Azobenzene-based two-dimensional polymer film full-light-operated neuromorphic device and preparation and application thereof

Abstract

The invention belongs to the field of organic / polymer neuromorphic devices, and particularly provides an azobenzene-based two-dimensional polymer film full-light-operated neuromorphic device as well as preparation and application thereof. The structure of the device is a classic sandwich structure, the bottom electrode is a glass substrate coated with ITO, and the active layer is a novel photosensitive two-dimensional polymer material TAPB-DCA-2DP film. Key synaptic functions such as paired pulse promotion / suppression (PPF / PPD) and long-term enhancement / suppression (LTP / LTD) are successfully simulated in the optical synaptic. In addition, all-optical synapses effectively perform AND and OR logic gate operations and are successfully integrated into a novel edge computing system for indium tin oxide (ITO) glass anomaly detection. The polymer memristor can realize storage and calculation integration, can be used for information storage, and has an excellent application prospect in the field of artificial intelligence.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic / polymer neuromorphic information storage, and specifically provides a preparation method and application of a lightweight and light-responsive polymer nano-neuromorphic device, and specifically relates to an organic nano-scale neuromorphic device with a large-area two-dimensional polymer film as an active layer, and its preparation method, testing method and application in the field of low-power optoelectronic information storage. Background Art

[0002] Neuromorphic computing is a new architecture that promises to overcome the von Neumann bottleneck by emulating the brain's ability to sense, process, and efficiently store information. Inspired by the brain's ability to highly parallelize and self-learn at low energy, neuromorphic systems aim to revolutionize computing by addressing the bottleneck caused by the physical separation of memory and central processing units in traditional von Neumann architectures. The development of artificial synaptic devices is crucial to the realization of neuromorphic computing, as it attempts to replicate the brain's synaptic plasticity using electronic components such as memristors and field-effect transistors. Conventional electronic and optoelectronic synapses face challenges such as high energy consumption and hardware redundancy, while the emergence of all-photon modulated synaptic memristors has attracted widespread attention due to their ultrafast operation, no electrical interconnect power loss, and high bandwidth, highlighting the urgent need for all-optical synaptic devices. Recently, many all-optical synapses based on various materials have been reported, including inorganic oxides, graphene, perovskites, transition metal sulfides, and black phosphorus. However, reports on all-optical synapses using two-dimensional polymers are still limited. In the past decade, two-dimensional materials have attracted great interest from scientists in the fields of physics, chemistry and materials science due to their unique structures and excellent properties. The "bottom-up" synthesis strategy of two-dimensional materials, such as two-dimensional polymers and two-dimensional covalent organic frameworks (COFs), is developing into an emerging research field due to the easy availability and abundance of building blocks, designable skeletons and various polymerization methods. Compared with traditional polymers, two-dimensional conjugated polymers have superior conjugation and chemical stability. Interfacial synthesis methods are widely used to prepare two-dimensional polymer materials, in which the interface acts as a confined two-dimensional space where precursors can be assembled or polymerized to form single or multilayer two-dimensional materials with controllable thickness and lateral size. Among the reported reactions, gas-liquid and liquid-liquid interfacial reactions have significant advantages such as extremely smooth interfaces, large continuous network scales and easy transfer. Summary of the invention

[0003] The purpose of the present invention is to provide an all-optically controlled neuromorphic device using a large-area two-dimensional polymer film as an active layer.

[0004] The second object of the present invention is to provide a synthesis route for a novel two-dimensional conjugated polymer used in the active layer of a synaptic device.

[0005] The third object of the present invention is to provide a method for preparing a neuromorphic device using a novel two-dimensional conjugated polymer film material as an active layer.

[0006] A fourth object of the present invention is to provide an application of a two-dimensional polymer neuromorphic device in a low-power optoelectronic information storage device.

[0007] The technical solution of the present invention:

[0008] A two-dimensional polymer film all-optically controlled neuromorphic device based on azobenzene, the device structure from bottom to top is:

[0009] 1. Glass substrate substrate;

[0010] 2. Indium tin oxide electrode (ITO);

[0011] 3.TAPB-DCA-2DP conjugated porous polymer film active layer;

[0012] 4.ITO electrode.

