Light-emitting device and manufacturing method thereof, display device and light-emitting film

Abstract

Disclosed are a light-emitting device and a manufacturing method thereof, a display device, and a light-emitting film. The light-emitting device includes a first electrode, a second electrode, and a light-emitting film disposed between the first electrode and the second electrode. The light-emitting film includes a fluorine-containing organic salt and quantum dots, wherein the quantum dots do not include cadmium, lead, or a combination thereof. The fluorine-containing organic salt includes at least one of boron and phosphorus, a substituted or unsubstituted C1-C30 hydrocarbon group, a non-metallic element capable of forming a fluorine-containing salt, and fluorine, and the non-metallic element includes carbon, nitrogen, oxygen, phosphorus, sulfur, or selenium.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority from Korean Patent Application No. 10-2019-0168242 filed in the Korean Intellectual Property Office on December 16, 2019, and all rights arising therefrom, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] Disclosed are a light emitting device, a method of manufacturing the device, and a light emitting film included in the device. Background Art

[0004] Quantum dots are a class of materials based on semiconductor nanocrystals. Quantum dots can exhibit a variable energy bandgap by controlling their size and / or composition. Quantum dots can emit light at a variety of wavelengths and, therefore, have applications in a variety of electronic devices, including displays. Summary of the Invention

[0005] One embodiment provides an (electro)luminescent device comprising quantum dots with improved properties.

[0006] Another embodiment provides a method of manufacturing the light emitting device.

[0007] Another embodiment provides a light emitting film included in the light emitting device.

[0008] According to one embodiment, a light-emitting device includes a first electrode, a second electrode (e.g., spaced apart from each other or facing each other), and a light-emitting film disposed between the first electrode and the second electrode, wherein the light-emitting film includes a fluorine-containing organic salt and quantum dots, wherein the quantum dots do not include cadmium, lead, or a combination thereof, and wherein the light-emitting film can be configured to emit light (e.g., red light, green light, or blue light).

[0009] The fluorine-containing organic salt includes at least one of boron or phosphorus (e.g., boron, phosphorus, or a combination thereof), a substituted or unsubstituted C1-C30 hydrocarbon group, a non-metallic element (e.g., salt), and fluorine, and

[0010] The non-metallic elements include carbon, nitrogen, oxygen, phosphorus, sulfur, or selenium.

[0011] The HOMO energy level of the light emitting film may be greater than or equal to about 5.7 electron volts (eV). The HOMO energy level may be measured using photoelectron spectroscopy analysis.

[0012] The HOMO energy level of the light emitting film may be greater than or equal to about 5.9 eV.

[0013] If the light emitting film emits red light, the HOMO energy level of the light emitting film may be greater than or equal to about 5.7 eV, greater than or equal to about 5.75 eV, greater than or equal to about 5.8 eV, or greater than or equal to about 5.85 eV.

[0014] If the light emitting film emits green light, the HOMO energy level of the light emitting film may be greater than or equal to about 5.7 eV, greater than or equal to about 5.75 eV, greater than or equal to about 5.8 eV, or greater than or equal to about 5.85 eV.

[0015] If the light emitting film emits blue light, a HOMO level of the light emitting film may be greater than or equal to about 5.9 eV.

[0016] The luminescent film may constitute at least a surface of the luminescent film. The fluorine-containing organic salt may be bonded to the quantum dots. At least a portion of the surface of the luminescent film may include the quantum dots and the fluorine-containing organic salt bonded to the quantum dots.

[0017] The fluorine-containing organic salt may include carbon Part, oxygen part, ammonium part, part, (selenium ) portion, matte portion, or a combination thereof.

[0018] The fluorine-containing organic salt may include fluoroborate, fluorophosphate, or a combination thereof.

[0019] The quantum dots may have a core-shell structure.

[0020] In an embodiment, the quantum dot may include a core including a first semiconductor nanocrystal and a shell disposed on the core, the core including a second semiconductor nanocrystal having a composition different from that of the first semiconductor nanocrystal.

[0021] The first semiconductor nanocrystal and the second semiconductor nanocrystal may independently include a II-VI compound, a III-V compound, a IV-VI compound, a Group IV element or compound, a I-III-VI compound, a I-II-IV-VI compound, or a combination thereof.

[0022] The first semiconductor nanocrystals may include indium, zinc, or a combination thereof.

[0023] The quantum dots may include zinc and sulfur in an outermost layer of the shell.

[0024] The quantum dots may include InP, InZnP, ZnSe, ZnSeTe, or a combination thereof.

[0025] The luminescent film may include boron. The molar ratio of boron to carbon may be greater than or equal to about 0.001:1, as measured by energy dispersive spectroscopy of the luminescent film.

[0026] In the light emitting film, a molar ratio of boron to carbon may be greater than or equal to about 0.1:1, or greater than or equal to about 0.5:1, as measured by energy dispersive spectroscopy of the light emitting film.

[0027] In the luminescent film, the molar amount of fluorine relative to carbon may be greater than or equal to about 0.5%, greater than or equal to about 1%, greater than or equal to about 2%, greater than or equal to about 3%, greater than or equal to about 5%, or greater than or equal to about 10%, as measured by energy dispersive spectroscopy of the luminescent film. In the luminescent film, the molar amount of fluorine relative to carbon may be less than or equal to about 50%, less than or equal to about 40%, less than or equal to about 30%, less than or equal to about 20%, or less than or equal to about 10%.

[0028] The luminescent film may include boron, and a molar ratio of fluorine to boron may be greater than or equal to about 4:1 and less than or equal to about 6:1, for example, as measured by energy dispersive spectroscopy of the luminescent film.

[0029] The light emitting film may include boron, and a molar ratio of fluorine to boron may be greater than or equal to about 0.03:1 and less than or equal to about 4:1.

[0030] The quantum dots may include zinc and chalcogen, and a molar ratio of carbon to the total moles of zinc and chalcogen may be less than or equal to about 8:1, for example, as measured by energy dispersive spectroscopy of the light emitting film.

[0031] The molar ratio of carbon to the total moles of zinc and chalcogen may be less than or equal to about 7:1.

[0032] The light emitting device may further include an electron assist layer adjacent to the light emitting film.

[0033] A difference between a conduction band edge energy level (eg, LUMO energy level) of the electron assist layer and a LUMO energy level of the light emitting film may be less than or equal to about 1 eV.

[0034] The electron assist layer may include nanoparticles of metal oxide.

[0035] The metal oxide may include zinc oxide, magnesium zinc oxide, tin oxide, titanium oxide, or a combination thereof.

[0036] The metal oxide can be represented by Chemical Formula 1:

[0037] Chemical formula 1

[0038] Zn 1-x Mx O

[0039] In Chemical Formula 1,

[0040] M is Mg, Ca, Zr, W, Li, Ti, Y, Al, or a combination thereof, and 0≤x≤0.5.

[0041] The nanoparticles may have an average particle size greater than or equal to about 0.5 nanometers (nm) and less than or equal to about 10 nm.

[0042] The light emitting film may have a thickness greater than or equal to about 10 nm and less than or equal to about 100 nm.

[0043] After heat treatment at 120° C. for 30 minutes, the light emitting film may have a photoluminescence efficiency that is greater than or equal to about 93% of the photoluminescence efficiency before the heat treatment.

[0044] The light emitting device may have a maximum external quantum efficiency greater than or equal to about 10%.

[0045] The light emitting device may have a light intensity greater than or equal to about 35,000 candelas per square meter (cd / m 2 ) at maximum brightness.

[0046] The light emitting device may exhibit a T95 lifetime of greater than or equal to about 2 hours, such as at a light intensity of about 650 cd / m 2 Measured at or below brightness.

[0047] The light emitting device may further include a hole auxiliary layer, such as a hole injection layer (HIL), a hole transport layer (HTL), or a combination thereof, disposed between the first electrode and the light emitting film.

[0048] The light emitting device may further include an electron assist layer, such as an electron injection layer (EIL), an electron transport layer (ETL), or a combination thereof, disposed between the second electrode and the light emitting film.

[0049] In another embodiment, a method of manufacturing the aforementioned light emitting device includes:

[0050] providing a structure including a first electrode, a second electrode, and a light-emitting film between the first electrode and the second electrode (for example, providing a first electrode, forming a light-emitting layer on the first electrode, and forming a second electrode on the light-emitting layer),

[0051] The forming of the light emitting film includes providing a quantum dot layer including a plurality of quantum dots, and treating the quantum dot layer with a solution including a fluorine-containing organic salt in a polar solvent.

[0052] The method may further include washing the treated quantum dot layer with a polar solvent one or more times.

[0053] The method may further include heat-treating the washed quantum dot layer at a temperature greater than or equal to about 80°C.

[0054] The polar solvent may include a C1-C10 alcohol.

[0055] Another embodiment provides a display apparatus including the aforementioned light emitting device (eg, electroluminescent device).

[0056] In another embodiment, the light-emitting film comprises a plurality of quantum dots and a fluorine-containing organic salt, wherein the plurality of quantum dots does not include cadmium, lead, or a combination thereof, and the fluorine-containing organic salt comprises a first portion and a second portion, wherein the first portion comprises oxygen Ammonium, carbon Sulfonium, or a combination thereof, the second portion includes tetrafluoroborate, hexafluorophosphate, or a combination thereof.

[0057] The first portion may include a substituted or unsubstituted C1-C30 hydrocarbon group.

[0058] The HOMO energy level of the light emitting film may be greater than or equal to about 5.7 eV.

[0059] The HOMO energy level of the light emitting film may be greater than or equal to about 5.8 eV.

[0060] The HOMO energy level of the light emitting film may be greater than or equal to about 5.9 eV.

[0061] The light emitting film may have a power of greater than or equal to about 300 mA / cm2 (mA / cm 2 ), greater than or equal to about 400mA / cm 2 , greater than or equal to about 450mA / cm 2 , or greater than or equal to about 500 mA / cm 2 The hole transport capability of a device measured at a predetermined voltage (eg, at 8 volts).

[0062] The light emitting film may be configured to emit red light, green light, or blue light.

[0063] When the light emitting film emits red light, a HOMO energy level of the light emitting film may be greater than or equal to about 5.7 eV.

[0064] When the light emitting film emits green light, a HOMO energy level of the light emitting film may be greater than or equal to about 5.7 eV.

[0065] When the light emitting film emits blue light, the HOMO energy level of the light emitting film may be greater than or equal to about 5.9 eV. The HOMO energy level of the light emitting film may be greater than or equal to about 6.0 eV.

[0066] The luminescent film may include boron, and a molar ratio of boron to carbon may be greater than or equal to about 0.001:1, greater than or equal to about 0.01:1, or greater than or equal to about 0.05:1 as measured by energy dispersive spectroscopy of the luminescent film.

[0067] The boron content may be greater than or equal to about 0.5 moles relative to 1 mole of carbon.

[0068] In energy dispersive spectroscopy of the light emitting film, a molar content of fluorine relative to carbon may be greater than or equal to about 0.5%.

[0069] The quantum dots may include zinc and chalcogen, and a molar ratio of carbon to a total content of zinc and chalcogen may be less than or equal to about 8 in energy dispersive spectroscopy of the light emitting film.

[0070] The molar ratio of carbon to the total content of zinc and chalcogen may be less than or equal to about 7.

[0071] In the light-emitting device (eg, electroluminescent device) of the embodiment, the fluorine-containing organic salt passivates the quantum dot-based light-emitting film (eg, light-emitting layer) and can improve the optical properties of the quantum dots in the light-emitting layer to increase the lifetime of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 is a schematic diagram showing energy levels of respective layers in a light emitting device according to a non-limiting embodiment.

[0073] Figure 2 is a cross-sectional view of a light emitting device according to one non-limiting embodiment.

[0074] Figure 3 is a cross-sectional view of a light emitting device according to one non-limiting embodiment.

[0075] Figure 4 is a schematic cross-sectional view of a light emitting device according to another non-limiting embodiment.

[0076] Figure 5 The photoluminescence spectrum of the thin film prepared in Experimental Example 1 is shown. DETAILED DESCRIPTION

[0077] The advantages and features of the present disclosure, as well as methods for achieving the same, will become apparent with reference to the following example embodiments, taken in conjunction with the accompanying drawings. However, the embodiments should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art.

[0078] If not otherwise defined, all terms (including technical and scientific terms) in this specification are used as commonly understood by those of ordinary skill in the art. It will be further understood that terms, such as those defined in common dictionaries, should be interpreted as having meanings consistent with their meanings in the context of the relevant art and may not be interpreted ideally or exaggeratedly unless clearly defined. The terms used herein are for the purpose of describing specific embodiments and are not intended to be limiting.

