Supramolecular compound film, general reconfigurable memristor and preparation method

Abstract

The invention discloses a supramolecular compound film, a general reconfigurable memristor and a preparation method, and relates to the technical field of memristors. The preparation method of the supramolecular compound film comprises the following steps: carrying out an ion exchange reaction on an ionic surfactant and polyoxometallic acid, adding the obtained supramolecular compound into a water-insoluble organic solvent, dripping the obtained solution onto the water surface, and forming the supramolecular compound film on the water surface after the organic solvent is volatilized. According to the invention, the ionic surfactant is utilized to exchange counter ions in polyoxometallic acid, so that the supramolecular compound which has higher solubility in an organic solvent and lower solubility in water is obtained, and then the supramolecular compound film is formed on the water surface by utilizing the solubility difference between the supramolecular compound in the organic solvent and the water. The supramolecular compound is independently prepared into the film, so that the problem that the polyoxometallic acid is difficult to form the film is solved, and the interference caused by introduction of other polymers during preparation of the film in the prior art is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of memristors, and in particular to a supramolecular complex thin film, a general reconfigurable memristor and a preparation method thereof. Background Art

[0002] Under the conditions of rich structure and composition design, polyoxometalates can exhibit definite and stable structures, uniform nano-sizes, various stable chemical and physical properties, and reversible multivalent redox reactions, and are often used as a material system for realizing memristive characteristics. However, polyoxometalates have poor solubility in organic solvents and are difficult to form films. Moreover, even after the existing modification of polyoxometalates, a specific amount of polyoxometalates needs to be doped in a polymer material with good film-forming properties to prepare a functional layer thin film, and the polymer material introduced into the functional layer thin film will affect the performance of polyoxometalates.

[0003] Therefore, the existing technology still needs to be improved and developed. Summary of the Invention

[0004] Based on the above deficiencies of the existing technology, the purpose of the present invention is to provide a supramolecular complex thin film, a general reconfigurable memristor and a preparation method thereof, aiming to solve the problem that it is difficult to prepare a polyoxometalate-based thin film using polyoxometalates in the prior art.

[0005] The technical solution of the present invention is as follows:

[0006] In the first aspect of the present invention, a preparation method of a supramolecular complex thin film is provided, which includes the following steps:

[0007] After an ionic surfactant and a polyoxometalate are subjected to an ion exchange reaction, a supramolecular complex is obtained;

[0008] The supramolecular complex is added to an organic solvent to obtain a first solution; the organic solvent is insoluble in water;

[0009] A water surface is provided, and the first solution is dropped onto the water surface. After the organic solvent in the first solution volatilizes, a supramolecular complex thin film is formed on the water surface.

[0010] Optionally, the polyoxometalate includes at least one of H4PW 11 VO 40 and H3PW 12 O 40 in the above formula.

[0011] Optionally, the ionic surfactant includes triethyl [4-({4,12,13-trihydroxytricyclo[6.2.2.2 3 ,6({tetradeca-1(11),3(14),4,6(13),8(12),9-hexaen-10-yl}oxy)butyl]ammonium, at least one of dimethyldioctadecylammonium and tetra-decylammonium bromide.

[0012] Optionally, the organic solvent includes at least one of chloroform and ortho-dichlorobenzene; and / or,

[0013] The molar ratio of the ionic surfactant to the polyoxometalate is (3.09 - 5.2):(0.5 - 0.6).

[0014] Optionally, after forming the supramolecular complex film on the water surface, the following steps are further included:

[0015] Dry the water to obtain the supramolecular complex film;

[0016] Or, pick up the supramolecular complex film on the water surface to obtain the supramolecular complex film.

[0017] Optionally, the step of performing an ion exchange reaction between the ionic surfactant and the polyoxometalate specifically includes:

[0018] Mix the ionic surfactant with a first solvent to obtain solution a;

[0019] Mix the polyoxometalate with a second solvent to obtain solution b;

[0020] After mixing solution a and solution b, stir for 2 - 5 h to perform an ion exchange reaction to obtain the supramolecular complex.

[0021] In the second aspect of the present invention, a supramolecular complex film is provided, wherein the supramolecular complex film is prepared by the preparation method as described above in the present invention.

