55 results about "Single layer graphene" patented technology

The application discloses an interlayer-coupled reduced graphene oxide (rGO) film, a preparation method and application thereof. Although single-layer graphene sheets have excellent intrinsic thermal conductivity, stacked graphene films have serious thermal anisotropy and poor out-of-plane thermal transport performance due to weak van der Waals interaction between layers. The application discloses a strategy for scalable preparation of an interlayer-coupled rGO film, which is connected by covalent carbon bonds between stacked layers. A representative 200 μm-thick film prepared by the strategy has in-plane and out-of-plane thermal conductivities of 1465±63 W·m ‑1 ·K ‑1 and 14.0±1.2 W·m ‑1 ·K ‑1 , respectively. Under an extreme heat flux of 1200 W·cm ‑2 , the film can reduce temperature by 110℃ within 20 s and has excellent cycle stability. The film has high thermal and electrical conductivity, and can realize fast, uniform and durable electrothermal heating, and can be applied to the field of advanced thermal management.

The invention relates to a method for epitaxial growth of single-layer graphene on a silicon carbide substrate, and belongs to the technical field of graphene preparation. The method comprises four steps of low-temperature high-vacuum preheating, polymer decomposition under vacuum, graphene growth and cooling. The growth substrate comprises two carbon source sheets of which the C surfaces are coated with polymers and a sheet to be grown, silicon carbide is adopted as the substrates of the carbon source sheet and the to-be-grown sheet, the substrates are placed in a growth graphite crucible, and the Si surface of the silicon carbide is placed downwards; the polymer is a solid carbon source. By adding a specific number of external carbon sources, the condition of rapid decomposition of the step edge can be effectively relieved, and the carbon concentration gradient during graphene growth is balanced, so that the growth of graphene is more inclined to quasi-equilibrium state growth. The graphene can be preferentially nucleated in the step, so that the condition of step coalescence caused by rapid decomposition of the edge of the step is inhibited, and the atomic-scale flat and clean silicon carbide-based epitaxial graphene can be obtained.

The invention discloses an infrared detector sensitive element structure, a preparation method and an infrared detector, and is applied to the field of infrared detection.The infrared detector sensitive element structure comprises a first electrode, a pyroelectric functional layer and a second electrode; the pyroelectric functional layer is a polyvinylidene fluoride based copolymer thin film layer, and the polyvinylidene fluoride based copolymer thin film layer directly absorbs infrared light; the first electrode is arranged on the surface of one side of the pyroelectric functional layer, the second electrode is arranged on the surface of the other side of the pyroelectric functional layer, and the surface, provided with the second electrode, of the pyroelectric functional layer is an infrared light incident surface; the second electrode is a single-layer graphene electrode; and the single-layer graphene electrode has permeability to infrared light. The polyvinylidene fluoride-based copolymer film layer is used as a pyroelectric functional layer, and the single-layer graphene electrode is used as an electrode of an infrared light incidence side, so that the thickness of the functional layer can be reduced, and the functional layer is enabled to directly dominate absorption of infrared radiation, thereby reducing the heat capacity of the device, and improving the response sensitivity and response speed of the device.

A silicon-phase change material hetero-integrated waveguide structure includes a silicon flat plate layer and a phase change material deposited on the silicon flat plate layer. A non-volatile waveguide phase shifter includes a base layer, a hetero-integrated waveguide structure and a silicon waveguide mode spot conversion structure fixed on the base layer, two ends of the hetero-integrated waveguide structure are symmetrically connected to the silicon waveguide mode spot conversion structure; the silicon waveguide mode spot conversion structure includes two silicon waveguides with narrow-to-wide and an ridge waveguide with wide-to-narrow arranged in axial symmetry; an aluminum oxide film is covered on the phase change material, a single-layer graphene is on the aluminum oxide film, and a metal layer is on the single-layer graphene, the metal layer includes two metal electrodes. The single-layer graphene forms ohmic contact with the metal electrodes, current passes through the graphene to generate heat, the heat is conducted through the aluminum oxide film below the single-layer graphene to provide heat required for phase change of the low-loss phase change material. The phase shifter has the advantages of compact structure, low insertion loss, small driving voltage, low phase change power consumption, non-volatile phase adjustment, etc. and can be used as a core optical path regulation device in an integrated optoelectronic chip.

