A porous quantum dot color conversion layer, a preparation method and application thereof

Abstract

This invention discloses a porous quantum dot color conversion layer, its preparation method, and its application. The method involves mixing a framework polymer, a porous polymer, quantum dots, and a solvent to form a mixed solution. After coating the solution onto a substrate, phase separation induced by solvent evaporation causes the framework polymer to preferentially solidify, forming a continuous phase to embed and fix the quantum dots. Simultaneously, the porous polymer accumulates to form discrete microphase domains. The porous polymer is then removed, transforming the microphase domains into pores, thus obtaining the porous quantum dot color conversion layer. This method is simple, and the resulting color conversion layer possesses high light conversion efficiency, excellent environmental stability, and patternability, making it suitable for display devices.

Description

Technical Field

[0001] This invention belongs to the technical field of semiconductor light-emitting materials and micro-display / lighting devices, specifically relating to a porous quantum dot color conversion layer, its preparation method, and its application. Background Technology

[0002] Quantum dots are widely used in color conversion layers for Mini / Micro-LED full-color displays due to their high photoluminescence quantum yield, high color purity, and tunable emission wavelength. However, under limited film thickness and quantum dot loading conditions, nanoscale quantum dots struggle to sufficiently scatter excitation light, resulting in short optical path lengths and low absorption probability of the excitation light within the color conversion layer, thus limiting color conversion efficiency. Simultaneously, waveguide / total internal reflection of the emitted light within the layer also leads to insufficient light extraction. To improve absorption and extraction efficiency, existing technologies often introduce scattering particles (such as TiO2 microparticles) to enhance scattering and extend the optical path. However, in inkjet printing with micron-sized nozzles, inorganic scattering particles are prone to gravitational sedimentation and aggregation, leading to irreversible nozzle clogging and poor pixel uniformity. Furthermore, traditionally physically mixed scattering particles cannot resolve the "coffee ring" effect of quantum dots at the film edges, resulting in uneven color distribution between the pixel center and edges. In addition, quantum dots are prone to physical aggregation during the film formation process and are susceptible to erosion by water and oxygen in the environment. Traditional dense films cannot achieve both high porosity and high stability. Summary of the Invention

[0003] This invention addresses the shortcomings of existing technologies by providing a method for preparing a porous quantum dot color conversion layer. Through the structural design of the quantum dot (QD) color conversion layer (CCL), a porous color conversion structure is constructed by utilizing spontaneous phase separation induced by polymers and applied in processes such as inkjet printing pixelation.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows:

[0005] A method for preparing a porous quantum dot color conversion layer, comprising:

[0006] A mixed solution is formed by mixing a framework polymer, a porous polymer, a solvent, and quantum dots.

[0007] The mixed solution is coated onto the substrate;

[0008] The solvent is evaporated, inducing phase separation in the mixed solution, wherein the framework polymer precipitates and solidifies before the porous polymer to form a continuous framework phase that embeds the quantum dots, while the porous polymer is enriched to form discrete microphase domains dispersed in the framework phase.

[0009] The porous polymer is removed, transforming the discrete microphase domain into pores, to obtain the porous quantum dot color conversion layer.

[0010] Optionally, the backbone polymer is selected from at least one of polystyrene (PS), polymethyl methacrylate (PMMA), polycarbonate (PC), polyvinylidene fluoride (PVDF), polylactic acid (PLA), polycaprolactone (PCL), polyurethane (PU), epoxy resin, or acrylic resin; the pore-forming polymer (P2) is selected from at least one of polyethylene glycol (PEG), polyethylene oxide (PEO), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), polyacrylic acid (PAA), or water-soluble copolymers; and the solvent is selected from chloroform, dichloromethane, tetrahydrofuran, 1,2-dichlorobenzene, chlorobenzene, toluene, xylene, anisole, or mixed solvents thereof.

[0011] Optionally, the molecular weight of the backbone polymer ranges from 5,000 to 5,000,000, the molecular weight of the pore-forming polymer ranges from 100 to 10,000, the mass ratio of the backbone polymer to the pore-forming polymer is 95:5 to 50:50, and the content of the quantum dots in the mixed solution is 0.1 to 200 mg / mL.

[0012] Optionally, the method for removing the porous polymer includes causing the porous polymer to collapse on its own or selectively eluting it.

