Photoelectric memristive device for multilevel storage and preparation method of photoelectric memristive device

Abstract

The invention relates to the technical field of photoelectric devices, in particular to a photoelectric memristor for multilevel storage and a preparation method of the photoelectric memristor. The photoelectric memristor comprises a supramolecular compound and a graphene electrode pair, wherein the supramolecular compound is connected between the graphene electrode pair; under the voltage of-1 V to 1 V, the supramolecular compound can form four different conductivity states. The supramolecular compound comprises a guest molecule A taking an amino group as a terminal, a guest molecule B with an ultraviolet light response group and a host molecule C with a large-size cavity structure. The three molecules form a supramolecular compound structure under Van der Waals force and hydrophobic interaction. According to the photoelectric memristor provided by the invention, stable four-state storage is realized through photoelectric coordinated regulation and control, and a feasible solution is provided for high-speed and high-density storage. The preparation method provided by the invention is mild in reaction condition, simple in process and beneficial to industrial and integrated production.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic device technology, and in particular to opto-memristor devices for multi-level storage and their fabrication methods. Background Technology

[0002] With the rise of technologies such as cloud computing, the Internet of Things, and artificial intelligence, human society's demand for information processing has exploded. However, existing storage technologies are gradually revealing their inherent performance bottlenecks when dealing with this massive data deluge, making it difficult to support the leapfrog development of modern technology. Specifically, current mainstream storage technologies suffer from problems such as low capacity and slow write / erase speeds when processing massive amounts of data.

[0003] Memristors are not only a new type of storage device, but also a core cornerstone of information technology in the post-Moore's Law era. Through their unique resistive properties, they break through the density and power consumption bottlenecks of traditional storage, while providing new technological pathways for in-memory computing and neuromorphic computing. With advancements in materials innovation, process optimization, and system integration, memristors are expected to completely replace existing storage technologies in the future and become core computing components in fields such as Artificial Intelligence (AI), the Internet of Things, and autonomous driving, propelling human society into a "low-power, high-intelligence" information age.

[0004] Opto-memristors are a new type of memristor device that integrates optical signal modulation and electrical signal response. Their core mechanism utilizes the synergistic effect of multiple physical fields—light (such as ultraviolet and visible light) and electricity—to achieve reversible control of the resistive state and non-volatile memory. Compared to traditional electrically modulated memristors, they overcome the limitations of single-signal modulation and, with their "optical-electrical dual-dimensional" characteristics, exhibit unique advantages in high-density storage. Multilevel storage memristors offer high-density storage, fast transmission speeds, and compatibility with Complementary Metal-Oxide-Semiconductor (CMOS) processes, providing significant advantages in improving energy efficiency and parallel computing capabilities.

[0005] In the application of opto-memristors towards high-density multi-bit storage, the selection of molecular materials faces multi-dimensional challenges, including bottlenecks in material stability and durability, the contradiction between photoresponse efficiency and energy consumption, cross-interference from multi-configuration modulation, and integration process and scalability challenges. These issues directly affect the performance, stability, and industrialization potential of the devices. Therefore, there is an urgent need to develop a novel opto-memristor device for multi-level storage. Summary of the Invention

[0006] The present invention aims to at least solve one of the technical problems existing in the related art. Therefore, the first objective of the present invention is to provide an opto-memristor device for multi-level storage; the second objective of the present invention is to provide a method for fabricating an opto-memristor device for multi-level storage.

[0007] To achieve the first objective, the technical solution adopted by this invention is as follows: An opto-memristor device for multi-level storage includes a supramolecular composite and a graphene electrode pair, wherein the supramolecular composite is connected between the graphene electrode pairs. Under the action of scanning voltage, the supramolecular complex can respond to voltage changes and form different conductivity states; The supramolecular complex comprises guest molecule A, guest molecule B, and host molecule C, and the structural formula of the supramolecular complex is shown below: ; Among them, in the structural formula The supramolecular complex is a guest molecule A, and the supramolecular complex is connected to the graphene electrode pair via an amide bond through the guest molecule A; In the structural formula The guest molecule is B; Wherein, R is a UV-responsive group, which can undergo a configurational change under UV light irradiation; In the structural formula Representative molecule C n is selected from 7 or 8.

[0008] The supramolecular complex contains guest molecule B, which exhibits redox properties. The positively charged pyridine group within it can switch between high and low resistance states in response to scanning voltage, generating memristor behavior. The main chain of guest molecule B in the supramolecular complex contains UV-responsive groups. Under UV irradiation, guest molecule B undergoes isomerization, causing the overall current value of the supramolecular complex to decrease / increase, generating four different resistance states and achieving high-density storage.

