462 results about "Boron diffusion" patented technology

The invention discloses a solar cell and a preparation method and application thereof, and relates to the technical field of solar cells. P-type doped regions and N-type doped regions are alternately arranged on the back surface of the crystalline silicon substrate, a boron diffusion doped layer, a first passivation layer and a first antireflection layer are sequentially arranged in the P-type doped regions, and a phosphorus-doped silicon oxide layer, a phosphorus-doped polycrystalline silicon layer, a second passivation layer and a second antireflection layer are sequentially arranged in the N-type doped regions from the surface of the crystalline silicon substrate. A traditional TBC battery P region mostly adopts a two-step process of intrinsic amorphous silicon deposition and boron diffusion to form a polycrystalline silicon layer, but the P region does not contain the polycrystalline silicon layer and can be prepared through a one-step boron diffusion process, so that the process steps can be reduced, and the process time can be shortened; and the action of laser and P-region polycrystalline silicon is avoided, the patterning difficulty of the battery is reduced, and the production yield of the battery can be greatly improved.

The invention discloses a low-cost high-cerium neodymium iron boron diffusion magnet and a preparation method and application thereof, and relates to the technical field of rare earth permanent magnet materials. Comprising the steps that a neodymium iron boron alloy casting piece Ce30 with the Ce content being 10 wt% and a neodymium iron boron alloy casting piece Ce50 with the Ce content being 15 wt% are prepared through burdening and smelting, after the Ce30 and Ce50 neodymium iron boron alloy casting pieces are evenly mixed, hydrogen decrepitation, jet milling, oriented pressing, cold isostatic pressing and vacuum sintering are sequentially carried out, and a high-cerium sintered neodymium iron boron matrix is obtained; carrying out grain boundary diffusion on the high-cerium sintered neodymium-iron-boron matrix to obtain a high-cerium neodymium-iron-boron diffused magnet; the performance of the blank prepared through the method is close to the N40 mark, the performance of the magnetic sheet after diffusion reaches the 38MT mark, the magnetic performance is kept at the high level, the Ce content is high, efficient utilization of the high-abundance element cerium is achieved, the production cost of the rare earth permanent magnet material is greatly reduced, industrial batch production can be achieved, and balanced utilization of rare earth resources is promoted.

The invention discloses a preparation method of a solar cell, and the method comprises the following steps: placing an N-type silicon wafer in a furnace tube of a diffusion furnace, and introducing nitrogen and oxygen into the furnace tube to form a first oxide layer on the surface of the silicon wafer; boron trichloride, oxygen and nitrogen are introduced into the furnace tube, so that a boron diffusion layer is formed on the surface, away from the silicon wafer, of the first oxide layer; introducing nitrogen into the furnace tube, and controlling the temperature of the furnace tube to be a first temperature so as to carry out oxygen-free propulsion of the boron element; introducing nitrogen and oxygen into the furnace tube, and controlling the temperature of the furnace tube to rise from the first temperature to a second temperature so as to carry out aerobic propulsion of the boron element; dry oxygen and wet oxygen are alternately introduced into the furnace tube for multiple times to form a second oxide layer; the temperature in the furnace tube is reduced, and dry oxygen continues to be introduced into the furnace tube; and nitrogen is introduced into the furnace tube, the temperature in the furnace tube is reduced, and boron diffusion of the silicon wafer is completed. According to the preparation method of the solar cell, the silicon wafer can have low surface concentration shallow junctions and uniform sheet resistance.

The invention relates to a manufacturing method of a solar cell and the solar cell, the back surface of the solar cell is provided with a first region and a second region, and a second electrode of the solar cell is arranged in the second region; the manufacturing method of the solar cell comprises the following steps: texturing a cell piece; carrying out boron diffusion on the battery piece; performing laser etching on the first region; the first area is subjected to groove type cleaning; and carrying out chain type cleaning on the second area. In the invention, the back surface of the battery piece is selectively etched through laser to remove the borosilicate glass layer in the first area and reserve the borosilicate glass layer in the second area, so that the first area of the battery piece is cleaned and polished in the subsequent preparation steps; the borosilicate glass layer of the second region protects the textured structure of the second region in the subsequent preparation step, so that the tunneling dielectric layer and the doped conductive layer in the second region also have textured structures, thereby increasing the contact area between the second electrode and the doped conductive layer, and improving the photoelectric conversion efficiency of the solar cell.

