Technology for production of metallic nanolayers on silver electric contacts of silicon solar cells using chemical method
FIELD: material engineering.
SUBSTANCE: method of application of metallic nanolayers in chemical method involves the technology of chemical sedimentation of metals, in particular of copper (Cu) at the speed 1 μm/min with the solution temperature 50 to 60°C. As the basic copper-containing reagent for applying metallic nanolayers on silver electric contacts of silicon solar cells the inorganic copper salts are used. Technical result of the invention is the thickening of frontal electric contact of solar cell by sedimentation of metals, in particular copper, with good electric conductivity, in order to compensate or improve its increased electric conductivity.
EFFECT: increased effectiveness of solar cell operation during transformation of high-density radiation and decreased self-cost of its manufacturing.
4 cl, 4 dwg
The invention relates to the coating of metal nanolayers by a chemical process, in particular on the silver electrical contacts of silicon solar cells.
The closest analogue of the present invention is an invention relating to a method of coating by chemical means for coating the product is suitable for forming a conductive film on the end faces of the metal or semiconductor (EN 2225460).
The disadvantage of this invention is the lack of selective deposition of metal from the chemical solution on the specific metal product.
The proposed method of applying metallic nanolayers chemical method consists in the use of technology chemical precipitation of metals, in particular copper (Cu), with a speed of 1 μm/min when the temperature of the solution from 50 to 60°C.
As the original copper-containing reagent for applying metallic nanolayers on silver electrical contacts of silicon solar cells used inorganic salts of copper.
The object of the invention is used, a solar cell based on crystalline silicon Si<P>/SiNx(70 nm)/Si<B> aluminum contact on the back plate and the front silver contact. Figure 1 shows the position of the desired silver contacts n the front surface of the silicon wafer.
On the exposed side of the silicon wafer has a front electrical contact of silver in the form of a lattice, which is made porous due to technical and economic requirements. The width of the individual strips is 120 μm, a height of 30 μm.
The efficiency of a solar cell can be increased by reducing the width of the contact strips to 50 μm and to increase its conductivity by filling the pores of the silver and the increase in thickness due to the cheap metal. Thus there is a need to improve the front contacts in current industrial standard technologies for the manufacturing of solar cells.
According to the existing technology manufacturing silver contact is made by applying silver paste on the surface of a silicon plate by punching through the metal mask. The height of the contact strips is 30 μm, the width of 120-140 microns. Next, the paste is dried with hot air for 1 minute Then the plate goes on the conveyor belt furnace annealing.
The burn paste in antirefleksionnoe SiN layer ARC is produced at temperatures 840-980°C. At the same time there is combustion of the organic components of the original paste and the formation of porous structure of the silver strips (2, 3). The deposition of copper on the silver should occur after the stage of annealing.
Technical the cue the invention - seal front electrical contact of the solar cell deposition of metal, in particular copper (Cu), good electrical conductivity to its high electrical resistance was compensated or superior.
It is proposed to fill the pores of the silver electrical contact with the metal particles and build up on its surface a layer of dense metal with a thickness of 5 microns.
Method of applying metal nanolayers on silver electrical contacts of silicon solar cells by chemical means according to the invention can be made as follows:
(1) industrial solar cell consisting of polycrystalline plates of a thickness exceeding 100 μm, immersed in a glass cuvette with a volume of 1 liter in solutions of inorganic salts of copper at 60°C;
(2) as chemical solutions are used, the following inorganic salts of copper:
- copper sulfate CuSO45H2O brand CHP;
the copper nitrate Cu(NO3)25H2O brand CHP;
- copper chloride CuCl25H2O brand CHP;
(3) coating silver electrical contact with the copper in the solution of nitrate of copper appears after 1 minute after immersion in it industrial solar cell. The coating thickness depends on the concentration of the solution. The most prominent color of the coating can be the concentration of salt 2.0 g of salt Cu/100 ml H 2O.
(4) the deposition of metal (Cu) occurs only on the silver pin stripes, this prevents the deposition of metal on the surface of the antireflective layer of a silicon wafer, its reverse side and edges (figure 4).
The use of this technology allows to ensure the implementation of the nanoparticles of metal (Cu) in the micropores front electric silver contact silicon solar cells, which in turn reduces the electrical resistance of the front contact on the serial solar cells.
In addition, the application of this technology provides the following features:
- high stability of the solutions on the chemical composition, the ease of dosing and correction of concentrations, low technological maintenance costs baths deposition;
- no increase in width of the contact strips over 50%;
- no reduction of the contact resistance and adhesion of the contact;
- no harmful to human health cyanide solutions and organic solvents.