[0079] As used herein, the singular forms "a (kind) (indefinite article) (a, an)" and "the" are intended to include plural forms, including "at least one (kind)", unless the content clearly indicates otherwise. "At least one (kind)" will not be interpreted as limiting "one (kind)". "Or" means "and / or". As used herein, the term "and / or" includes any and all combinations of one or more of the relevant listed items. It will be further understood that the term "include" and variations such as "comprising" when used in this specification indicate the presence of the stated features, regions, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more additional features, regions, wholes, steps, operations, elements, components, and / or collections thereof.

[0080] In the accompanying drawings, the thickness of layers, films, panels, regions, etc. is exaggerated for clarity. Throughout the specification, the same reference numerals represent the same elements. It will be understood that when an element, such as a layer, film, region, or substrate, is referred to as being "on" another element, it may be directly on the other element or there may be intervening elements. Conversely, when an element is referred to as being "directly on" another element, there are no intervening elements. In order to clearly illustrate the embodiments in the drawings, some parts that are not truly relevant to the description may be omitted.

[0081] It will be understood that although the terms "first," "second," "third," etc., may be used herein to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, or portion from another. Thus, a "first element," "component," "region," "layer," or "portion" discussed below may be referred to as a second element, component, region, layer, or portion without departing from the teachings herein.

[0082] As used herein, "about" is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations, or within ±10%, ±5%, relative to the stated value.

[0083] As used herein, when no definition is otherwise provided, "substituted" refers to the case where, in a compound or functional group, hydrogen is replaced by a substituent selected from the group consisting of C1-C30 alkyl, C2-C30 alkenyl, C2-C30 alkynyl, C6-C30 aryl, C7-C30 alkaryl, C1-C30 alkoxy, C1-C30 heteroalkyl, C3-C30 heteroalkylaryl, C3-C30 cycloalkyl, C3-C15 cycloalkenyl, C6-C30 cycloalkynyl, C2-C30 heterocycloalkyl, halogen (-F, -Cl, -Br, or -I), hydroxyl (-OH), nitro (-NO2), cyano (-CN), amino (-NRR', wherein R and R' are independently hydrogen), alkyl, C1-C30 alkyl, C2-C30 alkyl, C3-C30 heteroalkylaryl, C3-C30 cycloalkyl, C3-C15 cycloalkenyl, C6-C30 cycloalkynyl, C2-C30 heterocycloalkyl, halogen (-F, -Cl, -Br, or -I), hydroxyl (-OH), nitro (-NO2), cyano (-CN), amino (-NRR', wherein R and R' are independently hydrogen), alkyl, C1-C30 alkyl, C2-C30 hetero ... alkyl, C3-C or C1-C6 alkyl), an azido group (-N3), an amidine group (-C(=NH)NH2), a hydrazine group (-NHNH2), a hydrazone group (=N(NH2)), an aldehyde group (-C(=O)H), a carbamoyl group (-C(O)NH2), a thiol group (-SH), an ester group (-C(=O)OR, wherein R is a C1-C6 alkyl group or a C6-C12 aryl group), a carboxylic acid group or a salt thereof (-C(=O)OM, wherein M is an organic or inorganic cation), a sulfonic acid group (-SO3H) or a salt thereof (-SO3M, wherein M is an organic or inorganic cation), a phosphate group (-PO3H2) or a salt thereof (-PO3MH or -PO3M2, wherein M is an organic or inorganic cation), or a combination thereof.

[0084] As used herein, the term "Group" as in Group II, Group III, etc., refers to a Group of the Periodic Table of Elements.

[0085] As used herein, “Group II” refers to Group IIA and Group IIB, and examples of Group II metals may be Cd, Zn, Hg, and Mg, but are not limited thereto.

[0086] As used herein, “Group III” refers to Group IIIA and Group IIIB, and examples of Group III metals may be Al, In, Ga, and Tl, but are not limited thereto.

[0087] As used herein, "Group IV" refers to Group IVA and Group IVB, and examples of Group IV metals may be Si, Ge, and Sn, but are not limited thereto. As used herein, "metal" may include semimetals such as Si.

[0088] As used herein, “Group I” refers to Group IA and Group IB, and examples may include Li, Na, K, Rb, and Cs, but are not limited thereto.

[0089] As used herein, "Group V" refers to Group VA, and examples may include nitrogen, phosphorus, arsenic, antimony, and bismuth, but are not limited thereto.

[0090] As used herein, "Group VI" refers to Group VIA, and examples may include, but are not limited to, sulfur, selenium, and tellurium.

[0091] As used herein, a hydrocarbon group refers to a group comprising (or consisting of) carbon and hydrogen (e.g., an alkyl, alkenyl, alkynyl, or aryl group). A hydrocarbon group may be a group having a valence of 1 or greater formed by removing a hydrogen atom (e.g., at least one hydrogen atom) from an alkane, alkene, alkyne, or aromatic hydrocarbon. In a hydrocarbon group, a methylene group (e.g., at least one methylene group) may be replaced by an oxygen moiety, a carbonyl moiety, an ester moiety, -NH-, or a combination thereof.

[0092] Here, "aliphatic" may refer to a saturated or unsaturated straight chain or branched hydrocarbon group. For example, an aliphatic group may be an alkyl group, an alkenyl group, or an alkynyl group.

[0093] As used herein, "alkyl" refers to a straight-chain or branched saturated monovalent hydrocarbon group (methyl, ethyl, hexyl, etc.). As used herein, "alkenyl" refers to a straight-chain or branched monovalent hydrocarbon group having one or more carbon-carbon double bonds. As used herein, "alkynyl" refers to a straight-chain or branched monovalent hydrocarbon group having one or more carbon-carbon triple bonds.

[0094] Here, "aromatic" refers to an organic compound or group including an unsaturated cyclic group (e.g., at least one unsaturated cyclic group with delocalized π electrons) with delocalized π electrons. The term includes both hydrocarbon aromatics and heteroaromatics. As used herein, "aryl" refers to a group (e.g., phenyl or naphthyl) formed by removing hydrogen (e.g., at least one hydrogen) from an aromatic hydrocarbon. As used herein, "hetero" refers to one or more (e.g., 1-3) heteroatoms including the following: N, O, S, Si, P, or a combination thereof.

[0095] Hereinafter, the value of the work function, conduction band, or LUMO (or valence band or HOMO) energy level is expressed as an absolute value from the vacuum energy level. In addition, when the work function or energy level is referred to as "deep", "high", or "large", the work function or energy level has a large absolute value based on the vacuum energy level "0 eV", and when the work function or energy level is referred to as "shallow", "low", or "small", the work function or energy level has a small absolute value based on the vacuum energy level "0 eV".

[0096] In embodiments, the HOMO energy level and / or LUMO energy level described herein may be a value measured by photoelectron spectroscopy in air (e.g., a photoelectron spectrometer, model name AC3 manufactured by Riken Keiki Co. Ltd.) or a value measured by using UPS (UV absorption (optical band gap)).

[0097] In measurements involving photoelectron spectroscopy, when the photoelectron output is plotted on X / Y axes (with the horizontal axis as applied UV energy and the vertical axis as normalized photoelectron yield), the result is a curve that rises with a specific degree of inclination, and the HOMO level is the value at which the baseline intersects a straight line drawn from points in the rising slope region. Normalized photoelectron yield, (yield) n It is the ratio of photoelectron production achieved per unit of UV energy applied to the sample surface, “n” represents the intensity of the applied UV energy and has a value of about 0.3 to 1 (eg, 0.33).

[0098] The quantum yield (QY) can be easily and reproducibly measured using commercially available equipment (e.g., from Hitachi Co. Ltd or Hamamatsu Co. Ltd) and with reference to the instruction manual provided by the manufacturer. In an embodiment, the quantum efficiency can be measured by any method known to those of ordinary skill in the art. For example, the quantum efficiency can be measured by an absolute method or a relative method. The absolute method directly obtains the quantum yield by detecting the fluorescence of all samples using an integrating sphere. In the relative method, the fluorescence intensity of a standard sample (e.g., a standard dye) can be compared with the fluorescence intensity of an unknown sample to calculate the quantum yield of the unknown sample. Depending on the photoluminescence wavelength, coumarin 153, coumarin 545, rhodamine 101 inner salt, anthracene, and rhodamine 6G can be used as standard dyes, but are not limited thereto.

[0099] The term "average" as used in this disclosure (eg, average size of quantum dots) may be a mean or a median. In embodiments, the average may be a "mean" average.

[0100] As used herein, the expression "does not include cadmium (or other harmful heavy metals)" may refer to situations where the concentration of cadmium (or harmful heavy metals) may be less than or equal to about 100 parts per million by weight (ppmw), less than or equal to about 50 ppmw, less than or equal to about 10 ppmw, less than or equal to about 1 ppmw, less than or equal to about 0.1 ppmw, less than or equal to about 0.01 ppmw, or about zero. In embodiments, substantially no cadmium (or other heavy metals) may be present, or, if present, the amount of cadmium (or other heavy metals) may be less than or equal to the detection limit of a given analytical tool (e.g., inductively coupled plasma atomic emission spectrometry) or as an impurity level thereof.

[0101] When present as a luminescent material, quantum dots can contribute to increased luminous efficiency and improved color reproducibility of a light-emitting device. A display device based on electroluminescence (hereinafter, an electroluminescent display device) can be driven without an external light source. The electroluminescent display device includes a light-emitting device containing an electroluminescent material, in which electrons and holes injected from a first electrode and a second electrode are combined in a light-emitting layer to form excitons, and the excitons emit light. (See Figure 1 )

[0102] Hereinafter, a light emitting device according to an embodiment is described with reference to the accompanying drawings.

[0103] Figure 2 is a cross-sectional view of a light emitting device according to a non-limiting embodiment. Figure 2According to an embodiment, the light-emitting device 10 includes electrodes (a first electrode and a second electrode) spaced apart and each having a surface opposite to the other, and a light-emitting film 13 including a plurality of quantum dots disposed between the electrodes. A charge assisting layer may be disposed between the light-emitting film 13 and the electrodes. If the first electrode 11 is an anode and the second electrode 15 is a cathode, a hole assisting layer 12 that assists in the movement (transport / injection) of holes may be disposed between the first electrode and the light-emitting film, and an electron assisting layer 14 that assists in the movement (transport / injection) of electrons may be disposed between the second electrode and the light-emitting film.

[0104] In an embodiment, the light emitting device may include a substrate (not shown). The substrate may be provided on the first electrode 11 (eg, the main surface of the first electrode 11) or may be provided on the second electrode 15 (eg, the main surface of the second electrode 15). In an embodiment, the substrate may be provided on Figure 2 In an embodiment, the substrate may be disposed on the opposite side of the first electrode (e.g., below the first electrode). Figure 2 The substrate may be disposed on the opposite side of the second electrode 15 (e.g., above the second electrode). The substrate may be a substrate comprising an insulating material (e.g., an insulating transparent substrate). The substrate may include: glass; various polymers such as polyesters (e.g., polyethylene terephthalate (PET), polyethylene naphthalate (PEN)), polycarbonate, poly(meth)acrylate, polyimide, and poly(amide-imide); polysiloxane (e.g., PDMS); inorganic materials such as silicon, silicon oxide, and Al2O3; or combinations thereof, but are not limited thereto. Here, "transparent" refers to a transmittance of greater than or equal to about 85%, for example, greater than or equal to about 88%, greater than or equal to about 90%, greater than or equal to about 95%, greater than or equal to about 97%, or greater than or equal to about 99% for light of a predetermined wavelength (e.g., light emitted from quantum dots). The thickness of the substrate may be appropriately selected considering the substrate material, etc., but is not particularly limited. The transparent substrate may be flexible. The substrate may be omitted.

[0105] One of the first electrode 11 or the second electrode 15 may be an anode and the other may be a cathode. For example, the first electrode 11 may be an anode and the second electrode 15 may be a cathode, and vice versa.

[0106] The first electrode 11 may be made of a conductor such as a metal, a conductive metal oxide, or a combination thereof. The first electrode 11 may be made of, for example: a metal such as nickel, platinum, vanadium, chromium, copper, zinc, and gold, or an alloy thereof; a conductive metal oxide such as zinc oxide, indium oxide, tin oxide, indium tin oxide (ITO), indium zinc oxide (IZO), or fluorine-doped tin oxide; or a combination of a metal and an oxide such as ZnO and Al, or SnO2 and Sb; and the like, but not limited thereto. In an embodiment, the first electrode may include a transparent conductive metal oxide such as indium tin oxide. The work function of the first electrode may be higher than the work function of the second electrode to be described later. The work function of the first electrode may be lower than the work function of the second electrode to be described later.