[0022] In the third aspect of the present invention, a general-purpose reconfigurable memristor is provided, wherein the general-purpose reconfigurable memristor includes a bottom electrode, the supramolecular complex film as described above in the present invention, and an active metal electrode stacked in sequence from bottom to top.

[0023] Optionally, the bottom electrode includes a transparent conductive oxide;

[0024] The active metal electrode includes at least one of silver, copper, and iron;

[0025] The thickness of the supramolecular complex film is 10 - 100 nm.

[0026] In the fourth aspect of the present invention, a preparation method of the general-purpose reconfigurable memristor as described above in the present invention is provided, which includes the following steps:

[0027] Provide a bottom electrode;

[0028] Form a supramolecular complex thin film on the bottom electrode;

[0029] Form an active metal electrode on the supramolecular complex thin film to obtain the general reconfigurable memristor.

[0030] Beneficial effects: In the present invention, an ionic surfactant is used to exchange the counterions in the polyoxometalate, improving the solubility of the polyoxometalate in organic solvents (>20 mg / mL) and reducing its solubility in water. Then, a supramolecular complex thin film is formed on the water surface using the solubility difference of the ion-exchanged supramolecular complex in organic solvents and water. The present invention prepares the supramolecular complex into a thin film alone, without the assistance of other polymers with good film-forming properties, solving the problem of difficult film formation of polyoxometalates and avoiding the interference caused by the introduction of other polymers (such as polystyrene, polymethyl methacrylate, polyethylene glycol, etc.) when preparing thin films using modified polyoxometalates. Description of the drawings

[0031] Figure 1 It is a schematic structural diagram of the general reconfigurable memristor in the embodiment of the present invention.

[0032] Figure 2 It is the 1H NMR spectrum of the supramolecular complex in Example 1.

[0033] Figure 3 It is the voltage sweep curve of the general reconfigurable memristor in Example 1 under a current limit of 10 -4 A.

[0034] Figure 4 It is the voltage sweep curve of the general reconfigurable memristor in Example 1 under a current limit of 10 -3 A. Detailed implementation manners

[0035] The present invention provides a supramolecular complex thin film, a general reconfigurable memristor and a preparation method. To make the purpose, technical solution and effects of the present invention clearer and more definite, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] Unless otherwise defined, all technical terms and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0037] If the descriptions such as "first" and "second" are involved in the embodiments of the present invention, these descriptions of "first", "second", etc. are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features.

[0038] The embodiments of the present invention provide a method for preparing a supramolecular complex film, specifically providing a method for preparing a supramolecular complex film based on polyoxometalate by using polyoxometalate, which includes the following steps:

[0039] S11: After performing an ion exchange reaction between an ionic surfactant and polyoxometalate, a supramolecular complex is obtained;

[0040] S12: The supramolecular complex is added to an organic solvent to obtain a first solution; the organic solvent is insoluble in water;

[0041] S13: A water surface is provided, and the first solution is dropped onto the water surface. After the organic solvent in the first solution volatilizes, a supramolecular complex film is formed on the water surface.

[0042] In the present invention, the counterions in polyoxometalate are exchanged by an ionic surfactant to increase the solubility of polyoxometalate in an organic solvent (>20 mg / mL) and decrease its solubility in water. That is to say, after the ionic surfactant and polyoxometalate perform an ion exchange reaction, the solubility of the obtained supramolecular complex with the properties of polyoxometalate in the organic solvent (>20 mg / mL) is much greater than that of polyoxometalate, but the solubility of the supramolecular complex with the properties of polyoxometalate in water is very low. Then, by utilizing the solubility difference of the supramolecular complex obtained by ion exchange in the organic solvent and water, the first solution (containing the supramolecular complex) immiscible with water is dropped onto the water surface. After the organic solvent volatilizes, a dense supramolecular complex film is formed on the water surface. The present invention prepares the supramolecular complex into a film alone without the assistance of other polymers with good film-forming properties, solves the problem that polyoxometalate is difficult to form a film, and avoids the interference caused by the introduction of other polymers (such as polystyrene, polymethyl methacrylate, polyethylene glycol, etc.) when preparing a film by using modified polyoxometalate in the prior art.

