Flexible optoelectronic dual-controlled memristor and its preparation method and application

Abstract

The present invention relates to a flexible optoelectronic dual-controlled memristor and its preparation method and application. The flexible optoelectronic dual-controlled memristor includes a flexible substrate, a bottom electrode, a composite functional thin film, and a top electrode that are sequentially stacked. Among them, the materials of the bottom electrode and the top electrode are both selected from silver. The composite functional thin film includes a copper-based perovskite layer and a first hydrophobic polymer layer that are stacked. The top electrode is stacked on the first hydrophobic polymer layer, and the top electrode does not completely cover the first hydrophobic polymer layer. This flexible optoelectronic dual-controlled memristor exhibits various typical optoelectronic synaptic plasticities under light signal stimulation, and is almost unaffected by the bending curvature, the number of bending cycles, and the environment, and can be well applied to flexible electronic products.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic materials, and particularly to a flexible optoelectronic dual-controlled memristor and its preparation method and application. Background Art

[0002] In recent years, flexible electronic products have shown great research potential in the fields of wireless sensors, bendable mobile phones, wearable electronic devices, etc. As one of the crucial components in such devices, the construction of flexible optoelectronic dual-controlled memristors has become a current research hotspot. Traditional flexible optoelectronic dual-controlled memristors are mainly two-dimensional layered organic-inorganic lead halide perovskite-based memristors. Although such flexible optoelectronic dual-controlled memristors exhibit excellent memristive properties, the toxicity of the lead they contain cannot be ignored. To reduce toxicity, researchers have tried to use elements such as bismuth (III), antimony (III), or tin (II) to replace lead (II). However, trivalent cations including antimony (III) and bismuth (III) elements are difficult to form a two-dimensional layered structure, and tin (II) elements are easily oxidized to the more stable tin (IV). Therefore, there is an urgent need to develop a stable and reliable flexible optoelectronic dual-controlled memristor suitable for flexible scenarios. Summary of the Invention

[0003] Based on this, in view of the above problems, it is necessary to provide a flexible optoelectronic dual-controlled memristor and its preparation method and application. This flexible optoelectronic dual-controlled memristor exhibits various typical optoelectronic synaptic plasticity under light signal stimulation, and is hardly affected by the bending curvature, the number of bending cycles, and the environment, and can be well applied to flexible electronic products.

[0004] The present invention discloses a flexible optoelectronic dual-controlled memristor, which includes a flexible substrate, a bottom electrode, a composite functional thin film, and a top electrode stacked in sequence. Among them, the materials of the bottom electrode and the top electrode are both selected from silver. The composite functional thin film includes a stacked copper-based perovskite layer and a first hydrophobic polymer layer. The top electrode is stacked on the first hydrophobic polymer layer, and the top electrode does not completely cover the first hydrophobic polymer layer.

[0005] In one embodiment, the composite functional thin film further includes a second hydrophobic polymer layer. The second hydrophobic polymer layer is stacked between the copper-based perovskite layer and the bottom electrode, and the thickness ratio of the copper-based perovskite layer to the second hydrophobic polymer layer is 1:1.4 - 1:2.1.

[0006] In one embodiment, the copper-based perovskite layer is selected from (C6H5CH2NH3)2CuBr4 layer, (CH3NH3)CuBr3 layer, or (CH(NH2)2)2CuI4 layer.

[0007] In one embodiment, the thickness ratio of the copper-based perovskite layer to the first hydrophobic polymer layer is 1:1.4 - 1:2.1.

[0008] In one embodiment, the thickness of the copper-based perovskite layer is less than or equal to 50 nm.

[0009] In one embodiment, the flexible optoelectronic dual-control memristor satisfies at least one of the following conditions:

[0010] (1) The flexible substrate is selected from a flexible mica substrate, a polyimide substrate, or a polyethylene terephthalate substrate;

[0011] (2) The first hydrophobic polymer layer is selected from a polymethyl methacrylate layer, a parylene layer, or a polyurethane layer;

[0012] (3) The thickness of the top electrode is 90 nm - 110 nm;

[0013] (4) The thickness of the bottom electrode is 90 nm - 110 nm.

