Full-color display device based on quantum dots and manufacturing method thereof

Abstract

The invention relates to a full-color display device based on quantum dots and a manufacturing method thereof. In the device structure, a black glass substrate is used as a substrate, and a blue light LED chip is arranged on the black glass substrate; the color conversion layer is composed of a black glass matrix containing through holes, a bottom insulating layer, a quantum dot film and a top reflecting mirror, the quantum dot film contains quantum dots with protective layers, and the protective layers are provided with ligands containing photosensitive groups and cross-linking agents matched with the protective layers. And each through hole only contains one type of quantum dots, so that energy loss can be reduced, and color purity can be improved. The pixel points are composed of a plurality of through holes, black glass between the pixel points is thicker than black glass between the through holes, and crosstalk is reduced. During manufacturing, the photo-crosslinkable quantum dot solution is prepared firstly, then the blue light LED chip and the bottom insulating layer are manufactured on the substrate, the black glass substrate is attached, the quantum dot solution is filled and photo-cured, and finally the top reflecting mirror is formed. The method is flexible and adjustable in process, and the color purity, brightness and stability of the display device can be improved.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a full-color display device based on quantum dots and a method for manufacturing the same. Background Technology

[0002] Quantum dots (QDs) have shown potential in display technology, bio-imaging, photovoltaic devices and other fields due to their narrow emission spectrum, high color purity and size-tunable light-emitting properties. The practical application of quantum dots is highly dependent on their patterning capabilities, especially the ability to achieve high-precision and high-stability patterned structures at the micrometer / submicrometer scale.

[0003] Traditional quantum dot patterning processes require steps such as spin-coating photoresist, mask exposure, development, and etching to achieve patterning. However, components such as photoacid initiators and resin monomers in the photoresist are prone to physical adsorption or chemical reactions with ligands on the quantum dot surface, leading to increased surface defects and a decrease in photoluminescence quantum yield. Quantum dots are sensitive to polar solvents, and solvent penetration during etching may cause quantum dots to peel off or aggregate. In addition, quantum dots require repeated processes of coating, exposure, development, and resist removal, resulting in high process complexity and making it difficult to adapt to the production requirements of full-color display devices.

[0004] With the rise of the emerging field of Mini / Micro-LED, there is a need to optimize quantum dot-based full-color display technology to simultaneously meet the requirements of high precision, low loss, simple process, and high stability. Summary of the Invention

[0005] The purpose of this application is to provide a quantum dot-based full-color display device, which achieves direct patterning through photocrosslinking. By controlling the size of the quantum dot film and combining it with a specific device structure, the device performance is improved, the process is simplified, and damage is reduced, thereby realizing a quantum dot-based full-color display. The quantum dot-based full-color display device of this application includes: The substrate includes a black glass substrate and a blue LED chip formed on the substrate; A color conversion layer, comprising a black glass substrate and a plurality of through holes penetrating the black glass substrate, wherein each through hole comprises a bottom insulating layer, a quantum dot film and a top reflector stacked sequentially; The quantum dot film includes quantum dots and a crosslinking agent. The quantum dots in the quantum dot film include a protective layer. The protective layer includes ligands containing photosensitive groups. The crosslinking agent includes photosensitive groups that match the ligands on the protective layer.

[0006] In one embodiment, the quantum dots include red, green, or blue quantum dots, and the quantum dot film in each via contains only one type of quantum dot.

[0007] In one embodiment, a plurality of through holes constitute a display pixel, and each display pixel includes at least one through hole containing red quantum dots, green quantum dots and blue quantum dots.

[0008] In one embodiment, the thickness of the black glass between pixels is greater than the thickness of the black glass between vias within pixels.

[0009] In one embodiment, the photosensitive group of the ligand is a carbon-carbon double bond or a carbon-carbon triple bond, and the crosslinking agent includes an azide group.

[0010] This application also provides a method for fabricating a full-color display device based on quantum dots, including: Preparation of photocrosslinkable quantum dot solutions; Blue LED chips are fabricated on a black glass substrate as a base. A bottom reflector is formed on the blue LED chip; A black glass substrate is attached to the substrate, the black glass substrate including through holes that penetrate the black glass substrate, and the position of the through holes corresponds to the position of the blue LED chip. A quantum dot solution was added into the through-hole and photocured to form a quantum dot film on the bottom mirror inside the through-hole. A top mirror is formed on a quantum dot film.

