A composite memristor and liquid pool electrochemical reaction large frequency modulation oscillator device

Abstract

The present invention discloses a high-frequency modulation oscillator device for composite memristor and liquid pool electrochemical reaction, which relates to multiple fields such as electronic component technology, neuromorphic devices, and electronic information processing. The high-frequency modulation oscillator device comprises a DC power supply, a first electrode, a redox liquid pool, a second electrode, and a memristor. The conductive state transition is achieved through a threshold switching effect. By virtue of the series connection of the redox liquid pool and the memristor working circuit, a solid-liquid interface working environment is constructed. Driven by DC voltages of different amplitudes, the device can achieve stable oscillation in a wide frequency range from a few tenths of a hertz to several kilohertz. The device is suitable for multiple application scenarios such as simulating artificial neuron behavior, generating broadband pulse trains, and processing digital signals.

Description

Technical Field

[0001] The present invention relates to the fields of broadband signal generation and neuromorphic devices, and specifically to a frequency modulation oscillator device for electrochemical reaction of a composite memristor and a liquid pool. The frequency modulation range is wide, and can cover the frequency range from a few tenths of hertz to several kilohertz. Background Art

[0002] In the field of signal generation, traditional all-solid-state electronic frequency modulation methods, such as amplifier-based frequency modulation circuits, achieve signal frequency modulation by adjusting gain, feedback networks, or using voltage-controlled oscillators (VCOs). However, these circuits often suffer from high power consumption, limited frequency adjustment range, and complex circuit structures. Their limitations are particularly prominent in scenarios where wideband modulation is required.

[0003] In the field of neuromorphic devices, new oscillator devices that combine memristors, solid-state capacitors, and solid-state resistors have emerged in recent years. These devices utilize the threshold switching effect of memristors, that is, when the external voltage reaches or exceeds the threshold voltage of the memristor, its conductivity undergoes a reversible and significant nonlinear change between non-conduction and conduction, thereby realizing the switching function. This change mechanism originates from the formation and destruction of conductive filaments under the action of an electric field. Neuromorphic devices based on memristors can directly simulate the information transmission and processing process between neurons, and have the significant advantage of extremely low power consumption. In addition, the resistance adjustability and memory characteristics of memristors are similar to the long-term plasticity of synapses, enabling these devices to simulate certain key characteristics of biological neural networks, such as learning, memory, and decision-making. However, these neuromorphic devices based on memristors also have the defect of a narrow operating frequency range. For example Figure 2As shown in the figure, when different voltages are applied to a typical niobium oxide memristor composite solid-state resistor and solid-state capacitor device, the oscillation of the device is unstable at low frequencies, resulting in a large oscillation frequency error; and at high frequencies (frequencies above several hundred hertz), although the device can oscillate stably, the frequency range of stable oscillation of the device is limited, making it difficult to achieve cross-order regulation. This problem is common in various typical oscillating devices with memristor-capacitor-resistor architectures, such as the literature "Biological plausibility and stochasticity in scalable VO2 active memristorneurons[J].Nature communications,2018,9(1):4661" and "An artificial spikingafferent nerve based on Mott memristors for neurorobotics[J].Nature communications,2020,11(1):51". These devices can usually only oscillate stably in the high-frequency range, while there is a gap in stable oscillation in the low-frequency range. Given that the pulses of biological neurons are regular and stable, and their pulse frequencies cover a wide range (from a few tenths of a hertz to a kilohertz), devices such as composite memristors and solid-state resistors and capacitors cannot meet the needs of broadband signal processing and increasingly complex artificial neurons, especially the requirements for biocompatibility (biological neurons mostly operate in liquid environments).

[0004] Another difficulty faced by neuromorphic devices is the deep integration with the liquid environment. Currently, they are mainly connected to the solution environment directly through all-solid-state electronic devices. In the research of aluminum ion electronic devices, although liquid was introduced as a capacitor medium and the high dielectric constant of the liquid was used to enhance the charge storage capacity, this design focused more on improving the physical properties of the electronic device and did not fully integrate the advantages of the electrochemical reaction between the electrode and the liquid pool, limiting the device's ability to simulate the dynamic changes and learning processes in biological neural networks. In addition, some devices that sense glucose through interfacial oxidation reactions can sense chemical changes in the environment to a certain extent, but such designs often rely on additional artificial neuron pulse generation circuits or amplifier oscillation circuits to amplify weak electrochemical signals so that they can be identified and processed. Such a structure not only increases the complexity and cost of the system, but may also introduce additional noise and delays, affecting the overall performance and real-time performance of the neuromorphic system.

