Full-printing flexible metal oxide neuromorphic transistor device capable of being prepared in large scale

Abstract

The invention discloses a full-printing flexible metal oxide neuromorphic transistor device capable of being prepared on a large scale, which adopts a vertical structural design and sequentially comprises a PI (Polyimide) film substrate, a metal silver conductive layer (gate), a zirconium oxide (ZrOx) gate dielectric layer, an amorphous indium gallium zinc oxide (a-IGZO) metal oxide channel layer and a metal silver conductive layer (source and drain) from bottom to top. Wherein a grid electrode (G) of the neuromorphic transistor is a port signal input end of the transistor and is used for simulating a presynaptic membrane of a biological synapse. The conductance between the source electrode (S) and the drain electrode (D) is used for simulating the weight of biological synapses, and has good PFF simulation, SNDP, SDDP and SRDP synapses characteristics. By introducing the printing technology of full ink-jet printing, multiple layers of functional materials are directly deposited in the normal-temperature and normal-pressure environment, the large-scale preparation technological process is remarkably simplified, the production cost is reduced, and the requirement for large-scale integration is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparation of neuromorphic transistor devices, and in particular relates to a fully printed flexible metal oxide neuromorphic transistor device that can be prepared on a large scale. Background Art

[0002] Neuromorphic transistor devices are the core components of neuromorphic computing. Such devices are usually used to simulate the dynamic behavior between neurons and synapses to complete the storage and processing of information. Compared with the traditional von Neumann architecture, the neuromorphic computing architecture based on the underlying synaptic device has the advantages of low power consumption, high parallelism and efficient processing of perception tasks, which makes it particularly outstanding in processing complex cognitive computing and pattern recognition tasks. Among them, the ion migration process of the double-layer synaptic transistor is very similar to that of the biological synapse. These advantages make it an ideal data processing node for the development of bionic perception systems. However, most of the synaptic transistors with double layers reported so far are organic materials, but the device stability and life of organic materials are poor. Metal oxide materials are an alternative method. Neuromorphic transistors prepared based on this thin film material can obtain better electrical performance and device stability under the same use environment.

[0003] Metal oxide materials have attracted much attention in the research of new electronic devices in recent years due to their superior electrical properties, wide band gap, environmental stability and transparency. Among them, indium gallium zinc oxide (IGZO) and zirconium oxide (ZrOx) materials have been widely used in thin film transistors (TFTs) for display panels and flexible electronic devices. However, traditional metal oxide semiconductor devices are usually prepared by high temperature and high vacuum micro-nano processes such as sputtering and chemical vapor deposition. The preparation steps of these processes are complicated and costly, and it is difficult to achieve good compatibility with flexible substrates and large-scale device preparation.

[0004] With the rapid development of flexible electronic technology, traditional semiconductor manufacturing processes face many challenges in terms of flexibility, lightweight and low cost. As an emerging manufacturing technology, the flexible full-printing process directly deposits functional materials on the substrate at room temperature and pressure through methods such as inkjet printing and dispensing, so as to significantly reduce the manufacturing cost and energy consumption of microelectronic devices. Therefore, the application of full-printing technology in the manufacture of large-area, low-cost flexible electronic devices shows great application potential. At the same time, the flexible full-printing process also provides a new method for large-scale manufacturing of neuromorphic devices with high efficiency and low cost. Summary of the invention

[0005] The purpose of the present invention is to develop a fully printed flexible metal oxide neuromorphic transistor device that can be prepared on a large scale, aiming to solve the problems of high cost, complex process, and difficulty in large-scale integration faced by the current field of neuromorphic computing and flexible electronic devices through innovative manufacturing processes and material selection.