The invention relates to the technical field of magnetic materials, in particular to a grain boundary diffusion method of a neodymium-iron-boron rare earth permanent magnet material, which comprises the following steps: preparing a sintered neodymium-iron-boron diffusion matrix, a diffusion source being turbid liquid slurry consisting of a mixture of rare earth fluoride and rare earth oxide and a proper amount of organic solvent; the method comprises the following steps: processing a diffusion substrate into a required size, carrying out grain boundary diffusion treatment after oil removal and acid pickling treatment, coating the surface of the diffusion substrate with a diffusion source, drying the coated magnet, carrying out primary diffusion treatment, and carrying out secondary low-temperature tempering treatment. The diffusion method provided by the invention is simple in process, can effectively improve the coercive force of the neodymium-iron-boron magnet, especially the coercive force of a Ce-containing magnet, and is embodied in the following aspects: improving the anisotropic field of the surface of a crystal grain, improving the microstructure of a crystal boundary, effectively increasing the diffusion depth, obviously improving the coercive force of the magnet, and improving the coercive force of the neodymium-iron-boron magnet. And the original residual magnetism and the maximum magnetic energy product of the magnet are not obviously reduced.

The embodiment of the invention provides a back contact solar cell, a preparation method thereof and a photovoltaic module. The preparation method of the back contact solar cell comprises the following steps: providing a substrate, wherein the substrate comprises a silicon wafer, a first tunneling oxide layer and a first intrinsic amorphous silicon layer which are stacked in sequence; performing crystallization treatment on the first intrinsic amorphous silicon layer on the substrate so as to convert amorphous silicon in the first intrinsic amorphous silicon layer into polycrystalline silicon and obtain a first polycrystalline silicon layer; and carrying out boron diffusion on the first polycrystalline silicon layer to obtain a boron-doped layer. According to the method provided by the embodiment of the invention, after the first polycrystalline silicon layer is formed by performing crystallization treatment on the first intrinsic amorphous silicon layer, boron diffusion is performed on the first polycrystalline silicon layer, so that the boron-doped layer with a relatively good passivation effect can be obtained, and meanwhile, the process stability of preparing the back contact solar cell can be improved.

The invention relates to a preparation method of a solar cell piece and the solar cell piece, and the preparation method of the solar cell piece comprises the following steps: preparing a tunneling oxide layer on the surface of an n-type crystalline silicon substrate, depositing polycrystalline silicon on the surface of the tunneling oxide layer under a first condition, and forming a first polycrystalline silicon layer, polycrystalline silicon is deposited on the surface of the first polycrystalline silicon layer under a second condition to form a second polycrystalline silicon layer, the temperature T1 of the first condition is larger than the temperature T2 of the second condition, the crystallization rate in the first polycrystalline silicon layer is smaller than the crystallization rate in the second polycrystalline silicon layer, annealing treatment and boron diffusion are carried out on the first polycrystalline silicon layer and the second polycrystalline silicon layer under the same condition, and the polycrystalline silicon layer is formed. The first polycrystalline silicon layer is converted into a first doped polycrystalline silicon layer, the second polycrystalline silicon layer is converted into a second doped polycrystalline silicon layer, the ratio F of the concentration of the first doped polycrystalline silicon layer to the concentration of the second doped polycrystalline silicon layer is larger than or equal to 0.01 and smaller than or equal to 0.1, the boron doping concentration in the first doped polycrystalline silicon layer in direct contact with the tunneling oxide layer is reduced, and the passivation level is improved.