[0009] Furthermore, R is selected from , and Any one of them; Furthermore, the wavelength of the ultraviolet light is 310nm or 365nm.

[0010] When R is The structural changes of the supramolecular complex under ultraviolet light irradiation are shown below: ; When R is The structural changes of the supramolecular complex under ultraviolet light irradiation are shown below: ; When R is The structural changes of the supramolecular complex under ultraviolet light irradiation are shown below: ; When the supramolecular complex contains an azophenyl group in the main chain of guest molecule B. When the supramolecular complex undergoes a redox reaction at a voltage of -1V to 1V, it produces a high-conductivity state HC1 and a low-conductivity state LC1. When the supramolecular complex is irradiated with 365nm ultraviolet light, the azophenyl group in the guest molecule B changes from a trans configuration to a cis configuration, the delocalization of the guest molecule B decreases, and the conductivity of the supramolecular complex decreases. At a voltage of -1V to 1V, two new stable states, a high-conductivity state HC2 and a low-conductivity state LC2, are generated. The four conductivity states realize two-bit storage.

[0011] When the supramolecular complex contains stilbene groups in the main chain of guest molecule B. When the supramolecular complex undergoes a redox reaction at a voltage of -1V to 1V, it produces a high-conductivity state HC1 and a low-conductivity state LC1. When the supramolecular complex is irradiated with 310nm ultraviolet light, the stilbene group in the guest molecule B changes from a trans configuration to a cis configuration, the delocalization of the guest molecule B is weakened, the conductivity of the supramolecular complex decreases, and two new stable states, a high-conductivity state HC2 and a low-conductivity state LC2, are generated at a voltage of -1V to 1V. The four conductivity states realize multi-level storage.

[0012] When the supramolecular complex contains a diarylene group in the main chain of guest molecule B, When the supramolecular complex undergoes a redox reaction at a voltage of -1V to 1V, it produces a high-conductivity state HC1 and a low-conductivity state LC1. When the supramolecular complex is irradiated with 365nm ultraviolet light, the diarylene group in the guest molecule B changes from an open-ring structure to a closed-ring structure, and the conductivity of the supramolecular complex increases. At a voltage of -1V to 1V, two new stable states, the high-conductivity state HC2 and the low-conductivity state LC2, are generated. The four conductivity states realize multi-density storage.

[0013] Furthermore, the scanning voltage is -1V to 1V.

[0014] To achieve the second objective, the technical solution adopted by this invention is as follows: A method for fabricating an opto-memristor device for multi-level storage, comprising the following steps: S100. Using an amide condensation reaction, guest molecule A is connected to a graphene electrode pair to obtain a graphene electrode pair connected to guest molecule A. S200. Prepare a mixed solution containing guest molecule B and host molecule C. S300. Immerse the graphene electrode pair connected to guest molecule A into the mixed solution for at least 10 minutes to form a supramolecular complex of guest molecule A, guest molecule B and host molecule C, and the supramolecular complex is connected between the graphene electrode pairs to obtain a photoelectric memristor device for multi-level storage.

[0015] Further, in step S100, the reaction solvent for the amide condensation reaction is selected from pyridine, the reaction catalyst is selected from 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and the reaction atmosphere is an anhydrous and oxygen-free environment.

[0016] Furthermore, the preparation of the graphene electrode pair includes the following steps: S110. Graphene is grown on a copper sheet using chemical vapor deposition. S120. Transfer the graphene grown on the copper sheet to the clean silicon wafer surface to obtain a silicon wafer with a graphene layer on the surface. S130. Combining photolithography and oxygen plasma etching techniques, a preset shape of metal electrodes is defined on the graphene layer to obtain a patterned graphene silicon wafer. S140. Using vapor deposition technology, a metal material is vapor deposited on the patterned graphene layer to obtain a graphene layer with a metal electrode. S150: Using oxygen plasma etching and electron beam lithography, graphene electrode pairs with nanochannels are formed on a graphene layer loaded with metal electrodes.

[0017] Furthermore, in step S140, the metallic material includes metallic chromium (Cr) and metallic Au.

[0018] Further, in step S200, the solvent of the mixed solution is selected from water.

[0019] Further, in step S300, the ratio of the number of guest molecules A, guest molecules B and host molecules C in the mixed solution is 2:1:2.

