26 results about "Vacancy defect" patented technology

A method for adjusting the wide spectrum detection of transition metal chalcogenides by using vacancy defects belongs to the field of two-dimensional materials. In the method, transition metal oxides are used as metal sources, two different chalcogen elements are used as sulfur sources, and a single-layer ternary transition metal chalcogen compound with uniform element distribution is grown by using a chemical vapor deposition method. By using the difference in the stability of the chemical bonds between alloy elements, the unstable chemical bonds are broken by hydrogen-assisted annealing, and the generated chalcogen element vacancy defects are uniformly distributed in the ternary transition metal chalcogen compound. The chalcogen element vacancy defects introduce defect energy levels between the conduction band and the valence band of the transition metal chalcogen compound, generate new photoluminescence peaks, and widen the spectrum detection range. The experimental method is simple in process, good in repeatability, can accurately control the type, distribution and number of defects, and is suitable for large-scale production.

The invention relates to a construction method of a high-spin-selectivity photoelectric detector, and the method comprises the steps: setting a scattering region in the middle of a photoelectric detector model constructed by an armchair type Janus WSSe lattice, and enabling the regions at the two ends to serve as a left electrode and a right electrode respectively; the method comprises the following steps: introducing a vacancy defect of a single atomic level into a scattering region of a photoelectric detector, carrying out electronic local state analysis and impurity doping analysis on the scattering region after the defect is introduced, and screening out transition metal elements meeting preset conditions as doping elements; and performing bias voltage regulation and control on the photoelectric detector doped with the elements to construct a cooperative regulation and control strategy so as to complete construction of the photoelectric detector. According to the invention, through atomic scale defect introduction and transition metal doping modes, the photo-generated spinning current intensity, the spinning polarizability and the selective response ability to polarized light are significantly improved.

The invention provides a czochralski silicon single crystal growth method and device for cooperatively controlling volume microdefects and a silicon wafer. According to the method, a nitrogen-oxygen-vacancy ternary cooperative control strategy is implemented in the crystal pulling process, and the method specifically comprises the steps that the nitrogen doping amount is calculated in the charging stage, the rotating speed of a crucible and an airflow field are controlled in the melting and stabilizing stage to adjust the oxygen content, and a thermal field is shaped through an inverted-cone-shaped guide cylinder in the equal-diameter growth stage. And locking the V / G ratio of a silicon single crystal solid-liquid growth interface in a pure vacancy defect generation region by executing pulling speed locking logic. According to the invention, the nitrogen concentration in the crystal is limited in a low concentration range of 1 * 10 < 13 > to 5 * 10 < 13 > atoms / cm < 3 >, the oxygen concentration is controlled in a range of 11 to 13 ppma, and the high-concentration vacancy of the pure vacancy region is utilized to compensate the insufficient nucleation power under the low-nitrogen condition, so that the nitrogen-related defects are inhibited, the volume micro-defects with high density and uniformly distributed in the radial direction are obtained, and the high-purity nitrogen-containing crystal is obtained. And the gate oxide integrity of the silicon wafer is improved.

The invention belongs to the technical field of preparation of high-performance thermoelectric materials, and particularly relates to a method for assisting in optimizing a P-type tin telluride thermoelectric material grain boundary and defect structure through fused salt. The polycrystalline SnTe material is synthesized by adopting a molten salt medium auxiliary melting method. According to the method, directional attachment in the crystal growth process can be promoted in a high-temperature liquid phase environment, large-size crystal grains are formed, the density of large-angle crystal boundaries is remarkably reduced, meanwhile, a sub-crystal structure composed of small-angle crystal boundaries is formed in the crystal grains through induction, the carrier mobility is improved, and the electron transport performance is optimized. Besides, cation vacancy defects are introduced by regulating and controlling a reaction environment and a doping strategy, so that the carrier concentration can be effectively regulated, and the Seebeck coefficient is further improved. On the basis, multi-scale interface scattering can be further realized and the lattice thermal conductivity can be obviously reduced by compounding an exogenous nano structure such as Mg2Yb, and finally collaborative optimization of the electric heating performance is realized, so that the material obtains excellent thermoelectric performance in a wide temperature range.

