Cation source composition, quantum dot material and preparation method therefor, and light-emitting device

Abstract

The embodiments of the present disclosure relate to the field of display technology, and provide a cation source composition, a quantum dot material and a preparation method therefor, and a light-emitting device, which are at least used for solving the problems of solidification and clogging as well as damage and leakage of an injection system caused by high-temperature injection of a cation precursor. The cation source composition comprises: an organic acid salt, an auxiliary agent and a preset solvent. The organic acid salt comprises a metal cation. The auxiliary agent is at least configured to form a complex with the metal cation contained in the organic acid salt, such that the organic acid salt can be dissolved in the preset solvent at a preset temperature, wherein the preset temperature is greater than the solidification temperature of the preset solvent, and is less than or equal to 100°C; and the dipole moment of the preset solvent is less than or equal to a set threshold. The cation source composition is used for preparing a quantum dot material.

Description

Cation source composition, quantum dot materials and their preparation methods, and light-emitting devices Technical Field

[0001] This disclosure relates to the field of display technology, and in particular to a cation source composition, quantum dot materials and their preparation methods, and light-emitting devices. Background Technology

[0002] Quantum dots (QDs) are semiconductor nanocrystals with excellent luminescent properties, including broadband absorption, narrow-band emission, and continuously tunable peak positions. In the synthesis of core-shell quantum dots, a cation source composition is added to form the shell of the quantum dot. Summary of the Invention

[0003] On one hand, a cation source composition is provided. The cation source composition comprises: an organic acid salt, an auxiliary agent, and a preset solvent. The organic acid salt includes a metal cation. The auxiliary agent is configured at least to form a complex with the metal cation included in the organic acid salt, such that the organic acid salt is soluble in the preset solvent at a preset temperature. The preset temperature is greater than the freezing temperature of the preset solvent and less than or equal to 100°C; the dipole moment of the preset solvent is less than or equal to a set threshold.

[0004] In some embodiments, the threshold is set to be less than or equal to 0.5D.

[0005] In some embodiments, the adjuvant includes any one of the structures shown in the following general formula (I).

[0006] Wherein, X is nitrogen or phosphorus. * indicates the site where the auxiliary is coordinated with the metal cation included in the organic acid salt. R1, R2, and R3 may be the same or different, and are independently selected from hydrogen, substituted or unsubstituted C1-C10 straight-chain alkyl or branched-chain alkyl, and substituted or unsubstituted C6-C14 aryl, and R1, R2, and R3 may not be hydrogen simultaneously.

[0007] In some embodiments, in the structure shown in general formula (I), R1, R2 and R3 may be the same or different, and are independently selected from any one of substituted or unsubstituted C1 to C10 straight-chain alkyl or branched-chain alkyl and substituted or unsubstituted C6 to C14 aryl groups.

[0008] In some embodiments, X is phosphorus in the structure shown in general formula (I).

[0009] In some embodiments, the adjuvant includes at least one of trioctylphosphine, tri-n-butylphosphine, and diphenylphosphine.

[0010] In some embodiments, the adjuvant includes at least one of oleylamine and trioctylamine.

[0011] In some embodiments, the volume percentage of the auxiliaries in the cationic source composition ranges from 20% to 40%.

[0012] In some embodiments, organic acid salts include zinc organic acid salts.

[0013] In some embodiments, the organic zinc acid salt includes at least one of zinc oleate, zinc stearate, zinc acetylacetone, zinc palmitate, zinc myristate, and zinc laurate.

[0014] In some embodiments, the preset solvent includes at least one of 1-octadecene, alkane solvents, toluene, and chloroform.

[0015] In some embodiments, the molar concentration of the organic acid salt in the cation source composition ranges from 0.1 mmol / L to 1 mmol / L.

[0016] On the other hand, a method for preparing a quantum dot material is provided. The method includes: forming a quantum dot core; and forming a quantum dot shell on the surface of the quantum dot core. The material used to form the quantum dot shell includes the cation source composition as described in any of the above embodiments.

[0017] In some embodiments, the adjuvant includes any one of the structures shown in the following general formula (I).

[0018] * indicates the site where the auxiliary agent coordinates with the metal cation included in the organic acid salt. R1, R2, and R3 may be the same or different, and are independently selected from hydrogen, substituted or unsubstituted C1-C10 straight-chain alkyl or branched-chain alkyl, and substituted or unsubstituted C6-C14 aryl, and R1, R2, and R3 may not be hydrogen simultaneously. The quantum dot core includes cadmium; in the structure shown in general formula (I), X is phosphorus; or, the quantum dot core does not include cadmium; in the structure shown in general formula (I), X is phosphorus or nitrogen.

[0019] In some embodiments, forming a quantum dot shell on the surface of a quantum dot core includes: forming a first solution comprising a quantum dot core and a preset solvent; injecting a cation source composition and an anion source composition into the first solution to form the quantum dot shell. The temperature range of the cation source composition injected into the first solution is greater than the freezing temperature of the preset solvent and less than or equal to 100°C.

[0020] In some embodiments, the preset solvent is 1-octadecene, and the temperature range of the cationic source composition injected into the first solution is 5°C to 30°C.

[0021] In some embodiments, during the injection of the cation source composition into the first solution, the injection rate of the cation source composition ranges from 2 ml / h to 30 ml / h.

[0022] In some embodiments, the anion source composition includes an auxiliary agent and a pre-defined solvent, and further includes an anion. In the anion source composition, the auxiliary agent is capable of coordinating with the anion.

[0023] In some embodiments, the anions included in the anion source composition include selenium and / or sulfur.

[0024] In another aspect, a quantum dot material is provided. The quantum dot material is prepared using the preparation method described in any of the above embodiments.

[0025] In some embodiments, the quantum dot material includes a quantum dot body and an additive, wherein the additive is disposed in the quantum dot body.

[0026] In another aspect, a light-emitting device is provided. The light-emitting device includes a cathode, an anode, and a light-emitting layer. The anode and cathode are disposed opposite to each other. The light-emitting layer is disposed between the anode and the cathode. The material of the light-emitting layer includes quantum dot materials as described in any of the above embodiments. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in this disclosure, the accompanying drawings used in some embodiments of this disclosure will be briefly described below. Obviously, the drawings described below are only drawings of some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams and are not intended to limit the actual size of the product, the actual flow of the method, the actual timing of the signals, etc. involved in the embodiments of this disclosure.

[0028] Figure 1 is a flowchart of the preparation of quantum dot materials according to some embodiments;

[0029] Figure 2 is a flowchart illustrating the steps of adding the cation source composition to the first solution according to some embodiments;

[0030] Figure 3 is a structural diagram of a display panel according to some embodiments;

[0031] Figure 4 is a structural diagram of a display panel according to some other embodiments;

[0032] Figure 5 is a structural diagram of a display panel according to some other embodiments. Detailed Implementation

[0033] The technical solutions in some embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided in this disclosure are within the scope of protection of this disclosure.

[0034] Unless the context otherwise requires, throughout the specification and claims, the term "comprise" and its other forms, such as the third-person singular "comprises" and the present participle "comprising," are interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific example," or "some examples," etc., are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0035] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0036] "At least one of A, B and C" has the same meaning as "at least one of A, B or C", both including the following combinations of A, B and C: only A, only B, only C, combinations of A and B, combinations of A and C, combinations of B and C, and combinations of A, B and C.

[0037] "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0038] The use of “applies to” or “configured to” in this article implies an open and inclusive language that does not preclude applicability to or configuration to devices that perform additional tasks or steps.

[0039] As used herein, “about,” “approximately,” or “approximately” includes the stated value and the average value within an acceptable range of deviation from the given value, wherein the acceptable range of deviation is determined by a person skilled in the art taking into account the measurement under discussion and the error associated with the measurement of the given quantity (i.e., the limitations of the measurement system).

[0040] As used herein, “parallel,” “perpendicular,” and “equal” include the described situation and situations that are similar to the described situation, within an acceptable range of deviation, which is determined by those skilled in the art taking into account the measurement under discussion and the error associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, “parallel” includes absolute parallelism and approximate parallelism, where an acceptable range of deviation for approximate parallelism may be, for example, within 5°; “perpendicular” includes absolute perpendicularity and approximate perpendicularity, where an acceptable range of deviation for approximate perpendicularity may also be, for example, within 5°; “equal” includes absolute equality and approximate equality, where an acceptable range of deviation for approximate equality may be, for example, a difference between the two equals being less than or equal to 5% of either one.

[0041] It should be understood that when a layer or element is referred to as being on another layer or substrate, it can mean that the layer or element is directly on the other layer or substrate, or that there is an intermediate layer between the layer or element and the other layer or substrate.

[0042] This document describes exemplary embodiments with reference to cross-sectional views and / or plan views, which are idealized exemplary drawings. In the drawings, the thickness of layers and the area of ​​regions are enlarged for clarity. Therefore, variations in shape relative to the drawings are contemplated due to, for example, manufacturing techniques and / or tolerances. Thus, exemplary embodiments should not be construed as being limited to the shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing processes. For example, etched areas shown as rectangular would typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of the areas of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0043] It should be noted that, for example, 11-1 in the accompanying drawings of this disclosure indicates that component 11 belongs to component 1; for example, 221-220 in Figure 3 indicates that pixel defining layer 221 belongs to light-emitting functional layer 220; other similar reference numerals in the drawings also follow the above description. For example, 1 / 2 in the accompanying drawings of this disclosure indicates that structure 1 and structure 2 can both refer to this structure; for example, 101 / 100 in Figure 3 indicates that the first light-emitting device 101 and the light-emitting device 100 can both be represented by this structure. Other similar reference numerals in the accompanying drawings also follow the above description.