[0014] A method for preparing a flexible optoelectronic dual-control memristor as described above includes the following steps:

[0015] Form a bottom electrode on the surface of the flexible substrate, and the material of the bottom electrode is selected from silver;

[0016] First, form a copper-based perovskite layer on the surface of the bottom electrode, and then form a first hydrophobic polymer layer on the surface of the copper-based perovskite layer away from the bottom electrode. The copper-based perovskite layer and the first hydrophobic polymer layer form a composite functional thin film; and

[0017] Form a top electrode on the surface of the composite functional thin film, and the material of the top electrode is selected from silver to obtain a flexible optoelectronic dual-control memristor.

[0018] In one embodiment, when the copper-based perovskite layer is a (C6H5CH2NH3)2CuBr4 layer, the step of forming the copper-based perovskite layer on the surface of the bottom electrode includes:

[0019] Dissolve C6H5CH2NH3Br and CuBr2 in a solvent to obtain a precursor solution;

[0020] Form the precursor solution on the surface of the bottom electrode, and form a copper-based perovskite layer after heat annealing.

[0021] In one embodiment, in the precursor solution, the molar ratio of C6H5CH2NH3Br to CuBr2 is 1.8:1 - 2.2:1, and the mass fraction of C6H5CH2NH3Br is 60% - 68%;

[0022] And / or, the temperature of the heat annealing is 70°C - 80°C, and the time is 30 min - 50 min.

[0023] Application of a flexible optoelectronic dual - control memristor based on copper - based perovskite as described above in a neuromorphic circuit system.

[0024] In the flexible optoelectronic dual - control memristor provided by the present invention, the materials of the bottom electrode and the top electrode are both selected from silver, and the bottom electrode, the composite functional thin film, and the top electrode are sequentially stacked. Among them, Ag conductive filaments can be formed between the bottom electrode and the top electrode, and the copper - based perovskite layer in the composite functional thin film can generate additional electron - hole pairs under ultraviolet irradiation; under the action of an external voltage, the photo - induced electron - hole pairs split and move in opposite directions, forming an internal electric field in the same direction as the applied electric field, which helps the formation and breakage of Ag conductive filaments. Therefore, under ultraviolet irradiation, the on - off ratio of the flexible optoelectronic dual - control memristor can be increased to more than 60, which is more than 6 times that under non - ultraviolet irradiation conditions. Thus, after continuous ultraviolet stimulation, the flexible optoelectronic dual - control memristor provided by the present invention can effectively regulate the conductivity of the flexible optoelectronic dual - control memristor, realizing a "learning - forgetting - relearning" process similar to the brain and exhibiting various typical optoelectronic synaptic plasticities under optical signal stimulation.

[0025] In addition, in the flexible optoelectronic dual - control memristor based on copper - based perovskite materials provided by the present invention, the bottom electrode, the composite functional thin film, and the top electrode all have excellent bending resistance. At the same time, the first hydrophobic polymer layer in the composite functional thin film can reduce the direct contact between the copper - based perovskite layer and water, thereby improving the humidity stability of the copper - based perovskite layer. Therefore, the flexible optoelectronic dual - control memristor is hardly affected by the bending curvature, the number of bending cycles, and the environment, and can be well applied to flexible electronic products. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 Schematic structural diagram of a flexible optoelectronic dual - control memristor according to an embodiment provided by the present invention;

[0028] Figure 2 Schematic structural diagram of another flexible optoelectronic dual - control memristor according to an embodiment provided by the present invention;

[0029] Figure 3XRD spectrum of the copper-based perovskite layer in Example 1;

[0030] Figure 4 Test results of the effect of mechanical bending on the electrical properties of the flexible optoelectronic dual-control memristor provided in Example 1 in Test Example 1;

[0031] Figure 5 Test results of the ultraviolet radiation response characteristics of the flexible optoelectronic dual-control memristor provided in Example 1 in Test Example 2;

[0032] Figure 6 Test results of the ultraviolet radiation response characteristics of the flexible optoelectronic dual-control memristor provided in Example 1 in different forms of ultraviolet radiation in Test Example 3;

[0033] Figure 7 Test results of the ultraviolet radiation response characteristics of the flexible optoelectronic dual-control memristor provided in Comparative Example 1 in Test Example 4;

[0034] Figure 8 Test results of the ultraviolet radiation response characteristics of the flexible optoelectronic dual-control memristor provided in Example 1 in Test Example 4.

