A MXene / NiO heterojunction synaptic device, preparation method and application thereof

Abstract

The present invention provides a MXene / NiO heterojunction synaptic device, preparation method, and application thereof. The MXene / NiO heterojunction synaptic device comprises: a substrate having a bottom electrode disposed therein, wherein the bottom electrode is exposed on the upper surface of the substrate; a MXene / NiO heterojunction layer covering a portion of the substrate, the MXene / NiO heterojunction layer comprising a MXene layer and a NiO layer, the portion being the region of the substrate corresponding to the region excluding the bottom electrode; and a top electrode located on the top surface of the MXene / NiO heterojunction layer. The synaptic device of the present invention has an extremely fast and sensitive response to electrical pulses, has ultra-low energy consumption, and can be used to construct artificial neural network systems.

Description

Technical Field

[0001] The present invention relates to the technical field of artificial synaptic devices, and in particular to a MXene / NiO heterojunction synaptic device, a preparation method and applications thereof. Background Art

[0002] The memristor is a new type of information device. Proposed in 1971 by Chinese-American professor Shao-Tang Tsai, it represents a new passive circuit element beyond the well-known resistors, capacitors, and inductors. The resistance of a memristor changes with the amount of charge passing through it. When the charge level stops changing, the resistance remains at its previous value.

[0003] Memristors are considered an ideal candidate for artificial synapses and hold great promise for development in artificial neural network systems. However, the resistive switching materials used in existing memristors are typically single-layer inorganic crystals or organic small molecules, and their power consumption and response speed need to be improved. Summary of the Invention

[0004] The purpose of the present invention is to provide a MXene / NiO heterojunction synaptic device that can solve problems such as power consumption and response speed.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a MXene / NiO heterojunction synaptic device, comprising:

[0006] A substrate, wherein a bottom electrode is provided in the substrate, wherein the bottom electrode is exposed on the top surface of the substrate;

[0007] A MXene / NiO heterojunction layer covering a portion of the substrate, wherein the MXene / NiO heterojunction layer includes a MXene layer and a NiO layer, and the portion is the area corresponding to the substrate except for the bottom electrode;

[0008] A top electrode is located on top of the MXene / NiO heterojunction layer.

[0009] Optionally, the material of the top electrode is one of gold, silver, copper, aluminum, and indium tin oxide.

[0010] Optionally, the substrate is FTO conductive glass or ITO conductive glass.

[0011] In a second aspect, the present invention provides a preparation method for preparing a MXene / NiO heterojunction synaptic device as described above, comprising:

[0012] Obtaining a substrate, wherein a bottom electrode is exposed on an upper surface of the substrate, and the bottom electrode is disposed inside the substrate;

[0013] Spin-coating a NiO precursor solution on the top surface of the substrate to form a NiO thin film after treatment;

[0014] Spin coating a MXene precursor solution on the top surface of the NiO film to generate a MXene film after treatment;

[0015] Removing the MXene film and the NiO film from a portion of the area to expose the bottom electrode on the substrate to form a MXene / NiO heterojunction layer;

[0016] A top electrode is formed by electroplating on the MXene / NiO heterojunction layer.

[0017] Optionally, the NiO thin film is generated after the treatment, comprising:

[0018] Spin coating a NiO precursor solution on the top surface of the substrate to form a NiO gel wet film, wherein the NiO precursor solution is prepared by dissolving nickel acetate tetrahydrate in an organic solvent, and the organic solvent is at least one of glacial acetic acid, ethylene glycol methyl ether, acetylacetone or ethylene glycol;

[0019] The NiO gel wet film is sequentially subjected to a preset number of thin film treatments to obtain an initial NiO thin film, wherein the thin film treatment process includes drying, pyrolysis, pre-annealing, and repeated spin coating;

[0020] An annealing process is performed on the initial NiO thin film within an annealing temperature range to generate a NiO thin film.

