Three-terminal electrochemical device based on zinc ion deintercalation to regulate resistance

Abstract

The application provides a three-terminal electrochemical device based on zinc ion deintercalation to adjust resistance, comprising a gate electrode, a source electrode, a drain electrode and a channel existing between the source electrode and the drain electrode; wherein the channel is made of a zinc ion conductor capable of intercalating and deintercalating zinc ions to realize reversible adjustment of resistance. By arranging the zinc ion conductor capable of intercalating and deintercalating zinc ions between the source electrode and the drain electrode and forming the channel, reversible adjustment of resistance can be realized based on the change of zinc ion concentration of the channel. Since zinc and the zinc ion conductor are relatively stable in air and the voltage required in the zinc ion deintercalation process is low and the reversibility is high, the three-terminal electrochemical device has the advantages of high stability, low power consumption and high reversibility. Based on the scheme of the application, the performance of electrochemical devices such as nonvolatile memories can be improved.

Description

Technical Field

[0001] This invention relates to electrochemical devices, and in particular to three-terminal electrochemical devices based on zinc ion insertion / extraction regulation resistance. Background Technology

[0002] Currently, advanced semiconductor manufacturing processes have reached the 5nm size. For the 5nm process, on the one hand, the linewidth is approaching its physical limit, tunneling current increases significantly, and the short-channel effect becomes prominent. On the other hand, the complex manufacturing process not only drastically increases costs but also significantly slows down the pace of process advancement. The era of significantly improving device performance simply by updating the process is over. Therefore, traditional logic chips may struggle to keep up with the evolving computing demands in the future. Against this backdrop, neuromorphic computing (or neuro-inspired computing) has been proposed as an analog computing approach that promises to significantly reduce energy consumption and computation time.

[0003] With the deepening development of neuromorphic computing, the demand for non-volatile memory and artificial synapses in related systems is increasing. In 2008, R. Stanley Williams et al. proposed that non-volatile memory (memristor) at both ends can be prepared by relying on the redistribution of oxygen vacancies. At the same time, the article verified the potential of non-volatile memory in mimicking synaptic function. Subsequently, significant progress was made in research on electron-ion coupling transport, for example, (1) oxygen vacancies: in metal oxides such as ZnO, Ta2O5, CeO2, WO2, TiO2, and HfO2, +2 oxygen vacancies can redistribute under an external electric field, leading to phase separation and non-volatilely changing the device's resistance state; (2) silver and copper ions: silver and copper ions gain electrons at the electrode, undergo reduction reactions to generate metallic elements, and then generate a metal wire, changing the device's resistance state; (3) hydrogen ions: due to their small "ionic radius" and mass, hydrogen ions can easily enter the material lattice, and can then electrochemically dope carbon materials, metal oxide materials, etc., changing their resistance state; (4) lithium ions: similar to hydrogen ions, in the presence of an external field, lithium ions can reversibly extract and insert, causing changes in the material's band structure, thereby controlling the device's configuration. In particular, Li x CoO2, Li x WO3 and Li 4+x Ti5O 12 Materials such as these can undergo a metal-insulator phase transition as the bulk lithium-ion concentration changes, attracting considerable attention.

[0004] Although numerous non-volatile memories or artificial synapses based on electron-ion coupling processes already exist, they also have their own problems: for example, devices based on silver or copper ion redox reactions have poor reversibility (mainly because complete oxidation of the metal wire is difficult), devices based on lithium ion de-entrapment and intercalation have high power consumption, and many electrode materials and electrolytes are unstable in air. Therefore, finding more stable (water and oxygen insensitive), lower power consumption, and higher reversibility material systems is one of the key methods to improve the performance of related devices. Summary of the Invention

[0005] One object of the present invention is to overcome at least one technical defect in the prior art and provide a three-terminal electrochemical device based on zinc ion insertion / extraction regulation resistance.

[0006] A further objective of this invention is to provide a three-terminal electrochemical device with a material system that has high stability, low power consumption and high reversibility, thereby improving the performance of electrochemical devices such as non-volatile memories.

[0007] Another further objective of this invention is to improve the safety of three-terminal electrochemical devices.

[0008] Another objective of this invention is to enable three-terminal electrochemical devices to have a high on / off ratio and high reversibility.

[0009] In particular, the present invention provides a three-terminal electrochemical device based on zinc ion insertion / extraction regulation resistance, comprising: a gate electrode, a source electrode, a drain electrode, and a channel between the source electrode and the drain electrode; wherein the channel is made of a zinc ion conductor capable of inserting and extracting zinc ions to achieve reversible resistance regulation.

[0010] Optionally, the three-terminal electrochemical device further includes an electrolyte made of zinc ion conductor and connected to the channel, configured to exchange zinc ions with the channel under the action of an external electric field, so that zinc ions are inserted or extracted from the channel, thereby causing the band structure and crystal structure of the channel to undergo reversible changes.

[0011] Optionally, the channel transitions between a metallic phase and a non-metallic phase as the zinc ion concentration changes; and the channel has a non-volatile steady-state resistance when zinc ions are inserted or extracted.

[0012] Optionally, the zinc ion conductor forming the channel comprises Na2V6O 16 ·xH2O (x≥0) or α-MnO2.

[0013] Optionally, the electrolyte is present between the gate electrode and the source electrode, and between the gate electrode and the drain electrode, and is a non-electronic conductor, to isolate the gate electrode from the source electrode and to isolate the gate electrode from the drain electrode.

[0014] Optionally, the gate electrode, the source electrode, and the drain electrode are all electronic conductors, and the source electrode and the drain electrode are both non-zinc ion conductors.