[0107] The second electrode 15 may be made of a conductor such as a metal, a conductive metal oxide, and / or a conductive polymer. The second electrode 15 may be, for example, a metal such as aluminum, magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, silver, tin, lead, cesium, or barium, or an alloy thereof; a multilayer structure of materials such as LiF / Al, Li2O / Al, Liq / Al, LiF / Ca, and BaF2 / Ca, but is not limited thereto. In an embodiment, the second electrode may include a transparent conductive metal oxide such as indium tin oxide. The conductive metal oxide is the same as described above.

[0108] In an embodiment, the work function of the first electrode (e.g., anode) may be greater than or equal to about 4.0 electron volts (eV), greater than or equal to about 4.1eV, greater than or equal to about 4.2eV, greater than or equal to about 4.3eV, greater than or equal to about 4.4eV, greater than or equal to about 4.5eV, greater than or equal to about 4.6eV, greater than or equal to about 4.7eV, or greater than or equal to about 4.8eV and less than or equal to about 5.5eV, less than or equal to about 5.4eV, less than or equal to about 5.3eV, less than or equal to about 5.2eV, less than or equal to about 5.1eV, less than or equal to about 5.0eV, or less than or equal to about 4.9eV, but is not limited thereto.

[0109] The work function of the second electrode (e.g., cathode) may be greater than or equal to about 3.4 eV, for example, greater than or equal to about 3.5 eV, greater than or equal to about 3.6 eV, greater than or equal to about 3.7 eV, greater than or equal to about 3.8 eV, greater than or equal to about 3.9 eV, greater than or equal to about 4.0 eV, greater than or equal to about 4.1 eV, greater than or equal to about 4.2 eV, greater than or equal to about 4.3 eV, greater than or equal to about 4.4 eV, or greater than or equal to about 4.5 eV and less than or equal to about 5.0 eV, less than or equal to about 4.9 eV, less than or equal to about 4.8 eV, less than or equal to about 4.7 eV, less than or equal to about 4.6 eV, less than or equal to about 4.5 eV, or less than or equal to about 4.4 eV, but is not limited thereto.

[0110] At least one of the first electrode 11 and the second electrode 15 may be a light-transmitting electrode, and the light-transmitting electrode may be made of, for example, a conductive oxide such as zinc oxide, indium oxide, tin oxide, indium tin oxide (ITO), indium zinc oxide (IZO), or fluorine-doped tin oxide, or a single or multiple metal thin layers. If one of the first electrode 11 or the second electrode 15 is a non-light-transmitting electrode, the electrode may be made of, for example, an opaque conductor such as aluminum (Al), silver (Ag), or gold (Au).

[0111] The thickness of the electrode (the first electrode and / or the second electrode) is not particularly limited and can be appropriately selected in consideration of device efficiency. For example, the thickness of the electrode can be greater than or equal to about 5 nanometers (nm), for example, greater than or equal to about 50 nm, or greater than or equal to about 100 nm. For example, the thickness of the electrode can be less than or equal to about 100 μm, for example, less than or equal to about 10 μm, less than or equal to about 1 μm, less than or equal to about 900 nm, less than or equal to about 500 nm, less than or equal to about 400 nm, less than or equal to about 300 nm, less than or equal to about 200 nm, or less than or equal to about 100 nm.

[0112] In the device of the embodiment, the light-emitting film includes a fluorine-containing organic salt and a plurality of quantum dots. As used herein, the term "fluorine-containing organic salt" may include the salt itself or its residue (e.g., a residue of a fluorine-containing organic salt). The quantum dots do not include cadmium, lead, or a combination thereof. The fluorine-containing organic salt includes at least one of boron and phosphorus (e.g., boron, phosphorus, or boron and phosphorus), a substituted or unsubstituted C1-C30 (e.g., aliphatic or aromatic) hydrocarbon group, a non-metallic element (e.g., capable of forming In an embodiment, the "substituted or unsubstituted C1-C30 hydrocarbon group" may be a C1-C30 hydrocarbon group that may be unsubstituted or substituted with at least one substituent, for example, one or more groups having 1 to 30 carbon atoms. The non-metallic elements of the salt include carbon, nitrogen, oxygen, phosphorus, sulfur, or selenium. The HOMO energy level of the light-emitting film may be greater than or equal to about 5.7 eV. Salts may include carbon Salt, ammonium salt, oxygen Salt, salt, sulfonium salt, or salt, or a combination thereof.

[0113] The luminescent film may be configured to emit red light, green light, or blue light. If the luminescent film emits red light, the HOMO energy level of the luminescent film may be greater than or equal to about 5.7 eV, for example, greater than or equal to about 5.8 eV, greater than or equal to about 5.9 eV, or greater than or equal to about 5.95 eV. If the luminescent film emits green light, the HOMO energy level of the luminescent film may be greater than or equal to about 5.7 eV, for example, greater than or equal to about 5.8 eV, greater than or equal to about 5.9 eV, or greater than or equal to about 5.95 eV. If the luminescent film emits blue light, the HOMO energy level of the luminescent film may be greater than or equal to about 5.9 eV, for example, greater than or equal to about 5.95 eV, or greater than or equal to about 6.0 eV.

[0114] A quantum dot light-emitting device (hereinafter also referred to as a QD-LED) can emit light by applying a voltage to the device, and includes quantum dots as a light-emitting material. QD-LED is based on an emission principle different from that of an organic light-emitting diode (OLED), which uses an organic material as an emission center. The QD-LED can achieve pure colors (red, green, blue) with improved color reproducibility, and therefore, has gained attention and attention as a next-generation display device. QD-LED can be manufactured at a reduced cost by including a solution process, and can be expected to achieve increased stability because it is based on inorganic materials. Therefore, research and technological development for improving the optical properties and / or life characteristics of QD-LED is still ongoing and has significant commercial benefits.

[0115] In a non-limiting embodiment, the energy level diagram of a light emitting device (e.g., an electroluminescent device) having a quantum dot light emitting layer is shown in FIG. Figure 1 Reference Figure 1 During operation of the device, holes are injected from the anode (e.g., ITO) and may be transported across the HOMO of the hole transport layer (HTL) and the hole injection layer (HIL) and reach the HOMO of the light-emitting layer. Electrons are injected from the cathode (e.g., Al) and move along the LUMO of the electron transport layer (ETL) and reach the LUMO of the light-emitting layer, and the holes and electrons recombine in the light-emitting layer to emit light. During operation of the light-emitting device, charge accumulation may occur due to defects that may exist in the active region (e.g., in the light-emitting film). Charge accumulation may cause variable current-voltage (IV) characteristics of the device, which may have a negative impact on device reliability or lifetime characteristics.

[0116] In QD-LED devices, quantum dots, which typically have a large surface area relative to their corresponding bulk (bulk) composition counterparts, can be arranged in the form of a film. As a result, QD-LEDs can tend to have defects, for example, on the surface of the quantum dots, at or near the interface between the hole assist layer and the light-emitting film (or layer), and at or near the interface between the electron assist layer and the light-emitting layer. These defects can act as charge traps within the device, leading to charge accumulation and a consequent loss of the luminescent properties of the quantum dots. The inventors have found that the accumulated charge can cause a non-uniform charge distribution within the device and undesirable changes in the hole or electron resistance of the device, and therefore a consequent increase in the driving voltage of the device. The result is a deterioration in the luminescence and operating properties of the device.

[0117] Ligand exchange of individual quantum dots can enhance the passivation of the quantum dot surface. For example, ligand exchange with thiol compounds can improve the (photo)luminescence properties of the quantum dots. However, the inventors have discovered that the insulating properties of organic ligands can further limit the performance improvements of electroluminescent devices. Additionally, in electroluminescent devices, thiol ligands disposed on the surface of quantum dots can form disulfide bonds, particularly if a voltage is applied to the device, and thus, the thiol ligands can more easily detach from the quantum dot surface.

[0118] Halogen-based inorganic ligands can be used to further passivate the surface of individual quantum dots. The bond between the metal and the halide on the surface of the quantum dots can be expected to have a desired effect on the luminescent properties of the quantum dots. However, the present inventors have found that passivating the quantum dots with halogen-based inorganic ligands (e.g., metal halides) can cause significant degradation (e.g., degradation of the polymer) in adjacent structural layers (e.g., hole transport layers) and can have an adverse effect on the lifetime characteristics of the device.

[0119] In some cases, inserting an insulator interlayer between the light-emitting layer and the electron transport layer (ETL) can address exciton quenching or improve the hole-electron injection balance in the device. However, providing a uniform, thin insulating interlayer film can be technically difficult, and as a result, an increase in resistance can be expected with increased thickness, which can have additional adverse effects on device performance characteristics. When forming an interlayer film between a light-emitting film and a hole transport layer, uniformity of the interlayer can be difficult to achieve, and can pose additional challenges to forming a light-emitting film on the interlayer.

[0120] In the light-emitting device according to the embodiment, the quantum dots in the light-emitting film may have additional passivation provided by the fluorine-containing organic salt compound (e.g., the salt compound itself or its residue that may be formed therein), even when there is substantially no intermediate layer between the light-emitting layer and the adjacent structural layer (e.g., typical layers such as HTL and / or ETL). The device may exhibit improved physical properties such as improved light-emitting properties, increased lifetime, (thermal) stability, etc.

[0121] Thus, in the device of the embodiment, the light-emitting film includes a plurality of quantum dots and a fluorine-containing organic salt (e.g., the salt compound itself or a residue thereof that may be formed therein). The quantum dots may form (e.g., constitute) at least a portion of the surface of the light-emitting film. The light-emitting film may exhibit increased hole transport capability. The light-emitting film may exhibit improved thermal stability.

[0122] In an embodiment, the quantum dot may have a core-shell structure. The quantum dot may include a core and a shell disposed on the core, wherein the core includes a first semiconductor nanocrystal and the shell includes a second semiconductor nanocrystal having a composition different from that of the first semiconductor nanocrystal.

[0123] The quantum dots (e.g., the first semiconductor nanocrystal and / or the second semiconductor nanocrystal) may include a II-VI compound, a III-V compound, an IV-VI compound, a IV element or compound, a I-III-VI compound, an I-II-IV-VI compound, or a combination thereof. The luminescent film (or the quantum dots, the first semiconductor nanocrystal, or the second semiconductor nanocrystal) may not include harmful heavy metals such as cadmium, lead, mercury, or a combination thereof.

[0124] The II-VI compound may include a binary compound including ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, or a mixture thereof; a ternary compound including ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, or a mixture thereof; or a quaternary compound including HgZnTeS, HgZnSeS, HgZnSeTe, HgZnSTe, or a mixture thereof. The II-VI compound may further include a Group III metal.

[0125] The III-V compound may include a binary compound comprising GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, or a mixture thereof; a ternary compound comprising GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNPs, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, or a mixture thereof; or a quaternary compound comprising GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, or a mixture thereof. The III-V compound may further include a Group II element. An example of such a semiconductor nanocrystal may be InZnP.

[0126] The IV-VI group compound may include: a binary compound including SnS, SnSe, SnTe, or a mixture thereof; a ternary compound including SnSeS, SnSeTe, SnSTe, or a mixture thereof; or a quaternary compound including SnSSeTe.

[0127] Examples of the Group I-III-VI compound may include CuInSe 2 , CuInS 2 , CuInGaSe, or CuInGaS, but are not limited thereto.

[0128] Examples of the Group I-II-IV-VI compound may include CuZnSnSe or CuZnSnS, but are not limited thereto.

[0129] The Group IV element or compound may include: a single element (element) including Si, Ge, or a combination thereof; or a binary compound including SiC, SiGe, or a mixture thereof.

[0130] In an embodiment, the first semiconductor nanocrystal may include a metal and a non-metal, the metal including indium, zinc, or a combination thereof, and the non-metal including phosphorus, selenium, tellurium, sulfur, or a combination thereof. In an embodiment, the second semiconductor nanocrystal may include a metal and a non-metal, the metal including indium, zinc, or a combination thereof, and the non-metal including phosphorus, selenium, tellurium, sulfur, or a combination thereof.

[0131] In an embodiment, the first semiconductor nanocrystal may comprise InP, InZnP, ZnSe, ZnSeS, ZnSeTe, or a combination thereof, and / or the second semiconductor nanocrystal may comprise ZnSe, ZnSeS, ZnS, ZnTeSe, or a combination thereof. In an embodiment, the shell may comprise zinc, sulfur, and optionally selenium in the outermost layer.

[0132] In an embodiment, the quantum dots may emit blue or green light and have a core comprising ZnSeTe, ZnSe, or a combination thereof and a shell comprising a zinc chalcogenide (e.g., ZnS, ZnSe, and / or ZnSeS). In the shell, the amount of sulfur may increase or decrease in a radial direction (from the core toward the surface).