[0044] According to the quantum confinement effect, when the geometric radius of a semiconductor nanocrystal is smaller than the exciton Bohr radius of its bulk material, the energy levels of the valence and conduction bands exhibit a discrete distribution. In this case, the properties of the semiconductor nanocrystal become size-dependent. Semiconductor nanocrystals with radii (e.g., geometric radii) smaller than or close to the exciton Bohr radius are called quantum dots, with sizes ranging from, for example, 1 nm to 10 nm. Due to the aforementioned quantum confinement effect, quantum dots possess excellent luminescent properties such as broadband absorption, narrowband emission, and continuously tunable peak positions.

[0045] In some examples, quantum dot materials have a core-shell structure. In quantum dot materials with a core-shell structure, one material forms the core, and the other forms the shell. For example, the quantum dot material CdS@ZnS has a core-shell structure, with cadmium sulfide (CdS) as the core and zinc sulfide (ZnS) as the shell.

[0046] In some embodiments, the method for preparing quantum dot materials includes R1 to R2.

[0047] R1: Formation of a quantum dot core solution containing quantum dot cores.

[0048] R2: Injecting one or more precursors into the quantum dot core solution to grow a quantum dot shell on the surface of the quantum dot core. The injected precursors include cationic precursors.

[0049] For example, the cationic precursor can be injected into the quantum dot core solution using an injection pump.

[0050] For example, when the quantum dot material is a cadmium-based quantum dot material, zinc oleate or the like can be used as a cationic precursor during the epitaxial growth of the quantum dot shell.

[0051] In some implementations, the cationic precursor includes a cationic source and a nonpolar solvent, wherein the cationic source included in the cationic precursor is insoluble in the nonpolar solvent or is soluble only at high temperatures.

[0052] For example, when the cationic precursor includes zinc oleate and the nonpolar solvent 1-octadecene (ODE), zinc oleate dissolves only in ODE at high temperatures (it solidifies and precipitates at low temperatures). In some implementations, the zinc oleate precursor is added to the reaction system via slow, uniform injection at high temperatures (e.g., above 100°C) or via fractional injection. However, uniform injection using a syringe pump at high temperatures requires heating the long, thin injection tube, which can easily lead to uneven heating. Undercooling can cause tube blockage, while overheating can damage the injection system or even cause leakage. Fractional injection increases the error in injection volume, causing fluctuations in the concentration of unreacted cationic precursors in the reaction system, resulting in uneven quantum dot shell growth in R2 and changes in quantum dot peak positions.

[0053] For example, when the cationic precursor includes zinc stearate and ODE, the zinc stearate dispersed in the ODE will form a suspension. In some implementations, to avoid the cationic precursor adhering to the wall and affecting the injection accuracy, the cationic precursor is injected at a relatively fast rate, resulting in a faster growth rate of the quantum dot shell in R2, leading to poor size uniformity of the formed quantum dot material. Since the full width at half maximum (FWHM) of the quantum dot material is related to its size (e.g., diameter), inconsistent quantum dot size can cause problems such as increased FWHM and peak position shift.

[0054] Based on this, some embodiments of this disclosure provide a cation source composition to solve at least one of the above-mentioned technical problems. The cation source composition includes: an organic acid salt, an auxiliary agent, and a preset solvent. The organic acid salt includes a metal cation. The auxiliary agent is configured to at least form a complex with the metal cation included in the organic acid salt, such that the organic acid salt is soluble in the preset solvent at a preset temperature. The preset temperature is greater than the freezing temperature of the preset solvent and less than or equal to 100°C; the dipole moment of the preset solvent is less than or equal to a set threshold.

[0055] When the cation source composition includes an organic acid salt, and the organic acid salt includes a metal cation, the metal cation can be used as the cation required for growing the quantum dot shell, the organic acid salt can be used as the cation source required for growing the quantum dot shell, and the cation source composition can be used as the cation precursor injected during the growth of the quantum dot shell.

[0056] When an adjuvant forms a complex with the metal cations included in an organic acid salt, the solubility of the complex in a predetermined solvent is related to both the organic acid salt and the adjuvant. Therefore, the solubility of the complex can be adjusted by using the adjuvant so that the complex can dissolve in the predetermined solvent at a lower predetermined temperature. At this time, the organic acid salt, as part of the complex, can also dissolve in the predetermined solvent at a lower predetermined temperature, thereby increasing the solubility of the organic acid salt in the predetermined solvent.

[0057] For example, the preset temperature can be (Y+0.1)℃, 5℃, 10℃, 15℃, 18℃, 20℃, 25℃, 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, or 100℃, etc. Where Y is the freezing temperature of the preset solvent. For example, if the freezing temperature of the preset solvent is 5℃, then the preset temperature can be 5.1℃.

[0058] It should be understood that when the preset temperature is less than or equal to 100°C, the preset temperature is within a relatively low range. Moreover, by setting the preset temperature to be greater than the solidification temperature of the preset solvent, the preset solvent can be kept in a liquid state at the preset temperature, thereby making the cation source composition in a solution state, which is beneficial to the operability of injecting the cation source composition into the quantum dot core solution.

[0059] In related technologies, dipole moment can be used as a polarity parameter for organic materials; the smaller the dipole moment of an organic material, the lower its polarity. When the dipole moment of the preset solvent is less than or equal to a set threshold, the polarity of the preset solvent is relatively low.

[0060] Understandably, by including an auxiliary agent in the cationic source composition, and by setting the auxiliary agent to form a complex with the metal cation, the solubility of organic acid salts in a preset solvent with lower polarity can be improved. This allows organic acid salts that are originally insoluble or only soluble in the preset solvent under high temperature conditions to dissolve in the preset solvent at a lower preset temperature. Furthermore, the stability of the organic acid salts in the cationic source composition can be improved, ensuring the stability of the cationic source composition at the preset temperature. This has two advantages: first, it allows the temperature of the cationic source composition to be at a lower preset temperature when injected by the injection pump, avoiding problems such as solidification blockage, injection system damage, and leakage caused by high-temperature injection; second, it allows the cationic source composition to remain stable during a longer injection process, enabling a single injection of the cationic source composition. This allows for the achievement of the set injection amount, thus avoiding the need for multiple injections, reducing injection amount errors, and improving the uniformity of quantum dot shell growth rate. This prevents peak position variations caused by uneven quantum dot shell growth. Thirdly, it ensures the stability of the cation source composition during slow injection, resulting in a slower quantum dot shell growth rate, improved dimensional consistency of the formed quantum dot material, narrower half-width at half-maximum (WHM) of the emission spectrum, and avoids peak position shift issues. It also improves batch-to-batch consistency of quantum dot materials. Fourthly, in practical applications, it allows for the preparation and storage of larger quantities of cation source compositions, improving batch-to-batch consistency of the cation source composition and enhancing the overall stability of the quantum dot material preparation process.

[0061] As mentioned in the previous section, the dipole moment of the preset solvent is less than or equal to a set threshold. Here, the range of the set threshold is not limited, as long as it can make the polarity of the preset solvent low enough to meet the application requirements.

[0062] In some examples, the quantum dot core includes long-chain ligands, and in order for the long-chain ligands to dissolve in the quantum dot core solution, the quantum dot core solution contains a nonpolar solvent.

[0063] In some examples, in R2 of the above preparation method, the temperature of the quantum dot core solution is relatively high, for example, greater than or equal to 300°C, in order for the reaction to grow the quantum dot shell to proceed smoothly.

[0064] In some embodiments, the threshold is set to be less than or equal to 0.5D.

[0065] For example, the threshold can be set to 0, 0.05D, 0.1D, 0.15D, 0.2D, 0.25D, 0.3D, 0.34D, 0.4D, or 0.45D, etc.

[0066] When the threshold value is less than or equal to 0.5D, the dipole moment of the preset solvent is less than or equal to 0.5D, and the preset solvent is a non-polar solvent. This setting has two advantages: First, the polarity of the preset solvent is the same as or similar to the polarity of the solvent contained in the quantum dot core solution, so that after the cation source composition is injected into the quantum dot core solution, the quantum dot core can still remain in a dissolved state, which is beneficial to the quantum dot shell growth reaction. Second, when the preset solvent is a non-polar solvent, the preset solvent has the advantage of being more stable at high temperatures, so that the preset solvent can remain stable under the high temperature conditions required for the quantum dot shell growth reaction, which is beneficial to the quantum dot shell growth reaction.

[0067] In some embodiments, the preset solvent includes at least one of 1-octadecene, alkane solvents, toluene, and chloroform.

[0068] By setting the solvent to be nonpolar, as described in the previous section, it is beneficial to the quantum dot shell growth reaction. Moreover, 1-octadecene, alkane solvents, toluene and chloroform have the advantages of being readily available and having relatively low toxicity, which can reduce the material cost of synthesizing quantum dot materials to a certain extent and improve the safety of the cation source composition.

