53 results about "Magnesium doping" patented technology

Provided are a wide-temperature-range solid-state electrolyte, a preparation method thereof and use thereof in solid-state lithium metal batteries. The preparation method includes: dissolving a lithium salt and a magnesium salt in a solvent to obtain a mixed salt solution; and mixing the mixed salt solution with an ammonia fluoride solution, subjecting a resulting mixture to reaction, and subjecting a resulting reaction product to centrifugation, washing, and drying in sequence to obtain magnesium-doped lithium fluoride nanoparticles; and mixing the magnesium-doped lithium fluoride nanoparticles, a liquid plasticizer, a polymer monomer and a thermal initiator to obtain a liquid precursor, and subjecting the liquid precursor to curing to obtain the wide-temperature-range solid-state electrolyte, where the polymer monomer is a mixture of ethoxylated trimethylolpropane triacrylate and hexafluorobutyl methacrylate.

The invention discloses a rate type lithium iron phosphate positive electrode material, a preparation method and a battery thereof, firstly, iron phosphate is modified by dopamine hydrochloride, the surface activity of the iron phosphate is improved, subsequent doping of cobalt and magnesium is facilitated, meanwhile, excessive growth of crystal grains can be limited in high-temperature sintering, nitrogen and carbon are introduced into lithium iron phosphate, and the rate type lithium iron phosphate positive electrode material is prepared. A carbon-nitrogen coating layer is formed, so that the electronic conductivity is improved; then, isopropyl tri (dioctyl pyrophosphate acyloxy) titanate, cobalt oxide and magnesium oxide are adopted to prepare a doping agent, cobalt and magnesium are uniformly doped into lithium iron phosphate crystal lattices to form bulk phase doping, and cobalt and magnesium co-doping synergistically improves the electronic conductivity and structural stability of the lithium iron phosphate material; finally, a biomass carbon source beta-cyclodextrin is adopted for carbon coating, a uniform carbon layer is formed on the surface of the lithium iron phosphate, and the electrochemical performance of the lithium iron phosphate is further improved; the lithium iron phosphate material prepared by the method also has good electrochemical performance under high magnification.

The utility model belongs to the field of semiconductors, and discloses a multistage junction termination structure of a vertical GaN diode. The multistage junction termination structure comprises a sapphire substrate on which a GaN nodule layer grows; a silicon-doped n +-GaN layer is grown on the GaN nodule layer, a silicon-doped n-GaN layer is grown on the n +-GaN layer, a magnesium-doped p-GaN layer is grown on the n-GaN layer, and a magnesium-doped p +-GaN layer is grown on the p-GaN layer; etching from the p < + >-GaN layer to the n < + >-GaN layer, and preparing a negative electrode on the surface of the n < + >-GaN layer; etching from the p +-GaN layer to the p-GaN layer to form a continuous multi-stage step, and preparing a positive electrode on the surface of the p +-GaN layer; according to the utility model, after the multi-stage step junction termination structure is introduced, the electric field aggregation phenomenon is obviously relieved, which indicates that the junction termination structure effectively reduces the internal electric field peak value.

Disclosed are a negative electrode material for a secondary battery and a preparation method thereof, the negative electrode material enhancing the initial discharge capacity, initial efficiency and life characteristics of the secondary battery. The negative electrode material for a secondary battery according to the present disclosure comprises an active material having a carbon-coated surface, a conductive material, and a binder. The active material comprises a magnesium-doped composite. The magnesium-doped composite comprises silicon oxide (SiOx, 0.5<x≤2) nanoparticles, silicon (Si) nanoparticles, and magnesium oxide nanoparticles. The diameter of the magnesium oxide nanoparticles may be 30-150 nm.