[0043] Specifically, after an ion exchange reaction occurs between the ionic surfactant and the polyoxometalate, the anionic center of the polyoxometalate and the surfactant cation form a polyoxometalate embedded in the surfactant, namely a supramolecular complex, through electrostatic interaction and hydrogen bond interaction (the supramolecular complex contains the main framework of the polyoxometalate and has the properties of the polyoxometalate). The supramolecular complex has a relatively high solubility in water-insoluble organic solvents and a relatively low solubility in water. That is, in the present invention, the counterions in the polyoxometalate are exchanged with the ionic surfactant to obtain a supramolecular complex that has a much higher solubility in organic solvents than the polyoxometalate and a relatively low solubility in water, and then a supramolecular complex film is formed on the water surface by utilizing the difference in solubility of the supramolecular complex in organic solvents and water.

[0044] In step S11, in some embodiments, the molar ratio of the ionic surfactant to the polyoxometalate is (3.09 - 5.2):(0.5 - 0.6), for example, it can be 3.09:0.5, 3.2:0.5, 3.5:0.5, 3.8:0.5, 4:0.5, 4.5:0.5, 5:0.5, 5.2:0.5, 3.09:0.6, 3.2:0.6, 3.5:0.6, 3.8:0.6, 4:0.6, 4.5:0.6, 5:0.6 or 5.2:0.6, etc. This ratio can ensure that the ionic surfactant is in excess, enabling a sufficient ion exchange reaction between the two.

[0045] In some embodiments, the polyoxometalate includes at least one of H4PW 11 VO 40 (HPWV) and H3PW 12 O 40 (HPW), but is not limited thereto.

[0046] In some embodiments, the ionic surfactant includes at least one of triethyl[4-({4,12,13-trihydroxytricyclo[6.2.2.2 3,6 tetradeca-1(11),3(14),4,6(13),8(12),9-hexaene-10-yl}oxy)butyl]ammonium (C 54 H 70 NO 10 Br), dimethyldioctadecylammonium (DODA), and tetrabutylammonium bromide (TDA), but is not limited thereto. Taking H3PW 12 O 40 and C 54 H 70 NO 10 Br as an example, the two undergo an ion exchange reaction to form a supramolecular complex (C 54 H 70NO 10 )4PW 11 VO 40 The reaction equation of

[0047] 4C 54 H 70 NO 10 Br + H4PW 11 VO 40 =(C 54 H 70 NO 10 )4PW 11 VO 40 + 4HBr.

[0048] In some embodiments, the step of performing an ion exchange reaction between an ionic surfactant and a polyoxometalate specifically includes:

[0049] S111. Mix the ionic surfactant with a first solvent (such as methanol, etc.) to obtain solution a;

[0050] S112. Mix the polyoxometalate with a second solvent (such as ultrapure water, etc.) to obtain solution b;

[0051] S113. After mixing solution a and solution b, stir for 2 - 5 h (for example, it can be 2 h, 3 h, 4 h, or 5 h, etc.) to perform an ion exchange reaction, and then obtain the supramolecular complex.

[0052] In steps S111 and S113, the concentration of the ionic surfactant in solution a is 1.03 - 1.3 mmol / L, for example, it can be 1.03 mmol / L, 1.05 mmol / L, 1.1 mmol / L, 1.15 mmol / L, 1.2 mmol / L, 1.25 mmol / L, or 1.3 mmol / L, etc.

[0053] In steps S112 and S113, the concentration of the polyoxometalate in solution b is 0.25 - 0.3 mmol / L, for example, it can be 0.25 mmol / L, 0.26 mmol / L, 0.27 mmol / L, 0.28 mmol / L, 0.29 mmol / L, or 0.3 mmol / L, etc.

[0054] In step S113, the volume ratio of solution a to solution b is (3 - 4):2, for example, it can be 3:2, 3.5:2, or 4:2, etc.

[0055] In step S12, in some embodiments, the organic solvent can volatilize under normal temperature and pressure. In some embodiments, the organic solvent includes at least one of chloroform and orthodichlorobenzene, but is not limited thereto.

[0056] In the present invention, supramolecular complex films with different thicknesses can be prepared by repeating step S3 different numbers of times.

[0057] In step S13, after the supramolecular complex film is formed on the water surface, the following steps are further included:

[0058] S14, Drain the water to obtain the supramolecular complex film;

[0059] Or, pick up the supramolecular complex film on the water surface to obtain the supramolecular complex film.

[0060] An embodiment of the present invention further provides a supramolecular complex film, wherein the supramolecular complex film is prepared by the preparation method as described above in the embodiment of the present invention.

