331 results about "Boron diffusion" patented technology

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 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.

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.

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 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 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.

The invention relates to the technical field of solar cells, and discloses a laser-assisted etching slotting method for preparing high-doping-concentration P + polycrystalline silicon and application. The grooving method comprises the following steps: preparing a tunneling SiOx layer and an i-polysi layer on the back surface of a silicon wafer; performing patterning etching by using green picosecond laser so as to remove the i-polysi layer and the tunneling SiOx layer in a laser region; removing impurities in a laser area through single-side acid pickling; boron diffusion is carried out, P + polycrystalline silicon is formed on the i-polysi layer in the non-laser area, a P + emission layer is generated in the laser area, and a BSG layer is generated on the back faces of the P + polycrystalline silicon and the P + emission layer; performing patterning etching by using green picosecond laser to remove the BSG layer in the laser area; and carrying out alkali wet etching to remove the P + emission layer in the laser area so as to form a notch. According to the grooving method, the notch with the ideal grooving depth is formed, P + polycrystalline silicon with high doping concentration can be formed in the non-laser area to reduce the contact resistivity, and the cost is low.

The utility model discloses a boron diffusion reaction intake system and reaction equipment, the boron diffusion reaction intake system comprises a boron source intake assembly and a reaction intake assembly, the boron source intake assembly comprises a first intake pipe, a first intake port is used for introducing a boron source, the first intake port is used for directly communicating with a reaction cavity, and the reaction intake assembly comprises a second intake pipe; the reaction gas inlet assembly comprises at least one second gas inlet pipe, a second gas inlet is used for introducing oxygen or nitrogen, and the second gas inlet pipe is isolated from the first gas inlet pipe; the reaction equipment comprises the boron diffusion reaction gas inlet system. According to the utility model, the first gas inlet pipe and the second gas inlet pipe are isolated from each other, and a boron source and other reaction gases are respectively fed through the first gas inlet pipe and the second gas inlet pipe, so that the boron source gas and oxygen are prevented from being mixed outside the reaction cavity, and the possibility that the boron source gas and the reaction gases react in advance before entering the reaction cavity is reduced; the influence of a gas inlet mode on a gas field in the reaction cavity is reduced, and the uniformity of sheet resistance of the silicon wafer is improved.

The embodiment of the utility model provides a tail gas emission treatment device and boron diffusion equipment. The tail gas emission treatment device comprises a first cooling mechanism, a washing and filtering assembly, a second cooling mechanism, a vacuum pump and a collector which are communicated in sequence, wherein the first cooling mechanism is used for receiving tail gas of a boron diffusion furnace and cooling the tail gas; the washing and filtering assembly is used for filtering the tail gas cooled by the first cooling mechanism; the second cooling mechanism is used for carrying out secondary cooling on the tail gas filtered by the washing and filtering assembly so as to obtain purified tail gas; and the collector is used for obtaining the purified tail gas from the second cooling mechanism through the vacuum pump. The tail gas emission treatment device disclosed by the embodiment of the utility model has a good filtering effect on boron diffusion tail gas, a pipeline of the tail gas emission treatment device is prevented from being blocked, and the pressure in the tail gas emission treatment device is ensured to be stable, so that the service life of the device is prolonged.

The utility model discloses a tail gas emission system of boron diffusion equipment, and belongs to the field of waste gas treatment. The tail gas emission system of the boron diffusion equipment comprises a cooling bottle and a water filtering unit, the cooling bottle is used for cooling the high-temperature waste gas and outputting the cooled waste gas; the water filtration unit is used for providing at least two stages of water filtration for the cooled waste gas, the water filtration unit is provided with a liquid inlet pipeline and a gas path, and the liquid inlet pipeline is isolated from the gas path. The device has more than two stages of filtration, B2O3, BCl3 and Cl2 generated by boron diffusion equipment can be filtered to the greatest extent, so that the gas [YT1] substances cannot reach the tail discharge pipe at the rear end, the problem that the B2O3 is deposited on the diaphragm and the tail discharge pipe is avoided, and the maintenance period and the maintenance cost are reduced. And meanwhile, the liquid inlet pipeline is isolated from the gas path, so that a series of problems caused by the fact that the liquid remains in the gas path and then enters a subsequent system are avoided.