[0035] In the figure, 10, flexible substrate; 20, bottom electrode; 30, composite functional thin film; 301, copper-based perovskite layer; 302, first hydrophobic polymer layer; 303, second hydrophobic polymer layer; 40, top electrode. Detailed implementation manners

[0036] To facilitate the understanding of the present invention, the present invention will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. On the contrary, the purpose of providing these embodiments or examples is to make the understanding of the disclosure content of the present invention more thorough and comprehensive.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments or examples and are not intended to limit the present invention.

[0038] In the first aspect of the present invention, as Figure 1 shown, a flexible optoelectronic dual-control memristor is provided, which includes a flexible substrate 10, a bottom electrode 20, a composite functional thin film 30, and a top electrode 40 that are sequentially stacked. Among them, the materials of the bottom electrode 20 and the top electrode 40 are both selected from silver. The composite functional thin film 30 includes a stacked copper-based perovskite layer 301 and a first hydrophobic polymer layer 302. The first hydrophobic polymer layer 302 is attached to the top electrode 40, and the top electrode 40 does not completely cover the first hydrophobic polymer layer 302.

[0039] In the flexible optoelectronic dual - controlled memristor provided by the present invention, the materials of the bottom electrode 20 and the top electrode 40 are both selected from silver, and the bottom electrode 20, the composite functional thin film 30, and the top electrode 40 are sequentially stacked. Among them, an Ag conductive filament can be formed between the bottom electrode 20 and the top electrode 40, and the copper - based perovskite layer 301 in the composite functional thin film 30 can generate additional electron - hole pairs under ultraviolet irradiation; under the action of an external voltage, the photo - induced electron - hole pairs split and move in opposite directions, forming an internal electric field in the same direction as the applied electric field, which helps the formation and breakage of the Ag conductive filament. Therefore, under ultraviolet irradiation, the on - off ratio of the flexible optoelectronic dual - controlled memristor can be increased to more than 60, which is more than 6 times that under non - ultraviolet irradiation conditions. Thus, the flexible optoelectronic dual - controlled memristor provided by the present invention can effectively regulate the conductivity of the flexible optoelectronic dual - controlled memristor after continuous ultraviolet stimulation, realizing a "learning - forgetting - re - learning" process similar to the brain and exhibiting various typical optoelectronic synaptic plasticities under optical signal stimulation.

[0040] In one embodiment, the copper - based perovskite layer 301 is selected from a (C6H5CH2NH3)2CuBr4 layer, a (CH3NH3)CuBr3 layer, or a (CH(NH2)2)2CuI4 layer; preferably, the thickness of the copper - based perovskite layer 301 is less than or equal to 50 nm, including but not limited to 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, or 50 nm. Within the above range, the thickness of the copper - based perovskite layer 301 affects the turn - on voltage of the flexible optoelectronic dual - controlled memristor. The smaller the thickness of the copper - based perovskite layer 301, the smaller the turn - on voltage.

[0041] In one embodiment, the thickness of the top electrode 40 is 90 nm - 110 nm; the thickness of the bottom electrode 20 is 90 nm - 110 nm; within the above range, the thicknesses of the top electrode 40 and the bottom electrode 20 affect the ohmic contact effect between them and the composite functional thin film 30. The larger the thicknesses of the top electrode 40 and the bottom electrode 20, the better the ohmic contact effect between the top electrode 40 and the bottom electrode 20 and the composite functional thin film 30.