[0006] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions: The present invention first provides a fully printed flexible metal oxide neuromorphic transistor device that can be prepared on a large scale. From bottom to top, it is a polyimide (PI) film substrate, a metal silver (Ag) conductive layer, a zirconium oxide (ZrOx) gate dielectric layer, an amorphous indium gallium zinc oxide (a-IGZO) metal oxide channel layer, and a metal silver (Ag) conductive layer. The overall transistor adopts a vertical structure design. Among them, the gate (G) of the neuromorphic transistor is the port signal input end of the transistor, which is used to simulate the presynaptic membrane of the biological synapse. The conductance between the source (S) and the drain (D) is used to simulate the biological synaptic weight.

[0007] The present invention further provides a fully printed preparation method of the above-mentioned flexible metal oxide neuromorphic transistor device, and the specific preparation method comprises the following steps: (1) A polyimide (PI) film substrate is treated with UV / O3 for 2 minutes, the PI substrate is placed in a microelectronic printer and inkjet printed with silver ink, and a gradient temperature treatment is performed to obtain a metallic silver conductive layer; wherein the silver ink is composed of silver acetate, ammonium hydroxide, formic acid and 2,3-butanediol, the ink viscosity is 2-10 cP, and the particle size is less than 100 nm.

[0008] (2) The polyimide (PI) film substrate printed with the silver electrode was treated with UV / O3 for 5 minutes, and the zirconium oxide (ZrOx) gate dielectric layer was printed using the inkjet function of a microelectronic printer.

[0009] (3) Printing an IGZO channel layer on the ZrOx gate dielectric layer.

[0010] (4) Using the silver ink in step (1), a metal silver (Ag) conductive layer is printed on the IGZO channel layer, and the aspect ratio of the channel is 1:10, forming the source and drain.

[0011] (5) The sample is laser cut and the electrodes are connected to the leads to make multiple discrete devices.

[0012] Furthermore, in the silver ink of step (1), the concentration of silver acetate in the ammonium hydroxide / formic acid mixed solution is 0.5 g / mL, the added volume of 2,3-butanediol is 10% of the volume of the ammonium hydroxide / formic acid mixed solution, and the ammonium hydroxide / formic acid mixed solution is composed of ammonium hydroxide and formic acid in a volume ratio of 3:1.

[0013] The printer parameters were set as follows: printing voltage 37 V, substrate temperature 30 °C, nozzle aperture 20 μm, nozzle temperature 30 °C, the printed dot pitch was set to 35 μm, and adjacent ink droplets merged with each other to form a continuous straight line when inkjetted.

[0014] The gradient temperature rise treatment is to first heat at 90°C until the liquid film turns silver, then heat at 130°C for 10 minutes, and finally heat at 150°C for more than 30 minutes.

[0015] The silver electrode is 1.5 mm long and 0.5 mm wide, and the derived gate electrode is 0.5 mm long and 0.2 mm wide.

[0016] Furthermore, in step (2), the precursor ink of the zirconium oxide (ZrOx) gate dielectric layer is: zirconium oxychloride (ZrOCl4), acetonitrile and ethylene glycol, and zirconium oxychloride is dissolved in acetonitrile and ethylene glycol in a ratio of 3.5:6.5 to prepare a precursor ink with a concentration of 0.4 mol / L, and then vigorously stirred in air for 2 hours and filtered with a 0.45 μm polytetrafluoroethylene (PTFE) filter. The ink viscosity is 2-10 cP, and the particle size is less than 100 nm.

[0017] The printer parameters were set as follows: printing voltage 37V, substrate temperature 30°C, nozzle aperture 20μm, nozzle temperature 30°C, and the printed dot pitch was set to 30μm. The sample was then cured on a hot stage at 250°C for 5 minutes. This process needed to be repeated two to four times in order to achieve the required thickness (200-400nm) and good insulation. The ZrOx film was then hot-stage annealed at 300°C for 2 hours under normal pressure; low-temperature annealing will help achieve synaptic properties.