The invention provides a Cr2Se3 single crystal and a preparation method thereof, and relates to the technical field of crystal materials. According to the preparation method of the Cr2Se3 single crystal, the steps from raw material proportioning, cooked powder preparation to the single crystal growth process cooperate to inhibit impurity introduction and impurity phase generation, meanwhile, ordered arrangement of atoms is promoted, lattice vacancy and dislocation are eliminated, and the Cr2Se3 single crystal good in single-phase property, high in crystallinity and extremely low in defect density is prepared. Due to the high-purity and low-defect single-crystal structure, the semiconductor transport characteristic and antiferromagnetic orderliness of the single-crystal structure are guaranteed; meanwhile, interference of impurity scattering and lattice distortion is eliminated, the regulation and control effect of a magnetic field on the Cr atom magnetic moment is optimized, and the single crystal has the strong CMR effect close to-100%. And through cooperation of all the steps, it is ensured that the prepared Cr2Se3 single crystals are consistent in size, phase composition and structural integrity, and the preparation success rate and the controllability and repeatability of the process are greatly improved.

The invention belongs to the technical field of semiconductors, and relates to a method for improving single-layer WSe2 second harmonic signal intensity, which comprises the following steps of: preparing a single-layer WSe2 material; carrying out heavy ion radiation on the single-layer WSe2 material to generate defects in the single-layer WSe2 material; by controlling the energy of the heavy ion radiation, the defect concentration in the single-layer WSe2 material is controlled, so that the second harmonic signal intensity of the single-layer WSe2 material is improved. Vacancy defects and tiny disordered regions are introduced into the material, and intrinsic enhancement is realized on the basis that intrinsic photoelectric characteristics of a single-layer material are not changed. Compared with an external field regulation and control method, the defect caused by ion irradiation is permanent structural change, once the defect is formed, the enhancement effect always exists and does not need to be maintained by continuously consuming energy, and the key requirements of non-volatile property and low power consumption are met.

The invention discloses a GaN-based blue-green light LED epitaxial wafer based on a Zn-doped gradient composite buffer layer and a preparation method of the GaN-based blue-green light LED epitaxial wafer. The epitaxial wafer comprises a substrate, a zinc-doped gradient composite buffer layer and a gallium nitride-based epitaxial laminated structure, and the zinc element concentration is in gradient distribution along the growth direction, preferably, the zinc element concentration is gradually reduced from the side close to the substrate to the side far away from the substrate. And the buffer layer comprises at least two of a Zn3N2 layer, a constant component ZnGaN layer or a component gradient ZnGaN layer. During preparation, the buffer layer is grown at the temperature of 400-850 DEG C, concentration gradient is realized by adjusting the flow ratio of zinc-containing and gallium-containing precursors, and forced doping is realized by adopting a 10-50-time high-flow compensation strategy in a high-temperature interval. According to the invention, lattice constant soft landing is realized by supercell matching of Zn3N2 and GaN, and nitrogen vacancy point defects are passivated in situ by using Zn atoms. Experiments prove that the luminous efficiency of the chip can be improved by about 0.81%, the ESD (Electro-Static Discharge) 4000V yield is improved to more than 98.2%, and the crystal quality and the reliability of the device are obviously enhanced.

The invention provides a perovskite single crystal diode device based on spatial position defect regulation and a preparation method thereof. The method comprises the following steps: dropwise adding a precursor solution on a substrate layer on which metal with a high heat conductivity coefficient is deposited, and then heating to evaporate a solvent to form a perovskite single crystal layer. As the heat conductivity coefficient of the metal of the electrode layer is relatively high, the parts close to the two ends of the gold electrode in the perovskite single crystal growth process are faster in heat conduction and easy to generate more defect accumulation, and the middle overhead part is slower in heat conduction and relatively generates fewer defects, so that the regulation and control of defect distribution are realized; and a diode rectification effect of polarity reversal along with the change of a light spot position is realized on a transverse structure of a perovskite absorption layer. Structural defects are reasonably utilized, the photoelectric property of a perovskite device is flexibly regulated and controlled to expand application, the halogen vacancy defect concentration of different areas on the perovskite single crystal is regulated and controlled through the reaction temperature of the synthetic material, the overall charge transfer mechanism is changed, and the rectification characteristic that polarity can be reversed along with the change of the light spot position is achieved.