[0133] In an embodiment, the quantum dot emits red light or green light, and the core may include InP, InZnP, or a combination thereof. Also, the shell may include: a Group II metal including zinc, and a non-metal including at least one of sulfur and selenium.

[0134] In an embodiment, if the quantum dot has a core-shell structure, an alloyed intermediate layer may or may not be present at or near the interface between the core and the shell. The alloyed layer may include a uniform alloy, a composition concentration gradient alloy, or a combination thereof. The gradient alloy may have a concentration gradient in which the concentration of the element of the shell changes radially (e.g., decreases or increases toward the core).

[0135] In an embodiment, the shell may have a composition that changes in a radial direction. In an embodiment, the shell may be a multilayer shell comprising two or more layers. In the multilayer shell, two adjacent layers may have compositions that are different from each other. In the multilayer shell, at least one layer may independently include semiconductor nanocrystals having a single composition. In the multilayer shell, at least one layer may independently have alloyed semiconductor nanocrystals. In the multilayer shell, at least one layer may have a concentration gradient that changes in the radial direction with respect to the composition of the semiconductor nanocrystals.

[0136] In core-shell quantum dots, the material of the shell may have a band gap larger than the band gap of the core, but is not limited thereto. The material of the shell may have a band gap smaller than the band gap of the core, but is not limited thereto. In the case of a multilayer shell, the band gap of the outermost layer material of the shell may be larger than the band gap of the core and the inner layer material of the shell (the layer closer to the core). In the case of a multilayer shell, the semiconductor nanocrystals of each layer are selected to have an appropriate band gap, thereby effectively showing the quantum confinement effect.

[0137] Quantum dots of embodiments may include organic ligands, for example, bound to or coordinated on a surface.

[0138] The organic ligand may include RCOOH, RNH2, R2NH, R3N, RSH, R3PO, R3P, ROH, RCOOR, RPO(OH)2, RHPOOH, R2POOH, or a combination thereof. Here, each R is independently a substituted or unsubstituted C3-C40 aliphatic hydrocarbon group (e.g., alkyl, alkenyl, alkynyl, etc.), a substituted or unsubstituted C6-C40 aromatic hydrocarbon group (aryl), or a combination thereof.

[0139] Examples of the organic ligand may be: a thiol compound such as methyl mercaptan, ethyl mercaptan, propyl mercaptan, butyl mercaptan, pentyl mercaptan, hexyl mercaptan, octyl mercaptan, dodecyl mercaptan, hexadecyl mercaptan, octadecyl mercaptan, or benzyl mercaptan; an amine such as methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, octylamine, nonylamine, decylamine, dodecylamine, hexadecylamine, octadecylamine, dimethylamine, diethylamine, dipropylamine, tributylamine, or trioctylamine; a carboxylic acid compound 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, myristic acid, stearic acid, lauric acid, or benzoic acid; a phosphine; Compounds such as methyl phosphine, ethyl phosphine, propyl phosphine, butyl phosphine, pentyl phosphine, octyl phosphine, dioctyl phosphine, tributyl phosphine, or trioctyl phosphine; phosphine compounds or oxide compounds thereof such as methyl phosphine oxide, ethyl phosphine oxide, propyl phosphine oxide, butyl phosphine oxide, pentyl phosphine oxide, tributyl phosphine oxide, octyl phosphine oxide, dioctyl phosphine oxide, or trioctyl phosphine oxide; diphenyl phosphine, triphenyl phosphine compounds, or oxide compounds thereof; C5-C20 alkyl phosphinic acid or C5-C20 alkyl phosphinic acid such as hexyl phosphinic acid, octyl phosphinic acid, dodecane phosphinic acid, tetradecane phosphinic acid, hexadecane phosphinic acid, or octadecane phosphinic acid; and the like, but are not limited thereto.

[0140] The absorption / emission wavelength of the quantum dots can be adjusted by adjusting the composition and / or size of the quantum dots. The maximum emission peak wavelength of the quantum dots may have a wavelength in the range of ultraviolet to infrared wavelengths or higher. For example, the maximum emission peak wavelength of the quantum dots may be greater than or equal to about 300 nm, for example, greater than or equal to about 500 nm, greater than or equal to about 510 nm, greater than or equal to about 520 nm, greater than or equal to about 530 nm, greater than or equal to about 540 nm, greater than or equal to about 550 nm, greater than or equal to about 560 nm, greater than or equal to about 570 nm, greater than or equal to about 580 nm, greater than or equal to about 590 nm, greater than or equal to about 600 nm, or greater than or equal to about 610 nm. The maximum emission peak wavelength of the quantum dot may be less than or equal to about 800 nm, for example, less than or equal to about 700 nm, less than or equal to about 650 nm, less than or equal to about 640 nm, less than or equal to about 630 nm, less than or equal to about 620 nm, less than or equal to about 610 nm, less than or equal to about 600 nm, less than or equal to about 590 nm, less than or equal to about 580 nm, less than or equal to about 570 nm, less than or equal to about 560 nm, less than or equal to about 550 nm, or less than or equal to about 540 nm. The maximum emission wavelength of the quantum dot may be in the range of about 500 nm to about 650 nm.

[0141] The quantum dots may emit green light, and the maximum emission wavelength may be within a range of greater than or equal to about 500 nm (e.g., greater than or equal to about 510 nm) and less than or equal to about 560 nm (e.g., less than or equal to about 540 nm). The quantum dots may emit red light, and the maximum emission wavelength may be within a range of greater than or equal to about 600 nm (e.g., greater than or equal to about 610 nm) and less than or equal to about 650 nm (e.g., less than or equal to about 640 nm). The quantum dots may emit blue light, and the maximum emission wavelength may be within a range of greater than or equal to about 440 nm (e.g., greater than or equal to about 450 nm) and less than or equal to about 480 nm (e.g., less than or equal to about 465 nm).

[0142] The quantum dots may exhibit a photoluminescence spectrum having a relatively narrow full width at half maximum (FWHM). In embodiments, the quantum dots may have a full width at half maximum (FWHM) of about 45 nm or less, such as about 44 nm or less, about 43 nm or less, about 42 nm or less, about 41 nm or less, about 40 nm or less, about 39 nm or less, about 38 nm or less, about 37 nm or less, about 36 nm or less, or about 35 nm or less in the photoluminescence spectrum.

[0143] The quantum dots may have (e.g., may be configured to achieve) a quantum yield of greater than or equal to about 10%, such as greater than or equal to about 20%, greater than or equal to about 30%, greater than or equal to about 40%, greater than or equal to about 50%, greater than or equal to about 60%, 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%.

[0144] The quantum dots may have a size (e.g., an average size) greater than or equal to about 1 nm and less than or equal to about 100 nm (e.g., a particle diameter, or a particle diameter calculated from a two-dimensional area confirmed by electron microscopy analysis in the case of non-spherical particles). In an embodiment, the quantum dots may have an average size of about 1 nm to about 50 nm, for example, about 2 nm (or about 3 nm) to about 35 nm. In an embodiment, the quantum dots may have a size (e.g., an average size) 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. In an embodiment, the quantum dots may have a size (e.g., an average size) less than or equal to about 50 nm, less than or equal to about 40 nm, less than or equal to about 30 nm, less than or equal to about 25 nm, less than or equal to about 20 nm, less than or equal to about 19 nm, less than or equal to about 18 nm, less than or equal to about 17 nm, less than or equal to about 16 nm, or less than or equal to about 15 nm.

[0145] The quantum dots may have any shape. In embodiments, the shapes of the quantum dots may include spheres, polyhedra, pyramids, multipods, cubes, nanotubes, nanowires, nanofibers, nanosheets, nanoplates, or combinations thereof.

[0146] The quantum dots can be synthesized by any method. For example, several nanometer-sized semiconductor nanocrystals (such as quantum dots) can be synthesized by wet chemical processes. In the wet chemical process, nanocrystalline particles (such as quantum dots) are grown by reacting precursor materials in an organic solvent, and the growth of nanocrystals can be controlled by coordinating the organic solvent or ligand compound on the surface of the semiconductor nanocrystal. The semiconductor nanocrystals can be collected by the following process: the quantum dot product mixture is poured into an excess non-solvent to remove the excess organic material that is not coordinated to the surface, and the obtained mixture is centrifuged to separate the quantum dots. Specific examples of the non-solvent can include acetone, ethanol, and methanol, but are not limited to this.

[0147] The fluorine-containing organic salt (or its residue) included in the light-emitting film can contribute to the improvement of the performance / lifespan of the device. The fluorine-containing organic salt (or its residue) can be bound to the quantum dots (or on the surface of the quantum dots). The colloidally synthesized quantum dots have ligands with aliphatic chains on the surface, which are used for dispersibility, etc., but act as insulators in the device. In addition, the present inventors have found that it can be difficult for compounds based on fluorine inorganic salts (e.g., ZnF2) and the like to achieve (or exhibit or provide) the desired level of solubility. In addition, the present inventors have found that fluoride anions including boron or phosphorus (e.g., BF4 - PF6 - ) and metal portions may not provide quantum dots with substantial passivation and may result in only a very limited level of lifetime improvement (or essentially no lifetime improvement).

[0148] The present inventors have also found that (inorganic) acids with fluoride anions (eg, HBF4) or nitrosyl BF4 can cause substantial damage to the film and / or can lead to a significant decrease in the photoluminescence quantum efficiency (PL QY) of the quantum dots.

[0149] In contrast, in the device of the embodiment, the fluorine-containing organic salt can provide passivation, for example, by reacting with the surface of the quantum dots to passivate the surface of the quantum dots (e.g., even in a relatively simple process). Without wishing to be bound by any theory, it is believed that the fluorine-containing organic salt can provide a desired (e.g., necessary or relatively high) degree of reactivity for the surface exchange of quantum dots, while the surface exchange can not lead to (e.g., generate) additional defect levels in the quantum dots.

[0150] The fluorine-containing organic salt includes at least one of boron or phosphorus (e.g., B, P, or a combination thereof), a C1-C30 substituted or unsubstituted C1-C30 hydrocarbon group, a non-metallic element (e.g., a metal capable of forming Salt), and fluorine. For example, it can form The non-metallic elements of the salt include carbon, nitrogen, oxygen, phosphorus, sulfur, selenium, or combinations thereof.

[0151] The substituted or unsubstituted C1-C30 hydrocarbon group can be a C1 or greater, C5 or greater, C10 or greater, or C15 or greater and C30 or less, C25 or less, C20 or less, C15 or less, C10 or less, or C5 or less aliphatic hydrocarbon group (alkyl, alkenyl, or alkynyl). The substituted or unsubstituted C1-C30 hydrocarbon group can be a C6-C30 aromatic hydrocarbon group, for example, a phenyl or naphthyl. The substituted or unsubstituted C1-C30 hydrocarbon group can be a C3-C30 alicyclic hydrocarbon group such as a cyclohexyl. The carbon number of the hydrocarbon group can be 2 or greater, 3 or greater, 4 or greater, 5 or greater, or 6 or greater. The carbon number of the hydrocarbon group can be 30 or less, 25 or less, 20 or less, 15 or less, 10 or less, or 5 or less. The hydrocarbon group can be an alkyl group, an alkenyl group, an alkynyl group, an aryl group such as a naphthyl group, a heteroaryl group, an alicyclic group, or a combination thereof.

[0152] In an embodiment, the fluorine-containing organic salt (or its anion) may include fluoroborate, fluorophosphate, or a combination thereof. The anion of the fluorine-containing organic salt may be tetrafluoroborate, hexafluorophosphate, or a combination thereof. The fluorine-containing organic salt may have For example, the fluorine-containing organic salt may include carbon Part, oxygen part, ammonium part, part, or a combination thereof.

[0153] The fluorine-containing organic salt may be (R) x A + B - , wherein R is a substituted or unsubstituted C1-C30 aliphatic or aromatic hydrocarbon group, A is C, N, O, P, S, or Se, x is an integer of 1 or greater determined according to the valence of A, and B can be composed of BF4 - or PF6 - express.

[0154] In an embodiment, the fluorine-containing organic salt may be a salt including: R5C + 、R4N + 、R3O + 、R3S + 、R3Se + , or R4P + , wherein R is the same or different and is a C1-C10 aliphatic hydrocarbon group (e.g., alkyl, alkenyl, alkynyl), a C6-C20 aromatic hydrocarbon group, a C3-C30 alicyclic hydrocarbon group, or a combination thereof. The fluorine-containing organic salt may include trialkyloxytetrafluoroborate (e.g., trimethyloxytetrafluoroborate ), tetraalkylammonium tetrafluoroborate (e.g., tetraethylammonium tetrafluoroborate), trialkyloxy hexafluorophosphate (For example, triethyl hexafluorophosphate ), or a combination thereof.

