Artificial synaptic device based on chiral perovskite and preparation method thereof

Abstract

The invention relates to an artificial synaptic device based on chiral perovskite and a preparation method thereof. The device sequentially comprises a substrate, a comb-shaped bottom electrode, a chiral perovskite functional layer and a comb-shaped top electrode from bottom to top, wherein the projection direction of the bottom electrode comb teeth and the projection direction of the top electrode comb teeth are crossed at an angle of 90 degrees; the chemical general formula of the chiral perovskite functional layer is A < 1-x > A'x PbX3, A is a chiral organic cation, A 'is an achiral organic cation, and X is one or more of Cl <->, Br <-> and I. The device obtained by the invention can respond to a chiral optical signal and complete processing and storage of chiral information, and has an excellent brain synaptic-like function at the same time.

Description

Technical Field

[0001] This invention relates to the field of electronic devices, and in particular to artificial synaptic electronic devices and their systematic applications. Background Technology

[0002] With the rapid development of artificial intelligence, neuromorphic computing, and other fields, traditional electronic devices based on the von Neumann architecture have become increasingly inadequate to meet the demands of high parallelism, low power consumption, and biomimetic intelligent computing due to bottlenecks such as separation of storage and computation, data transmission latency, and excessive power consumption. Artificial synaptic devices, as core units simulating the function of human brain synapses, can integrate signal reception, processing, and storage, and are considered a key support for building next-generation neuromorphic computing systems, thus becoming a research hotspot in the field of electronic devices in recent years. An ideal artificial synaptic device needs to possess core characteristics similar to biological synapses, such as synaptic plasticity (including long-term potentiation (LTP), long-term inhibition (LTD), and short-term plasticity), low power consumption, high stability, and good scalability. To achieve these characteristics, researchers have explored various material systems for fabricating artificial synaptic devices. Among them, perovskite materials, with their outstanding advantages such as excellent photoelectric conversion efficiency, high carrier mobility, tunable band structure, and solution-based fabrication, show broad application prospects in the field of artificial synaptic devices.

[0003] However, most existing perovskite-based artificial synaptic devices use non-chiral perovskite materials (e.g., Zhang Peng, Chen Gengxu. Fabrication and performance study of artificial photosynaptic transistors based on two-dimensional ferroelectric perovskite [J]. Journal of Functional Materials and Devices, 2025, 31(01):64-69.DOI:10.20027 / j.gncq.2025.0007., Rong Yang. Research on interface regulation of tin-based perovskite transistors and their application in neuromorphic optoelectronic devices [D]. Harbin Institute of Technology, 2025.), and their functions mainly rely on the regulation of traditional physical and chemical signals such as photoelectric and electrical signals, making it difficult to simulate biomimetic functions such as chiral recognition that are common in biological systems. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing photoelectric synaptic devices in achieving chiral information transmission and processing by providing an artificial synaptic device based on chiral perovskite and its fabrication method. This device uses chiral perovskite as the photoelectric conversion layer, coupled with a precisely matched structure of "comb-shaped transparent bottom electrode - chiral perovskite functional layer - comb-shaped metal top electrode," with the bottom and top electrodes perpendicularly intersecting at 90°. During fabrication, the perpendicularly intersecting comb-shaped electrodes are fabricated by precisely controlling the ratio of chiral organic cation salts to non-chiral organic cation salts, combined with precise film formation techniques such as mask magnetron sputtering or electron beam evaporation. The device obtained by this invention can respond to chiral light signals and complete the processing and storage of chiral information, while also possessing excellent neuromorphic synaptic functions.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: An artificial synaptic device based on chiral perovskite comprises, from bottom to top, a substrate, a comb-shaped bottom electrode, a chiral perovskite functional layer, and a comb-shaped top electrode, forming a core multilayer structure of "substrate-bottom electrode-chiral perovskite functional layer-top electrode". Among them, the projection direction of the bottom electrode comb teeth intersects the projection direction of the top electrode comb teeth at 90°. The substrate is a rigid substrate or a flexible substrate; The rigid substrate is either optical glass or sapphire substrate; The flexible substrate is one of polyethylene terephthalate (PET), polyimide (PI), and polyethylene naphthalate (PEN).