[0005] Therefore, developing a large-frequency modulation oscillation device for electrochemical reaction of composite memristor and liquid pool has become a technical problem that needs to be solved urgently in this field. Summary of the Invention

[0006] To solve the above problems, the present invention designs an artificial neuron working model based on the working principle of biological neurons and synapses. This model is also the working model of the large-scale frequency modulation oscillator device disclosed in the present invention. Figure 3 As shown, this model demonstrates the workings of a typical biological neuron and its synapses. Biological neurons transmit and activate information through the transmission of neurotransmitters across chemical synapses. In the biomimetic model of the present invention, a memristor acts as a neuron, two electrodes simulate synapses, and ions in a redox couple pool between the electrodes act as neurotransmitters in the synaptic cleft. The resulting oscillating device, combining the composite memristor and the electrochemical reaction in the pool, has a wide frequency spectrum coverage, from a few tenths of a hertz to several kilohertz.

[0007] Specifically, the present invention is achieved through the following technical solutions:

[0008] First, the present invention provides a composite memristor and a liquid pool electrochemical reaction large frequency modulation oscillator device, the device includes a DC power supply, a first electrode, a redox couple liquid pool, a second electrode and a threshold switching memristor, such as Figure 1 As shown in the device structure diagram, the positive electrode of the DC power supply is connected to the first electrode, and the negative electrode is connected in series with the threshold switching memristor and the second electrode in sequence. A gap is formed between the first and second electrodes to accommodate the redox liquid pool, which together form a closed circuit. The redox liquid pool is an ion solution containing redox pairs. The equivalent circuit diagram of the device is shown in Figure 4 shown.

[0009] The materials of the first electrode and the second electrode can be selected from platinum, gold, carbon or ITO according to specific experimental conditions, while the conductive wire can be made of conventional copper wire or other materials.

[0010] The threshold switching memristor mentioned above refers to a memristor with a threshold switching effect. The term "threshold switching effect" means that when the applied voltage exceeds the threshold voltage, the resistance suddenly drops sharply, changing from a high resistance (HR) state to a low resistance (LR) state. When the applied voltage is lower than the holding voltage, the resistance suddenly rises sharply, changing from a low resistance (LR) state to a high resistance (HR) state.

[0011] The threshold switching memristor is a conventional memristor in the art. The memristor structure prepared in the embodiment is referenced from the literature "Effect of electrode materials on resistive switching behavior of NbO x-based memristive devices[J].Scientific Reports,2023,13(1):17003”, the design disclosed in the paper consists of a three-layer structure of bottom electrode, resistive switching layer and top electrode, such as Figure 5 As shown in the figure, the materials for the top and bottom electrodes can be selected from platinum, gold, tungsten, or titanium nitride, depending on the memristor's manufacturing process. The resistive switching layer can be made of metal oxides (such as niobium oxide) or binary compounds of nonmetals and chalcogenides (such as silicon telluride). Before the fabricated memristor is connected to a circuit, a scan voltage below 3V but exceeding its threshold voltage is applied to it, in order to induce a threshold switching effect, thus creating a threshold-switching memristor.

[0012] In the aforementioned AFM oscillator device, the DC power supply voltage must be higher than the memristor threshold voltage. Furthermore, during device operation, the maximum voltage drop across the memristor must not be lower than the threshold voltage, and the minimum voltage drop must not be higher than the holding voltage. Preferably, the DC power supply voltage should be lower than 3V and higher than the memristor threshold voltage. The term "threshold voltage" refers to the voltage at which the device begins switching states (rapidly switching from a high resistance state to a low resistance state) when the applied voltage exceeds a certain threshold. The term "holding voltage" refers to the minimum voltage required for the memristor to maintain its low resistance state after switching to that state.

