CN115295670A - Preparation method of laser boron-doped battery emitter, battery and preparation system - Google Patents
Preparation method of laser boron-doped battery emitter, battery and preparation system Download PDFInfo
- Publication number
- CN115295670A CN115295670A CN202210957546.0A CN202210957546A CN115295670A CN 115295670 A CN115295670 A CN 115295670A CN 202210957546 A CN202210957546 A CN 202210957546A CN 115295670 A CN115295670 A CN 115295670A
- Authority
- CN
- China
- Prior art keywords
- laser
- silicon substrate
- boron
- battery
- preparation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000002360 preparation method Methods 0.000 title claims abstract description 38
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 140
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 140
- 239000010703 silicon Substances 0.000 claims abstract description 140
- 239000000758 substrate Substances 0.000 claims abstract description 129
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims abstract description 83
- 238000000034 method Methods 0.000 claims abstract description 74
- 229910052796 boron Inorganic materials 0.000 claims abstract description 62
- 239000005388 borosilicate glass Substances 0.000 claims abstract description 43
- 230000008569 process Effects 0.000 claims abstract description 38
- 238000004140 cleaning Methods 0.000 claims abstract description 31
- 238000012545 processing Methods 0.000 claims abstract description 29
- 238000009792 diffusion process Methods 0.000 claims abstract description 23
- 238000000137 annealing Methods 0.000 claims abstract description 11
- 238000001039 wet etching Methods 0.000 claims description 20
- 238000001035 drying Methods 0.000 claims description 15
- 238000004519 manufacturing process Methods 0.000 claims description 15
- 238000005224 laser annealing Methods 0.000 claims description 11
- 239000002253 acid Substances 0.000 claims description 8
- 238000005530 etching Methods 0.000 claims description 8
- 241001270131 Agaricus moelleri Species 0.000 claims description 6
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 claims description 6
- 239000000126 substance Substances 0.000 claims description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 6
- XGCTUKUCGUNZDN-UHFFFAOYSA-N [B].O=O Chemical group [B].O=O XGCTUKUCGUNZDN-UHFFFAOYSA-N 0.000 claims description 5
- 230000005641 tunneling Effects 0.000 claims description 5
- 229910021421 monocrystalline silicon Inorganic materials 0.000 claims description 4
- 230000008439 repair process Effects 0.000 claims description 4
- 238000007639 printing Methods 0.000 claims description 3
- 238000004070 electrodeposition Methods 0.000 claims 1
- 238000006243 chemical reaction Methods 0.000 abstract description 9
- 230000006798 recombination Effects 0.000 abstract description 8
- 238000005215 recombination Methods 0.000 abstract description 8
- 238000011049 filling Methods 0.000 abstract description 5
- CFOAUMXQOCBWNJ-UHFFFAOYSA-N [B].[Si] Chemical compound [B].[Si] CFOAUMXQOCBWNJ-UHFFFAOYSA-N 0.000 abstract description 3
- 239000011521 glass Substances 0.000 abstract description 3
- 239000013078 crystal Substances 0.000 description 14
- 235000012431 wafers Nutrition 0.000 description 8
- 238000005516 engineering process Methods 0.000 description 6
- 230000009471 action Effects 0.000 description 5
- 230000008901 benefit Effects 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- 238000005554 pickling Methods 0.000 description 5
- 238000001816 cooling Methods 0.000 description 4
- 239000012530 fluid Substances 0.000 description 4
- 230000007547 defect Effects 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- 238000005245 sintering Methods 0.000 description 3
- 239000007791 liquid phase Substances 0.000 description 2
- 238000002161 passivation Methods 0.000 description 2
- 238000005096 rolling process Methods 0.000 description 2
- 238000007650 screen-printing Methods 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 229910021419 crystalline silicon Inorganic materials 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000004298 light response Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000001465 metallisation Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 1
- 229920005591 polysilicon Polymers 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
- H01L31/1804—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof comprising only elements of Group IV of the Periodic Table
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/26—Bombardment with radiation
- H01L21/263—Bombardment with radiation with high-energy radiation
- H01L21/268—Bombardment with radiation with high-energy radiation using electromagnetic radiation, e.g. laser radiation
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Electromagnetism (AREA)
- General Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- High Energy & Nuclear Physics (AREA)
- Optics & Photonics (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Weting (AREA)
Abstract
The invention discloses a preparation method of a laser boron-doped battery emitter, a battery and a preparation system, wherein the preparation method of the battery emitter comprises the following steps: selecting a silicon substrate; cleaning the silicon substrate for texturing; carrying out boron diffusion on the silicon substrate to obtain a p + layer and a borosilicate glass layer; processing the position of the grid line by using a first laser device to obtain a p + + region; annealing the silicon substrate by using a second laser device; removing the borosilicate glass layer on the silicon substrate; the invention solves the problem of realizing SE preparation by laser one-time doping, the laser processes the boron silicon glass reserved after boron diffusion, the boron silicon glass is used as a boron source to dope a silicon substrate, a heavily doped region is formed at the position of a grid line, and after a battery piece is metallized, the contact resistance can be reduced, the filling factor of the battery is increased, the recombination of electrons and holes below the grid line is reduced, and the open-circuit voltage of the battery is improved; the shallow doped region reduces recombination, increases the short-circuit current of the cell, and finally effectively improves the conversion efficiency of the cell.
