130 results about "Crystallographic defect" patented technology

The invention discloses a Bridgman method growth gallium oxide single crystal abnormity detection method based on multi-mode perception, and relates to the technical field of single crystal preparation, and the method comprises the following steps: S1, collecting optical signals of a melt surface area in a Bridgman method growth gallium oxide single crystal process through a sensor array, synchronously acquiring temperature field data or infrared thermal image data of the region; the method comprises the following steps: acquiring an original spectral data set covering a local area according to a radiation signal under a micron-order spatial resolution, and obtaining initial radiation distribution information; according to the anomaly detection method for growing the gallium oxide single crystal by the Bridgman method based on multi-mode perception, dynamic tracking and accurate positioning of component anomaly in the growth process of the Bridgman method are realized, and an effective technical means is provided for improving the growth quality of the gallium oxide single crystal, reducing crystal defects and improving the process control capability.

The application discloses a method for rapidly and nondestructively detecting the quality of silicon carbide crystals, which comprises the following steps: placing the silicon carbide crystals on a computer tomography (CT) carrier table, and rapidly and nondestructively detecting the typical defects in the silicon carbide crystals by means of computer tomography under specific parameters, image contrast and the identification of the topographic features, so as to directly obtain the defect topography, density distribution and the evolution of the defects with the growth process of the measured ingot at different sections, and significantly improve the visualization degree of the defects in the silicon carbide crystals.

The invention discloses a wide-temperature-range perovskite optical storage material and a preparation method and application thereof, the chemical general formula of the wide-temperature-range perovskite optical storage material is CsCdCl3: xSb < 3 + >, yMn < + >, Mn < + > is Zr < 4 + >, Sn < 2 + >, Hf < 4 + > or Gd < 3 + >, x is more than 0 and less than 0.06, and y is more than 0 and less than 0.02. The perovskite crystal can generate free carriers under excitation of X-rays or 365-nanometer ultraviolet light, the carriers can be stored in a crystal defect trap, and the storage temperature of the carriers covers an ultra-wide temperature range from 100 K to 350 K, so that wide-temperature-range X-ray imaging, information storage and anti-counterfeiting application can be realized.

The invention discloses a 7N single crystal copper preparation process based on zone melting and crystal orientation control, which specifically comprises the following steps: S1, raw material pretreatment: purifying 4N copper to 5N grade by adopting electrolytic refining of a nitric acid system, and the carbon content after acid pickling is less than or equal to 1ppm; the invention relates to the technical field of metal material preparation. According to the 7N single crystal copper preparation process based on zone melting and crystal orientation control, impurities in a material are redistributed in a melting zone through local heating, so that separation and removal of the impurities are achieved, in single crystal copper preparation, zone melting can remarkably reduce the content of the impurities in copper, the purity of the copper is improved, and the yield of the 7N single crystal copper is improved. By accurately controlling parameters such as the temperature gradient and the cooling rate in the smelting and solidification process, optimization of crystal orientation is achieved, single crystal copper with an ideal crystal structure can be obtained, the performance of the single crystal copper is improved, and impurities can be removed and crystal defects can be reduced through zone smelting; and crystal orientation control can optimize the crystal structure and improve the performance.

The invention discloses a temperature control method for crystal growth and a related device, and the method comprises the steps: firstly obtaining image data in a crystal growth process, then extracting an aperture image from the image data, obtaining a plurality of aperture thicknesses corresponding to a plurality of positions in the aperture image according to a fixed angle, and carrying out the temperature control of the crystal growth, and then the temperature is controlled based on the ratio of the number of the aperture thicknesses exceeding the preset threshold to the total number of the apertures corresponding to the plurality of aperture thicknesses, so that whether the number of the aperture thicknesses exceeding the preset threshold is too large or too small can be determined by analyzing the image of the aperture part on the surface of the crystal; whether the single crystal grows uniformly or not and whether the temperature is appropriate or not are judged and determined, the cost is low, the anti-interference capacity is high, accurate temperature information can be obtained, the crystal can grow uniformly by controlling the temperature in the crystal growth process, crystal defects are avoided, and the crystal quality is improved.

