Patterned quantum dot light-emitting array and manufacturing method therefor

Abstract

The present invention provides quantum dots having polarity, and a manufacturing method therefor, the quantum dots, used to manufacture electroluminescent devices by means of patterning using electrophoresis, comprising: a core part; a shell part surrounding the core part; at least one ligand part coupled to the shell part; and a polar part coupled to the ligand part and having either positive or negative polarity.

Description

Patterned quantum dot luminescent array and method for manufacturing the same

[0001] The present invention relates to a quantum dot having polarity and a method for manufacturing the same, and more particularly, to a quantum dot having polarity and a method for manufacturing the same, which can be utilized for manufacturing a quantum dot pattern, an electroluminescent element, and a display device through patterning using an electrophoretic method by controlling the zeta potential through ligand substitution of the quantum dot.

[0002] The present invention is a method for manufacturing polar quantum dots as a high-brightness self-luminous material applicable to VR / AR technology, one of the 10 key industries of the "5G+ Strategy" announced by the government in 2019. The VR / AR market size in 2020 is expected to be 18.8 billion dollars, and among VR / AR technologies, LCD-based LCoS has very low brightness due to a complex optical system with a transmittance of less than 30%, and OLED-based OLEDoS has low resolution due to limitations in patterning technology, resulting in a screen-door effect, which reduces realism, and therefore requires ultra-fine pixel formation technology and high-brightness self-luminous element technology.

[0003] In light of these points, the quantum dot manufacturing technology described below, which exhibits high material efficiency during the patterning process, is expected to have a significant impact on the development of low-cost, ultra-high-resolution displays.

[0004] Quantum dots possess unique chemical, optical, and physical properties that differ from those of conventional bulk materials, and these properties are significantly influenced by the size of the nanoparticles. This is known as the quantum dot effect. Group II-VI semiconductor nanomaterials, in particular, exhibit high luminous efficiency and allow for easy control of particle size at the nanometer level. Therefore, they are widely used in biological applications, LED materials, single-electron transistors, solar cells, and photocatalytic materials. To maintain size uniformity, many studies have been conducted on methods using surfactants. However, surfactants strongly bind to quantum dots, which poses significant limitations in their application. Furthermore, removing surfactants for direct application of quantum dots can lead to agglomeration and clumping, decreased thermal and optical stability due to oxygen and water in the air, and loss of their inherent properties, leading to stability issues. Therefore, extensive research has focused on methods for coating quantum dots with polymers and other stabilizers.

[0005] Meanwhile, the core-shell nanocomposite structure not only improves the stability and dispersibility of the core material inside, but also allows for the use of shell materials with unique properties to impart additional functions to those of a single core material. Therefore, efforts have been made to realize the core-shell nanocomposite structure using emulsion polymerization, atomic transfer radical polymerization, graft polymerization, layer-by-layer polymerization, etc. However, the drawbacks of the above methods include complex processes and the use of expensive reactants. In addition, during the production of the core-shell, there is a problem that the stability of the quantum dots decreases and agglomeration and lumping occur during the surfactant removal process, which prevents the original properties of the core material from being maintained.

[0006] Therefore, considering the direct application of quantum dots, there is a strong demand for a new manufacturing method that can be mass-produced by a simple and inexpensive process, which can coat the surface of quantum dots with a polymer while maintaining the stability of the quantum dots and their inherent properties, and which allows for easy patterning of quantum dots.

[0007] The purpose of the present invention is to solve the above problems, and the purpose of the present invention is to provide a full-color quantum dot light-emitting array in which at least one polar portion is formed by controlling the zeta potential through ligand substitution of at least one ligand portion and a quantum dot, thereby forming a quantum dot having either a positive or negative polarity, and the quantum dot is patterned.

[0008] The technical problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0009] According to one embodiment of the present invention, a patterned quantum dot light-emitting array comprises: a base substrate; electrode pads arranged on the substrate; and an array in which clusters of red, green, and blue quantum dots are patterned and arranged on the electrode pads, wherein the electrode pads include independent pads of each of the red, green, and blue quantum dots.

[0010] In an embodiment of the present invention, the clusters of red, green and blue quantum dots patterned on the array may each form a pixel.