[0061] As a non-linear electronic component different from resistors, inductors, and capacitors, a memristor is an emerging semiconductor device that breaks through the von Neumann bottleneck and enables efficient neuromorphic computing. However, currently, different neural network computations have different characteristic requirements for the characteristics of memristors. The weight mapping in artificial neural networks requires the memristor to have a non-volatile characteristic of maintaining different resistance states for a long time, while the recurrent neural computation for realizing time feature extraction requires the memristor to have a volatile characteristic of spontaneously relaxing from a low-resistance state to a high-resistance state without an input signal stimulus. A memristor with a single characteristic is difficult to meet different neural network applications. And dedicated memristors with different characteristics require specific cumbersome processes for preparation and different raw materials, which leads to complex preparation process integration and device interconnection, increasing the difficulty of memristors in different applications and thus restricting the development of memristors. Therefore, it is of great significance to develop a general-purpose reconfigurable memristor with volatility and non-volatility by using simple materials through simple processing techniques. Based on this, the present invention provides a general-purpose reconfigurable memristor, wherein the general-purpose reconfigurable memristor includes a bottom electrode, the supramolecular complex film as described above in the present invention, and an active metal electrode, which are sequentially stacked from bottom to top. Specifically, as Figure 1 shown, the general-purpose reconfigurable memristor includes a substrate 1, a bottom electrode 2, a supramolecular complex film 3, and an active metal electrode 4, which are sequentially stacked from bottom to top.

[0062] In the present invention, the supramolecular complex film is used as the memristor switching layer. The redox reaction of the supramolecular complex with the active metal electrode results in the formation of conductive filaments in the film, thereby realizing the switching characteristics of the memristor. At the same time, by changing the limiting current, the memristor can exhibit both volatility and non-volatility.

[0063] Specifically, the presence of the polyoxometalate moiety in the supramolecular complex makes the supramolecular complex an effective material for capturing charges. Through the capture and release of charges, the active metal can undergo redox reactions and migrate, thereby generating conductive filaments. That is to say, the reversible redox effect of the supramolecular complex on the multivalent states of active metal electrodes such as silver and copper can promote the migration of the active metal electrodes, thereby forming conductive filaments in the thin film to connect the electrodes at both ends of the memristor, realizing the change of resistance, and thus realizing the switching characteristics of the memristor. At the same time, the prepared reconfigurable memristor can exhibit volatile switching characteristics under a smaller limiting current and non-volatile switching characteristics under a larger limiting current, thereby realizing the reconfigurability from volatile to non-volatile. Because at a lower current, the migration effect of the supramolecular complex on the active metal electrode is weak, and the formed conductive filaments are thinner. Without the stimulation of an electric field, the conductive filaments will break spontaneously, resulting in the memristor spontaneously changing from the low-resistance state to the high-resistance state when the voltage is removed, that is, the volatile switching characteristic. At a higher current, the migration effect of the supramolecular complex on the active metal electrode is strong, and the formed conductive filaments are thicker and difficult to break spontaneously. Therefore, the memristor needs to be stimulated by a reverse voltage to break the conductive filaments, so as to change from the low-resistance state to the high-resistance state under the action of an external electric field, that is, the non-volatile switching characteristic. The reconfigurable characteristics of volatility and non-volatility of the memristor in the present invention can meet the requirements in different application scenarios (such as the application requirements of different neural networks), making the memristor more versatile. At present, other memristors based on polyoxometalate composite thin films or doped with polyoxometalates in polymer thin films cannot achieve reconfigurability due to the interference of polymers such as polystyrene, polymethyl methacrylate, and polyethylene glycol, and only have a single switching characteristic. Moreover, the reconfigurable memristor based on the supramolecular complex provided by the present invention uses environmentally friendly and simple materials, has a simple preparation process, low cost, and avoids the problems of large potential material toxicity of perovskite devices and the high cost of oxide devices that require vapor deposition equipment. It is suitable for large-area promotion and can be widely applied in high-tech fields such as information technology.

[0064] In some embodiments, the reconfigurability of the general reconfigurable memristor is manifested as being volatile at a lower current, such as below 10 -4 A current, and non-volatile at a higher current, such as from 10 -4 A to 10 -3 A current.