The use of cheap reagents for the deposition of metal, giving the opportunity to reduce the cost of manufactured industrial solar cells, meets the following conditions:
- temperature deposition of metal does not exceed 50-60°C;
the deposition rate of the metal with the hat 1 μm/min;
the deposition can be made from aqueous solutions
Scientific and technical aspects of the developed method consists in minimizing the impact of working solutions on the environment and their compatibility with existing manufacturing technology industrial solar cells.
1. Method of applying metal nanolayers chemical method, characterized in that for the deposition of metal on the surface of the silver contact industrial solar cell as chemical solutions used inorganic salts of copper.
2. The method according to claim 1, characterized in that the temperature of deposition of the metal (copper) from the chemical solution of inorganic salts of copper is in the range from 50 to 60°C.
3. The method according to claim 1, characterized in that the deposition rate of the metal (copper) from the chemical solution of inorganic salts of copper is 1 μm/min
4. The method according to claim 1, characterized in that the deposition of metal (copper) from the chemical solution of inorganic salts of copper occurs only on the silver contact strips industrial solar cell, this prevents the deposition of metal on the surface of the antireflective layer of a silicon wafer, its reverse side and edges.
SUBSTANCE: in the method to manufacture Cu-Ge ohmic contact on the surface of the plate n-GaAs or epitaxial heterostructure GaAs with n-layer a resistive mask is developed, fims of Ge and Cu are deposited, the first thermal treatment is carried out in the atmosphere of atomic hydrogen at the temperature from 20 to 150°C and density of hydrogen atoms flow to the surface of the plate equal to 1013-1016 at.cm-2 s-1. Plates are withdrawn from a vacuum chamber of a spraying plant, the resistive mask is removed before or after the first thermal treatment, and the second thermal treatment is carried out.
EFFECT: reduced value of the given contact resistance.
7 cl, 1 dwg
SUBSTANCE: method to metallise elements in products of electronic engineering includes application of a sublayer of a metallising coating on one of substrate surfaces with previously formed topology of elements in an appropriate product, and this sublayer is a system of metals with the specified thickness, providing for adhesion of the main layer of the metallising coating, formation of topology - protective photoresistive mask of the main layer of metallising coating, local application of the main layer of the metallising coating, removal of protective mask, removal of a part of the sublayer arranged outside the topology of the main layer of the metallising coating. Application of the sublayer of the metallising coating is carried out with the total thickness of 0.1-0.5 mcm, directly onto the specified sublayer additionally a technological layer is applied from an easily oxidable metal with thickness of 0.1-0.5 mcm, and formation of the metallising coating topology is carried out on the technological layer from the easily oxidable metal. Prior to local application of the main layer of the metallising coating a part of the technological layer is removed from the easily oxidable metal via the specified protective mask, and removal of the remaining part of the technological layer from the easily oxidable metal is carried out prior to removal of a part of the sublayer of the metallising coating arranged outside the topology of the main layer of the metallising coating.
EFFECT: increased quality of the metallising coating and reliability of electronic engineering products, improved electrical characteristics, increased yield of good products.
6 cl, 3 dwg, 1 tbl
SUBSTANCE: proposed method comprises pre-cleaning of GaSb p-junction conductance by ion-plasma etching to depth of 5-30 nm with subsequent deposition by magnetron sputtering of adhesion titanium 5-30 nm-thick layer and platinum 20-100 nm-thick barrier layer, evaporating thermally of 50-5000 nm-thick silver layer and 30-200nm-thick gold layer for contact with ambient medium.
EFFECT: reproducible ohmic contact with low specific junction resistance.
2 cl, 1 dwg
SUBSTANCE: method of depositing platinum layers onto a substrate involves pre-formation of an intermediate adhesion layer from a mixture of platinum and silicon dioxide nanocrystals on a silicon oxide and/or nitride surface. The intermediate adhesion layer with thickness 1-30 nm can be formed via simultaneous magnetron sputtering using magnetrons with platinum and silicon dioxide targets, respectively.
EFFECT: high quality of elements, processes, reliability during prolonged use, adhesion of the deposited layers to the substrate.
8 cl, 3 dwg
SUBSTANCE: method of making an ohmic contact to GaAs based on thin Ge and Cu films involves formation a mask on the surface of an n-GaAs wafer in order to perform lift-off lithography, deposition of thin Ge and Cu films onto the surface of the n-GaAs wafer, first thermal treatment in a single vacuum cycle with the deposition process, removing the n-GaAs wafer from the vacuum chamber, removing the mask and second thermal treatment. First thermal treatment is carried out in an atmosphere of atomic hydrogen at temperature 150-460°C and hydrogen atom flux density on the surface of the n-GaAs wafer equal to 1013-1016 at.cm2 s-1.
