Quantum dot collaborative coupling mixed color display pixel structure and device

Abstract

The invention relates to a quantum dot collaborative coupling mixed color display pixel structure and a device thereof, the structure comprises a first electrode, a second electrode and a containing cavity located between the first electrode and the second electrode, and the containing cavity is filled with electronic ink. The electronic ink comprises quantum dot-pigment particle complexes with at least two different colors, the complexes are formed by connecting quantum dots to the surfaces of pigment particles, and the complexes with different colors have different potentials. The quantum dots can absorb short-wavelength light and convert the short-wavelength light into fluorescent light with narrow half-peak width to increase the display color gamut, and the pigment particles are responsible for absorbing long-wavelength light to avoid color deviation. The size of the containing cavity is preferably in the range of 100 nm to 50 mm, the size of the quantum dots is in the range of 2 nm to 30 nm, and high material flexibility is provided. The display device adopts the pixel structure, has the characteristics of high brightness, wide color gamut, high color accuracy and quick response, and is suitable for various application scenes.

Description

Technical Field

[0001] The present application relates to the technical field of display devices, and in particular to a quantum dot cooperatively coupled color mixing display pixel structure and device. Background Art

[0002] In the current display technology field, LED, LCD and OLED technologies dominate with their bright colors and high contrast. However, these technologies also face the disadvantages of severe reflection under strong light and the need for continuous power supply to maintain display. In order to solve these problems, color reflective display technology came into being. It uses ambient light as a light source, which not only has low energy consumption, but also good visibility, especially in terms of increasingly rich and natural color expression, which can provide a more immersive visual experience. With the continuous advancement of technology, color reflective display technology is gradually becoming a new favorite in the display field, and is expected to replace traditional display technology in certain application scenarios and lead the innovation of display technology.

[0003] As a representative of reflective paper-like displays, electronic paper has shown great potential in the field of outdoor displays with its ultra-thin, light and paper-like visual experience. Even under strong sunlight, electronic paper can maintain good visual effects without reading dead angles. At present, electronic paper technology covers a variety of technical routes such as electrophoretic display, electrowetting display, MEMS electromechanical interference display, cholesterol liquid crystal display, etc. Among them, electrophoretic display technology has been successfully commercialized and occupies the vast majority of the electronic paper market share. However, the existing color display technology is still in its infancy, the domestic research scope is relatively narrow, and the core technology is mainly in the hands of E-ink, which has led to problems such as limited supply and high costs. In addition, existing color electronic paper products generally have problems such as slow refresh speed, low resolution, low imaging saturation, small color gamut, rigid display and high cost. These problems need to be solved urgently to promote the further development and application of technology.

[0004] As a cutting-edge technology for new display materials, quantum dots have become a strong competitor for the next generation of display technology with their high luminous efficiency, pure color and low energy consumption. Colloidal quantum dots have broad application prospects in the display field due to their small particle size, discrete energy levels, high color purity and coverage of the entire visible spectrum. At the same time, quantum dots can also reduce costs through solution preparation, making the new quantum dot display technology have broad market prospects. However, the application of quantum dots in display also faces some challenges, such as the immaturity of electric injection (QLED) technology and the stability of quantum dots in photoexcitation (such as QDs-LCD). These problems have led to the obstruction of the industrialization process of quantum dot display technology, as well as problems such as high cost and short life.

[0005] Applying quantum dots to color reflective display technology can not only avoid the problem of blue light aging, but also use its high efficiency and narrow light emission characteristics to improve refresh speed, resolution, imaging saturation and color gamut. However, there are relatively few studies on the application of quantum dots in color reflective display technology, and there are some technical difficulties. For example, how to truly apply quantum dots to reflective display and achieve synergistic effects is still one of the problems that need to be solved urgently. Most of the existing research requires backlight to excite quantum dots to realize electronic paper display, which deviates from the original intention of reflective display. In addition, the problem of quantum dot materials having no absorption and direct reflection in the long-wave band also leads to large deviations in color display and cannot effectively improve the color gamut of display devices.

[0006] As the mainstream technology for realizing color reflective display, electrophoretic display technology has the advantages of bistable characteristics, low energy consumption, flexible display and good stability, but it still faces the problems of slow response speed and poor color display effect. Quantum dot display technology faces problems such as blue light aging and thermal aging caused by the close distance to the excitation light source, which makes the packaging cost of the applied display products high and the life span short. Therefore, in the field of quantum dot synergistic color reflective display, the technical problems that need to be solved include: how to make quantum dots effectively absorb and reflect light of specific colors in the long wavelength band to improve the color gamut; how to achieve full reflective display to avoid backlighting and continuous power consumption; and how to improve the stability and life of quantum dots to reduce packaging costs and extend product life. Summary of the invention

[0007] The purpose of the present application is to provide a quantum dot cooperatively coupled color mixing display pixel structure, which can realize accurate control of reflective display color to improve color gamut, brightness and response frequency. The purpose of the present application is achieved through the following technical solutions. The quantum dot cooperatively coupled color mixing display pixel structure of the present application includes a first electrode, a second electrode, a receiving cavity and electronic ink in the receiving cavity, wherein the receiving cavity is formed between the first electrode and the second electrode; The electronic ink includes at least two quantum dot-pigment particle complexes of different colors, wherein the quantum dot-pigment particle complexes are formed by quantum dots connected to the surface of pigment particles; Among them, quantum dot-pigment particle complexes of different colors have different electric potentials.