[0042] In addition, in the flexible optoelectronic dual - controlled memristor based on copper - based perovskite materials provided by the present invention, the bottom electrode 20, the composite functional thin film 30, and the top electrode 40 all have excellent bending resistance. At the same time, the hydrophobic polymer layer in the composite functional thin film 30 can reduce the direct contact between the copper - based perovskite layer 301 and water, thereby improving the humidity stability of the copper - based perovskite layer 301. Therefore, the flexible optoelectronic dual - controlled memristor is hardly affected by the bending curvature, the number of bending cycles, and the environment, and can be well applied to flexible electronic products.

[0043] In another embodiment, as Figure 2 shown, the composite functional film 30 further includes a second hydrophobic polymer layer 303. The second hydrophobic polymer layer 303 is attached to the copper-based perovskite layer 301 and the bottom electrode 20, thereby further reducing the direct contact between the copper-based perovskite layer 301 and water, and thus further improving the humidity stability of the copper-based perovskite layer 301.

[0044] In one embodiment, the first hydrophobic polymer layer 302 is selected from a polymethyl methacrylate layer, a polyimide layer, or a polyethylene terephthalate layer; preferably, the first hydrophobic polymer layer 302 is selected from a polymethyl methacrylate layer.

[0045] In one embodiment, the thickness ratio of the copper-based perovskite layer 301 to the first hydrophobic polymer layer 302 is 1:1.4 - 1:2.1, including but not limited to 1:1.4, 1:1.45, 1:1.5, 1:1.55, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:1.2, 1:2.1. Within the above range, the thickness ratio affects the switching voltage and thermal stability of the flexible optoelectronic dual-control memristor. The smaller the thickness ratio, the smaller the switching voltage; the larger the thickness ratio, the better the thermal stability. In one embodiment, the thickness of the first hydrophobic polymer layer is 70 nm - 90 nm, including but not limited to 70 nm, 72 nm, 74 nm, 76 nm, 78 nm, 80 nm, 82 nm, 84 nm, 86 nm, 88 nm, or 90 nm.

[0046] In one embodiment, the selection of the thickness and type of the second hydrophobic polymer layer 303 can refer to the thickness and type of the first hydrophobic polymer layer 302.

[0047] In one embodiment, the material of the flexible substrate 10 is selected from a flexible mica substrate; the thickness is 40 μm - 60 μm, including but not limited to 40 μm, 45 μm, 50 μm, 55 μm, or 60 μm.

[0048] In the second aspect of the present invention, there is provided a preparation method of a flexible optoelectronic dual-control memristor as described above, including the following steps:

[0049] S10, forming a bottom electrode 20 on the surface of the flexible substrate 10, and the material of the bottom electrode 20 is selected from silver;

[0050] S20, first forming a copper-based perovskite layer 301 on the surface of the bottom electrode 20, and then forming a first hydrophobic polymer layer 302 on the surface of the copper-based perovskite layer 301 away from the bottom electrode 20. The copper-based perovskite layer 301 and the first hydrophobic polymer layer 302 form a composite functional film 30; and

[0051] S30. Form a top electrode 40 on the surface of the composite functional film 30. The material of the top electrode 40 is selected from silver to obtain a flexible optoelectronic dual-control memristor.

[0052] In step S10, there is no limitation on the method of forming the bottom electrode 20 on the surface of the flexible substrate 10. In one embodiment, the bottom electrode 20 is formed on the surface of the flexible substrate 10 by magnetron sputtering. Preferably, the process parameters of magnetron sputtering are: the sputtering power is 75W - 85W, the sputtering time is 35min - 45min, the sputtering temperature is 95°C - 105°C, and the process pressure is 0.8Pa - 1.2Pa.

[0053] In one embodiment, before the step of forming the bottom electrode 20 on the surface of the flexible substrate 10, the flexible substrate 10 is cleaned to remove the contamination on the surface of the flexible substrate 10. The cleaning process depends on the type of the flexible substrate 10. When the flexible substrate 10 is selected from a flexible mica substrate, the flexible mica substrate is cleaned with ethanol and water in sequence.