The invention discloses a reference lattice adaptive reconstruction method for Wigner-Seitz point defect identification, which is characterized in that based on an off-location lattice, defects in the off-location lattice are classified, in the first type of defects, firstly, interstitial sub defects in local defects are removed, so that only vacancy defects are left in a system, and in the second type of defects, the interstitial sub defects in local defects are removed; then, defect areas of vacancy defects are gradually replaced by perfect lattices through lattice symmetry operation, if the defect areas are still not replaced, additional lattice symmetry operation is iterated in the process until all the defect areas are replaced by the perfect lattices, and finally, a reconstructed perfect reference lattice is obtained through combination. The reference lattice self-adaptive reconstruction method is still effective even in a very complex environment, and the defects of a traditional WS and other point defect recognition method are overcome or solved.

This invention provides a Cr2Se3 single crystal and its preparation method, relating to the field of crystal materials technology. The Cr2Se3 single crystal preparation method, from raw material proportioning and powder preparation to single crystal growth, involves coordinated steps to suppress impurity introduction and impurity phase formation, while simultaneously promoting ordered atomic arrangement and eliminating lattice vacancies and dislocations, resulting in a Cr2Se3 single crystal with good single-phase properties, high crystallinity, and extremely low defect density. The high-purity, low-defect single crystal structure ensures its semiconductor transport properties and antiferromagnetic order; it also eliminates interference from impurity scattering and lattice distortion, optimizing the magnetic field's control over the magnetic moments of Cr atoms, enabling the single crystal to exhibit a strong CMR effect approaching -100%. Furthermore, the coordinated steps ensure consistency in size, phase composition, and structural integrity of the prepared Cr2Se3 single crystal, significantly improving the success rate, process controllability, and repeatability.

The application discloses a kind of high-temperature-resistant cubic boron nitride single crystals and preparation method thereof.The method uses BN raw material as main body, adjusts boron and nitrogen activity by using B / N chemical potential buffer fluxing system, and realizes carbon and silicon cooperative introduction by C-Si slow-release doping system;At the same time, oxygen trapping agent is spatially isolated from the main growth zone to reduce the oxygen activity of the reaction system and reduce the entry of oxygen trapping agent into the crystal growth interface.After growth is completed, high-pressure in-situ annealing is carried out under non-pressure relief condition to promote point defect migration, combination and local structure adjustment.The obtained cBN single crystal has low oxygen content, low sp2 related signal, narrow Raman half-width, high room temperature hardness and high hardness retention rate after high temperature treatment.The method can effectively reduce oxygen pollution, vacancy defects and sp2 impurities, improve the structure quality, hardness and high-temperature service stability of cBN single crystal.

The invention relates to the technical field of semiconductor photocatalytic materials, in particular to a preparation method of crystal face controllable nano titanium dioxide, which comprises the following steps: establishing an anatase type TiO2 model; one or more external atom sources selected from a C atom source, an N atom source, a Fe atom source, a Co atom source, a Ni atom source, a Cu atom source, a Zn atom source, a Mo atom source, a Sn atom source and a W atom source are introduced into crystal lattices of the TiO2 model according to the doping proportions of the different external atom sources, the specific positions of the different external atom sources in the crystal lattices and the like. Foreign atoms are introduced into TiO2 crystal lattices and surfaces, the crystal lattice structure, electron cloud distribution, the surface dangling bond state and vacancy defects of the TiO2 crystal lattices are changed, the surface energy of the {101} crystal face and the {001} crystal face is regulated and controlled fundamentally, and accurate regulation and control of the exposure proportion of the crystal faces can be achieved without depending on a traditional fluorine ion additive.