[0006] The comb-shaped bottom electrode is a transparent conductive electrode, derived from one of ITO, FTO, or aluminum-doped zinc oxide (AZO). These materials have high light transmittance (visible light transmittance ≥85%), low sheet resistance (≤20Ω / □), and good conductivity. The thickness of the bottom electrode is 50-200nm.

[0007] The top electrode is a metal electrode, one of gold (Au), silver (Ag), or platinum (Pt); its thickness is 30-100 nm.

[0008] The general chemical formula of the chiral perovskite functional layer is A. 1-x A ’ x PbX3; Wherein: A is a chiral organic cation, specifically one of (R)-(-)-1-phenylethylamine ion and (S)-(+)-1-phenylethylamine ion; A' is a non-chiral organic cation selected from methylamine ions (MA). + CH3NH3 + ), formamidinium ion (FA) + CH(NH2)2 + One of them; X is Cl - ,Br - I - One or more of the following; the range of x is 0 ≤ x < 1; The thickness of the chiral perovskite functional layer is controlled to be 50-500 nm.

[0009] The method for fabricating the artificial synaptic device based on chiral perovskite includes the following steps: Step 1: Substrate pretreatment: The substrate is placed in acetone, ethanol and deionized water in sequence for ultrasonic cleaning. Each ultrasonic cleaning time is 15-30 minutes and the ultrasonic power is 80-120W. Step 2: Bottom electrode preparation: Select the corresponding preparation process according to the substrate type, and prepare the bottom electrode on the surface of the pretreated substrate by mask magnetron sputtering or electron beam evaporation; after the bottom electrode is prepared, place it in an annealing furnace and anneal at 100-200℃ for 30-60 minutes in an air or nitrogen atmosphere to obtain a comb-shaped bottom electrode. The process parameters for magnetron sputtering are: sputtering power 200-300W, sputtering pressure 0.3-0.5Pa, sputtering temperature at room temperature, and target-substrate distance 8-12cm; the process parameters for electron beam evaporation are: vacuum degree ≤5×10⁻⁶. -4 Pa, evaporation rate 0.1-0.5 nm / s.

[0010] Step 3: Preparation of chiral perovskite functional layer: According to the proportions in the general chemical formula of the chiral perovskite functional layer, chiral organic cation salts, non-chiral organic cation salts, lead salts, and halogen salts are dissolved in a solvent and stirred under a nitrogen atmosphere for 2-6 hours at a stirring temperature of 30-50℃ to obtain a chiral perovskite precursor solution. Subsequently, the precursor solution is coated onto the surface of the bottom electrode by spin coating or blade coating. After coating, solvent annealing is performed first by placing the sample in the vapor of the solvent used in the precursor solution and annealing at room temperature for 5-30 minutes. After solvent annealing, thermal annealing is performed under an atmosphere at 60-120℃ for 10-60 minutes to obtain the chiral perovskite functional layer. Specifically, the chiral organic cation salt is (R)-(-)-1-phenylethylamine ion or (S)-(+)-1-phenylethylamine ion; The non-chiral organic cation salt is specifically MA + or FA + ; Halogenated lead salts are lead iodide or lead bromide; The concentration of the precursor solution is 0.8-1.5 mol / L; The spin coating process parameters are: rotation speed 3000-5000 r / min, spin coating time 20-40 s, and drop volume 50-100 μL; The spraying process parameters are: scraper running speed 5-15mm / s, scraper gap 50-150μm. Step 4: Top Electrode Fabrication: Place the sample with the bottom electrode and chiral perovskite functional layer into a vacuum coating apparatus. Fabricate the top electrode on the surface of the chiral perovskite functional layer obtained in Step 3 using mask magnetron sputtering or electron beam evaporation. The direction of the top electrode comb teeth intersects the bottom electrode comb teeth at a 90° angle. After the top electrode is fabricated, post-annealing can be performed as needed (annealing temperature 60-100℃, annealing time 10-20 min, nitrogen atmosphere). The process parameters for magnetron sputtering are: sputtering power 100-200W, sputtering gas pressure 0.2-0.4Pa, sputtering temperature at room temperature, and target-substrate distance 8-10cm. The process parameters for electron beam evaporation are: vacuum degree ≤ 5 × 10⁻⁶. -4 Pa, evaporation rate 0.05-0.2 nm / s; the pattern and size of the top electrode are controlled by a mask during the fabrication process; The effective area of ​​both electrodes is 0.01-0.1 cm². 2 .

