Perovskite quantum dot-based naked-eye 3D display structure and preparation method thereof

Abstract

This invention belongs to the field of display technology and discloses a naked-eye 3D display structure based on perovskite quantum dots and its fabrication method. Full-color display is achieved by precisely controlling the composition and luminescence properties of the quantum dots. The structure uses a blue LED as the excitation layer, driving red CsPb(Br) light... 1‑x I x A pixel array film with alternating red and green CsPbBr3 quantum dots (Br / I = 1:4–1:5) achieves narrow wavelength emission (FWHM < 25 nm, QY > 90%) at 620–630 nm and 520–530 nm, respectively. The fabrication method includes: synthesizing red and green quantum dots via ligand-assisted reprecipitation, optimizing the halogen ratio and surface ligands; fabricating micron-scale pixel array films (2–200 μm) using micro-nano printing or inkjet printing processes; integrating the excitation layer, emissive layer, filter layer, and lens group, and combining with a driving circuit to control pixel synergistic emission, achieving multi-view light field reconstruction. This technology boasts advantages such as high color purity, high luminous efficiency, and low cost, making it suitable for advertising, medical imaging, and virtual reality fields, supporting dynamic refresh rates ≥ 120 Hz and Rec. 2020 color gamut coverage.

Description

Technical Field

[0001] This invention belongs to the field of display technology and relates to a naked-eye 3D display structure based on perovskite quantum dots and its preparation method. Specifically, it relates to naked-eye 3D display technology and the application of quantum dot luminescent materials, and is particularly suitable for naked-eye 3D display devices with high resolution and high color purity. Background Technology

[0002] Since the mid-20th century, display technology has undergone iterative upgrades from CRT cathode ray tubes to liquid crystal displays (LCDs) and organic light-emitting diodes (OLEDs). Current mainstream display technologies have achieved high resolution, wide color gamut, and low power consumption, but two-dimensional planar displays cannot meet the natural human need for spatial depth perception. Glasses-free 3D technology, by simulating the principle of binocular parallax in the human eye, can present stereoscopic images without the need for auxiliary devices, becoming an important development direction for next-generation display technology. Market research institutions predict that the global glasses-free 3D display market will exceed $50 billion by 2025, demonstrating enormous application potential in advertising, education, and healthcare.

[0003] Current glasses-free 3D technology mainly relies on three optical solutions: gratings, lenticular lenses, and multi-view imaging. The light-emitting cores of existing glasses-free 3D displays mostly use traditional phosphors and organic light-emitting materials to construct the light-emitting layer. Traditional phosphors suffer from a wide full width at half maximum (FWHM) (typically greater than 50 nm) and low color purity, resulting in a narrow color gamut coverage and poor color reproduction. Organic light-emitting materials face the problem of insufficient quantum yield (generally below 70%), and the size of the light-emitting unit is difficult to further reduce. Furthermore, the size limitations of the light-emitting unit in existing glasses-free 3D display technologies hinder the improvement of display resolution, failing to meet the demands of high-end displays for fine image quality. The insufficient optical properties of traditional light-emitting materials also lead to high energy consumption, restricting the widespread application of glasses-free 3D display technology.

[0004] Perovskite quantum dots (PQDs) are a new generation of semiconductor nanomaterials with unique advantages, but there is currently no technical solution to combine the excellent optical properties of perovskite quantum dots with naked-eye 3D displays to solve the above-mentioned shortcomings. Summary of the Invention

[0005] The purpose of this invention is to address the technical problems of low color purity, insufficient quantum yield, and limited resolution caused by the size limitation of the light-emitting unit in existing naked-eye 3D display materials. This invention provides a naked-eye 3D display based on perovskite quantum dots, which achieves high color purity, high resolution, and low energy consumption naked-eye 3D display by taking advantage of the excellent optical properties and small size (around 10 nm) of perovskite quantum dots.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A naked-eye 3D display structure based on perovskite quantum dots includes an excitation layer and an emissive layer. The excitation layer uses blue LEDs. The emissive layer is a perovskite quantum dot pixel array film, made of alternating red and green perovskite quantum dots. Specifically, the red and green perovskite quantum dots are CsPbX3 (X=Cl / Br / I) type quantum dots. By precisely adjusting the ratio of halogens Br and I, the red quantum dots achieve emission at a wavelength of 620-630 nm, and the green quantum dots achieve emission at a wavelength of 520-530 nm. The half-width at half-maximum (FWHM) of the red and green perovskite quantum dots is <25 nm, and the quantum yield (QY) is >90%. Assembling the excitation layer and the emissive layer forms a display structure with a pixel array exhibiting high luminous performance.