[0015] Optionally, the electrolyte is in liquid, gel, or solid state, and its decomposition voltage is greater than or equal to the electrochemical voltage at which zinc ions are reversibly inserted and removed from the channel.

[0016] Optionally, the gate electrode is zinc, a zinc alloy, or the positive and negative electrode material of a zinc-ion battery.

[0017] Optionally, the zinc ion conductor forming the channel is doped with an electronic conductor.

[0018] Optionally, the three-terminal electrochemical device further includes a substrate, which serves as the base for the source electrode, the drain electrode, the channel and / or the gate electrode, and is made of an insulating material.

[0019] The present invention relates to a three-terminal electrochemical device based on zinc ion insertion / extraction regulation resistance. This device utilizes a zinc ion conductor capable of inserting and extracting zinc ions, formed between the source and drain electrodes, to create a channel. The resistance can be reversibly adjusted based on changes in the zinc ion concentration within the channel. Since zinc and zinc ion conductors are relatively stable in air, and the zinc ion insertion / extraction process requires low voltage and exhibits high reversibility, the three-terminal electrochemical device of this invention possesses advantages such as high stability, low power consumption, and high reversibility. Based on the solution of this invention, it is beneficial to improve the performance of electrochemical devices such as non-volatile memories.

[0020] Furthermore, the three-terminal electrochemical device of the present invention based on zinc ion insertion / extraction regulation resistance uses zinc ion conductor as electrolyte, so it can use a medium with a pH close to neutral, which is almost non-corrosive and can be made of non-flammable and non-explosive materials. Compared with traditional electrochemical devices based on electron-ion coupling process, it has higher safety performance.

[0021] Furthermore, the three-terminal electrochemical device of the present invention based on zinc ion insertion / extraction regulation resistor has the function of switching between a conductor and an insulator because the channel changes between a metallic phase and a non-metallic phase as the zinc ion concentration changes. This enables the three-terminal electrochemical device of the present invention to achieve a high switching ratio and has high reversibility.

[0022] Furthermore, experimental verification revealed that the three-terminal electrochemical device based on zinc ion intercalation / deintercalation regulation resistor of the present invention has multiple continuously adjustable and distinguishable resistance states, and can flexibly switch resistance states under the action of an external electric field. The resistance state variable is correlated with the specific values ​​of parameters such as the pulse width and amplitude of the external voltage, which facilitates complex encoding and can achieve practical purposes such as good information storage. It can perform the work of a traditional memristor and can also simulate the function of a biological synapse, translating upstream stimulation signals into channel electrical signals.

[0023] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0024] The following sections will describe some specific embodiments of the invention in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0025] Figure 1 This is a schematic structural diagram of a three-terminal electrochemical device based on a zinc ion intercalation / deintercalation regulating resistor according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic structural diagram of a three-terminal electrochemical device based on a zinc ion insertion / extraction regulation resistor according to another embodiment of the present invention (the dashed lines in the diagram represent perspective).

[0027] Figure 3 This is a schematic top view of a substrate with a mask according to an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the substrate and source and drain electrodes after mask removal according to an embodiment of the present invention;

[0029] Figure 5 The impedance state change curves of the device in Embodiment 1 of the present invention under several different pulse widths and amplitude modulation signals are shown.

[0030] Figure 6 The results of the modulation test of the device in Embodiment 2 of the present invention under the action of two opposite stimulation signals (single pulse signal, applied continuously 30 times) are shown.

[0031] Figure 7 The impedance state change curves of the device after experiencing different numbers of modulation signals in Embodiment 4 of the present invention are shown. The pulse width of each modulation signal is 300ms, the amplitude is -1.4V, and the application interval is 500ms.

[0032] Figure 8The impedance state change curves of the device in Embodiment 5 of the present invention after two different control signals are shown.

[0033] Figure 9 This diagram shows the substrate after mask removal and the source, drain, and gate electrodes in Embodiment Six of the present invention. Detailed Implementation

[0034] Reference will now be made in detail to embodiments of the invention, one or more of which are illustrated in the accompanying drawings. The various embodiments provided are intended to explain the invention and not to limit it. In fact, various modifications and variations to the invention will be apparent to those skilled in the art without departing from the scope or spirit of the invention. For example, a feature illustrated or described as part of one embodiment may be used with another embodiment to produce yet another embodiment. Therefore, the invention is intended to cover such modifications and variations within the scope of the appended claims and their equivalents.

[0035] The following reference Figures 1 to 9 This invention describes a three-terminal electrochemical device based on a zinc ion insertion / extraction regulation resistor according to embodiments of the present invention. In the description of the invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. When a feature "comprises or includes" one or more of the features it encompasses, unless otherwise specifically stated, this indicates that other features are not excluded and may be further included.

[0036] Figure 1 This is a schematic structural diagram of a three-terminal electrochemical device based on a zinc ion insertion / extraction regulation resistor according to an embodiment of the present invention. The three-terminal electrochemical device generally includes a gate electrode, a source electrode, a drain electrode, and a channel existing between the source electrode and the drain electrode. Figure 1 As shown, 1 is the source electrode, 2 is the drain electrode, 3 is the channel, 4 is the electrolyte, 5 is the gate electrode, and 6 is the substrate.

[0037] The channel is made of a zinc ion conductor that can insert and extract zinc ions, thereby achieving reversible resistance adjustment. In this embodiment, the zinc ion conductor refers to a material in which zinc ions can move; it can be a single material or a composite of multiple materials. By inserting and extracting zinc ions, the zinc ion concentration in the channel can be adjusted, thereby regulating the resistance of the channel. For example, under the action of a certain external voltage, the channel can insert zinc ions from its exterior; under the action of another reverse external voltage, the channel can extract zinc ions from its exterior.