[0020] The above-described one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: This invention provides a photoelectric memristor device for multi-level storage, comprising a supramolecular complex and graphene electrode pairs, with the supramolecular complex connected between the graphene electrode pairs. Under voltage conditions of -1V to 1V, the supramolecular complex can form four different conductance states. The supramolecular complex includes a guest molecule A terminated with an amino group, a guest molecule B with a UV-responsive group, and a host molecule C with a large-size cavity structure. These three molecules form a supramolecular complex structure through van der Waals forces and hydrophobic interactions. Guest molecule B in the supramolecular complex has a positively charged pyridine group, which undergoes a redox reaction under voltage, achieving switching between high and low resistance states. Furthermore, the main chain of guest molecule B contains a UV-responsive group; under UV irradiation, the molecular configuration changes, and the overall conductance of the supramolecular complex shows an increasing / decreasing trend, forming two new bistable states under the influence of a scanning voltage. This photoelectric memristor achieves stable four-state storage through photoelectric synergistic regulation, providing a feasible solution for high-speed, high-density storage.

[0021] This invention provides a method for fabricating photoelectric memristors for multi-level storage, which features mild reaction conditions and simple processes, making it suitable for industrial and integrated production.

[0022] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of an opto-memristor device for multi-level storage provided in an embodiment of the present invention.

[0024] Figure 2 This is the current-voltage (IV) curve of the opto-memristor device sample 1 for multi-level storage provided in Embodiment 4 of the present invention.

[0025] Figure 3 This is the IV curve of sample 2 of the opto-memristor device for multi-level storage provided in Embodiment 4 of the present invention.

[0026] Figure label: 1. Supramolecular complex; 11. Guest molecule A; 12. Guest molecule B; 13. Host molecule C; 2. Graphene electrode pair. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. The following embodiments are used to illustrate this invention, but cannot be used to limit the scope of this invention.

[0028] In the following embodiments, unless otherwise specified, the experimental methods used are conventional methods, and the materials and reagents used are commercially available, unless otherwise specified, and are carried out in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions.

[0029] like Figure 1 As shown, an opto-memristor device for multi-level storage includes a supramolecular composite 1 and a graphene electrode pair 2, wherein the supramolecular composite 1 is connected between the graphene electrode pair 2. Under the action of scanning voltage, the supramolecular complex 1 can respond to voltage changes and form different conductivity states; The supramolecular complex comprises guest molecule A11, guest molecule B12, and host molecule C13, and the structural formula of the supramolecular complex is shown below: ; Among them, in the structural formula The supramolecular complex is a guest molecule A, and the supramolecular complex is connected to the graphene electrode pair via an amide bond through the guest molecule A; In the structural formula The guest molecule is B, and R is a UV-responsive group, which can undergo a configurational change under UV light irradiation. In the structural formula Representative molecule C n is selected from 7 or 8.

[0030] Example 1 Preparation of supramolecular complexes The process is as follows: I. Preparation of guest molecule A .

[0031] In a 50 mL dry round-bottom flask, add 300 mg of 2-(2-bromoethyl)-1H-indene, and slowly add 40–50 mmol of NH3·H2O (excess to promote complete reaction). Place the flask in a 60 °C water bath and heat under reflux for 5 h with stirring. Cool to room temperature and transfer the reaction solution to a 50 mL round-bottom flask. Use a rotary evaporator (40 °C water bath, vacuum 0.08 MPa) to remove excess ammonia and ethanol, yielding a brownish-yellow oily residue. Add 5 mL of distilled water to the residue, extract with ethyl acetate (5 mL × 3), and purify by silica gel column chromatography using a mixed solvent of dichloromethane (DCM) and methanol (MeOH) (DCM to MeOH volume ratio 9:1). Collect the fraction, remove the solvent by rotary evaporation, and obtain a colorless to pale yellow oily liquid guest molecule A (approximately 180 mg). 1 H NMR, 13 The C NMR and TOF-ESI+ characterization data are as follows: 1 ¹H NMR (500MHz, chloroform-d): δ 7.47–7.40 (m, 1H), 7.40–7.28 (m, 3H), 6.72–6.68 (m, 1H), 3.57 (t, J=0.8, 2H), 2.98 (tt, J=6.7, 5.0, 2H), 2.81 (td, J=4.9, 1.3, 2H), 1.95 (d, J=13.3, 1H); 13 C NMR (125MHz, chloroform-d): δ 144.72, 144.23, 141.88, 129.98, 128.22, 127.55, 124.30, 122.53, 41.44, 40.49, 38.50; TOF-ESI+:(m / z) C 11 H 13 N 159.1048.

