162 results about "Pulsed laser deposition" patented technology

The invention relates to a laser processing method for a coated armor structure of wear-resistant super-hydrophobic aluminum bronze, which comprises the following steps of: preparing an aluminum bronze workpiece, polishing and cleaning, depositing a ceramic wear-resistant film on the surface of the workpiece by adopting pulse laser, and etching the ceramic wear-resistant film by adopting femtosecond laser, so as to obtain a coated armor structure of the wear-resistant super-hydrophobic aluminum bronze. And then chemical modification of the wear-resistant armor structure is completed through heat treatment, chemical modification of the micro-nano surface structure is completed, and the wear-resistant super-hydrophobic aluminum bronze is obtained. The wear-resistant ceramic film and the wear-resistant armor structure can resist wear together, double guarantee is provided for the internal hydrophobic microstructure, the super-hydrophobic wear resistance of the surface of a component in underwater equipment can be improved, the service life of the component can be prolonged, and the problem of marine organism corrosion is solved.

The invention provides a pulse laser deposition process online monitoring device and method, and relates to the technical field of material preparation and process monitoring, the pulse laser deposition process online monitoring device comprises a growth cavity, a substrate supporting mechanism and a target material supporting mechanism which are arranged in the growth cavity, a pulse laser for ablating a target material, and a spectrum acquisition unit, the optical signal acquisition module is used for acquiring an optical signal radiated by plasma plume generated by ablating a target material by the pulse laser; and the spectrum analysis unit is connected with the spectrum acquisition unit and is used for receiving the light signals acquired by the spectrum acquisition unit and analyzing and processing the light signals so as to obtain the state information of the plasma plume. According to the online monitoring scheme, the extreme ultraviolet spectrum diagnosis technology and the pulse laser deposition process are deeply fused, so that the film growth process is accurately controlled, and the process is optimized.

The invention relates to a femtosecond laser processing method for a periodic ferrocobalt oxide single crystal stripe nanostructure, which comprises the following steps of: firstly, preparing a strontium titanate single crystal substrate, and depositing a single crystal epitaxial ferrocobalt oxide film (CFO) on the substrate through pulsed laser; and the included angle between the polarization direction of the femtosecond laser and the lattice orientation of the film is adjusted according to a preset crystallographic direction, so that the surface of the film is induced by the femtosecond laser to form a stripe-shaped periodic surface structure. The single crystal epitaxial cobalt ferrite film prepared by the method has a highly ordered nano structure, and the specific surface area and surface active sites of the material are remarkably improved, so that the application performance of the material in the fields of gas sensing and the like is enhanced.

The present invention discloses a flexible sensor based on an oxide wrinkle structure and a preparation method thereof, comprising: using a solid-phase method to prepare a Sr3Al2O6 target material and a La-BaTiO3 target material respectively; using a pulsed laser deposition technique to prepare a "La-BaTiO3 / Sr3Al2O6 / SrTiO3" heterostructure using the Sr3Al2O6 target material and the BaTiO3 target material on a SrTiO3 single crystal substrate; using a water-soluble method to electrostatically adsorb a polydimethylsiloxane (PDMS) film on the "La-BaTiO3 / Sr3Al2O6 / SrTiO3" heterostructure. The La-BaTiO3 film was then peeled off from the structure to create a "La-BaTiO3 / PDMS" heterostructure. A gold (Au) electrode was grown on the "La-BaTiO3 / PDMS" heterostructure using magnetron sputtering to create an "Au / PDMS / La-BaTiO3" heterostructure. Another PDMS film was attached to the Au electrode surface of the "Au / PDMS / La-BaTiO3" heterostructure by electrostatic adsorption for encapsulation, resulting in a piezoresistive sensor with the "PDMS / Au / La-BaTiO3 / PDMS" heterostructure. This preparation method offers high process controllability, and the resulting flexible piezoresistive sensor exhibits high precision, high sensitivity, and high reliability. The flexible piezoresistive sensor can adapt to changes in various surfaces and shapes and has a wide range of applications.