[0155] The amount of quantum dots and the amount of fluorine-containing organic salt in the film can be adjusted so that the luminescent film can exhibit a desired composition. The composition of the luminescent film can be confirmed by appropriate means (e.g., energy dispersive spectroscopy based on an electron microscope, such as TEM-EDX or SEM EDX).

[0156] In embodiments, the light emitting film may include boron, and a molar ratio of boron to carbon may be greater than or equal to about 0.001:1, greater than or equal to about 0.005:1, greater than or equal to about 0.01:1, greater than or equal to about 0.05:1, greater than or equal to about 0.1:1, greater than or equal to about 0.2:1, greater than or equal to about 0.3:1, greater than or equal to about 0.4:1, greater than or equal to about 0.5:1, greater than or equal to about 0.6:1, greater than or equal to about 0.7:1, greater than or equal to about 0.8:1, greater than or equal to about 0.9:1, or greater than or equal to about 1:1. The molar ratio of boron to carbon may be less than or equal to about 0.6:1, less than or equal to about 0.5:1, or less than or equal to about 0.4:1, for example, as measured by energy dispersive spectroscopy of the light emitting film.

[0157] In embodiments, the luminescent film may include phosphorus, and a molar ratio of phosphorus to carbon may be greater than or equal to about 0.001:1, greater than or equal to about 0.005:1, greater than or equal to about 0.01:1, greater than or equal to about 0.05:1, greater than or equal to about 0.1:1, greater than or equal to about 0.2:1, greater than or equal to about 0.3:1, greater than or equal to about 0.4:1, greater than or equal to about 0.5:1, greater than or equal to about 0.6:1, greater than or equal to about 0.7:1, greater than or equal to about 0.8:1, greater than or equal to about 0.9:1, or greater than or equal to about 1:1. The molar ratio of phosphorus to carbon may be less than or equal to about 0.6:1, less than or equal to about 0.5:1, or less than or equal to about 0.4:1, for example, as measured by energy dispersive spectroscopy of the luminescent film.

[0158] In embodiments of the light-emitting film including boron, the molar ratio of fluorine to boron may be greater than or equal to about 4:1, or about 4.5:1. In embodiments of the light-emitting film, the molar ratio of fluorine to boron may be less than or equal to about 6:1, less than or equal to about 5.5:1, or less than or equal to about 5:1. The molar ratio of fluorine to boron can be measured by energy dispersive spectroscopy of the light-emitting film.

[0159] The quantum dots may include zinc and a chalcogen (e.g., sulfur, selenium, or sulfur and selenium), and the molar ratio of carbon relative to the total moles of zinc and chalcogen (e.g., sulfur, selenium, or sulfur and selenium) may be less than or equal to about 10: 1, less than or equal to about 9: 1, less than or equal to about 8: 1, less than or equal to about 7: 1, less than or equal to about 6: 1, or less than or equal to about 5: 1. The molar ratio of carbon relative to the total moles of zinc and chalcogen (e.g., sulfur, selenium, or sulfur and selenium) may be greater than or equal to about 1: 1, greater than or equal to about 2: 1, greater than or equal to about 3: 1, greater than or equal to about 4: 1, or greater than or equal to about 5: 1, for example, as measured by energy dispersive spectroscopy of the light emitting film.

[0160] In embodiments, in the light-emitting film, a molar ratio of carbon to a metal (e.g., zinc) included in the quantum dots may be greater than or equal to about 1:1, greater than or equal to about 2:1, 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, or greater than or equal to about 8: 1. The molar ratio of carbon to a metal (e.g., zinc) included in the quantum dots may be less than or equal to about 20:1, less than or equal to about 15:1, less than or equal to about 10:1, less than or equal to about 9:1, less than or equal to about 8:1, less than or equal to about 7:1, less than or equal to about 6:1, less than or equal to about 5:1, or less than or equal to about 4:1, for example, as measured by energy dispersive spectroscopy of the light-emitting film.

[0161] The light-emitting film may have a thickness of about 5 nanometers (nm) or greater, such as about 6 nm or greater, about 7 nm or greater, about 8 nm or greater, about 9 nm or greater, about 10 nm or greater, about 11 nm or greater, about 12 nm or greater, about 13 nm or greater, about 14 nm or greater, about 15 nm or greater, about 16 nm or greater, about 17 nm or greater, about 18 nm or greater, about 19 nm or greater, about 20 nm or greater, about 21 nm or greater, about 22 nm or greater, about 23 nm or greater, about 24 nm or greater, about 25 nm or greater, about 30 nm or greater, or about 35 nm or greater. The light-emitting film may include two or more quantum dot monolayers. The luminescent film may have a thickness of less than or equal to about 100 nm, for example, less than or equal to about 90 nm, less than or equal to about 80 nm, less than or equal to about 70 nm, less than or equal to about 60 nm, less than or equal to about 50 nm, less than or equal to about 40 nm, less than or equal to about 35 nm, less than or equal to about 30 nm, or less than or equal to about 25 nm.

[0162] In an embodiment, at least a portion of the surface of the light-emitting film (or the surface of the light-emitting film) may not include a thiol compound (e.g., a thiol compound bound to the plurality of quantum dots). The thiol compound may be a monothiol compound, a cis-dithiol compound, or a combination thereof.

[0163] The plurality of quantum dots may further include a carboxylic acid compound on its surface. The carboxylic acid compound may be an organic ligand originally present on the surface of the quantum dots. The carboxylic acid compound may include a C6-C30 aliphatic carboxylic acid compound. The carboxylic acid compound may include a ligand derived from a compound represented by RCOOH (wherein R is a C12 or greater alkyl or a C12 or greater alkenyl) in a limited amount.

[0164] The light-emitting film may be disposed on a substrate. The substrate may include an electrode, a hole auxiliary layer (e.g., a hole injection layer, a hole transport layer, or a combination thereof), an electron auxiliary layer, or a combination thereof in the light-emitting device. The substrate may be a light-transmitting or transparent substrate.

[0165] The light-emitting film may exhibit an absolute value of an energy level (e.g., HOMO and / or LUMO) that is increased compared to a light-emitting film without a fluorine-containing organic salt according to an embodiment by adopting the aforementioned configuration and / or composition of the light-emitting film. Therefore, the energy level thus adjusted can reduce the barrier to the flow of charge (e.g., electron flow) from an adjacent charge-assisting layer (e.g., an electron transport layer) to the light-emitting layer in the light-emitting device. Therefore, in an embodiment, the HOMO energy level of the light-emitting film of the embodiment may be greater than or equal to about 5.7 eV, greater than or equal to about 5.75 eV, greater than or equal to about 5.8 eV, greater than or equal to about 5.85 eV, greater than or equal to about 5.9 eV, greater than or equal to about 5.95 eV, greater than or equal to about 6 eV, greater than or equal to about 6.05 eV, or greater than or equal to about 6.1 eV.

[0166] The luminescent film can emit light of a desired wavelength. The wavelength (or center wavelength, hereinafter referred to as wavelength) of the emitted light (of the maximum luminescence peak) can be greater than or equal to about 430 nm, greater than or equal to about 440 nm, greater than or equal to about 450 nm, greater than or equal to about 460 nm, greater than or equal to about 470 nm, greater than or equal to about 480 nm, greater than or equal to about 490 nm, greater than or equal to about 500 nm, greater than or equal to about 510 nm, greater than or equal to about 520 nm, greater than or equal to about 530 nm, greater than or equal to about 540 nm, greater than or equal to about 550 nm, greater than or equal to about 560 nm, greater than or equal to about 570 nm, greater than or equal to about 580 nm, greater than or equal to about 590 nm, greater than or equal to about 600 nm, greater than or equal to about 610 nm, greater than or equal to about 620 nm, greater than or equal to about 630 nm, greater than or equal to about 640 nm, or greater than or equal to about 650 nm. The wavelength of the emitted light may be less than or equal to about 750 nm, less than or equal to about 740 nm, less than or equal to about 730 nm, less than or equal to about 720 nm, less than or equal to about 710 nm, less than or equal to about 700 nm, less than or equal to about 690 nm, less than or equal to about 680 nm, less than or equal to about 670 nm, less than or equal to about 660 nm, less than or equal to about 650 nm, less than or equal to about 640 nm, less than or equal to about 630 nm, less than or equal to about 620 nm, less than or equal to about 610 nm. m, less than or equal to about 600 nm, less than or equal to about 590 nm, less than or equal to about 580 nm, less than or equal to about 570 nm, less than or equal to about 560 nm, less than or equal to about 550 nm, less than or equal to about 540 nm, less than or equal to about 530 nm, less than or equal to about 520 nm, less than or equal to about 510 nm, less than or equal to about 500 nm, less than or equal to about 490 nm, less than or equal to about 480 nm, less than or equal to about 470 nm, or less than or equal to about 460 nm.

[0167] The emitted light may be red light, green light, blue light, or amber (or orange) light.

[0168] The wavelength of the red light may be greater than or equal to about 590 nm, greater than or equal to about 600 nm, greater than or equal to about 610 nm, greater than or equal to about 620 nm, greater than or equal to about 630 nm, greater than or equal to about 640 nm, or greater than or equal to about 650 nm. The wavelength of the red light may be less than or equal to about 750 nm, less than or equal to about 740 nm, less than or equal to about 730 nm, less than or equal to about 720 nm, or less than or equal to about 710 nm.

[0169] The wavelength of the green light may be greater than about 490 nm, greater than or equal to about 495 nm, greater than or equal to about 500 nm, greater than or equal to about 510 nm, greater than or equal to about 520 nm, greater than or equal to about 530 nm, greater than or equal to about 540 nm, or greater than or equal to about 550 nm. The wavelength of the green light may be less than or equal to about 560 nm, less than or equal to about 550 nm, less than or equal to about 540 nm, or less than or equal to about 530 nm.

[0170] The wavelength of the blue light may be greater than or equal to about 400 nm, greater than or equal to about 410 nm, greater than or equal to about 420 nm, greater than or equal to about 430 nm, greater than or equal to about 440 nm, greater than or equal to about 450 nm, or greater than or equal to about 460 nm. The wavelength of the blue light may be less than or equal to about 490 nm, less than or equal to about 480 nm, less than or equal to about 470 nm, less than or equal to about 460 nm, or less than or equal to about 450 nm.

[0171] In an embodiment, if red light is emitted, the HOMO energy level of the light emitting film may be greater than or equal to about 5.7 eV, greater than or equal to about 5.8 eV, or greater than or equal to about 5.9 eV.

[0172] In an embodiment, if the light emitting film emits green light, the HOMO energy level of the light emitting film may be greater than or equal to about 5.7 eV, greater than or equal to about 5.8 eV, or greater than or equal to about 5.9 eV.

[0173] In an embodiment, if the light emitting film emits blue light, the HOMO energy level of the light emitting film may be greater than or equal to about 5.9 eV, or greater than or equal to about 6.0 eV.

[0174] Between the LUMO and HOMO energy levels of the light-emitting film, or between the LUMO energy level (E LUMO ) and the conduction band edge energy (E) of the material capable of transporting and injecting electrons. 导带边缘 ) may be greater than or equal to about 0.5 eV, e.g., greater than or equal to about 0.6 eV, and / or less than about 1.5 eV, e.g., less than or equal to about 1 eV.

[0175] refer to Figure 2 The device of the embodiment may further include a hole auxiliary layer 12 between the anode 11 (e.g., the first electrode) and the light emitting film 13. The hole auxiliary layer 12 may be one or two or more layers and may include, for example, a hole injection layer, a hole transport layer, and / or an electron blocking layer (not shown).

[0176] The hole assisting layer 12 may have a HOMO energy level that may match the HOMO energy level of the light emitting film 13 , and as a result, migration from the hole assisting layer 12 to the light emitting film 13 may be facilitated.

[0177] The HOMO energy level of the hole auxiliary layer (e.g., hole transport layer) 12 adjacent to the light emitting film may be appropriately adjusted in consideration of the HOMO energy level of the light emitting film 13. In an embodiment, the hole auxiliary layer 12 may include a hole injection layer disposed near the first electrode 11 and a hole transport layer disposed near the light emitting film 13.

[0178] The material included in the hole auxiliary layer 12 is not particularly limited. In an embodiment, the hole auxiliary layer may exhibit relatively high hole conductivity. The material of the hole auxiliary layer may include an organic monomolecular compound, a polymer compound, or a combination thereof. For example, the material of the hole auxiliary layer may include at least one of the following: poly (9,9-dioctyl-fluorene-co-N-(4-butylphenyl)-diphenylamine) (TFB), polyarylamine (polyarylamine), poly (N-vinylcarbazole) (PVK), poly (3,4-ethylenedioxythiophene) (PEDOT), poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), polyaniline, polypyrrole, N,N,N',N'-tetrakis (4-methoxyphenyl)-benzidine (TPD), 4 ,4'-bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl (α-NPD), 4,4',4"-tris[phenyl(m-tolyl)amino]triphenylamine (m-MTDATA), 4,4',4"-tris(N-carbazolyl)-triphenylamine (TCTA), 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC), p-type metal oxides (e.g., NiO, WO3, MoO3, etc.), carbon-based materials such as graphene oxide, or combinations thereof, but not limited thereto.