[0032] II. Preparation of Guest Molecule B The process is as follows: preparation The procedure is as follows: 4-Phenyridine (1 g), 2-bromoethylamine hydrobromide (1.2 g), and anhydrous acetone (100 ml) were added sequentially to a 250 ml two-necked flask. The mixture was refluxed for 4 days under a nitrogen atmosphere. The reaction solution was then filtered to obtain a white solid. (Approximately 0.9g), its 1 H NMR, 13 The C NMR and TOF-ESI+ characterization data are as follows: 1H NMR (400MHz, D2O): δ 8.80 (d, J=7.0Hz, 2H), 8.28 (d, J=6.9Hz, 2H), 7.86 (d, J=6.6Hz, 2H), 7.70-7.31 (m, 3H), 4.88 (t, J=6.7Hz, 2H), 3.64 (t, J=6.7Hz, 2H); 13 C NMR (125MHz, D2O): δ 148.50, 148.45, 138.95, 132.14, 130.10, 128.33, 123.43, 63.29, 42.58; TOF-ESI+): (m / z)C 13 H 16 N2Br2 357.96.

[0033] Under an argon atmosphere, azobenzene-4,4'-dicarbonyl chloride (50 mg) and DCM (5 ml) were added to a 50 ml three-necked flask and stirred in an ice bath for 10 min to obtain a DCM solution of azobenzene-4,4'-dicarbonyl chloride. compound 115 mg of the compound was dissolved in 5 ml of DCM, and then 0.1 ml of triethylamine was added. After 10 min of ice bath reaction, the previously obtained DCM solution of azobenzene-4,4'-dicarbonyl chloride was slowly added. The mixture was stirred in an ice bath for 0.5 h, then heated to room temperature and stirred for 3 h. The reaction was then quenched with 5 ml of deionized water. The mixture was washed sequentially with 0.1 M HCl solution and saturated NaHCO3 solution. The organic phase was collected and purified by silica gel column chromatography (using a mixed solvent of DCM and MeOH in a volume ratio of 9:1) to obtain guest molecule B. 1 H NMR, 13 The C NMR and TOF-ESI+ characterization data are as follows: 1 H NMR (500MHz, chloroform-) d ): δ 9.09-9.04(m, 2H), 8.68(d, J =7.3, 1H), 8.55(t, J =5.4, 1H), 7.97-7.91(m, 2H), 7.80-7.74(m, 2H), 7.64-7.57(m, 2H), 7.47-7.37(m, 2H), 4.92(tt, J =4.5, 0.8, 2H), 3.92(dt, J =5.4, 4.5, 2H); 13C NMR (125MHz, chloroform-) d ): δ 166.32, 156.22, 148.64, 148.50, 147.94, 138.95, 133.57, 132.17, 130.10, 129.08, 128.33, 123.44, 122.18, 61.25, 41.84; TOF-ESI+:(m / z)C 40 H 36 N6O2632.29.

[0034] The main molecule, C-cucurbita[8]urea, is commercially available and its structural formula is shown below: .

[0035] III. The preparation process of the supramolecular complex is as follows: Guest molecule A (5.8 mg) is placed in a two-necked round-bottom flask, and then a 1 cm × 1 cm graphene electrode device and pyridine (10 ml) are added. Under anhydrous and oxygen-free conditions, the mixture is allowed to stand for 48 h to allow guest molecule A to connect with the graphene electrode pair. After washing with acetone and water, the graphene electrode device connected with guest molecule A is obtained. Dissolve guest molecule B (0.193 mg) in water (10 ml) to prepare an aqueous solution of guest molecule B; The host molecule C (0.97 mg) was dissolved in an aqueous solution (4.55 ml) of the guest molecule B to prepare a mixed solution containing the guest molecule B and the host molecule C. The ratio of the number of guest molecules B to the number of host molecules C in the mixed solution was 1:2. The graphene electrode device connected to the guest molecule A was immersed in the mixed solution for 10 min. The guest molecules A, B and C formed a supramolecular complex under the van der Waals forces and hydrophobic interactions. The ratio of the number of guest molecules A, B and C in the supramolecular complex was 2:1:2.

[0036] Example 2 Preparation of supramolecular complexes The process is as follows: I. Preparation of guest molecule A The process is the same as in Example 1.