Description
Technical Field
The invention relates to the field of solar cell processing, in particular to a method for realizing preparation of a TOPCon cell Selective Emitter (SE) by laser boron doping, a cell preparation method and a cell preparation system.
Background
At present, TOPCon battery technology has already begun to be produced on a large scale, and Selective Emitter (SE) technology has many advantages as an important means for improving battery conversion efficiency on battery production line. The method has the characteristics of reducing the contact resistance of the battery and the metal grid line, improving the open-circuit voltage and the fill factor of the battery and the like, and the efficiency of the auxiliary battery is improved by more than 0.2%. Therefore, how to design a method for realizing TOPCon cell SE by laser boron doping, which is simple to control and low in cost, is a technical problem to be solved urgently in the industry.
Disclosure of Invention
In order to overcome the defects in the prior art, the invention provides a preparation method of a laser boron-doped battery emitter, a battery and a preparation system.
The invention adopts the technical scheme that a method for realizing preparation of a TOPCon battery selective emitter by laser boron doping is designed, and comprises the following steps: 002. selecting n-type monocrystalline silicon as a silicon substrate; 004. cleaning and texturing two sides of the silicon substrate; 006. carrying out boron diffusion on the upper surface of the silicon substrate to obtain a shallow doped p + layer of boron and a borosilicate glass layer positioned on the upper surface of the shallow doped p + layer; 008. processing the position of a grid line by using a first laser device, and doping boron atoms in the borosilicate glass layer to the position of the grid line, wherein the boron atoms in the borosilicate glass layer are actually doped in a shallow doped p + layer at the position of the grid line to form a heavily doped p + + region; 010. annealing the upper surface of the silicon substrate by using a second laser device so as to repair local damage caused when the boron atoms are doped into the silicon substrate; 012. and carrying out wet etching to remove the borosilicate glass layer on the upper surface of the silicon substrate so as to finish the preparation of the selective emitter.
The boron-oxygen bonded chemical bond in the borosilicate glass absorbs energy transmitted by laser light in the first laser device, and breaks to become the boron atom in a free state, and the boron atom migrates from the inside of the borosilicate glass toward the silicon substrate. The laser power in the first laser device is high, and the boron-oxygen bonded chemical bond absorbs the energy transferred by the laser in the first laser device, which is high, and is broken.
Doping the boron atoms into the silicon substrate under the laser action of the first laser device, and simultaneously enabling the surface of the silicon substrate to have local damage, performing laser processing on the silicon substrate 1 in the step 010 to enable crystal lattices on a path through which a laser beam passes to be locally melted, and matching the crystal lattices again after cooling to form the silicon substrate in a single crystal state for repairing the local damage.
The first laser device adopts a continuous laser or a pulse laser with the laser wavelength of 355nm-2000 nm.
The technological parameters of the first laser device are as follows: the laser power is 10-4000W, the laser processing speed is 1-100 m/s, the light spot of the laser focused on the surface of the silicon substrate is a Gaussian light spot or a flat-top light spot of 40-150 microns, and the process processing line width of the laser processing the surface of the silicon substrate is 40-150 microns; optionally, the flat-topped light spot is a flat-topped light spot with uniformly distributed energy.
The second laser device adopts a pulse laser with the laser wavelength of 355nm-2000 nm.
The process parameters of the second laser device are as follows: the laser power is 10W-4000W, the light spot of the laser focused on the surface of the silicon substrate is a Gaussian light spot or a flat-top light spot with the size of 40 micrometers-300 millimeters, the laser annealing temperature is 10-1200 ℃, and the laser annealing process time is 0-120min; optionally, the flat-topped light spot is a flat-topped light spot with uniformly distributed energy.
The wet etching uses a chain type wet etching device, the chain type wet etching device sequentially adopts a pickling process, a cleaning process and a drying process, hydrofluoric acid with the concentration of 10% -40% is adopted in the pickling process, the pickling temperature is 15-45 ℃, and the pickling time is 10-120 s; pure water is adopted in the cleaning procedure, the cleaning temperature is 15-45 ℃, and the cleaning time is 10-120 s; in the drying procedure, the drying temperature is 15-45 ℃, and the drying time is 10-120 s.
The invention also designs a preparation method of the TOPCon structure battery by laser boron doping, which comprises the method for realizing the TOPCon battery SE preparation by laser boron doping, and also comprises the following steps: double-sided electrodes are prepared on two sides of the silicon substrate through a printing device, the position of a grid line on the upper surface of the silicon substrate is the position of the electrode, the contact part of the electrode and the silicon substrate is a heavily doped p + + region, and a region between the electrodes is a lightly doped p + layer.
Before the double-sided electrode is prepared, the method further comprises the following steps: preparing an antireflection layer on the upper surface of the silicon substrate, and preparing a tunneling oxide layer on the lower surface of the silicon substrate.