[0013] Furthermore, all its synaptic behaviors function under ultraviolet and blue light; key synaptic functions such as paired pulse facilitation / depression (PPF / PPD) and long-term potentiation / depression (LTP / LTD) are successfully simulated in this optical synapse; the all-optical synapse effectively performs "AND" and "OR" logic gate operations and is successfully integrated into a new edge computing system for indium tin oxide (ITO) glass anomaly detection.

[0014] The present invention also provides a method for preparing the polymer memory device having non-volatile storage and rewritable properties, comprising the following steps:

[0015] 1) Clean the glass substrate coated with ITO and dry it;

[0016] 2) depositing the TAPB-DCA-2DP thin film on a pre-cleaned ITO plate;

[0017] 3) vacuum drying the obtained device overnight to remove excess solution;

[0018] 4) Finally, an ITO top electrode is plated on the active layer to obtain the device ITO / TAPB-DCA-2DP / ITO.

[0019] Further preferably, the preparation method specifically comprises the following steps:

[0020] 1) Wash the ITO-coated glass substrate (preferably 1.5 cm×1.5 cm) with detergent and deionized water, then wash in ethanol, acetone and isopropanol respectively (preferably for 15 minutes) and dry.

[0021] 2) Cover the ITO glass with a polymer layer with a thickness of 100nm-200nm, and vacuum dry overnight to remove excess solution.

[0022] 3) Using a magnetron sputtering method, an ITO top electrode (preferably with a thickness of 100-150 nm and an area of ​​about 0.4×0.4 mm 2) is plated on the active layer through a mask, and finally a device ITO / TAPB-DCA-2DP / ITO is obtained.

[0023] The structure of the polymer TAPB-DCA-2DP in the active layer film provided by the present invention is shown in the following formula:

[0024]

[0025] The preparation method of the polymer TAPB-DCA-2DP active layer of the present invention is as follows:

[0026] Synthesis of a: 4-iodoaniline is added to a nitrobenzene solution of concentrated acetic acid. The reaction mixture is heated to 45°C and stirred overnight. After the reaction is completed, distilled water is added to the reaction mixture, the resulting precipitate is filtered and washed with water. The crude product is recrystallized from hot ethanol to obtain compound a as orange crystals.

[0027] Synthesis of b: A mixture of a, potassium acetate and bis(diboron) was stirred in dioxane under an argon atmosphere. After 15 minutes, PdCl2(dppf)2 was added and stirred at 90°C overnight. After the reaction was completed, the mixture was concentrated and dried, and the crude boron diazene ester was purified by column chromatography (ethyl acetate: hexane = 1:20). An orange solid compound b was isolated.

[0028] Synthesis of Azo-DCA: 4-bromo-2,6-diformylpyridine was added to a 100 mL three-necked round-bottom flask containing compound b and Pd(PPh3)4 and synthesized under an argon atmosphere. The reaction mixture was then mixed with a degassed 1:1 THF / H2O solvent mixture containing NaHCO3. The mixture was refluxed at 85°C under an inert argon atmosphere for 24 hours. After the reaction was complete, water was added to the mixture and the aqueous layer was extracted with dichloromethane. The combined organic layers were dried over magnesium sulfate, filtered, and concentrated to dryness. The resulting orange solid was purified by column chromatography (CH2Cl2) to give orange Azo-DCA.

[0029] Synthesis of TAPB-DCA-2DP: Azo-DCA was dissolved in CH2Cl2 as the organic phase. Subsequently, pure water was slowly added to the top layer of the CH2Cl2 solution, ensuring that the CH2Cl2 / H2O interface remained stable. TAPB and TsOH·H2O solution were slowly added dropwise to CH3CN and H2O. The beaker was covered to maintain stability and prevent airflow. After 72 hours of reaction at room temperature, a transparent, smooth film was clearly observed at the interface of the two immiscible phases.

