23 results about "Lattice defects" patented technology

A method is presented for locating charge traps in a crystal lattice. The method includes: arranging a local probe having an inversion-symmetric lattice defect, wherein energy levels of the lattice defect are non-linearly Stark-shiftable by means of charge traps in the crystal lattice; determining Stark-shifted photoluminescence emission spectra, wherein each of the photoluminescence emission spectra is determined in a respective scanning operation by means of photoluminescence excitation in the crystal lattice; determining an integrated spectrum by integrating the photoluminescence emission spectra; determining jump probabilities from consecutive ones of the photoluminescence emission spectra and determining a charge trap configuration from the jump probabilities; determining simulated spectra by means of Monte Carlo simulation based on the determined charge trap configuration and a resulting Stark shift; and determining an optimal spatial arrangement of the charge traps neighboring the local probe by comparing the integrated spectrum with the simulated spectra.

The invention belongs to the technical field of nano material preparation, and particularly relates to a method for synthesizing ordered-structure high-entropy nano particles through microwave induction. Through interaction of a microwave field and a multi-element metal precursor, diffusion limitation of a traditional high-temperature solid-phase method is broken through, and structure ordering and element uniform distribution of the high-entropy nanoparticles are achieved. The metal precursor generates molecular polarization in a microwave field due to dielectric loss, so that molecular-level instantaneous temperature rise in a reaction system is realized, and the hysteresis of traditional heat conduction is overcome. In addition, different metal ions generate a selective heating effect in a microwave field due to the difference of dielectric constants, and synchronous activation and atomic diffusion of 5-14 kinds of principal element metal in the high-entropy alloy are promoted. In a microwave environment, more diffusion paths can be provided by introducing lattice defects, so that diffusion and ordering of atoms are promoted. The high-entropy nanoparticles synthesized by microwave induction have the characteristics of ordered structure, uniform components and small particle size.

This invention provides a highly efficient method for separating or concentrating lattice defect-containing nanoparticles (NDs). [Solution] A method for separating or concentrating lattice defect-containing ND particles, comprising irradiating a dispersion containing at least two types of ND particles selected from nanodiamond (ND) particles having at least one type of lattice defect and ND particles without the lattice defect with at least one type of excitation laser light having an energy greater than or equal to the resonance absorption energy of the lattice defect and at least one type of stimulated emission laser light, thereby selectively moving the ND particles having the lattice defect by the absorption optical pressure generated by the absorption of at least one type of excitation laser light and the stimulated recoil force generated by the action of at least one type of stimulated emission laser light, wherein the excitation laser light transitions electrons in the ground state of the ND particles to an excited state, and the stimulated emission laser light transitions electrons in the excited state to the ground state faster than spontaneous emission to generate stimulated recoil force.

The invention discloses a volatile threshold switching device based on an atomic-scale geometric confinement layer and a preparation method thereof. The device comprises a substrate layer, a bottom electrode layer, a functional active layer, a geometric confinement layer and a top electrode layer which are stacked in sequence, the functional active layer is used for providing active metal ions to form conductive filaments; the functional active layer is made of a two-dimensional layered ferroelectric material; the geometric confinement layer is made of hexagonal boron nitride sheets, and the thickness range of the hexagonal boron nitride sheets is 1-5 hexagonal boron nitride atomic layers. According to the invention, the h-BN material with atomic-scale lattice defects is introduced as the geometric confinement layer, and the diameter of the conductive filament formed by copper ions in the functional active layer is physically limited by using the atomic-scale ion sieve effect of the h-BN material, so that the problem of failure caused by overgrowth of the filament in a traditional device is solved.

The invention provides a quantum dot, a preparation method thereof and a light-emitting device. According to the preparation method disclosed by the invention, after the M1M2N1 quantum dot core is formed, the metal element M2 second precursor is added, so that the surface of the M1M2N1 quantum dot core is rich in M2 cations, lattice defects can be effectively reduced, and the PLQY of the quantum dot is remarkably improved.

The present invention provides a method for epitaxial growth of silicon carbide to reduce native defects. Under the predetermined temperature of not less than 1500°C and the predetermined pressure of not less than 50 mbar defined in step S1, hydrogen is introduced in step S2 to etch the doped silicon carbide substrate. In this step, a doping source gas of not less than 0.06% of the hydrogen flow rate is introduced to adjust the collision frequency between hydrogen molecules and the substrate, thereby reducing or avoiding the situation where hydrogen etching may lead to excessive removal of the substrate atomic layer. In step S3, in addition to the introduction of hydrogen and doping source gases, a chlorine-containing gas of not more than 0.4% of the hydrogen flow rate is introduced to cooperate with the hydrogen to refine the etching and enhance the mobility of the etched carbon and silicon to avoid the formation of silicon clusters on the substrate. A carbon-containing source gas of not more than 0.04% of the hydrogen flow rate is introduced to fill the carbon vacancies caused by etching by carbon atom migration, thereby reducing deep energy level traps caused by lattice defects.