The invention belongs to the technical field of semiconductor materials and devices, and discloses a low-temperature thermal evaporation deposition tellurium / germanium heterojunction photoelectric detector and a preparation method thereof. The photoelectric detector comprises a germanium substrate, a tellurium thin film, a metal top electrode and a metal bottom electrode, the tellurium thin film is a polycrystalline tellurium film layer containing a micron-sized large domain, the surface roughness is lower than 1nm, and the tellurium thin film is in close contact with the germanium substrate to form a heterojunction; the metal top electrode is a platinum / gold laminated electrode, and the metal bottom electrode is an indium gallium alloy / copper foil electrode. The tellurium thin film with large crystal domain and low roughness grows on the germanium substrate through a-low temperature (-80 DEG C to-160 DEG C) thermal evaporation deposition process, and the electrode is prepared by combining a micro-nano processing technology. Compared with traditional molecular beam epitaxy, pulse laser deposition and other methods, the method is low in process cost and compatible with the integrated circuit technology, and the obtained heterojunction photoelectric detector has the excellent rectification characteristic and infrared light response and is suitable for large-scale preparation and practical application.

The invention discloses a multi-component superconducting target material, a preparation method thereof and a multi-component alternating PLD (Pulsed Laser Deposition) film deposition method. The preparation method comprises the following steps that S01, the shape structure of each component target material is designed according to the component condition of the multi-component superconducting target material, a plurality of partial target material structures are obtained, the partial target material structures are all fan-shaped structures, and all the partial target material structures are combined into a complete cylinder; s02, respectively preparing partial target material blanks according to partial target material structures designed in the step S01; s03, combining all parts of target material blanks into a cylinder, and performing high-pressure tabletting treatment to obtain a cylindrical composite target blank; and S04, carrying out plasma sintering treatment on the cylindrical composite target blank, and cooling to obtain the multi-component superconducting target material. According to the multi-component superconducting target material, the interval distribution of the doping phases in the c-axis direction is accurately regulated and controlled, and then the target material structure is matched through technological parameters, so that active control over the longitudinal interval of pinning centers is achieved.

The utility model relates to pulse laser deposition equipment which comprises a light source, a scanning assembly and a deposition assembly, the light source is used for emitting pulse laser, the scanning assembly is arranged on the side, in the first direction, of the light source, and the scanning assembly comprises a first fixed mirror and a second fixed mirror which are sequentially arranged in the propagation direction of the pulse laser; and the pulse laser sequentially passes through the first fixed mirror and the second fixed mirror, is propagated along a second direction and is incident to the deposition assembly. The scanning assembly is arranged to be capable of moving relative to the light source in the first direction so that the pulse laser passing through the scanning assembly can enter different positions of the deposition assembly, the deposition assembly comprises a target material and a substrate, and the surface, facing the substrate, of the target material is used for receiving the pulse laser. Wherein the first direction and the second direction intersect with each other. According to the method and the device, the large-area or large-size substrate can be deposited, and the film layer on the deposited substrate has better uniformity.

This invention provides a PVD-grown undoped ε-Ga₂O₃ thin film and its preparation method. The preparation method includes the following steps: Step S1, preparing a substrate and target material, and placing them in the main deposition chamber of a physical vapor deposition (PVD) apparatus; Step S2, heating the substrate to above 650°C, introducing oxygen as the growth atmosphere gas, and using a gallium oxide target material with a tin atomic ratio of 0.5-2.5% to deposit a first thin film on the substrate; Step S3, depositing an aluminum oxide layer as a diffusion barrier layer on the surface of the first thin film; Step S4, using a pure gallium oxide target material, depositing a thin film on the surface of the aluminum oxide layer; cooling to room temperature to obtain the undoped ε-Ga₂O₃ thin film. The undoped ε-Ga₂O₃ photodetector prepared by the pulsed laser deposition system of this invention has a much higher PDCR value than tin-doped ε-Ga₂O₃ devices.