[0037] II. Preparation of Guest Molecule B The process is as follows: in, The preparation process is the same as in Example 1; Under an argon atmosphere, 50 mg of 4,4'-stilbene dicarboxylic acid and 5 ml of DCM were added to a 50 ml three-necked flask and stirred in an ice bath for 10 min to obtain a DCM solution of 4,4'-stilbene dicarboxylic acid. compound 115 mg of the substance was dissolved in 5 ml of DCM, and then 0.1 ml of triethylamine was added. After continuing the reaction in an ice bath for 10 min, the previously obtained DCM solution of 4,4'-stilbene dicarboxylic acid was slowly added. The mixture was stirred in an ice bath for 0.5 h, then heated to room temperature and stirred at room temperature for 3 h. The reaction was then quenched with 5 ml of deionized water. The mixture was washed sequentially with 0.1 M HCl solution and saturated NaHCO3 solution. The organic phase was collected and purified by silica gel column chromatography using a mixed solvent of petroleum ether (PE) and DCM (PE to DCM volume ratio of 9:1) to obtain solid guest molecule B. 1 H NMR, 13 The C NMR and TOF-ESI+ characterization data are as follows: 1 H NMR (500MHz, chloroform-) d ): δ 9.09-9.04(m, 2H), 8.68(d, J =7.3, 2H), 8.09(t, J =5.5, 1H), 7.91-7.85 (m, 2H), 7.64-7.58 (m, 2H), 7.61-7.52 (m, 2H), 7.47-7.37 (m, 3H), 4.92 (tt, J =4.5, 0.8, 2H), 3.92(dt, J =5.4, 4.5, 2H); 13 C NMR (125MHz, chloroform-) d ): δ 166.98, 148.64, 148.50, 141.08, 138.95, 134.47, 132.17, 130.10, 128.99, 128.33, 128.04, 127.44, 123.44, 61.25, 41.84; TOF-ESI+:(m / z)C 42 H 38 N4O2630.29.

[0038] The main molecule, C-cucurbita[8]urea, was commercially available.

[0039] III. The preparation process of the supramolecular complex is as follows: Guest molecule A (4.9 mg) is placed in a two-necked round-bottom flask, and then a 1 cm × 1 cm graphene electrode device and pyridine (10 ml) are added. Under anhydrous and oxygen-free conditions, the mixture is allowed to stand for 48 h to allow guest molecule A to connect with the graphene electrode pair. After washing with acetone and water, the graphene electrode device connected with guest molecule A is obtained. Dissolve guest molecule B (0.176 mg) in water (10 ml) to prepare an aqueous solution of guest molecule B; The host molecule C (1.03 mg) was dissolved in an aqueous solution (4.80 ml) of the guest molecule B to prepare a mixed solution containing the guest molecule B and the host molecule C. The ratio of the number of guest molecules B to the number of host molecules C in the mixed solution was 1:2. The graphene electrode device connected to the guest molecule A was immersed in the mixed solution for 10 min. The guest molecules A, B and C formed a supramolecular complex under van der Waals forces and hydrophobic interactions. The ratio of the number of guest molecules A, B and C in the supramolecular complex was 2:1:2.

[0040] Example 3 Preparation of supramolecular complexes The process is as follows: I. Preparation of guest molecule A The process is the same as in Example 1.

[0041] II. Preparation of Guest Molecule B The process is as follows: in, The preparation process is the same as in Example 1; Under an argon atmosphere, 50 mg of 4,4'-(cyclopent-1-en-1,2-diyl)bis(5-methylthiophen-2-carboxylic acid) and 5 ml of DCM were added to a 50 ml three-necked flask and stirred in an ice bath for 10 min to obtain a DCM solution of 4,4'-(cyclopent-1-en-1,2-diyl)bis(5-methylthiophen-2-carboxylic acid). compound 100 mg of the substance was dissolved in 5 ml of DCM, and then 0.08 ml of triethylamine was added. After continuing the reaction in an ice bath for 10 min, a DCM solution of 4,4'-(cyclopent-1-en-1,2-diyl)bis(5-methylthiophene-2-carboxylic acid) obtained earlier was slowly added. The mixture was stirred in an ice bath for 0.5 h, then heated to room temperature and stirred at room temperature for 3 h. The reaction was then quenched with 5 ml of deionized water. The mixture was washed sequentially with 0.1 M HCl solution and saturated NaHCO3 solution. The organic phase was collected and purified by silica gel column chromatography (using a mixed solvent of DCM and MeOH in a volume ratio of 9:1) to obtain guest molecule B. 1 H NMR, 13 The C NMR and TOF-ESI+ characterization data are as follows: 1 H NMR (500MHz, chloroform-) d): δ 9.09-9.04(m, 1H), 8.74-8.65(m, 1H), 7.64-7.58(m, 1H), 7.47-7.37(m, 1H), 4.95(tt, J =4.6, 0.9, 1H), 3.94(q, J =4.7, 1H), 3.17-3.11 (m, 1H); 13 C NMR (125MHz, chloroform-) d ): δ 164.46, 148.64, 148.50, 145.75, 139.01, 138.95, 136.08, 135.30, 132. 17, 130.10, 128.33, 127.94, 123.44, 61.21, 41.76, 36.41, 25.37, 15.54; TOF-ESI+:(m / z)C 43 H 42 N4O2S2710.27.