The present invention provides a preparation method for a selective emitter, a solar cell and a preparation method therefor, and a photovoltaic module. The preparation method for a selective emitter comprises the following steps: (1) cleaning an N-type silicon wafer; (2) performing boron diffusion on the silicon wafer, and forming a P layer on the surface of the silicon wafer; (3) using laser to dope a gate line area of the silicon wafer; (4) cleaning to remove a borosilicate glass layer and the P layer on the surface of the silicon wafer; and (5) performing high-temperature treatment on the silicon wafer, forming a selective emitter on one surface of the silicon wafer, and forming a tunneling layer on the other surface of the silicon wafer. According to the preparation method provided by the present invention, by means of one-step oxidation, the selective emitter is formed on one surface of the silicon wafer, and the tunneling layer is formed on the other surface of the silicon wafer, such that there is no need to independently prepare the tunneling layer, thereby simplifying the preparation process flow of a cell, improving the processing efficiency of the cell, and facilitating large-scale promotion and application.

The utility model relates to a filter assembly, a tail gas treatment device and boron diffusion production equipment, the filter assembly comprises a filter element and a filter cartridge, the filter element is provided with a first end and a second end along a first direction, and the filter element is provided with a plurality of filter through holes along the first direction; the filter element is positioned in the filter cartridge; the filter cartridge is provided with an air inlet and an air outlet; the air inlet is communicated with an exhaust pipe of a vacuum furnace of the boron diffusion production equipment, and the air outlet is communicated with a tail exhaust pipe of the boron diffusion production equipment; tail gas exhausted by the exhaust pipe can enter the filtering through hole through the gas inlet and the first end in sequence, and can be exhausted to the tail exhaust pipe through the second end and the gas outlet in sequence after being filtered; a plurality of water injection blind holes extending in the first direction are formed in the filter element, and openings of the water injection blind holes are formed in the second end; a first water injection port is formed in the filter cartridge and is communicated with the opening through a water pipe; and the filter element is made of a porous material. According to the technical scheme, harmful substances such as B2O3 in the tail gas can be fully and effectively removed, and the filtering efficiency is high.

The invention discloses a preparation method of a solar cell, which belongs to the technical field of solar cells and comprises the following steps of: selecting an N-type silicon substrate and performing double-sided texturing; performing boron diffusion doping on the front surface of the silicon substrate to form a P + doping layer and a borosilicate glass layer on the front surface, and forming a borosilicate glass layer on the back surface; removing the borosilicate glass layer on the back surface of the N-type silicon substrate, and carrying out alkali washing and polishing on the back surface of the N-type silicon substrate; forming a polycrystalline silicon layer and a polycrystalline silicon layer on the back and the front of the substrate; performing phosphorus diffusion on the polycrystalline silicon layer on the substrate; removing the phosphorosilicate glass layer on the front side, the borosilicate glass layer, the N + polycrystalline silicon layer and the borosilicate glass layer and the phosphorosilicate glass layer on the back side; depositing a front passivation layer and a front antireflection layer on the P + doping layer on the front of the substrate; electrode printing sintering is carried out on the front and back of the substrate; the reverse bias voltage applied by the first LECO process is 3-10V, and the reverse bias voltage applied by the second LECO process is 11-20V. And the black edge problem caused by overburning is reduced by increasing the LECO for the second time.

A preparation and diffusion treatment method for a high-performance diffusion coating used for a sintered neodymium-iron-boron magnet. The method comprises the following steps: the preparation of alloy powders, the preparation of glue, the preparation of a diffusion coating, a pretreatment, coating with the coating, surface drying, and a heat treatment. By controlling the components and particle size of the alloy powders, the compounding of the glue, an anti-bonding powder and an auxiliary agent ensures that under the condition of a relatively small usage amount of a diffusion heavy rare earth metal, the coercive force is greatly improved, the residual magnetism is almost not reduced or is slightly reduced, and the phenomena of the shedding of the coating and the bonding of magnetic sheets after diffusion are avoided.

