1177 results about "Seed crystal" patented technology

Crystal growth systems with a baffle are provided. In one example, a crystal growth system for growing crystalline material, the crystalline material including silicon carbide, includes a seed holder configured to hold a silicon carbide seed crystal. The seed crystal provides a growth surface for growth of the silicon carbide crystalline material. The system includes a crucible at least partially defining a crystal growth chamber. The system includes a source material. The system includes one or more baffles within the crystal growth chamber and spaced apart from the source material. The one or more baffles include one or more apertures defined through the one or more baffles. The baffle includes a long dimension that is non-perpendicular to the growth surface of the seed crystal.

The invention relates to a czochralski method-based crystal growth interface shape detection method and device. The method comprises the steps that: a seed crystal temperature T and an interface electromotive force U at the same time in a crystal growth process are collected, and a T-U curve of the interface electromotive force U changing with the seed crystal temperature T is obtained; the change trend of the shape of a crystal growth interface in real time is judged by observing the deviation between the T-U curve and a reference line, wherein the reference line is a straight line passing through the starting point of the T-U curve, and the slope of the straight line is the Seebeck coefficient of the crystal. The invention also relates to a device used by the method. The detection method provided by the invention can detect the change trend of the shape of the crystal growth interface in real time in the crystal growth process, and can be applied to Czochralski method growth equipment for various single crystals such as lithium niobate, lithium tantalate, sapphire, yttrium aluminum garnet and the like.

The invention relates to the technical field of molten salt, in particular to nitro binary molten salt and a preparation method thereof. The preparation method comprises the following steps: mixing sodium carbonate and a potassium hydroxide solution, and then adding a starch-based grafted crystal inhibitor to inhibit crystallization; adding a nitric acid aqueous solution in two stages, and introducing eutectic seed crystals to guide nucleation at the end of the first stage; crystal distribution is optimized through falling film evaporation and concentration and setting of partial reflux; and after spraying granulation, carrying out short-time melting reforming and controlled cooling in an inert atmosphere. According to the method, the composition uniformity and the structural stability of the molten salt are remarkably improved, so that the product has a melting point close to a theoretical eutectic point, low supercooling degree, high melting latent heat and excellent thermal cycling stability and corrosion resistance, and is suitable for an industrial heat storage system running for a long time.

The invention discloses a method for reducing the content of rare earth carbonate oil, which comprises the following steps: adding rare earth carbonate seed crystals and pure water into a precipitation tank, feeding a rare earth chloride solution after extraction separation into the precipitation tank, adding an ammonium bicarbonate solution, and carrying out precipitation reaction to obtain rare earth carbonate; the method comprises the following steps: treating rare earth carbonate with hydrochloric acid, converting into a rare earth chloride solution, and filtering the rare earth chloride solution to remove oil to obtain a refined rare earth chloride solution; adding rare earth carbonate into a precipitation tank as a seed crystal, adding the refined rare earth chloride solution and the prepared ammonium bicarbonate solution into the precipitation tank, and carrying out precipitation reaction to produce oil-free rare earth carbonate. According to the invention, oil entrained in the extraction feed liquid and oil dissolved in the feed liquid can be removed, and the quality of the rare earth carbonate product is improved.

The invention discloses a forming method of a flash memory unit. The forming method comprises the following steps: providing a semiconductor substrate; forming a tunneling oxide layer on the semiconductor substrate; forming nanocrystalline silicon particles on the tunneling oxide layer; forming an isolation insulating layer on the tunneling oxide layer and the nanocrystalline silicon particles; and forming a control grid on the isolation insulating layer, wherein the step of forming the nanocrystalline silicon particles on the tunneling oxide layer comprises: forming an amorphous silicon layer on the tunneling oxide layer; and performing repeated seed crystal particle forming processes on the amorphous silicon layer, wherein surface annealing treatment is performed between two adjacent seed crystal particle forming processes, and an annealing process is performed after the last seed crystal particle forming process. The flash memory unit can be used for storing a large quantity of electrons, and has high performance.

The invention relates to the technical field of crystal growth, in particular to a device and a method for diversion growth of silicon carbide single crystals. The invention provides a device for diversion growth of silicon carbide single crystals. The device comprises a crucible, a first rotary lifting shaft and a turbine liquid pump kit, the turbine liquid pump kit comprises a flow guide baffle, the upper portion of the flow guide baffle is connected with the first rotary lifting shaft, a seed crystal support with seed crystals is installed on the lower portion of the flow guide baffle, turbine blades are installed on the flow guide baffle and evenly distributed around the seed crystals, and the height of the lower ends of the turbine blades is smaller than that of the seed crystals. The invention provides a device and a method for diversion growth of silicon carbide single crystals, which can improve the transmission stability and transmission efficiency of solute in a solution and improve the long-time growth stability of crystals.