[0069] For example, alkane solvents can be solvents with 10 or fewer carbon atoms. For instance, alkane solvents can be hexane, heptane, or n-octane.

[0070] Because alkane solvents have a high number of carbon atoms in their structure, the pre-set solvent tends to be solid or near-solid under certain conditions, which may affect its usability. Therefore, by setting the pre-set solvent to have 10 or fewer carbon atoms, the pre-set solvent can remain liquid under more conditions, maintaining good fluidity. This is beneficial for the dissolution of organic acid salts by the pre-set solvent and can improve the injection effect of the cationic source composition.

[0071] In some embodiments, the adjuvant includes any one of the structures shown in the following general formula (I).

[0072] Where X is nitrogen (N) or phosphorus (P).

[0073] * indicates the site where the auxiliary agent coordinates with the metal cations included in the organic acid salt.

[0074] R1, R2, and R3 may be the same or different, and are independently selected from hydrogen, substituted or unsubstituted C1-C10 straight-chain alkyl or branched-chain alkyl, and substituted or unsubstituted C6-C14 aryl, and R1, R2, and R3 may not be hydrogen at the same time.

[0075] Here, straight-chain alkyl refers to the group remaining after removing one hydrogen atom from a straight-chain alkane; branched-chain alkyl refers to the group remaining after removing one hydrogen atom from a branched-chain alkane; aryl refers to the group remaining after removing one hydrogen atom from an aromatic compound containing a carbon atom. A Cx straight-chain alkyl refers to a straight-chain alkyl compound with x carbon (C) atoms, where x is a positive integer. For an understanding of Cx aryl and Cx branched-chain alkyl, please refer to the above content; it will not be repeated here.

[0076] For example, R1 is selected from any one of the following: substituted or unsubstituted C1-C3 straight-chain alkyl or branched alkyl, substituted or unsubstituted C1-C5 straight-chain alkyl or branched alkyl, substituted or unsubstituted C1-C7 straight-chain alkyl or branched alkyl, substituted or unsubstituted C1-C10 straight-chain alkyl or branched alkyl, substituted or unsubstituted C6-C10 aryl, and substituted or unsubstituted C6-C14 aryl.

[0077] For example, when R1 is selected from substituted C1 to C10 straight-chain alkyl or branched-chain alkyl or substituted C6 to C14 aryl, the number of substituents is, for example, 1, 1 to 2 or 1 to 3; the types of substituents are, for example, C1 to C3 straight-chain alkyl or branched-chain alkyl, C1 to C5 straight-chain alkyl or branched-chain alkyl, or C1 to C8 straight-chain alkyl or branched-chain alkyl.

[0078] For example, the C1 to C3 straight-chain alkyl or branched alkyl may include any one of methyl, ethyl, n-propyl and isopropyl.

[0079] For example, the C1 to C5 straight-chain alkyl or branched alkyl may include any one of methyl, ethyl, n-propyl, isopropyl, butylene, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, and neopentyl.

[0080] For example, the C1-C8 straight-chain alkyl or branched alkyl groups may include methyl, ethyl, n-propyl, isopropyl, butylene, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, 2-methylpentyl, 3-methylpentyl, 2,3-dimethylbutyl, 2,2-dimethylbutyl, n-heptyl, 2,2-dimethylpentyl, 2,3-dimethylpentyl, 3-methylhexyl, 2,4-dimethylpentyl, 3,3-dimethylpentyl, 2,2,3-trimethylbutyl, 2-methylhexyl, 3-ethylpentyl, n- The first of the following: octyl, 2-methylheptyl, 3-methylheptyl, 4-methylheptyl, 2,2-dimethylhexyl, 2,3-dimethylhexyl, 2,4-dimethylhexyl, 2,5-dimethylhexyl, 3,3-dimethylhexyl, 3,4-dimethylhexyl, 3-ethylhexyl, 2,2,3-trimethylpentyl, 2,2,4-trimethylpentyl, 2,3,3-trimethylpentyl, 2,3,4-trimethylpentyl, 2-methyl-3-ethylpentyl, 3-methyl-3-ethylpentyl, and 2,2,3,3-tetramethylbutyl.

[0081] In some examples, X is nitrogen and the auxiliary is an organic amine compound containing an amine group; in other examples, X is phosphorus and the auxiliary is an organic phosphine compound containing a phosphine group.

[0082] For example, one or more combinations of nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) can be used to perform qualitative or quantitative analysis of the additives in the cationic source composition.

[0083] With the above configuration, the auxiliary agent contains an amino group (e.g., a primary, secondary, or tertiary amino group) or a phosphono group (e.g., a primary, secondary, or tertiary phosphono group). Thus, using the phosphono or amino group, the auxiliary agent can coordinate with the metal cation included in the organic acid salt, allowing the auxiliary agent to form a complex with the organic acid salt. Furthermore, by ensuring that R1, R2, and R3 are not simultaneously hydrogen, the auxiliary agent can include organic groups (straight-chain alkyl, branched-chain alkyl, or aryl groups), which increases the solubility of the auxiliary agent in the predetermined solvent, facilitating the formation of a complex with the organic acid salt.

[0084] In some examples, in the structure shown in general formula (I), two of R1, R2 and R3 are hydrogen, one of which is selected from any of the substituted or unsubstituted C1 to C10 straight-chain alkyl or branched-chain alkyl and the substituted or unsubstituted C6 to C14 aryl group, in which case the auxiliary includes a primary amino group or a primary phosphine group.

[0085] In some other examples, in the structure shown by general formula (I), one of R1, R2 and R3 is hydrogen, and the other two are the same or different, and are independently selected from any one of substituted or unsubstituted C1 to C10 straight-chain alkyl or branched-chain alkyl and substituted or unsubstituted C6 to C14 aryl groups, in which case the auxiliaries include secondary amino groups or secondary phosphine groups.

[0086] When the additives include primary amine, primary phosphine, secondary amine, or secondary phosphine, the hydrogen atoms contained in the primary amine, primary phosphine, secondary amine, or secondary phosphine have certain reactivity, which makes the quantum dot shell growth reaction faster, and may result in poor size uniformity of the formed quantum dot material.

[0087] Therefore, in some embodiments, in the structure shown in general formula (I), R1, R2 and R3 may be the same or different, and are independently selected from any one of substituted or unsubstituted C1 to C10 straight-chain alkyl or branched-chain alkyl and substituted or unsubstituted C6 to C14 aryl groups.

[0088] In some embodiments, in the structure shown in general formula (I), X is phosphorus, and R1, R2 and R3 may be the same or different, and are independently selected from any one of substituted or unsubstituted C1 to C10 straight-chain alkyl or branched-chain alkyl and substituted or unsubstituted C6 to C14 aryl groups.

[0089] In some other examples, in the structure shown by general formula (I), X is nitrogen, and R1, R2 and R3 are the same or different, and are independently selected from any one of substituted or unsubstituted C1 to C10 straight-chain alkyl or branched-chain alkyl and substituted or unsubstituted C6 to C14 aryl groups.

[0090] For an understanding of substituted or unsubstituted C1-C10 straight-chain alkyl or branched-chain alkyl groups and substituted or unsubstituted C6-C14 aryl groups, please refer to the foregoing content, which will not be repeated here.

[0091] With the above settings, the atoms connected to phase X in the additive do not include hydrogen atoms. In this way, compared with the case where the atoms connected to phase X in the additive include hydrogen atoms, the reactivity of the additive can be lower. Thus, the reaction rate of the quantum dot shell growth reaction is slower, and the size uniformity of the formed quantum dot material is improved.

[0092] In some examples, in the structure shown in general formula (I), X is nitrogen, and the auxiliary is an organic amine compound. This organic amine compound may react with the organic material in the quantum dot core solution, reducing the content of the organic material in the quantum dot core solution. For example, in some cases, to improve the stability of the metal element in solution, the quantum dot core material in the quantum dot core solution includes oleic acid coordinated to the metal element (e.g., cadmium). Under the high-temperature conditions of R2, the amine group (e.g., a primary, secondary, or tertiary amine) readily reacts with oleic acid, causing at least part of the oleic acid to lose its function of improving the stability of the metal element.

[0093] In some examples, in the structure shown by general formula (I), X is nitrogen and the auxiliary is an organic amine compound. The binding force between the organic amine compound and the metal cation in the organic acid salt is relatively weak, so the content of the auxiliary in the cation source composition needs to be relatively high so that the organic acid salt can be dissolved in the preset solvent at a preset temperature.

[0094] Therefore, in some embodiments, X is phosphorus in the structure shown in general formula (I).

[0095] By setting it this way, compared to the case where X is nitrogen and the additive is an organic amine compound, on the one hand, it can avoid the additive reacting with the organic materials in the quantum dot core material, keeping the content of organic materials within a set range to improve the stability of the formed quantum dot material; on the other hand, it can make the additive more compatible with the metal cations included in the organic acid salt, which is beneficial to improving the stability of the complex formed by the additive and the organic acid salt, and can enhance the effect of the additive in improving the solubility and stability of the organic acid salt.