[0011] The solvent for the chiral perovskite precursor solution in step 3 is one or more mixed solvents selected from N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and γ-butyrolactone; wherein, when a mixed solvent is used, the volume ratio of DMF to DMSO is preferably 3:1-5:1.

[0012] The application of the artificial synaptic device based on chiral perovskite is characterized by its use as a core unit of the next-generation brain-like computing system. It can be used to construct a neuromorphic chip with chiral recognition function, solve the bottleneck of storage and operation separation in the traditional von Neumann architecture, and realize accurate signal classification and multi-dimensional information fusion processing in complex vector light environments.

[0013] The essential features of this invention are as follows: This invention overcomes the technical limitations of existing optoelectronic synaptic devices, which can only process basic optical information such as light intensity and wavelength. Through material innovation and structural optimization, it constructs a novel artificial synaptic device that combines chiral information processing capabilities with excellent brain-like synaptic functions. Its core substantive features are reflected in the following three aspects: 1. This invention is the first to use chiral organic-inorganic hybrid perovskite materials as the core functional layer of an artificial synaptic device, creatively integrating chiral optical activity with photoelectric synaptic performance. Unlike existing photoelectric materials such as metal oxides and ordinary two-dimensional materials that lack chiral characteristics, chirality is one of the fundamental characteristics of life activities. The chiral structure of biomolecules (such as amino acids and sugars) determines the specificity of their physiological functions, and the signal transmission process of neural synapses is also closely related to the recognition and interaction of chiral molecules. The chiral perovskite material selected in this invention, through the introduction of chiral organic cations (such as (R)-(-)-1-phenylethylamine ions and (S)-(+)-1-phenylethylamine ions), endows the material with chiral optical activity that specifically recognizes left-handed / right-handed circularly polarized light, realizing the integrated function of "chiral recognition-photoelectric conversion-synaptic weight regulation," thus overcoming the core technical bottleneck of existing devices being unable to process chiral information at the material level.

[0014] 2. This invention designs a layered core structure of "transparent bottom electrode - chiral perovskite functional layer - metal top electrode", achieving synergistic performance through precise matching of components and parameters of each layer. At the same time, by controlling the thickness of the functional layer (50-500nm), the light absorption efficiency and carrier transport efficiency are balanced, ensuring that the device has both excellent chiral recognition performance and synaptic plasticity (such as short-term plasticity, long-term plasticity, and pulse time-dependent plasticity).

[0015] 3. The fabrication process is compatible with industrial applications. The fabrication method provided by this invention adopts mature microelectronic processes such as magnetron sputtering, electron beam evaporation, and spin coating. Through a process route of "gradient cleaning - plasma activation - layered fabrication - precise annealing," it achieves efficient device fabrication. The maximum process temperature does not exceed 200℃, and it is compatible with both rigid (ITO glass, silicon wafers) and flexible (PET, PI) substrates, overcoming the limitations of existing synaptic device fabrication processes that require high temperatures and are only compatible with a single substrate. At the same time, the combination of solvent annealing and thermal annealing optimizes the perovskite crystal quality, reduces defect density, and improves device stability.

[0016] 4. Through innovation in materials and structure, this invention upgrades artificial synaptic devices from traditional "basic optical information processing" to "chiral optical information processing," endowing neuromorphic systems with entirely new chiral recognition and information processing functions, thus breaking through the application boundaries of existing neuromorphic systems.

[0017] The beneficial effects of this invention are as follows: 1. Breakthrough in Chiral Recognition and Information Processing Functions: This invention innovatively uses chiral perovskite materials as the core functional layer, utilizing their unique chiral optical activity (such as circular dichroism and optical rotation) to enable the device to specifically respond to left-handed or right-handed circularly polarized light signals, achieving accurate recognition of different chiral light signals. This breaks through the limitation of existing photoelectric synaptic devices that can only process basic information such as natural light intensity and wavelength, endowing the neuromorphic system with a brand-new function of chiral information processing.