A device for crystal growth and a crystal growth method. The device comprises a seed crystal holder, a seed crystal connecting rod, and a state detection assembly. The seed crystal holder is connected to one end of the seed crystal connecting rod, and the state detection assembly is configured to detect a seed crystal holder state of the seed crystal holder, wherein the seed crystal holder state reflects the state of the seed crystal holder relative to a melt, and the melt is used for crystal growth.

The invention discloses a method for preparing battery-grade nickel sulfate through collaborative purification of crude nickel sulfate and crude nickel carbonate. According to the method, crude nickel sulfate is dissolved firstly, then crude nickel carbonate is utilized for batch synergistic neutralization, and the alkalinity of the nickel carbonate is effectively utilized to reduce extra acid and alkali consumption. And then through multi-stage fine purification, including Fe oxidation and preliminary precipitation, Cr (VI) reduction and high-pH precipitation, main impurities such as iron, chromium, aluminum and the like are efficiently removed. And after the mother liquor is adsorbed by activated carbon and trace impurities are removed by strong-acid cation exchange resin, vacuum evaporation and concentration are carried out, and seed crystals are introduced for cooling crystallization, so that pure NiSO4. 6H2O crystals are obtained. The whole technological process pays attention to resource recycling, washing water recycling and nickel recycling of nickel-containing filter residues, waste gas and waste liquid are treated, and clean production is achieved. The nickel sulfate product prepared by the method is high in purity, meets the battery grade standard, and has good economic benefits and environmental benefits.

The present application relates to a kind of methods and applications of growing bismuth-doped rare-earth iron garnet BRIG crystal by guided mode pulling-top seed crystal method.For solving the problems of large internal stress, many defects, difficult to prepare thick film of single crystal in the current liquid phase epitaxy method of growing BRIG crystal;And the problems of long growth cycle, difficult to obtain seed crystal in top seed crystal method, the present application combines the fast growth of guided mode pulling crystal and the high-quality single crystal growth of top seed crystal method, and invents guided mode pulling-top seed crystal method to realize the fast growth of high-quality BRIG single crystal.First, the large-size doped rare-earth iron garnet crystal with high lattice matching and similar composition is quickly grown by guided mode pulling method, which is cut into centimeter-level seed crystal, and high-quality BRIG bulk single crystal is quickly grown by TSSG method.The crystal grown by this method has the advantages of small internal stress, less cracking, good uniformity, fast crystal growth, etc., and has obvious advantages in high-performance magneto-optical isolator.

The invention provides a single crystal silicon rod drawing method and system based on dynamic parameter linkage, and the method comprises the steps: implementing a temperature gradient dynamic control strategy according to different stages of single crystal silicon rod drawing; a linkage strategy of a rotation rate and a pulling speed is adopted, and the rotation rate of the seed crystal is kept at a high rotation speed in the initial stage of pulling to stabilize a melt interface; meanwhile, a stepped dynamic adjustment strategy is adopted for the lifting speed, low-speed lifting is kept in the initial stage so as to ensure the melt stability, and then the lifting speed is linearly increased according to the increase of the diameter of the silicon rod; and the crucible lifting speed is adjusted in real time based on a self-adaptive adjustment strategy, so that the crucible lifting speed and the increase of the diameter of the silicon rod are kept synchronous, the stability of the melt liquid level height is maintained, and the fluctuation of the dopant concentration is prevented. By dynamically adjusting the temperature gradient, the rotation rate, the pulling speed and the crucible lifting speed, thermal stress is reduced, melt convection is stabilized, the radial uniformity of the silicon wafer is improved, and the requirements of a BC battery for low-defect and high-uniformity doping are met.

The invention provides a continuous crystallization method of block-shaped trehalose crystals, which comprises the following steps: stimulating trehalose syrup to crystallize to form seed syrup, growing the crystal at 60-65 DEG C for 1-2 hours, and then cooling and crystallizing to obtain the block-shaped trehalose crystals, the cooling crystallization is three-stage cooling crystallization and comprises the following steps: cooling to 50-55 DEG C at a cooling rate of 0.5-0.8 DEG C / h, then cooling to 40-43 DEG C at a cooling rate of 1-1.5 DEG C / h, and then cooling to 25-30 DEG C at a cooling rate of 2-2.5 DEG C / h. Compared with a commercially available trehalose product, the purity of the trehalose product is greater than 99.8%, the length-diameter ratio is less than 2: 1, the grain size of 97wt% or more seed crystals is greater than 60 meshes, the filtering time is shortened by 62.2%, the bulk density of the product is improved by 49.3%, the particles are uniform, and when the trehalose product is compounded with other products, the proportioning amount can be accurately mastered, and the quality of the compounded product is improved.

The invention provides a method for recycling lithium from waste lithium iron phosphate batteries. The method comprises the following steps: pretreating the waste lithium iron phosphate battery to obtain positive electrode powder; mixing the positive electrode powder, the buffer leaching agent solution and the lithium salt seed crystal suspension, and carrying out leaching reaction to obtain a lithium-rich leaching solution; and carrying out post-treatment on the lithium-rich lixivium to prepare a lithium salt product. According to the method, the buffer leaching agent solution and the lithium salt seed crystal suspension are adopted to play a synergistic effect, the selective leaching efficiency of lithium can be effectively improved, and the buffer leaching agent not only can destroy the lattice structure of the positive electrode material and promote dissolution of lithium ions, but also can effectively relieve pH fluctuation to avoid generation of impurity colloids; the lithium salt seed crystal suspension can further reduce co-dissolution of transition metal ions and other impurities through the same ion effect, so that the finally prepared lithium salt product is high in purity and high in yield.

The invention discloses a method for synthesizing a wide-distribution precursor. Relates to the field of ternary materials. The method for synthesizing the wide-distribution precursor comprises the following steps: S1, carrying out a precipitation reaction of the precursor in a reaction kettle, and maintaining the pH value of a reaction system below a nucleation point of the precursor material; and S2, discontinuously adding pre-prepared seed crystals into the reaction kettle in the reaction process so as to control the particle size distribution of the precursor in the reaction kettle. The method provided by the invention does not need to frequently adjust the pH value to carry out traditional kernel pressing operation, simplifies the process steps, reduces the dependence on the experience of operators, and reduces the problems of particle size fault or excessive kernel generation and the like caused by pH fluctuation.

The invention discloses an anti-cracking calcium silicate board and a preparation method thereof, and relates to the technical field of light building materials. The method comprises the following steps: carrying out ball milling, acid pickling and silane coupling agent surface modification on quartz sand to obtain alkylated quartz sand; and carrying out dry mixing on the mixture, metakaolin, silica fume and cement. The linen fiber is subjected to alkali treatment and hydroxyethyl acrylate graft modification, and the PVA fiber is subjected to silane coupling agent and nano silicon dioxide coating treatment. Dispersing graphene oxide, carboxylated styrene-butadiene emulsion and other assistants in water, adding the dry mixture, uniformly stirring, and then adding the two modified fibers to prepare mixed slurry; and finally, carrying out pressure forming, pre-curing, high-pressure steam curing and drying to obtain a finished product. Through substrate silanization, fiber grafting / nanocrystalline seed modification and synergistic introduction of graphene oxide and elastic emulsion, the interface bonding strength and toughness are remarkably enhanced, crack initiation and propagation are effectively inhibited, and the plate has excellent cracking resistance.

The invention belongs to the technical field of environmental catalysis, and discloses a preparation method and application of a two-dimensional oriented nanosheet Cu-SSZ-39 molecular sieve, the preparation method comprises the following steps: (1) mixing an inorganic base, a silicon source, an organic template agent, water, a USY molecular sieve and an SSZ-39 seed crystal to form initial gel; (2) carrying out hydrothermal reaction and carrying out double-temperature crystallization to obtain an M-SSZ-39 molecular sieve; (3) carrying out ammonium ion exchange to obtain an NH4-SSZ-39 molecular sieve; and (4) adding the NH4-SSZ-39 molecular sieve into the copper precursor solution, carrying out heat-enhanced stirring and dipping, and then drying and calcining to obtain the two-dimensional nano flaky Cu-SSZ-39 catalyst. The preparation method is improved, and dual-temperature crystallization is matched with heat strengthening impregnation, so that a synergistic strategy of carrier morphology regulation and accurate active site construction is realized, and the technical problems of narrow working temperature window, serious internal diffusion limitation and low active site utilization rate of a traditional Cu-SSZ-39 catalyst are solved.