[0018] Compared with traditional granular zirconium oxide ink, the precursor ink using zirconium oxychloride as raw material is less likely to produce stratification effect and less likely to clog the nozzle, which is beneficial to extend the service life of the nozzle. Compared with other common zirconium oxide precursors, zirconium oxychloride has greater advantages in solubility, dispersibility, and temperature resistance. The specific comparison is shown in Table 1. For the choice of solvent, ethylene glycol is relatively cheaper than other alcohols, so it is more suitable for the manufacture of large-scale flexible neuromorphic devices. Although ethanol is also cheaper, it has strong volatility, which is not conducive to long-term industrial production, and will have a greater impact on the performance and uniformity of the film.

[0019] Table 1 Comparison of properties of several common zirconia precursor materials .

[0020] As for the annealing temperature, temperatures above 300°C will weaken the hysteresis performance of the device, and the hysteresis almost disappears at 400 degrees. Therefore, 300°C is used as the annealing temperature of the zirconium oxide of the present invention. Due to the decrease in annealing temperature, the annealing time should also be increased accordingly, from the conventional 1h annealing time to 2h.

[0021] Furthermore, in step (3), the IGZO precursor ink is: indium nitrate hydrate (In(NO3)3·xH2O), gallium nitrate hydrate (Ga(NO3)3·xH2O) and zinc nitrate hydrate (Zn(NO3)2·xH2O), dimethoxyethanol (2-Methoxyethanol), the molar ratio of the three metal nitrates is 9:1:2, and the total molar concentration of metal ions is 0.2 mol / L; the ink viscosity is 2-10 cP, and the particle size is less than 100 nm. After the ink is prepared, it needs to be vigorously stirred in the air for 2 hours and filtered with a 0.45 μm polytetrafluoroethylene (PTFE) filter.

[0022] The printer parameters were set as follows: printing voltage 37 V, substrate temperature 30 ° C, nozzle aperture 20 μm, nozzle temperature 30 ° C. The printed dot pitch was set to 30 μm.

[0023] In this step, In:Zn:Ga=9:2:1 is selected to increase the In content ratio. The increase of In will increase the conductivity because In can effectively provide free electrons, thereby increasing the carrier concentration; increasing the In content will also improve the transmittance of the film, especially in the visible light range, so that it performs better in optoelectronic applications; increasing the In content appropriately can also improve the thermal stability of the film, making it more stable in a high temperature environment and reducing the risk of phase change during thermal annealing.

[0024] Since the annealing temperature of the zirconium oxide film is fixed at 300°C, if the temperature of the IGZO exceeds 300°C, it will affect the hysteresis and synaptic performance of the device. Therefore, the same annealing temperature as the zirconium oxide film is used for annealing the film. The annealing time adopts the conventional 1h annealing. After printing, annealing is performed, the temperature is set to 300°C, and the duration is 1 hour. Low temperature annealing will be conducive to the realization of synaptic characteristics.

[0025] Compared with the prior art, the present invention has the following beneficial effects: 1. This new device is based on the double-layer effect formed by oxygen vacancies and oxygen ions in the metal oxide gate dielectric. Compared with traditional transistors, it has a μF / cm -2 It has the characteristics of ultra-large gate capacitance, high carrier density and low power consumption.

[0026] 2. It can realize the response test of various pulse excitation signals and the simulation of various synaptic behaviors, such as postsynaptic excitation current, double pulse facilitation (PPF), etc. These functions enable it to accurately simulate the complex behavior of biological neural networks and lay the foundation for the hardware implementation of neuromorphic computing and artificial neural networks.

[0027] 3. The present invention introduces the full inkjet printing technology to directly deposit multiple layers of functional materials under normal temperature and pressure, which significantly simplifies the scale preparation process and reduces production costs to meet the needs of large-scale integration. Compared with traditional semiconductor manufacturing processes, full printing technology avoids the use of high temperature, high energy consumption and harmful chemicals, and meets the requirements of green manufacturing and sustainable development. By promoting this technology, the negative impact of electronic device manufacturing on the environment can be effectively reduced.

[0028] 4. Metal oxide materials (such as IGZO) have high transparency, which allows metal oxide transistors to be used in transparent electronic devices and display technologies. Organic transistors usually have low transparency, which limits their application in transparent devices. At the same time, metal oxide transistors have stronger stability and service life.