EFFECT: low value of the reduced contact resistance of the ohomic contacts made.
4 cl, 1 dwg
SUBSTANCE: method of making interconnections of a semiconductor device involves formation of a silicon structure in an insulating layer, in which semiconductor devices are formed, contact wells and trenches under future interconnection conductors, successive deposition of an adhesive-wetting layer and a solid catalyst layer at the bottom and wall of the contact wells and trenches, filling the depressions of contact wells and trenches with carbonaceous material through stimulated plasma chemical deposition of the carbon structure from the gas phase on the solid catalyst layer and planarisation of the surface of the silicon structure.
EFFECT: high thermal stability and reduced heating of IC interconnections in conditions of reduction of their cross-sectional area and high current density, low resistivity of the interconnection material compared to carbon nanotubes.
3 cl, 3 dwg
SUBSTANCE: in manufacturing method of multi-level copper metallisation of VLSIC, which involves application operations of metal and dielectric layers, photolithography and selective etching of those layers, chemical mechanical polishing of dielectric layers, to plate of silicium, which is coated with dielectric material with vertical conductors of underlying structure, which protrude on its surface, there applied is multi-layered conducting film consisting of adhesive barrier, etched and auxiliary layers; grooves are formed in auxiliary layer before etched layers by electrochemical method; copper horizontal conductors are grown inside grooves in open sections of etched layer till grooves are fully filled; the second auxiliary layer is applied to surface of plate, and in that layer holes are made to the surface of horizontal copper conductors; vertical copper conductors are grown by electrochemical method in open sections of horizontal conductors till holes for vertical conductors are fully filled; then, auxiliary layers are removed; conducting layers between horizontal copper conductors are removed; dielectric layers are applied to surface of the plate by smoothing and filling methods, and then dielectric material layers are removed above vertical conductors by means of chemical and mechanical polishing method.
EFFECT: improving quality of copper conductors.
16 cl, 11 dwg, 1 tbl
SUBSTANCE: method of forming contact drawing from nickel on silicon wafers involves formation of a dielectric film with windows, chemical deposition of nickel in said windows and formation of a nickel silicide interlayer from the gas phase during thermal decomposition of nickel tetracarbonyl vapour at temperature 200-300°C, pressure in the system of (1-10)-10-1 mm Hg and rate of supplying nickel tetracarbonyl vapour equal to 0.5-2 ml/min per dm2 of the covering surface. The nickel layer is then removed up to the nickel silicide layer through chemical etching and nickel is deposited via chemical deposition onto the nickel silicide interlayer in the window of the dielectric film.
EFFECT: invention enables formation of a transparent contact for an electroconductive layer based on nickel with low ohmic resistance, independent of the type of conductivity and degree of doping of the silicon surface.
1 ex, 1 tbl
SUBSTANCE: in the method of making a multilayer ohmic contact to n-GaAs, involving creation of a double-layer photoresist mask on the surface of a wafer, layerwise deposition of films based on Ge and Au with film thickness corresponding to eutectic composition, and common thickness of 50-300 nm, deposition of Ni-based films with thickness of 10-100 nm, diffusion barrier films with thickness of 10-200 nm, and a top Au film having thickness of 10-1000 nm, removal of the double-layer photoresist mask and thermal treatment of the contacts in an inert atmosphere, deposition of Ge, Au, Ni and Au films onto the a GaAs surface is performed with flight angle of atoms of these materials relative the normal to the surface of the wafer lying in the range of 0-2°, and deposition of a diffusion barrier film based on Ti, Ta, W, Cr, Pt, Pd, TiW, TIN, TaN or WN is performed with flight angle atoms β=n×α, where α is flight angle of Ge, Au, Ni atoms, n=2-10. Thermal treatment is carried out for 1-30 minutes or in a fast thermal annealing device for 30-300 seconds.
EFFECT: low value of reduced contact resistance of the multilayer ohmic contacts.
2 cl, 6 dwg
SUBSTANCE: method involves notching in bulk of a silicon wafer and silicone removing from the wafer back to uncover notch bottoms. Notching enables silicone pattern formation to represent hollow cell walls that is followed with wall-through oxidation to form a dielectric SiO2 conduit system. Silicon removing from the back of the wafer can be conducted by the deep plasma etch process.
EFFECT: high strength of the insulating element which can be used for manufacturing various MEMS devices in bulk of a standard silicon wafer.
2 cl, 13 dwg
SUBSTANCE: probe for locally enhanced spectrums of surface-enhanced Raman scattering the carbon nanotube alloyed with cerium atoms.
