784 results about "Self assembled" patented technology

The invention discloses a self-assembled monomolecular layer material with an asymmetric intermediate core and a preparation method and application thereof, and belongs to the field of solar cells. The self-assembled monomolecular layer material is formed by combining an asymmetric intermediate core with anchoring groups such as phosphonic acid and sulfonic acid, has good hydrophobicity and high light transmittance, can be used as a hole transport layer material, and is used for preparing organic solar cells and perovskite solar cells with p-i-n structures, the organic solar cell achieves the maximum energy conversion efficiency of 18.9%, shows excellent environmental stability, still keeps 95% or above of the initial performance after being stored in air for 480 h, and is far superior to a traditional device based on a PEDOT: PSS interface layer. By designing and developing a series of self-assembled monomolecular layer materials with asymmetric intermediate cores, the energy conversion efficiency and environmental stability of the solar cell can be remarkably improved.

The invention belongs to the technical field of perovskite solar cells, and provides synthesis and application of a novel self-assembled monomolecular hole transport material with conjugated extended tail ends. According to the self-assembled monomolecular hole transport material, a carbazole group is used as a terminal core, an aromatic ring is introduced to the terminal of carbazole to extend a conjugated structure, an alkyl chain is used as a connecting unit, phosphoric acid or acetic acid is used as an anchoring group, and the self-assembled monomolecular hole transport material with conjugated extended terminal is formed. And the stability, the hole transport property, the hole extraction capability and the interface passivation capability of the material are improved. Experiments show that the self-assembled monomolecular hole transport material has an HOMO energy level matched with a perovskite layer, and hole transport is facilitated. When the self-assembled monomolecular hole transport material disclosed by the invention is applied to a trans-perovskite solar cell with a band gap of 1.53 eV, the photoelectric conversion efficiency as high as 26.11% is obtained, and excellent device stability is shown.

The invention discloses a preparation method of a rapidly-formed Janus structure stretchable electrode, an electrode material system is a material system composed of thermoplastic polyurethane (TPU), liquid metal particles and N, N-dimethylformamide (DMF), and electrode forming comprises two self-assembly processes. In the first self-assembly process, the liquid metal particles rapidly settle to form a Janus structure under the action of gravity; and a second self-assembly process: quickly dissolving DMF in water under the action of phase separation, and quickly separating out TPU to form a porous structure. The whole electrode forming process is about 15 seconds, which is the fastest stretchable electrode film forming process so far. The electrode has high conductivity, high stretchability and insensitivity to tensile strain, the electrode can spontaneously form a Janus structure with one conductive side and the other insulated side so as to achieve a self-protection structure for the whole electrode, and the electrode is expected to be applied to the flexible electronic fields of electronic skin, human body information detection, stretchable electronic devices and the like.

The invention belongs to the technical field of micro-nano processing, and particularly relates to a preparation method and application of a metal micro-nano tube array. Comprising the following steps: preparing a metal layer on the surface of a substrate; coining glue is sprayed on the surface of the metal layer, then coining is conducted through a template, and a micro glue column array is formed after curing; a plasma etching process is adopted, the micro glue column array is used as a mask, the metal layer exposed out of the gaps in the bottom of the micro glue column array is etched, and a structure with the micro glue columns wrapped by metal is formed; and removing the rubber columns in the structure of the metal-coated micro rubber columns to obtain the metal micro-nano tube array. According to the invention, a residual-layer-free imprinting technology is adopted, the problem of glue layer residue in traditional imprinting is avoided, and the etching uniformity is improved. A plasma dynamic balance process is adopted, the side wall redeposition effect of etching by-products is utilized, and the metal micro-nano tubes are formed in a self-assembly mode. The prepared metal micro-nano tube array has high aspect ratio compatibility, and the nano tube array with the aspect ratio as high as 10: 1 can be realized.

The invention discloses a modified hole transport layer and a preparation method thereof, a perovskite solar cell and a power utilization device, and belongs to the technical field of solar cells. The modified hole transport layer comprises a hole transport layer and a modified layer arranged on the surface of one side, far away from a substrate, of the hole transport layer; the material of the hole transport layer comprises a self-assembly single-layer material and an organic amine salt; and the material of the modified layer comprises organic amine salt. The organic amine salt is used as an additive to modify the self-assembled single-layer material to prepare the hole transport layer, and the organic amine salt is further used as a surface treating agent to modify the hole transport layer, so that the problems of distribution uniformity and surface wettability of the self-assembled single-layer material can be solved; the efficiency of the large-area perovskite assembly is effectively improved, and the large-area processing requirement is met.

Disclosed herein are methods for fabricating IC structures that include stacked vias providing electrical connectivity between metal lines of different layers of a metallization stack, as well as resulting IC structures. An example IC structure includes a first and a second metallization layers, including, respectively, a bottom metal line and a top metal line. The IC structure further includes a via that has a bottom via portion and a top via portion, where the top via portion is stacked over the bottom via portion (hence, the via may be referred to as a “stacked via”). The bottom via portion is coupled and self-aligned to the bottom electrically conductive line, while the top via portion is coupled and self-aligned to the top electrically conductive line. The bottom via portion is formed using selective growth, e.g., assisted by a self-assembled monolayer (SAM) material.

The invention discloses a perovskite solar cell, a preparation method thereof, a cell module and a laminated cell. The perovskite solar cell comprises a composite hole transport layer and a perovskite light absorption layer, the perovskite light absorption layer is located on one side of the composite hole transport layer, and the composite hole transport layer comprises polyvinyl acetate and an SAM material. Therefore, the polyvinyl acetate is of a cross-linked network structure and can play a role in stabilizing the SAM material and inhibiting the SAM material from diffusing to the perovskite light absorption layer, so that the stability of the self-assembled monomolecular layer is improved, and the stability of the perovskite solar cell is improved; in the perovskite solar cell, carbonyl oxygen in polyvinyl acetate can be coordinated with uncoordinated metal ions in the perovskite light absorption layer to realize passivation of a bottom interface of the perovskite light absorption layer, so that interface recombination is reduced, and the performance of the perovskite solar cell is improved.

The invention provides a self-assembled hypha flexible carbon electrode material and a preparation method and application thereof, and belongs to the technical field of battery packs. The preparation method of the self-assembled hypha flexible carbon electrode material comprises the following steps: treating basswood with white rot fungus mycelia, crushing and roasting to obtain porous basswood / hypha composite carbon powder; and putting the porous basswood / hypha composite carbon powder and a carbon nanotube into a sterilized conical flask containing a potato glucose culture solution, inoculating gloeophyllum trabeum, performing activation culture, adding a dopamine hydrochloride aqueous solution, performing polymerization after ultraviolet irradiation, taking out and tabletting to obtain the self-assembled hypha flexible carbon electrode material. In the preparation process of the self-assembled hypha flexible carbon electrode material, the flexible carbon electrode material is synthesized by taking porous basswood / hypha composite carbon powder as a matrix, taking gloeophyllum trabeum hypha as an adhesive, taking polydopamine as a reinforcing agent and adding carbon nanotubes as a conductive reinforcing material, so that the technical problem of poor cycle performance of a lithium ion battery is solved.

The invention discloses a preparation method of a perovskite battery and the perovskite battery, and the preparation method of the perovskite battery comprises the steps: providing a substrate which is provided with a first surface; a metal oxide layer is formed on the first surface through an atomic layer deposition technology, and raw materials of the atomic layer deposition technology comprise an organic metal source and a water source; preparing a self-assembled molecular layer on the metal oxide layer by adopting a spraying process; and forming a perovskite active layer, an electron transport layer and a first conductive layer which are arranged in a laminated manner on one side, away from the substrate, of the self-assembled molecular layer. The problem that the compactness of a subsequent self-assembled film layer is reduced due to the process for preparing a metal oxide film layer in the prior art is solved.

The invention belongs to the technical field of organic photoelectric materials, and particularly discloses a multifunctional organic semiconductor material with cyano phosphonic acid as an anchoring group and a preparation method and application of the multifunctional organic semiconductor material. The cyano group in the anchoring group can effectively increase the deprotonation capability of phosphonic acid and enhance the hydrophilicity of the anchoring group, so that the material has unique amphiphilic characteristics and shows good wettability, and further, the high-quality perovskite thin film is obtained. Meanwhile, F atoms in the arylamine enhance the interface interaction between the hole transport layer and the perovskite layer, thereby further regulating the crystallization of the perovskite, passivating the bottom interface defect of the perovskite, and inhibiting the non-radiative recombination of the interface. The organic semiconductor material is highly conjugated in molecules and good in photo-thermal stability. When the hole transport layer is applied to a trans-perovskite solar cell, the photoelectric conversion efficiency of more than 24.5% can be obtained, and the hole transport layer shows a good industrial application prospect.

The invention relates to the technical field of new energy, in particular to an extensible composite hole transport layer and a perovskite solar cell based on the extensible composite hole transport layer, and a preparation method of the perovskite solar cell comprises the following steps: forming a nickel oxide film on transparent conductive glass through magnetron sputtering; soaking the nickel oxide thin film to form a self-assembled monomolecular layer; forming a perovskite active layer on the self-assembled monomolecular layer; forming an electron transport layer on the perovskite active layer; and forming an electrode on the electron transport layer. According to the method, the preparation size of the hole transport layer can be expanded, and the photoelectric conversion efficiency of the perovskite solar cell can be improved.

The embodiment of the invention provides a perovskite solar cell, a preparation method thereof, a photovoltaic module and a photovoltaic system, and relates to the technical field of perovskite solar cells. The perovskite solar cell comprises a self-assembly single layer, an interface modification layer and a perovskite light absorption layer which are stacked in sequence, the material of the interface modification layer comprises acetophenone oxime. The acetophenone oxime interface modification layer is introduced between the self-assembly monolayer and the perovskite light absorption layer, and groups such as carboxyl in acetophenone oxime interact with each other, so that the problem of poor wettability of the self-assembly monolayer caused by an SAM molecular material can be improved, the phenomenon of uneven coverage of a perovskite film can be effectively relieved, and the perovskite light absorption performance is improved. According to the perovskite solar cell provided by the invention, a compact perovskite light absorption layer with high crystal quality can be conveniently formed, and unsaturated N atoms in the oximido group can passivate defects at the interface of the perovskite light absorption layer and the self-assembly single layer and can be coordinated with free Pb < + >, so that the short-circuit current density, the open-circuit voltage and the photoelectric conversion efficiency of the perovskite solar cell are improved.

The invention discloses a modified thermal insulation coating and a preparation method and application thereof, and belongs to the field of building energy-saving materials. One modified compound is a thermo-sensitive polyelectrolyte layer-by-layer self-assembled alumina microsphere formed by alternately depositing polyethyleneimine and polyacrylic acid through electrostatic interaction, and the polyelectrolyte layer can dynamically swell or shrink along with the temperature to adjust the heat conductivity coefficient; and the other is magnesium silicate nanofiber coated with silicon dioxide and then grafted with fluorosilane, the hydrophobicity is improved by utilizing the low surface energy of the fluorosilane, and meanwhile, the binding force with a polymer interface is enhanced. The coating further comprises fumed silica, a dispersing agent, a defoaming agent and other auxiliaries. The preparation method comprises the following steps: sequentially adding the components into a high-speed dispersion machine, mixing, adjusting the viscosity, filtering and packaging. The coating has the advantages of intelligent temperature-sensitive adjustment, low heat conductivity, strong adhesion and weather resistance; the material is suitable for long-acting heat preservation in the fields of buildings, industrial equipment and cold chains.

The invention discloses a preparation method of a perovskite active layer, a perovskite battery and a perovskite material, and belongs to the technical field of perovskite batteries. According to the invention, bisphosphonate is added when the perovskite active layer is prepared, and the bisphosphonate is obtained by carrying out a deprotonation reaction on 1-aminodecane-1, 1-diphosphonic acid and methylamine, formamidine iodine or cesium carbonate. The bisphosphonate can be anchored on the surface of the substrate and form a self-assembled monomolecular structure, a simple and effective coating process is realized, the bisphosphonate structure of the bisphosphonate is beneficial to anchoring on the substrate, the possibility and effectiveness of anchoring the substrate are increased, the combination of the perovskite active layer and the substrate is enhanced, the formation of nano-pores is reduced, and the photoelectric conversion efficiency is improved. In addition, the introduced cations MA < + >, FA < + > and Cs < + > not only can enhance the self-assembly capability of the bisphosphonate, but also can be used as nucleating agents to promote the growth of perovskite crystals and improve the quality of the perovskite crystals.

The invention discloses a preparation method and application of circumferentially limited supercritical foaming self-packaging TENG, and the preparation method comprises the following steps: uniformly mixing a PDMS precursor and a curing agent, pouring the mixture into a mold, and putting the mold into a vacuum oven for curing to obtain a PDMS film; adhering the PDMS film to the middle position of the PI film through a double-sided nickel conductive adhesive tape, then putting the PDMS film into a mold, putting a thermoplastic elastomer on the upper layer, and performing hot pressing by using a vacuum auxiliary hot press to obtain a prefabricated sample; putting the prefabricated sample into a supercritical foaming reaction kettle, controlling the temperature to 70-130 DEG C, injecting supercritical fluid into the foaming reaction kettle, after the prefabricated sample and the supercritical fluid form a saturated and stable blending system, maintaining for 0.8-1.5 hours, taking out the blended system, and naturally cooling to room temperature, so as to obtain the TENG. The preparation method has the beneficial effects that the self-assembled and self-packaged TENG with the bionic dome structure is successfully prepared through cooperation of a supercritical fluid technology and a limited foaming strategy, and the technical scheme of the self-assembled and self-packaged TENG obtains breakthrough progress in the aspects of the preparation process, the structural design and the environmental adaptability.

The present invention provides a carbon-based iron-nitrogen composite material, a preparation method and application thereof, and a lithium-ion battery. The preparation method uses nitrogen-containing ligands and ferrous salts as raw materials, generates an iron-containing complex through a self-assembly reaction between the two, and then dries and calcines the iron-containing complex to obtain a carbon-based iron-nitrogen composite material. The carbon-based iron-nitrogen composite material obtained by calcining the iron-containing complex prepared by the preparation method includes carbon, Fe 3 C.Fe 3 A material with multiple components such as N and Fe, and having a layered structure and a hollow tubular particle structure attached to the surface of the layered structure. The carbon-based iron-nitrogen composite material having the above components and the layered structure and the hollow tubular structure is used in lithium-ion batteries, which can make lithium ions migrate more easily therein, thereby effectively improving the gram capacity and stability of lithium-ion batteries, and enabling lithium-ion batteries to be used for a long period of time. The nitrogen-containing ligand has a structure shown in formula (I). #imgabs0#

The invention belongs to the field of solar cells, and particularly relates to a hole transport layer, a perovskite solar cell, a preparation method and application. The hole transport layer sequentially comprises a NiOx layer and a self-assembly monomolecular layer from the thickness direction; the self-assembled monomolecular layer comprises a self-assembled monomolecular layer material and 1-hydroxypyrazole. The prepared perovskite solar cell is excellent in photovoltaic performance, and the preparation process is simple.

The invention provides a trans-perovskite solar cell containing a fluorine arene phosphoric acid function compensation layer and a preparation method thereof, and the solar cell comprises a conductive substrate, a hole transport layer, a self-assembly monomolecular layer, a function compensation layer, a light active layer, an electron transport layer, a hole blocking layer and a back electrode which are sequentially stacked from bottom to top. The material of the function compensation layer is fluorine-containing aromatic hydrocarbon phosphoric acid. The fluorine-containing aromatic phosphoric acid provided by the invention can make up the anchoring defect on the basis of a self-assembled monomolecular layer, and can effectively passivate the defect at the bottom of perovskite through a plurality of active sites at the same time; the problem of non-ideal performance and stability caused by excessive defects at the self-assembled monomolecular layer / perovskite buried bottom interface of the trans-perovskite solar cell is solved, and a valuable scheme is provided for commercialization of the trans-perovskite solar cell in the future.

The invention relates to a high-throughput screening method and system for a self-assembled single-layer thermal interface material and a medium. The high-throughput screening method comprises the following steps: constructing an interface heat transport simulation system based on a self-assembled monomolecular layer; screening set preparation is carried out on the end group structure, and an end group screening set and a pre-calculation set are constructed; carrying out molecular dynamics simulation on the self-assembled monomolecular layer corresponding to the pre-calculation set to obtain a physical association index; training a machine learning model by taking the physical association index as a machine learning objective function; carrying out machine learning prediction on the uncalculated screening candidate data set based on the trained machine learning model, and carrying out parallel screening of physical association indexes to obtain a simulation verification set; and carrying out molecular dynamics simulation for verification. Compared with the prior art, high-throughput screening of the self-assembled single-layer thermal interface material is achieved, and the method has important significance on solid-liquid interface heat conduction characteristic regulation and control design under data driving.

The invention discloses a method for preparing a silicon-carbon composite negative electrode material through an electrostatic self-assembly technology, and belongs to the technical field of lithium ion battery negative electrode materials. According to the invention, lignin is used as a biomass carbon source and lauryl sodium sulfate (SDS) and poly (diallyldimethylammonium chloride) (PDDA) are used as activators through a simple electrostatic self-assembly technology; a proper amount of nano silicon and PDDA are subjected to in-situ adsorption, and lignin and SDS are subjected to in-situ adsorption; a self-assembly process is carried out through the positive and negative charge attraction effect among colloidal particles, so that effective compounding of the nano silicon particles and the biomass carbon is realized; and performing vacuum drying, and performing one-stage sintering in a tubular furnace to obtain the silicon-carbon composite negative electrode material. Based on the problems of non-uniform particle size, easy agglomeration and great abrasion of a silicon-carbon composite material in a traditional mechanical synthesis technology, the invention improves the compounding efficiency of the silicon-carbon material and improves the problems of volume expansion of a silicon negative electrode, slow migration rate of lithium ions, poor cycle performance and the like.

The invention relates to a perovskite cell with a self-assembly monomolecular layer and a preparation method, and a perovskite assembly with the self-assembly monomolecular layer is suitable for being arranged on an external substrate, and comprises a transparent conductive layer, a hole transport layer, a perovskite active layer, an electron transport layer, a hole barrier layer, a back electrode and the self-assembly monomolecular layer. Wherein the self-assembled monomolecular layer is arranged between the hole transport layer and the perovskite active layer, a solution of a precursor of the self-assembled monomolecular layer comprises phosphorylcholine chloride and Me-4PACz, and a solvent of the precursor of the self-assembled monomolecular layer is a mixed solvent of ethanol and isopropanol; according to the invention, the phosphorylcholine chloride and the Me-4PACz are introduced, so that the interface performance, the photoelectric conversion efficiency and the long-term stability of the perovskite cell are remarkably optimized.

The invention relates to a hole transport layer material for an inverted perovskite solar cell, the inverted perovskite solar cell and application, the hole transport layer material is a self-assembled monomolecular layer hole transport material, and the self-assembled monomolecular layer hole transport material comprises an organic compound with the following general formula: # imgabs0 #, r1 and R2 represent independently substituted C6-C15 aryl groups, and the substituent group is a methoxy group or a methylthio group; according to the inverted perovskite cell, holes of the hole transport layer can be reduced, the film forming quality can be improved, and the defects of the lower interface of the perovskite photosensitive layer can be passivated, so that the open-circuit voltage (Voc) and the fill factor (FF) of the inverted perovskite cell are effectively improved, and the photoelectric conversion efficiency of the perovskite cell is effectively improved; and the photoelectric conversion efficiency of the perovskite solar cell is optimal.

The invention discloses an electrode assembly and a preparation method thereof, a self-assembled solid-state battery and a preparation method thereof, and an electric device. The method for preparing the electrode assembly comprises the following steps: (1) preparing a composite solid electrolyte material: the composite solid electrolyte material comprises an inorganic material, a thermoplastic elastomer and a lithium salt, the inorganic material comprises an inorganic ceramic material and / or an inorganic solid electrolyte, and the composite solid electrolyte material is obtained by dry mixing; and (2) applying the composite solid electrolyte material between a pole piece and a release layer for hot pressing so as to obtain the electrode assembly. By adopting the method, the electrode assembly which is good in solid-solid interface contact, high in ionic conductivity, excellent in thermal stability, uniform and compact in solid electrolyte layer thickness, smooth in surface and free of pores can be prepared, and the interface problem in the solid-state battery assembling process is effectively solved; and meanwhile, a flexible solid-state battery interface can be constructed through one-step hot press molding, the interface impedance is reduced, and batch production of the electrode assembly is realized.

The invention discloses a repeatedly-granulated silicon-carbon material with a self-assembled conductive structure as well as a preparation method and application thereof, and belongs to the technical field of lithium ion battery materials. The preparation method comprises the following steps: mixing the carbon source with the softening point of 150-200 DEG C and the nano silicon powder in a mixer to obtain a uniformly mixed material; adding the mixture into a high-temperature coating machine for primary sintering, and sieving by a mesh sieve to obtain submicron-scale primary granulation silicon-carbon precursor microspheres; placing the silicon-carbon precursor microspheres subjected to primary granulation, a carburant, graphene oxide, cryptocrystalline graphite and graphite with D50 of 9-12 [mu] m in a mixer for uniform mixing, and adding the materials into a high-temperature coating machine for secondary sintering. The invention develops the multi-granulation silicon-carbon material with the self-assembled conductive structure, which has the advantages of high safety in the production process, high first coulombic efficiency, slow long-cycle attenuation and excellent long-cycle stability and rate capability, the overall expansion rate of the material is relieved, and the electron / ion conductivity of the material is improved.

The invention discloses aramid nanofiber insulation paper with a self-assembled layered structure and a preparation method thereof.The preparation method comprises the steps that firstly, a modified basalt filler with ZIF-8 on the surface is prepared through a surface in-situ growth method, and then stably existing modified basalt fiber / aramid nanofiber dispersion liquid is obtained through an in-situ coating method; and finally, carrying out vacuum filtration to form the modified basalt / aramid nanofiber insulation paper with the self-assembled layered structure. The obtained insulation paper has low thermal conductivity, high breakdown strength, excellent mechanical properties and electrical insulating properties, can be used in the fields of electronic thermal management, buildings and the like, and has extremely high use value.

The invention relates to the technical field of functional materials, in particular to a metal-DNA aptamer self-assembled nano material as well as a preparation method and application thereof. The metal-DNA aptamer self-assembled nano material comprises two DNA aptamers, a copper source and ascorbic acid, wherein the two DNA aptamers are used for modifying an azide group and an alkynyl group respectively; and copper is coordinated with a five-membered ring formed by a reaction through a copper-catalyzed azide-alkynyl cycloaddition reaction, so that the Cu-DNA aptamer self-assembled nano material is obtained. The problem that an existing metal-DNA self-assembly nanometer material cannot stably exist in a physiological environment is solved, and meanwhile, the application of the metal-DNA self-assembly nanometer material in chemokinetic tumor treatment is achieved by precisely recognizing tumor cells in a targeted mode.

The invention discloses a three-dimensional porous graphene / ferric oxide electromagnetic shielding composite film and a preparation method thereof, and belongs to the technical field of functional composite materials. In order to reduce or eliminate electromagnetic radiation, the three-dimensional porous rGO / Fe3O4 composite material is prepared by taking nano Fe3O4 and GO as raw materials and adopting a graphene oxide reduction self-assembly nanoparticle capturing method. The porous 3D rGO / Fe3O4 composite electromagnetic shielding material is obtained by mixing a dispersing agent and Fe3O4, adding the mixture into a graphene oxide dispersion liquid and capturing nano Fe3O4 through a graphene oxide reduction self-assembly process. Drying the 3D rGO / Fe3O4, and then mixing the 3D rGO / Fe3O4 with waterborne polyurethane to prepare an rGO / Fe3O4 / waterborne polyurethane composite coating; and coating the slurry on a base material to prepare the rGO / Fe3O4 electromagnetic shielding film. The preparation process is simple and easy to control, and raw materials are low in cost, easy to obtain and environmentally friendly; the graphene-based composite electromagnetic shielding material which is light in weight, high in strength, good in stability, good in flexibility and high in electromagnetic shielding efficiency can be prepared at present.

The invention discloses a hole transport layer, a preparation method thereof and a solar cell. The hole transport layer comprises an SAM (single self-assembled monomolecular layer) material and a buried material, and the buried material comprises F-type phosphate group-containing molecules. According to the invention, the technical problems of poor coverage of a hole transport material SAM on a transparent conductive oxide (TCO) substrate and weak transmission capability in a perovskite cell or a laminated cell in the prior art can be solved. The hole transport layer is more uniform, the interface transmission loss is smaller, and the filling factor and the conversion efficiency are remarkably improved when the hole transport layer is used for the solar cell.

Method to form low-contact-resistance contacts to source / drain features are provided. A method of the present disclosure includes receiving a workpiece including an opening that exposes a surface of an n-type source / drain feature and a surface of a p-type source / drain feature, selectively depositing a first silicide layer on the surface of the p-type source / drain feature while the surface of the n-type source / drain feature is substantially free of the first silicide layer, depositing a metal layer on the first silicide layer and the surface of the n-type source / drain feature, and depositing a second silicide layer over the metal layer. The selectively depositing includes passivating the surface of the surface of the n-type source / drain features with a self-assembly layer, selectively depositing the first silicide layer on the surface of the p-type source / drain feature, and removing the self-assembly layer.

The present invention relates to a photovoltaic crystalline silicon waste treatment technology, and in particular to a method for preparing a carbon-coated porous silicon-based lithium battery negative electrode material from photovoltaic crystalline silicon waste, comprising the following steps: 1) reducing the size of the photovoltaic crystalline silicon waste to a submicron level; 2) dissolving the treated photovoltaic crystalline silicon waste in a CH3CH2OH solution of NaOH, filtering, washing, drying, sintering and oxidizing the product, and finally etching it with a NaOH solution at room temperature to obtain porous silicon particles; 3) mixing the obtained porous silicon particles and CaCO3 in deionized water, ultrasonically dispersing to obtain a self-assembled porous silicon-CaCO3 particle precursor, centrifuging and washing to complete solid-liquid separation, and pyrolyzing the precursor with citric acid as a carbon source under an inert gas atmosphere to obtain the carbon-coated porous silicon-based lithium battery negative electrode material. The method of the present invention can not only effectively utilize the crystalline silicon waste generated in a silicon wafer cutting process, but also reduce the cost of preparing the silicon negative electrode material. At the same time, the design of the porous carbon coating structure also solves the problem of insufficient stability of the silicon-based lithium battery negative electrode material.