[0054] In step S20, there is no limitation on the method of forming the copper-based perovskite layer 301 on the surface of the bottom silver electrode and forming the first hydrophobic polymer layer 302 on the surface of the copper-based perovskite layer 301 away from the bottom electrode 20. In one embodiment, when the molecular formula of the copper-based perovskite is (C6H5CH2NH3)2CuBr4, the step of forming the copper-based perovskite layer 301 on the surface of the second silver electrode includes:

[0055] S201. Dissolve C6H5CH2NH3Br and CuBr2 in a solvent to obtain a precursor solution;

[0056] S202. Form the precursor solution on the surface of the second electrode and form the copper-based perovskite layer 301 after heat annealing.

[0057] In step S201, in order to better dissolve C6H5CH2NH3Br and CuBr2, preferably, the solvent is selected from at least one of N,N-dimethylformamide, dimethyl sulfoxide or dimethylacetamide.

[0058] In one embodiment, in the precursor solution, the molar ratio of C6H5CH2NH3Br to CuBr2 is 1.8:1 - 2.2:1, so as to avoid the residue of C6H5CH2NH3Br or CuBr2 in the copper-based perovskite layer 301, which affects the optoelectronic performance of the flexible optoelectronic dual-control memristor.

[0059] In one embodiment, the mass fraction of C6H5CH2NH3Br in the precursor solution is 60% - 68%, including but not limited to 60%, 61%, 62%, 63%, 64%, 64.33%, 65%, 66%, 67% or 68%.

[0060] In step S202, before the step of forming the precursor solution on the surface of the second electrode, the precursor solution is filtered, and preferably a filter with a pore size of 0.20 µm - 0.4 µm is used to filter the precursor solution.

[0061] In one embodiment, the temperature of the heat annealing is preferably 70°C - 80°C, and the time is preferably 30 min - 50 min.

[0062] In one embodiment, the step of forming the hydrophobic polymer layer on the surface of the copper-based perovskite layer 301 includes: first forming the polymer solution on the surface of the copper-based perovskite layer 301, and then annealing the hydrophobic polymer layer.

[0063] In step S30, there is no limitation on the manner of forming the first silver electrode on the surface of the hydrophobic polymer layer. In one embodiment, the first silver electrode is formed on the surface of the hydrophobic polymer layer by magnetron sputtering; preferably, the process parameters of magnetron sputtering are: the sputtering power is 75 W - 85 W, the sputtering time is 35 min - 45 min, the sputtering temperature is 95°C - 105°C, and the process pressure is 0.8 Pa - 1.2 Pa.

[0064] In the third aspect of the present invention, there is provided an application of the flexible optoelectronic dual-control memristor of the copper-based perovskite as described above in a neuromorphic circuit system.

[0065] Hereinafter, the flexible optoelectronic dual-control memristor, its preparation method and application will be further described through the following specific examples.

[0066] Example 1

[0067] A flexible mica substrate with a thickness of 50 µm is used as the flexible substrate 10. The flexible mica substrate is ultrasonically cleaned with ethanol and deionized water in sequence to remove surface stains. A silver electrode with a thickness of 100 nm is formed on the flexible mica substrate by magnetron sputtering as the bottom electrode 20 to obtain a silver-plated mica substrate. The silver-plated mica substrate is further cleaned by ultraviolet ozone for a duration of 30 minutes.

[0068] HBr and C6H5CH2NH3 were mixed in a molar ratio of 1:1 and placed in 10 mL of ethanol. Then, the mixture was placed in an ice bath and stirred for 3 hours to synthesize a C6H5CH2NH3Br solution. The obtained C6H5CH2NH3Br solution was placed on an evaporation platform at 60 °C for evaporation. The white precipitate was collected and washed six times with ether. The obtained white precipitate was dried in an oven at 60 °C for 60 hours. The synthesized C6H5CH2NH3Br and CuBr2 were dissolved in 0.2 mL of N,N-dimethylformamide in a molar ratio of 2:1 to prepare a 0.5 mol / L precursor solution. The prepared precursor solution was filtered through a filter with a pore size of 0.20 µm and spin-coated on a silver-plated mica substrate. Then, it was annealed on a heating platform at 75 °C for 40 minutes to form a copper-based perovskite layer 301 with a thickness of 40 nm. The XRD spectrum of the copper-based perovskite layer 301 is as Figure 3 shown, and from Figure 3 it can be seen that the XRD characteristic peaks of (C6H5CH2NH3)2CuBr4 do not overlap with the peaks of the original C6H5CH2NH3Br and CuBr2, indicating that no raw material residues were detected in the copper-based perovskite layer 301.