[0011] In one embodiment, the preparation of a photocrosslinkable quantum dot solution specifically includes: dissolving quantum dots in an organic solvent to perform ligand exchange, so that the surface of the quantum dots contains ligands including photosensitive groups, and adding crosslinking agent molecules containing ligands that match the ligands on the quantum dots.

[0012] In one embodiment, an oxide layer is also formed on the surface of the quantum dot.

[0013] In one embodiment, the photosensitive group of the ligand is a carbon-carbon double bond or a carbon-carbon triple bond, and the crosslinking agent includes an azide group.

[0014] In one embodiment, the through-hole is filled with a quantum dot solution containing red, green, or blue quantum dots, and then cured by light irradiation after filling.

[0015] Compared with the prior art, this application has the following beneficial effects: This application utilizes a direct patterning method to achieve regional selective curing of quantum dot films by using the photo-triggered reaction between photosensitive ligands modified on the quantum dot surface and crosslinking agents. This avoids the physical adsorption or chemical reaction between photoresist components and quantum dot surface ligands, prevents the increase of surface defects and avoids the decay of photoluminescence quantum yield, and ensures the color purity and luminescence stability of quantum dots.

[0016] This application utilizes a cross-linking network formed by direct photopolymerization to anchor quantum dots, supporting multi-layer stacking and cross-linking of red, green, and blue quantum dot films within vias. Each via contains only a single type of quantum dot (red / green / blue), and the via's position is controlled by laser drilling positioning technology, aligning it with the blue LED chip to form an independent sub-pixel unit. Vertical integration of the three primary colors (RGB) can be achieved in a single photopolymerization process, reducing process steps and improving yield.

[0017] The oxide layer generated in situ on the quantum dot surface serves as a passivation layer, isolating it from oxygen and moisture corrosion and preventing degradation. The combined design of a high-reflectivity mirror at the bottom and a low-reflectivity mirror at the top confines the non-specific wavelength quantum dot excitation light within the excitation cavity, improving light utilization. Simultaneously, the black glass substrate and the black glass between the vias enhance contrast and eliminate inter-pixel light interference. Furthermore, this application integrates the TFT driving circuit, blue LED chip, and quantum dot color conversion layer onto the black glass substrate, utilizing the matching thermal expansion coefficients to eliminate the effects of thermal stress. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the quantum dot-based full-color display device in this application; Figure 2 This is a flowchart of the fabrication method of the quantum dot-based full-color display device in this application; Figure 3 This is a schematic diagram of the structure in the fabrication method of the quantum dot-based full-color display device in this application; Figure 4 This is a schematic diagram of the photocuring principle of quantum dot solution in this application.

[0019] Explanation of reference numerals in the attached figures: 100, substrate; 110, blue LED chip; 200, color conversion layer; 210, black glass substrate; 220, through hole; 230, bottom insulating layer; 240, quantum dot film; 250, top reflector. Detailed Implementation

[0020] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0021] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0022] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0023] Traditional photolithography processes suffer from a significant decrease in quantum dot luminescence efficiency due to the interaction between photoresist residue and quantum dot surface ligands (such as ligand substitution and occupancy of surface passivation sites). Full-color display devices require a balance between stability and high luminescence efficiency. To improve display stability, it is necessary to maintain the chemical integrity of the quantum dot surface, preserve high luminescence efficiency, and avoid solvent compatibility issues. Please refer to [link / reference]. Figure 1 This application first realizes a full-color display device based on quantum dots through structural optimization, specifically including: The substrate 100 includes a black glass substrate and a blue LED chip 110 formed on the substrate; The color conversion layer 200 includes a black glass substrate 210 and a plurality of through holes 220 penetrating the black glass substrate 210. Each through hole 220 includes a bottom insulating layer 230, a quantum dot film 240 and a top reflector 250 stacked sequentially. The quantum dot film 240 includes quantum dots and a crosslinking agent. The quantum dots in the quantum dot film 240 include a protective layer. The protective layer includes ligands containing photosensitive groups. The crosslinking agent includes photosensitive groups that match the ligands on the protective layer.