A preparation method for a TOPCon double-POLO battery structure. The method comprises: forming a double-POLO structure on the front face and back face of a silicon wafer, wherein a local POLO structure is formed on the front face. A coating mask is combined with a laser to form the local POLO structure on the front face, thereby improving a metal contact composite current on the front face and also avoiding a current loss, and thus greatly improving the battery efficiency. An inorganic oxide mask that is used can be easily removed by means of a laser of a conventional SE laser device, and the damage of the laser to a silicon substrate is less. The solution for implementing poly patterning by using a laser has good compatibility with a production line. The remaining mask after texturing is performed can be removed by means of hydrofluoric acid pickling, which can be combined with conventional acid pickling after texturing is performed, without the need for extra cleaning devices and processes. Boron diffusion is performed after local POLO is formed on the front face, and boron doping can be implemented in a front-face POLO area and a suede area at the same time, thereby simplifying the preparation steps for the local POLO structure on the front face.

The embodiment of the invention relates to the photovoltaic field, and provides a back contact cell and a processing method thereof, a back contact laminated cell and a photovoltaic module, and the processing method comprises the step of texturing a substrate. And carrying out boron diffusion on the substrate to form a boron-doped layer and a borosilicate glass layer on the surface of the substrate. And performing laser etching on the first region and the second region of the substrate, and removing the boron-doped layer, the borosilicate glass layer and part of the substrate in the first region and the second region. And carrying out phosphorus expansion on the substrate, and forming a polycrystalline silicon layer and a phosphorosilicate glass layer on the surface of the substrate. And performing laser etching on the substrate to remove the phosphorosilicate glass layers in the second area and the third area. And texturing the substrate and removing the phosphorosilicate glass layer in the first region and the polycrystalline silicon layers in the second region and the third region to form a textured surface in the second region. And forming a passivation layer on the substrate. Electrode paste is printed in the first area and the third area and sintered. And sintering the back surface of the substrate. The design can improve the double-sided rate and the efficiency of the back contact battery.

The invention relates to the technical field of solar cells, and particularly discloses a high-boron-doped single-mask TBC solar cell structure and a manufacturing method thereof.In the process of forming a patterned region, a P region does not need a mask structure, and through the combination of boron diffusion doping, annealing and two-time laser doping treatment, the high-boron-doped single-mask TBC solar cell structure is obtained. The boron atom doping concentration of the polycrystalline silicon layer is greatly improved, so that the boron-doped polycrystalline silicon layer in the P region is high in doping concentration and uniform in doping. According to the TBC solar cell prepared by the method, the processes of preparing and removing the mask structure are simplified, the technological process is short, the manufacturing cost is low, the contact resistance is reduced, the passivation effect is improved, the filling factor of the cell is increased, and the efficiency of the cell is improved. And the open-circuit voltage and the photoelectric conversion efficiency of the battery are improved.

The invention discloses a TBC solar cell and a preparation method thereof. The preparation method of the TBC solar cell comprises the following steps: cleaning and polishing an N-type silicon substrate; depositing a first tunneling oxide layer and a first intrinsic polycrystalline silicon layer on the back surface; boron diffusion; performing laser grooving, etching and cleaning; depositing a second tunneling layer and a second intrinsic polycrystalline silicon layer on the back surface; phosphorus diffusion; performing laser grooving, etching and cleaning; depositing an aluminum oxide film and an anti-reflection film on two sides; and preparing a metal electrode. According to the invention, the phosphorus-doped polycrystalline silicon layer is added on the boron-doped polycrystalline silicon layer, the second tunneling layer of the interlayer can form a secondary gettering effect, and the passivation level of the boron-doped polycrystalline silicon layer is improved. A built-in electric field formed by the two PN junctions generates more carriers, more holes are forced to be gathered and transversely transmitted at the boron-doped polycrystalline silicon layer and more easily collected by a metal electrode, and a back suede structure and a carrier collection optimization structure are added on the basis of not increasing the process flow.

The invention discloses conductive paste, a conductive electrode, a preparation method of the conductive electrode and a crystalline silicon solar cell, and belongs to the technical field of photovoltaic cells, the conductive paste comprises glass powder, silver, nickel and an organic carrier, the glass powder comprises B2O3, corrosive oxide and non-corrosive oxide, and the nickel is added to replace part of silver, so that the usage amount of silver in the conductive paste is reduced, and the cost is reduced. In addition, the molar ratio range of the corrosive oxide and the non-corrosive oxide in the glass powder is limited to be 0.7-2.6. The first passivation layer arranged on the boron diffusion emitter is opened during high-temperature sintering, and the oxidability and the flowability of the glass powder can be balanced to inhibit or delay the formation of an oxidized nickel shell on the surface of the nickel powder, so that a laser enhanced contact post-treatment process is matched; and the photoelectric conversion efficiency of the crystalline silicon solar cell is ensured.

The invention relates to a preparation method of a local ITO interconnected perovskite-TOPCon laminated cell, which comprises the following steps: taking an n-type monocrystalline silicon wafer as a substrate, cleaning and texturing, diffusing boron on the back to form a P + emitter, oxidizing at high temperature, and treating the surface through acid etching and alkali polishing; sequentially preparing a tunneling oxide layer and a phosphorus-doped polycrystalline silicon layer on the front surface, annealing and crystallizing, depositing an aluminum oxide film and a multi-layer silicon nitride film on the back surface after cleaning, and depositing a single-layer silicon nitride film on the front surface; preparing a back metal electrode, etching according to a designed pattern to remove a local silicon nitride film on the front surface, sequentially preparing an ITO interconnection layer, a hole transport layer, a perovskite layer, a passivation layer, an electron transport layer and an ITO transparent conductive layer on the front surface, and finally preparing a front metal electrode and solidifying to form a contact electrode. According to the invention, the problems of back corrosion risk, effective area loss and tedious process in the existing method are solved, full-size manufacturing is realized, the cell performance is improved, and industrialization is easier.

The invention discloses a dynamic optimization method and system for a boron diffusion process of a photovoltaic cell and electronic equipment. Comprising the following steps: collecting process parameters and sheet resistance data, and associating the process parameters and the sheet resistance data to form a process parameter set; optimizing a process parameter set, removing noise data and incomplete data, and extracting an available feature data set; dividing the feature data set into a training set and a verification set, and training to obtain a nonlinear regression model for predicting resistance data under different feature data; carrying out validity verification on the nonlinear regression model, and constructing an optimization function to reduce a difference value between a predicted value and an actual value; and deploying a nonlinear regression model in the diffusion process, adjusting the process parameters of the diffusion process in real time according to the predicted value, and optimizing the obtained sheet resistance data. The problem that the boron diffusion process is difficult to accurately adjust by a traditional process control method can be solved.

The invention belongs to the technical field of photovoltaic cells, and particularly relates to a back contact photovoltaic cell, a back contact photovoltaic cell assembly and a preparation method, and the method comprises the steps: providing an N-type silicon wafer which is provided with a double-sided texturing structure, and the textured surface is of a pyramid structure after texturing; boron diffusion is carried out on the backlight surface of the silicon wafer to form a P + doping layer, and meanwhile, a lightly doped P-type region is formed on the illuminated surface of the silicon wafer through diffusion and dissipation; performing laser film opening on the backlight surface P + doping layer to form P region and N region structures which are distributed in a staggered manner; depositing a tunneling oxide layer and a phosphorus-doped amorphous silicon layer in the N region, and annealing the tunneling oxide layer and the phosphorus-doped amorphous silicon layer to form an N + polycrystalline silicon layer; printing etching slurry on the surface of the P region, performing etching slurry film opening, removing phosphorosilicate glass and forming an isolation gap between the P region and the N region; and the film is opened by printing etching slurry, so that the suede cannot generate thermal damage.