The invention provides a photoelectric conversion method and application thereof. The photoelectric conversion method comprises the following steps: enabling light with a selected wavelength to irradiate a heterojunction device so as to enable the heterojunction device to generate light current and / or light potential difference; wherein the heterojunction device is composed of a GaN layer and single-layer graphene (SLG) which are in direct contact, and the contact face of the GaN layer and the SLG is the N face or the r face of GaN. Influences of different types of GaN lattice orientations on the photoelectric characteristics of the GaN / SLG heterojunction structure are deeply studied, a preferable application direction of constructing the GaN / SLG heterojunction structure by taking an N surface or an r surface as a contact surface for photoelectric conversion is provided, dark current can be obviously reduced, photoelectric conversion efficiency, responsivity, maximum output power and the like can be obviously improved, and the GaN / SLG heterojunction structure can be widely applied to the field of photoelectric conversion. A solution with excellent performance is provided for the application of the GaN / SLG heterojunction structure in the photoelectric conversion field, such as a photoelectric detector, a solar cell or a photoelectric artificial synapse.

The invention provides a method and a device for measuring the transverse spatial resolution of a confocal Raman microscope, and relates to the technical field of optical measurement and micro-spectrum. The method comprises the following steps: positioning a linear edge area on a single-layer graphene sample by using a confocal Raman microscope, and preparing the single-layer graphene sample on a silicon oxide substrate; determining a linear scanning path and a scanning step length from the exposed area of the substrate to the sample area in the positioned area of the linear edge along the direction vertical to the linear edge by using a confocal Raman microscope; in the moving process of the single-layer graphene sample, determining a plurality of scanning points on the linear scanning path based on the scanning step length, and collecting a Raman spectrum signal of each scanning point; and determining the transverse spatial resolution of the confocal Raman microscope based on the Raman spectrum of each scanning point. By adopting the method provided by the invention, the accuracy of the transverse spatial resolution of the confocal Raman microscope can be improved.

The application discloses a manufacturing method of a graphene back gate electrode terahertz wave modulator, which comprises the following steps: growing and transferring a first layer of graphene; photoetching a graphene back gate pattern; photoetching a back gate electrode pattern and preparing a back gate electrode; growing a medium layer; growing and transferring a second layer of graphene; photoetching a graphene strip pattern and preparing a graphene strip; photoetching an open resonant ring pattern and preparing an open resonant ring metal. The application discloses a terahertz wave modulator, which comprises a high-resistance substrate, a graphene back gate electrode layer and a high-K gate medium layer which are sequentially bonded from bottom to top; the high-K gate medium layer is provided with an array of graphene strips and an open resonant ring metal, the open resonant ring metal is arranged around the graphene strips and is in physical contact with the graphene strips. The application constructs a back gate electrode on a single layer of graphene, thereby getting rid of the absorption of a conductive substrate to terahertz waves and effectively improving the modulation efficiency of the terahertz wave modulator to terahertz waves.

The application provides a method and device for measuring lateral spatial resolution of a confocal Raman microscope, and relates to the field of optical measurement and microscopic spectroscopy technology. The method comprises the following steps: positioning a region of a straight edge on a single-layer graphene sample by using a confocal Raman microscope, wherein the single-layer graphene sample is prepared on a silicon oxide substrate; determining a straight scanning path and a scanning step in a direction perpendicular to the straight edge from a bare region of the substrate to a sample region in the region of the straight edge which has been positioned by using the confocal Raman microscope; determining a plurality of scanning points on the straight scanning path based on the scanning step in the process of moving the single-layer graphene sample, and collecting Raman spectrum signals of the scanning points; and measuring the lateral spatial resolution of the confocal Raman microscope based on the Raman spectrum of each scanning point. By using the method provided in the application, the accuracy of the lateral spatial resolution of the confocal Raman microscope can be improved.

