Single-molecule memristor based on supramolecular assembly and preparation method thereof

Abstract

This invention relates to the field of microelectronic device technology, and more particularly to a single-molecule memristor-rectifier device based on supramolecular assembly and its fabrication method. The fabrication method involves covalently linking a guest molecule B to the ends of a graphene electrode pair, ensuring a stable and tight interfacial bond between the supramolecular functional molecule and the electrode. Subsequently, the graphene electrode pair connected to the guest molecule B is immersed in a solution containing a host molecule A and a guest molecule C, forming a supramolecular functional molecule between the graphene electrode pairs. The guest molecule C in the supramolecular functional molecule possesses intrinsic redox activity; its molecular structure itself can undergo reversible electron gain and loss processes, thereby achieving controllable and reversible adjustment of the intramolecular charge distribution. Under the influence of an electric field, the reversible redox reaction of the guest molecule C triggers significant changes in the intramolecular charge distribution and electron transport characteristics, ultimately achieving reliable switching between high and low resistance states of the device.

Description

Technical Field

[0001] This invention relates to the field of microelectronic device technology, and in particular to a single-molecule memristor-rectifier device based on supramolecular assembly and its fabrication method. Background Technology

[0002] With the rapid evolution of artificial intelligence and big data technologies, the demand for computing efficiency, storage density, and multi-functional integration in electronic devices is growing exponentially. The traditional von Neumann architecture, due to its separation of in-memory and computing, suffers from high latency and high energy consumption, becoming a core bottleneck in technological development. Memristors, as a fundamental element of the fourth type of circuit, can overcome architectural limitations thanks to their in-memory computing advantages. If integrated with a rectifier (diode), they can further solve problems of signal interference and reverse current loss, possessing irreplaceable potential in high-end applications.

[0003] Single-molecule memristors (core size 1-3nm) combine ultra-high integration density and low power consumption, theoretically meeting the needs of multi-functional integration. However, existing technologies face two major obstacles: first, it is difficult to accurately position single molecules at the electrode interface, and there is a lack of effective fixation technology; second, the molecular-electrode contact interface has poor stability, making it difficult to build a long-term stable charge transport channel, which not only restricts mass production but also hinders the efficient integration and performance optimization of rectification functions.

[0004] Memristor-rectifier devices, by integrating resistive switching and self-rectification characteristics, effectively solve the problems of excessive creep current and the need for external selectors in traditional memristor arrays, and have significant application value in high-density storage and in-memory computing. Currently, self-rectifying memristors based on oxide, perovskite, and two-dimensional materials have achieved high rectification ratios, good durability, and high-speed switching performance, and are compatible with Complementary Metal-Oxide-Semiconductor (CMOS) processes. However, these devices still face key bottlenecks such as the difficulty in balancing rectification and resistive switching performance, poor device uniformity, random conductive filaments, insufficient environmental and thermal stability, and uncontrollable initialization / activation processes. At the array level, there are problems such as incomplete suppression of large-scale creep current and significant parasitic effects. At the process and industrialization level, there is a lack of unified standards, low yield, and an immature industry chain. Furthermore, the circuit and algorithm ecosystem for adapting device characteristics is still incomplete.

[0005] The single-molecule memristor-rectifier (1D1R) device has achieved proof-of-principle and breakthrough in single-junction performance, marking a significant milestone in atomic-level electronics and promising to overcome existing technological bottlenecks. Summary of the Invention

[0006] The present invention aims to at least solve one of the technical problems existing in the related art. To this end, the first objective of the present invention is to provide a single-molecule memristor-rectifier device based on supramolecular assembly; the second objective of the present invention is to provide a method for fabricating a single-molecule memristor-rectifier device based on supramolecular assembly.

[0007] To achieve the first objective, the technical solution adopted by this invention is as follows:

[0008] A single-molecule memristor-rectifier device based on supramolecular assembly includes a first graphene electrode, a supramolecular functional molecule, and a second graphene electrode. The first graphene electrode and the second graphene electrode form a graphene electrode pair, and the supramolecular functional molecule is connected between the graphene electrode pairs.

[0009] The supramolecular functional molecular structure is selected from any of the following:

[0010] ,

[0011] ;

[0012] in, and The chemical structural formula is n is an integer from 6 to 10;

[0013] The gap between the graphene electrode pairs is a nanometer gap.