The invention provides a single crystal seeding skew detection method and system, electronic equipment and a storage medium, and the detection method comprises the following steps: in a seeding step, obtaining images of seed crystal growth shapes in groups; a detection area of the image is divided into two areas according to the central axis of the original seed crystal, the pixel proportion of the growth shape of the seed crystal to the area where the seed crystal is located in each area is calculated, and the deviation value of the pixel proportion is calculated; judging whether the seed crystal in each image is skewed or not according to the deviation value; acquiring the number of images with skewed seed crystals in each group; and judging whether a preset condition is met or not according to the proportion of the number of the images with the skewed seed crystals in each group to the total number of the images in each group, and outputting an alarm signal if the preset condition is met. The method has the beneficial effects that real-time monitoring and early warning are carried out on the growth shape of the seed crystal in the seeding process, so that accurate judgment on whether the growth of the seed crystal is skewed or not is realized, the automation level is improved, and potential safety hazards are reduced.

The invention provides silver powder with high crystallinity and narrow particle size distribution and a preparation method thereof, and belongs to the technical field of metal powder preparation. The preparation method comprises the following steps: preparing a silver nitrate solution, an ascorbic acid solution, a stabilizer solution, a dispersant solution, a seed crystal solution, a nitric acid solution and a surface modifier solution; adding the stabilizer solution and the nitric acid solution into the seed crystal solution, and mixing to obtain a solution A with specific PH; the dispersing agent solution is added into the silver nitrate solution for mixing, and a solution B is obtained; adding the solution B and an ascorbic acid solution into the solution A, fully reacting, and collecting a precipitate; and washing the precipitate, adding a surface modifier solution, fully stirring, drying, and dispersing to obtain the target silver powder. Different reaction mixed solutions are prepared step by step and then mixed according to a specific sequence, and the submicron silver powder with the high crystallinity and the large specific surface area is prepared through a simple and controllable method.

The invention belongs to the technical field of semiconductors, and particularly relates to a silicon carbide crystal and a liquid phase growth method thereof. Compared with the prior art, the liquid phase growth method provided by the invention adopts the seed crystal support with the diameter smaller than that of the seed crystal, and meanwhile, the temperature and the pressure are increased and reduced after crystal growth is finished, so that volatilization of metal on the crystal surface and on the side surface of the seed crystal support is promoted, and cracks caused by different thermal expansion coefficients of the surface metal and silicon carbide in the cooling process are reduced.

The invention provides a preparation method of ultra-low thermal conductivity silicon-based aerogel, and relates to the field of aerogel material preparation, and the preparation method comprises the following steps: S1, preparing a component A and a component B. The component A is prepared by fully mixing a silicon source, a modified silicon dioxide seed crystal, absolute ethyl alcohol and deionized water, then slowly adding an acid catalyst, and carrying out hydrolysis; the component B is a basic catalyst solution obtained by uniformly mixing deionized water and stronger ammonia water; step S2, gelling: fully mixing the component A and the component B to obtain wet gel, and then mixing the wet gel with a fiber felt to obtain a wet gel felt; step S3, aging; and S4, performing supercritical drying. According to the method, by introducing the modified silicon dioxide seed crystal, the thermal conductivity of a solid structure of the aerogel is effectively reduced, meanwhile, formation of macropores, communicating pores and the like is inhibited, and the performance of the aerogel is improved.

The application discloses a potassium fluorotantalate crystallization purification method, and relates to the technical field of tantalum hydrometallurgy and fluorotantalate crystallization purification. The method comprises the following steps: filtering a tantalum-containing fluorine acid solution, adding a potassium source and a tantalum-niobium separation type composite crystallization regulator, stirring and complexing, seed induction, controlled cooling crystallization, graded removal of the regulator, solid-liquid separation, and potassium fluoride containing fluorine acid washing to obtain primary purified potassium fluorotantalate crystals, and then redissolving the primary purified potassium fluorotantalate crystals in a fluorine-containing acid solution, correcting the K / Ta molar ratio, repeatedly regulating and crystallizing, graded removal of the regulator, washing, and drying to obtain high-purity potassium fluorotantalate. The regulator can reduce the entrainment of niobium impurities and reduce the residual amount of the regulator itself, thereby improving the purity of the product and the Ta yield.