[0179] For example, the hole-assisting layer (e.g., a hole transport layer, a hole injection layer, or a combination thereof) may have a thickness of greater than or equal to about 1 nm, greater than or equal to about 5 nm, greater than or equal to about 10 nm, greater than or equal to about 15 nm, greater than or equal to about 20 nm, or greater than or equal to about 25 nm and less than or equal to about 500 nm, less than or equal to about 400 nm, less than or equal to about 300 nm, less than or equal to about 200 nm, less than or equal to about 100 nm, less than or equal to about 90 nm, less than or equal to about 80 nm, less than or equal to about 70 nm, less than or equal to about 60 nm, or less than or equal to about 50 nm, but is not limited thereto.

[0180] The hole injection layer and / or the hole transport layer may be formed by a solution process (eg, spin coating, etc.) or a deposition process.

[0181] refer to Figure 2 , the electron auxiliary layer 14 is arranged between the light-emitting layer 13 and the second electrode 15. The electron auxiliary layer 14 may include, for example, an electron injection layer, an electron transport layer, and / or a hole (or electron) blocking layer. The electron auxiliary layer may be, for example, an electron injection layer (EIL) that promotes electron injection, an electron transport layer (ETL) that promotes electron transport, or a hole blocking layer (HBL) that blocks hole movement, or a combination thereof. For example, the electron injection layer may be arranged between the electron transport layer and the cathode. For example, the hole blocking layer may be arranged between the light-emitting layer and the electron transport (injection) layer, but is not limited thereto. The thickness of each layer may be appropriately selected. For example, the thickness of each layer may be greater than or equal to about 1 nm and less than or equal to about 500 nm, but is not limited thereto. The electron injection layer may be an organic layer formed by deposition. The electron transport layer may include inorganic oxide nanoparticles or may be an organic layer formed by deposition.

[0182] The electron transport layer (ETL) may include, for example, at least one of 1,4,5,8-naphthalene-tetracarboxylic dianhydride (NTCDA), bathocuproine (BCP), tris[3-(3-pyridyl)-

[0014] borane (3TPYMB), LiF, Alq3, Gaq3, Inq3, Znq2, Zn(BTZ)2, BeBq2, ET204 (8-(4-(4,6-di(naphthalene-2-yl)-1,3,5-triazin-2-yl)phenyl)quinolone), 8-hydroxyquinoline lithium (Liq), n-type metal oxides (e.g., ZnO, HfO2, etc.), or combinations thereof, but not limited thereto.

[0183] The electron assist layer 14 may include a plurality of metal oxide nanoparticles. The nanoparticles may include a metal oxide containing zinc. The metal oxide may include zinc oxide, zinc magnesium oxide, or a combination thereof. The metal oxide may include Zn 1-x M x O (wherein M is Mg, Ca, Zr, W, Li, Ti, Y, Al, or a combination thereof, and 0≤x≤0.5). In an embodiment, in Chemical Formula 1, M may be magnesium (Mg). In an embodiment, in Chemical Formula 1, x may be greater than or equal to about 0.01 and less than or equal to about 0.3, for example, less than or equal to about 0.25, less than or equal to about 0.2, or less than or equal to about 0.15.

[0184] In an embodiment, the absolute value of the LUMO of the quantum dots included in the light-emitting layer may be smaller than the absolute value of the LUMO of the metal oxide. The nanoparticles may have an average size of greater than or equal to about 1 nm, for example, greater than or equal to about 1.5 nm, greater than or equal to about 2 nm, greater than or equal to about 2.5 nm, or greater than or equal to about 3 nm and 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 nm, or less than or equal to about 5 nm. The nanoparticles may not be rod-shaped. The nanoparticles may not be nanowire-shaped.

[0185] The hole blocking layer (HBL) may include, for example, at least one of 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA), bathocuproine (BCP), tris[3-(3-pyridyl)-

[0066] borane (3TPYMB), LiF, Alq3, Gaq3, Inq3, Znq2, Zn(BTZ)2, BeBq2, or a combination thereof, but not limited thereto.

[0186] In embodiments, the thickness of each of the electron assisting layer 14 (e.g., the electron injection layer, the electron transport layer, or the hole blocking layer) may be greater than or equal to about 5 nm, greater than or equal to about 6 nm, greater than or equal to about 7 nm, greater than or equal to about 8 nm, greater than or equal to about 9 nm, greater than or equal to about 10 nm, greater than or equal to about 11 nm, greater than or equal to about 12 nm, greater than or equal to about 13 nm, greater than or equal to about 14 nm, greater than or equal to about 15 nm, greater than or equal to about 16 nm, greater than or equal to about 17 nm, or greater than or equal to about 18 nm. The present invention may include, but is not limited to, about 17 nm or greater, about 18 nm or greater, about 19 nm or greater, or about 20 nm or greater and about 120 nm or less, about 110 nm or less, about 100 nm or less, about 90 nm or less, about 80 nm or less, about 70 nm or less, about 60 nm or less, about 50 nm or less, about 40 nm or less, about 30 nm or less, or about 25 nm or less.

[0187] The device according to the embodiment may have a normal structure. Figure 3The device includes an anode 10, such as a metal oxide-based transparent electrode (e.g., an ITO electrode), disposed on a transparent substrate 100, and a cathode 50 (e.g., facing the anode) that may include a conductive metal (Mg, Al, etc.) (e.g., having a relatively low work function). A hole auxiliary layer 20 (e.g., a hole injection layer of PEDOT:PSS and / or p-type metal oxide, and / or a hole transport layer of TFB and / or PVK) may be disposed between the transparent electrode 10 and the light-emitting layer 30. The hole injection layer may be close to the transparent electrode, and the hole transport layer may be close to the light-emitting layer. An electron auxiliary layer 40, such as an electron injection layer / transport layer, may be disposed between the quantum dot light-emitting layer 30 and the cathode 50.

[0188] In an embodiment, a device according to another embodiment may have an inverted structure. For example, referring to Figure 4 The cathode 50 is provided on a transparent substrate 100, for example, a metal oxide-based transparent electrode (e.g., ITO), and the anode 10 may include a metal (Au, Ag, etc.) (e.g., having a relatively high work function). For example, an (optionally doped) n-type metal oxide (crystalline Zn metal oxide) may be provided between the transparent electrode 50 and the light-emitting layer 30 as an electron auxiliary layer 40 (e.g., an electron transport layer). MoO3 or other p-type metal oxides may be provided between the metal anode 10 and the quantum dot light-emitting layer 30 as a hole auxiliary layer 20 (e.g., a hole transport layer including TFB and / or PVK, and / or a hole injection layer including MoO3 or other p-type metal oxides).

[0189] In an embodiment, the light emitting device may have a brightness greater than or equal to about 10,000 cd / m 2 , greater than or equal to approximately 15,000 cd / m 2 , greater than or equal to approximately 18,000 cd / m 2 , or greater than or equal to approximately 20,000 cd / m 2 In embodiments, the device may have a T50 of about 10 hours (hr) or greater, about 15 hr or greater, about 20 hr or greater, about 25 hr or greater, about 30 hr or greater, about 35 hr or greater, about 40 hr or greater, about 45 hr or greater, or about 50 hr or greater.

[0190] The device according to an embodiment may have a maximum external quantum efficiency (EQE) of about 7% or greater, for example, about 7.5% or greater, or about 7.7% or greater. In an embodiment, the device may have a T95 of about 6 hr or greater, about 25 hr or greater, about 30 hr or greater, about 35 hr or greater, about 40 hr or greater, about 45 hr or greater, or about 50 hr or greater.

[0191] The device of the embodiment may emit blue light. The blue light may have a maximum emission peak wavelength greater than or equal to about 445 nm, greater than or equal to about 448 nm, or greater than or equal to about 450 nm and less than or equal to about 460 nm, less than or equal to about 458 nm, or less than or equal to about 455 nm. The emission peak of the blue light may have a full width at half maximum (FWHM) of less than or equal to about 21 nm, for example, less than or equal to about 20 nm, less than or equal to about 19 nm, less than or equal to about 18 nm, or less than or equal to about 17 nm.

[0192] The light emitting film may have a power of greater than or equal to about 300 mA / cm2 (mA / cm 2 ), greater than or equal to about 400mA / cm 2 , greater than or equal to about 450mA / cm 2 , or greater than or equal to about 500 mA / cm 2 The hole transport capability of the electrode is measured at a predetermined voltage (eg, at about 8 volts).

[0193] The hole transport capability can be measured using a hole only device (HOD). In an embodiment, the HOD may have a structure of anode (e.g., ITO) / HIL such as PEDOT:PSS layer / HTL such as TFB layer / QD light-emitting layer / HTL such as organic HTL / HIL such as HAT-CN layer / anode such as Ag. The thickness of each layer can be appropriately selected, for example, as described herein. The quantum dot emission layer may have a thickness of 15-40 nm. As an upper hole transport layer, an organic HTL / HAT-CN (dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexanitrile) layer may be sequentially thermally deposited to have thicknesses of 35-40 nm and 10-15 nm, respectively. The organic HTL includes a compound having a bicarbazole moiety and a biphenyl moiety. While applying voltage to the obtained HOD, a current depending on the voltage can be measured by an appropriate source meter (eg, Keithley 2635B source meter), and the hole transporting ability can be evaluated.

[0194] In another embodiment, a method for manufacturing the aforementioned light-emitting device includes providing a first electrode and a second electrode, and forming a light-emitting film between the first electrode and the second electrode. The method may include providing a first electrode; forming a light-emitting film on the first electrode; and providing a second electrode on the light-emitting film. In an embodiment, forming the light-emitting film includes providing a quantum dot layer including a plurality of quantum dots; and treating the quantum dot layer with a solution including a fluorine-containing organic salt in a polar solvent.

[0195] The method may further include forming a charge assisting layer (e.g., a hole injection layer or a hole transport layer) on the first electrode (e.g., an anode) before forming the light emitting film. The method may further include forming a charge assisting layer (e.g., an electron transport layer or an electron injection layer) on the light emitting film before forming the second electrode.

[0196] The details of the first electrode, the second electrode, the light-emitting film, the quantum dots, the fluorine-containing organic salt, and the charge-assisting layer are the same as those described above.

[0197] The formation method is appropriately selected taking into account the type of forming material, the thickness of the electrode / layer to be manufactured, etc. The formation method may include a solution (wet) process, deposition, or a combination thereof. For example, the hole auxiliary layer 12, the light-emitting film 13, and the electron auxiliary layer 14 can be obtained by, for example, a solution process. The solution process may include, for example, spin coating, slit coating, inkjet printing, nozzle printing, spraying, and / or doctor blade coating, but is not limited thereto.

[0198] In an embodiment, when the electron assist layer includes an inorganic material, the electron assist layer may be formed by performing a wet process. In an embodiment, the wet process may include a sol-gel method. In an embodiment, the wet process may include: coating a dispersion in which nanoparticles are dispersed in a polar solvent on a quantum dot light-emitting film (for example, by spin coating, etc.); and drying and annealing it. The polar solvent may include a C1-C10 alcohol solvent such as ethanol, a C2-C20 sulfoxide solvent such as dimethyl sulfoxide, a C2-C20 amide solvent such as dimethylformamide, or a combination thereof, but is not limited thereto. The annealing may be performed at a predetermined temperature (for example, a temperature greater than or equal to about 60°C, or greater than or equal to about 70°C and less than or equal to about 100°C, for example, less than or equal to about 90°C, less than or equal to about 80°C, or less than or equal to about 75°C), for example, under vacuum, but is not limited thereto.

[0199] The formation of the quantum dot layer can be carried out as follows: obtaining or preparing a dispersion comprising quantum dots, and applying or depositing it on a substrate or a charge auxiliary layer in an appropriate manner (e.g., spin coating, inkjet printing, etc.). The applied or deposited quantum dot layer can be heat-treated for drying. The heat treatment temperature is not particularly limited and can be appropriately selected taking into account the boiling point of the organic solvent used to prepare the dispersion. For example, the heat treatment temperature may be greater than or equal to about 60°C, for example, greater than or equal to about 70°C. The organic solvent of the dispersion comprising quantum dots is not particularly limited and can therefore be appropriately selected. In an embodiment, the organic solvent may include a (substituted or unsubstituted) aliphatic hydrocarbon organic solvent, a (substituted or unsubstituted) aromatic hydrocarbon organic solvent, an acetate solvent, or a combination thereof.