The invention relates to a novel high-precision laser etching method for a high-thermal-conductivity metal film on the surface of an organic material. According to the principle that the arrangement mode of atoms in crystal lattices is determined by crystal defects, crystal sizes and crystal orientations in metal materials, so that the transfer mode of heat energy through phonons and electrons is influenced, and by regulating and controlling the crystal structures of the metal materials, the transverse heat conduction area of instantaneous laser energy in the metal film is reduced; therefore, the energy longitudinally conducted to the interface of the metal film and the substrate under the action of the laser is increased, so that the temperature of the interface of the laser spot edge area is higher than the thermal decomposition temperature of the substrate material, and the solid stripping phenomenon is generated. The method provided by the invention solves the problem that high-thermal-conductivity metal subjected to laser etching is easy to remain at present, improves the precision of a laser etching pattern, and has scientific and industrial practical potential.

The utility model discloses a crystal position adjusting mechanism of a crystal defect detection device, which comprises a cabinet body, a cabinet door is arranged on the cabinet body, detection components are arranged on the cabinet body and the cabinet door, and a displacement component is arranged in the cabinet body. According to the utility model, after the crystal is clamped, the two L-shaped plates drive the crystal to move towards the center of the cabinet body, and because the balls are higher than the supporting base and the bottom of the crystal is higher than the supporting base, the crystal is not contacted with the supporting base during movement, and when the extension lengths of the two electric telescopic rods are consistent, the crystal is located at the center of the cabinet body; at the moment, the electric telescopic rods are stopped, the two electric telescopic rods are retracted, the crystal falls to the center position of the supporting base, and due to the fact that the crystal is moved through the two electric telescopic rods at the moment, the crystal cannot be pushed in one direction, the crystal can move forwards or deviate due to inertia when the electric telescopic rods stop moving, and it can be guaranteed that the crystal is in a straightening state and is centered.

To provide a photonic bandgap type vacant core fiber suitable for transmission in two wavelength bands, and an optical communication system using the same. [Solution] The porous core fiber comprises a cladding portion having a porous structure arranged to surround the porous core portion and form a photonic crystal in which the porous core portion is a crystal defect, and propagates a first light having a wavelength of 1000 nm to 1150 nm and a second light having a wavelength of 1530 nm to 1625 nm in the porous core portion, and the transmission loss of the first light is 10 times or less the transmission loss of the second light.

There is described a method of manufacturing a substrate for an optoelectronic device. The method has the steps of: supporting a first layer of a first crystalline material on a second layer of a second crystalline material different from said first crystalline material thereby exposing crystalline defects at a surface of said first layer; etching said first layer using first etching conditions, at least some of said crystalline defects expanding into pores running from said surface of the first layer towards said second layer; and heating said first and second layers up to a first temperature for a first period of time within a given environment, said heating transforming said pores into nanovoids attracting at least some of said crystalline defects away from said surface. In some embodiments, the method has a step of reheating the layers or a step of forming a pore containing region within the first layer.

A quantum computing device includes an optical resonator having a resonant wavelength band. A crystalline material including a crystal defect is contained within the optical resonator. The crystal defect has a ground state and an excited state, which has an emission wavelength in the resonant wavelength band. A source electrode and a drain electrode are disposed on opposing sides of the crystal defect and configured to apply a first electric field in the crystalline material along a longitudinal axis. A gate electrode is disposed in proximity to the crystal defect and configured to apply to the crystalline material a second electric field transverse to the longitudinal axis. Control circuitry is configured to apply a first voltage between the source and drain electrodes to control a charge state of the crystal defect and to apply a second voltage to the gate electrode to tune the emission wavelength.