[0065] In some embodiments, the bottom electrode includes a transparent conductive oxide. In some specific embodiments, the transparent conductive oxide includes indium tin oxide (ITO).

[0066] In some embodiments, the active metal electrode includes at least one of silver, copper, and iron, but is not limited thereto.

[0067] In some embodiments, the thickness of the bottom electrode is 23 to 185 nm, and for example, it can be 23 nm, 25 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm or 185 nm, etc. The width of the bottom electrode can be 100 μm, etc., but the specific width can be adjusted according to actual needs.

[0068] In some embodiments, the thickness of the active metal electrode is 50 to 100 nm, and for example, it can be 50 nm, 60 nm, 70 nm, 80 nm, 90 nm or 100 nm, etc. The width of the active metal electrode can be 100 μm, etc., but the specific width can be adjusted according to actual needs.

[0069] In some embodiments, the thickness of the supramolecular complex thin film is 10 to 100 nm, and for example, it can be 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm or 100 nm, etc.

[0070] The embodiment of the present invention also provides a preparation method of a general-purpose reconfigurable memristor, which includes the following steps:

[0071] S21. Provide a bottom electrode;

[0072] S22. Form a supramolecular complex thin film on the bottom electrode;

[0073] S23. Form an active metal electrode on the supramolecular complex thin film to obtain the general-purpose reconfigurable memristor.

[0074] The reconfigurable memristor based on supramolecular complex provided by the present invention uses environmentally friendly and simple materials, has a simple preparation process, low cost, avoids the problems of large potential material toxicity of perovskite devices and the high cost of oxide devices requiring vapor deposition equipment, is suitable for large-area promotion, and can be widely applied to high-tech fields such as information technology.

[0075] In step S21, in some embodiments, the bottom electrode is prepared by a magnetron sputtering method. Specifically, a plurality of strip-shaped transparent conductive oxide electrodes arranged at intervals can be prepared on a glass substrate by a magnetron sputtering method as the bottom electrode.

[0076] In step S22, in some embodiments, the step of forming a supramolecular complex thin film on the bottom electrode specifically includes:

[0077] After performing an ion exchange reaction between an ionic surfactant and a polyoxometalate, a supramolecular complex is obtained;

[0078] The supramolecular complex is added to an organic solvent to obtain a first solution; the organic solvent is insoluble in water;

[0079] A water surface is provided, and the first solution is dropped onto the water surface. After the organic solvent in the first solution evaporates, a supramolecular complex film is formed on the water surface;

[0080] The bottom electrode is placed in the water below the supramolecular complex film and then lifted upward. After separating from the water surface, the supramolecular complex film is placed on the bottom electrode; alternatively, the bottom electrode is placed in the water below the supramolecular complex film and the water is drained, then the supramolecular complex film is formed on the bottom electrode.

[0081] In step S23, in some embodiments, an active metal electrode is formed on the supramolecular complex film by one of the methods of thermal evaporation or sputtering. The vacuum degree during the preparation process is controlled below 10 -4 Pa. Specifically, several strip-shaped metal (such as silver, copper, or iron, etc.) electrodes spaced apart can be prepared on the supramolecular complex film by one of the methods of thermal evaporation or sputtering as the active metal electrodes.

[0082] The present invention will be further described below through specific examples.

[0083] In the following examples, unless otherwise specified, the materials used are commercially available products that can be obtained through commercial channels.

[0084] Example 1

[0085] This example provides a preparation method for a general reconfigurable memristor, including the following steps:

[0086] (1) Preparation of the bottom electrode

[0087] After cleaning a transparent glass substrate with a length of 2 cm, a width of 2 cm, and a thickness of 1.1 mm, a transparent strip-shaped ITO electrode with a thickness of 185 nm, a length of 1.6 cm, and a width of 100 μm is sputtered on it through a shadow mask by means of magnetron sputtering, a total of 11 strips, and the spacing between adjacent two ITO electrodes is 1.5 mm.