[0038] In this embodiment, a zinc ion conductor capable of inserting and extracting zinc ions is placed between the source and drain electrodes to form a channel. The resistance can be reversibly adjusted based on changes in the zinc ion concentration within the channel. Since zinc and the zinc ion conductor are relatively stable in air, and the zinc ion insertion / extraction process requires a low voltage and has high reversibility, the three-terminal electrochemical device of this embodiment possesses advantages such as high stability, low power consumption, and high reversibility. Based on this embodiment, the performance of electrochemical devices such as non-volatile memories can be improved.

[0039] On the one hand, the voltage of ion extraction-intercalation in zinc ion conductors is generally lower than that in other metal ion systems (because Zn 2+ The redox potential of Zn is higher than that of Li. + / Li、Na + (e.g., Li, etc.). Since the device operates based on the reversible insertion-extraction of zinc ions, a lower potential results in a lower operating voltage, thus reducing power consumption. Furthermore, because zinc and most zinc-ion conductors are stable in air, the device can be exposed to an atmospheric environment without concern for instability. Lithium-ion based devices exhibit poor chemical stability; certain states of the material often react with water, oxygen, carbon dioxide, and even nitrogen (lithium metal can be oxidized by nitrogen) in the air, causing device deactivation. Therefore, the device of this embodiment offers advantages in terms of state stability while reducing manufacturing and packaging requirements and costs.

[0040] In some alternative embodiments, the channel transitions between a metallic and a non-metallic phase depending on the zinc ion concentration. That is, by inserting or de-inserting zinc ions, the zinc ion concentration in the channel changes, allowing the channel to transition from a metallic phase to a non-metallic phase, or vice versa. Therefore, the channel possesses the ability to transition between a conductor and an insulator, enabling the three-terminal electrochemical device of this embodiment to achieve a high on / off ratio and high reversibility.

[0041] In some alternative embodiments, the channel transitions between a nonmetallic phase and another nonmetallic phase as the zinc ion concentration changes. That is, the channel can acquire multiple different, distinguishable resistance states as the zinc ion concentration changes.

[0042] The channel can exchange zinc ions with any external object, such as a medium that has zinc ion conduction or deintercalation functions.

[0043] In some alternative embodiments, the three-terminal electrochemical device based on zinc ion insertion / extraction regulation resistance may further include an electrolyte made of zinc ion conductor and connected to the channel, and configured to exchange zinc ions with the channel under the action of an external electric field, so that zinc ions are inserted or extracted from the channel, thereby enabling reversible changes in the band structure and crystal structure of the channel.

[0044] For example, when the gate electrode receives a control voltage (i.e., external voltage) signal, a control electric field is generated. The electrolyte and channel exchange zinc ions under the influence of this control electric field. When the control voltage is within range A, zinc ions in the channel are released into the electrolyte; when the control voltage is within range B, zinc ions in the electrolyte are inserted into the channel. Changes in the zinc ion concentration in the channel cause transformations in the material's crystal structure and band structure, resulting in changes in carrier concentration and altering the channel resistance state. The voltage ranges A / B correspond to the electrochemical windows for zinc ion insertion / extraction in the channel, which can be determined through theoretical calculations or experimental measurements, as detailed in the following examples.

[0045] In some embodiments, optionally, any voltage value within the aforementioned intervals A and B does not exceed the decomposition voltage of the electrolyte. That is, the decomposition voltage of the electrolyte is greater than or equal to the electrochemical voltage of the channel for reversible insertion and extraction of zinc ions, in order to ensure the service life of the device.

[0046] The zinc ion conductor used to make the electrolyte can be any medium with zinc ion conduction or deintercalation functions. It refers to a material in which zinc ions can move; it can be a single material or a composite of multiple materials. The three-terminal electrochemical device based on zinc ion deintercalation regulating resistance in this embodiment uses a zinc ion conductor as the electrolyte. Therefore, it can use a medium with a near-neutral pH, is almost non-corrosive, and can be made of non-flammable and non-explosive materials. Thus, compared to traditional electrochemical devices based on electron-ion coupling processes, it has higher safety performance.

[0047] In devices based on ion extraction-intercalation, liquid or quasi-solid electrolytes are frequently used. For hydrogen ion systems, the electrolytes used have a low pH value, leading to higher device costs (materials need to be resistant to acid corrosion) and potential leakage and hazards in case of device failure. For lithium ion systems, the electrolytes used are flammable and toxic (especially the two most common lithium salts, LiPF6 and LiClO4). The zinc ion electrolyte used in this embodiment has a more suitable pH value and does not pose flammable or explosive hazards.

[0048] The related devices mentioned in the various embodiments of the present invention refer to electrochemical devices that can perform the same functions as the devices of the present invention, including memory, artificial synapses, etc.

[0049] The position of the electrolyte in the three-terminal electrochemical device can be set according to actual needs, as long as it can exchange zinc ions with the channel. In some optional embodiments, the electrolyte is present between the gate electrode and the source electrode, and between the gate electrode and the drain electrode, and is a non-electronic conductor to isolate the gate electrode from the source electrode, and to isolate the gate electrode from the drain electrode.

[0050] The gate electrode, source electrode, and drain electrode are all electronic conductors, and the source electrode and drain electrode are both non-zinc ion conductors. The source electrode and drain electrode are in contact with the electrolyte. Therefore, when the source electrode and drain electrode are both non-zinc ion conductors, the reaction between the source electrode and drain electrode and zinc ions in the electrolyte can be avoided.

