Fibrous photoelectric sensing and memory integrated device and preparation method thereof

Abstract

This invention discloses a fibrous optoelectronic sensing and memory integrated device and its fabrication method. The device includes a first electrode unit and a second electrode unit spirally wound together. The first electrode unit includes a flexible carbon nanotube fiber electrode and n-type TiO₂ uniformly distributed on its surface. 2‑x Nanowire array; the second electrode unit includes a flexible carbon nanotube fiber electrode and a p-type MoS2 nanosheet array uniformly distributed on its surface, wherein the n-type TiO2... 2‑x The nanowire array and the p-type MoS2 nanosheet array are in close contact and can form a heterojunction interface. The device of the present invention can effectively simulate the electrical synaptic plasticity functions, such as pulse facilitation, long and short duration plasticity, and the "learning-memory-consolidation" behavior of optical signals; and also has excellent flexibility and optical memory function that is not affected by the incident light angle, and can be freely woven into fabrics to realize a wearable visual perception and memory integrated fabric system.

Description

Technical Field

[0001] This invention relates to a novel optoelectronic sensing and memory integrated device, specifically a fiber-like wearable optoelectronic sensing and memory integrated device and its preparation method, belonging to the technical field of optoelectronic materials and functional devices. Background Technology

[0002] Wearable electronics are an attractive emerging platform for close human interaction. Among them, electronic textiles, which can seamlessly connect to the human body, are a natural carrier for artificial intelligence. In human interaction with the outside world, the visual system plays a crucial role, as over 80% of external information is received through our eyes. Current artificial vision systems can continuously and in real-time perceive external image information, but they always generate a large amount of redundant data. Unfortunately, the physical separation of perception and memory units in existing visual systems leads to excessive storage space consumption and high power consumption. In contrast, the human visual system, with its sensory retinal neurons, not only directly responds to light stimuli but also performs first-stage imaging for storage and processing. Therefore, exploring novel, multifunctional devices that integrate visual perception and memory functions holds promise for wearable visual systems, but it remains a significant challenge.

[0003] Previously reported fiber-based photodetectors can sense ultraviolet light signals, but unfortunately, they cannot remember the sensed light signals; that is, their photocurrent disappears instantly when the light is removed. Artificial optoelectronic sensing and memory integrated devices, which can respond to electronic / optical stimuli and simultaneously achieve temporary memory, provide a suitable option for the development of artificial vision systems. In particular, two-terminal optoelectronic sensing and memory integrated devices are considered promising for mimicking biological synaptic behavior due to their simple structure, similar to biological synapses and continuously modulated electrical conductance. However, due to their rigid planar structure, these rigid planar substrates are often attached to rough and easily deformable textiles, resulting in poor performance and even degradation over time; in addition, they inevitably sacrifice the flexibility and breathability of textiles to some extent. As a basic unit of textiles, one-dimensional fibers have many unique advantages, such as light weight, ultra-flexibility, and omnidirectional light absorption, which are of great significance for future electronics; at the same time, with mature weaving technology, they can be further freely woven into breathable textiles. Therefore, developing robust and flexible functional fibers provides a convenient way to achieve high-performance textiles. Summary of the Invention

[0004] The main objective of this invention is to provide a fiber-like device and its fabrication method that can simultaneously respond to light and electrical stimulation and can memorize the sensed light signals, thereby enabling wearable applications that integrate visual perception and memory, in order to overcome the shortcomings of the prior art.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0006] This invention provides a fibrous optoelectronic sensing and memory integrated device, comprising: at least one first electrode unit and at least one second electrode unit spirally wound together, wherein the first electrode unit comprises a flexible carbon nanotube fiber electrode and n-type TiO₂ uniformly distributed on the surface of the flexible carbon nanotube fiber electrode. 2-x Nanowire array; the second electrode unit includes a flexible carbon nanotube fiber electrode and a p-type MoS2 nanosheet array uniformly distributed on the surface of the flexible carbon nanotube fiber electrode.

[0007] Among them, the n-type TiO 2-x The nanowire array and the p-type MoS2 nanosheet array are in close contact and can form a heterojunction interface.

[0008] This invention also provides a method for fabricating a fiber-like optoelectronic sensing and memory integrated device, comprising:

[0009] n-type TiO₂ was grown on the surface of a flexible carbon nanotube fiber electrode using a hydrothermal method. 2-x Nanowire arrays were used to fabricate the first electrode unit;

[0010] A second electrode unit was prepared by growing a p-type MoS2 nanosheet array on the surface of a flexible carbon nanotube fiber electrode using a hydrothermal method.