[0013] Optionally, the solvent evaporation can be natural evaporation or heating to promote evaporation in order to regulate the pore structure.

[0014] Optionally, the characteristic size of the pore is 10 nm to 10 μm.

[0015] Optionally, the pores are randomly distributed in the plane direction of the membrane layer, and are any one or a combination of through holes, semi-through holes, or closed holes in the thickness direction.

[0016] Optionally, the coating method includes drop coating, spin coating, and inkjet printing.

[0017] Optionally, at least two mixed solutions are prepared, with quantum dots in different mixed solutions having different emission colors; the different mixed solutions are deposited at different positions on the substrate by inkjet printing to obtain a multicolor pixel unit array.

[0018] A porous quantum dot color conversion layer is obtained by the above-described method for preparing porous quantum dot color conversion layers.

[0019] A display device includes a light-emitting array for providing excitation light, and the aforementioned porous quantum dot color conversion layer; wherein the porous quantum dot color conversion layer is patterned into a multicolor pixel unit array containing quantum dots of different light-emitting colors.

[0020] In one specific embodiment, polymethyl methacrylate (PMMA) with a molecular weight range of 10,000 to 2,000,000 is selected as the backbone polymer P1, polyethylene glycol (PEG) with a molecular weight range of 100 to 500 is selected as the porous polymer P2, xylene is selected as the solvent S, and perovskite quantum dots (QDs) are selected. A PMMA-xylene solution and a PEG-xylene solution with a molecular weight range of 1 to 100 mg / mL are prepared. The PMMA-xylene solution, PEG-xylene solution, and perovskite quantum dots are stirred at room temperature to obtain a homogeneous and stable quaternary solution system. The mass ratio of PMMA to PEG in the mixed solution is 95:5 to 50:50, and the content of perovskite quantum dots is 0.1 to 200 mg / mL. The mixed solution is coated on a substrate and the solvent is allowed to evaporate completely to obtain the porous quantum dot color conversion layer.

[0021] In one specific embodiment, a first mixed solution and a second mixed solution of quantum dots with different luminescent colors are prepared, and deposited on a substrate by inkjet printing to form multiple pixel units arranged at intervals, thereby obtaining a multicolor pixel unit array. The resulting multicolor quantum dot color conversion layer is used for full-color display.

[0022] The beneficial effects of this invention are as follows:

[0023] 1) Process-friendly: Completely eliminates inorganic scattering particles, significantly improves ink stability, and is suitable for pixelation processes such as inkjet printing;

[0024] 2) Significant optical gain: Under the same quantum dot loading, the light conversion efficiency (CCE) and light extraction efficiency (LEE) are improved simultaneously, effectively suppressing blue light leakage;

[0025] 3) High environmental stability: The P1 framework forms a dense physical barrier for the quantum dots, which plays an in-situ micro-encapsulation role and significantly improves the stability against water and oxygen.

[0026] 4) Excellent pixel consistency: By utilizing the counteracting effect of Marangoni reflux and solvent evaporation gradient during phase separation, the migration of solute to the contact line is suppressed, fundamentally eliminating the "coffee ring effect" of inkjet printing, resulting in a pixel structure with a flat top and improving the uniformity of the display viewing angle.

[0027] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the solvent evaporation-induced phase separation and pore formation mechanism in the example.

[0029] Figure 2This is a schematic diagram illustrating the optical mechanism of the presence or absence of a porous structure in relation to the coupling of excitation light absorption and emission light in this embodiment.

[0030] Figure 3 Schematic diagram of through hole, semi-through hole and closed hole in the embodiment;

[0031] Figure 4 This is a schematic diagram of the preparation of a porous quantum dot color conversion layer by drop-coating / spin-coating in Example 1;

[0032] Figure 5 (a) Optical micrographs of perovskite-PMMA-xylene films, (b) perovskite-PMMA / PEG-xylene films;

[0033] Figure 6 The diagram shows the optical testing of Example 1 and Comparative Example 1, where the thin film of Example 1 is represented by QDs-PMMA / PEG and the thin film of Comparative Example 1 is represented by QDs-PMMA.

