Independent chiral liquid crystal optical device based on dynamic frequency regulation and control and preparation method thereof

Abstract

The invention discloses an independent chiral liquid crystal optical device based on dynamic frequency regulation and control and a preparation method of the independent chiral liquid crystal optical device. The independent chiral liquid crystal optical device comprises a conductive substrate, an alignment layer, a cholesteric liquid crystal layer with a stable polymer and an electrode, the precursor mixture is prepared from a nematic phase liquid crystal matrix, a chiral dopant, a polymerizable liquid crystal monomer and a photoinitiator; and the screw pitch of the cholesteric liquid crystal layer is dynamically regulated and controlled through the frequency of an alternating current electric field, so that the dynamic regulation of the selective reflection center wavelength is realized. The cholesteric liquid crystal is packaged between the two conductive substrates, the spiral structure and the photonic band gap characteristics of the cholesteric liquid crystal are accurately regulated and controlled through alternating current electric field frequency parameters, real-time dynamic modulation of the output light wavelength and the circular polarization state is achieved, the limitation of concentration curing of a traditional chiral agent is broken through, and the chiral liquid crystal is obtained. The dynamic reconfigurable control of output characteristics of circularly polarized light is realized, and the dynamic reconfigurable circularly polarized light engine is used as a universal circularly polarized light engine, has a plug-and-play characteristic, and can be directly integrated with various light emitting units.

Description

Technical Field

[0001] This invention relates to the field of liquid crystal materials and dynamic control technology, and in particular to an independent chiral liquid crystal optical device based on frequency dynamic control and its preparation method. Background Technology

[0002] In the current field of liquid crystal optical modulation technology, there are two main technical directions and their significant limitations. On the one hand, voltage-controlled nematic liquid crystal (LCD) technology, although widely used in the display field, achieves phase delay modulation of linearly polarized light by adjusting the electric field intensity to change the orientation of liquid crystal molecules. However, its inherent limitation is that it can only modulate the phase of polarized light and cannot directly generate or dynamically control the output characteristics of circularly polarized light. This limitation greatly restricts its application in advanced optoelectronic systems that require circularly polarized light modulation.

[0003] On the other hand, chiral-doped cholesteric liquid crystal (CLC) technology utilizes the self-assembly properties of helical superstructures to achieve selective reflection or transmission of circularly polarized light at specific wavelengths, showing application potential in fields such as anti-counterfeiting labels. However, this technology heavily relies on the concentration of chiral agents to fix the helical structure, resulting in the photonic bandgap being fixed immediately after preparation, lacking dynamic reconfigurability. Currently, the core bottleneck in this technology lies in the lack of an effective solution for real-time dynamic control of the circular polarization characteristics of cholesteric liquid crystals through electrical signals. Neither the linear polarization control of nematic liquid crystals nor the static circular polarization characteristics of cholesteric liquid crystals can meet the urgent need of modern optoelectronic systems for dynamically tunable circularly polarized light sources. Although existing cholesteric liquid crystal photonic materials can achieve bandgap control through pitch changes, most rely on slow-response external fields such as temperature, illumination, or electric field intensity, and have not yet achieved real-time dynamic control driven by AC frequency. This results in limited controllability of the liquid crystal photonic bandgap, making it impossible to achieve continuously tunable dynamic photonic bandgap structures and meet the requirements for fine spectral control with multi-frequency response.

[0004] Furthermore, existing circularly polarized light-emitting devices (such as organic circularly polarized OLEDs and chiral perovskite emissive layers) are mostly unidirectional light-emitting systems, making it impossible to achieve the fusion of tunable color changing and circularly polarized light emission within the same device. These devices have complex structures, incompatible material systems, and difficult-to-integrate fabrication processes, thus presenting significant limitations in applications such as high-end optical displays, anti-counterfeiting coding, and machine vision recognition. These technological gaps not only restrict their further development in cutting-edge fields such as 3D displays, quantum information processing, and dynamic anti-counterfeiting, but also limit their widespread application in modern optoelectronic systems. Summary of the Invention

[0005] This invention provides an independent chiral liquid crystal optical device based on dynamic frequency control and its fabrication method, in order to solve the technical problems of low system integration, fixed functions, and poor compatibility in traditional circularly polarized light acquisition schemes.

[0006] In view of the above technical problems, embodiments of the present invention provide an independent chiral liquid crystal optical device based on frequency dynamic modulation, comprising:

[0007] Conductive substrate;

[0008] An alignment layer coated on a conductive substrate;

[0009] A polymer-stabilized cholesteric liquid crystal layer is formed by injecting a precursor mixture between two conductive substrates; the precursor mixture is made of a nematic liquid crystal matrix, a chiral dopant, a polymerizable liquid crystal monomer, and a photoinitiator; and the pitch of the cholesteric liquid crystal layer is dynamically controlled by the frequency of an alternating electric field, thereby achieving dynamic adjustment of its selective reflection center wavelength.

[0010] Electrodes are used to apply an alternating electric field to achieve dynamic control of the pitch of the cholesteric liquid crystal layer.

