Memristor and preparation method thereof

Abstract

The invention discloses a memristor and a preparation method thereof, which are characterized in that a dielectric layer is obtained by using a colloid containing a biological material base, so that high-valued utilization of the biological material is realized, and the dielectric layer is applied to the memristor to realize the effect that the memristor still keeps a stable memristive effect at a high scanning rate; in addition, conversion between the memristive effect and the rectification effect of the device can be achieved by controlling the scanning rate, and application of the electronic device in multiple scenes in the future can be widened.

Description

Technical Field

[0001] The invention belongs to the technical field of storage device manufacturing and relates to a memristor and a preparation method thereof. Background Art

[0002] Against the backdrop of the rapid development of digitalization and informatization, computing and storage electronic devices based on the traditional von Neumann architecture have been unable to meet people's needs for low power consumption, large storage, and high computing speed. This is due to the fact that its architecture cannot achieve simultaneous computing and storage, which is also a characteristic problem that restricts its further development. In addition, under Moore's Law, the electronic devices that carry this architecture have approached physical limits. Inspired by the human brain, simulating the synaptic structure of the human brain to develop neuromorphic computing is expected to solve this problem.

[0003] Memristor, or memristor for short, has a typical structure that is very similar to the synaptic structure of the human brain. This device is used to characterize the relationship between magnetic flux and charge. It is worth noting that its resistance is determined by the charge passing through it, which also means that this device has the ability of memory resistance. In other words, if the high and low resistance states of the memristor (corresponding to logic "1" and "0" respectively) are continuously switched by controlling the current, data storage can be achieved. Since HP researchers published an article titled "The Lost Memristor" in the journal "Nature" in 2008, the preparation and application of memristors have been widely studied by scholars and companies at home and abroad.

[0004] Structurally, memristors are mainly composed of upper and lower conductive layers and a middle functional layer. The material and characteristics of the functional layer largely determine the performance of the memristor. However, most memristors are made of inorganic materials, which are usually expensive, non-biocompatible and non-degradable, making them difficult to apply to the preparation of implantable devices and difficult to be naturally degraded.

[0005] In addition, in the research on memristors, it is necessary to improve their response rate and broaden their application scenarios while maintaining their memristive effect, 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 of the invention

[0007] In order to overcome the above problems, the inventors have conducted intensive research and developed a memristor and a method for preparing the same, in which a dielectric layer is obtained by containing a biomaterial-based colloid, which not only realizes the high-value utilization of biomaterials, but also applies the dielectric layer to the memristor, so that the memristor can maintain a stable memristive effect at a high scanning rate; in addition, the conversion between the device's memristive effect and the rectification effect can be achieved by controlling the scanning rate, which helps to broaden the application of electronic devices in multiple scenarios in the future, thereby completing the present invention.

[0008] Specifically, the purpose of the present invention is to provide the following aspects: (We will add when the manuscript is transferred next time)

[0009] In a first aspect, a dielectric layer material is provided, wherein the dielectric layer material contains a biomaterial-based colloid, and the biomaterial-based colloid contains a polyphenol compound.

[0010] The biomaterial-based colloid comprises biomaterials, and the biomaterials are plant-derived peels, roots, leaves and / or fruits containing polyphenol compounds.

[0011] Wherein, the biomaterial-based colloid further comprises a thermoplastic fluorine-containing polymer, and the mass ratio of the biomaterial to the thermoplastic fluorine-containing polymer is (0.5-3):1, preferably (1-2):1.

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

[0013] In a second aspect, a method for preparing a dielectric layer is provided, the method comprising:

[0014] Step 1, preparing a biomaterial-based colloid, and forming a biomaterial-based colloid layer based on the biomaterial-based colloid;

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

[0016] in,

[0017] In step 1, the prepared biomaterial-based colloid contains polyphenol compounds.

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

[0019] Step 1-1, preparing the biomaterial into a fine powder biomatrix;

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

[0021] Step 1-3, mixing the premix with a thermoplastic fluorine-containing polymer to obtain the biomaterial-based colloid.