[0021] Optionally, the preparation ratio of the nickel acetate tetrahydrate to the organic solvent is in the range of 0.01 mol: 15 mL to 0.01 mol: 25 mL.

[0022] Optionally, generating a MXene film after the treatment comprises:

[0023] Spin coating a MXene precursor solution on the top surface of the substrate to form a MXene gel wet film, wherein the MXene precursor solution is a titanium carbide colloidal aqueous solution based on hydrofluoric acid wet stripping;

[0024] The MXene gel wet film is sequentially subjected to a preset number of thin film treatments to obtain an initial MXene thin film, wherein the thin film treatment process includes drying, pyrolysis, pre-annealing, and repeated spin coating;

[0025] Based on the initial MXene film, an annealing treatment is performed within an annealing temperature range to generate a MXene film.

[0026] Optionally, the spin coating includes at least a first spin coating and a second spin coating, the rotation speed of the first spin coating is 500-800 rpm, and the rotation speed of the second spin coating is 2000-3000 rpm.

[0027] Optionally, the preset number of times ranges from 3 to 6 times, and the drying temperature range corresponding to the drying is 50 to 100°C; the pyrolysis temperature range corresponding to the pyrolysis is 150 to 200°C, and the pyrolysis time interval is 4 to 10 minutes; the pre-annealing temperature range corresponding to the pre-annealing is 300 to 400°C, and the pre-annealing time interval is 5 to 10 minutes; the annealing temperature range corresponding to the annealing is 600 to 700°C, and the annealing time interval is 10 to 15 minutes.

[0028] In a third aspect, the present invention provides an application of the MXene / NiO heterojunction synaptic device as described above or the MXene / NiO heterojunction synaptic device prepared by the preparation method as described above in the field of artificial neural network systems.

[0029] Based on the above, the present invention provides a MXene / NiO heterojunction synaptic device, which has a NiO layer formed on a substrate, and then a MXene layer is formed on the basis of the NiO layer, and then the NiO layer and the MXene layer together constitute a MXene / NiO heterojunction layer. The MXene / NiO heterojunction layer enables the synaptic device to obtain better conductivity and stability, and the MXene film can make the resistance value of the synaptic device continuously variable and the change is controllable and adjustable, thereby realizing the biomimetic function of synaptic function and having broad application prospects. In addition, the synaptic device has an extremely fast and sensitive response to electrical pulses, has ultra-low energy consumption, can solve problems such as power consumption and response speed, and can be used to construct artificial neural network systems. In addition, the preparation method of the present invention has simple operating steps, readily available raw materials, low cost, low energy consumption, high efficiency, and is easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 Schematic diagram of the MXene / NiO heterojunction synaptic device structure in an embodiment of the present invention;

[0032] Figure 2 1 is a flow chart of a method for preparing a MXene / NiO heterojunction synaptic device according to an embodiment of the present invention;

[0033] Figure 3 This is an IV curve diagram of the MXene / NiO heterojunction synaptic device in an embodiment of the present invention when a ±3V voltage is applied;

[0034] Figure 4 This is an IV curve diagram of a cycle test of a synaptic device based on a MXene / NiO heterojunction in an embodiment of the present invention;

[0035] Figure 5 Schematic diagram of simulating synaptic weight inhibition under cyclic scanning of a forward voltage applied to a MXene / NiO heterojunction-based synaptic device according to an embodiment of the present invention;

[0036] Figure 6 Schematic diagram of simulating synaptic weight enhancement in a MXene / NiO heterojunction-based synaptic device under reverse voltage cyclic scanning in an embodiment of the present invention;

[0037] Figure 7 Schematic diagram of a MXene / NiO heterojunction-based synaptic device simulating long-term synaptic plasticity in an embodiment of the present invention;

[0038] Figure 8 Schematic diagram of the conductance memory curve of the MXene / NiO heterojunction-based synaptic device after long-term potentiation in an embodiment of the present invention;

[0039] Figure 9 Schematic diagram of a MXene / NiO heterojunction-based synaptic device simulating synaptic short-term depression in an embodiment of the present invention;