[0013] The term "redox pair" refers to a reducing substance and its corresponding oxidized form. When a voltage is applied, the reducing substance loses electrons (oxidizes) at the anode, while the oxidizing substance gains electrons (reduces) at the cathode, thereby achieving a reversible redox electrochemical reaction. The ion solution containing the redox pair can be selected from either an iron-based or iodine-based electrolyte. For example, in the embodiment of the present invention, FeCl2 and FeCl3 are prepared with ferric chloride and ferrous chloride. 3+ and Fe 2+ The ion concentration of each ion solution is 1 mol / L iron redox couple; the commercially available iodine I3 - / I - Redox couple electrolyte.

[0014] In the large-scale frequency modulation oscillator device disclosed in the present invention, the redox couple in the liquid pool undergoes an electrochemical reaction under the action of an external electric field, wherein electrons flow out from the negative electrode of the power supply and flow into the cathode (second electrode) through the wire. The oxidizing ions are reduced and consumed at the cathode, resulting in a decrease in the concentration of oxidizing ions near its surface. The high-concentration oxidizing ions in the bulk liquid pool diffuse and transfer to the low-concentration area on the cathode surface. The opposite process occurs at the anode (first electrode), such as Figure 5 This process realizes the diffusion of ions in the solution and the exchange of electrons at the solid-liquid interface, thereby achieving circuit conduction at the solid-liquid interface.

[0015] Secondly, the present invention provides a method for preparing the above-mentioned large frequency modulation oscillator device, and the specific steps are as follows:

[0016] 1) Electroforming memristor: Use an active meter (e.g., Keithley 2450) to apply a scan voltage below 3V but above the memristor's threshold voltage to the memristor for electroforming. Initially, the memristor is in a high resistance (HR) state, but when the scan voltage increases to the memristor's threshold voltage, the memristor quickly switches to a low resistance (LR) state. Subsequently, when the scan voltage gradually decreases until it is below the memristor's holding voltage, the memristor quickly switches to a high resistance (HR) state. This marks the completion of the electroforming process, and a memristor with threshold switching characteristics has been successfully obtained. The memristor threshold switching characteristics are shown in the figure below. Figure 6 shown.

[0017] 2) Device Assembly: Connect one end of the electroformed memristor to the negative terminal of a DC power supply, and the other end to the second electrode. Connect the positive terminal of the DC power supply to the first electrode. Next, drip approximately 50 microliters of a redox ionic liquid onto the first electrode. Place the second electrode over the liquid, maintaining a gap between the electrodes. This allows the redox liquid to flow between the two electrodes and completely cover the first and second electrode areas (the areas in contact with the liquid). This completes the fabrication of the AFM oscillator.

[0018] Furthermore, the above-mentioned memristor is prepared by the following steps:

[0019] S01, exposing a pattern model on a substrate (the substrate material can be silicon oxide, quartz wafer, etc.) on which photoresist is spin-coated, and then developing.

[0020] The photolithography step is a conventional technique in the art, such as using a UVLitho-ACA PRO lithography machine manufactured by Hezhi Technology (Suzhou) Co., Ltd. The photolithography parameters can be adjusted according to the actual situation, such as a photolithography time of 500ms and a light intensity of 0.5. A pattern model is photolithographically formed on a substrate coated with AZ-5214 photoresist, and then developed. This step refers to the "Dropout neuronal unit with tunable probability based on NbO x stochasticmemristor for efficient suppression of overfitting[J].

[0021] Microelectronic Engineering, 2022, 259: 111778".

[0022] S02, using magnetron sputtering technology, sequentially photolithography and sputtering the target material on the substrate after photolithography in step S01 to form a bottom electrode, a resistive switching layer, and a top electrode, and then peeling them off to obtain a memristor;

[0023] The above-mentioned "sputtering" is a conventional technique in the art. For example, in the embodiment, a Q150TES high-precision multifunctional vacuum metal sputtering instrument produced by Quorum Technologies is used to sputter the target material on the bottom electrode, the resistive switching layer, and the top electrode respectively according to the manufacturing process of the memristor;

[0024] The stripping step involves placing the sample, after sputtering the target material, in an acetone solution for 5 minutes. Then, ultrasonically cleaning it with a 3W ultrasonic cleaner for 10 seconds to remove all other components, leaving only the target material. The sample is then placed in an isopropyl alcohol solution and ultrasonically cleaning it with a 3W ultrasonic cleaner for 10 seconds to remove the acetone. The sample is then removed and dried with nitrogen to obtain the memristor.