[0051] The electrolyte's form can be set according to actual needs, such as liquid, gel, or solid. Preferably, the electrolyte is a gel electrolyte or a liquid electrolyte. The thickness of the electrolyte is adjustable, denoted as H. For example, 100nm < H ≤ 20μm, optionally, 20nm < H ≤ 100nm, optionally, 20μm < H ≤ 200μm, optionally, 200μm < H ≤ 1mm, optionally, H ≤ 20nm, optionally, 1mm ≤ H.

[0052] The region between the source and drain electrodes is the channel region. The channel length (i.e., the distance between the source and drain electrodes) is adjustable, denoted as L. For example, 50nm < L ≤ 100μm; optionally, L ≤ 5nm; optionally, 5nm < L ≤ 50nm; optionally, 100μm < L ≤ 500μm; optionally, 500μm < L ≤ 1mm; optionally, L ≥ 1mm.

[0053] The zinc ion concentration in the zinc ion conductor used to form the channel can be variable. When the zinc ion concentration changes, the interactions between electrons and atoms, electrons and ions, and electrons and phonons within the channel material change. At the same time, in order to maintain electron neutrality, the electron concentration in the channel material also changes, which may lead to changes in electron-electron, electron-hole, and hole-hole interactions. Therefore, the electronic conductivity of the channel material will inevitably change, thereby achieving practical purposes such as information storage.

[0054] Experimental verification revealed that the three-terminal electrochemical device based on zinc ion intercalation / deintercalation regulation resistor in this embodiment has multiple continuously adjustable and distinguishable resistance states, and can flexibly switch resistance states under the action of an external electric field. The resistance state variable is correlated with the specific values ​​of parameters such as the pulse width and amplitude of the external voltage, which facilitates complex encoding and can achieve practical purposes such as good information storage. It can perform the work of a traditional memristor and can also simulate the function of a biological synapse, translating upstream stimulation signals into channel electrical signals.

[0055] This invention does not limit the crystal form of the zinc ion conductor used to form the channel. Preferably, the channel is a single crystal; alternatively, the channel material is polycrystalline; alternatively, the channel material is amorphous. This invention also does not limit whether the channel is an element. Optionally, the channel is a mixture; alternatively, the channel is an element.

[0056] In some embodiments, the zinc ion conductor forming the channel is doped with an electronic conductor. That is, the channel is a mixture of a zinc ion conductor and j wt.% electronic conductor. The addition of the electronic conductor is beneficial for the zinc ion conductor to obtain electron supply when its zinc ion concentration is changed, but it also increases the leakage current of the channel and reduces the switching ratio of the device. A trade-off needs to be made when designing the device. Of course, the device may also not use conductive additives. Optionally, j ≥ 10; optionally, 5 ≤ j < 10; optionally, 3 ≤ j < 5; preferably, j < 3. This embodiment does not limit the type of electronic conductor; optionally, it is selected from the group including but not limited to carbon nanotubes, graphene, reduced graphene oxide, carbon black, graphite and titanium particles; preferably, the electronic conductor as a conductive additive is carbon nanotubes; preferably, the electronic conductor as a conductive additive is reduced graphene oxide.

[0057] The zinc ion conductors used to form the channel include Na2V6O 16 The channel is constructed using xH₂O (x≥0) or α-MnO₂, and exhibits non-volatile steady-state resistance during zinc ion insertion and extraction. By using the aforementioned materials as the zinc ion conductor to construct the channel, reversible transitions in band structure and crystal structure occur during zinc ion insertion and extraction. Furthermore, the channel possesses non-volatile steady-state resistance and multiple continuously adjustable, distinguishable resistance states, enabling reversible resistance adjustment.

[0058] It is important to emphasize that the device of this invention primarily relies on the electrochemical ion insertion / extraction mechanism of zinc ions in a zinc-ion conductor, which shares some similarities with zinc-ion batteries in its specific process. However, although some advancements in zinc-ion batteries may be applicable to the device of this invention (e.g., solid electrolytes with higher ionic conductivity, electrode materials with higher reversibility and faster ion insertion / extraction rates, etc.), many of these materials are not suitable for this invention. In particular, this invention requires the zinc-ion conductor to have a band structure and resistance-state switching performance that varies with the zinc ion concentration.

[0059] This invention requires that the zinc ion conductor used as a channel material have a band structure that changes with the zinc ion concentration, but does not limit how the band structure transforms. For example, the zinc ion conductor can transform between a metallic phase and a non-metallic phase, or between a non-metallic phase and another non-metallic phase.

[0060] To facilitate device fabrication, components such as channels and electrodes can be fabricated on a substrate. In other words, the three-terminal electrochemical device also includes a substrate, which serves as the base for the source electrode, drain electrode, channel, and / or gate electrode. The substrate is made of an insulating material and does not undergo redox reactions with the electrolyte and / or gate electrode within the range of the controlled voltage signal. The substrate material is not specifically limited in this invention; it can be a rigid substrate or a flexible substrate (when fabricating flexible three-terminal devices), selected according to specific needs. For example, it can be selected from materials including, but not limited to, glass, Al₂O₃, polyimide, polyethylene terephthalate, polymethyl methacrylate, and polypropylene. Preferably, the substrate material is not a zinc ion conductor.

[0061] In some alternative embodiments, the device may not require a substrate; for example, a three-terminal device may be fabricated directly on the electrolyte.

[0062] In the three-terminal electrochemical devices of the above embodiments, the relative positions of the source electrode, drain electrode, and gate electrode are not specifically limited. Optionally, the source electrode, drain electrode, and gate electrode in the device may be located in the same horizontal plane; or, the source electrode and drain electrode may be located in the same horizontal plane, while the gate electrode may be located in a separate horizontal plane.

[0063] like Figure 1 As shown, the three-terminal electrochemical device includes an insulating substrate 6 on which a source electrode 1 and a drain electrode 2 are disposed. A channel 3 is located between the source electrode 1 and the drain electrode 2; this channel is where device modulation primarily occurs. An electronically insulating electrolyte 4 covers the source electrode 1, the drain electrode 2, and the channel 3. The source electrode 1 and the drain electrode 2 are located on one side (e.g., the lower side) of the electrolyte 4, and a gate electrode 5 is located on the other side (e.g., the upper side).

[0064] When using the device, connect the gate electrode 5 and the source electrode 1 to an external control signal, such as V. GS Above, the source electrode 1 and the drain electrode 2 are connected to an external read signal V. SD Or I SD The channel resistance R was calculated. SD =V SD / I SD Under external control signal V GS When disconnected, the resting-state resistance of the device is read by reading the signal. When the external control signal V... GS After a period of time, the voltage is applied between the gate electrode 5 and the source electrode 1 and then turned off. Due to the change in the zinc ion concentration in the channel material, the channel resistance changes, causing the device to enter a new resistive state. The resistance value of the new resistive state is also determined by V. SD Or I SD Signal detected.

[0065] Figure 2This is a schematic structural diagram of a three-terminal electrochemical device based on a zinc ion insertion / extraction regulating resistor according to another embodiment of the present invention, wherein the left side of the paper is the front view and the right side of the paper is the top view. Figure 2 As shown, the three-terminal electrochemical device of this embodiment includes an insulating substrate 6b, on which a source electrode 1b, a drain electrode 2b, and a gate electrode 5b are mounted. A channel 3b lies between the source electrode 1b and the drain electrode 2b, which is the location where device modulation mainly occurs. An electronically insulating electrolyte 4b covers the source electrode 1b, drain electrode 2b, channel 3b, and gate electrode 5b. In this embodiment, the source electrode 1b, drain electrode 2b, and gate electrode 5b are all located on the same horizontal plane.

[0066] When using the device, connect the gate electrode 5b and the source electrode 1b to an external control signal, such as V. GS Above, the source electrode 1b and the drain electrode 2b are connected to an external read signal V. SD Or I SD The channel resistance R was calculated. SD =V SD / I SD Under external control signal V GS When disconnected, the resting resistance value of the device is read from the signal. When the external control signal V... GS After a period of time, the voltage is applied between the gate electrode 5b and the source electrode 1b and then turned off. Due to the change in the zinc ion concentration in the channel material, the channel resistance changes, causing the device to enter a new resistive state. The resistance value of this new resistive state is also determined by V. SD Or I SD Signal detected.

[0067] The devices in the above embodiments can operate independently (i.e., a single device already possesses complete functionality) or be integrated on a large scale. This invention does not limit the application of the devices. When the devices of this invention are operating, whether individually or in large-scale integration, care should be taken to ensure that their regulating voltage does not exceed the voltage window of the electrolyte, nor does it exceed the voltage window for the reversible insertion and extraction of zinc ions in the zinc ion conductor of the channel. Otherwise, device performance and service life will be affected.

[0068] This invention also provides a method for fabricating a three-terminal electrochemical device based on zinc ion insertion / extraction regulation resistance. This fabrication method generally includes the following steps:

[0069] Step S1: Fabricate the source and drain electrodes. For example, the source and drain electrodes can be fabricated on a substrate. Fabrication methods include, but are not limited to, electron beam evaporation deposition, thermal evaporation deposition, atomic layer deposition, magnetron sputtering deposition, chemical vapor deposition, or physical adsorption bonding. The source and drain electrodes are made of conductive materials. The substrate is a non-conductive material, i.e., an insulating substrate, including but not limited to silicon, silicon oxide, polymers, or glass.

[0070] Step S2, preparing the channel. A zinc ion conductor capable of inserting and extracting zinc ions to achieve reversible resistance adjustment is placed between the source electrode and the drain electrode to form a channel between the source electrode and the drain electrode.

[0071] In fabricating the channel, the channel region is first formed between the source and drain electrodes using methods such as photolithography, electron beam etching, focused particle beam etching, chemical etching, and mechanical lift-off. The channel region refers to the area between the source and drain electrodes that does not contain electrode material. If the channel region is already formed during the fabrication of the source and drain electrodes, this step is unnecessary. The channel can be fabricated using methods such as electron beam evaporation deposition, thermal evaporation deposition, magnetron sputtering deposition, atomic layer deposition, chemical vapor deposition, or physical adsorption bonding. In particular, when using physical adsorption bonding, the channel material may contain a binder.

[0072] Step S3: Prepare the electrolyte. The electrolyte is prepared by methods such as spin coating, drop coating, electron beam evaporation deposition, magnetron sputtering deposition, or atomic layer deposition.

[0073] Step S4: Fabrication of the gate electrode. The gate electrode is fabricated using methods such as electron beam evaporation deposition, thermal evaporation deposition, atomic layer deposition, magnetron sputtering deposition, chemical vapor deposition, or physical adsorption bonding.

[0074] The above steps are suitable for preparing, for example Figure 1 The diagram illustrates a three-terminal electrochemical device based on zinc ion insertion / extraction regulation resistance. The specific selection and preparation methods of each material can be found in other embodiments of this disclosure, and the same applies below. Figure 2 The fabrication process of the three-terminal electrochemical device based on zinc ion insertion / extraction regulation resistance shown generally includes the following steps:

[0075] Step A: Fabricate the source electrode, drain electrode, and gate electrode on an insulating substrate. Fabrication methods include, but are not limited to, electron beam evaporation deposition, thermal evaporation deposition, atomic layer deposition, magnetron sputtering deposition, chemical vapor deposition, or physical adsorption bonding. The source electrode, drain electrode, and gate electrode are all conductive materials. The substrate is a non-conductive material, including but not limited to silicon, silicon oxide, polymers, or glass. A channel region is fabricated between the source and drain electrodes using methods such as photolithography, electron beam etching, focused particle beam etching, chemical etching, or mechanical lift-off. The channel region refers to the area between the source and drain electrodes that does not contain electrode material. If a channel region has already been formed during the fabrication of the source and drain electrodes, this step is unnecessary.