[0024] The substrate 100 is made of black glass, which reduces the interference of external light on the internal optical path of the display device, improves the contrast of the displayed image, and makes the displayed colors more vivid and pure. A blue LED chip 110 is formed on the black glass substrate. The blue LED chip 110 serves as an excitation light source and works in conjunction with the quantum dots in the quantum dot film 240 to excite the quantum dots to emit the required red and green light. At the same time, it can combine with the blue light emitted by itself to form the three primary colors for full-color display.

[0025] The color conversion layer 200 consists of a black glass substrate 210 and multiple through-holes 220 penetrating the black glass substrate 210. The black substrate 210 provides structural support for the through-holes 220, and its inherent black color further reduces light crosstalk between pixels, improving display clarity and color purity. The position and size of each through-hole 220 are precisely controlled to ensure correspondence with the position of the blue LED chip 110, thereby achieving accurate light excitation and color conversion. Within each through-hole 220, a bottom insulating layer 230, a quantum dot film 240, and a top reflector 250 are stacked sequentially. The bottom insulating layer 230 has insulating properties, isolating the quantum dot film from the underlying structure. The top reflector 250 has specific reflective properties, allowing light of specific wavelengths to pass through while reflecting other wavelengths back into the through-hole 220 to continue participating in the excitation process, further improving light utilization and color purity.

[0026] The quantum dots in the quantum dot film 240 serve as the light-emitting core, exhibiting size and quantum confinement effects. Their emission wavelength can be tuned by controlling the size of the quantum dots, thus achieving a wide range of emission from blue to red light. To protect the performance and stability of the quantum dots, a protective layer is applied to their surface. This protective layer not only prevents the quantum dots from reacting with oxygen, moisture, and other elements in the external environment, thus preventing performance degradation, but also provides a basis for subsequent functional modifications.

[0027] The protective layer contains ligands with photosensitive groups, and the crosslinking agent contains photosensitive groups that match the ligands on the protective layer. When irradiated with light of a suitable wavelength, the crosslinking agent undergoes a photocrosslinking reaction with the ligands on the quantum dot surface, forming a stable crosslinking network that firmly fixes the quantum dots in the film, preventing aggregation or migration of the quantum dots during subsequent processing and use, thereby ensuring the uniformity and stability of the quantum dot film 240. Simultaneously, the photocrosslinking reaction is regioselective; by controlling the area and time of light irradiation, the quantum dot film 240 can be cured at specific locations, thus simplifying the process.

[0028] The use of a black glass substrate and black glass matrix 210 effectively absorbs ambient light and reduces inter-pixel crosstalk, ensuring clear black-and-white contrast even in bright environments. Blacks are deeper and whites are purer, thus improving overall display contrast. The bottom insulating layer 230, the top reflector 250, and the high color purity of the quantum dots themselves result in purer emission of the red, green, and blue primary colors, reducing color straying and mixing, and producing more vibrant and realistic colors to meet the demands of high-definition and wide color gamut displays. Furthermore, the through-hole design 220 in the black glass matrix 210 allows for the formation of the RGB quantum dot film 240 through a single photopolymerization process, eliminating the need for additional masks and reducing repetitive processes such as coating, exposure, development, and removal of the adhesive. This allows for precise control of the manufacturing process.

[0029] The top reflector 250 confines light that does not meet the emission wavelength requirements within the through-hole 220, allowing the light to fully excite the quantum dot to emit light and efficiently transmit the light of the required wavelength, reducing light loss, improving light utilization, increasing the light intensity emitted by the quantum dot, and enhancing the overall brightness of the display device, thereby achieving a brighter display effect under the same light source power.