[0042] The main molecule, C-cucurbita[8]urea, was commercially available.

[0043] III. The preparation process of the supramolecular complex is as follows: Guest molecule A (5.2 mg) is placed in a two-necked round-bottom flask, and then a 1 cm × 1 cm graphene electrode device and pyridine (10 ml) are added. Under anhydrous and oxygen-free conditions, the mixture is allowed to stand for 48 h to allow guest molecule A to connect with the graphene electrode pair. After washing with acetone and water, the graphene electrode device connected with guest molecule A is obtained. Dissolve guest molecule B (0.203 mg) in water (10 ml) to prepare an aqueous solution of guest molecule B; The host molecule C (0.98 mg) was dissolved in an aqueous solution (4.60 ml) of the guest molecule B to prepare a mixed solution containing the guest molecule B and the host molecule C. The ratio of the number of guest molecules B to the number of host molecules C in the mixed solution was 1:2. The graphene electrode device connected to the guest molecule A was immersed in the mixed solution for 10 min. The guest molecules A, B and C formed a supramolecular complex under the van der Waals forces and hydrophobic interactions. The ratio of the number of guest molecules A, B and C in the supramolecular complex was 2:1:2.

[0044] Example 4 The fabrication process for opto-memristor devices used in multi-level storage is as follows: 1. Graphene is grown on copper sheets using chemical vapor deposition.

[0045] A copper sheet (1.2cm × 10cm) was placed in a glass petri dish and immersed in 5% acetic acid for 15 minutes to remove the oxide layer and stains on the surface of the copper sheet. After removing the copper sheet, it was washed three times with deionized water and twice with anhydrous ethanol, and then dried with nitrogen to obtain a clean copper sheet. The copper sheet was placed on a quartz plate and placed together in the tube furnace of a chemical vapor deposition instrument. The temperature was raised to 1030℃, and graphene was grown at this temperature for 25 minutes in a mixed atmosphere of methane and hydrogen (flow ratio 1.6:8, total flow rate 10 sccm). Then it was cooled to room temperature to obtain a copper sheet covered with graphene.

[0046] 2. Transfer the graphene grown on the copper sheet to the clean surface of the silicon wafer to obtain a silicon wafer with a graphene-coated surface layer.

[0047] Place the silicon wafer (1.5cm × 1.5cm) in a crystallizing dish, add a mixed solution of 30% hydrogen peroxide (12ml) and 98% concentrated sulfuric acid (28ml), let it stand at 120℃ for 2 hours, pour out the liquid, add deionized water and ultrasonically clean for 3 minutes, repeat 3 times, remove the silicon wafer and blow it dry with nitrogen gas to obtain a clean silicon wafer.

[0048] A copper sheet coated with graphene was adhered to a glass slide using transparent adhesive. The slide was then placed on a spin coater, and polymethyl methacrylate (PMMA) 950 was added. The coating was first spin-coated at 600 rpm for 8 seconds, then at 3000 rpm for 30 seconds, followed by curing on a 180°C hot plate for 2 minutes. The PMMA-coated copper sheet was cut into 1cm x 1cm pieces and floated in a saturated ferric chloride solution for 2 hours until the copper was completely dissolved. The floating PMMA / graphene composite film was then sequentially transferred to a 0.1 mmol / L dilute hydrochloric acid solution (soaking for 30 minutes to remove residual copper ions), deionized water (soaking for 3 minutes), a 0.1 mmol / L potassium hydroxide solution (soaking for 20 minutes to neutralize the acidity), and then deionized water (soaking for 3 minutes). The composite film was then transferred to a clean silicon wafer surface and allowed to stand for 12 hours to allow complete adhesion. The silicon wafer covered with the composite film was immersed in acetone solution for 2 minutes to remove the surface PMMA support layer. After removal, it was rinsed with deionized water and dried with nitrogen to obtain a clean graphene silicon wafer.