[0011] The fiber-shaped optoelectronic sensing and memory integrated device is obtained by spirally winding at least one first electrode unit and at least one second electrode unit together.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0013] The n-type TiO contained in the fiber-like optoelectronic sensing and memory integrated device provided by this invention 2-x The nanowire array and the p-type MoS2 nanosheet array form a heterojunction, which effectively simulates the electrical synaptic plasticity functions such as pulse facilitation and long and short duration plasticity; the "learning-memory-consolidation" behavior of optical signals; and the device also has excellent flexibility and optical memory function that is not affected by the incident light angle, and can be freely woven into fabrics to realize a wearable visual perception memory integrated fabric system. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of a fiber-shaped optoelectronic sensing and memory integrated device in a typical embodiment of the present invention;

[0016] Figure 2 This is a scanning electron microscope image of a fiber-shaped optoelectronic sensing and memory integrated device in a typical embodiment of the present invention;

[0017] Figure 3 This is a test diagram of the electrical synaptic characteristics of a fiber-shaped optoelectronic sensing and memory integrated device in a typical embodiment of the present invention;

[0018] Figure 4 This is a simulation diagram of the "learning-memory-consolidation" behavior of the fiber-shaped optoelectronic sensing and memory integrated device under the stimulation of light signals in a typical embodiment of the present invention;

[0019] Figure 5 This is a schematic diagram of multiple fibrous optoelectronic sensing and memory integrated devices woven into a fabric in a typical embodiment of the present invention. Detailed Implementation

[0020] In response to the shortcomings of existing technologies, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention, which mainly provides a fiber-like device that can simultaneously respond to light and electrical stimulation and can memorize the sensed light signals, thereby realizing wearable applications and integrating visual perception and memory, as well as its preparation method.

[0021] The following will further explain the technical solution, its implementation process, and its principles. However, it should be understood that within the scope of this invention, the above-mentioned technical features of this invention and the technical features specifically described below (in embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be described in detail here.

[0022] As one aspect of the technical solution of this invention, a fiber-shaped optoelectronic sensing and memory integrated device is described below. Figure 1 As shown, it specifically includes:

[0023] At least one first electrode unit and at least one second electrode unit are spirally wound together. The first electrode unit includes a flexible carbon nanotube fiber electrode and an n-type TiO2 uniformly covering the surface of the flexible carbon nanotube fiber electrode.2-x The nanowire array; the second electrode unit includes a flexible carbon nanotube fiber electrode and a p-type MoS2 nanosheet array uniformly covering the surface of the flexible carbon nanotube fiber electrode.

[0024] In this invention, n-type TiO 2-x A nanowire array and a p-type MoS2 nanosheet array are in close contact to form a heterojunction, resulting in a fibrous optoelectronic sensing and memory integrated device containing oxygen vacancies.

[0025] In some preferred embodiments, n-type TiO 2-x Nanowire arrays and p-type MoS2 nanosheet arrays are densely and uniformly coated on the surface of carbon nanotube fiber electrodes, and then the two are helically wound to form a fibrous optoelectronic sensing and memory integrated device structure. The specific mechanism lies in: n-type TiO2... 2-x The nanowire array is in close contact with the p-type MoS2 nanosheet array, and the integrated optoelectronic sensing and memory function is achieved through the formation of a pn heterojunction and TiO2. 2-x The transport and collection of photogenerated carriers are achieved through oxygen vacancy migration and are accomplished through internal flexible carbon nanotube fiber electrodes.

[0026] The p-MoS2 nanosheets / n-TiO formed by this invention 2-x A nanowire array-type optoelectronic sensing and memory integrated device can simulate biological synaptic plasticity, including pulse facilitation and long / short duration plasticity, by applying electrical stimulation. Furthermore, this fibrous optoelectronic sensing and memory device effectively promotes photogenerated carrier separation under ultraviolet light stimulation, and facilitates the separation of photogenerated carriers at the heterojunction interface and TiO₂. 2-x The migration of oxygen vacancies allows this integrated sensing and memory device to simulate the biological process of "learning-memorizing-consolidating" photocurrent. The fibrous optoelectronic sensing and memory integrated device, using carbon nanotube fibers as flexible electrodes, exhibits excellent flexibility, and the illumination angle has virtually no impact on the device's performance.

[0027] As one of the preferred solutions, the n-type TiO 2-x Nanowire arrays are grown on the surface of flexible carbon nanotube fiber electrodes via a hydrothermal method.

[0028] Furthermore, the diameter of the flexible carbon nanotube fiber electrode is 10-250 μm.

[0029] Furthermore, the n-type TiO 2-x TiO contained in nanowire array 2-x The nanowires have a diameter of 30-200 nm and a height of 0.5-2.5 μm.

[0030] As one of the preferred options, the p-type MoS2 nanosheet array is grown on the surface of a flexible carbon nanotube fiber electrode via a hydrothermal method and subsequent reduction.

[0031] Furthermore, the thickness of the MoS2 nanosheets contained in the p-type MoS2 nanosheet array is 0.5-3 nm, and the diameter is 5-50 nm.

[0032] As one of the preferred options, the n-type TiO₂ in the fiber-like optoelectronic sensing and memory integrated device 2-x The content of nanowire array is 50-80 wt%, and the content of p-type MoS2 nanosheet array is 20-50 wt%.

[0033] Another aspect of the present invention provides a method for fabricating the aforementioned fiber-like optoelectronic sensing and memory integrated device, comprising:

[0034] n-type TiO₂ was grown on the surface of a flexible carbon nanotube fiber electrode using a hydrothermal method. 2-x Nanowire arrays were used to fabricate the first electrode unit;

[0035] A second electrode unit was prepared by growing a p-type MoS2 nanosheet array on the surface of a flexible carbon nanotube fiber electrode using a hydrothermal method.

[0036] At least one first electrode unit and at least one second electrode unit are spirally wound together to assemble the two into the fiber-shaped optoelectronic sensing and memory integrated device.

[0037] Furthermore, the first electrode unit and the second electrode unit are twisted and intertwined to form a typical fiber-like optoelectronic sensing and memory integrated device.

[0038] In some preferred embodiments, the preparation method includes: immersing a flexible carbon nanotube fiber electrode in a first solution containing a titanium source and reacting it at 70-120°C for 0.5-3 hours to form TiO2 nanoparticles on the surface of the carbon nanotube fiber electrode, thereby obtaining a carbon nanotube fiber electrode coated with TiO2 nanoparticles.

[0039] The TiO2 nanoparticle-coated carbon nanotube fiber electrode was immersed in a second solution containing a titanium source and heated for 2-12 hours at a pressure of 2-5 MPa and a temperature of 80-230°C. Finally, the obtained product was annealed and reduced in a hydrogen atmosphere to obtain n-type TiO2 containing oxygen vacancies on the surface of the flexible carbon nanotube fiber electrode. 2-x Nanowire array.

[0040] Further, the titanium source in the first solution containing a titanium source or the second solution containing a titanium source includes TiCl4, TiCl3, and C. 16 H 36 Any one or more combinations of O4Ti, etc., but not limited to this.

[0041] Furthermore, the concentration of the titanium source in the first solution containing the titanium source is 0.1-0.5 mol / L.

[0042] Furthermore, the concentration of the titanium source in the second solution containing the titanium source is 20-100 mmol / L.

[0043] Furthermore, the second solution containing the titanium source includes the titanium source, HCl, and water, wherein the volume ratio of HCl to water can be 1:3 to 2:1.

[0044] In some preferred embodiments, the annealing reduction treatment is performed at a temperature of 350-650°C for a time of 0.5-3 hours.

[0045] Furthermore, the preparation method further includes: firstly subjecting the flexible carbon nanotube fiber electrode to plasma pretreatment for 5-15 min, and then growing n-type TiO2 on the surface of the flexible carbon nanotube fiber electrode. 2-x Nanowire array.

[0046] In some preferred embodiments, the preparation method includes: subjecting a mixed reaction system comprising a flexible carbon nanotube fiber electrode, molybdate, thiourea and water to a hydrothermal reaction at a pressure of 1-5 MPa and a temperature of 140-240 °C for 8-26 h, thereby uniformly and densely growing a p-type MoS2 nanosheet array on the surface of the flexible carbon nanotube fiber electrode.

[0047] Further, the mass ratio of the molybdate to thiourea is 1-3:3-1. The molybdate may be ammonium molybdate and / or sodium molybdate, but is not limited to these.

[0048] As a more preferred embodiment, the fabrication steps of the fiber-shaped optoelectronic sensing and memory integrated device are as follows:

[0049] (1) First electrode unit (i.e., TiO2) 2-x Fabrication of nanowire array carbon nanotube fiber electrodes: First, the flexible carbon nanotube fiber electrodes were pretreated with plasma for 5-15 minutes. Uniform and dense TiO₂ was then prepared on the flexible carbon nanotube fiber electrodes via hydrothermal method and hydrogen reduction. 2-xNanowire array. More specifically, the obtained carbon nanotube fiber electrodes were directly immersed in a TiCl4 (0.1-0.5M) aqueous solution and cultured at 70-120℃ for 0.5-3h to cultivate uniform TiO2 nanoparticles on the carbon nanotube fiber electrode matrix. Subsequently, the carbon nanotube fiber electrodes coated with the above TiO2 nanoparticles were transferred to a 100mL PTFE-lined autoclave containing a 20-100mM TiCl4 HCl / deionized water (volume ratio 1:1) mixed solution. Furthermore, the PTFE-lined autoclave was heated at 80-230℃ for 2-12h to obtain the final sample. The prepared sample was washed three times with deionized water and dried overnight in a vacuum oven at 60℃. The obtained TiO2 nanoparticles were then... 2-x Nanowire array samples were annealed and reduced at 350-650℃ for 0.5-3 hours under a hydrogen atmosphere to prepare TiO2 containing oxygen vacancies. 2-x sample.

[0050] (2) Preparation of the first electrode unit (i.e., the MoS2 nanosheet array carbon nanotube fiber electrode): The original carbon nanotube fiber electrode and the mixed solution (specifically, 1.031 g ammonium molybdate tetrahydrate and 0.918 g thiourea in 90 mL deionized water) were transferred to a 100 mL high-pressure reactor lined with polytetrafluoroethylene. Hydrothermal experiments were conducted at 140-240 °C for 8-26 h. Finally, the electrode was washed three times with deionized water and dried overnight in a vacuum oven at 60 °C to prepare a uniformly dense MoS2 nanosheet array grown on the carbon nanotube fiber electrode.

[0051] (3) Device assembly: By twisting TiO 2-x Typical fibrous optoelectronic sensing and memory integrated devices were fabricated using nanowire array carbon nanotube fiber electrodes and MoS2 nanosheet array carbon nanotube fiber electrodes, and then fixed onto a flexible PET substrate. After electrical connection, their performance can be characterized. For fabric arrays, the fabricated multi-fiber optoelectronic sensing and memory integrated devices were carefully woven into the fabric using needles, and the terminal electrodes of the devices were connected to external circuitry.

[0052] This invention weaves multiple fibrous optoelectronic sensing and memory integrated devices into a flexible fabric, ultimately realizing not only wearable optical image sensing, but also a fabric system for memorizing light images.

[0053] Through the above technical solution, the fiber shape of the present invention endows the optoelectronic sensing and memory integrated device with excellent flexibility and optical memory function that is unaffected by the incident light angle; carbon nanotube fiber electrodes and n-type TiO2 2-xThe fibrous optoelectronic sensing and memory integrated device formed by the heterojunction of nanowire array and p-type MoS2 nanosheet array can be freely woven into fabric to realize a wearable visual sensing and memory integrated fabric system.

[0054] To make the objectives, technical solutions, and applications of this invention clearer, the technical solutions of this invention will be further described in detail below with reference to several preferred embodiments and accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. The implementation conditions used in the following embodiments can be further adjusted according to actual needs; implementation conditions not specified are generally conditions in conventional experiments.

[0055] Example 1

[0056] One such Figure 1 The fibrous optoelectronic sensing and memory integrated device shown includes carbon nanotube fiber electrodes and TiO2. 2-x Nanowire array carbon nanotube fiber electrode, MoS2 nanosheet array carbon nanotube fiber electrode and n-type TiO2 2-x A heterojunction composed of a nanowire array and a p-type MoS2 nanosheet array.

[0057] The fiber-like optoelectronic sensing and memory integrated device in this embodiment is fabricated using a hydrothermal growth method, and the specific fabrication method is as follows:

[0058] 1. Preparation of TiO2 nanowire array carbon nanotube fiber electrode: First, the carbon nanotube fiber electrode was pretreated with plasma for 5 min. A uniform and dense TiO2 nanowire array covering the carbon nanotube fiber electrode was prepared via a hydrothermal method. Specifically, the obtained carbon nanotube fiber electrode was directly immersed in a TiCl4 (0.2 M) aqueous solution and cultured at 100 °C for 1 h, resulting in the formation of uniform TiO2 nanoparticles on the carbon nanotube fiber electrode matrix. Subsequently, the TiO2 nanoparticle-coated carbon nanotube fiber electrode was transferred to a 100 mL PTFE-lined autoclave containing a 1:1 volumetric HCl / deionized water mixture of 75 mM TiCl4. The PTFE-lined autoclave (pressure 5 MPa) was then heated at 150 °C for 6 h to obtain the final sample. The prepared sample was washed three times with deionized water and dried overnight at 60 °C in a vacuum oven. The obtained TiO2 sample was then annealed and reduced under a hydrogen atmosphere to obtain TiO2 nanowires. 2-x The hydrogen annealing treatment was carried out at a temperature of 350℃ for 3 hours.

[0059] 2. Preparation of MoS2 nanosheet array carbon nanotube fiber electrode: The original carbon nanotube fiber electrode and the mixed solution (specifically, 1.031 g ammonium molybdate tetrahydrate and 0.918 g thiourea in 90 mL deionized water) were transferred to a 100 mL polytetrafluoroethylene-lined autoclave. A hydrothermal experiment was conducted at 4 MPa and 200 °C for 20 h. Finally, the electrode was washed three times with deionized water and dried overnight in a vacuum oven at 60 °C to prepare a uniformly dense MoS2 nanosheet array grown on the carbon nanotube fiber electrode.

[0060] 3. Device assembly: By twisting TiO 2-x Typical fibrous optoelectronic sensing and memory integrated devices were fabricated using carbon nanotube fiber electrodes and MoS2 carbon nanotube fiber electrodes and fixed on a flexible PET substrate. After electrical connection, their performance can be characterized.

[0061] 4. For fabric arrays, multiple prepared fibrous optoelectronic sensing and memory integrated devices are carefully woven into the fabric using needles, and the terminal electrodes of the devices are connected to external circuits.

[0062] The inventors in this case also characterized and analyzed the fabricated fibrous optoelectronic sensing and memory integrated device, with the following results:

[0063] Figure 2 This is a scanning electron microscope image of the fiber-shaped optoelectronic sensing and memory integrated device. Figure 3 This is a test diagram of the electrical synaptic characteristics of a fiber-reinforced optoelectronic sensing and memory integrated device. Figure 4 This is a simulation diagram of the "learning-memory-consolidation" behavior of a fiber-optic integrated sensing and memory device under optical signal stimulation. Figure 5 This is a schematic diagram of weaving multiple fiber-shaped optoelectronic sensing and memory integrated devices into a fabric.

[0064] Example 2

[0065] 1. Preparation of TiO2 nanowire array carbon nanotube fiber electrode: First, the carbon nanotube fiber electrode was pretreated with plasma for 5 min. A uniform and dense TiO2 nanowire array covering the carbon nanotube fiber electrode was prepared via a hydrothermal method. Specifically, the obtained carbon nanotube fiber electrode was directly immersed in a TiCl4 (0.2 M) aqueous solution and cultured at 90 °C for 3 h to cultivate uniform TiO2 nanoparticles on the carbon nanotube fiber electrode matrix. Subsequently, the TiO2 nanoparticle-coated carbon nanotube fiber electrode was transferred to a 100 mL PTFE-lined autoclave containing a 100 mM TiCl4 HCl / deionized water (volume ratio 1:1) mixed solution. The PTFE-lined autoclave (pressure 4 MPa) was then heated at 180 °C for 3 h to obtain the final sample. The prepared sample was washed three times with deionized water and dried overnight at 60 °C in a vacuum oven. The obtained TiO2 sample was then reduced under a hydrogen atmosphere to obtain TiO2. 2-x The hydrogen annealing treatment was carried out at a temperature of 450℃ for 2 hours.

[0066] 2. Preparation of MoS2 nanosheet array carbon nanotube fiber electrode: The original carbon nanotube fiber electrode and the mixed solution (specifically, 1.031 g ammonium molybdate tetrahydrate and 0.918 g thiourea in 90 mL deionized water) were transferred to a 100 mL polytetrafluoroethylene-lined autoclave. A hydrothermal experiment was conducted at 5 MPa and 140 °C for 26 h. Finally, the electrode was washed three times with deionized water and dried overnight in a vacuum oven at 60 °C to prepare a uniformly dense MoS2 nanosheet array grown on the carbon nanotube fiber electrode.

[0067] 3. Device assembly: By twisting TiO 2-x Typical fibrous optoelectronic sensing and memory integrated devices were fabricated using carbon nanotube fiber electrodes and MoS2 carbon nanotube fiber electrodes and fixed on a flexible PET substrate. After electrical connection, their performance can be characterized.

[0068] Example 3

[0069] 1. Preparation of TiO2 nanowire array carbon nanotube fiber electrode: First, the carbon nanotube fiber electrode was pretreated with plasma for 5 min. A uniform and dense TiO2 nanowire array covering the carbon nanotube fiber electrode was prepared via a hydrothermal method. Specifically, the obtained carbon nanotube fiber electrode was directly immersed in a TiCl3 (0.3 M) aqueous solution and cultured at 70 °C for 3 h to cultivate uniform TiO2 nanoparticles on the carbon nanotube fiber electrode matrix. Subsequently, the TiO2 nanoparticle-coated carbon nanotube fiber electrode was transferred to a 100 mL PTFE-lined autoclave containing a 2:1 volumetric HCl / deionized water solution with 95 mM TiCl3. The PTFE-lined autoclave (pressure 3 MPa) was then heated at 160 °C for 6 h to obtain the final sample. The prepared sample was washed three times with deionized water and dried overnight at 60 °C in a vacuum oven. The obtained TiO2 sample was then reduced under a hydrogen atmosphere to obtain TiO2 nanowires. 2-x The hydrogen annealing treatment was carried out at a temperature of 350℃ for 3 hours.

[0070] 2. Preparation of MoS2 nanosheet array carbon nanotube fiber electrode: The original carbon nanotube fiber electrode and the mixed solution (specifically, 3.093 g ammonium molybdate tetrahydrate and 0.918 g thiourea in 90 mL deionized water) were transferred to a 100 mL polytetrafluoroethylene-lined autoclave. A hydrothermal experiment was conducted at 3 MPa and 240 °C for 8 h. Finally, the electrode was washed three times with deionized water and dried overnight in a vacuum oven at 60 °C to prepare a uniformly dense MoS2 nanosheet array grown on the carbon nanotube fiber electrode.

[0071] 3. Device assembly: By twisting TiO 2-x Typical fibrous optoelectronic sensing and memory integrated devices were fabricated using carbon nanotube fiber electrodes and MoS2 carbon nanotube fiber electrodes and fixed on a flexible PET substrate. After electrical connection, their performance can be characterized.

[0072] Example 4

[0073] 1. Preparation of TiO2 nanowire array carbon nanotube fiber electrode: First, the carbon nanotube fiber electrode was pretreated with plasma for 15 min. A uniform and dense TiO2 nanowire array covering the carbon nanotube fiber electrode was prepared via a hydrothermal method. Specifically, the obtained carbon nanotube fiber electrode was directly immersed in a TiCl4 (0.1 M) aqueous solution and cultured at 80 °C for 2.5 h, resulting in the formation of uniform TiO2 nanoparticles on the carbon nanotube fiber electrode matrix. Subsequently, the TiO2 nanoparticle-coated carbon nanotube fiber electrode was transferred to a 100 mL PTFE-lined autoclave containing a 1:1 (volume ratio) HCl / deionized water solution with 75 mM TiCl4. The PTFE-lined autoclave (pressure 5 MPa) was then heated at 80 °C for 12 h to obtain the final sample. The prepared sample was washed three times with deionized water and dried overnight at 60 °C in a vacuum oven. The obtained TiO2 sample was then reduced under a hydrogen atmosphere to obtain TiO2 nanoparticles. 2-x The hydrogen annealing treatment was carried out at a temperature of 350℃ for 3.5 hours.

[0074] 2. Preparation of MoS2 nanosheet array carbon nanotube fiber electrode: The original carbon nanotube fiber electrode and the mixed solution (specifically, 1.051 g sodium molybdate tetrahydrate and 0.918 g thiourea in 90 mL deionized water) were transferred to a 100 mL polytetrafluoroethylene-lined autoclave. A hydrothermal experiment was conducted at 4 MPa and 180 °C for 24 h. Finally, the electrode was washed three times with deionized water and dried overnight in a vacuum oven at 60 °C to prepare a uniformly dense MoS2 nanosheet array grown on the carbon nanotube fiber electrode.

[0075] 3. Device assembly: By twisting TiO 2-x Typical fibrous optoelectronic sensing and memory integrated devices were fabricated using carbon nanotube fiber electrodes and MoS2 carbon nanotube fiber electrodes and fixed on a flexible PET substrate. After electrical connection, their performance can be characterized.

[0076] Example 5

[0077] 1. Preparation of TiO2 nanowire array carbon nanotube fiber electrode: First, the carbon nanotube fiber electrode was pretreated with plasma for 10 min. A uniform and dense TiO2 nanowire array covering the carbon nanotube fiber electrode was prepared via a hydrothermal method. Specifically, the obtained carbon nanotube fiber electrode was directly immersed in a TiCl4 (0.5 M) aqueous solution and cultured at 120 °C for 1 h, resulting in the formation of uniform TiO2 nanoparticles on the carbon nanotube fiber electrode matrix. Subsequently, the TiO2 nanoparticle-coated carbon nanotube fiber electrode was transferred to a 100 mL PTFE-lined autoclave containing a 20 mM TiCl4 HCl / deionized water (volume ratio 1:3) mixed solution. The PTFE-lined autoclave (pressure 2 MPa) was then heated at 230 °C for 2 h to obtain the final sample. The prepared sample was washed three times with deionized water and dried overnight in a vacuum oven at 60 °C. The obtained TiO2 sample was then reduced at 500℃ for 4 hours under a hydrogen atmosphere to obtain TiO2. 2-x The hydrogen annealing treatment was carried out at a temperature of 650℃ for 0.5 hours.

[0078] 2. Preparation of MoS2 nanosheet array carbon nanotube fiber electrode: The original carbon nanotube fiber electrode and the mixed solution (specifically, 1.031 g ammonium molybdate tetrahydrate and 2.738 g thiourea in 90 mL deionized water) were transferred to a 100 mL polytetrafluoroethylene-lined autoclave. A hydrothermal experiment was conducted at 1 MPa and 220 °C for 10 h. Finally, the electrode was washed three times with deionized water and dried overnight in a vacuum oven at 60 °C to prepare a uniformly dense MoS2 nanosheet array grown on the carbon nanotube fiber electrode.

[0079] 3. Device assembly: By twisting TiO 2-x Typical fibrous optoelectronic sensing and memory integrated devices were fabricated using carbon nanotube fiber electrodes and MoS2 carbon nanotube fiber electrodes and fixed on a flexible PET substrate. After electrical connection, their performance can be characterized.

[0080] Comparative Example 1

[0081] The difference between this comparative example and Example 1 is that it does not contain TiO2. 2-x Nanowire array carbon nanotube fiber electrode, i.e., carbon nanotube fiber electrode not covered with n-type TiO2. 2-x Nanowire array.

[0082] The resulting device will not exhibit electrical synaptic characteristics because it is not covered with n-type TiO₂. 2-xWhen nanowire arrays are used, the transport behavior of the device changes, and the interface barrier is insufficient to induce synaptic behavior. More importantly, simulations of the "learning-memory-consolidation" behavior under optical signal stimulation cannot be displayed; only a conventional photodetector signal is shown, indicating that the n-type TiO2 is not covered. 2-x Nanowire arrays cannot simulate synapse-related behavior.

[0083] Comparative Example 2

[0084] The difference between this comparative example and Example 1 is that it does not include a MoS2 nanosheet array carbon nanotube fiber electrode, that is, the carbon nanotube fiber electrode is not covered with a p-type MoS2 nanosheet array.

[0085] The final electrical synaptic characteristics test results of the obtained device showed a conventional linear change with no obvious hysteresis curve, indicating that the presence of the p-type molybdenum disulfide nanosheet array is crucial for simulating synaptic behavior. The simulation results of the "learning-memory-consolidation" behavior under optical signal stimulation showed a conventional photodetector signal with no delayed photoconductive effect, indicating that the p-type MoS2 nanosheet array is essential for the formation of the heterojunction.

[0086] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments, and obtained relatively ideal results in all cases.

[0087] It should be understood that the examples described above are merely illustrative of the technical concept and features of the present invention, intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and should not be used to limit the scope of protection of the present invention. All equivalent transformations or modifications made according to the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A fiber-shaped optoelectronic sensing and memory integrated device, characterized in that, The device includes at least one first electrode unit and at least one second electrode unit arranged spirally wound around each other. The first electrode unit includes a flexible carbon nanotube fiber electrode and n-type TiO₂ uniformly distributed on the surface of the flexible carbon nanotube fiber electrode. 2-x Nanowire array; the second electrode unit includes a flexible carbon nanotube fiber electrode and a p-type MoS2 nanosheet array uniformly distributed on the surface of the flexible carbon nanotube fiber electrode. Among them, the n-type TiO 2-x The nanowire array and the p-type MoS2 nanosheet array are in close contact and can form a heterojunction interface.

2. The fiber-shaped optoelectronic sensing and memory integrated device according to claim 1, characterized in that: The n-type TiO 2-x Nanowire arrays are grown on the surface of flexible carbon nanotube fiber electrodes via hydrothermal methods; and / or, the p-type MoS2 nanosheet arrays are grown on the surface of flexible carbon nanotube fiber electrodes via hydrothermal methods. And / or, the diameter of the flexible carbon nanotube fiber electrode is 10-250 µm.

3. The fiber-like optoelectronic sensing and memory integrated device according to claim 1, characterized in that: The n-type TiO 2-x TiO contained in nanowire array 2-x The nanowires have a diameter of 30-200 nm and a height of 0.5-2.5 µm.

4. The fiber-shaped optoelectronic sensing and memory integrated device according to claim 1, characterized in that: The p-type MoS2 nanosheet array contains MoS2 nanosheets with a thickness of 0.5-3 nm and a diameter of 5-50 nm.

5. The fiber-like optoelectronic sensing and memory integrated device according to claim 1, characterized in that: n-type TiO in the fiber-like optoelectronic sensing and memory integrated device 2-x The content of nanowire array is 50-80 wt%, and the content of p-type MoS2 nanosheet array is 20-50 wt%.

6. The method for fabricating the fiber-like optoelectronic sensing and memory integrated device according to any one of claims 1-5, characterized in that, include: n-type TiO₂ was grown on the surface of a flexible carbon nanotube fiber electrode using a hydrothermal method. 2-x Nanowire arrays were used to fabricate the first electrode unit; A second electrode unit was prepared by growing a p-type MoS2 nanosheet array on the surface of a flexible carbon nanotube fiber electrode using a hydrothermal method. The fiber-shaped optoelectronic sensing and memory integrated device is obtained by spirally winding at least one first electrode unit and at least one second electrode unit together.

7. The preparation method according to claim 6, characterized in that, include: A flexible carbon nanotube fiber electrode is immersed in a first solution containing a titanium source and reacted at 70-120 °C for 0.5-3 h to form TiO2 nanoparticles on the surface of the carbon nanotube fiber electrode, thus obtaining a carbon nanotube fiber electrode coated with TiO2 nanoparticles. The TiO2 nanoparticle-coated carbon nanotube fiber electrode was immersed in a second solution containing a titanium source and heated for 2-12 h at a pressure of 2-5 MPa and a temperature of 80-230 °C. Finally, the obtained product was annealed and reduced in a hydrogen atmosphere to obtain n-type TiO2 containing oxygen vacancies on the surface of the flexible carbon nanotube fiber electrode. 2-x Nanowire array.

8. The preparation method according to claim 7, characterized in that: The titanium source in the first solution containing a titanium source or the second solution containing a titanium source includes TiCl4, TiCl3, and C. 16 H 36 Any one or more combinations of O4Ti; And / or, the concentration of the titanium source in the first solution containing the titanium source is 0.1-0.5 mol / L; And / or, the concentration of the titanium source in the second solution containing the titanium source is 20-100 mmol / L; the second solution containing the titanium source includes the titanium source, HCl, and water; And / or, the annealing reduction treatment is performed at a temperature of 350-650 °C for a time of 0.5-3 h; And / or, the preparation method further includes: first subjecting the flexible carbon nanotube fiber electrode to plasma pretreatment for 5-15 min, and then growing n-type TiO on the surface of the flexible carbon nanotube fiber electrode. 2-x Nanowire array.

9. The preparation method according to claim 6, characterized in that, include: A mixed reaction system containing flexible carbon nanotube fiber electrodes, molybdate, thiourea and water was subjected to a hydrothermal reaction at a pressure of 1-5 MPa and a temperature of 140-240 ℃ for 8-26 h, thereby uniformly and densely growing p-type MoS2 nanosheet arrays on the surface of the flexible carbon nanotube fiber electrodes.

10. The preparation method according to claim 9, characterized in that: The mass ratio of the molybdate to thiourea is 1-3:3-1; and / or the molybdate includes ammonium molybdate and / or sodium molybdate.

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