[0025] The memristor fabrication process is a conventional method in the art, as described in the reference “Total ionizing dose effects of gamma-ray radiation on NbO x -based selector devices for crossbar array memory[J].IEEE Transactions on Nuclear Science, 2017, 64(6):1535-1539” disclosed in the preparation method.

[0026] Secondly, the present invention provides a method for testing and using the above-mentioned large-amplitude frequency modulation oscillator device, and the specific steps are as follows:

[0027] A DC power supply (such as a Tektronix AFG31000 or Keithley 2450 generator) is used to apply voltage to the working circuit. The real-time current changes in the circuit are measured using a current amplifier. The voltage divider waveforms of the liquid pool and memristor are recorded using an oscilloscope (such as a RIGOL DHO4204) to obtain the electrical responses of the composite memristor and liquid pool electrochemical reaction device under different DC voltages.

[0028] For example, in Example 1, a device using a composite niobium oxide and an iron electrolyte cell was used, and by applying a DC voltage stimulus, a stable oscillation of the current in the circuit was observed, such as Figure 7 As shown in Figure 1, by changing the DC power supply voltage, the oscillation frequency is adjusted from a few tenths of a hertz to several kilohertz. During this period, as the voltage increases, the resistance state of the memristor and the voltage divider at both ends change, causing the impedance and voltage divider of the liquid pool to change. The voltage change at both ends of the liquid pool is shown in Figure 1. Figure 8As shown in Figure 2, changes in the DC power supply output voltage affect both the circuit oscillation and the oscillation of the solution partial pressure. Under varying DC voltages, the solution partial pressure decreases as the DC voltage decreases. Unlike all-solid-state resistors and capacitors, the solution's impedance response changes significantly with changes in partial pressure. In particular, a decrease in the partial pressure between the first and second electrodes increases the equivalent capacitance at the solid-liquid interface, enabling stable oscillation at low frequencies.

[0029] Due to its exceptional wide-band frequency modulation characteristics, the device is capable of generating frequency signals spanning multiple orders of magnitude. This performance significantly surpasses that of other existing composite memristor oscillator devices, filling a gap in the field of complex signal generation and effectively addressing the shortcomings of artificial neurons in simulating the low-frequency pulses of biological neurons. By introducing a liquid environment, this device further enhances the similarity between artificial neurons and biological neurons and greatly simplifies the oscillation circuit structure. This device not only boasts an extremely simple structure but also offers stable oscillation signals and the integration of electrochemical reactions between the liquid pool and electrodes. It can achieve stable oscillations over a wide frequency range from a few tenths of a hertz to several kilohertz, making it suitable for a variety of applications, including simulating artificial neuron behavior, generating wide-band pulse trains, and digital signal processing. In summary, this device not only achieves breakthroughs in performance but also demonstrates its unique value and potential in a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a diagram of the structure of a composite memristor and a large frequency modulation oscillator device for electrochemical reactions in a liquid pool;

[0031] Wherein: 1 - DC power supply; 2 - memristor; 3 - redox solution; 4 - first electrode; 5 - second electrode; A - ammeter. Redox solution 3, first electrode 4, and second electrode 5 form a liquid pool for electrochemical reaction.

[0032] Figure 2 It is the equivalent circuit diagram and electrical performance diagram of the oscillator device of the composite memristor and solid-state circuit element;

[0033] Among them, a is the equivalent circuit diagram of the oscillation device of the composite memristor and solid-state circuit elements; b is the error diagram of the device oscillation frequency under different voltages, which intuitively shows the instability of the device at low frequencies and the stability at high frequencies.

[0034] Figure 3 Biological neuron information transmission and synaptic biological working model and the artificial neuron working model of the present invention.

[0035] Figure 4 This is the equivalent circuit diagram of the composite memristor and the large-amplitude frequency modulation oscillator device of the liquid pool electrochemical reaction.