The invention also designs a system for preparing the TOPCon battery selective emitter by laser boron doping, which comprises wet etching equipment, a diffusion furnace, a first laser device, a second laser device and chain wet etching equipment which are sequentially arranged, wherein the wet etching equipment is used for cleaning and etching the two sides of the silicon substrate; the diffusion furnace is used for carrying out boron diffusion on the upper surface of the silicon substrate to obtain a shallow doped p + layer of boron and a borosilicate glass layer positioned on the upper surface of the shallow doped p + layer; the first laser device is used for processing a grid line position, and doping boron atoms in the borosilicate glass layer to the grid line position to form a heavily doped p + + region; the second laser device is used for annealing the upper surface of the silicon substrate and repairing local damage caused by doping the boron atoms into the silicon substrate; the chain type wet method equipment is used for removing the borosilicate glass layer on the upper surface of the silicon substrate.
In the technical route of N-type batteries, the TOPCon (Tunnel Oxide Passivated Contact) technology has the excellent characteristics of low attenuation, low power temperature coefficient, high double-sided rate, high weak light response capability and the like. The technology firstly prepares a tunneling oxide layer of 1-2 nanometers on the back of the cell, then deposits a doped polysilicon layer, and the two layers form a passivation contact structure together, thereby providing good interface passivation for the back of the silicon chip.
The technical scheme provided by the invention has the beneficial effects that:
the invention solves the technical problem of realizing SE preparation by laser one-time doping in the TOPCon battery technology, the laser processes borosilicate glass reserved on the surface of a silicon substrate after boron diffusion, the borosilicate glass is used as a boron source to selectively dope the silicon substrate, a heavily doped region is formed at the position of a grid line, and after a battery piece is metalized (the metallization of the battery piece is realized by screen printing and sintering, and then an electrode is printed at the position of the grid line), the contact resistance can be reduced, the filling factor of the battery is increased, the recombination of electrons and holes below the grid line is reduced, and the open-circuit voltage of the battery is improved; the shallow doped region reduces recombination, increases the short-circuit current of the cell, and finally effectively improves the conversion efficiency of the cell.
Drawings
The invention is described in detail below with reference to embodiments and the attached drawings, wherein:
FIG. 1 is a schematic structural diagram of a silicon substrate in various steps according to a preferred embodiment of the present invention;
FIG. 2 is a flow chart of a manufacturing method of the preferred embodiment of the invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Example one
The invention discloses a method for realizing preparation of a TOPCon battery selective emitter by laser boron doping, which refers to a flow chart shown in figure 2 and comprises the following steps:
002. selecting n-type monocrystalline silicon as a silicon substrate 1;
004. cleaning and texturing the two sides of the silicon substrate 1;
006. carrying out boron diffusion on the upper surface of the silicon substrate 1 to obtain a shallow doped p + layer 2 of boron and a borosilicate glass layer 3 positioned on the upper surface of the shallow doped p + layer 2;
008. processing the positions of the grid lines by using a first laser device 5, and doping boron atoms in the borosilicate glass layer 3 to the positions of the grid lines to form a heavily doped p + + region 4;
010. annealing the upper surface of the silicon substrate 1 by using a second laser device 6 to repair local damage caused when the boron atoms are doped into the silicon substrate 1;
012. and carrying out wet etching to remove the borosilicate glass layer 3 on the upper surface of the silicon substrate 1, thereby completing the preparation of the selective emitter.
Fig. 1 shows a schematic structural view of a silicon substrate 1 in various processes in a preferred embodiment, and illustrates the preparation of a TOPCon cell selective emitter. The invention solves the technical problem of realizing SE preparation by laser one-time doping in the TOPCon battery technology, namely, borosilicate glass reserved on the surface of the silicon substrate 1 after boron diffusion is processed by laser, and the borosilicate glass is used as a boron source to selectively dope the silicon substrate 1. The boron-oxygen bonded chemical bond in the borosilicate glass absorbs energy transmitted by the laser beam in the first laser device 5, which is high, and breaks, and becomes the boron atom in a free state, and the boron atom migrates from the inside of the borosilicate glass toward the silicon substrate.
In fig. 1, only the step 004 of cleaning and texturing the upper surface of the silicon substrate 1 to form the pyramid-shaped textured surface, and the steps 006, 008, 010, and 012 all indicate the process treatment performed on the upper surface of the silicon substrate 1.
The processing area of the first laser device 5 is a grid line position, which refers to a position where an electrode is printed in advance, the boron atom concentration of a shallow doping area is increased at the grid line position to form a heavy doping area, and then a structure with shallow doping and heavy doping staggered is formed on the upper surface of the silicon substrate 1, namely, the contact part of the electrode and the silicon substrate is a heavy doping p + + area 4, and the area between the electrodes is a shallow doping p + layer 2. A sintered metal electrode is printed in the heavily doped region and is in contact with the metal electrode, so that the contact resistance is reduced, the filling factor of the battery is increased, the recombination of electrons and holes below a grid line is reduced, and the open-circuit voltage of the battery is improved; the shallow doped region reduces recombination, increases the short-circuit current of the cell, and finally effectively improves the conversion efficiency of the cell.
In some existing methods, a p + + layer with high surface concentration is adopted as a laser doping boron source in the boron diffusion process, and no p + layer is formed; or an external boron source (other equipment is used as a supply device of the boron source), compared with the prior art, the invention can simplify the preparation difficulty and reduce the cost.