[0069] A polymethyl methacrylate solution was spin-coated on the surface of the copper-based perovskite layer 301 and annealed at 50 °C for 5 minutes to form a polymethyl methacrylate layer with a thickness of 80 nm as the first hydrophobic polymer layer 302.

[0070] A circular silver electrode with a thickness of 100 nm and a diameter of 100 µm was deposited on the surface of the polymethyl methacrylate layer by magnetron sputtering as the top electrode 40, obtaining a flexible optoelectronic dual-control memristor.

[0071] Test Example 1

[0072] Test the effect of mechanical bending on the electrical properties of the flexible optoelectronic dual-control memristor prepared in Example 1. The test results are as Figure 4 shown. Figure 4 In (a) of Figure 4 shows a schematic diagram of the structure of the flexible optoelectronic dual-control memristor in the bent state. The bending degree of the flexible optoelectronic dual-control memristor can be adjusted by changing the length of L. The shorter L is, the greater the bending degree of the flexible optoelectronic dual-control memristor. Figure 4 In (b) of Figure 4As can be seen from (c) in [reference], after 500 bending cycles, the high resistance state (HRS) and low resistance state (LRS) of the flexible optoelectronic dual - control memristor remain relatively stable. This result indicates that the flexible optoelectronic dual - control memristor has good mechanical flexibility.

[0073] Test Example 2

[0074] The response characteristics of the flexible optoelectronic dual - control memristor prepared in Test Example 1 to ultraviolet (UV) radiation are as follows Figure 5 shown as Figure 5 In (a) of [reference], the I - V characteristic curve of the flexible optoelectronic dual - control memristor under no - light condition and the schematic diagram of the test circuit are shown. As can be seen from (a) in Figure 5 [reference], all bias voltages are applied to the top electrode 40, while the bottom electrode 20 is grounded. Under the forward voltage scan, the flexible optoelectronic dual - control memristor switches from the high resistance state (HRS) to the low resistance state (LRS), and the set voltage is 0.25 V. Under the reverse voltage scan, the flexible optoelectronic dual - control memristor returns to the low resistance state, and the reset voltage is - 0.24 V. The I - V characteristic curve of the flexible optoelectronic dual - control memristor under ultraviolet irradiation is as Figure 5 shown in (b) of [reference]. Compared with the I - V characteristic curve of the flexible optoelectronic dual - control memristor under no - light condition, the set voltage and reset voltage of the flexible optoelectronic dual - control memristor under ultraviolet irradiation are significantly reduced to 0.19 V and - 0.2 V respectively; compared with the I - V characteristic curve of the flexible optoelectronic dual - control memristor under no - light condition, the operating voltage of the flexible optoelectronic dual - control memristor under ultraviolet irradiation is lower.

[0075] Figure 5 (c) in [reference] and (d) in [reference 5] respectively show the fatigue characteristics and retention characteristics of the flexible optoelectronic dual - control memristor with and without ultraviolet irradiation. As can be seen from (c) in Figure 5 [reference], after 1000 resistive switching cycles with or without ultraviolet irradiation, the high resistance state and low resistance state of the flexible optoelectronic dual - control memristor do not show significant changes. It can be seen that the flexible optoelectronic dual - control memristor provided by the present invention has excellent storage stability under ultraviolet irradiation. In addition, when the flexible optoelectronic dual - control memristor performs resistance switching without ultraviolet irradiation, its switching ratio is only 10. Under ultraviolet irradiation, the switching ratio increases significantly to 60, which is 6 times that under non - ultraviolet irradiation conditions. As can be seen from (d) in Figure 5 [reference], the resistances of the flexible optoelectronic dual - control memristor in the LRS and HRS show excellent retention characteristics up to 1×10 4 s with and without ultraviolet irradiation.

