A bidirectional unipolar regulation method based on organic memristor

Abstract

The application is a kind of bidirectional unipolar regulation method based on organic memristor, which takes bidirectional unipolar voltage regulation of organic memristor as the object, induces oxygen ion transmission to build ion conduction mechanism through voltage regulation or pulse scanning, and realizes bidirectional unipolar voltage regulation. Through the regulation of oxygen ion transport of inorganic resistance change layer and organic functional layer, a kind of bidirectional unipolar voltage regulation memristor is obtained, which is based on the regulation of oxygen ions. The function layer oxygen ion transport can be accurately regulated by a simple voltage regulation or pulse scanning method, so as to build an ion conduction mechanism and realize bidirectional unipolar regulation. By extracting the conductance state of the memristor, unipolar multi-value storage is realized; and the memristor can be applied to simulate the function of neuron synapse.

Description

Technical Field

[0001] This invention belongs to the fields of semiconductor technology and neuromorphic hardware, specifically relating to a bidirectional unipolar modulation method based on organic memristors. Background Technology

[0002] Currently, with the rapid development of the information age, Moore's Law and the von Neumann architecture in traditional theory are gradually failing to meet the demands of storage and computation. Therefore, using different mechanisms to expand the in-memory computing unit is a necessary measure to break through the development of artificial intelligence at the hardware level. Memristors with reconfigurable, history-dependent resistive switching behavior are among the most promising technologies for constructing analog neural networks for neuromorphic computing. Achieving voltage regulation under unipolar conditions also greatly expands the application prospects of memristor neuromorphic chips.

[0003] Organic memristors are devices fabricated from organic materials. Organic materials are rich in functional groups and possess lightweight, mechanical flexibility, and ductility. Organic conjugated polymers, whose properties depend on the interactions within their single chains, have conductivity that can be precisely tuned between doped or photo-excited insulator-like and metal-like states, and exhibit good thermal and UV stability.

[0004] Unipolarity refers to the polarity of the voltage, i.e., positive or negative voltage. Traditional memristor devices require repeated switching between positive and negative voltages to achieve write / erase or excitation / inhibition functions. Unipolar memristors, however, require only a single voltage polarity for control. Utilizing the magnitude of the voltage (SVDP), they exhibit suppression (erase) at low voltages and enhancement (write) at high voltages. Because unipolar control can precisely regulate the increase or decrease of conductance under a single voltage direction, unipolar organic memristors play a significant role in simulating biological synaptic functions, i.e., they can simulate the excitation and inhibition behaviors of biological synapses under voltages of the same polarity.

[0005] Organic conjugated polymers, such as PEDOT:PSS, undergo interconversion between oxidized and reduced states under different bias voltages, leading to variations in their high and low resistance states. Therefore, researchers have conducted in-depth studies on the conductivity changes of PEDOT:PSS-based memristors. For example, the single-layer memristor Ag / PEDOT:PSS / Ta exhibits increased conductivity in both positive and negative directions (ACS Appl. Mater. Interfaces 2012, 4, 447-453). Furthermore, by introducing quantum dots to form an Al / PEDOT:PSS:GODs / Cu structure, the characteristics of increased positive conductivity and decreased negative conductivity can be achieved (NPG Asia Materials. 2017, 9, 413). Combining PEDOT:PSS materials with perovskite materials to fabricate multilayer memristors also achieves voltage modulation under different polarities (Adv. Mater. 2018, 30, 1805454). However, most devices can only achieve bipolar voltage regulation at present, and there are few successful cases of research on unipolar modulation of organic memristors, let alone unipolar regulation that can be achieved in both directions.

[0006] Unipolar modulation not only has advantages in simulating biological synapses, but also has wide applications in neuromorphic computing and intelligent applications. Therefore, developing new material systems, architectures, and fabrication processes suitable for unipolar-modulated flexible memristor devices is particularly important. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides a bidirectional unipolar control method based on organic memristors. By controlling the organic memristor with bidirectional unipolar voltage, multi-level switching characteristics can be achieved, which can be used for synaptic plasticity function simulation.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0009] This invention is a bidirectional unipolar control method based on organic memristors. The method is characterized by using a bidirectional unipolar voltage-controlled organic memristor as the target, and constructing an ion conduction mechanism by inducing oxygen ion transport through voltage control or pulse scanning to achieve bidirectional unipolar voltage control.