The application provides a thin film with an epsilon phase gallium oxide hetero-epitaxial structure and a preparation method thereof, which comprises, from bottom to top, a substrate layer, a first gallium oxide layer and a second gallium oxide layer; the first gallium oxide layer is an epsilon phase gallium oxide layer doped with magnesium Mg, and the magnesium Mg doping acts as an acceptor type trap in the epsilon phase gallium oxide, effectively compensates for the donor type defects of the epsilon phase gallium oxide, and improves the overall resistivity of the epsilon phase gallium oxide thin film. The preparation method adopts a metal organic chemical vapor deposition method, and the growth temperature of the second gallium oxide layer is higher than that of the first gallium oxide layer; and the molar flow ratio of the magnesium source to the gallium source is controlled to be 0.0001-0.1 during preparation. The application introduces appropriate Mg doping through a nucleation layer stage, so that the Mg acts as an acceptor type trap to compensate for donor type defects, while improving the crystal nucleation quality, reducing dislocations and leakage channels, and realizing the dual optimization of the crystal quality and electrical performance of the epsilon phase gallium oxide thin film, thereby effectively reducing the thin film leakage current and improving the resistivity.

This invention discloses a biomimetic tactile-pain-sensitive dual-modal flexible pressure sensor and its fabrication method. The sensor comprises an upper electrode, a tactile-pain-sensitive piezoelectric sensing component, and a lower electrode. The electrode employs an elastic substrate layer / modified functional layer / conductive network. The tactile-pain-sensitive piezoelectric sensing component comprises a magnesium-doped zinc oxide nanomaterial composite layer designed based on a concentration gradient and an elastic polymer composite layer, as well as a common ground electrode. The tactile sensing layer achieves high sensitivity by blending high-concentration Mg-ZnO nanorod filler with PDMS; the pain sensing layer uses low-concentration Mg-ZnO nanorod filler, resulting in lower sensitivity. Independent signal pathways are formed through the common ground electrode, enabling dual-modal sensing of tactile perception and pain alarm. The sensor fabricated in this invention possesses advantages such as high sensitivity, wide detection range, and strong resistance to signal crosstalk, and can be applied to biomimetic sensing fields such as intelligent robots and wearable devices.

The application discloses a flexible boron nitride homojunction pn and a preparation method, wherein a sulfur-doped n-type boron nitride film is grown on a sapphire substrate through a low-pressure chemical vapor deposition technology; a magnesium-doped p-type boron nitride film is grown on a copper substrate through a low-pressure chemical vapor deposition technology; the sulfur-doped n-type boron nitride film and the magnesium-doped p-type boron nitride film are transferred to a flexible substrate through a polymethyl methacrylate assisted liquid phase exfoliation technology, and heat treatment is conducted in an argon atmosphere to obtain a flexible boron nitride homojunction pn. The application realizes efficient n-type and p-type doping of the boron nitride film, and prepares a boron nitride-based homojunction pn on the flexible substrate through a large-area film exfoliation and transfer technology. The homojunction structure has high lattice matching degree and low junction formation energy, further develops the preparation and research of van der Waals homojunctions in the field of ultrawide bandgap materials, and has great application prospect in the fields of optoelectronic devices and high-power power electronic devices.

The invention discloses a Micro LED epitaxial growth method suitable for multiple current densities and an epitaxial structure. The method comprises the step of sequentially growing an n-type GaN layer, a V-shaped pit forming layer, a multi-quantum well light-emitting layer, a low-temperature p-GaN layer, an electron blocking layer and a high-temperature p-GaN layer on a substrate. The core of the method is that growth parameters of a V-shaped pit forming layer and a low-temperature p-GaN layer are cooperatively adjusted according to the target working current density m of the Micro LED device: when m is increased, growth conditions are controlled to increase the size of an opening of a V-shaped pit, and meanwhile, the thickness of the low-temperature p-GaN layer is increased and the magnesium doping concentration of the low-temperature p-GaN layer is reduced; and when m is reduced, reverse adjustment is carried out. Through linkage regulation and control of the key parameters, it is ensured that the hole injection depth is matched with the position of the light-emitting quantum well under different current densities, and the problems that the light-emitting efficiency of a Micro LED is unstable and voltage drifts in different application scenes are effectively solved.