[0088] (2) Preparation of the first solution

[0089] Mix C 54 H 70 NO 10 Br with methanol to obtain C 54 H 70 NO 10Solution a with a Br concentration of 1.03 moL / L;

[0090] Mix HPWV with ultrapure water to obtain solution b with an HPWV concentration of 0.25 mol / L;

[0091] Mix solution a and solution b in a volume ratio of 3:2, stir for 2 h for ion exchange reaction, then filter, repeatedly rinse the insoluble matter obtained after filtration with ultrapure water and methanol, and after drying, obtain a supramolecular complex. Its proton nuclear magnetic resonance spectrum is as Figure 2 shown. It can be seen that after the ion exchange reaction between the surfactant and the polyoxometalate, the anion center of the polyoxometalate and the surfactant cation form a supramolecular complex (C 54 H 70 NO 10 )4PW 11 VO 40 .

[0092] Mix the supramolecular complex with chloroform, place it in an ultrasonic cleaner and ultrasonically dissolve it for 15 min, then let it stand for 15 min to obtain the first solution with a supramolecular complex concentration of 15 mg / mL.

[0093] (3) Drop-casting film formation

[0094] Turn the side of the transparent glass substrate with the ITO electrode upwards, place it in a glass dish with a diameter of about 8 cm containing ultrapure water, and let the water surface submerge the transparent glass substrate with the ITO electrode on its surface. Pipette 5 μL of the first solution onto the water surface (i.e., the ultrapure water liquid surface). After waiting for 10 min for the chloroform in the first solution to evaporate completely, a supramolecular complex film is formed on the ultrapure water liquid surface. After using a syringe to extract the ultrapure water in the glass dish, the supramolecular complex film (with a thickness of 20 nm) covers the ITO electrode.

[0095] (4) Annealing

[0096] Place the transparent glass substrate with the supramolecular complex film and the ITO electrode on a heating stage, anneal at 60 °C for 20 min to remove the residual water on the substrate, and the annealing atmosphere is the atmospheric atmosphere.

[0097] (5) Evaporating the active metal electrode

[0098] Use thermal evaporation to evaporate through a shadow mask. During the evaporation process, the rate is controlled at 0.1 angstrom per second, and the vacuum degree is controlled below 10 -4 Pa. Prepare strip-shaped silver electrodes with a thickness of 75 nm, a length of 1.6 cm, and a width of 100 μm on the supramolecular complex film, with a total of 8 electrodes. The spacing between adjacent two silver electrodes is 1.5 mm to obtain the described general reconfigurable memristor.

[0099] In Example 1, the voltage sweep curve of the general reconfigurable memristor at 10 -4 A under current limiting is as Figure 3 shown. It can be seen that during the voltage sweep of 10 -4 A under current limiting, it switches from the high-resistance state to the low-resistance state, and the low-resistance state spontaneously returns to the high-resistance state, indicating that the general reconfigurable memristor has volatile switching characteristics.

[0100] In Example 1, the voltage sweep curve of the general reconfigurable memristor at 10 -3 A under current limiting is as Figure 4 shown. It can be seen that during the forward voltage sweep of 10 -3 A under current limiting, it switches from the high-resistance state to the low-resistance state, while during the reverse voltage sweep, when the low-resistance state returns to the high-resistance state, an external stimulus is required to return from the low-resistance state to the high-resistance state, indicating that the general reconfigurable memristor has non-volatile switching characteristics.

[0101] Example 2

[0102] This example provides a preparation method for a general reconfigurable memristor, including the following steps:

[0103] (1) Prepare the bottom electrode

[0104] After cleaning a transparent glass substrate with a length of 2 cm, a width of 2 cm, and a thickness of 1.1 mm, use magnetron sputtering to sputter 8 transparent strip-shaped ITO electrodes with a thickness of 185 nm, a length of 1.6 cm, and a width of 100 μm on it through a shadow mask. The distance between adjacent two ITO electrodes is 1.5 mm.

[0105] (2) Prepare the first solution

[0106] The difference from the preparation method of the first solution in Example 1 is only that chloroform is replaced with ortho-dichlorobenzene, and it is filtered with an organic nylon filter head before use.

[0107] (3) Dropwise form a film

[0108] Place the side of the transparent glass substrate with the ITO electrodes on the surface facing up in a glass dish with a diameter of about 10 cm filled with ultrapure water, and the water surface submerges the transparent glass substrate with the ITO electrodes on the surface. Absorb 10 μL of the first solution and drop it on the water surface (i.e., the ultrapure water liquid surface). After waiting for 30 min, the ortho-dichlorobenzene in the first solution volatilizes completely, and a supramolecular complex film is formed on the ultrapure water liquid surface. After using a syringe to extract the ultrapure water in the glass dish, the supramolecular complex film (with a thickness of 20 nm) covers the ITO electrodes.