[0029] 5. The device uses a flexible substrate PI and various flexible film materials, making it bendable and stretchable, which greatly increases the use scenarios and scope of the device and provides a component basis for the use and development of flexible wearable devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 1 is a structural diagram of the neuromorphic transistor of the present invention; in the figure: 1—source (Ag), 2—drain (Ag), 3—IGZO channel layer, 4—ZrOx gate dielectric, 5—gate (Ag), 6—PI flexible substrate.

[0031] Figure 2 The flowchart of the preparation of the large-scale fully printed flexible metal oxide neuromorphic transistor device of the present invention.

[0032] Figure 3 This is a schematic diagram of the double-layer effect of the present invention; before charging (left), after charging (right). In the figure: — oxygen vacancies (uncharged), — ionized oxygen vacancies (positively charged), —Oxygen ions (negatively charged).

[0033] Figure 4 The neuromorphic transistor device of the present invention is DS = 0.1V transfer curve.

[0034] Figure 5This is the simulated double pulse facilitation characteristic phenomenon of the neuromorphic transistor device of the present invention.

[0035] Figure 6 is the PPF index of the neuromorphic transistor device of the present invention.

[0036] Figure 7 The synaptic characteristic spike number-dependent plasticity simulated for the neuromorphic transistor device of the present invention.

[0037] Figure 8 The synaptic characteristic spike timing-dependent plasticity simulated by the neuromorphic transistor device of the present invention.

[0038] Fig. 9 The pulse frequency-dependent plasticity of the synaptic characteristics simulated by the neuromorphic transistor device of the present invention. DETAILED DESCRIPTION

[0039] Figure 1 This is a diagram of the internal structure of the neuromorphic transistor of the present invention, which includes, from top to bottom, a source 1 and a drain 2, an IGZO channel layer 3, a ZrOx gate dielectric 4, a gate 5 and a PI flexible substrate 6; the source and the drain are located in the same plane on the IGZO channel layer, the aspect ratio of the channel is 1:10, and they are led out to the substrate.

[0040] Figure 2 The flowchart of the preparation of the large-scale fully printed flexible metal oxide neuromorphic transistor device of the present invention.

[0041] The following is a large-scale batch preparation process of the novel neuromorphic transistor of the present invention, and the specific preparation method includes the following steps: (1) Treat the polyimide (PI) film substrate with UV / O3 for 2 minutes, place the PI substrate on the base of the inkjet printer and turn on the adsorption function of the printer to make the PI substrate fit better with the base. The flat surface will be more conducive to the printing and preparation of silver electrodes. The specific materials of the silver ink are silver acetate, ammonium hydroxide and formic acid. Dissolve silver acetate (2g) in 4ml of ammonium hydroxide and formic acid mixed solution (the ratio of the two is 3:1), and add a small amount of 2,3-butanediol (10% volume percentage) as a wetting agent and thickener. The ink viscosity is 2-10cP and the particle size is less than 100nm. The printer parameters are set as follows: printing voltage 37V, substrate temperature 30°C, nozzle aperture 20μm, nozzle temperature 30°C, and the printed dot spacing is set to 35μm. Adjacent ink droplets will merge with each other to form a continuous straight line when inkjet. The metal silver electrode is patterned and printed. The specific electrode pattern is as follows Figure 2(a) is shown. Then, a gradient temperature rise post-treatment is performed, first heating at 90°C until the liquid film turns silver, then heating at 130°C for 10 minutes, and finally heating at 150°C for more than 30 minutes. The electrode square resistivity is about 1.3Ω / square, the silver electrode is 1.5mm long and 0.5mm wide, and the derived gate electrode is 0.5mm long and 0.2mm wide.

[0042] (2) The polyimide (PI) film substrate printed with silver electrodes was treated with UV / O3 for 5 minutes, and the zirconium oxide (ZrOx) gate dielectric layer was printed using the inkjet function of a microelectronic printer. The gate dielectric layer was 1.5 mm long and 0.5 mm wide. The specific structure is as follows: Figure 2 As shown in (b), a homemade ink is used in this step. The specific materials are: zirconium oxychloride (ZrOCl4), acetonitrile and ethylene glycol. Zirconium oxychloride is dissolved in acetonitrile and ethylene glycol in a ratio of 3.5:6.5 to prepare a precursor ink with a concentration of 0.4 mol / L, and then vigorously stirred in air for 2 hours and filtered with a 0.45μm polytetrafluoroethylene (PTFE) filter. The ink viscosity is 2-10cP and the particle size is less than 100nm. The printer parameters are set as follows: printing voltage 37V, substrate temperature 30°C, nozzle aperture 20μm, nozzle temperature 30°C, and the printed dot spacing is set to 30μm. The sample is then cured on a hot stage at 250°C for 5 minutes. This process is repeated 4 times to achieve the required thickness of 200-400nm and good insulation. Then, the ZrOx film is hot-stage annealed at 300°C for 2 hours under normal pressure.

[0043] (3) Continue to use the inkjet function of the microelectronic printer to pattern print a rectangular IGZO channel layer slightly smaller (length and width are less than 10μm) than the gate dielectric layer on the semi-finished product of step (2). The schematic diagram of this step is shown in Figure 2 (c) As shown. In this step, a homemade ink is used. The specific materials are: In(NO3)3·xH2O, Ga(NO3)3·xH2O and Zn(NO3)2·xH2O are dissolved in dimethoxyethanol in a molar ratio of 9:1:2. The total molar concentration of metal ions is 0.2mol.L, the ink viscosity is 2-10cP, and the particle size is less than 100nm. After the ink is prepared, it needs to be vigorously stirred in the air for 2 hours and filtered with a 0.45μm polytetrafluoroethylene (PTFE) filter. The printer parameters are set as follows: printing voltage 37V, substrate temperature 30°C, nozzle aperture 20μm, nozzle temperature 30°C. The printed dot spacing is set to 30μm. Then annealing is performed, the temperature is set to 300℃, and the duration is 1 hour.

[0044] (4) The semi-finished product after step (3) is further processed by the inkjet printing function of the microelectronic printer to form a metal silver (Ag) conductive layer. The aspect ratio of the channel is 1:10, and the pattern shape of the source and drain is as follows: Figure 2 (d) As shown. The specific materials of the ink and the parameter settings of the printer are the same as those in step (1). The metal silver electrode is patterned and then subjected to gradient temperature post-treatment, first heated at 90°C until the liquid film turns silver, then heated at 130°C for 10 minutes, and finally heated at 150°C for more than 30 minutes; (5) The sample is laser cut, and the gold wires are connected to the three electrodes respectively using a gold wire welding machine. Multiple discrete devices are made. The device prepared by the present invention can be directly compatible with flexible electronic device applications, and can also be compatible with standard SOT-23 packaging to be made into discrete components. The schematic diagram of the packaged device is shown in Figure 2 (e) as shown. Figure 2 (f) is a schematic diagram of the layer structure of the device.

[0045] This new metal oxide neuromorphic device is mainly based on the double electric layer effect produced by the metal oxide gate dielectric, which can achieve advanced ultra-low operating voltage (less than 1V) and neuromorphic computing functions. Figure 3 As shown in the figure, the specific process of the double electric layer effect is depicted. Under the action of the gate electric field, the ionized oxygen vacancies migrate to the channel layer, resulting in the accumulation of positive charge at the interface between the channel and the gate dielectric; at the same time, the oxygen ions migrate to the interface between the gate dielectric and the gate, resulting in the accumulation of negative charge. Due to the existence of high polarization, the accumulated ions at the interface cause counterclockwise hysteresis. Finally, a dense double electric layer with a spacing of only nm is formed at the interface of the channel / electrolyte and the gate / dielectric, and μF / cm is generated. -2 The ultra-large gate capacitance of the MOSFET can reduce the overall device power consumption.