[0008] In one embodiment, the color of the pigment particles in the quantum dot-pigment particle complex is selected from red, blue, yellow, cyan or magenta.

[0009] In one embodiment, the electronic ink also includes white pigment particles.

[0010] In one embodiment, the electronic ink includes red, blue and yellow quantum dot-pigment particle complexes, the yellow quantum dot-pigment particle complexes and white pigment particles are at a negative potential, and the red quantum dot-pigment particle complexes and blue quantum dot-pigment particle complexes are at a positive potential.

[0011] In one embodiment, at least one color of the quantum dot-pigment particle complex also has two or more different electrical potentials.

[0012] In one embodiment, the quantum dots are attached to the pigment particles via cross-linkable ligands.

[0013] In one embodiment, the size of the accommodating cavity is in the range of 100 nm-50 mm.

[0014] In one embodiment, the pigment particles of different colors have the same size, and the quantum dot size is in the range of 2nm-30nm.

[0015] In addition, the present application also provides a quantum dot cooperatively coupled color mixing display device including an array-arranged pixel structure, wherein the pixel structure is the aforementioned pixel structure.

[0016] In one of the embodiments, a backlight source is also included.

[0017] Compared with the prior art, this application has the following beneficial effects: This application combines quantum dots with traditional pigment particles to form a quantum dot-pigment particle complex, and uses the fluorescence characteristics of quantum dots to narrow the spectral emission range and improve color purity. Quantum dots can absorb short-wavelength light and convert it into high-efficiency fluorescence, and its fluorescence half-peak width is usually less than 25nm, thereby effectively narrowing the final light spectrum and increasing the display color gamut. At the same time, the high fluorescence quantum yield of quantum dots improves the utilization rate of illumination light, increases the brightness of reflective display devices, and not only improves color expression, but also enhances the visual experience.

[0018] By introducing quantum dots while retaining the pigment particles, this application solves the problem of long-wavelength light leakage that may be caused when quantum dots are used alone. The pigment particles can absorb long-wavelength illumination light that quantum dots cannot absorb, thereby avoiding huge deviations in the color of the light spectrum. This combination not only narrows the half-width and further increases the color gamut, but also ensures precise color control. The use of quantum dot synergistically coupled color-mixing capsules, combined with the thin film preparation process of traditional electrophoretic color reflective display devices, makes the display device have better color consistency and higher stability, meeting the needs of high-quality color display.

[0019] The small size of quantum dots (diameter in the range of 2nm-30nm) and the large number of ligands and potentials on their surface increase the overall specific surface area and loading capacity in the reflective display fluid, thereby increasing the movement speed under the action of an external field and improving the response speed of the reflective display. The fluorescent properties of quantum dots enable color reflective display devices to maintain good display effects in dark environments. The fluorescence of quantum dots is stimulated by the backlight excitation light source, which makes up for the disadvantage of low brightness of reflective displays in dark environments and achieves high-brightness, high-quality display around the clock.

[0020] This application is based on the design of quantum dot synergistically coupled color-mixing capsules, making full use of the thin film preparation process of traditional electrophoretic color reflective display devices. This process is mature, simple and easy to implement, which reduces production costs and improves production efficiency. At the same time, the composite use of quantum dots and pigment particles not only retains the advantages of traditional pigment particles, but also gives play to the unique properties of quantum dots, achieving dual optimization of performance and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of a quantum dot cooperatively coupled color mixing display pixel structure in one embodiment of the present application; Figure 2 A schematic diagram of the structure of a quantum dot cooperatively coupled color mixing display device in one embodiment of the present application.

[0022] Explanation of reference numerals: 100, first electrode; 200, receiving cavity; 210, quantum dot-pigment particle complex; 220, white pigment particle; 300, second electrode. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. It is to be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some structures related to the present application are shown in the accompanying drawings, rather than all structures. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0024] The terms "including" and "having" and any variations thereof in this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices.

[0025] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0026] With the continuous advancement of display technology, people's requirements for color performance, brightness, response speed and environmental adaptability are increasing. Although traditional electrophoretic color reflective display technology has certain advantages in cost, energy consumption and readability, it still has certain limitations in color gamut width, brightness and display effects in dark environments. In order to break through these technical bottlenecks, the present application proposes a new quantum dot cooperatively coupled mixed color display pixel structure and device. This structure and device combine the fluorescent properties of quantum dots and the color performance capabilities of traditional pigment particles. Through composite design and electrophoretic control technology, high-precision color control, optimized narrowing of the spectrum, improved brightness and good display effects in dark environments are achieved. The following will introduce in detail the technical features, implementation methods and technical effects achieved of this quantum dot cooperatively coupled mixed color display pixel structure. Please refer to Figure 1 , Figure 1 It is a structural schematic diagram of a quantum dot cooperatively coupled mixed color display pixel structure in an embodiment of the present application. The quantum dot cooperatively coupled mixed color display pixel structure in a preferred embodiment of the present application includes a first electrode 100, a second electrode 300, a receiving cavity 200 and electronic ink in the receiving cavity 200, the receiving cavity 200 is formed between the first electrode 100 and the second electrode 300, the electronic ink includes at least two quantum dot-pigment particle complexes 210 of different colors, the quantum dot-pigment particle complexes 210 are formed by quantum dots connected to the surface of pigment particles, wherein quantum dot-pigment particle complexes 210 of different colors have different electric potentials.