[0034] Figure 7 This is a schematic diagram of the inkjet-printed pixelated porous quantum dot color conversion layer in Example 2;

[0035] Figure 8 This is a schematic diagram of the full-color Micro-LED device structure in Example 2;

[0036] Figure 9 A fluorescence microscope image of the quantum dot color conversion layer of the green pixel unit array in Example 2;

[0037] Figure 10 for Figure 9 The fluorescence intensity grayscale value distribution curve of the green pixel unit array;

[0038] Figure 11 for Figure 9 Scanning electron microscope image of the internal microstructure of the green pixel unit. Detailed Implementation

[0039] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments. The accompanying drawings are merely illustrative to facilitate a better understanding of the invention, and their specific proportions can be adjusted according to design requirements.

[0040] The method for preparing the porous quantum dot color conversion layer in this embodiment is based on a design scheme for an efficient and stable quantum dot color conversion layer with micro / nano-scale porous structure induced by polymer phase separation. It utilizes a quaternary system composed of a framework polymer (P1), a porous polymer (P2), a solvent (S), and quantum dots (QDs) to construct a three-dimensional spatially ordered structure of "quantum dot - continuous framework phase (P1) - discrete porous phase (P2 formation)" by regulating the polymer phase separation kinetics.

[0041] P1 and P2 initially exist as a homogeneous solution in solvent S, but their solubility parameters and precipitation kinetics differ significantly. As solvent S evaporates, the system undergoes aggregation-growth phase separation. P1 preferentially solidifies to form a continuous matrix framework, while P2 accumulates to form discrete microphase domains. After complete solvent evaporation and subsequent treatment (such as P2 self-collapse or selective elution), the original P2 phase domain transforms into a high-density porous structure, forming a porous film layer containing embedded quantum dots. A schematic diagram of this mechanism is shown below. Figure 1 As shown.

[0042] The porous membrane described above differs from disordered or general porous membranes; instead, it is designed to meet color conversion requirements and is scale-matched to the optical gain structure.

[0043] Specifically, the porous structure can be multidimensionally controlled by the P1 / P2 mass ratio, polymer molecular weight, solvent, polymer solution concentration, and environmental conditions. The characteristic size of the pores is located in the range of 10 nm-10 μm, placing them on the same order of magnitude or within the distribution range of the excitation light wavelength. Without significantly reducing the film transmittance, the significant refractive index difference (∆n≈0.2-1) between the pores (air, n≈1.0) and the polymer framework (P1, n≈1.2-2.0) induces strong Mie scattering or Rayleigh-Mie transition scattering effects within the film, generating blue or ultraviolet excitation wavelengths. This high scattering environment forces the excitation light to undergo multiple refractions and reflections within the film, multiplying the effective propagation path of photons within the color conversion layer, significantly increasing the quantum dot's capture probability of the excitation light, and simultaneously breaking the total internal reflection condition, greatly improving the coupling efficiency of the emitted light. The optical mechanism is as follows: Figure 2 As shown.

[0044] The pores are preferably highly uniform and randomly distributed without long-range order in the planar direction of the film layer to avoid diffraction color shift or angle-dependent light emission problems caused by the formation of periodic structures; in the thickness direction, the pores can be any or a combination of through-holes, semi-through-holes, or closed-holes, such as... Figure 3 As shown, semi-through holes and closed holes are more conducive to providing sufficient refractive index difference while maintaining effective embedding of quantum dots, so as to achieve a balance between scattering enhancement and structural stability.

[0045] In a porous membrane, the affinity of P1 polymer segments for quantum dot surface ligands and the repulsive effect generated during phase separation allow quantum dots to be "locked in situ" and enriched within a continuous solid framework formed by P1, rather than being exposed at the pore interface. The steric hindrance effect of the polymer effectively counteracts the van der Waals attraction between quantum dots, fixing them within the continuous P1 phase and suppressing their migration, aggregation, and rearrangement during subsequent phase separation. This results in a highly uniform distribution of quantum dots within the color conversion layer at the microscale. The dense P1 framework acts as a micron-level physical barrier, effectively blocking the path of water vapor and oxygen permeation into the quantum dots, allowing the color conversion layer to maintain excellent environmental weather resistance while possessing high porosity. By utilizing the counteracting effect of Marangoni reflux and solvent evaporation gradient during phase separation, solute migration towards the contact line is suppressed, fundamentally eliminating the "coffee ring effect" of inkjet printing. This results in a pixel structure with a flat top, improving the uniformity of the display viewing angle.

[0046] In summary, a perfect synergy between "enhanced optical scattering" and "material stability" has been achieved. The pores, acting as scattering centers, solve the problems of insufficient light absorption and difficult light extraction under limited film thickness (especially in Mini / Micro-LED pixelated scenarios); while the P1 continuous phase provides a stable micro-encapsulation environment for the quantum dots. The combination of these two elements achieves a simultaneous improvement in the light conversion efficiency (CCE) and environmental stability of the quantum dot color conversion layer without introducing nozzle clogging and aggregation problems caused by inorganic scattering particles.

[0047] In material selection, the framework polymer (P1) and porous polymer (P2) are chosen to be polymers soluble in the same solvent but with different solubilities. The framework polymer (P1) needs to cure earlier, form the framework, and coat the quantum dots. It typically has relatively low solubility in the solvent (S) or is more prone to precipitation during evaporation, such as PS, PMMA, PC, PVDF, PLA, PCL, PU (thermoplastic / photocurable polyurethane), epoxy / acrylic resins, etc. The porous polymer (P2) is soluble in the same solvent as P1 but undergoes phase separation during evaporation. It is relatively more solvent-friendly (S) or can be selectively removed, such as PEG, PEO, PVP, PVA, PAA, and partially water-soluble copolymers. The solvent (S) can be chloroform, dichloromethane, tetrahydrofuran (THF), 1,2-dichlorobenzene, chlorobenzene, toluene, xylene, anisole, and their mixtures; its evaporation rate determines the phase separation kinetics. The quantum dots (QDs) used are cadmium-based, phosphorus-based, and perovskite-based QDs.

[0048] Example 1

[0049] Taking the PMMA / PEG / xylene / perovskite system as an example, porous quantum dot color conversion layers are prepared by drop coating / spin coating, which is suitable for backlight films.

[0050] like Figure 4 As shown, the method for preparing the porous quantum dot color conversion layer in this embodiment includes the following steps:

[0051] 1) Polymethyl methacrylate (PMMA) with a molecular weight of 35,000 was selected as the backbone polymer P1, polyethylene glycol (PEG) with a molecular weight of 200 was selected as the pore polymer P2, xylene was selected as the solvent S, and perovskite quantum dots (QDs) were selected.

[0052] 2) Weigh out 500 mg of PMMA and PEG and dissolve them in 10 mL of xylene respectively;

[0053] 3) Add 2 mL of PEG-xylene solution and 100 mg of perovskite quantum dots to 8 mL of PMMA-xylene solution, and stir at room temperature to obtain a homogeneous and stable quaternary solution system.

[0054] 4) Drop an appropriate amount of the above solution onto the surface of the glass substrate and allow it to spread naturally or spin-coat into a film;

[0055] 5) After the xylene has completely evaporated, a porous quantum dot film is obtained as a porous quantum dot color conversion layer, denoted as perovskite-PMMA / PEG-xylene polymer film, with a thickness of about 200 μm.

[0056] Comparative Example 1

[0057] Weigh 500 mg of PMMA and dissolve it in 10 mL of xylene. Add 100 mg of perovskite quantum dots and stir at room temperature to obtain a homogeneous and stable ternary solution system. Drop an appropriate amount of the above solution onto the surface of a glass substrate and allow it to spread naturally or spin-coat to form a film. After the xylene has completely evaporated, the resulting quantum dot film serves as the quantum dot color conversion layer and is denoted as the perovskite-PMMA-xylene film, with a thickness of approximately 200 μm.

[0058] like Figure 5 As shown, the perovskite-PMMA-xylene film of Comparative Example 1 is smooth and free of pinholes. After adding the pore-forming polymer PEG, a porous structure is formed on the surface of the perovskite-PMMA / PEG-xylene polymer film of Example 1, with an average pore diameter of approximately 4.89 μm and a pore density of 8932.91 mm². -2 .

[0059] Spectrometer testing showed that, compared to Comparative Example 1, the porous quantum dot color conversion layer film of Example 1 exhibited an increase in blue light absorption rate from 66.18% to 84.71%, and a PL intensity increase of 21.48%. Figure 6 As shown.

[0060] Example 2

[0061] Taking the PMMA / PEG / xylene / perovskite system as an example, inkjet printing of pixelated porous quantum dot color conversion layers is suitable for display pixelation.

[0062] like Figure 7 As shown, the method for preparing the porous quantum dot color conversion layer in this embodiment includes the following steps:

[0063] 1) Polymethyl methacrylate (PMMA) with a molecular weight of 10,000 was selected as the backbone polymer P1, polyethylene glycol (PEG) with a molecular weight of 200 was selected as the pore polymer P2, xylene was selected as the solvent S, and perovskite quantum dots (QDs) were selected.

[0064] 2) Weigh out 100 mg of PMMA and PEG respectively and dissolve them in 10 mL of xylene;

[0065] 3) Add 2 mL of PEG-xylene solution and 100 mg of perovskite quantum dots to 8 mL of PMMA-xylene solution, and stir at room temperature to obtain a homogeneous and stable quaternary solution system.

[0066] 4) The inkjet printing technology is used to deposit the layer at specific locations on the glass substrate 11. After curing, a pixelated porous quantum dot color conversion layer is obtained. The distance between the inkjet printing tip and the substrate is set to 50 μm, the printing voltage waveform is set to square wave (duty cycle of 75%), the printing voltage is 1000V, and the frequency is 1000Hz. Among them, a red pixel unit R is formed by a CsPb(Br / I)3@SiO2 quantum dot system, a green pixel unit G is formed by a CsPbBr3 quantum dot system, and they are arranged in an array with the blank blue light transmission area B (as blue pixel unit) to form the pixelated porous quantum dot color conversion layer 1. The thickness of each pixel unit R and G is about 2.3 μm.

[0067] 5) The pixelated porous quantum dot color conversion layer 1 is combined with the blue Micro-LED chip array 2 to realize a full-color Micro-LED device. The blue Micro-LED chip array 2 includes a substrate 21 and a plurality of blue Micro-LED units 22 disposed on the substrate 21. Each Micro-LED unit 22 corresponds one-to-one with a pixel unit R / G / B, such as... Figure 8 As shown.

[0068] For ease of explanation, a quantum dot color conversion layer for a pure green pixel unit array was fabricated using the above method. Each green pixel unit had a diameter of 30 μm, a thickness of 2.3 μm, and a spacing of 50 μm, and was tested.

[0069] like Figure 9As shown, under ultraviolet excitation, the quantum dot color conversion layer prepared by inkjet printing exhibits a neatly arranged array of green fluorescent pixels. The pixel edges are clear, with no obvious ink satellite splashes or pore formation, indicating that the printing ink has good rheological properties and jetting stability.

[0070] like Figure 10 As shown, the curve exhibits a highly regular periodic waveform, with each peak representing a pixel. The peaks are evenly spaced and have a relatively consistent half-width at half-height, confirming the printing process's extremely high positioning accuracy and spread-size control. The highest grayscale value of each peak remains relatively constant (approximately 160-170), with minimal fluctuation. This indicates that the deposition amount of quantum dot material is highly consistent across different pixel units, thus ensuring brightness uniformity in large-area displays. Observing the envelope shape of a single peak, its top exhibits a relatively flat "square wave" or "flat-top" characteristic, without significant edge bi-peak protrusions. This indicates that the "coffee ring effect" during the drying process is effectively suppressed, resulting in uniform distribution of quantum dots within the pixel.

[0071] like Figure 11 As shown, it can be clearly observed that the color conversion layer film is not a dense solid, but rather exhibits a uniformly distributed porous network structure with pore sizes distributed at the nanometer scale. This unique porous structure acts as a strong scattering center in optics. When excitation light enters this layer, the porous structure significantly increases the transmission path of photons within the color conversion layer, thereby increasing the absorption probability of the quantum dots for excitation light and significantly improving the color conversion efficiency (CCE). Simultaneously, this porous framework structure helps release the internal stress generated during the drying or curing process of the film, preventing film cracking during large-area printing and improving the mechanical stability of the film. Furthermore, in the homogeneous initial system of PMMA-PEG-quantum dots-xylene, the hydrophobic long-chain organic ligands (such as oleic acid and oleylamine) anchored on the perovskite quantum dot surface endow it with typical low surface energy characteristics. According to the "like dissolves like" principle and the Flory-Huggins solution theory, the interaction parameters between the organic ligands on the quantum dot surface and the hydrophobic PMMA segments are small, exhibiting extremely strong thermodynamic affinity. In contrast, the high polarity of PEG segments (high ether bond content) leads to significant thermodynamic repulsion towards hydrophobic quantum dots. This difference in affinity drives the pre-enrichment of quantum dots into the PMMA solvation region at the molecular scale.