The technical scheme of the invention has the advantages that: after light doping is carried out on the surface of the silicon substrate 1, the position of a grid line, which is to be printed with an electrode in the subsequent step, is contacted with a silicon wafer for heavy doping, and light doping is carried out on the position between electrodes, so that the composition of a diffusion layer can be reduced, the short-wave response of light can be improved, and meanwhile, the contact resistance of a front metal electrode and silicon is reduced, so that the short-circuit current, the open-circuit voltage and the filling factor are better improved, and the conversion efficiency is improved.
The boron atoms are doped into the silicon substrate 1 under the laser action of the first laser device 5, and meanwhile, local damage occurs on the surface of the silicon substrate 1, so that after the grid line is processed by the first laser device 5, the silicon substrate 1 battery piece is subjected to laser annealing treatment through the second laser device 6, the lattice mismatch in the silicon substrate 1 caused by laser processing is repaired, the recombination of holes and electrons is reduced, and the conversion efficiency of the battery is further improved. That is, in the 010 step, the silicon substrate 1 is subjected to laser processing so that the crystal lattice on the path through which the laser beam passes is locally melted, and after cooling, the crystal lattice is re-matched to form a silicon substrate in a single crystal state for repairing the local damage.
And after the annealing is not finished, the silicon substrate 1 battery piece enters wet equipment, the borosilicate glass layer 3 on the surface of the silicon substrate 1 is removed, and the preparation of the TOPCon battery selective emitter SE is finished.
In the whole preparation method, an additionally added boron source is not used as a doping source, compared with the prior art, the process difficulty is reduced, the manufacturing cost of the cell is reduced, meanwhile, the production process and the process of the subsequent cell are not changed, the practicability of the method provided by the invention is greatly improved, the TOPCon cell selective emitter SE is successfully prepared, the contact resistance of the silicon substrate 1 and the metal electrode is reduced in a laser processing area, and the filling factor of the cell is increased; the shallow doped region reduces recombination, increases the short-circuit current of the cell, and finally can effectively improve the conversion efficiency of the cell.
After the preparation of the selective emitter is completed:
step 014: coating films on the upper surface and the lower surface of the silicon substrate 1, namely manufacturing a tunneling oxide layer on the lower surface of the battery piece and manufacturing an antireflection layer on the upper surface of the battery piece;
step 016: after the step 014, electrodes were prepared on both sides of the silicon substrate 1 (i.e., electrodes were prepared on the upper and lower surfaces, respectively) by screen printing and sintering, thereby completing the preparation of the high-efficiency TOPCon cell.
Example two
On the basis of the first embodiment, the first laser device 5 adopts a continuous laser or a pulse laser with the laser wavelength of 355nm-2000 nm. The laser power is 10-4000W, the laser processing speed is 1-100 m/s, the light spot focused on the surface of the silicon substrate 1 by the laser is a Gaussian light spot with the size of 40-150 microns or a flat-top light spot with uniformly distributed energy, the light spot is square or round and comprises geometrical shapes such as rectangle, square, round, oval and the like, and the process line width for processing the surface of the silicon substrate 1 by the laser is 40-150 microns. Laser SE processing, which is performed by combining laser parameters with laser emitters having better penetration and high thermal effects, such as infrared laser emitters, is a key to solving the problem of doping B (boron) in BSG into P +. In the prior art, the B source is generally an external B source such as boron source slurry, and other processes and equipment are additionally introduced to add the boron source, which increases the production cost.
The laser effect of the first laser device 5 enables boron atoms in the borosilicate glass layer to be doped into the silicon substrate 1 (a boron source in the borosilicate glass is separated out by utilizing the high energy of the laser and enters the silicon substrate 1), meanwhile, local damage occurs on the surface of the silicon substrate 1, through the step 010, laser processing is carried out on the silicon substrate 1, so that crystal lattices on a path through which a laser beam passes are locally melted, and after cooling, the crystal lattices are matched again to form a silicon substrate in a single crystal state for repairing the local damage.
In the preferred embodiment, the first laser device 5 is used to process the grid line position, and the laser directly acts on the borosilicate glass, the laser used in the process can be a continuous laser with 500W infrared 1064nm wavelength, and optionally, the power used by the laser is 180W, the scanning speed of the laser is 20m/s, and the laser processing line width is 90 microns during the process of processing the silicon substrate 1 by the laser. The laser with infrared 1064nm has better permeability to crystalline silicon, the action of the infrared laser on the silicon substrate 1 can be directly acted on a deeper area inside the silicon substrate 1, the borosilicate glass layer 3 on the surface of the silicon substrate 1 is processed by utilizing the better penetrability and higher thermal effect of the infrared laser, a boron-oxygen combined chemical bond in the borosilicate glass is broken due to the absorption of higher laser-transmitted energy and becomes a free state, laser-doped boron atoms are free from the inside of the borosilicate glass and move towards the fused silicon substrate 1 under the action of higher laser power, the energy transmitted to the boron atoms is larger due to the higher energy of the laser, and the fused area and depth of the silicon substrate 1 layer below the borosilicate glass layer 3 are larger and deeper relative to the laser phosphorus-doped SE of the laser on a p-type battery. Therefore, the free boron atoms with higher energy can enter the silicon substrate 1 deeper through diffusion movement to form a p + + heavily doped region. Through the test of the square resistance of the cell, the reduction amplitude of the square resistance is more than or equal to 40 omega, the diffusion depth of the ECV test is more than or equal to 0.7 micron, and the surface doping concentration of the silicon substrate 1 is more than 1E +19atoms/cm 3 And the concentration decrease is gentle.
