Memristor and method for manufacturing the same

Abstract

The application discloses a memristor and a preparation method thereof. A dielectric layer is obtained by containing a biomaterial-based colloid, high-value utilization of the biomaterial is realized, the dielectric layer is applied to the memristor, and the effect that the memristor still maintains stable memristor effect at a high scanning speed is realized. In addition, by controlling the scanning speed, the conversion between the device memristor effect and the rectification effect can be realized, which helps to widen the multi-scene application of the electronic device in the future.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of memory manufacturing, and relates to a memristor and a preparation method thereof. BACKGROUND

[0002] Under the background of rapid development of digitization and informatization, the computing and storage electronic devices based on the traditional von Neumann architecture have been difficult to meet the demand of people for low power consumption, large storage and high operation rate. This is due to the fact that the architecture cannot realize the synchronization of operation and storage, which is also a characteristic problem that limits its further development. In addition, the electronic devices carrying the architecture under Moore's law have approached the physical limit. Inspired by the human brain, developing neuromorphic computing by simulating the structure of human brain synapses is expected to solve this problem.

[0003] Memristor, also known as memristor, has a structure very similar to that of human brain synapses. This device is used to represent the relationship between magnetic flux and charge. It is worth noting that its resistance is determined by the charge passing through it, which means that the device has the ability to resist memory. In other words, if the continuous switching of high and low resistance states (corresponding to logic "1" and "0", respectively) of the memristor is controlled by controlling the current, the storage of data can be realized. Since Hewlett-Packard researchers published an article entitled "Finding the Missing Memristor" in the journal Nature in 2008, the preparation and application of memristors have been widely studied by scholars and enterprises at home and abroad.

[0004] In terms of structure, the memristor is mainly composed of upper and lower conductive layers and an intermediate functional layer. The material and characteristics of the functional layer determine the performance of the memristor to a great extent. However, most memristors are made of inorganic materials, which are usually expensive, non-biocompatible and non-degradable, making it difficult to be used for the preparation of implantable devices and to be naturally degraded.

[0005] In addition, in the research on memristors, it is necessary to improve the response rate while maintaining the memristive effect and to broaden the application scenarios, which will greatly improve the wide applicability of this basic electronic device.

[0006] In view of the above reasons, it is urgent to propose a memristor with excellent performance. SUMMARY

[0007] In order to overcome the above problems, the present inventors have made intensive research and have developed a memristor and a preparation method thereof, so as to obtain a dielectric layer containing a biomaterial-based colloid, to realize high-value utilization of biomaterials, and to apply the dielectric layer to a memristor, so as to realize the effect that the memristor still maintains stable memristor effect at a high scanning rate. In addition, the conversion between the device memristor effect and the rectification effect can be realized by controlling the scanning rate, which helps to broaden the multi-scene application of electronic devices in the future, thereby completing the present application.

[0008] Specifically, the present application aims to provide the following aspects:

[0009] In a first aspect, a dielectric layer material containing a biomaterial-based colloid containing a polyphenolic compound is provided.

[0010] The biomaterial-based colloid includes a biomaterial, which is a plant-derived pericarp, root, leaf and / or fruit containing a polyphenolic compound.

[0011] The biomaterial-based colloid further includes a thermoplastic fluoropolymer, and the mass ratio of the biomaterial to the thermoplastic fluoropolymer is (0.5-3):1, preferably (1-2):1.

[0012] When the dielectric layer material is used to prepare a dielectric layer in contact with an electrode, the dielectric layer includes a biomaterial-based colloid layer and an insulating layer.

[0013] In a second aspect, a preparation method of a dielectric layer is provided, which includes:

[0014] Step 1: preparing a biomaterial-based colloid to form a biomaterial-based colloid layer;

[0015] Step 2: coating an insulating layer on the surface of the biomaterial-based colloid layer to obtain the dielectric layer;

[0016] The biomaterial-based colloid includes a biomaterial, which is a plant-derived pericarp, root, leaf and / or fruit containing a polyphenolic compound.

[0017] In step 1, the prepared biomaterial-based colloid contains a polyphenolic compound.