[0018] 2. Excellent neuromorphic synaptic performance and stability: The chiral synaptic device possesses excellent synaptic plasticity and can stably realize core neuromorphic synaptic functions such as pulse number-dependent plasticity (SNDP) and pulse frequency-dependent plasticity (SFDP). Figure 2-7 Furthermore, by optimizing the composition and fabrication process of the chiral perovskite, the device exhibits excellent mechanical stability (synaptic performance degradation ≤3% after 100 bending tests), providing a high-quality device foundation for constructing a high-performance, high-reliability neuromorphic computing system. Figure 8 ). Attached Figure Description

[0019] Figure 1 This is a schematic diagram of an artificial synaptic device based on chiral perovskite; the left side is a top view; the right side is a triaxial view. 1-Substrate; 2-Comb-shaped bottom electrode; 3-Chiral perovskite layer; 4-Comb-shaped top electrode perpendicular to the bottom electrode at 90 degrees.

[0020] Figure 2 This is a graph showing the photocurrent test results of the chiral perovskite artificial synaptic device in Example 1 under a single left / right chiral light, used to mimic the excitatory postsynaptic current (EPSC) of a nerve under a single spike.

[0021] Figure 3 The graph shows the photocurrent test results of the chiral perovskite artificial synaptic device in Example 2 under a single left / right chiral light, used to simulate the excitatory postsynaptic current (EPSC) of nerves under a single spike.

[0022] Figure 4 The image shows the photocurrent results of the chiral perovskite artificial synaptic device in Example 1 under stimulation by 10 consecutive left-handed light at frequencies of 2 / 4 / 6 Hz, used to mimic pulse frequency-dependent plasticity.

[0023] Figure 5 The image shows the photocurrent results of the chiral perovskite artificial synaptic device in Example 1 under 5 / 10 / 15 left-handed chiral light stimulations, used to mimic pulse number-dependent plasticity.

[0024] Figure 6The image shows the photocurrent results of the chiral perovskite artificial synaptic device in Example 2 under stimulation by 10 consecutive right-handed light at frequencies of 2 / 4 / 6 Hz, used to mimic pulse frequency-dependent plasticity.

[0025] Figure 7 The image shows the photocurrent results of the chiral perovskite artificial synaptic device in Example 2 under 5 / 10 / 15 right-handed chiral light stimulations, used to mimic pulse number-dependent plasticity.

[0026] Figure 8 This is the result of the change in postsynaptic current of nerve excitability under a single peak after bending 0-100 times in chiral perovskite in Example 2. Detailed Implementation

[0027] The present invention will be specifically illustrated below with specific examples. These examples will help those who are interested in the research and thinking of the present invention, but will not limit the present invention in any way.

[0028] In this invention, the bottom electrode and the top electrode serve as the two electrical terminals of the device, respectively. The bottom electrode and the top electrode are perpendicular to each other at 90°, used to apply an external electric field and collect carrier signals in the device. The chiral perovskite functional layer is the core functional unit of the device. It is made of perovskite material with high chiral optical activity and excellent photoelectric properties. It can specifically respond to left-handed or right-handed circularly polarized light signals. Through the generation, transport and capture / release of photoinduced carriers, it realizes the dynamic control of chiral recognition and photoinduced synaptic weights, thereby completing the functions of chiral information transmission, processing and storage.

[0029] The substrate provides a stable support for the device, and a rigid or flexible substrate can be selected according to the actual application scenario requirements. The rigid substrate has good flatness, high temperature resistance and mechanical strength, and can provide a stable base for the subsequent fabrication of electrodes and functional layers. It is suitable for fixed scenarios with high requirements for device mechanical stability (such as desktop neuromorphic computing modules). The flexible substrate has good flexibility, lightweight and bendability, and also has a certain degree of high temperature resistance. It is compatible with the fabrication process of flexible devices and is suitable for emerging application scenarios such as wearable devices and flexible electronics.

[0030] The comb-shaped bottom electrode is a transparent conductive electrode. Its transparency ensures that the light signal can pass smoothly through and reach the chiral perovskite functional layer, realizing effective coupling of light and electrical signals. This type of material has high light transmittance (visible light transmittance ≥85%), low sheet resistance (≤20Ω / □) and good conductivity, which can efficiently collect and transport charge carriers. The thickness of the bottom electrode is controlled between 50-200 nm. When the thickness is less than 50 nm, the electrode continuity is poor and the conductivity and transmittance are unstable. When the thickness is greater than 200 nm, the electrode brittleness increases and the transmittance decreases significantly, affecting the light modulation effect.