[0022] In a third aspect, a biomaterial-based colloid is provided, wherein the biomaterial-based colloid contains polyphenol compounds.

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

[0024] Wherein, the memristor further includes 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 the surface of the lower electrode;

[0027] Step II, plating a top electrode on the 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 polyphenol compound.

[0029] The beneficial effects of the present invention include:

[0030] (1) The dielectric layer provided by the present invention contains a biomaterial-based colloid, which not only realizes the high-value utilization of biomaterials, but also applies them to memristors. The obtained memristors have fast response at high scanning rates.

[0031] (2) The biomaterial-based colloid in the dielectric layer provided by the present invention combines biomaterial with thermoplastic fluorine-containing polymer, and the obtained memristor can maintain a stable memristive effect at an excellent high scanning rate.

[0032] (3) The memristor provided by the present invention can achieve the conversion between the device's memristive effect and 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 THE DRAWINGS

[0033] By reading the detailed description of the preferred specific embodiments below, various other advantages and benefits of the present invention will become clear to those of ordinary skill in the art. The drawings in the specification are only used for the purpose of illustrating the preferred embodiments and are not considered to be limitations of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative work.

[0034] In the attached picture:

[0035] FIG1( a ) shows a current-voltage (IV) characteristic curve of a memristor of a Cu / insulating layer / Ti structure prepared in Comparative Example 1 under a scanning voltage of -1V to 1V and a scanning rate of 4V / S for 100 cycles;

[0036] FIG1( b ) shows a current-voltage (IV) characteristic curve of the memristor of the Cu / biomaterial-based colloidal layer / Ti structure prepared in Comparative Example 2 under a scanning voltage of -1V to 1V and a scanning rate of 4V / S for 100 cycles;

[0037] FIG2( a ) shows a current-voltage (IV) characteristic curve of the memristor prepared in Example 1 under a scanning voltage of -1V to 1V and a scanning rate of 4V / S for 100 cycles;

[0038] FIG2( b ) shows the log(I) and V characteristic curves on a logarithmic scale for the first cycle of the cycle test in FIG2( a );

[0039] FIG3( a ) shows a current-voltage (IV) characteristic curve of the memristor prepared in Example 1 at a scan voltage of -1V to 1V and a scan rate of 3V / S;

[0040] FIG3( b ) shows a current-voltage (IV) characteristic curve of the memristor prepared in Example 1 at a scan voltage of -1V to 1V and a scan rate of 4V / S;

[0041] FIG3( c ) shows a current-voltage (IV) characteristic curve of the memristor prepared in Example 1 at a scanning voltage of -1V to 1V and a scanning rate of 5V / S;

[0042] FIG4( a ) shows a graph of high and low resistance states of the memristor prepared in Example 1 at a scan rate of 4 V / S and 100 cycles;

[0043] FIG4( b ) shows a box plot of the HRS / LRS ratio of the memristor prepared in Example 1 versus the number of cycles. DETAILED DESCRIPTION

[0044] The following will refer to the attached Figure 1(a) to Figure 4(b) Specific embodiments of the present invention are described in more detail. Although specific embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0045] It should be noted that certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. This specification and claims do not use the difference in nouns as a way to distinguish components, but use the difference in the functions of the components as the criterion for distinction. As mentioned throughout the specification and claims, "including" or "comprising" is an open term, so it should be interpreted as "including but not limited to". The subsequent description of the specification is a preferred embodiment of the present invention, but the description is based on the general principles of the specification and is not intended to limit the scope of the present invention. The scope of protection of the present invention shall be determined by the attached claims.

[0046] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front", "rear", etc. indicate positions or positional relationships based on the working state of the present invention, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", and "fourth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0047] To facilitate understanding of the embodiments of the present invention, further explanation will be given below by taking specific embodiments as examples in conjunction with the accompanying drawings, and each of the accompanying drawings does not constitute a limitation on the embodiments of the present invention.