[0109] (4) Annealing

[0110] Place the transparent glass substrate with the supramolecular complex thin film and ITO electrode on the heating stage, and anneal at room temperature for 30 min to remove the residual water on the substrate. The annealing atmosphere is the atmospheric atmosphere.

[0111] (5) Evaporating the active metal electrode

[0112] The steps are the same as those for evaporating the active metal electrode in Example 1 to obtain the general reconfigurable memristor.

[0113] Example 3

[0114] This example provides a method for preparing a general reconfigurable memristor, including the following steps:

[0115] (1) Preparing the bottom electrode

[0116] After cleaning the transparent glass substrate with a length of 2 cm, a width of 2 cm, and a thickness of 1.1 mm, use magnetron sputtering to sputter 8 transparent strip-shaped ITO electrodes with a thickness of 185 nm, a length of 1.6 cm, and a width of 100 μm on it through a shadow mask. The distance between adjacent two ITO electrodes is 1.5 mm.

[0117] (2) Preparing the first solution

[0118] The preparation method is the same as that of the first solution in Example 1.

[0119] (3) Dropwise forming a film

[0120] Place the side of the transparent glass substrate with the ITO electrode facing up into a glass dish with a diameter of about 10 cm filled with ultrapure water. The water surface submerges the transparent glass substrate with the ITO electrode on its surface. Absorb 5 μL of the first solution and drop it on the water surface (i.e., the ultrapure water liquid surface). After waiting for 10 min, the chloroform in the first solution volatilizes completely, and a supramolecular complex thin film is formed on the ultrapure water liquid surface. After using a syringe to extract the ultrapure water in the glass dish, the supramolecular complex thin film (with a thickness of 20 nm) covers the ITO electrode.

[0121] (4) Annealing

[0122] Place the transparent glass substrate with the supramolecular complex thin film and ITO electrode on the heating stage, and anneal at room temperature for 20 min to remove the residual water on the substrate. The annealing atmosphere is the atmospheric atmosphere.

[0123] (5) Evaporating the active metal electrode

[0124] Use thermal evaporation to evaporate through a shadow mask. During the evaporation process, the rate is controlled at 0.1 Å / s, and the vacuum degree is controlled at 10-4 Below Pa, strip-shaped copper electrodes with a thickness of 75 nm, a length of 1.6 cm, and a width of 100 μm are prepared on the supramolecular complex film, with a total of 8 electrodes. The spacing between adjacent silver electrodes is 1.5 mm, and the universal reconfigurable memristor is obtained.

[0125] Example 4

[0126] This example provides a method for preparing a universal reconfigurable memristor, including the following steps:

[0127] (1) Prepare the bottom electrode

[0128] It is the same as the step of preparing the bottom electrode in Example 1.

[0129] (2) Prepare the first solution

[0130] The difference from the method of preparing the first solution in Example 1 is only that:

[0131] Replace C 54 H 70 NO 10 Br with DODA; replace HPWV with HPW.

[0132] (3) Dropwise form a film

[0133] It is the same as the step of dropwise forming a film in the example.

[0134] (4) Anneal

[0135] It is the same as the annealing step in Example 1.

[0136] (5) Evaporate and deposit an active metal electrode

[0137] It is the same as the step of evaporating and depositing an active metal electrode in Example 1, and the universal reconfigurable memristor is obtained.

[0138] Example 5

[0139] This example provides a method for preparing a universal reconfigurable memristor, including the following steps:

[0140] (1) Prepare the bottom electrode

[0141] It is the same as the step of preparing the bottom electrode in Example 1.

[0142] (2) Prepare the first solution

[0143] The difference from the method of preparing the first solution in Example 1 is only that:

[0144] Replace C 54 H 70 NO 10 Br with TDA.

[0145] (3) Dropwise liquid film formation

[0146] It is the same as the dropwise liquid film formation step in the embodiment.

[0147] (4) Annealing

[0148] It is the same as the annealing step in Example 1.

[0149] (5) Evaporating and depositing an active metal electrode

[0150] It is the same as the step of evaporating and depositing an active metal electrode in Example 1 to obtain the universal reconfigurable memristor.