[0040] Figure 10 Schematic diagram of simulating synaptic short-term potentiation using a MXene / NiO heterojunction-based synaptic device in an embodiment of the present invention;

[0041] Figure 11 Schematic diagram of the postsynaptic excitation current of the synaptic device based on MXene / NiO heterojunction in an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0043] Figure 1 A MXene / NiO heterojunction synaptic device is provided in an embodiment of the present invention. Figure 1As shown, the MXene / NiO heterojunction synaptic device specifically includes:

[0044] A substrate 100 is provided with a bottom electrode 101 (such as Figure 1 101a and 101b), wherein the bottom electrode is exposed on the top surface of the substrate.

[0045] Optionally, the substrate may be FTO conductive glass or ITO conductive glass.

[0046] A MXene / NiO heterojunction layer 110 covers a partial area of ​​the substrate, wherein the MXene / NiO heterojunction layer includes a MXene layer 112 and a NiO layer 111 , and the partial area is the area corresponding to the substrate except the bottom electrode.

[0047] The MXene layer 112 is obtained by spin-coating a MXene precursor solution to obtain a MXene gel wet film, and then drying, pyrolyzing, pre-annealing, and repeatedly spin-coating the MXene gel wet film.

[0048] The NiO layer 111 is obtained by spin-coating a NiO precursor solution to obtain a NiO gel wet film, and then drying, pyrolyzing, pre-annealing, and repeatedly spin-coating the NiO gel wet film.

[0049] Furthermore, the NiO layer 111 is located on a side close to the substrate, and the MXene layer 112 is located on a side close to the MXene layer. The MXene layer 112 and the NiO layer 111 form a MXene / NiO heterojunction layer 110 .

[0050] A top electrode 120 is located on the top surface of the MXene / NiO heterojunction layer 110 .

[0051] In one embodiment, the material of the top electrode 120 is one of gold, silver, copper, aluminum, and indium tin oxide. From the perspective of saving resources, the top electrode in the embodiment of the present invention is preferably made of copper.

[0052] Optionally, the top electrode can be a structure of several electrode blocks, and correspondingly, the bottom electrode on the substrate can also be a structure of an electrode block. When measuring the synaptic device of the MXene / NiO heterojunction, the top electrode and the bottom electrode can be connected to the measuring instrument at the same time to realize the measurement of the synaptic device of the MXene / NiO heterojunction.

[0053] In addition, the measuring instrument may be a Keithley 2400 digital source multimeter, which is used to measure the MXene / NiO heterojunction synaptic device.

[0054] Based on the above, the present invention provides a MXene / NiO heterojunction synaptic device, which has a NiO layer formed on a substrate, and then a MXene layer is formed on the basis of the NiO layer, and then the NiO layer and the MXene layer together constitute a MXene / NiO heterojunction layer. The MXene / NiO heterojunction layer enables the synaptic device to obtain better conductivity and stability, and the MXene film can make the resistance value of the synaptic device continuously variable and the change is controllable and adjustable, thereby realizing the biomimetic function of synaptic function and having broad application prospects. In addition, the artificial synaptic device has an extremely fast and sensitive response to electrical pulses, has ultra-low energy consumption, can solve problems such as power consumption and response speed, and can be used to construct artificial neural network systems. In addition, the preparation method of the present invention has simple operating steps, readily available raw materials, low cost, low energy consumption, high efficiency, and is easy to implement.

[0055] Based on the above, an embodiment of the present invention further discloses a method for preparing a MXene / NiO heterojunction synaptic device. Figure 2 Schematic diagram of the steps of the method for preparing a MXene / NiO heterojunction synaptic device in an embodiment of the present invention.

[0056] Step S21 : obtaining a substrate, wherein a bottom electrode is exposed on the top surface of the substrate, and the bottom electrode is arranged inside the substrate.

