A micro high-precision perovskite erasable circularly polarized patterned device and a preparation method thereof

Abstract

The application discloses a micro high-precision perovskite erasable circular polarization patterning device and a preparation method thereof. The micro high-precision perovskite erasable circular polarization patterning device comprises, from top to bottom, the following structures: a cholesteric liquid crystal layer, a transparent separation layer, a light-emitting pattern layer and a substrate. The micro high-precision perovskite erasable circular polarization patterning device utilizes the ultra-high peak intensity of femtosecond laser and the digital processing characteristics of a laser direct writing system to realize high-precision micro patterning in a specified area of a perovskite thin film, and the pattern is only visible in fluorescence, and the pattern disappears after heat treatment; meanwhile, the device has high precision and excellent fluorescence characteristics, and has wide application prospects in the fields of information encryption, optical switches and multiple anti-counterfeiting.

Description

Technical Field

[0001] This invention relates to the field of erasable patterning technology, and in particular to a miniature, high-precision perovskite erasable circularly polarized patterning device and its fabrication method. Background Technology

[0002] Patterning technology is one of the core technologies in modern optoelectronics, micro-nano manufacturing, and information functional devices, and is widely used in many cutting-edge fields such as display, sensing, encryption, anti-counterfeiting, and micro-optical components. Traditional patterning methods include photolithography, electron beam lithography, and inkjet printing. While these technologies have certain advantages in terms of resolution and stability, they also have limitations such as complex processes, high costs, environmental unfriendliness, and difficulty in achieving dynamic reversibility. Especially in fields such as information encryption and dynamic anti-counterfeiting, higher requirements are placed on the controllable generation and erasure of patterns, necessitating the development of novel, high-precision patterning methods with reversible characteristics.

[0003] Metal halide perovskites, due to their excellent optoelectronic properties, such as high photoluminescence quantum yield, tunable emission wavelength, high color purity, and low-cost processing, are considered ideal candidate materials for next-generation optoelectronic devices, achieving remarkable research results in fields such as solar cells, light-emitting diodes, photodetectors, and advanced anti-counterfeiting. As a fluorescent material, perovskites possess tunable emission wavelength, high photoluminescence quantum yield, high color purity, and low-cost processing, making them ideal for information storage, encryption, and anti-counterfeiting applications.

[0004] However, traditional perovskite patterning techniques mostly rely on methods such as photolithography, nanoimprinting, or ion implantation. These methods often require multiple processes, making it difficult to achieve high-precision patterns at the micrometer or even nanometer scale. Furthermore, once a pattern is formed, it is difficult to erase or modify, limiting its use in applications requiring repeated writing and erasing. In addition, most existing technologies cannot simultaneously achieve fluorescent visibility and bright-field invisibility of the pattern, which is particularly important in high-end anti-counterfeiting and information encryption applications.

[0005] Femtosecond laser direct writing technology has proven to be an effective technique for the precise fabrication and engineering design of material microstructures in both time and space. Due to its extremely high peak power and extremely short pulse duration, femtosecond lasers can achieve sub-micron level high-precision fabrication in a variety of materials with minimal heat-affected zone, making them ideal for the micro- and nano-fabrication of heat-sensitive materials such as perovskites. By controlling laser parameters (such as power, scanning speed, and wavelength), localized phase transitions, defects, or lattice reconstructions can be induced in perovskite thin films, thereby achieving localized modulation of fluorescence properties and forming fluorescent patterns. This technology combines the advantages of high resolution, non-contact operation, and flexible controllability, making it particularly suitable for the fabrication of micro- and nano-optoelectronic devices and functional patterns.

[0006] On the other hand, circularly polarized light-emitting materials have unique value in fields such as 3D display, information encryption, and optical anti-counterfeiting. Cholesteric liquid crystals, due to their self-assembled helical structure which can produce selective reflection and circularly polarized fluorescence enhancement effects, are widely used in the construction of circularly polarized light-emitting devices. Combining cholesteric liquid crystal layers with fluorescent materials allows for the modulation of the emission polarization state, further enhancing the information dimension and security of the device.