[0036] Figure 5This is a structural schematic diagram of a composite memristor and a large-amplitude frequency modulation oscillator device for electrochemical reactions in a liquid pool.

[0037] Figure 6 is the threshold switching characteristic diagram of the memristor;

[0038] Initially, the memristor is in a high resistance (HR) state. However, when the scan voltage increases to the threshold voltage of the memristor, the memristor can quickly change to a low resistance (LR) state. Subsequently, when the scan voltage gradually decreases until it is lower than the holding voltage of the memristor, the memristor can quickly change to a high resistance (HR) state.

[0039] Figure 7 It is a composite niobium oxide memristor and Fe 2+ / Fe 3+ A diagram showing the large-scale frequency modulation characteristics of an oscillating device for electrochemical reactions in a liquid cell;

[0040] Figure a is a waveform diagram of the device showing large-scale frequency modulation at different voltages. The frequency spans multiple orders of magnitude, so different time scales are used: 10s, 1s, 0.1s, 10ms, 1ms, and 0.1m from bottom to top, demonstrating the device's frequency modulation capability. Figure b is a diagram of the device's oscillation frequency at different voltages, intuitively showing the device's stable frequency modulation capability.

[0041] Figure 8 It is the voltage waveform and voltage statistics diagram at both ends of the liquid cell under different DC power supply output voltages;

[0042] Among them, a is the voltage waveform at both ends of the liquid pool of the device under the output voltage of the DC power supply, and Figure b is the statistical curve of the maximum and minimum values ​​of the voltage drop at both ends of the liquid pool under the output voltage of the DC power supply. It can be seen that the voltage drop at both ends of the liquid pool will decrease as the DC voltage decreases, and the impedance response of the solution will change significantly with the change of voltage drop. Therefore, when the voltage drop between the first and second electrodes decreases, it will cause the equivalent capacitance of the solid-liquid interface to increase, thereby achieving stable oscillation at low frequency.

[0043] Figure 9 This is the voltage-frequency graph of the composite silicon telluride memristor and the iodine electrolyte cell at different voltages;

[0044] It can be seen that the device exhibits the characteristic of a significant increase in frequency with increasing voltage, from a few tenths of a hertz to several thousand hertz, demonstrating its excellent frequency modulation range and wide application potential.

[0045] above Figure 2 、 Figure 7 and Figure 9 All are based on the literature "Microscopic Modeling and Optimization of NbO xThe test method disclosed in "Mott Memristor for Artificial Neuron Applications[J].IEEE Transactions on Electron Devices, 2022, 69(12):6686-6692" tests the oscillation frequency of the oscillating device of the composite memristor under different voltages by gradually increasing the voltage. DETAILED DESCRIPTION

[0046] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. Hereinafter, embodiments of the present invention will be described in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0047] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art in the art to which the present invention pertains. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art and, unless defined as such herein, will not be interpreted in an idealized or overly formal sense.

[0048] The manufacturer of the lithography machine used in the embodiment is Hezhi Technology (Suzhou) Co., Ltd., the lithography machine model is UVLitho-ACA PRO, and the light source is ultraviolet light.

[0049] The metal sputtering instrument is a Q150TES high-precision multifunctional vacuum metal sputtering instrument produced by Quorum Technologies.

[0050] Positive photoresist developer was purchased from Jiangyin Jianghua Microelectronics Materials Co., Ltd., model ZX-238;

[0051] High-purity indium particles were purchased from Aladdin.

[0052] Example 1 Preparation of Fe-based composites with niobium oxide memristors 3+ / Fe 2+ Amplitude-modulated frequency oscillator device for electrochemical cells

[0053] 1) Select single-side polished P-type silicon wafers produced by China Electronics Technology Group Corporation 46, with a diameter of 100±0.3mm, a thickness of 400±15μm, and a crystal orientation of <100> ±0.5°, surface oxide layer thickness 300nm.

[0054] The boron-doped silicon dioxide surface of the silicon wafer is used as an insulating substrate, with a resistivity of 0.05-0.2Ω·cm. AZ5214 photoresist is used and spin-coated at a speed of 3500 rpm for 1 minute and 30 seconds using a spin coater.

[0055] 2) Place the silicon wafer spin-coated in 1) on a hot plate and heat at 100° C. for 5 minutes to cure the photoresist.