[0096] In some embodiments, the adjuvant includes at least one of trioctylphosphine, tri-n-butylphosphine, and diphenylphosphine.

[0097] For example, the adjuvant includes one of trioctylphosphine, tri-n-butylphosphine, and diphenylphosphine; for example, the adjuvant includes trioctylphosphine; and for another example, the adjuvant includes at least two of trioctylphosphine, tri-n-butylphosphine, and diphenylphosphine, for example, the adjuvant includes trioctylphosphine and tri-n-butylphosphine.

[0098] On the one hand, trioctylphosphine, tri-n-butylphosphine, and diphenylphosphine are readily available, and when the auxiliaries include at least one of these, the material cost of synthesizing quantum dot materials can be reduced to some extent. On the other hand, by setting the auxiliaries to include organophosphine compounds, as mentioned above, firstly, it can prevent the auxiliaries from reacting with the organic materials in the quantum dot core material, thereby improving the stability of the formed quantum dot material; secondly, it can enhance the binding ability of the auxiliaries with the metal cations included in the organic acid salts, thereby improving the effect of the auxiliaries in improving the solubility and stability of the organic acid salts.

[0099] Furthermore, when the additives include trioctylphosphine and / or tri-n-butylphosphine, the atoms connected to phase X in the additives do not include hydrogen atoms. Thus, as mentioned above, the reaction rate of the quantum dot shell growth reaction can be slowed down, thereby improving the size uniformity of the formed quantum dot material.

[0100] In some embodiments, the adjuvant includes at least one of oleylamine and trioctylamine.

[0101] Oleylamine and trioctylamine are readily available, and the material cost of synthesizing quantum dot materials can be reduced to some extent when at least one of the additives is included. Moreover, when the additive includes trioctylamine, the atoms bonded to phase X in the additive do not include hydrogen atoms. Thus, as mentioned above, the reaction rate of the quantum dot shell growth reaction can be slowed down, thereby improving the size uniformity of the formed quantum dot materials.

[0102] In some embodiments, the volume percentage of the auxiliaries in the cationic source composition ranges from 20% to 40%.

[0103] For example, the volume percentage of the adjuvant in the cationic source composition can be measured by one or more of ultraviolet-visible spectroscopy (UV-Vis), high performance liquid chromatography (HPLC), nuclear magnetic resonance spectroscopy, and thermogravimetric analysis.

[0104] For example, the volume percentage of the additive in the cationic source composition can be 20%, 22%, 25%, 28%, 30%, 32%, 35%, 37%, or 40%, etc.

[0105] When the volume percentage of the additive in the cationic source composition is high (e.g., above 40%), the viscosity of the cationic source composition is relatively high, making it difficult to inject and increasing the operational difficulty during the injection of the cationic source composition into the quantum dot core solution. When the volume percentage of the additive in the cationic source composition is low (e.g., below 20%), the effect of the additive in improving the solubility and stability of the organic acid salt is relatively poor, and problems such as solidification blockage, injection system damage and leakage, or poor size uniformity of the formed quantum dot material may still occur. In some examples, the additive is trioctylphosphine (TOP), and the organic acid salt is zinc acetate. When the volume percentage of trioctylphosphine in the cationic source composition is 20%, the cationic source composition gradually solidifies at around 80°C.

[0106] Therefore, by setting the volume percentage of the auxiliary agent in the cationic source composition to be in the range of 20% to 40%, the volume percentage of the auxiliary agent in the cationic source composition can be kept within a suitable range. This can reduce the operational difficulty of injecting the cationic source composition into the quantum dot core solution while ensuring that the auxiliary agent can improve the solubility and stability of organic acid salts.

[0107] The above is an exemplary description of the structure of the additives and the volume ratio of the additives in the cationic source composition. The following will provide an example of the case of organic acid salts in the cationic source composition.

[0108] In some examples, the organic acid salts include organic acid cadmium salts; in these cases, the cations contained in the quantum dot shell include cadmium ions.

[0109] For example, when the organic acid salt includes a cadmium organic acid salt, the quantum dot body in the formed quantum dot material may include at least one of CdSe@CdS, CdTe@CdSe, ZnSe@CdS, and ZnTe@CdSe. For an understanding of the materials of the core and shell of the aforementioned quantum dot materials, please refer to the description of CdS@ZnS in the preceding section, which will not be repeated here.

[0110] In some embodiments, the organic acid salt includes an organic zinc salt; in this case, the cation contained in the quantum dot shell includes zinc ions.

[0111] For example, when the organic acid salt includes an organic zinc salt, the quantum dot bulk in the formed quantum dot material may include CdSe@ZnS, InP@ZnS, CdSe@ZnTe, and Cd 1-x Zn x At least one of S@ZnS, where 0 <x<1。

[0112] When the cations contained in the quantum dot shell include zinc ions, firstly, the quantum dot shell material containing zinc ions can provide a larger band gap, which can avoid optical quenching and improve the luminescence efficiency of the quantum dot material; secondly, the quantum dot shell material containing zinc ions has higher stability, which improves the stability (e.g., chemical stability and / or photostability) of the formed quantum dot material; and thirdly, the quantum dot shell material containing zinc ions has lower toxicity, which can improve the safety of the formed quantum dot material.

[0113] For example, the organic zinc acid salt is an organic zinc acid salt that includes 10 to 22 carbon atoms in its molecule.

[0114] For example, the number of carbon atoms included in the molecule of an organic zinc acid salt can be 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 or 22.

[0115] In some embodiments, the organic zinc acid salt includes at least one of zinc oleate, zinc stearate, zinc acetylacetone, zinc palmitate, zinc myristate, and zinc laurate.

[0116] Among them, zinc palmitate has 16 carbon atoms in its molecule, zinc myristate has 14 carbon atoms in its molecule, and zinc laurate has 12 carbon atoms in its molecule.

[0117] In some examples, the organic zinc acid salt includes one of zinc oleate, zinc stearate, zinc acetylacetonate, zinc palmitate, zinc myristate, and zinc laurate; for example, the organic zinc acid salt includes zinc oleate; in still other examples, the organic zinc acid salt includes at least two of zinc oleate, zinc stearate, zinc acetylacetonate, zinc palmitate, zinc myristate, and zinc laurate; for example, the organic zinc acid salt includes zinc oleate and zinc acetylacetonate.

[0118] The aforementioned organic zinc acid salts have the advantage of being readily available. When the organic zinc acid salts include at least one of zinc oleate, zinc stearate, zinc acetylacetone, zinc palmitate, zinc myristate, and zinc laurate, the material cost of synthesizing quantum dot materials can be reduced to some extent.

[0119] In some embodiments, the molar concentration of the organic acid salt in the cation source composition ranges from 0.1 mmol / L to 1 mmol / L.

[0120] For example, the molar concentration of the organic acid salt in the cation source composition may be 0.1 mmol / L, 0.2 mmol / L, 0.3 mmol / L, 0.4 mmol / L, 0.5 mmol / L, 0.6 mmol / L, 0.7 mmol / L, 0.8 mmol / L, 0.9 mmol / L, or 1 mmol / L, etc.

[0121] For example, the molar concentration of organic acid salts in the cation source composition can be measured using a thermogravimetric analyzer and / or a Fourier transform infrared spectrometer.

[0122] When the molar concentration of organic acid salts in the cation source composition is high (e.g., greater than 1 mmol / L), the viscosity of the cation source composition is relatively high, making it difficult to inject and increasing the operational difficulty of injecting the cation source composition into the quantum dot core solution. Furthermore, a high molar concentration of organic acid salts in the cation source composition results in a larger amount of organic acid salt injected into the reaction system per unit time, potentially leading to a faster growth rate of the quantum dot shell and increasing the size inhomogeneity of the formed quantum dot material. Conversely, a low molar concentration of organic acid salts in the cation source composition (e.g., less than 0.1 mmol / L) results in a slower growth rate of the quantum dot shell, which is detrimental to the large-scale production of quantum dot materials. Therefore, setting the molar concentration of organic acid salts in the cation source composition to a range of 0.1 mmol / L to 1 mmol / L allows for a suitable range of concentration, ensuring a suitable growth rate for the quantum dot shell reaction, reducing the operational difficulty of injecting the cation source composition into the quantum dot core solution, and improving the size uniformity of the formed quantum dot material.

[0123] Some embodiments of this disclosure also provide a method for preparing quantum dot materials, as shown in Figure 1, including steps S1 and S2.

[0124] S1: Formation of quantum dot nuclei.

[0125] S2: A quantum dot shell is formed on the surface of the quantum dot core. The material used to form the quantum dot shell includes the cation source composition as described in any of the above embodiments.

[0126] The beneficial effects of the above-mentioned quantum dot material preparation method are the same as those of the cation source composition described in some of the above embodiments, and will not be repeated here.

[0127] In some embodiments, a quantum dot core (i.e., S1) is formed, including S1.1 to S1.2.

[0128] S1.1: Prepare a metal ion source solution.

[0129] For example, a metal ion source can be prepared by reacting a metal oxide (e.g., cadmium oxide or zinc oxide) or a metal oxyacid salt (e.g., zinc acetate) with an acid (e.g., oleic acid).

[0130] For example, the solvent in the metal ion source solution is a nonpolar solvent.