EFFECT: increased spatial resolution in the zone of location of studied object.
1 dwg, 3 dwg
SUBSTANCE: the invention relates to chemistry, in particular, to growing crystals from gas-vapour phase. The method includes low-temperature processing of fullerene powder C60 in the dynamic vacuum of 10-4 Pa at the temperature of 720 K for three hours, then the processed powder is sublimated in the dynamic vacuum of 10-4 Pa at the temperature of 880 K for 8 hours, initial fullerene crystals C60 are grown from the sublimated powder in sealed quartz vessels at the temperature of 880 K and the temperature difference between the evporation zone and the growth zone of 5 K during 1-5 days. The final fullerene crystals C60 are grown from the initial crystals in conditions similar to the growth conditions for initial crystals.
EFFECT: production of fullerene crystals C60 with high structural perfection, relatively large size (4-8 mm length, 3-4 mm width and 1-2 mm thickness) almost without contaminants.
3 dwg, 1 ex
SUBSTANCE: the invention relates to nanotechnology and nanostructures, in particular, to methods of deposition of thin films on a metal plate. Ultra-high vacuum is created in a vacuum chamber, MgO particles are deposited on the metal plate and then they are heated. The evaporable particles of MgO are deposited. They are formed after MgO powder applied to the tungsten spiral is heated up to 2500-2700 C°. The plate is the atom-free surface of the metal crystal oriented in such a way so it will facilitate the MgO (111) film formation.
EFFECT: production of oriented MgO (111) film on a clean metal plate.
FIELD: nanoindustry and chemical industry.
SUBSTANCE: invention refers to nanoindustry and chemical industry and can be used in the course of production of copper oxide nanopowders. The way to get nanosized particles of copper oxide is based on the use of copper salt that is represented by the cupric salt of N,N'-dinitrourea with the use of a solvent. The mentioned copper salt undergoes direct interaction with the spirit represented by dimethyl sulfoxide or dimethyl formamide. The obtained solution is heated at the temperature of 110 - 150°C within 1 - 6 h, and from the obtained suspension the copper oxide powder is extracted.
EFFECT: getting of a high quality target product with good purity, homogeneity and dispersiveness characteristics with the considerable improvement of processibility and ecological compatibility of the process.
1 dwg, 4 dwg, 6 ex
SUBSTANCE: invention refers to nanotechnology. Carbon nanotubes are produced. As a carbon-bearing substance antracite, crozzling coal, shungite, coak, charcoal or their mixture is used. The carbon-bearing substance is powdered with the particle size of 150-1,000 nm in mill1. Then the obtained powder is mixed in forehearth 2 with the flow of neutral gas that has a temperature within the range from 275 to 750 K and the pressure within the range from 0.15 to 0.8 MPa. The obtained two-phase mixture passes through nozzles 5. The two-phase flow that was formed after interaction of the colliding currents is separated in separator 7, filtered in filter 8. The carbon nanotubes collected in the collector are classified according to their size and fraction.
EFFECT: reduction of the prime cost with the same high quality of carbon nanotubes.
FIELD: milling technologies.
SUBSTANCE: invention relates to the technology of the mineral shungite milling to the effect of receiving of nanosized particles used as an active filler in production of elastomeric compounds; the mineral shungite is taken as a basic sample with the size of microparticles of 0÷100 micron, grinding is executed in the planetary ball mill loading into the grinding bowl the basic components in the proportion from 1.5:1:1.5 to 2.5:1:3 by volume: basic shungite - branched spirit - milling balls with the diameter 0.5÷5 mm; the milling processes is performed with adding of the branched spirits with the number of the carbon atoms not more than eight, at that the (OH) group is located not at the outmost carbon atom; the temperature of the basic mixture does not exceed 150°C and the milling process is executed in the grinding bowl located on the planetary disc of the planetary ball mill at the speed of 100÷700 revolutions per minute reversing rotation every 5÷10 minutes within up to 6 hours of the nonstop milling process; the grinding bowl is revolving about its axis but in the opposite direction relatively the rotation of the planetary disc securing the multiple increase of the milling energy and smaller particles sizes thereby; after milling the shungite to the size of particles within the limits of 5÷50 nm the substance is dried in the drying box during 0.5÷6 hours at the temperature of about 80÷250°C and thereafter the milled mineral is packaged into airtight containers.
EFFECT: application of this method allows to provide the elastomeric compounds incorporating shungite as the active component with high mechanical and operation characteristics.
5 cl, 3 dwg, 2 tbl
SUBSTANCE: invention relates to the photolithography and can be applied to microelectronics; the essence of the invention is as follows: the method of production of the topological image in the chrome film includes the following stages: coating of the roentgen amorphous chrome film by means of vacuum dispersion in the vacuum chamber via the electron-optical method or the method of magnetron deposition, formation of the layer of the photoresist, exposure of photoplates, chemical etching, ion-beam processing of the roentgen amorphous chrome film in the vacuum chamber filled in with a gas mixture using the Kauffman source as the ion beam, removal of the remainder of the photoresist mask, chemical etching of the chrome film in the ceric etch with application of sulphuric acid, at that roentgen amorphous chrome film is applied with the range of thickness from 150 nm to 500 nm, the photoresist layer thickness is to be no less 250 nm, the ion-beam processing of the roentgen amorphous chrome film is executed through the photoresist mask within no less than 30 seconds with the help of the mesh Kaufman ion source at the pressure of the gas mixture (4-6)-10-2 Pa, at that the gas mixture contains argon counting to 70 - 95% of the total mass, khladon 218 (С3F8) - 30 - 5 % of the total mass, and residual gases; removal of the remainder of the photoresist mask is executed by a weak 0.5% alkaline solution; the carrier material with the chrome film is flushed by distilled water.
EFFECT: provision of the image of a set topology due to the essential difference of etching rates of crystalline and amorphous extents of chrome in the chemical etch.
8 cl, 2 dwg
SUBSTANCE: invention is related to the method of producing nanocomposite material and it can be used in packaging, wire (non-flammable insulation of electrical wires) and other industries. The method includes melt mixing of low density polyethylene and layered silicate. As layered silicate, natural montmorillonite is used being modified with quaternary ammonium salt. Before melt mixing, low density polyethylene is preliminarily shearly degraded at high temperature in a single screw dispergator with three temperature zones.
EFFECT: pre-treatment of the polymer helps to overcome incompatibility of the filler and material polymer base and, consequently, to significantly enhance the mechanical properties of the nanomaterial being produced.
1 dwg, 4 tbl
SUBSTANCE: method to manufacture a superconducting tape on the basis of Nb3Sn compound includes the following subsequent stages: - assembly of a multilayer pack from alternating Nb- and Cu-foils with thickness of 0.1-0.3 mm, which is first exposed to diffusion welding, then to rolling on a vacuum rolling mill, and further to rolling at room temperature until the tape thickness is 0.1-0.3 mm; - assembly of a multilayer pack from multilayer Nb/Cu-foils with thickness of 0.1-0.3 mm, produced after the first stage, exposed to the same treatment as at the first stage, until the tape thickness is 0.1-0.5 mm; - assembly of a multilayer pack from strips of tin bronze, containing (10-12) wt % Sn, with thickness of 0.3-0.5 mm and sections of Nb/Cu-tape produced at the previous stage, its arrangement in a shell from annealed copper foil with thickness of 0.1-0.3 mm, welding and rolling until the tape thickness is 0.2-0.3 mm, at certain ratio of thicknesses and quantities of niobium and bronze layers and annealing of the produced composite tape at 600-850°C for 1-350 hr.
EFFECT: increased critical density of tape current and improved stabilising properties.
SUBSTANCE: nanosized silicon with particle size of 5-100 nm is added as a light stabiliser to the recipe of the composition during mixture or synthesis of ingredients thereof. In the surface layer, particles contain silicon dioxide in amount of 0.25-2.5 wt %, having stable spectral absorption of medium-wave UV radiation in the 200-420 nm range. This effect is retained at high temperatures of approximately up to 650 K.
EFFECT: obtaining coatings which do not change colour and operational properties and retain colour- and weather resistance.
2 tbl, 7 ex
FIELD: carbon materials.
SUBSTANCE: weighed quantity of diamonds with average particle size 4 nm are placed into press mold and compacted into tablet. Tablet is then placed into vacuum chamber as target. The latter is evacuated and after introduction of cushion gas, target is cooled to -100оС and kept until its mass increases by a factor of 2-4. Direct voltage is then applied to electrodes of vacuum chamber and target is exposed to pulse laser emission with power providing heating of particles not higher than 900оС. Atomized target material form microfibers between electrodes. In order to reduce fragility of microfibers, vapors of nonionic-type polymer, e.g. polyvinyl alcohol, polyvinylbutyral or polyacrylamide, are added into chamber to pressure 10-2 to 10-4 gauge atm immediately after laser irradiation. Resulting microfibers have diamond structure and content of non-diamond phase therein does not exceed 6.22%.
EFFECT: increased proportion of diamond structure in product and increased its storage stability.