Large-amplitude frequency modulation oscillating device combined with memristor and liquid pool electrochemical reaction

Abstract

The invention discloses a large-amplitude frequency modulation oscillation device combined with a memristor and a liquid pool electrochemical reaction, and relates to the fields of electronic component technology, neuromorphic devices, electronic information processing and the like. The large-amplitude frequency modulation oscillating device comprises a direct-current power supply, a first electrode, a redox liquid pool, a second electrode and a memristor, conducting state transformation is achieved through the threshold switching effect, a solid-liquid interface working environment is constructed by means of series connection of the redox liquid pool and a memristor working circuit, and the large-amplitude frequency modulation oscillating device is driven by direct-current voltages with different amplitudes. The device can realize stable oscillation in a broadband range from several hertz to several kilohertz at a zero point, and is suitable for various application scenes such as artificial neuron behavior simulation, broadband pulse sequence generation, digital signal processing and the like.

Description

Technical Field

[0001] The present invention relates to the field of broadband signal generation and neuromorphic devices, and in particular to a frequency modulation oscillator device of composite memristor and liquid pool electrochemical reaction, which has a wide frequency modulation range and can cover a frequency range from a few tenths of a 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) and other structures. However, such circuits often have problems such as high power consumption, limited frequency adjustment range, and complex circuit structure. Especially in scenarios where wideband modulation is required, their limitations are particularly prominent.

[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 will undergo 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 neural 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; 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 all types of typical memristor-capacitor-resistor architecture oscillation devices, such as "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), such composite memristors and solid-state resistors and capacitors cannot meet the needs of broadband signal processing and increasingly complex artificial neurons, especially the requirements of biocompatibility (biological neurons mostly work in liquid environments).

[0004] Another difficulty faced by neuromorphic devices is the deep integration with the liquid environment. At present, 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 electronic devices and did not fully integrate the electrochemical reaction advantages of electrodes and liquid pools, limiting the device's ability to simulate 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 a composite memristor and a liquid pool has become a technical problem that needs to be solved urgently in this field. Summary of the invention

[0006] In view of the above problems, the present invention designs an artificial neuron working model based on the working principle of biological neurons and synapses. The model is also the working model of the large frequency modulation oscillator device disclosed in the present invention. Figure 3 As shown, the model shows the working model of a typical biological neuron and its synapse. Biological neurons transmit and activate information through the transmission of neurotransmitters between chemical synapses. In the biomimetic model of the present invention, the memristor acts as a neuron, the two electrodes simulate the synapse, and the ions in the redox pair liquid pool between the two electrodes act as neurotransmitters in the synaptic gap. The obtained composite memristor and the oscillating device of the liquid pool electrochemical reaction have a wide frequency spectrum coverage, covering the frequency band from a few tenths of 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 large frequency modulation oscillator device for electrochemical reaction of a liquid pool, the device comprising a DC power supply, a first electrode, a redox pair liquid pool, a second electrode and a threshold switch type 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 switch type memristor and the second electrode in sequence. A gap for accommodating the redox liquid pool is formed between the first electrode and the second electrode, which together constitute a closed loop. The redox liquid pool is an ion solution containing a redox pair. 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 above-mentioned threshold switching memristor 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 will suddenly drop sharply and change from a high resistance (HR) state to a low resistance (LR) state. When the applied voltage is lower than the holding voltage, the resistance will suddenly rise sharply and change 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 behaviour of NbO x-based memristive devices[J].Scientific Reports,2023,13(1):17003”, which consists of a three-layer structure of bottom electrode, resistive switching layer and top electrode, such as Figure 5 As shown; the materials of the top electrode and the bottom electrode can be selected from materials such as platinum, gold, tungsten or titanium nitride according to the manufacturing process of the memristor. The material of the resistive layer can be selected from metal oxides (such as niobium oxide, etc.) or binary compounds of non-metals and chalcogen elements (such as silicon telluride). Before the memristor is prepared and connected to the circuit, a scanning voltage lower than 3V but higher than its threshold voltage needs to be applied to it to give it a threshold switching effect, thereby obtaining a threshold switching type memristor.

[0012] In the above-mentioned large frequency modulation oscillator device, the DC power supply voltage must be higher than the memristor threshold voltage. At the same time, during the operation of the device, the highest voltage division across the memristor must not be lower than the threshold voltage, and the lowest voltage division 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 value at which the device starts to switch states (rapidly switch from a high resistance state to a low resistance state) when the applied voltage exceeds a certain threshold, and the term "holding voltage" refers to the minimum voltage required for the memristor to maintain the state after switching to the low resistance state.

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

[0014] In the large frequency modulation oscillator device disclosed in the present invention, the redox pairs in the liquid pool undergo an electrochemical reaction under the action of an external electric field, wherein electrons flow out from the negative electrode of the power source and flow into the cathode (the second electrode) through a wire, and 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 phase liquid pool diffuse and transfer to the low-concentration area on the cathode surface, and the opposite process occurs at the anode (the 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 ammeter (such as Keithley 2450) to apply a scan voltage lower than 3V but higher than its 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 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 less than the holding voltage of the memristor, the memristor can quickly change 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 threshold switching characteristics of the memristor are shown in the figure below. Figure 6 shown.

[0017] 2) Assemble the device: Connect one end of the electroformed memristor to the negative electrode of the DC power supply, and the other end to the second electrode; the positive electrode of the DC power supply is connected to the first electrode. Then, drip about 50 microliters of redox ion liquid onto the first electrode, and then cover the second electrode with the solution and keep a gap with the first electrode, so that the redox liquid sandwiched between the two electrodes can flow and completely cover the first electrode and the second electrode area (the surface in contact with the solution). At this point, the above-mentioned large frequency modulation oscillator device is completed.

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

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

[0020] The photolithography step is a conventional technique in the art, such as using a UVLitho-ACA PRO photolithography machine manufactured by Hezhi Technology (Suzhou) Co., Ltd. The photolithography parameters can be adjusted according to the actual situation, such as lithography time 500ms, light intensity 0.5, etc., and a pattern model is photolithographically formed on a substrate with AZ-5214 photoresist spin-coated, and then developed. This step refers to "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, on the substrate after photolithography in step S01, sequentially photolithography and sputtering the target material 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 technology 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 to the bottom electrode, the resistive switching layer, and the top electrode respectively according to the manufacturing process of the memristor;

[0024] The stripping step includes placing the sample after the target material is sputtered in an acetone solution, soaking for 5 minutes, and then using an ultrasonic cleaner to perform ultrasound at a power of 3W for 10s to wash away other parts and leave the target part. Then, the sample is placed in an isopropanol solution and ultrasound is performed at a power of 3W for 10s to wash away the acetone, and then the sample is fished out and blown dry with nitrogen to obtain a 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”.

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

[0027] A DC power supply (such as Tektronix AFG31000 or Keithley 2450 generator) is used to apply voltage in the working circuit, and the real-time change of current in the circuit is measured by a current amplifier. The voltage divider waveform curves of the liquid pool and memristor are recorded by 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.

[0028] For example, in Example 1, a device using a composite niobium oxide and an iron electrolyte cell can be observed to have a stable oscillation of the current in the circuit by applying a DC voltage stimulus, such as Figure 7 As shown in the figure, by changing the DC power supply voltage, the oscillation frequency is adjusted from a few tenths of a hertz to a few 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 8As shown in the figure. The change of DC power supply output voltage will affect the oscillation of the line and the oscillation of the solution partial pressure. Under different DC voltages, the solution partial pressure will decrease as the DC voltage decreases. Unlike all-solid-state resistors and capacitors, the impedance response of the solution will change significantly with the change of partial pressure. In particular, when the partial pressure 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.

[0029] Because the device exhibits excellent large-scale frequency modulation characteristics, it can generate frequency signals spanning multiple orders of magnitude. This performance significantly surpasses other current composite memristor oscillator devices, fills the gap in the field of complex signal generation, and effectively makes up for the shortcomings of artificial neurons in simulating low-frequency pulses of biological neurons. By introducing a liquid environment, this device further improves the similarity between artificial neurons and biological neurons and greatly simplifies the oscillation circuit structure. This device not only has the advantages of extremely simple structure, but also has the advantages of stable oscillation signals and electrochemical reactions that integrate liquid pools and electrodes. It can achieve stable oscillations in a wide frequency range from a few tenths of a hertz to several thousand hertz, and is suitable for a variety of application scenarios such as simulating artificial neuron behavior, wide-band pulse sequence generation, and digital signal processing. In summary, this device not only achieves a breakthrough in performance, but also demonstrates its unique value and potential in the field of application. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a diagram of the composition of the composite memristor and the large frequency modulation oscillator device of the electrochemical reaction of the liquid pool;

[0031] Among them, 1-DC power supply; 2-memristor; 3-redox solution; 4-first electrode; 5-second electrode; A-ammeter. The redox solution 3, the first electrode 4, and the 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 diagram of the present invention.

[0035] Figure 4 It is the equivalent circuit diagram of the composite memristor and the large frequency modulation oscillation device of the liquid pool electrochemical reaction.

[0036] Figure 5It is a structural schematic diagram of a composite memristor and a large 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, but 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 less 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+ The large frequency modulation characteristic diagram of the oscillating device of the liquid cell electrochemical reaction;

[0040] Among them, a is the waveform diagram of the device with large frequency modulation under different voltages. The frequency spans multiple orders of magnitude, so different time scales are selected, from bottom to top, 10s, 1s, 0.1s, 10ms, 1ms, and 0.1m, respectively, which shows the frequency modulation capability of the device. b is the oscillation frequency diagram of the device under different voltages, which intuitively shows the stable frequency modulation capability of the device.

[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 divider at both ends of the liquid pool under the output voltage of the DC power supply. It can be seen that the voltage divider at both ends of the liquid pool will decrease with the decrease of the DC voltage, and the impedance response of the solution will change significantly with the change of the voltage divider. Therefore, when the voltage divider 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] Fig. 9 It 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 Fig. 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 solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention will be described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted 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 those generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

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

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

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

[0053] 1) Select single-sided polished P-type silicon wafers produced by China Electronics Technology Group Corporation 46 Institute, with a silicon wafer 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 surface substrate, and its resistivity is 0.05-0.2Ω·cm. AZ5214 photoresist is used and is spin-coated at a speed of 3500 rpm for 1 minute and 30 seconds by 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 the photolithography machine for photolithography, and set the photolithography parameters to illumination time 500ms and illumination intensity 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 a target pattern.

[0058] 5) Place the silicon wafer in 4) into a metal sputtering instrument and sputter platinum (30 nm thickness, sputtering for 200 s with a current of 20 mA in a high-purity argon environment) as the bottom electrode of the target memristor.

[0059] 6) Soak the sputtered silicon wafer in 5) in acetone for 5 minutes, and then use an ultrasonic cleaner to clean it for 10 seconds at a power of 3W to remove the 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 in 7) into a metal sputtering instrument, and sputter niobium oxide (20 nm thick, sputtered for 600 s with 80 mA current in a mixed gas with an argon-oxygen ratio of 3:1) and platinum (30 nm thick, sputtered for 200 s with 20 mA current in a high-purity argon environment) in sequence, 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 taken out, placed in isopropanol, and then cleaned with ultrasound at 3W power for 10 seconds, and finally dried with nitrogen. The niobium oxide memristor in this embodiment was prepared by 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 in 10) and use a Keithley 2450 meter to apply a 2V scan voltage (exceeding the memristor threshold voltage) and connect a 1kΩ resistor in series to protect the memristor. Observe the current change. When the memristor reversibly changes from a high resistance state to a low resistance state with the scan voltage, the electroforming is completed and a threshold switching memristor is obtained for standby use.

[0065] 12) Use an electronic balance to weigh 13.5 g of FeCl3·6H2O and 9.9 g of FeCl2·4H2O reagents, and put them into a beaker in turn. Add 50 mL 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, drip the mixed solution on the first electrode, and then cover the second electrode to allow the solution to diffuse and cover the surfaces of the two 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. may also be used.

[0068] 14) One end of the threshold switching memristor prepared in 11) is connected to the negative electrode of a DC power supply (Tektronix AFG31000) through a copper wire, and the other end is connected to the second electrode. The first electrode is connected in series with the positive electrode of the DC power supply to form a closed loop, and a large frequency modulation oscillator device is obtained.

[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 is 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 liquid pool and memristor voltage waveform curves 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, with the increase of the output voltage of the DC power supply, 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 capability.

[0071] Example 2 Preparation of a Silicon Telluride Memristor Composite I - / I3 - Electrolyte large frequency modulation oscillator

[0072] 1) Select China Electronics Technology Group Corporation 46th Institute to manufacture single-sided polished P-type silicon wafers with a silicon wafer diameter of 100±0.3mm, a silicon wafer 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 silicon dioxide surface doped with boron on the silicon wafer was used as an insulating substrate, and its resistivity was 0.05-0.2 Ω·cm. AZ5214 photoresist was used and spun at 3500 rpm for 1 minute and 30 seconds by a spin coater.

