86 results about "In situ doping" patented technology

The invention discloses a sulfide solid electrolyte stable in wet air, a preparation method thereof and a battery, and belongs to the technical field of all-solid-state batteries, the sulfide solid electrolyte comprises the following raw materials in parts by weight: 20-100 parts of sulfide solid electrolyte and 1 part of metal halide component, the chemical formula of the sulfide solid electrolyte is Li < 6-x > PS < 5-x > Cl < 1 + x >, 0 < = x < = 0.6, the metal halide component comprises at least one metal halide, the chemical formula of the metal halide is MXn, n is greater than or equal to 2 and less than or equal to 4, M is one of Zr, Al, Zn, Sn, Sb and Bi, and X is one of F, Cl, Br and I. The metal halide and the sulfide solid electrolyte in a specific ratio are mixed, subjected to ball milling and then subjected to annealing treatment, and an in-situ doping coating layer is obtained on the surface of the sulfide solid electrolyte; and under the condition that the ionic conductivity of the sulfide solid electrolyte is slightly influenced, the wet air stability of the sulfide solid electrolyte is effectively improved.

The invention discloses a group III chloride ex-situ doped cadmium telluride thin film solar cell and a preparation method thereof, and the cadmium telluride thin film solar cell comprises a substrate layer, a transparent conductive oxide thin film layer, a high-resistance buffer layer, a cell window layer, a cell layer, a back contact layer and a back electrode layer which are sequentially arranged from bottom to top. The cell layer comprises an absorption layer and a IIICl3 layer coated on the upper surface of the cell window layer, and IIICl3 is chloride of the III main group element. According to the III-group chloride ex-situ doping method provided by the invention, the III-group chloride can be dissolved in an organic solution, room-temperature solution deposition is allowed, III-group cations are easy to diffuse at a relatively low annealing temperature, and a complex annealing process is not needed to activate a dopant; through a simple solution process and low-temperature activation, efficient doping of the CdTe absorption layer is effectively realized, and the open-circuit voltage and the overall photoelectric conversion efficiency of the cell are remarkably improved.

The invention specifically discloses a preparation method of a FeZn diatomic nano enzyme with adjacent double metal sites. The product is of a planar sheet structure, chitosan serves as a chelating support, and the product is prepared through in-situ doping of bimetallic precursors of Fe and Zn in a competitive coordination and high-temperature pyrolysis mode. The preparation method comprises the following steps: taking chitosan as a sacrificial template, taking ferric nitrate and zinc chloride as precursors, and carrying out in-situ conversion on the metal precursors into bimetallic atom sites by virtue of a high-temperature pyrolysis means, so as to prepare the FeZn diatomic nano-enzyme. FeZn diatoms exist in an adjacent state, the peroxidase-like activity of the FeZn diatoms is larger than that of monatomic Fe nano-enzyme and monatomic Zn nano-enzyme, the FeZn diatoms have excellent storage stability and high-temperature-resistant catalytic stability, and the preparation method has the advantages of being high in expandability, simple in process, green in raw material, stable in diatom structure and the like.

The invention discloses a preparation method and application of an aldol condensation catalyst with a Si-O-Zr framework constructed through in-situ doping. The preparation method mainly comprises preparation and application of the Si-O-Zr framework constructed through in-situ doping and the aldol condensation catalyst. Wherein the in-situ doping construction of the Si-O-Zr framework mainly utilizes the pre-hydrolysis matching of a silicon source and the hydrolysis / polycondensation rate between a zirconium source to realize the atomic-scale dispersion of the active component, a proper pore structure can be provided for the subsequent loading of the active component, the possibility of clustering of the active component is reduced, the catalytic activity is further improved, and the method is simple in preparation and low in cost. The method is suitable for subsequent large-scale industrial application.

The invention provides an antimony-based chalcogenide film with (hk1) dominant orientation and a preparation method and application thereof, and belongs to the technical field of semiconductor photovoltaic materials. According to the method, the crystal orientation of the antimony-based chalcogenide film is regulated and controlled by doping PbI2 in situ under the simple solution method (water bath or hydrothermal) deposition condition, and research results show that the solution method is adopted to introduce PbI2, so that the antimony-based chalcogenide film can be remarkably induced to preferentially grow along the (hk1) direction, grain boundary scattering and inter-chain potential barriers are effectively weakened, and the crystal orientation of the antimony-based chalcogenide film is improved. The carrier longitudinal migration and collection efficiency is improved, so that the VOC loss is reduced, and the final battery performance is improved; the method provided by the invention not only provides a new thought for preparing the high-orientation antimony-based chalcogenide film, but also lays a technical foundation for design and optimization of a bottom battery material in a future laminated battery.