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

[0049] Furthermore, the biomaterial-based colloid comprises a biomaterial, and the biomaterial is a plant-derived peel, root, leaf and / or fruit rich in polyphenolic compounds, such as papaya peel.

[0050] In the existing technology, memristors are difficult to apply to the preparation of implantable devices and are difficult to be naturally degraded. The memristor effect is poor or unstable. Applying environmentally friendly and renewable biomaterials to memristors to improve the performance of memristors may be a new idea, which will greatly reduce the manufacturing cost of memristors without causing environmental problems.

[0051] The inventors unexpectedly discovered that the memristor obtained by obtaining biomaterial-based colloids from biomaterials, especially papaya peel-based colloids obtained from papaya peel as the substrate, has excellent performance and maintains a stable memristor effect even at high scanning rates; in addition, it exhibits a rectification effect at a specific scanning rate. This device that regulates the memristor effect and the rectification effect based on the scanning rate has broad prospects for multi-scenario applications in future electronic devices. It is obvious that obtaining biomaterial-based colloids from biomaterials can, first, solve the problem of biomaterial waste accumulation, second, be low-cost and easy to operate, third, be degradable and renewable, and fourth, recover valuable products as much as possible, and better achieve the harmless disposal and reuse of biomaterials.

[0052] According to the present invention, the biomaterial-based colloid further comprises a thermoplastic fluorinated polymer. The biomaterial-based colloid prepared by using the biomaterial as the matrix and the thermoplastic fluorinated polymer as the colloidal dispersion is beneficial to enhancing the adhesion between the biomaterial and the lower electrode and the insulating layer.

[0053] Furthermore, the thermoplastic fluorine-containing polymer is selected from any one or more of polyvinylidene fluoride, carboxymethyl cellulose, and styrene-butadiene rubber latex, preferably polyvinylidene fluoride.

[0054] According to the present invention, the thermoplastic fluorine-containing polymer has good mechanical strength and toughness, can be used for a long time in a wide temperature range and basically maintains its performance, is easy to form a film, and has good chemical stability, temperature stability, excellent mechanical properties and processability. In particular, the thermoplastic fluorine-containing polymer represented by polyvinylidene fluoride has properties such as heat resistance, chemical resistance and UV resistance, and the alternating CH 2 and CF 2 The groups give polyvinylidene fluoride unique polarity and affect its solubility and dielectric properties.

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

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

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

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

[0059] Step 1-3, mixing the premix with a thermoplastic fluorine-containing polymer to obtain the biomaterial-based colloid.

[0060] In step 1-1, the biological material is plant-derived peel, root, leaf and / or fruit rich in polyphenolic compounds, such as papaya peel.

[0061] In step 1-1, the biological material is a biological material that matures in the same harvest period. For example, papaya peel is a papaya peel with green and yellow peel picked in the same harvest period.

[0062] In step 1-1, the biomaterial is ball-milled to obtain a fine powder biomatrix.

[0063] In step 1-1, the ball milling process has a direct effect on the fine powdered biomatrix.

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

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

[0066] According to the present invention, 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 obtained biomaterial-based colloid is low. When the ball milling power is too high, the balls do not move towards each other, and the material can neither be stirred nor crushed. When the ball milling power is 30 to 60W, especially 40W, stirring and crushing can be ensured to be carried out simultaneously.

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

[0068] According to the present invention, to improve the dispersion degree and physical and mechanical properties of fine powder biomatrix, appropriate ball milling time is very important. As the ball milling time increases, the dispersion of fine powder biomatrix becomes more and more uniform, and the particles become smaller and smaller due to the ball milling effect. If the ball milling time is too long, the activity of fine powder biomatrix will continue to increase during the ball milling process, the ball milling efficiency will decrease, and the work hardening will be serious. Therefore, it is not advisable to extend the ball milling time excessively.

[0069] According to the present invention, in order to quickly and efficiently prepare the biomaterial into a fine powder biomatrix, the biomaterial is preferably washed, dried, ground and sieved before ball milling.