The embodiment of the invention discloses a donor-receptor complementary co-doped hafnium oxide-based ferroelectric film material and a preparation method thereof. The method comprises the following steps: according to the composition of the donor-receptor complementary co-doped hafnium oxide-based ceramic target material, mixing raw material powder to obtain mixed raw material powder; calcining the mixed raw material powder under a preset condition; pressing and molding the calcined product into a target material green body; and sintering the target material green body to obtain the donor-receptor complementary co-doped hafnium oxide-based ceramic target material. Wherein the composition of the donor-acceptor complementary co-doped hafnium oxide-based ceramic target material is expressed as AxByHf (1-x-y) O2, A is a donor and comprises elements niobium and tan, and B is an acceptor and comprises elements yttrium and lanthanum; x is more than 0.01 and less than 0.05, and y is more than 0.01 and less than 0.05; the raw material powder containing the donor comprises niobium oxide and tantalum oxide, and the raw material powder containing the acceptor comprises yttrium oxide and lanthanum oxide; and taking the donor-acceptor complementary co-doped hafnium oxide-based ceramic target material as a sputtering target, and obtaining the donor-acceptor complementary co-doped hafnium oxide-based ferroelectric material film by using a pulse laser deposition method.

The invention provides an anti-ferroelectric-paraelectric laminated energy storage capacitor and a preparation method thereof. The preparation method at least comprises the following steps: S1, depositing a bottom electrode layer on a substrate; s2, depositing a first dielectric layer through a pulse laser deposition process, wherein the material of the first dielectric layer is a paradielectric material; s3, a second dielectric layer is deposited through the pulse laser deposition technology, the second dielectric layer at least sequentially comprises an anti-ferroelectric layer and a paraelectric layer, the anti-ferroelectric layer is made of an anti-ferroelectric material, and the paraelectric layer is made of a paraelectric material; s4, repeating the step S3 for multiple times; and S5, depositing a top electrode layer. According to the preparation method disclosed by the invention, the antiferroelectric-paraelectric laminated film is formed in a layering form, and a structure in which the antiferroelectric dielectric layer and the paraelectric dielectric layer are circularly and alternately deposited and molded is constructed, so that the direct interface flatness between the antiferroelectric layer and the paraelectric dielectric layer is solved, the performance of a non-polar / reversed-polarity interface region between the layers is improved, and defects are reduced; the energy storage density of the energy storage capacitor is increased, and the efficiency is improved.

The invention belongs to the field of film sensors, and discloses a preparation method of a lanthanum aluminate / strontium titanate nanostructure for hydrogen detection, which comprises the following steps: preparing a strontium titanate single crystal substrate, depositing a single crystal epitaxial lanthanum aluminate film on the strontium titanate single crystal substrate by pulse laser to obtain a single crystal epitaxial lanthanum aluminate / strontium titanate material; then, a stripe-shaped periodic surface nanostructure is formed on the surface of the single crystal epitaxial lanthanum aluminate thin film through femtosecond laser induction, a lanthanum aluminate / strontium titanate nanostructure is obtained, and then precious metal nanoparticles are deposited on the surface of the lanthanum aluminate / strontium titanate nanostructure. According to the preparation method, the highly-ordered single-crystal lanthanum aluminate / strontium titanate heterogeneous film is obtained by accurately controlling pulse laser deposition process parameters, and a nano stripe periodic structure is prepared on the surface of lanthanum aluminate by accurately controlling pulse femtosecond laser processing parameters, so that the specific surface area is effectively increased, gas adsorption sites are increased, and the specific surface area of the lanthanum aluminate / strontium titanate heterogeneous film is increased. And the gas charge transmission capability of the lanthanum aluminate / strontium titanate interface two-dimensional electron gas is improved.

The application provides a ferroelectric metal and a preparation method and application thereof. The ferroelectric metal of the application is composed of cubic silicon carbide crystals and doping elements doped therein, wherein the concentration of the doping elements is greater than or equal to 1*10 18 cm ‑3 The material of the application can be prepared by a chemical vapor deposition method, a high-temperature solution growth method, a solid-phase sintering method, a pulse laser deposition method and the like. Since the conductivity of metal, the switching characteristics of ferroelectric and the force-electric coupling characteristics of piezoelectric are integrated, the ferroelectric metal of the application has great application value in the fields of high-performance transducers, high-sensitivity sensors, low-power micro-electro-mechanical system (MEMS), next-generation multifunctional electronic devices and the like.