[0076] Step B involves fabricating the channel using methods such as electron beam evaporation deposition, thermal evaporation deposition, magnetron sputtering deposition, atomic layer deposition, chemical vapor deposition, or physical adsorption bonding. Specifically, when using physical adsorption bonding, the channel material may contain a binder.

[0077] Step C involves preparing the electrolyte using methods such as spin coating, drop coating, electron beam evaporation deposition, magnetron sputtering deposition, or atomic layer deposition.

[0078] The following will describe in detail the preparation method of a three-terminal electrochemical device based on zinc ion insertion / extraction regulation resistor with more specific embodiments.

[0079] Example 1:

[0080] (1) Substrate preparation

[0081] Glass was selected as the insulating substrate. The glass substrate was placed successively in deionized water, acetone, and alcohol, and sonicated for at least 10 minutes each time. After drying the alcohol with nitrogen, a mask for the source and drain electrodes was fabricated on the glass substrate using polyimide. A top view of the mask is shown below. Figure 3 . Figure 3 This is a schematic top view of a substrate with a mask according to an embodiment of the present invention. 6c is a glass substrate, and 7c is a polyimide mask.

[0082] (2) Fabrication of source and drain electrodes

[0083] A glass substrate was placed in a thermal evaporation apparatus to prepare Ti / Au electrodes by thermal evaporation, with thicknesses of 5 nm and 20 nm, respectively.

[0084] The electrode shape after removing the polyimide mask is shown in the figure. Figure 4 . Figure 4 This is a schematic diagram of the substrate after mask removal and the source and drain electrodes according to an embodiment of the present invention; where 1c and 2c are the source and drain electrodes, respectively. W is the width of the source and drain electrodes. The area between the source and drain electrodes is a channel region, and L is the channel length. In this embodiment, the width of the source and drain electrodes is 4 mm, and the channel length is approximately 100 μm.

[0085] The mask and source / drain electrodes will not be illustrated in the following embodiments, and those skilled in the art can clearly understand them by referring to these embodiments.

[0086] (3) Preparation of channels

[0087] Na₂V₆O was synthesized via a hydrothermal method. 16 xH2O nanowires, and Na2V6O 16 A self-supporting film composed of xH2O nanowires is placed on the surface of the channel region.

[0088] (4) Preparation of electrolyte and grid electrode

[0089] A glass fiber diaphragm and electrolyte are used to cover the channel material. In this embodiment, the electrolyte used is 2 mol / L. - 1Aqueous solution of ZnSO4. Zinc foil was used as the gate electrode, covering the surface of a glass fiber film.

[0090] (5) Device packaging

[0091] The device is sealed by encapsulating it with a Parafilm membrane. This encapsulation primarily prevents water evaporation from the liquid electrolyte in this embodiment from affecting device performance; it is not a necessary step in the fabrication of the device in this invention.

[0092] After the device is packaged, its performance can be tested. The testing methods are as follows:

[0093] The source and drain electrodes are connected to an external constant current source, and the voltage between the source and drain electrodes is continuously monitored. The gate and source electrodes are connected to an external voltage source. In this embodiment, the applied voltage source outputs a square wave signal with a pulse width of t. ON The amplitude is V GS Outside of the pulse width time, the gate and source electrodes are in an off state. Figure 5 The impedance state change curves of the device in Embodiment 1 of the present invention under several pulse widths and amplitude modulation signals are shown. Figure 5 a. Displays the response of the device's resistance state to positive modulation signals of the same pulse width but different amplitudes (positive means increasing the device's resistance); Figure 5 b. Display the response of the device's resistive state to positive modulation signals of the same amplitude but different pulse widths; Figure 5 c shows the response of the device's resistance state to negative modulation signals of the same pulse width but different amplitudes (negative means that the device's resistance decreases); Figure 5 The display shows the response of the device's resistance state to negative modulation signals of the same amplitude but different pulse widths. The results show that the device can complete the resistance state switching under a 100ms pulse width and a -0.1V pulse signal, and the change in resistance depends on the specific values ​​of the pulse width and amplitude, facilitating complex encoding. Specifically, in the voltage range of 0 to -1.0V (i.e., range A mentioned above), zinc ions are inserted into the channel, increasing the channel resistance; in the voltage range of -1.0 to -2.0V (i.e., range B mentioned above), zinc ions are extracted from the channel, decreasing the channel resistance.

[0094] Since devices with non-volatile resistive state switching capabilities have been proven to be used in fields such as random access storage, biological synapse simulation, and multiply-accumulate operation acceleration, the three-terminal electrochemical device of this invention has broad application prospects. Furthermore, the entire fabrication process of the device of this invention can be completed under atmospheric conditions, without the need for inert atmosphere protection or humidity control, greatly simplifying the device fabrication process.

[0095] Example 2:

[0096] Compared with Example 1, this example only changes step (3) of the device fabrication method; the other steps are the same as in Example 1. In this example, step (3) is changed to:

[0097] Na₂V₆O was synthesized via a hydrothermal method. 16 xH2O nanowires. The dried Na2V6O... 16 • xH2O, conductive carbon black, and polyvinylidene fluoride (PVDF) were mixed in a mass ratio of 18:1:1. The mixture was dissolved in N-methylpyrrolidone and then drop-coated into the channel region. After vacuum drying at 120°C for 12 hours, Na2V6O was obtained. 16 Channels formed by a mixture of xH2O.