This invention discloses a magnesium-doped sodium fluorinated iron phosphate material with a double coating of sodium phosphate and carbon layer, its preparation method, and its application. The magnesium-doped sodium fluorinated iron phosphate material uses Na₂Fe₂O₃ as the substrate. x Mg y The core is composed of PO4F, coated with a sodium phosphate layer, and an outermost conductive carbon layer. Fe has a +2 valence, 0.05 ≤ y ≤ 0.10, and x + y = 1. This invention achieves surface phosphate enrichment through a single ball milling process by adding excess phosphorus and sodium sources. Molten sodium phosphate is then pre-sintered to coat the pre-sintered particles, improving the material's cycle performance. High-temperature sintering achieves carbon coating, enhancing electronic conductivity. This single ball milling and sintering process forms a uniform sodium phosphate and carbon double coating on the material surface, reducing interfacial side reactions between the material and the electrolyte and improving problems such as low discharge capacity and poor rate performance caused by the material's low intrinsic conductivity.

The invention provides a magnesium-doped MXene dual-network hydrogel adsorbent as well as a preparation method and application thereof. The preparation method comprises the following steps: dispersing MXene in deionized water, adding a magnesium source, carrying out ion exchange reaction, and carrying out centrifugal separation, washing and drying after the reaction is finished, so as to obtain magnesium-doped MXene; the preparation method comprises the following steps: dissolving an acrylamide monomer and an acrylic monomer in deionized water, adding a cross-linking agent and an initiator, and uniformly mixing to obtain a pre-polymerized solution; and dispersing magnesium-doped MXene in deionized water, adding the pre-polymerization solution, uniformly stirring, and carrying out polymerization reaction to obtain the magnesium-doped MXene dual-network hydrogel adsorbent. According to the preparation method, the dispersity and adsorption activity of MXene can be remarkably improved through magnesium doping, meanwhile, the double-network hydrogel can provide rich adsorption sites and a three-dimensional network structure, and the adsorption capacity and the mechanical strength are further enhanced. The adsorbent has high adsorption capacity, excellent mechanical property and good cycle stability, and is suitable for efficiently removing copper and lead ions in water.

This invention discloses a bimetallic ion-doped sodium vanadium fluorophosphate cathode material and its preparation method, belonging to the technical field of secondary battery cathode materials. The chemical formula of the sodium vanadium fluorophosphate cathode material of this invention is Na. 3‑x Mg x V 2‑y Ti y (PO4)2F3, where 0.01≤x≤0.03, 0.025≤y≤0.075. This invention, through synergistic optimization of the composition and preparation method of sodium vanadium fluorophosphate cathode material, promotes selective titanium doping at vanadium sites and selective magnesium doping at sodium sites, effectively improving the specific capacity, cycle stability, and rate performance of the cathode material. Therefore, sodium-ion batteries assembled using the cathode material of this invention exhibit superior overall performance, demonstrating good capacity retention under both high and low current density conditions, providing an effective way to improve the performance of sodium-ion battery cathode materials.

Laboratory Catalytic Device for Using Magnesium-Doped Zinc Ferrichromite

The application discloses a magnesium-doped cobalt-nitrogen co-modified biochar composite material and a preparation method and application thereof, and belongs to the technical field of sewage treatment. The preparation method comprises the following steps: pyrolyzing agricultural waste under an inert atmosphere to obtain biochar; and through an impregnation-pyrolysis process, soluble cobalt salt, magnesium salt and a nitrogen source are combined with the biochar to obtain the magnesium-doped cobalt-nitrogen co-modified biochar composite material. According to the application, the electronic structure of cobalt is regulated through magnesium doping, and a stable Co-N x and Mg-O-Co interface is formed by combining nitrogen coordination, so that the activation capacity of the composite material on peroxymonosulfate is enhanced. When the material activates peroxymonosulfate, thiamethoxam is efficiently degraded through a free radical and non-free radical synergistic path, and the material has the advantages of low metal ion leaching rate, wide pH adaptation range, strong anti-interference capacity and the like, and exhibits excellent degradation performance on neonicotinoid insecticides such as thiamethoxam in a complex water environment.