[0030] The quantum dots encompass red, green, and blue quantum dots. In practical quantum dot-based full-color display device designs, the quantum dot film 240 within each via 220 is limited to containing only one type of quantum dot. This single-type quantum dot configuration in each via 220 reduces energy loss between different quantum dots. In traditional hybrid quantum dot designs, energy transfer and reabsorption may occur between different types of quantum dots, causing some light energy to be lost as heat. By classifying and placing quantum dots in different vias 220, blue light can more effectively excite the corresponding quantum dots, improving the conversion efficiency of light energy to visible light. This results in a brighter display effect with the same power input, or reduced power consumption without sacrificing brightness, extending the lifespan of the display device.

[0031] Red and green quantum dots are responsible for converting the blue light emitted by the blue LED chip 110 into specific wavelengths of red and green light, respectively. Since each through-hole 220 contains only one type of quantum dot, the emission wavelengths of red and green light are highly singular and stable, avoiding mutual interference and energy transfer between different types of quantum dots. This allows the display device to accurately display the three primary colors of red, green, and blue, achieving high-purity color display, meeting the requirements of high-definition and high color gamut displays, and bringing users a more realistic and vibrant visual experience.

[0032] Blue quantum dots possess unique optical properties. In one scenario, they can absorb stray light that may be present within the device, including light from the blue LED chip that doesn't meet the wavelength requirements for emitted blue light, and convert this stray light into blue light for emission. This property helps to further purify and optimize the blue light emitted by the display device, reducing interference from stray light on display colors, improving the purity and quality of blue light, and making the blue display more vibrant and pure. In another specific design scenario, when the light energy emitted by the blue LED chip 110 can directly meet the display requirements without additional blue light conversion, the blue quantum dots in the corresponding via 220 can be left blank. In this case, the via 220 corresponding to the blue quantum dots mainly serves as a light transmission channel and structural support, allowing the blue light emitted by the blue LED chip 110 to pass through the wavelength filter of the top reflector and mix with the red and green light emitted from other vias 220 after quantum dot conversion, achieving full-color display.

[0033] In the structural design of quantum dot-based full-color display devices, multiple through-holes 220 are used to form a single display pixel. Specifically, each display pixel contains at least one through-hole 220 containing red quantum dots, one containing green quantum dots, and one containing blue quantum dots. A regular array arrangement can be used to achieve uniform light distribution and optimal color mixing, depending on different display requirements and device design specifications. The size of the through-holes 220 can also be adjusted based on the luminescent characteristics of the contained quantum dots and the overall display requirements of the pixel. For example, because the human eye has varying sensitivities to different colors, the sizes of the through-holes 220 for different colors may be differentiated to achieve a more balanced color display. For colors to which the human eye is less sensitive, the corresponding through-hole 220 size may be appropriately increased to increase the amount of light emitted, thereby ensuring the brightness balance of the three primary colors (red, green, and blue) throughout the display pixel, ultimately presenting more natural and realistic colors. Color reproduction is achieved by controlling the luminescent intensity and proportion of each color quantum dot. The through-hole 220 structure physically isolates quantum dots of different colors, allowing light of each color to be emitted and propagated in relatively independent spaces, thereby reducing the possibility of crosstalk and further improving the uniformity of the display and the accuracy of the colors.

[0034] In the structural design of quantum dot-based full-color display devices, the thickness of the black glass is differentiated, with the thickness of the black glass between pixels set to be greater than the thickness of the black glass between the through-holes 220 within the pixels. From a structural design perspective, the black glass between pixels acts as an isolation barrier; thicker black glass provides stronger physical isolation, effectively preventing light leakage between adjacent pixels and strictly separating the light from different pixels.

[0035] Thicker black glass between pixels reduces light crosstalk between adjacent pixels. When displaying complex images, each pixel needs to independently and accurately display its corresponding color and brightness information. If light leakage occurs between pixels, pixels that should display a single color will be interfered with by the light from surrounding pixels, causing color mixing, blurring image edges, and loss of detail. Thicker black glass effectively blocks this crosstalk, ensuring that each pixel can emit light independently and accurately, thereby improving display clarity and color purity.