[0057] Step S22, spin-coating a NiO precursor solution on the top surface of the substrate to form a NiO thin film after treatment;

[0058] Step S23, spin-coating a MXene precursor solution on the top surface of the NiO film to generate a MXene film after treatment;

[0059] Step S24: removing the MXene film and the NiO film in a partial area to expose the bottom electrode on the substrate to form a MXene / NiO heterojunction layer;

[0060] Step S25: electroplating to form a top electrode on the MXene / NiO heterojunction layer.

[0061] Optionally, in step S21, in order to obtain a clean substrate, the substrate may be cleaned to remove contaminants on the substrate surface. In one embodiment, the substrate may be FTO conductive glass, and the steps for cleaning the FTO conductive glass are as follows:

[0062] The substrate FTO conductive glass is placed in deionized water for ultrasonication for 5 to 10 minutes; then placed in anhydrous ethanol for ultrasonication for 5 to 10 minutes, and finally the substrate is placed in a drying oven for drying to obtain clean FTO conductive glass.

[0063] Optionally, before spin coating the NiO precursor solution in step S22 or spin coating the MXene precursor solution in step S23, the NiO precursor solution or the MXene precursor solution needs to be prepared.

[0064] In one embodiment, the NiO precursor solution is prepared by dissolving 0.01 mol of nickel acetate tetrahydrate (NiC4H6O4·4H2O) in 15-25 mL of an organic solvent, wherein the organic solvent may be composed of 5-9 mL of glacial acetic acid, 5-9 mL of ethylene glycol methyl ether, and 4-6 mL of acetylacetone; and the MXene precursor solution is a single / few-layer titanium carbide (Ti3C2Tx) colloidal aqueous solution wet-exfoliated by hydrofluoric acid;

[0065] After the NiO precursor solution and the MXene precursor solution are prepared, step S22 is started, and the NiO precursor solution is spin-coated on the upper top surface of the substrate to form a NiO thin film after treatment. In one embodiment, the NiO precursor solution can be spin-coated on the upper top surface of the substrate to determine a NiO gel wet film, wherein the NiO precursor solution is prepared by dissolving nickel acetate tetrahydrate in an organic solvent, and the organic solvent is at least one of glacial acetic acid, ethylene glycol methyl ether, acetylacetone, or ethylene glycol;

[0066] Furthermore, the preparation ratio of the nickel acetate tetrahydrate to the organic solvent is in the range of 0.01 mol: 15 mL to 0.01 mol: 25 mL.

[0067] The NiO gel wet film is sequentially subjected to a preset number of thin film treatments to obtain an initial NiO thin film, wherein the thin film treatment process includes drying, pyrolysis, pre-annealing, and repeated spin coating;

[0068] An annealing process is performed on the initial NiO thin film within an annealing temperature range to generate a NiO thin film.

[0069] In addition, the spin coating includes at least a first spin coating and a second spin coating, the first spin coating is a low speed of 500 to 800 rpm, the low speed first spin coating is used for initial spinning, the second spin coating has a high speed of 2000 to 3000 rpm, and the high speed second spin coating is used for uniform coating, so that the NiO precursor solution is evenly coated on the surface of the substrate to obtain a NiO thin film gel wet film.

[0070] Optionally, the preset number of times ranges from 3 to 6 times, and the drying temperature range corresponding to the drying is 50 to 100°C; the pyrolysis temperature range corresponding to the pyrolysis is 150 to 200°C, and the pyrolysis time interval is 4 to 10 minutes; the pre-annealing temperature range corresponding to the pre-annealing is 300 to 400°C, and the pre-annealing time interval is 5 to 10 minutes; the annealing temperature range corresponding to the annealing is 600 to 700°C, and the annealing time interval is 10 to 15 minutes.