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

[0071] Furthermore, the drying temperature and time are not particularly limited as long as they can dry the biomaterial. Typically, the drying temperature is 38 to 60°C, preferably 40 to 50°C, such as 45°C; the drying time is 6 to 18 hours, preferably 8 to 12 hours, such as 10 hours.

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

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

[0074] In step 1-2, the organic solvent is any one or more of N-methylpyrrolidone, carboxymethyl cellulose, and styrene-butadiene rubber latex, preferably N-methylpyrrolidone.

[0075] Among them, organic solvents disperse biomaterials, which is beneficial to improve the dispersibility of biomaterials in thermoplastic fluoropolymers in the later stage, and organic solvents represented by N-methylpyrrolidone have high temperature resistance and oxidation resistance.

[0076] In step 1-2, the volume ratio (w / v) of the fine powder biomatrix mass to the organic solvent is 0.6% to 1.2%, preferably 0.7% to 1%, and more preferably 0.8%. As the volume of the organic solvent increases, the dispersion of the fine powder biomatrix becomes more uniform, but excessive organic solvent increases the workload of subsequent treatments such as vacuum filtration and centrifugation.

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

[0078] According to the present invention, the solubility of the fine powdered biomatrix in the organic solvent increases with increasing temperature, but too high a temperature may destroy the structure of the polyphenol compounds; the solubility of the fine powdered biomatrix in the organic solvent increases with increasing stirring time, but too long a time does not cause more fine powdered biomatrix to dissolve in the organic solvent.

[0079] In step 1-2, after the dissolution step of the fine powdered organism in the organic solvent is completed, the obtained liquid is vacuum filtered and centrifuged to remove impurities, and the supernatant is the obtained premix.

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

[0081] Preferably, the supernatant is stored in a low temperature environment such as 4° C. for future use to avoid contamination by bacteria.

[0082] In step 1-3, the mass ratio of the fine powder biomatrix to the thermoplastic fluorine-containing polymer in the premix is ​​(0.5-3):1, preferably (1-2):1, and more preferably 1:1.

[0083] According to the present invention, 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, and the thickness of the biomaterial-based colloid layer is smaller than the thickness of the insulating layer. The thickness of the biomaterial-based colloid layer is 1 to 2.8 μm, preferably 1.5 to 2.5 μm, for example 2 μm; the thickness of the insulating layer is 4 to 5 μm, preferably 3.5 to 4.5 μm, for example 4 μm.

[0084] According to the present invention, the insulating layer is an organic polymer, preferably selected from any one or more of 3,4-ethylenedioxythiophene monomer, carboxymethyl cellulose, and styrene-butadiene rubber latex, and more preferably 3,4-ethylenedioxythiophene monomer. The organic polymer is beneficial to enhancing its adhesion to the upper electrode and the biomaterial-based colloidal layer.

[0085] In a second aspect, a method for preparing the dielectric layer according to the first aspect is provided, the method comprising:

[0086] Step 1, preparing a biomaterial-based colloid, and forming a biomaterial-based colloid layer based on the biomaterial-based colloid;

[0087] Step 2: coating an insulating layer on the surface of the biomaterial matrix layer to obtain the dielectric layer.

[0088] In step 2, the biomaterial-based colloid layer and the insulating layer are dried, and the structural layer of the biomaterial-based colloid layer and the insulating layer is a dielectric layer.

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

[0090] According to a fourth aspect, a memristor is provided, the memristor comprising the dielectric layer according to the first aspect, and an upper electrode and a lower electrode, wherein the dielectric layer is sandwiched between the upper electrode and the lower electrode.

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

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

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

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

[0095] Among them, if the thickness of the upper electrode and / or the lower electrode is too low, it will lead to excessive path current and high energy consumption; if the thickness is too high, the resistance switching effect will be weakened or even disappear.

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

[0097] In one embodiment, the memristor is subjected to a high scan rate such as 4Vs -1 It exhibits stable resistance switching behavior, and the high and low resistance states are very stable within 100 cycles, with a difference of ~5330Ω between the high and low resistance states.