[0010] The bidirectional unipolar voltage-controlled organic memristor comprises a four-layer structure, consisting of a bottom electrode layer, a conjugated polymer organic functional layer, an inorganic resistive switching layer, and a top electrode, from bottom to top.

[0011] The conjugated polymer organic functional layer is a PEDOT:PSS organic functional layer that has undergone low-temperature annealing, serving as an ion collecting layer.

[0012] The resistive switching layer is an inorganic resistive switching layer, which serves as an ion-providing layer. The inorganic resistive switching layer is an oxide thin film, and the material of the inorganic resistive switching layer is a non-stoichiometric oxide. The thickness of the inorganic resistive switching layer is 50-200 nm.

[0013] The bottom electrode is indium tin oxide (ITO) and is used for inputting external power supply signals.

[0014] The top electrode is a noble metal, and the weight ratio of PEDOT to PSS in the conjugated polymer organic functional layer is 1:2.5.

[0015] Organic memristors that achieve bidirectional unipolarity can apply corresponding modulation voltages or modulation pulses to the functional layer through the top electrode layer and the bottom electrode layer to induce ion transport and achieve regulation of bidirectional unipolar function. Specifically:

[0016] The voltage regulation is achieved by using an I / V voltage scanning method to perform positive and negative voltage regulation on the memristor unit. Specifically:

[0017] The method for controlling the forward unipolar write voltage is as follows: take 0V as the starting voltage and 8V or higher as the stopping voltage during the forward I / V voltage scan, keep the scan point interval between 0.5 and 1.5, and the step voltage between 0.005 and 0.05 to scan the memristor cell.

[0018] The method for controlling the forward unipolar erase voltage is as follows: take 0V as the starting voltage and 7V or less as the stopping voltage during the forward I / V voltage scan, keep the scan point interval between 0.5 and 1.5, and the step voltage between 0.005 and 0.05 to scan the memristor cell;

[0019] The method for controlling the negative unipolar write voltage is as follows: take 0V as the starting voltage and a voltage less than or equal to -8V as the stopping voltage during the negative I / V voltage scan, keep the scan point interval between 0.05 and 1.5, and the step voltage between 0.005 and 0.05 to scan the memristor cell.

[0020] The method for controlling the negative unipolar erase voltage is as follows: take 0V as the starting voltage and a voltage greater than or equal to -7V as the stopping voltage during the negative I / V voltage scan, keep the scan point interval between 0.5 and 1.5, and the step voltage between 0.005 and 0.05 to scan the memristor unit.

[0021] By adjusting the operating voltage, step voltage, and scan point interval, the magnitude of the oxygen ion flux transported in a single operation was precisely controlled, thus constructing an ion transport mechanism with high-voltage writing and low-voltage suppression, achieving unipolar regulation.

[0022] The memristor unit is controlled by positive and negative pulses using a pulse scanning method, specifically as follows:

[0023] When the memristor unit is positively pulse-controlled using a pulse scanning method, the pulse width is 20ms to 100ms, the pulse adjustment interval is 20ms to 100ms, and the step voltage is 0.005-0.05.

[0024] When the memristor unit is negatively pulse-controlled using a pulse scanning method, the pulse width is 20ms to 100ms, the pulse adjustment interval is 20ms to 100ms, and the step voltage is 0.005-0.05.

[0025] By adjusting the pulse width and pulse adjustment step size, the content of oxygen ions in the oxide can be better matched. The number of oxygen ions determines the distance between adjacent oxygen vacancies, thereby finely controlling the energy required for conductivity transport and achieving unipolar control.

[0026] A further improvement of the present invention is that, for the organic memristor, the modulation voltage and current are denoted as V. t ,

[0027] When V t At ≥8V, the organic memristor exhibits a current level that increases with each scan cycle, demonstrating positive write storage characteristics; after pulse stimulation, the current level after each subsequent pulse stimulation is higher than that after the previous pulse stimulation, which can simulate the excitation characteristics in biological synapses.

[0028] When V t At ≤7V, the organic memristor exhibits a forward erasure characteristic where the current level decreases with each scan cycle. After pulse stimulation, the current level after each subsequent pulse stimulation is lower than that after the previous pulse stimulation, which can simulate the inhibitory characteristics in biological synapses.