This invention belongs to the field of new energy material preparation technology and discloses a method for controlling the doping sites of high-nickel layered cathode materials. This method addresses the problems of unclear doping site occupancy and difficulty in precise site control in existing elemental doping technologies, which lead to insufficient material structural stability and poor cycle performance consistency. It proposes a scheme to selectively adjust magnesium doping sites by introducing magnesium as a doping element in stages. This includes: introducing magnesium salt in the co-precipitation stage to achieve synergistic doping of magnesium at transition metal sites and lithium sites; and introducing magnesium salt in the lithiation stage to achieve single doping of magnesium at transition metal sites. By controlling the magnesium doping sites, the stability of the layered structure is significantly enhanced, lattice oxygen loss and layered structure collapse are suppressed, thereby greatly improving the cycle stability and electrochemical performance of high-nickel layered cathode materials. Furthermore, this invention has a simple process, is easy to operate, and is suitable for large-scale production.

The invention discloses a preparation method and application of a surface active coating, and belongs to the technical field of artificial joint coatings. A magnesium-doped porous titanium dioxide nanotube array layer and a zinc-strontium co-doped mesoporous bioactive glass release layer are formed on the surface of a substrate; the single performance such as the bonding strength, the osteogenic activity and the antibacterial ability of the coating is exceeded, and more importantly, the unification and the continuous high efficiency of the performance are realized through the gradient and synergistic system design of the coating; a new solution is provided for solving the two major problems of artificial joint replacement, namely sterile looseness and antibacterial ability, and the method has extremely high clinical transformation value and market prospect.

This invention relates to the field of lithium manganese iron phosphate (LFP) cathode materials, specifically to a high-performance LFP cathode material and its preparation method. This method addresses the limitations of existing LFP cathode materials in terms of cycle charge retention and voltage decay. The preparation method uses lithium, iron, manganese, phosphorus, doped metal compounds, carbon, and 3,4-ethylenedioxythiophene as raw materials. Through the synergistic effect of magnesium doping and 3,4-ethylenedioxythiophene coating, the electronic conductivity and ion diffusion coefficient of LFP are significantly improved, thus enhancing the rate performance of the material. Furthermore, the cycle stability and overall performance of the material are greatly improved.

The invention provides a modulation-doped aluminum nitride / diamond heterojunction material and a preparation method, and belongs to the technical field of semiconductors, and the preparation method comprises the following steps: preparing a hydrogen terminal layer on a diamond substrate to form a hydrogen terminal diamond substrate; growing an intrinsic aluminum nitride layer on the hydrogen terminal layer in an oriented manner; and modulating and growing a magnesium-doped aluminum nitride functional layer on the intrinsic aluminum nitride layer to form a hierarchical interface charge transport channel. According to the preparation method of the modulation-doped aluminum nitride / diamond heterojunction material provided by the invention, directional regulation and control of interface carriers are realized through hierarchical structural design of the surface of the hydrogen terminal diamond in combination with precise process control of pulse laser deposition, the carrier mobility and charge transport efficiency of the heterojunction are remarkably improved, and the performance of the material is improved. The aluminum nitride / diamond heterojunction material with high electrical characteristics is obtained, and the technical contradiction that process feasibility and electrical property optimization cannot be considered in the prior art is solved.

The invention belongs to the technical field of electronic materials, and discloses a magnesium-strontium double-doped calcium fluoride crystal and a preparation method and application thereof.The method comprises the steps that firstly, disodium ethylene diamine tetraacetate is chelated with calcium and magnesium ions, and the calcium and magnesium ions and villiaumite are subjected to a coordination exchange reaction to prepare a magnesium-doped calcium fluoride microsphere precursor; regulating and controlling hydrolysis of 3-aminopropyltriethoxysilane through an absolute ethyl alcohol-deionized water mixed solvent, and realizing uniform anchoring and deposition of strontium ions by virtue of an interface connection effect of the 3-aminopropyltriethoxysilane, so as to construct a magnesium-strontium double-doped precursor with a core-shell structure; carrying out hot pressed sintering in a CF4 / Ar mixed atmosphere to obtain a high-density polycrystalline blank; and finally, finishing crystal oriented growth by adopting a Bridgman-Stockbarger method. Through the synergistic effect of the components in the whole process, gradient uniform doping of magnesium and strontium ions is achieved, lattice distortion is effectively eliminated, the optical uniformity, the anti-laser-damage threshold value and the mechanical stability of the crystal are improved, and the prepared crystal can be widely applied to manufacturing of special electronic materials such as semiconductor wafers and the like and has good industrialization prospects.

The application discloses a perovskite diode with photoelectric conversion function and a preparation method thereof. The perovskite diode comprises a transparent substrate, a cathode, an electron transport layer, an interface layer, a perovskite active layer, a hole transport layer and an anode in sequence. The electron transport layer is zinc oxide or magnesium-doped zinc oxide. The interface layer is serine or phenethyl ammonium bromide, which is used for inhibiting the fluorescence quenching effect of zinc oxide or magnesium-doped zinc oxide on the perovskite. The perovskite active layer is prepared from a precursor solution containing AX, BX2 and serine, wherein A is a monovalent cation, B is a divalent metal cation and X is a monovalent anion. The application simultaneously realizes effective photoelectric conversion and electric-optical conversion functions in a single perovskite diode, and balanced photovoltaic and luminescent performances are obtained.

The invention discloses a doping regeneration method of a waste ternary material, and belongs to the technical field of lithium battery material regeneration. The doping regeneration method of the waste ternary material comprises the following steps: crushing a waste ternary positive plate, and sorting to respectively obtain a current collector and ternary powder; adding magnesium oxide into the ternary powder, mixing, carrying out mechanical fusion to obtain a ternary material containing a magnesium oxide coating layer, and carrying out first-stage sintering; and adding lithium salt into the sintered ternary material, and carrying out second-stage sintering. According to the method, the interface of the ineffective material is doped in a controllable and quantitative co-doping mode of Mg < 2 + > / F <->, a magnesium doping proportion formula and a sintering condition formula are established according to the Ni content, and repairing and regeneration of the medium-high nickel ternary material are completed. Wherein the introduced Mg < 2 + > / F <-> element forms a co-doped structure on an interface, a more stable interface structure is newly built, and the problems that the high-nickel ternary material is poor in solid-phase repair regeneration performance and low in quality are solved.

This invention discloses a preparation process for magnesium-doped modified nickel-iron-manganese-based precursor materials, belonging to the field of electrode material preparation. The invention includes the following steps: (1) solution preparation; (2) preparation of the reaction substrate; (3) feeding; (4) nucleation reaction; (5) growth reaction; (6) magnesium doping modification; (7) aging reaction; (8) washing; and (9) drying. This invention utilizes magnesium-modified doped nickel-iron-manganese-based materials and employs an intermittent process to prepare sodium electrode precursors. By controlling factors such as the solid content, flow rate, and pH value of the reactants, the structure and morphology of the crystals can be precisely controlled. Simultaneously, the particle size distribution of the precursor can be well adjusted, thereby preparing sodium electrode precursor materials with uniform particle size.

The invention discloses a lithium-sulfur battery diaphragm material and a preparation method thereof, the material is a magnesium-doped nickel oxide metal oxide, the preparation method comprises the following steps: (1) mixing and dissolving a magnesium source, a nickel source and resorcinol in deionized water, dropwise adding an acidic solution, and heating to 60-90 DEG C; (2) dropwise adding a formaldehyde solution, stirring until the solution is gelled into gel, and drying; and (3) carrying out heat preservation for 2-4 hours in a muffle furnace at 550-900 DEG C, and carrying out high-temperature calcination. The material is a hollow nano-microsphere composed of metal oxide nano-particles of magnesium-doped nickel oxide, the specific surface area of the material is large, the hollow porous structure can absorb polysulfide and catalytically convert the polysulfide at the same time, the shuttle effect of the polysulfide is inhibited through the adsorption-catalysis synergistic effect, and the adsorption-catalysis efficiency is improved. The redox reaction kinetics of the lithium-sulfur battery is enhanced, the high utilization rate of active substances is realized, and the cycling stability of the battery is greatly improved.

The present application relates to a kind of magnesium-metal co-doped prelithiation silicon-oxygen composite material and its preparation method and lithium ion battery.The preparation method includes the following specific steps: providing micron silicon powder, silicon dioxide and magnesium powder are ball milled and mixed, and lithium carboxymethyl cellulose is added to vacuum high-temperature sintering, to obtain magnesium-doped silicon monoxide precursor;Magnesium-doped silicon monoxide precursor is added to the solution of 1-10wt% metal salt, filtration, vacuum drying, carbonization after drying, to obtain magnesium-metal co-doped silicon-oxygen material;Magnesium-metal co-doped silicon-oxygen material and prelithiation agent are mixed, and high-temperature sintering is carried out to obtain prelithiation silicon-oxygen material;Prelithiation silicon-oxygen material and organic reagent are mixed and coated, dried to obtain magnesium-metal co-doped prelithiation silicon-oxygen composite material.The present application provides a kind of magnesium-metal co-doped prelithiation silicon-oxygen composite material and lithium ion battery with good power performance and excellent cycle performance.

The invention relates to the field of lithium manganese iron phosphate positive electrode materials, in particular to a high-performance lithium manganese iron phosphate positive electrode material and a preparation method thereof, and aims to solve the problem that the existing lithium manganese iron phosphate positive electrode material has relatively large limitation in the aspects of cyclic charging maintenance and cyclic charging voltage attenuation. According to the preparation method, a lithium source, an iron source, a manganese source, phosphorus, a doped metal compound, a carbon source and 3, 4-ethylenedioxythiophene are used as raw materials, and through the synergistic effect of metal element magnesium doping and 3, 4-ethylenedioxythiophene coating, the electronic conductivity and the ion diffusion coefficient of lithium manganese iron phosphate are remarkably improved, and the rate capability of the material is improved; the cycling stability of the material is greatly improved, and the performance of the material is improved.

The invention provides a silicon-based composite negative electrode material for an all-solid-state lithium battery and a preparation method of the silicon-based composite negative electrode material. The silicon-based composite negative electrode material for the all-solid-state lithium battery comprises the following components in percentage by mass: 55-90% of a silicon substrate, which comprises silicon powder or a silicon carbon material; the magnesium doping agent comprises magnesium powder and magnesium nitride, and the mass fraction of the magnesium doping agent is 5%-40%; and the auxiliary component comprises a conductive agent and an adhesive. According to the silicon-based composite negative electrode material for the all-solid-state lithium battery and the preparation method of the silicon-based composite negative electrode material, metal magnesium and magnesium nitride are doped into a silicon-based negative electrode, so that collaborative lithium storage of silicon and lithium deposition is realized, lithium dendrite growth can be effectively inhibited, interface contact is improved, rate performance is improved, and energy density and cycling stability are improved.