[0049] Third, by combining photolithography and oxygen plasma etching techniques, a pre-defined shape of metal electrodes is defined on the graphene layer to obtain a patterned graphene silicon wafer.

[0050] A clean graphene silicon wafer was placed on a spin coater, and photoresist was added. The wafer was then spin-coated at 600 rpm for 8 seconds, followed by spin-coating at 3000 rpm for 30 seconds. It was then pre-baked on a 110°C hot plate for 3 minutes. The photoresist-coated graphene silicon wafer was then exposed on a photolithography machine, and after development, a rectangular pattern was formed. The developed wafer was then placed in an oxygen plasma etching machine, with oxygen introduced (flow rate 50 sccm, pressure 10 Pa), and etched at 50 W for 60 seconds to remove the graphene not covered by the photoresist. After etching, the wafer was immersed in acetone solution for 5 minutes to remove residual photoresist. The wafer was then removed, rinsed with anhydrous ethanol, and dried with nitrogen to obtain a rectangular graphene silicon wafer.

[0051] Fourth, using vapor deposition technology, metal materials are deposited on patterned graphene layers to obtain graphene layers with gold electrodes.

[0052] Photolithography is performed on the patterned graphene silicon wafer to create electrode shapes. The processed graphene silicon wafer is then placed in a thermal evaporation deposition apparatus, the chamber door is closed, and a vacuum of 3 × 10⁻⁶ is applied. -4 Pa. Using electron beam evaporation, an 8 nm chromium layer was first deposited at a rate of 0.1 nm / s (to enhance the adhesion between the metal and graphene), followed by an 80 nm gold layer at a rate of 0.5 nm / s. After evaporation, the device was immersed in acetone solution for 10 min to remove excess photoresist and surface metal layers. After removal, it was rinsed with acetone, dichloromethane, and deionized water, and dried with nitrogen to obtain a graphene layer with a gold electrode.

[0053] 5. Using oxygen plasma etching and electron beam lithography, graphene electrode pairs with nanochannels are formed on graphene layers loaded with metal electrodes.

[0054] The device with grown gold electrodes underwent electron beam exposure pretreatment: PMMA 950 was spin-coated on a spin coater at 500 rpm for 8 seconds, followed by spin-coating at 2000 rpm for 30 seconds, and then pre-baked on a 180°C hot stage for 2 minutes. The device was then placed in the vacuum chamber of the electron beam exposure instrument, and a vacuum of 5 × 10⁻⁶ was applied. -5 The device was exposed to a preset pattern (a dashed line 100 nm long and 4 nm wide) at a pressure of Pa. After exposure, it was developed for 10 seconds with a developer (a mixture of methyl isobutyl ketone and isopropanol, with a volume ratio of 1:3). The device was then removed, rinsed with deionized water, and dried with nitrogen to form a nanoscale etching mask. The device was then placed in an oxygen plasma etching instrument, and oxygen was introduced (flow rate 50 sccm, pressure 10 Pa). The exposed graphene region was etched at a power of 50 W. During the etching process, the conductivity of the device was tested in real time using a room-temperature probe station until the current reached zero, at which point the etching was stopped, resulting in a graphene electrode pair with nanochannels.

[0055] VI. Synthesize supramolecular complexes and connect them between graphene electrode pairs.

[0056] Following the methods for preparing supramolecular complexes in Examples 1 and 3 respectively, supramolecular complexes were synthesized and connected between graphene electrode pairs with nanochannels. The devices were then removed, rinsed with pure water, and dried to obtain Sample 1 and Sample 2 of optoelectronic memristor devices for multi-level storage.

[0057] Sample 1 and Sample 2 were tested using a room temperature probe station, a source meter (DECITIC B2900B), and ultraviolet lamps (AC 90V~230V, wavelengths 310nm and 365nm).

[0058] The testing process for Sample 1 was as follows: First, a scanning voltage of -1V to 1V was applied to Sample 1. Under this voltage, Sample 1 exhibited a high-conductivity state HC1 and a low-conductivity state LC1, achieving information storage. Then, Sample 1 was irradiated with 365nm ultraviolet light, causing the azophenyl group in the supramolecular complex structure to change from a trans to a cis configuration. Afterward, a scanning voltage of -1V to 1V was applied to Sample 1. Due to reduced molecular conjugation and weakened delocalization, the conductivity of the supramolecular complex decreased, resulting in two conductivity states: a high-conductivity state HC2 and a low-conductivity state LC2. Sample 1 achieved four-state storage through photoelectric synergy, as shown in the test results. Figure 2 As shown, this result demonstrates the successful fabrication of an opto-memristor device for multi-level storage.

