, greater than or equal to about 140°C, greater than or equal to 150°C, greater than or equal to about 200°C, greater than or equal to about 230°C, or greater than or equal to about 250°C and less than or equal to about 340°C, less than or equal to about 320°C, less than or equal to about 310°C, less than or equal to about 300°C, less than or equal to about 280°C, less than or equal to about 250°C, less than or equal to about 230°C, or any combination of the thresholds described herein). The first semiconductor nanocrystal, the selenium precursor, and the sulfur precursor (e.g., a thiol compound; a reaction product of an alkylphosphine compound and sulfur; or a combination thereof) are infused into the heated mixture. Selenium and sulfur precursors can be injected (e.g., independently once or twice or more) to form a shell with the desired composition. There are no particular restrictions on the injection method for each precursor, and they can be performed simultaneously or sequentially.

[0204] Forming the second semiconductor nanocrystal may include forming a first layer comprising zinc, selenium, and sulfur on the first semiconductor nanocrystal, and forming a second layer comprising zinc, selenium, and sulfur on the first layer. During shell formation, the appropriate content of each precursor (e.g., zinc precursor, sulfur precursor, and / or selenium precursor) can be tuned by taking into account the structure / composition of the final core-shell quantum dot.

[0205] The type of zinc precursor is not particularly limited and can be appropriately selected. For example, the zinc precursor can be Zn metal powder, alkylated Zn compounds, alcohol Zn, carboxylic acid Zn, nitric acid Zn, perchloric acid Zn, sulfate Zn, acetylacetone Zn, halide Zn, cyanide Zn, hydroxide Zn, oxide Zn, peroxide Zn, or combinations thereof. Zinc precursors can be 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. Zinc precursors can be used alone or in combination of two or more types. As described above, in the embodiments, the formation of a second semiconductor nanocrystal can be carried out without the use of zinc chloride.

[0206] Organic ligands may include RCOOH, RNH2, R2NH, R3N, RSH, RH2PO, R2HPO, R3PO, RH2P, R2HP, R3P, ROH, RCOOR', RPO(OH)2, RHPOOH, R2POOH (where R and R' are independently substituted or unsubstituted C1 to C40 (or C3 to C24) aliphatic hydrocarbon groups (e.g., alkyl, alkenyl, alkynyl) or substituted or unsubstituted C6 to C40 (or C6 to C24) aromatic hydrocarbon groups (e.g., C6 to C20 aryl)) or combinations thereof. Organic ligands can coordinate to the surface of the obtained nanocrystals and can enable the nanocrystals to be well dispersed in solution and / or affect the luminescent and / or electrical properties of quantum dots. Examples of organic ligands may include: thiols, such as methanethiol, ethanethiol, propanethiol, butanethiol, pentylenetetran, hexanethiol, octylthiol, dodecylthiol, hexadecylthiol, octadecylthiol, or benzylthiol; amines, such as methylamine, ethylamine, propylamine, butylamine, pentylemine, hexylamine, octylamine, dodecylamine, hexadecylamine, octadecylamine, dimethylamine, diethylamine, or dipropylamine; carboxylic acids, such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, octanoic acid, dodecanoic acid, hexadecanoic acid, octadecanoic acid, oleic acid, or 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 propylphosphine, substituted or unsubstituted butylphosphine, substituted or unsubstituted pentylphosphine, or substituted or unsubstituted methylphosphine. Unsubstituted octylphosphine (e.g., trioctylphosphine (TOP)); phosphine oxides, such as substituted or unsubstituted methylphosphine oxides (e.g., trimethylphosphine oxide, methyldiphenylphosphine oxide, etc.), substituted or unsubstituted ethylphosphine oxides (e.g., triethylphosphine oxide, ethyldiphenylphosphine oxide, etc.), substituted or unsubstituted propylphosphine oxides, substituted or unsubstituted butylphosphine oxides, or substituted or unsubstituted octylphosphine oxides (e.g., trioctylphosphine oxide (TOPO)); diphenylphosphine, triphenylphosphine compounds, or their oxide compounds; hypophosphinolic acids; C5 to C20 alkyl hypophosphinolic acids (such as hexylphosphinolic acid, octylphosphinolic acid, dodecylphosphinolic acid, tetradecylphosphinolic acid, hexadecylphosphinolic acid, octadecylphosphinolic acid); or C5 to C20 alkylphosphinolic acids; and so on, but not limited thereto. Organic ligands may be used alone or in mixtures of two or more.

[0207] Organic solvents may be selected from: 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, or squalane; C6 to C30 aromatic hydrocarbons, such as phenyldodecane, phenyltetradecane, or 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 or benzyl ethers; and combinations thereof. The type and amount of solvent can be appropriately selected taking into account the precursor and organic ligand.

[0208] There are no particular limitations on the type of indium precursor, and it can be suitably selected. Indium precursors may include indium powder, alkylated (e.g., C1 to C8 alkylated) indium compounds, indium alcohols (e.g., C1 to C18 alcohols), indium carboxylic acids (e.g., C1 to C18 carboxylic acids), indium nitrate, indium perchlorate, indium sulfate, indium acetylacetone, indium halide, indium cyanide, indium hydroxide, indium oxide, indium peroxide, indium carbonate, or combinations thereof. Indium precursors may include indium carboxylate (such as indium oleate and indium myristate), indium acetate, indium hydroxide, indium chloride, indium bromide, and indium iodide. The formation of indium precursors can be carried out under vacuum at a temperature greater than or equal to about 100°C or greater than or equal to about 120°C and less than or equal to about 200°C.

[0209] There are no particular restrictions on the type of phosphorus precursor, and it can be selected appropriately. The phosphorus precursor can be tris(trimethylsilyl)phosphine, tris(dimethylamino)phosphine, triethylphosphine, tributylphosphine, trioctylphosphine, triphenylphosphine, tricyclohexylphosphine, dimethylaminophosphine, diethylaminophosphine, or combinations thereof.

[0210] The mixture obtained by implanting a phosphorus precursor in the formation of the first semiconductor nanocrystal or core particles can be heated to a temperature greater than or equal to about 150°C, greater than or equal to about 200°C, greater than or equal to about 250°C, or greater than or equal to about 270°C and less than or equal to about 300°C, less than or equal to about 290°C, less than or equal to about 280°C, less than or equal to about 270°C, or less than or equal to about 260°C. During the core formation process, if desired, a precursor (e.g., an indium precursor, a phosphorus precursor, and / or a zinc precursor) can be additionally implanted once or more.

[0211] There are no particular restrictions on the nucleation reaction time, and it can be appropriately selected by taking into account the reactivity between precursors and the nucleation temperature.