[0011] This invention also provides a method for fabricating an independent chiral liquid crystal optical device based on frequency dynamic modulation, comprising:

[0012] S1. The conductive substrate is pretreated and surface treated sequentially to enhance its hydrophilicity and wettability.

[0013] S2. Coating an alignment layer on a conductive substrate and inducing anisotropic orientation anchoring of the alignment layer by ultraviolet light irradiation;

[0014] S3. A precursor mixture is formed by mixing a nematic liquid crystal matrix, a chiral dopant, a polymerizable liquid crystal monomer, and a photoinitiator. The precursor mixture is then injected between two conductive substrates to form a polymer-stable cholesteric liquid crystal layer. The selective reflection center wavelength of the cholesteric liquid crystal is adjusted by regulating the concentration of the chiral dopant.

[0015] S4. The polymer-stabilized cholesteric liquid crystal layer is cured under ultraviolet light to form a polymer network, thereby stabilizing the helical structure of the cholesteric liquid crystal layer.

[0016] In this invention, by encapsulating cholesteric liquid crystal between two conductive substrates, and precisely controlling its helical structure and photonic bandgap characteristics using AC electric field frequency parameters, real-time dynamic modulation of the output light wavelength and circular polarization state is achieved. Specifically, the working mechanism of this device is based on the precise modulation of the liquid crystal helical structure by the AC electric field frequency. By synchronously controlling the color-changing emission and the pitch (photonic bandgap) of the cholesteric liquid crystal at a specific AC frequency, dynamic synergistic control of the emission color and circular polarization state is achieved, thereby realizing color-changing circularly polarized emission. This process breaks through the limitations of traditional chiral agent concentration-based curing, achieving dynamic and reconfigurable control of the output characteristics of circularly polarized light (including center wavelength, polarization direction, bandwidth, etc.). The chiral helical structure of the liquid crystal can be dynamically changed by frequency driving. This enables continuous control of the photonic bandgap; at the same time, the chiral ratio adjustment at different frequencies enables the circular polarization characteristics of the liquid crystal layer to be synchronously coupled with the emission wavelength of ACEL, forming a new type of light-emitting system with adjustable frequency, variable color, and controllable polarization.

[0017] This invention serves as a universal "circularly polarized light engine," possessing plug-and-play characteristics and directly integrating with various light-emitting units (such as LEDs / lasers). This front-end / back-end compatible design allows it to impart high-purity circularly polarized light and dynamic color-changing capabilities without altering the original light source structure. This breakthrough technology solves the long-standing technical challenge of separating the generation and dynamic control of circularly polarized light, providing crucial technical support for next-generation optoelectronic systems. In terms of technical implementation, this invention employs a polymer-stabilized cholesteric composite system formed by nematic liquid crystal E7, chiral materials, and different monomers, constructing a unique frequency-responsive optoelectronic composite structure. Through a frequency dynamic synergistic control mechanism, precise control of optoelectronic properties is achieved: the emission color of the light-emitting unit and the pitch of the chiral liquid crystal molecules are synchronously controlled by changes in the frequency of the alternating current electric field; the chiral liquid crystal layer performs polarization selection on the output light based on its photonic crystal properties, ultimately achieving synchronous control of the emission characteristics and circular polarization state output through a single frequency parameter.

[0018] In summary, this invention not only represents technological innovation but also holds significant implications for application prospects. It opens up new technical solutions for fields such as anti-counterfeiting, machine learning, and virtual reality / augmented reality (VR / AR), and is expected to promote the development and application of related technologies. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a flowchart of a method for fabricating an independent chiral liquid crystal optical device based on frequency dynamic control in one embodiment of the present invention;

[0021] Figure 2 This is a structural diagram of a polymer-stabilized cholesteric liquid crystal integrated AC-PEL powder electroluminescent device according to an embodiment of the present invention.

[0022] Figure 3 This is a circular dichroism spectrum of the liquid crystal material at different frequencies in one embodiment of the present invention;

[0023] Figure 4 This is a circularly polarized emission (CPL) spectrum of the device in one embodiment of the present invention;

[0024] Figure 5 This is a graph showing the light emission asymmetry factor G of the device in one embodiment of the present invention;

[0025] Figure 6 This is a graph showing the change of the g-value of the device with frequency under different center wavelength conditions in one embodiment of the present invention.

[0026] The reference numerals in the accompanying drawings are as follows:

[0027] 1-Electrode, 2-Light-emitting layer, 3-Electrode, 4-Substrate, 5-Cholesteric liquid crystal layer. Detailed Implementation

[0028] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0029] An embodiment of the present invention provides an independent chiral liquid crystal optical device based on frequency dynamic modulation, comprising:

[0030] Conductive substrate;

[0031] An alignment layer coated on a conductive substrate;

[0032] A polymer-stabilized cholesteric liquid crystal layer is formed by injecting a precursor mixture between two conductive substrates; the precursor mixture is made of a nematic liquid crystal matrix, a chiral dopant, a polymerizable liquid crystal monomer, and a photoinitiator; and the pitch of the cholesteric liquid crystal layer is dynamically controlled by the frequency of an alternating electric field, thereby achieving dynamic adjustment of its selective reflection center wavelength.