[0011] In an embodiment of the present invention, the red pad and the green pad among the electrode pads may include a main electrode portion extending in one direction while being spaced apart from each other, and a branch portion extending in a direction perpendicular to the main electrode portion, and the branches of the red pad and the green pad may be arranged to intersect and be spaced apart from each other at equal intervals to form symmetry.

[0012] In an embodiment of the present invention, the blue pad may be arranged to start from one side of the main electrode portion of the red pad and the green pad and pass between the spaced branch portions of the red pad and the green pad without branching.

[0013] In an embodiment of the present invention, the electrode pad is a transparent electrode, and may include, for example, ITO.

[0014] In an embodiment of the present invention, the quantum dot may include a core-shell structure, and a ligand including a hydrocarbon chain may be attached to the shell surface.

[0015] In an embodiment of the present invention, the ligand may have one of positive or negative polarity.

[0016] In an embodiment of the present invention, the quantum dots may be formed using an electrophoresis method and then formed on the electrode pad using a water dispersion method.

[0017] In an embodiment of the present invention, the ligand may be attached to the shell as a binding group, the binding group may include an SH group, and the ligand may include a mercapto group.

[0018] In an embodiment of the present invention, the quantum dots may include quantum dots of different sizes, and the clusters of red, green, and blue quantum dots may have different heights.

[0019]

[0020] In addition, the present invention for achieving the above purpose provides a quantum dot having polarity, characterized in that it comprises a core portion; a shell portion surrounding the core portion; at least one ligand portion bonded to the shell portion; and a polar portion bonded to at least the ligand portion and having one of positive and negative polarities.

[0021] In an embodiment of the present invention, at least one ligand moiety may be characterized as being a hydrocarbon chain.

[0022] Additionally, in an embodiment of the present invention, the polar portion may be characterized by having a polarity of either the positive electrode or the negative electrode by ligand substitution with the at least one ligand portion.

[0023] In addition, the present invention provides a method for manufacturing a quantum dot used for manufacturing an electroluminescent device through patterning using an electrophoresis method, comprising: (a) preparing a non-polar quantum dot; (b) surface-modifying the non-polar quantum dot; (c) washing the surface-modified quantum dot; and (d) dispersing the washed quantum dot in water to produce a polar quantum dot; and a method for manufacturing a polar quantum dot characterized in that the quantum dot has one of a positive polarity and a negative polarity by ligand substitution.

[0024] In an embodiment of the present invention, the step (b) may be characterized by including: (b1) a step of preparing a container containing a dispersion solution and an acid compound or a base compound having a mercapto functional group; (b2) a step of introducing the non-polar quantum dots into the container and then heating them; and (b3) a step of reacting the dispersion solution, the acid compound or the base compound having a mercapto functional group, and the non-polar quantum dots at a preset temperature for a preset time.

[0025]

[0026] In an embodiment of the present invention, the step (c) may be characterized by including: (c1) a step of preparing a washing container containing an organic solvent; (c2) a step of washing by alternately performing a process of dispersing and precipitating the surface-modified quantum dots in the organic solvent; and (c3) a step of drying the washed quantum dots by at least one of natural drying and vacuum drying to remove residual solvent.

[0027] In an embodiment of the present invention, the step (d) may be characterized by including: (d1) forming a quantum dot dispersion solution by dispersing quantum dots from which the residual solvent has been removed in a buffer solution; (d2) removing aggregates and impurities of quantum dots present in the quantum dot dispersion solution by centrifugation; (d3) mixing a pH-adjusted buffer solution with the quantum dot dispersion solution; and (d4) imparting charges to the surface-modified quantum dots by adjusting the pH.

[0028] According to an embodiment of the present invention according to the above configuration, there is an effect that pixel implementation at a level close to the limit of general semiconductor processes can be possible without changing the technical difficulty even when the resolution increases during patterning of self-luminous elements. This is comparable to the fact that even in the case of the most advanced inkjet printing in the past, development was slow due to a difficult process and it was difficult to implement pixels at the nanometer level close to the limit of semiconductor processes. In addition, since it is possible to place polarized QDs at a desired location based on an electrophoresis method, it is possible to design optical integrated circuits, and it is a promising technology that can also implement QLEDoS, a display for VR and AR, and its commercialization is expected.