This invention discloses a method, system, and substrate for single-molecule detection based on defect-engineered two-dimensional materials. The method includes the following steps: obtaining a two-dimensional material layer; subjecting the two-dimensional material layer to plasma bombardment to introduce nanopore defects of a predetermined density and size, thereby forming a defect-engineered two-dimensional material substrate, wherein the nanopore defects include vacancy defects, which are used to modulate the band gap of the two-dimensional material layer and enhance the charge transfer effect between it and the analyte molecule; adsorbing the analyte molecule onto the surface of the defect-engineered two-dimensional material substrate; and performing Raman spectroscopy on the defect-engineered two-dimensional material substrate with the adsorbed analyte molecule to obtain a surface-enhanced Raman scattering signal. This invention enables the defect-engineered two-dimensional material substrate to generate an extremely strong surface-enhanced Raman scattering signal, thereby achieving ultra-high sensitivity detection of analytes at low concentrations or even single-molecule levels.

This application belongs to the field of microelectronic devices, specifically disclosing a self-rectified memristor and its fabrication method. This application employs multi-element synergistic ion implantation into the functional layer. Rare gas ions introduce pure vacancy defects to regulate the interface barrier between the first electrode and the functional layer, forming a barrier difference and achieving a self-rectification effect. Non-metallic elements, acting as interstitial atoms or substitutional impurities, convert some vacancy defects into first composite defects. By changing the charge distribution, the energy level of the comprehensive defect at the interface between the first electrode and the functional layer is regulated to achieve the Poul-Frenkel electron emission mechanism. Metallic elements, acting as substitutional impurities, convert some comprehensive defects into second composite defects. By changing the bonding valence state, the concentration of the comprehensive defect at the interface between the first electrode and the functional layer is regulated to achieve resistive switching stability. This allows for precise control of the defect concentration and energy level, resulting in a fixed site that does not frequently move, thus preventing leakage current and improving its fatigue resistance and consistency.

The invention provides a quantum magnetic sensor based on oxygen injection silicon carbide and a magnetic field sensing method thereof. The device is simple in structure, relatively low in cost, relatively convenient to use and very easy to popularize and use. The silicon carbide double-vacancy defect is prepared by adopting oxygen ion implantation and subsequent annealing processes, so that the yield and the defect density of the double-vacancy defect are greatly improved, and the sensitivity of magnetic field sensing is improved. According to the invention, the laser and microwave power used during detection is optimized, the measurement sensitivity is improved to a great extent, and the sensing sensitivity obtained by an experiment can reach hundreds of nT magnitude.

The invention relates to a non-equilibrium surface oxygen vacancy induced rapid optical transition material and a preparation method thereof. The non-equilibrium surface oxygen vacancy induced rapid optical transition material has an ATiO3-at-ATiO3-x core-shell structure, the core structure is a complete and ordered ATiO3 crystal lattice, and the shell structure is a disordered ATiO3-x amorphous structure containing non-equilibrium surface oxygen vacancy defects; wherein A is Mg, Ca, Sr or Ba; x is more than 0 and less than 1.5.

This invention relates to the field of thin film material preparation technology, specifically to a method for preparing a single-crystal transition metal nitride epitaxial thin film with an anti-perovskite structure. In a molecular beam epitaxy (MBE) apparatus, after heating the single-crystal substrate, a transition metal atom beam and an active nitrogen atom beam generated by a radio frequency plasma source are supplied simultaneously and independently. By precisely controlling the beam ratio, growth is kept within a narrow stoichiometric window. During growth, in-situ real-time monitoring is performed using reflective high-energy electron diffraction to ensure the film grows in a two-dimensional layered manner. Finally, the film is slowly cooled in an active nitrogen atmosphere. This method can prepare single-crystal thin films with atomically flat surfaces, high phase purity, excellent crystallinity, and a clear epitaxial relationship, exhibiting fewer nitrogen vacancy defects and significantly optimized magnetic and other physical properties.