[0056] 3) Place the silicon wafer in 2) on the sample stage of a photolithography machine for photolithography, and set the photolithography parameters to an illumination time of 500 ms and an illumination intensity of 0.5.

[0057] 4) Place the silicon wafer after photolithography in 3) into a positive photoresist developer for 1 minute to remove the photoresist in the exposed part and form the target pattern.

[0058] 5) Place the silicon wafer prepared in 4) in a metal sputtering apparatus and sputter platinum (30 nm thick, sputtering for 200 s at 20 mA in a high-purity argon environment) to serve as the bottom electrode of the target memristor.

[0059] 6) Soak the sputtered silicon wafer in acetone for 5 minutes. After 5 minutes, use an ultrasonic cleaner at 3W for 10 seconds to remove residual photoresist and other impurities.

[0060] 7) Repeat steps 1) to 4) to prepare for sputtering the resistive switching layer and the top electrode.

[0061] 8) Place the silicon wafer from 7) in a metal sputtering apparatus and sequentially sputter niobium oxide (20 nm thick, sputtered at 80 mA for 600 s in a 3:1 argon / oxygen mixture) and platinum (30 nm thick, sputtered at 20 mA for 200 s in a high-purity argon environment) to serve as the resistive layer and top electrode of the target memristor, respectively.

[0062] 9) Repeat step 6) to obtain a niobium oxide memristor.

[0063] 10) The silicon wafer (niobium oxide memristor) in 9) was quickly removed and placed in isopropyl alcohol. The silicon wafer was then ultrasonically cleaned at 3W for 10 seconds and dried with nitrogen. The niobium oxide memristor in this embodiment was prepared according to the method disclosed in the reference "Total ionizing dose effects of gamma-ray radiation on NbOx-based selector devices for crossbar array memory [J]. IEEE Transactions on Nuclear Science, 2017, 64(6): 1535-1539".

[0064] 11) Electroform the niobium oxide memristor from 10). Using a Keithley 2450 meter, apply a 2V sweep voltage (exceeding the memristor's threshold voltage) and connect a 1kΩ resistor in series to protect the memristor. Observe the current flow. When the memristor reversibly changes from a high-resistance state to a low-resistance state in response to the sweep voltage, the electroforming is complete and a threshold-switching memristor is obtained for future use.

[0065] 12) Use an electronic scale to weigh 13.5g of FeCl3·6H2O and 9.9g of FeCl2·4H2O reagents, and place them in a beaker in sequence. Add 50mL of deionized water or ultrapure water to make FeCl3·6H2O. 3+ and Fe 2+ Mixed ion solution; in this example, Fe 3+ and Fe 2+ The molar ratio is 1:1, and the concentration is 1 mol / L. In the specific implementation, other Fe 3 + and Fe 2+ ratio and ion concentration, can achieve the purpose of the invention.

[0066] 13) Use indium particles to connect the copper wires to the two electrodes respectively, drop the mixed solution on the first electrode, and then cover the second electrode to allow the solution to spread and cover the surfaces of both electrodes.

[0067] In this embodiment, the first electrode and the second electrode are both made of ITO, and are rectangular with a length of 2 mm and a width of 2 mm. In specific implementations, other conventional electrode materials such as gold, platinum, carbon, etc. can also be used.

[0068] 14) Connect one end of the threshold-switching memristor prepared in 11) to the negative terminal of a DC power supply (Tektronix AFG31000) via a copper wire, and the other end to the second electrode. Connect the first electrode in series with the positive terminal of the DC power supply to form a closed circuit, thereby obtaining a high-frequency oscillator.

[0069] The composition diagram of the composite memristor and the large frequency modulation oscillator device for the electrochemical reaction of the iron electrolyte liquid pool prepared in this embodiment is shown in FIG. Figure 1 As shown in the figure, the equivalent circuit diagram is as follows Figure 4 As shown, the structural principle diagram is as follows Figure 5 shown.