[0098] In a fifth aspect, a method for preparing the memristor according to 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 glass sheet coated with titanium, FTO coated with titanium, or ITO coated with titanium.

[0104] In step I, the dielectric layer includes a biomaterial-based colloid layer and an insulating layer, a biomaterial-based colloid is pre-coated on the surface of the lower electrode, a biomaterial-based colloid layer is formed based on the biomaterial-based colloid, and then an insulating layer is coated on the surface of the biomaterial-based colloid layer. Preferably, the biomaterial-based colloid and the insulating layer are coated by spin coating, which makes it easy to control the thickness of the biomaterial-based colloid layer and the insulating layer, and to obtain a biomaterial-based colloid layer and an insulating layer with consistent density.

[0105] In step I, after the biomaterial-based colloid layer and the insulating layer are coated, they are dried at a temperature of 40 to 80°C for 8 to 24 hours. If the drying temperature is too low, the drying time will be extended; if the drying temperature is too high, the insulating layer may become brittle; if the drying time is too short, the drying effect cannot be achieved. It is unnecessary to dry for too long. The above drying conditions are more appropriate. Preferably, the temperature is 45 to 60°C for 10 to 18 hours; more preferably, the temperature is 50°C for 12 hours.

[0106] Step II, plating an upper electrode on the surface of the dielectric layer to obtain the memristor.

[0107] In step II, a layer of upper electrode is preferably sputtered on the surface of the dielectric layer by magnetron sputtering. The magnetron sputtering can effectively improve the adhesion between the prepared upper electrode and the dielectric layer and make the surface of the upper electrode as flat as possible.

[0108] Among them, the argon flux of magnetron sputtering is 3-8sccm, preferably 4-6sccm, for example 5sccm; the pressure in the sputtering chamber is 1-1.5Pa, preferably 1.1-1.3Pa, for example 1.2Pa; the power is 70-90W, preferably 75-85W, for example 80W; 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 have a direct impact on the thickness of the upper electrode. Within the above parameter range, a more ideal upper electrode thickness is obtained.

[0109] Example

[0110] The present invention is further described below through specific examples, but these examples are merely exemplary and do not constitute any limitation to the scope of protection of the present invention.

[0111] Example 1

[0112] (1) Papaya with green-yellow peels in the same harvest period was picked and peeled, the collected papaya peels were washed with water, then dried at 45° C. for 10 h, and then mechanically ground into powder and passed through a 60-mesh sieve. The papaya peel powder was then ball-milled for 30 min using a planetary ball mill at a material-to-ball ratio of 1:50 and a power of 40 W to obtain a fine powder biomatrix;

[0113] 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), and the mixture was kept at 60°C for 1.5 h using a constant temperature magnetic stirrer. The supernatant was then collected by vacuum filtration, and the supernatant was centrifuged at 5000 r / min for 5 min. The supernatant was stored at 4°C for later use. The supernatant collected this time was the premix;

[0114] The premix is ​​mixed with polyvinylidene fluoride to form a colloid to prepare a biomaterial-based colloid, and the mass ratio of the papaya peel in the premix to the thermoplastic fluorine-containing polymer is 1:1.

[0115] (2) A glass sheet pre-coated with 102.513 nm titanium was used as a substrate, and a biomaterial-based colloid was first spin-coated on the titanium surface, and then 3,4-ethylenedioxythiophene monomer was spin-coated on the biomaterial-based colloid surface. After the spin coating was completed, it was dried at a temperature of 50° C. for 12 h, and the operation of coating the biomaterial-based colloid layer and the insulating layer on the titanium surface was completed, wherein the thickness of the biomaterial-based colloid layer was ∼2 μm, and the thickness of the insulating layer was ∼4 μm.