[0131] S1.2: Add an anion source. The metal ion source reacts with the anion source to obtain quantum dot nuclei.

[0132] For example, the anion source can be a sulfur ion source or a selenium ion source.

[0133] For example, the reaction temperature between the metal ion source and the anion source is 300°C.

[0134] In some embodiments, the preparation method further includes S2A before forming a quantum dot shell (i.e., S2) on the surface of the quantum dot core.

[0135] S2A: Preparation of a cation source composition.

[0136] In some embodiments, a cation source composition (i.e., S2A) is prepared, comprising S2A.1 to S2A.2.

[0137] S2A.1: Provides a cation source solution.

[0138] For example, a cation source solution can be obtained by reacting a metal oxide (e.g., cadmium oxide or zinc oxide) or an organometallic acid salt (e.g., zinc acetate) with an organic acid (e.g., oleic acid) under vacuum conditions.

[0139] For example, a cation source (e.g., an organic acid salt, such as zinc acetylacetonate) can be directly dissolved in a preset solvent to obtain a cation source solution. The dissolution conditions are, for example, under a high-temperature nitrogen atmosphere.

[0140] For example, the solvent in the cation source solution is a nonpolar solvent.

[0141] S2A.2: Under a nitrogen atmosphere, an auxiliary agent is added to the cation source solution, stirred, and cooled to room temperature to obtain an anion source composition.

[0142] In S2A.2, the cation source composition remains stable and does not solidify or precipitate organic acid salts.

[0143] For example, during the process of adding the auxiliary agent to the cation source solution, the temperature of the cation source solution is 100℃ to 150℃, such as 100℃, 110℃, 120℃, 130℃, 140℃ or 150℃.

[0144] In some embodiments, a quantum dot shell (i.e., S2) is formed on the surface of the quantum dot core, including S2.1 and S2.2.

[0145] S2.1: Form a first solution, which includes quantum dot cores and a preset solvent.

[0146] S2.2: As shown in Figure 2, a cation source composition and an anion source composition are injected into a first solution to form a quantum dot shell. The temperature range of the cation source composition injected into the first solution is greater than the solidification temperature of the preset solvent and less than or equal to 100°C.

[0147] In some examples, the cation source composition and the anion source composition are injected into the first solution separately using multiple independently configured injection pumps.

[0148] For example, during the process of injecting the cation source composition into the first solution, the temperature range of the first solution is 250°C to 350°C, such as 250°C, 270°C, 290°C, 300°C, 310°C, 330°C, or 350°C. By setting it in this way, the temperature of the reaction system formed by the first solution and the cation source composition can be relatively high, which is beneficial to the growth of quantum dot shells.

[0149] Understandably, by setting the first solution to include a preset solvent and the cation source composition to include a preset solvent, the number of solvent types in the reaction system formed by the first solution and the cation source composition can be reduced, which can reduce the occurrence of side reactions and improve the uniformity of the distribution of quantum dot cores and organic acid salts in the reaction system. This can also improve the consistency of the quantum dot shell growth rate, thereby improving the photoelectric properties of the formed quantum dot material.

[0150] Furthermore, by including an auxiliary agent in the cationic source composition, and setting the auxiliary agent to form a complex with the metal cation, the organic acid salt can be dissolved in a preset solvent at a preset temperature. In this way, the temperature of the cationic source composition injected into the first solution can be the preset temperature, that is, the temperature range of the cationic source composition injected into the first solution is greater than the solidification temperature of the preset solvent and less than or equal to 100°C. Thus, the problems of solidification blockage, injection system damage and leakage caused by high temperature injection can be avoided.

[0151] In some embodiments, the preset solvent is 1-octadecene (ODE), and the temperature range of the cationic source composition injected into the first solution is 5°C to 30°C.

[0152] For example, the preset solvent is ODE, and the temperature at which the cation source composition is injected into the first solution can be 5°C, 7°C, 9°C, 10°C, 12°C, 14°C, 16°C, 18°C, 20°C, 22°C, 24°C, 25°C, 27°C, 29°C or 30°C.

[0153] For example, the organic acid salt in the cation source composition is zinc oleate or zinc acetylacetonate, etc.

[0154] By setting the temperature of the cation source composition injected into the first solution to be greater than or equal to 5°C, which is higher than the freezing temperature of the preset solvent, the ODE can be kept in a liquid state at the preset temperature, thus making the cation source composition a solution. This improves the operability of injecting the cation source composition into the quantum dot core solution. Furthermore, by setting the temperature of the cation source composition injected into the first solution to be less than or equal to 30°C, the cation source composition can be injected into the first solution at room temperature without heating the injection equipment. This avoids uneven heating of the equipment, which could lead to coagulation and blockage, and also prevents damage and leakage to the injection system due to overheating.

[0155] In some embodiments, during the injection of the cation source composition into the first solution, the injection rate of the cation source composition ranges from 2 ml / h to 30 ml / h.

[0156] For example, during the process of injecting the cation source composition into the first solution, the injection rate of the cation source composition can be 2 ml / h, 5 ml / h, 8 ml / h, 10 ml / h, 12 ml / h, 15 ml / h, 17 ml / h, 20 ml / h, 23 ml / h, 25 ml / h, 27 ml / h, or 30 ml / h, etc.

[0157] When the injection rate of the cation source composition is low (e.g., less than 2 ml / h), the growth rate of the quantum dot shell is slow, which is not conducive to the large-scale production of quantum dot materials. Conversely, when the injection rate is high (e.g., greater than 30 ml / h), the amount of organic acid salt injected into the reaction system per unit time is greater, which may lead to a faster growth rate of the quantum dot shell and potentially increase the size inhomogeneity of the formed quantum dot material. Therefore, setting the injection rate of the cation source composition within the range of 2 ml / h to 30 ml / h allows the injection rate to remain within a suitable range, ensuring the growth rate of the quantum dot shell is also within an appropriate range. This is beneficial for improving the size uniformity of the formed quantum dot material and thus enhancing its photoelectric properties.

[0158] In some embodiments, the adjuvant includes any one of the structures shown in the following general formula (I).

[0159] * indicates the site where the auxiliary agent coordinates with the metal cations included in the organic acid salt.

[0160] R1, R2, and R3 may be the same or different, and are independently selected from hydrogen, substituted or unsubstituted C1-C10 straight-chain alkyl or branched-chain alkyl, and substituted or unsubstituted C6-C14 aryl, and R1, R2, and R3 may not be hydrogen at the same time.

[0161] For an understanding of R1, R2, and R3, please refer to the descriptions of R1, R2, and R3 in the preceding sections; they will not be repeated here.

[0162] As mentioned above, through the above configuration, using phosphine or amine groups, the auxiliaries can coordinate with the metal cations included in the organic acid salts, thereby forming complexes with the organic acid salts. Moreover, by ensuring that R1, R2, and R3 are not all hydrogen at the same time, the solubility of the auxiliaries in the preset solvent can be increased, which is beneficial for the formation of complexes between the auxiliaries and the organic acid salts.

[0163] In some embodiments, the quantum dot core includes cadmium; in the structure shown in general formula (I), X is phosphorus.

[0164] For example, when the quantum dot core includes cadmium, the quantum dot bulk in the formed quantum dot material may include CdSe@ZnS, CdSe@CdS, CdTe@CdSe, CdSe@ZnTe, and Cd 1-x Zn x At least one of S@ZnS. Wherein, 0 <x<1。

[0165] In some examples, the quantum dot core also includes oleic acid coordinated to cadmium.

[0166] With the above settings, compared to the case where X is nitrogen and the additive is an organic amine compound, on the one hand, the reaction between the additive and the oleic acid in the quantum dot core can be avoided, keeping the oleic acid content within a set range to improve the stability of the formed quantum dot material; on the other hand, the binding ability of the additive to the metal cations (such as zinc) included in the organic acid salt is stronger, which is beneficial to improving the stability of the complex formed by the additive and the organic acid salt, and can enhance the effect of the additive in improving the solubility and stability of the organic acid salt.

[0167] In some other embodiments, the quantum dot core does not include cadmium; in the structure shown in general formula (I), X is phosphorus or nitrogen.

[0168] For example, the quantum dot core may include elements such as zinc or indium.

[0169] For example, when the quantum dot core does not contain cadmium, the quantum dot body in the formed quantum dot material may include at least one of InP@ZnS, ZnTe@CdSe, and ZnSe@CdS.

[0170] When the quantum dot core does not contain cadmium, the material of the quantum dot core belongs to a cadmium-free system. In some examples, oleic acid is not suitable as a ligand for the quantum dot core in a cadmium-free system. In this case, the probability of the auxiliaries reacting with the organic material in the quantum dot core is relatively low. The auxiliaries can be organic amine compounds or organophosphorus compounds, i.e., in the structure shown in general formula (I), X can be phosphorus or nitrogen.

[0171] In some embodiments, the anion source composition includes an auxiliary agent and a pre-defined solvent, and further includes an anion. In the anion source composition, the auxiliary agent is capable of coordinating with the anion.

[0172] For example, the anion source composition includes at least one of trioctylphosphine, tri-n-butylphosphine, and diphenylphosphine.