[0046] V DS = 0.1V transfer curve is as follows Figure 4 As shown in Figure 2, the voltage applied to the gate is swept from −1 V to 5 V with a scanning step of 0.02 V. The synaptic transistor exhibits a 10 6The on / off ratio and significant hysteresis loop of the fully inkjet-printed synaptic transistor are similar to those of the IGZO synaptic transistor (Sheng Li; Hanbai Lyu; Jiean Li; Yongli He; Xingxun Gao; QingWan; Yi Shi*; Lijia Pan*; Multiterminal Ionic Synaptic transistor withArtificial Blink Reflex Function, IEEE Electron Device Letters, 2021, 42(3):351-354) manufactured by magnetron sputtering. This shows that the performance of the fully inkjet-printed synaptic transistor is not inferior to that of the devices manufactured by traditional methods.

[0047] When in use, a single or multiple voltage pulse signals can be applied. Under the influence of a forward voltage pulse, the ionized oxygen vacancies in the metal oxide gate dielectric migrate to the channel, inducing an excitatory postsynaptic current (EPSC) in the channel. When the voltage pulse is removed, the induced oxygen vacancies and oxygen ions will move in the opposite direction and return to the initial state. At this time, the channel current will still act on the oxygen vacancies and oxygen ions that have not been completely reset, and the EPSC signal will slowly decrease.

[0048] Under the action of multiple voltage pulses, after the excitatory postsynaptic current generated by the first pulse, the oxygen vacancies and oxygen ions at the gate dielectric / channel interface and the gate / gate dielectric will gradually drift back to the equilibrium state. If the next voltage pulse arrives during this process, some of the oxygen vacancies / oxygen ions that have not returned will be superimposed on the number of oxygen vacancies / oxygen ions ionized this time, inducing more carriers in the channel, making the excitatory postsynaptic current triggered this time stronger, thus producing phenomena such as double pulse facilitation (PPF).

[0049] The PPF of the device is Figure 5 As shown in the figure, two consecutive voltage pulses (amplitude of 1.6V, pulse width of 10ms) are applied to the gate, and the current surge increases from 92.5nA to 127.7nA, and the transistor exhibits a high gain factor of 1.38. The principle behind this gain is that after the first pulse voltage, some oxygen ions and ionized oxygen vacancies that previously formed the EDL remain in the gate dielectric, and applying a voltage pulse again in an extreme time will form a larger pulse current because of these.

[0050] The PPF index of the device is as follows: Figure 6As shown in the figure, two consecutive voltage pulses (amplitude of 1.5V) are applied to the gate. As the pulse interval increases, the PPF index slowly decreases. This is because the increase in the pulse interval will lead to a decrease in the concentration of oxygen ions and ionized oxygen vacancies, which will lead to a decrease in the EPSC caused by the next pulse.

[0051] The synaptic properties simulated by the device made by the present invention are SNDP (pulse number dependent plasticity), SDDP (pulse time dependent plasticity), and SRDP (pulse frequency dependent plasticity). Figure 7 , 8 As shown in Figure 9, the postsynaptic current increases with the increase of quantity, time and frequency. The basic function of synapses in organisms has been successfully simulated.

[0052] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A fully printed flexible metal oxide neuromorphic transistor device that can be mass-produced, characterized in that: The neuromorphic transistor device is designed with a vertical structure, which includes, from bottom to top, a polyimide film substrate, a bottom metal silver conductive layer, a zirconium oxide gate dielectric layer, an amorphous indium gallium zinc oxide metal oxide channel layer, and a top metal silver conductive layer; wherein, the bottom metal silver conductive layer leads to a gate, which is a port signal input end of the transistor and is used to simulate the presynaptic membrane of a biological synapse; the top metal silver conductive layer located on the amorphous indium gallium zinc oxide metal oxide channel layer is a source and a drain, respectively, and the conductance between the source and the drain is used to simulate the biological synaptic weight; each layer of the flexible metal oxide neuromorphic transistor is printed by inkjet printing.