[0033] Electrodes are used to apply an alternating electric field to achieve dynamic control of the pitch of the cholesteric liquid crystal layer.

[0034] like Figure 1 As shown, this invention provides a method for fabricating an independent chiral liquid crystal optical device based on dynamic frequency modulation. The key step lies in the precise and meticulous control of the electrodes, alignment layer, liquid crystal layer, and ultraviolet curing process, including:

[0035] S1. The conductive substrate is pretreated and surface treated sequentially to enhance its hydrophilicity and wettability.

[0036] In one embodiment, step S1 further includes the following sub-steps:

[0037] S101, A glass substrate coated with indium tin oxide (ITO) or a transparent conductive material is selected as the substrate; the substrate may also be AZO, FTO, graphene, silver nanowires or ultrathin gold / silver composite transparent electrodes.

[0038] S102. Pre-treat the conductive substrate by ultrasonic cleaning with acetone, ethanol and deionized water in sequence, with the cleaning time for each solvent controlled at 15-20 minutes to ensure that the substrate surface is thoroughly clean.

[0039] S103. Remove the conductive substrate and dry it to remove residual moisture and impurities from the surface. Perform surface treatment on the cleaned substrate by ultraviolet ozone treatment for 10-15 minutes or oxygen plasma treatment for 30-60 seconds to enhance the hydrophilicity and wettability of the substrate, thereby laying a good foundation for subsequent process steps.

[0040] S2. Coat an alignment layer on a conductive substrate and induce anisotropic orientation anchoring of the alignment layer by ultraviolet light irradiation.

[0041] In one embodiment, step S2 further includes the following sub-steps:

[0042] S201. Select a light-controlled alignment material (such as PI, SDI, BrilliantYellow, PAAD / LIA, etc.) and use a spin coating process to uniformly coat the film onto the surface of the ITO substrate. The spin coating is divided into two stages: first, spin at 800 rpm for 5-6 seconds for pre-spreading, and then spin at 3000 rpm for 35-45 seconds to form a uniform film and uniformly coat the film onto the substrate surface.

[0043] S202. Anneal the substrate in an oven at 100°C for 10-12 minutes to remove solvent and stabilize the film.

[0044] S203 uses linearly polarized ultraviolet light with a wavelength of 355-405nm to irradiate along a preset target orientation direction, inducing anisotropy (typical total exposure 50-500mJcm⁻²), providing precise orientation anchoring for liquid crystal molecules (planar alignment or pretilt angle / patterned alignment as needed). When higher mechanical strength or mass production compatibility is required, friction-type polyimide (PI) alignment can also be used, such as parallel alignment PI: SE-150, AL1254, JALS-204; vertical alignment PI: SE-1211, JALS-214, etc., which are also oriented by unidirectional rubbing with a cloth after curing at 180-230°C.

[0045] S3. A precursor mixture is formed by mixing a nematic liquid crystal matrix, a chiral dopant, a polymerizable liquid crystal monomer, and a photoinitiator. The precursor mixture is then injected between two conductive substrates to form a polymer-stable cholesteric liquid crystal layer. The selective reflection center wavelength of the cholesteric liquid crystal is adjusted by regulating the concentration of the chiral dopant.

[0046] In one embodiment, step S3 further includes the following sub-steps:

[0047] S301. Nematic liquid crystal matrix (E7), chiral dopant (R / S5011), polymerizable liquid crystal monomer (RM257), and photoinitiator (Irgacure651) are mixed in the following proportions: nematic liquid crystal matrix (E7) is 23%~46%, chiral dopant (R / S5011) is 2%~4%, polymerizable liquid crystal monomer (RM257) is 25%~51%, and photoinitiator (Irgacure651) is 1%~8%. The mixture is magnetically stirred at 80-100°C for 2-3 hours until fully dissolved and homogenized to form a clear and uniform precursor mixture. The nematic liquid crystal matrix can also be selected from E48, MLC-6815, ZLI / BL series, or a 5CB hybrid system; the chiral dopant can also be selected from R811 / S811, CB15, R1011, etc.; the polymerizable liquid crystal monomers can also be used in combination with RM82, RM105, RM23, RM32, RM606, etc. to adjust the crosslinking density and glass transition temperature. The addition of polymerizable liquid crystal monomers can improve the curing pitch and texture stability. The photoinitiator can also be selected from 184, 1173, 369, TPO / TPO-L, etc., to match the light source according to the absorption spectrum; the polymerizable liquid crystal monomers and photoinitiators are used in the subsequent curing process.

[0048] S302. The concentration of the chiral dopant and the selective reflection center wavelength of the cholesteric liquid crystal satisfy the following approximate relationship, which is expressed as follows:

[0049] (1)

[0050] in, Indicates the selective reflection center wavelength. Indicates the average refractive index. The pitch of a cholesteric liquid crystal is represented by the mole fraction of the chiral dopant and the pitch. They are approximately inversely proportional.