Disclosed herein is a furnace for producing single crystal boules, the furnace comprising a furnace wall; a plurality of crucibles, where each crucible is operative to contain a melt that is contacted by a different pull rod; where each pull rod is attached to seed crystal; a first drive system that is located above the furnace and is configured to drive a first main shaft that is either in a geared or belted communication with a plurality of first planetary shafts; where each pull rod is in rotary communication at least one planetary shaft; where each pull rod is operative to contact the melt while undergoing rotary and translational motion with respect to a melt in one of the plurality of crucibles; where each crucible is surrounded by an induction coil and a refractory lining; and wherein each induction coil and refractory lining lie within the furnace wall.

The invention relates to the technical field of synthesis of inorganic porous materials, in particular to a hierarchical pore ZSM-5 molecular sieve and a synthesis method thereof.The method comprises the steps that an aqueous solution of a guiding agent serves as a solvent, an aluminum source is dissolved in the solvent to form a mixed solution, a chelating agent and a silicon source are added into the mixed solution, the chelating agent and the silicon source react to form a chelate, seed crystals are added, and the hierarchical pore ZSM-5 molecular sieve is obtained. According to the present invention, the guiding agent can be adsorbed on the surface of the seed crystal to obtain the mixed gel, and the hierarchical pore ZSM-5 molecular sieve is obtained after the hydrothermal reaction of the mixed gel, and the synthesized hierarchical pore ZSM-5 molecular sieve has the typical MFI type micropore channel, the micropore-mesopore-macropore combined hierarchical pore structure and the ultra-large particle size of 10-35 [mu] m, the method has a huge application prospect in the chemical fields of macromolecular catalysis, adsorption and the like.

The present disclosure provides a vanadium electrolyte, a preparation method and use thereof. The method includes: adding sulfuric acid into vanadium-containing ore, and stirring to obtain a mixture; curing the mixture to obtain a clinker; leaching the clinker with water to obtain a vanadium-containing leaching solution; adding a first impurity-removing agent into the vanadium-containing leaching solution to obtain a first purified solution; adding an oxidizing agent, a ferric phosphate dihydrate seed crystal and a second impurity-removing agent into the first purified solution to obtain a second purified solution; adding a reducing agent and a flocculating agent into the second purified solution, and filtering a resultant solution to obtain a filtered solution; mixing the filtered solution with an extraction liquid to obtain a vanadium-supported organic phase; stripping the vanadium-supported organic phase to obtain a stripping liquid; and removing an organic phase from the stripping liquid to obtain the vanadium electrolyte.

The application discloses a preparation method of a novel composite SERS substrate based on MXene and trace detection application thereof, and particularly relates to the technical field of nanomaterials and spectral detection technology, wherein the substrate takes single-layer MXene nanosheets as a carrier; after synthesis, ZnO crystal seeds are subjected to mediated growth, and the Zeta potential difference between the MXene nanosheets and the ZnO crystal seeds is utilized to make the ZnO crystal seeds loaded on the surface of the MXene nanosheets through electrostatic adsorption to obtain a MXene / ZnO composite material; an Ag@Au core-shell structure is modified on the MXene / ZnO composite material, and finally, a MXene / ZnO@Ag@Au composite material, namely the composite SERS substrate, is obtained.

This invention provides a method for growing single crystals of group III nitrides that can improve crystal quality. [Solution] A method for growing a group III nitride single crystal, comprising: an initial nucleation step S1 in which a seed substrate having a plurality of seed crystals made of group III nitride single crystals formed on its upper surface is immersed in a mixed molten liquid stored in a crucible to form a plurality of initial nuclei; a planarization step S2 in which the seed substrate is repeatedly immersed in the mixed molten liquid and then lifted out, and heated in a nitrogen atmosphere to fill the spaces between adjacent initial nuclei with group III nitride single crystals and flatten the crystal plane; and a thickening step S3 in which the seed substrate having the flattened crystal plane is immersed in a mixed molten liquid stored in a crucible to form a thickened group III nitride single crystal on the seed substrate, wherein in the initial nucleation step S1, the mixed molten liquid does not contain alkali metals and alkaline earth metals other than Na, and in the thickening step S3, the mixed molten liquid contains alkali metals or alkaline earth metals other than Na.

The application discloses a kind of solid waste-based cementing material of coal-fired power plant and preparation method thereof, belong to building material technical field.The material is made of the following weight parts of raw materials: 50-70 parts of fly ash, 10-30 parts of mineral powder, 10-30 parts of desulfurization gypsum, 1-5 parts of activator, 1-5 parts of seed crystal.The key of its preparation method lies in by implanting pre-synthesized C-S-H seed crystal, as nucleation base point in the hydration process of cementing material, effectively stimulate the potential activity of solid waste, induce the formation of dense hydration product structure.Cementing material prepared by the application has the advantages of high strength, low cost, environmental protection, etc., realizes the high value-added resource utilization of solid waste of coal-fired power plant.