[0007] Although existing research has attempted to combine perovskite and liquid crystal materials to construct devices with polarized light emission characteristics, a patterned integrated device that can achieve high precision, reversible erasure, and circularly polarized light emission is still lacking. In particular, current technologies have not yet provided a complete solution for achieving miniaturization, high precision, and reversibility simultaneously.

[0008] In summary, it is crucial to develop a micro-patterned perovskite device with high precision, reversible erasure, and circularly polarized light emission characteristics, as well as its fabrication method. Summary of the Invention

[0009] To address the shortcomings and deficiencies of the existing technologies, this invention provides a miniature, high-precision perovskite erasable circularly polarized patterned device and its fabrication method. This invention utilizes femtosecond laser direct writing technology to achieve high-precision miniature patterning on a luminescent pattern layer (perovskite thin film). This pattern is visible only under fluorescence and invisible under bright field conditions, and can be completely erased by low-temperature thermal treatment, restoring its luminescent properties. Simultaneously, by integrating a cholesteric liquid crystal layer, the device can emit circularly polarized fluorescence with a high asymmetry factor, enhancing the dimensionality and security of optical information.

[0010] The femtosecond laser direct writing technology (femtosecond laser direct writing perovskite erasable patterning technology) described in this invention has several significant characteristics: First, the femtosecond laser pulse width is extremely short, on the femtosecond scale (10^6 Hz). -15 (s), the focused energy density can reach 10 14 -10 15 W / cm 2First, the patterning process can induce localized nonlinear absorption and energy deposition in perovskite films. Second, the addition of polymers (such as PMMA) to the perovskite films can achieve high flatness and uniformity, making them suitable for high-precision femtosecond laser direct writing. Furthermore, the polymers can precisely control the laser ablation points to obtain higher resolution patterns. Third, by precisely controlling the femtosecond laser intensity, only a small portion of the focused spot exceeds the perovskite ablation threshold, allowing the feature size to break through the optical diffraction limit and achieve high-precision patterning. Fourth, the femtosecond laser-induced patterning process occurs inside the perovskite film, and the pattern is only visible under fluorescence excitation, not under bright field, providing excellent concealment. Fifth, after low-temperature heat treatment (75-80℃), the patterned perovskite film can be completely erased, and the fluorescence intensity can be restored to more than 95% of the initial value, achieving reversible erasure. Sixth, by integrating a cholesteric liquid crystal layer, the device can emit circularly polarized fluorescence with a high asymmetry factor, further enhancing the dimensionality of information encryption.

[0011] The purpose of this invention is to provide a micro high-precision perovskite erasable circularly polarized patterned device, wherein the micro high-precision perovskite erasable circularly polarized patterned device comprises, from top to bottom, the following structure: a cholesteric liquid crystal layer, a transparent separator layer, a light-emitting pattern layer, and a substrate; in, The cholesteric liquid crystal layer is prepared from liquid crystal monomers, chiral dopants, and photoinitiators; The luminescent pattern layer is a polymer-encapsulated perovskite film.

[0012] Furthermore, the polymer is selected from one or more of polyvinylidene fluoride, polymethyl methacrylate, polyvinyl acetate, cellulose acetate, polysulfone, polyamide, polyimide, polycarbonate, polystyrene, polyvinyl chloride, polyvinyl alcohol, ABS plastic, and polyacrylonitrile.

[0013] Furthermore, the perovskite film is a perovskite nanocrystalline film.

[0014] Furthermore, the transparent separating layer is OCA optical adhesive.

[0015] Furthermore, the liquid crystal monomer is selected from one or more of RM-257, HCM-008, and 5CB, the chiral dopant is selected from one or more of LC-756 and R5011, and the photoinitiator is I-651.