The invention relates to the technical field of heat conduction materials, and particularly discloses a high-heat-conductivity graphene heat conduction cable and a preparation method thereof.The high-heat-conductivity graphene heat conduction cable comprises a strip-shaped flexible heat conduction belt and metal components welded to the two ends of the flexible heat conduction belt and used for being connected with a heating device; the heat conductivity of the flexible heat conduction belt is 500-2500W / (m.K); the flexible heat conduction belt is formed by stacking and connecting a plurality of graphene heat conduction sheets, and the graphene heat conduction sheets comprise modified graphene, nanometer aluminum oxide particles and nanometer silicon carbide particles. The modified graphene is obtained by modifying graphene oxide with a liquid crystal modifier. According to the high-thermal-conductivity graphene heat-conducting cable, the structure of the single-layer graphene heat-conducting layer is optimized while the problem of connection of the multiple graphene heat-conducting layers is solved, and the thermal conductivity of the single-layer graphene heat-conducting layer in the longitudinal direction and the transverse direction is improved; moreover, the graphene heat-conducting layer is combined with the metal component, so that the use scene of the heat-conducting cable is enlarged, and the applicability of the heat-conducting cable is effectively improved.

The invention discloses a preparation method of a graphite material with low porosity and high bending strength. The preparation method comprises the following steps: S1, calcining one or two of pitch coke or petroleum coke to obtain calcined coke, crushing, and screening to obtain nanoscale calcined coke powder; s2, mixing nanoscale calcined coke powder, sulfur powder and single-layer graphene powder, and adding kerosene as a wet mixing medium to obtain a uniform mixture; s3, carrying out atomization granulation on the mixture obtained in S2 to form a nearly spherical particle mixture, and carrying out three-way unequal cold press molding and baking to obtain a green body; s4, carrying out air pressure roasting on the green body under vacuum and inert gas protection, and cooling to room temperature to obtain a graphite roasting product; s5, cleaning the surface of the graphite roasting product, and performing dipping treatment to obtain a dipped product blank; and S6, carrying out graphitization treatment on the impregnated product blank to obtain the graphite material. According to the invention, the grain size is reduced while graphite pores are reduced, and the prepared graphite material has good mechanical properties.

The application discloses a graphene-coated surface saturable absorber device of a multimode optical fiber with an internal microstructure, which adopts a mixed structure of graphene and a graded-index multimode optical fiber. The saturable absorber device comprises a first single-mode optical fiber, a mixed structure based on a multimode optical fiber, and a second single-mode optical fiber. The mixed structure based on the multimode optical fiber is composed of a tapered graded-index multimode optical fiber with an internal microstructure and a single-layer graphene film. The graded-index multimode optical fiber is first subjected to a micro-tapering treatment, then a microstructure is inscribed in the core inside the taper waist, then the graphene film is coated on the surface of the taper waist of the optical fiber, and finally the single-mode optical fibers are fused at both ends of the multimode optical fiber. The saturable absorber combines the nonlinear multimode interference effect in the multimode optical fiber and the saturable absorption characteristics of graphene, can perform secondary compression on the pulse width of a high-energy pulse, and thus obtains an ultrashort pulse. The application has the advantages of a solid structure, strong stability, a high damage threshold and the like, and provides an effective technical means for obtaining a stable ultrashort pulse mode locking.

The invention relates to the technical field of metasurface electro-optical devices, in particular to a low-loss mid-infrared electro-optical modulator based on graphene and ITO and a preparation method thereof, SiO2, Al2O3, graphene, TiO2 and ITO are sequentially arranged in the electro-optical modulator from bottom to top, and Si is embedded in SiO2 to serve as a central waveguide. Single-layer graphene and ITO with the thickness of 30 nm are placed in a staggered mode to form a heterojunction, change of carriers in the Si waveguide is caused, and then modulation of the change of effective refraction in the Si waveguide is achieved; besides, the graphene and the ITO form a parallel-plate capacitor, the switching energy of the modulator is reduced, high modulation efficiency is achieved, and finally, metal electrodes are placed on the graphene and the ITO respectively, so that voltage directly controls heterojunction. According to experimental verification, a high extinction ratio is achieved under low insertion loss, and multi-rate modulation can be achieved.