The application belongs to the method for improving the energy conversion efficiency and stability of organic-inorganic hybrid perovskite solar cells, and the main content is that ethyl benzene sulfonyl lactam (PSAD) containing sulfonamide functional group is combined with-NH2 and Pb 2+ in perovskite material respectively through hydrogen bond and coordination effect to passivate the crystal defects caused by the two kinds of functional groups and cations in perovskite crystal grains. The oxygen atom of the sulfoxide group in PSAD can not only fix the organic amine ion in perovskite through hydrogen bond, but also can form Pb 2+ …O coordination bond with Pb to passivate the defects caused by Pb. The method passivates the grain boundary, reduces the non-radiation recombination of carriers, enhances the charge transport of perovskite thin film, and significantly improves the energy conversion efficiency and stability of perovskite solar cells. The additive PSAD is cheap and easy to obtain, which provides the possibility for industrialization.

This application provides a method for preparing nano-sized orthogonal iron phosphate and a method for preparing lithium iron phosphate cathode materials, relating to the field of electrode materials. The method for preparing nano-sized orthogonal iron phosphate includes: mixing a first ferrous salt solution with a first phosphorus source solution and an oxidant to perform a co-precipitation reaction to obtain amorphous iron phosphate; mixing the amorphous iron phosphate with water to form a slurry, controlling the slurry particle size, and then adding a crystal transformation aid to the slurry, followed by aging under stirring conditions at a pH of 0.8–1.5 to obtain nano-sized orthogonal iron phosphate; wherein the crystal transformation aid includes a second ferrous salt and a second phosphorus source. The iron phosphate prepared in this application is single-crystal nano-sized orthogonal iron phosphate, reducing the grinding pressure at the lithium iron phosphate end. Simultaneously, its unique octahedral structure is more stable than monoclinic iron phosphate produced by conventional processes, with fewer crystal defects and higher lattice integrity, effectively avoiding the generation of magnetic foreign matter during sintering and contributing to the performance of lithium iron phosphate materials.

This invention provides a method for preparing a high-performance potassium adsorbent for potassium extraction from seawater, belonging to the field of ion adsorbent technology. The present invention features a large potassium adsorption capacity, high ion exchange site density, and outstanding enrichment capacity for low-concentration potassium ions. It exhibits very low adsorption capacity for calcium and magnesium ions in the influent, precisely rejecting high concentrations of coexisting sodium, calcium, and magnesium ions, achieving exclusive adsorption only for potassium ions, resulting in high purity of the enriched product. It possesses a highly stable crystal framework structure resistant to acids and alkalis, improving the cycling stability of the potassium adsorbent. The small crystal size is beneficial for increasing the adsorption capacity of the potassium adsorbent; due to the small crystal size, growth is more complete, with fewer crystal defects, which is conducive to improving selectivity and cycling stability. The three-stage calcination crystallization process allows different materials to undergo precise chemical reactions or crystal growth at different temperature stages, facilitating the acquisition of potassium adsorbent crystals with high adsorption capacity, high selectivity, and high cycling stability.

The application provides a thermoelectric material, a preparation method thereof and a thermoelectric device, and the chemical formula of the thermoelectric material is Sn (1‑x‑y) Cu x La y Se, wherein 0<=x<=0.2 and 0 The thermoelectric material provided by the application is doped with lanthanum (La) and / or copper (Cu) to effectively control the polycrystalline tin selenide lattice arrangement and macroscopically, so that the thermoelectric material has high hole carrier concentration and dense crystal defects, thereby improving the ZT value of the thermoelectric material Sn (1‑x‑y) Cu x La y Se, and further improving the thermoelectric conversion efficiency of the thermoelectric material. Meanwhile, the thermoelectric material has a wide temperature range, can effectively utilize heat energy exceeding 200 DEG C, and has good application prospect.

The invention relates to the field of carbon-loaded nano-catalysts, in particular to a one-dimensional zigzag ultrathin Pt-based nano-shell catalyst which is coated on a carbon nanotube and has abundant defects and a preparation method of the one-dimensional zigzag ultrathin Pt-based nano-shell catalyst. According to the catalyst, a carbon nanotube film is used as a substrate, magnetron sputtering is carried out at room temperature, then rapid annealing is carried out, and finally a one-dimensional zigzag ultrathin Pt-based nano shell is formed and uniformly coats a carbon nanotube bundle. The ultrathin Pt-based nano shell has abundant surface structures (high-index edge steps) and a large number of crystal defects such as twin crystals and stacking faults, the electronic structure of surface atoms is adjusted, and the adsorption / desorption strength of an intermediate is optimized, so that the catalytic activity is influenced. According to the method, efficient and controllable preparation of the defect type Pt-based nanowire catalyst is achieved, the activity and stability of the catalyst are improved, the method can be suitable for various catalytic reactions related to fuel cells, and the method is expected to be a practical method for large-scale preparation and application of the catalyst.