The present disclosure provides a trench gate semiconductor device and a preparation method thereof. The trench gate semiconductor device comprises a substrate, a drift region and a body region. The drift region is arranged on the surface of the substrate and has a first conductivity type. The body region is epitaxially formed on the surface of the drift region away from the substrate and is an in-situ doped region with a second conductivity type. In the embodiment of the present disclosure, the body region is directly epitaxially formed, which can reduce the lattice damage in the body region, thereby reducing the interface defects between the body region and the gate oxide layer, and further improving the channel mobility. In addition, the tailing effect of the channel caused by ion implantation can be avoided, thereby improving the threshold voltage stability.

The invention provides a method for constructing a composite material MIL-101 (Fe) / KBiO3 by a solvothermal in-situ doping method, which comprises the following steps: adding FeCl3. 6H2O into N, N-dimethylformamide to obtain a liquid A; terephthalic acid and KBiO3 are added into N, N-dimethylformamide, and liquid B is obtained; and carrying out ultrasonic dispersion on the liquid A and the liquid B, carrying out heat treatment washing with a solvent at 110 DEG C, and drying to obtain the composite material MIL-101 (Fe) / KBiO3. The invention also provides application of the composite material MIL-101 (Fe) / KBiO3, and the composite material MIL-101 (Fe) / KBiO3 is used for photocatalytic degradation of Cr (VI). The composite material KBiO3 / MIL-101 (Fe) is prepared by adopting a solvothermal in-situ doping method, and the photocatalytic performance of the MIL-101 (Fe) on Cr (VI) is remarkably improved. The prepared composite material MIL-101 (Fe) / KBiO3 has a remarkable improvement effect in the field of degradation of heavy metal Cr (VI, and a new material choice is provided for heavy metal pollution treatment.

The application relates to a preparation method of a germanium-based source-drain material and application thereof, and relates to the field of germanium-based source-drain materials. A germanium-aluminum thin film is grown on a germanium-based substrate through co-deposition of germanium and aluminum. When the substrate temperature is 215-383 DEG C, X-ray diffraction (XRD) tests show that the germanium-aluminum thin film is a single crystal structure, the crystal quality is good, and there is no segregation of aluminum on the surface. Hall test shows that the germanium-aluminum thin film is self-doped with p type, and the activated hole concentration is as high as 8*10 20 According to the characterization results of a time-of-flight secondary ion mass spectrometer (TOF-SIMS), the diffusion length of aluminum atoms on an undoped germanium-based substrate is less than 4 nm / decade, and the germanium-based source-drain material can be applied to the preparation of p-type in-situ doping and p+ / n shallow junction of an advanced node process of a germanium-based logic circuit.

The application discloses an in-situ cross-linked boron-doped lithium manganese iron phosphate positive electrode material and a preparation method thereof, relates to the technical field of materials, and is characterized in that a lithium source is mixed with an iron source, a manganese source and a phosphorus source, and then sintering is performed to obtain an alkaline lithium manganese iron phosphate precursor; the lithium manganese iron phosphate precursor is mixed with a multi-hydroxy carbon source and a boron-containing compound, and a cross-linking reaction is performed; and finally, high-temperature carbonization is performed to obtain the boron-doped lithium manganese iron phosphate positive electrode material. The method utilizes the cross-linking reaction of the multi-hydroxy carbon source and the boron-containing compound through an in-situ cross-linking mechanism to form a borate ester bond. Sintering is performed again to form a carbon coating layer, and synchronous in-situ doping of boron is achieved. The carbon coating layer constructed through the method is more stable, and the boron is preferentially doped at the P position near the manganese, effectively reduces Mn-O distortion, increases Li-O bond length, and thus improves the electrochemical stability, cycle performance and rate performance of the material.