[0051] S303. By controlling the concentration of the chiral dopant, the selective reflection of the center wavelength is achieved. Adjust to the target band.

[0052] S304. The precursor mixture is injected between two glass substrates coated with indium tin oxide (ITO) through capillary effect, and the interlayer spacing is controlled by spacer microspheres. The typical particle size of the spacer microspheres is 30-40 micrometers, and the areal density of the spacer microspheres is 50-200 microspheres / cm².

[0053] S305 uses UV-curable adhesive for edge sealing, leaving only the injection port open. A secondary sealing is performed after the mixture fills the cavity to ensure the cavity is free of air bubbles and contamination. The curing adhesive can be NOA series or epoxy-acrylate blend.

[0054] Understandably, cholesteric liquid crystals possess a unique helical structure in which liquid crystal molecules are arranged in a helical pattern around an axis. The period of this helical structure (i.e., the pitch) The chiral dopant determines the optical properties of the liquid crystal, especially the selective reflection wavelength. A chiral dopant is a substance doped into a liquid crystal to adjust the helical structure of the liquid crystal molecules; the concentration of the chiral dopant directly affects the pitch. Specifically, the mole fraction of the chiral dopant and the pitch... The relationship is approximately inversely proportional, which means that as the concentration of the chiral agent increases, the pitch... Decrease; when the concentration of the chiral agent decreases, the pitch decreases. Increase. According to formula (1), the selective reflection wavelength... With pitch Directly proportional. Therefore, by adjusting the concentration of the chiral agent, the pitch can be changed. This allows for the adjustment of selective reflection wavelengths. For example, if the target wavelength is 520-620nm (green to red light), the pitch can be adjusted by changing the concentration of the chiral agent. and average refractive index The product falls within this range. The specific steps for adjustment can be: determine the target wavelength range, for example, 520-620 nm. Next, measure the average refractive index. The average refractive index of the liquid crystal material used is determined through experiments or literature review. Then, the required pitch is calculated. : Calculate the pitch corresponding to the target wavelength according to formula (1). Then adjust the chiral agent concentration according to the pitch. The inverse relationship with the mole fraction of the chiral agent allows for adjustment of the chiral agent concentration to achieve the desired pitch. The calculated value was achieved. Finally, experimental verification was conducted by preparing samples and measuring their selective reflection wavelengths to verify whether the target wavelength band was reached.

[0055] S4. The polymer-stabilized cholesteric liquid crystal layer is cured under ultraviolet light to form a polymer network, thereby stabilizing the helical structure of the cholesteric liquid crystal layer. Ultraviolet curing is a crucial step in ensuring the stability of the liquid crystal layer.

[0056] In one embodiment, step S4 further includes the following sub-steps:

[0057] S401. Under a nitrogen or inert atmosphere, perform a two-step curing process using 365nm ultraviolet light. First, pre-curing is performed at a light intensity of 1mW / cm² for 30-120 seconds to lightly lock the texture and reduce flowability. Then, complete curing is performed at a light intensity of 5-10mW / cm² for 5-10 minutes to form a polymer network, thereby stabilizing the helical structure of the cholesteric liquid crystal layer and suppressing distortion caused by external field or temperature fluctuations. Alternatively, a 405nm light source and a matched initiator can be used. During curing, the polymerizable monomers undergo a cross-linking reaction to form a polymer network, thereby stabilizing the cholesteric helical structure and suppressing distortion caused by external field or temperature fluctuations.

[0058] S402, cured at 30-35°C to maintain planar single-domain texture, or post-cured at 60-80°C to fine-tune the selected reflection bandwidth, resulting in a uniform, low-scattering thickness of 30-40 mm. The single-domain PSCLC thin film (also known as polymer-stabilized cholesterol texture, PSCT) exhibits excellent optical uniformity and repeatable selective reflection due to the uniform distribution of spacer microspheres.

[0059] The independent chiral liquid crystal optical device of this invention solves the core problems of low system integration, fixed functions and poor compatibility in traditional circularly polarized light acquisition schemes. This invention encapsulates cholesteric liquid crystal between two conductive substrates and uses AC electric field frequency parameters to precisely control its helical structure and photonic bandgap characteristics, thereby realizing real-time dynamic modulation of the output light wavelength and circular polarization state.

[0060] Specifically, the device operates based on the precise modulation of the liquid crystal helical structure by the frequency of the alternating current electric field. By synchronously controlling the pitch (photonic bandgap) of the color-changing luminescence and the cholesteric liquid crystal at a specific AC frequency, it achieves dynamic synergistic control of the emitted color and circular polarization state, thereby realizing color-changing circularly polarized luminescence. This process overcomes the limitations of traditional chiral agent concentration-based curing, enabling dynamic and reconfigurable control of the circularly polarized light output characteristics (including center wavelength, polarization direction, bandwidth, etc.). The chiral spiral of the liquid crystal can be dynamically changed by frequency driving. This enables continuous control of the photonic bandgap; at the same time, the chiral ratio adjustment at different frequencies enables the circular polarization characteristics of the liquid crystal layer to be synchronously coupled with the emission wavelength of ACEL, forming a new type of light-emitting system with adjustable frequency, variable color, and controllable polarization.