[0030] The specific reaction route is as follows:

[0031]

[0032] The specific preparation method of the polymer film TAPB-DCA-2DP is as follows:

[0033] (1) Synthesis of a: 4-iodoaniline (9.1 mmol) was added to a concentrated acetic acid nitrobenzene solution (11.0 mmol); the reaction mixture was heated to 45° C. and stirred overnight; after post-treatment, compound a was obtained as orange crystals;

[0034] (2) Synthesis of b: A mixture of a (3.2 mmol), potassium acetate (5.1 mmol) and bis(diboron) (4.9 mmol) was stirred in dioxane under an argon atmosphere; after 15 minutes, PdCl2(dppf)2 was added and stirred at 90°C overnight; after the reaction was completed, an orange solid compound b was obtained after post-treatment;

[0035] (3) Synthesis of Azo-DCA: 4-bromo-2,6-diformylpyridine (2.36 mmol) was added to a 100 mL three-necked round-bottom flask containing compound b (2.36 mmol) and Pd(PPh3)4 (0.10 mmol) and synthesized under an argon atmosphere; the reaction mixture was then mixed with a degassed 1:1 THF / H2O solvent mixture containing NaHCO3; the mixture was refluxed at 85°C under an inert argon atmosphere for 24 hours; after the reaction was completed, orange Azo-DCA was obtained after post-treatment;

[0036] (4) Azo-DCA (0.18 mmol) was dissolved in 40 mL of CH2Cl2 as the organic phase. Subsequently, pure water was slowly added to the top layer of the CH2Cl2 solution, ensuring that the CH2Cl2 / H2O interface remained stable. TAPB (0.12 mmol) and TsOH·H2O (0.15 mmol) solutions were slowly added dropwise to 30 ml of CH3CN and 10 ml of H2O. The beaker was covered to maintain stability and prevent airflow. After 72 hours of reaction at room temperature, a transparent, smooth film was clearly observed at the interface of the two immiscible phases.

[0037] The present invention also provides an application of the organic nano-neuromorphic device using the large-area two-dimensional conjugated polymer as an active layer in the field of low-power information storage.

[0038] Furthermore, under ultraviolet and blue light, the device exhibits distinctly different resistance states, which can be defined as on and off states to store data as "0" and "1" in binary, and can still retain data after power is removed.

[0039] Furthermore, the application is the application of a two-dimensional conjugated polymer memory with an ultra-small threshold voltage in a low-power optoelectronic nanoscale neuromorphic device.

[0040] The present invention proposes to use a two-dimensional conjugated polymer material as an active layer of a neuromorphic device, and designs and synthesizes a two-dimensional conjugated polymer. The present invention selects Azo-DCA and TAPB as reaction monomers, and synthesizes a two-dimensional conjugated polymer film TAPB-DCA-2DP with light-responsive characteristics through a Schiff base reaction.

[0041] The neuromorphic device based on ITO / TAPB-DCA-2DP / ITO of the present invention has excellent stability and will have good application prospects in lightweight intelligent neuromorphic storage devices. Because the present invention uses pure polymer as the active layer, it can be prepared into a nanoscale device using electron beam lithography and stripping technology, while the general products covalently grafted with two-dimensional materials, such as black phosphorus (BP) and graphene, may make the lattice film of the device uneven once the same technology is used, and the use of pure polymers just solves this problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is the current-voltage (IV) characteristic conversion diagram of the ITO / TAPB-DCA-2DP / ITO device under ultraviolet light or blue light irradiation.

[0043] Figure 2 Modulation of the 32-state photosensitive synaptic weight of ITO / TAPB-DCA-2DP / ITO by UV light irradiation and the retention performance of the 32-state conductance of ITO / TAPB-DCA-2DP / ITO under UV light irradiation.

[0044] Figure 3 This is a diagram showing the modulation of the 32-state photosensitive synaptic weights of ITO / TAPB-DCA-2DP / ITO by blue illumination and the retention performance of the 32-state conductance of ITO / TAPB-DCA-2DP / ITO under blue illumination.