[0031] The top electrode is a metal electrode with excellent conductivity, good chemical stability and film-forming properties, which can ensure the long-term stable operation of the device. The chiral perovskite functional layer is the core of the device's chiral recognition and synaptic functions. Its material is selected from chiral organic-inorganic hybrid perovskite, with the general chemical formula A. 1-x A' x PbX3, where: A is a chiral organic cation, a key component endowing perovskite materials with chiral optical activity; the introduction of chiral organic cations can regulate the crystal structure and chiral optical properties of perovskite materials; A' is a non-chiral organic cation, used to regulate the crystal stability and photoelectric properties of perovskite materials; Pb is lead ion, a core component of the inorganic metal cation framework, forming a stable perovskite crystal structure with halide ions; X is halide ion, and by regulating the type and ratio of halide ions, the band gap width of perovskite materials can be precisely controlled (the band gap width can be adjusted between 1.5-2.3 eV), thereby matching the chiral optical signal response requirements of different wavelength bands; the value of x ranges from 0 ≤ x < 1, and by adjusting the ratio of A and A', the crystal quality and photoelectric properties of the material can be optimized while ensuring the chiral optical activity of the material. The thickness of the chiral perovskite functional layer is controlled to be 50-500 nm. If the thickness is too small, it will result in insufficient light absorption, low carrier generation efficiency, and weak synaptic signal response. If the thickness is too large, it will increase the carrier transport path, leading to an increased carrier recombination probability. At the same time, it may introduce more crystal defects, affecting the synaptic plasticity and stability of the device.

[0032] Example 1: Fabrication of Left-Hydrochilled Perovskite Artificial Synaptic Devices Based on Rigid Substrates 1. Substrate pretreatment: 1.5cm×1.5cm optical glass was selected as a rigid substrate and ultrasonically cleaned in acetone, ethanol and deionized water in sequence. Each ultrasonic cleaning time was 20min and the ultrasonic power was 100W. After ultrasonic cleaning, the substrate was dried in a nitrogen atmosphere and then placed in a plasma cleaner. A mixture of argon and oxygen (volume ratio 3:1) was introduced and the processing power was set to 80W for 10min to obtain a clean and highly active optical glass substrate.

[0033] 2. Bottom Electrode Fabrication: An ITO bottom electrode was fabricated on the surface of a pretreated optical glass substrate using magnetron sputtering. The sputtering parameters were: sputtering power 250 W, sputtering pressure 0.4 Pa, sputtering temperature at room temperature, and target-substrate distance 10 cm. After fabrication, the sample was placed in an annealing furnace and annealed in air at 150 °C for 45 min, resulting in an ITO bottom electrode with a thickness of 100 nm (transmittance ≥88%, sheet resistance ≤15 Ω / □). The comb-shaped electrode had a tooth width of 80 μm, a tooth pitch of 80 μm, and 20 teeth with a tooth length of 5 mm, resulting in an effective area of ​​0.08 cm². 2 .

[0034] 3. Fabrication of chiral perovskite functional layers: (1) Preparation of precursor solution: (R)-(-)-1-phenylethylamine iodide (chiral organic cation salt), methylamine iodide (MAI, non-chiral organic cation salt), and lead iodide (PbI2) were selected as raw materials and prepared according to the stoichiometric ratio A 0.8 A' 0.2 PbX3 (A is (R)-(-)-1-phenylethylamine ion, A' is MA) + X is I - Weigh the raw material and dissolve it in a mixed solvent of DMF and DMSO (volume ratio 4:1). Stir at 40°C for 4 hours under a nitrogen atmosphere to obtain A. 0.8 A' 0.2 A homogeneous, transparent, levorotatory chiral perovskite precursor solution with a PbX3 concentration of 1.2 mol / L; (2) Coating and annealing: The above precursor solution was coated onto the substrate surface after ITO bottom electrode deposition by spin coating. The spin coating process parameters were: rotation speed 4000 r / min, spin coating time 30 s, and drop volume 80 μL. After coating, the sample was placed in a DMF vapor atmosphere for solvent annealing for 15 min. Then, it was thermally annealed in a nitrogen atmosphere at a temperature of 80 °C for 30 min, finally forming a left-handed chiral perovskite functional layer with a thickness of 200 nm.