[0029] Furthermore, embodiments of the present invention can be applied to the development of single-photon light sources necessary for realizing quantum information communication technology, and such self-luminous devices are expected to be utilized and developed for quantum communication / computing, etc., as they enable direct control of photons with low-power, high-frequency electrical signals.

[0030] More specifically, according to the present invention, since at least one polar portion has a zeta potential controlled through ligand substitution of at least one ligand portion and a quantum dot, and thus has either a positive or negative polarity, it can be utilized to manufacture a quantum dot pattern, an electroluminescent element, and a display device through patterning using an electrophoretic method.

[0031] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the composition of the invention described in the claims.

[0032] FIG. 1 and FIG. 2 are conceptual diagrams showing quantum dots having polarity according to one embodiment of the present invention.

[0033] FIG. 3 is a flowchart showing a method for manufacturing a quantum dot having polarity according to an embodiment of the present invention.

[0034] FIG. 4 is a drawing showing the structure of a patterned quantum dot light-emitting array manufactured according to one embodiment of the present invention.

[0035] FIG. 5 and FIG. 6 are conceptual diagrams illustrating a process of identifying and analyzing the characteristics of a quantum dot pattern arranged by a method for arranging quantum dots having polarity according to one embodiment of the present invention, performing device engineering, and implementing a final quantum dot pattern.

[0036] Figures 7 (a), (b), and (c) are drawings that actually measure quantum dot patterns arranged by a method for arranging quantum dots having polarity according to one embodiment of the present invention.

[0037] Figure 8 (a) is a drawing of a quantum dot pattern drafted using CAD, and Figure 8 (b) is an actual photograph of a quantum dot pattern emitting light when power is applied.

[0038] Figure 9 is a graph comparing the technical difficulty of a quantum dot pattern arranged using a method for arranging polarized quantum dots according to an embodiment of the present invention with that of the prior art. Figure 9 illustrates a process of the prior art for implementing nanometer-level pixels and the process of the present invention.

[0039]

[0040] The embodiments of the present invention are provided for the purpose of illustrating the technical concept of the present invention. The scope of the rights of the present invention is not limited to the embodiments presented below or the specific descriptions of these embodiments.

[0041] All technical and scientific terms used in this invention, unless otherwise defined, have the meanings commonly understood by those skilled in the art to which this invention pertains. All terms used in this invention have been selected for the purpose of more clearly explaining the invention and are not intended to limit the scope of the rights provided for in this invention.

[0042] Expressions such as “comprising,” “having,” and the like used in the present invention should be understood as open-ended terms that imply the possibility of including other embodiments, unless otherwise stated in the phrase or sentence in which the expression is included.

[0043] The singular expressions described in the present invention may include plural meanings unless otherwise stated, and this also applies to the singular expressions described in the claims.

[0044] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[0045] Patterned quantum dot luminescent array

[0046] In the present invention, the structure of a patterned quantum dot light-emitting array is described with reference to the structure of FIG. 4 according to one embodiment, and the quantum dot light-emitting array may be a full-color display.

[0047] According to one embodiment of the present invention, a patterned quantum dot light-emitting array comprises: a base substrate; electrode pads arranged on the substrate; and an array in which clusters of red, green, and blue quantum dots are patterned and arranged on the electrode pads, wherein the electrode pads include independent pads of each of the red, green, and blue quantum dots.

[0048] In an embodiment of the present invention, the clusters of red, green and blue quantum dots patterned on the array may each form a pixel.

[0049] In an embodiment of the present invention, the red pad and the green pad among the electrode pads may include a main electrode portion extending in one direction while being spaced apart from each other, and a branch portion extending in a direction perpendicular to the main electrode portion, and the branches of the red pad and the green pad may be arranged to intersect and be spaced apart from each other at equal intervals to form symmetry.

[0050] In an embodiment of the present invention, the blue pad may be arranged to start from one side of the main electrode portion of the red pad and the green pad and pass between the spaced branch portions of the red pad and the green pad without branching.

[0051] In an embodiment of the present invention, the electrode pad is a transparent electrode, and may include, for example, ITO.

[0052] In an embodiment of the present invention, the quantum dot may include a core-shell structure, and a ligand including a hydrocarbon chain may be attached to the shell surface.