[0029] When V t At ≤-8V, the organic memristor exhibits a negative write characteristic where the current level increases with each scan cycle. After pulse stimulation, the current level after each subsequent pulse stimulation is higher than that after the previous pulse stimulation, which can simulate the excitation characteristics in biological synapses.

[0030] When V t At ≥-7V, the organic memristor exhibits a negative erasure characteristic, with the current level decreasing with each scan cycle. After pulse stimulation, the current level after each subsequent pulse stimulation is higher than that after the previous pulse stimulation, which can simulate the inhibitory characteristics in biological synapses.

[0031] The beneficial effects of this invention are:

[0032] 1. This invention achieves bidirectional symmetrical unipolar modulation by limiting the operating voltage, thereby improving its application capabilities.

[0033] 2. This invention achieves bidirectional symmetrical unipolar pulse modulation by changing the stimulation pulse, adjusting the pulse width and interval duration.

[0034] 3. This invention uses the method of regulating ion transport to regulate the movement of charge carriers inside the memristor, which is easier to regulate by adjusting the voltage or the pulse width.

[0035] 4. Because it uses conjugated polymer materials dominated by ion transport, it can switch between different functions in the positive and negative directions by modulating the working voltage or pulse stimulation, which is more promising than unidirectional bipolar materials.

[0036] 5. By improving the device structure, instead of adopting the traditional memristor sandwich structure, the consistency and reconfigurability of the device are guaranteed.

[0037] 6. The memristor provided by this invention improves the stability of organic memristor devices through atomic layer deposition technology and effectively reduces the operating current, making low-power application scenarios and neuromorphic computing possible.

[0038] The organic memristor obtained based on this invention can change the internal carrier transport by changing the operating voltage or pulse of the device, thereby realizing the positive and negative unipolar control characteristics induced by oxygen ions in the device, which has great value in neuromorphic computing and biological synapse simulation. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the organic memristor device structure of the present invention.

[0040] Figure 2 This is a continuous current-voltage curve of the organic memristor of the present invention when a positive voltage of 3V is applied.

[0041] Figure 3 This is a continuous current-voltage curve of the organic memristor of the present invention when a positive voltage of 10V is applied.

[0042] Figure 4 This is a continuous current-voltage curve of the organic memristor of the present invention when a negative -3V voltage is applied.

[0043] Figure 5 This is a continuous current-voltage curve of the organic memristor described in this invention when a negative -10V voltage is applied.

[0044] Figure 6 This is a diagram showing the dual-pulse facilitation characteristics of the organic memristor of this invention under a positive 8V pulse stimulus.

[0045] Figure 7 This is a diagram showing the double-pulse suppression characteristics of the organic memristor of this invention under a positive 7V pulse stimulus.

[0046] Figure 8 This is a diagram showing the dual-pulse facilitation characteristics of the organic memristor described in this invention when subjected to a negative -9V pulse stimulus.

[0047] Figure 9 This is a diagram showing the dual-pulse suppression characteristics of the organic memristor described in this invention when subjected to a negative -7V pulse stimulus. Detailed Implementation

[0048] The embodiments of the present invention will be disclosed below with reference to the drawings. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details are not intended to limit the invention. That is, in some embodiments of the invention, these practical details are not essential.

[0049] like Figure 1 As shown, this invention provides a bidirectional unipolar voltage-controlled organic memristor, which comprises a four-layer structure, consisting of a bottom electrode layer, a conjugated polymer organic functional layer, an inorganic resistive switching layer, and a top electrode, from bottom to top. The conjugated polymer organic functional layer is a PEDOT:PSS organic functional layer that has undergone low-temperature annealing, with a PEDOT to PSS weight ratio of 1:2.5. The top electrode is a noble metal, and the bottom electrode is indium tin oxide (ITO). The inorganic resistive switching layer material is non-stoichiometric alumina (AlO2). x Hafnium oxide (HfO) x Titanium oxide (TiO) x , where x is greater than 0, and the thickness of the inorganic resistive switching layer is 50-200nm.