[0035] 4. Top Electrode Fabrication: The sample with the bottom electrode and chiral perovskite functional layer was placed in a vacuum coating apparatus, and an Au top electrode was fabricated on the surface of the functional layer using electron beam evaporation. The evaporation process parameters were: vacuum degree ≤ 5 × 10⁻⁶. -4 Pa, evaporation rate 0.1 nm / s; the comb electrode has 20 teeth with a tooth width of 80 micrometers, a tooth pitch of 80 micrometers, and a tooth length of 5 millimeters, resulting in an effective area of ​​0.08 cm². 2The thickness is 60 nm, and the orientation is perpendicular to the bottom electrode at 90°. After the fabrication is completed, it is annealed in a nitrogen atmosphere at a temperature of 80°C for 15 min to finally obtain a left-handed chiral perovskite artificial synapse device based on a rigid substrate.

[0036] Example 2: Fabrication of right-handed chiral perovskite artificial synaptic devices based on flexible substrates 1. Substrate pretreatment: A 2cm×2cm PET film was selected as the flexible substrate and ultrasonically cleaned in acetone, ethanol and deionized water in sequence. Each ultrasonic cleaning time was 15 minutes and the ultrasonic power was 80W. After ultrasonic cleaning, the substrate was dried with nitrogen and then subjected to plasma treatment. The treatment gas was a mixture of argon and oxygen (volume ratio 3:1) with a treatment power of 60W and a treatment time of 8 minutes to obtain a clean PET flexible substrate.

[0037] 2. Bottom Electrode Fabrication: An AZO bottom electrode was fabricated on the surface of a pretreated PET substrate using a spray coating method. The concentration of the precursor solution was 0.8 mol / L, the spraying temperature was 180℃, and the spraying pressure was 0.3 MPa. After fabrication, the electrode was annealed under a nitrogen atmosphere at 120℃ for 30 min to obtain an AZO bottom electrode with a thickness of 80 nm (transmittance ≥86%, sheet resistance ≤18 Ω / □). The comb-shaped electrode has a tooth width of 80 μm, a tooth pitch of 80 μm, and 20 teeth with a tooth length of 5 mm, resulting in an effective area of ​​0.08 cm². 2 .

[0038] 3. Fabrication of chiral perovskite functional layers: (1) Preparation of precursor solution: (S)-(+)-1-phenylethylamine bromide (chiral organic cation salt), formamidinium iodide (FAI, non-chiral organic cation salt), and lead bromide (PbBr2) were selected as raw materials and prepared according to the stoichiometric ratio A 0.9 A' 0.1 PbX3 (A is (S)-(+)-1-phenylethylamine ion, A' is FA) + X is Br - Weigh the raw material, dissolve it in γ-butyrolactone solvent, and stir at 35°C for 3 hours under a nitrogen atmosphere to obtain A. 0.9 A' 0.1 A homogeneous, transparent, dextrorotatory chiral perovskite precursor solution with a PbX3 concentration of 1.0 mol / L; (2) Coating and annealing: The precursor solution was coated onto the substrate surface after the AZO bottom electrode was prepared by the blade coating method. The blade coating speed was 10 mm / s and the blade coating gap was 100 μm. After coating, the substrate was placed in a γ-butyrolactone vapor atmosphere for solvent annealing for 20 min. Then, it was thermally annealed in a nitrogen atmosphere at a temperature of 70 °C for 40 min to form a right-handed chiral perovskite functional layer with a thickness of 150 nm.

[0039] 4. Top Electrode Fabrication: The Ag top electrode was fabricated using magnetron sputtering. The sputtering parameters were: sputtering power 150 W, sputtering pressure 0.3 Pa, room temperature sputtering, and target-substrate distance 9 cm. The comb electrode had a tooth width of 80 μm, a tooth pitch of 80 μm, a tooth length of 5 mm (20 teeth in total), and an effective area of ​​0.08 cm². 2 The thickness is 50nm, and the orientation is perpendicular to the bottom electrode at 90°. The post-annealing parameters are: nitrogen atmosphere, 70℃, 12min, and finally a right-handed chiral perovskite artificial synapse device based on a flexible substrate is obtained.