The invention discloses a femtosecond laser induced fused quartz surface oxygen vacancy defect micro-area prefabrication and selective repair method and system, and belongs to the field of laser precision machining and optical material modification. According to the method, irradiation parameters of femtosecond laser on the surface of fused quartz in an oxygen-containing atmosphere are controlled, and the nonlinear absorption effect of the femtosecond laser is utilized, so that two functions are realized: firstly, oxygen vacancy defects with quantitative concentration can be controllably prefabricated in a specified micro-area, and the problem that atomic-scale defects are difficult to position and characterize is solved; and 2, performing selective bonding repair on the positioned oxygen vacancy defect, so that the chemical composition of the defect area is recovered to be close to an ideal stoichiometric ratio. According to the system, a visual positioning module, a parameter mapping module and a cooperative control module are integrated, and full-automatic accurate operation is achieved. The surface roughness change of the area repaired through the method is smaller than 0.04 nm, the method has the advantages of being free of damage, controllable and high in precision, and an effective technical approach is provided for improving the laser damage threshold value of the fused quartz optical element.

This invention discloses a liquid thermoelectric material with low thermal conductivity n-type Ag4Sn0.5S2Te, its preparation method, and its application. The low thermal conductivity n-type Ag4Sn... 0.5 The chemical formula of S2Te-type liquid thermoelectric materials is Ag4Sn. 0.5 S2Te belongs to the cubic crystal system, space group; Ag4Sn 0.5 The chemical formula for creating Te vacancy defects in S2Te through thermoelectric performance optimization is Ag4Sn. 0.5 S2Te 0.92 The n-type Ag4Sn with low thermal conductivity 0.5 S2Te-type liquid thermoelectric materials consist of an anionic rigid framework composed of SnS4 tetrahedral units at the edge centers and Te atoms at the face centers, within which Ag ions move. This method employs a high-temperature vacuum solid-state synthesis technique to synthesize Ag4Sn materials. 0.5 S2Te exhibits 0.22–0.32 Wm at 300–823 K. ‑1 K ‑1 The material exhibits ultra-low thermal conductivity and is a uniformly molten compound that maintains a stable cubic phase in the range of 200–1100 K, modulated by Te vacancy defects and Ag4Sn. 0.5 S2Te 0.92 It achieves a thermoelectric figure of merit as high as 0.74, which is 95% higher than the intrinsic value.

This invention discloses a MnO2 pseudocapacitive material containing cation vacancy defects, its preparation method, and its applications. In the preparation process, different types and amounts of pre-doped ions are introduced during hydrothermal treatment, followed by etching in acid and alkaline solutions. By optimizing the etching conditions, the pre-doped ions are selectively dissolved, forming cation vacancies in the MnO2 lattice, ultimately yielding the MnO2 pseudocapacitive material containing cation vacancy defects. The preparation method provided by this invention is characterized by its simple process, easily controllable reaction, and low cost, making it suitable for large-scale production of pseudocapacitive materials containing cation vacancy defects.

The invention provides a two-dimensional indium selenide intrinsic defect regulation and control method and an application thereof in a photoelectric detector, and solves the problems that an existing regulation and control strategy aiming at serious performance discreteness of the photoelectric detector caused by uncontrollable internal defect level of a two-dimensional indium selenide material still stays at a qualitative level, and quantitative correlation between defects and device performance cannot be determined. And precise regulation and control are difficult to realize. According to the method, a low-temperature (150-200 DEG C) and high-vacuum (10 <-4 > Pa) annealing environment is selected, so that the generation of the selenium vacancy defect is mild and controllable, the targeted regulation and control of the selenium vacancy defect level can be realized, the tendency of lattice structure reconstruction and non-crystallization transformation of the indium selenide material can be effectively inhibited, and the method has remarkable controllability and purposiveness.

The application relates to the technical field of hydrogen storage materials, and provides an efficient preparation method of magnesium hydride as a hydrogen storage medium. In the method, elemental magnesium powder and hard particles such as silicon carbide are uniformly mixed under the protection of argon; then the mixture is placed in a ball milling device, mechanical ball milling is carried out under a specific hydrogen pressure environment, and finally the target material magnesium hydride is collected. The core of the method is to introduce hard particles such as silicon carbide as a micro-processing medium. In the ball milling process, the particles can effectively cut the dense magnesium hydride layer formed on the surface of magnesium particles from the microscale, so that a large number of defects such as crystal lattice vacancies and dislocations are introduced into the material. The defects significantly enhance the diffusion dynamics of hydrogen atoms, provide an efficient channel for the continuous combination of hydrogen and unreacted magnesium, fundamentally accelerate the progress of the hydrogenation reaction, and significantly improve the generation efficiency of magnesium hydride. The method is simple in process and low in cost, and is suitable for large-scale application.