[0061] This device can serve as a universal "circularly polarized light engine," featuring plug-and-play functionality and direct integration with various light-emitting units (such as LEDs / lasers). This front-end / back-end compatible design allows it to impart high-purity circularly polarized light and dynamic color-changing capabilities to existing light sources without altering their structure. This breakthrough technology solves the long-standing technical challenge of separating circularly polarized light generation from dynamic control, providing crucial technical support for next-generation optoelectronic systems.

[0062] In terms of technical implementation, this invention employs a polymer-stabilized cholesteric composite system formed by nematic liquid crystal E7, chiral materials, and different monomers to construct a unique frequency-responsive optoelectronic composite structure. Through a dynamic frequency-coordinated modulation mechanism, precise control of optoelectronic properties is achieved: the emission color of the emitting unit and the pitch of the chiral liquid crystal molecules are synchronously modulated by changes in the frequency of the alternating current field. The chiral liquid crystal layer, based on its photonic crystal properties, performs polarization selection on the output light, ultimately achieving synchronous control of the luminescence characteristics and the circularly polarized output through a single frequency parameter.

[0063] In summary, this invention not only represents technological innovation but also holds significant implications for application prospects. It opens up new technical solutions for fields such as anti-counterfeiting, machine learning, and virtual reality / augmented reality (VR / AR), and is expected to promote the development and application of related technologies.

[0064] Next, to illustrate how to fabricate and integrate polymer-stabilized cholesteric liquid crystals (PSCLCs) with different types of alternating current electroluminescent (ACEL) light source devices to achieve frequency-dynamically modulated circularly polarized light-emitting devices, two specific embodiments are provided.

[0065] In one specific embodiment, such as Figure 2 As shown, this is a polymer-stabilized cholesteric liquid crystal integrated AC-PEL powder electroluminescent device. The fabrication process of the AC-PEL light-emitting device is as follows:

[0066] Step 1: Preparation of substrate and lower electrode:

[0067] Material selection: ITO glass or ITO-PET is selected as the substrate.

[0068] Cleaning: Perform ultrasonic cleaning, followed by acetone, ethanol, and deionized water for 10-20 minutes each. Drying: Dry at 120°C for 10 minutes. Surface Treatment: Perform UV-ozone or O2 plasma treatment for 5-10 minutes to increase surface wettability and cleanliness.

[0069] Step 2: Preparation of dielectric-luminescent composite paste:

[0070] Solvent system: Select 1-2 of MEK, MIBK, cyclohexanone, ethyl acetate, NMP, and DMF. For flexible substrates, low-temperature volatile systems (MEK / MIBK) are preferred.

[0071] Medium binder phase: PVDF, PVDF-HFP, PVDF-TrFE, PVDF-TrFE-CFE, etc. are used, with a total solids content of 10-30 wt%.

[0072] Luminescent powder preparation: Use ZnS:Cu, ZnS:Cu,Cl, or ZnS:Cu,Al, with a particle size of 5-30. Additives: Dispersant (BYK / Solsperse, 0.26-1.0wt%), leveling agent / defoamer (0.05-0.3wt%), plasticizer (DBP / phosphate ester, 0-3wt%).

[0073] Mixing-dispersion: First, perform planetary mixing for 5-10 minutes, then perform three-roll milling or bead milling (ZrO2 particle size 0.3-0.5mm, 30-90 minutes, temperature not exceeding 30°C) until D90 is less than 35-40. To avoid screen clogging during printing, the viscosity is set according to process requirements.

[0074] Step 3: Film Formation (Dielectric-Light Emitting Composite Layer):

[0075] Screen printing: Use 200-325 mesh screen. Squeegee hardness: 70-0ShA. Gap: 1-2mm. Single wet film thickness: 20-60. Blade / slot coating: Target dry film thickness 20-80 mm Spin coating: Spin at 500 rpm for 5 seconds, then at 1500-2500 rpm for 30-60 seconds, repeating multiple times to achieve the target thickness; thus obtaining a uniform, dense, pinhole-free, and void-free composite layer, with high-medium filler uniformly coating the luminescent particles and forming a continuous medium phase.

[0076] Step 4: Drying and Shaping

[0077] Step-by-step drying: Dry at 60°C for 5 minutes. Dry at 90°C for 10 minutes. Dry at 110-130°C for 10-20 minutes; the temperature can be raised to 150°C for glass substrates. PVDF-TrFE / -CFE system: Hold at 90-110°C for 10-20 minutes; this ensures that residual solvent is less than 1 wt%, and the dry film thickness and sheet resistivity / dielectric loss meet design requirements.

[0078] Step 5: Upper electrode deposition / printing:

[0079] Vacuum evaporation: Al thickness 100-200nm or Ag thickness 80-150nm, for mask patterning. Conductive silver paste printing: thickness 8-20nm. Curing time is 10-20 minutes at 120-150°C. Transparent electrode: AgNW film: Spray coating or transfer printing. PEDOT:PSS: Spin coating thickness is 80-150nm, cured at 120°C for 10 minutes. Low-temperature sputtering of ITO at temperatures below 120°C can also be used.