[0014] Furthermore, the supramolecular functional molecule is connected to the graphene electrode pair via amide bonds.

[0015] Furthermore, the gap between the graphene electrode pairs is 1 nm to 10 nm.

[0016] Furthermore, the graphene electrode pair is a point electrode pair.

[0017] To achieve the second objective, the technical solution adopted by this invention is as follows:

[0018] A method for fabricating a single-molecule memristor-rectifier device based on supramolecular assembly, used to fabricate any of the above-mentioned single-molecule memristor-rectifier devices based on supramolecular assembly, includes the following steps:

[0019] S100. Graphene electrode pairs are fabricated on a substrate to obtain graphene electrode device I.

[0020] S200. The graphene electrode device I is immersed in solution I containing guest molecule B, and the guest molecule B is connected to the end of the graphene electrode pair by condensation reaction to obtain graphene electrode device II.

[0021] The structural formula of the guest molecule B is shown below:

[0022] ;

[0023] S300. The graphene electrode device II is immersed in solution II containing host molecule A and guest molecule C. By utilizing the van der Waals forces, π-π interactions and hydrophobic interactions between molecules, supramolecular functional molecules are formed between the graphene electrode pairs to obtain a single-molecule memristor-rectifier device based on supramolecular assembly.

[0024] The structural formula of the main molecule A is shown below:

[0025] n is an integer from 6 to 10;

[0026] The guest molecule C is selected from any of the following:

[0027] , .

[0028] Based on host-guest specific interactions, supramolecular technology has the advantages of precise recognition, efficient connection and reversibility and tunability. It can solve the problems of single-molecule localization and interface stability, and can also build asymmetric charge transport channels through asymmetric assembly, providing a natural solution for single-molecule rectification-memristor (1D1R) dual-function integration.

[0029] The host molecule A in the supramolecular functional molecule has a cone-shaped structure, which is hydrophobic inside and hydrophilic outside. It can form an ordered monolayer or supramolecular structure through non-covalent interactions such as hydrogen bonding, hydrophobic interaction, and van der Waals forces. It stably binds guest molecule A and guest molecule C through host-guest inclusion. The inclusion of guest molecule C by host molecule A has the following characteristics:

[0030] Firstly, the conjugated thiophene skeleton of Formula I and the hydrophobic parts such as the alkyl chain and benzene ring of Formula II can enter the hydrophobic cavity of cyclodextrin, while the hydrophilic / charged end groups (pyridine cations, amino groups) are exposed outside the cavity and form hydrogen bonds or electrostatic interactions with the cyclodextrin hydroxyl groups.

[0031] Secondly, the pyridine cations of formulas I and II can form electrostatic interactions and hydrogen bonds with the hydroxyl groups at the orifice of cyclodextrin;

[0032] Third, Formula I, which has a high degree of conjugation, can also undergo π-π stacking with cyclodextrin, further enhancing inclusion stability;

[0033] Fourth, the flexible alkyl chain of Formula II can be conformed to be adjusted, making it easier to adapt to the cyclodextrin cavity.

[0034] In addition, the main molecule A has a rigid cyclic skeleton, stable chemical properties, and is resistant to high temperature and acid and alkali environments, which is conducive to constructing functional devices with good stability.

[0035] When the supramolecular functional molecules are applied to 1D1R devices, the amino terminus of guest molecule B can form a covalent bond with the end of the graphene electrode pair, thereby achieving a stable and tight interfacial bond between the supramolecular functional molecules and the electrodes. Guest molecule C possesses intrinsic redox activity, and its molecular structure itself can undergo reversible electron gain and loss processes, thus enabling controllable and reversible adjustment of the intramolecular charge distribution. Under the action of an electric field, the supramolecular functional molecules can induce significant changes in the intramolecular charge distribution and electron transport characteristics through the reversible redox reaction of guest molecule C, ultimately achieving reliable switching between high and low resistance states of the device.

[0036] Further, in step S200, the solvent of solution I is selected from pyridine.

[0037] Furthermore, in step S300, the solvent of solution II is selected from water.

[0038] Further, in step S300, when the guest molecule C is guest molecule C1, the synthesis includes the following steps:

[0039] S310, with Using raw materials, intermediate I was synthesized, with the structural formula shown below:

[0040] ;

[0041] S320, using the intermediate I and The reaction was carried out to synthesize intermediate II, the structural formula of which is shown below:

[0042] ;

[0043] S330, using the intermediate II and The reaction synthesizes the guest molecule C1.