EXAMPLE III
On the basis of the first embodiment or the second embodiment, the second laser device 6 adopts a pulse laser with the laser wavelength of 355nm-2000 nm.
The process parameters of the second laser device 6 are as follows: the laser power is 10W to 4000W, the light spot focused on the surface of the silicon substrate 1 by the laser is a Gaussian light spot with the size of 40 microns to 300 millimeters or a flat-top light spot with uniformly distributed energy, the shape of the light spot is square or circular and comprises geometrical shapes such as rectangle, square, circle, ellipse and the like, the laser annealing temperature is 10 ℃ to 1200 ℃, and the laser annealing process time is 0 to 120min.
In the preferred embodiment, the second laser device 6 may use a 1064nm nanosecond laser with a laser power of 100W and an annealing temperature of 800 ℃. Since the silicon substrate 1 is processed by the high-power infrared laser device 5 in the step 008, boron atoms are diffused into the silicon substrate 1, and meanwhile, the silicon substrate 1 is damaged by the laser processing region due to the high-power laser action, such as mismatch of crystal silicon lattices and breakage of chemical bonds of atomic connection, and the main function of laser annealing is to repair the damage of the silicon substrate 1 due to the high-power laser processing of the silicon substrate 1. When a laser beam irradiates the surface of the doped silicon substrate 1, the crystal lattice of the material of the silicon substrate 1 is heated through electro-optical coupling in a short time, so that the crystal lattice on the path which the laser beam passes through is locally melted, and when the atoms in the crystal lattice leave the equilibrium positions of the atoms, the solid phase is converted into the liquid phase, and the crystal lattices are matched again. When the laser beam penetrates through the silicon substrate 1 with the depth larger than the damage depth of the silicon substrate 1 to reach a monocrystalline layer of the silicon substrate 1, and monocrystalline silicon is epitaxially grown at a liquid phase position on the surface of the monocrystalline region which is not damaged by doping after cooling, so that the effect of repairing and eliminating the lattice defect of the silicon substrate 1 is achieved. The method for repairing and eliminating the silicon substrate 1 lattice defect by using the laser annealing mode has the advantages that the process is stable, compared with the conventional annealing furnace, the laser annealing can effectively reduce the energy consumption of equipment, greatly reduce the annealing time, greatly improve the productivity, reduce the running cost of the equipment and the cost of a battery piece, and increase the competitiveness of a client in the TOPCon battery piece market.
Example four
On the basis of the first embodiment, the second embodiment or the third embodiment, further, a wet method device is used for removing the borosilicate glass layer 3 on the upper surface of the silicon substrate 1, a chain type wet etching device is used for wet etching, the chain type wet etching device sequentially adopts an acid cleaning process, a cleaning process and a drying process, hydrofluoric acid with the concentration of 10% -40% is adopted in the acid cleaning process, the acid cleaning temperature is 15-45 ℃, and the acid cleaning time is 10-120 s; pure water is adopted in the cleaning procedure, the cleaning temperature is 15-45 ℃, and the cleaning time is 10-120 s; in the drying procedure, the drying temperature is 15-45 ℃, and the drying time is 10-120 s.
When silicon substrate 1 got into chain wet process equipment, the back (be the lower surface) up, the higher authority that has borosilicate glass layer 3 down, spray the water film to silicon substrate 1's back earlier after getting into chain wet process equipment, the back of protection silicon substrate 1 is not by acidizing fluid etching effect, send silicon substrate 1 into the descaling bath again, gyro wheel in the pickling bath body drives silicon substrate 1 at the acidizing fluid upper surface uniform velocity removal, the gyro wheel is through special treatment, there are a lot of microgrooves in the surface, the gyro wheel has acidizing fluid when rotatory, the acidizing fluid shifts to silicon substrate 1's borosilicate glass layer 3, get rid of borosilicate glass layer 3 through the mode of this kind of gyro wheel area liquid.
In the cleaning process, the silicon substrate 1 enters a pure water cleaning tank, and the silicon substrate 1 is cleaned in an immersion and spraying manner. The washing time is about 10s, and the water temperature is 25 ℃ at normal temperature.
In the drying process, hot air is used for simultaneously blowing and drying the front surface and the back surface of the silicon substrate 1, and the drying time is about 10 s.
EXAMPLE five
The invention also discloses a preparation method of the TOPCon structure battery realized by laser boron doping, which comprises the method for realizing the TOPCon battery selective emitter by laser boron doping, and also comprises the following steps: electrodes are prepared on two sides of the silicon substrate 1 through a printing and sintering device, the position of a grid line on the upper surface of the silicon substrate 1 is the position of the electrode, the contact part of the electrode and the silicon substrate is a heavily doped p + + region 4, the region between the electrodes is a lightly doped p + layer 2, namely the region between one electrode on the upper surface and the adjacent electrode is the lightly doped p + layer 2.