[0080] The preparation process of the polymer-stabilized cholesteric liquid crystal in this embodiment is as follows:

[0081] Electrode fabrication stage:

[0082] Material Selection: Glass substrate plated with indium tin oxide (ITO) is used. Cleaning: Rigorous ultrasonic cleaning is performed, followed by 20 minutes each of acetone, ethanol, and deionized water. Surface Treatment: Ultraviolet ozone treatment is performed to thoroughly remove contaminants and enhance surface hydrophilicity.

[0083] Alignment layer processing stage:

[0084] Material Selection: Photo-aligned material PI was used. Coating: The film was uniformly coated onto the ITO surface via spin coating (800 rpm / 5 s pre-spreading, 3000 rpm / 40 s film formation). Annealing: The film was annealed at 100°C for 10 minutes to remove solvent and stabilize the film. Orientation Induction: Linearly polarized ultraviolet light (380 nm) was used to irradiate the film along the target orientation direction to induce anisotropy, providing precise orientation anchoring for the liquid crystal molecules.

[0085] Liquid crystal layer preparation stage:

[0086] Material mixing: Nematic liquid crystal E7, chiral dopant (R / S5011, doping concentration 0.35%), polymerizable liquid crystal monomer (RM257, addition amount 30wt%), and photoinitiator (Irgacure651, 0.5wt%) were heated and stirred at 80-100°C for 3 hours to form a homogeneous mixture. Wavelength determination: The concentration of the chiral agent directly determines the selective reflection wavelength of the cholesteric liquid crystal.

[0087] Packaging stage:

[0088] The above mixture is injected between two glass substrates coated with a transparent conductive layer (ITO) via capillary effect. Positioning: It is autonomously positioned and encapsulated under the action of hydrophilic-hydrophobic interfacial tension.

[0089] UV curing stage:

[0090] Conditions: Irradiation with 365nm ultraviolet light at a specific intensity (pre-curing at 1mW / cm² for 30 seconds, followed by complete curing at 7mW / cm² for 10 minutes) under a nitrogen atmosphere. This causes polymerizable monomers to crosslink and form a polymer network, stabilizing the cholesteric helical structure.

[0091] Final product: Under ultraviolet light irradiation, the prepolymer system solidifies into a uniform MCCP film, ultimately forming a polymer-stabilized cholesteric liquid crystal with a dense structure and highly uniform optical properties.

[0092] In another specific embodiment, a polymer-stabilized cholesteric liquid crystal integrated NCI-ACEL non-injection AC electroluminescent device is provided. The fabrication process of the NCI-ACEL light-emitting device is as follows:

[0093] Step 1: ITO electrode fabrication:

[0094] Material Selection: ITO transparent electrode (substrate) is selected, with a glass thickness of 0.5-0.7 mm and an ITO thickness of 100-150 nm. Cleaning: Rigorous ultrasonic cleaning is performed, followed by sequential cleaning with acetone, ethanol, and deionized water for 20 minutes each. Surface Treatment: Ultraviolet ozone treatment is performed to thoroughly remove contaminants and enhance surface hydrophilicity.

[0095] Step 2: Dielectric layer fabrication:

[0096] Material selection: Al2O3 is used as the dielectric layer. Preparation method: The Al2O3 dielectric layer is prepared by atomic layer deposition (ALD) technology, with a thickness of 30-80 nm (preferably 50-70 nm).

[0097] Step 3: Preparation of the hole injection layer:

[0098] Material selection: PEDOT:PSS with a high work function formulation such as Al 4083 was used as the hole injection layer (HIL). Preparation method: PEDOT:PSS was coated by spin coating to a thickness of 20-40 nm.

[0099] Step 4: Preparation of the hole transport layer:

[0100] Material selection: TCTA was used as the hole transport layer (HTL). Fabrication method: TCTA was deposited by vapor deposition to a thickness of 20-35 nm.

[0101] Step 5: Preparation of the quantum dot hybrid light-emitting layer:

[0102] Material selection: A blend of red and green quantum dots (R+G=1:9) was used as the luminescent layer. Preparation method: The quantum dot hybrid luminescent layer was coated by spin coating, with a total thickness of 25-45 nm.

[0103] Step 6: Fabrication of the electron transport layer:

[0104] Material selection: ZnO was used as the electron transport layer (ETL). Preparation method: The ZnO electron transport layer was prepared by colloidal nanoparticle film method or low-temperature ALD technology, with a thickness of 20-35 nm or 10-20 nm by low-temperature ALD.

[0105] Step 7: Top electrode fabrication:

[0106] Material selection: Al or Ag is used as the top electrode. Fabrication method: The top electrode is deposited by vapor deposition, with an Al thickness of 100-150 nm and an Ag thickness of 80-120 nm.

[0107] The process for preparing this polymer-stabilized cholesteric liquid crystal is as follows:

[0108] Electrode fabrication stage:

[0109] A glass substrate coated with indium tin oxide (ITO) is used. Rigorous ultrasonic cleaning is performed, followed by 20 minutes each of acetone, ethanol, and deionized water. Ultraviolet ozone treatment is then applied to thoroughly remove contaminants and enhance surface hydrophilicity.

[0110] Alignment layer processing stage:

[0111] Using photo-oriented material PI.

[0112] The coating was uniformly applied to the ITO surface by spin coating (800 rpm / 5s pre-spreading, 3000 rpm / 40s film formation).

[0113] Anneal at 100°C for 10 minutes to remove solvent and stabilize the film.

[0114] Linearly polarized ultraviolet light at 380 nm is used to irradiate along the target orientation direction to induce anisotropy, providing precise orientation anchoring for liquid crystal molecules.

[0115] Liquid crystal layer preparation stage:

[0116] Nematic liquid crystal E7, chiral dopant (R / S5011, doping concentration 0.35%), polymerizable liquid crystal monomer (RM257, addition amount 30wt%), and photoinitiator (Irgacure 651, 0.5wt%) were heated and stirred at 80-100°C for 3 hours to form a homogeneous mixture. The concentration of the chiral agent directly determines the selective reflection wavelength of the cholesteric liquid crystal.

[0117] Packaging stage:

[0118] The mixture is injected between two glass substrates coated with an inductively conductive layer (ITO) via capillary action. This allows the substrate to autonomously position itself and complete encapsulation under the influence of hydrophilic-hydrophobic interfacial tension.

[0119] UV curing stage:

[0120] Under a nitrogen atmosphere, the polymer was irradiated with 365nm ultraviolet light at a specific intensity (pre-curing at 1mW / cm² for 30 seconds, followed by complete curing at 7mW / cm² for 10 minutes). This caused the polymerizable monomers to crosslink and form a polymer network, stabilizing the cholesteric helical structure. Under ultraviolet light irradiation, the prepolymer system cured into a uniform MCCP film. Ultimately, a polymer-stabilized cholesteric liquid crystal with a dense structure and highly uniform optical properties was formed.

[0121] In the above embodiments, Figure 3 The circular dichroism spectral characteristics of the liquid crystal material at different frequencies are shown in all embodiments. Spectroscopy is an important technique for studying the chirality (optical activity) of a substance; it reflects the chiral characteristics of a substance by measuring the difference in absorption of left-handed and right-handed circularly polarized light. From... Figure 3 As observed, the liquid crystal material exhibits specific circular dichroism signals with changing frequency, confirming that the configured liquid crystal material possesses significant optical activity. Optical activity means that the material can selectively absorb or scatter circularly polarized light with different directions of rotation, which is the basis for generating circularly polarized light.

[0122] like Figure 4 As shown, the circularly polarized emission signal is measured after the light emitted by the device is selectively filtered by a chiral liquid crystal layer. Circularly polarized emission refers to the device's ability to emit circularly polarized light with a specific rotation direction (left-handed or right-handed). This demonstrates that the chiral liquid crystal layer can effectively and selectively filter light, giving the output light circularly polarized characteristics. This is a crucial step in achieving circularly polarized light emission and is essential for many optical applications.

[0123] like Figure 5 As shown, the emission asymmetry factor G is an important indicator for measuring the purity of circularly polarized light. The higher the G value, the higher the purity of the circularly polarized light. Figure 4 The light emission asymmetry factor G of the device under different conditions is shown. Figure 5The displayed G value is as high as 1.5, indicating that the device can generate circularly polarized light with extremely high purity. The G value directly reflects the quality of circularly polarized light; a high G value means that the device performs excellently in generating circularly polarized light, which is crucial for applications requiring high-purity circularly polarized light (such as optical communication and quantum computing).

[0124] like Figure 6 As shown, the curves of the device's g-value as a function of frequency are presented under different center wavelength conditions (470-600nm). The g-value here likely refers to a parameter related to circular polarization performance; its specific meaning can be determined through specific experiments. Figure 5 The study further revealed the device's dynamic control capability, showing that the g-value of the device exhibited a significant response to frequency changes at different center wavelengths. This means that the circular polarization performance of the device can be controlled by changing the frequency; and at specific frequencies, the g-value can reach above 2.0. This indicates that the circular polarization performance can be actively modulated by changing the frequency of the AC electric field. This dynamic control capability is a key characteristic for realizing variable color circularly polarized light-emitting devices, providing solid data support for the practical application of the device. In other words, the characteristics of the device's emitted circularly polarized light can be adjusted in real time as needed to meet the requirements of different application scenarios.

[0125] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A frequency-dynamically modulated independent chiral liquid crystal optical device, characterized in that, include: Conductive substrate; An alignment layer coated on a conductive substrate; A polymer-stabilized cholesteric phase liquid crystal layer was prepared by injecting a precursor mixture between two conductive substrates. The precursor mixture is made of a nematic liquid crystal matrix, a chiral dopant, a polymerizable liquid crystal monomer, and a photoinitiator; and the pitch of the cholesteric liquid crystal layer is dynamically controlled by the frequency of the alternating electric field, thereby achieving dynamic adjustment of its selective reflection center wavelength; Electrodes are used to apply an alternating electric field to achieve dynamic control of the pitch of the cholesteric liquid crystal layer.