[0212] There are no particular restrictions on the type of selenium precursor, and it can be appropriately selected. For example, selenium precursors may include, but are not limited to, selenium-trioctylphosphine (Se-TOP), selenium-tributylphosphine (Se-TBP), selenium-triphenylphosphine (Se-TPP), or combinations thereof. The selenium precursor may be injected once or more (e.g., twice or more).

[0213] In the method of the embodiments, a sulfur precursor (hereinafter, the first sulfur precursor) may be implanted in the initial stage of forming the second semiconductor nanocrystal (e.g., the first layer). A sulfur precursor (hereinafter, the second sulfur precursor) may be implanted again in the later stage of forming the second semiconductor nanocrystal (e.g., the second layer). The first sulfur precursor may include a thiol compound. The second sulfur precursor may include sulfur dispersed in an alkylphosphine. The thiol compound may include a thiol compound having an aliphatic hydrocarbon group having 4 to 20 carbon atoms (e.g., dodecylthiol), such as alkylthiols. The second sulfur precursor may include sulfur powder (e.g., sulfur-octadecene (S-ODE), sulfur-trioctylphosphine (S-TOP), sulfur-tributylphosphine (S-TBP), sulfur-triphenylphosphine (S-TPP), sulfur-trioctylamine (S-TOA), or trimethylsilyl sulfide), mercaptopropylsilane, trimethylsilyl sulfide, ammonium sulfide, sodium sulfide, or combinations thereof in an organic solvent dispersion. The content ratio between the first sulfur precursor and the second sulfur precursor can be appropriately selected. The content ratio between the first sulfur precursor and the second sulfur precursor can be about 1:0.1 to about 1:10, about 1:0.2 to about 1:5, about 1:0.3 to about 1:3, about 1:0.4 to about 1:2.5, about 1:0.5 to about 1:2, or a combination of corresponding boundary values.

[0214] The formation temperature of the second semiconductor nanocrystal (or shell) can be appropriately selected. In embodiments, the formation temperature of the second semiconductor nanocrystal (or shell) can be greater than or equal to about 240°C, greater than or equal to about 270°C, greater than or equal to about 280°C, greater than or equal to about 290°C, greater than or equal to about 300°C, greater than or equal to about 310°C, or greater than or equal to about 315°C. In embodiments, the shell formation temperature can be less than or equal to about 350°C, less than or equal to about 340°C, less than or equal to about 330°C, or less than or equal to about 325°C. The formation temperatures of the first layer and the second layer can be the same or different.

[0215] In one embodiment, the temperature at which the first layer is formed can be higher than the temperature at which the second layer is formed. In another embodiment, the temperature at which the first layer is formed can be lower than the temperature at which the second layer is formed. The difference between the temperature at which the first layer is formed and the temperature at which the second layer is formed can be greater than or equal to about 10°C, greater than or equal to about 20°C, greater than or equal to about 30°C, greater than or equal to about 40°C, greater than or equal to about 50°C, or greater than or equal to about 60°C.

[0216] There is no particular limitation on the reaction time used to form the second semiconductor nanocrystal (or shell), and it can be appropriately selected. For example, the reaction time for forming the second semiconductor nanocrystal (or shell) can be, for example, greater than or equal to about 20 minutes, greater than or equal to about 25 minutes, greater than or equal to about 30 minutes, greater than or equal to about 35 minutes, greater than or equal to about 40 minutes, greater than or equal to about 45 minutes, greater than or equal to about 50 minutes, greater than or equal to about 55 minutes, or greater than or equal to about 1 hour, but is not limited thereto. The reaction time used to form the second semiconductor nanocrystal (or shell) can be less than or equal to about 3 hours.

[0217] Each precursor / compound can be added in a single step or multiple times during the formation of the second semiconductor nanocrystal (or shell). When precursors, etc., are added in stages, the reaction can be carried out for a predetermined time in each step (e.g., greater than or equal to about 5 minutes, greater than or equal to about 10 minutes, or greater than or equal to about 15 minutes). The reaction can be carried out in an inert gas atmosphere, in air, or in a vacuum, but is not limited thereto.

[0218] When forming the second semiconductor nanocrystal (e.g., the first or second layer), the selenium precursor may be added once or more (e.g., twice or more, or three or more times).

[0219] When forming a second semiconductor nanocrystal (or shell) involves forming a first layer and a second layer, the appropriate reaction time can be selected according to the desired shell composition, the type of precursor, and the reaction temperature.

[0220] The formation of the second semiconductor nanocrystal (or shell) (or the formation of the first and / or second layer) (e.g., independently of each other) takes place for more than or equal to about 40 minutes, for example, more than or equal to about 50 minutes, more than or equal to about 60 minutes, more than or equal to about 70 minutes, more than or equal to about 80 minutes, or more than or equal to about 90 minutes. The reaction time for forming the second semiconductor nanocrystal (or shell) (or forming the first and / or second layer) can (e.g., independently of each other) be less than or equal to about 4 hours, for example, less than or equal to about 3 hours, less than or equal to about 2 hours, less than or equal to about 1 hour, or less than or equal to about 30 minutes.

[0221] In the reaction system used to form the shell, the selenium content per mole of indium can be greater than or equal to about 2 moles, or greater than or equal to about 3 moles and less than or equal to about 23 moles, less than or equal to about 20 moles, less than or equal to about 10 moles, or less than or equal to about 5 moles.

[0222] In the reaction system used to form the shell, the sulfur content per mole of indium can be greater than or equal to about 2 moles, greater than or equal to about 6 moles, greater than or equal to about 7 moles, greater than or equal to about 8 moles, greater than or equal to about 9 moles, or greater than or equal to about 10 moles and less than or equal to about 20 moles, less than or equal to about 14 moles, less than or equal to about 13 moles, less than or equal to about 12 moles, less than or equal to about 11 moles, less than or equal to about 10 moles, or less than or equal to about 9.5 moles.

[0223] In the reaction system used to form the shell, the sulfur content per mole of indium can be greater than or equal to about 3 moles, greater than or equal to about 6 moles, greater than or equal to about 7 moles, greater than or equal to about 8 moles, greater than or equal to about 9 moles, or greater than or equal to about 10 moles and less than or equal to about 14 moles, less than or equal to about 13 moles, less than or equal to about 12 moles, less than or equal to about 11 moles, less than or equal to about 10 moles, or less than or equal to about 9.5 moles.

[0224] In the reaction system used to form the shell, the content of thiols per mole of indium can be greater than or equal to about 1 mole, greater than or equal to about 4 moles, greater than or equal to about 5 moles, greater than or equal to about 6 moles, greater than or equal to about 7 moles, greater than or equal to about 8 moles, greater than or equal to about 9 moles, or greater than or equal to about 10 moles and less than or equal to about 14 moles, less than or equal to about 13 moles, less than or equal to about 12 moles, less than or equal to about 11 moles, less than or equal to about 10 moles, or less than or equal to about 9.5 moles.

[0225] In the reaction system used to form the shell, the content of the second sulfur precursor per mole of indium can be greater than or equal to about 0 moles, greater than or equal to about 1 mole, greater than or equal to about 3 moles, greater than or equal to about 5 moles, greater than or equal to about 7 moles, greater than or equal to about 9 moles, or greater than or equal to about 10 moles and less than or equal to about 9 moles, less than or equal to about 8 moles, less than or equal to about 7 moles, less than or equal to about 6 moles, less than or equal to about 5 moles, less than or equal to about 4 moles, less than or equal to about 3 moles, or less than or equal to about 2 moles.

[0226] Adding a non-solvent to the final reaction solution can separate the nanocrystals coordinated to the organic ligands (e.g., precipitation). The non-solvent can be a polar solvent miscible with the solvent used in the reaction, and the nanocrystals are not dispersed therein. 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 that of the above solvents, or combinations thereof. Separation can be performed by centrifugation, precipitation, chromatography, or distillation. If necessary, the separated nanocrystals can be added to a washing solvent and then washed. There are no particular limitations on the washing solvent, and solvents having a solubility parameter similar to that of the organic solvent or organic ligand can be used. Non-solvents or washing solvents include: ethanol; alkane solvents such as hexane, heptane, and octane; chloroform; aromatic solvents such as toluene and benzene; or combinations thereof, but are not limited thereto.

[0227] The luminescent nanostructures can be dispersed in a dispersion solvent. The luminescent nanostructures can form an organic solvent dispersion. The organic solvent dispersion may not include water and / or a water-miscible organic solvent. The dispersion solvent can be suitably selected. The dispersion solvent may include the aforementioned organic solvents. The dispersion solvent may include substituted or unsubstituted C1 to C40 aliphatic hydrocarbons, substituted or unsubstituted C6 to C40 aromatic hydrocarbons, or combinations thereof.

[0228] The luminescent nanostructures of the embodiments may have an (absolute) quantum efficiency greater than or equal to about 80%, greater than or equal to about 81%, greater than or equal to about 82%, greater than or equal to about 83%, greater than or equal to about 84%, greater than or equal to about 85%, or greater than or equal to about 90%. The luminescent nanostructures may have a full width at half maximum (FWHM) of 55 nm or less (e.g., less than or equal to about 55 nm, such as less than or equal to about 50 nm, less than or equal to about 45 nm, less than or equal to about 44 nm, less than or equal to about 43 nm, less than or equal to about 42 nm, less than or equal to about 41 nm, or less than or equal to about 40 nm). The luminescent nanostructures in their dispersed state in organic solvents may have an FWHM greater than or equal to about 40 nm, greater than or equal to about 42 nm, or greater than or equal to about 43 nm. The luminescent nanostructures in their dispersed state in organic solvents may have an FWHM less than or equal to about 50 nm.

[0229] The (e.g., average) size of the luminescent nanostructure can be greater than or equal to about 1 nm, greater than or equal to about 2 nm, greater than or equal to about 3 nm, greater than or equal to about 4 nm, or greater than or equal to about 5 nm. The luminescent nanostructure can be configured to emit green light while having a reduced size. The (average) size can be less than or equal to about 10 nm, less than or equal to about 9 nm, less than or equal to about 8 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, less than or equal to about 5.5 nm, less than or equal to about 5 nm, or less than or equal to about 4.95 nm. The size can be the particle diameter.

[0230] The size (when the luminescent nanostructure is not spherical) can be the diameter calculated by converting the two-dimensional area, confirmed by transmission electron microscopy analysis, into a circle. The size can also be a value calculated from the composition of the quantum dots. Here, dimensions such as size (e.g., the size associated with the luminescent nanostructure) can refer to the average size (e.g., the average size).

[0231] There are no particular restrictions on the shape of the luminescent nanostructures, and they may include, for example, spherical, polyhedral, pyramidal, multi-armed or cubic nanotubes, nanowires, nanofibers, nanosheets or combinations thereof, but are not limited thereto.

[0232] The luminescent nanostructures may include the aforementioned organic ligands and / or organic solvents on their surface. The organic ligands and / or organic solvents may bind to the surface of the luminescent nanostructures.

[0233] As defined in part by the UV-Vis absorption spectrum, the absorbance ratio of the luminescent nanostructure of the embodiment at the first absorption peak or at a wavelength of about 450 nm to the absorbance at a wavelength of about 350 nm can be greater than or equal to about 0.078:1, greater than or equal to about 0.09:1, greater than or equal to about 0.1:1, greater than or equal to about 0.11:1, greater than or equal to about 0.12:1, greater than or equal to about 0.2:1, greater than or equal to about 0.21:1, greater than or equal to about 0.22:1, greater than or equal to about 0.23:1, greater than or equal to about 0.24:1, greater than or equal to about 0.25:1, or greater than or equal to about 0.26:1. In the UV-Vis absorption spectrum of the luminescent nanostructure, the absorbance ratio at the first absorption peak wavelength or at a wavelength of about 450 nm to the absorbance at a wavelength of about 350 nm can be less than or equal to about 0.4:1, less than or equal to about 0.3:1, less than or equal to about 0.29:1, less than or equal to about 0.28:1, less than or equal to about 0.27:1, less than or equal to about 0.26:1, or less than or equal to about 0.255:1. As defined in part by the UV-Vis absorption spectrum, the luminescent nanostructure of the embodiment can have an absorbance ratio that can be defined by a range derived from any of the maximum and minimum ratios described above.

[0234] Luminescent nanostructures can exhibit UV-Vis absorption spectra with positive differential coefficients (i.e., tangential slope) at approximately 450 nm. (Ref) Figure 1B The differential coefficient values ​​can be greater than about 0, for example, greater than or equal to about 0.001, greater than or equal to about 0.002, greater than or equal to about 0.003, greater than or equal to about 0.004, greater than or equal to about 0.005, or greater than or equal to about 0.006. The differential coefficient values ​​can be less than or equal to about 0.03, less than or equal to about 0.025, less than or equal to about 0.02, less than or equal to about 0.015, less than or equal to about 0.01, less than or equal to about 0.0095, less than or equal to about 0.009, or less than or equal to about 0.0085. For incident light sources greater than or equal to about 450 nm and less than or equal to 470 nm, the luminescent nanostructures of the embodiments can exhibit increased efficiency and increased absorbance. The derivative of df(x) / dx (tangential slope) at about 450 nm in the UV-Vis absorption curve can be easily measured through simple analysis of the curves.

[0235] In the UV-Vis absorption spectrum of the luminescent nanostructure, the first absorption peak wavelength can be in the range greater than about 450 nm and less than the photoluminescence peak wavelength. For example, the first absorption peak wavelength can be in the range of about 455 nm, about 460 nm, about 465 nm, about 470 nm, about 475 nm, or about 480 nm. The first absorption peak wavelength can also be in the range of about 505 nm, about 500 nm, about 495 nm, or about 490 nm.

[0236] Luminescent nanostructures can be constructed to have valley depths greater than or equal to about 0.2, greater than or equal to about 0.25, greater than or equal to about 0.3, greater than or equal to about 0.35, or greater than or equal to about 0.4 in their UV-Vis absorption spectra, as defined by the following formula:

[0237] 1-(Abs 谷 / Abs 第一 ) = VD

[0238] Among them, Abs 第一 It is the absorbance at the first absorption peak, and Abs 谷 It is the absorbance at the lowest point of the valley adjacent to the first absorption peak.

[0239] In the UV-Vis absorption spectrum of luminescent nanostructures, the lowest point of the valley can be in the wavelength range of less than or equal to about 450 nm and greater than or equal to about 400 nm or greater than or equal to about 420 nm.

[0240] The first composite of the embodiment can be prepared by a composition comprising (e.g., via polymerization or the like) luminescent nanostructures.

[0241] The composition may include: (e.g., multiple) luminescent nanostructures as described in the examples; optional monomers, dispersants, or combinations thereof; and (organic) solvents (and / or liquid carriers). The dispersant may disperse the quantum dots. The dispersant may include a carboxylic acid-containing compound (monomer or polymer). 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.

[0242] The details of the luminescent nanostructures in the composition are as described above. The content of the luminescent nanostructures in the composition can be appropriately adjusted considering the end use (e.g., a color conversion layer such as a luminescent color filter or a color conversion panel). In the compositions (or complexes) of the examples, the content of (a plurality of) quantum dots is greater than or equal to about 1 wt%, based on the total weight or total solids of the composition or complex, 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 of the composition or complex, the content of the luminescent nanostructures 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%.

[0243] Here, the total solids content in the composition (e.g., when the composition includes an organic solvent) can correspond to the content of the corresponding component in the quantum dot composite. For example, in the case of a solvent-free system in which the composition does not include an organic solvent, the content range in the composition can correspond to the content range in the composite.

[0244] In the compositions according to the embodiments, the dispersant can help ensure the dispersibility of the luminescent nanostructures or metal oxide particles as described below. In the embodiments, the dispersant may include (e.g., an organic compound containing a carboxylic acid group) (e.g., a monomer or polymer), such as a binder polymer. The dispersant or binder polymer may be an insulating polymer.

[0245] Organic compounds containing carboxylic acid groups may include: a combination of monomers or copolymers thereof comprising a first monomer, a second monomer and an optional third monomer, wherein the first monomer comprises a carboxylic acid group and a carbon-carbon double bond, the second monomer has a carbon-carbon double bond and a hydrophobic portion but does not have a carboxylic acid group, and the optional third monomer has a carbon-carbon double bond and a hydrophilic portion but does not have a carboxylic acid group.

[0246] Polymers containing multiple aromatic rings or combinations thereof (hereinafter, cardo adhesives), wherein the polymers containing multiple aromatic rings include a carboxylic acid group (-COOH) and have a skeletal structure in which two of the aromatic rings are bonded to a quaternary carbon atom, the quaternary carbon atom being a constituent atom of another ring portion in the main chain; or

[0247] Their combination.

[0248] The dispersant may include a first monomer, a second monomer, and an optional third monomer.

[0249] In the composition, based on the total weight or total solids of the composition or composite, the content of the dispersant (or binder polymer) 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 not limited thereto. Based on the total weight or total solids 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 of the composition or composite, the content of the dispersant (or binder polymer) may be from about 0.5 wt% to about 55 wt%.

[0250] The composition may include polymerizable (e.g., photopolymerizable) monomers containing carbon-carbon double bonds. Monomers may include (e.g., photopolymerizable) (meth)acryloyl monomers. Monomers may be precursors for insulating polymers.

[0251] Based on the total weight or total solids 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 of the composition or complex, the photopolymerizable monomer content 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%.

[0252] The photoinitiator in the composition can be used for the photopolymerization of the above monomers.

[0253] An initiator is a compound that promotes a free radical reaction (e.g., the free radical polymerization of monomers) by generating free radical chemicals under mild conditions (e.g., by heat or light). Initiators can be thermal initiators or photoinitiators. There are no particular limitations on the initiator, and it can be appropriately selected.

[0254] In the composition, the initiator content can be appropriately adjusted considering the type and amount of polymerizable monomers. In the examples, based on the total weight (or total solids content weight) of the composition, the initiator content can be greater than or equal to about 0.01 wt%, for example, 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 / or less than or equal to about, for example, 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.

[0255] The composition may also include (multifunctional or monofunctional) thiols, metal oxide particles, or combinations thereof, wherein the thiols have at least one thiol group at the end.

[0256] Metal oxide particles may include TiO2, SiO2, BaTiO3, Ba2TiO4, ZnO, or combinations thereof.

[0257] In the composition, based on the total weight (or total solids content) of the composition, the content of metal oxide particles 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%. The metal oxide particles may be non-luminescent. Here, the term metal oxide may include oxides of metals or half-metals.

[0258] The metal oxide particles can have a suitably chosen diameter without particular limitation. The diameter of the metal oxide particles 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.

[0259] (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.

[0260] Based on the total weight (or total solids weight) of the composition, 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 (or total solids weight) of the composition, 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%.

[0261] 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.; dimethyl sulfoxide; 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, or ethyl lactate; ethers, such as diethyl ether, dipropyl ether, dibutyl ether, etc.; tetrahydrofuran; 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; or combinations thereof, but not limited thereto.

[0262] The type and amount of organic solvent are appropriately determined taking into account the aforementioned main components (i.e., quantum dots, dispersants, polymerizable monomers, initiators, and, if present, thiols) and the types and amounts of other additives described later. The composition comprises a amount of solvent in addition to the desired amount of solids (non-volatile components).

[0263] The composition (e.g., an inkjet composition) may have a viscosity at 25°C greater than or equal to about 4 centipoise (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.

[0264] When used for inkjet printing, the composition is discharged onto a substrate at room temperature and can be formed, for example, by heating, into a first composite film or its pattern. While possessing the aforementioned viscosity, the ink composition may have a surface tension at 23°C greater than or equal to about 21 Newtons per meter (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.

[0265] The compositions of the embodiments may also include, for example, additives included in the composition for use as a photoresist or ink composition. Additives may include light diffusing agents, leveling agents, coupling agents, etc. Additional details regarding such materials and their suitability for ink compositions can be found in US-2017-0052444-A1.

[0266] The compositions according to the embodiments can be prepared by a method comprising the following steps: preparing a quantum dot dispersion comprising the luminescent nanostructures, dispersant, and solvent of the embodiments described above; and mixing the quantum dot dispersion with an initiator, a polymerizable monomer (e.g., an acryloyl monomer), an optional thiol compound, optional metal oxide particles, and optional additives described above. Each of the above components may be mixed sequentially or simultaneously, but the order of mixing is not particularly limited.

[0267] The compositions according to the embodiments can be used to provide patterning of quantum dot composites (e.g., quantum dot polymer composites). The compositions can provide quantum dot-polymer composites via (e.g., free radical) polymerization. The compositions according to the embodiments can be photoresist compositions containing quantum dots that can be applied to them using photolithography processes. The compositions according to the embodiments can be ink compositions that can be patterned by printing (e.g., droplet emission methods such as inkjet printing).

[0268] In embodiments, the color conversion layer (or patterned film of quantum dot-polymer composite) can be prepared using a photoresist composition. The method may include the following steps: forming a film of the above composition on a substrate; optionally pre-baking the film; exposing selected areas of the film to light (e.g., at a wavelength less than or equal to about 400 nm); and developing the exposed film with an alkaline developing solution to obtain a pattern of the quantum dot-polymer composite.

[0269] Reference Figure 9A The above composition is coated onto a substrate using appropriate methods such as spin coating or slot coating to achieve a predetermined thickness. Optionally, the formed film can be pre-baked (PRB). Pre-baking can be performed by selecting appropriate conditions from known conditions such as temperature, time, and atmosphere.

[0270] The formed (or optionally pre-baked) film is exposed to light of a predetermined wavelength under a mask with a predetermined pattern. The wavelength and intensity of the light can be selected by considering factors such as the type and amount of the (photo)initiator, the type and amount of quantum dots, etc.

[0271] The exposed film is treated with an alkaline developing solution (e.g., immersion or spraying) to dissolve the unexposed areas of the composite to obtain the desired pattern. Alternatively, the obtained pattern can be post-baked (POB) at, for example, from 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) to improve the crack resistance and solvent resistance of the pattern.

[0272] When the color conversion layer or patterned film of a quantum dot composite has multiple repeating portions (i.e., color conversion regions), a quantum dot composite with a desired pattern can be obtained by: preparing a composition comprising multiple quantum dots having desired luminescent properties (photoluminescence peak wavelength, etc.); and depositing the composition to form repeating portions (e.g., red-emitting quantum dots, green-emitting quantum dots, or optionally blue-emitting quantum dots). The pattern can be repeatedly printed (e.g., two or more times, or three or more times) as needed to obtain a quantum dot-polymer composite with a desired pattern. For example, the quantum dot-polymer composite can have a pattern with at least two repeating color portions (e.g., RGB portions). Such a quantum dot-polymer composite pattern can be used as a photoluminescent color filter in a display device.

[0273] Ink compositions can be used to fabricate patterned films of color conversion layers or quantum dot composites, the ink compositions being configured to form patterns using an inkjet method. (See reference...) Figure 9BThe method may include the following steps: providing an ink composition; providing a substrate (e.g., wherein the pixel region is patterned with electrodes and optionally dikes, etc.); depositing the ink composition on the substrate (or pixel region) to provide, for example, a first quantum dot layer (or a first region); and depositing the ink composition on the substrate (or pixel region) to provide, for example, a second quantum dot layer (or a second region). The formation of (multiple) first quantum dot layers (regions) and (multiple) second quantum dot layers (regions) may be performed simultaneously or sequentially.

[0274] Ink compositions can be deposited using a suitable droplet ejector, such as an inkjet or nozzle printing system (e.g., with an ink reservoir and at least one printhead). The deposited ink composition can be removed by solvent and a (first or second) quantum dot layer can be provided by heated polymerization. This method can provide highly precise quantum dot-polymer composite films or patterned films in a cost-effective manner and in a relatively short time.

[0275] A first composite including luminescent nanostructures (e.g., a polymer composite, hereinafter also referred to as a quantum dot composite) may include: a (polymer) matrix; and one embodiment of the luminescent nanostructures dispersed within the matrix. The quantum dot composite may also include metal oxide particles dispersed in the matrix. The (polymer) matrix may include cross-linked polymers and / or linear polymers. Cross-linked polymers may include mercaptoolefin 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.

[0276] In the quantum dot composite, the contents of quantum dots and metal oxide particles are the same as described above. In the quantum dot composite, the matrix content can be greater than or equal to about 10 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%, greater than or equal to about 50 wt%, or greater than or equal to about 60 wt%. In the quantum dot composite, the matrix content can be less than or equal to about 90 wt%, less than or equal to about 80 wt%, less than or equal to about 70 wt%, less than or equal to about 60 wt%, less than or equal to about 50 wt%, or less than or equal to about 40 wt%. In the quantum dot composite, the total content of quantum dots and metal oxide particles can be greater than or equal to about 10 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%, greater than or equal to about 50 wt%, or greater than or equal to about 60 wt%. In the quantum dot composite, the matrix content can be less than or equal to about 90 wt%, less than or equal to about 80 wt%, less than or equal to about 70 wt%, less than or equal to about 60 wt%, less than or equal to about 50 wt%, or less than or equal to about 40 wt%.

[0277] The matrix may include the above-mentioned dispersants (e.g., adhesive monomers or polymers containing carboxylic acid groups), polymers of polymerizable monomers having carbon-carbon double bonds (at least one, e.g., at least two, at least three, at least four or at least five) (e.g., insulating polymers), and polymers of polymerizable monomers and thiol compounds having at least one (e.g., two or more) thiol groups.

[0278] In embodiments, the polymer matrix may include crosslinked polymers, linear polymers, or combinations thereof. Crosslinked polymers may include mercaptoolefin 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. The descriptions of quantum dots, dispersants, polymerizable monomers, and (poly)thiol compounds are the same as described above.

[0279] The color conversion panel may also have an incident light blocking layer, a color filter layer, or a first filter layer (hereinafter referred to as the first filter layer) on each composite. The first filter layer may be disposed between the bottom surface of the first portion (R) and the second portion (G) and a substrate (e.g., an upper substrate) or on the upper surface of the substrate. The first filter layer may be a sheet with an opening in the portion corresponding to the blue pixel area (third portion), and thus may be formed in the portions corresponding to the first and second portions. That is, the first filter layer may be integrally formed in a location other than where it overlaps with the third portion, but this disclosure is not limited thereto. Two or more first filter layers may be separated from each other in locations where they overlap with the first and second portions and optionally the third portion. When the light source includes a green light-emitting element, a green light blocking layer may be disposed on the third portion.

[0280] The first filter layer can block light with a predetermined wavelength region, such as the visible light region, and can transmit light with other wavelength regions. For example, it 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 these colors. The first filter layer can transmit blue light and block green light, and can be disposed on a blue light emitting pixel.

[0281] The first filter layer can essentially block incident light while transmitting light within the desired wavelength range. The transmittance of the first filter layer for light within the desired wavelength range 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%.

[0282] A first filter layer configured to selectively transmit red light can be disposed at a position superimposed on the portion emitting red light, and a first filter layer configured to selectively transmit green light can be disposed at a position superimposed on the portion emitting green light. 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.

[0283] The first area can be positioned overlapping the green-emitting portion. The second area can be positioned overlapping the red-emitting portion. The third area can be positioned overlapping the blue-emitting portion.

[0284] 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.

[0285] A protective layer, a second filter layer, or a combination thereof may be disposed between the display panel and the color conversion panel. The protective layer may include a transparent insulating material. A second filter layer may also be included, which transmits at least a portion of the third light (incident light) and reflects at least a portion of the first light and / or the second light (e.g., recycled red / green or yellow light). The first light may be red light, the second light may be green light, and the third light may be blue light. For example, 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 and be reflected. The reflected green and red light may pass through the first and second portions and be directed to the outside of the display device.

[0286] The second filter layer or the first filter layer can be formed as an integrated layer with a relatively flat surface.

[0287] The first filter layer may include a polymer film comprising a dye and / or pigment that absorbs light in the wavelength 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.

[0288] 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.

[0289] In the following text, reference will be made to Figure 5A A more detailed description follows. A color filter layer 230 is positioned such that light passing through the color conversion layer 270 travels in the direction of its emission, for example, through the upper substrate 210. The color filter layer 230 may include color filters 230a, 230b, and 230c disposed in each sub-pixel PX1, PX2, and PX3 and selectively transmit light of different wavelength spectra. Color filters 230a, 230b, and 230c may selectively transmit light of the same wavelength spectrum as the color displayed in each sub-pixel PX1, PX2, and PX3, and may also selectively transmit light of an emission spectrum converted in each region of the color conversion layer 270.

[0290] For example, first sub-pixel PX1, second sub-pixel PX2, and third sub-pixel PX3 display red, green, and blue, respectively. When light in each of the red, green, and blue emission spectra is emitted from the first color conversion region 270a, the second color conversion region 270b, and the light-transmitting region 270c, the first color filter 230a is superimposed on the first color conversion region 270a and can be a red filter; the second color filter 230b is superimposed on the second color conversion region 270b and can be a green filter; and the third color filter 230c is superimposed on the light-transmitting region 270c and can be a blue filter. The first color filter 230a, the second color filter 230b, or the third color filter 230c may include pigments or dyes that selectively transmit light of the red, green, or blue wavelength spectra but absorb and / or reflect light of other wavelength spectra.

[0291] The color filter layer 230 can more precisely filter light emitted from the color conversion layer 270, thereby enhancing the color purity of light emitted toward the upper substrate 210. For example, a first color filter 230a superimposed on the first color conversion region 270a can block light not converted by the quantum dots 271a of the first color conversion region 270a (or reduce the transmission of light not converted by the quantum dots 271a of the first color conversion region 270a), and transmit converted light to enhance the color purity of light (e.g., light with a red emission spectrum). For example, a second color filter 230b superimposed on the second color conversion region 270b can block light not converted by the quantum dots 271b of the second color conversion region 270b (or reduce the transmission of light not converted by the quantum dots 271b of the second color conversion region 270b), and transmit converted light to enhance the color purity of light (e.g., light with a green emission spectrum). For example, a third color filter 230c superimposed on the light-transmitting region 270c can block light other than light with the blue emission spectrum, and, for example, enhance the color purity of light with the blue emission spectrum. For example, at least some of the first color filter 230a, the second color filter 230b, and the third color filter 230c can be omitted; for example, the third color filter 230c superimposed on the light-transmitting region 270c can be omitted.

[0292] The light-blocking pattern 220 can separate each sub-pixel PX1, PX2, and PX3 and is disposed between adjacent sub-pixels PX1, PX2, and PX3. The light-blocking pattern 220 can be, for example, a black matrix. The light-blocking pattern 220 can be superimposed on the edges of adjacent color filters 230a, 230b, and 230c.

[0293] A planarization layer 240 may be disposed between the color filter layer 230 and the color conversion layer 270, and may reduce or eliminate step differences caused by the color filter layer 230. The planarization layer 240 may comprise organic materials, inorganic materials, organic-inorganic materials, or combinations thereof. The planarization layer 240 may comprise, for example, oxides, nitrides, or oxynitrides (e.g., silicon oxide, silicon nitride, silicon oxynitride, or combinations thereof), but is not limited thereto. The planarization layer 240 may be one, two, or more layers, and may cover the entire surface of the substrate 210.

[0294] Encapsulation layer 290 may cover color conversion layer 270 and separator 250, and may include a glass plate, metal film, organic film, inorganic film, organic-inorganic film, or combination thereof. Organic films may include, for example, acrylic resin, (meth)acrylic resin, polyisoprene, vinyl resin, epoxy resin, polyurethane resin, cellulose resin, perylene resin, or combination thereof, but are not limited thereto. Inorganic films may include, for example, oxides, nitrides, and / or oxynitrides (e.g., silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, aluminum oxynitride, zirconium oxide, zirconium nitride, zirconium oxynitride, titanium oxide, titanium nitride, titanium oxynitride, hafnium oxide, hafnium nitride, hafnium oxynitride, tantalum oxide, tantalum nitride, tantalum oxynitride, lithium fluoride, or combination thereof), but are not limited thereto. Organic-inorganic films may include, for example, polyorganosiloxane, but are not limited thereto. Encapsulation layer 290 may be one, two, or more layers.

[0295] The light-transmitting layer 300 can be disposed between the light-emitting panel 100 and the color conversion panel 200. The light-transmitting layer 300 can be, for example, a filler material. The light-transmitting layer 300 can include organic materials, inorganic materials, organic-inorganic materials, or combinations thereof, and can include, for example, epoxy resin, organosilicon compounds, polyorganosiloxanes, or combinations thereof.

[0296] The aforementioned display panel can be included in various electronic devices. These electronic devices may include, but are not limited to, various display devices, sensor devices, solar cells, imaging sensors, photodetectors, etc. The luminescent nanostructures of the embodiments can be included in electronic devices. Such electronic devices may include, but are not limited to, portable terminal devices, monitors, laptops, televisions, electronic displays, cameras, automobiles, etc. The electronic device may be a portable terminal device, monitor, laptop, or television that includes a display device (or luminescent element) containing quantum dots. The electronic device may be a camera or portable terminal device that includes an image sensor containing quantum dots. The electronic device may be a camera or vehicle that includes a photodetector containing quantum dots.

[0297] 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.

[0298] Example

[0299] Analytical methods

[0300] [1] UV-Vis spectroscopy

[0301] UV-Vis spectral analysis was performed using an Agilent Cary 5000 spectrophotometer to obtain UV-Vis absorption spectra. The absorbance at 350 nm and 450 nm was then used to calculate the absorbance ratio as follows:

[0302] Absorbance ratio = A450 / A350

[0303] A450: Absorbance at 450nm

[0304] A350: Absorbance at 350nm.

[0305] [2] ICP analysis

[0306] Inductively coupled plasma atomic emission spectroscopy (ICP-AES) was performed using a Shimadzu ICPS-8100.

[0307] [3] Calculation of spectral overlap ratio:

[0308] Based on the given UV-Vis absorption spectrum of the quantum dots and the emission spectrum of the blue-green light source, A and B are measured, and B / A (spectral overlap ratio) is calculated.

[0309] Here, the area of ​​overlap between the UV-Vis absorption spectrum of columinescent nanostructure A and the maximum emission peak of the first light (blue light) in the wavelength range of less than or equal to about 500 nm corresponds to the area of ​​overlap between the UV-Vis absorption spectrum of columinescent nanostructure B and the maximum emission peak of the second light (green light) in the wavelength range of greater than about 500 nm corresponds to the area of ​​overlap between the UV-Vis absorption spectrum of columinescent nanostructure B and the maximum emission peak of the second light (green light) in the wavelength range of greater than about 500 nm.

[0310] [4] Incident light absorbance and light conversion efficiency

[0311] The absorbance and light conversion efficiency of blue incident light are measured using the UV-Vis absorption spectrum and photoemission spectrum of a given quantum dot, according to the following formula.

[0312] Light conversion efficiency (%) = A / B

[0313] Blue light absorbance (%) = [(B-B') / B] × 100 (%)

[0314] A: The amount of green light emitted from the complex with a wavelength greater than approximately 500 nm.

[0315] B: The amount of blue incident light with a wavelength less than or equal to approximately 500 nm.

[0316] B': The amount of blue incident light with a wavelength of less than or equal to about 500 nm that has passed through the quantum dot.

[0317] Reference Example 1: Preparation of InZnP Cores

[0318] In a 250 mL reaction flask, zinc acetate and oleic acid were dissolved in 1-octadecene and heated under vacuum at 120 °C, then cooled to room temperature to provide a zinc oleate solution.

[0319] Indium acetate and lauric acid were added to a reaction flask and heated to 120°C under vacuum. After 1 hour, nitrogen was added to the reaction flask. As the temperature in the reaction flask increased to 250°C, a mixed solution of tris(trimethylsilyl)phosphine (TMS3P) and trioctylphosphine was rapidly injected into the reaction flask, and the reaction proceeded. When the reaction was complete, the reaction solution was cooled to room temperature, a non-solvent (acetone) was added to promote precipitation, and the reaction mixture was then centrifuged to separate the precipitate, which was then dispersed in toluene.

[0320] Indium, zinc, and phosphorus were used in a molar ratio of 6:7:4.5. As a result of absorption spectral analysis of the obtained InZnP cores, the cores exhibited a first absorption wavelength of approximately 430 nm.

[0321] Example 1

[0322] (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.

[0323] In a 2L flask, zinc acetate and oleic acid were dissolved in trioctylamine and then vacuum-treated at 120°C for 10 minutes. Nitrogen was added to the reaction flask, and the reaction solution was heated to a reaction temperature of 280°C. A toluene dispersion of the first semiconductor nanocrystal according to Reference Example 1, Se / TOP, and dodecyl mercaptan were added to the reaction flask. As the reaction proceeded, a stock solution of S / TOP was added to the reaction solution to obtain a reaction solution comprising a luminescent nanostructure containing the first semiconductor nanocrystal and a second semiconductor nanocrystal on at least a portion of the surface of the first semiconductor nanocrystal.

[0324] The total reaction time was 75 minutes, and the content of the precursor per mole of indium was adjusted to have the ICP composition shown in Table 1. Dodecylthiol and S / TOP had a molar ratio of 1:0.4.

[0325] After adding excess ethanol to the reaction solution, the luminescent nanostructures (hereinafter referred to as QD) were separated by centrifugation. After centrifugation, the supernatant was discarded, and the collected precipitate was dried and dispersed in toluene to obtain a solution of the luminescent nanostructures (hereinafter referred to as QD solution).

[0326] (2) The obtained QDs were analyzed by ICP-AES, and the results are shown in Table 1. The obtained QDs (in solution or complex state) were analyzed by UV-Vis spectroscopy, and the results are shown in Table 2.

[0327] Example 2

[0328] Except for adjusting the content of Se / TOP and sulfur precursor relative to 1 mole of indium and the reaction time to have the composition and size shown in Table 1, the luminescent nanostructures were obtained according to the same method as in Example 1.

[0329] The obtained QDs were analyzed by ICP-AES and UV-Vis spectroscopy, and the results are shown in Tables 1 and 2.

[0330] Compare Example 1, Compare Example 2 and Compare Example 3

[0331] Selenium was dispersed in trioctylphosphine to prepare a Se / TOP stock solution, and sulfur was dispersed in trioctylphosphine to prepare an S / TOP stock solution. Zinc acetate and oleic acid were dissolved in trioctylamine in a 200 mL reaction flask and then vacuum-treated at 120 °C for 10 min. Nitrogen was added to the reaction flask while the resulting solution was heated to 320 °C, and a toluene dispersion of the first semiconductor nanocrystals was added to the flask. A predetermined amount of Se / TOP was added to the flask in several separate portions to form a ZnSe layer on the first semiconductor nanocrystals. Subsequently, the S / TOP stock solution was added to the reaction solution at the reaction temperature to form a ZnS layer on the ZnSe layer. The total reaction time was set to 40 min, and the contents of the Se and S precursors based on 1 mole of indium were adjusted to have the compositions shown in Table 1.

[0332] The obtained QDs were analyzed by ICP-AES and UV-Vis spectroscopy, and the results are shown in Tables 1 and 2.

[0333] Table 1

[0334]

[0335]

[0336] Table 2

[0337] First absorption peak wavelength (nm) A450:A350 Example 1 Approximately 465 0.21:1 Example 2 Approximately 480 0.15:1 Comparison Example 1 Approximately 510 0.11:1 Comparison Example 2 Approximately 450 0.13:1 Compare Example 3 Approximately 497 0.15:1

[0338] Experimental Example

[0339] Considering the UV-Vis absorption curves of quantum dots from Examples 1 to 2 and Comparative Examples 1 to 3, the spectral overlap (A, B) of the absorption curve of the luminescent nanostructure with each of the emission spectra of blue incident light (for wavelengths less than or equal to about 500 nm) and the emission spectra of green incident light (for wavelengths greater than about 500 nm) was measured. Based on the measured spectral overlap values, the relationship between the spectral overlap ratio (B / A) and the absorption peak position (first absorption peak) of the luminescent nanostructure was determined. The results are shown in... Figure 7A and Figure 7B middle.