[0044] Further, in step S300, when the guest molecule C is guest molecule C2, the synthesis includes the following steps:

[0045] S301. Utilization and The reaction synthesized intermediate III, the structural formula of which is shown below:

[0046] ;

[0047] S302, using the intermediate III and The reaction synthesizes the guest molecule C2.

[0048] Furthermore, in step S300, the molar ratio of host molecule A to guest molecule C in solution II is 1:1.

[0049] The above-described one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects:

[0050] The present invention provides a method for fabricating a single-molecule memristor-rectifier device based on supramolecular assembly. The method utilizes a condensation reaction to form a covalent bond between the amino terminus of guest molecule B and the end of a graphene electrode pair. Subsequently, the graphene electrode pair connected with guest molecule B is immersed in a solution containing host molecule A and guest molecule C. By utilizing the van der Waals forces, π-π interactions, and hydrophobic interactions between molecules, supramolecular functional molecules are further formed between the graphene electrode pairs.

[0051] The single-molecule memristor-rectifier device based on supramolecular assembly provided by this invention features a covalent bond between the amino terminus of guest molecule B in the supramolecular functional molecule and the end of the graphene electrode pair, ensuring a stable and tight interfacial bond between the supramolecular functional molecule and the electrode. Guest molecule C possesses intrinsic redox activity, and its molecular structure itself can undergo reversible electron gain and loss processes, thereby achieving controllable and reversible adjustment of the intramolecular charge distribution. Under the influence of an electric field, the supramolecular functional molecule can induce significant changes in the intramolecular charge distribution and electron transport characteristics through the reversible redox reaction of guest molecule C, ultimately achieving reliable switching between high and low resistance states of the device.

[0052] 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

[0053] Figure 1 This is a schematic diagram of the structure of the supramolecular functional molecule (the structural formula of guest molecule C is Formula I) provided in Embodiment 3 of the present invention after being connected with the graphene electrode pair.

[0054] Figure 2 This is a schematic diagram of the structure of the supramolecular functional molecule (the structural formula of guest molecule C is formula II) provided in Embodiment 3 of the present invention after being connected with the graphene electrode pair.

[0055] Figure 3 This is a schematic diagram of the structure of the single-molecule memristor-rectifier device based on supramolecular assembly provided in Embodiment 3 of the present invention.

[0056] Figure 4 This is the current-voltage curve of a single-molecule memristor-rectifier device based on supramolecular assembly after testing the current response characteristics when the guest molecule is C1, as provided in Embodiment 3 of the present invention.

[0057] Figure 5 This is the current-voltage curve of the single-molecule memristor-rectifier device based on supramolecular assembly after testing the current response characteristics when the guest molecule is C2, as provided in Embodiment 3 of the present invention.

[0058] Figure label:

[0059] 1. First graphene electrode; 2. Supramolecular functional molecule; 3. Second graphene electrode. Detailed Implementation

[0060] 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.

[0061] 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.

[0062] Example 1

[0063] Synthetic guest molecule C1 The process is as follows:

[0064] I. Synthetic Intermediate I .

[0065] Under a nitrogen atmosphere, 2-chloroethanethiol (0.193 g, 2.00 mmol) was dissolved in anhydrous N,N-dimethylformamide (DMF) (5 mL), and the solution was cooled to 0 °C and stirred for 10 min at this temperature. Then, NaH (52.8 mg, 2.20 mmol) was added in portions (approximately 10 mg each time, at 2–3 min intervals), and stirring continued until bubbles (H2) stopped escaping (approximately 15–30 min). After the temperature was raised to room temperature (approximately 25 °C), a DMF solution containing I2 (1.00 mmol, 253.8 mg) was added dropwise (5 mL). After the addition was complete, the reaction was stirred and the mixture was analyzed by thin-layer chromatography. Chromatography (TLC) (developing solvent: n-hexane / ethyl acetate = 10:1, colorimetric method: iodine fuming, detection every 30 min), after the reaction reached the endpoint, saturated Na2S2O3 aqueous solution was added dropwise to the reaction solution while stirring until the brown color of iodine in the reaction solution completely disappeared. Then, water (10 mL) was added to the reaction system and stirred evenly to terminate the reaction. Subsequently, the reaction solution was extracted with ethyl acetate (10 mL × 3 times), the organic phase was collected and dried with Na2SO4, concentrated under reduced pressure, and purified by silica gel column chromatography (mobile phase: n-hexane / ethyl acetate, volume ratio of 15:1). The eluent was collected, concentrated under reduced pressure, and dried to obtain a yellowish-white solid intermediate I. Its characterization data are shown below:

[0066] 1 H NMR (500MHz, CDCl3): δ=7.16 (s, 2H);

[0067] 13 C NMR (125MHz, CDCl3): δ=130.17, 119.36, 115.35;

[0068] TOF-ESI(+)(m / z)C6H2C l2 S4: 273.2291.

[0069] II. Synthetic Intermediate II .

[0070] Intermediate I (100 mg), 4-pyridine-1-chlorobenzene (50 mg), and anhydrous acetone (100 mL) were added sequentially to a two-necked flask. The mixture was stirred for 10–15 min until the solid was completely dissolved. The mixture was then refluxed under a nitrogen atmosphere for 5 days. After naturally cooling to room temperature (approximately 25 °C), the mixture was filtered to obtain a filter cake. The filter cake was washed with diethyl ether (10 mL × 3 times) and dried to obtain a white solid intermediate II. Its characterization data are shown below:

[0071] 1H NMR (500MHz, CDCl3): δ=9.33(d, J =7.2, 2H), 8.40 (d, J =7.0, 2H), 7.69 (s, 2H), 7.60–7.54 (m, 2H), 7.39 (s, 1H), 7.33 (s, 1H);

[0072] 13 C NMR (125MHz, CDCl3): δ=151.38, 146.69, 135.51, 135.47, 133.09, 130.16, 129.52, 123.07, 122.68, 119.80, 119.50, 116.85, 114.18;

[0073] TOF-ESI (+) (m / z)C 17 H 10 C l2 NS4: 427.4109.

[0074] III. Synthesis of the target guest molecule C1.

[0075] Intermediate II (100 mg), 4-pyridinephenol (100 mg), and anhydrous acetone (100 mL) were added sequentially to a two-necked flask. The mixture was stirred for 10–15 min until the solid was completely dissolved. The mixture was then refluxed under a nitrogen atmosphere for 5 days. After naturally cooling to room temperature (approximately 25 °C), the mixture was filtered to obtain a filter cake. The filter cake was washed with diethyl ether (10 mL × 3 times) and dried to obtain a white solid target guest molecule C1. Its characterization data are shown below:

[0076] 1 H NMR (400MHz, CDCl3): δ=9.33 (d, J=7.2, 4H), 8.40 (dd, J=14.4, 7.1, 2H), 8.37 (dd, J=14.4 ,7.1,2H),7.78(m,2H),7.67(m,2H),7.57(m,2H),7.36(m,2H),7.03(s,1H),6.78(m,2H);

[0077] 13 C NMR (400MHz, CDCl3): δ=158.75, 151.38, 150.53, 146.71, 146.69, 135.51, 135.47, 133.24, 133.09, 129.52, 128.58, 123.09, 123.07, 122.50, 119.06, 117.11, 116.30;

[0078] TOF-ESI (+) (m / z)C 28 H 19 N2ClOS4: 563.0509.

[0079] Example 2

[0080] Synthetic guest molecule C2 The process is as follows:

[0081] I. Synthetic Intermediate III .

[0082] Under a nitrogen atmosphere, 4-phenylpyridine (5 mmol) and acetonitrile (20 mL) were added to a dry flask and stirred to dissolve. After cooling to 0–5 °C in an ice bath, 1,7-dibromoheptane (5.5 mmol) was slowly added dropwise, followed by potassium carbonate (5.5 mmol) in portions. After the addition was complete, the reaction system was slowly heated to room temperature (approximately 25 °C) and stirred for 2–4 h. The reaction was monitored by TLC (using dichloromethane / methanol as the eluent, with a volume ratio of 9:1). The reaction was terminated immediately when the spot of the 4-phenylpyridine starting material disappeared. The mixture was concentrated under reduced pressure by distillation and purified by column chromatography (using petroleum ether / ethyl acetate as the eluent, with a volume ratio of 50:1). After concentration under reduced pressure and drying, a white powder intermediate III was obtained. Its characterization data are shown below:

[0083] 1 H NMR (500MHz, CDCl3): δ=9.55–9.49(m, 2H), 8.68(d, J =7.3, 2H), 7.64–7.56 (m, 2H), 7.43 (m, 2H) 7.41 (s, 1H), 4.82 (tt, J =6.4, 1.0, 2H), 3.44(t, J =4.7, 2H), 2.03(tt, J =7.7, 6.2, 2H), 1.90–1.81 (m, 2H), 1.48–1.38 (m, 4H), 1.41–1.31 (m, 2H);

[0084] 13 C NMR (125MHz, CDCl3): δ=148.65, 145.92, 138.95, 132.14, 130.10, 128.33, 123.36, 61.35, 33.71, 33.21, 31.69, 29.13, 28.41, 26.21;

[0085] TOF-ESI (+) (m / z)C 18 H 23 BrN: 333.2909.

[0086] II. Synthesis of the target guest molecule C2.

[0087] Under a nitrogen atmosphere, intermediate III (10 mmol, 2.74 g), benzylamine (10 mmol, 1.18 mL), anhydrous potassium carbonate (20 mmol, 2.76 g), and anhydrous acetonitrile (100 mL) were added to a dry 250 mL round-bottom flask. After magnetic stirring to ensure complete dispersion of the solids, the reaction system was slowly heated to 80 °C and refluxed with stirring for 24 h. After the reaction was complete, the system was allowed to cool naturally to room temperature (approximately 25 °C). The solid salts were then removed by suction filtration using a Buchner funnel. The filtrate was collected and distilled under reduced pressure (40 °C, 0.05 MPa). The crude product was obtained. Ethyl acetate (50 mL) was added to the crude product, and the mixture was stirred until the crude product was completely dissolved. The resulting solution was transferred to a separatory funnel and washed with saturated saline (30 mL × 2 times). After standing and separating the layers, the organic phase was collected and dried with anhydrous magnesium sulfate (5 g) for 30 min. The filtrate was collected and concentrated by vacuum distillation. The concentrate was purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate, volume ratio 10:1). The eluent was collected and the eluent was removed by vacuum distillation to obtain a colorless oily guest molecule C2. Its characterization data are shown below:

[0088] 1 H NMR (400MHz, CDCl3): δ=9.55–9.49 (m, 2H), 8.68 (d, J=7.4, 2H), 7.73 (m, 2H), 7.64–7.56 (m, 2H), 7.4–7.37 (m, 3H), 7.36–7.22 (m, 3H), 4.82 (t, J=6.3, 1.0, 2H), 3.92–3.86 (m, 3H), 2.73 (q, J=5.2, 2H), 2.03 (t, J=7.7, 6.2, 2H), 1.50 (m, 2H), 1.43 (m, 2H), 1.33 (m, 2H), 1.33 (m, 2H);

[0089] 13 C NMR (400MHz, CDCl3): δ=148.65, 145.92, 139.68, 138.95, 132.14, 130.10, 128.63, 128 .33, 128.30, 127.61, 123.36, 61.35, 53.96, 49.25, 31.69, 29.26, 29.21, 27.40, 26.21;

[0090] TOF-ESI (+) (m / z)C 25 H 31 N2: 359.2483.

[0091] Example 3

[0092] like Figure 1 , Figure 2 and Figure 3 As shown, the single-molecule memristor-rectifier device based on supramolecular assembly includes a first graphene electrode 1, a supramolecular functional molecule 2, and a second graphene electrode 3. The first graphene electrode 1 and the second graphene electrode 3 form a graphene electrode pair, and the supramolecular functional molecule 2 is connected between the graphene electrode pairs.

[0093] The supramolecular functional molecular structure formula is selected from any of the following:

[0094] ,

[0095] ;

[0096] in, and The chemical structural formula is n is an integer between 6 and 10.

[0097] The fabrication method of a single-molecule memristor-rectifier device based on supramolecular assembly includes the following steps:

[0098] S100. Graphene electrode pairs are fabricated on a substrate to obtain graphene electrode device I.

[0099] S200. The graphene electrode device I is immersed in solution I containing guest molecule B, and the guest molecule B is connected to the end of the graphene electrode pair by condensation reaction to obtain graphene electrode device II.