[0200] The formed quantum dot layer is treated with a solution comprising the fluorine-containing organic salt in a polar solvent. The method may include washing the treated film with a polar solvent one or more times (e.g., at least once or at least twice). The method may include heat-treating the washed film at a temperature greater than or equal to about 60° C., such as greater than or equal to about 65° C., greater than or equal to about 70° C., greater than or equal to about 75° C., or greater than or equal to about 80° C. Treating the quantum dot layer (e.g., with a solution comprising the fluorine-containing organic salt) may include contacting, coating, or applying.

[0201] The amount and / or concentration of the solution of the fluorine-containing organic salt dissolved in the polar solvent may be selected in consideration of the desired composition of the luminescent film. In an embodiment, the amount of the fluorine-containing organic salt solution used may be greater than or equal to about 100 milliliters (mL), greater than or equal to about 500 milliliters (mL), greater than or equal to about 1 liter (L) and less than or equal to about 100 L, less than or equal to about 50 L, or less than or equal to about 40 L, based on a square meter area (m 2 ) to be treated. The concentration of the fluorine-containing organic salt in the solution can be adjusted to greater than or equal to about 0.1 grams per liter (g / L) and less than or equal to about 200 g / L. Before treating the quantum dot layer with the solution, the plurality of quantum dots can include native ligands on their surfaces. The native ligands can include the aforementioned carboxylic acid compound.

[0202] The polar solvent may include an organic solvent. The polar solvent may include an alcohol, a ketone solvent, an acetate solvent, a nitrile solvent, an amide solvent, a sulfoxide solvent, a pyridine solvent, or a combination thereof having a C1-C10 straight or branched hydrocarbon group. For example, the polar solvent may include, for example, methanol, ethanol, propanol, isopropanol, butanol, pentanol, hexanol, heptanol, acetone, ethyl acetate, acetonitrile, DMF, DMAc, DMSO, NMP, or a combination thereof.

[0203] Treatment (e.g., treatment of the quantum dot layer) may include contacting the solution with the quantum dot layer (film). The contacting may include spraying, dipping, dropwise addition (dropwise addition), or a combination thereof, but is not limited thereto. The contacting may be performed in conjunction with stirring, heating, or a combination thereof. Treatment methods include, but are not limited to, spin coating, screen printing, doctor blade printing, and brushing.

[0204] The method may further include washing the treated film one or more times with a polar solvent. During the washing step, at least a portion of the fluorine-containing organic salt not bound to the plurality of quantum dots may be removed. The method may further include heat-treating the washed film at a temperature greater than or equal to about 60° C. and less than or equal to about 150° C.

[0205] Hereinafter, specific embodiments of the present invention are provided. However, the embodiments described below are only for specifically illustrating or explaining the present invention, and thus the scope of the present invention should not be limited.

[0206] Analytical methods

[0207] [1] Photoluminescence analysis and UV spectroscopy

[0208] (1) The photoluminescence (PL) spectra of the fabricated quantum dot nanocrystals were obtained using a Hitachi F-7000 spectrophotometer at an irradiation wavelength of 380 nm.

[0209] (2) UV spectroscopy was performed using a Hitachi U-3310 spectrophotometer to obtain UV-visible absorption spectra.

[0210] [2]TEM and TEM-EDX analysis

[0211] (1) Transmission electron microscopy analysis of the top surface or cross-section of the fabricated device or structure was performed using a UT F30 Tecnai electron microscope.

[0212] (2) SEM-EDX analysis of the top surface or cross section of the fabricated device or structure was performed using SEM-Tecnai G2.

[0213] [3]HOMO and LUMO energy level measurements

[0214] The measurement was performed using a surface analyzer (Model AC-3, photoelectron spectrometer in air) from Riken Keiki Co. Ltd. in air or UPS (UV absorption (optical band gap)).

[0215] [4] Electroluminescence spectroscopy

[0216] The electroluminescent properties of the obtained quantum dot light-emitting devices were evaluated using a Keithley 2200 source measurement device and a Minolta CS2000 spectroradiometer (current-voltage-brightness measurement device). The current, brightness, and electroluminescence (EL) depending on the current applied to the device were measured using the current-voltage-brightness measurement device, and the external quantum efficiency was calculated.

[0217] [5] Lifespan characteristics

[0218] T50 (hr): time in hours (hr) taken for the device to reach a brightness of 50% compared to the initial brightness when the device is driven at a predetermined brightness (eg, 650 nits).

[0219] T95 (hr): time in hours (hr) taken for the device to reach 95% of the initial brightness when the device is driven at a predetermined brightness (eg, 650 nits).

[0220] [6] Evaluation of hole transport ability

[0221] HOD (ITO / PEDOT:PSS / TFB / QD emitting layer / organic HTL) was fabricated as follows / HAT-CN / Ag). The ITO patterned substrate was surface treated with ultraviolet (UV)-ozone (UVO). A PEDOT:PSS layer was spin-coated to a thickness of 30 nanometers (nm), which was then heat-treated to remove residual organic material. As a hole transport layer (HTL), a TFB layer was spin-coated to a thickness of 25 nm, which was then heat-treated to remove residual organic material. A quantum dot dispersion was spin-coated to a thickness of 25 nm to form a light-emitting layer, which was then heat-treated to remove residual organic material. As an upper hole transport layer, an organic HTL / HAT-CN (dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexanitrile) layer was sequentially thermally deposited to have thicknesses of 36 nm and 10 nm, respectively. The organic HTL includes a compound having a biphenyl moiety and a dicarbazole moiety. Under a mask, silver (Ag) was thermally deposited to form an electrode. A sealing resin / glass was used to seal the device.

[0222] The current depending on the voltage was measured by a Keithley 2635B source meter while applying a voltage to the obtained HOD, and the hole transport capability was evaluated.

[0223] Reference Example 1: Preparation of Quantum Dots (BQDs)

[0224] (1) Selenium (Se) and tellurium (Te) were dispersed (individually added) in trioctylphosphine (TOP) to provide a 2 molar (M) Se / TOP stock solution and a 0.1 M Te / TOP stock solution. 0.125 millimoles (mmol) of zinc acetate and oleic acid (OA) were combined in a reactor containing trioctylamine and heated at 120° C. under vacuum. After 1 hour, nitrogen was added to the reactor.

[0225] After heating the reactor to 300°C, the prepared Se / TOP and Te / TOP stock solutions were rapidly injected into the reactor at a Te:Se molar ratio of 1:25. After the reaction was complete, acetone was added to the reaction solution, which was then rapidly cooled to room temperature. The reaction mixture was centrifuged to provide a precipitate, which was then dispersed in toluene to provide ZnTeSe cores.

[0226] (2) 1.8 mmol (0.336 g) of zinc acetate and oleic acid were combined into a reaction flask including trioctylamine and heated at 120°C for 10 minutes under vacuum. Nitrogen (N2) was added to the reaction flask, and the reaction flask was then heated at 180°C. The ZnTeSe cores obtained as above were added to the reaction flask, followed by injection of the Se / TOP and S / TOP prepared by dispersing sulfur in trioctylphosphine at a concentration of 1 M. The reaction temperature was adjusted to about 280°C. After the reaction was completed, the reaction flask was cooled, ethanol was added, and the obtained nanocrystals were separated by centrifugation and dispersed in toluene to provide ZnTeSe / ZnSeS core-shell quantum dots. It was confirmed that the obtained blue light-emitting quantum dots (BQDs) had a first absorption peak wavelength of 410 nm, a PL wavelength of 453 nm, and a quantum yield (QY) of 85%.

[0227] Synthesis of metal oxide nanoparticles

[0228] Reference Example 2: ZnMgO synthesis

[0229] Zinc acetate dihydrate and magnesium acetate tetrahydrate were added to dimethyl sulfoxide in a reactor to provide the following chemical formula, and the reactor was heated at 60° C. in air. Subsequently, an ethanol solution of tetramethylammonium hydroxide pentahydrate was added dropwise to the reactor at a rate of 3 milliliters per minute (mL / min). The obtained mixture was stirred for 1 hour, and the generated Zn 1-x Mg x O nanoparticles were separated by centrifugation and dispersed in ethanol to obtain Zn x Mg 1-x O nanoparticles, where x=0.15.

[0230] X-ray diffraction analysis of the obtained nanoparticles confirmed the formation of ZnO crystals. Transmission electron microscopy analysis of the obtained nanoparticles showed that the particles had an average size of about 3 nm.

[0231] Manufacturing of luminescent films

[0232] Comparative Example 1:

[0233] The BQD dispersion obtained from Reference Example 1 was spin-coated on a glass substrate to provide a film. The formed film was heat-treated at 80° C. for 30 minutes to provide a light-emitting film, OA (oleic acid).

[0234] Comparative Example 2-1:

[0235] An ethanol solution of Zn(BF4)2 (concentration: 100 g / L) was added dropwise onto the film obtained by the same method as in Comparative Example 1. After 1 minute, the Zn(BF4)2-treated film was spun to remove the remaining solution, and the film was washed with ethanol. The washed film was heat-treated at 80°C for 30 minutes to provide a luminescent film.

[0236] Comparative Example 2-2:

[0237] An ethanol solution of ZnCl2 (concentration: 100 g / L) was added dropwise onto the film obtained by the same method as in Comparative Example 1. After 1 minute, the ZnCl2-treated film was rotated to remove the remaining solution, and the obtained film was washed with ethanol. The washed film was heat-treated at 80°C for 30 minutes to provide a luminescent film.

[0238] Example 1-1:

[0239] Trimethyloxadiazine tetrafluoroborate An ethanol solution of (Me3OBF4) (concentration: 100 g / L) was added dropwise onto the film obtained by the same method as in Comparative Example 1. After 1 minute, the Me3OBF4-treated film was spun to remove the remaining solution, and the resulting film was washed with ethanol. The washed film was heat-treated at 80°C for 30 minutes to provide a luminescent film.

[0240] Example 1-2:

[0241] A light-emitting film was obtained in the same manner as in Example 1-1, except that an ethanol solution of tetraethylammonium tetrafluoroborate (Et4NBF4) (concentration: 5 g / L) was used instead of the ethanol solution of Me3OBF4 (100 g / L).

[0242] Example 1-3:

[0243] A light-emitting film was obtained in the same manner as in Example 1-1, except that triethylamine hexafluorophosphate was used. The ethanol solution of (Et3OPF6) (concentration: 100 g / L) replaced the ethanol solution of Me3OBF4 (100 g / L).

[0244] Experimental Example 1

[0245] The photoluminescence analysis of the films of Comparative Example 1 (denoted as OA), Comparative Example 2-1 (denoted as Zn(BF4)2), and Example 1-1 (denoted as OMe3BF4) was performed, and the PL spectra are shown together in Figure 5 middle.

[0246] Depend on Figure 5 PL spectra of Example 1-1 confirmed that the light-emitting film of Example 1-1 exhibited an increase in light-emitting efficiency of at least about 65% compared to the light-emitting film of Comparative Example 1. Example 1-1 also exhibited significantly increased light-emitting efficiency compared to the light-emitting film of Comparative Example 2-1.

[0247] Experimental Example 2

[0248] The HOMO energy level and the LUMO energy level of the films obtained from Comparative Examples 1, 2-1, 2-2 and Example 1-1 and the film of ZnMgO particles obtained from Reference Example 2 were measured.

[0249] Table 1

[0250]

[0251] The results in Table 1 indicate that the luminescent film treated with a fluorine-containing organic salt from Example 1-1 has higher HOMO and LUMO absolute values ​​than the luminescent films of Comparative Examples 1, 2-1, and 2-2. LUMO level measurements indicate that the ZnMgO film has a LUMO (i.e., conduction band edge) energy level of 4.3 eV. The LUMO difference between the luminescent film of Example 1 and the ZnMgO film was 0.9 eV.

[0252] Experimental Example 3

[0253] The films obtained from Comparative Example 1 and Example 1-1 were subjected to SEM-EDX analysis. The results are shown in Table 2.

[0254] Table 2

[0255]

[0256] From the results in Table 2, it was confirmed that fluorine and boron were detected in the light-emitting film treated with the fluorine-containing organic salt in Example 1.

[0257] Experimental Example 4: PL Changes after Thermal Shock

[0258] The films of Comparative Examples 1, 2-2, and Example 1-1 were heat-treated at 120° C. for 30 minutes under a nitrogen atmosphere. Photoluminescence analysis (spectra) of each film before and after the heat treatment was obtained, and changes in the luminous efficiency of each film obtained by the heat treatment were measured, and the results are shown in Table 3.