Before the double-sided electrode is prepared, the method further comprises the following steps: preparing an antireflection layer on the upper surface of the silicon substrate, and preparing a tunneling oxide layer on the lower surface of the silicon substrate.
Compared with the method for realizing the preparation of the TOPCon battery SE by secondary boron diffusion and laser boron source slurry doping provided in the industry at present, the invention provides a method for realizing the preparation of the TOPCon battery SE by laser primary processing, and the laser processing utilizes the boron source in boron-silicon glass subjected to boron diffusion as a laser-doped boron raw material, does not need to additionally introduce other procedures and equipment to add the boron source, has simple process procedures, does not need to reintroduce equipment except the laser procedure, and reduces the equipment cost. Meanwhile, the method for preparing the TOPCon cell SE by laser boron doping does not change the process sequence and the process characteristics in the subsequent production process of the subsequent silicon substrate 1 cell. In the invention, a set of laser boron doped SE equipment and a set of laser annealing equipment are added in the existing TOPCon cell production line, so that the equipment cost is low, the automation degree is high, meanwhile, the photoelectric conversion efficiency of the TOPCon cell can be effectively improved by adding the laser boron diffusion SE process, the cell efficiency is improved by over 0.2 percent, the approval of users is obtained, the advantages of the clients in the TOPCon cell production are improved, the competitiveness of the clients in the cell market is increased, and an effective, quick and low-cost path is provided for the improvement of the TOPCon cell photoelectric conversion efficiency.
Example six
The invention also discloses a system for realizing the preparation of the TOPCon battery selective emitter by laser boron doping, which comprises wet etching equipment, a diffusion furnace, a first laser device, a second laser device and chain wet etching equipment which are sequentially arranged, wherein the equipment is sequentially arranged and corresponds to the preparation equipment involved in the preparation step of the selective emitter in the first embodiment (or the second embodiment, or the third embodiment, or the fourth embodiment or the fifth embodiment).
Specifically, the wet etching equipment is used for cleaning and etching the two sides of the silicon substrate, the wet etching equipment is a groove type equipment for multiple purposes, a plurality of groove bodies which are sequentially arranged in parallel are used as a processing groove for etching, a carrying device such as a manipulator is matched for carrying silicon wafers to be processed between the groove and the groove, usually, the silicon wafers are carried in a carrier, and the manipulator realizes the transfer of the silicon wafers through the carrying carrier.
The diffusion furnace is used for carrying out boron diffusion on the upper surface of the silicon substrate to obtain a shallow doped p + layer of boron and a borosilicate glass layer positioned on the upper surface of the shallow doped p + layer;
the first laser device is used for processing the positions of the grid lines, and boron atoms in the borosilicate glass layer are doped to the positions of the grid lines to form a heavily doped p + + region;
the second laser device is used for annealing the upper surface of the silicon substrate and repairing local damage caused by doping the boron atoms into the silicon substrate;
the chain type wet method equipment is used for removing the borosilicate glass layer on the upper surface of the silicon substrate.
The chain type wet method equipment can refer to the fourth embodiment, specifically, the chain type wet method equipment adopts a driving roller to drive the silicon wafer, the driving roller is erected on the groove body, the driving roller is partially immersed in the solution, the single silicon wafer is conveyed through the rolling of the driving roller, and during the period, when the silicon wafer passes through the corresponding process groove or the cleaning groove, the solution is attached to the lower surface of the silicon wafer along with the rolling of the driving roller.
The foregoing examples are illustrative only and not intended to be limiting. Any equivalent modifications or variations without departing from the spirit and scope of the present application should be included in the scope of the claims of the present application.
Claims (10)
1. A method for realizing preparation of a TOPCon battery selective emitter by laser boron doping is characterized by comprising the following steps:
002. selecting n-type monocrystalline silicon as a silicon substrate (1);
004. cleaning and texturing two sides of the silicon substrate;
006. carrying out boron diffusion on the upper surface of the silicon substrate to obtain a shallow doped p + layer (2) of boron and a borosilicate glass layer (3) positioned on the upper surface of the shallow doped p + layer;
008. processing the positions of the grid lines by using a first laser device (5), and doping boron atoms in the borosilicate glass layer to the positions of the grid lines to form a heavily doped p + + region (4);
010. annealing the upper surface of the silicon substrate by using a second laser device (6) so as to repair local damage caused when the boron atoms are doped into the silicon substrate;
012. and carrying out wet etching to remove the borosilicate glass layer on the upper surface of the silicon substrate so as to finish the preparation of the selective emitter.
2. The method for realizing TOPCon cell selective emitter fabrication by laser boron doping according to claim 1, wherein the boron-oxygen bonded chemical bonds in the borosilicate glass absorb the energy delivered by the laser in the first laser device (5) and break to become the boron atoms in a free state, which travel from the inside of the borosilicate glass towards the silicon substrate.