[0045] Figure 4It is the corresponding circuit schematic diagram, the working principle of the light-controlled "AND" gate and "OR" gate, and the It curve of the optical logic gate of the "AND" gate and "OR" gate.

[0046] Figure 5 Truth table for AND and OR gates.

[0047] Figure 6 This is the ITO / TAPB-DCA-2DP / ITO device diagram.

[0048] Figure 7 This is the carbon NMR spectrum of DCA-TAPB. DETAILED DESCRIPTION

[0049] The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the features and advantages of the present invention can be more clearly understood.

[0050] Preparation method of all-light-controlled neuromorphic devices based on large-area two-dimensional conjugated polymers of azobenzene:

[0051] 1) The ITO-coated glass substrate (1.5 cm×1.5 cm) was washed with detergent and deionized water, and then washed in ethanol, acetone and isopropanol for 15 minutes respectively and dried.

[0052] 2) A 100 nm thick polymer thin film TAPB-DCA-2DP layer was coated on the ITO glass by a deposition method, and then vacuum dried overnight to remove excess solution.

[0053] 3) Using magnetron sputtering method, ITO top electrode (thickness = 100nm) with an area of ​​about 0.4×0.4mm 2 .

[0054] 4) Plated on the active layer through a mask plate to finally obtain the device ITO / TAPB-DCA-2DP / ITO.

[0055] The specific preparation method of the above polymer film TAPB-DCA-2DP is as follows:

[0056] (1) Synthesis of a: 4-iodoaniline (9.1 mmol) was added to a concentrated acetic acid nitrobenzene solution (11.0 mmol); the reaction mixture was heated to 45° C. and stirred overnight; after post-treatment, compound a was obtained as orange crystals;

[0057] (2) Synthesis of b: A mixture of a (3.2 mmol), potassium acetate (5.1 mmol) and bis(diboron) (4.9 mmol) was stirred in dioxane under an argon atmosphere; after 15 minutes, PdCl2(dppf)2 was added and stirred at 90°C overnight; after the reaction was completed, an orange solid compound b was obtained after post-treatment;

[0058] (3) Synthesis of Azo-DCA: 4-bromo-2,6-diformylpyridine (2.36 mmol) was added to a 100 mL three-necked round-bottom flask containing compound b (2.36 mmol) and Pd(PPh3)4 (0.10 mmol) and synthesized under an argon atmosphere; the reaction mixture was then mixed with a degassed 1:1 THF / H2O solvent mixture containing NaHCO3; the mixture was refluxed at 85°C under an inert argon atmosphere for 24 hours; after the reaction was completed, orange Azo-DCA was obtained after post-treatment;

[0059] (4) Azo-DCA (0.18 mmol) was dissolved in 40 mL of CH2Cl2 as the organic phase. Subsequently, pure water was slowly added to the top layer of the CH2Cl2 solution, ensuring that the CH2Cl2 / H2O interface remained stable. TAPB (0.12 mmol) and TsOH·H2O (0.15 mmol) solutions were slowly added dropwise to 30 ml of CH3CN and 10 ml of H2O. The beaker was covered to maintain stability and prevent airflow. After 72 hours of reaction at room temperature, a transparent, smooth film was clearly observed at the interface of the two immiscible phases.

[0060] ( Figure 7 )

[0061] Effect Example 1

[0062] Figure 1 The current-voltage (IV) characteristic conversion diagram of the ITO / TAPB-DCA-2DP / ITO device under UV or blue light irradiation; the optical switching behavior of the ITO / TAPB-DCA-2DP / ITO device between the high resistance state and the low resistance state was studied under UV and blue light irradiation. Initially, a forward voltage sweep was performed on the device. After irradiation with UV light of 365nm wavelength for 300 seconds, the current increased from 0.011A to 0.067A, indicating a transition from low to high conductivity, consistent with the photoinduced trans to cis isomerization ( Figure 1 a). Subsequently, the device was exposed to blue light for 300 seconds to initiate the cis-to-trans transition of azobenzene, and the current dropped to the initial value ( Figure 1 b). A similar trend was observed during the reverse voltage sweep ( Figure 1 c and 1d).