[0151] After testing, the universal reconfigurable memristors in Example 2, Example 3, Example 4 and Example 5 have similar properties to the universal reconfigurable memristor in Example 1, and can exhibit volatility at a lower current and non-volatility at a higher current.

[0152] In summary, the present invention provides a supramolecular complex thin film, a universal reconfigurable memristor and a preparation method. In the present invention, the counterions in polyoxometalate are exchanged by an ionic surfactant to improve the solubility of polyoxometalate in organic solvents, expanding the application scenarios of polyoxometalate. At the same time, taking advantage of the difference in solubility of the modified polyoxometalate, i.e., the supramolecular complex, in organic solvents and water, a first solution immiscible with water is dropped onto the water surface, and a dense supramolecular complex thin film is obtained on the water surface after the organic solvent volatilizes, thus overcoming the difficulty of polyoxometalate in forming a film and eliminating the need for the assistance of other polymers with good film-forming properties, avoiding the influence of polymers. In the present invention, the reconfigurable memristor prepared based on the supramolecular complex can exhibit both volatility and non-volatility. The coexistence of volatility and non-volatility of the reconfigurable memristor can simultaneously meet the application requirements of different neural networks, broadening the preparation ideas and applications of universal memristors.

[0153] It should be understood that the application of the present invention is not limited to the above examples. For those of ordinary skill in the art, improvements or transformations can be made according to the above description, and all such improvements and transformations should fall within the protection scope of the appended claims of the present invention.

Claims

1. A method for preparing a supramolecular complex thin film, characterized in that, It includes the following steps: After an ion exchange reaction between an ionic surfactant and a polyoxometalate, a supramolecular complex is obtained; The supramolecular complex is added to an organic solvent to obtain a first solution; the organic solvent is insoluble in water; A water surface is provided, and the first solution is dropped onto the water surface. After the organic solvent in the first solution volatilizes, a supramolecular complex thin film is formed on the water surface.

2. The preparation method according to claim 1, characterized in that, The polyoxometalate includes at least one of H4PW 11 VO 40 and H3PW 12 O 40 .

3. The preparation method according to claim 1, wherein The ionic surfactant includes at least one of triethyl[4-({4,12,13-trihydroxytetracyclo[6.2.2.2 3,6 tetradeca-1(11),3(14),4,6(13),8(12),9-hexaene-10-yl}oxy)butyl]ammonium, dimethyldioctadecylammonium, and tetrabutylammonium bromide.

4. The preparation method according to claim 1, characterized in that The organic solvent includes at least one of chloroform and o-dichlorobenzene; and / or, The molar ratio of the ionic surfactant to the polyoxometalate is (3.09 - 5.2):(0.5 - 0.6).

5. The preparation method according to claim 1, characterized in that, After the supramolecular complex thin film is formed on the water surface, it further includes the following steps: The water is drained to obtain the supramolecular complex thin film; Or, the supramolecular complex thin film on the water surface is fished up to obtain the supramolecular complex thin film.

6. The preparation method according to claim 1, characterized in that, The step of performing an ion exchange reaction between an ionic surfactant and a polyoxometalate specifically includes: The ionic surfactant is mixed with a first solvent to obtain solution a; The polyoxometalate is mixed with a second solvent to obtain solution b; After the solution a and the solution b are mixed, stirring is carried out for 2 - 5 h for an ion exchange reaction to obtain the supramolecular complex.

7. A supramolecular complex thin film, characterized in that, The supramolecular complex thin film is prepared by the preparation method according to any one of claims 1 - 6.

8. A general-purpose reconfigurable memristor, characterized in that, The general-purpose reconfigurable memristor includes a bottom electrode, the supramolecular complex thin film according to claim 7, and an active metal electrode, which are sequentially stacked from bottom to top.

9. The general reconfigurable memristor according to claim 8, characterized in that, The bottom electrode includes a transparent conductive oxide; The active metal electrode includes at least one of silver, copper, and iron; The thickness of the supramolecular complex thin film is 10 - 100 nm.

10. A method for preparing the general reconfigurable memristor according to any one of claims 8-9, characterized in that, It includes the following steps: A bottom electrode is provided; A supramolecular complex thin film is formed on the bottom electrode; An active metal electrode is formed on the supramolecular complex thin film to obtain the general-purpose reconfigurable memristor.

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