The invention discloses a heat treatment process of an alloy drill bit, which belongs to the field of alloy and comprises the following steps: S1, after the alloy drill bit is primarily machined and formed, carrying out vacuum pretreatment, heat preservation and heating; s2, the drill bit is rapidly transferred into a sectional temperature control carburizing furnace to be subjected to main carburizing treatment, the temperature is controlled between 930 DEG C and 960 DEG C, the carburizing time ranges from 3 hours to 4 hours, and the carburizing depth is controlled between 0.3 mm and 0.6 mm; s3, after carburizing is completed, subarea multi-speed cooling is carried out, quenching is carried out for 20 seconds at the temperature of 850 DEG C or above, controlled cooling is carried out for 60 seconds within the range of 550 DEG C to 650 DEG C, slow cooling is carried out for 80 seconds at the temperature of 200 DEG C or below, and a refined martensite complex phase structure is obtained; s4, after cooling is completed, double-section tempering treatment is carried out; and S5, performing ultrahigh-pressure static boriding diffusion treatment. The method has the beneficial effects that the processing uniformity, the structure stability, the wear resistance and the corrosion resistance of the alloy drill bit are effectively improved and the service life of the alloy drill bit is effectively prolonged by adopting staged temperature control, different cooling media and a directional quenching technology.

The invention relates to the technical field of solar cells, and particularly discloses a TOPCon cell with a domain surface structure and a preparation method of the TOPCon cell. The TOPCon battery comprises an N-type silicon substrate, the front surface of the N-type silicon substrate is divided into an emitter region and a non-emitter region, the emitter region is of a planar structure, the non-emitter region is of a pyramid textured structure, and the boron doping concentration of the emitter region is higher than that of the non-emitter region. According to the invention, the silicon oxide layer is generated in the emitter region through the laser oxidation process, so that local planarization is realized; in combination with selective boron diffusion doping, the contradiction between the contact resistance and the light absorption efficiency of the traditional TOPCon cell is solved; the specific process comprises the steps of alkali polishing, laser oxidation, texturing, doping, passivation, electrode printing and the like. And the process is stable, is compatible with the existing production line, and has remarkable industrial application value.

The utility model discloses a TOPCon cell structure which comprises a silicon substrate layer, the front surface of the silicon substrate layer is provided with a front surface grid line, an antireflection film layer, an alumina layer and a boron diffusion emitter layer from outside to inside in sequence, and the back surface of the silicon substrate layer is provided with a tunneling oxide layer, a doped polycrystalline silicon layer, a silicon nitride layer and a back surface grid line from inside to outside in sequence. An ultrathin silicon oxide layer is arranged in the doped polycrystalline silicon layer, and the thickness of the ultrathin silicon oxide layer is 0.8 nm to 2.0 nm. According to the TOPCon cell structure, the doping concentration of the poly layer can be effectively improved, the back passivation effect of the poly layer is further improved, back contact is improved, meanwhile, the ultra-thin silicon oxide layer structure can play a role in blocking phosphorus atoms, the phosphorus atoms are prevented from expanding and penetrating, and passing of carriers is not affected.

The invention discloses a preparation method of a solar cell and the solar cell, and the preparation method comprises the steps: firstly providing an N-type silicon substrate, carrying out boron diffusion doping processing on one side of a first surface of the N-type silicon substrate, and carrying out phosphorus diffusion doping processing on one side of a second surface of the N-type silicon substrate; wherein the first surface and the second surface are two surfaces, deviating from each other, of the N-type silicon substrate, the first surface is a suede surface, the second surface is a polished surface, then a first passive film layer is formed on the first surface, a second passive film layer is formed on the second surface, and finally a main-grid-free process is adopted. And carrying out silk-screen printing and sintering treatment on one side of the first passive film layer and / or one side of the second passive film layer to form a plurality of fine grids, and preparing the solar cell. By means of the method, the effective utilization area of the surface of the solar cell is increased, excessive occupation of the surface area of the solar cell due to arrangement of the main grid is reduced, and the effect that the whole solar cell is high in photoelectric conversion efficiency is achieved.