[0071] That is, the NiO thin film can be generated by dropping the NiO precursor solution onto a sizing machine using a disposable syringe, first spinning at a low speed (800 rpm) for 15 seconds, then spinning at a high speed (2500 rpm) for 20 seconds, so that the NiO precursor solution is evenly coated on the substrate surface to obtain a NiO thin film gel wet film. The NiO thin film gel wet film is then placed on a constant temperature heating table, dried at 80°C for 3 minutes, pyrolyzed at 150°C for 4 minutes, and pre-annealed at 300°C for 5 minutes to obtain a layer of NiO initial thin film. The above process is then repeated three times (i.e., spinning four layers of film) to obtain a film sample of the desired thickness. The sample is then placed in a rapid annealing furnace and annealed at 600°C for 10 minutes to obtain a NiO thin film.

[0072] Furthermore, in step S23, a MXene precursor solution is spin-coated on the top surface of the NiO film to generate a MXene film after treatment. The method of implementing the method can be specifically as follows:

[0073] Spin coating a MXene precursor solution on the top surface of the substrate to form a MXene gel wet film, wherein the MXene precursor solution is a titanium carbide colloidal aqueous solution based on hydrofluoric acid wet stripping;

[0074] The MXene gel wet film is sequentially subjected to a preset number of thin film treatments to obtain an initial MXene thin film, wherein the thin film treatment process includes drying, pyrolysis, pre-annealing, and repeated spin coating;

[0075] Based on the initial MXene film, an annealing treatment is performed within an annealing temperature range to generate a MXene film.

[0076] In addition, the spin coating includes at least a first spin coating and a second spin coating. The first spin coating is a low speed of 500 to 800 rpm, and the low-speed first spin coating is used for initial spinning. The second spin coating has a high speed of 2000 to 3000 rpm, and the high-speed second spin coating is used for uniform coating, so that the MXene precursor solution is evenly coated on the surface of the NiO film to obtain a MXene film.

[0077] Among them, the preset number of times ranges from 3 to 6 times, the drying temperature range corresponding to the drying is 50 to 100°C; the pyrolysis temperature range corresponding to the pyrolysis is 150 to 200°C, and the pyrolysis time interval is 4 to 10 minutes; the pre-annealing temperature range corresponding to the pre-annealing is 300 to 400°C, and the pre-annealing time interval is 5 to 10 minutes; the annealing temperature range corresponding to the annealing is 600 to 700°C, and the annealing time interval is 10 to 15 minutes.

[0078] In an optional embodiment, the MXene precursor solution may be filtered with filter paper to eliminate impurities in the MXene precursor solution and improve the quality of the MXene film.

[0079] The steps for obtaining a MXene film can be: using a disposable syringe to drop the MXene precursor solution onto a sizing machine for spinning, first spinning at a low speed (800 rpm) for 15 seconds, then spinning at a high speed (2500 rpm) for 20 seconds, so that the MXene precursor solution is evenly coated on the surface of the NiO film to obtain a MXene gel wet film. The MXene gel wet film is then placed on a constant temperature heating table and dried at 80°C for 3 minutes. The MXene gel wet film is then dried, and then pyrolyzed at 150°C for 4 minutes, and pre-annealed at 300°C for 5 minutes to obtain a layer of MXene initial film. This process is then repeated 3 times (i.e., spinning 4 layers of film) to obtain a film sample of the desired thickness, which is then placed in a rapid annealing furnace and annealed at 600°C for 10 minutes to obtain a MXene film.

[0080] Furthermore, in step S25, a top electrode is formed by electroplating on the MXene / NiO heterojunction layer. The step of forming the top electrode may be: using a mask combined with DC magnetron to sputter Au metal on the MXene / NiO heterojunction layer, so that the Au metal is plated on the MXene / NiO heterojunction layer to form a layer of metal Au dot electrode (refer to Figure 1 As shown in Figure 2), after forming the top electrode, a synaptic device based on MXene / NiO heterojunction is prepared. The structural layers of the synaptic device are Au dot electrode / MXene film / NiO film / FTO conductive glass (as shown in Figure 2). Figure 1 shown)

[0081] Furthermore, in order to verify the performance of the MXene / NiO heterojunction synaptic device, a voltage test was performed on it in the embodiment of the present invention.