[0340] based on Figure 7A and Figure 7B The results confirm that the color conversion panels with luminescent nanostructures, including those in Examples 1 and 2, exhibit spectral overlap of less than or equal to 0.6 when irradiated with mixed incident light.

[0341] Reference Figure 8 As a result, compared with the optical properties of the color conversion panel including the quantum dot composite of the comparative example in the case of mixed incident light, the color conversion panel including the quantum dot composite of the example in the case of mixed incident light can exhibit improved optical properties, for example, incident light absorbance greater than or equal to about 89% and light conversion efficiency greater than or equal to about 45%.

[0342] While this disclosure has been described in conjunction with exemplary embodiments now considered practical, it will be understood that the invention is not limited to the disclosed embodiments. Rather, the invention 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: Illuminated panel; as well as The color conversion panel has a surface opposite to the surface of the light-emitting panel. The light-emitting panel is configured to emit incident light including a first light and a second light. The first light has a maximum emission peak wavelength in the range of greater than or equal to 450 nm and less than or equal to 480 nm, and the second light has a maximum emission peak wavelength in the range of greater than or equal to 500 nm and less than or equal to 580 nm. The color conversion panel includes: a color conversion layer, including a color conversion area; and optional partitions defining each area of ​​the color conversion layer, wherein the color conversion area includes a first area corresponding to the green pixel. The first region includes a first composite, which comprises a matrix and multiple luminescent nanostructures dispersed within the matrix, and The UV-Vis absorption spectrum of the luminescent nanostructure, the maximum emission peak of the first light, and the maximum emission peak of the second light overlap to satisfy the following equation: B / A≤0.6 Among them, the area of ​​overlap between the UV-Vis absorption spectrum of the co-luminescent nanostructure A and the maximum emission peak of the first light in the wavelength range of less than or equal to 500 nm corresponds to the area of ​​overlap between the UV-Vis absorption spectrum of the co-luminescent nanostructure B and the maximum emission peak of the second light in the wavelength range of greater than or equal to 500 nm corresponds to the area of ​​overlap between the two light. Specifically, A is determined by adjusting the height of the first absorption peak and the height of the maximum emission peak of the first light in the UV-Vis absorption spectrum of the luminescent nanostructure to be equal, and B is determined by adjusting the height of the first absorption peak and the height of the maximum emission peak of the second light in the UV-Vis absorption spectrum of the luminescent nanostructure to be equal.

2. The display panel according to claim 1, wherein, The light-emitting panel includes a first electrode, a second electrode, and a light-emitting layer disposed between the first electrode and the second electrode.

3. The display panel according to claim 2, wherein, The light-emitting layer consists of organic compounds and dopants.

4. The display panel according to claim 2, wherein, The light-emitting layer includes a first light-emitting layer and a second light-emitting layer disposed on the first light-emitting layer, wherein the first light-emitting layer is configured to emit a first light and the second light-emitting layer is configured to emit a second light.

5. The display panel according to claim 4, wherein, The light-emitting layer also includes a first charge-generating layer disposed between the first light-emitting layer and the second light-emitting layer, and optionally a charge-assisting layer disposed between the first electrode and the first light-emitting layer, between the second electrode and the second light-emitting layer, or between the first electrode and the first light-emitting layer and between the second electrode and the second light-emitting layer.

6. The display panel according to claim 2, wherein, The light-emitting layer includes a second light-emitting layer disposed between two or more first light-emitting layers, a first light-emitting layer disposed between two or more second light-emitting layers, or a combination thereof, and The first light-emitting layer is configured to emit a first light, and the second light-emitting layer is configured to emit a second light.

7. The display panel according to claim 1, wherein, The incident light does not include red light with a wavelength greater than or equal to 600 nanometers and less than or equal to 680 nanometers.

8. The display panel according to claim 1, wherein, The maximum emission peak wavelength of the second light is in the range of greater than or equal to 515 nanometers and less than or equal to 530 nanometers, and The maximum emission peak wavelength of the first light is in the range of greater than 440 nanometers and less than or equal to 465 nanometers.

9. The display panel according to claim 1, wherein, The maximum photoluminescence peak wavelength of the luminescent nanostructure is in the range of greater than or equal to 520 nm and less than or equal to 550 nm.

10. The display panel according to claim 1, wherein, The difference between the wavelength of the first absorption peak and the wavelength of the maximum photoluminescence peak of the luminescent nanostructure is greater than or equal to 45 nm and less than or equal to 65 nm.

11. The display panel according to claim 1, wherein, In the UV-Vis absorption spectrum of the luminescent nanostructure, the absorbance ratio at 450 nm to that at 350 nm is greater than 0.078:

1.

12. The display panel according to claim 1, wherein, The luminescent nanostructures exhibit a UV-Vis absorption spectrum with a positive differential coefficient at 450 nm.

13. The display panel according to claim 1, wherein, The luminescent nanostructures include: a first semiconductor nanocrystal, comprising a group III-V compound; and a second semiconductor nanocrystal, comprising a zinc chalcogenide. Group III-V compounds include indium and phosphorus. Zinc sulfides include zinc, selenium, and sulfur, and The luminescent nanostructures do not contain cadmium.

14. The display panel according to claim 13, wherein, In the plurality of luminescent nanostructures, the molar ratio of sulfur to selenium is greater than 2:1, or In the plurality of luminescent nanostructures, the molar ratio of sulfur to indium is greater than or equal to 7:1 and less than or equal to 15:1, or In the plurality of luminescent nanostructures, the molar ratio of selenium to indium is greater than or equal to 2.5:1 and less than or equal to 7:

1.

15. The display panel according to claim 1, wherein, When confirmed by electron microscopy analysis, the luminescent nanostructures have an average size of less than or equal to 6 nanometers.

16. The display panel according to claim 1, wherein, In spectral overlap, B / A is less than or equal to 0.

5.

17. The display panel according to claim 1, wherein, The first composite material or color conversion panel has an incident light absorbance greater than or equal to 89% as defined by the following formula: Incident light absorbance (%) = [(B-B') / B] × 100 (%) B: The amount of incident light with a wavelength less than or equal to 500 nm, and B': The amount of incident light with a wavelength of less than or equal to 500 nm that has passed through the first complex.

18. The display panel according to claim 1, wherein, The first composite material or color conversion panel has a light conversion efficiency greater than or equal to 45% as defined by the following formula: A / B (%) = Light Conversion Rate A: The amount of green light emitted from the first complex with a wavelength greater than or equal to 500 nm, and B: The amount of incident light with a wavelength of less than or equal to 500 nm.

19. The display panel according to claim 1, wherein, The color conversion area also includes a second area corresponding to the red pixel, a third area corresponding to the blue pixel, or a combination thereof.

20. An electronic device comprising a display panel according to any one of claims 1 to 19.

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