[0070] The large frequency modulation oscillator device prepared in this embodiment was tested by applying voltage through a DC power supply, measuring the real-time change of current in the circuit through a current amplifier, and recording the voltage waveform curve of the liquid pool and memristor through an oscilloscope (such as RIGOL DHO4204) to obtain the electrical response of the composite memristor and liquid pool electrochemical reaction device under different DC voltages. The test results are as follows: Figure 7As shown in the figure, as the output voltage of the DC power supply increases, the pulse oscillation of the device becomes more and more intensive and grows across orders of magnitude. By adjusting the applied voltage, the oscillation frequency can be stably and continuously adjusted over a wide range from a few tenths of a hertz to several kilohertz, demonstrating excellent frequency regulation capabilities.

[0071] Example 2 Preparation of a Silicon Telluride Memristor Composite I - / I3 - Electrolyte-based Amplitude Frequency Modulation Oscillator

[0072] 1) Select China Electronics Technology Group Corporation 46th Institute to manufacture single-side polished P-type silicon wafers with a diameter of 100±0.3mm, a thickness of 400±15μm, and a crystal orientation of <100> ±0.5°, the thickness of the oxide layer on the silicon wafer surface is 300nm.

[0073] The boron-doped silicon dioxide surface of the silicon wafer was used as the insulating substrate, with a resistivity of 0.05-0.2 Ω·cm. AZ5214 photoresist was used and spun on at 3500 rpm for 1 minute and 30 seconds.

[0074] 2) Place the silicon wafer spin-coated in 1) on a hot plate and heat at 100°C for 5 minutes to cure the photoresist.

[0075] 3) Place the silicon wafer in 2) on the sample stage of a photolithography machine for photolithography, and set the photolithography parameters to an illumination time of 500 ms and an illumination intensity of 0.5.

[0076] 4) Place the silicon wafer after photolithography in 3) into a positive photoresist developer for 1 minute to remove the photoresist in the exposed part and form the target pattern.

[0077] 5) Place the silicon wafer in 4) into a metal sputtering instrument and sputter tungsten (60 nm thickness, sputtering with 80 mA current for 300 s in a high-purity argon environment) as the bottom electrode of the target memristor.

[0078] 6) Soak the sputtered silicon wafer in acetone for 5 minutes. After 5 minutes, use an ultrasonic cleaner at 3W for 10 seconds to remove residual photoresist and other impurities.

[0079] 7) Repeat steps 1) to 4) to prepare for sputtering the resistive switching layer and the top electrode.

[0080] 8) Place the silicon wafer from 7) in a metal sputtering apparatus and sequentially sputter silicon telluride (20 nm thick, sputtered at 40 mA for 200 s in a high-purity argon environment) and tungsten (60 nm thick, sputtered at 80 mA for 300 s in a high-purity argon environment) to serve as the resistive layer and top electrode of the target memristor, respectively.

[0081] 9) Soak the sputtered silicon wafer in acetone for 5 minutes, and then use an ultrasonic cleaner at 3W for 10 seconds to remove the remaining photoresist and other impurities to obtain a silicon telluride memristor. The silicon telluride memristor in this embodiment is described in the reference "The ovonic threshold switching characteristics in SixTe 1-x Preparation method disclosed in "based selector devices. Applied Physics A 124.11(2018):734"

[0082] 10) Quickly remove the silicon wafer (silicon telluride memristor) from 9), place it in isopropyl alcohol, and then ultrasonically clean it using an ultrasonic cleaner at 3W for 10 seconds. Finally, take it out and blow dry it with nitrogen.

[0083] 11) Electroform the silicon telluride memristor from 10) using a Keithley 2450 meter. Apply a sweep voltage of 1.5V (above the memristor threshold voltage). Observe the current. When the memristor reversibly switches from a high-resistance state to a low-resistance state as the sweep voltage changes, electroforming is complete and a threshold-switching memristor is obtained for future use.

[0084] 12) Use indium particles to connect the copper wires to the two electrodes respectively, and then place them in an iodine electrolyte (purchased from OPV Technology Co., Ltd., model OPV-AN-I, the electrolyte composition includes iodine, anhydrous lithium iodide, PMI, guanidine isothiocyanate, TBP acetonitrile, I - Concentration: 0.07 mol / L, I3 - Concentration: 0.07 mol / L. In specific applications, other commercially available iodine-based electrolytes can also be used. 50 μL of the electrolyte can be dropped onto the first electrode, and then the second electrode is placed on top, allowing the electrolyte to diffuse and cover the surfaces of both electrodes to form an electrochemical liquid cell.