[0082] Figure 3 This is a single IV curve of the MXene / NiO heterojunction synaptic device under voltage test. Figure 3As shown, the horizontal axis Voltage (V) is the currently applied voltage, and the vertical axis Current (mA) is the current after the voltage is applied. It can be seen that Figure 3 Among them, 1, 2, 3, and 4 have certain non-overlapping "windows", which are consistent with the two-terminal nonlinear characteristics of artificial synaptic devices.

[0083] Figure 4 The IV curve of the MXene / NiO heterojunction synaptic device is obtained by cycling the voltage 50 times and taking the logarithm of the current log10. The horizontal axis Voltage (V) is the current applied, and the vertical axis Current (mA) is the current after the voltage is applied. Figure 4 It can be observed that the curve corresponding to the MXene / NiO heterojunction synaptic device has the asymmetric characteristics of the Set / Reset curve of the artificial synaptic device.

[0084] Figure 5 and Figure 6 The curve of synaptic weight change simulation for MXene / NiO heterojunction synaptic device. The horizontal axis Voltage (V) is the current applied voltage, and the vertical axis Current (mA) is the current after the voltage is applied. Figure 5 It can be observed that the synaptic weight is gradually depressed as the number of scans increases; Figure 6 It can be observed that the synaptic weight gradually increases with the increase in the number of scans, so the MXene / NiO heterojunction synaptic device can well simulate the change of synaptic weight.

[0085] Figure 7 Schematic diagram of MXene / NiO heterojunction synaptic device simulating long-term synaptic plasticity. The horizontal axis Times (s) is the time parameter, and the vertical axis Conductance (#) is the conductance parameter, such as Figure 7 As shown in the figure, (1) is long-term potentiation (LTP) and (2) is long-term depression (LTD). Figure 7 It can be observed that after 5 seconds of long-term potentiation, the enhancement amplitude of synaptic weights gradually stabilizes; after 3 seconds of long-term depression, the strength of synaptic weights can be quickly suppressed to a lower range.

[0086] Figure 8 The memory curve of the conductance of the MXene / NiO heterojunction synaptic device after long-term potentiation and removal of the applied voltage. The horizontal axis Times(s) is the time parameter, and the vertical axis Conductance(#) is the conductance parameter. Figure 8 It can be observed that the device has very good conductance memory capability, and the enhancement of synaptic weight can remain unchanged for a long time without external stimulation.

[0087] Figure 9 and Figure 10 This figure shows the current response of a MXene / NiO heterojunction synaptic device under the stimulation of positive and negative triangular voltage signals, used to simulate synaptic short-term depression (STD) and short-term plasticity (STP). The horizontal axis (Pulse (#)) represents the pulse parameter, the left vertical axis (Voltage (V)) represents the currently applied voltage, and the right vertical axis (Current (mA)) represents the current after the voltage is applied.

[0088] Figure 11 Simulate postsynaptic excitatory current (EPSC) for MXene / NiO heterojunction synaptic devices.

[0089] Performance test results show that the device can simulate the functions of biological synapses and can be used to build artificial neural network systems.

[0090] Based on the above, it can be seen that the artificial synaptic device based on the MXene / NiO heterojunction of the present invention has a better conductivity than the NiO thin film memristor device with lower conductive filament growth ability, and the memristor phenomenon can be observed more clearly. The synapse can simulate important synaptic functions, including the enhancement and inhibition of synaptic weights, long-term potentiation (LTP), long-term depression (LTD), short-term potentiation (STP), short-term depression (STD) and postsynaptic excitation current (EPSC). The MXene / NiO heterojunction memristor device has better performance than the NiO thin film memristor device prepared by the same process. In addition, the synaptic device has an extremely fast and sensitive response to electrical pulses, has ultra-low energy consumption, and can be used to construct an artificial neural network system. The preparation method has simple operation steps, readily available raw materials, low cost, low energy consumption, high efficiency, and is easy to implement.

[0091] The above describes multiple embodiment schemes provided by the embodiments of the present invention. The various optional methods introduced in each embodiment scheme can be combined and cross-referenced with each other without conflict, thereby extending a variety of possible embodiment schemes, which can all be considered as embodiment schemes disclosed and open in the embodiments of the present invention.

[0092] Although the embodiments of the present invention are disclosed above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A MXene / NiO heterojunction synaptic device, characterized in that: include: A substrate, wherein a bottom electrode is provided in the substrate, wherein the bottom electrode is exposed on the top surface of the substrate; A MXene / NiO heterojunction layer covering a portion of the substrate, wherein the MXene / NiO heterojunction layer includes a MXene layer and a NiO layer, and the portion is the area corresponding to the substrate except for the bottom electrode; a top electrode located on top of the MXene / NiO heterojunction layer; Wherein, the material of the top electrode is one of gold, silver, copper, aluminum, and indium tin oxide; The substrate is FTO conductive glass or ITO conductive glass; A method for preparing a MXene / NiO heterojunction synaptic device is characterized by: Obtaining a substrate, wherein a bottom electrode is exposed on an upper surface of the substrate, and the bottom electrode is disposed inside the substrate; Spin coating a NiO precursor solution on the top surface of the substrate to form a NiO gel wet film, wherein the NiO precursor solution is prepared by dissolving nickel acetate tetrahydrate in an organic solvent, and the organic solvent is at least one of glacial acetic acid, ethylene glycol methyl ether, acetylacetone or ethylene glycol; The NiO gel wet film is sequentially subjected to a preset number of thin film treatments to obtain an initial NiO thin film, wherein the thin film treatment process includes drying, pyrolysis, pre-annealing, and repeated spin coating; Performing an annealing treatment within an annealing temperature range on the initial NiO film to generate a NiO film; Spin coating a MXene precursor solution on the top surface of the NiO film to generate a MXene film after treatment; Removing the MXene film and the NiO film from a portion of the area to expose the bottom electrode on the substrate to form a MXene / NiO heterojunction layer; A top electrode is formed by electroplating on the MXene / NiO heterojunction layer.

2. The MXene / NiO heterojunction synaptic device according to claim 1, characterized in that: The preparation ratio of the nickel acetate tetrahydrate to the organic solvent is in the range of 0.01 mol: 15 mL to 0.01 mol: 25 mL.

3. The MXene / NiO heterojunction synaptic device according to claim 1, characterized in that: The MXene film is generated after the treatment, including: Spin coating a MXene precursor solution on the top surface of the substrate to form a MXene gel wet film, wherein the MXene precursor solution is a titanium carbide colloidal aqueous solution based on hydrofluoric acid wet stripping; The MXene gel wet film is sequentially subjected to a preset number of thin film treatments to obtain an initial MXene thin film, wherein the thin film treatment process includes drying, pyrolysis, pre-annealing, and repeated spin coating; Based on the initial MXene film, an annealing treatment is performed within an annealing temperature range to generate a MXene film.

4. The MXene / NiO heterojunction synaptic device according to claim 1, wherein: The spin coating includes at least a first spin coating and a second spin coating. The rotation speed of the first spin coating is 500-800 rpm, and the rotation speed of the second spin coating is 2000-3000 rpm.

5. The MXene / NiO heterojunction synaptic device according to claim 1, characterized in that: The preset number of times ranges from 3 to 6 times, and the drying temperature range corresponding to the drying is 50 to 100°C; the pyrolysis temperature range corresponding to the pyrolysis is 150 to 200°C, and the pyrolysis time interval is 4 to 10 minutes; the pre-annealing temperature range corresponding to the pre-annealing is 300 to 400°C, and the pre-annealing time interval is 5 to 10 minutes; the annealing temperature range corresponding to the annealing is 600 to 700°C, and the annealing time interval is 10 to 15 minutes.

6. Application of the MXene / NiO heterojunction synaptic device according to claims 1 to 5 in the field of artificial neural network systems.

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