11results about How to "Low growth temperature" patented technology

The invention relates to a preparation method of a cerium-doped lutetium yttrium silicate crystal, and relates to the technical field of scintillation crystal preparation. Compared with a traditional Czochralski method, the cerium-doped lutetium yttrium silicate is prepared through a flame fusion method, the growth speed of the flame fusion method is 15-20 mm / h, the growth rate is higher, consumable items such as an iridium crucible are not needed, mutual reaction between a high-temperature melt and the crucible is avoided, the cost is effectively reduced, and the cerium-doped lutetium yttrium silicate is obtained. The limitation of a crucible material on preparation of high-melting-point oxide crystals is eliminated, the crystal quality is improved, and the growth period is short.

The application discloses a light emitting diode epitaxial wafer and a preparation method thereof and a light emitting diode, and relates to the field of semiconductor photoelectric devices. The light emitting diode epitaxial wafer comprises a substrate and a buffer layer, a non-doped GaN layer, an N-type GaN layer, a multi-quantum well layer, an intercalation layer, an electron blocking layer and a P-type GaN layer arranged on the substrate in sequence; the intercalation layer comprises an AlN layer and a superlattice layer; the superlattice layer comprises P-AlN layers, P-InN layers and P-GaN layers which are stacked in sequence, and the number of periods is greater than or equal to 2. By implementing the application, the light emitting efficiency of the light emitting diode can be improved.

The present invention provides a flux for silicon carbide crystal growth, a cubic silicon carbide crystal and a growth method thereof, belonging to the technical field of crystal growth, wherein the flux is an alloy comprising a rare earth metal, a transition metal and carbon: the molar ratio of the rare earth metal to the transition metal is 1:9 to 9:1. The flux provided by the present invention can reduce the growth temperature of silicon carbide crystals, realize the growth of silicon carbide crystals at a lower temperature, and at the same time can increase the solubility of carbon in silicon melt, increase the concentration of carbon in silicon melt in the early stage of crystal growth, and realize obtaining high-quality and large-sized silicon carbide crystals in a shorter time.

The invention relates to a silicon carbide-based membrane, a synthesis method and a purification device for domestic sewage, and relates to the technical field of sewage treatment.The silicon carbide-based membrane is prepared from silicon carbide (SiC), borosilicate glass frit, a pore-forming agent and an adhesive, the particle size of the silicon carbide is 0.5-35 microns, the weight fraction of the borosilicate glass frit is 10-25 wt% of the weight of the SiC, and the weight fraction of the pore-forming agent is 10-25 wt% of the weight of the adhesive. The pore-forming agent is at least one of graphite powder, polymethyl methacrylate and polyvinyl chloride and accounts for 1-10wt% of the weight of SiC, the adhesive is at least one of polyvinyl alcohol and polyethylene glycol and accounts for 5-10wt% of the weight of SiC, the mass fraction of Al2O3 in the borosilicate glass material is 1-7%, and the mass fraction of Al2O3 in the borosilicate glass material is 1-7%. The bending strength and the acid-base tolerance of the silicon carbide-based membrane in the purification device can be improved, and meanwhile, the silicon carbide-based membrane also has relatively high purification performance on oily sewage.

The application discloses a preparation method of gamma-phase germanium selenide nanosheets. The application realizes controllable preparation of high-quality gamma-phase germanium selenide nanosheets by adopting a normal-pressure vapor deposition method and based on a rapid cooling strategy. The application realizes controllable growth of gamma-phase germanium selenide nanosheets with different lateral sizes by controlling growth temperature. The application does not need to plate a catalyst such as gold on a substrate surface, and the preparation process is relatively simple. The prepared gamma-phase germanium selenide nanosheets have great application potential in flexible sensors, photoelectric devices, especially near-infrared photoelectric detectors and the like. The gamma-phase germanium selenide nanosheets prepared by the application are still very stable after being placed in air for half a year, and also provide a good experimental platform for subsequent physical property research on the material.

The application discloses a semiconductor laser epitaxial structure and a manufacturing method thereof. The semiconductor laser epitaxial structure comprises a multi-quantum well layer, the multi-quantum well layer is a periodic structure, each period comprises a well layer, a cap layer and a barrier layer in sequence, and the well layer comprises InGaN material; the cap layer comprises an AlGaN layer, an InGaN layer and a P-type AlGaN layer in sequence, the AlGaN layer is adjacent to the well layer, and the P-type AlGaN layer is adjacent to the barrier layer; the cap layer structure protects the well layer from thermal shock and ensures the crystal quality of the well layer.

The invention provides a preparation method of an oxide single crystal thick film, which comprises the following steps of: transferring a metal source precursor into a crucible of a metal source area of vacuum growth equipment, and simultaneously placing a substrate on a substrate support of a growth area of the vacuum growth equipment; vacuumizing the vacuum growth equipment, and heating the metal source region and the growth region from room temperature; filling inert gas into the vacuum growth equipment, continuously heating the growth area to 900 DEG C to 1400 DEG C, and simultaneously continuously heating the metal source area to 1100 DEG C to 1500 DEG C; the temperatures of the metal source region and the growth region are kept unchanged, carrier gas and reaction gas are introduced into the vacuum growth equipment, the carrier gas directionally conveys metal sub-oxide formed by reaction after the metal source precursor is heated to the surface of the substrate, and the reaction gas and the metal sub-oxide are fully mixed and react on the surface of the substrate to grow the oxide single crystal thick film. The preparation method is simple, low in cost and suitable for large-scale batch production.

This invention discloses a graphene-coated silicon nanocomposite material, its preparation method, and its application, belonging to the field of battery materials technology. The preparation method of this composite material includes: firstly, removing the oxide layer on the surface of the silicon nanocomposite and performing plasma activation to obtain silicon nanocomposite with active sites and functional groups on the surface; dispersing it in a carbon source precursor solution, mixing it evenly, and then centrifuging and drying it at low temperature to obtain a silicon-coated precursor; under inert gas protection, carbonizing the silicon-coated precursor at 500-700℃ and simultaneously introducing it into a catalyst precursor, then introducing a carrier gas containing hydrogen and carbon, and heat-treating it at 800-950℃; finally, acid washing, water washing, and drying to obtain the target material. This invention achieves low-temperature controllable growth of graphene by optimizing process parameters. In the prepared core-shell composite material, 1-30 few-layer graphene shells are tightly bonded to the silicon nanocomposite core. When used as a negative electrode active material for lithium-ion batteries, it exhibits high specific capacity, excellent cycle stability, and rate performance. The process is easily scalable and has promising application prospects.

The present application discloses a method for preparing boron nitride nanotubes and boron nitride nanotubes, the preparation method comprising weighing raw materials into a reactor, the raw materials comprising carbonate, magnesium oxide and a boron precursor; heating the reactor to a reaction temperature under an inert atmosphere to generate a precursor, the reaction temperature being 850 to 1200°C; placing the reactor under an ammonia atmosphere, maintaining the reaction temperature, and continuously reacting to generate boron nitride nanotubes; cooling the reactor to room temperature under an inert atmosphere to obtain boron nitride nanotubes. The preparation method of the present application can grow boron nitride nanotubes at a relatively low temperature of 850°C, and a large amount of high-quality boron nitride nanotubes can be obtained at 950°C, effectively reducing the synthesis temperature of boron nitride nanotubes, reducing the preparation cost of boron nitride nanotubes, and contributing to the wide application and industrial production of boron nitride nanotubes.

The present invention provides a device and method for liquid phase growth of silicon carbide crystals, belonging to the field of crystal growth technology, the device includes a crucible assembly, a seed crystal rod assembly, a heating assembly located outside the crucible assembly, and a heat preservation assembly wrapping the crucible assembly, the seed crystal rod assembly and the heating assembly; the crucible assembly includes a first crucible and a second crucible arranged in sequence from outside to inside; the first crucible is provided with a detachable crucible cover, and the crucible cover is provided with a fixing component for fixing the seed crystal rod assembly; the inner bottom surface of the first crucible is provided with a boss; the outer bottom of the second crucible is provided with a groove matching the shape of the boss, and the middle of the groove is provided with a pushing assembly for pushing, pulling and rotating the second crucible; the pushing assembly passes through the bottom of the first crucible, the heating assembly and the heat preservation assembly in sequence. The device provided by the present invention can ensure the temperature stability of the silicon carbide crystal growth process, while avoiding the problem of excessive jitter during the seed crystal pulling and rotation process.

A GaN single-chip white light emitting tube with p-NiO as the cap layer and a preparation method thereof, belonging to the field of semiconductor light emitting devices and their preparation technology. The device is composed of a substrate, a GaN buffer layer, an n-type Si-doped GaN electron injection layer, a multi-quantum well active light emitting layer, a p-type Mg-doped Al z Ga 1‑z The active light-emitting layer is composed of blue light Al y1 Ga 1‑y1 N carrier confinement layer, blue light multiple quantum well In x1 Ga 1‑x1 N material active light emitting layer, yellow light Al y2 Ga 1‑y2 N carrier confinement layer, yellow light multiple quantum well In x2 Ga 1‑x2 The present invention utilizes the characteristics of high hole concentration, wide band gap and low refractive index of p-NiO, so that the device has good hole injection and light and carrier confinement, reduces the influence of high temperature growth on the active light-emitting layer, and improves the device performance.