[0018] The step 1 includes the following sub-steps:

[0019] Step 1-1: preparing a biomaterial into a fine powder-shaped biomaterial;

[0020] Step 1-2: dissolving the fine powder-shaped biomaterial in an organic solvent to obtain a premix;

[0021] Step 1-3: mixing the premix with a thermoplastic fluoropolymer to obtain the biomaterial-based colloid.

[0022] In a third aspect, a biomaterial-based colloid containing a polyphenolic compound is provided.

[0023] In a fourth aspect, a memristor is provided, wherein a dielectric layer of the memristor is made of the dielectric layer material of the first aspect.

[0024] The memristor further comprises an upper electrode and a lower electrode, and the dielectric layer is sandwiched between the upper electrode and the lower electrode.

[0025] In a fifth aspect, a method for preparing a memristor is provided, the method comprising:

[0026] Step I: coating a dielectric layer on a surface of a lower electrode;

[0027] Step II: plating an upper electrode on a surface of the dielectric layer to obtain the memristor.

[0028] In Step I, the dielectric layer contains a biomaterial-based colloid, and the biomaterial-based colloid contains a polyphenolic compound.

[0029] The present application has the following beneficial effects:

[0030] (1) The dielectric layer provided by the present application contains a biomaterial-based colloid, which not only realizes high-value utilization of biomaterials, but also applies biomaterials to a memristor, and the obtained memristor has fast response at high scanning rate.

[0031] (2) The biomaterial-based colloid in the dielectric layer provided by the present application is combined with a thermoplastic fluoropolymer, and the obtained memristor can maintain stable memristor effect at high scanning rate.

[0032] (3) The memristor provided by the present application can realize the conversion between the device memristor effect and the rectification effect by controlling the scanning rate, which helps to broaden the application of electronic devices in multiple scenarios in the future. BRIEF DESCRIPTION OF DRAWINGS

[0033] Various other advantages and benefits of the present application will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included solely for purposes of illustrating the preferred embodiments and are not to be construed as a limitation of the present application. It should be readily understood that the drawings depicted are only some embodiments of the present application and that any other drawings similarly drawn can be derived from the attached drawings without employing creative faculty.

[0034] In the drawings:

[0035] Figure 1(a) shows the current-voltage (I-V) characteristic curve of the Cu / insulating layer / Ti structure memristor prepared in Comparative Example 1 under a scanning voltage of -1V~1V and a scanning rate of 4V / S, after 100 cycles of testing;

[0036] Figure 1(b) shows the current-voltage (I-V) characteristic curve of the Cu / biomaterial-based colloid layer / Ti structure memristor prepared in Comparative Example 2 under a scanning voltage of -1V~1V and a scanning rate of 4V / S, after 100 cycles of testing;

[0037] Figure 2(a) shows the current-voltage (I-V) characteristic curve of the memristor prepared in Example 1 under a scanning voltage of -1V~1V and a scanning rate of 4V / S, after 100 cycles of testing;

[0038] Figure 2(b) shows the log (I) and V characteristic curve in the logarithmic scale of the first cycle of testing in Figure 2(a);

[0039] Figure 3(a) shows the current-voltage (I-V) characteristic curve of the memristor prepared in Example 1 under a scanning voltage of -1V~1V and a scanning rate of 3V / S;

[0040] Figure 3(b) shows the current-voltage (I-V) characteristic curve of the memristor prepared in Example 1 under a scanning voltage of -1V~1V and a scanning rate of 4V / S;

[0041] Figure 3(c) shows the current-voltage (I-V) characteristic curve of the memristor prepared in Example 1 under a scanning voltage of -1V~1V and a scanning rate of 5V / S;

[0042] Figure 4(a) shows the high-low resistance state cycle 100 times graph of the memristor prepared in Example 1 under a scanning rate of 4V / S;

[0043] Figure 4(b) shows the HRS / LRS ratio cycle times box plot of the memristor prepared in Example 1. DETAILED DESCRIPTION

[0044] Specific embodiments of the present application will be described in greater detail below with reference to the accompanying drawings. Although specific embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present application can be more thoroughly understood and so that the scope of the present application can be completely conveyed to those skilled in the art.