[0053] In an embodiment of the present invention, the ligand may have one of positive or negative polarity.

[0054] In an embodiment of the present invention, the quantum dots may be formed using an electrophoresis method and then formed on the electrode pad using a water dispersion method.

[0055] In an embodiment of the present invention, the ligand may be attached to the shell as a binding group, the binding group may include an SH group, and the ligand may include a mercapto group.

[0056] In an embodiment of the present invention, the quantum dots may include quantum dots of different sizes, and the clusters of red, green, and blue quantum dots may have different heights.

[0057]

[0058] Below, the details of each configuration of the patterned quantum dot light-emitting array and its manufacturing method are described.

[0059]

[0060] 1. Quantum dots with polarity (100)

[0061] Hereinafter, a quantum dot having polarity according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

[0062] Figures 1(a) and 1(b) are conceptual diagrams illustrating quantum dots having polarity according to one embodiment of the present invention. Figure 2 is a cross-sectional perspective view illustrating quantum dots having polarity according to one embodiment of the present invention.

[0063] Referring to (a), (b) and (2) of FIG. 1, a quantum dot (100) having polarity according to an embodiment of the present invention is used to manufacture an electroluminescent device through patterning using an electrophoresis method.

[0064] Conventional quantum dots mainly used cadmium, but recently, eco-friendly cadmium-free quantum dots (green quantum dots without cadmium) materials have been developed and used.

[0065] Quantum dots (12) refer to semiconductor nanocrystals having a quantum confinement effect, and may have an average diameter of about 1 to 20 nm. The type of quantum dots (12) used in the technology disclosed in the present specification is not particularly limited, and examples thereof include materials of group II-VI, group III-V, and group IV. Specifically, the quantum dots (12) may be at least one selected from the group consisting of ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, GaN, GaP, GaAs, GaSb, InP, InAs, InSb, AlS, AlP, AlAs, AlSb, PbS, PbSe, Ge, and Si. The quantum dots (12) may have a single structure or a core-shell structure.

[0066] Additionally, quantum dots (100) can be synthesized primarily by a wet process in which a precursor material is added to an organic solvent and nanoparticles are grown. Depending on the degree of growth of the nanoparticles, light of various wavelengths can be obtained by controlling the energy band gap.

[0067]

[0068] The above-mentioned quantum dot (100) is also commonly referred to as a quantum dot (QD), and this quantum dot (100) includes a core portion (110), a shell portion (120), a ligand portion (130), and a polar portion (140).

[0069] Referring to FIG. 2, the core portion (110) is a spherical central body and is located at the center of the quantum dot (100). The core portion (110) is configured to increase the high quantum efficiency and structural stability of the quantum dot (100).

[0070] Referring to (a), (b) and (2) of FIG. 1, the shell portion (120) may be spherical in shape with a predetermined thickness surrounding the core portion (110). In addition, the shell portion (120) helps to achieve effective removal of confinement and surface states of charge carriers such as electrons and charges, thereby improving quantum yield and stability.

[0071] Additionally, the shell (120) serves to protect against environmental changes and photo-oxidative decomposition.

[0072] In addition, the surface of the shell portion (120) has a structure in which a ligand portion (130), which is a polymer ligand, is attached to facilitate dispersion and control, as shown in (a) and (b) of FIG. 1 and FIG. 2.

[0073] The ligand portion (130) is bonded to the shell portion (120), and at least one can be formed as shown in (a), (b) of FIG. 1 and FIG. 2.

[0074] Additionally, at least one ligand moiety (130) may be a hydrocarbon chain.

[0075] Specifically, one side of the ligand portion (130) is connected to a binding group (e.g., -SH, -COOH) bonded to the surface of the shell portion (120), and the other side of the ligand portion (130) is connected to a polar portion (140) such as -NH3+, -COO-, -SO3-.

[0076] The ligand (130) not only physically protects the nanocrystal from the surrounding environment, but also helps prevent Auger recombination effects by enhancing the photoluminescence quantum yield due to effective passivation of electron traps.

[0077] The polar portion (140) is bonded to the ligand portion (130) as shown in (a) and (b) of FIG. 1 and has either a positive or negative polarity.