[0098] The device testing method is the same as in Example 1, except for the control signal. The specific application method of the control signal is as follows: first, apply 30 consecutive pulse widths t... ON =300ms, amplitude V GS A pulse signal of -0.8V is applied at 30-second intervals. Then, 30 pulses with a pulse width of t are applied consecutively. ON =300ms, amplitude V GS A pulse signal of -1.3V is emitted at 30-second intervals.

[0099] The results are as follows Figure 6 As shown. Figure 6 The results of the modulation test of the device in Embodiment 2 of the present invention under the action of two opposing stimulation signals (a single pulse signal, applied continuously 30 times) are shown. The amplitude V in the first 30 pulses... GS Under the control of a pulse signal of -0.8V, the device's resistance continuously increases, resulting in 30 distinct states; and in the latter 30 states with amplitude V... GS Under the control of a pulse signal of -1.3V, the device's resistance gradually returns to near its initial value. The device exhibits multiple continuously adjustable and distinguishable resistance states, and is reversible.

[0100] Example 3:

[0101] Compared with Example 2, this example only changes step (4) of the device fabrication method; the other steps are the same as in Example 2. In this example, step (4) is changed to:

[0102] Spin-coated gel electrolyte is applied to the channel material and allowed to stand for a period of time before use. The gel electrolyte is prepared by ultrasonically dispersing graphite oxide in water, and then dissolving polyvinyl alcohol and zinc trifluoromethanesulfonate in the graphite oxide dispersion in an 85°C water bath. After the gel electrolyte has solidified, zinc foil is used as the gate electrode to cover the electrolyte surface.

[0103] After 1, 5, and 10 consecutive 300ms pulse width, -1.4V amplitude modulation signals (with an interval of 500ms between adjacent modulation signals), the device's impedance switching curve is as follows: Figure 6 As shown in the comparison of Examples 2 and 3, it can be demonstrated that the device is compatible with a variety of electrolytes, as long as they have a high zinc ion diffusion rate and low electronic conductivity. In practical applications, suitable liquid, gel, or solid electrolytes can be selected according to specific circumstances to meet different needs.

[0104] Example 4:

[0105] Compared with Example 2, this example only changes step (3) of the device fabrication method; the other steps are the same as in Example 2. In this example, step (3) is changed to:

[0106] α-MnO2 nanowires were synthesized via a hydrothermal method. Dry α-MnO2, conductive carbon black, and polyvinylidene fluoride (PVDF) were mixed in a mass ratio of 17:2:1. Na2V6O was also synthesized via a hydrothermal method. 16 xH2O nanowires. The dried Na2V6O... 16 • xH2O, conductive carbon black, and polyvinylidene fluoride (PVDF) were mixed in a mass ratio of 18:1:1. The mixture was dissolved in N-methylpyrrolidone and then drop-coated into the channel region. It was then vacuum-dried at 120°C for 12 hours. The amount of conductive carbon black in this example is increased compared to Example 2 because the electronic conductivity of α-MnO2 is too low to ensure sufficient electron supply during zinc ion insertion / extraction. This invention does not limit the specific composition and content of the channel material; it can be changed according to actual needs, only requiring that it contains at least one zinc ion conductor, and that its zinc ion concentration is variable.

[0107] Figure 7 The diagram shows the resistance state change curves of the device in Embodiment 4 of the present invention after experiencing different numbers of modulation signals. Each modulation signal has a pulse width of 300 ms, an amplitude of -1.4 V, and an application interval of 500 ms. Figure 7 As shown, the device fabricated in this embodiment can rise to a resistance state and maintain it for at least 2500 seconds under the control of an electrical signal with a pulse width of 500ms and an amplitude of -1.0V (for α-MnO2, interval A is 0 to -1.4V). The sustaining time is >500000%, demonstrating good non-volatility. Under the control of an electrical signal with a pulse width of 500ms and an amplitude of -1.8V (for α-MnO2, interval B is -1.4 to -2.0V), the initial resistance state can be recovered, verifying the reversibility of the device's resistance state switching.

[0108] Example 5:

[0109] Compared with Example 2, this example only changes step (4) of the device fabrication method, replacing the glass fiber membrane and electrolyte in step (4) with a dense solid electrolyte. The other steps are the same as in Example 2.

[0110] In this embodiment, the solid electrolyte is prepared as follows: a Zn film is prepared on a polyvinyl butyral film using magnetron sputtering, followed by placement in an NH4F atmosphere to generate ZnF2. The ZnF2 / polyvinyl butyral film is placed on the channel surface and then immersed in ethanol to remove the polyvinyl butyral. Finally, zinc foil is used as the gate electrode to cover the electrolyte surface.

[0111] This embodiment demonstrates that the present invention is applicable not only to liquid electrolytes but also to solid electrolytes, as long as they are zinc ion conductors and not electronic conductors.

[0112] Solid electrolytes are advantageous for reducing the thickness of the electrolyte layer, decreasing device size, and thus increasing integration density. In this embodiment, the solid electrolyte can also be replaced with materials such as NaTi2(PO4)3 and / or zinc-ion-substituted montmorillonite. Besides magnetron sputtering or electron beam evaporation, solid electrolytes can also be prepared directly using solid electrolyte sheets, i.e., by mixing solid electrolyte material powder with polyvinyl alcohol, compacting the mixture, and then sintering it at high temperature to form a dense ceramic sheet.

[0113] Example 6:

[0114] (1) Substrate preparation

[0115] Glass was selected as the insulating substrate. The glass substrate was placed successively in deionized water, acetone, and alcohol, and sonicated for 10 minutes each time. After the alcohol was dried with nitrogen, PMMA (poly(methylmethacrylate, abbreviated as PMMA) masks for the source, drain, and gate electrodes were prepared on the glass substrate by electron beam exposure. Here, PMMA is used as a mask for thermal evaporation.

[0116] (2) Fabrication of source, drain and gate electrodes

[0117] A glass substrate is placed in a thermal evaporation apparatus to prepare Ti / Au electrodes, which serve as source and drain electrodes.

[0118] The electrode shape after removing the PMMA mask is shown in the figure. Figure 9 . Figure 9This diagram illustrates the substrate and source, drain, and gate electrodes after mask removal in Embodiment Six of the present invention. The device is symmetrical from left to right. 6d is the insulating substrate, 1d and 2d are the Ti / Au source and drain electrodes, and 5d is the Ti / Au / Zn gate electrode. In this embodiment, the source and drain electrodes are 4 mm wide and the channel length is 100 μm. The gate electrode is 4 mm wide and 20 mm long, and the distance between the gate electrode and the channel is 100 μm.

[0119] Steps (3)-(5) in this embodiment are the same as steps (3)-(5) in Embodiment 1 (not repeated here), except that the Zn gate electrode is no longer prepared, because it has already been prepared in step (2).

[0120] This embodiment demonstrates that the specific structure of the device does not affect its performance. Figure 1 The structure shown is one and Figure 2 Both of the structures shown can achieve the same effect. Inspired by this invention, possible structures not shown in the embodiments should also be within the scope of protection of this invention, as long as the principles they rely on are the same as those of this invention: external field control of the concentration of zinc ions in the channel (through zinc ion de-entry-entry) and causing a change in the band structure of the material, so that the device switches between different resistive states.

[0121] Example 7:

[0122] Compared to Example 1, this example only changes the gate electrode material from Zn foil to Li pre-intercalated with zinc ions. 0.45 V₂O₅·xH₂O material. The method for pre-intercalating zinc ions is: to add Li₂O₅·xH₂O... 0.45 V₂O₅·xH₂O powder was placed on the surface of zinc foil, ZnSO₄ aqueous solution was added dropwise, and the mixture was compacted and allowed to stand for 24 hours. The powder was then collected and washed with acetone.

[0123] Example 8:

[0124] Compared to Example 1, this example only changes the gate electrode material from Zn foil to a stainless steel electrode. Based on Examples 7 and 8, it can be demonstrated that the gate electrode material of the device is not limited to zinc foil, as long as it is an electronic conductor capable of generating a local electric field via an external circuit signal, thereby causing a redistribution of zinc ions within the device. Preferably, the gate electrode material should be zinc, a zinc-containing alloy, or the positive and negative electrode materials of a zinc-ion battery. This is because these materials can release zinc ions, thereby maintaining a stable ion concentration in the electrolyte. This ensures easier zinc insertion / extraction in the channel material and prevents the electrolyte from decomposing due to charge imbalance during regulation.

[0125] The device disclosed in this invention has a simple fabrication process, can be mass-produced, and is suitable for various signal generation, information recording, or processing scenarios. It can meet the development needs of fields such as non-volatile storage, artificial intelligence, and deep learning, and has broad application prospects.

[0126] Therefore, those skilled in the art should recognize that although numerous exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Thus, the scope of the present invention should be understood and construed as covering all such other variations or modifications.

Claims

1. A three-terminal electrochemical device based on zinc ion insertion / extraction regulation resistance, comprising: A gate electrode, a source electrode, a drain electrode, and a channel existing between the source electrode and the drain electrode; wherein... The channel is made of a zinc ion conductor that can insert and extract zinc ions to achieve reversible resistance adjustment; The zinc ion conductor used to form the channel includes Na2V6O. 16 • xH2O (x≥0) nanowires enable the channel to undergo reversible changes in band structure and crystal structure during zinc ion insertion / extraction; The channel transitions between the metallic and nonmetallic phases as the zinc ion concentration changes, and the channel exhibits a non-volatile steady-state resistance during the insertion or extraction of zinc ions; or The channel transitions between one nonmetallic phase and another as the zinc ion concentration changes, thereby obtaining multiple different and distinguishable resistance states. The gate electrode is made of zinc or a zinc-containing alloy; and The zinc ion conductor forming the channel is doped with an electronic conductor.

2. The three-terminal electrochemical device according to claim 1 further comprises: An electrolyte, made of zinc ion conductors and connected to the channel, is configured to exchange zinc ions with the channel under the action of an external electric field, so that zinc ions are inserted into or extracted from the channel, thereby causing a reversible change in the band structure and crystal structure of the channel.

3. The three-terminal electrochemical device according to claim 2, wherein, The electrolyte is present between the gate electrode and the source electrode, and between the gate electrode and the drain electrode, and is a non-electronic conductor, in order to isolate the gate electrode from the source electrode and the drain electrode.

4. The three-terminal electrochemical device according to claim 2, wherein, The gate electrode, the source electrode, and the drain electrode are all electronic conductors, and the source electrode and the drain electrode are both non-zinc ion conductors.

5. The three-terminal electrochemical device according to claim 2, wherein, The electrolyte is in liquid, gel, or solid state, and its decomposition voltage is greater than or equal to the electrochemical voltage at which zinc ions are reversibly inserted and removed from the channel.

6. The three-terminal electrochemical device according to claim 1, further comprising: The substrate, which serves as the base for the source electrode, the drain electrode, the channel and / or the gate electrode, is made of an insulating material.

7. The three-terminal electrochemical device according to claim 1, wherein, The proportion of the electronic conductor to the zinc ion conductor is j wt.%, where 5 ≤ j < 10, or 3 ≤ j < 5, or 0. <j<3。

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