Quantum dot collaborative coupling reflective display device and manufacturing method thereof

Abstract

The invention relates to a quantum dot collaborative coupling reflective display device and a manufacturing method thereof, the device comprises a plurality of precisely arranged pixel structures, and each pixel structure is further subdivided into sub-pixel structures of different colors so as to realize precise control of full-color display. Each sub-pixel structure comprises a first electrode, a second electrode and a containing cavity formed between the first electrode and the second electrode, and the containing cavity is filled with electronic ink. The black pigment particles and the quantum dot-pigment particle complex have different potentials under the action of an electric field and can be driven by the electric field to generate ordered migration, so that dynamic regulation and control of display contents are realized. The quantum dots can absorb incident light with a specific wavelength and convert the incident light into light with a corresponding color by virtue of unique fluorescence characteristics of the quantum dots, and the black pigment particles are responsible for absorbing light with a non-target wavelength, so that the contrast ratio is enhanced. And due to the application of the quantum dot-pigment particle complex, the display device can present richer and more accurate colors, and the visual experience is improved.

Description

Technical Field

[0001] The present application relates to the technical field of display devices, and in particular to a quantum dot cooperatively coupled reflective display device and a method for manufacturing the same. Background Art

[0002] With the continuous development of display technology, the current mainstream LED, LCD and OLED display technologies have dominated various display devices with their bright colors and high contrast. However, these technologies have serious reflections under strong light and require continuous power supply, which limits their application in certain specific environments. In order to overcome these limitations, color reflective display technology came into being. This technology uses ambient light for display, which not only has low energy consumption, but also good visibility, and the color performance is increasingly rich and natural, which can provide an immersive visual experience. With the continuous advancement of technology, color reflective display technology is expected to replace some traditional display technologies.

[0003] Electronic paper is a general term for reflective paper-like displays. It is ultra-thin, light, and has extremely low energy consumption, and can achieve a visual experience like paper. Even in the sun, electronic paper has the advantages of no blind spots for reading and good visual effects. At present, electronic paper technology covers a variety of technical routes such as electrophoretic display, electrowetting display, MEMS electromechanical interference display, and cholesterol liquid crystal display. 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. In addition, quantum dots, as a cutting-edge technology for new display materials, have become a strong competitor for the next generation of display technology due to their high luminous efficiency, pure color, and low energy consumption. Colloidal quantum dots have small particle size, discrete energy levels, high color purity, can cover the entire visible spectrum, and can be prepared by solution to reduce costs. However, quantum dot display technology also faces many challenges. For example, QLED technology is immature and industrialization will take some time; although QDs-LCD has launched products, the stability of quantum dots leads to high costs and short life. How to maintain the high efficiency and stability of quantum dots in display devices is the main challenge facing quantum dot display technology.

[0004] Applying quantum dots to color reflective display technology can avoid blue light aging, and its high efficiency and narrow light emission characteristics are expected 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 many technical difficulties. For example, how to truly apply quantum dots to reflective display and achieve synergistic efficiency is still one of the problems that need to be solved urgently. Summary of the invention

[0005] The purpose of the present application is to provide a quantum dot cooperatively coupled reflective display device, which utilizes the advantages of quantum dots in converting short-wavelength light and having a narrow half-peak width of luminescence and the characteristics of pigment particles with strong long-wavelength absorption, and applies quantum dot-pigment particle complexes to electrophoretic color reflective displays to solve the problems of long response time, narrow color gamut, and low brightness in traditional electrophoretic color reflective displays. The monochrome micro-nano capsule technology is used to solve the problems of large capsule thickness, long response time, complex electric field regulation, and difficult color grayscale in traditional electrophoretic color reflective displays.

[0006] The objective of the present application is achieved through the following technical solutions: the quantum dot cooperatively coupled reflective display device of the present application comprises a plurality of pixel structures, each pixel structure comprises a sub-pixel structure of a different color, each sub-pixel structure comprises a first electrode, a second electrode and a receiving cavity between the first electrode and the second electrode; The accommodating cavity includes electronic ink, the electronic ink includes black pigment particles and quantum dot-pigment particle complexes, and in sub-pixel structures of different colors, the color of the pigment particles in the quantum dot-pigment particle complexes is the color of the corresponding sub-pixel structure; The black pigment particles and the quantum dot-pigment particle complex have different potentials.

[0007] In one embodiment, the proportion of the black pigment particles is in the range of 20-80%.

[0008] In one embodiment, the colors of the pigment particles in the quantum dot-pigment particle complex include red, blue and yellow.

[0009] In one embodiment, the black pigment particles have a positive potential, and the quantum dot-pigment particle complex has a negative potential.

[0010] In one embodiment, the quantum dot-pigment particle complex has two or more different potentials.

[0011] In one embodiment, the quantum dot-pigment particle complex connects the quantum dots to the pigment particles via cross-linkable ligands, and also includes sub-pixels formed by black pigment particles and white pigment particles.

[0012] In one embodiment, the potential of the black pigment particles and the quantum dot-pigment particle complex is in the range of -5 eV to 5 eV.

[0013] In one of the embodiments, the pixel structure further includes a filter.

[0014] In addition, the present application also provides a method for manufacturing a quantum dot cooperatively coupled reflective display device, comprising: Prepare quantum dot pigment particle complex inks of various colors, including red, blue and yellow, and prepare black pigment particles and white pigment particles; To manufacture sub-pixel structures of different colors, a receiving cavity is first formed, and electronic ink is filled in the receiving cavity, wherein the electronic ink includes ink formed by black pigment particles and quantum dot-pigment particle complexes and ink formed by black pigment particles and white pigment particles; The accommodating cavity is arranged between the first electrode and the second electrode, and accommodating cavities of different colors are arranged between the first electrode and the second electrode to form sub-pixel structures of different colors.

[0015] In one embodiment, the sub-pixel structure is formed on a substrate having a backlight source.

[0016] Compared with the prior art, this application has the following beneficial effects: This application introduces quantum dots into the capsules of electrophoretic color reflective display, making full use of the characteristics of quantum dots in converting short-wavelength light and having a narrow half-peak width of emission (<25nm), effectively narrowing the spectral range of the final light output, thereby significantly increasing the display color gamut. Compared with traditional pigment particles, the efficient fluorescence conversion of quantum dots (fluorescence quantum yield >90%) improves the utilization rate of illumination light, thereby improving the display brightness.

[0017] The small size (2nm-30nm in diameter) and high specific surface area of ​​quantum dots increase the load in the fluid and the speed of movement under the action of the external field, thereby shortening the response time and improving the dynamic performance of the display device. While using quantum dots, the pigment particles are retained in the capsule to absorb the long-wavelength illumination light that the quantum dots cannot effectively absorb, avoiding the huge deviation of the color of the light spectrum caused by the use of quantum dots alone, and ensuring the accuracy of the color. At the same time, through the synergistic effect of quantum dots and pigment particles, the half-peak width is narrowed, the color gamut is further increased, and the color expression is improved.

[0018] Each sub-pixel contains only monochrome micro-nano capsules of the corresponding color, which simplifies the electric field control logic. Display can be achieved by controlling the target color particles to electrophoretically move to the upper layer. The electric field change can be used for finer grayscale adjustment, which improves the accuracy and consistency of color control. The manufacturing process of monochrome micro-nano capsules is relatively simple, the interference between particles is reduced, the electrophoresis speed and efficiency are improved, and the accuracy of electric field control is enhanced. The mixed film-making process of capsules of multiple colors is also simpler, ensuring color uniformity and consistency. The quantum dot cooperatively coupled reflective display device and its manufacturing method of the present application, by introducing quantum dots, retaining pigment particles, and adopting monochrome micro-nano capsule technology and other innovative means, effectively solves the problems of long response time, narrow color gamut, low brightness, etc. in traditional electrophoretic color reflective display, and enhances environmental adaptability and process efficiency, providing a new solution for the development of electrophoretic color reflective display technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of a pixel structure in one embodiment of the present application; Figure 2 It is a schematic diagram of the structure of a quantum dot cooperatively coupled reflective display device in one embodiment of the present application.

[0020] Explanation of the reference numerals: 100, pixel structure; 110, sub-pixel structure; 200, first electrode; 300, receiving cavity; 310, black pigment particles; 320, quantum dot-pigment particle complex; 400, second electrode; 500, filter. DETAILED DESCRIPTION

[0021] 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.

[0022] 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.

[0023] 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.

[0024] In the field of display technology that pursues higher image quality, faster response speed and stronger environmental adaptability, quantum dots are gradually becoming one of the technologies that promote the innovation of display technology due to their unique luminescence characteristics and adjustable spectral properties. Although traditional electrophoretic color reflective display devices have advantages in energy saving and lightness, they still have bottlenecks in response time, color gamut coverage and brightness performance in dark environments. In order to break through these limitations, the present application proposes a quantum dot cooperatively coupled reflective display pixel device and a method for making it. This technology combines the advantages of quantum dots and pigment particles, and uses the efficient fluorescence characteristics of quantum dots to convert short-wavelength light, as well as the powerful ability of pigment particles to absorb long wavelengths, to achieve fine control of the spectrum and enhance color expression. At the same time, by introducing monochrome micro-nano capsule technology, the structural design of the display device is further optimized, the capsule thickness is reduced, and the electric field control logic is simplified, thereby significantly improving the response speed and color consistency while maintaining the simplicity of the process. The specific structure and working principle of this quantum dot cooperatively coupled reflective display pixel device will be described in detail below. Please refer to Figure 1 , Figure 2 A quantum dot cooperatively coupled reflective display device in a preferred embodiment of the present application includes a plurality of pixel structures 100, each pixel structure 100 includes sub-pixel structures 110 of different colors, each sub-pixel structure 110 includes a first electrode 200, a second electrode 400 and a receiving cavity 300 between the first electrode 200 and the second electrode 400, the receiving cavity 300 includes electronic ink, the electronic ink includes black pigment particles 310 and quantum dot-pigment particle complexes 320, in the sub-pixel structures 110 of different colors, the color of the pigment particles in the quantum dot-pigment particle complexes 320 is the color of the corresponding sub-pixel structure 110, wherein the black pigment particles 310 and the quantum dot-pigment particle complexes 320 have different electric potentials.

[0025] The quantum dot cooperatively coupled reflective display device is composed of a plurality of precisely arranged pixel structures 100, each pixel structure 100 is further subdivided into sub-pixel structures 110 of different colors to achieve precise control of full-color display, improve display resolution, and enhance the richness and accuracy of color expression. Inside each sub-pixel structure 110, a microenvironment consisting of a first electrode 200, a second electrode 400, and a receiving cavity 300 formed therebetween is constructed. The receiving cavity 300 is filled with electronic ink of a special proportion. The electronic ink is a complex system composed of black pigment particles 310 and quantum dot-pigment particle complexes 320. The black pigment particles 310 are responsible for absorbing light of non-target wavelengths to enhance contrast, while the quantum dot-pigment particle complexes 320 utilize the unique fluorescence properties of the quantum dots therein to convert incident light of a specific wavelength into luminescence of a corresponding color, thereby achieving precise color control. In the sub-pixel structures 110 of different colors, the color of the pigment particles in the quantum dot-pigment particle complex 320 matches the color of the corresponding sub-pixel structure 110, ensuring that each sub-pixel can emit pure and highly saturated target color light, further improving the fidelity and color purity of the display effect. The specific form of the accommodating cavity 300 is not limited, and can be a capsule.

[0026] In addition, the black pigment particles 310 and the quantum dot-pigment particle complex 320 have different potentials under the action of the electric field, and this characteristic enables them to migrate in an orderly manner under the drive of the electric field. When an appropriate electric field is applied, the black pigment particles 310 will move toward a certain electrode, while the quantum dot-pigment particle complex 320 will move in the opposite direction, thereby realizing dynamic regulation of the displayed content. This migration mechanism based on potential difference not only improves the response speed, but also reduces energy consumption, so that the display device can optimize energy efficiency while maintaining high performance. Through the application of the quantum dot-pigment particle complex 320, the spectrum can be finely regulated, so that the display device can present richer and more accurate colors and enhance the visual experience. The introduction of the black pigment particles 310 effectively absorbs light of non-target wavelengths, enhances the display contrast, and makes the image clearer and three-dimensional.

[0027] Quantum dots, with their unique properties, play multiple positive roles in the display device of the present application. First, quantum dots can absorb short-wavelength light and efficiently convert it into fluorescence with a specific wavelength and extremely narrow fluorescence half-width (usually less than 25nm). This feature achieves accurate narrowing of the light spectrum at the spectral level, thereby greatly widening the display color gamut, making the color performance richer and fuller. Secondly, these short-wavelength lights may be absorbed by pigment particles and converted into heat, causing light energy loss. However, with the intervention of quantum dots, this part of the light energy can be efficiently converted into fluorescence (the fluorescence quantum yield generally exceeds 90%), improving the utilization rate of illumination light. This transformation directly improves the brightness of the reflective display device, making the display effect brighter and clearer. In addition, the quantum dots themselves are small in size (usually between 2nm and 30nm in diameter), and have a large number of ligands and potentials on the surface, which not only increases the overall specific surface area and load in the reflective display fluid, but also increases the movement speed of the quantum dots under the action of the electric field. This change directly speeds up the response speed of the reflective display, making the screen switching faster and smoother.

[0028] While applying quantum dots to reflective display technology, we cleverly retain the pigment particles in the display capsules. This strategy not only optimizes display performance but also ensures high-precision color presentation.

[0029] If quantum dots are used only as pigment particles, the final light emission spectrum will be the superposition of the quantum dot reflection spectrum (generated by irradiation with a full-wavelength illumination source) and the fluorescence spectrum (generated by excitation with a short-wavelength illumination source). Due to the weak absorption capacity of quantum dots in the long-wavelength range, compared with the light emission spectrum of pigment particles, the quantum dot light emission spectrum will have light leakage in the long-wavelength region. This light leakage will not only cause deviations in the displayed color, but may also cause a huge difference between the final presented color and the design target. In order to overcome this challenge, the present application retains pigment particles in the color reflective display. The introduction of pigment particles, with its excellent long-wavelength light absorption capacity, effectively fills the insufficient absorption of quantum dots in the long-wavelength region. In this way, the synergistic effect of quantum dot fluorescence and pigment particle absorption narrows the final light emission spectrum and eliminates the light leakage phenomenon in the long-wavelength region. The optimized spectrum is not only more conducive to achieving wide color gamut display, but also ensures high-quality color presentation.

[0030] Through precise control, the size of the capsule is reduced, the thickness of the capsule is reduced, and the electrode spacing is reduced, which not only effectively reduces the driving voltage, but also increases the movement speed of the electrophoretic particles, thereby greatly improving the response speed of the display device and bringing a smoother visual experience to the user. In terms of color presentation, the present invention realizes the precise control of monochrome micro-nano capsules. Each sub-pixel point only contains monochrome micro-nano capsules of the color corresponding to the pixel point, and the capsules of other colors remain in a normally black state, making the electric field control more concise and efficient. It is only necessary to adjust the electric field to control the electrophoresis of the target color particles to the upper layer. At the same time, through the fine adjustment of the electric field, the precise control of the grayscale can be further achieved, thereby improving the delicacy and layering of the display. In addition, the present invention also simplifies the capsule manufacturing process. Since each capsule contains only two types of particles (quantum dot-pigment particle complex 320 and black pigment particles 310), the mutual interference between particles is greatly reduced, and the electrophoresis speed and efficiency are improved. This design also improves the accuracy of electric field control, so that the color consistency is significantly improved. When preparing a film of capsules of various colors, the capsules of various colors are evenly mixed and evenly distributed in a single layer, so that the film making process can be easily completed, greatly simplifying the production process.

[0031] In the implementation of quantum dot cooperative coupling monochrome micro-nano capsule technology, there are no excessive restrictions on quantum dots, pigment particles, cooperative coupling materials, electrophoretic liquid solvents and other aspects. Not only can quantum dots, pigment particles and cooperative coupling materials exist in the form of solutions, but they can also be replaced with powder forms. This replacement can further simplify the preparation process and improve production efficiency. It also helps to improve the stability and dispersibility of the material. In the selection of electrophoretic liquid solvents, it is not limited to traditional solvents, but can be flexibly selected according to actual needs. One or more solvents such as chloroform, toluene, chlorobenzene, alkanes, alkenes, aromatic hydrocarbons, alcohols, ethyl acetate, halogenated alkanes, halogenated alkenes, halogenated aromatic hydrocarbons, diol derivatives, ketones, toluene and its homologues (such as o-xylene, m-xylene, p-xylene), fluorocarbons, esters, tetrahydrofuran, petroleum ether, dimethyl sulfoxide, water, etc. are mixed. This diverse solvent selection can optimize electrophoretic performance and improve the response speed and color performance of display devices. The selection of quantum dots is not limited to a single type of quantum dots, but one or more quantum dot luminescent materials with different morphologies and central emission wavelengths in the range of 350nm to 1000nm can be incorporated. In addition, quantum dot materials can be mixed with other types of luminescent materials (such as phosphors, organic luminescent materials, etc.) to further broaden the color gamut and improve color saturation.

[0032] Similarly, in the selection of pigment particles, one or more pigment particles of different morphologies with peak reflection wavelengths in the range of 350nm to 1000nm can also be added. In addition, we can also mix the pigment particles with other spectral materials with high reflectivity (>20%) to improve the brightness and contrast of reflective display devices. In the core and shell materials of quantum dots, diversified replacements can also be made. For example, single-core nanoparticles such as CdSe, CdTe, CdS, ZnSe, ZnTe, ZnS, CuInS, CuInSeS, AgInS, AgInSeS, InP, CuZnSe, ZnMnSe, PbS, PbSe can be selected as the core material of quantum dots. At the same time, one or more layers of CdSe, CdS, ZnO, ZnS, ZnSe, ZnTe or alloy materials can be coated on the outside of the core material to improve the stability and luminous efficiency of quantum dots. In the selection of pigment particles, you can also try to use organic dyes, organic inks, inorganic dyes, inorganic inks, natural pigments, artificial synthetic pigments, graphite, metal oxides and their particles of different morphologies, metals and their particles of different morphologies, SiO2, etc. as materials for pigment particles. This diverse selection can further enrich the color performance of display devices and improve the color authenticity and restoration. Through the optimization of the above technical features, the preparation efficiency and production efficiency of quantum dot synergistic coupling monochrome micro-nano capsule technology can be improved in specific application scenarios, and the performance of the corresponding display devices can be optimized.

[0033] Furthermore, in the technical solution of the present application, it is not limited to traditional capsule materials, but can flexibly select various plastic materials including polystyrene, polypropylene, polyvinyl chloride, polyethylene, acrylonitrile-butadiene, polycarbonate, polyamide, thermoplastic polyurethane, low-density polyethylene, high-density polyethylene, polyethylene terephthalate, polyethylene naphthalate, polyphenylene ether, silicone plastic, polymethyl methacrylate, etc. as the preparation material of the capsule according to actual needs. In addition, glass, rubber, glue, natural polymers (such as gelatin), polyamide, silicone rubber, polyvinyl alcohol, various celluloses, starch, etc. can also be selected as alternative materials for capsules to further broaden the scope of application and meet the needs of different fields. In terms of the size of quantum dots, pigment particles and capsules, in theory, no matter how large the size is, as long as reflective display can be achieved, it can be applied in the technical solution of the present application, and the size of quantum dots, pigment particles and capsules can be flexibly adjusted according to actual needs to achieve the best display effect and performance.

[0034] In terms of pixel arrangement, a high degree of flexibility is also maintained. No matter what pixel arrangement is adopted, as long as it does not affect the implementation effect of the technical solution of the present application, it can be applied, so that the technical solution of the present application can adapt to different display needs and application scenarios. In the preparation process of the display panel, not only can the functional film materials and additive materials be added or replaced, but also customized designs can be made according to actual needs. In terms of excitation light source materials and luminous wavelengths, any light source material that can emit light can be used as long as it can make quantum dots produce fluorescence and display effects. At the same time, since quantum dot materials can absorb short-wavelength light and convert it into long-wavelength light for emission, any light source with a central luminous wavelength less than the maximum luminous wavelength of the incorporated quantum dot material can also be directly used. The technical solution of the present application can not only broaden the scope of application of quantum dot collaborative coupling monochrome micro-nano capsule technology, but also further improve its performance and service life.

[0035] In one embodiment, the proportion of the black pigment particles 310 is in the range of 20-80%. The appropriate addition of black pigment particles 310 can improve the color contrast of the display device. When the proportion of black pigment particles 310 is controlled between 20% and 80%, the relationship between color contrast and brightness is balanced by precisely adjusting the content of black pigment particles 310, thereby achieving a clearer and more vivid display effect. In a reflective display device, by setting the proportion of black pigment particles 310 in the range of 20% to 80%, we can effectively reduce the scattering and reflection of light inside the display device, thereby improving the purity of the black area and making the display effect more realistic and delicate.

[0036] In one embodiment, the colors of the pigment particles in the quantum dot-pigment particle complex 320 include red, blue and yellow. By selecting red, blue and yellow as the basic colors, most of the visible spectrum can be covered, laying a solid foundation for achieving full-color display, and providing a broad space for subsequent color adjustment and optimization, so that the display device can present a more delicate and rich color level. Quantum dot materials, with their unique luminescent properties and tunability, can accurately match and enhance the color performance of pigment particles. On the basis of red, blue and yellow pigment particles, quantum dots can further refine the color range and improve color accuracy, so that the display device can more accurately restore the colors of the real world. The design of the quantum dot-pigment particle complex 320 effectively enhances the color stability by combining the fluorescence effect of quantum dots with the scattering effect of pigment particles. Even under long-term use or changes in ambient light, the display device can still maintain stable color performance and extend its service life.

[0037] In one embodiment, the black pigment particles 310 are at a positive potential, and the quantum dot-pigment particle complex 320 is at a negative potential. By giving the black pigment particles 310 a positive potential and the quantum dot-pigment particle complex 320 a negative potential, the mutual attraction between the charges can be utilized, which not only helps to improve the color stability and contrast of the display device, but also effectively reduces the agglomeration phenomenon between the pigment particles and the quantum dots, and improves the uniformity of the display effect. The positive potential of the black pigment particles 310 and the negative potential of the quantum dot-pigment particle complex 320 enable the two to present colors more accurately under the interaction of charges. The black pigment particles 310 can absorb and block most of the light to form a high-purity black background, while the quantum dots can absorb light of a specific wavelength and emit fluorescence of different colors, thereby forming a sharp color contrast with the pigment particles, improving the color expression and layering of the display device, and the optimization of the charge interaction and the accuracy of the color presentation jointly improve the performance stability of the display device.

[0038] In one embodiment, the quantum dot-pigment particle complex 320 has more than two different potentials. By finely regulating the potentials of different components in the complex, the displacement of the quantum dots under the action of the electric field is precisely fine-tuned. This fine-tuning mechanism enables the complex to show unprecedented richness and delicacy in color performance, while greatly improving its ability to adapt to the color requirements of different application scenarios. Specifically, when the complex changes from one state to another, due to the different potentials of the components, their movement speed and distance in the electric field will be different. By accurately controlling the time of the electric field, the movement distance of each component inside the complex can be effectively regulated, thereby achieving differentiated color display. This differentiated color performance not only meets the needs of diversified application scenarios for color accuracy, but also brings users a more realistic, delicate and vivid visual experience.

[0039] In one embodiment, the quantum dot-pigment particle complex 320 connects the quantum dots to the pigment particles through a cross-linkable ligand, and also includes sub-pixels formed by black pigment particles 310 and white pigment particles. By using a cross-linkable ligand to connect the quantum dots to the pigment particles, the firmness and stability of the composite structure is achieved, which not only avoids the agglomeration and shedding of the quantum dots, but also improves the mechanical strength and durability of the composite, thereby ensuring the long-term stable operation of the display device. The close combination of the quantum dots and the pigment particles enables the composite to present a richer and more delicate color level. At the same time, the addition of black pigment particles 310 and white pigment particles further improves the contrast and color purity of the sub-pixels. By accurately controlling the proportion of black pigment particles 310 in the electronic ink, the brightness and contrast of the sub-pixels can be effectively adjusted, thereby achieving accurate optimization of the display effect.

[0040] In one embodiment, the potentials of the black pigment particles 310 and the quantum dot-pigment particle complex 320 are in the range of -5eV to 5eV. By introducing specific functional groups and charge regulators, their potentials are successfully controlled between -5eV and 5eV. The selection of this potential range not only ensures that a stable charge interaction can be formed between the pigment particles and the quantum dots, but also avoids charge agglomeration and instability that may be caused by excessively high potentials. The black pigment particles 310 and the quantum dot-pigment particle complex 320 whose potentials are controlled within the above range can present richer and more delicate color levels, and have better electronically controlled control accuracy.

[0041] In one embodiment, the pixel structure 100 further includes a filter 500. One or more layers of filter 500 are formed on the pixel structure 100, which can filter out unnecessary light according to different spectral characteristics and only allow light of a specific wavelength to pass through, so that the display device can present purer and brighter colors, while avoiding the interference of stray light on color performance, thereby improving contrast and color purity. By accurately filtering out unnecessary light, the filter 500 ensures that only light of the target wavelength can reach the observer, thereby achieving a more realistic and delicate color performance. The filter 500 can effectively block the interference of stray light and background light, so that the contrast of the display device is improved. This feature is particularly important in dark environments or high-brightness environments, and can ensure the clarity and readability of the displayed content. In outdoor or strong light environments, the filter 500 can significantly reduce the interference of external light on the display device and maintain color stability and consistency.

[0042] The display panel can be equipped with a side-entry excitation light source. In a dark environment, the light source can backlight and excite quantum dots to achieve efficient fluorescent light emission, thereby improving the display effect of the display device in a dark environment, enhancing the applicability of the display device, and making up for the shortcomings of reflective display devices in dark conditions. The excitation method of the excitation light source can be flexibly adjusted according to actual needs, including but not limited to advanced methods such as flat backlight and flat panel light emission. The diverse excitation methods not only provide a rich selection of visual effects for the display device, but also further enhance its expressiveness and adaptability under different lighting conditions.

[0043] By selecting a backlight excitation light source, quantum dots can be effectively excited and emit fluorescence, thus making up for the lack of brightness of reflective displays in dark environments. In a dark environment without sufficient lighting intensity, traditional reflective display devices are difficult to achieve high-brightness display effects by reflecting light alone, and the unique properties of quantum dots enable them to emit bright light under the excitation of a light source. The quantum dot light emission has a narrower half-peak width and can emit purer and more concentrated light, thereby improving the color gamut and brightness of the display device. Compared with traditional pigment particles, quantum dots can not only emit light under the excitation of a light source, but also achieve a wider color gamut coverage and higher brightness output. Therefore, with the help of quantum dots, color reflective display devices can show excellent display effects even in dark environments, bringing users a clearer and more vivid visual experience.

[0044] In addition, the present application also provides a method for manufacturing a quantum dot cooperatively coupled reflective display device, comprising: preparing a quantum dot pigment particle composite ink of multiple colors, including red, blue and yellow, and preparing black pigment particles 310 and white pigment particles; To manufacture sub-pixel structures 110 of different colors, firstly, a receiving cavity 300 is formed, and electronic ink is filled in the receiving cavity 300. The electronic ink includes ink formed by black pigment particles 310 and quantum dot-pigment particle complexes 320 and ink formed by black pigment particles 310 and white pigment particles; The receiving cavity 300 is disposed between the first electrode 200 and the second electrode 400 , and receiving cavities 300 of different colors are disposed between the first electrode 200 and the second electrode 400 to form sub-pixel structures 110 of different colors.

[0045] In one embodiment, the sub-pixel structure 110 is formed on a substrate having a backlight source. Specific embodiments Some specific implementation methods will be further introduced below to further explain the technical solution of this application in detail.

[0047] First, a variety of quantum dot pigment particle complex inks for reflective display are prepared, covering key colors (such as red, green, and blue) other than white and black. At the same time, white pigment particle inks and black pigment particle inks are also prepared to meet the needs of different color displays. The surfaces of these five particle materials are specially treated to give them specific Zeta potential values ​​ranging from -5eV to 5eV (preferably -500meV to 500meV) to ensure stable interactions between particles. Next, each quantum dot pigment particle complex ink is mixed with a black pigment particle ink in a certain proportion (the proportion of black ink is adjustable between 0% and 100%, preferably in the range of 20% to 80%, and the specific proportion is determined according to the reflective spectra of the two ink materials and the final desired display color effect) to form three binary color inks of red and black, green and black, and blue and black. At the same time, the white pigment particle ink is mixed with the black pigment particle ink in a similar proportion (also adjustable between 0% and 100%, preferably in the range of 20% to 80%) to obtain a black and white binary color ink. Subsequently, these binary color inks are respectively coated into monochrome micro-nano capsules (as a containing cavity). Since each capsule contains black ink as the background color, and each capsule contains only one color for display except black, these capsules are called monochrome capsules. The shape of these monochrome micro-nano capsules can be flexibly designed, as long as the ink solvent is not leaked. The diameter of the circumscribed sphere of the capsule body ranges from 1nm to 5mm, preferably from 0.5μm to 100μm, to meet different display requirements. At both ends of the capsule, the positive and negative circuits are connected so that the electric field can be applied inside the capsule. Then, the four monochrome micro-nano capsules (red, green, blue, and white) are evenly mixed and flattened into a single layer and placed between the upper and lower active matrix control electrodes. A set of electrodes corresponding to each sub-pixel unit can control one or more capsules under its contact (as long as they are within the range of this set of electrodes). In this way, these capsules can realize precise regulation of the reflective display color under the control of the electric field, thereby forming a sub-pixel point in the reflective display device. In this way, the color performance of reflective display devices can be significantly improved, and their display effects and adaptability under different lighting conditions can be enhanced.

[0048] The preparation process of quantum dot pigment particle complex ink is as follows: First, a uniform and monodisperse pigment particle solution is prepared as the starting material. On this basis, a cross-linkable ligand A is introduced to perform the key ligand exchange step, using the functional groups on the cross-linkable ligand A with stronger coordination ability or the shorter chain length advantage compared to the original ligand to effectively replace the original ligand on the surface of the pigment particle. 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 regulated to achieve the best ligand exchange effect.

[0049] Next, in order to further optimize the surface properties of the pigment particles, an appropriate amount of short-chain polar ligands were added to the system. These short-chain polar ligands will selectively replace part of the cross-linkable ligands A that have been bound to the surface of the pigment particles, thereby enriching the types and distribution of ligands on the surface of the pigment particles and improving the stability and dispersibility of the pigment particles. Through the above ligand exchange process, pigment particles with cross-linkable ligands A and polar short-chain ligands on the surface are obtained.

[0050] Next, the ligand exchange on the surface of the quantum dots is carried out. A uniform and monodisperse quantum dot solution is used as the starting material, and a cross-linkable ligand B is introduced to perform the ligand exchange step. In this process, the functional group on the cross-linkable ligand B successfully replaces the original ligand on the surface of the quantum dots by virtue of its stronger coordination ability or shorter chain length advantage compared to the original ligand. In order to achieve effective ligand exchange, the temperature of the reaction system and the concentration of the cross-linkable ligand B are regulated. Subsequently, an appropriate amount of short-chain polar ligands are added to the system, which 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 cross-linkable ligands B and polar short-chain ligands are finally obtained. Finally, a quantum dot-pigment particle complex is prepared, a certain amount of quantum dot solution with an appropriate concentration is added to the pigment particle solution, and the cross-linking reaction between the cross-linkable ligands A and B is triggered by ultraviolet light irradiation, heating or adding an initiator, so that a strong connection is established between the quantum dots and the pigment particles, thereby successfully obtaining a quantum dot-pigment particle complex. During the entire preparation process, the reaction conditions of each step, such as temperature, time, ligand concentration, etc., were monitored to ensure that each step of the reaction could achieve the expected effect. At the same time, we conducted detailed characterization and performance tests on the products of each step to verify the stability of their structure and properties.

[0051] Specifically, in the red sub-pixel electrode, the electric field control technology is cleverly used to achieve precise control of four uniformly distributed micro-nano capsules. By adjusting the direction, intensity and change rate of the electric field, it can be ensured that only the red capsules are colored under specific conditions. Specifically, when a suitable electric field is applied, the red quantum dot complex pigment particles in the red capsule will be electrophoresed to the upper layer of the capsule, while the black pigment particles will be electrophoresed to the lower layer of the capsule. In this way, the red color presented by the red quantum dot complex pigment particles becomes the display color of the capsule, while the black pigment particles are hidden in the lower layer as the background color. In addition, by precisely controlling the electric field parameters, it is also possible to control some red quantum dot complex pigment particles and some black pigment particles to be electrophoresed to the upper layer of the capsule at the same time, while the remaining particles are electrophoresed to the lower layer of the capsule, thereby achieving a delicate display of black, red and grayscale. At the same time, for the capsules of other colors, the electric field parameters are adjusted to make them non-colorful. Specifically, the black pigment particles are electrophoresed to the upper layer of the capsule, while the colored quantum dot complex pigment particles or white pigment particles are electrophoresed to the lower layer of the capsule. In this way, the black color presented by the black pigment particles becomes the display color of these capsules (or called non-color, because they do not show any color other than black at this time). The electric field regulation technology not only achieves precise control of the pigment particles in the micro-nano capsules, but also improves the color expression and grayscale layering of the reflective display device. By flexibly adjusting the electric field parameters, a richer and more delicate color display effect can be achieved, providing users with a more realistic and vivid visual experience.

[0052] The green, blue and white sub-pixels are controlled in the same way, that is, only the monochrome micro-nano capsules corresponding to the color of each sub-pixel are used for display, and each pixel independently controls the displayed color. The electric field control only needs to be adjusted to control the electrophoresis of the color particles to the upper layer, and various changes in the electric field can be used to further accurately control the grayscale adjustment. Each pixel can achieve full-color display through the color display and grayscale adjustment of its multiple (red, green, blue and white in this case) sub-pixels, and the display color gamut is completely determined by all sub-pixel spectra. In addition, a layer of filter can be added above each sub-pixel except white to make the spectrum narrower and the display color gamut wider.

[0053] As can be seen from the above, the present application applies quantum dots to sub-pixels of traditional electrophoretic color reflective display devices, which can narrow the spectral luminescence range, effectively increase the color gamut, and greatly improve the display brightness and response frequency, bringing a revolutionary breakthrough to display technology. While applying quantum dots, the presence of pigment particles in the capsule is retained, so that 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, further narrowing the half-peak width, and increasing the color gamut to ensure the accuracy and richness of the displayed colors. The quantum dot cooperative coupling reflective display pixel device technology proposed in this application not only retains many advantages of traditional electrophoretic color reflective display devices in the capsule film preparation process, such as mature technology and low cost, but also successfully solves the problems of large capsule thickness, long response time, complex electric field regulation, and difficult color grayscale in traditional technologies, injecting new vitality into the development of electrophoretic color reflective display technology and providing possibilities for its wider application fields.

[0054] The above is only a specific implementation of the present application, and any other 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 reflective display device, characterized in that: It comprises a plurality of pixel structures, each pixel structure comprises sub-pixel structures of different colors, and each sub-pixel structure comprises a first electrode, a second electrode, and a receiving cavity between the first electrode and the second electrode; The accommodating cavity includes electronic ink, the electronic ink includes black pigment particles and quantum dot-pigment particle complexes, and in sub-pixel structures of different colors, the color of the pigment particles in the quantum dot-pigment particle complexes is the color of the corresponding sub-pixel structure; The black pigment particles and the quantum dot-pigment particle complex have different potentials.

2. The quantum dot cooperatively coupled reflective display device according to claim 1, characterized in that: The proportion of the black pigment particles is in the range of 20-80%.

3. The quantum dot cooperatively coupled reflective display device according to claim 1, characterized in that: The colors of the pigment particles in the quantum dot-pigment particle complex include red, blue and yellow.

4. The quantum dot cooperatively coupled reflective display device according to claim 1, characterized in that: The black pigment particles have a positive potential, and the quantum dot-pigment particle complex has a negative potential.

5. The quantum dot cooperatively coupled reflective display device according to claim 4, characterized in that: The quantum dot-pigment particle complex has two or more different potentials.

6. The quantum dot cooperatively coupled reflective display device according to claim 1, characterized in that: The quantum dot-pigment particle complex connects the quantum dots to the pigment particles via cross-linkable ligands, and also includes sub-pixels formed by black pigment particles and white pigment particles.

7. The quantum dot cooperatively coupled reflective display device according to claim 6, characterized in that: The potentials of the black pigment particles and the quantum dot-pigment particle complex are in the range of -5 eV to 5 eV.

8. The quantum dot cooperatively coupled reflective display device according to claim 1, characterized in that: The pixel structure also includes a filter.

9. A method for manufacturing a quantum dot cooperatively coupled reflective display device, characterized in that: include: Prepare quantum dot pigment particle complex inks of various colors, including red, blue and yellow, and prepare black pigment particles and white pigment particles; To manufacture sub-pixel structures of different colors, a receiving cavity is first formed, and electronic ink is filled in the receiving cavity, wherein the electronic ink includes ink formed by black pigment particles and quantum dot-pigment particle complexes and ink formed by black pigment particles and white pigment particles; The accommodating cavity is arranged between the first electrode and the second electrode, and accommodating cavities of different colors are arranged between the first electrode and the second electrode to form sub-pixel structures of different colors.

10. The method for manufacturing a quantum dot cooperatively coupled reflective display device according to claim 9, characterized in that: The sub-pixel structure is formed on a substrate having a backlight source.

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