[0050] In the bidirectional unipolar voltage-controlled organic memristor fabrication method of the present invention, a specific organic memristor device is designed and fabricated by means of layer stacking. The fabrication steps include: fabricating an organic functional layer on the indium tin oxide bottom electrode, then fabricating an inorganic resistive switching layer metal oxide on the organic functional layer, and finally fabricating a metal top electrode on the inorganic resistive switching layer. Figure 1 To fabricate the structure of a bidirectional unipolar voltage-controlled organic memristor device, specifically taking alumina as the inorganic resistive switching layer as an example, the fabrication method of the aforementioned bidirectional unipolar voltage-controlled organic memristor includes the following steps:

[0051] I. Substrate Preprocessing

[0052] (1) First, the indium tin oxide bottom electrode is cleaned by acetone, ethanol and deionized water respectively. That is, it is cleaned by oscillating in an ultrasonic cleaner at 100 kHz, power 50-90% and temperature 0-20℃ for 5-15 minutes.

[0053] (2) After cleaning, use a nitrogen gun to blow the indium tin oxide substrate until the surface moisture is dried;

[0054] (3) Place the substrate dried with a nitrogen gun into an electric heating drying oven and dry it at a temperature of 90-120℃ for 20-40 minutes.

[0055] (4) Place the dried substrate into a UV ozone cleaner and clean for 5-15 minutes;

[0056] II. Preparation of Organic Functional Layer Thin Films by Solution Spin Coating

[0057] (1) Pretreatment of the organic conjugated polymer PEDOT:PSS solution: First, stir continuously on a magnetic stirring platform for 30-60 minutes; then filter using a polytetrafluoroethylene filter head with a pore size of 0.45μm to remove impurities from the PEDOT:PSS solution.

[0058] (2) Prepare PEDOT:PSS organic functional layer by solution spin coating at a speed of 1000-6000 rpm for 20-60 seconds;

[0059] (3) After spin coating, anneal at 80-120℃ for 20-40 minutes in a vacuum electric heating drying oven to prepare PEDOT:PSS organic functional layer film.

[0060] III. Preparation of Inorganic Resistive Switching Thin Films using Atomic Layer Deposition System

[0061] (1) A non-stoichiometric oxide film is obtained as an inorganic resistive switching layer by a thermal atomic layer deposition thin film preparation system. First, the atomic layer deposition film is degassed, and then the coating chamber is heated to 20-100℃. The film formed in step three is placed in the coating chamber.

[0062] (2) After the thin film is placed in the coating chamber, the chamber is heated to 150-200℃ and waited for 30-60 minutes until the temperature jumps and stabilizes.

[0063] (3) The trimethylaluminum precursor source in the thermal atom deposition equipment is deposited onto the substrate surface through the trimethylaluminum precursor ALD valve for 10-20ms to obtain the trimethylaluminum precursor.

[0064] (4) Use inert nitrogen gas to clean the trimethylaluminum precursor for 15-20 seconds.

[0065] (5) The deionized water precursor in the deionized water precursor source bottle in the thermal atom deposition equipment is introduced into the trimethylaluminum precursor through the deionized water precursor ALD valve for 15ms to obtain a non-stoichiometric alumina film with a thickness of 0.010-0.015nm.

[0066] (6) Use inert nitrogen gas to clean the deionized water precursor for 15-20 seconds.

[0067] (7) Repeat the above steps 70-90 times to obtain a non-stoichiometric thin film with a thickness of about 5-20 nm;

[0068] (8) While maintaining the chamber temperature at 150°C, perform high-temperature annealing for 30-60 minutes.

[0069] (9) After annealing, the temperature of the coating chamber is reduced to 20-100℃ and allowed to stabilize.

[0070] (10) Remove the film and shut down the atomic layer deposition system.

[0071] IV. Preparation of Top Electrode using Vacuum Evaporation Coating Technology

[0072] (1) Place the thin film formed in step four into a vacuum evaporation coating equipment and add a metal source;

[0073] (2) The vacuum degree of the vacuum evaporation equipment is controlled at 5×10. -4 pa, evaporation rate at An aluminum electrode with a thickness of approximately 90-150 nm was obtained by evaporating metal and using a strip patterned mask.

[0074] (2) Under the premise of maintaining the original vacuum pressure, complete the annealing treatment of the top electrode film, and the annealing time is 20-50 minutes;

[0075] (3) Remove the substrate from the vacuum evaporation coating equipment to obtain the organic memristor described in this invention.