The invention relates to a substrate structure with low dislocation density and a growth method and application thereof, and belongs to the technical field of semiconductor materials. The growth method comprises the following steps: S1, putting a basic substrate into a reaction chamber; s2, introducing a first growth source, a second growth source and a doped metal source into the reaction chamber, and periodically adjusting the flow of the doped metal source to prepare an upper substrate layer on the basic substrate to obtain a substrate structure; wherein each growth cycle comprises a first growth stage and a second growth stage, and the flow of the doped metal source in the first growth stage is smaller than that of the doped metal source in the second growth stage, so that a plurality of doped cluster micro-masks which are arranged at intervals are formed in the second growth stage; the doped cluster micro-mask is used as a mask of the first growth stage in the next growth cycle so as to realize lateral epitaxial growth. According to the invention, the doped cluster micro-mask is formed by in-situ doping self-assembly to induce a 3D growth mode, so that the dislocation density of the substrate structure is reduced.

The application discloses MOF-5 derived single-atom solvent and a preparation method thereof, and belongs to the technical field of nano catalytic materials and liquid catalytic preparation. The preparation method uses MOF-5 as a zinc source and a structure template, in-situ dopes a target metal salt, and through one-step high-temperature pyrolysis and a zinc component volatilization strategy, a metal single-atom highly-dispersed nitrogen-doped carbon-based solid material is prepared; the material is further dispersed in a suitable solvent, and is subjected to homogenization treatment to form a highly-stable MOF-5 derived single-atom solvent which can be stored for a long time. The method utilizes the unique high porosity and uniform metal distribution characteristics of MOF-5, and combines the zinc species volatility under high temperature, so that efficient anchoring and stable dispersion of various metal single atoms are realized, the process is simple, and the universality is strong, and the method provides a new way for controllable preparation of a high-performance single-atom liquid catalytic system.

The invention relates to the technical field of semiconductor production, in particular to a high-growth-rate EPI production method which comprises the following steps: S1, removing oxide on the surface of a silicon substrate by adopting in-situ hydrogen annealing and repairing lattice defects; a gradient temperature rising strategy is adopted in the preheating stage, and slip lines caused by thermal stress are reduced; s2, in a chemical vapor deposition reaction cavity, adopting a double-gas-path injection system, wherein in a main gas path, mixed gas of high-flow SiH2Cl2 and H2 is used as a main silicon source; in the auxiliary gas path, trace SiH4 and HCl are used for inhibiting gas phase nucleation and adjusting the surface reaction activity; s3, adopting a double-area temperature control reaction cavity, wherein a central area is a high-temperature area, and rapid deposition of silicon atoms is promoted; the marginal area is a low-temperature area and inhibits marginal lattice distortion; the pressure of the reaction cavity is controlled to be 50-100 Torr; s4, in-situ doping and real-time monitoring: synchronously introducing phosphorane or diborane in the growth process, monitoring the doping concentration fluctuation in real time through a light emission spectrum, and feeding back and adjusting the gas proportion.

This invention relates to a pH-responsive multifunctional nanoplatform M@FNPs, a drug-loaded composition MP@FNPs, its preparation method, and its applications, belonging to the fields of nanomaterials and biomedical materials technology. The preparation method of the pH-responsive multifunctional nanoplatform M@FNPs includes the following steps: in-situ doping of ZIF-8 with ferric ions during synthesis to obtain iron-doped ZIF-8; dissolving magnesium peroxide nanoparticles and iron-doped ZIF-8 in a solvent; ultrasonicating to load the magnesium peroxide nanoparticles onto the iron-doped ZIF-8; and drying to obtain the final product. The MP@FNPs of this invention, by integrating pH-responsive release, self-supply of hydrogen peroxide and oxygen, and continuous GSH depletion functions, can specifically activate a self-maintaining cascade reaction in the tumor microenvironment, disrupting the redox homeostasis of tumor cells and inducing ferroptosis, thereby effectively overcoming the resistance of tumor cells to platinum-based drugs and synergistically enhancing the efficacy of chemotherapy-immunotherapy.

This invention provides a lithium-cobalt composite oxide, its preparation method, and its application, belonging to the field of lithium-ion battery technology. The general formula of the lithium-cobalt composite oxide of this invention is: Li c Co 1d e‑ f M d Q e E f O2·r Li a Co 1‑b T b O 4 / 3 (a×r+c) / (1+r)≤1; M, Q, and E are each independently selected from at least one of Mg, Al, Ni, Mn, Y, La, Zr, F, P, B, Ti, Cu, and Na; T is at least one of Y, Al, B, Ni, and Mn. This invention introduces elements with different doping forms, utilizing in-situ precursor doping, self-doping, and coating. The synergistic effect of various elements suppresses the irreversible phase transition of cobalt-containing cathode materials coated with T-element materials under high voltage, improving the structural stability of the cathode material, thereby achieving good electrochemical performance with good cycle performance under high voltage.

The invention provides a sulfur-nitrogen co-doped porous carbon nanosheet electrode material and a preparation method thereof. The sulfur-nitrogen co-doped porous carbon nanosheet electrode material is prepared by taking a waste mushroom stick as a carbon source and combining in-situ doping and a template method; the sulfur-nitrogen co-doped porous carbon nanosheet electrode material is 3-8 wt%, the sulfur content is 1-5 wt%, the specific surface area is not less than 1800 m < 2 > / g, the pore volume is not less than 1.2 cm < 3 > / g, the nitrogen element exists in the forms of pyridine nitrogen, pyrrole nitrogen and graphite nitrogen, and the sulfur element exists in the forms of C-S-C covalent bonds and-SOx-functional groups. According to the invention, the carbon nanosheet material with high specific surface area, hierarchical porous structure and uniform sulfur and nitrogen co-doping is prepared by a simple and green method, and the preparation method has important significance for promoting the development of high-performance electrode materials.

The invention discloses an in-situ doping, coating, upgrading and regenerating method for a waste ternary positive electrode material, and belongs to the technical field of battery recovery. The method comprises the following steps: calcining the waste ternary positive electrode material in an oxidizing atmosphere to obtain a pure-phase intermediate; ball-milling and mixing the pure-phase intermediate with a lithium source and M oxides (aluminum oxide, silicon dioxide and the like) to form a mixture; according to the method, in-situ doping, coating, upgrading and regeneration of the waste ternary positive electrode material are realized through a pyrogenic process, and the obtained regenerated ternary positive electrode material has excellent electrochemical performance and cycling stability.

The invention discloses an anti-radiation photosensitive transistor and electronic equipment, and relates to the technical field of transistors, the anti-radiation photosensitive transistor comprises a substrate, a channel layer, a gate dielectric layer, an electrode structure and a two-dimensional semiconductor material layer; the channel layer is located on the substrate, is made of a high-forbidden-bandwidth semiconductor material and comprises a non-photosensitive functional region and a solar-blind photosensitive region, and the non-photosensitive functional region and the solar-blind photosensitive region form an RESURF structure through in-situ doping gradient transition; the gate dielectric layer is located between the gate and the solar-blind photosensitive region and is made of a high-dielectric-constant material; the two-dimensional semiconductor material layer is located between the source electrode and the solar-blind photosensitive region, and the two-dimensional semiconductor material layer and the material of the solar-blind photosensitive region form a Van der Waals heterojunction. The integrated structure synergistically improves the extreme environment radiation resistance, solar blind photosensitive sensitivity and single particle burning resistance reliability of the device, enhances the total ionizing dose resistance, uniformizes electric field distribution, relieves interface stress, optimizes carrier transport, inhibits trapped charge accumulation and local thermal runaway, and gives consideration to high photosensitive response and high breakdown voltage. And the method adapts to extreme high-voltage scenes.

The application relates to the technical field of graphene materials, in particular to a two-dimensional graphene-based photoelectric conversion device and a preparation method thereof, the preparation method comprises the following steps: S1. nickel foil pretreatment, S2. obtaining a B-doped P-type graphene-nickel foil film, S3. obtaining a B, P and N co-doped graphene-nickel foil film, S4. gold quantum dot loading, S5. etching, silicon wafer transfer printing, drying and electrode establishment. The two-dimensional graphene-based photoelectric conversion device provided by the application is an ultrathin two-dimensional photoelectric conversion device which can convert light energy into electric energy and can also be used as an energy supply system of a micro device; in-situ doping is realized in the graphene growth stage through CVD doping, two kinds of doping are realized on the same graphene film through a mask method, N-type doped graphene and P-type doped graphene and an ultrathin and stable two-dimensional graphene-based PN junction are obtained.

The invention provides a channel threshold regulation and control method and a GAANS device. The channel threshold regulation and control method comprises the following steps that S1, a germanium-silicon layer and a silicon layer are sequentially grown on the surface of a substrate in an epitaxial mode to form a laminated layer, and doping is carried out when the germanium-silicon layer is grown in an epitaxial mode; and S2, carrying out heat treatment on the substrate on which the laminated layer is formed, so that doped elements in the germanium-silicon layer enter the surface of the silicon layer. According to the channel threshold regulation and control method, the laminated germanium-silicon layer is subjected to in-situ doping and heat treatment, so that the surface of the nanosheet channel of the GAA NS device is slightly doped, the intrinsic material is still arranged in the middle of the nanosheet channel, the channel threshold regulation can be realized, and meanwhile, the influence on the mobility is relatively small.

