13results about How to "Reduce dislocation" patented technology

The invention discloses a graphene composite perovskite manganese oxide polycrystalline ceramic and a preparation method and application thereof, and belongs to the technical field of non-refrigeration high-sensitivity infrared detection. The chemical expression of the graphene composite perovskite manganese oxide polycrystalline ceramic is La < 0.81 > (Ca < 0.03 > Sr < 0.16 >) MnO3: Gy, G is graphene, y is the mass fraction of graphene in perovskite manganese oxide composite powder, and y is equal to 0.1-0.2%. The TCR value of the prepared polycrystalline ceramic can reach 30% or above, the Tk value is close to 300K, the polycrystalline ceramic has excellent adaptability to room temperature work and excellent sensitivity to temperature change, and when the polycrystalline ceramic is applied to an uncooled infrared detector, the detection precision of the uncooled infrared detector can be effectively improved.

The invention relates to a 4-inch low-dislocation indium antimonide lt; 211gt, 211gt; the invention discloses a preparation method of directional single crystals and belongs to the technical field of photoelectric materials. According to the method, a Czochralski method is adopted to grow the single crystal, a resistance furnace is arranged on the periphery of an induction coil of a heating device, and by accurately controlling heating conditions, designing a proper temperature field in a growth chamber and further combining growth conditions such as the state of a solid-liquid interface, the pulling speed, the rotating speed and particularly the shoulder expanding angle in the crystal growth process, the single crystal is obtained. The longitudinal temperature gradient in the crystal growth process is reduced, and the dislocation density of the large-size indium antimonide single crystal with the diameter of 4 inches can be obviously reduced, so that indium antimonide is enabled to be lt; 211gt, 211gt; the dislocation density of the directional single crystal is less than 100 / cm < 2 >.

The invention discloses a deep ultraviolet LED chip preparation method and a deep ultraviolet LED chip. The deep ultraviolet LED chip preparation method comprises the steps of growing an AlN buffer layer and a first AlGaN layer on a substrate; depositing a metal film on the first AlGaN layer to obtain a deep ultraviolet LED growth template; performing high-temperature rapid annealing on the deep ultraviolet LED growth template, and converting the metal film into a plurality of metal balls; performing graphical etching on the first AlGaN layer based on the graphical mask of the plurality of metal balls; the plurality of metal balls are cleaned through an acid solution, so that the top surface of the AlGaN insertion layer is exposed; forming an AlGaN transition layer on the AlGaN insertion layer through secondary epitaxy to form a substrate; and depositing a light-emitting element structure on the AlGaN transition layer. The patterned AlGaN insertion layer is arranged, so that the stress brought by the substrate and the AlN layer can be relieved, the dislocation density of the active region is reduced, and the luminous efficiency of the deep ultraviolet LED chip is improved.

This application provides a cathode material precursor and its preparation method, a cathode material, and a lithium-ion battery, relating to the field of new energy technology. The cathode material precursor is a secondary particle composed of primary particles, forming a composite structure. It includes an inner layer arranged radially along the center of the cathode material precursor and an outer layer composed of sheet-like primary particles stacked flat and enclosing the inner layer. The outer layer's sheets are perpendicular to the pressure direction during compaction, resulting in a secondary particle mechanical strength higher than that of common radial or block-shaped secondary particles. After inheriting this structure, the cathode material can achieve a higher compaction density than common secondary particle products, significantly improving the material's energy density. The secondary particles in this application have different sheet orientations between their inner and outer layers. The sintered cathode material inherits this characteristic structure, resulting in different expansion and contraction directions during charge-discharge cycles. This avoids or reduces the formation of cracks that could cause particle structure collapse, thereby improving cycle performance.

The present application relates to the technical field of inorganic semiconductor materials, and in particular to a silicon-based two-dimensional gallium nitride and its van der Waals epitaxial preparation method and application. The van der Waals epitaxial preparation method of silicon-based two-dimensional gallium nitride provided in the present application comprises: using gallium metal or gallium oxide as a gallium source, using urea as a nitrogen source, and using a silicon wafer with a van der Waals material on the surface as a growth substrate, and using a vapor deposition method to prepare a silicon-based two-dimensional gallium nitride material. The present application uses van der Waals epitaxial technology to prepare silicon-based two-dimensional gallium nitride on a van der Waals substrate by regulating growth parameters. The silicon-based two-dimensional gallium nitride has high crystal quality, good stability, low preparation cost, fast synthesis speed, and adjustable size and thickness. It can be used as a light detection component of a photodetector for ultraviolet detection.