3. The method for realizing TOPCon cell selective emitter fabrication by laser boron doping according to claim 1, wherein the first laser device (5) employs a continuous laser or a pulsed laser with a laser wavelength of 355nm-2000 nm.
4. A method for implementing TOPCon cell selective emitter fabrication by laser boron doping according to claim 3, wherein the process parameters of the first laser device (5) are: the laser power is 10-4000W, the laser processing speed is 1-100 m/s, the laser spot focused on the surface of the silicon substrate (1) is a Gaussian spot or a flat-top spot of 40-150 microns, and the process line width of the laser processing on the surface of the silicon substrate is 40-150 microns.
5. Laser boron doping method for TOPCon cell selective emitter fabrication according to claim 1, characterized in that the second laser device (6) uses a continuous or pulsed laser with a laser wavelength of 355nm-2000 nm.
6. The method for realizing TOPCon cell selective emitter fabrication by laser boron doping according to claim 5, wherein the process parameters of the second laser device (6) are: the laser power is 10W to 4000W, the facula of the laser focused on the surface of the silicon substrate (1) is a Gaussian facula or a flat-top facula of 40 microns to 300 mm, the temperature of laser annealing is 10 ℃ to 1200 ℃, and the time of the laser annealing process is 0 to 120min.
7. The method for realizing TOPCon battery selective emitter preparation by laser boron doping as claimed in claim 1, wherein said wet etching uses a chain type wet etching apparatus, said chain type wet etching apparatus sequentially adopting an acid cleaning process, a cleaning process, and a drying process,
hydrofluoric acid with the concentration of 10% -40% is adopted in the acid cleaning process, the acid cleaning temperature is 15 ℃ -45 ℃, and the acid cleaning time is 10-120 s;
pure water is adopted in the cleaning procedure, the cleaning temperature is 15-45 ℃, and the cleaning time is 10-120 s;
in the drying procedure, the drying temperature is 15-45 ℃, and the drying time is 10-120 s.
8. A method for preparing a TOPCon structure cell by laser boron doping, which comprises the method for preparing a TOPCon cell selective emitter by laser boron doping according to any one of claims 1 to 7, and further comprises:
be in through printing device silicon substrate (1) two sides preparation electrode, the upper surface grid line position of silicon substrate is the electrode position, the electrode with silicon substrate contact site is heavily doped p + + district (4), the region between the electrode is shallow doping p + layer (2).
9. The method of claim 8, further comprising, prior to forming the electrode:
preparing an antireflection layer on the upper surface of the silicon substrate, and preparing a tunneling oxide layer on the lower surface of the silicon substrate.
10. A system for realizing TOPCon battery selective emitter preparation by laser boron doping is characterized by comprising: the silicon substrate etching device comprises a wet-process etching device, a diffusion furnace, a first laser device, a second laser device and a chain-type wet etching device which are sequentially arranged, wherein the wet-process etching device is used for cleaning and etching the two sides of the silicon substrate (1); the diffusion furnace is used for carrying out boron diffusion on the upper surface of the silicon substrate (1) to obtain a shallow doped p + layer (2) of boron and a borosilicate glass layer (3) positioned on the upper surface of the shallow doped p + layer on the upper surface; the first laser device is used for processing the positions of the grid lines, and boron atoms in the borosilicate glass layer are doped to the positions of the grid lines to form a heavily doped p + + region (4); the second laser device is used for annealing the upper surface of the silicon substrate and repairing local damage caused by doping the boron atoms into the silicon substrate; the chain type wet method equipment is used for removing the borosilicate glass layer on the upper surface of the silicon substrate.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210957546.0A CN115295670A (en) | 2022-08-10 | 2022-08-10 | Preparation method of laser boron-doped battery emitter, battery and preparation system |
| PCT/CN2023/104093 WO2024032224A1 (en) | 2022-08-10 | 2023-06-29 | Preparation method for laser boron-doped battery emitter, and battery and preparation system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210957546.0A CN115295670A (en) | 2022-08-10 | 2022-08-10 | Preparation method of laser boron-doped battery emitter, battery and preparation system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115295670A true CN115295670A (en) | 2022-11-04 |
Family
ID=83827325
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210957546.0A Pending CN115295670A (en) | 2022-08-10 | 2022-08-10 | Preparation method of laser boron-doped battery emitter, battery and preparation system |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN115295670A (en) |
| WO (1) | WO2024032224A1 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115911186A (en) * | 2023-01-30 | 2023-04-04 | 通威太阳能(眉山)有限公司 | Solar cell and preparation method thereof |
| CN116885049A (en) * | 2023-09-07 | 2023-10-13 | 武汉帝尔激光科技股份有限公司 | Laser doping method and TOPCON solar cell |