[0100] The structural formula of the guest molecule B is shown below:

[0101] ;

[0102] S300. The graphene electrode device II is immersed in solution II containing host molecule A and guest molecule C. By utilizing the van der Waals forces, π-π interactions and hydrophobic interactions between molecules, supramolecular functional molecules are formed between the graphene electrode pairs to obtain a single-molecule memristor-rectifier device based on supramolecular assembly.

[0103] The structural formula of the main molecule A is shown below:

[0104] n is an integer from 6 to 10;

[0105] The guest molecule C is selected from any of the following:

[0106] , .

[0107] Taking a host molecule A as γ-cyclodextrin (γ-CD) and a guest molecule C with the structural formula of Formula I as an example, the fabrication process of a single-molecule memristor-rectifier device based on supramolecular assembly is as follows:

[0108] The structural formula of γ-cyclodextrin (γ-CD) is shown below:

[0109] ;

[0110] I. Silicon wafer pretreatment.

[0111] Place a square silica wafer (1cm×1cm) in a standard piranha cleaning solution (30% hydrogen peroxide and 98% concentrated sulfuric acid in a volume ratio of 3:7), boil at 110℃ for 2.5h, then sonicate for 15min. After treatment, wash with deionized water and acetone 2-3 times each, and then air dry for later use.

[0112] 2. Prepare single-layer graphene and transfer it onto a silicon wafer.

[0113] A copper sheet (2cm × 8cm) was soaked in acetic acid for 15 minutes, then cleaned sequentially with water, ethanol, and acetone, and dried. It was then placed in a chemical vapor deposition (CVD) instrument, with methane and hydrogen as reactant gases, and heated to 1030℃ for graphene growth. After growth, polymethyl methacrylate (PMMA) was spin-coated onto the graphene surface at 4000 rpm. The sheet was then baked at 180℃ for 2 minutes. After baking, excess PMMA and graphene on the back of the copper foil were etched using oxygen plasma, resulting in a PMMA-monolayer graphene-copper foil structure. After cutting it into 1cm×1cm square pieces, place them in a saturated ferric chloride solution until the copper foil dissolves, obtaining a PMMA-graphene film containing a single layer of graphene. The film is then washed sequentially with a 6wt% hydrochloric acid aqueous solution, water, a 5wt% potassium hydroxide aqueous solution, and water. After washing, the film is transferred to the pretreated silicon wafer. Subsequently, the silicon wafer is immersed in an acetone solution for 12 hours to remove PMMA, resulting in a silicon wafer loaded with a single layer of graphene.

[0114] III. Fabrication of silicon wafers with electrode patterns.

[0115] The first step, photolithography and evaporation, is as follows: Photoresist is deposited onto the monolayer graphene surface of the silicon wafer and spin-coated evenly at 4000 rpm. It is then heated at 110 °C for 3 minutes for baking. After baking, the photolithography machine, vacuum pump, and main valve of the gas cylinder are turned on. The corresponding marked photomask is loaded, and the silicon wafer is placed in the center of the sample stage. Exposure is initiated at 300W power for 2 seconds, followed by 10 seconds of development, 15 seconds of ultrapure water fixing, and drying with a nitrogen gun. Then, the vacuum level of the thermal resistance evaporation coating machine is evaporated to approximately 5 × 10⁻⁶. -5 After Pa, 9 nm thick chromium and 70 nm thick gold are deposited on the surface of the silicon wafer (the area of ​​the marked pattern retained after development). After the deposition is completed, the silicon wafer is immersed in acetone for 12 hours. Then, the pattern outside the illuminated area is washed off with acetone. After the sample is taken out, it is rinsed clean with acetone to obtain the marked silicon wafer.

[0116] The second step, photolithography and etching, is as follows: The exposure and development methods for the second step are the same as those for the first step. The developed device is placed in a reactive ion etching (RIE) machine and etched for 45 seconds. Then, the photoresist on the surface of the device is rinsed with acetone. The third step, photolithography, is then performed. The exposure and development methods for the second step are the same as those for the first two steps. After this photolithography step, a silicon wafer with electrode patterns is obtained.

[0117] IV. Fabrication of graphene electrode devices I.