[0045] It should be noted that some terms are used in the description and claims herein throughout. It is to be understood that a person skilled in the art can use different names to refer to the same component. The description and claims herein do not take the difference in names as a way to distinguish components, but take the difference in functions of components as the criterion for distinction. As mentioned throughout the description and claims, "including" or "comprising" is an open term, which should be interpreted as "including but not limited to". The subsequent description is a preferred embodiment for implementing the present application, and the description is for the purpose of illustrating the general principles of the present application, but not to limit the scope of the present application. The scope of protection of the present application is defined by the appended claims.

[0046] In the description of the present application, it should be noted that the terms "upper", "lower", "inner", "outer", "front", "back", etc. indicate the orientation or positional relationship in the working state of the present application, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third", "fourth" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0047] In order to facilitate the understanding of the embodiments of the present application, the following will be further explained and described with specific examples in conjunction with the accompanying drawings, and each drawing does not constitute a limitation on the embodiments of the present application.

[0048] In a first aspect, a dielectric layer material is provided, which contains a biomaterial-based colloid, and the biomaterial-based colloid contains a polyphenol compound.

[0049] Further, the biomaterial-based colloid includes a biomaterial, and the biomaterial is a plant-derived pericarp, root, leaf and / or fruit rich in polyphenol compounds, such as papaya peel.

[0050] In the prior art, it is difficult for a memristor to be suitable for the preparation of implantable devices and to be naturally degraded, and the memristive effect is poor or unstable. It may be a new idea to apply environmentally friendly and renewable biomaterials to memristors to improve the performance of memristors, which will greatly reduce the manufacturing cost of memristors and will not cause environmental problems.

[0051] The inventors surprisingly found that a biomaterial-based colloid obtained from a biomaterial, in particular a papaya skin-based colloid obtained from papaya skin, has excellent performance of a memristor, that is, stable memristor effect is maintained even at a high scanning rate; in addition, a rectification effect is exhibited at a specific scanning rate, and such a device for regulating the memristor effect and the rectification effect based on the scanning rate has a wide prospect in the multi-scene application of future electronic devices. It is obvious that obtaining a biomaterial-based colloid from a biomaterial can solve the problem of accumulation of biomaterial waste, is low in cost and easy to operate, is biodegradable and renewable, and can recycle valuable products as much as possible, thereby achieving harmless disposal and reuse of biomaterials.

[0052] According to the present application, the biomaterial-based colloid further comprises a thermoplastic fluoropolymer. Wherein, the biomaterial-based colloid prepared by taking the biomaterial as a matrix and the thermoplastic fluoropolymer as a colloidal dispersion is beneficial to enhancing the adhesion between the biomaterial and the lower electrode and the insulating layer.

[0053] Further, the thermoplastic fluoropolymer is selected from any one or several of polyvinylidene fluoride, carboxymethyl cellulose, and butadiene-styrene rubber emulsion, and is preferably polyvinylidene fluoride.

[0054] According to the present application, the thermoplastic fluoropolymer has good mechanical strength and toughness, can be used for a long time and basically maintains its performance in a wide temperature range, is easy to film, and has good chemical stability, temperature stability, excellent mechanical properties and processability. In particular, the thermoplastic fluoropolymer represented by polyvinylidene fluoride has properties such as heat resistance, chemical resistance and ultraviolet resistance, and the alternating arrangement of CH2 and CF2 groups on the chain segment of polyvinylidene fluoride also endows polyvinylidene fluoride with unique polarity and affects the solubility and dielectric properties.

[0055] According to the present application, the mass ratio of the biomaterial and the thermoplastic fluoropolymer is (0.5-3):1, preferably (1-2):1, and more preferably 1:1.

[0056] In the present application, the biomaterial-based colloid is prepared by comprising the following steps:

[0057] Step 1-1, preparing the biomaterial into a fine powder-shaped biomatrix;

[0058] Step 1-2, dissolving the fine powder-shaped biomatrix in an organic solvent to obtain a premix;

[0059] Step 1-3, mixing the premix with a thermoplastic fluoropolymer to prepare the biomaterial-based colloid.