The invention discloses an Ag-sensitized core-shell Ag (at) CdS (at) ZnS quantum dot as well as preparation and application thereof. The quantum dot comprises a silver nanoparticle inner core, a cadmium sulfide middle layer coating the silver nanoparticle inner core, and a zinc sulfide outer layer coating the cadmium sulfide middle layer, a core-shell structure of silver nanoparticle inner core-cadmium sulfide middle layer-zinc sulfide outer layer is constructed, CdS and ZnS shell layers are coated step by step, lattice defects can be reduced, meanwhile, Ag is introduced, the plasma resonance effect can be improved, and the quantum yield and the detection sensitivity to nitro explosives are remarkably improved.

The invention provides a CVD (Chemical Vapor Deposition) growth method of low-dimensional telluride doped single crystal Ag2Te1-xSex. The method comprises the following steps: 1) preparing a precursor, namely growing polycrystal Ag2Te1-xSex from Ag powder, Te powder and Se powder in different proportions through a CVT (Chemical Vapor Transfer) method; (2) precursor treatment: grinding the polycrystalline Ag2Te1-xSex into powder; and 3) single crystal growth: taking the polycrystal Ag2Te1-xSex powder as a reaction source, and generating single crystal Ag2Te1-xSex through a CVD (chemical vapor deposition) growth method (namely, a chemical vapor deposition method). By means of CVD growth and doping, appropriate doping elements are introduced into the low-dimensional telluride, lattice defects are controlled, and then the thermoelectric performance of the low-dimensional telluride is optimized; the single crystal Ag2Te1-xSex nanosheet obtained by the method has the characteristics of large size, high quality and the like, the surface flatness is high, lattice defects are few, and the application potential of the single crystal Ag2Te1-xSex nanosheet in electronic devices can be effectively improved.

The invention relates to the technical field of gallium tetrachloride, in particular to a stable gallium tetrachloride crystal material and a preparation method thereof, the crystal is a triclinic system, the space group is shown in the specification, the crystal structure is a zero-dimensional GaCl4 tetrahedral cluster structure, and Ga < 3 + > and four Cl <-> form edge shared tetrahedral coordination. The stable gallium tetrachloride crystal material has a regular triclinic system structure, accurate and controllable lattice parameters, uniform Ga-Cl bond length and bond angle distribution and no obvious lattice defect, the chemical stability and the thermal stability of the crystal are remarkably improved, the hydrolysis rate is low in a normal-temperature and high-humidity environment, the crystal is not easy to decompose at a high temperature, and the application requirements under extreme working conditions can be met.

The present invention discloses a method for encapsulating single perovskite nanocrystal particles induced by ammonia vapor and confined by ligands. This method involves purifying perovskite nanocrystals prepared by hot injection, capped with APTES and OA, and repaired with PbX2 for lattice defects, before dispersing them in toluene. A ligand and an organosilane are then added, and the mixture is stirred in an ammonia vapor atmosphere to produce SiO2-encapsulated monodisperse perovskite nanocrystal particles. The CsPbX3@SiO2 core-shell structure particles prepared using this method can nearly intactly preserve the crystal structure and excellent optical properties of CsPbX3, significantly improving the stability of the nanocrystals while maintaining their small size and monodispersity. These particles are suitable as building blocks for advanced nanofabrication technologies, particularly in display technology, anti-counterfeiting, and other fields.

The present invention discloses a method for preparing a CZT high-energy resolution radiation chip, belonging to the field of electrical component production technology, comprising: S1. growing a CZT crystal; S2. preparing a desired CZT sheet using the CZT crystal; S3. injecting a certain dose of fluoride ions into the CZT sheet; S4. performing an annealing process on the CZT sheet after the fluoride ion injection to uniformly diffuse the fluoride ions in the CZT sheet, thereby improving lattice defects during CZT crystal growth; S5. injecting indium ions into the cathode surface layer of the CZT sheet to increase the resistivity of the CZT sheet and change the energy band structure of the CZT sheet to generate a stronger radiation signal; S6. performing an annealing process again to make the indium ions more uniformly distributed on the surface layer of the CZT sheet; S7. platinum-plating the cathode surface of the CZT sheet and indium-plating the anode surface of the CZT sheet; S8. connecting the CZT sheet to the cathode and anode of a detector, respectively, and then encapsulating the CZT sheet in a housing. The present invention has the advantages of improving lattice defects and increasing the carrier migration lifetime product.