[0259] Table 3

[0260]

[0261] From the results, it was confirmed that the light-emitting film of Example 1-1 showed improved thermal stability compared with the light-emitting films of Comparative Examples 1 and 2-2.

[0262] Experimental Example 5

[0263] The hole transport capabilities of the light emitting films according to Comparative Examples 1 and 2-2 and Examples 1-1 to 1-3 were measured, and the results are shown in Table 4.

[0264] Table 4

[0265] <![CDATA[Current density at 8 V (mA / cm 2 )]]> Comparative Example 1 (OA) 0.22 <![CDATA[Comparative Example 2-2 (ZnCl2)]]> 226 <![CDATA[Example 1-1, Me3OBF4]]> 603 <![CDATA[Examples 1-2, Et4NBF4]]> 479 <![CDATA[Examples 1-3, Et3OPF6]]> 749

[0266] From these results, it was confirmed that the current density of each of the films of Examples 1-1 to 1-3 was significantly increased by replacing the ligand with the corresponding fluorine-containing organic salt in the light-emitting films of Examples 1-1, 1-2, and 1-3. Therefore, it is understood that the embodied (embodied) light-emitting devices including the light-emitting films of Examples 1-1 to 1-3 have a low driving voltage, and such results also indicate that the light-emitting films of the Examples exhibit increased hole conductivity.

[0267] Experimental Example 6

[0268] Scanning electron microscope energy dispersive spectroscopy was performed on the light emitting films according to Comparative Example 1 and Example 1-1, and the results are shown in Table 5.

[0269] Table 5

[0270] EDX molar ratio Comparative Example 1 Example 1-1 B:C 0 / 14.73 9.12 / 9.82＝0.92 F:C 0 / 14.73 0.32 / 9.82＝0.03

[0271] Example 2

[0272] A light-emitting device having a structure of ITO / PEDOT:PSS / TFB / Me3OBF4-treated light-emitting film / ZnMgO / Al was manufactured according to the following method.

[0273] Prepare an ethanol solution of Me3OBF4 (concentration: 100 g / L).

[0274] The ITO-deposited glass substrate was surface-treated with UV-ozone for 15 minutes. A PEDOT:PSS solution (HCStarks) was spin-coated on the treated glass substrate, which was then heat-treated at 150°C for 10 minutes in an air atmosphere, and then heat-treated at 150°C for 20-30 minutes in an N2 atmosphere to provide a hole injection layer (HIL) having a thickness of 30 nm. Subsequently, a poly[(9,9-dioctylfluorene-2,7-diyl-co-(4,4'-(N-4-butylphenyl)diphenylamine]] solution (TFB) (Sumitomo) was spin-coated on the hole injection layer (HIL) and heat-treated at 150°C for 30 minutes to provide a hole transport layer (HTL) having a thickness of 25 nm.

[0275] The quantum dot solution obtained from Reference Example 1 was spin-coated on the HTL to provide a film, which was then washed with ethanol and heat-treated at 80° C. for 30 minutes to provide a quantum dot layer having a thickness of 25 nm.

[0276] The (above) Me3OBF4 solution was added dropwise onto the heat-treated quantum dot layer and after 1 minute, the resulting film was spun to remove any excess or remaining solution and washed with ethanol. The washed layer was heat-treated at 80°C for 30 minutes to provide a luminescent film.

[0277] A solution of ZnMgO nanoparticles of Reference Example 2 was spin-coated on the light-emitting film and heat-treated at 80°C for 30 minutes to provide an electron transport layer (ETL). Aluminum (Al) was vacuum-deposited to a thickness of 100 nm on the ETL to provide a second electrode. The electroluminescent properties of the resulting device were evaluated, and the results are shown in Table 6.

[0278] Comparative Example 3

[0279] A light-emitting device having a structure of ITO / PEDOT:PSS / TFB / ZnCl2-treated light-emitting film / ZnMgO / Ag was manufactured according to the same procedure as in Example 2, except that a ZnCl2 ethanol solution (concentration: 100 g / L) was used instead of the (Me3OBF4) solution during formation of the light-emitting layer. The electroluminescent properties of the obtained device were evaluated, and the results are shown in Table 3.

[0280] Comparative Example 4

[0281] A light-emitting device having a structure of ITO / PEDOT:PSS / TFB / Zn(BF4)2-treated light-emitting film / ZnMgO / Al was manufactured according to the same procedure as in Example 2, except that a Zn(BF4)2 ethanol solution (concentration: 100 g / L) was used instead of the Me3OBF4 solution during formation of the light-emitting layer. The electroluminescent properties of the resulting device were evaluated, and the results are shown in Table 6.

[0282] Table 6

[0283]

[0284] "Maximum Cd / A" is the maximum value of the luminance efficiency expressed in candela / ampere, for example, obtained from the current versus luminance curve.

[0285] From the results of Table 6, it is confirmed that the device according to Example 2 shows an increased lifespan together with significantly increased brightness and efficiency compared to the devices according to Comparative Examples 3 and 4.

[0286] Example 3

[0287] A light-emitting device having a structure of ITO / PEDOT:PSS / TFB / luminescent film treated with Et4NBF4 / ZnMgO / Al was manufactured according to the same procedure as in Example 2, except that an Et4NBF4 ethanol solution (concentration: 5 g / L) was used instead of the (Me3OBF4) solution during the formation of the light-emitting film.

[0288] Example 4

[0289] A light-emitting device having a structure of ITO / PEDOT:PSS / TFB / luminescent film treated with Et3OPF6 / ZnMgO / Al was manufactured according to the same procedure as in Example 2, except that an Et3OPF6 ethanol solution (concentration: 100 g / L) was used instead of the (Me3OBF4) solution during the formation of the light-emitting film.

[0290] Comparative Example 5

[0291] A light-emitting device having a structure of ITO / PEDOT:PSS / TFB / nitrosyl BF4-treated light-emitting film / ZnMgO / Al was manufactured according to the same procedure as in Example 2, except that a nitrosyl BF4 ethanol solution (concentration: 100 g / L) was used instead of the (Me3OBF4) solution during formation of the light-emitting film. The electroluminescent properties of the resulting device were evaluated, and the results are shown in Table 7.

[0292] Comparative Example 6

[0293] A light-emitting device having a structure of ITO / PEDOT:PSS / TFB / HBF4-treated light-emitting film / ZnMgO / Al was manufactured according to the same procedure as in Example 2, except that an HBF4 ethanol solution (concentration: 100 g / L) was used instead of the Me3OBF4 solution during formation of the light-emitting film. The electroluminescent properties of the resulting device were evaluated, and the results are shown in Table 7.

[0294] Experimental Example 6

[0295] T50 of the devices according to Examples 2 to 4 and the light-emitting devices according to Comparative Examples 3 to 6 were measured, and the results are shown in Table 7.

[0296] Table 7

[0297] Luminous film T50(hr) Comparative Example 3 <![CDATA[ZnCl2]]> 13.8 Comparative Example 4 <![CDATA[Zn(BF4)2]]> 22.7 Comparative Example 5 <![CDATA[Nitrosyl BF4]]> 4.7 Comparative Example 6 <![CDATA[HBF4]]> LED not operating Example 2 <![CDATA[Me3OBF4]]> 45.5 Example 3 <![CDATA[Et4NBF4]]> 34.9 Example 4 <![CDATA[Et3OPF6]]> 52.0

[0298] From the results of Table 7, it is confirmed that the light emitting device according to the embodiment may exhibit improved lifespan characteristics compared to the light emitting device according to the comparative example.

[0299] While the present disclosure has been described with respect to what are presently considered to be practical example embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

[0300] Explanation of symbols

[0301] 10: Light-emitting devices

[0302] 11: First electrode

[0303] 12: Hole auxiliary layer

[0304] 13: Luminous film

[0305] 14: Electronic auxiliary layer

[0306] 15: Second electrode

Claims

1. Light-emitting devices, including a first electrode, a second electrode, and a light emitting film provided between the first electrode and the second electrode, wherein the luminescent film comprises a fluorine-containing organic salt and quantum dots, and the quantum dots do not comprise cadmium, lead, or a combination thereof, wherein the fluorine-containing organic salt comprises at least one of boron or phosphorus, a substituted or unsubstituted C1-C30 hydrocarbon group, a non-metallic element, and fluorine, and wherein the non-metallic elements include carbon, oxygen, sulfur, or selenium, wherein the fluorine-containing organic salt comprises carbon Part, oxygen part, portion, matte portion, or a combination thereof. 2 . The light emitting device according to claim 1 , wherein at least a portion of a surface of the light emitting film includes the quantum dots and the fluorine-containing organic salt bound to the quantum dots. The light-emitting device according to claim 1 , wherein the HOMO energy level of the light-emitting film is greater than or equal to 5.7 eV. The light emitting device of claim 1 , wherein the light emitting film is configured to emit red light, green light, or blue light.

5. The light emitting device according to claim 4, wherein If the light-emitting film emits red light, the HOMO energy level of the light-emitting film is greater than or equal to 5.7 eV; If the light-emitting film emits green light, the HOMO energy level of the light-emitting film is greater than or equal to 5.7 eV; or If the light emitting film emits blue light, the HOMO level of the light emitting film is greater than or equal to 5.9 eV. The light emitting device according to claim 1 , wherein the fluorine-containing organic salt comprises fluoroborate, fluorophosphate, or a combination thereof. 7 . The light emitting device of claim 1 , wherein the quantum dot comprises a core and a shell disposed on the core, the core comprising a first semiconductor nanocrystal, and the shell comprising a second semiconductor nanocrystal having a composition different from that of the first semiconductor nanocrystal.

8. The light emitting device according to claim 1, wherein The light-emitting film is configured to emit red light, and a HOMO energy level of the light-emitting film is greater than or equal to 5.7 eV; The light-emitting film is configured to emit green light, and a HOMO energy level of the light-emitting film is greater than or equal to 5.85 eV; or The light emitting film is configured to emit blue light, and a HOMO energy level of the light emitting film is greater than or equal to 6 eV. 9 . The light-emitting device according to claim 1 , wherein the light-emitting film comprises boron, and a molar ratio of boron to carbon is greater than or equal to 0.001:1 as measured by energy dispersive spectroscopy of the light-emitting film. 10 . The light emitting device according to claim 1 , wherein the light emitting film comprises boron, and a molar ratio of fluorine to boron is greater than or equal to 4:1 and less than or equal to 6:

1. The light emitting device of claim 1 , further comprising an electron assist layer adjacent to the light emitting film. 12 . The light emitting device of claim 11 , wherein a difference between a conduction band edge of the electron assist layer and a LUMO energy level of the light emitting film is less than or equal to 1 eV. The light emitting device of claim 11 , wherein the electron assist layer comprises nanoparticles of metal oxide. The light emitting device according to claim 1 , wherein the light emitting film has a thickness greater than or equal to 10 nanometers and less than or equal to 100 nanometers.

15. The light emitting device according to claim 1, wherein the maximum external quantum efficiency of the light emitting device is greater than or equal to 10%, and The maximum brightness of the light emitting device is greater than or equal to 35,000 cd / m 2 .

16. The light emitting device of claim 1, wherein the light emitting device exhibits a T95 lifetime greater than or equal to 2 hours when measured while operating at a brightness of 650 candelas / square meter.

17. A display device comprising the light emitting device according to any one of claims 1 to 16.

18. Luminous film, including a plurality of quantum dots, the quantum dots not including cadmium, lead, or a combination thereof, and a fluorine-containing organic salt bound to the quantum dots, The fluorine-containing organic salt comprises a first part and a second part, the first part is an oxygen carbon Sulfonium, or a combination thereof, the second portion is tetrafluoroborate, hexafluorophosphate, or a combination thereof.

19. The luminescent film of claim 18, wherein the first portion comprises a substituted or unsubstituted C1-C30 hydrocarbon group.

20. The luminescent film of claim 18, wherein The light emitting film is configured to emit red light, green light, or blue light, and If the light-emitting film emits red light, the HOMO energy level of the light-emitting film is greater than or equal to 5.7 eV, If the light-emitting film emits green light, the HOMO energy level of the light-emitting film is greater than or equal to 5.7 eV, or If the light emitting film emits blue light, the HOMO level of the light emitting film is greater than or equal to 5.9 eV.

21. The luminescent film of claim 18, wherein the luminescent film is as defined in any one of claims 9, 10, and 14.

22. A method for manufacturing a light emitting device according to any one of claims 1 to 16, comprising: providing a structure including a first electrode, a second electrode, and a light emitting film between the first electrode and the second electrode, The forming of the light emitting film includes providing a quantum dot layer including a plurality of quantum dots, and treating the quantum dot layer with a solution including a fluorine-containing organic salt in a polar solvent.

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