[0059] The testing process for sample 2 was as follows: A scanning voltage of -1V to 1V was applied to sample 2. Under the influence of this scanning voltage, sample 2 exhibited a high-conductivity state HC1 and a low-conductivity state LC1, achieving information storage. Then, sample 2 was irradiated with 365nm ultraviolet light, causing the diarylene group in the supramolecular complex structure to change from an open-ring to a closed-ring structure. Subsequently, a scanning voltage of -1V to 1V was applied to sample 2. Due to the complete and highly delocalized large π-conjugated system of the diarylene closed-ring state, the conductivity of the supramolecular complex increased, resulting in two conductivity states: a high-conductivity state HC2 and a low-conductivity state LC2, under the influence of the scanning voltage. Sample 2 achieved four-state storage through photoelectric synergy, and the test results are as follows. Figure 3 As shown, this result demonstrates the successful fabrication of an opto-memristor device for multi-level storage.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; 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; and these 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.

Claims

1. An opto-memristor device for multi-level storage, characterized in that, It includes a supramolecular composite and a graphene electrode pair, wherein the supramolecular composite is connected between the graphene electrode pairs; Under the action of scanning voltage, the supramolecular complex can respond to voltage changes and form different conductivity states; The supramolecular complex comprises guest molecule A, guest molecule B, and host molecule C, and the structural formula of the supramolecular complex is shown below: ； Among them, in the structural formula The supramolecular complex is a guest molecule A, and the supramolecular complex is connected to the graphene electrode pair via an amide bond through the guest molecule A; In the structural formula The guest molecule is B; Wherein, R is a UV-responsive group, which can undergo a configurational change under UV light irradiation; In the structural formula Representative molecule C n is selected from 7 or 8.

2. The opto-memristor device for multi-level storage as described in claim 1, characterized in that, R is selected from , and Any one of them.

3. The opto-memristor device for multi-level storage as described in claim 1, characterized in that, The wavelength of the ultraviolet light is 310nm or 365nm.

4. The opto-memristor device for multi-level storage as described in claim 1, characterized in that, The scanning voltage is -1V to 1V.

5. A method for fabricating an opto-memristor device for multi-level storage, characterized in that, The method for fabricating the opto-memristor device for multi-level storage as described in any one of claims 1 to 4 comprises the following steps: S100. Using an amide condensation reaction, guest molecule A is connected to a graphene electrode pair to obtain a graphene electrode pair connected to guest molecule A. S200. Prepare a mixed solution containing guest molecule B and host molecule C. S300. Immerse the graphene electrode pair connected to guest molecule A into the mixed solution for at least 10 minutes to form a supramolecular complex of guest molecule A, guest molecule B and host molecule C, and the supramolecular complex is connected between the graphene electrode pairs to obtain a photoelectric memristor device for multi-level storage.

6. The method for fabricating an opto-memristor device for multi-level storage as described in claim 5, characterized in that, In step S100, the reaction solvent for the amide condensation reaction is selected from pyridine, the reaction catalyst is selected from 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and the reaction atmosphere is an anhydrous and oxygen-free environment.

7. The method for fabricating an opto-memristor device for multi-level storage as described in claim 5, characterized in that, The preparation of the graphene electrode pair includes the following steps: S110. Graphene is grown on a copper sheet using chemical vapor deposition. S120. Transfer the graphene grown on the copper sheet to the clean silicon wafer surface to obtain a silicon wafer with a graphene layer on the surface. S130. Combining photolithography and oxygen plasma etching techniques, a preset shape of metal electrodes is defined on the graphene layer to obtain a patterned graphene silicon wafer. S140. Using vapor deposition technology, a metal material is vapor deposited on the patterned graphene layer to obtain a graphene layer with a metal electrode. S150: Using oxygen plasma etching and electron beam lithography, graphene electrode pairs with nanochannels are formed on a graphene layer loaded with metal electrodes.

8. The method for fabricating an opto-memristor device for multi-level storage as described in claim 7, characterized in that, In step S140, the metallic material includes metallic chromium (Cr) and metallic Au.

9. The method for fabricating an opto-memristor device for multi-level storage as described in claim 5, characterized in that, In step S200, the solvent of the mixed solution is selected from water.

10. The method for fabricating an opto-memristor device for multi-level storage as described in claim 5, characterized in that, In step S300, the ratio of guest molecules A, guest molecules B to host molecules C in the mixed solution is 2:1:2.

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