[0076] Memristors are typically used to simulate synaptic function, where the upper and lower electrodes act as the anterior and posterior synapses, respectively, and the operating current of the device acts as the synaptic weight for signal transmission. In other words, memristors can simulate the excitation and inhibition processes of biological synapses. Bidirectional unipolarity indicates that unipolar voltage modulation of synaptic weights can be achieved both in the positive and negative directions, achieving the same performance.

[0077] Figure 2The image shows the current-voltage characteristics of a bidirectional unipolar voltage-controlled organic memristor under 10 consecutive 3V forward voltage scans. It can be observed that the current level gradually decreases with increasing scan count, exhibiting multi-stage switching characteristics. After 10 3V forward voltage scans, the current level is between 5-20μA, and the current-voltage curve is stable, indicating that the device has low power consumption.

[0078] Figure 3 The image shows the current-voltage characteristics of a bidirectional unipolar voltage-controlled organic memristor under 10 consecutive 10V forward voltage scans. It can be seen that the device does not exhibit a sudden increase in current level; rather, the current level gradually increases with the number of scans, demonstrating multi-stage switching characteristics. After 10 10V forward voltage scans, the current level ranges from 50-300μA, and the current-voltage curve remains stable, indicating that the device has low power consumption characteristics.

[0079] Figure 4 The diagram shows the current-voltage characteristics of a bidirectional unipolar voltage-controlled organic memristor under 10 consecutive -3V forward voltage scans. As the number of scans increases, the current level gradually decreases, exhibiting multi-stage switching characteristics. After 10 consecutive scans, its response current level is approximately 0.6-2μA, and the current-voltage curve remains stable, demonstrating low power consumption.

[0080] Figure 5 This is a unipolar voltage-controlled current-voltage characteristic curve of a bidirectional unipolar voltage-controlled organic memristor under 10 consecutive -10V forward voltage scans. As the number of scans increases, the current level of the device gradually increases, exhibiting multi-stage switching characteristics. After 10 10V forward voltage scans, the current level is between 2-15μA, and the current-voltage curve is stable without sudden increases or decreases in current, consistent with the characteristics of analog memristors.

[0081] Figure 6 This is a unipolar pulse modulation diagram, showing the dual-pulse facilitation characteristics of an organic memristor with bidirectional unipolar pulse modulation under two consecutive 8V positive pulse stimuli. As the number of stimulations increases, the current level of the device increases, which can simulate the excitation characteristics of biological synapses.

[0082] Figure 7 The diagram shows the unipolar pulse modulation characteristic of an organic memristor with bidirectional unipolar pulse modulation under two consecutive 7V positive pulse stimuli. As the number of stimulations increases, the current level of the device decreases, which can simulate the biological synaptic inhibition characteristics.

[0083] Figure 8This is a unipolar pulse modulation diagram, showing the dual-pulse facilitation characteristics of an organic memristor with bidirectional unipolar pulse modulation under two consecutive -9V positive pulse stimuli. As the number of stimulations increases, the current level of the device increases, which can simulate the excitation characteristics of biological synapses.

[0084] Figure 9 The diagram shows the unipolar pulse modulation characteristic of an organic memristor with bidirectional unipolar pulse modulation under two consecutive -7V positive pulse stimuli. As the number of stimulations increases, the current level of the device decreases, which can simulate the biological synaptic inhibition characteristics.

[0085] Therefore, it can be concluded that under positive and negative voltage scans of ±3V, the current level of this device decreases, exhibiting erase characteristics; under positive and negative voltage scans of ±10V, the current level increases, exhibiting write characteristics. This achieves bidirectional unipolar voltage regulation. Under bidirectional high voltages, the current gradually increases, simulating the excitation characteristics of biological synapses; under bidirectional low voltages, the current gradually decreases, simulating the inhibition characteristics of biological synapses.

[0086] In summary, this device can achieve bidirectional unipolar control.

[0087] The bidirectional unipolar control method of the present invention takes a bidirectional unipolar voltage-controlled organic memristor as the target, and constructs an ion conduction mechanism by inducing oxygen ion transport through voltage regulation or pulse scanning to achieve bidirectional unipolar voltage regulation.

[0088] The voltage regulation is achieved by using an I / V voltage scanning method to perform positive and negative voltage regulation on the memristor unit.