The invention relates to a sensor head (4a-d) for a frequency analyzer (2a-d) comprising a crystal defect resonator (20a-d), an optical pump emitter (14) for exciting the crystal defect resonator (20a-d), a magnetic field unit (30) for generating a magnetic field with a magnetic field gradient along the crystal defect resonator (20a-d), an RF waveguide (22) and a radiation detector (10) for detecting luminescence radiation (42) from the crystal defect resonator (20a-d). To achieve easy manufacturability of the frequency analyzer (2a-d), it is proposed that the crystal defect resonator (20a-d) has a polycrystalline structure.

The invention provides a monocrystalline silicon crystal defect distribution detection method which comprises the following steps: cutting a monocrystalline silicon raw material to obtain a crude sample, and pretreating the crude sample to obtain a pretreated sample; sequentially carrying out primary corrosion, thermal oxidation treatment, secondary corrosion and defect corrosion on the pretreated sample to obtain a sample to be detected; acquiring a plurality of image data of the surface of the to-be-tested sample by using an optical microscope, respectively identifying the crystal defect density in each image data, and recording a position density associated data set according to the test position of the acquired image data; and based on the position density associated data group, drawing a defect radial distribution diagram taking the test position as an abscissa and the defect density as an ordinate, and confirming the distribution mode of the monocrystalline silicon crystal defects. The detection method disclosed by the invention is simple to operate, pollution is prevented from being introduced, the distribution condition of crystal defects can be rapidly and accurately detected, and guidance is provided for adjustment of a crystal growth process.

The invention discloses a quantitative correction method for the influence of detector crystal defects on imaging quality, and the method comprises the steps: S1, generating a standardized characteristic spectrum fusing defect physical parameters through multi-modal detection and theoretical model calculation; s2, partitioning the detector array by taking the map as guidance, and sequentially executing signal-level differentiation conditioning, projection-level feature embedding reconstruction and image-level differentiation post-processing; s3, establishing a bidirectional iteration feedback link, and dynamically optimizing front-end acquisition and rear-end reconstruction parameters; and S4, constructing a full-link database and realizing incremental training and self-adaptive updating of the model by utilizing the full-link database. According to the invention, full-link and self-adaptive cooperative correction starting from the physical nature of defects is realized, and the precision and robustness of an imaging system are remarkably improved.

The present application relates to the technical field of crystal nondestructive testing, and particularly relates to a crystal defect nondestructive testing method and system based on pumped probe transient absorption spectrum, which comprises the following steps: detecting a target region of a crystal to be tested by using pump light and probe light; collecting a transient absorption image of the target region according to a preset time delay between the pump light and the probe light, and extracting a target risk region; focusing the pump light and the probe light, and performing point-by-point scanning on the target risk region by using the focused pump light and probe light; collecting three-dimensional transient absorption intensity distribution and defect dynamic evolution data of each scanning point in the target risk region under different time delays; performing correlation calibration based on the transient absorption image and the three-dimensional transient absorption intensity distribution to obtain defect parameters; and constructing a damage prediction model based on sample damage threshold data, and outputting damage threshold prediction results according to the defect parameters. The purpose is to realize nondestructive and rapid detection of internal defects of deuterated potassium dihydrogen phosphate crystals.