The present disclosure relates to the technical field of solar cells. Disclosed are a solar cell, a preparation method therefor and a use thereof. A P-type doped region and an N-type doped region are alternately arranged on the back surface of a crystalline silicon substrate; a boron diffusion doped layer, a first passivation layer and a first anti-reflection layer are sequentially formed in the P-type doped region; and a phosphorus-doped silicon oxide layer, a phosphorus-doped polycrystalline silicon layer, a second passivation layer and a second anti-reflection layer are sequentially formed on the surface of the crystalline silicon substrate in the N-type doped region. The P regions of traditional TBC cells mostly adopt a two-step process of depositing intrinsic amorphous silicon and performing boron diffusion to form a polycrystalline silicon layer. However, the P region of the present disclosure does not contain a polycrystalline silicon layer, and can be prepared by a one-step boron diffusion process, which can reduce the process steps and shorten the process time. The interaction between laser and the polycrystalline silicon in the P region is also avoided, the difficulty of cell patterning is reduced, and the production yield of cells can be greatly improved.

The invention discloses a half photovoltaic cell and a preparation method thereof, and the method comprises the following steps: S1, carrying out the texturing of an original silicon wafer, and forming a semi-finished cell; s2, carrying out boron diffusion treatment on one surface of the semi-finished battery piece to form a PN junction, namely a front surface; s3, laser is adopted to complete slotting with the specified line number on the front face of the semi-finished battery piece subjected to boron diffusion treatment according to a set pattern; s4, enabling the slotted semi-finished battery piece to enter a BSG and alkali polishing process, cleaning and removing a surface damage layer; and S5, after tunneling oxide layer preparation and doped polycrystalline silicon deposition are sequentially carried out on the back surface of the cleaned semi-finished battery piece, grooving treatment is carried out on the back surface of the cleaned semi-finished battery piece again, and the grooving position corresponds to the grooving position on the front surface of the cleaned semi-finished battery piece. According to the invention, after the boron diffusion and tunneling doped polycrystalline silicon processes, the front and back surfaces of the cell are slotted through the laser, and the repair and passivation are realized by using the subsequent existing process without adding passivation equipment, so that the space is saved, and the cost and the recovery difficulty are reduced.

The embodiment of the invention provides an N-type TOPCon battery and a preparation method thereof, and in the preparation method of the N-type TOPCon battery provided by the embodiment of the invention, after boron diffusion and laser doping, a silicon wafer is oxidized by adopting mixed gas of oxygen and water vapor, so that the oxidation rate is increased, the process temperature can be effectively reduced, the process time can be effectively shortened, and the production efficiency of the N-type TOPCon battery is improved. The doping concentration of boron atoms on the surface of the silicon wafer is remarkably reduced, impurity recombination is reduced, the open voltage of the cell is improved, the boron atom doping junction depth can be reduced, the short-wave light response in sunlight is improved, and the current is improved; in addition, the reduction of the oxidation temperature also reduces the generation of silicon substrate and boron-oxygen defect compound pairs, and reduces the blackening defect of concentric rings.

The invention relates to a preparation process of a TBC battery. The TBC battery comprises a substrate; the substrate is polished and cleaned; the doping treatment process comprises a first doping process and a second doping process, the first doping process is used for carrying out boron diffusion, and the second doping process is used for carrying out phosphorus diffusion; performing a high-temperature annealing process of high-temperature junction pushing on the substrate treated by the doping treatment process; carrying out PSG removal and front surface and side surface alkali polishing processes on the substrate treated by the high-temperature annealing process; and depositing an aluminum oxide layer, a silicon nitride layer and an electrode on the substrate. Boron expansion and phosphorus expansion are respectively carried out on the substrate, and junction pushing is not carried out; boron diffusion and phosphorus diffusion knot pushing processes are carried out in the same high-temperature environment, so that the thermal history is shortened, the energy consumption is reduced, the process flow is simplified, the production cost is reduced, and the production efficiency is improved.

The invention belongs to the technical field of solar cell manufacturing, and provides a step temperature cycle propulsion boron diffusion process and application thereof. The boron diffusion technology comprises the steps that a silicon wafer is placed in boron diffusion equipment, pre-oxidation, pre-deposition and stepped temperature circulation boron diffusion propelling are sequentially carried out on the silicon wafer, and the stepped temperature circulation boron diffusion propelling procedure comprises an initial stage, a middle stage and a final stage which are sequentially carried out. A circulation mode of heating oxygen-free boron expansion and pushing junction and then cooling oxygen-filled boron expansion and pushing junction is adopted in each stage for multiple times of circulation, and the heating temperature and the cooling temperature of each stage are optimized, so that a boron expansion doping layer is formed on the surface of the silicon wafer. According to the boron diffusion process, the oxidation temperature can be reduced, the concentric circle defect can be eliminated, the junction depth and the surface doping concentration of boron diffusion doping can be increased, the uniformity of boron diffusion doping can be improved, the FF, Jsc, Uoc and Eta of the battery can be further improved, the thermal budget can be reduced, and the service life of equipment can be prolonged.