[0078] Specifically, the polar portion (140) has either a positive or negative polarity through ligand substitution with at least one ligand portion (140).

[0079] According to one embodiment of the present invention as described above, the quantum dot (100) can be used to manufacture an electroluminescent device through patterning using an electrophoresis method, as it has either a positive or negative polarity.

[0080] 2. Method for manufacturing quantum dots with polarity

[0081] Hereinafter, a method for manufacturing a quantum dot having polarity according to one embodiment of the present invention will be described with reference to FIGS. 3, 5, and 6.

[0082]

[0083] FIG. 3 is a flowchart showing a method for manufacturing a quantum dot having polarity according to one embodiment of the present invention.

[0084] FIG. 5 and FIG. 6 are conceptual diagrams illustrating a process of identifying and analyzing the characteristics of a quantum dot pattern arranged by a method for arranging quantum dots having polarity according to one embodiment of the present invention, performing device engineering, and implementing a final quantum dot pattern.

[0085]

[0086] A method for manufacturing a quantum dot having polarity according to one embodiment of the present invention is a method for manufacturing a quantum dot used for manufacturing an electroluminescent device through patterning using an electrophoresis method, comprising the steps of (a) preparing a non-polar quantum dot (S100), (b) surface-modifying a non-polar quantum dot (S200), (c) washing the surface-modified quantum dot (S300), and (d) dispersing the washed quantum dot in water to produce a polar quantum dot (100) (S400), wherein the quantum dot (100) has either a positive polarity or a negative polarity due to ligand substitution.

[0087]

[0088] Here, the electroluminescent element is an element applied to a display device for visual output, such as a TV or monitor, and may be, for example, QLED.

[0089] The above step (a) is a preparatory step for manufacturing a quantum dot (100) having the illustrated polarity, and may include (b1) a step of preparing a container containing a dispersion solution and an acid compound or a base compound having a mercapto functional group, (b2) a step of introducing non-polar quantum dots into the container and then heating them, and (b3) a step of reacting the dispersion solution, the acid compound or the base compound having a mercapto functional group, and the non-polar quantum dots at a preset temperature for a preset time.

[0090] In the step (b), a method of adding a charged substance to a dispersion solution of quantum dots and heating it can be used to modify the surface of the quantum dots as shown in FIGS. 3 and 4. Examples of the substance used to modify the surface of the quantum dots include acid or base compounds having a mercapto functional group, and specifically, mercaptoacetic acid (MAA), 3-mercaptopropionic acid, cysteamine, aminoethanethiol, or N,N-dimethyl-2-mercaptoethyl ammonium can be used alone or in combination. The reaction temperature during surface modification can be carried out in a temperature range of 25 to 200 degrees for 30 minutes to 10 hours, preferably 1 to 10 hours.

[0091]

[0092] Next, the step (c) is a step for removing residual substances and impurities coexisting with the surface-modified quantum dots, including (c1) a step for preparing a washing container containing an organic solvent, (c2) a step for washing by alternately performing the processes of dispersing and precipitating the surface-modified quantum dots in the organic solvent, and (c3) a step for removing the residual solvent by drying the washed quantum dots by at least one of natural drying and vacuum drying.

[0093] That is, when the reaction is completed in the step (b) above, a washing process is performed in the step (c). At this time, the washing process may be repeated by dispersing in an organic solvent and then precipitating it. In order to achieve sufficient washing, it is preferable to repeat the process 3 to 10 times. When the washing is completed as described above, it is preferable to remove the residual solvent in the washed quantum dots by a method such as natural drying or vacuum drying. By removing the residual solvent, the formation of quantum dot aggregates can be more effectively prevented. In order to sufficiently remove the residual solvent, it is preferable to vacuum dry for 1 to 12 hours.

[0094] In this way, when the residual solvent is removed, the quantum dots can be dispersed in a solvent for use, such as water or a buffer solution such as Tris buffer, to form a quantum dot dispersion solution. Since the dispersion solution contains not only surface-modified quantum dots but also aggregates and impurities of the quantum dots, these can be removed by methods such as column filtration and centrifugation, with centrifugation being preferred.