[0040] Performance testing and experimental results analysis: The performance of the devices prepared in Examples 1 and 2 was tested using a Keithley 4200A-SCS semiconductor analysis and testing system in a closed, nitrogen-filled glove box at an ambient temperature of 25 degrees Celsius. The results are as follows: 1. Chirality recognition performance: The device in Example 1 recognizes left-handed circularly polarized light (wavelength 340nm, 1 μW / cm²). 2 It exhibits a specific response, with an excitatory post-excitation current (EPSC) of 2.95 nA under a single left-handed optical pulse, and a weaker response of 2.45 nA to right-handed circularly polarized light. Figure 2 The device in Example 2 exhibits a responsivity of 2.71 nA for right-handed circularly polarized light and a weaker response of 2.50 nA for left-handed circularly polarized light, demonstrating that the device possesses efficient chiral recognition capability. Figure 3 ); 2. Synaptic Performance: Both devices can stably achieve core brain-like synaptic functions such as pulse number-dependent plasticity and pulse frequency-dependent plasticity. The device in Example 1 exhibits significant superposition characteristics under left-handed pulsed light stimulation at frequencies of 2 / 4 / 6 Hz. Figure 4 The maximum current can reach 19.76 nA; under left-handed pulsed light stimulation with stimulation numbers of 5 / 10 / 15, the maximum current is directly proportional to the stimulation number. When the stimulation number is 15, the current is 28.33 nA. Figure 5 The device in Example 2 also exhibits significant superposition characteristics under right-handed pulsed light stimulation at frequencies of 2 / 4 / 6 Hz, with a maximum current reaching 18.53 nA. Figure 6Under right-handed pulsed light stimulation with stimulation numbers of 5 / 10 / 15, the maximum current is directly proportional to the stimulation number. When the stimulation number is 15, the current is 22.82 nA. Figure 7 ).

[0041] 3. Stability: The flexible device in Example 2 exhibits a performance degradation of ≤3% after 100 bending cycles, demonstrating good flexibility tolerance. Figure 8 ).

[0042] As can be seen from the above embodiments, the present invention utilizes chiral organic-inorganic hybrid perovskite as the core functional layer of the device, endowing the material with chiral optical activity that specifically recognizes left-handed / right-handed circularly polarized light. This solves the core defect of existing devices that can only process basic information such as light intensity and wavelength and cannot achieve chiral recognition. This lays the foundation for future applications in fields such as high-density, high-security optical storage and dense communication using left-handed / right-handed circularly polarized light as information carriers.

[0043] The above implementation examples and test results are intended to provide researchers in related fields with a certain research foundation. Any other actions that do not involve substantial research changes, including modifications, simplifications, substitutions, and other simple changes to experimental conditions, should be protected within the scope of this invention.

[0044] Matters not covered in this invention are common knowledge.

Claims

1. An artificial synaptic device based on chiral perovskite, characterized in that, The device comprises, from bottom to top, a substrate, a comb-shaped bottom electrode, a chiral perovskite functional layer, and a comb-shaped top electrode. Among them, the projection direction of the bottom electrode comb teeth intersects the projection direction of the top electrode comb teeth at 90°. The general chemical formula of the chiral perovskite functional layer is A. 1-x A ’ x PbX3; Wherein: A is a chiral organic cation, which is (R)-(-)-1-phenylethylamine ion or (S)-(+)-1-phenylethylamine ion; A' is a non-chiral organic cation, specifically a methylamine ion (MA). + CH3NH3 + ), formamidinium ion (FA) + CH(NH2)2 + One of them; X is Cl - ,Br - I - One or more of the following; the range of x is 0 ≤ x < 1.

2. The artificial synaptic device based on chiral perovskite as described in claim 1, characterized in that, The thickness of the chiral perovskite functional layer is 50-500 nm.