[0036] In the preparation and performance optimization of quantum dot display materials, ligands and crosslinking agents play crucial roles. In this application, the photosensitive groups carried by the ligands are selected as carbon-carbon double bonds (C=C) or carbon-carbon triple bonds (C≡C), and the crosslinking agent is a compound containing azide groups (-N3). When the ligands carry carbon-carbon double or triple bonds, these photosensitive groups can undergo photopolymerization under ultraviolet light or other specific light irradiation. During the formation of the quantum dot film 240, the ligands can form a stable polymer network structure on the surface of the quantum dots through photopolymerization. The crosslinked structure can fix the position of the quantum dots, keeping them in a relatively independent state, thereby effectively suppressing energy transfer and ensuring that each quantum dot can emit light independently and efficiently, improving the luminescence uniformity and stability of the entire quantum dot film 240.

[0037] The specific materials of quantum dots include, but are not limited to, II-VI quantum dots (e.g., CdSe / ZnS, CdSe / CdS quantum dots, etc.), III-V quantum dots (e.g., InP, GaAs quantum dots, etc.), perovskite quantum dots (e.g., CsPbX3, CH3NH2Pb2X3 quantum dots, etc.), or mononuclear nanoparticles of the above-mentioned materials coated with one or more layers of, but not limited to, any one or at least two of, CdS, ZnO, ZnS, ZnSe, ZnTe or alloy materials.

[0038] Quantum dot solvents, but not limited to, are one or more of the following solvents: chloroform, toluene, chlorobenzene, alkanes, alkenes, aromatic hydrocarbons, alcohols, ethyl acetate, haloalkanes, haloalkenes, haloaromatic hydrocarbons, diol derivatives, ketones, etc.

[0039] Photosensitizers include, but are not limited to, hydrogen-abstracting photosensitizers such as benzophenone and 2,4-dihydroxybenzophenone, cleavage photosensitizers such as 2-hydroxy-2-methyl-1-phenylpropanone and 1-hydroxycyclohexylphenyl ketone, and cationic photosensitizers such as diazonium salts and diaryliodomonium salts.

[0040] Please see Figures 2 to 4 This application also provides a method for fabricating a full-color display device based on quantum dots, comprising: Preparation of photocrosslinkable quantum dot solutions; A blue LED chip 110 is fabricated on a black glass substrate as a substrate 100; A bottom insulating layer 230 is formed on the blue LED chip 110; A black glass substrate 210 is attached to the substrate 100. The black glass substrate 210 includes a through hole 220 that penetrates the black glass substrate 210. The position of the through hole 220 corresponds to the position of the blue LED chip 110. A quantum dot solution is added into the through hole 220 and photocured to form a quantum dot film 240 on the bottom mirror inside the through hole 220. A top mirror is formed on the quantum dot film 240.

[0041] In this preparation method, a photocrosslinkable quantum dot solution is first prepared. Suitable photosensitive ligands and crosslinking agents are added to the quantum dot solution. The photosensitive ligands contain photosensitive groups such as carbon-carbon double or triple bonds, while the crosslinking agents contain highly reactive groups such as azide groups. By precisely controlling reaction conditions, such as temperature, reaction time, and stirring speed, the photosensitive ligands and crosslinking agents are uniformly modified onto the quantum dot surface, forming a stable quantum dot solution with photocrosslinking properties. This photocrosslinkable quantum dot solution not only forms a robust thin film structure during subsequent photocuring but also effectively protects the quantum dots from external environmental influences, improving their stability and luminescence efficiency.

[0042] A blue LED chip 110 is fabricated on a black glass substrate as the substrate 100 of the display device. The black glass substrate has good optical absorption properties. Advanced semiconductor manufacturing processes are used to fabricate the blue LED chip 110 to ensure the uniformity and stability of the chip's light emission. The chip's size, shape, and electrode layout are controlled to ensure compatibility with subsequent process steps. A bottom insulating layer is then formed on the blue LED chip 110. Using thin film deposition techniques such as physical vapor deposition (PVD) and chemical vapor deposition (CVD), a reflective material is uniformly deposited on the surface of the blue LED chip 110 to form a bottom reflective mirror with high reflectivity.