[0089] The following is a method for positive and negative voltage regulation of the organic memristor prepared in Example 1 using an I / V voltage scanning method, specifically including the following steps:

[0090] (1) Select a memristor unit and attach two probes to the top electrode and bottom electrode regions respectively. The probe connected to the top electrode is grounded, and a positive voltage is applied to the probe connected to the bottom electrode. The positive voltage scanning range is 2 to 10V, and the current Icc is limited to 1μA-10mA.

[0091] (2) Perform 10 forward I / V scans on the memristor unit, with a scan range of 0V-3V, a step voltage of 0.01V, and a forward scan current limit of Icc = 100μA.

[0092] (3) Perform 10 forward I / V scans on the memristor unit, with a scan range of 0V-10V and a step of 0.01V. The forward scan current limit is Icc = 10mA.

[0093] (4) Select the same memristor unit as described above, and attach the two probes to the top electrode and bottom electrode areas respectively. The probe connected to the top electrode is grounded, and the probe connected to the bottom electrode is given a positive voltage. The negative voltage scanning range is -2 to -10V, and the current Icc is limited to 1μA-10mA.

[0094] (5) Perform 10 forward IV scans on the memristor unit, with a scan range of 0V-(-3)V and a step of 0.01V. The forward scan current limit is Icc = 100μA.

[0095] (6) Perform 10 forward IV scans on the memristor unit, with a scan range of 0V-(-10)V and a step of 0.01V. The forward scan current limit is Icc = 10mA.

[0096] The following is a method for positive and negative voltage regulation of the organic memristor prepared in Example 1 using a pulse scanning method, specifically including the following steps:

[0097] (1) Select a memristor unit and attach the two probes to the top electrode and bottom electrode areas respectively. The probe connected to the top electrode is grounded, and the probe connected to the bottom electrode is given a positive voltage.

[0098] (2) The pulse width was adjusted to 100ms, the pulse step to 0.005-0.05, and the pulse interval to 20ms-100ms, and the memristor unit was scanned. The pulse start size was 0.5-3V, the pulse end size was 2-7V, and the current limit was 1mA. It showed that after the second pulse stimulation, the current level was lower than that after the first pulse stimulation, simulating the characteristics of biological synaptic inhibition.

[0099] (3) The pulse width was adjusted to 100ms, the pulse step to 0.005-0.05, and the pulse interval to 20ms-100ms, and the memristor unit was scanned. The pulse start size was 0.5-3V, the pulse end size was 8-10V, and the current limit was 1mA. It showed that after the second pulse stimulation, the current level was higher than that after the first pulse stimulation, simulating the excitation characteristics of biological synapses.

[0100] (4) The pulse width was adjusted to 100ms, the pulse step to 0.005-0.05, and the pulse interval to 20ms-100ms, and the memristor unit was scanned. The pulse start size was 0.5-3V, the pulse end size was (-2)-(-7)V, and the current limit was 1mA. It showed that after the second pulse stimulation, the current level was lower than that after the first pulse stimulation, simulating the characteristics of biological synaptic inhibition.

[0101] (5) The pulse width was adjusted to 100ms, the pulse step to 0.005-0.05, and the pulse interval to 20ms-100ms, and the memristor unit was scanned. The pulse start size was 0.5-3V, the pulse end size was (-8)-(-10)V, and the current limit was 1mA. The result showed a higher current level after the second pulse stimulation than after the first pulse stimulation, simulating the excitation characteristics of biological synapses.

[0102] This invention provides a bidirectional unipolar voltage-controlled memristor by regulating oxygen ion transport in the inorganic resistive switching layer and the organic functional layer. Based on oxygen ion modulation, this memristor allows for precise control of oxygen ion transport in the functional layer through simple voltage regulation or pulse scanning methods, thereby constructing an ion conduction mechanism and achieving bidirectional unipolar regulation. By extracting the conductance states of the memristor, unipolar multi-valued storage is achieved; furthermore, the memristor can be used to simulate the function of neuronal synapses.