[0173] By incorporating additives into the anion source composition, the stability of the anion can be improved. Furthermore, by including pre-selected solvents in the anion source composition, cation source composition, and first solution, the number of solvent types in the reaction system formed by these components can be reduced, minimizing side reactions and improving the uniformity of distribution of quantum dot cores, organic acid salts, and anions within the reaction system. This enhances the consistency of quantum dot shell growth rate and ultimately improves the photoelectric properties of the formed quantum dot material. Moreover, by including additives in both the anion source composition and cation source composition, the number of organic materials in the reaction system can be reduced, further minimizing side reactions.

[0174] In some embodiments, the anion source composition includes anions comprising selenium and / or sulfur. In this case, the quantum dot shell contains anions comprising selenium and / or sulfur.

[0175] For example, in cases where the anion source composition includes selenium as an anion and the cation source composition includes zinc as a metal cation, the quantum dot shell material can be zinc selenide (ZnSe).

[0176] For example, in cases where the anion source composition includes sulfur as an anion and the cation source composition includes zinc as a metal cation, the quantum dot shell material can be zinc sulfide (ZnS).

[0177] For example, in cases where the anions included in the anion source composition are selenium and sulfur, and the metal cations included in the cation source composition are zinc, the material of the quantum dot shell can be zinc sulfoselenide.

[0178] For example, in the material of the quantum dot shell, the molar ratio of cations (e.g., zinc) to the aforementioned metal anions is 1:1.

[0179] When the anions contained in the quantum dot shell include selenium and / or sulfur, the quantum dot shell material has a larger band gap, which can form type I quantum dots and improve the performance of the formed quantum dots.

[0180] Some embodiments of this disclosure also provide a quantum dot material. The quantum dot material is prepared using the preparation method described in any of the above embodiments.

[0181] The beneficial effects of the quantum dot materials described above are the same as those of the preparation methods of quantum dot materials described in some of the above embodiments, and will not be repeated here.

[0182] In some embodiments, the quantum dot material includes a quantum dot body and an additive, wherein the additive is disposed in the quantum dot body.

[0183] In some examples, the quantum dot bulk is group II-VI quantum dots, such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgSe, HgTe, HgS, and Hg. x Cd 1-x Te, Hg x Cd 1-x S, Hg x Cd 1-x Se, Hg x Zn 1-x Te, Cd x Zn 1-x Se, or Cd x Zn 1-x S, etc., of which 0 <x<1。

[0184] In other examples, the quantum dot bulk has a core-shell structure, such as CdSe@ZnS, CdSe@CdS, InP@ZnS, CdTe@CdSe, CdSe@ZnTe, ZnTe@CdSe, ZnSe@CdS, or Cd 1-x Zn x S@ZnS, etc.

[0185] In other examples, the quantum dot bulk is CuInS2, CuInSe2, or AgInS2, etc.

[0186] Understandably, when quantum dot materials include additives that are located within the quantum dot matrix, the stability of the quantum dot matrix can be improved by utilizing the additives, thereby enhancing the stability of the quantum dot material.

[0187] In some examples, the quantum dot material also includes a ligand material liganded to the quantum dot body. Exemplarily, the ligand material may be selected from any one or more combinations of organic acids, organic amines, organophosphorus compounds, and organothiols; for example, the ligand material may be oleic acid, oleylamine, or dodecyl mercaptan, etc.

[0188] Some embodiments of this disclosure also provide a light-emitting device 100. As shown in Figures 3 and 4, the light-emitting device 100 includes a cathode 120, an anode 110, and a light-emitting layer 130. The anode 110 and the cathode 120 are disposed opposite to each other. The light-emitting layer 130 is disposed between the anode 110 and the cathode 120. The material of the light-emitting layer 130 includes the quantum dot material as described in any of the above embodiments.

[0189] The beneficial effects of the above-mentioned light-emitting devices are the same as those of the quantum dot materials described in some of the above embodiments, and will not be repeated here.

[0190] For example, as shown in Figures 3 and 4, the anode 110 and the cathode 120 can be arranged opposite each other along a first direction X.

[0191] For example, the materials of the anode 110 and the cathode 120 may be the same or different, and can be independently selected from at least one of conductive metal oxide materials (e.g., transparent conductive metal oxide materials), conductive glass (e.g., transparent conductive glass), conductive polymers (e.g., transparent conductive polymers), and metallic materials (e.g., opaque metallic materials). The conductive metal oxide materials are, for example, indium tin oxide (ITO), fluorine-doped tin oxide (FTO), or indium zinc oxide (IZO), etc., and the metallic materials are, for example, aluminum (Al), silver (Ag), or magnesium-silver alloy (Mg:Ag), etc. The conductive polymers are, for example, polyaniline (PANI), polycarbazole (PZ), polythiophene (PTh), or polypropylene (PPy), etc.

[0192] During operation, voltages are applied to the anode 110 and the cathode 120 respectively, generating an electric field between them. This field drives the holes in the anode 110 and the electrons in the cathode 120 to recombine in the quantum dot light-emitting layer 130, generating excitons (i.e., electron-hole pairs). The excitons then undergo radiative transitions back to the ground state, emitting photons and thus emitting light.

[0193] In some embodiments, as shown in Figures 3 and 4, to improve luminous efficiency, the light-emitting device 100 further includes an electron transport unit 140 located on the side of the light-emitting layer 130 near the cathode 120 and in contact with the light-emitting layer 130. The electron transport unit 140 includes, for example, at least one of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (EBL).

[0194] In some embodiments, as shown in Figures 3 and 4, to improve luminous efficiency, the light-emitting device 100 further includes a hole transport unit 150 located on the side of the light-emitting layer 130 near the anode 110 and in contact with the light-emitting layer 130. The hole transport unit 150 includes, for example, at least one of a hole injection layer (HIL) 151, a hole transport layer (HTL) 152, and an electron blocking layer (EBL).

[0195] By setting up film layers such as hole transport unit 150 and electron transport unit 140, it is equivalent to setting transition steps between anode 110 and light-emitting layer 130, and between cathode 150 and light-emitting layer 130, which reduces the potential barrier height that carrier transitions need to overcome, resulting in higher luminous efficiency.

[0196] Some embodiments of this disclosure provide a display panel 200. As shown in Figures 3 to 5, the display panel 200 includes a plurality of light-emitting devices 100 as described in any of the above embodiments.

[0197] The aforementioned display panel 200 can be applied to a display device. The display device can be any display device that displays either moving (e.g., video) or stationary (e.g., still images), and whether it displays text or images. More specifically, the display panel of the described embodiment is contemplated for implementation in or associated with a variety of electronic devices, such as (but not limited to) mobile phones, wireless devices, personal data assistants (PDAs), handheld or portable computers, GPS receivers / navigators, cameras, MP4 video players, camcorders, game consoles, watches, clocks, calculators, television monitors, flat panel displays, computer monitors, automotive displays (e.g., odometer displays, etc.), navigators, cockpit controllers and / or displays, displays of camera views (e.g., displays of rearview cameras in vehicles), electronic photographs, electronic billboards or signs, projectors, architectural structures, packaging and aesthetic structures (e.g., displays of images of a piece of jewelry), etc.

[0198] For example, a plurality of light-emitting devices 100 may be arranged along a second direction Y, wherein the first direction X intersects (e.g., is perpendicular to) the second direction Y, and the second direction Y is, for example, a direction parallel to the plane where the substrate 210 is located.

[0199] In some embodiments, as shown in Figures 3 and 4, the plurality of light-emitting devices 100 of the display panel 200 include at least one first light-emitting device 101, at least one second light-emitting device 102, and at least one third light-emitting device 103. Under the action of a driving voltage, the first light-emitting device 101 is configured to emit a first color light (e.g., blue light), the second light-emitting device 102 is configured to emit a second color light (e.g., green light), and the third light-emitting device 103 is configured to emit a third color light (e.g., red light). Thus, the brightness (grayscale) of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 can be adjusted respectively, and multiple colors can be displayed through color combination and superposition, thereby achieving full-color display of the display panel 200.

[0200] It should be understood that, as shown in Figures 3 and 4, when the multiple light-emitting devices 100 of the display panel 200 include at least one first light-emitting device 101, at least one second light-emitting device 102 and at least one third light-emitting device 103, the materials of the light-emitting layer 131 of the first light-emitting device 101, the light-emitting layer 132 of the second light-emitting device 102 and the light-emitting layer 133 of the third light-emitting device 103 are different, so as to achieve the purpose of emitting different colors of light.

[0201] In some embodiments, as shown in FIG5, the display panel 200 includes a substrate 210 and a light-emitting functional layer 220 disposed on one side of the substrate 210, the light-emitting functional layer 220 including a plurality of light-emitting devices 100.

[0202] For example, the material of the substrate 210 can be a rigid material, such as glass, to realize a rigid substrate display; or the material of the substrate 210 can also be a flexible material, such as polyimide (PI) or polyethylene terephthalate (PET), to realize a flexible substrate display.

[0203] In some examples, as shown in FIG3, the anode 110 may be located on the side of the light-emitting layer 130 closer to the substrate 210, and the cathode 120 may be located on the side of the light-emitting layer 130 away from the substrate 210. In this case, the light-emitting device 100 may be referred to as a positive light-emitting device, and the structure of the light-emitting device 100 includes, for example, an anode 110, a hole transport unit 150, a light-emitting layer 130, an electron transport unit 140, and a cathode 120 arranged sequentially in the direction away from the substrate 210.