[0095] Lastly, the above step (d) is a step in which quantum dots (100) having the desired polarity are completed, and includes (d1) a step of forming a quantum dot dispersion solution in which quantum dots from which residual solvent has been removed are dispersed in a buffer solution, (d2) a step of removing quantum dot aggregates and impurities present in the quantum dot dispersion solution by centrifugation, (d3) a step of mixing a pH-adjusted buffer solution into the quantum dot dispersion solution, and (d4) a step of imparting a charge to the surface-modified quantum dots by adjusting the pH.

[0096] To achieve this, a dispersion solution is first prepared. The surface-modified quantum dot dispersion solution can be used in water at a concentration of at least 1 wt%, preferably at least 3 wt%. Using a dispersion solution at this concentration allows for the formation of a uniform, dense monolayer.

[0097] After dispersing the surface-modified quantum dots as described above in a solvent, the pH of the quantum dot dispersion solution is adjusted by mixing a pH-controlled buffer solution. The quantum dot dispersion solvent is not particularly limited as long as it allows pH adjustment, and water or a polar solvent can be used. The pH of the quantum dot dispersion solution can be in the range of 6 to 9, and preferably, a pH of 7 to 8.

[0098] By controlling the pH depending on the material used for surface modification, a desired charge can be imparted to the surface of a quantum dot (100). For example, when a quantum dot (12) capped with oleic acid is used and the surface is modified with cysteamine (CAm) and mercaptopropionic acid (MPA), respectively, and then dispersed in water at pH 6 and pH 8, a positive charge (-NH3+) and a negative charge (-COO-), which are polar parts (140), are imparted to the other end of the ligand part (130), respectively, thereby forming a quantum dot (100) with polarity.

[0099]

[0100] In one embodiment, in a ligand substitution technique for water-dispersed quantum dots, a polar ligand substitution technique can be applied to form a thin film using electrophoresis and improve uniformity.

[0101] To improve the fairness, the pH and zeta potential of the quantum dot dispersion solution are adjusted (>± 70 mV @ pH 6-8) and the stability of the water-dispersed quantum dots is improved according to the quantum dot ligand anchor group (single and multiple anchor ligands).

[0102]

[0103] Furthermore, to realize a QD structure for ultra-bright light emission, RGB quantum dot materials with II-VI and III-V compositions are synthesized. Specifically, excitation dynamics are controlled by adjusting the shell thickness and core / shell junction barrier, and the formation of surface traps is suppressed through optimization of conditions by introducing ligand anchor groups.

[0104]

[0105] 3. Method for arranging polar quantum dots using electrophoresis

[0106] A full-color display can be implemented by arranging quantum dots using the methods of steps (e) and (f) described below.

[0107] (e) Step includes (e1) a step of preparing a polar solvent accommodated in an array container and polar quantum dots (100) dispersed in the polar solvent, (e2) a step of immersing a positive electrode substrate and a negative electrode substrate on which a preset pattern is formed in a polar solvent, and (e3) a step (S530) of electrically connecting a power supply unit to the positive electrode substrate and the negative electrode substrate and applying power to the positive electrode substrate and the negative electrode substrate to form an electric field in the preset pattern, and the form of the electric field includes direct current (DC) and alternating current (AC).

[0108]

[0109] First, the step (e) above may further include a step (S505) of FEM simulating a quantum dot (100) having polarity before the step (e1), as shown in the drawing located on the far left of FIG. 5.

[0110] Next, as in step (a) above, a polar solvent and polar quantum dots (100) dispersed in the polar solvent are prepared, which are accommodated in an array container as shown in the drawing in the center of FIG. 5.

[0111] At this time, the polar solvent may include at least one of water, deionized water (DIW), acetone, ether, chloroform, ethyl acetate, isopropyl alcohol (IPA), hexane, benzene, and toluene. In addition to the polar solvents mentioned above, any solvent that can act as a polar solvent may be applied.

[0112] Additionally, the above-mentioned quantum dots (100) having polarity may be in a dispersed state due to zeta potential or may be in a dispersed state due to ligand substitution.

[0113] Additionally, the polar quantum dots can have at least one of a positive charge and a negative charge in a polar solvent.

[0114] In the above step (e3), the potential difference and current of the two electrodes are applied to the positive electrode substrate and the negative electrode substrate by using only direct current (DC) or alternating current (AC), or a combination of direct current (DC) and alternating current (AC), from the power supply unit.