The present invention relates to a powder for manufacturing a BiTe-based n-type thermoelectric material, a BiTe-based n-type thermoelectric material manufactured using the powder, and a manufacturing method thereof. More specifically, the present invention relates to a method for manufacturing a BiTe-based n-type thermoelectric material by using Bi, Sb, and Te. x Sb 2-x The present invention relates to a powder for producing a BiTe-based n-type thermoelectric material, which has a composition of Te3 (where x is 1.0≦x≦1.9) but contains Te vacancy defects, and in which an excess amount of Te is contained in the crystal grains and crystal grain system; a BiTe-based n-type thermoelectric material produced using the powder; and a method for producing the material.

The application discloses a defect-state half-Heusler thermoelectric material, a preparation method and application, and relates to the technical field of thermoelectric materials. The problems of high intrinsic lattice thermal conductivity of the existing half-Heusler thermoelectric material and the limitation of the preparation process of the conventional melting method due to the difference in melting points of component elements are solved. The material is a half-Heusler thermoelectric material composed of non-stoichiometric Zr, Ni and Bi elements and having intrinsic vacancy defects in the crystal structure, and the chemical formula is Zr 0.88 NiBi. A preparation method of the defect-state half-Heusler thermoelectric material is also provided. Zr, Ni and Bi elements are taken in a preset proportion, high-energy ball milling is used to ball mill raw materials, and mixed powder without block condensation is obtained; a hot-pressing sintering process is used to solidify the mixed powder to obtain a hot-pressing sintering sample; high-temperature annealing is performed on the hot-pressing sintering sample, and the sample is cooled to room temperature to obtain a finished product. The half-Heusler material has low lattice thermal conductivity and excellent performance.

The invention discloses a VC / Al2O3 / FeCoNi phase derived in-situ composite material as well as a preparation method and application thereof, and belongs to the field of electromagnetic wave absorbing materials. The invention aims to solve the problem of how to enhance the magnetic dielectric effect and interface polarization of the MAX phase derivative in electromagnetic attenuation. Iron, cobalt and nickel magnetic metal elements are introduced into MAX phase derived vanadium carbide by a solid-phase reaction method and a molten salt method, the VC / Al2O3 / FeCoNi composite wave-absorbing material with a layered structure is synthesized, and all the magnetic metal elements are uniformly distributed in layered VC with lattice defects. The VC / Al2O3 / FeCoNi composite material prepared by the method disclosed by the invention has a heterogeneous interface structure and abundant vacancy defects, and the unique structural design synchronously realizes triple effects of enhancing magnetic loss, introducing abundant interface polarization and optimizing impedance matching. The invention excavates the potential of the MAX phase derivative in the field of electromagnetic attenuation.

The invention discloses a method for directly growing a high-quality oriented molybdenum disulfide (MoS2) film on an unannealed sapphire substrate. The core innovation of the method is as follows: (1) zinc sulfide (ZnS) is adopted as a controllable sulfur source, and controllable, continuous and stable supply of a sulfur monomer is realized by accurately regulating and controlling the concentration and the introduction time of the zinc sulfide (ZnS); (2) introducing an oxygen-driven growth regulation and control mechanism, and effectively regulating and controlling the growth of the MoS2 crystal domain by optimizing an oxygen introduction time node, oxygen concentration and the like; and (3) low-concentration oxygen is used for in-situ defect passivation, and the sulfur vacancy defect concentration in the MoS2 thin film is remarkably reduced and repaired. Experimental results show that the oriented MoS2 film grown based on the method has excellent optical quality, the photoluminescence intensity of the oriented MoS2 film can reach 40000 counts when the laser power is 32.5 uW, the sulfur vacancy defect of molybdenum disulfide can be effectively passivated through low-concentration oxygen annealing, and the photoluminescence intensity of the oriented MoS2 film is improved by dozens of times.