[0063] Due to the photoisomerization properties of the active layer TAPB-DCA-2DP film, the device can be converted between cis and trans, thereby adjusting the device performance. The current-voltage characteristic diagram of the ITO / TAPB-DCA-2DP / ITO device ( Figure 1), from which it can be seen that the device ITO / TAPB-DCA-2DP / ITO shows optical switching performance under UV and blue light. The test steps are as follows:

[0064] Initially, a forward voltage sweep was performed on the device. After irradiation with UV light at a wavelength of 365 nm for 300 seconds, the current increased from 0.011 A to 0.067 A, indicating a transition from low to high conductivity, consistent with the photoinduced trans to cis isomerization. Subsequently, the device was exposed to blue light for 300 seconds, and the azobenzene cis to trans transition occurred, and the current dropped to the initial value. A similar trend was observed during the reverse voltage sweep.

[0065] Effect Example 2

[0066] like Figure 2 , through 2.5mW / cm 2 The 32-state photoresponsive synaptic weight can be reversibly modulated by ultraviolet light. Continuous application of ultraviolet light pulses on the ITO / TAPB-DCA-2DP / ITO device causes the photocurrent to change from 5.9×10 -8 A increases linearly to 18.9×10 -8 A. ( Figure 2 a) Maintain consistent performance over a duration of 2500 seconds. Figure 2 b)

[0067] Effect Example 3

[0068] like Figure 3 , through 15.0mW / cm 2 The blue light illumination can reversibly modulate the synaptic weight of 32 states. Continuous application of blue light pulses on the ITO / TAPB-DCA-2DP / ITO device causes the photocurrent to change from 26.1×10 -8 A is reduced to 8.6×10 - 8 A. ( Figure 3 a) 32 different conductance states are clearly identifiable and demonstrate exceptional durability and stability, maintaining consistent performance over a duration of 2500 seconds. ( Figure 3 b)

[0069] Effect Example 4

[0070] like Figure 4, schematic diagram of the ITO / TAPB-DCA-2DP / ITO-based device as an optical logic gate for signal processing. The four input signals (00, 10, 01, 11) correspond to the four combinations of "on" (1) and "off" (0), where "1" is defined as ultraviolet irradiation and "0" is defined as no irradiation, and the photocurrent input signal is obtained. In the (11) state, the measured photocurrent is about 7nA, while in the (00), (10) and (01) states, the photocurrent is less than 5nA. When the photocurrent is lower than 6nA, the output signal is (0), and when the photocurrent is higher than 6nA, the output signal is (1). Figure 4 a is an "OR" logic gate, Figure 4 b is an "AND" logic gate.

[0071] Effect Example 5

[0072] like Figure 5 , a truth table was obtained, indicating that the output signal is (1) only when the input signal is (11). In addition, an optical OR gate was successfully constructed. These findings show that the logic circuit created by ITO / TAPB-DCA-2DP / ITO devices can effectively convert optical signals into digital signals. Different input digital signals can be obtained by monitoring the pattern of photocurrent changes.

[0073] The above-mentioned preparation steps, effect examples and attached data are preferred embodiments of the present invention. Other embodiments within the protection scope can also obtain the above-mentioned beneficial effects, which will not be described in detail here. It should be pointed out that for ordinary technicians in this technical field, without departing from the concept of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as within the protection scope of the present invention.

Claims

1. A two-dimensional polymer film all-optically controlled neuromorphic device based on azobenzene, characterized in that: Its structure from bottom to top is: (1) Glass substrate; (2) Indium tin oxide electrode ITO; (3) polymer TAPB-DCA-2DP film active layer; (4)ITO electrode.

2. The azobenzene-based two-dimensional polymer film all-optically controlled neuromorphic device according to claim 1, characterized in that: All its synaptic behaviors function under ultraviolet and blue light; key synaptic functions such as paired pulse facilitation / depression (PPF / PPD) and long-term potentiation / depression (LTP / LTD) are successfully simulated in this optical synapse; the all-optical synapse effectively performs "AND" and "OR" logic gate operations and is successfully integrated into a new edge computing system for indium tin oxide (ITO) glass anomaly detection.