A family of novel diazirine-based molecules as well as methods of manufacture and uses thereof are disclosed. These compounds allow non-functionalized polymers, such as polyolefins, to crosslink via C—H insertion. Such a C—H insertion process is useful, for example, for forming protective topical coatings on low surface energy films, for the covalent adhesive bonding of such films, or for creating rigid 3-dimensional polymeric structures by in-situ doping and activation of the crosslinker. The crosslinkers can be activated thermally, by UV radiation or by an electric potential.

A method for preparing a phosphorus-doped electrode inducing Ti4O7 lattice strain and its application in electrocatalytic enhanced advanced purification of pharmaceutical wastewater. Through the in-situ P-doping process, PH3 generated on the surface of Ti4O7 undergoes redox reaction to form new O vacancies, and P is doped into the Ti4O7 lattice to form Ti-O-P structure. O vacancies are conducive to improving the conductivity of the system, and can also increase the Ti 3+ active sites, strengthen · OH production. The construction of P sites can realize its adjustment of CO3 2‑ adsorption and activation, and further reduce its conversion to CO3 ·‑ reaction energy barrier, inhibit CO3 2‑ quenching of · OH. At the same time, in the process of CO3 ·‑ , CO3 2‑ transfers electrons to the electrode surface, which effectively migrates to Ti 3+ sites through O vacancies, inhibits the tendency of high-valence conversion in the catalytic process, thereby realizing · OH stable and efficient production, and effectively degrading antibiotics in pharmaceutical wastewater.

The invention belongs to the technical field of catalyst preparation, and particularly discloses a Ni / TiO2-ZSM-22 catalyst as well as a preparation method and application thereof. According to the catalyst, a titanium source is directly introduced when a ZSM-22 molecular sieve is synthesized, in-situ doping modification of titanium on a ZSM-22 molecular sieve framework is achieved, and then an active component Ni is loaded on a modified carrier by adopting an equivalent-volume impregnation method, so that the catalyst is obtained. In-situ doped titanium is used as a multifunctional auxiliary agent to promote the ZSM-22 molecular sieve to form a pore channel structure of a mesoporous-microporous hierarchical pore structure, rich oxygen vacancies are formed, the dispersity of active metal nickel (Ni) is improved, nickel is used for effectively covering strong acid sites of the molecular sieve to regulate and control an acidic environment, and the molecular sieve is prepared into the ZSM-22 molecular sieve. The catalyst shows excellent hydrodeoxygenation activity and isomerization capability in a hydrodeoxygenation isomerization reaction of methyl oleate, and shows excellent selectivity to C8-C18.

This invention relates to an in-situ carbon-doped p-type hexagonal boron nitride thin film and its preparation method, belonging to the field of semiconductor thin film preparation and doping technology. The invention employs low-pressure chemical vapor deposition (LPCVD) technology to grow an intrinsic hBN thin film buffer layer on a substrate via the reaction BCl3 + NH3 → hBN + HCl. Then, in-situ doping is performed on the buffer layer using Cp2Mg as a dopant source. After controlled cooling, the in-situ carbon-doped p-type hexagonal boron nitride thin film is obtained. The growth rate and thickness of the film can be controlled by the growth temperature and the growth source flow rate, while its electrical properties and doping concentration can be adjusted by the heating temperature of the dopant source and the dilution ratio. The method described in this invention is simple, stable, and produces uniform doping, enabling the preparation of p-type hBN thin films with high hole concentrations. Furthermore, through heteroepitaxial growth and other methods, various semiconductor devices can be formed with other semiconductor materials.

The invention provides an in-situ doping-gradient quenching integrated preparation method of coal-based graphene quantum dots, and relates to the technical field of graphene quantum dot preparation, and the method comprises the following steps: pretreating a coal raw material; mixing the pretreated coal raw material with a doping agent, and carrying out in-situ doping reaction, so that carboxyl of the doping agent and a coal aromatic ring are subjected to esterification reaction to form a C-O-X covalent bond; in the in-situ doping reaction process, gradient quenching treatment is synchronously carried out; according to the method, in-situ doping and gradient quenching are synchronously carried out, the steps of firstly preparing GQDs, then doping and independently cooling in a traditional method are omitted, the preparation steps are simplified, the production period is shortened, the yield is improved, an in-situ doping technology is adopted, a C-O-X covalent bond is formed through esterification of a doping agent carboxyl and a coal aromatic ring, doping elements are uniformly distributed in the GQDs, and the performance of the GQDs is improved. The segregation problem of post-doping is avoided, and the performance of the material is effectively improved.