The application discloses a kind of optical nerve unit device, the construction method of deep learning optical nerve network, it is related to neural network technical field, including contact metal electrode, graphical graphene array, dielectric layer film and substrate, the graphical graphene array is contacted with dielectric layer film formed on substrate, the contact metal electrode is contacted with graphical graphene array and is used to generate electric field with substrate, regulate device output optical signal as the input weight of synapse, the graphical graphene array includes graphene and infrared light source wave, the graphene is single-layer graphene, the graphical graphene array unit is periodic strip, the beneficial effects of the application are: compared with other materials, graphical graphene is due to high carrier density and support surface plasmon propagation, provides an incomparable advantage, i.e. in room temperature to terahertz range in the wavelength of mid-infrared can be in situ dynamically tuned by using gate voltage.

The invention relates to a method for preparing corner graphene on an insulating substrate. The method comprises the following steps: S1, forming a single-layer graphene layer with a first reference straight edge on the surface of the insulating substrate through chemical deposition; and S2, another single-layer graphene layer with a second reference straight edge is formed on the surface of the single-layer graphene layer formed in the step S1 through chemical deposition, a torsion angle is formed between the first reference straight edge and the second reference straight edge, and the torsion angle is not 0 degree. According to the method for preparing the corner multilayer graphene on the insulating substrate, high-quality corner graphene can be prepared, and meanwhile, organic pollution and mechanical damage are prevented from being introduced into the corner graphene in the transfer process.

The invention discloses a vertical heterojunction photoelectric synapse transistor and preparation and application thereof. The device sequentially comprises a back gate substrate (gate / gate medium), a single-layer graphene bottom electrode, a p-type rube layer, an n-type F16-CuPc layer and a top electrode from bottom to top, and rubree / F16-CuPc forms an II-type heterojunction, and short-channel vertical transmission is formed, so that photo-generated excitons are efficiently dissociated on an interface and vertically collect current. According to the device, 365-780nm wide spectrum detection and optical / electric driving synaptic plasticity (including paired pulse promotion and time width / frequency / pulse number dependence) are realized in a single structure, and retina-like denoising and contrast enhancement are realized based on time domain selectivity retention. The invention has the advantages of wide process window, easy array, low dark current, low energy consumption and good stability, and is suitable for wearable vision, weak light imaging and edge cognition processing.

The application discloses a "sandwich" structure MoS2 / graphene nanosheet catalyst and a preparation and application thereof. The catalyst has a "sandwich" nanosheet structure in which two-layer MoS2 layers and single-layer graphene layers sandwiched therebetween are stacked in parallel. In the catalyst, the interlayer spacing of MoS2 is larger than that of pure MoS2, the nanosheet size is smaller, and the stacking layer number is less, which is beneficial to fully expose the catalytic hydrogenation active sites of MoS2 edge sites. The catalyst preparation method comprises the following steps: dissolving ammonium tetrathiomolybdate, a reducing agent and a saccharide material in water, fully mixing to form a transparent solution; crystallizing h; and after solid-liquid separation, solid washing and drying of the obtained product, roasting, and cooling, the "sandwich" structure MoS2 / graphene nanosheet catalyst is obtained. The saccharide material used in the method is cheap and easy to obtain, and the synthesis condition is easy to control, so that large-scale industrial application can be realized. The "sandwich" structure MoS2 / graphene nanosheet catalyst of the application has excellent catalytic hydrogenation activity and stability in a polycyclic aromatic hydrocarbon catalytic hydrogenation reaction.

The invention provides an industrial-scale graphene film ultrafast reel-to-reel deposition method which comprises the following steps: vacuumizing the inside of CVD (Chemical Vapor Deposition) equipment to be in a vacuum state, filling pretreatment gas, and pretreating a copper foil serving as an initial substrate; filling mixed gas of methane and inert gas into the CVD equipment, and changing the vacuum state in a cavity of the CVD equipment into a low-pressure state of 1-100 Torr; after the temperature in the CVD equipment chamber is increased to the preset temperature, the copper foil is rotated in a roll-to-roll mode at the transmission speed of 300-2000 mm / min, chemical vapor deposition is conducted on the copper foil in the CVD equipment chamber, and the graphene film is prepared on the surface of the copper foil. Compared with the prior art, the preparation rate of the graphene film can be increased by about 7 times, the length of the prepared single-layer graphene film can reach 1000 m or above, and the method is suitable for industrial-scale mass production preparation of the high-quality single-layer graphene film.

The present application relates to the technical field of sleeper manufacturing, and discloses a continuous chemical vapor deposition preparation method of high-purity single-layer graphene, which comprises the following steps: a) using methane as a carbon source precursor gas, and mixing the methane with hydrogen gas at a volume ratio of 1:15 to form a mixed gas; b) adding 0.05% of tungsten hexafluoride as an auxiliary catalyst in the mixed gas; c) introducing the mixed gas above a pretreated copper substrate material; and d) performing a chemical vapor deposition reaction at a constant temperature of 1000 DEG C and under a pressure condition of 150 Pa to form single-layer graphene; the present application improves the uniformity and quality of the graphene film. The trace amount of tungsten hexafluoride added as an auxiliary catalyst optimizes the growth conditions of the graphene, the residues on the substrate are completely removed through the alternate cleaning of ultrapure water and isopropyl alcohol and the drying by nitrogen blowing, the occurrence of oxidation is prevented, and the purity of the product is improved.

The application relates to a micro-system liquid gate type field effect sensing chip and a manufacturing method and application thereof, and belongs to the technical field of field effect sensing chips, comprising a substrate, the substrate is provided with a source electrode, a drain electrode and a gate electrode, a single-layer graphene is arranged on a channel between the source electrode and the drain electrode, and a self-assembled functional factor is decorated on the gate electrode. The application has the advantages of high selectivity, high sensitivity, high stability, simple operation, economy and portability from the perspective of actual demand and application. In the solid gel micro-system, the preparation of a to-be-detected sample is reduced, and the sensitivity of a detection system is improved, so that problems such as instability, difficulty in stabilization and false signals of a traditional liquid detection system are solved; the gel micro-system is combined with a specific detection method to form a detection system with good detection effect and application universality, and excellent detection effect is exhibited in tetracycline detection.

The invention discloses a semi-polar surface GaN film prepared based on Van der Waals epitaxy and a semiconductor device. The semi-polar surface GaN film is prepared based on Van der Waals epitaxy through the following steps: preparing semi-polar (11-22) surface aluminum nitride as a substrate; preparing a nitrogen-doped graphene layer; the nitrogen-doped graphene layer is a single layer of graphene, and the nitrogen-doped graphene layer is transferred to the semipolar (11-22) surface aluminum nitride; and growing a GaN thin film on the nitrogen-doped graphene layer through Van der Waals epitaxy to obtain the semi-polar surface GaN thin film. According to the preparation method for preparing the semi-polar surface GaN thin film based on Van der Waals epitaxy, the semi-polar surface GaN thin film is prepared by adopting the semi-polar AlN substrate based on remote epitaxy in Van der Waals epitaxy, and the nitrogen-doped graphene is adopted, so that the prepared semi-polar surface GaN can eliminate a polarization effect and can be used for preparing the semi-polar surface GaN thin film. And a key material basis is provided for high-performance green light / yellow orange light LEDs, lasers and power electronic devices.

The invention discloses an organic composite positive electrode material based on polycarbonyl micromolecules / graphene oxide, a preparation method of the organic composite positive electrode material and a battery. The preparation method comprises the following steps: step 1, preparing polycarbonyl organic micromolecules; and 2, uniformly compounding the polycarbonyl small organic molecules and graphene oxide by adopting an anti-solvent method, so that the polycarbonyl small organic molecules are coated by the graphene oxide to obtain the organic composite positive electrode material based on the polycarbonyl small molecules / graphene oxide, wherein the mass ratio of the polycarbonyl organic small molecules to the graphite oxide is 1: 1-3: 1. According to the invention, the theoretical specific capacity of the multi-carbonyl small organic molecules is improved, and the initial voltage of the multi-carbonyl small organic molecules is improved to 2.8 V; the multi-carbonyl small organic molecules are uniformly compounded with graphene oxide, so that the multi-carbonyl small organic molecules are completely coated by single-layer graphene. The compounding of the carbon material and the organic matter can effectively inhibit the dissolution of the organic material in the electrolyte so as to improve the cycling stability. In addition, the conductive skeleton of the carbon material can effectively enhance the conductivity of the organic material.

This invention belongs to the field of thermosetting polymer composite material preparation technology, and particularly to graphene-reinforced high-density epoxy composite materials for casting molding and their preparation method. The method uses a two-component epoxy resin system as the continuous phase and graphene as both a functional filler and a reinforcing filler. First, component A and component B are premixed in a specific ratio. Then, graphene is added stepwise and mixed at low speed. Subsequently, a vacuum degassing process is performed, followed by preheating the mold for casting, a second vacuuming process, and step-curing at 80℃ / 140℃. The graphene is preferably one of high-purity multilayer graphene, few-layer graphene, or single-layer graphene, and the addition process can be carried out in two, three, or four steps depending on the number of layers and the difference in bulk density. This method can balance the uniformity of graphene dispersion, slurry workability, product density, and consistent black surface appearance. The resulting products are suitable for electronic packaging, potting compounds, functional structural components, and thermally and electrically conductive castings.

A method of forming a fiber includes providing a sheet of a single layer of graphene or an oxidative analogue of graphene and applying force to the sheet to induce bending in the sheet and increase an aspect ratio thereof, thereby forming the fiber.

The invention relates to the technical field of lithium battery manufacturing, in particular to a pole piece integrated temperature sensor and a preparation method, the pole piece integrated temperature sensor is directly integrated on a lithium ion battery negative electrode current collector, and the sensor sequentially comprises a transition layer, a first electrode layer, a second electrode layer, a third electrode layer and a fourth electrode layer from bottom to top, the sensing layer is a rare earth doped tantalum oxynitride film deposited on the transition layer; the packaging layer is a single-layer graphene thin film deposited on the sensing layer, and the graphene thin film is of a mesoporous structure with the pore diameter being 2-5 nm. According to the invention, the rare earth doped tantalum oxynitride high-sensitivity sensing layer and the graphene mesoporous encapsulation layer are directly integrated on the battery current collector, so that zero-distance and in-situ real-time monitoring of the heat production core in the battery is realized.

The application discloses a heterojunction transistor with sub-nanometer channel length and sub-nanometer gate width and a preparation method. A PN junction heterojunction is constructed by using a single-layer CVD graphene and a single-layer CVD two-dimensional material. A vertical PN junction with a thickness less than 1 nm is used as a device channel, and the channel length is equal to the thickness of the heterojunction. A gate structure uses the edges of the graphene and the two-dimensional material layer as gate electrodes, and the gate width is equal to the thickness of the heterojunction, reaching sub-1 nm. The source electrode, the drain electrode and the gate electrode are separated into three independent terminals through gap etching. The Fermi energy level of the graphene is adjusted by the gate voltage, the barrier height of the PN junction is changed, and the switching control of the device is realized. The bottom silicon gate can also assist in the regulation to further optimize the setting range of the gate voltage. The application solves the problems of the short channel effect and the gate control of the silicon-based device, simplifies the preparation process, realizes wafer-level mass production, and meets the development needs of the ultra-miniaturization of integrated circuits.