| CN117117043A (en) * | 2023-10-20 | 2023-11-24 | 苏州腾晖光伏技术有限公司 | Method for forming N-type passivation contact battery and manufacturing system thereof |
| CN117457805A (en) * | 2023-12-25 | 2024-01-26 | 正泰新能科技股份有限公司 | TOPCon battery, preparation method thereof and photovoltaic module |
| WO2024032224A1 (en) * | 2022-08-10 | 2024-02-15 | 常州捷佳创精密机械有限公司 | Preparation method for laser boron-doped battery emitter, and battery and preparation system |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20150007396A (en) * | 2013-07-10 | 2015-01-21 | 현대중공업 주식회사 | Method for fabricating bi-facial solar cell |
| CN110993728A (en) * | 2019-11-12 | 2020-04-10 | 浙江爱旭太阳能科技有限公司 | Manufacturing method of single crystal silicon SE-PERC battery annealed by infrared laser |
| CN110880541A (en) * | 2019-11-14 | 2020-03-13 | 上海交通大学 | Novel-structure n-type crystalline silicon PERT double-sided battery and preparation method thereof |
| CN111106183A (en) * | 2019-12-26 | 2020-05-05 | 湖南红太阳光电科技有限公司 | Method for preparing back full-passivation contact solar cell by using tubular PECVD (plasma enhanced chemical vapor deposition) and back full-passivation contact solar cell |
| CN111524797A (en) * | 2020-04-26 | 2020-08-11 | 泰州中来光电科技有限公司 | Preparation method of selective emitter |
| CN114464701A (en) * | 2022-01-17 | 2022-05-10 | 常州时创能源股份有限公司 | Diffusion method of crystalline silicon solar cell and application thereof |
| CN115295670A (en) * | 2022-08-10 | 2022-11-04 | 常州捷佳创精密机械有限公司 | Preparation method of laser boron-doped battery emitter, battery and preparation system |
-
2022
- 2022-08-10 CN CN202210957546.0A patent/CN115295670A/en active Pending
-
2023
- 2023-06-29 WO PCT/CN2023/104093 patent/WO2024032224A1/en unknown
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2024032224A1 (en) * | 2022-08-10 | 2024-02-15 | 常州捷佳创精密机械有限公司 | Preparation method for laser boron-doped battery emitter, and battery and preparation system |
| CN115911186A (en) * | 2023-01-30 | 2023-04-04 | 通威太阳能(眉山)有限公司 | Solar cell and preparation method thereof |
| CN116885049A (en) * | 2023-09-07 | 2023-10-13 | 武汉帝尔激光科技股份有限公司 | Laser doping method and TOPCON solar cell |
| CN116885049B (en) * | 2023-09-07 | 2023-11-28 | 武汉帝尔激光科技股份有限公司 | Laser doping method and TOPCON solar cell |
| CN117117043A (en) * | 2023-10-20 | 2023-11-24 | 苏州腾晖光伏技术有限公司 | Method for forming N-type passivation contact battery and manufacturing system thereof |
| CN117117043B (en) * | 2023-10-20 | 2024-01-26 | 苏州腾晖光伏技术有限公司 | Method for forming N-type passivation contact battery and manufacturing system thereof |
| CN117457805A (en) * | 2023-12-25 | 2024-01-26 | 正泰新能科技股份有限公司 | TOPCon battery, preparation method thereof and photovoltaic module |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2024032224A1 (en) | 2024-02-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN115295670A (en) | Preparation method of laser boron-doped battery emitter, battery and preparation system | |
| KR100974221B1 (en) | Method for forming selective emitter of solar cell using laser annealing and Method for manufacturing solar cell using the same | |
| CN107394012A (en) | A kind of silicon chip laser doping SE diffusion technique | |
| CN101777606B (en) | Crystalline silicon solar battery selective diffusion process | |
| WO2017020689A1 (en) | Back contact type solar cell based on p-type silicon substrate and preparation method therefor | |
| WO2017049801A1 (en) | Silicon wafer surface passivation method and n-type bifacial cell preparation method | |
| CN102569522A (en) | Method for preparing local back contact structure of high efficiency crystalline silicon solar cell | |
| CN106057951A (en) | Double-sided solar cell based on P type silicon substrate and preparation method thereof | |
| WO2017020690A1 (en) | Back-contact solar cell based on p-type silicon substrate | |
| CN113948611B (en) | P-type IBC battery, preparation method thereof, assembly and photovoltaic system | |
| CN106784152B (en) | A kind of preparation method of IBC batteries | |
| CN107240621A (en) | A kind of method for making selective doping structure | |
| CN106024983B (en) | Solar cell and preparation method thereof | |
| CN113809205A (en) | Preparation method of solar cell | |
| KR101370126B1 (en) | Method for forming selective emitter of solar cell using annealing by laser of top hat type and Method for manufacturing solar cell using the same | |
| CN111106188B (en) | N-type battery, preparation method of selective emitter of N-type battery and N-type battery | |
| CN104300032A (en) | Single crystal silicon solar ion implantation technology | |
| CN112117334A (en) | Preparation method of selective emitter and preparation method of solar cell | |
| CN112909128A (en) | Manufacturing method of heterojunction solar cell and heterojunction solar cell | |
| CN113314627B (en) | PERC solar cell and preparation method thereof | |
| CN110931598A (en) | Manufacturing method of secondary annealed single crystal silicon SE-PERC battery | |
| CN103187478A (en) | Solar battery doped region forming method | |
| CN109509812A (en) | A kind of production method of crystal silicon solar energy battery emitter | |
| JPH0529638A (en) | Manufacture of photoelectric transducer | |
| CN106328735A (en) | C-Si/a-Si/mc-Si solar cell structure and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |