99results about How to "Improve crystal quality" patented technology

The invention relates to the technical field of semiconductor light emitting diodes, and discloses a composite patterned substrate and a preparation method thereof. The preparation method comprises the following steps: preparing a SiO2 film layer on a substrate; coining glue is prepared on the SiO2 film layer; transferring the pattern of the soft template to the SiO2 film layer by using a nanoimprint technology; performing etching treatment on the SiO2 film layer to form a graphic structure with a preset morphology, and etching to remove part of the substrate material to form a pit to obtain a patterned substrate; preparing an AlN layer on the substrate, filling the pit with the AlN layer, and covering the surface of the graphic structure; carrying out photoetching treatment and etching treatment on the AlN layer, so that the AlN layer is filled in the pit and covers the side surface of a part of the pattern structure; and carrying out annealing treatment, and removing the residual photoresist to obtain the composite patterned substrate. By implementing the preparation method provided by the invention, the obtained composite patterned substrate can improve the crystal quality of the epitaxial layer, thereby improving the internal quantum efficiency and final brightness of the chip.

The application discloses a multi-channel shaft kiln for calcining magnesite, wherein a distributing vehicle and a discharging device are located at the top and bottom of a kiln body. The kiln body is provided with a preheating section, a calcining section and a roasting section from top to bottom, and square strip-shaped channels are arranged in the kiln. A combustion chamber is arranged in the furnace wall on both sides of the calcining section with a width of 40-80 cm, the combustion chamber is built by hollow integral combustion bricks, the combustion chamber is communicated with the calcining section by cross-distributed through holes, the through hole outlet is downwardly inclined, and an inclined convex block is arranged at the top. The lower part of the roasting section is provided with an upper collecting opening and a lower expanding opening structure, an air pressure pipe is arranged in the inclined brick of the upper collecting opening, the opening of the air pressure pipe is downwardly inclined and communicated with the roasting section, and the lower expanding opening is matched with the upper semicircular surface of the discharging device. The middle part of the upwardly inclined distributing main pipe of the distributing vehicle is communicated with the branch pipe which is inclined and changed in direction, and a change valve is arranged in the main branch pipe. The application provides a comprehensive solution of the shaft kiln with high calcining quality, energy saving, low investment and long service life for calcining magnesite, and can also be used for high-quality calcining of small-particle materials.

The invention provides a surface-modified perovskite nanocrystal and a preparation method and application thereof, and the surface-modified perovskite nanocrystal comprises: a perovskite nanocrystal having a chemical composition of ABX3; wherein A is selected from at least one of Cs < + >, CH3NH3 < + > and HC (NH2) 2 < + >; b is selected from at least one of Pb < 2 + >, Sn < 2 + >, Ge < 2 + > and Mn < 2 + >; x is selected from halogen anions; the surface of the perovskite nanocrystal is coated with an organic ligand layer; the organic ligand comprises a halogenated organic ligand. In the surface modified perovskite nanocrystal, the surface of the perovskite nanocrystal is coated with the organic ligand layer, so that surface defects can be effectively passivated at the same time, and the surface integrity and the crystallization quality of the nanocrystal are remarkably improved. And due to the surface consistency, the defect state density is reduced, and the exciton and phonon coupling coefficient is reduced, so that a non-radiative composite channel is remarkably inhibited, and the optical performance of the perovskite nanocrystal is remarkably improved.

This invention discloses a method for preparing high-purity oxygen-free copper, relating to the field of metallurgical technology. The method includes multi-stage electrolytic refining, gradient-heating vacuum melting, inert gas-protected refining, electron beam melting, hydrogen plasma arc melting, directional solidification, and post-treatment steps. The multi-stage electrolytic refining utilizes a specific component electrolyte and periodically commutated current; vacuum melting is combined with bidirectional electromagnetic stirring; inert gas-protected refining is combined with a gradient reduction composite covering agent; electron beam and hydrogen plasma arc melting achieve deep purification and deoxidation; and directional solidification and two-stage annealing ensure product performance. The high-purity oxygen-free copper prepared by this invention has a conductivity of 102.3% IACS, a copper content ≥99.9999%, and an oxygen content <1.0 ppm. It exhibits high purity, low oxygen content, and excellent conductivity. The process is stable and controllable, making it suitable for high-end electronics applications.

This utility model discloses an electroslag remelting furnace for mold steel, relating to the field of metallurgical technology. It includes a base, a coil, and a lifting mechanism. A multi-stage crystallizer is fixedly installed on the base. The multi-stage crystallizer consists of multiple individual crystallizers, each with its own cooling chamber. A mounting base is fixedly installed at the upper end of the multi-stage crystallizer, and a sealing mechanism is fixedly installed at the upper end of the mounting base. The beneficial effect lies in the fact that the weight of the electrodes is detected by a pressure sensor. Based on the change in electrode weight, the magnitude of the magnetic field generated by the coil is adjusted, thereby improving the flow of the molten pool within the multi-stage crystallizer, reducing segregation, and preventing excessive turbulence that could lead to slag entrapment. Furthermore, the independent crystallizers and individual cooling chambers allow for different melting processes of the electroslag in different areas, avoiding uneven cooling or temperature imbalance during the melting process and effectively improving the crystallization quality of the product.

This invention relates to a silicon carbide crystal growth apparatus and method for improving crystal quality. A support member is provided on one of the following: the crucible lid, the side wall of the crucible body, or between the crucible lid and the crucible body. The support member is made of a material with a melting point or sublimation point less than or equal to the silicon carbide crystal growth temperature. This allows the crucible body and lid to form an open channel before silicon carbide crystal growth. After heating to the crystal growth temperature, the support member melts or sublimates, closing the crucible body and lid into a closed system. This invention effectively solves the problem of difficulty in removing impurities from the crucible in a closed system. For high-purity semi-insulating silicon carbide crystals, it helps improve purity and crystal quality. For doped conductive silicon carbide crystals, it can improve the uniformity of doping concentration, thereby improving the uniformity of resistivity distribution.

This invention relates to the preparation technology of two-dimensional material composites, specifically a method for coating two-dimensional materials onto the surface of non-metallic particles based on a high-temperature growth process. This method is suitable for the large-scale preparation of continuously coated non-metallic particulate materials. The invention employs a three-step method to form continuously coated two-dimensional materials on the surface of non-metallic particles: First, a continuous metal catalyst coating layer with a nanometer-thickness is formed on the surface of the non-metallic particles; then, the coated non-metallic particles are mixed with micron-sized powder of the same metal catalyst composition; next, a continuously coated two-dimensional material film is grown on the surface of the non-metallic particles using a high-temperature catalytic reaction; finally, the metal catalyst is removed, yielding the two-dimensional coated non-metallic particulate material. This invention can achieve the formation of two-dimensional material coating layers on the surface of a large number of non-metallic particles. The two-dimensional materials exhibit continuous, non-overlapping microstructures, high coating rates, and high crystallinity. Furthermore, this method is easily scalable.

The invention provides a method for heteroepitaxial growth of a gallium arsenide material on silicon by introducing laser surface treatment. The method comprises the following steps: growing a gallium arsenide low-temperature layer with a low crystallization degree on a silicon substrate, and crystallizing the surface layer of the gallium arsenide low-temperature layer by adopting a laser surface treatment mode; growing a gallium arsenide medium-temperature layer on the gallium arsenide low-temperature layer after the surface layer crystallization treatment, and purifying the surface layer crystalline state of the gallium arsenide medium-temperature layer by adopting a laser surface layer treatment mode; and growing a gallium arsenide high-temperature layer on the gallium arsenide medium-temperature layer after the surface layer crystalline state purification treatment. Under the condition that the crystallization degree of the whole gallium arsenide epitaxial layer is reserved, the crystallization degree of the local part, namely the upper surface of the epitaxial layer, is improved, the inhibition effect on dislocation is enhanced, and the optimization of the crystal quality of the whole epitaxial structure is realized. The dislocation penetrating to the surface of the whole epitaxial structure during heteroepitaxial growth of the gallium arsenide material on the silicon substrate is remarkably reduced, and a brand new way is opened up for preparing semiconductor photoelectric devices.

This invention discloses an epitaxial wafer for a deep ultraviolet (UV) light-emitting diode (LED) and its fabrication method, relating to the field of semiconductor optoelectronic devices. The UV LED epitaxial wafer includes a substrate and a buffer layer, an N-type AlGaN layer, an active layer, an electron blocking layer, and a P-type AlGaN layer sequentially grown on the substrate. The active layer has a periodic structure, with each period comprising a sequentially stacked quantum well layer and a quantum barrier layer, and the number of periods in the active layer is ≥2. The quantum barrier layer comprises a sequentially stacked AlInGaN layer and a P-AlInGaN layer. Implementing this invention can effectively improve the luminous efficiency of deep ultraviolet LEDs.

This invention provides a microgap suspension device and a microgap inverted suspension heat treatment process, comprising the following steps: adding p-aminobenzenesulfonic acid to a solvent, mixing thoroughly, and then adding carbon nanotubes to obtain a carbon nanotube dispersion; stirring the carbon nanotube dispersion under heating conditions to obtain a p-aminobenzenesulfonic acid-modified carbon nanotube dispersion; coating a substrate surface with a lead bromide solution, then coating the lead bromide surface with a cesium bromide solution, then coating the cesium bromide surface with the p-aminobenzenesulfonic acid-modified carbon nanotube dispersion; and finally performing heat treatment through a microgap suspension device to form a photoactive layer film. The microgap inverted suspension heat treatment process of this invention, through controllable height suspension heat treatment, ensures that the film is almost unconstrained by the rigidity of the substrate during thermal expansion and cooling contraction, thus making it suitable for flexible substrates as well. It also avoids direct contact damage to flexible substrates during high-temperature heat treatment.

The invention provides a red-light nitride epitaxial wafer, a preparation method thereof and a Micro-LED. The red-light nitride epitaxial wafer comprises a sapphire substrate, an insertion structure, an n-type nitride pattern structure layer, a light-emitting layer and a p-type metal nitride layer, the insertion structure penetrates through the n-type nitride pattern structure layer, the light-emitting layer and part of the p-type metal nitride layer and comprises a composite Si nano-column and a composite regulation and control layer, and the composite Si nano-column comprises a Si nano-column and a semi-ellipsoid structure; the composite regulation and control layer comprises a protection layer and a buffer layer, the protection layer is arranged on the outer wall of the Si nano-column, and the buffer layer is arranged on the area between the adjacent composite Si nano-columns; and an n-type nitride pattern structure layer, a light-emitting layer and a p-type metal nitride layer are laminated on the buffer layer between the adjacent composite Si nano columns. The In component merging and uniformity can be improved, the light-emitting efficiency and brightness of the Micro-LED are improved, the half-peak width of the light-emitting wavelength is reduced, and the color purity of display application is improved.

The invention provides a preparation method of a tin-doped scaly nano gallium oxide thin film solar blind ultraviolet photoelectric detector. The preparation method comprises the following steps: carrying out cleaning pretreatment on a single crystal GaN substrate; depositing an Au thin film on the pretreated single crystal GaN substrate to serve as a catalyst layer; the preparation method comprises the following steps: mixing Ga2O3, diamond and SnO2 powder according to a certain mass ratio to prepare a precursor; putting the single crystal GaN substrate deposited with the Au thin film and a precursor into a CVD furnace, and growing according to preset gas flow, pressure intensity, reaction temperature and reaction time to obtain a tin-doped scaly nano gallium oxide thin film; and respectively preparing electrodes on the surface of the tin-doped scaly nano gallium oxide thin film and the surface of the GaN substrate by adopting a radio frequency magnetron sputtering method. The conductivity of the thin film is improved through tin doping, the specific surface area and light absorption are increased through the scaly nanostructure, high-performance deep ultraviolet photoelectric detection is achieved, and the technical problem that in the prior art, the dark current of a device is high is solved.

This invention relates to the field of semiconductor optoelectronic devices, specifically disclosing a Micro-LED epitaxial structure, which sequentially comprises a substrate, a buffer layer, an N-type GaN layer, a stress relief layer, a first superlattice layer, an electron modulation layer, a light-emitting layer, a hole modulation layer, a second superlattice layer, and a P-type GaN layer; the stress relief layer includes In... α Ga 1‑α The N-layer and the first GaN layer; the first superlattice layer includes In. x Ga 1‑x N-layer and second GaN layer; electronic modulation layer includes Al a Ga 1‑a The light-emitting layer includes an N-layer and a third GaN layer, and the light-emitting layer includes an In layer. y Ga 1‑y N quantum well layer and quantum barrier layer, hole modulation layer including Al b Ga 1‑b N layers and In c Ga 1‑c N-layer, the second superlattice layer includes In z Ga 1‑z The N-layer and the fourth GaN layer have the following parameters: y > x > α, y > z, a ≥ b, and the number of periods in the light-emitting layer is ≤ 8. Implementing this invention can improve the luminous efficacy and luminous uniformity of Micro-LEDs at low current densities.

This invention provides a light-emitting diode epitaxial wafer and its fabrication method. The light-emitting diode epitaxial wafer includes a substrate, and a buffer layer, an undoped GaN layer, an N-type GaN layer, a multiple quantum well layer, an electron blocking layer, and a P-type GaN layer sequentially deposited on the substrate. The buffer layer includes a nitrided graphene buffer layer, an h-BN buffer layer, and a B-type GaN layer sequentially deposited on the substrate. x Al 1‑x N buffer layer, AlN buffer layer, wherein, the B x Al 1‑x The boron content in the N-buffer layer gradually decreases along the growth direction of the epitaxial layer. This invention achieves this by sequentially arranging a graphene nitride buffer layer, an h-BN buffer layer, and a boron buffer layer between the substrate and the epitaxial structure. x Al 1‑x N-buffer layers and AlN-buffer layers reduce lattice mismatch between structures, lower defect density, and improve the overall quality of LED epitaxial wafers.

This invention relates to the field of photoelectric detection technology, specifically to a diamond immersion detector. The invention utilizes ultra-wide bandgap boron-doped p-type diamond single crystal (PDSC) as the photoelectrode to construct a vacuum ultraviolet immersion photodetector with a PDSC-ultrapure water-Pt structure. The PDSC immersion photodetector prepared by this invention exhibits a responsivity as high as 87.8 mA / W under zero bias and 193 nm excitation wavelength conditions, which is close to the photoresponsivity shown by standard commercial Si detectors; furthermore, under low optical power excitation, the responsivity of the PDSC immersion detector can reach as high as 670 mA / W. The immersion detector of this invention is a low-cost, self-powered, and highly sensitive vacuum ultraviolet photodetector with good stability, showing promising application prospects for 193 nm power monitoring in deep ultraviolet light source lithography machines.

This invention discloses a high-mobility spin field-effect transistor (SFET), comprising a source electrode, a drain electrode, a gate electrode, a semiconductor channel, and a substrate. Compared to existing SFETs based on a single semiconductor channel, this semiconductor channel structure offers advantages such as tunable band structure, high mobility, tunable carrier concentration and type, and long spin diffusion length. Compared to traditional substrate-based SFETs, this invention introduces a substrate with piezoelectric properties, allowing for the modulation of carrier spin transport within the semiconductor channel through the surface polarization electric field of the substrate. This effectively reduces the turn-on or turn-off voltage and improves gate control. Compared to existing SFET fabrication processes, this invention optimizes the crystal quality of the spin tunneling layer, increases carrier spin polarization, thereby improving the device's on / off ratio and reducing operating current.

This invention discloses a β-Ga₂O₃ nanowire / diamond heterostructure, its preparation method, and its applications. The method includes the following steps: dropping Ga metal droplets onto an auxiliary substrate; placing the diamond substrate and the auxiliary substrate in the same temperature zone of a tube furnace; introducing a mixed gas of H₂ and Ar into the tube furnace under negative pressure, using O₂ entering from the outside and residual O₂ in the tube furnace as the O source, and growing β-Ga₂O₃ nanowires on the diamond surface without catalysis. The method of this invention eliminates the need for additional annealing treatment and pre-laying of metal catalysts on the diamond substrate, and avoids the phenomenon of O₂ etching of the diamond substrate under high-temperature conditions. β-Ga₂O₃ nanowires are epitaxially grown on the diamond surface through the vapor deposition of Ga. This method is simple and low-cost.

This application relates to the field of two-dimensional semiconductor material preparation technology, specifically to a method for preparing monolayer molybdenum disulfide by dual-sulfur source chemical vapor deposition, comprising the following steps: Step 1, providing a chemical vapor deposition reaction chamber having an upstream region, a growth region, and a downstream region; Step 2, arranging a molybdenum-containing precursor in the growth region, and arranging a substrate above or opposite to the molybdenum-containing precursor; Step 3, arranging a first sulfur-containing precursor in the upstream region and a second sulfur-containing precursor in the downstream region; Step 4, introducing a carrier gas into the reaction chamber and heating it to cause the first sulfur-containing precursor, the second sulfur-containing precursor, and the molybdenum-containing precursor to volatilize and undergo a chemical vapor deposition reaction on the substrate surface to form a monolayer molybdenum disulfide. This invention employs a dual-sulfur source strategy, achieving large-size, uniform, and low-defect preparation of monolayer MoS2, facilitating widespread application.

The application discloses high-quality bismuth-based perovskite monocrystals and a preparation method and application thereof. The preparation method of the high-quality bismuth-based perovskite monocrystals comprises the following steps: S1, preparing a single crystal growth precursor solution of the bismuth-based perovskite; S2, performing heat aging treatment on the prepared single crystal growth precursor solution; and S3, controlling the single crystal growth precursor solution after the heat aging treatment to crystallize and grow the bismuth-based perovskite monocrystals. The heat aging process of the precursor solution can obviously reduce the nucleation rate, effectively improve the crystallization quality, and finally obtain large-size high-quality bismuth-based perovskite monocrystals. The method has the advantages of simple process, strong operability, mild growth conditions, low required temperature, energy saving, low equipment requirement, low cost, high success rate, no need of additional seed crystals, and continuous growth of large-size high-quality perovskite monocrystals.

The application discloses a boron nitride van der Waals epitaxial gallium nitride microwave material and a growth method. An ammonia-rich aluminum nitride nucleation layer is introduced on the surface of a boron nitride two-dimensional material, thereby providing high-density nucleation sites for the growth of a subsequent gallium nitride transition layer. The aluminum nitride nucleation layer is subjected to annealing treatment to block grain boundary dislocations. A gallium nitride transition layer with low temperature and high V / III ratio is introduced to promote a lateral epitaxial mode in the initial growth of the gallium nitride, thereby accelerating the turning and blocking of threading dislocations. The growth process of a gallium nitride buffer layer is high-temperature and low-V / III-ratio, thereby promoting the gallium nitride buffer layer to be in a layered epitaxial mode, improving the material surface morphology and crystal quality. A gallium nitride channel layer with high temperature and high V / III ratio is introduced to improve the electron transport characteristics. The technical scheme is based on a material growth method such as MOCVD, and the material is developed through one-time epitaxy technology. Through epitaxy technology improvement and process control, the material with high surface flatness, crystal quality and electron transport characteristics is developed.

The invention provides a lead halide perovskite seed crystal and a preparation method thereof, and a lead halide perovskite microcrystal and a preparation method thereof. The preparation method of the lead halide perovskite seed crystal comprises the following steps: mixing a pseudo-halogen additive, first AX, first BX2 and a first solvent to form first sol, and heating the first sol to separate out crystals to obtain the lead halide perovskite seed crystal. The microcrystal is prepared by using the seed crystal as a raw material through slow heating crystallization. According to the method provided by the invention, the crystallization quality can be improved while the crystallization speed is increased.

The invention discloses an Ag monatomic modified In2O3 single crystal film prepared based on pulse voltage discharge, a method thereof and a gas sensitive sensor, and the method comprises the following steps: 1) placing a substrate in a vacuum cavity of magnetron sputtering equipment, taking an indium oxide target as an In source, and growing on the substrate through a magnetron sputtering technology to obtain an indium oxide single crystal film; the substrate is yttrium oxide stabilized zirconia (YSZ); (2) placing the indium oxide single crystal thin film obtained in the step (1) on a vacuum chamber sample table which is internally provided with a pulse voltage discharge electrode and an Ag target material, evaporating Ag particles based on a pulse voltage discharge process, and depositing the Ag particles on the surface of the indium oxide single crystal thin film material to form dispersed clusters; and annealing to obtain the Ag single atom modified In2O3 single crystal thin film. The synthesis of a sensitive material with a high atom utilization rate and a stable structure is realized, and an advanced NO2 gas sensing device with high sensitivity and high selectivity is obtained.

The utility model relates to high -purity antimony processing equipment technical field, concretely is a kind of high -purity antimony vacuum distillation pipe device, including bushing, for guiding antimony steam to enter into tray inside;Tray, tray is provided with gas guide hole, grating, for condensing receiving material;Conical tube, conical tube is conical, for low boiling point impurity and a small amount of antimony condensation.The high -purity antimony vacuum distillation pipe device in this device, by setting 5-10 trays from top to bottom in bushing, and the gas guide hole of adjacent two layers of trays is cross arrangement, make steam present S type route movement.This design greatly increases the movement path and contact area of antimony steam in device, effectively controls steam flow state, avoids the phenomenon that antimony steam appears uneven distribution, over-condensation or condensation is not sufficient in condensation process, significantly improves the condensation efficiency and crystallization quality of high -purity antimony.

The application discloses a method for epitaxially growing an alpha-Ga2O3 film based on a tert-butyl alcohol precursor under normal pressure by MOCVD, and comprises the following steps: cleaning a substrate, placing the cleaned substrate on a reaction chamber base of a metal organic chemical vapor deposition (MOCVD) device, introducing nitrogen into the reaction chamber, adjusting the air pressure of the reaction chamber to normal pressure, performing high-temperature pretreatment on the substrate in the reaction chamber, wherein the high-temperature pretreatment is performed at 1000-1200 DEG C for 15-30 min, cooling the substrate to 570-630 DEG C, taking triethyl gallium as a gallium source precursor and taking tert-butyl alcohol as an oxygen source precursor, and growing an alpha-Ga2O3 film sample on the substrate, and cooling the alpha-Ga2O3 film sample to room temperature while introducing nitrogen to obtain an alpha-Ga2O3 film. The method can be used to prepare a high-quality, high-speed-grown pure-phase metastable alpha-Ga2O3 film.

The application provides a semiconductor device and a manufacturing method thereof, and the semiconductor device comprises a substrate, a first gallium oxide bulk layer on the substrate, a gallium oxide epitaxial layer on the first gallium oxide bulk layer, wherein the gallium oxide epitaxial layer comprises a plurality of stacked structures, each of the stacked structures comprises a silicon-doped gallium oxide layer and a non-silicon-doped gallium oxide layer which are stacked, and a second gallium oxide bulk layer on the gallium oxide epitaxial layer. The gallium oxide epitaxial layer of the application comprises a plurality of stacked structures, each of the stacked structures comprises a silicon-doped gallium oxide layer and a non-silicon-doped gallium oxide layer which are stacked, and the gallium oxide bulk layers are respectively formed in front of and behind the gallium oxide epitaxial layer, so that the electron mobility of the gallium oxide epitaxial layer can be effectively improved, the doping efficiency is improved, the crystal quality of the gallium oxide epitaxial layer is improved, and the gallium oxide epitaxial layer is widely applied in the field of power devices.

This invention relates to the field of ammonium dihydrogen phosphate (MDP) production technology. It discloses an apparatus and method for producing low-impurity, fully water-soluble MDP using a concentrated acid process. The apparatus comprises sequentially connected systems for acid adjustment, neutralization reaction, impurity removal and aging, filtration and separation, triple-effect concentration, continuous steady-state crystallization, and drying. The core of the method lies in the neutralization system, which employs a three-stage series connection of a rapid ammoniation reactor, a tubular reactor, and a slurry tank to achieve segmented pH control for neutralization. Furthermore, it innovatively uses self-produced ammonium fluoride as a purification agent, combined with pH reversal technology, to deeply remove metallic impurities such as Fe, Al, and Mg from wet-process phosphoric acid. After concentration, the slurry undergoes a unique de-crystallization-steady-state crystallization system to obtain large-size, high-purity crystals. This method enables the stable production of high-end MDP with a main content ≥99% and water-insoluble matter ≤0.01% using low-cost wet-process phosphoric acid as raw material, achieving a phosphorus yield of over 71%, and can replace thermal process products.

The invention discloses a preparation method of single crystal cuprous oxide nanoparticles with high crystal quality. The preparation method of the monocrystal cuprous oxide nanoparticles comprises the following steps: irradiating an aqueous solution of cupric acetate by using an ultraviolet light source to generate the cuprous oxide nanoparticles in situ. The cuprous oxide nano-particles with extremely high crystal quality can be rapidly induced and synthesized at normal temperature and normal pressure, complex equipment, a vacuum environment, lengthy reaction time or subsequent annealing treatment is not needed, and the method is simple and convenient to operate, mild in condition, low in cost and environmentally friendly.

This invention belongs to the field of third-generation semiconductor material processing technology. It discloses a method and system for laser-based lift-off of curved silicon carbide. This invention establishes a target curved surface model and generates a corresponding three-dimensional processing path. During laser scanning, the beam wavefront is modulated in real time, and the lateral position and depth of the focus point within the material are simultaneously controlled. Optical aberrations caused by the material's high refractive index are compensated for. The entire process requires no mechanical movement of the focusing axis, forming a continuous and precise three-dimensional modification layer within the ingot. Finally, external force is applied along this modification layer to achieve low-damage, high-efficiency curved surface lift-off. This invention overcomes the limitation of traditional laser lift-off, which can only obtain planar wafers. It can directly construct any preset three-dimensional curved surface separation path within a silicon carbide ingot with a flat surface, thereby lifting out silicon carbide wafers with specific curvatures such as convex, concave, or free-form surfaces in a single operation.

This invention discloses a method for preparing halide perovskite thin films and their applications. The preparation method includes the following steps: S1, providing a substrate; S2, mixing a precursor salt with a lactone solvent to form a precursor mixture; S3, depositing the obtained precursor solution onto the surface of the substrate and annealing it to form a perovskite thin film. This invention, by introducing a monocyclic lactone, overcomes the limitations of the traditional DMF / DMSO solvent system, significantly expanding the material compatibility range of solution processing, enabling stable film formation over a wider range of concentrations and temperatures. Utilizing the unique coordination ability and volatility characteristics of this type of lactone, crystallization kinetics can be effectively controlled, promoting more uniform and dense perovskite grain growth, significantly reducing the defect density inside the film, thereby obtaining a film with high crystallinity.

The application discloses a kind of conical dielectric array InGaN quantum dot structure and preparation method, including substrate, GaN template layer, conical dielectric array layer, first InGaN quantum dot layer, first GaN barrier layer, second InGaN quantum dot layer, second GaN barrier layer;GaN template layer is grown on substrate;Conical dielectric array layer is grown on GaN template layer;First InGaN quantum dot layer is grown on GaN template layer;First GaN barrier layer is uniformly grown and completely covers on first InGaN quantum dot layer;Second InGaN quantum dot layer is grown on first GaN barrier layer;Second GaN barrier layer is uniformly grown and completely covers on second InGaN quantum dot layer;Multiple periodic InGaN quantum dot layer, GaN barrier layer, are repeatedly grown on second GaN barrier layer in sequence, form multilayer InGaN quantum dot structure.The application can realize the accurate adjustment of quantum dot density, size, distribution etc., and the grown InGaN quantum dot has the advantages of simple process and high crystal quality.