[0060] In step 1-1, the biological material is a plant-derived peel, root, leaf and / or fruit rich in polyphenols, for example, papaya peel.

[0061] In step 1-1, the biological material is a biological material matured in the same harvest period. For example, the papaya peel is the peel of a greenish-yellow papaya picked in the same harvest period.

[0062] In step 1-1, the biological material is ball milled to obtain a fine powder-like biological matrix.

[0063] In step 1-1, the ball milling process directly affects the fine powder-like biological matrix.

[0064] The ball loading amount is determined according to the required ball milling efficiency to achieve the best impact and grinding state. Too high or too low ball loading amount will directly affect the ball milling process of the fine powder-like biological matrix. Preferably, the ball-to-material weight ratio is 30-70:1, more preferably, the ball-to-material weight ratio is 40-60:1, for example, the ball-to-material weight ratio is 50:1.

[0065] In step 1-1, the ball milling power is 30-60W, preferably 35-50W, and more preferably 40W.

[0066] According to the present application, ball milling is a centrifugal motion. When the ball milling power is too low, the test requirements cannot be met, and the quality of the biological material-based gel obtained is low. When the ball milling power is too high, the balls do not move towards each other, and the material cannot be stirred or broken. When the ball milling power is 30-60W, especially 40W, stirring and breaking can be performed simultaneously.

[0067] In step 1-1, the ball milling time is 20-60min, preferably 25-40min, and more preferably 30min.

[0068] According to the present application, to improve the dispersion degree and physical and mechanical properties of the fine powder-like biological matrix, the appropriate ball milling time is very important. With the extension of the ball milling time, the dispersion of the fine powder-like biological matrix becomes more and more uniform, and the particles become smaller due to the ball milling effect. If the ball milling time is too long, the activity of the fine powder-like biological matrix will continuously increase during the ball milling process, the ball milling efficiency will decrease, and the work hardening will be serious. Therefore, it is not desirable to excessively prolong the ball milling time.

[0069] According to the present application, in order to quickly and efficiently prepare the biological material into a fine powder-like biological matrix, the biological material is preferably washed, dried, ground and sieved before ball milling.

[0070] The collected biological material can be washed with water.

[0071] Further, the temperature and time for drying the biological material are not particularly limited as long as the biological material can be dried. Generally, the temperature for drying is 38-60 °C, preferably 40-50 °C, for example 45 °C; and the time for drying is 6-18 h, preferably 8-12 h, for example 10 h.

[0072] In step 1-1, the grinding method can be manual grinding or mechanical grinding, preferably simple and easy mechanical grinding.

[0073] In step 1-1, the biological material is ground into powder and then sieved through a 40-120 mesh sieve to obtain a biological material powder with uniform particle size. Preferably, the biological material is sieved through a 50-80 mesh sieve, for example, a 60 mesh sieve. Grinding and sieving the biological material first facilitates obtaining a powder of uniform size.

[0074] In step 1-2, the organic solvent is any one or several of N-methyl pyrrolidone, carboxymethyl cellulose, and styrene-butadiene rubber emulsion, preferably N-methyl pyrrolidone.

[0075] The organic solvent disperses the biological material, which is beneficial to improving the dispersibility of the biological material in the thermoplastic fluoropolymer later, and the organic solvent represented by N-methyl pyrrolidone has high temperature resistance and oxidation resistance.

[0076] In step 1-2, the ratio of the mass of the fine powder of the biological matrix to the volume of the organic solvent (w / v) is 0.6%-1.2%, preferably 0.7-1%, more preferably 0.8%. As the volume of the organic solvent increases, the dispersibility of the fine powder of the biological matrix becomes more uniform, but excessive organic solvent will increase the workload of subsequent processes such as vacuum filtration and centrifugal processing.

[0077] In step 1-2, in order to accelerate the solubility of the fine powder of the biological matrix in the organic solvent and dissolve as much of the fine powder of the biological matrix as possible in the organic solvent, the mixture of the fine powder of the biological matrix and the organic solvent is stirred at 50-80 °C for 1-3 h, preferably at 55-70 °C for 1.2-2 h, more preferably at 60 °C for 1.5 h.

[0078] According to the present application, the solubility of the fine powder of the biological matrix in the organic solvent increases with increasing temperature, but too high a temperature can damage the structure of the polyphenolic compounds; the solubility of the fine powder of the biological matrix in the organic solvent increases with increasing stirring time, but too long a time does not result in more fine powder of the biological matrix being dissolved in the organic solvent.

[0079] In step 1-2, after the dissolving step of the fine powder-like biological material in the organic solvent is completed, the obtained liquid is subjected to vacuum filtration and centrifugation treatment to remove impurities, and the supernatant is obtained as the premix.

[0080] Further, the speed of the centrifugation is 4000-8000 r / min, and the centrifugation time is 3-10 min; for example, the speed of the centrifugation is 5000 r / min, and the centrifugation time is 5 min.

[0081] Preferably, the supernatant is stored at a low temperature environment, such as 4°C, for standby use, to avoid bacterial contamination.

[0082] In step 1-3, the mass ratio of the fine powder-like biological material matrix to the thermoplastic fluoropolymer in the premix is (0.5-3):1, preferably (1-2):1, and more preferably 1:1.

[0083] According to the present application, when the dielectric layer material is used to prepare a dielectric layer in contact with an electrode, the dielectric layer comprises a biological material-based colloid layer and an insulating layer, and the thickness of the biological material-based colloid layer is smaller than the thickness of the insulating layer. The thickness of the biological material-based colloid layer is 1-2.8 μm, preferably 1.5-2.5 μm, for example 2 μm; and the thickness of the insulating layer is 4-5 μm, preferably 3.5-4.5 μm, for example 4 μm.

[0084] According to the present application, the insulating layer is an organic polymer, which is preferably selected from any one or several of 3,4-ethylenedioxythiophene monomer, carboxymethyl cellulose, and butadiene-styrene rubber emulsion, and is more preferably 3,4-ethylenedioxythiophene monomer. The organic polymer is beneficial to enhancing the adhesion between the electrode and the biological material-based colloid layer.

[0085] In a second aspect, a preparation method of the dielectric layer of the first aspect is provided, and the method comprises:

[0086] Step 1, preparing a biological material-based colloid to form a biological material-based colloid layer;

[0087] Step 2, coating an insulating layer on the surface of the biological material-based colloid layer to obtain the dielectric layer.

[0088] In step 2, after the biological material-based colloid layer and the insulating layer are dried, the structure layer of the biological material-based colloid layer and the insulating layer is the dielectric layer.

[0089] In a third aspect, a biological material-based colloid is provided, wherein the biological material-based colloid contains polyphenolic compounds, and the biological material-based colloid is used to prepare a dielectric layer in contact with an electrode.

[0090] In a fourth aspect, a memristor is provided, comprising the dielectric layer of the first aspect, and an upper electrode and a lower electrode, the dielectric layer being sandwiched between the upper electrode and the lower electrode.

[0091] In an embodiment, the memristor comprises an upper electrode / insulating layer-biomaterial-based colloid layer / lower electrode structure.

[0092] According to the present application, the thickness of the upper electrode is 300-320 nm, preferably 310-313 nm, for example 312.511 nm.

[0093] Further, the upper electrode is a metal layer, preferably selected from gold, silver, copper, titanium or aluminum, more preferably copper.

[0094] According to the present application, the thickness of the lower electrode is 95-110 nm, preferably 100-105 nm, for example 102.513 nm.

[0095] If the thickness of the upper electrode and / or the lower electrode is too low, the passage current is too large, and the energy consumption is high; if the thickness is too high, the resistive switching effect is weakened or even disappears.

[0096] Further, the lower electrode is based on titanium, a titanium-coated glass sheet, a titanium-coated FTO or a titanium-coated ITO.

[0097] In an embodiment, the memristor exhibits stable resistive switching behavior at a high scanning rate, such as 4 Vs -1 The high and low resistance states are very stable within 100 cycles, and the difference between the high and low resistance states is about 5330 Ω.