The invention discloses a growth method for improving the crystal forming rate of indium phosphide single crystals, and belongs to the technical field of crystal growth. The multiple temperature zones are sequentially arranged in the heating furnace from top to bottom in the vertical direction in advance, the temperature of each temperature zone is decreased in a stepped mode, and in the growth process of crystals, the position of the boron nitride crucible is slowly decreased through the lifting system while each temperature zone is controlled to be decreased, so that the growth of the crystals is completed. Therefore, the purposes of effectively adjusting the uniformity of the temperature field and slowly lowering the position of the boron nitride crucible are achieved, slow growth of indium phosphide single crystals is achieved, dislocation can be greatly reduced, and the doping uniformity and the crystallization rate are improved. The technical problems that the indium phosphide single crystal is low in crystallization rate, high in crystal dislocation and uneven in carrier concentration and electron mobility distribution are effectively solved.

The present invention relates to a pelvic prosthesis, comprising a pelvic support and an acetabular cup, a connecting mechanism detachably mounted on the pelvic support and used to connect the acetabular cup; the connecting mechanism comprises a first connecting column mounted on the pelvic support, a second connecting column mounted on the acetabular cup, and a support arm for connecting the first connecting column and the second connecting column; the support arm is configured to restore the rotation center of the acetabular cup by adjusting the angle between the first connecting column and the pelvic support and the angle between the second connecting column and the acetabular cup. The acetabular rotation center restoration can meet the needs of different osteotomy situations, and has the characteristics of simple structure, mass production, wide applicability, and easy promotion.

The invention discloses an electric pulse auxiliary cutting-rolling composite surface strengthening device and a machining method, and relates to the technical field of metal material surface treatment, the electric pulse auxiliary cutting-rolling composite surface strengthening device comprises a rolling device and an electric pulse auxiliary turning device; the rolling device comprises a fixed base, a mounting sleeve and rolling assemblies, and the multiple rolling assemblies are evenly arranged in an inner cavity of the mounting sleeve in the circumferential direction; the rolling assembly comprises a floating base, a rolling base, a guide cylinder and a rolling end cover which are connected in sequence, a spherical cavity is formed between the guide cylinder and the rolling end cover, and balls are installed in the spherical cavity; the electric pulse auxiliary turning device comprises a first electric brush and a second electric brush, the first electric brush is installed on the lathe bed and makes contact with the chuck mechanism, the second electric brush is installed on the fixed base and used for making contact with the workpiece, and the first electric brush and the second electric brush are connected with the positive electrode and the negative electrode of the pulse power source respectively. The electric pulse treatment is introduced into the cutting process, the rolling effect can be enhanced, thermal stress and thermal deformation can be reduced during rolling, and the machining precision is improved.

The utility model provides a crucible device for silicon carbide single crystal growth, and relates to the technical field of semiconductor growth. The crucible device comprises a barrel-shaped growth crucible, a filter body and a limiting block, the filter body and the limiting block are located in the growth crucible, the filter body comprises a barrel-shaped main body part and an annular transverse plate part, the bottom of the main body part is connected with the bottom wall of the growth crucible, the transverse plate part is connected between the growth crucible and the main body part in a bridging mode, so that a cavity is formed between the filter body and the growth crucible, and the limiting block is located in the cavity. The main body part is provided with an airflow channel, and the limiting block is located in the internal space of the main body part, extends in the vertical direction and is attached to the bottom of the growth crucible. According to the utility model, the gas initial-stage transmission rate of silicon carbide powder in the growth crucible can be reduced, so that the silicon loss amount of the silicon carbide powder is reduced, and meanwhile, carbon particles and impurities which are sublimated and transported by the powder are filtered, so that various defects and dislocations such as carbon wrappage and microtubes in the crystal growth process are reduced, the utilization rate of the silicon carbide powder can be improved, and the production cost is reduced. The production cost is reduced.