The application discloses a TiAl alloy, a deformation heat treatment method and application, and the alloy is as follows: Ti-(43-48)Al-(0-8)X-(0-0.5)Z, wherein X is one or two or more of Nb, Mo, Cr, Ta, V and Mn elements; Z is one or two or more of Fe, C, N, O, B and Si elements; the alloy is a fine-grain duplex structure, the fine-grain duplex structure is composed of fine-size sheet group and equiaxial gamma grains; the size of the sheet group is 20-40 mu m, the size of the gamma grain is 10-20 mu m, and the volume fraction of the gamma grain is 30-60%; firstly, high-density crystal defects are generated in the original structure by controlling the deformation temperature, the deformation rate and the deformation amount of the pre-deformation treatment; and then, the fine-grain near-sheet structure or the duplex structure is obtained by controlling the holding temperature and the holding time in the isothermal heat treatment process.

A method of identifying defects in crystals includes the following steps. A silicon carbide crystal to be identified for defects is sliced to obtain a test piece. An etching process is performed on the test piece. Etching conditions of the etching process includes the following. An etchant including potassium hydroxide is used, and etching is performed at a temperature of 400° C. to 550° C. in an environment where dry air or oxygen is introduced, so as to form etching pits of threading edge dislocations (TED) and threading screw dislocations (TSD) in the test piece. After the etching process is performed, a diameter ratio (TED / TSD) of the etching pits of the threading edge dislocations (TED) and the threading screw dislocations (TSD) observed by an optical microscope in the test piece is in a range of 0.2 to 0.5.

In silicon carbide crystal growth, this method eliminates the need for precise control of temperature gradients and gas flow paths, suppresses the occurrence of crystal defects and thermal distortion, and improves the efficiency of silicon carbide raw material utilization, thereby increasing the productivity of silicon carbide substrates and reducing manufacturing costs. [Solution] By sublimating the silicon carbide sublimation surface of the raw material substrate and applying gravitational acceleration to transport the silicon carbide growth surface of the growth substrate stably and uniformly, it is possible to form multiple silicon carbide growth layers simultaneously without requiring a temperature gradient. Furthermore, by preventing the silicon carbide raw material from leaking from the back surface of the growth substrate or from the gap between it and the raw material substrate, the utilization efficiency of the silicon carbide raw material is increased, thereby enabling improved productivity and reduced manufacturing costs.

This invention provides a radially temperature-adjustable crystal growth apparatus and method, relating to the field of silicon carbide crystal growth technology, to improve the technical problem of inconvenient radial temperature gradient adjustment of the crystal to be grown in the prior art. It includes a heating furnace, a crucible, and a radial temperature gradient adjustment device; the crystal to be grown and silicon carbide powder are respectively arranged inside the crucible; the radial temperature gradient adjustment device is disposed on the top wall, and includes a driving component and multiple heat reflectors connected to the driving component; the multiple heat reflectors selectively move above the crystal to be grown under the action of the driving component to reflect at least a portion of the heat above the crystal to be grown to the crystal, thereby adjusting the radial temperature gradient at the growth interface of the crystal. This invention can effectively reduce crystal defects, improve substrate yield, and obtain the desired crystal morphology.

The utility model provides a gallium arsenide LED epitaxial structure and an LED chip. The gallium arsenide LED epitaxial structure comprises a gallium arsenide substrate; the N-type semiconductor layer, the active layer and the P-type semiconductor layer are sequentially stacked on the surface of one side of the substrate; wherein a composite buffer layer is arranged between the gallium arsenide substrate and the N-type semiconductor layer; the composite buffer layer comprises a first GaAs buffer layer, a defect growth layer and a defect stop layer which are sequentially arranged on the surface of the gallium arsenide substrate, the defect growth layer is used for expanding crystal defects of the first GaAs buffer layer, and the defect stop layer stops growth of the crystal defects by changing the growth direction of the crystal defects. On the basis of the arrangement, crystal defects such as epitaxial layer dislocation, stacking defects and the like and even slippage which are formed by taking scratches, defects and the like on the surface of the gallium arsenide substrate as starting points can be effectively avoided, the crystal growth quality is improved, and meanwhile, the cost is slightly increased. And the method is particularly suitable for high-power LEDs and small-size (such as Mini and Micro) LEDs.