[0085] In this embodiment, the first electrode and the second electrode used are both made of platinum, and are rectangular with a length of 3 cm and a width of 3 cm. They are used to increase the solid-liquid contact area and reduce the interface impedance. In specific implementations, other conventional electrodes such as gold, carbon and other materials can also be used.

[0086] 13) Connect one end of the threshold switching memristor in 11) to the negative terminal of a DC power supply via a copper wire, and the other end to the second electrode. Connect the first electrode in series with the positive terminal of the DC power supply to form a closed circuit, thereby obtaining a high-frequency oscillator.

[0087] The device structure is shown in the figure Figure 1 As shown, the equivalent circuit diagram is as Figure 4 As shown, the structural principle diagram is as follows Figure 5 shown.

[0088] Apply voltage to the DC power supply, test the large frequency modulation oscillator device of silicon telluride memristor composite iodine electrolyte prepared in this embodiment, and measure the current change in the circuit. The experimental results are as follows: Figure 9 (iodine electrolyte, solvent acetonitrile, I - and I3 - The concentration of each is 0.07 mol / L), as shown in Figure 2, with the increase of voltage, the frequency increases from a few tenths of Hz to several kilohertz, showing excellent frequency tuning ability.

Claims

1. A composite memristor and liquid pool electrochemical reaction large frequency modulation oscillator device, characterized in that: The device comprises a DC power supply, a first electrode, a redox liquid pool, a second electrode, and a threshold switching memristor; the positive electrode of the DC power supply is connected to the first electrode via a wire, and the negative electrode is connected in series with the memristor and the second electrode via wires in sequence; a gap is provided between the first and second electrodes to accommodate the redox liquid pool, and the redox liquid pool is an ionic solution containing redox pairs; The solution containing the redox pair is any one of an iron-based or iodine-based electrolyte; The ion concentration in the redox solution pool is 0.07-1 mol / L.

2. The composite memristor and liquid pool electrochemical reaction large frequency modulation oscillator device according to claim 1, characterized in that: The DC power supply voltage is higher than the threshold voltage of the threshold switch type memristor.

3. The composite memristor and liquid pool electrochemical reaction large frequency modulation oscillator device according to claim 1, characterized in that: The solution containing the redox pair is Fe 3+ / Fe 2+ Ionic solution, I3 - / I - Any of the electrolytes.

4. The composite memristor and liquid pool electrochemical reaction large frequency modulation oscillator device according to claim 1, characterized in that: The threshold switching memristor consists of a bottom electrode, a resistive layer and a top electrode; the material of the resistive layer is selected from one of niobium oxide or silicon telluride, and the material of the top electrode is selected from one of platinum, gold tungsten or titanium nitride; the material of the bottom electrode is selected from one of platinum, gold, tungsten or titanium nitride; the material of the first electrode is selected from one of platinum, gold, carbon or ITO, and the material of the second electrode is selected from one of platinum, gold, carbon or ITO.

5. A method for preparing a composite memristor and a high-frequency modulation oscillator device for liquid pool electrochemical reaction as claimed in any one of claims 1 to 4, characterized in that: Including steps: S01, connecting one end of the threshold switching memristor to a DC power supply and the other end to the second electrode; S02, connecting the other end of the DC power supply to the first electrode through a wire; S03, introducing a redox liquid pool between the first electrode and the second electrode to form a closed loop, thereby completing the preparation of the composite memristor and the large frequency modulation oscillator device for the electrochemical reaction of the liquid pool.

6. The preparation method according to claim 5, characterized in that The threshold switching memristor preparation steps include: S01, coating a photoresist on a silicon oxide substrate and forming a patterned mask by photolithography technology; S02, using thin film deposition and photoresist stripping technology, sequentially depositing a patterned bottom electrode material, a resistive switching layer material, and a top electrode material to obtain a patterned memristor structure; S03, using an electric meter to apply a scanning voltage less than 3V and exceeding the threshold voltage of the memristor to the memristor prepared in step S02 for electroforming, thereby obtaining a threshold switching memristor.

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