[0115] In addition, the step (e) includes, after the step (e3), a step (e4) in which polar quantum dots (100) dispersed in a polar solvent are arranged in at least one of a preset pattern of a positive electrode substrate and a preset pattern of a negative electrode substrate and patterned by an electrophoresis method, and a step (e5) in which the positive electrode substrate and the negative electrode substrate are taken out of the polar solvent and dried (S550).

[0116] In the above step (e4), the quantum dots (100) that are polarized by the electric field formed when electricity is applied in the drawing in the center of FIG. 6 move to the predetermined pattern of the positive electrode substrate and the predetermined pattern of the negative electrode substrate by the force of attraction.

[0117] Specifically, a quantum dot (100) having a negative polarity moves to a preset pattern on a positive electrode substrate, and a quantum dot (100) having a positive polarity moves to a preset pattern on a negative electrode substrate.

[0118]

[0119] Additionally, the preset patterns of the positive and negative electrode substrates can be set as desired by the user.

[0120] Thereafter, in the step (e5), the positive electrode substrate and the negative electrode substrate, on which the quantum dots (100) having polarity in a preset pattern are settled, are taken out from the polar solvent and dried, thereby forming a light-emitting quantum dot pattern.

[0121] In addition, after the above step (e5), a full-color quantum dot pattern can be implemented through a monochromic and full-color patterning process.

[0122] In addition, it is possible to manufacture a multi-layered electroluminescent device using the above-described full-color quantum dot pattern, and to implement a full-color display device having high resolution and high definition, such as a QLED to which the electroluminescent device is applied.

[0123] Next, the present invention includes a step (S600) of inspecting and implementing a quantum dot pattern (f) after the step (e5).

[0124]

[0125] FIG. 6 is a conceptual diagram illustrating a process of identifying and analyzing the characteristics of a quantum dot pattern arranged by a method for arranging quantum dots having polarity according to one embodiment of the present invention, performing device engineering, and implementing a final quantum dot pattern.

[0126] Referring to FIG. 6, the step (f) includes a step of identifying and analyzing the characteristics of a quantum dot pattern (S610), a step of device engineering the quantum dot pattern (S620), and a step of implementing the quantum dot pattern (S630).

[0127]

[0128] Figures 7 (a), (b), and (c) are drawings that actually measure quantum dot patterns arranged by a method for arranging quantum dots having polarity according to one embodiment of the present invention.

[0129] Figure 7 (a) shows a quantum dot pattern patterned at 10x30㎛ (1352 ppi), Figure 8 (b) shows a quantum dot pattern patterned at 6x18㎛ (2252 ppi), and Figure 8 (c) shows a quantum dot pattern patterned at 4x12㎛ (3378 ppi).

[0130] According to the present invention, as shown in (a), (b), and (c) of FIG. 7, quantum dot patterns of different sizes can be implemented by setting the preset patterns of the positive electrode substrate and the negative electrode substrate as desired.

[0131] Figure 8 (a) is a drawing of a quantum dot pattern drafted using CAD, and Figure 8 (b) is an actual photograph of a quantum dot pattern emitting light when power is applied.

[0132] Figure 9 is a graph comparing the technical difficulty of a quantum dot pattern arranged using a method for arranging polarized quantum dots according to an embodiment of the present invention with that of the prior art. Figure 9 illustrates a process of the prior art for implementing nanometer-level pixels and the process of the present invention.

[0133] Processes based on process technologies other than conventional inkjet printing are far from commercialization levels, and even the most advanced inkjet printing is slow to develop due to the difficult process, and there are difficulties in implementing nanometer-level pixels that are close to the limits of semiconductor processing.

[0134]

[0135] However, through the processor according to the present invention, pixel implementation at a level close to the limit of a general semiconductor process is possible without changing the technical difficulty even with an increase in resolution.

[0136]

[0137] The above description is merely an illustrative example of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the technical idea of ​​the present invention, and the scope of the technical idea of ​​the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

Claims

1. Base board; Electrode pads arranged on the above substrate; and An array in which clusters of red, green and blue quantum dots are patterned and arranged on the electrode pads, The above electrode pads include independent pads for each of red, green and blue quantum dots. Patterned quantum dot luminescent array.