This invention relates to the field of organic functional crystal growth technology, specifically a method for growing organic crystals based on the control of the included angle of the inner wall of a crucible. The method employs a quartz crucible with an axisymmetric conical inner cavity, and controls the included angle β of the inner wall of the crucible to be 10°–30°, preferably 15°–20°. After loading the organic crystal raw material into the crucible, a vacuum of 1×10⁻⁶ is applied. ‑2 After being sealed by welding, and after passing the pre-growth inspection and sealing, the melt is placed in a Bridgman crystal growth furnace for heating and melting and held at that temperature for 24 hours. The axial temperature gradient is controlled, and the melt is directionally solidified and grown from bottom to top at a rate of 1-1.5 mm / h. The organic single crystal is then slowly cooled to obtain the organic single crystal. This invention optimizes the melt flow field and solid-liquid interface by adjusting the crucible angle, reduces the radial temperature gradient, reduces defects such as crystal cracks and dislocations, and improves crystal integrity and optical uniformity. The process is simple, has good repeatability, and is suitable for large-size, high-quality growth of organic scintillation crystals and organic optoelectronic crystals.

The application provides a preparation method of a single crystal thin film with low defects, and at least comprises the following steps: step S1, providing a substrate and placing the substrate in a reaction cavity; the pressure in the reaction cavity is less than 20 tor, and the process temperature of the substrate is lower than 900 DEG C; step S2, introducing a first deposition gas into the reaction cavity to form an N-type single crystal thin film on the surface of the substrate; the first deposition gas comprises a raw material gas and an N-type doping gas; step S3, switching to introduce a second deposition gas into the reaction cavity to form a P-type single crystal thin film on the surface of the N-type single crystal thin film; the second deposition gas comprises a raw material gas and a P-type doping gas; and the raw material gas is a silicon source precursor or a germanium source precursor. The preparation method can reduce the defects of the single crystal thin film and improve the film quality.

The embodiment of the invention relates to a preparation method of an N-polarity AlN / GaN epitaxial structure. The method comprises the following steps: growing a metal polarity AlN film layer on a substrate; extending a metal polarity AlN epitaxial layer on the metal polarity AlN film layer; extending a polarity inversion layer on the metal polarity AlN epitaxial layer, wherein the polarity inversion layer is provided with a multi-layer strain SiN / AlN epitaxial structure; extending an N-polarity AlN epitaxial layer on the polarity inversion layer; and growing an N-polarity GaN epitaxial layer on the N-polarity AlN epitaxial layer. A substrate (sapphire, a Si substrate, a SiC substrate and the like) which is relatively low in price is used for replacing an AlN substrate which is high in price, a metal polarity AlN thick film is grown firstly, and a metal polarity AlN epitaxial layer is combined to reduce dislocation and release stress; then, on the basis, a polarity inversion layer with a multi-layer strain SiN / AlN epitaxial structure is formed through transition epitaxy, so that AlN with metal polarity is converted into AlN with nitrogen polarity; moreover, an N-polarity AlN epitaxial layer is further grown on the polarity inversion layer to reduce dislocation and release stress, and GaN, namely an N-polarity GaN epitaxial layer, is grown on the surface of the N-polarity AlN, so that the N-polarity AlN / GaN epitaxial structure material which has excellent N-polarity electrical properties and a flat surface is finally obtained, and the preparation cost can be controlled, thereby being more convenient for industrial popularization.

The invention discloses a semiconductor structure capable of reducing defect density and a manufacturing method. The manufacturing method comprises the following steps: growing a BNO buffer layer on a substrate; sequentially growing a first transition layer of BxAl (1-x) NO and a second transition layer of GaxAl (1-x) N on the BNO buffer layer; when the first transition layer is grown, the value of x is gradually reduced from 1 to 0, and the growth temperature is gradually increased from the first temperature to the second temperature; when the second transition layer is grown, the value of x is gradually increased from 0 to 1, the growth temperature is gradually reduced from a second temperature to a third temperature, and the second temperature is higher than the first temperature and the third temperature; and growing an epitaxial layer on the second transition layer to form a semiconductor structure. According to the invention, the BNO buffer layer, the first transition layer of BxAl (1-x) NO and the second transition layer of BxAl (1-x) NO are arranged between the substrate and the epitaxial layer, and the concentration of Al in the first transition layer of BxAl (1-x) NO and the concentration of Al in the second transition layer of GaxAl (1-x) N are gradually increased and then gradually reduced to carry out linear change, so that the defect density is effectively reduced.