[0043] Subsequently, a black glass substrate 210 is bonded onto the substrate 100. This black glass substrate 210 contains multiple through-holes 220 penetrating the substrate 210, and the positions of the through-holes 220 correspond one-to-one with the positions of the blue LED chips 110. During the bonding process, a high-precision bonding process is employed to ensure a tight bond between the black glass substrate 210 and the substrate 100, thereby guaranteeing the structural stability and optical performance of the display device. The black glass substrate 210 not only provides isolation and protection, preventing light crosstalk between adjacent pixels, but also further absorbs ambient light, improving the black level performance and contrast of the displayed image.

[0044] Next, the prepared quantum dot solution is added into the through-hole 220 and photocured to ensure uniform filling of the space. Then, the quantum dot solution in the through-hole 220 is irradiated with ultraviolet light of a specific wavelength and intensity to trigger the photochemical reaction of the photosensitive ligand and crosslinking agent. During the photocuring process, carbon-carbon double or triple bonds undergo photopolymerization, and the azide groups decompose to produce nitride intermediates and initiate crosslinking reactions, causing the quantum dot solution to gradually solidify and form a uniform and dense quantum dot film 240 on the bottom reflector within the through-hole 220.

[0045] Finally, a top reflector is formed on the quantum dot film 240. The top reflector, also fabricated using high-reflectivity materials and advanced thin-film deposition technology, reflects the red and green light emitted from the quantum dot film 240 back towards the display direction, while reducing light scattering in other directions, thus improving the light extraction efficiency and color purity of the display device. By precisely controlling the thickness and reflectivity of the top reflector, it works in conjunction with the bottom reflector to form an effective optical resonant cavity, further enhancing the luminous intensity and color saturation of the quantum dots.

[0046] Easy to adjust and improve the process: During the manufacturing process, each process step can be flexibly adjusted and optimized according to different display requirements and application scenarios. For example, by changing the formula and concentration of the quantum dot solution, the color performance of the display device can be adjusted; by optimizing the structure and materials of the reflector, the light energy utilization efficiency and light emission angle can be improved; by adjusting the parameters of the photocuring process, the thickness and morphology of the quantum dot film 240 can be controlled.

[0047] The preparation of photocrosslinkable quantum dot solutions specifically includes: dissolving quantum dots in an organic solvent to perform ligand exchange, so that the surface of the quantum dots contains ligands including photosensitive groups; adding crosslinking agent molecules containing ligands that match the ligands on the quantum dots; the crosslinking agent and the ligands on the surface of the quantum dots undergo a photocrosslinking reaction to form a stable crosslinking network, thereby firmly fixing the quantum dots in the film.

[0048] It also includes forming an oxide layer on the surface of quantum dots. The protective layer can prevent quantum dots from reacting with oxygen, moisture and other substances in the external environment, which would lead to a decrease in the performance of quantum dots. It can also provide a basis for subsequent functional modification. The specific materials of the oxide protective layer can be oxides such as SiO2, Al2O3, ZnO, SnO2, TiO2, etc. The formation method can be either sol-gel method or atomic layer deposition method.

[0049] Quantum dot solutions of red, green, or blue quantum dots are filled into the through-hole 220 respectively. After filling, the solution is simultaneously cured by light irradiation. In a preferred embodiment, the light emitted by the blue LED chip 110 is used for curing, and the black glass substrate 210 is used as a mask. No additional mask setting or adjustment of light size or position is required. Specific Implementation The following will further introduce some specific implementation methods to provide a more detailed explanation of the technical solution of this application.

[0051] Example 1 Oxide coating: An 8 nm SiO2 oxide protective layer was formed on the quantum dot surface using a sol-gel method to isolate it from water and oxygen corrosion. 3-Trimethoxysilane propyl acrylate was grafted onto the oxide protective layer surface via a silane coupling reaction. The modified quantum dots were dispersed in toluene, and a solution of photocrosslinkable bis(azidophenyl) quantum rods was added. The concentration of the quantum rods was approximately 30 mg / ml, and the content of the photosensitive crosslinking agent was 10 wt%.

[0052] The unexposed areas of the quantum rods are dissolved in toluene, with a development time of approximately 1 minute. Residual solvent is then removed by nitrogen purging or low-temperature annealing (70°C, 10 minutes) to obtain a patterned quantum dot film, which is the first layer of the quantum dot patterned film. A second layer of the film is then formed on the substrate of this first layer by a mixture of quantum dots and photosensitive crosslinking molecules. The second layer is then exposed to 365 nm UV light, and the unexposed areas are washed away with a non-polar solvent, resulting in two patterned films. This process is repeated as needed to obtain a multilayer patterned quantum rod film.