[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 the photolithography machine for photolithography, and set the photolithography parameters to illumination time 500ms and illumination intensity 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 a target pattern.

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

[0078] 6) Soak the sputtered silicon wafer in 5) in acetone for 5 minutes, and then use an ultrasonic cleaner to clean it for 10 seconds at a power of 3W to remove the 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 in 7) into a metal sputtering instrument, and sputter silicon telluride (20 nm thickness, sputtered for 200 s with a current of 40 mA in a high-purity argon environment) and tungsten (60 nm thickness, sputtered for 300 s with a current of 80 mA in a high-purity argon environment) in sequence, 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 to clean the silicon wafer for 10 seconds at a power of 3W to remove the residual photoresist and other impurities, thereby obtaining a silicon telluride memristor. The silicon telluride memristor in this embodiment is referred to in the literature “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 take out the silicon wafer (silicon telluride memristor) in 9), put it into isopropyl alcohol, and then use an ultrasonic cleaner at a power of 3W for 10 seconds, and finally take it out and blow it dry with nitrogen.

[0083] 11) Electroform the silicon telluride memristor in 10) and apply a 1.5V scan voltage (exceeding the memristor threshold voltage) using a Keithley 2450 meter. Observe the current change. When the memristor reversibly changes from a high resistance state to a low resistance state as the scan voltage changes, the electroforming is completed and a threshold switching memristor is obtained for later use.

[0084] 12) Connect the copper wires to the two electrodes respectively with indium particles, and then place them in an iodine electrolyte (purchased from Opivit Technology Co., Ltd., model OPV-AN-I, the electrolyte composition includes iodine, anhydrous lithium iodide, PMI, guanidine isothiocyanate, TBP acetonitrile, I - Concentration: 0.07mol / L, I3 - Concentration: 0.07 mol / L. In specific applications, other commercially available iodine electrolytes can also be used to drop 50 microliters on the first electrode, and then cover the second electrode to allow the electrolyte to diffuse and cover the surfaces of the two electrodes to form an electrochemical liquid pool.

[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, which 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 electrode of the DC power supply through a copper wire, and connect the other end to the second electrode. Connect the first electrode to the positive electrode of the DC power supply in series to form a closed loop, and obtain a large frequency modulation oscillator device.

[0087] Device composition diagram Figure 1 As shown, the equivalent circuit diagram is as follows Figure 4 As shown, the structural principle diagram is as follows Figure 5 shown.

[0088] A voltage is applied to the DC power supply to detect the large frequency modulation oscillator device of the silicon telluride memristor composite iodine electrolyte prepared in this embodiment, and the current change in the measuring circuit is implemented. The experimental results are as follows: Fig. 9 (iodine electrolyte, solvent acetonitrile, I - and I3 - The concentrations of the two samples were all 0.07 mol / L), as shown in Figure 2, with the increase of voltage, the frequency increased from a few tenths of Hz to several kilohertz, showing excellent frequency tuning ability.

Claims

1. A composite memristor and a liquid pool electrochemical reaction large frequency modulation oscillator device, characterized in that: The invention comprises a direct current power supply, a first electrode, a redox liquid pool, a second electrode and a threshold switch type memristor; the positive electrode of the direct current power supply is connected to the first electrode through a wire, and the negative electrode is connected in series with the memristor and the second electrode in sequence through a wire; there is a gap between the first electrode and the second electrode to accommodate the redox liquid pool, and the redox liquid pool is an ion solution containing redox pairs.

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 ion concentration in the redox liquid pool is 0.07-1 mol / L.

4. 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 any one of an iron-based electrolyte or an iodine-based electrolyte.

5. The composite memristor and liquid pool electrochemical reaction large frequency modulation oscillator device according to claim 4, characterized in that: The solution containing the redox pair is Fe 3+ / Fe 2+ Ionic solution, I3 - / I - Any of the electrolytes.

6. 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, 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.

7. A method for preparing a composite memristor and a large frequency modulation oscillator device for liquid pool electrochemical reaction as claimed in any one of claims 1 to 6, characterized in that: Includes steps: S01, connecting one end of the threshold switching memristor to a DC power supply, and the other end to a 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.

8. The preparation method according to claim 7, characterized in that: The threshold switch type 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 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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