[0204] In other examples, as shown in FIG4, the cathode 120 may be located on the side of the light-emitting layer 130 closer to the substrate 210, and the anode 110 may be located on the side of the light-emitting layer 130 away from the substrate 210. In this case, the light-emitting device 100 may be referred to as an inverted light-emitting device, and the structure of the light-emitting device 100 includes, for example, a cathode 120, an electron transport unit 140, a light-emitting layer 130, a hole transport unit 150, and an anode 110 arranged sequentially in the direction away from the substrate 210.

[0205] In some embodiments, as shown in Figures 3 to 5, the light-emitting functional layer 220 in the display panel 200 further includes a pixel defining layer 221, which has a plurality of openings Q, and a plurality of light-emitting devices 100 can be configured one-to-one with the plurality of openings Q.

[0206] In some examples, as shown in FIG5, the display panel 200 further includes a driving circuit layer 230 disposed between the substrate 210 and the light-emitting functional layer 220, the driving circuit layer 230 including a plurality of pixel driving circuits 231. The pixel driving circuits 231 include, for example, a plurality of transistor TFTs.

[0207] For example, the pixel driving circuit 231 can generate a driving current. Each light-emitting device 100 can emit light under the driving action of the driving current generated by the corresponding pixel driving circuit 231. The light emitted by multiple light-emitting devices 100 cooperates with each other, thereby enabling the display panel 200 to perform the display function.

[0208] In some examples, as shown in FIG5, the display panel 200 also includes an encapsulation layer 240 disposed on the side of the light-emitting functional layer 220 away from the substrate 210.

[0209] The technical solutions provided in this disclosure will be described in detail and by way of the following experimental examples and comparative examples.

[0210]

Example 1

[0211] Example 1 prepared a cationic source composition A1 including the adjuvant trioctylphosphine (TOP), and quantum dot material A2 was prepared using cationic source composition A1. The preparation method of quantum dot material A2 in Example 1 includes M1 to M3.

[0212] M1: Synthetic quantum dot nuclei CdZnSe that emit red light, specifically including M1.1 to M1.3.

[0213] M1.1: Add cadmium oxide (90 mg), zinc acetate (165 mg), oleic acid (5 ml) and 1-octadecene (ODE, 10 ml) to a three-necked flask and mix well to obtain the first mixture.

[0214] M1.2: React the first mixture at 120°C under vacuum for 30 minutes until the solid is completely dissolved to obtain the second solution.

[0215] M1.3: Convert the three-necked flask to a nitrogen atmosphere, heat the second solution to 300°C, then add 3 ml of a 0.5 M trioctylphosphine (TOP) solution of selenium to the second solution and react for 1 h to obtain the first solution.

[0216] M2: Preparation of the cation source composition A1, specifically including M2.1 to M2.3.

[0217] M2.1: Add zinc acetate (2.2 g, 12 mmol), oleic acid (12 ml) and 1-octadecene (12 ml) to a reaction vessel to obtain a second mixture.

[0218] M2.2: React the second mixture at 120°C under vacuum until all zinc acetate is dissolved and no more bubbles are generated, to obtain the third solution.

[0219] M2.3: The reaction vessel was switched to a nitrogen atmosphere, and trioctylphosphine (TOP, 12 mmol) was added. After stirring, the mixture was cooled to room temperature to obtain the cation source composition A1. The trioctylphosphine constituted 33% of the volume of the cation source composition A1.

[0220] M3: Form a quantum dot shell to obtain quantum dot material A2, specifically including M3.1 to M3.2.

[0221] M3.1: Maintain the temperature of the first solution prepared in M1 at 300℃. Using a syringe pump, inject 6 ml of the room-temperature cation source composition A1, 3 ml of a 0.3M Se-TOP-ODE solution (TOP to ODE ratio of 1:2), and 3 ml of a 0.3M S-TOP-ODE solution (TOP to ODE ratio of 1:2) into a three-necked flask to carry out the quantum dot shell growth reaction. The molar ratio of Zn to (Se+S) injected into the three-necked flask is approximately 1:1, and the injection rate of the cation source composition, Se-TOP-ODE solution, and S-TOP-ODE solution is the same: 6 ml / h.

[0222] M3.2: Purification yields quantum dot material A2.

[0223] In this embodiment, the photoluminescence quantum yield (PLQY) and emission spectrum of the prepared quantum dot material A2 were measured. The results showed that the PLQY of quantum dot material A2 was 78%. In the emission spectrum of quantum dot material A2, the peak wavelength was 628 nm and the full width at half maximum (FWHM) was 22 nm.

[0224] Comparative Example 1

[0225] Comparative Example 1 prepared a comparative cation source composition A1' without additives, and quantum dot material A2' was prepared using the comparative cation source composition A1'. The preparation method of the comparative quantum dot material A2' in Comparative Example 1 includes N1 to N3. Wherein, N1 is the same as M1 in Example 1.

[0226] N2: The preparation of the comparative cation source composition A1' specifically includes N2.1 to N2.2.

[0227] N2.1: Add zinc acetate (2.2 g, 12 mmol), oleic acid (12 ml) and 1-octadecene (24 ml) to a reaction vessel to obtain a second mixture.

[0228] N2.2: The second mixture was reacted at 120°C under vacuum until all zinc acetate was dissolved and no more bubbles were generated, to obtain the comparative cation source composition A1'.

[0229] N3: Form a quantum dot shell to obtain the comparative quantum dot material A2', specifically including N3.1 to N3.2.

[0230] N3.1: Keep the temperature of the first solution prepared by N1 at 300°C, and use a syringe pump to quickly inject 6 ml of the control cation source composition A1' at a temperature greater than 100°C, 3 ml of 0.3 M Se-ODE solution, and 3 ml of 0.3 M S-ODE solution into the three-necked flask to carry out the quantum dot shell growth reaction.

[0231] N3.2: Purification yields the comparative quantum dot material A2'.

[0232] In this comparative example, the photoluminescence quantum yield (PLQY) and emission spectrum of the prepared comparative quantum dot material A2' were measured. The results show that the photoluminescence quantum yield (PLQY) of the comparative quantum dot material A2' is 54%. In the emission spectrum of the comparative quantum dot material A2', the peak wavelength is 620 nm and the full width at half maximum (FWHM) is 28 nm.

[0233] Table 1 shows a comparison of the measurement results of Example 1 and Comparative Example 1.

[0234] Table 1

[0235] As shown in Table 1, compared to Comparative Example 1, the quantum dot material A2 prepared in Example 1 has a higher photoluminescence quantum yield (PLQY) and a smaller full width at half maximum (FWHM). Furthermore, the peak value of the comparative quantum dot material A2' prepared in Comparative Example 1 exhibits a blue shift. This indicates that by including the additive in the cationic source composition, firstly, the cationic source zinc oleate can be dissolved in the solvent ODE at room temperature, thereby ensuring that the temperature of the cationic source composition injected into the first solution is room temperature; secondly, the uniformity of the quantum dot shell growth rate can be improved, thus improving the size uniformity of the quantum dot material and resulting in a lower FWHM; and thirdly, crystal phase defects caused by excessively rapid or uneven growth of the quantum dot shell can be avoided, thereby improving the luminescence efficiency of the quantum dot material. In addition, when the cationic source composition includes the additive, changes in the quantum dot peak position caused by uneven growth rate of the quantum dot shell can be avoided, and the exchange of zinc and cadmium ions caused by a sudden increase in the zinc content in the first solution can be avoided, further preventing peak position changes.

[0236]

Example 2

[0237] Example 2 prepared a cationic source composition B1 including the adjuvant trioctylphosphine (TOP), and used the cationic source composition B1 to prepare quantum dot material B2. The preparation method of quantum dot material B2 in Example 2 includes P1 to P3. Among them, P1 is the same as M1 in Example 1, and P3 is the same as M3 in Example 1.

[0238] P2: Preparation of the cation source composition B1, specifically including P2.1 to P2.3.

[0239] P2.1: Add zinc oxide (977 mg, 12 mmol), oleic acid (OA, 12 ml) and 1-octadecene (12 ml) to the reaction vessel to obtain the second mixture.

[0240] P2.2: React the second mixture at 120°C under vacuum for 30 to 60 minutes until no more bubbles are generated. Then, heat the second mixture to 300°C and react for another 20 minutes until all zinc oxide is dissolved.

[0241] P2.3: The reaction vessel was switched to a nitrogen atmosphere and cooled to 120°C. Then, trioctylphosphine (TOP, 12 mmol) was added, stirred, and cooled to room temperature to obtain the cation source composition B1.

[0242] In this embodiment, the photoluminescence quantum yield (PLQY) and emission spectrum of the prepared quantum dot material B2 were measured. The results show that the photoluminescence quantum yield (PLQY) of quantum dot material B2 is 74%. In the emission spectrum of quantum dot material B2', the peak wavelength is 625 nm and the full width at half maximum (FWHM) is 24 nm.