The invention discloses a rare earth modified amorphous aluminum-nickel catalyst with a gradient pore structure and a preparation method of the rare earth modified amorphous aluminum-nickel catalyst, and belongs to the technical field of catalyst preparation. The catalyst comprises an amorphous aluminum-nickel alloy matrix and rare earth oxide nanocrystals dispersed in the amorphous aluminum-nickel alloy matrix, and rare earth oxide is composed of lanthanum oxide, cerium oxide and praseodymium oxide. The preparation method comprises the steps of alloy smelting, alloy crushing, programmed activation, ultrasonic-electric field auxiliary treatment, washing, post-load modification, roasting reduction and protection storage. The activity and selectivity of the catalyst are improved by adopting ternary rare earth synergistic modification, a gradient pore structure is constructed by adopting a programmed three-section activation method to optimize the mass transfer efficiency, accurate regulation and control of the pore structure are realized by adopting ultrasonic-electric field assisted treatment, and the structural stability of the catalyst is improved by adopting in-situ doping and post-loading composite modification. The catalyst provided by the invention is suitable for selective hydrogenation reactions of saccharides such as xylose hydrogenation for preparing xylitol, glucose hydrogenation for preparing sorbitol and the like.

The invention provides a ternary positive electrode material and a preparation method and application thereof, the ternary positive electrode material comprises a mixture of LiNi < x > Co < y > Mn < z > O < 2 > particles coated with LiF, LiF particles and MgO particles, x is greater than 0, y is greater than 0, z is greater than 0, and x + y + z = 1. According to the ternary positive electrode material provided by the invention, direct contact between the positive electrode material and an electrolyte can be reduced through LiF coating, side reaction is reduced, LiF particles and MgO particles can gradually release F <-> and Mg < 2 + > in the working process of a battery, and in-situ doping of a material bulk phase is realized to stabilize the structure, so that the cycling stability of the battery is effectively improved; in addition, the preparation method provided by the invention is simple and suitable for large-scale application.

The invention provides a TOPCon solar cell, a preparation method thereof and a photovoltaic module. The cell comprises an n-type silicon wafer, a tunneling oxide layer and a doped polycrystalline silicon layer, the tunneling oxide layer and the doped polycrystalline silicon layer are located on the back face of the silicon wafer, and the cell is characterized in that the concentration of the doped polycrystalline silicon layer is larger than 5E20, and the tunneling oxide layer is compact in intrinsic, complete in structure and free of pinhole defects. The preparation method comprises the following steps: depositing a tunneling oxide layer and an intrinsic polycrystalline silicon layer on the back surface of a silicon wafer by adopting an LPCVD (Low Pressure Chemical Vapor Deposition) mode; and performing in-situ doping on the intrinsic polycrystalline silicon layer by adopting a PECVD (Plasma Enhanced Chemical Vapor Deposition) mode to form a heavily doped amorphous silicon layer and an oxidation protection layer. According to the TOPCon solar cell, the uniform and compact tunneling oxide layer and the heavily-doped amorphous silicon layer can be obtained, excellent ohmic contact can be formed when the TOPCon solar cell and the metal electrode are sintered, the contact resistance is remarkably reduced, and the TOPCon solar cell has higher open-circuit voltage and FF.

This invention discloses a method for preparing a composite poly-Si thin film, comprising: depositing and growing an intrinsic poly-Si thin film on a single-crystal silicon substrate using a vertical double-layer hot-wire array thermal field design and a high-temperature hot-wire silane pyrolysis technique; and introducing trace amounts of NH3 or N2O gas to generate Si in situ. x N y or SiO x N y A quantum dot barrier layer is formed by introducing a doping source, PH3 or B2H6, for in-situ doping to obtain a doped source layer. The grown poly-Si thin film with the composite structure is then annealed using vacuum rapid annealing or laser annealing to activate the doping source and promote crystal growth. This process produces a poly-Si thin film with a composite structure of "intrinsic layer + barrier layer + doped layer," which improves carrier mobility and reduces parasitic absorption. This structure shows promising application prospects for developing photovoltaic cells and optoelectronic devices.