2. The method for preparing a fully printed flexible metal oxide neuromorphic transistor device that can be prepared on a large scale according to claim 1, characterized in that: The following steps are involved: (1) The polyimide film substrate is treated with UV / O3 for 2 minutes, the PI substrate is placed in a microelectronic printer and inkjet printed with silver ink, and a gradient temperature treatment is performed to obtain a bottom metallic silver conductive layer; wherein the silver ink is composed of silver acetate, ammonium hydroxide, formic acid and 2,3-butanediol; (2) The polyimide film substrate printed with silver electrodes was treated with UV / O3 for 5 minutes, and the zirconium oxide gate dielectric layer was inkjet printed; (3) inkjet printing an amorphous indium gallium zinc oxide metal oxide channel layer on the zirconium oxide gate dielectric layer; (4) using the silver ink of step (1) to inkjet print a top metal silver conductive layer on the IGZO channel layer, wherein the aspect ratio of the channel is 1:10, forming a source electrode and a drain electrode; (5) Cut the sample and connect the electrodes to the leads to make multiple discrete devices.

3. The method for preparing a fully printed flexible metal oxide neuromorphic transistor device that can be prepared on a large scale according to claim 2, characterized in that: The inkjet printing has a printing voltage of 37V, a substrate temperature of 30°C, a nozzle aperture of 20 μm, and a nozzle temperature of 30°C.

4. The method for preparing a fully printed flexible metal oxide neuromorphic transistor device that can be prepared on a large scale according to claim 2, characterized in that: In the silver ink of step (1), the concentration of silver acetate in the ammonium hydroxide / formic acid mixed solution is 0.5 g / mL, the added volume of 2,3-butanediol is 10% of the volume of the ammonium hydroxide / formic acid mixed solution, and the ammonium hydroxide / formic acid mixed solution is composed of ammonium hydroxide and formic acid in a volume ratio of 3:

1.

5. The method for preparing a fully printed flexible metal oxide neuromorphic transistor device that can be prepared on a large scale according to claim 2, characterized in that: The gradient temperature rise treatment in step (1) is to first heat at 90°C until the liquid film turns silver, then heat at 130°C for 10 minutes, and finally heat at 150°C for more than 30 minutes.

6. The method for preparing a fully printed flexible metal oxide neuromorphic transistor device that can be prepared on a large scale according to claim 2, characterized in that: In the step (2), the precursor ink of the zirconium oxide gate dielectric layer is composed of zirconium oxychloride, acetonitrile and ethylene glycol, the volume ratio of acetonitrile to ethylene glycol is 3.5:6.5, and the molar concentration of zirconium oxychloride is 0.4 mol / L.

7. The method for preparing a fully printed flexible metal oxide neuromorphic transistor device that can be prepared on a large scale according to claim 2, characterized in that: The step (2) further includes curing at 250° C. for 5 minutes after inkjet printing, and repeating the inkjet printing to achieve the required thickness.

8. The method for preparing a fully printed flexible metal oxide neuromorphic transistor device that can be prepared on a large scale according to claim 2, characterized in that: In step (3), the IGZO precursor ink is composed of indium nitrate hydrate, gallium nitrate hydrate, zinc nitrate hydrate and dimethoxyethanol, and the total molar concentration of metal ions is 0.2 mol / L; the molar ratio of indium, gallium and zinc ions is 9:1:

2.

9. The method for preparing a fully printed flexible metal oxide neuromorphic transistor device that can be prepared on a large scale according to claim 2, characterized in that: In step (3), annealing treatment is performed after printing, the annealing temperature is 300° C., and the annealing time is 1 h.

10. The method for preparing a fully printed flexible metal oxide neuromorphic transistor device that can be prepared on a large scale according to claim 2, characterized in that: The dot pitch of steps (1) and (4) is 35 μm, and the dot pitch of steps (2) and (3) is 30 μm.

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