2. In paragraph 1, The clusters of red, green and blue quantum dots patterned on the above array each form a pixel, Patterned quantum dot luminescent array.

3. In paragraph 1, Among the above electrode pads, the red pad and green pad are Main electrode parts extending in one direction and spaced apart from each other, Including a branch extending in a orthogonal direction from the above main electrode portion, The branches of the red pad and the green pad are arranged to intersect and are spaced apart from each other at equal intervals to form symmetry. Patterned quantum dot luminescent array.

4. In paragraph 3, The above blue pad is arranged so as to start from one side of the main electrode portion of the above red pad and green pad and pass between the spaced branch portions of the above red pad and green pad without branching. Patterned quantum dot luminescent array.

5. In paragraph 1, The above electrode pad is a transparent electrode, Patterned quantum dot luminescent array.

6. In paragraph 1, The above quantum dot comprises a core-shell structure, A ligand containing a hydrocarbon chain is attached to the above shell surface. Patterned quantum dot luminescent array.

7. In paragraph 6, The above ligand has either a positive or negative polarity, Patterned quantum dot luminescent array.

8. In paragraph 6, The above quantum dots It is formed using an electrophoresis method and then formed on the electrode pad using a water dispersion method. Patterned quantum dot luminescent array.

9. In paragraph 6, The above ligand is attached as a binding group to the shell, wherein the binding group comprises a SH group and the ligand comprises a mercapto group; Patterned quantum dot luminescent array.

10. In paragraph 1, The above quantum dots include quantum dots of different sizes, The clusters of red, green and blue quantum dots have different heights. Patterned quantum dot luminescent array.

11. Step of preparing aqueous dispersions of red, green and blue quantum dots substituted with ligands; A step of immersing each of the red, green and blue electrode pads in the aqueous dispersion to form an electrode pad having patterned quantum dots formed thereon; and A step of forming a patterned quantum dot light-emitting array by arranging the electrode pads on a base substrate; comprising; A method for fabricating a patterned quantum dot luminescent array.

12. In paragraph 11, The above patterned quantum dot light-emitting array is the patterned quantum dot light-emitting array of claim 1. A method for fabricating a patterned quantum dot luminescent array.

13. In paragraph 11, The step of preparing the above quantum dot aqueous dispersion is; (a) a step of preparing a quantum dot having nonpolarity; (b) a step of surface modifying the non-polar quantum dot; (c) a step of washing the surface-modified quantum dots; and (d) a step of dispersing the washed quantum dots in water to generate polar quantum dots; A method for fabricating a patterned quantum dot luminescent array.

14. In paragraph 13, Step (b) above, (b1) a step of preparing a container containing a dispersion solution and an acid compound or a base compound having a mercapto functional group; (b2) a step of heating the non-polar quantum dots after introducing them into the receiving container; and (b3) a step of reacting the dispersion solution, the acid compound or base compound having the mercapto functional group, and the non-polar quantum dots at a preset temperature for a preset time; characterized in that it includes; A method for fabricating a patterned quantum dot luminescent array.

15. In paragraph 13, Step (c) above, (c1) a step of preparing a washing container containing an organic solvent; (c2) a washing step in which the surface-modified quantum dots are alternately dispersed and precipitated in the organic solvent; and (c3) a step of removing residual solvent by drying the washed quantum dots by at least one of natural drying and vacuum drying; characterized in that it includes; A method for fabricating a patterned quantum dot luminescent array.

16. In paragraph 13, Step (d) above, (d1) a step of forming a quantum dot dispersion solution by dispersing quantum dots from which the residual solvent has been removed in a buffer solution; (d2) a step of removing quantum dot aggregates and impurities present in the quantum dot dispersion solution by centrifugation; (d3) a step of mixing a pH-adjusted buffer solution into the quantum dot dispersion solution; and (d4) a step of controlling the pH to impart a charge to the surface-modified quantum dots; characterized in that it includes; A method for fabricating a patterned quantum dot luminescent array.

17. In paragraph 11, The step of forming an electrode pad on which patterned quantum dots are formed is as follows. The above red, green and blue electrode pads are immersed in each aqueous solution, and the immersion times are different. A method for fabricating a patterned quantum dot luminescent array.

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