2. A method for fabricating an independent chiral liquid crystal optical device based on frequency dynamic modulation, characterized in that, include: S1. The conductive substrate is pretreated and surface treated sequentially to enhance its hydrophilicity and wettability. S2. Coating an alignment layer on a conductive substrate and inducing anisotropic orientation anchoring of the alignment layer by ultraviolet light irradiation; S3. A precursor mixture is formed by mixing a nematic liquid crystal matrix, a chiral dopant, a polymerizable liquid crystal monomer, and a photoinitiator. The precursor mixture is then injected between two conductive substrates to form a polymer-stable cholesteric liquid crystal layer. The selective reflection center wavelength of the cholesteric liquid crystal is adjusted by regulating the concentration of the chiral dopant. S4. The polymer-stabilized cholesteric liquid crystal layer is cured under ultraviolet light to form a polymer network, thereby stabilizing the helical structure of the cholesteric liquid crystal layer.

3. The method for fabricating an independent chiral liquid crystal optical device based on frequency dynamic control according to claim 2, characterized in that, Step S1 further includes the following sub-steps: S101. Select a glass substrate coated with indium tin oxide (ITO) or a transparent conductive material as the substrate. S102. Pre-treat the conductive substrate by ultrasonic cleaning with acetone, ethanol and deionized water in sequence, with the cleaning time for each solvent controlled at 15-20 minutes. S103. Remove the conductive substrate and dry it to remove residual moisture and impurities from the surface. Perform surface treatment on the cleaned substrate by ultraviolet ozone treatment for 10-15 minutes or oxygen plasma treatment for 30-60 seconds to enhance the hydrophilicity and wettability of the substrate.

4. The method for fabricating an independent chiral liquid crystal optical device based on frequency dynamic control according to claim 2, characterized in that, Step S2 further includes the following sub-steps: S201. Select a photo-aligned material and use a spin coating process to uniformly coat the film onto the surface of the substrate ITO. The spin coating is divided into two stages: first, spin at 800 rpm for 5-6 seconds for pre-spreading, and then spin at 3000 rpm for 35-45 seconds to form a uniform film and uniformly coat the film onto the substrate surface. S202. Anneal the substrate in an oven at 100°C for 10-12 minutes to remove solvent and stabilize the film. S203 uses linearly polarized ultraviolet light with a wavelength of 355-405nm to irradiate along a preset target orientation direction, inducing anisotropy and providing precise orientation anchoring for liquid crystal molecules.

5. The method for fabricating an independent chiral liquid crystal optical device based on frequency dynamic control according to claim 3, characterized in that, Step S3 further includes the following sub-steps: S301. Mix nematic liquid crystal matrix E7, chiral dopant R / S5011, polymerizable liquid crystal monomer RM257 and photoinitiator Irgacure 651 in proportion, and stir magnetically at 80-100°C for 2-3 hours. After complete dissolution, form a clear and homogeneous precursor mixture with the homogenate. S302. The concentration of the chiral dopant and the selective reflection center wavelength of the cholesteric liquid crystal satisfy the following approximate relationship: The approximate relationship expression is as follows: （1） in, Indicates the selective reflection center wavelength. Indicates the average refractive index. The pitch of a cholesteric liquid crystal is represented by the mole fraction of the chiral dopant and the pitch. They are approximately inversely proportional; S303. By controlling the concentration of the chiral dopant, the selective reflection of the center wavelength is achieved. Adjust to the target band; S304. The precursor mixture is injected between two glass substrates coated with indium tin oxide (ITO) through capillary effect, and the interlayer spacing is controlled by spacer microspheres. The typical particle size of the spacer microspheres is 30-40 micrometers, and the surface density of the spacer microspheres is 50-200 microspheres / cm². S305. Use UV-curable adhesive for edge sealing, leaving only the injection port. After the mixture fills the cavity, perform a second sealing to ensure that the cavity is free of air bubbles and contamination.

6. The method for fabricating an independent chiral liquid crystal optical device based on frequency dynamic control according to claim 5, characterized in that, Step S4 further includes the following sub-steps: S401. Under nitrogen or inert atmosphere, use 365nm ultraviolet light for two-step curing: first, pre-curing with a light intensity of 1mW / cm² for 30-120 seconds; then, complete curing with a light intensity of 5-10mW / cm² for 5-10 minutes to form a polymer network, thereby stabilizing the helical structure of the cholesteric liquid crystal layer and suppressing distortion caused by external field or temperature fluctuations. S402, cured at 30-35°C to maintain planar single-domain texture, or post-cured at 60-80°C to fine-tune the selected reflection bandwidth, resulting in a uniform, low-scattering thickness of 30-40 mm. Single-domain PSCLC thin films.

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