The invention relates to a GaN HEMT epitaxial wafer and a manufacturing method thereof. The manufacturing method of the present invention comprises: a step for preparing a Si (111) substrate; a step of forming a Nucleation Region (Nucleation Region) on the Si (111) substrate, and a step of forming a Nucleation Region (Nucleation Region) on the Si (111) substrate; a step of forming a stress regulation region on the nucleating layer region, and a step of forming a stress regulation region on the nucleating layer region; a step of forming a high impedance buffer layer region (Buffer Region) on the stress regulation region; and forming an active layer region including a channel layer and a barrier layer on the buffer layer region. In particular, the step of forming the nucleation layer region is characterized in that a layer comprising aluminum nitride (AlN) and a layer comprising silicon carbide (SiC) or silicon carbonitride (SiCN) are laminated. According to the invention, crystal defects can be minimized and residual stress can be effectively controlled.

This technology suppresses the generation of thermal strain during crystal growth, enabling the realization of high-quality SiC single crystals with a low crystal defect density. [Solution] A SiC single crystal substrate is used, comprising a first main surface and a second main surface located opposite the first main surface, wherein the first main surface is a surface inclined with an off-angle of 0° to 8° with respect to the {0001} plane. Here, incident light having two mutually orthogonal polarization components and a wavelength of 520 nm is incident on the first main surface, and the phase difference between the first emitted light and the second emitted light emitted from the second main surface is measured. In the distribution of phase differences obtained, the average value of the phase difference is 10 nm or less, and the maximum value of the phase difference is 70 nm or less.

A virtual wafer technique for fabricating semiconductor devices is disclosed, and more particularly, a method for fabricating semiconductor devices includes epitaxially depositing a heavily doped substrate layer substantially free of crystal defects on a lightly doped virtual substrate. A device region of a semiconductor device can be fabricated around the heavily doped substrate layer prior to removal of the lightly doped virtual substrate.

The invention discloses a directional solidification purification method and system for industrial silicon. The method comprises the following steps: soaking silicon powder with mixed acid to remove a surface oxide layer and metal impurities; mixing and melting the soaked silicon powder and a slag former according to the ratio of 10: 1, and continuously stirring for 30 minutes; and after standing for 10 minutes, removing furnace slag on the surface of the melt, and enabling the furnace slag to flow into a slag tank to obtain the silicon melt, so that the removal rate of Fe impurities is greater than or equal to 98%. After a flux is added into the silicon melt, stirring is performed, so that impurities such as Al, Ca and B can be effectively removed; a reactive gas is blown into the bottom of the silicon melt, and the silicon melt is partially vacuumized, so that Al, Ca, Mg and P can be efficiently removed, and B impurities can be partially removed; by means of crucible high-temperature control and induction coil arrangement, Lorentz force distribution can be optimized for Al / Ca impurities, impurity segregation is more thorough, crystal defects are reduced, and the requirement for solar grade silicon purity is met. And finally, a directional solidification method is adopted, so that most of metal impurities can be gathered at the tail end of the silicon ingot, and the product purity reaches 99.5% or above.

The utility model discloses a crucible structure for reducing silicon carbide initial crystal defects, and relates to the technical field of silicon carbide crystal growth. Comprising a crucible body, a guide cylinder is connected to the inner wall of the upper portion of the crucible body, and seed crystals are placed on the guide cylinder; the guide cylinder is of a cylindrical structure with upper and lower openings, the bottom and the inner wall of the guide cylinder are both located in the crucible body, a plurality of air leakage channels are formed in the cylinder wall of the guide cylinder, one end of each air leakage channel communicates with the top of the guide cylinder, and the other end communicates with the bottom or the inner wall of the guide cylinder; the internal space of the crucible body is communicated with the external space of the crucible body through the air leakage channel; the inner diameter of the air leakage channel is micron-sized; according to the utility model, the micron-sized gas leakage channel is additionally arranged in the guide cylinder, so that the leakage rate of the Si atmosphere at the initial stage of crystal growth is improved, the C / Si ratio in the atmosphere at the initial stage of crystal growth is improved, the occurrence probability of multiple types at the initial stage of crystal growth is reduced, and the yield of silicon carbide single crystals is further improved.