[0116] A metal copper Cu top electrode was sputtered on the surface of the insulating layer using a magnetron sputtering apparatus (5 sccm argon flux, 1.2 Pa pressure in the sputtering chamber, 80 W power, and 76 min sputtering time). The thickness of the Cu top electrode was 312.511 nm, and a memristor with a Cu / insulating layer-biomaterial-based colloidal layer / Ti structure was obtained.

[0117] Figure 2(a) shows the current-voltage (IV) characteristic curve of the fabricated memristor under a -1V to 1V scan voltage and a 4V / S scan rate for 100 cycles. Figure 2(b) shows the log(I) and V characteristic curves on a logarithmic scale for the first cycle of the cycle test in Figure 2(a). Combining Figures 2(a) and 2(b), it can be clearly seen that the fabricated memristor exhibits an obvious resistance switching effect in the forward scan voltage region.

[0118] FIG3(a) shows the current-voltage (IV) characteristic curve of the prepared memristor at a scanning voltage of -1V to 1V and a scanning rate of 3V / S, FIG3(b) shows the current-voltage (IV) characteristic curve of the prepared memristor at a scanning voltage of -1V to 1V and a scanning rate of 4V / S, and FIG3(c) shows the current-voltage (IV) characteristic curve of the prepared memristor at a scanning voltage of -1V to 1V and a scanning rate of 5V / S. By comparative analysis, it can be found that the prepared memristor exhibits an obvious resistance switching effect at scanning rates of 3V / S and 4V / S, but when the scanning rate is increased to 5V / S, the prepared memristor exhibits a typical self-rectification effect.

[0119] Figure 4(a) shows the high and low resistance states (HRS, LRS) of the fabricated memristor at a scan rate of 4V / S versus 100 cycles; Figure 4(b) shows a box plot of the HRS / LRS ratio versus the number of cycles of the fabricated memristor. It is clear that the high and low resistance ratio (HRS / LRS) of the fabricated memristor reaches nearly 5330Ω, while exhibiting excellent stability.

[0120] Comparative Example

[0121] Comparative Example 1

[0122] A glass sheet pre-coated with 102.513 nm titanium was used as a substrate, and 3,4-ethylenedioxythiophene monomer (PEDOT) was spin-coated on the titanium surface. After the spin coating was completed, it was dried at a temperature of 50°C for 12 hours to complete the operation of coating an insulating layer on the titanium surface, wherein the thickness of the insulating layer was ~4 μm.

[0123] A Cu top electrode was sputtered on the surface of the insulating layer using a magnetron sputtering apparatus (5 sccm argon flux, 1.2 Pa pressure in the sputtering chamber, 80 W power, and 76 min sputtering time). The thickness of the Cu top electrode was 312.511 nm, and a memristor with a Cu / insulating layer / Ti structure was obtained.

[0124] Comparative Example 2

[0125] (1) Papaya with green-yellow peels in the same harvest period was picked and peeled, the collected papaya peels were washed with water, then dried at 45° C. for 10 h, and then mechanically ground into powder and passed through a 60-mesh sieve. The papaya peel powder was then ball-milled for 30 min using a planetary ball mill at a material-to-ball ratio of 1:50 and a power of 40 W to obtain a fine powder biomatrix;

[0126] 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), and the mixture was kept at 60°C for 1.5 h using a constant temperature magnetic stirrer. The supernatant was then collected by vacuum filtration, and the supernatant was centrifuged at 5000 r / min for 5 min. The supernatant was stored at 4°C for later use. The supernatant collected this time was the premix;

[0127] The premix is ​​mixed with polyvinylidene fluoride to form a colloid to prepare a biomaterial-based colloid, and the mass ratio of the papaya peel in the premix to the thermoplastic fluorine-containing polymer is 1:1.

[0128] (2) A glass sheet pre-coated with 102.513 nm titanium was used as a substrate, and a biomaterial-based colloid was spin-coated on the titanium surface. After the spin coating was completed, the biomaterial-based colloid layer was dried at 50° C. for 12 h to complete the coating of the biomaterial-based colloid layer on the titanium surface, wherein the thickness of the biomaterial-based colloid layer was ∼2 μm.