Method for localizing charge traps in a crystal lattice comprising the following steps: - Arrange, on a crystal lattice (13), a local probe (11) with an inversion-symmetric lattice defect, wherein energy levels of the lattice defect are non-linearly strongly displaceable by means of charge traps (12) in the crystal lattice (13); - Determining strongly shifted photoluminescence emission spectra (62) using a readout unit (10), wherein each of the photoluminescence emission spectra (62) is determined in a respective scanning operation by means of photoluminescence excitation in the crystal lattice (13); - Determining an integrated spectrum (61) by integrating the photoluminescence emission spectra (62); - Determining jump probabilities (92) from successive photoluminescence emission spectra (62) and determining a charge trap configuration from the jump probabilities (92), wherein the charge trap configuration comprises a set of charge trap states of charge traps (12) adjacent to the local probe (11); - Determining simulated spectra (60) using Monte Carlo simulation based on the determined charge trap configuration and the resulting Stark shift, whereby spatial arrangements of the neighboring charge traps (12) are varied and - Determining an optimal spatial arrangement of the adjacent charge traps (12) by comparing the integrated spectrum (61) with the simulated spectra (60).

The invention belongs to the technical field of mineral material detection, and provides a natural fluorite mineral lattice defect detection method which comprises the following steps: providing crystal structure information through XRD (X-Ray Diffraction), realizing atomic-scale morphology observation through TEM (Transmission Electron Microscope), analyzing component distribution through SIMS (Sequence Ion Mass Spectrometry), and confirming electron / vibration characteristics through Raman / EPR (Electronic Performance Resonance), the method is suitable for characterizing point defects such as impurity substitution, vacancy and interstitial ions, macrostructure characterization (such as unit cell parameter change) and microdefect chemistry (such as ratio) of fluorite defects can be considered, the method has three-dimensional analysis capability on defect space distribution, accurate judgment on defect types in fluorite is realized, and misjudgment in the prior art is overcome.

The application discloses a preparation method of a quantum dot light-emitting device based on an ion additive, utilizes single halogen Br to synthesize CsPbBr3 metal halide perovskite quantum dot material, and fundamentally avoids inherent problems caused by mixed halogen perovskite nanocrystal material, i.e. halogen phase separation under an electric field. By adding an ion additive, i.e. (2-bromoethyl)diphenyl sulfonium trifluoromethane sulfonate, into the quantum dot, as a kind of anion and cation ligand, the ion additive is strongly combined with the perovskite quantum dot surface and fills the lattice defects on the perovskite quantum dot surface, so that the quantum dot is provided with a more perfect lattice structure and stronger surface stability, defect-induced non-radiation recombination and spectrum shift caused by ripening are effectively inhibited, and the LED device prepared based on the perovskite quantum dot has higher light-emitting efficiency and operation life.

This invention provides a metal halide dual-mode luminescent material and its rapid microwave synthesis method, belonging to the field of luminescent material technology. Through precise ion doping design and controllable synthesis process, the metal halide dual-mode luminescent material of this invention achieves excellent luminescent performance, integrating up-conversion and down-conversion luminescence capabilities in the same system. It can be used in fields such as multi-mode optical anti-counterfeiting, information encryption, and integrated bio-imaging and diagnosis. The rapid microwave synthesis method is efficient and controllable, avoiding component volatilization and lattice defects caused by high-temperature and long-term processing. It achieves atomic-level uniform doping, has good process repeatability, is suitable for large-scale preparation, and meets the requirements of green synthesis and low-cost manufacturing.

The invention discloses a perovskite nanocrystalline single particle packaging method based on ammonia water vapor induction and ligand confinement. According to the method, APTES prepared by a thermal injection method and OA are terminated, perovskite nanocrystals with lattice defects repaired by PbX2 are purified and then dispersed in toluene, ligands and organosilane are added, a stirring reaction is carried out in the atmosphere of ammonia water vapor, and monodisperse perovskite nanocrystal particles packaged by SiO2 are prepared. The CsPbX3-coated SiO2 core-shell structure particles prepared by the method can maintain the crystal structure and excellent optical performance of CsPbX3 almost without damage, the stability of nanocrystals is remarkably improved, meanwhile, the small size and monodisperse characteristics are maintained, and the CsPbX3-coated SiO2 core-shell structure particles are suitable for serving as a construction unit of an advanced nanometer manufacturing technology and particularly suitable for the fields of display technologies, anti-counterfeiting and the like.