A vertical Ga₂O₃ metal-oxide-semiconductor field-effect transistor (MOSFET) is disclosed that includes a gallium oxide substrate, an undoped drift layer positioned on the substrate, and a magnesium-doped gallium oxide current blocking layer arranged on the drift layer. A source layer is positioned on the current blocking layer, and a trench extends through the source layer, the current blocking layer, and at least partially into the drift layer. A gate dielectric and gate contact are located within the trench. The device may include a source contact electrically connected to the source layer and a drain contact electrically connected to the substrate. Methods for forming the device include epitaxial growth and metal-organic chemical vapor deposition, with magnesium doping performed in-situ. The structure enables high-voltage operation with low leakage and improved breakdown characteristics for power electronics applications.

The application provides a magnesium-doped tin dioxide composite material and a preparation method and application thereof, and belongs to the technical field of lithium ion batteries. The magnesium-doped tin dioxide composite material is obtained by adopting a sol-gel method to perform carbon-coating treatment on tin by using a carbon source and then performing a hydrothermal reaction with magnesium. The magnesium-doped tin dioxide composite material realizes a synergistic lithium storage effect of magnesium and tin elements in the charging and discharging process by introducing the second-phase magnesium element. On the one hand, the volume expansion of the tin-based negative electrode material can be effectively relieved, powder agglomeration can be inhibited, and the material structure can be stabilized; on the other hand, the effect of providing electrochemical active sites can be achieved, the electrochemical performance of the negative electrode material can be further improved, and more possible ideas for the wide application of the tin-based negative electrode material are provided.

A device including an activated p-type layer comprising a III-Nitride based Mg-doped layer grown by vapor phase deposition or a growth method different from MBE. The p-type layer is activated through a sidewall of the p-type layer after the removal of defects from the sidewall thereby increasing a hole concentration in the p-type layer. In one or more examples, the device includes an active region between a first n-type layer and the p-type layer; a second n-type layer on the p-type layer; and a tunnel junction between the second n-type layer and the p-type layer, and the activated p-type layer has a hole concentration characterized by a current density of at least 100 Amps per centimeter square flowing between the first n-type layer and the second n-type layer in response to a voltage of 4 volts or less applied across the first n-type layer and the second n-type layer.

The application discloses a kind of rate type lithium iron phosphate positive electrode material, preparation method and battery thereof, first using hydrochloric acid dopamine to modify treatment to iron phosphate, improve the surface activity of iron phosphate, it is beneficial to subsequent cobalt, magnesium doping, can limit grain excessive growth in high-temperature sintering, and introduce nitrogen carbon in lithium iron phosphate inside, form carbon nitrogen coating layer, improve electronic conductivity;Then, using isopropyl tri (dioctyl pyrophosphoric acid acyl oxygen) titanate, cobalt oxide and magnesium oxide to prepare dopant, make cobalt, magnesium evenly doped into lithium iron phosphate crystal lattice to form phase doping, cobalt magnesium co-doped synergistically improve the electronic conductivity and structural stability of lithium iron phosphate material;Finally, using biomass carbon source β-cyclodextrin carries out carbon coating, forms uniform carbon layer on the surface of lithium iron phosphate, further improves the electrochemical performance of lithium iron phosphate;Lithium iron phosphate material prepared by the application also has good electrochemical performance under high rate.

Embodiments according to the present invention provide a high-quality E-mode GaN HEMT power semiconductor epitaxy wafer comprises a GaN channel region in which a 2DEG (2-dimensional electron gas) is formed; an AlGaN barrier region formed on the GaN channel region; and a p-type semiconductor region formed on the AlGaN barrier region, wherein the p-type semiconductor region has a first doping region having a minimum doping concentration at a boundary with the AlGaN barrier region and an increasing magnesium (Mg) doping concentration in a thickness direction, and a second doping region having the minimum doping concentration on a back surface of the AlGaN barrier region, in which the magnesium (Mg) doping concentration decreases in a thickness direction after passing a maximum doping concentration.