[0129] A metal copper Cu top electrode was sputtered on the surface of the insulating layer using a magnetron sputtering apparatus (5 sccm argon flux, 1.2 Pa pressure in the sputtering chamber, 80 W power, and 76 min sputtering time). The thickness of the Cu top electrode was 312.511 nm, and a memristor with a Cu / biomaterial-based colloidal layer / Ti structure was obtained.

[0130] Figure 1(a) shows the current-voltage (IV) characteristic curve of the memristor of the Cu / insulating layer / Ti structure prepared in comparative example 1 under a scanning voltage of -1V to 1V and a scanning rate of 4V / S for 100 cycles. Figure 1(b) shows the current-voltage (IV) characteristic curve of the memristor of the Cu / biomaterial-based colloid layer / Ti structure prepared in comparative example 2 under a scanning voltage of -1V to 1V and a scanning rate of 4V / S for 100 cycles. It can be seen that the memristor prepared with a single layer of PEDOT has excellent stability but a small resistance switching window; and although the resistance switching window of the memristor prepared with a single layer of papaya peel powder is significantly improved, the stability of the memristor is poor.

[0131] The present invention is described in detail above in combination with preferred embodiments and exemplary examples. However, it should be noted that these specific embodiments are only illustrative explanations of the present invention and do not constitute any limitation on the protection scope of the present invention. Without exceeding the spirit and protection scope of the present invention, various improvements, equivalent substitutions or modifications may be made to the technical content of the present invention and its embodiments, which all fall within the protection scope of the present invention. The protection scope of the present invention shall be subject to the attached claims.

Claims

1. A dielectric layer material, It is characterized in that The dielectric layer material contains biomaterial-based colloid, and the biomaterial-based colloid contains polyphenol compounds.

2. The dielectric layer material according to claim 1, It is characterized in that Preferably, the biomaterial-based colloid comprises biomaterial, and the biomaterial is plant-derived peel, root, leaf and / or fruit containing polyphenol compounds.

3. The dielectric layer material according to claim 2, It is characterized in that The biomaterial-based colloid further comprises a thermoplastic fluorine-containing polymer, and the mass ratio of the biomaterial to the thermoplastic fluorine-containing polymer is (0.5-3):1, preferably (1-2):

1.

4. The dielectric layer material according to claim 1, It is characterized in that When the dielectric layer material is used to prepare a dielectric layer in contact with an electrode, the dielectric layer comprises a biomaterial-based colloid layer and an insulating layer.

5. A method for preparing a dielectric layer, It is characterized in that The method comprises: Step 1, preparing a biomaterial-based colloid, and forming a biomaterial-based colloid layer based on the biomaterial-based colloid; Step 2, coating an insulating layer on the surface of the biomaterial-based colloid layer to obtain the dielectric layer; in, In step 1, the prepared biomaterial-based colloid contains polyphenol compounds.

6. The method according to claim 5, It is characterized in that The step 1 includes the following sub-steps: Step 1-1, preparing the biomaterial into a fine powder biomatrix; Step 1-2, dissolving the fine powder biomatrix in an organic solvent to obtain a premix; Step 1-3, mixing the premix with a thermoplastic fluorine-containing polymer to obtain the biomaterial-based colloid.

7. A biomaterial-based colloid, It is characterized in that The biomaterial-based colloid contains polyphenol compounds.

8. A memristor, It is characterized in that The dielectric layer of the memristor is made of the dielectric layer material described in any one of claims 1 to 5.

9. The memristor according to claim 8, It is characterized in that The memristor further includes an upper electrode and a lower electrode, and the dielectric layer is sandwiched between the upper electrode and the lower electrode.

10. A method for preparing a memristor, It is characterized in that The method comprises: Step I, coating a dielectric layer on the surface of the lower electrode; Step II, plating a top electrode on the surface of the dielectric layer to obtain the memristor; In step I, the dielectric layer contains a biomaterial-based colloid, and the biomaterial-based colloid contains a polyphenol compound.

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