The invention relates to the technical field of gas-sensitive sensing materials, in particular to a C3N4 / ZnSnO3 nano composite material, a preparation method and application thereof.The C3N4 / ZnSnO3 nano composite material is prepared by mixing, calcining and grinding a ZnSnO3 nano material and C3N4 nanosheets according to a specific proportion (1 wt%-5 wt% of the C3N4 nanosheets), the ZnSnO3 component prepared through a hydrothermal method has excellent chemical uniformity and nanoscale particle size, and the content of the ZnSnO3 component in the gas-sensitive sensing material is higher than that of the C3N4 nanosheets in the gas-sensitive sensing material. Abundant lattice defects are induced to be generated in the calcining process; the doping of C3N4 realizes ultrastructure regulation and control through physical mixing, surface active sites are significantly increased, and the problems of high working temperature and insufficient response performance of a ZnSnO3-based gas sensitive material in the prior art are solved.

The invention provides a high-entropy spinel oxide synthesized by a carbon thermal shock method as well as a preparation method and application thereof, and relates to the technical field of high-entropy spinel oxides. According to the method, calcining treatment is carried out by adopting a carbon thermal shock method, so that the Oswald curing process of crystal grains in the preparation process can be effectively inhibited, and after metal atoms form a high-entropy single phase, no enough time is provided for surface migration and crystal grain growth, so that a nano material with relatively small crystal grain size is obtained, and abundant surface active sites are provided for gas-solid reaction. Secondly, due to the non-equilibrium and non-steady-state characteristics of the carbon thermal shock process, the high-temperature instantaneous state of the material is'frozen 'in the shock cooling process, a large number of non-thermodynamically-balanced lattice defects, especially oxygen vacancies, are easily introduced, and meanwhile, the local reducing atmosphere of the carbon substrate can also promote formation of the oxygen vacancies.

The invention discloses a preparation method of a molecular beam epitaxy vacuum evaporation Fe < 1-x > Al < x > alloy, which realizes real-time monitoring of component proportion in the evaporation process through a quartz crystal oscillation and mass spectrum coupling technology. According to the method, the evaporation temperature of metal iron and aluminum is adjusted through an in-situ monitoring dynamic feedback system, meanwhile, a substrate temperature changing process is introduced to inhibit interface diffusion and eliminate lattice defects, compared with a traditional MBE process, atomic-scale component control is achieved through accurate evaporation source temperature control and element component monitoring, and the method is suitable for large-scale production. The problems of stress accumulation and component deviation in alloy epitaxy are solved. The prepared Fe < 1-x > Al < x > single crystal film has the characteristics of large-area flatness, controllable thickness and good interface mutability, and is suitable for soft X-ray conversion materials in magnetoelectric coupling devices, high-frequency soft magnetic elements and inertial confinement fusion experiments.

The present invention discloses a method for correcting lattice defects of silicon-based materials based on electric field action. The method for correcting lattice defects of silicon-based materials based on electric field action of the present invention corrects the lattice defects of the silicon-based material itself and the lattice defects generated during the wet etching process by preheating the silicon-based material after wet etching and applying a direct current electric field. Under high temperature conditions, the electron wind force generated by the electric field force acts on related electrons and atoms, so that the silicon-based material is restored to its original state, thereby improving the quality factor of the silicon-based material, enhancing its application performance and increasing its application prospects.

The present application belongs to the technical field of temperature measurement, especially high-temperature temperature measurement, and specifically provides a defect construction method of C-axis preferred orientation AlN film for high-temperature temperature measurement, to improve temperature interpretation accuracy. The present application uses a medium-frequency reactive magnetron sputtering method to realize the preparation of C-axis preferred orientation AlN film, and in the sputtering process, uniform and controllable lattice defects are constructed in the C-axis preferred orientation AlN film through the method of active gas doping. The lattice defect construction method provided by the present application is simple in process, good in stability and repeatability, does not need neutron irradiation, and is low in cost. The C-axis preferred orientation AlN film with uniform and controllable lattice defects as a temperature sensitive material can realize high-temperature temperature measurement and improve temperature interpretation accuracy.

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 present disclosure provides a quantum dot and preparation method thereof, and a light-emitting device. In the preparation method, after forming the M1M2N1 quantum dot core, the metal element M2 second precursor is added to make the surface of the M1M2N1 quantum dot core rich with M2 cations, which may effectively reduce lattice defects and significantly improve the PLQY of the quantum dot.