[0072] Furthermore, it is understandable that by employing a similar method to fabricate a three-color pixelated porous quantum dot color conversion layer based on red quantum dot pixel units / green quantum dot pixel units / blue quantum dot pixel units, and combining it with an ultraviolet Micro-LED chip array to realize a full-color Micro-LED device, a similar effect can also be achieved.

[0073] In the above embodiments, a particle-free strong scattering scheme is adopted, and a porous structure for Mie scattering is achieved only through polymer phase separation to generate a "gas-solid" interface, which can be adapted to high-precision inkjet printing. By constructing a Mie scattering porous structure that matches the excitation light wavelength, the effective path of photons within the layer is extended many times under extremely thin film thickness, and the total internal reflection effect is broken, simultaneously improving the excitation light absorption rate and the emission light coupling rate. The selective phase distribution mechanism of the P1 / P2 system during the volatilization process is utilized to achieve uniform anchoring and in-situ micro-encapsulation of quantum dots in the continuous framework phase, improving the dispersion uniformity and environmental robustness of quantum dots. The hydrodynamics generated by P1 / P2 phase separation suppresses the non-uniform migration of solute, and multi-dimensional controllable adjustment of pixel morphology, pore size, pore density and gradient distribution is achieved to meet the special requirements of light field distribution for different optoelectronic display applications.

[0074] The above embodiments are only used to further illustrate a porous quantum dot color conversion layer of the present invention, its preparation method and application. However, the present invention is not limited to the embodiments. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing a porous quantum dot color conversion layer, characterized in that, include: A mixed solution is formed by mixing a framework polymer, a porous polymer, a solvent, and quantum dots. The mixed solution is coated onto the substrate; The solvent is evaporated, inducing phase separation in the mixed solution, wherein the framework polymer precipitates and solidifies before the porous polymer to form a continuous framework phase that embeds the quantum dots, while the porous polymer is enriched to form discrete microphase domains dispersed in the framework phase. The porous polymer is removed, transforming the discrete microphase domain into pores, to obtain the porous quantum dot color conversion layer.

2. The method for preparing a porous quantum dot color conversion layer according to claim 1, characterized in that: The backbone polymer is selected from at least one of polystyrene, polymethyl methacrylate, polycarbonate, polyvinylidene fluoride, polylactic acid, polycaprolactone, polyurethane, epoxy resin, and acrylic resin; the porogenic polymer is selected from at least one of polyethylene glycol, polyethylene oxide, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid, and water-soluble copolymers; the solvent is selected from chloroform, dichloromethane, tetrahydrofuran, 1,2-dichlorobenzene, chlorobenzene, toluene, xylene, anisole, or a mixture thereof.

3. The method for preparing a porous quantum dot color conversion layer according to claim 1, characterized in that: The mass ratio of the framework polymer to the porous polymer is 95:5 to 50:50, and the content of the quantum dots in the mixed solution is 0.1 to 200 mg / mL.

4. The method for preparing a porous quantum dot color conversion layer according to claim 1, characterized in that: The method for removing the porous polymer includes causing the porous polymer to collapse spontaneously or selectively eluting it.

5. The method for preparing a porous quantum dot color conversion layer according to claim 1, characterized in that: The characteristic size of the pore is 10 nm to 10 μm.

6. The method for preparing a porous quantum dot color conversion layer according to claim 1, characterized in that: The pores are randomly distributed in the plane direction of the membrane layer, and in the thickness direction they are any one or a combination of through holes, semi-through holes, or closed holes.

7. The method for preparing a porous quantum dot color conversion layer according to claim 1, characterized in that: The coating methods include drop coating, spin coating, and inkjet printing.

8. The method for preparing a porous quantum dot color conversion layer according to claim 1, characterized in that: Prepare at least two mixed solutions, with quantum dots in different mixed solutions having different emission colors; deposit the different mixed solutions at different locations on the substrate by inkjet printing to obtain a multicolor pixel unit array.

9. A porous quantum dot color conversion layer, which is obtained by the preparation method of the porous quantum dot color conversion layer according to any one of claims 1 to 8.

10. A display device, characterized in that: It includes a light-emitting array for providing excitation light, and a porous quantum dot color conversion layer as described in claim 9; wherein the porous quantum dot color conversion layer is patterned into a multicolor pixel unit array containing quantum dots of different emitting colors.

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