[0098] In a fifth aspect, a method for preparing the memristor of the third aspect is provided, the method comprising:

[0099] Step I: coating a dielectric layer on the surface of the lower electrode;

[0100] Step II: plating an upper electrode on the surface of the dielectric layer to obtain the memristor.

[0101] More specifically:

[0102] Step I: coating a dielectric layer on the surface of the lower electrode.

[0103] In step I, the lower electrode is based on titanium, a titanium-coated glass sheet, a titanium-coated FTO or a titanium-coated ITO.

[0104] In Step I, the dielectric layer comprises a biomaterial-based colloid layer and an insulating layer, the biomaterial-based colloid is coated on the surface of the lower electrode in advance, the biomaterial-based colloid layer is formed based on the biomaterial-based colloid, and then the insulating layer is coated on the surface of the biomaterial-based colloid layer. Preferably, the biomaterial-based colloid and the insulating layer are coated in a spin coating manner, which is easy to control the thickness of the biomaterial-based colloid layer and the insulating layer and is easy to obtain the biomaterial-based colloid layer and the insulating layer with consistent density.

[0105] In Step I, after the biomaterial-based colloid layer and the insulating layer are coated, drying is performed at a temperature of 40-80°C for 8-24h. If the drying temperature is too low, the drying time will be inevitably prolonged; if the drying temperature is too high, the insulating layer may be embrittled; if the drying time is too short, the drying effect cannot be achieved; and if the drying time is too long, it is unnecessary. Under the above drying conditions, it is relatively appropriate. Preferably, drying is performed at a temperature of 45-60°C for 10-18h; more preferably, drying is performed at a temperature of 50°C for 12h.

[0106] In Step II, a layer of upper electrode is plated on the surface of the dielectric layer to obtain the memristor.

[0107] In Step II, a layer of upper electrode is sputtered on the surface of the dielectric layer in a magnetron sputtering manner. The magnetron sputtering can effectively improve the adhesion between the obtained upper electrode and the dielectric layer and make the surface of the upper electrode as flat as possible.

[0108] In the magnetron sputtering, the argon flux is 3-8sccm, preferably 4-6sccm, for example 5sccm; the pressure in the sputtering cavity is 1-1.5Pa, preferably 1.1-1.3Pa, for example 1.2Pa; the power is 70-90W, preferably 75-85W, for example 80W; and the sputtering time is determined according to the thickness of the upper electrode, and the time required is usually 60-90min, preferably 70-80min, for example 76min. The above parameters directly affect the thickness of the upper electrode, and within the above parameter range, a relatively ideal thickness of the upper electrode is obtained. Embodiment

[0109] The present application is further described below by specific examples, but these examples are merely exemplary and do not constitute any limitation on the scope of protection of the present application.

[0110] Embodiment 1

[0111] (1) The papaya with greenish yellow peel in the same harvesting period was picked and peeled. The collected papaya peel was washed with water and then dried at 45°C for 10h. The dried papaya peel was mechanically ground into powder and then passed through a 60-mesh sieve. The powder was ball milled in a planetary ball mill under the conditions of a material-to-ball ratio of 1:50 and a power of 40W for 30min to obtain a fine powder as the biomaterial base;

[0112] The mass of the fine powdered biomatrix and the volume of N-methylpyrrolidone were added to a 50 mL round-bottom flask at a ratio of 0.8% (w / v), incubated at 60 °C for 1.5 h by a constant temperature magnetic stirrer, then the supernatant was collected by vacuum filtration, and the supernatant was centrifuged at a speed of 5000 r / min for 5 min, and the obtained supernatant was stored at 4 °C for standby, and the supernatant collected this time was the premix;

[0113] The premix was mixed with polyvinylidene fluoride to form a colloid, and a biomaterial-based colloid was prepared. At this time, the mass ratio of papaya skin in the premix to the thermoplastic fluoropolymer was 1:1.