The invention discloses a solar single-crystal efficient TOPCon + SE battery piece ultrahigh sheet resistance diffusion process which mainly comprises a front boron process, an SE process and a rear oxidation process, and the front boron process comprises high-temperature oxidation before diffusion and a diffusion process composed of three-step diffusion and heating propulsion. According to the invention, a layer of SiO2 can be coated on the surface of the silicon wafer through high-temperature oxidation before diffusion and is used as an anti-reflection film layer; the PN junction is prepared by adopting a step-by-step diffusion method, so that the advantage of good junction uniformity can be realized, boron can be uniformly distributed on the surface of a silicon wafer through a specific boron diffusion method, and meanwhile, boron elements can be better deposited on the surface of the silicon wafer through variable-temperature diffusion and propulsion; by adding the SE process, the square resistance can reach 700-800 ohms, the junction depth in the grid line area is deeper, the increase of ohms becomes better, the cell center recombination is reduced due to the lower surface concentration, and the open-circuit voltage of the cell is improved; and the post-oxidation process has an annealing effect and can repair lattice damage and the like.

The invention relates to a preparation method of a TOPCon battery, which comprises the following steps of: performing double-sided texturing on an N-type silicon substrate, and performing boron diffusion on the textured surface on the front surface to form a P + emitter layer and a borosilicate glass layer; polishing the back surface, and printing a mask layer on a non-metallization area on the polished surface; sequentially depositing a tunneling oxide layer and a phosphorus-doped polycrystalline silicon layer on the back surface of the N-type silicon substrate; scanning the non-metallization area on the back surface by using laser, and removing the phosphorosilicate glass layer, the phosphorus-doped polycrystalline silicon layer and the tunneling oxide layer on the surface by using alkali liquor; removing the borosilicate glass layer and the phosphorosilicate glass layer on the front surface of the N-type silicon substrate, the phosphorosilicate glass layer on the back surface of the N-type silicon substrate and the tunneling oxide layer and the mask layer remained in the non-metallization area; depositing an aluminum oxide layer and a silicon nitride layer on the front surface and the back surface of the N-type silicon substrate; and respectively printing metal electrodes on the metalized areas on the front surface and the back surface of the N-type silicon substrate to obtain the TOPCon battery. The invention has the effects of reducing the possibility that the N-type silicon substrate is damaged and improving the overall efficiency of the battery.

The invention discloses a boron diffusion method of a solar cell and the solar cell. The boron diffusion method comprises the following steps: forming a boron-doped layer for a cell substrate in an oxidation furnace tube to obtain a primarily-doped boron substrate, the boron-doped layer comprising a deep-junction boron diffusion layer and a borosilicate glass layer which are laminated from inside to outside; taking out the primarily-doped boron matrix from the oxidation furnace tube, and cooling the primarily-doped boron matrix until the cooled temperature is not higher than 200 DEG C; putting the cooled primarily-doped boron substrate into the preheated oxidation furnace tube again, and heating the primarily-doped boron substrate in an oxygen-free environment to activate non-active boron atoms in the boron-doped layer; and carrying out oxidation source absorption treatment on the deep-junction boron diffusion layer in the primarily-doped boron substrate, and redistributing boron atoms in the deep-junction boron diffusion layer. According to the boron diffusion method, the amount of active boron atoms contained in the surface of the deep-junction boron diffusion layer of the solar cell is increased, the boron doping concentration peak value in the deep-junction boron diffusion layer is reduced, the boron doping concentration distribution is relatively uniform, and the contact resistance between the metal electrode and the deep-junction boron diffusion layer is reduced.

The invention discloses a novel Topcon solar cell double-sided rate improvement method, which belongs to the field of Topcon cells, and comprises the following steps: selecting an N-type silicon substrate and carrying out double-sided texturing to obtain a textured silicon wafer; performing boron diffusion on the front surface of the textured silicon wafer to form a P + doping layer and a borosilicate glass layer; removing the borosilicate glass layer on the front surface of the silicon wafer after boron diffusion and the doped layer expanded on the back surface and the edge of the silicon wafer; a first tunneling oxide layer is formed on the surface of the silicon wafer substrate, and three doped polycrystalline silicon layers with different densities are deposited and formed without deposition pressure; performing low-pressure oxidation to form a silicon dioxide masking film, and then performing phosphorus diffusion segmented propulsion to obtain an initial battery piece; removing the wound-plated polycrystalline silicon on the front surface and the edge of the primary battery piece; printing silver aluminum paste, printing silver paste on the back surface, drying and sintering, and then carrying out light injection treatment. The double-sided rate of the Topcon battery is improved through the cooperation of the steps of controlling the alkali polishing process time, reducing the size of a back tower footing after alkali polishing, reducing the number of silk-screen printing grid lines, reducing the width of the grid lines and the like.