[0007] Furthermore, the Br / I ratio in the red quantum dots is 1:4-1:5.

[0008] Furthermore, only Br is used in green quantum dots.

[0009] A glasses-free 3D display based on perovskite quantum dots, in addition to the above-mentioned display structure, also includes a filter layer and a lens display, with blue LEDs, perovskite quantum dot pixel array film filter layer and lens display being sequentially bonded together.

[0010] The fabrication method of perovskite quantum dot pixel array film includes the following steps: CsPbX3 (X=Cl / Br / I) quantum dots corresponding to red and green light were synthesized respectively. By adjusting the ratio of halogens Cl, Br, and I, the emission wavelength of red perovskite quantum dots was controlled to be 620-630 nm, and the emission wavelength of green perovskite quantum dots was controlled to be 520-530 nm. The performance of quantum dots was detected by fluorescence spectroscopy to ensure that the full width at half maximum (FWHM) was <25 nm and the quantum yield (QY) was >90%. Qualified quantum dot materials were screened for future use.

[0011] Furthermore, the preparation methods for green perovskite quantum dots include: 1) Mix PbBr2 and TOAB in a molar ratio of 1:2 and dissolve them in toluene or chlorobenzene to obtain solution A with a total concentration of 0.25-0.35 M; 2) Dissolve Cs₂CO₃ in octanoic acid to obtain solution B with a total concentration of 0.8-0.12 M; 3) Dissolve FA(Ac) in octanoic acid to obtain solution C with a concentration of 0.15-0.25 M; 4) Dissolve DDAB in toluene or chlorobenzene to obtain a concentration of 5-20 mg / mL. -1 Solution D; 5) Quickly inject 0.7-1 mL of solution B and 0-0.3 mL of solution C into 9 mL of solution A. Stir magnetically for 3-8 min at room temperature, then add 1-5 mL of solution D. Continue stirring for 1-3 min, then add ethyl acetate or methyl acetate at a volume ratio of 1:1-1:3 for extraction. After centrifugation, collect the precipitate and disperse it in n-hexane or n-octane. Then add ethyl acetate or methyl acetate at a volume ratio of 1:1-1:3 for extraction, collect the precipitate, and disperse it in n-octane or n-hexane. After centrifugation, obtain the green light perovskite quantum dot material.

[0012] Furthermore, the preparation methods for red-light perovskite quantum dots include: 1) Mix PbBr2, PbI2, and TOAB in a molar ratio of 0.16:0.84:2-0.2:0.8:2, and dissolve them in toluene or chlorobenzene to obtain solution A with a total concentration of 0.25-0.35 M; 2) Dissolve Cs₂CO₃ in octanoic acid to obtain solution B with a total concentration of 0.8-0.12 M; 3) Dissolve FA(Ac) in octanoic acid to obtain solution C with a concentration of 0.15-0.25 M; 4) Dissolve DDAB in toluene or chlorobenzene to obtain a concentration of 5-20 mg / mL. -1 Solution D; 5) Quickly inject 0.7-1 mL of solution B and 0-0.3 mL of solution C into 9 mL of solution A. After stirring magnetically for 3-8 min at room temperature, add 1-5 mL of solution D and continue stirring for 1-3 min. Then, add ethyl acetate or methyl acetate at a volume ratio of 1:1-1:3 for extraction. After centrifugation, collect the precipitate and disperse it in n-hexane or n-octane. Then, add ethyl acetate or methyl acetate at a volume ratio of 1:1-1:3 for extraction. Collect the precipitate and disperse it in n-octane or n-hexane. After centrifugation, the red light perovskite quantum dot material is obtained.

[0013] A method for fabricating a glasses-free 3D display based on perovskite quantum dots includes the following steps: Step S1. Preparation of CsPbX3 type perovskite quantum dots: Step S2. Fabrication of the pixel array film: Using micro-nano printing or inkjet printing processes, a light-emitting layer film with alternating red and green perovskite quantum dot pixels, i.e. a pixel array film, is prepared on a transparent substrate; due to the small size of quantum dots, micron-level pixels (2μm-200μm) can be achieved.

[0014] Step S3. Assembly of the core light-emitting structure: A blue LED array is used as the excitation layer and aligned and bonded to the perovskite quantum dot pixel array film prepared above. The blue light emitted by the blue LED can efficiently excite the red and green quantum dots to emit red and green light respectively. The lighting sequence of the blue LED is controlled by the circuit connection to achieve the coordinated light emission of red and green pixels.

[0015] Step S4. Overall assembly of the naked-eye 3D display screen: The aforementioned core light-emitting structure is combined with a naked-eye 3D imaging lens group and fixed inside the display screen housing to form a lens display screen; the drive circuit and control module are connected to complete the overall assembly of the naked-eye 3D display screen based on perovskite quantum dots; the drive circuit can control the light emission intensity and timing of the pixel array, and work with the lens group to achieve naked-eye 3D visual effects.

[0016] Compared with the prior art, the beneficial effects of the present invention include: Excellent optical performance: The narrow half-width (<25 nm) characteristic of perovskite quantum dots enables the display to have extremely high color purity, a color gamut coverage far exceeding that of traditional materials, and color reproduction close to natural colors; high quantum yield (>90%) greatly improves luminous efficiency, reduces display energy consumption, and has strong luminous stability.

[0017] Breakthrough in resolution: Perovskite quantum dots are so small that they can be made into ultra-fine pixel array films, which greatly reduces the pixel pitch and enables a qualitative leap in the resolution of naked-eye 3D displays, meeting the demand for fine image quality in high-end displays.

[0018] Simple and easy to implement: The combination of the excitation layer and the light-emitting layer has a simple structure, strong compatibility with the preparation process, facilitates large-scale production, and reduces manufacturing costs. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the naked-eye 3D display screen based on perovskite quantum dots according to the present invention; In the figure, 1 is a blue LED, 2 is a perovskite quantum dot pixel array film, 3 is a filter layer, and 4 is a lens display screen. Detailed Implementation

[0020] The best implementation of the present invention will be described in detail below with reference to the accompanying drawings.

[0021] In this embodiment, the quantum dots are synthesized using a ligand-assisted reprecipitation method, and the blue LED emits light at a wavelength of 450-460 nm to ensure efficient excitation of the red and green quantum dots.

[0022] Example 1: Fabrication of a glasses-free 3D display based on perovskite quantum dots Step S1. Preparation of CsPbX3 type perovskite quantum dots: CsPbX3 (X=Cl / Br / I) quantum dots corresponding to red and green light were synthesized respectively. By adjusting the ratio of halogens Cl, Br, and I, the emission wavelength of the red quantum dots was controlled to be 620 nm and the emission wavelength of the green quantum dots was controlled to be 525 nm. The performance of the quantum dots was detected by fluorescence spectroscopy to ensure that the full width at half maximum (FWHM) was <25 nm and the quantum yield (QY) was >90%. Qualified quantum dot materials were screened for future use.

[0023] Step S2. Fabrication of the pixel array film: Using micro-nano printing or inkjet printing processes, a light-emitting layer film with alternating red and green perovskite quantum dot pixels, i.e. a pixel array film, is prepared on a transparent substrate; due to the small size of quantum dots, micron-level pixels (2μm-200μm) can be achieved.

[0024] Step S3. Assembly of the core light-emitting structure: A blue LED array is used as the excitation layer and aligned and bonded to the perovskite quantum dot pixel array film prepared above. The blue light emitted by the blue LED can efficiently excite the red and green quantum dots to emit red and green light respectively. The lighting sequence of the blue LED is controlled by the circuit connection to achieve the coordinated light emission of red and green pixels.

[0025] Step S4. Overall assembly of the naked-eye 3D display screen: The aforementioned core light-emitting structure is combined with a naked-eye 3D imaging lens group and fixed inside the display screen housing to form a lens display screen; the drive circuit and control module are connected to complete the overall assembly of the naked-eye 3D display screen based on perovskite quantum dots; the drive circuit can control the light emission intensity and timing of the pixel array, and work with the lens group to achieve naked-eye 3D visual effects.

[0026] Example 2 In step S1 of Example 1, the synthesis of green perovskite quantum dot material includes the following steps: 1) Mix PbBr2 and TOAB in a molar ratio of 1:2 and dissolve them in toluene or chlorobenzene to obtain solution A with a total concentration of 0.3 M; 2) Dissolve Cs2CO3 in octanoic acid to obtain solution B with a total concentration of 0.1 M; 3) Dissolve FA(Ac) in octanoic acid to obtain a 0.2 M solution C; 4) Dissolve DDAB in toluene or chlorobenzene to obtain a concentration of 10 mg / mL. -1 Solution D; 5) Quickly inject 0.85 mL of solution B and 0.15 mL of solution C into 9 mL of solution A. After stirring magnetically for 5 min at room temperature, add 3 mL of solution D and continue stirring for 2 min. Then, add ethyl acetate or methyl acetate at a volume ratio of 1:2 for extraction. After centrifugation, collect the precipitate and disperse it in n-hexane or n-octane. Then, add ethyl acetate or methyl acetate at a volume ratio of 1:2 for extraction. Collect the precipitate and disperse it in n-octane or n-hexane. After centrifugation, obtain the green light perovskite quantum dot material.

[0027] Example 3 In step S1 of Example 1, the synthesis of red-light perovskite quantum dot material includes the following steps: 1) Mix PbBr2, PbI2, and TOAB in a molar ratio of 0.2:0.8:2 and dissolve them in toluene or chlorobenzene to obtain solution A with a total concentration of 0.3 M; 2) Dissolve Cs2CO3 in octanoic acid to obtain solution B with a total concentration of 0.1 M; 3) Dissolve FA(Ac) in octanoic acid to obtain a 0.2 M solution C; 4) Dissolve DDAB in toluene or chlorobenzene to obtain a concentration of 10 mg / mL. -1 Solution D; 5) Quickly inject 0.85 mL of solution B and 0.15 mL of solution C into 9 mL of solution A. After stirring magnetically for 5 min at room temperature, add 3 mL of solution D and continue stirring for 2 min. Then, add ethyl acetate or methyl acetate at a volume ratio of 1:2 for extraction. After centrifugation, collect the precipitate and disperse it in n-hexane or n-octane. Then, add ethyl acetate or methyl acetate at a volume ratio of 1:2 for extraction. Collect the precipitate and disperse it in n-octane or n-hexane. After centrifugation, the red light perovskite quantum dot material is obtained.

[0028] Comparative Example 1: Fabrication of a naked-eye 3D display based on organic light-emitting materials Step S1. Preparation of organic light-emitting materials: Dissolve green organic light-emitting materials (such as PFSO, PFO, G2, Ir(ppy)3, etc.) in the corresponding solvents, and dissolve red organic light-emitting materials (such as CN-PPV, PF-Red, R3, Ir(piq)3, etc.) in the corresponding solvents.

[0029] Step S2. Fabrication of pixel array film: Using micro-nano printing or inkjet printing technology, a light-emitting layer film with alternating red and green organic light-emitting material pixels is formed on a transparent substrate, namely pixel array film.

[0030] The subsequent fabrication process is the same as in Example 1 based on perovskite quantum dots. However, due to the photoelectric properties of the organic light-emitting material itself, the resulting display screen has low color purity, a wide emission half-peak, and a color gamut performance far inferior to that of the perovskite quantum dot display screen. Furthermore, the hydrodynamic diameter of the organic light-emitting material is 10~50 nm, and its pixel resolution is also inferior to that of the perovskite quantum dot display screen.