[0103] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A bidirectional unipolar control method based on organic memristors, characterized in that: This control method targets a bidirectional unipolar voltage-controlled organic memristor. It constructs an ion conduction mechanism by inducing oxygen ion transport through voltage regulation or pulse scanning to achieve bidirectional unipolar voltage regulation. The bidirectional unipolar voltage-controlled organic memristor comprises a four-layer structure, consisting of a bottom electrode layer, a conjugated polymer organic functional layer, an inorganic resistive switching layer, and a top electrode, from bottom to top. The conjugated polymer organic functional layer is a PEDOT:PSS organic functional layer that has undergone low-temperature annealing. The inorganic resistive switching layer is an oxide thin film. The top electrode is a noble metal, and the bottom electrode is indium tin oxide (ITO). For the organic memristor, let the modulation voltage and current be V. t , When V t At ≥8V, the organic memristor exhibits a current level that increases with each scan cycle, demonstrating positive write storage characteristics; after pulse stimulation, the current level after each subsequent pulse stimulation is higher than that after the previous pulse stimulation, which can simulate the excitation characteristics in biological synapses. When V t At ≤7V, the organic memristor exhibits a forward erasure characteristic where the current level decreases with each scan cycle. After pulse stimulation, the current level after each subsequent pulse stimulation is lower than that after the previous pulse stimulation, which can simulate the inhibitory characteristics in biological synapses. When V t At ≤-8V, the organic memristor exhibits a negative write characteristic where the current level increases with each scan cycle. After pulse stimulation, the current level after each subsequent pulse stimulation is higher than that after the previous pulse stimulation, which can simulate the excitation characteristics in biological synapses. When V t At ≥-7V, the organic memristor exhibits a negative erasure characteristic, with the current level decreasing with each scan cycle. After pulse stimulation, the current level after each subsequent pulse stimulation is higher than that after the previous pulse stimulation, which can simulate the inhibitory characteristics in biological synapses.

2. The bidirectional unipolar control method based on organic memristors according to claim 1, characterized in that: The voltage modulation range is positive voltage +2V to +10V and negative voltage -2V to -10V.

3. The bidirectional unipolar control method based on organic memristors according to claim 2, characterized in that: Voltage regulation is employed by using an I / V voltage scanning method to perform positive and negative voltage regulation on the memristor unit. Specifically: The method for controlling the forward unipolar write voltage is as follows: take 0V as the starting voltage and 8V or higher as the stopping voltage during the forward I / V voltage scan, keep the scan point interval between 0.5 and 1.5, and the step voltage between 0.005 and 0.05 to scan the memristor cell. The method for controlling the forward unipolar erase voltage is as follows: take 0V as the starting voltage and 7V or less as the stopping voltage during the forward I / V voltage scan, keep the scan point interval between 0.5 and 1.5, and the step voltage between 0.005 and 0.05 to scan the memristor cell; The method for controlling the negative unipolar write voltage is as follows: take 0V as the starting voltage and a voltage less than or equal to -8V as the stopping voltage during the negative I / V voltage scan, keep the scan point interval between 0.05 and 1.5, and the step voltage between 0.005 and 0.05 to scan the memristor cell. The method for controlling the negative unipolar erase voltage is as follows: take 0V as the starting voltage and a voltage greater than or equal to -7V as the stopping voltage during the negative I / V voltage scan, keep the scan point interval between 0.5 and 1.5, and the step voltage between 0.005 and 0.05 to scan the memristor unit.

4. The bidirectional unipolar control method based on organic memristors according to claim 1, characterized in that: The memristor unit is controlled by positive and negative pulses using a pulse scanning method, specifically as follows: When the memristor unit is positively pulse-controlled using a pulse scanning method, the pulse width is 20ms to 100ms, the pulse adjustment interval is 20ms to 100ms, and the step voltage is 0.005-0.

05. When the memristor unit is negatively pulse-controlled using a pulse scanning method, the pulse width is 20ms to 100ms, the pulse adjustment interval is 20ms to 100ms, and the step voltage is 0.005-0.

05.

5. The bidirectional unipolar control method based on organic memristors according to claim 1, characterized in that: The inorganic resistive switching layer material is non-stoichiometric alumina (AlO₂). x Hafnium oxide (HfO) x Titanium oxide (TiO) x , where x is greater than 0.

6. The bidirectional unipolar control method based on organic memristors according to claim 5, characterized in that: The thickness of the inorganic resistive switching layer is 50-200 nm.

7. The bidirectional unipolar control method based on organic memristors according to claim 1, characterized in that: The weight ratio of PEDOT to PSS in the conjugated polymer organic functional layer is 1:2.5.

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