[0118] A layer of PMMA (spin-coating method as above) is spin-coated onto the electrode pattern on a silicon wafer and then baked. Electron beam lithography (EBL) is then used to etch dashed lines (the dashed lines are positioned between each pair of gold electrodes, with a total length of 60 μm, each dashed segment being 150 nm long and spaced 40 nm apart) onto the PMMA layer, resulting in a graphene array of dot electrodes. These graphene array electrodes are then developed in a solution of isopropanol diluted with methyl isobutyl ketone (volume ratio of isopropanol to methyl isobutyl ketone is 1:3). Subsequently, oxygen plasma reactive ion etching is used for etching. During this process, carboxyl groups are generated at the ends of the graphene, ultimately yielding graphene dot electrode pairs with a spacing of 1 nm to 10 nm.

[0119] The conductivity of the graphene point electrode pairs was tested using a probe station. The voltage was set to 0.5 V, and the conductivity of each gold electrode-graphene-gold electrode pair was detected. It was determined whether the graphene at the dotted line was completely broken (if it was completely broken, no obvious conductivity signal could be detected). If it was not completely broken, the RIE etching step was repeated or the current was increased to burn it off. Finally, a silicon wafer with graphene electrode pairs was obtained, which was denoted as graphene electrode device I.

[0120] III. Utilizing condensation reactions to make guest molecule B Connected to the carboxyl groups at the ends of the graphene electrode pair.

[0121] Guest molecule B (0.5 mg), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (0.3 mg), and anhydrous pyridine (10 mL) were added sequentially to a two-necked flask. The reactants were sonicated for 15 min to ensure complete dissolution and homogeneity. Then, graphene electrode device I was placed inside. The air in the flask was replaced with nitrogen and sealed. The flask was allowed to stand at room temperature (approximately 25 °C) for 48 h. After that, the device was removed, rinsed with water and acetone, and dried with nitrogen to obtain graphene electrode device I loaded with guest molecule B, which was designated as graphene electrode device II.

[0122] The host molecule A (γ-cyclodextrin, γ-CD) (0.5 μmol) and guest molecule C (guest molecule C1 or guest molecule C2) (0.5 μmol) were dissolved in ultrapure water (10 ml) to prepare a mixed aqueous solution with a concentration of 50 µmol / L and a molar ratio of γ-CD to guest molecule C of 1:1. Then, the graphene electrode device II was immersed in this mixed solution and left to stand overnight at room temperature. (During this process, the host molecule A, guest molecule B, and guest molecule C self-assembled in the solution through intermolecular van der Waals forces, π-π interactions, and hydrophobic interactions to form a supramolecular host-guest complex, that is, supramolecular functional molecules were formed between the graphene electrode pairs.) After that, the device was taken out, rinsed with water and acetone in sequence, and dried with nitrogen to obtain a single-molecule memristor-rectifier device based on supramolecular assembly.

[0123] IV. Testing the performance of single-molecule memristor-rectifier devices based on supramolecular assembly.

[0124] At room temperature of 25℃, the current response characteristics of a single-molecule memristor-rectifier device (guest molecule C is guest molecule C1) based on supramolecular assembly were tested using a semiconductor parameter analyzer and an ST-500 probe station (test parameters were set as follows: scan voltage range -1 to 1V, voltage step size 3mV). The test results are as follows. Figure 4As shown in the figure, the device exhibits a significant current jump when scanning to 0.5V in the forward direction, corresponding to the transition from a high-resistivity state "0" to a low-resistivity state "1". The underlying mechanism is that the pyridine ring of guest molecule C1 is reduced to a free radical state, triggering a reconstruction of the charge transport channels within the supramolecular assembly. During the reverse voltage scan, the free radical state of guest molecule C1 reverses, causing the device to jump from the low-resistivity state "1" back to the high-resistivity state "0", completing a full reversible switching between high and low resistance states. Furthermore, because its molecules are modified with electron-donating and electron-withdrawing groups at both ends, it differs significantly from the large π-conjugated system formed by the anchoring molecule (guest molecule B). Under the drive of an external electric field, charge rearrangement occurs within the supramolecular functional molecule, causing the device's resistance state to switch reversibly with the change of voltage polarity, ultimately achieving precise control of high and low resistance states. This results in a significant asymmetric characteristic in the overall current response of the device under forward and reverse bias voltages.