[0114] (2) A glass sheet pre-plated with 102.513 nm titanium was used as a substrate. The biomaterial-based colloid was first spin-coated on the titanium surface, and then 3,4-ethylenedioxythiophene monomers were spin-coated on the surface of the biomaterial-based colloid. After spin-coating, drying was performed at a temperature of 50 °C for 12 h. The operation of coating the biomaterial-based colloid layer and the insulating layer on the titanium surface was completed. The thickness of the biomaterial-based colloid layer was ~2 μm, and the thickness of the insulating layer was ~4 μm.

[0115] A Cu upper electrode was sputtered on the surface of the insulating layer using a magnetron sputtering instrument (argon flux of 5 sccm, sputtering cavity pressure of 1.2 Pa, power of 80 W, sputtering time of 76 min). The thickness of the Cu upper electrode was 312.511 nm, and a memristor with a Cu / insulating layer-biomaterial-based colloid layer / Ti structure was obtained.

[0116] Figure 2(a) shows the current-voltage (I-V) characteristic curve of the prepared memristor under a scanning voltage of -1V~1V and a scanning rate of 4V / S, and Figure 2(b) shows the log (I) and V characteristic curve in the logarithmic scale of the first cycle of the cycle test in Figure 2(a). It can be clearly seen from Figures 2(a) and 2(b) that the prepared memristor exhibits obvious resistance switching effect in the positive scanning voltage region.

[0117] Figure 3(a) shows the current-voltage (I-V) characteristic curve of the prepared memristor under a scanning voltage of -1V~1V and a scanning rate of 3V / S, Figure 3(b) shows the current-voltage (I-V) characteristic curve of the prepared memristor under a scanning voltage of -1V~1V and a scanning rate of 4V / S, and Figure 3(c) shows the current-voltage (I-V) characteristic curve of the prepared memristor under a scanning voltage of -1V~1V and a scanning rate of 5V / S. Through comparative analysis, it can be found that the prepared memristor exhibits obvious resistance switching effect at a scanning rate of 3 V / S and 4 V / S, but when the scanning rate is increased to 5 V / S, the prepared memristor exhibits typical self-rectifying effect.

[0118] Figure 4(a) shows the high and low resistance states (HRS, LRS) of the prepared memristor at a 4V / S scan rate for 100 cycles; Figure 4(b) shows the HRS / LRS ratio of the prepared memristor for the number of cycles, which shows that the high and low resistance ratio (HRS / LRS) of the prepared memristor can reach nearly 5330 Ω, while showing excellent stability. Comparative Example

[0119] Comparative Example 1

[0120] A glass sheet pre-plated with 102.513 nm of titanium was used as a substrate, and 3,4-ethylenedioxythiophene monomer (PEDOT) was spin-coated on the titanium surface. After spin-coating, the sample was dried at a temperature of 50°C for 12 hours to complete the coating of the insulating layer on the titanium surface, wherein the thickness of the insulating layer was ~4 μm.

[0121] A Cu top electrode was sputtered on the surface of the insulating layer using a magnetron sputtering instrument (argon flux of 5 sccm, sputtering cavity pressure of 1.2 Pa, power of 80 W, sputtering time of 76 min), and the thickness of the Cu top electrode was 312.511 nm, thereby obtaining a memristor with a Cu / insulating layer / Ti structure.

[0122] Comparative Example 2 Comparative Example 3

[0123] (1) The papaya peel of the same harvest period was picked, and the peel was washed with water and then dried at 45°C for 10 hours. The dried peel was mechanically ground into powder and then passed through a 60-mesh sieve. The powder was then ball-milled in a planetary ball mill at a material-to-ball ratio of 1:50 and a power of 40 W for 30 minutes to obtain a fine powder as a biological matrix;

[0124] The mass of the fine powder biological matrix and the volume of N-methylpyrrolidone were added to a 50-mL round-bottom flask at a ratio of 0.8% (w / v), and the mixture was incubated at 60°C for 1.5 hours by a constant-temperature magnetic stirrer. The supernatant was then collected by vacuum filtration, and the supernatant was centrifuged at a speed of 5000 r / min for 5 minutes. The obtained supernatant was stored at 4°C for standby, and the collected supernatant was a premix.

[0125] The premix was mixed with polyvinylidene fluoride to form a colloid, and a biological material-based colloid was prepared. At this time, the mass ratio of the papaya peel in the premix to the thermoplastic fluoropolymer was 1:1.