[0027] The quantum dot cooperatively coupled mixed color display pixel structure is composed of a first electrode 100, a second electrode 300 and a receiving cavity 200 located therebetween. The receiving cavity 200 is filled with electronic ink, which contains at least two quantum dot-pigment particle complexes 210 of different colors. These complexes are made by connecting quantum dots to the surface of pigment particles. Each color of the complex has unique potential characteristics to ensure precise control under the action of an electric field. In quantum dot collaborative coupling color mixing display technology, the introduction of quantum dots has brought changes to traditional electrophoretic color reflective display. Quantum dots can absorb short-wavelength light and convert it into fluorescence with a specific wavelength. The half-peak width of this fluorescence is extremely narrow (usually less than 25nm), which narrows the spectrum of the final light output, thereby increasing the display color gamut and bringing a more colorful, real and natural visual experience. The efficient fluorescence conversion ability of quantum dots (fluorescence quantum yield is usually more than 90%) enables short-wavelength light that might have been absorbed by pigment particles and converted into heat to be effectively utilized, which not only improves the utilization rate of lighting light, but also improves the brightness of reflective display devices, and can present clear and bright pictures even in dim light environments.

[0028] In addition, the small size of quantum dots themselves (usually between 2nm and 30nm in diameter) and the large number of ligands and surface potentials they carry in the fluid increase the overall specific surface area and overall load in the fluid, while increasing the speed of movement under the action of an external field. This change directly improves the response speed of the reflective display, making the screen switching smoother and faster, and bringing users a smoother visual experience. The efficient fluorescence conversion ability of quantum dots allows short-wavelength light that would otherwise be wasted to be effectively utilized, converted into fluorescence and illuminate the screen, thereby improving the brightness of reflective display devices. The small size of quantum dots and the ligands and surface potential characteristics they carry increase the overall specific surface area and load in the fluid, while increasing the speed of movement under the action of an external field, which improves the response speed of the reflective display.

[0029] In the reflective display technology of the present application, the combination of quantum dots and pigment particles can improve display performance and avoid color deviation. Specifically, quantum dots and pigment particles are used together in display capsules, and the two work together. Quantum dots are mainly responsible for absorbing short-wavelength illumination light and converting it into fluorescence with a narrow half-width. This process narrows the light emission spectrum and increases the display color gamut, while pigment particles are responsible for absorbing long-wavelength illumination light that quantum dots cannot effectively absorb, thereby avoiding color deviation caused by insufficient absorption of long wavelengths by quantum dots. If quantum dots are used as pigment particles alone for reflective display, the final light emission spectrum will be a superposition of the quantum dot reflection spectrum (derived from the full-wavelength irradiation of the illumination light source) and the fluorescence spectrum (derived from the short-wavelength excitation of the illumination light source). However, due to the extremely weak absorption capacity of quantum dots in the long-wavelength region, compared with the light emission spectrum of pigment particles, the quantum dot light emission spectrum will leak light in the long-wavelength region. This light leakage will not only cause the saturation of the displayed color to decrease, but may also cause the final color to deviate greatly from the design expectations. The color reflective display technology solution of the present application retains pigment particles, which not only make up for the shortcomings of quantum dots in long-wavelength absorption, but also ensure the accuracy of light emission in the long-wavelength region. Under the joint action of quantum dots and pigment particles, the final light emission spectrum is not only significantly narrowed, but also eliminates the color deviation caused by long-wavelength light leakage of quantum dots, making the spectral characteristics more conducive to the display of wide color gamut and high-quality colors, bringing users a more realistic, delicate and layered visual experience.

[0030] The specific form of the accommodating cavity 200 is not limited, and it can be a capsule. In the process of realizing the quantum dot cooperative coupling color mixing display technology, there is a high degree of material flexibility. The constituent materials of the capsule can be selected and replaced according to specific needs and application scenarios. These materials include but are not limited to a series of plastic materials, such as polystyrene, polypropylene, polyvinyl chloride, polyethylene (including low-density polyethylene and high-density polyethylene), acrylonitrile-butadiene copolymer, polycarbonate, polyamide (such as nylon), thermoplastic polyurethane, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), etc. In addition, other non-plastic materials can also be selected. Such as glass (especially optical glass, due to its excellent light transmittance and chemical stability), rubber (providing elasticity and sealing), glue (for bonding and sealing), natural polymer materials (such as gelatin, with biocompatibility and good film-forming properties), polyamide (a high-performance polymer with excellent mechanical properties and thermal stability), silicone rubber (high temperature resistance, oxidation resistance, and radiation resistance), polyvinyl alcohol (with excellent film-forming properties and water solubility), various celluloses (such as cellulose acetate, with good transparency and thermoplasticity) and starch (a renewable and degradable natural polymer), etc. By flexibly selecting capsule materials, the adaptability of quantum dot synergistic coupling color mixing display technology can be improved, making it applicable to a wider range of environments and scenarios, such as high temperature, low temperature, humidity, corrosion and other harsh conditions. By selecting suitable materials, the performance of display capsules can be optimized, such as improving light transmittance efficiency, enhancing mechanical strength, and extending service life. In some cases, by selecting lower-cost and easier-to-process materials, the production cost of quantum dot synergistic coupling color mixing display technology can be reduced, and its market competitiveness can be improved.

[0031] In quantum dot cooperative coupling color mixing display technology, the color of pigment particles is not limited to the traditional three primary colors (red, blue, and yellow), but also extends to cyan and magenta. Such color selection provides richer color combinations and higher color accuracy for display technology. Furthermore, the material state properties are selected, not limited to the traditional solution form. According to specific needs, quantum dots, pigment particles, and cooperative coupling materials can be replaced from solution form to powder form. This transformation not only improves the stability and storage convenience of the material, but also helps to optimize display performance, such as improving color saturation and contrast. In the selection of electrophoretic liquid solvents, in addition to common organic solvents such as chloroform, toluene, and chlorobenzene, it can also be a variety of solvents such as alkanes, olefins, aromatic hydrocarbons, alcohols, ethyl acetate, and halogenated alkanes, halogenated olefins, halogenated aromatic hydrocarbons, diol derivatives, ketones and other special solvents. In addition, solvents such as tetrahydrofuran, petroleum ether, dimethyl sulfoxide, and environmentally friendly water solvents can also be used. In the selection of quantum dots, not only can the number of quantum dots be adjusted, but also their morphology and luminescence wavelength can be changed to meet different display requirements. For example, one or more quantum dot luminescent materials with different morphologies and central emission wavelengths in the range of 350nm to 1000nm can be added. These quantum dots can emit various colors of light from ultraviolet light to near-infrared light. In addition, quantum dot materials can be mixed with other types of luminescent materials (such as phosphors, organic luminescent materials, etc.) to achieve more complex and diverse display effects. By selecting pigment particles of various colors and adjusting the types, morphologies and luminescence wavelengths of quantum dots, richer and more accurate color displays can be achieved. The selection and mixed use of multiple solvents can meet different processing requirements, optimize the dispersibility and stability of quantum dots and pigment particles during electrophoresis, and thus improve display performance. By adjusting the number of quantum dots, morphologies and luminescence wavelengths, and mixing with other types of luminescent materials, customized display effects can be achieved to meet user needs for different application scenarios.

[0032] The core materials of quantum dots are not limited to traditional sulfide or selenide semiconductor materials such as CdSe, CdTe, and CdS, but can be extended to diversified semiconductor materials such as ZnSe, ZnTe, ZnS, CuInS, CuInSeS, AgInS, and AgInSeS, and even alloy materials such as InP, CuZnSe, and ZnMnSe, as well as lead-based semiconductor materials such as PbS and PbSe, and Cd-based, In-based, and Zn-based alloy materials, and even perovskite materials. The selection of these materials not only enriches the luminescence performance of quantum dots, but also improves their stability and environmental adaptability. In the shell design of quantum dots, not only can a layer of semiconductor materials such as CdSe, CdS, ZnO, ZnS, ZnSe, and ZnTe be coated on the outside of the core material of the quantum dot to form a single-layer shell structure, but also a multi-layer shell can be coated according to demand. These shell materials can be any one of the above-mentioned semiconductor materials or a combination of at least two. Such a multi-layer shell structure design not only helps to protect the core of the quantum dot from interference from the external environment, but also can further regulate its luminescence performance and stability. In the selection of pigment particle materials, in addition to the common organic dyes and organic inks, it can also be inorganic dyes, inorganic inks, natural pigments, artificial synthetic pigments and other materials. It also includes graphite, metal oxides and their particles of different morphologies (such as nanorods, nanosheets, etc.), metals and their particles of different morphologies (such as gold balls, silver balls, etc.) and SiO2 and other inorganic materials.

[0033] Specifically, the electronic ink also includes white pigment particles 220. The introduction of white pigment particles 220 is an important part of color matching. These white pigment particles 220 can improve the brightness and contrast of the display effect. The addition of white pigment particles 220 enables the electronic ink to reproduce colors more accurately and brightly when displaying white or light-colored areas, while enhancing the layering and clarity of the overall picture. In the selection of white pigment particles 220, white pigments with high reflectivity and high stability are used, such as titanium dioxide (TiO 2 ), inorganic white pigments such as zinc oxide (ZnO), and specially treated organic white pigments. These materials not only have excellent color expression and weather resistance, but also maintain good dispersion and stability in electronic ink. In addition, by precisely controlling the particle size, shape and concentration of the white pigment particles 220, the optical properties and display effects of the electronic ink are further optimized. By adjusting these parameters, a more delicate and uniform white display effect can be achieved, while reducing the scattering and interference effects between particles, thereby improving the clarity and color accuracy of the picture.

[0034] Specifically, the electronic ink includes red, blue, and yellow quantum dot-pigment particle complexes 210, the yellow quantum dot-pigment particle complexes 210 and the white pigment particles 220 are at a negative potential, and the red quantum dot-pigment particle complexes 210 and the blue quantum dot-pigment particle complexes 210 are at a positive potential. By regulating the potential of these complexes, not only is the quantum dot-pigment particle complex 210 efficiently and orderly arranged under the action of the electric field, but the color stability and contrast of the electronic ink are also improved. In the process of potential regulation, electrophoretic deposition technology is used to guide the directional movement and deposition of quantum dot-pigment particle complexes 210 and white pigment particles 220 with different potentials in the electronic ink by precisely controlling the intensity and direction of the electric field, thereby ensuring the uniform distribution of the complexes and particles in the display area and achieving fine regulation of the color level. In addition, the surfaces of the quantum dot-pigment particle complex 210 and the white pigment particles 220 are specially treated to enhance their charge stability and dispersibility. These treatment measures include surface coating, functional group modification, etc., to improve the stability and compatibility of the complex and particles in the electronic ink, thereby further improving the stability and consistency of the display effect.

[0035] In order to further control the display effect, at least one color of the quantum dot-pigment particle complex 210 also has two or more different potentials. By controlling the potentials of different components in the complex, the displacement of the quantum dots under the action of the electric field can be further fine-tuned, making the complex more rich and delicate in color expression, and easier to meet the color requirements of different application scenarios. Specifically, when changing from one state to another, the distances moved by complexes with different potentials in a certain period of time are different. By controlling the time, the movement of the complex can be differentiated, so that different colors can be displayed.

[0036] Specifically, quantum dots are connected to pigment particles through cross-linkable ligands. The cross-linkable ligands not only have the chemical properties of efficiently combining with specific functional groups on the surface of quantum dots and pigment particles, but also contain functional groups that can undergo cross-linking reactions in their molecular structures, such as hydroxyl, carboxyl, amino or vinyl. Through a carefully designed synthesis path, these ligands can chemically bond with quantum dots and pigment particles at the same time to form a stable and structurally ordered composite structure. The introduction of cross-linkable ligands enhances the binding strength between quantum dots and pigment particles. Compared with physical adsorption or weak chemical bonding, the composite structure formed by chemical bonds is more stable and can effectively resist the damage to the composite structure caused by external environments such as solvents, temperature or light changes, thereby extending the service life of the composite. The selection and design of cross-linkable ligands can further regulate the surface state of quantum dots, reduce non-radiative transitions caused by surface defects, and thus improve the luminescence efficiency and quantum yield of quantum dots. At the same time, the presence of ligands also helps to reduce the energy transfer loss between quantum dots and pigment particles, ensuring that the composite fully demonstrates the excellent luminescence performance of quantum dots while maintaining the color stability of pigment particles. Through the connection of cross-linkable ligands, quantum dots and pigment particles can form a uniform dispersion system, avoiding the agglomeration of quantum dots and the sedimentation of pigment particles, which is beneficial to the uniform distribution of the complex in substrates such as coatings and inks, and also improves the processing performance of the complex and the quality of the final product.

[0037] Specifically, the size of the accommodating cavity 200 is preferably in the range of 100nm-50mm. The selection of this size range is intended to optimize the arrangement and performance of quantum dots, pigment particles or capsules in the accommodating cavity 200 to meet the needs of different application scenarios. The above size range is a preferred range, but in principle, the realization of reflective display does not depend on the size of a specific quantum dot, pigment particle or capsule. As long as it can be effectively encapsulated in the accommodating cavity 200 and can achieve the effect of reflective display under the irradiation of light, the size of these particles can be used in the technical solution of this application. By designing the size of the accommodating cavity 200 to a wide range of 100nm to 50mm, it can provide great flexibility and versatility for the selection of quantum dots, pigment particles or capsules. According to specific application requirements, particles of different sizes can be selected to construct a reflective display structure, thereby achieving the best optical performance and visual effects. The size of the accommodating cavity 200 has an important influence on the visual effect of the reflective display. By accurately controlling the size of the accommodating cavity 200, the arrangement and distribution of particles in the cavity can be optimized, and the scattering and interference effects can be reduced, thereby improving the clarity and contrast of the reflective display. Quantum dots, pigment particles or capsules of different sizes have different optical properties and color expressions. By adjusting the size of the accommodating cavity 200, the needs of various application scenarios can be met.

[0038] Specifically, the pigment particles of different colors are the same size, and the quantum dot size is in the range of 2nm-30nm.

[0039] See also Figure 2 In addition, the present application also provides a quantum dot cooperatively coupled color mixing display device including an array-arranged pixel structure, wherein the pixel structure is the aforementioned pixel structure. The present application focuses on a specific pixel structure implementation method, but does not mean to limit the pixel arrangement method or other aspects of the display panel preparation process. Whether it is the traditional RGB stripe arrangement, Pentile arrangement, or the more advanced Delta arrangement, Diamond arrangement, etc., the change in the pixel arrangement method should not be regarded as a deviation from the innovation of the present application. These different arrangements are intended to optimize the pixel density, viewing angle performance and color uniformity of the display panel, and are consistent with the basic principles and core technical innovations of the quantum dot cooperatively coupled color mixing display device, that is, using the unique optical properties of quantum dots to achieve efficient color mixing display. Therefore, any change in the pixel arrangement method can be applied within the technical solution of the present application as long as it can maintain or improve the overall performance of the display device. In the process of preparing the display panel, the selection of functional film materials, the addition or replacement of additive materials, etc. are also key factors affecting the display performance. For example, the use of more advanced barrier layer materials can reduce the impact of the external environment on the performance of quantum dots and improve the stability and life of the display device; and the addition of specific light stabilizers or antioxidants can further enhance the weather resistance and luminous efficiency of quantum dots. The quantum dot cooperatively coupled color mixing display device provided in this application not only has a unique pixel structure design, but also has extremely high flexibility and scalability. Whether it is a change in the pixel arrangement or an adjustment in the display panel preparation process, as long as the overall performance of the display device can be maintained or improved, it can be used.

[0040] Specifically, it also includes a backlight source. In terms of the excitation method of the backlight source, the present application is not limited to the traditional flat-panel backlight mode, but allows the use of a variety of methods including light emission on the flat panel. The changes in these excitation methods are intended to optimize the distribution and utilization of light, thereby improving the brightness and color uniformity of the display device. In terms of the selection of light source materials, the technical solution of the present application also shows extremely high flexibility and inclusiveness. Any material that can emit light, as long as its luminous wavelength can excite quantum dots to produce fluorescence, should be regarded as a potential light source material. In particular, since quantum dot materials have unique wavelength conversion characteristics, they can absorb short-wavelength light and convert it into long-wavelength fluorescence. Therefore, any light source with a central luminous wavelength less than the maximum luminous wavelength of the incorporated quantum dot material is suitable for the display device of the present application, so that the present application can flexibly select light sources of different wavelengths and types to meet the needs of different application scenarios.

[0041] Traditional reflective displays often cannot achieve high-brightness display effects due to the loss of sufficient lighting intensity. Quantum dots can emit bright fluorescence under the excitation of light sources, thus making up for this deficiency. In addition, quantum dots also have a narrower half-width and a wider color gamut, which can further enhance the color expression and brightness of the display device. In terms of manufacturing process, this application is based on quantum dot synergistic coupling mixed color capsules and adopts the traditional electrophoretic color reflective display device film preparation process. This process is not only mature and reliable, but also simple to make, and can effectively reduce production costs and improve production efficiency. At the same time, due to the synergistic effect of quantum dots and pigment particles, the color consistency and stability of the display device are improved. By introducing a backlight system, a flexible excitation method and a wide range of light source material options, as well as the unique optical properties of quantum dots, it is possible to overcome the problem of low brightness of traditional reflective displays in dark environments and achieve high-quality color display effects. Specific embodiments Some specific implementation methods will be further introduced below to further explain the technical solution of this application in detail.

[0043] This application first prepares a variety of quantum dot pigment particle complex inks specifically for reflective display, specifically covering the three basic colors of red, yellow, and blue, and additionally prepares white pigment particle inks for white display. These granular materials have been specially treated, and their surfaces are given different Zeta potential values, which can be different values ​​or different positive and negative charge states. This design is intended to provide the necessary charge driving force for the subsequent electrophoresis process. Next, the four carefully prepared granular material inks are mixed in a specific proportion, and the mixture is coated in a capsule material. This capsule material not only has good sealing and stability, but also includes positive and negative circuits at both ends, so that the electric field can be smoothly applied to the inside of the capsule.

[0044] By adjusting the direction, intensity and change pattern of the electric field, the electrophoretic behavior and upper and lower position distribution of the four granular materials in the capsule can be precisely controlled. This precise electrophoretic control mechanism enables the reflective display color of the capsule to be dynamically adjusted according to demand, thereby achieving precise color control. In order to build a complete reflective display device, several such capsules are laid out into a single layer and placed between the upper and lower layers of active matrix control electrodes. A set of electrodes corresponding to each pixel unit can independently control one or more capsules below it. When the electric field acts on these capsules, they will be controlled by the electric field at the same time, thereby achieving precise control of the reflective display color. In this way, each capsule becomes an independent pixel point, and a large number of such pixel point arrays are arranged together to form the display panel of the reflective display device. Finally, this display panel composed of array pixel points, combined with the quantum dot cooperative coupling color mixing technology mentioned above, becomes a high-performance quantum dot cooperative coupling color mixing display device.

[0045] First, a series of quantum dot pigment particle complex inks specifically for reflective display are prepared. These inks cover a variety of basic colors other than white (such as red, yellow, blue, etc., and the specific color types can be flexibly adjusted according to needs). At the same time, a white pigment particle ink for achieving white display is also required. These particle materials are specially treated, and their surfaces are given Zeta potentials of different values ​​or positive and negative states. The potential value range is carefully set between -5 electron volts (eV) and 5eV, and more preferably, in the range of -500 millielectron volts (meV) to 500meV to ensure the stable electrophoretic behavior of the particles in the electric field. Next, these carefully prepared particle material inks are mixed in a predetermined ratio. This ratio is highly adjustable, and the proportion of each ink can be flexibly changed in the range of 0% to 100%, but in order to ensure the best color effect and display performance, the ratio is usually set in the preferred range of 10% to 60%. The selection of this ratio is based on the reflective spectral characteristics of each ink material and the final desired display color effect.

[0046] The mixed ink is then encapsulated in a containment cavity formed by a capsule material. The capsule material has a high degree of freedom in shape and can be spherical, cylindrical or any other shape as long as the ink solvent is not leaked. At the same time, the shell of the capsule can be closed or have an opening (but the opening needs to be specially treated to ensure that the ink does not leak). In order to optimize the display effect and preparation process, the diameter of the circumscribed sphere of the capsule body ranges from 100 nanometers (nm) to 50 millimeters (mm), and more preferably, it is in the range of 1 micrometer (μm) to 500μm.

[0047] The preparation process of quantum dot pigment particle complex ink is described as follows: the initial step is to prepare a uniform and monodisperse pigment particle solution, on this basis, introduce cross-linkable ligand A to perform the key ligand exchange step. The core of this step is to replace the original ligand on the surface of the pigment particle by using the functional group with stronger coordination ability on the cross-linkable ligand A or by using the shorter chain length advantage compared to the original ligand. In order to ensure the efficiency and accuracy of the ligand exchange process, the temperature of the reaction system and the concentration of the cross-linkable ligand A are carefully controlled to achieve the best ligand exchange effect.

[0048] Next, in order to further optimize the surface properties of the pigment particles, a small amount of short-chain polar ligands are added to the system. These short-chain polar ligands will selectively replace part of the cross-linkable ligand A that has been bound to the surface of the pigment particles. This process further enriches the types and distribution of ligands on the surface of the pigment particles, thereby improving the stability and dispersibility of the pigment particles.

[0049] Through the above ligand exchange process, pigment particles with surface modification of cross-linkable ligand A and polar short-chain ligands are finally obtained. These pigment particles not only have excellent stability and dispersibility, but also the cross-linkable ligand A on their surface provides a basis for subsequent cross-linking reactions and the preparation of composite inks. The entire preparation process requires strict control of reaction conditions, such as temperature, time, ligand concentration, etc., to ensure that each step of the reaction can achieve the desired effect.

[0050] The second step of the preparation process focuses on the ligand exchange on the surface of quantum dots. Specifically, a uniform and monodisperse quantum dot solution is used as the starting material, and a cross-linkable ligand B is introduced into it to perform a ligand exchange step. In this step, the functional group on the cross-linkable ligand B successfully replaces the original ligand on the surface of the quantum dot by virtue of its stronger coordination ability than the original ligand, or the advantage of a shorter chain length. In order to achieve effective ligand exchange, the temperature of the reaction system and the concentration of the added cross-linkable ligand B are strictly controlled. Subsequently, a small amount of short-chain polar ligands are added to the system. These ligands will selectively replace part of the cross-linkable ligand B that has been bound to the surface of the quantum dots. After this series of ligand exchange processes, quantum dots with surfaces modified with both cross-linkable ligands B and polar short-chain ligands are finally obtained.

[0051] In the third step, the quantum dot-pigment particle complex is prepared by adding a certain amount of quantum dot solution with appropriate concentration to the pigment particle solution. Then, I trigger the cross-linking reaction between the cross-linkable ligands A and B by means of ultraviolet light irradiation, heating or adding an initiator. This reaction establishes a strong connection between the quantum dots and the pigment particles, thus obtaining a quantum dot-pigment particle complex.

[0052] During the entire preparation process, the reaction conditions of each step, such as temperature, time, ligand concentration, etc., were strictly monitored to ensure that each step of the reaction could achieve the expected effect. At the same time, the products of each step were carefully characterized and tested for performance to verify the stability of their structure and properties. Through this series of careful design and operation, high-quality quantum dot pigment particle complexes were successfully prepared.

[0053] This application integrates the unique properties of quantum dots to achieve innovative breakthroughs in display technology. Specifically, the narrow light line width, high light efficiency, and zeta potential mobility of quantum dots after ligand exchange are utilized to successfully connect quantum dots to the surface of pigment particles, forming a quantum dot-pigment particle complex that can not only emit quantum dot fluorescence, but also superimpose with the reflected light of the pigment particles themselves, thereby improving brightness and light output.