[0125] At room temperature of 25℃, the current response characteristics of a single-molecule memristor-rectifier device (guest molecule C is guest molecule C2) based on supramolecular assembly were tested using a Keysight B1500A semiconductor parameter analyzer and an ST-500 probe station (test parameters were set as follows: scan voltage range -1 to 1V, voltage step size 3mV). The test results are as follows. Figure 5 As shown in the figure, the current response of the device under both forward and reverse biases exhibits asymmetric characteristics. The device only completes the full reversible switching between high and low resistance states under forward bias. This is because the guest molecule C2 contains only one side of a pyridine ring that can be reduced to a free radical state, while the benzene ring on the other side cannot be reduced to a free radical.

[0126] The above results demonstrate that the supramolecular assembly-based single-molecule memristor-rectifier device provided by this invention possesses excellent rectification performance and memristor functionality. Furthermore, due to the highly reversible host-guest interaction, heating can induce the dissociation of the inclusion compound, thereby replacing the guest molecule. The functional guest molecule C can switch between guest molecules C1 and C2, which significantly improves the fatigue resistance of the memristor-rectifier device and endows it with a certain degree of repairability.

[0127] 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. A single-molecule memristor-rectifier device based on supramolecular assembly, characterized in that, It includes a first graphene electrode, a supramolecular functional molecule, and a second graphene electrode, wherein the first graphene electrode and the second graphene electrode form a graphene electrode pair, and the supramolecular functional molecule is connected between the graphene electrode pairs. The supramolecular functional molecular structure is selected from any of the following: 、 ； in, and The chemical structural formula is n is an integer from 6 to 10; The gap between the graphene electrode pairs is a nanometer gap.

2. The single-molecule memristor-rectifier device based on supramolecular assembly as described in claim 1, characterized in that, The supramolecular functional molecule is connected to the graphene electrode pair via amide bonds.

3. The single-molecule memristor-rectifier device based on supramolecular assembly as described in claim 1, characterized in that, The gap between the graphene electrode pairs is 1 nm to 10 nm.

4. The single-molecule memristor-rectifier device based on supramolecular assembly as described in claim 1, characterized in that, The graphene electrode pair is a point electrode pair.

5. A method for fabricating a single-molecule memristor-rectifier device based on supramolecular assembly, characterized in that, The method for fabricating a single-molecule memristor-rectifier device based on supramolecular assembly as described in any one of claims 1 to 4 comprises the following steps: S100. Graphene electrode pairs are fabricated on a substrate to obtain graphene electrode device I. S200. The graphene electrode device I is immersed in solution I containing guest molecule B, and the guest molecule B is connected to the end of the graphene electrode pair by condensation reaction to obtain graphene electrode device II. The structural formula of the guest molecule B is shown below: ； S300. The graphene electrode device II is immersed in solution II containing host molecule A and guest molecule C. By utilizing the van der Waals forces, π-π interactions and hydrophobic interactions between molecules, supramolecular functional molecules are formed between the graphene electrode pairs to obtain a single-molecule memristor-rectifier device based on supramolecular assembly. The structural formula of the main molecule A is shown below: n is an integer from 6 to 10; The guest molecule C is selected from any of the following: 、 。 6. The method for fabricating a single-molecule memristor-rectifier device based on supramolecular assembly as described in claim 5, characterized in that, In step S200, the solvent of solution I is selected from pyridine.

7. The method for fabricating a single-molecule memristor-rectifier device based on supramolecular assembly as described in claim 5, characterized in that, In step S300, the solvent of solution II is selected from water.

8. The method for fabricating a single-molecule memristor-rectifier device based on supramolecular assembly as described in claim 5, characterized in that, In step S300, when the guest molecule C is guest molecule C1, the synthesis includes the following steps: S310, with Using raw materials, intermediate I was synthesized, with the structural formula shown below: ； S320, using the intermediate I and The reaction was carried out to synthesize intermediate II, the structural formula of which is shown below: ； S330, using the intermediate II and The reaction synthesizes the guest molecule C1.

9. The method for fabricating a single-molecule memristor-rectifier device based on supramolecular assembly as described in claim 5, characterized in that, In step S300, when the guest molecule C is guest molecule C2, the synthesis includes the following steps: S301. Utilization and The reaction synthesized intermediate III, the structural formula of which is shown below: ； S302, using the intermediate III and The reaction synthesizes the guest molecule C2.

10. The method for fabricating a single-molecule memristor-rectifier device based on supramolecular assembly as described in claim 5, characterized in that, In step S300, the molar ratio of host molecule A to guest molecule C in solution II is 1:1.

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