The application discloses a photoconductive microwave switch based on single-layer graphene and gold nanoparticle film modification and a preparation method thereof, and belongs to the technical field of microwave communication and optoelectronic devices, and comprises a microstrip line structure with a gap and a semiconductor switch chip which is connected across the microstrip line structure conductor band on both ends of the gap, wherein the semiconductor switch chip comprises an intrinsic silicon substrate, a composite modification layer and two electrode regions, the composite modification layer is located on the surface of the intrinsic region between the two electrode regions, and comprises single-layer graphene and a gold nanoparticle film in sequence. The composite modification layer is arranged, the excitation concentration of laser on the carrier is greatly enhanced, efficient conduction of the switch can be realized by using only a conventional low-power continuous laser, and the system power consumption and hardware cost are greatly reduced.

The application discloses a graphene skin electrode based on conductive polymer transfer and a preparation method thereof. The graphene skin electrode based on conductive polymer transfer is a dry electrode obtained by covering a conductive polymer film on a single-layer graphene film. In the application, a surfactant and an ionic liquid are added into a pure PEDOT:PSS solution, and then a light, uniform and continuous conductive polymer film is formed on the surface of the graphene. The graphene improves the crystallinity of a PEDOT main chain, and the interaction significantly improves the conductivity of the electrode. The graphene skin electrode based on conductive polymer transfer prepared in the application is an ultrathin dry electrode with high transparency and high conductivity, can be conformally attached to the skin, and can be used for electro-physiological signal detection.

The invention discloses a Nafion / graphene-based composite film as well as a preparation method and application thereof. The Nafion / graphene-based composite film is of a multi-layer composite structure Nafion / Nafion (L) / graphene / Nafion (L) / graphene / Nafion; wherein the Nafion (L) is a buffer layer formed by a liquid Nafion solution; the graphene is single-layer graphene; the graphene coverage degree is 99% or above. The prepared composite membrane is used for hydrogen isotope separation in a liquid water environment, the separation ratio reaches 9 or above, and the electrolysis stability exceeds 400 hours.

The application discloses a femtosecond laser-induced cross-scale gold fractal structure and a storage-free PUF and key generation method thereof, and comprises the following steps: preparing a gold near-percolation film on a substrate; scanning the film by using a femtosecond laser beam, forming a gold random fractal structure with a random fractal network by inducing local surface plasmon resonance and Marangoni convection, and the characteristic size of the gold random fractal structure is adjustable in the nanometer to micrometer scale; obtaining an optical microscopic image and a resistance value of the structure as optical and electrical PUF responses respectively; performing binarization, confusion and hash processing on the two, and generating an encrypted key on site; when the structure contains a single-layer graphene layer, a Raman spectrum of the single-layer graphene layer can also be obtained as an independent authentication response. The application realizes high security, storage-free on-site key generation and encryption by using the prepared inherent random structure, solves the contradiction between security and practicability of a traditional PUF, and the structure is easy to integrate and compatible with existing mainstream hardware encryption algorithms.

The application discloses a wafer-level graphene-silicon three-terminal phototransistor and a preparation method thereof. The emitter stage of the transistor is a silicon substrate covered with a silicon oxide layer, and a silicon window is etched in the silicon oxide layer. The silicon substrate is a doped silicon substrate. The base electrode comprises single-layer graphene in the silicon window region, which is opposite to the doping mode of the silicon substrate, and forms a shallow Schottky junction with the silicon substrate. The base electrode graphene extends from the silicon window to the position of the metal electrode corresponding to the silicon oxide surface. A tunnel layer is arranged between the metal electrode and the base electrode graphene. The collector electrode comprises collector single-layer graphene isolated from the base electrode graphene through the tunnel layer, and extends to the position of the metal electrode corresponding to the silicon oxide surface. The base electrode graphene, the tunnel layer and the collector graphene form a tunnel junction. The application utilizes the barrier difference between graphene-silicon and graphene-graphene-silicon Schottky junction to enhance the rectification characteristics, and can realize large-scale and low cost.