[0016] Another object of the present invention is to provide a method for fabricating the aforementioned micro-high-precision perovskite erasable circularly polarized patterned device, the method comprising the following steps: S1. Add the polymer and perovskite precursor to a solvent, heat and stir to obtain a perovskite precursor solution, then coat the perovskite precursor solution onto a substrate and anneal to obtain a light-emitting pattern layer. S2. The liquid crystal monomer, chiral dopant, and photoinitiator are mixed, heated and stirred to obtain a liquid crystal mixture, which is then coated onto a PVA alignment layer and aligned, and cured to obtain a cholesteric liquid crystal layer. S3. Coat the surface of the luminescent pattern layer with OCA optical adhesive, and cover the cholesteric liquid crystal layer on the OCA optical adhesive to obtain the micro high-precision perovskite erasable circularly polarized patterned device.

[0017] Furthermore, in step S1, the annealing temperature is 60-90℃.

[0018] Furthermore, in step S1, the annealing time is 10-30 minutes.

[0019] Further, in step S2, the mass ratio of the liquid crystal monomer, chiral dopant, and photoinitiator is (90-95):(1-5):(0.1-1).

[0020] The pattern formed by the patterning of the luminescent pattern layer described in this invention is visible only under a fluorescence microscope and not under a bright-field microscope.

[0021] The pattern of the luminescent pattern layer described in this invention is invisible under both fluorescence and bright-field microscopes after heat treatment.

[0022] In the luminescent pattern layer of this invention, the molecular formula of the perovskite is ABX3; wherein A is selected from Cs. + CH3NH3 + or CH5N2 + One or more of the following; B is selected from one or more of Pb, Ti, Ge, In, Ag, Sb, Bi, Al, Sn, Cu, or Mn; X is selected from Cl. - ,Br - or I - One or more of them.

[0023] Another objective of this invention is to provide the application of the aforementioned micro high-precision perovskite erasable circularly polarized patterned device in the fields of information encryption and multi-layer anti-counterfeiting.

[0024] The present invention has the following beneficial effects: (1) This invention achieves high-precision, reversible patterning: Micrometer-level high-precision patterns are created on the luminescent pattern layer using femtosecond laser direct writing technology (femtosecond laser wavelength 800-1000nm, power 12-15mW, scanning speed 20-40μm / s). The patterns are visible only under fluorescence and not under bright field. Furthermore, the patterns can be completely erased by low-temperature heat treatment (temperature 75-80℃, time 5-15min), making them invisible under both fluorescence and bright field microscopes, and restoring the luminescent properties to over 95% of their initial intensity. This characteristic has significant advantages in scenarios requiring repeated writing and erasing, such as information encryption and dynamic anti-counterfeiting.

[0025] (2) This invention possesses excellent circularly polarized light emission characteristics: through the integrated design of the cholesteric liquid crystal layer and the light-emitting pattern layer, the device can emit a high asymmetry factor (g). lum The circularly polarized fluorescence enhances the dimensionality and security of optical information, making it suitable for high-end anti-counterfeiting, 3D display, and polarized light detection.

[0026] (3) The preparation process of this invention is simple, highly compatible and stable: the luminescent pattern layer and the ultraviolet-cured cholesteric liquid crystal layer are prepared by solution method. The process conditions are mild, the cost is low and it can be prepared in large areas; the femtosecond laser processing is non-contact, the heat-affected zone is small, the pattern resolution is high and the repeatability is good; the luminescent pattern layer has excellent water and oxygen stability, the overall structure of the device is stable and has good practical application prospects. Attached Figure Description

[0027] Figure 1 A schematic diagram of the structure of the miniature high-precision perovskite erasable circular polarization patterned device of the present invention is shown.

[0028] Figure 2 A schematic flowchart of the method for preparing the luminescent pattern layer according to the present invention is shown.

[0029] Figure 3 A transmission electron microscope (TEM) image of the luminescent patterned layer prepared in the example is shown.

[0030] Figure 4 The absorption spectrum of the luminescent patterned layer prepared in the example is shown under ultraviolet excitation.

[0031] Figure 5 A cross-sectional SEM image of the cholesteric phase liquid crystal layer prepared in the example is shown.

[0032] Figure 6 The POM diagram of the cholesteric phase liquid crystal layer prepared in the examples is shown.

[0033] Figure 7 The circular polarization spectrum of the cholesteric liquid crystal layer of the embodiment under 400 nm excitation is shown.

[0034] Figure 8 The spectrum shows the wavelength matching degree between the reflection band of the cholesteric liquid crystal layer and the emission peak of the luminescent pattern layer in the micro-high precision perovskite erasable circularly polarized patterned device prepared in the embodiment.

[0035] Figure 9 The fluorescence micrographs (UV excitation) of the patterned luminescent pattern layer prepared in test example (1) and the fluorescence micrographs of the patterned luminescent pattern layer after erasure are shown, along with the changes in fluorescence emission spectra.

[0036] Figure 10 Bright-field micrographs of the patterned luminescent pattern layer and the erased patterned luminescent pattern layer of test example (1) are shown. in, Figure 10 (a) shows a bright-field micrograph of the patterned luminescent patterned layer of test example (1); Figure 10 (b) shows a bright-field micrograph of the erased patterned luminescent pattern layer of test example (1).

[0037] Figure 11 The images show fluorescence images of the pattern of a miniature, high-precision perovskite erasable circularly polarized patterned device before thermal erasure, with and without a color filter, on a left-handed circularly polarized filter, and on a right-handed circularly polarized filter. The images also show fluorescence images of the pattern of the same device after thermal erasure, with and without a color filter, on a left-handed circularly polarized filter, and on a right-handed circularly polarized filter. The image size is 180 × 200 μm. Detailed Implementation

[0038] To more clearly illustrate the technical solution of the present invention, the following embodiments are provided. Unless otherwise stated, the raw materials, reactions, and post-processing methods appearing in the embodiments are all commercially available raw materials and technical methods well known to those skilled in the art.

[0039] The terms "preferred," "more preferably," and "more suitable" used in this invention refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0040] It should be understood that, except in any operational instance or otherwise indicated, the amounts or all figures representing ingredients used, for example, in the specification and claims, should be understood to be modified by the term "about" in all cases. Therefore, unless otherwise stated, the numerical parameters set forth in the following specification and appended claims are approximate values ​​varying according to the desired performance to be obtained according to the invention.

[0041] The femtosecond laser used in this invention is the Coherent Chameleon model.

[0042] The embodiments of the present invention use the following raw materials: The PMMA used in this embodiment of the invention has an average molecular weight of 120,000 and was purchased from Beijing Benoway Biotechnology.

[0043] Example A miniature high-precision perovskite erasable circularly polarized patterned device, comprising the following structure from top to bottom: a cholesteric liquid crystal layer (10 μm), a transparent separator layer (100 μm), a light-emitting pattern layer (4.5 μm), and a glass substrate (1 mm). in, The cholesteric liquid crystal layer is prepared from liquid crystal monomers, chiral dopants, and photoinitiators; The luminescent pattern layer is a polymer-encapsulated perovskite film.

[0044] The method for fabricating the micro high-precision perovskite erasable circularly polarized patterned device includes the following steps: S1-1. Place 0.02571g OAI, 0.09222g PbI2, 0.05196g CsI, and 1g PMMA in a 10mL brown bottle, add 5mL DMF, heat and stir at 60℃ for 5h to obtain a perovskite precursor solution. S1-2. The perovskite precursor solution is drop-coated onto a glass substrate, and then the glass substrate is placed on a spin coater and spin-coated at a speed of 2500 r / min for 30 s to obtain a perovskite precursor film. S1-3. Transfer the perovskite precursor film to a 90°C hot stage and anneal for 10 min to obtain a luminescent pattern layer (PMMA-coated CsPbI3 perovskite nanocrystalline film). S2-1. A blank glass substrate is ultrasonically cleaned in acetone solution, ethanol solution, and deionized water for 30 minutes in sequence and then dried. The cleaned glass substrate is then irradiated in an ultraviolet ozone generator for 10 minutes. A 5 wt% polyvinyl alcohol (PVA) aqueous solution is prepared and spin-coated onto the glass substrate at 2000 rpm for 30 seconds. The substrate is then transferred to a hot stage at 60°C and kept for 1 hour to evaporate the solvent, resulting in a glass substrate with a PVA layer on its surface. The side of the glass substrate with the PVA layer is then oriented and rubbed vertically to form a PVA alignment layer with parallel grooves, resulting in a glass substrate with an alignment layer. S2-2, Place 94mg of liquid crystal monomer RM-257, 5mg of chiral dopant LC-756 and 1mg of photoinitiator I-651 in a 5mL brown bottle, add 2mL of dichloromethane, and heat with magnetic stirring at 75℃ until the dichloromethane is completely evaporated to obtain a liquid crystal mixture. S2-3. Heat the liquid crystal mixture to a point above the clearing point, then dot the liquid crystal mixture onto the PVA alignment layer. Press another clean glass substrate onto the PVA alignment layer and gently rub it along the friction direction of the PVA alignment layer to assist in liquid crystal alignment. Then cure it under ultraviolet light for 2 minutes. Peel off the glass substrate with the alignment layer and the other clean glass substrate with a blade to obtain the cholesteric liquid crystal layer. S3. Coat the surface of the luminescent pattern layer with OCA optical adhesive, and cover the cholesteric liquid crystal layer on the OCA optical adhesive to obtain the micro high-precision perovskite erasable circularly polarized patterned device.

[0045] Figure 1 A schematic diagram of the structure of the miniature high-precision perovskite erasable circular polarization patterned device of the present invention is shown.

[0046] Figure 2 A schematic flowchart of the method for preparing the luminescent pattern layer according to the present invention is shown.

[0047] Figure 3 A transmission electron microscope (TEM) image of the luminescent patterned layer prepared in the example is shown.

[0048] Depend on Figure 3 It can be seen that the luminescent pattern layer prepared in the example is a perovskite nanocrystalline thin film.

[0049] Figure 4 The absorption spectrum of the luminescent patterned layer prepared in the example is shown under ultraviolet excitation.

[0050] Figure 4 The instrument used was a Lambd 950, by Figure 4 It can be seen that the luminescent pattern layer has an exciton absorption peak at 688nm.

[0051] Figure 5 A cross-sectional SEM image of the cholesteric phase liquid crystal layer prepared in the example is shown.

[0052] Figure 6 The POM diagram of the cholesteric phase liquid crystal layer prepared in the examples is shown.

[0053] Figure 5 The instrument used was a ZEISS Ultra55. Figure 6 The instrument used was a LEICA DM2700P, manufactured by... Figure 5 , Figure 6 It can be seen that the cholesteric liquid crystal layer prepared in the examples is a cholesteric liquid crystal thin film.

[0054] Figure 7 The circular polarization spectrum of the cholesteric liquid crystal layer of the embodiment under 400 nm excitation is shown.

[0055] Figure 7 Using a fluorescence spectrophotometer FL970, by Figure 7 It can be seen that the miniature high-precision perovskite erasable circularly polarized patterned device has excellent circularly polarized light emission characteristics.

[0056] Figure 8 The spectrum shows the wavelength matching degree between the reflection band of the cholesteric liquid crystal layer and the emission peak of the luminescent pattern layer in the micro-high precision perovskite erasable circularly polarized patterned device prepared in the embodiment.

[0057] Figure 8 The instrument used was an Ocean Optics Mayo 2000PRO spectrometer, developed by [company name missing]. Figure 8 It can be seen that the photonic bandgap of the cholesteric liquid crystal layer is in the range of 665nm-710nm; the emission peak of the luminescent pattern layer is located at 688nm, which matches the photonic bandgap of the cholesteric liquid crystal layer.

[0058] Comparative Example The difference between the comparative example and the embodiment is that: In S1-1, PMMA is not added, and the luminescent pattern layer is prepared according to S1.

[0059] Because it lacks polymer PMMA encapsulation, the prepared luminescent pattern layer has weak fluorescence intensity and poor stability. The fluorescence is completely quenched after 2 days, making it unsuitable for subsequent patterning, erasure, and device integration.

[0060] Test case The performance of the luminescent pattern layer in the embodiment was tested.

[0061] 1. Preparation method: (1) Patterning: The femtosecond laser direct writing system was configured with a wavelength of 800 nm, a pulse width of 200 fs, a laser power of 15 mW, and a scanning speed of 40 μm / s. The luminescent pattern layer described in the example was placed on a displacement platform. The height of the displacement platform was adjusted by observing with a CCD to focus the femtosecond laser onto the surface of the luminescent pattern layer. The pre-designed pattern was imported into the system, and the femtosecond laser moved along a set path. Upon completion, a high-precision patterned luminescent pattern layer with a brightness invisible and fluorescence visible was obtained, with a pattern size of 100 × 100 μm. 2 .

[0062] Erase patterning: The high-precision patterned luminescent pattern layer is placed on a 78°C hot table for 10 minutes to obtain an erased patterned luminescent pattern layer.

[0063] The difference between (2) and (1) is: Patterning: Modify the laser power to 12mW and the scanning speed to 20μm / s; Erasure patterning: Change the hot plate treatment time from 78℃ for 10 minutes to 75℃ for 15 minutes.

[0064] The difference between (3) and (1) is: Patterning: Modify the femtosecond laser wavelength to 400nm.

[0065] 2. Testing: Test A: The luminescent pattern layer of (1) was tested.

[0066] The fluorescence intensity of the luminescent pattern layer (1) was tested using a fluorescence spectrophotometer (FL970 Plus). The results showed that the fluorescence intensity of the erased patterned luminescent pattern layer remained at 96% of the initial intensity (the intensity of the luminescent pattern layer in S1-3 of the example).

[0067] Figure 9 The fluorescence micrographs (UV excitation) of the patterned luminescent pattern layer prepared in test example (1) and the fluorescence micrographs of the patterned luminescent pattern layer after erasure are shown, along with the changes in fluorescence emission spectra.

[0068] Figure 9 Using a fluorescence spectrophotometer FL970, by Figure 9 It can be seen that the patterned luminescent pattern layer gradually disappears with increasing heating time. Simultaneously, the changes in pl (pl) in both patterned and unpatterned regions are presented, showing that pl gradually recovers with increasing heating time. Furthermore, a narrow full width at half maximum (FWHM) pl peak is observed at 688 nm. Figure 4 The corresponding exciton absorption peak is located at 688 nm.

[0069] Figure 10 Bright-field micrographs of the patterned luminescent pattern layer and the erased patterned luminescent pattern layer of test example (1) are shown. in, Figure 10 (a) shows a bright-field micrograph of the patterned luminescent patterned layer of test example (1); Figure 10 (b) shows a bright-field micrograph of the erased patterned luminescent pattern layer of test example (1).

[0070] Depend on Figure 9 and Figure 10 It can be seen that the pattern is only visible under fluorescence excitation and not visible under bright field.

[0071] Test B: Test (2): The resulting luminescent pattern layer also exhibits excellent fluorescent patterning effect and erasable performance, similar to test A.

[0072] Test C: Test (3): Because the luminescent pattern layer has linear absorption at this wavelength, high-precision patterning cannot be achieved, and clear micro-patterns cannot be obtained at the same power level.

[0073] Application examples The miniature high-precision perovskite erasable circularly polarized patterning device described in this invention is applied to the field of high-end anti-counterfeiting.

[0074] According to the patterning method of test example (1), pattern information is written on the perovskite thin film by direct writing with femtosecond laser, and then the stacking process is performed according to the method of the embodiment to obtain a miniature high-precision perovskite erasable circularly polarized patterned device.

[0075] The pattern is invisible under natural light; however, when excited by ultraviolet light, different pattern information can be displayed sequentially by observing through left-handed and right-handed circular polarizers, thus achieving optical encryption of the polarization dimension.

[0076] Meanwhile, following the erasure patterning method of test example (1), the micro high-precision perovskite erasure circular polarization patterning device is subjected to erasure patterning treatment (thermal treatment erasure), and the pattern will disappear.

[0077] Figure 11The images show fluorescence images of the pattern of a miniature, high-precision perovskite erasable circularly polarized patterned device before thermal erasure, with and without a color filter, on a left-handed circularly polarized filter, and on a right-handed circularly polarized filter. The images also show fluorescence images of the pattern of the same device after thermal erasure, with and without a color filter, on a left-handed circularly polarized filter, and on a right-handed circularly polarized filter. The image size is 180 × 200 μm.

[0078] Depend on Figure 11 As can be seen, the pattern is clearly visible after femtosecond laser processing under ultraviolet light irradiation. When observed under a left-handed circular polarizer, the brightness of the pattern is attenuated, while the pattern is not visible under a right-handed circular polarizer. This is because the cholesteric liquid crystal layer can only transmit left-handed circularly polarized light (reflects right-handed circularly polarized light). After subsequent heat treatment to erase the pattern, it disappears and cannot be seen regardless of whether there is a color filter or not.

[0079] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0080] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A miniature, high-precision perovskite erasable circularly polarized patterned device, characterized in that, The micro high-precision perovskite erasable circularly polarized patterned device comprises, from top to bottom, the following structure: a cholesteric liquid crystal layer, a transparent separator layer, a light-emitting pattern layer, and a substrate; in, The cholesteric liquid crystal layer is prepared from liquid crystal monomers, chiral dopants, and photoinitiators; The luminescent pattern layer is a polymer-encapsulated perovskite film.

2. The miniature high-precision perovskite erasable circularly polarized patterned device according to claim 1, characterized in that, The polymer is selected from one or more of polyvinylidene fluoride, polymethyl methacrylate, polyvinyl acetate, cellulose acetate, polysulfone, polyamide, polyimide, polycarbonate, polystyrene, polyvinyl chloride, polyvinyl alcohol, ABS plastic, and polyacrylonitrile.

3. The miniature high-precision perovskite erasable circularly polarized patterned device according to claim 1, characterized in that, The perovskite film is a perovskite nanocrystalline film.

4. The miniature high-precision perovskite erasable circularly polarized patterned device according to claim 1, characterized in that, The transparent separator layer is OCA optical adhesive.

5. The miniature high-precision perovskite erasable circularly polarized patterned device according to claim 1, characterized in that, The liquid crystal monomer is selected from one or more of RM-257, HCM-008, and 5CB, the chiral dopant is selected from one or more of LC-756 and R5011, and the photoinitiator is I-651.

6. The method for fabricating the micro high-precision perovskite erasable circularly polarized patterned device according to any one of claims 1-5, characterized in that, The method for fabricating the micro high-precision perovskite erasable circularly polarized patterned device includes the following steps: S1. Add the polymer and perovskite precursor to a solvent, heat and stir to obtain a perovskite precursor solution, then coat the perovskite precursor solution onto a substrate and anneal to obtain a light-emitting pattern layer. S2. The liquid crystal monomer, chiral dopant, and photoinitiator are mixed, heated and stirred to obtain a liquid crystal mixture, which is then coated onto a PVA alignment layer and aligned, and cured to obtain a cholesteric liquid crystal layer. S3. Coat the surface of the luminescent pattern layer with OCA optical adhesive, and cover the cholesteric liquid crystal layer on the OCA optical adhesive to obtain the micro high-precision perovskite erasable circularly polarized patterned device.

7. The method for fabricating a micro high-precision perovskite erasable circularly polarized patterned device according to claim 6, characterized in that, In step S1, the annealing temperature is 60-90℃.

8. The method for fabricating a micro high-precision perovskite erasable circularly polarized patterned device according to claim 6, characterized in that, In step S1, the annealing time is 10-30 minutes.

9. The method for fabricating a micro high-precision perovskite erasable circularly polarized patterned device according to claim 6, characterized in that, In step S2, the mass ratio of the liquid crystal monomer, chiral dopant, and photoinitiator is (90-95):(1-5):(0.1-1).

10. The application of the miniature high-precision perovskite erasable circularly polarized patterned device according to any one of claims 1-5 in the fields of information encryption and multi-layer anti-counterfeiting.

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