The invention relates to the technical field of crystal growth control, in particular to a multi-sensor-based crystal growth furnace temperature control system, which comprises a crystal unit, a heating unit, a stirring unit, a gas conveying unit, a lifting unit, a temperature acquisition unit, a saturation accounting unit, an identification unit and an analysis unit, wherein the crystal unit is provided with a sublimation area and a seed crystal area; the temperature acquisition unit detects temperature distribution and gradient through multiple sensors; the saturation accounting unit and the recognition unit are used for calculating the solution supersaturation degree and monitoring crystal contour features through an optical detector respectively; the analysis unit is used for determining the growth rate according to the contour characteristics, judging the crystal quality by comparing the overlap ratio of an actual growth curve and an expected growth curve, intelligently diagnosing reasons when the crystal quality is unqualified, adjusting the gas phase conveying rate aiming at the impurity enrichment problem to improve stirring, correcting the temperature ratio between regions aiming at the heat dissipation problem, and realizing multi-parameter linkage regulation and control.

The application discloses a method for preparing a large-size single crystal by a crucible-free method and belongs to the technical field of semiconductor material preparation. The method comprises the following steps: a. providing a plurality of small-size seed crystals, wherein the seed crystals are single crystal seed crystals; b. splicing the plurality of small-size seed crystals to form a large-size composite seed crystal; c. performing single crystal growth on the composite seed crystal, wherein in the single crystal growth process, a single crystal region with a growth advantage gradually expands and dominates through crystal direction competition; d. processing the grown single crystal region with the expanded and dominant single crystal into a new seed crystal for splicing and growth in the next round; and e. repeating steps b-d to obtain a large-size single crystal. The method ingeniously bypasses the problem of a traditional expanding process through a strategy of "dividing the whole into parts and iterative optimization", can prepare a high-quality single crystal with a size far greater than that of an initial seed crystal on the basis of a small-size seed crystal at a low cost, and provides a brand-new and effective technical path for a size breakthrough of gallium oxide and other single crystals.

The invention discloses a treatment process and a treatment system for crystallization of photovoltaic wastewater calcium fluoride sludge, limestone particles and photovoltaic sludge are mixed according to a mass ratio of 3%-5% to obtain a homogeneous mixed material, the homogeneous mixed material is pre-dried and then fed into a rotary kiln, sintering is carried out at 1200-1500 DEG C for 1.5-3 hours, and the sintered material is cooled to room temperature. Calcium fluoride is attached to the surface of the silicate framework, sulfur trioxide and calcium oxide are released at the same time, after sintering is finished, the material is subjected to annealing treatment in a rotary kiln, calcium fluoride seed crystals accounting for 0.1%-1.0% of the total mass of the material are added, calcium fluoride crystals are induced to grow directionally and be repaired, and the calcium fluoride is obtained. According to the method, the purity of calcium fluoride is increased to 75%-85%, the sulfur content in the product can be controlled to be 0.1% or below, and the cold compressive strength of the pellets prepared from the product reaches 2.5 MPa or above.

A dual-mode asymmetric P-I-N perovskite radiation detector and its fabrication method are disclosed, belonging to the field of radiation detector technology. The method first involves preparing a perovskite single-crystal precursor solution. A small amount of this solution is used for seed crystal growth at a constant temperature, with the seed crystal serving as the seed for CsPbBr3 single-crystal growth on a P-type substrate. Next, a MAPbBr3 solution is prepared, and MAPbBr3 single crystals are grown to form the I layer. Finally, MAPbBr3 (Bi) is prepared... 3+ A doped solution was used to grow MAPbBr3 (Bi) as the N-layer. 3+ A dual-mode asymmetric P-I-N perovskite radiation detector is obtained by fabricating top and bottom electrodes using a doped single crystal. This invention utilizes the forward conduction and reverse cutoff characteristics of the P-I-N structure. When a negative voltage is applied to the N layer for forward bias, X-rays incident on the P layer are used for radiation detection, exciting the photoconductivity gain and achieving a sensitivity far exceeding that of CsPbBr3 single crystals; simultaneously, MAPbBr3 (Bi 3+ The doped single crystal has a natural shielding effect on soft X-rays, enabling high-sensitivity detection of hard X-rays in the I layer when X-rays are incident on the N layer with positive pressure and reverse P-I-N bias.