3. The artificial synaptic device based on chiral perovskite as described in claim 1, characterized in that, The substrate is a rigid substrate or a flexible substrate; The rigid substrate is optical glass or sapphire. The flexible substrate is one of polyethylene terephthalate, polyimide, and polyethylene naphthalate; The comb-shaped bottom electrode is made of a transparent conductive electrode, one of ITO, FTO, and AZO; the thickness of the bottom electrode is 50-200nm. The comb-shaped top electrode is made of metal, specifically gold, silver, or platinum, and has a thickness of 30-100 nm.

4. The artificial synaptic device based on chiral perovskite as described in claim 1, characterized in that, The effective area of ​​both electrodes is 0.01-0.1 cm². 2 .

5. The method for fabricating an artificial synaptic device based on chiral perovskite as described in claim 1, characterized in that, Includes the following steps: Step 1: Substrate pretreatment: The substrate is placed in acetone, ethanol and deionized water in sequence for ultrasonic cleaning. Each ultrasonic cleaning time is 15-30 minutes and the ultrasonic power is 80-120W. Step 2: Bottom electrode preparation: Select the corresponding preparation process according to the substrate type, and prepare the bottom electrode on the surface of the pretreated substrate by mask magnetron sputtering or electron beam evaporation; after the bottom electrode is prepared, place it in an annealing furnace and anneal at 100-200℃ for 30-60 minutes in an air or nitrogen atmosphere to obtain a comb-shaped bottom electrode. The process parameters for magnetron sputtering are: sputtering power 200-300W, sputtering pressure 0.3-0.5Pa, sputtering temperature at room temperature, and target-substrate distance 8-12cm; the process parameters for electron beam evaporation are: vacuum degree ≤5×10⁻⁶. -4 Pa, evaporation rate 0.1-0.5 nm / s; Step 3: Preparation of chiral perovskite functional layer: The precursor solution is coated onto the surface of the bottom electrode by spin coating or blade coating. After coating, solvent annealing is performed first. The sample is placed in the vapor of the solvent used in the precursor solution and solvent annealed at room temperature for 5-30 min. After solvent annealing, it is thermally annealed at 60-120℃ for 10-60 min in an atmosphere to obtain the chiral perovskite functional layer. Specifically, the chiral organic cation salt is (R)-(-)-1-phenylethylamine ion or (S)-(+)-1-phenylethylamine ion; The non-chiral organic cation salt is specifically MA + or FA + ; Halogenated lead salts are lead iodide or lead bromide; The concentration of the precursor solution is 0.8-1.5 mol / L; Step 4: Top electrode preparation: Place the sample with the bottom electrode and the chiral perovskite functional layer into a vacuum coating instrument, and prepare the top electrode on the surface of the chiral perovskite functional layer obtained in Step 3 by mask magnetron sputtering or electron beam evaporation. The direction of the comb teeth of the top electrode intersects the direction of the comb teeth of the bottom electrode at 90°. After the top electrode is prepared, anneal it at 60-100℃ in a nitrogen atmosphere for 10-20 min. The process parameters for magnetron sputtering are: sputtering power 100-200W, sputtering gas pressure 0.2-0.4Pa, sputtering temperature at room temperature, and target-substrate distance 8-10cm. The process parameters for electron beam evaporation are: vacuum degree ≤ 5 × 10⁻⁶. -4 Pa, evaporation rate 0.05-0.2 nm / s.

6. The method for fabricating an artificial synaptic device based on chiral perovskite as described in claim 1, characterized in that, The spin coating process parameters in step (3) are: rotation speed 3000-5000 r / min, spin coating time 20-40 s, and drop volume 50-100 μL; The spraying process parameters are: scraper running speed 5-15mm / s, scraper gap 50-150μm.

7. The method for fabricating an artificial synaptic device based on chiral perovskite as described in claim 1, characterized in that, In step (3), the preparation of the chiral perovskite precursor solution includes: dissolving the chiral organic cation salt, the non-chiral organic cation salt, the lead salt and the halogen salt in a solvent according to the proportions in the general chemical formula of the chiral perovskite functional layer, stirring for 2-6 hours under a nitrogen atmosphere at a stirring temperature of 30-50°C to obtain the chiral perovskite precursor solution.

8. The application of the chiral perovskite-based artificial synaptic device as described in claim 1, characterized in that, Used to construct neuromorphic chips with chirality recognition capabilities.

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