[0076] Test Example 3

[0077] The optical properties of the flexible optoelectronic dual - controlled memristor were studied by irradiating it with different forms of ultraviolet light, and the test results are as follows Figure 6 shown. As Figure 6 shown in (a) of 2 , when the flexible optoelectronic dual - controlled memristor was exposed to ultraviolet light with an intensity of 4.01 mW / cm Figure 6 and a wavelength of 375 nm for 10 seconds, the photocurrent response increased rapidly. After removing the ultraviolet light source irradiation, the photocurrent gradually decreased, which confirmed that the synaptic weight of the flexible optoelectronic dual - controlled memristor could be improved by ultraviolet stimulation. To further verify the photo - excitation plasticity induced by ultraviolet stimulation, the paired - pulse facilitation (PPF) of photo - excitation was studied, and the test results are as follows 2 shown in (b) of Figure 6 . Different from the PPF behavior of electrical excitation, when the flexible optoelectronic dual - controlled memristor was irradiated with two consecutive ultraviolet pulses with a width of 2 s and an intensity of 4.01 mW / cm 2 , compared with the first ultraviolet pulse, the amplitude of the photocurrent response generated during the second ultraviolet pulse irradiation was larger. As the interval between the two consecutive ultraviolet pulses increased, the coefficient of photo - excitation PPF gradually decreased and approached 0%. 2 Shown in (c) of Figure 6 is the change in photocurrent response when the fixed ultraviolet irradiation time was 10 s and the light intensity gradually increased from 2.01 mW / cm Figure 6 shown in (d) of 2 is the photocurrent response of the flexible optoelectronic dual - controlled memristor under four consecutive ultraviolet stimulations with a duration of 5 s and an intensity of 4.01 mW / cm Figure 6 . As can be seen from (d) of

[0078] Comparative Example 1

[0079] Comparative Example 1 was carried out with reference to Example 1, except that the top electrode was replaced with a platinum electrode.

[0080] Test Example 4

[0081] Test Example 1 and Comparative Example 1 provide the response characteristics of the flexible optoelectronic dual - controlled memristor to ultraviolet radiation. The response characteristics of the flexible optoelectronic dual - controlled memristor provided by Comparative Example 1 are as Figure 7 shown. The response characteristics of the flexible optoelectronic dual - controlled memristor provided by Example 1 are as Figure 8 shown.

[0082] As Figure 7 shown, the flexible optoelectronic dual - controlled memristor provided by Comparative Example 1 has only two resistance states, namely the low - resistance state and the high - resistance state. In contrast, the I - V characteristic curve of the flexible optoelectronic dual - controlled memristor provided by Example 1 has also changed. As can be seen from Figure 8 (a) in it, under the positive and negative voltage scans, the current of the flexible optoelectronic dual - controlled memristor changes continuously and slowly. This slow regulation is an important basis for realizing bidirectional conductivity regulation in synaptic bionics. To further demonstrate the continuously adjustable electrical properties of the flexible optoelectronic dual - controlled memristor provided by Example 1 in the DC scan mode, four consecutive scans were carried out in the positive and negative voltage directions. The test results are as Figure 8 (b) in it and Figure 8 (c) in it shown; among them, Figure 8 (b) in it shows the I - V characteristic curve of the flexible optoelectronic dual - controlled memristor after applying four consecutive positive scan voltages. As can be seen from Figure 8 (b) in it, the current of the flexible optoelectronic dual - controlled memristor gradually increases with the increase of the number of scans. Figure 8 (c) in it shows the I - V characteristic curve of the flexible optoelectronic dual - controlled memristor after applying four consecutive negative scan voltages. As can be seen from Figure 8 (c) in it, under the action of the negative scan voltage, the current of the flexible optoelectronic dual - controlled memristor decreases with the increase of the number of scans. The above results show that the conductance of this flexible optoelectronic dual - controlled memristor can be bidirectionally regulated under DC voltage scans. Figure 8 (d) in it shows the durability of the flexible optoelectronic dual - controlled memristor provided by Example 1. As can be seen from Figure 8 (d) in it, even after 1000 consecutive cycles, the resistance values of the high - resistance state and the low - resistance state do not show obvious fluctuations.