3. The all-optically controlled neuromorphic device based on azobenzene two-dimensional polymer film according to claim 1, characterized in that: The structure of the TAPB-DCA-2DP film in the polymer film active layer is shown in the following formula:

4. The all-optically controlled neuromorphic device based on azobenzene two-dimensional polymer film according to claim 1, characterized in that: The polymer film TAPB-DCA-2DP is prepared by the following steps: (1) Synthesis of a: 4-iodoaniline was added to a nitrobenzene solution of concentrated acetic acid; the reaction mixture was heated to 45° C. and stirred continuously overnight; after post-treatment, compound a was obtained as orange crystals; (2) Synthesis of b: A mixture of a, potassium acetate and diboron was stirred in dioxane under an argon atmosphere; after 15 minutes, PdCl2(dppf)2 was added and stirred at 90°C overnight; after the reaction was completed, an orange solid compound b was obtained after post-treatment; (3) Synthesis of Azo-DCA: 4-bromo-2,6-diformylpyridine was added to a 100 mL three-necked round-bottom flask containing compound b and Pd(PPh3)4, and the mixture was synthesized under an argon atmosphere; the reaction mixture was then mixed with a degassed 1:1 THF / H2O solvent mixture containing NaHCO3; the mixture was refluxed at 85°C under an inert argon atmosphere for 24 hours; after the reaction was completed, orange Azo-DCA was obtained after post-treatment; (4) Synthesis of TAPB-DCA-2DP: Azo-DCA was dissolved in CH2Cl2 as the organic phase; then, pure water was slowly added to the top layer of the CH2Cl2 solution to ensure that the CH2Cl2 / H2O interface remained stable; TAPB and TsOH·H2O solution were slowly added dropwise to CH3CN and H2O; the beaker was covered to maintain stability and prevent airflow; after reacting at room temperature for 72 hours, a transparent, smooth film was clearly observed at the interface of the two immiscible phases.

5. A method for preparing azobenzene-based two-dimensional polymer film all-optically controlled neuromorphic device according to claim 1, characterized in that: The steps include: 1) Clean the glass substrate coated with ITO and dry it; 2) depositing TAPB-DCA-2DP on a pre-cleaned ITO plate; 3) vacuum drying the obtained device overnight to remove excess solution; 4) Finally, an ITO top electrode is plated on the active layer to obtain the device ITO / TAPB-DCA-2DP / ITO.

6. A method for preparing a two-dimensional polymer film all-optically controlled neuromorphic device based on azobenzene according to claim 1, characterized in that: The specific steps include: 1) Clean the ITO-coated glass substrate with detergent and deionized water, then wash and dry in ethanol, acetone and isopropanol respectively; 2) depositing a TAPB-DCA-2DP thin film on a pre-cleaned ITO plate with a thickness of about 100nm-200nm; 3) The obtained device is then thoroughly vacuum dried overnight to remove excess solution; 4) Finally, the ITO top electrode is plated on the active layer through a mask using a magnetron sputtering method; 5) Finally, the device ITO / TAPB-DCA-2DP / ITO is obtained.

7. A polymer TAPB-DCA-2DP film, the structure of which is shown in the following formula:

8. An application of the azobenzene-based two-dimensional polymer film all-optically controlled neuromorphic device according to any one of claims 1 to 4 in a low-power information storage device.

9. The application of the all-optically controlled neuromorphic device in a low-power information storage device as claimed in claim 8, characterized in that: All its synaptic behaviors function under ultraviolet and blue light; the key synaptic functions of paired pulse facilitation / depression (PPF / PPD) and long-term potentiation / depression (LTP / LTD) were successfully simulated in this optical synapse; in addition, the all-optical synapse effectively performs "AND" and "OR" logic gate operations and is successfully integrated into a new edge computing system for anomaly detection on indium tin oxide (ITO) glass.

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