[0126] (2) using a glass sheet pre-plated with 102.513 nm titanium as a substrate, spin-coating a biomaterial-based colloid on the titanium surface, drying at a temperature of 50°C for 12 hours after spin-coating to complete the operation of coating the biomaterial-based colloid layer on the titanium surface, wherein the thickness of the biomaterial-based colloid layer is ~2 μm.

[0127] The metal copper Cu upper electrode is sputtered on the surface of the insulating layer by using a magnetron sputtering instrument (argon flux of 5 sccm, sputtering cavity pressure of 1.2 Pa, power of 80 W, and sputtering time of 76 min), and the thickness of the Cu upper electrode is 312.511 nm, thereby obtaining a memristor with a Cu / biomaterial-based colloid layer / Ti structure.

[0128] FIG. 1(a) shows the current-voltage (I-V) characteristic curve of the Cu / insulating layer / Ti structure memristor prepared in Comparative Example 1 under a scanning voltage of -1V~1V and a scanning rate of 4V / S, and FIG. 1(b) shows the current-voltage (I-V) characteristic curve of the Cu / biomaterial-based colloid layer / Ti structure memristor prepared in Comparative Example 2 under a scanning voltage of -1V~1V and a scanning rate of 4V / S, and it can be seen that the stability of the memristor prepared by the single-layer PEDOT is excellent but the resistance switching window is small; and although the resistance switching window of the memristor prepared by the single-layer papaya skin powder is significantly improved, the stability of the memristor is poor.

[0129] The above describes the present application in detail in combination with preferred embodiments and exemplary examples. However, it needs to be declared that these specific embodiments are only illustrative explanations of the present application, and do not constitute any limitation on the protection scope of the present application. Various improvements, equivalent replacements or modifications can be made to the technical content and embodiments of the present application without exceeding the spirit and protection scope of the present application, and these all fall within the protection scope of the present application. The protection scope of the present application is subject to the appended claims.

Claims

1. A method of fabricating a memristor, comprising: The method comprises: Picking the same harvest period of greenish yellow papaya and peeling it, washing the collected papaya peel with water, then drying it at 45 °C for 10 h, then mechanically grinding it into powder through a 60 mesh sieve, and then using a planetary ball mill to ball mill the papaya peel powder under the conditions of a material-ball ratio of 1:50 and a power of 40 W for 30 min to obtain a fine powder biobased matrix; The mass of the fine powder biobased matrix and the volume of N-methylpyrrolidone are added to a 50 mL round-bottom flask at a ratio of 0.8% w / v, incubated at 60 °C for 1.5 h by a constant temperature magnetic stirrer, then the supernatant is collected by vacuum filtration, and then the supernatant is centrifuged at a speed of 5000 r / min for 5 min, and the obtained supernatant is stored at 4 °C for standby, and the collected supernatant is the premix; Mix the premix with polyvinylidene fluoride to form a colloid to obtain a biomaterial-based colloid, and the mass ratio of papaya peel in the premix to thermoplastic fluoropolymer is 1:1; A glass sheet pre-plated with 102.513 nm titanium is used as a substrate, the biomaterial-based colloid is first spin-coated on the titanium surface, then 3,4-ethylenedioxythiophene monomer is spin-coated on the surface of the biomaterial-based colloid, and after spin-coating, the biomaterial-based colloid layer and the insulating layer are coated on the titanium surface by drying at a temperature of 50 °C for 12 h, wherein the thickness of the biomaterial-based colloid layer is ~2 μm, and the thickness of the insulating layer is ~4 μm; A Cu top electrode is sputtered on the surface of the insulating layer by using a magnetron sputtering instrument with an argon flux of 5 sccm, a sputtering cavity pressure of 1.2 Pa, a power of 80 W, and a sputtering time of 76 min, and the thickness of the Cu top electrode is 312.511 nm, thereby obtaining a memristor with a Cu / insulating layer-biomaterial-based colloid layer / Ti structure. The biomaterial-based colloid contains polyphenolic compounds.

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