The application discloses a method for preparing large-size rare earth barium copper oxygen superconducting target material and relates to the technical field of superconducting target material preparation. The method realizes the compatibility of a single set of molds with various specifications of target materials by optimizing the design of cold isostatic pressing molds, adopting a composite mold structure comprising upper and lower cover plates, a cylinder, isolation pads, a replaceable elastic lining and a clamp, and can press multiple target materials at a time by setting multiple isolation pads, and is suitable for the preparation of target materials with a diameter of 8-12 inches and a thickness of 10-20 mm. The preparation process comprises the following steps of mold assembly, superconducting powder filling and vibration treatment, segmented pressure cold isostatic pressing treatment, blank shaping, oxygen atmosphere sintering and grinding machine processing. The mold generality design and batch pressing technology of the application significantly improve the production efficiency, reduce the mold cost and powder loss, and at the same time, ensure the density (relative density 80%-85%) and surface flatness (less than or equal to 0.5 mm) of the target material, and meet the strict requirements of large-size target materials for high-end superconducting thin film preparation such as pulsed laser deposition.

The application discloses a low-onset-voltage gallium oxide power diode, and mainly solves the problems of high-onset-voltage and low-breakdown-voltage of the existing gallium oxide power diode. The gallium oxide power diode comprises a cathode (4), a substrate (1), a beta-Ga2O3 drift layer (2) and an anode (5) from bottom to top, and is characterized in that: a ferroelectric material PZT dielectric layer (3) formed by an outer circular ring and an inner circular ring is arranged between the beta-Ga2O3 drift layer and the anode, so that when a positive voltage is applied above the PZT, positive charges are generated at the anode interface, electrons are attracted and accumulated to reduce the onset voltage; when a negative voltage is applied above the PZT, negative charges are generated at the anode interface to form a high-resistance area, and the breakdown voltage of the device is improved. The ferroelectric material PZT dielectric layer (3) is a ferroelectric material PZT field ring formed by pulse laser deposition, photolithography and dry etching. The application can effectively reduce the onset voltage of the device, improve the breakdown voltage of the device, and can be used for rectifiers and direct current converters of power electronic systems.

The application discloses a scanning target holder device and a pulsed laser deposition device. The scanning target holder device comprises a first transmission unit, a first main body and a hollow mounting cylinder, the first main body is mounted to the outside of a coating chamber, and the mounting cylinder is rotatable relative to the first main body; a second transmission unit is mounted to the mounting cylinder, the second transmission unit comprises a second main body and a mounting shaft, the mounting shaft is rotatable relative to the second main body, the mounting shaft is provided with an input part and an output part, the input part is located at the outside of the mounting cylinder, and the output part is located at the inside of the mounting cylinder; a support is used for supporting a target material, is mounted to the output part and is arranged in the coating chamber; a first driving part drives the second transmission unit to rotate so that the support revolves; and a second driving part is connected with the input part and drives the mounting shaft to rotate so that the support mounted on the output part of the mounting shaft rotates. The scanning target holder device can improve the stability of the device.

The present invention discloses a gas sensor based on a confined CeO2 nanoparticle thin film, its preparation method and application. The gas sensor based on the confined CeO2 nanoparticle thin film includes a substrate, and a confined CeO2 / carbon thin film layer is on the surface of the substrate. The particle size of the confined CeO2 is 5-20 nm, and it is confined and grown in an amorphous carbon matrix, having a high degree of dispersion. The preparation method of the nanoparticle thin film is simple and rapid, and the whole preparation process only takes dozens of minutes. That is, first, a CeO2 / carbon thin film is obtained by pulsed laser deposition technology, and then a confined CeO2 nanoparticle thin film is obtained by combining rapid annealing treatment. The confined CeO2 nanoparticle thin film is in-situ grown on the surface of a commercial flat Al2O3 gas-sensitive substrate and can directly be used as the sensitive layer of a resistive semiconductor gas sensor. The sensor can effectively detect the volatile organic compound (VOC) triethylamine and exhibits remarkable response, excellent stability and selectivity.

The invention discloses a substrate resistance heating device and a pulse laser deposition system, the substrate resistance heating device comprises a base, the base is provided with a mounting position with an opening in the front side, the left side and the right side of the mounting position are respectively provided with a conductive part, and the conductive parts are connected with copper wires; the resistance heating structure comprises a mounting part and a substrate, the mounting part is inserted into the mounting position, the mounting part can move front and back and can be taken out from the front side of the mounting position, the substrate is arranged on the mounting part and is made of a conductive material, and when the mounting part is inserted into the mounting position, a conductive path is formed between the substrate and the conductive parts on the left side and the right side. The device is simple in structure, low in cost, low in energy loss, high in heating speed and convenient to install and operate.

The invention relates to a monoclinic crystal (310) crystal face gallium oxide single crystal film and a preparation method thereof, a Ga2O3 single crystal film is an epitaxial single crystal film with a monoclinic structure, and the growth crystal face is Ga2O3 (310). The selected substrate is a sapphire substrate, a hexagonal gallium nitride substrate, a hexagonal silicon carbide substrate and the like which are high in heat conductivity and low in cost and are of a trigonal structure. The out-of-plane epitaxial relationship and the in-plane epitaxial relationship between the thin film and the substrate are AND respectively. The pulse laser deposition adopts a crystal solid-state laser, the laser wavelength is 266nm, and the growth temperature is lower than 600 DEG C. A transmission spectrum of the Ga2O3 single crystal film in a visible region shows that the transmittance in a range of 300-700nm is about 80%, the optical band gap of the film is about 4.6 eV, the surface square root roughness is less than 0.5 nm, and the Ga2O3 single crystal film is an excellent gallium oxide semiconductor candidate material crystal face.

The invention relates to the technical field of material performance testing, in particular to a novel ultrafast IV ferroelectric material testing method, and provides the following scheme aiming at the problems that in the prior art, a ferroelectric material IV testing method is low in speed, low in time resolution, low in precision and incapable of accurately reflecting the electrical performance of a ferroelectric material under ultrafast voltage excitation. A hardware-level synchronous test system composed of a waveform generator / fast measurement unit (WGFMU) and a dual remote induction and switch unit (RSU) is constructed, a ferroelectric sample is prepared in combination with pulsed laser deposition (PLD) in a standardized mode, then a special voltage waveform signal is edited, and accurate test of the current-voltage characteristics of the ferroelectric material under the nanosecond time scale is achieved. According to the method, the defects of an existing IV test method in the aspects of test speed, time resolution and test precision are overcome, and the electrical performance of the ferroelectric material under high-frequency and rapid change working conditions can be reflected more truly.

The present invention relates to a method for preparing a dual-wavelength laser-induced periodic cerium oxide surface nanostructure, which includes the process of pulsed laser depositing a cerium oxide thin film on a niobium-doped strontium titanate substrate; the process of introducing an ultraviolet-wavelength laser to irradiate and anneal the cerium oxide thin film to obtain a dense cerium oxide thin film; and the process of introducing an infrared-wavelength laser to induce the formation of periodic nanostructures on the surface of the dense cerium oxide thin film. The present invention has the advantage of improving the uniformity of the periodic nanostructures on the cerium oxide surface.

There is provided a method of forming a bismuth-containing gallium oxide-based semiconductor film on a base material by a pulse laser deposition method using a target containing gallium oxide and bismuth oxide. In the method, the temperature of the base material is set to 650° C. to 1,000° C., and the laser intensity is set to 1.0 J / cm2 to 10.0 J / cm2. The bismuth-containing gallium oxide-based semiconductor film of the present disclosure has a proportion of the number of atoms of bismuth of 0.50 at % to 10.00 at % with respect to the total of the numbers of atoms of bismuth and gallium and has a β-gallia structure. The bismuth-containing gallium oxide-based semiconductor component of the present disclosure has a base material and the bismuth-containing gallium oxide-based semiconductor film that is laminated on the base material.

The invention discloses a superconducting tape film preparation method, which comprises the following steps: when a superconducting tape is subjected to film preparation through a pulsed laser deposition (PLD) or metal organic chemical vapor deposition (MOCVD) process, multiple thermal crystallization-quenching process steps are carried out, that is, the superconducting tape sequentially passes through a thermal crystallization region and a quenching region for multiple times, each time the superconducting tape is heated in the thermal crystallization area to complete directional crystallization, and then the superconducting tape enters the quenching area to be rapidly cooled. The multi-time'thermal crystallization-quenching 'process step is realized by a multi-stage'thermal crystallization-quenching' functional unit, and in the multi-stage'thermal crystallization-quenching 'functional unit, a plurality of thermal crystallization areas and quenching areas are sequentially and crossly arranged to form a plurality of stages of temperature control. According to the method, the problem of warping of the thick film of the superconducting tape is solved through stress release.

This invention discloses a method for preparing epitaxial stress-controlled polarized metals, belonging to the field of functional oxide thin film preparation. The method includes: performing a special high-temperature annealing pretreatment on a YAlO3(111) substrate; calibrating the pulsed laser deposition rate and using a moving mask technique to prepare a wedge-shaped thin film with continuously varying thickness; and precisely controlling key process parameter windows such as growth temperature, laser energy density, oxygen partial pressure, and the distance between the target and the substrate. This invention obtains an ideal nucleation template by optimizing the substrate pretreatment process, achieves linear modulation of the thickness gradient by precisely controlling the matching of the mask moving speed and deposition rate, and obtains a high-quality polarized metal thin film with a room temperature resistivity as low as 173 μΩ·cm and stability across the entire temperature range by systematically optimizing key process parameters. This method has the advantages of high repeatability, high control precision, and wide applicability, and can be extended to the preparation of other perovskite oxide thin films, showing broad application prospects in the field of polarized electronic devices.

The utility model discloses a kind of pulse laser deposition optical path adjusting device, including pedestal, mounting seat, reflection component, focusing component and scanning driver.Laser enters optical path adjusting device, by first reflector and second reflector reflection to focusing lens, focusing lens focuses on laser and hits on target material, scanning driver moves along first direction by driving mounting seat, mounting seat drives first reflector, second reflector and focusing lens whole body moves, so that laser can scan and move and hit on target material, and can be moved by focusing actuator driving focusing lens along second direction relative to mounting seat and adjust position, adjust the focal point of focusing lens relative to target material position, so that both can adjust the size of light spot on target material, and can also realize light spot on target material and scan and move and adjust position, improve target material utilization and coating uniformity.

This invention relates to the field of semiconductor materials, specifically to an aluminum nitride thin film with different crystal orientations, its preparation method, and its applications. The invention provides a method for preparing aluminum nitride thin films with different crystal orientations, comprising the following steps: S1, selecting a single-crystal substrate with a corresponding crystal orientation according to the crystal orientation requirements of the target aluminum nitride thin film; S2, annealing the single-crystal substrate and introducing a nitrogen ion source to activate the surface of the single-crystal substrate by ion bombardment; S3, performing pre-bombardment and thin film deposition using pulsed laser deposition, and obtaining an aluminum nitride thin film with the target crystal orientation by controlling the growth temperature and growth gas pressure. This invention provides a universal, efficient, and controllable solution by organically combining three steps: "substrate crystal orientation selection - surface activation modification - synergistic control of growth parameters," successfully achieving high-quality and controllable preparation of aluminum nitride thin films with multiple crystal orientations on a single-pulse laser deposition platform.

The invention relates to a method for regulating and controlling the retentivity of a ferroelectric domain wall memory through the size of a device, which comprises the following steps of: epitaxially growing a BiFeO3 film with the thickness of 200nm on a SrTiO3 (001) substrate which is beveled by 2 degrees, ensuring the quality of the film by adopting pulsed laser deposition, and forming a Pt planar electrode structure on the surface of the film through magnetron sputtering, electron beam photoetching and reactive ion etching, the polarization overturning area is controlled by adjusting the electrode gap, the retentivity is tested by combining an I-V curve and a PFM spectrum, and the result shows that when the overturning area is larger than 7 * 10 < 6 > nm < 2 >, the device can keep the polarization state for a long time, and when the area is reduced to 1.3 * 10 < 4 > nm < 2 >, the retentivity disappears. According to the invention, the retention rule of size dependence is defined, the influence of a depolarization field and ferroelastic energy is effectively overcome, and the reliability and information retention time of the memory are remarkably improved.

The invention relates to a resistive random access memory based on ferroelectric domain wall current leading and a preparation method thereof. The method comprises the following steps: epitaxially growing a BiFeOfilm on a [001] SrTiO single crystal substrate which is beveled at 2 degrees in a [100] direction, and inducing to form a periodic stripe domain structure of which a 71-degree domain wall is parallel to a (101) plane by utilizing the limiting characteristic of the beveled substrate; preparing a top electrode by adopting pulse laser deposition or magnetron sputtering; the electron beam lithography technology is used for preparing a nanoscale planar electrode pair structure type device, ultraviolet lithography is used for preparing a capacitance type device with a micron-sized electrode, and good scale dependence and current response characteristics are achieved. By using the electrode deposited by magnetron sputtering, the defect is introduced at the interface, the change of the Schottky barrier in the polarization overturning process is counteracted, the current of the diode can be effectively suppressed, and the real domain wall current is obtained.

The invention relates to a memory cell based on a ferroelectric topological domain and a preparation method of the memory cell. The memory cell comprises a ferroelectric nano island array and electrodes, and the electrode is positioned in the center of the ferroelectric nano island array. The preparation method of the memory cell based on the ferroelectric topological domain comprises the following steps: preparing a ferroelectric nano island array on a substrate through a pulse laser deposition method and an argon ion beam etching method, and depositing a circular electrode at the central position of the ferroelectric nano island array through a focused ion beam assisted deposition method, and obtaining the memory cell based on the ferroelectric topological domain. According to the method, a new method is provided for constructing a novel low-dimensional topological electronics device, and compared with a traditional storage unit, the prepared ferroelectric topological storage unit array device is improved in integration level and density.

The invention relates to the technical field of LED epitaxial wafers, in particular to an LED epitaxial wafer, a preparation method of the LED epitaxial wafer and an LED chip, and the method comprises the following steps: firstly, carrying out cleaning and hydrofluoric acid etching treatment on a sapphire substrate, and growing a Sn-doped Li5GaO8 buffer layer through pulse laser deposition; then growing an n-type GaN layer through a chemical vapor deposition method, preparing a ZnGa2O4 seed layer through pulsed laser deposition, forming an InGaN quantum dot array through strain induced phase separation, then constructing a gradient In component quantum well, depositing a BaTiO3 ferroelectric layer through magnetron sputtering, and neutralizing a built-in electric field through electron beam polarization; and finally, growing a gradient doped p-type GaN layer by adopting a circulating annealing process, and assembling a KZnPO4 nanosheet ordered array on the surface of the gradient doped p-type GaN layer by adopting a vertical pulling technology. Therefore, the problems of poor heat dissipation, low luminous efficiency, high efficiency attenuation, short service life and the like of the LED epitaxial wafer are solved.

The invention relates to a composite buffer layer structure for a high-temperature superconducting tape, a preparation method of the composite buffer layer structure and the superconducting tape, and belongs to the technical field of high-temperature superconducting materials. The composite buffer layer structure comprises a first buffer layer and a flattened cap layer which is formed by epitaxial growth of lanthanum strontium manganese oxide (LSMO) on the first buffer layer through a pulse laser deposition technology. By introducing the LSMO flattening cap layer, the interface roughness is reduced to the atomic level while the excellent texture quality is maintained, and an almost ideal growth template is provided for the superconducting layer. According to the design, the problem that the quality of the superconducting layer is reduced due to the fact that the surface appearance of a traditional buffer layer is rough is effectively solved, the current-carrying performance of the superconducting tape is remarkably improved, and the high-temperature superconducting tape is a breakthrough solution for promoting the second-generation high-temperature superconducting technology to develop to higher performance.