[0054] The narrow line width characteristics of quantum dot fluorescence make the complex far superior to traditional pigment particles in color gamut performance. In color display, the high color purity of the three primary colors of red, green and blue is the key to achieving rich colors. The spectral line width of quantum dot fluorescence is narrower than the reflected light of pigment particles. Therefore, the quantum dot pigment particle complex is superior in color purity and can show a wider color gamut than pigment particles. In addition, the high zeta potential and electrophoretic mobility of quantum dots increase the mobility of the pigment particle complex under the action of the electric field, thereby improving the response speed. By precisely controlling the direction, intensity and change rate of the electric field, the orderly electrophoresis and upper and lower position distribution of the four particle materials in the capsule can be achieved, thereby accurately controlling the reflective display color of the capsule. When constructing a reflective display device, multiple capsules are laid out into a single layer and placed between the upper and lower active matrix control electrodes. A group of electrodes corresponding to each pixel unit can independently control one or more capsules below it, thereby achieving precise control of the reflective display color. Each capsule becomes an independent pixel point, and a large number of pixel point arrays are arranged to form a display panel, thereby forming a quantum dot collaboratively coupled color mixing display device.

[0055] It is worth mentioning that the four color particles in this application (white pigment particle ink, yellow quantum dot pigment particle complex ink, red quantum dot pigment particle complex ink and blue quantum dot pigment particle complex ink) have different zeta potentials and charge properties. By flexibly adjusting the direction of the electric field and the magnitude and change rate of the driving voltage, the particles of different colors can be accurately controlled to be electrophoresed to the top layer, thereby realizing the display of different colors. When all color particles are not electrophoresed to the top layer, the capsule displays black. In addition, in order to further improve the display effect of the display device in a dark environment, a side-entry excitation light source can be added to the display panel. Under backlight excitation, the quantum dots can emit bright fluorescence, thereby making up for the shortcomings of the reflective display device in a dark environment. This function is optional and can be increased or decreased according to actual needs.

[0056] As can be seen from the foregoing, the present application proposes an innovative quantum dot cooperatively coupled mixed color display pixel structure and device thereof. The structure is composed of a first electrode, a second electrode and a receiving cavity located therebetween, the receiving cavity being filled with electronic ink, the electronic ink comprising at least two different colors of quantum dot-pigment particle complexes, these complexes are formed by firmly connecting the quantum dots to the surface of the pigment particles through cross-linkable ligands, and the complexes of different colors have unique potential characteristics, ensuring precise control under the action of an electric field.

[0057] The introduction of quantum dots has brought further optimization to traditional electrophoretic color reflective displays. Quantum dots can absorb short-wavelength light and convert it into narrow half-width (usually less than 25nm) fluorescence with a specific wavelength, thereby narrowing the light spectrum, increasing the display color gamut, and providing a richer, more realistic and natural visual experience. At the same time, the efficient fluorescence conversion ability of quantum dots (fluorescence quantum yield is usually more than 90%) effectively improves the utilization rate of illumination light and the brightness of display devices, and can present clear and bright images even in dim light environments. In addition, the small size of quantum dots and the large number of ligands and surface potential characteristics they carry increase the overall specific surface area and load in the fluid, increase the movement speed, and thus improve the response speed of reflective displays.

[0058] The above is only a specific implementation of the present application, and any improvements made based on the concept of the present application are deemed to be within the protection scope of the present application.

Claims

1. A quantum dot cooperatively coupled color mixing display pixel structure, characterized in that: The electronic ink storage device comprises a first electrode, a second electrode, a receiving cavity and electronic ink in the receiving cavity, wherein the receiving cavity is formed between the first electrode and the second electrode; The electronic ink includes at least two quantum dot-pigment particle complexes of different colors, wherein the quantum dot-pigment particle complexes are formed by quantum dots connected to the surface of pigment particles; Among them, quantum dot-pigment particle complexes of different colors have different electric potentials.

2. The quantum dot cooperatively coupled color mixing display pixel structure according to claim 1, characterized in that: The color of the pigment particles in the quantum dot-pigment particle complex is selected from red, blue, yellow, cyan or magenta.

3. The quantum dot cooperatively coupled color mixing display pixel structure according to claim 2, characterized in that: The electronic ink also includes white pigment particles.

4. The quantum dot cooperatively coupled color mixing display pixel structure according to claim 3, characterized in that: The electronic ink includes red, blue and yellow quantum dot-pigment particle complexes, the yellow quantum dot-pigment particle complexes and white pigment particles are at a negative potential, and the red quantum dot-pigment particle complexes and blue quantum dot-pigment particle complexes are at a positive potential.

5. The quantum dot cooperatively coupled color mixing display pixel structure according to claim 1, characterized in that: The quantum dot-pigment particle complex of at least one color also has two or more different potentials.

6. The quantum dot cooperatively coupled color mixing display pixel structure according to claim 1, characterized in that: The quantum dots are attached to the pigment particles via cross-linkable ligands.

7. The quantum dot cooperatively coupled color mixing display pixel structure according to claim 1, characterized in that: The size of the accommodating cavity is in the range of 100 nm-50 mm.

8. The quantum dot cooperatively coupled color mixing display pixel structure according to claim 1, characterized in that: The pigment particles of different colors are the same size, and the quantum dot size is in the range of 2nm-30nm.

9. A quantum dot cooperatively coupled color mixing display device, characterized in that: A pixel structure is provided which is arranged in an array, wherein the pixel structure is the pixel structure according to any one of claims 1 to 8.

10. The quantum dot cooperatively coupled color mixing display device according to claim 9, characterized in that: Also includes a backlight.

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