The invention discloses a boron doping method, a boron doping structure and a back contact battery. The method comprises the following steps: step 1) pre-crystallization treatment; step 2) pre-oxidation; (3) boron diffusion; wherein the pre-crystallization treatment is to treat the amorphous silicon layer in the silicon wafer base material in a gradient variable pressure mode in an inert gas atmosphere. According to the method, before pre-oxidation and boron diffusion, amorphous silicon is converted into microcrystalline silicon in a gradient transformation manner, and gradual crystallization is realized, so that lattice stress is reduced, gradient distribution of grain sizes can be realized, the problem of uneven grain sizes caused by a single crystallization condition and the problem of doping concentration fluctuation caused by an unordered structure of the amorphous silicon are avoided, and the yield of the amorphous silicon is improved. According to the method, the boron atoms can be transferred to a balance position more easily, an ordered structure is formed, the distribution is more uniform, the boron-doped structure with better sheet resistance uniformity is obtained, and the photoelectric conversion efficiency of the back contact battery based on the boron-doped structure is further improved.

The invention relates to the technical field of TOPCon batteries, in particular to a TOPCon battery and a preparation method thereof. The preparation method of the TOPCon battery comprises the following steps: texturing a silicon wafer; performing boron diffusion doping on the front surface of the silicon wafer; carrying out acid washing and alkali washing polishing on the back surface of the silicon wafer; a first tunneling layer, a first doped polycrystalline silicon layer, a second tunneling layer and a second doped polycrystalline silicon layer are sequentially deposited on the back face of the silicon wafer, high-temperature annealing is conducted on the silicon wafer, and temporary protection layers are formed in an emitting electrode grid line area and a non-emitting electrode grid line area on the back face of the silicon wafer; performing film opening treatment on the temporary protection layer in a non-emitter grid line area; forming a textured structure on a non-emitter grid line area on the back surface of the silicon wafer; and pickling the silicon wafer. According to the technical scheme, the absorption of sunlight by the TOPCon cell can be improved, and the conversion efficiency of the TOPCon cell can be improved.

The invention relates to the technical field of solar cells, and discloses a TBC cell and a preparation method thereof.The preparation method comprises the steps that a tunneling layer and an intrinsic amorphous silicon layer are prepared on the back face of a silicon wafer; a first barrier layer is locally prepared on the back surface of the intrinsic amorphous silicon layer; boron diffusion enables the intrinsic amorphous silicon layer in a non-first barrier layer region to be converted into a boron-doped polycrystalline silicon layer; removing the local first barrier layer through laser patterning to expose the intrinsic amorphous silicon layer in a laser area; performing wet etching to form a Gap region, and exposing the boron-doped polycrystalline silicon layer and the intrinsic amorphous silicon layer in a non-laser region; locally preparing a second barrier layer on the back surfaces of the Gap region silicon wafer and the boron-doped polycrystalline silicon layer; phosphorus diffusion enables the exposed intrinsic amorphous silicon layer to be converted into a phosphorus-doped polycrystalline silicon layer; removing the second barrier layer and performing texturing; according to the method, the Gap region can be easily formed, the boron-doped polycrystalline silicon layer and the phosphorus-doped polycrystalline silicon layer have no height difference, the working procedures are few, the damage is little, the cost is low, and the battery efficiency can be improved.

The utility model is suitable for the technical field of solar cells, and provides a back contact solar cell, a cell assembly and a photovoltaic system, and the back contact solar cell comprises a silicon substrate which is provided with a back surface and a front surface which are oppositely arranged; the P-type doped polycrystalline silicon layer is positioned in a first region on the back surface of the silicon substrate; the N-type doped polycrystalline silicon layer is positioned in a second region on the back surface of the silicon substrate, and the first region is different from the second region; wherein the thickness of the N-type doped polycrystalline silicon layer is greater than that of the P-type doped polycrystalline silicon layer. According to the back contact solar cell provided by the utility model, the etching difficulty of the P-type doped polycrystalline silicon can be reduced, the patterning process of the P-type doped polycrystalline silicon can be conveniently realized, the boron diffusion treatment process of the P-type doped polycrystalline silicon layer is facilitated, the P-type doped polycrystalline silicon layer with relatively high concentration can be conveniently prepared, and the cell efficiency is improved.