[0031] The technical effects of the glasses-free 3D display screen based on perovskite quantum dots described in this application are based on the inherent optical and electrical properties of perovskite quantum dot materials, combined with the well-known 3D display technology principles in the relevant technical field. The application involves theoretical analysis and reasonable derivation of the core structural design, key manufacturing process, and process parameter ranges of each step of the perovskite quantum dot glasses-free 3D display screen disclosed in this application. The materials and processes used in this application are all conventional and feasible methods in the relevant technical field. The combination of various technical features has a clear logical correlation and technical synergy, and its technical effects are reasonably achievable.

[0032] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A glasses-free 3D display structure based on perovskite quantum dots, characterized in that, include: The excitation layer uses a blue LED (1); The light-emitting layer is a perovskite quantum dot pixel array film (2), composed of red quantum dots CsPb(Br) 1-x I x Composed of alternating arrangements of 3 and green quantum dots CsPbBr3; Among them, red quantum dots achieve emission at a wavelength of 620-630 nm by adjusting the Br / I ratio, while green quantum dots, containing only Br, achieve emission at a wavelength of 520-530 nm; the half-width at half-maximum (FWHM) of red and green quantum dots is <25 nm, and the quantum yield (QY) is >90%.

2. The display structure according to claim 1, characterized in that, The red quantum dot CsPb(Br) 1-x I x The molar ratio of Br / I in 3 is 1:4 to 1:

5.

3. The display structure according to claim 1, characterized in that, The preparation method of green quantum dots CsPbBr3 includes the following steps: 1) Mix PbBr2 and TOAB in a molar ratio of 1:2 and dissolve them in toluene or chlorobenzene to form a solution A with a concentration of 0.25-0.35 M; 2) Dissolve Cs₂CO₃ in octanoic acid to form a solution B with a concentration of 0.8-0.12 M; 3) Dissolve FA(Ac) in octanoic acid to form a solution C with a concentration of 0.15-0.25 M; 4) Dissolve DDAB in toluene or chlorobenzene to form a solution D with a concentration of 5-20 mg / mL; 5) Add 0.7-1 mL of solution B and 0-0.3 mL of solution C to 9 mL of solution A, stir at room temperature for 3-8 min, then add 1-5 mL of solution D and continue stirring for 1-3 min; 6) Add ethyl acetate at a volume ratio of 1:1 to 1:3 for extraction, centrifuge to collect the precipitate and disperse it in n-hexane or n-octane. Repeat the extraction steps and centrifuge to obtain green quantum dots.

4. The display structure according to claim 1, characterized in that, Red quantum dots CsPb(Br) 1-x I x The preparation method of )3 includes the following steps: 1) Mix PbBr2, PbI2 and TOAB in a molar ratio of 0.16:0.84:2 to 0.2:0.8:2, and dissolve in toluene or chlorobenzene to form a solution A with a concentration of 0.25-0.35 M; 2) The subsequent steps are the same as steps 2)-6) in claim 3, and finally red quantum dots are obtained.

5. The display structure according to claim 1, characterized in that, The perovskite quantum dot pixel array film is prepared by micro-nano printing or inkjet printing process, with a pixel size of 2-200 μm, and red and green quantum dot pixels are alternately arranged on a transparent substrate.

6. A method for assembling a naked-eye 3D display core structure based on perovskite quantum dots, characterized in that, include: A blue LED array is used as the excitation layer and aligned and bonded with the perovskite quantum dot pixel array film as described in claim 1. By controlling the timing of blue LED illumination through circuitry, red and green pixels can emit light in tandem.

7. A glasses-free 3D display screen based on perovskite quantum dots, characterized in that, include: The core light-emitting structure as described in claim 6; A filter layer (3) is attached to the surface of the perovskite quantum dot pixel array film (2); The lens display screen (4) is bonded to the filter layer (3); Among them, the blue LED (1), the perovskite quantum dot pixel array film (2), the filter layer (3) and the lens display screen (4) are sequentially stacked and encapsulated in the display screen shell.

8. The display structure according to claim 1, characterized in that, The red and green perovskite quantum dots need to be detected by fluorescence spectroscopy, and the screening conditions are: full width at half maximum (FWHM) ≤ 25 nm and quantum yield (QY) ≥ 90%.

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