[0053] A bottom insulating layer is deposited on a blue LED chip using a coating and patterning process to obtain a light source driving system, with the bottom reflector being a DBR.

[0054] Black glass was used as the quantum dot color conversion layer. Through holes with a size approximately equal to that of the LED chip light source were obtained through laser drilling and etching processes and then attached to the aforementioned light source driving sample.

[0055] Subsequently, the photocrosslinkable quantum dot solution was used to form a quantum dot film using inkjet printing and photolithography. Under a mask, the film was exposed to ultraviolet light for 120 seconds, and finally developed with a developer to obtain a patterned quantum rod film. By adjusting the process parameters, stacking of quantum dots of different colors could be achieved.

[0056] A top reflector is deposited in all the holes using a coating and patterning process. The top reflector is a DBR, which has a lower reflectivity than the bottom insulating layer, ensuring light emission from the front. Finally, it is encapsulated to obtain a complete micro LED display system with high color gamut and high resolution.

[0057] Example 2 Al₂O₃ was formed on the surface of quantum dots by atomic layer deposition (ALD) to create an oxide protective film. A silane containing di[(1,1-dimethyl-2-propynyl)oxy]dimethylsilane was then grafted onto the oxide protective film surface via a silane coupling reaction. The modified quantum dots were dispersed in hexane, and a solution of photocrosslinkable diazidene-type quantum rods was added. The concentration of the quantum rods was approximately 30 mg / ml, and the content of the photosensitive crosslinking agent was 1 wt%.

[0058] The unexposed areas of the quantum rods are dissolved in octane, with a development time of approximately 1 minute. Residual solvent is then removed by low-temperature annealing (60°C, 10 minutes), yielding a patterned quantum dot film, which is the first layer of the quantum dot patterned film. A second layer of the film is then formed on the substrate of this first layer by applying a mixture of quantum dots and photosensitive crosslinking molecules. The second layer is then exposed to 365 nm UV light, and the unexposed areas are washed away with a non-polar solvent, resulting in two patterned films. This process is repeated as needed to obtain a multilayer patterned quantum rod film.

[0059] A bottom insulating layer was deposited on a blue LED chip using deposition and patterning processes to obtain a light source driving system, in which the combination of reflectors is a photonic crystal. Black glass was used as a quantum dot color conversion layer, and through-holes approximately the same size as the LED chip light source were obtained through laser drilling and etching processes, and then attached to the aforementioned light source driving sample. Subsequently, a photocrosslinkable quantum dot solution was used to form a quantum dot thin film using inkjet printing and photolithography. The film was then exposed to ultraviolet light for 120 seconds under a mask, and finally developed with a developer to obtain a patterned quantum rod thin film. By adjusting process parameters, the stacking of quantum dots of different colors could be achieved.

[0060] A top reflector is deposited in all the holes using a coating and patterning process. The top reflector is a photonic crystal with a lower reflectivity than the bottom insulating layer, ensuring light emission from the front. Finally, it is encapsulated to obtain a complete micro LED display system with high color gamut and high resolution.

[0061] As described above, this application proposes a full-color display device based on quantum dots and its fabrication method. In terms of device structure, the substrate is a black glass substrate on which a blue LED chip is placed as the excitation light source. The color conversion layer consists of a black glass substrate and multiple through-holes running through it. Each through-hole contains a bottom insulating layer, a quantum dot film, and a top reflector stacked sequentially. In the quantum dot film, the quantum dots have a protective layer with ligands containing photosensitive groups, and the crosslinking agent contains matching photosensitive groups. The top reflector has specific reflective properties, improving light utilization and color purity. The quantum dot types cover red, green, and blue quantum dots, with each through-hole containing only one type, reducing energy loss, improving light conversion efficiency, and ensuring color purity. The display pixels are composed of multiple through-holes, and the through-hole size and arrangement can be adjusted according to requirements to achieve color balance and accurate reproduction. The thickness of the black glass between pixels is greater than that between through-holes, reducing light crosstalk and improving clarity and color purity. The ligand photosensitive groups are selected from carbon-carbon double or triple bonds, and the crosslinking agent is selected from compounds containing azide groups, forming a stable polymer network.

[0062] In terms of fabrication method, a photocrosslinkable quantum dot solution is first prepared. Suitable photosensitive ligands and crosslinking agents are added to the quantum dot solution, and the reaction conditions are controlled to ensure uniform modification on the quantum dot surface. A blue LED chip is fabricated on a black glass substrate to form a bottom reflector. The black glass substrate is then laminated, with its vias corresponding to the positions of the blue LED chip. The quantum dot solution is added into the vias and photocured to form a thin film. A top reflector is then formed on the thin film. This method is easy to adjust, allowing for changes in the quantum dot solution formulation, optimization of the reflector structure materials, and adjustment of photocuring parameters as needed. Furthermore, the fabrication of the quantum dot solution also includes forming an oxide protective layer on the quantum dot surface; after the vias are filled with the quantum dot solution, back-side illumination can be used for simultaneous curing without the need for an additional mask.

[0063] The above is only one specific implementation of this application, and any other improvements made based on the concept of this application shall be considered within the scope of protection of this application.

Claims

1. A full-color display device based on quantum dots, characterized in that, include: The substrate includes a black glass substrate and a blue LED chip formed on the substrate; A color conversion layer, comprising a black glass substrate and a plurality of through holes penetrating the black glass substrate, wherein each through hole comprises a bottom insulating layer, a quantum dot film and a top reflector stacked sequentially; The quantum dot film includes quantum dots and a crosslinking agent. The quantum dots in the quantum dot film include a protective layer. The protective layer includes ligands containing photosensitive groups. The crosslinking agent includes photosensitive groups that match the ligands on the protective layer.

2. The quantum dot-based full-color display device according to claim 1, characterized in that, The quantum dots include red, green, or blue quantum dots, and each through-hole contains only one type of quantum dot film.

3. The quantum dot-based full-color display device according to claim 2, characterized in that, Multiple through holes form a display pixel, and each display pixel includes at least one through hole containing red quantum dots, green quantum dots and blue quantum dots.

4. The quantum dot-based full-color display device according to claim 3, characterized in that, The thickness of the black glass between pixels is greater than the thickness of the black glass between the through holes within the pixels.

5. The quantum dot-based full-color display device according to claim 1, characterized in that, The photosensitive group of the ligand is a carbon-carbon double bond or a carbon-carbon triple bond, and the crosslinking agent includes an azide group.

6. A method for fabricating a full-color display device based on quantum dots, characterized in that, include: Preparation of photocrosslinkable quantum dot solutions; Blue LED chips are fabricated on a black glass substrate as a base. A bottom insulating layer is formed on the blue LED chip; A black glass substrate is attached to the substrate, the black glass substrate including through holes that penetrate the black glass substrate, and the position of the through holes corresponds to the position of the blue LED chip. A quantum dot solution was added into the through-hole and photocured to form a quantum dot film on the bottom mirror inside the through-hole. A top mirror is formed on a quantum dot film.

7. The method for fabricating a full-color display device based on quantum dots according to claim 6, characterized in that, The preparation of photocrosslinkable quantum dot solutions specifically includes: dissolving quantum dots in an organic solvent to perform ligand exchange, so that the surface of the quantum dots contains ligands including photosensitive groups, and adding crosslinking agent molecules containing ligands that match the ligands on the quantum dots.

8. The method for fabricating a full-color display device based on quantum dots according to claim 7, characterized in that, It also includes forming an oxide layer on the surface of quantum dots.

9. The method for fabricating a full-color display device based on quantum dots according to claim 7, characterized in that, The photosensitive group of the ligand is a carbon-carbon double bond or a carbon-carbon triple bond, and the crosslinking agent includes an azide group.

10. The method for fabricating a full-color display device based on quantum dots according to claim 6, characterized in that, The through-holes are filled with quantum dot solutions of red, green, or blue quantum dots, respectively, and then cured by light exposure after filling.

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