The present invention relates to the field of solar cells, and discloses a transverse and longitudinal composite multi-junction TBC solar cell and a preparation method thereof. The TBC solar cell comprises an N-type silicon wafer, the front side of which is provided with a pyramid velvet surface and a passivation layer in sequence; the back side of the N-type silicon wafer is provided with a deposition area A and a deposition area B distributed in a cross-finger shape; the gap between the deposition area A and the deposition area B is an isolation area, and the surface of the isolation area is provided with a pyramid velvet surface and a passivation layer in sequence; the surface of the deposition area A is provided with a boron diffusion layer A, a phosphorus diffusion layer A, a tunneling oxide layer A, a phosphorus diffusion layer B, a passivation layer and an electrode layer in sequence; the surface layer of the N-type silicon wafer located at the bottom of the deposition area B is a boron diffusion layer B, and the surface of the deposition area B is provided with a tunneling oxide layer B, a boron diffusion layer C, a passivation layer and an electrode layer in sequence. The TBC solar cell of the present invention has a transverse and longitudinal composite multi-junction structure, which is conducive to further improving the battery conversion efficiency of the battery, and at the same time reducing the battery preparation cost and technical difficulty.

The invention relates to the technical field of photovoltaic cells, and discloses a selective passivation contact structure, a preparation method thereof and application of the selective passivation contact structure to preparation of a selective TOPCon cell. The method comprises the steps that a first tunneling oxide layer, first thin intrinsic amorphous silicon with the high crystallization rate and second thick intrinsic amorphous silicon with the low crystallization rate are sequentially prepared on the back face of a silicon wafer; boron diffusion doping is carried out, so that the first boron-doped polycrystalline silicon and the second boron-doped polycrystalline silicon have difference in doping concentration and crystallization rate; in the alkali etching process after laser patterning, first boron-doped polycrystalline silicon and a first tunneling oxide layer in a back non-electrode contact area are reserved by utilizing the etching rate difference of an alkaline solution on BSG and two layers of boron-doped polycrystalline silicon with different doping concentrations and crystallization rates; and the first tunneling oxide layer, the first boron-doped polycrystalline silicon and the second boron-doped polycrystalline silicon in the back electrode contact region are reserved. According to the method, the process steps can be simplified, parasitic absorption and recombination are reduced, passivation and transverse transmission are improved, and the cell efficiency is improved.

The invention discloses a preparation method of a TBC battery electrode grid line, the electrode grid line and a TBC battery, and belongs to the technical field of solar cells, and the preparation method comprises the following steps: carrying out double-sided polishing on a silicon wafer; sequentially depositing a tunneling oxide layer and an intrinsic polycrystalline silicon layer on the back surface of the silicon wafer, and performing boron diffusion; digging an N region and a PN connection partition region on the back surface of the silicon wafer; sequentially depositing a tunneling oxide layer and an intrinsic polycrystalline silicon layer on the back surface of the silicon wafer, and performing phosphorus diffusion on the basis of the tunneling oxide layer and the intrinsic polycrystalline silicon layer; digging a P region and a GAP region on the back surface of the silicon wafer, and digging a hole channel by using a second laser; removing the borosilicate glass layer and the phosphorosilicate glass layer in the pore channel area; sequentially depositing an aluminum oxide layer and a silicon nitride layer on the surface of the silicon wafer; printing non-burn-through slurry in the main grid areas of the P area and the N area through the silk screen printing plate; and carrying out laser-assisted sintering on the auxiliary grid line pore channel region. The completeness of a passivation film layer structure on the back surface of the battery piece is ensured, meanwhile, the contact area of a metal electrode and a silicon substrate is reduced, and metal contact recombination is effectively reduced.