[0243] Table 2

[0244] As shown in Tables 1 and 2, the quantum dot material B2 prepared in Example 2 has slightly lower performance than that in Example 1. This may be because zinc oxide has lower activity compared to zinc acetate.

[0245]

Example 3

[0246] Example 3 prepared a cationic source composition C1 including the adjuvant trioctylphosphine (TOP), and used the cationic source composition C1 to prepare quantum dot material C2. The preparation method of quantum dot material C2 in Example 3 includes T1 to T3. Among them, T1 is the same as M1 in Example 1.

[0247] T2: Preparation of the cation source composition C1, specifically including T2.1 to T2.2.

[0248] T2.1: Zinc acetylacetonate (3.16 mg, 12 mmol) and 1-octadecene (24 ml) were added to a reaction vessel to obtain a third mixture. The third mixture was heated to 120 °C and evacuated for 10 min to remove water and oxygen.

[0249] T2.2: The reaction vessel was switched to a nitrogen atmosphere, and trioctylphosphine (TOP, 12 mmol) was added. After stirring until completely dissolved, the mixture was cooled to room temperature to obtain the cation source composition C1.

[0250] T3: Form a quantum dot shell to obtain quantum dot material A2, specifically including M3.1 to M3.2.

[0251] T3.1: Maintaining the temperature of the first solution prepared in T1 at 300℃, use a syringe pump to uniformly inject 6 ml of the room-temperature cation source composition C1 and 6 ml of a 0.3 M Se-TOP-ODE solution (TOP to ODE ratio of 1:2) into a three-necked flask to carry out the quantum dot shell growth reaction. The molar ratio of Zn to Se injected into the three-necked flask is approximately 1:1, and the injection rate of both the cation source composition and the Se-TOP-ODE solution is the same: 6 ml / h.

[0252] T3.2: Purification yields quantum dot material C2.

[0253]

Example 4

[0254] Example 4 prepared a cationic source composition A1 including the adjuvant trioctylphosphine (TOP), and used cationic source composition A1 to prepare quantum dot material D2. The preparation method of quantum dot material D2 in Example 4 is similar to the preparation method of quantum dot material A2 in Example 1, with the only difference being:

[0255] (1) The first solution prepared in M1 contains CdZnSe quantum dot nuclei that emit blue light.

[0256] (2) In M3.1, the following are injected into the three-necked flask: 6 ml of cation source composition A1 at room temperature and 6 ml of 0.3M S-ODE solution for the growth reaction of quantum dot shells. The molar ratio of Zn to S injected into the three-necked flask is approximately 1:1.

[0257]

Example 5

[0258] Example 5 prepared a cationic source composition A1 including the adjuvant trioctylphosphine (TOP), and used cationic source composition A1 to prepare quantum dot material E2. The preparation method of quantum dot material E2 in Example 5 is similar to the preparation method of quantum dot material A2 in Example 1, with the only difference being:

[0259] (1) Replace M1 with M1'.

[0260] M1': Synthetic quantum dot nuclei CdZnSe that emit green light, specifically including M1'.1 to M1'.3.

[0261] M1'.1: Add cadmium oxide (4 mmol), oleic acid and 1-octadecene to a 100 ml three-necked flask, evacuate for 10 min and then switch to a nitrogen atmosphere to obtain a cadmium precursor solution with a concentration of 0.15 M.

[0262] M1'.2: Add zinc oxide (20 mmol), oleic acid and 1-octadecene to a 100 ml three-necked flask, evacuate for 10 min and then switch to a nitrogen atmosphere to obtain a zinc precursor solution with a concentration of 0.5 M.

[0263] M1'.3: In a three-necked flask, add 2 ml of the cadmium precursor solution prepared by M1'.1, 8 ml of the zinc precursor solution prepared by M1'.2, and 10 ml of ODE. Heat to 300 degrees and add 3 ml of 0.5 M trioctylphosphine solution of selenium. React for 1 h to obtain the first solution.

[0264] (2) In M3.1, the following are injected into the three-necked flask: 6 ml of cation source composition A1 at room temperature and 6 ml of S-ODE solution with a concentration of 0.3 M, for the growth reaction of quantum dot shells. The molar ratio of Zn to S injected into the three-necked flask is approximately 1:1.

[0265] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A cation source composition, comprising: Organic acid salts, auxiliaries, and a preset solvent; the organic acid salts include metal cations, and the auxiliaries are configured to at least form a complex with the metal cations included in the organic acid salts, such that the organic acid salts are soluble in the preset solvent at a preset temperature; Wherein, the preset temperature is greater than the freezing temperature of the preset solvent and less than or equal to 100°C; the dipole moment of the preset solvent is less than or equal to a set threshold.

2. The cation source composition according to claim 1, wherein, The set threshold is less than or equal to 0.5D.

3. The cation source composition according to claim 1 or 2, wherein, The adjuvant includes any one of the structures shown in the following general formula (I); Where X is nitrogen or phosphorus; * indicates the site where the auxiliary agent coordinates with the metal cations included in the organic acid salt; R1, R2, and R3 may be the same or different, and are independently selected from hydrogen, substituted or unsubstituted C1-C10 straight-chain alkyl or branched-chain alkyl, and substituted or unsubstituted C6-C14 aryl, and R1, R2, and R3 may not be hydrogen at the same time.

4. The cation source composition according to claim 3, wherein, In the structure shown in general formula (I), R1, R2 and R3 may be the same or different, and are independently selected from any one of substituted or unsubstituted C1 to C10 straight-chain alkyl or branched-chain alkyl and substituted or unsubstituted C6 to C14 aryl groups.

5. The cation source composition according to claim 3, wherein, In the structure shown in general formula (I), X is phosphorus.

6. The cation source composition according to any one of claims 1 to 5, wherein, The adjuvant includes at least one of trioctylphosphine, tri-n-butylphosphine, and diphenylphosphine.

7. The cation source composition according to any one of claims 1 to 6, wherein, The adjuvant includes at least one of oleylamine and trioctylamine.

8. The cation source composition according to any one of claims 1 to 7, wherein, The volume percentage of the auxiliary agent in the cationic source composition ranges from 20% to 40%.

9. The cation source composition according to any one of claims 1 to 8, wherein, The organic acid salts include zinc salts of organic acids.

10. The cation source composition according to claim 9, wherein, The organic zinc acid salts include at least one of zinc oleate, zinc stearate, zinc acetylacetone, zinc palmitate, zinc myristate, and zinc laurate.

11. The cation source composition according to any one of claims 1 to 10, wherein, The preset solvent includes at least one of 1-octadecene, alkane solvents, toluene, and chloroform.

12. The cation source composition according to any one of claims 1 to 11, wherein, In the cation source composition, the molar concentration of the organic acid salt ranges from 0.1 mmol / L to 1 mmol / L.

13. A method for preparing a quantum dot material, comprising: Forming quantum dot nuclei; A quantum dot shell is formed on the surface of the quantum dot core; The material used to form the quantum dot shell includes the cation source composition as described in any one of claims 1 to 12.

14. The method for preparing quantum dot materials according to claim 13, wherein, The adjuvant includes any one of the structures shown in the following general formula (I); * indicates the site where the auxiliary agent coordinates with the metal cations included in the organic acid salt; R1, R2, and R3 may be the same or different, and are independently selected from hydrogen, substituted or unsubstituted C1 to C10 straight-chain alkyl or branched-chain alkyl, and substituted or unsubstituted C6 to C14 aryl, and R1, R2, and R3 are not all hydrogen at the same time. Wherein, the quantum dot core includes cadmium; in the structure shown in general formula (I), X is phosphorus; or, The quantum dot core does not contain cadmium; in the structure shown in general formula (I), X is phosphorus or nitrogen.

15. The method for preparing quantum dot materials according to claim 13 or 14, wherein, The formation of a quantum dot shell on the surface of the quantum dot core includes: A first solution is formed, the first solution comprising the quantum dot core and the preset solvent; The cation source composition and the anion source composition are injected into the first solution to form the quantum dot shell; The temperature range of the cation source composition injected into the first solution is greater than the solidification temperature of the preset solvent and less than or equal to 100°C.

16. The method for preparing quantum dot materials according to claim 15, wherein, The preset solvent is 1-octadecene, and the temperature range of the cationic source composition injected into the first solution is 5°C to 30°C.

17. The method for preparing quantum dot materials according to claim 15 or 16, wherein, During the injection of the cation source composition into the first solution, the injection rate of the cation source composition ranges from 2 ml / h to 30 ml / h.

18. The method for preparing quantum dot materials according to any one of claims 15 to 17, wherein, The anion source composition includes the auxiliary agent and the preset solvent, and further includes anion; in the anion source composition, the auxiliary agent is capable of coordinating with the anion.

19. The method for preparing quantum dot materials according to claim 18, wherein, The anions included in the anion source composition include selenium and / or sulfur.

20. A quantum dot material, prepared by any one of claims 13 to 19.

21. The quantum dot material according to claim 20, wherein, The quantum dot material includes a quantum dot body and the additive, wherein the additive is disposed within the quantum dot body.

22. A light-emitting device, comprising: Anode and cathode arranged opposite each other; A light-emitting layer is disposed between the anode and the cathode; The material of the light-emitting layer includes the quantum dot material as described in claim 20 or 21.

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