[0083] The technical features of the above - described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above - described embodiments are described. However, as long as the combinations of these technical features do not conflict, they should all be considered as the scope recorded in this specification.

[0084] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A flexible optoelectronic dual-controlled memristor, characterized in that, It includes a flexible substrate, a bottom electrode, a composite functional thin film, and a top electrode which are sequentially stacked. Among them, the materials of the bottom electrode and the top electrode are both selected from silver. The composite functional thin film includes a stacked copper-based perovskite layer and a first hydrophobic polymer layer. The top electrode is stacked on the first hydrophobic polymer layer, and the top electrode does not completely cover the first hydrophobic polymer layer. Among them, the thickness of the copper-based perovskite layer is less than or equal to 50 nm, the thickness of the top electrode is 90 nm - 110 nm, and the thickness of the bottom electrode is 90 nm - 110 nm.

2. The flexible optoelectronic dual-control memristor according to claim 1, characterized in that, The composite functional thin film further includes a second hydrophobic polymer layer. The second hydrophobic polymer layer is stacked between the copper-based perovskite layer and the bottom electrode. The thickness ratio of the copper-based perovskite layer to the second hydrophobic polymer layer is 1:1.4 - 1:2.

1.

3. The flexible optoelectronic dual-control memristor according to claim 1, characterized in that The copper-based perovskite layer is selected from (C6H5CH2NH3)2CuBr4 layer, (CH3NH3)CuBr3 layer, or (CH(NH2)2)2CuI4 layer.

4. The flexible optoelectronic dual-control memristor according to claim 1, characterized in that, The thickness ratio of the copper-based perovskite layer to the first hydrophobic polymer layer is 1:1.4 - 1:2.

1.

5. The flexible optoelectronic dual-control memristor according to any one of claims 1 to 4, characterized in that, The flexible substrate is selected from a flexible mica substrate, a polyimide substrate, or a polyethylene terephthalate substrate.

6. The flexible optoelectronic dual-controlled memristor according to any one of claims 1 to 4, characterized in that, The first hydrophobic polymer layer is selected from a polymethyl methacrylate layer, a parylene layer, or a polyurethane layer.

7. A method for preparing a flexible optoelectronic dual-control memristor according to any one of claims 1 to 6, characterized in that, It includes the following steps: Form a bottom electrode on the surface of the flexible substrate. The material of the bottom electrode is selected from silver. First, form a copper-based perovskite layer on the surface of the bottom electrode, and then form a first hydrophobic polymer layer on the surface of the copper-based perovskite layer away from the bottom electrode. The copper-based perovskite layer and the first hydrophobic polymer layer form a composite functional thin film. And Form a top electrode on the surface of the composite functional thin film. The material of the top electrode is selected from silver to obtain a flexible optoelectronic dual-control memristor.

8. The preparation method of the flexible optoelectronic dual-control memristor according to claim 7, characterized in that, When the copper-based perovskite layer is selected from (C6H5CH2NH3)2CuBr4 layer, the step of forming the copper-based perovskite layer on the surface of the bottom electrode includes: Dissolve C6H5CH2NH3Br and CuBr2 in a solvent to obtain a precursor solution. Form the precursor solution on the surface of the bottom electrode and form a copper-based perovskite layer after heat annealing.

9. The preparation method of the flexible optoelectronic dual-control memristor according to claim 8, wherein, In the precursor solution, the molar ratio of C6H5CH2NH3Br to CuBr2 is 1.8:1 - 2.2:1, and the mass fraction of C6H5CH2NH3Br is 60% - 68%. And / or, the temperature of heat annealing is 70°C - 80°C, and the time is 30 min - 50 min.

10. Application of the flexible optoelectronic dual-control memristor of the copper-based perovskite according to any one of claims 1 to 6 in a neuromorphic circuit system.

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