CN117410387B - Thin grid structure of crystalline silicon solar cell and preparation method thereof - Google Patents
Thin grid structure of crystalline silicon solar cell and preparation method thereof Download PDFInfo
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- CN117410387B CN117410387B CN202311722633.9A CN202311722633A CN117410387B CN 117410387 B CN117410387 B CN 117410387B CN 202311722633 A CN202311722633 A CN 202311722633A CN 117410387 B CN117410387 B CN 117410387B
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- 238000002360 preparation method Methods 0.000 title claims abstract description 10
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- 239000002184 metal Substances 0.000 claims abstract description 36
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- 238000001035 drying Methods 0.000 claims abstract description 13
- 238000002161 passivation Methods 0.000 claims abstract description 9
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- 238000000034 method Methods 0.000 claims description 29
- 238000007650 screen-printing Methods 0.000 claims description 17
- 229910001111 Fine metal Inorganic materials 0.000 claims description 16
- 229910052782 aluminium Inorganic materials 0.000 claims description 13
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- 238000004519 manufacturing process Methods 0.000 claims description 10
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- 238000003618 dip coating Methods 0.000 claims description 2
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- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 abstract description 22
- 229910052709 silver Inorganic materials 0.000 abstract description 22
- 239000004332 silver Substances 0.000 abstract description 22
- 230000000052 comparative effect Effects 0.000 description 62
- 239000010410 layer Substances 0.000 description 31
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- 229910001152 Bi alloy Inorganic materials 0.000 description 11
- 239000010949 copper Substances 0.000 description 11
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- KHZAWAWPXXNLGB-UHFFFAOYSA-N [Bi].[Pb].[Sn] Chemical compound [Bi].[Pb].[Sn] KHZAWAWPXXNLGB-UHFFFAOYSA-N 0.000 description 10
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- 239000011248 coating agent Substances 0.000 description 9
- 238000000576 coating method Methods 0.000 description 9
- 238000011049 filling Methods 0.000 description 9
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 8
- 238000007639 printing Methods 0.000 description 7
- 229910001128 Sn alloy Inorganic materials 0.000 description 5
- 229910045601 alloy Inorganic materials 0.000 description 5
- 239000000956 alloy Substances 0.000 description 5
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 4
- 238000005336 cracking Methods 0.000 description 4
- 229910052759 nickel Inorganic materials 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 229910052710 silicon Inorganic materials 0.000 description 4
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- PQIJHIWFHSVPMH-UHFFFAOYSA-N [Cu].[Ag].[Sn] Chemical compound [Cu].[Ag].[Sn] PQIJHIWFHSVPMH-UHFFFAOYSA-N 0.000 description 2
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- 239000000523 sample Substances 0.000 description 2
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- 229910000969 tin-silver-copper Inorganic materials 0.000 description 2
- JJPWJEGNCRGGGA-UHFFFAOYSA-N 4-[[2-[5-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]-1,3,4-oxadiazol-2-yl]acetyl]amino]benzoic acid Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C1=NN=C(O1)CC(=O)NC1=CC=C(C(=O)O)C=C1 JJPWJEGNCRGGGA-UHFFFAOYSA-N 0.000 description 1
- DEXFNLNNUZKHNO-UHFFFAOYSA-N 6-[3-[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]piperidin-1-yl]-3-oxopropyl]-3H-1,3-benzoxazol-2-one Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C1CCN(CC1)C(CCC1=CC2=C(NC(O2)=O)C=C1)=O DEXFNLNNUZKHNO-UHFFFAOYSA-N 0.000 description 1
- 229910017944 Ag—Cu Inorganic materials 0.000 description 1
- 229910016331 Bi—Ag Inorganic materials 0.000 description 1
- 229910000881 Cu alloy Inorganic materials 0.000 description 1
- 229910000676 Si alloy Inorganic materials 0.000 description 1
- 229910018956 Sn—In Inorganic materials 0.000 description 1
- 229910001297 Zn alloy Inorganic materials 0.000 description 1
- XNRNVYYTHRPBDD-UHFFFAOYSA-N [Si][Ag] Chemical compound [Si][Ag] XNRNVYYTHRPBDD-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
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- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
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- 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
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- 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
- H01L31/02—Details
- H01L31/0224—Electrodes
- H01L31/022408—Electrodes for devices characterised by at least one potential jump barrier or surface barrier
- H01L31/022425—Electrodes for devices characterised by at least one potential jump barrier or surface barrier for solar cells
- H01L31/022433—Particular geometry of the grid contacts
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- 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
- H01L31/04—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 adapted as photovoltaic [PV] conversion devices
- H01L31/06—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 adapted as photovoltaic [PV] conversion devices characterised by potential barriers
- H01L31/068—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 adapted as photovoltaic [PV] conversion devices characterised by potential barriers the potential barriers being only of the PN homojunction type, e.g. bulk silicon PN homojunction solar cells or thin film polycrystalline silicon PN homojunction solar cells
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Abstract
The invention belongs to the technical field of solar cells, and particularly relates to a crystalline silicon solar cell fine grid structure and a preparation method thereof. The preparation method of the thin gate structure of the crystalline silicon solar cell comprises the following steps: paving a layer of conductive paste with the thickness not exceeding 5 mu m on the surface of the crystalline silicon solar cell, drying, and sintering at 500-850 ℃ to form a plurality of conductive paste thin grid lines; the consumption of the conductive paste can eliminate the passivation layer and complete ohmic contact between the fine grid and the emitter; the thin metal wires are parallelly paved on the height direction of the conductive paste thin grid wires in a laser auxiliary welding mode, and a thin grid structure of the crystalline silicon solar cell is obtained; the implementation position of the laser beam of the laser auxiliary welding is on the crystalline silicon solar cell within 100 mu m from the thin metal wire; the maximum length of the cross section of the thin metal wire is not more than 200 mu m. The invention can directly and obviously reduce the silver consumption of the thin grid of the crystalline silicon solar cell and improve the electrical property.
Description
Technical Field
The invention belongs to the technical field of solar cells, and particularly relates to a crystalline silicon solar cell fine grid structure and a preparation method thereof.
Background
With the continuous development of solar cells, the development and manufacture of efficient, stable, low-cost solar cells is a focus of attention in the current industry. At present, the front and back sides of crystalline silicon solar cells in the market are usually provided with a main grid and a thin grid in a screen printing mode, battery pieces of the main grid line and the thin grid line are welded with a welding strip, and current collected by the thin grid is converged to the main grid and then transmitted to the welding strip.
The conductive paste in the crystalline silicon solar cell is mainly silver-aluminum paste or silver paste, the consumption is high, and the high manufacturing cost of the crystalline silicon solar cell is caused because the silver-aluminum paste or silver paste is generally expensive.
In order to reduce the amount of silver aluminum paste or silver paste used, there is a 0BB technology currently available. The 0BB technology is to replace the battery cell main grid with a welding strip, and the welding strip is directly contacted with the fine grid to lead out current in the assembly link. The 0BB technology can eliminate the silver consumption of the main grid part, improve the power and the yield, but cannot directly reduce the silver consumption of the thin grid line with higher proportion in the cost.
The conventional screen printing method is adopted to print the fine grid on the solar cell, sintering is carried out after the fine grid is printed, the consumption of silver paste or silver aluminum paste is reduced, the line height of the fine grid is reduced, the line resistance of the fine grid is affected, the collection current of the fine grid is increased, the current is converged to the main grid, and the photoelectric conversion efficiency of the crystalline silicon solar cell is reduced.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a thin gate structure of a crystalline silicon solar cell and a preparation method thereof.
In a first aspect, the present invention provides a method for preparing a thin gate structure of a crystalline silicon solar cell, which is implemented by adopting the following technical scheme: the preparation method of the thin gate structure of the crystalline silicon solar cell comprises the following steps:
paving a layer of conductive paste with the thickness not exceeding 5 mu m on the surface of the crystalline silicon solar cell, drying, and sintering at 500-850 ℃ to form a plurality of conductive paste thin grid lines; the consumption of the conductive paste can eliminate the passivation layer and complete ohmic contact between the fine grid and the emitter;
the thin metal wires are parallelly paved on the height direction of the conductive paste thin grid wires in a laser auxiliary welding mode, and a thin grid structure of the crystalline silicon solar cell is obtained; the implementation position of the laser beam of the laser auxiliary welding is on the crystalline silicon solar cell within 100 mu m from the thin metal wire; the maximum length of the cross section of the thin metal wire is not more than 200 mu m.
The method for preparing the thin gate structure of the crystalline silicon solar cell is simple to operate, and simultaneously meets the effects of improving the efficiency and reducing the cost of the crystalline silicon solar cell. Compared with the conventional conductive paste for the thin grid line of the existing crystalline silicon solar cell, the thickness of the conductive paste is not less than 10 mu m, and the thickness of the conductive paste in the invention is not more than 5 mu m, so that the consumption of the conductive paste can be greatly reduced, and the manufacturing cost of the crystalline silicon solar cell is greatly reduced. The consumption of the conductive paste is less, the damage to the emitter caused by excessive etching is avoided while the passivation layer is eliminated and the ohmic contact between the thin gate and the emitter is completed, and the conversion efficiency of the crystalline silicon solar cell is improved.
However, the inventor finds that the line resistance of a fine grid structure of conductive paste with the thickness of not more than 5 μm is higher and the electrical performance is poorer when only one layer of conductive paste with the thickness of not more than 5 μm is paved on the surface of the crystalline silicon solar cell in the research process.
According to the invention, the thin metal wires are horizontally connected on the conductive paste thin grid line structure, so that the line resistance of the conductive paste thin grid line is reduced, and the conversion efficiency of the crystalline silicon solar cell is improved.
The sintering process at 500-850 ℃ is carried out before the thin metal wires are connected, the thin metal wires have no defect of being oxidized in the sintering process, and the wire resistance of the thin grid structure of the crystalline silicon solar cell is reduced, so that the conversion efficiency of the crystalline silicon solar cell is improved.
The inventor finds that the conductive adhesive or the non-conductive adhesive can better bond the conductive paste thin grid line and the thin metal wire, but the aging resistance of the conductive adhesive or the non-conductive adhesive is poor, and the attenuation rate of the photoelectric conversion efficiency of the crystalline silicon solar cell is serious. The infrared welding is generally that the whole crystalline silicon solar cell is heated, the cell is easy to warp, and the thin grid line of the conductive paste is thin and fine, so that the overselding phenomenon is easy to occur. And both infrared welding and manual welding of thin wires require a coating that aids in the welding action.
The laser beam implementation position of the laser auxiliary welding adopted by the invention is positioned on the crystalline silicon solar cell near the thin metal wire, and can generate photo-generated carriers, and the partial current is formed and heat is generated by combining deflection voltage of 10V or more than 10V, so that the thin grid line of the conductive paste and the thin metal wire are connected. The laser beam implementation position of the laser auxiliary welding is on the crystalline silicon solar cell within 100 mu m from the thin metal wire, which shows that the laser auxiliary welding is different from the conventional laser welding, the conventional laser welding is implemented on a welded object, and the heat generated by laser is directly used for welding, so that the crystalline silicon solar cell is seriously damaged due to the excessively high energy and temperature corresponding to the conventional laser welding, and the crystalline silicon solar cell thin grid structure is not suitable for the crystalline silicon solar cell thin grid structure.
More importantly, the silver in the thin grid line of the conductive paste is melted by the local high temperature generated by the laser auxiliary welding, so that the thin metal line and the thin grid line of the conductive paste can be connected, the phenomena of cold joint, overselding and hidden cracking are not easy to occur, and the warpage is lower than that corresponding to infrared welding and manual welding. Meanwhile, the silver in the conductive paste fine grid line is melted by the local high temperature generated by laser auxiliary welding, and acts on silicon substrate in the battery piece to form silver-silicon alloy, so that the contact optimization of the crystalline silicon solar cell fine grid and the emitter is further enhanced, the contact resistance of the crystalline silicon solar cell is reduced, and the filling factor and the photoelectric conversion efficiency of the crystalline silicon solar cell are improved. In addition, the controllability of the laser auxiliary welding is good, and only a very thin anti-oxidation coating layer is needed for the thin metal wire corresponding to the laser auxiliary welding.
Preferably, the laser beam of the laser-assisted welding is applied to a crystalline silicon solar cell sheet at a distance of 10-50 μm from the thin metal wire.
In a more preferred embodiment of the invention, the laser beam of the laser-assisted welding is applied at a position on the crystalline silicon solar cell sheet 20 μm from the thin metal wire.
In the present invention, the conductive paste is suitable for crystalline silicon solar cells, including but not limited to silver paste or silver-aluminum paste, wherein the silver content in the silver paste or silver-aluminum paste may be normal content, such as 75wt% or more and 75wt% or less.
Preferably, the way of paving the layer of conductive paste on the surface of the crystalline silicon solar cell is selected from any one of screen printing, laser transfer printing, spray coating, dip coating or extrusion.
In a preferred embodiment of the present invention, a layer of conductive paste is laid on the surface of the crystalline silicon solar cell sheet in a screen printing manner.
Preferably, the cross-sectional shape of the thin metal wire is selected from any one of a circle, an ellipse, a rectangle, a trapezoid, or a triangle.
In a preferred embodiment of the present invention, the thin metal wire has a circular cross-sectional shape.
Preferably, the fine metal wire is selected from any one of a fine copper wire, a fine tin-clad copper wire, a fine tin alloy-clad copper wire, a fine silver alloy-clad copper wire, a fine aluminum wire, a fine silver-clad aluminum wire, a fine silver alloy-clad aluminum wire, a fine tin-clad aluminum wire, and a fine tin alloy-clad aluminum wire.
The composition of the tin alloy layer of the fine tin alloy coated copper wire In the invention is one or more selected from Sn-Pb-Bi alloy, sn-Pb-Ag alloy, sn-Pb-Sb alloy, sn-Ag-Cu alloy, sn-Ag alloy, sn-Cu alloy, sn-Sb alloy, sn-Bi-Ag alloy, sn-Zn alloy and Sn-In alloy.
In a preferred embodiment of the present invention, the thin metal wire is a thin copper wire or a thin tin alloy clad copper wire.
The invention preferably uses a fine copper wire or a fine tin alloy Bao Tongxian with a certain oxidation preventing effect, for example, a tin alloy coating or a nickel layer with a thickness of not more than 1 μm or other oxidation preventing treatment fine copper wire.
In a second aspect, the invention provides a front fine grid structure of a crystalline silicon solar cell, which is realized by adopting the following technical scheme:
the front fine grid structure of the crystalline silicon solar cell is manufactured by the manufacturing method of the crystalline silicon solar cell fine grid structure.
Preferably, the front fine grid structure of the crystalline silicon solar cell comprises a front conductive paste fine grid line and a front fine metal line connected to the front conductive paste fine grid line in the height direction, wherein the width of the front conductive paste fine grid line is not more than 30 mu m, the height of the front conductive paste fine grid line is not more than 5 mu m, and the maximum length of the cross section of the front fine metal line is not more than 30 mu m.
In the present invention, the maximum length of the cross section of the front surface thin metal wire includes any one of 25 to 30 μm, 20 to 25 μm, 15 to 20 μm, 10 to 15 μm, 5 to 10 μm, or less than 5 μm.
The smaller the width of the front conductive paste thin grid line and the maximum length of the cross section of the front thin metal line, the more the shading area of the front surface of the crystalline silicon solar cell can be reduced, so that the short-circuit current and the photoelectric conversion efficiency of the crystalline silicon solar cell are improved.
More preferably, the width of the front side conductive paste thin grid line is 15-30 μm, the height of the front side conductive paste thin grid line is 2.5-3.5 μm, and the maximum length of the cross section of the front side thin metal line is 15-30 μm.
In a preferred embodiment of the invention, the front side thin metal wire has a maximum cross-sectional length of 15-20 μm.
In a third aspect, the invention provides a back fine grid structure of a crystalline silicon solar cell, which is realized by adopting the following technical scheme:
the back fine grid structure of the crystalline silicon solar cell is manufactured by the manufacturing method of the crystalline silicon solar cell fine grid structure.
Preferably, the back fine grid structure of the crystalline silicon solar cell comprises a back conductive paste fine grid line and a back fine metal line connected to the back conductive paste fine grid line in the height direction, wherein the width of the back conductive paste fine grid line is not more than 200 mu m, the height of the back conductive paste fine grid line is not more than 5 mu m, and the maximum length of the cross section of the back fine metal line is not more than 200 mu m.
The shading area of the back side of the crystalline silicon solar cell has less influence on the photoelectric conversion efficiency than the front side of the crystalline silicon solar cell. Particularly in the back contact cell, the light shielding area has less influence on photoelectric conversion efficiency.
More preferably, the width of the back side conductive paste thin gate line is 20-180 μm, the height of the back side conductive paste thin gate line is 2.5-3.5 μm, and the maximum length of the cross section of the back side thin metal line is 20-180 μm.
In a preferred embodiment of the present invention, the width of the back side conductive paste thin gate line is 20-100 μm, the height of the back side conductive paste thin gate line is 2.5-3.5 μm, and the maximum length of the cross section of the back side thin metal line is 20-100 μm.
In summary, the invention has the following beneficial effects:
1. the method for preparing the thin gate structure of the crystalline silicon solar cell is simple to operate, and simultaneously meets the effects of improving the efficiency and reducing the cost of the crystalline silicon solar cell.
2. The conductive paste which has the thickness of not more than 5 mu m and can eliminate the passivation layer and finish ohmic contact between the thin gate and the emitter is paved on the surface of the crystalline silicon solar cell, so that the consumption of the conductive paste can be reduced, damage to the emitter caused by excessive etching is avoided, and the conversion efficiency of the crystalline silicon solar cell is improved. The thin metal wires are horizontally connected to the conductive paste thin grid line structure, so that the line resistance of the conductive paste thin grid line is reduced, the conductivity of the crystalline silicon solar cell thin grid structure is improved, and the conversion efficiency of the crystalline silicon solar cell is greatly improved.
3. The invention adopts laser auxiliary welding to connect the thin metal wire with the thin grid wire of the conductive paste, is not easy to generate the phenomena of cold joint, overselding and hidden cracking, has low warpage, can also act on the silicon substrate in the cell, further enhances the contact optimization of the thin grid and the emitter of the crystalline silicon solar cell, reduces the contact resistance of the crystalline silicon solar cell, and further improves the filling factor and the photoelectric conversion efficiency of the crystalline silicon solar cell. In addition, the controllability of laser auxiliary welding is good, and the laser auxiliary welding only needs a layer of very thin anti-oxidation coating corresponding to the thin metal wire, so that the conductivity is better.
Drawings
The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain, without limitation, the invention.
Fig. 1 is a schematic structural diagram of a thin gate structure of a crystalline silicon solar cell according to the present invention.
Fig. 2 is a schematic top view of a thin gate structure of a crystalline silicon solar cell according to the present invention.
Fig. 3 is a front view schematically showing a thin gate structure of a crystalline silicon solar cell according to the present invention.
In the figure: 1. a thin metal wire; 2. fine grid lines of conductive paste; 3. crystalline silicon solar cells.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described in conjunction with the detailed description and examples, and it is apparent that the described examples are some, but not all, examples of the present invention. Thus, the following detailed description of the embodiments of the invention is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The following description is made with reference to specific examples.
Examples
The invention provides a crystalline silicon solar cell fine grid structure, which is shown in figures 1-3, and consists of a plurality of conductive paste fine grid lines 2 paved on a crystalline silicon solar cell sheet 3 and fine metal lines 1 paved on the conductive paste fine grid lines 2 in a parallel manner in the height direction, wherein the thickness of the conductive paste fine grid lines 2 is not more than 5 mu m, and the maximum length of the cross section of each fine metal line 1 is not more than 200 mu m.
The preparation method of the TOPCON battery front fine grid structure provided in the embodiment 1 comprises the following steps:
s1, printing a layer of AX301 silver-aluminum paste with the height of 3.5 mu m, the width of 17 mu m and the number of 168 manufactured by the photoelectric technology (Jiangsu) limited company on the front side of an N-type TOPCO battery piece through screen printing, and drying for 30S at the temperature peak value of 200 ℃ and sintering for 1.5min at the temperature peak value of 740 ℃ under the condition of the belt speed of 12000mm/min to form a front-side conductive paste thin grid line;
s2, parallelly overlaying the thin copper wires with the diameter of 17 mu m on the height direction of the front-side conductive paste thin grid wires prepared in the step S1 in a laser auxiliary welding mode to obtain a TOPCO battery front-side thin grid structure; the laser beam implementation position of the laser auxiliary welding is 20 mu m away from the thin copper wire, the power of the laser auxiliary welding corresponding to the laser beam is 80W, the scanning speed of the laser beam is 80000mm/s, the scanning time of the laser beam is 3s, and the deflection voltage is 10V; the surface of the fine copper wire contained a tin-lead-bismuth alloy coating of 1 μm (the tin-lead-bismuth alloy contained 43wt% of Sn, 43wt% of Pd, and 14wt% of Bi).
Example 2 provides a method for preparing a top cell front fine grid structure, which is different from example 1 only in that the surface of the fine copper wire contains a tin-silver-copper alloy coating of 1 μm (the tin-silver-copper alloy contains 95.9wt% of Sn, 3.5wt% of Ag, and 0.6wt% of Cu).
Example 3 provides a method for preparing a top cell front side fine grid structure, which differs from example 1 only in that the fine copper wire surface contains a nickel layer of 1 μm.
Comparative example 1 provides a method for preparing a TOPCon battery front fine grid structure, comprising the following steps:
a layer of AX301 type silver aluminum paste with the height of 10 mu m, the width of 22 mu m and the number of 168 is printed on the front surface of an N type TOPCO battery piece through screen printing, and the front surface fine grid structure of the TOPCO battery is obtained after drying for 30s at the temperature peak value of 200 ℃ and sintering for 1.5min at the temperature peak value of 740 ℃ under the condition of the belt speed of 12000 mm/min.
Comparative example 2 provides a method for preparing a TOPCon battery front fine grid structure, comprising the following steps:
a layer of AX301 silver-aluminum paste with the height of 3.5 mu m, the width of 17 mu m and the number of 168 is printed at the front fine grid of the N-type TOPCO battery piece through screen printing, and the front fine grid structure of the TOPCO battery is obtained after drying for 30s at the temperature peak value of 200 ℃ and sintering for 1.5min at the temperature peak value of 740 ℃ under the condition of the belt speed of 12000 mm/min.
Comparative example 3 provides a method for preparing a TOPCon battery front fine grid structure, comprising the following steps:
s1, printing a layer of AX301 silver-aluminum paste with the height of 3.5 mu m, the width of 17 mu m and the number of 168 crystal-wave photoelectric technologies (Jiangsu) limited company at the front fine grid position of an N-type TOPCON battery piece through screen printing, and drying for 30S at the temperature peak value of 200 ℃ under the condition of the belt speed of 12000mm/min to obtain a front conductive paste fine grid line structure;
s2, parallelly stacking fine copper wires with the diameter of 17 mu m on the height direction of the fine grid wires of the front-side conductive paste prepared in the step S1 by adopting conductive adhesive (purchased from Hangao Co., ltd., model LOCTITE ABLESTIK CE 3103), curing for 30min at 150 ℃, and sintering for 1.5min at the temperature peak value of 740 ℃ under the condition of the belt speed of 12000mm/min to obtain the front-side fine grid structure of the TOPCON battery; wherein, the conductive adhesive is evenly sprayed on the lower surface of the fine copper wire contacted with the fine grid line, and the dosage of the conductive adhesive is 0.03g/cm 2 The method comprises the steps of carrying out a first treatment on the surface of the The surface of the fine copper wire contains a nickel layer of 1 μm.
Comparative example 4 provides a method for preparing a TOPCon battery front side fine grid structure, which is different from example 1 only in the step S2, wherein the operation steps of the step S2 are as follows:
s2, parallelly overlaying a fine copper wire with the diameter of 17 mu m on the height direction of the fine grid line of the front-side conductive paste prepared in the step S1 by adopting conductive adhesive (purchased from Hangao Co., ltd., model LOCTITE ABLESTIK CE 3103), and curing for 30min at 150 ℃ to obtain a front-side fine grid structure of the TOPCO battery; wherein, the conductive adhesive is evenly sprayed on the lower surface of the fine copper wire contacted with the fine grid line, and the dosage of the conductive adhesive is 0.03g/cm 2 The method comprises the steps of carrying out a first treatment on the surface of the The surface of the fine copper wire contains a nickel layer of 1 μm.
Comparative example 5 provides a method for preparing a TOPCon battery front side fine grid structure, which is different from example 1 only in the step S2, wherein the operation steps of the step S2 are as follows:
the method comprises the steps of (1) parallelly paving 17 mu m-diameter thin copper wires on the height direction of the front-side conductive paste thin grid wires prepared in the step (S1) in an automatic infrared welding mode to obtain a TOPCO battery front-side thin grid structure; wherein the power of automatic infrared welding is 3500W, the temperature of automatic infrared welding is 185 ℃, and the time of automatic infrared welding is 1.2s; the surface of the fine copper wire contained a tin-lead-bismuth alloy coating of 1 μm (the tin-lead-bismuth alloy contained 43wt% of Sn, 43wt% of Pd, and 14wt% of Bi).
Comparative example 6 provides a method for preparing a TOPCon battery front side fine grid structure, which is different from example 1 only in the step S2, wherein the operation steps of the step S2 are as follows:
the thin copper wires with the diameter of 17 mu m are parallelly paved on the height direction of the thin grid wires of the front-side conductive paste prepared in the step S1 in a manual welding mode, and a front-side thin grid structure of the TOPCO battery is obtained; wherein the temperature of manual welding is 185 ℃, and the time of manual welding is 1.2s; the surface of the fine copper wire contained a 3 μm tin-lead-bismuth alloy coating (tin-lead-bismuth alloy having a Sn content of 43wt%, a Pd content of 43wt%, and a Bi content of 14 wt%).
Examples 1-3 and comparative examples 1-6 above used the same model of TOPCon battery cells, the same spacing of fine grid lines, the same conductive paste, the same baking conditions, and the same sintering temperature and time.
The TOPCO battery front side fine grid structure conductive paste thickness of 3.5 μm and fine grid line width of 17 μm in the above examples 1-3 and comparative examples 2-6, the TOPCO battery front side fine grid structure conductive paste thickness of 10 μm and fine grid width of 22 μm in comparative example 1, and the wet weight (the quality of the AX301 silver aluminum paste printed on the battery sheet) of the battery sheet corresponding to the front side fine grid structure of examples 1-3 and comparative examples 2-6 was only 27% of the wet weight of the battery sheet corresponding to the front side fine grid structure of comparative example 1, which greatly reduced the silver consumption of the TOPCO battery front side fine grid structure.
Meanwhile, the TOPCon batteries for corresponding tests were obtained by screen printing the same front main grid, the same back main grid and the same back fine grid on the basis of the front fine grid structures of the TOPCon batteries prepared in examples 1 to 3 and comparative examples 1 to 6, respectively.
The electrical properties of the top fine grid structures of the top batteries prepared in examples 1-3 and comparative examples 1-6 were represented by testing the electrical properties of each corresponding top battery, each corresponding top battery using the same test conditions, and the gain or attenuation of each of examples 1-3 and comparative examples 2-6 relative to comparative example 1 was shown, and the test data are shown in table 1. Wherein Δff refers to the fill factor value of the relative gain or attenuation, data is positive when the fill factor is relative to the gain, and data is negative when the fill factor is relative to the attenuation; Δrc refers to the contact resistance value of the relative gain or decay, with positive data when the contact resistance is relative to the gain and negative data when the contact resistance is relative to the decay; ΔRgl refers to a line resistance value of relative gain or attenuation, data is positive when the line resistance is relative to gain, and data is negative when the line resistance is relative to attenuation; Δisc refers to a short-circuit current value that is relatively gain or attenuated, the data being positive when the short-circuit current value is relatively gain, and the data being negative when the short-circuit current value is relatively attenuated; Δncell refers to a conversion efficiency value of relative gain or attenuation, with positive data when the conversion efficiency is relative to gain and negative data when the conversion efficiency is relative to attenuation.
Table 1 electrical performance test data for examples 1-3 and comparative examples 2-6
| ΔNcell(%) | ΔFF(%) | ΔIsc(A) | ΔRc(mohm) | ΔRgl(ohm) | |
| Example 1 | 0.18 | 0.49 | 0.126 | -0.251 | -0.314 |
| Example 2 | 0.20 | 0.51 | 0.128 | -0.283 | -0.345 |
| Example 3 | 0.27 | 0.64 | 0.137 | -0.653 | -0.356 |
| Comparative example 2 | -1.36 | -5.22 | 0.075 | -0.059 | 32.154 |
| Comparative example 3 | -0.09 | -0.13 | -0.114 | 1.652 | 1.132 |
| Comparative example 4 | 0.05 | 0.01 | 0.107 | 0.005 | -0.224 |
| Comparative example 5 | 0.12 | 0.11 | 0.116 | -0.052 | -0.292 |
| Comparative example 6 | 0.08 | 0.02 | 0.104 | 0.078 | -0.146 |
As can be seen from the data in table 1, in example 1, a layer of conductive paste having a thickness of 3.5 μm (width of 17 μm) was screen-printed, and then a thin copper wire having a thickness of 17 μm was parallel-stacked on the height direction of the front side conductive paste thin gate line prepared in step S1 by means of laser-assisted welding, and in comparative example 1, a layer of conductive paste having a thickness of 10 μm (width of 22 μm) was screen-printed, and compared with comparative example 1, example 1 not only greatly reduced the manufacturing cost of the front side thin gate structure of the TOPCon battery, but also prevented damage caused by excessive etching of the emitter while eliminating the passivation layer and completing ohmic contact of the thin gate and the emitter, thereby improving the short-circuit current and photoelectric conversion efficiency of the front side thin gate structure of the TOPCon battery.
As can be seen from the experimental data of example 1, comparative example 4 and comparative example 2 in table 1, comparative example 2 only screen-prints a layer of conductive paste with a thickness of 3.5 μm, and TOPCon cell front side fine grid structure corresponding to comparative example 2 has higher line resistance, lower short circuit current, filling factor and photoelectric conversion efficiency, which means that TOPCon cell front side fine grid structure only lays a layer of conductive paste for eliminating passivation layer and completing ohmic contact between fine grid and emitter electrode, has higher line resistance and poor electrical performance.
As can be seen from the experimental data of example 1, comparative example 4 and comparative example 3 in table 1, in comparative example 3, the TOPCon battery front fine grid structure prepared by the preparation process of firstly paving slurry, drying, then bonding fine copper wires, and finally sintering is poor in conductivity of the fine metal wires after the sintering process, and the conductive slurry cannot well eliminate the passivation layer and complete ohmic contact between the fine grid and the emitter, so that the contact resistance and the wire resistance of the TOPCon battery front fine grid structure are improved, and the short circuit current, the filling factor and the photoelectric conversion efficiency of the TOPCon battery front fine grid structure are reduced.
As can be seen from comparing the experimental data of examples 1-3 and comparative examples 4-6 in table 1, examples 1-3 adopt a laser-assisted welding mode to horizontally connect the fine grid line and the fine metal line of the conductive paste, comparative examples 5-6 adopt an automatic infrared welding mode and a manual welding mode, comparative example 4 adopts a conductive adhesive bonding mode, and examples 1-3 adopt a laser-assisted welding mode to have lower contact resistance corresponding to the fine grid of the crystalline silicon solar cell, and have higher short-circuit current, filling factor and photoelectric conversion efficiency; comparative examples 5-6 have higher contact resistance corresponding to thin grids of crystalline silicon solar cells by automatic infrared welding and manual welding, and lower short-circuit current, filling factor and photoelectric conversion efficiency. The laser-assisted welding can further enhance the contact optimization of the thin grid and the emitter of the crystalline silicon solar cell, and reduce the contact resistance of the crystalline silicon solar cell, so that the filling factor and the photoelectric conversion efficiency of the crystalline silicon solar cell are improved. Meanwhile, the cost of the laser auxiliary welding is obviously lower than that of the conductive adhesive, and the operation of bonding the conductive adhesive is more complex than that of the laser auxiliary welding.
The cell sheet containing the top cell front fine grid structure corresponding to examples 1-3 and comparative examples 3-6 was placed on a sample stage of a profilometer (model SP1103W-sek, purchased from the company of the mechanical and electrical technologies of shanghai), and a contact probe was scanned in a direction parallel to the grid line and perpendicular to the grid line, respectively, using a low pressure mode to obtain a height difference between the center of the silicon wafer and the left and right sides; the scanning was repeated, the average height difference of 5 battery pieces was identified as the warpage of the battery pieces, and the test results are shown in table 2.
EL images were obtained by a Pede EL-C30 tester, whether the battery pieces containing TOPCON batteries corresponding to examples 1-3 and comparative examples 3-6 had a hidden crack phenomenon or not was observed, the number of cracks in which 10 battery pieces had hidden cracks was counted, and the test results are shown in Table 2.
The thin copper wire tails soldered in the TOPCon cell front side fine grid structures corresponding to examples 1-3 and comparative examples 4-6 were terminated to a dynamometer of a cell peel tester (model SG-2103, available from gold go detection equipment limited, su-state) and peeled off at a constant speed of 6mm/s at about 180 deg., the dynamometer recorded the change in pull-off force in newtons at a sampling rate of 100 s-1. The thin copper wires in the front thin grid structure of the TOPCon battery corresponding to the pull examples 1-3 and the comparative examples 4-6 are counted, the number of times that the pull-off force is less than 0.1N in 4 thin copper wires at the same position on 5 battery pieces and the thin grid wires of the conductive paste on the battery pieces are intact (marked as virtual welding at the moment) is counted, the number of times that the pull-off force is less than 0.1N in 4 thin copper wires at the same position on 5 battery pieces and the conductive paste on the battery pieces has no thin grid wire residue and directly exposes the surface of the passivation layer of the silicon wafer (marked as overspray at the moment) is counted, and the test results are shown in table 2.
TABLE 2 test data for warpage, hidden crack, cold joint and overseld phenomena
| Warp degree (mu m) | Number of cracks | Number of dummy welds | Number of overseld | |
| Example 1 | 7 | 0 | 0 | 0 |
| Example 2 | 5 | 0 | 0 | 0 |
| Example 3 | 6 | 0 | 0 | 0 |
| Comparative example 3 | 5 | 0 | / | / |
| Comparative example 4 | 6 | 0 | / | / |
| Comparative example 5 | 29 | 3 | 0 | 5 |
| Comparative example 6 | 17 | 17 | 12 | 7 |
As can be seen from Table 2, the laser-assisted welding adopted in examples 1-3 of the present invention has good controllability, can connect the thin metal wire with the thin grid line of the conductive paste, is not easy to generate the phenomena of cold joint, overseld and hidden crack, and has low warpage. While the automatic infrared welding of comparative example 5 is easy to generate overselding and hidden cracking, the warping degree is high, the manual welding of comparative example 6 is difficult, the virtual welding, hidden cracking and overselding are easy to generate, and the warping degree is high.
Embodiment 4 provides a method for preparing a TOPCon battery back fine grid structure, which comprises the following steps:
s1, printing a layer of AX101 silver paste with the height of 3.5 mu m, the width of 17 mu m and the number of 168 manufactured by the photoelectric technology (Jiangsu) limited company on the back surface of an N-type TOPCO battery piece through screen printing, and forming a back surface conductive paste fine grid line after drying for 30S at the temperature peak value of 200 ℃ and sintering for 1.5min at the temperature peak value of 740 ℃ under the condition of the belt speed of 12000 mm/min;
s2, parallelly laying the fine copper wires with the diameter of 17 mu m on the height direction of the back conductive paste fine grid wires prepared in the step S1 in a laser auxiliary welding mode to obtain a TOPCO battery back fine grid structure; the laser beam implementation position of the laser auxiliary welding is 20 mu m away from the thin copper wire, the power of the laser auxiliary welding corresponding to the laser beam is 80W, the scanning speed of the laser beam is 80000mm/s, the scanning time of the laser beam is 3s, and the deflection voltage is 10V; the surface of the fine copper wire contained a tin-lead-bismuth alloy coating of 1 μm (the tin-lead-bismuth alloy contained 43wt% of Sn, 43wt% of Pd, and 14wt% of Bi).
Comparative example 7 provides a method for preparing a TOPCon battery back fine grid structure, comprising the following steps: a layer of AX101 silver paste with the height of 10 mu m, the width of 22 mu m and the number of 168 manufactured by the photoelectric technology (Jiangsu) limited company is printed on the back surface of an N-type TOPCO battery piece through screen printing, and the back surface fine grid structure of the TOPCO battery is obtained after the silver paste is dried for 30s at the temperature peak value of 200 ℃ and sintered for 1min at the temperature peak value of 740 ℃ under the condition of the belt speed of 12000 mm/min.
The example 4 and comparative example 7 above used the same model TOPCon battery cells and the same spacing of the thin grid lines.
The thickness of the conductive paste of the back fine grid structure of the TOPCon battery in the above example 4 is 3.5 μm, the width of the fine grid line is 17 μm, the thickness of the conductive paste of the back fine grid structure of the TOPCon battery in the comparative example 7 is 10 μm, the width of the fine grid is 22 μm, the wet weight (the mass of AX101 silver paste printed on the battery sheet) of the battery sheet of the corresponding back fine grid structure of the example 4 is only 27% of the wet weight of the battery sheet of the corresponding back fine grid structure of the comparative example 7, and the silver consumption of the back fine grid structure of the TOPCon battery is greatly reduced.
Meanwhile, the TOPCon battery for testing was obtained by screen printing the same front fine grid, the same front main grid and the same back main grid on the basis of the back fine grid structures of the TOPCon batteries prepared in example 4 and comparative example 7, respectively.
The electrical properties of the back side fine grid structure of the TOPCon batteries prepared in example 4 and comparative example 7 were represented by testing the electrical properties of the TOPCon batteries for the corresponding test in example 4 and comparative example 7, and the same test conditions were used for the TOPCon batteries for the corresponding test in example 4 and comparative example 7.
ΔNcell, ΔFF, and ΔIsc for example 4 were 0.16%, 0.43%, and 0.122A, respectively, and ΔRc for example 4 was-0.244 mohm and ΔRgl was-0.292 ohm, respectively, relative to comparative example 7. The TOPCON cell back fine gate structure has the advantages that compared with the TOPCON cell back fine gate structure of pure slurry, the TOPCON cell back fine gate structure has the advantages that the electrical performance is greatly improved, the contact resistance and the line resistance of the crystalline silicon solar cell are reduced, and the filling factor, the short-circuit current and the photoelectric conversion efficiency of the crystalline silicon solar cell are improved.
Embodiment 5 provides a method for preparing a back fine grid structure of an IBC battery, which comprises the following steps:
s1, printing a layer of SP7881-X aluminum paste with the height of 3.5 mu m and the width of 40 mu m manufactured by Hunan Lide electronic paste Co., ltd. On the back surface P area of an IBC battery through screen printing, and drying for 20S at the temperature peak value of 210 ℃ under the condition of the belt speed of 12000 mm/min;
s2, printing a layer of AX101 silver paste with the height of 3.5 mu m and the width of 40 mu m produced by the photoelectric technology (Jiangsu) limited company on the back surface N area of the IBC battery piece prepared in the step S1 through screen printing, and drying for 30S at the temperature peak value of 200 ℃ under the condition that the belt speed is 12000mm/min, wherein the width of the fine grid line is 40 mu m;
s3, sintering the IBC battery piece dried in the step S1 and the step S2 for 45 seconds at the peak temperature of 750 ℃ under the condition of the belt speed of 12000mm/min to obtain a back conductive paste fine grid line;
s4, parallelly overlaying the thin copper wires with the diameter of 40 mu m on the height direction of the back conductive paste thin grid wires prepared in the step S1 in a laser auxiliary welding mode to obtain an IBC battery back thin grid structure; the laser beam implementation position of the laser auxiliary welding is 20 mu m away from the thin copper wire, the power of the laser auxiliary welding corresponding to the laser beam is 80W, the scanning speed of the laser beam is 80000mm/s, the scanning time of the laser beam is 3s, and the deflection voltage is 10V; the surface of the fine copper wire contained a tin-lead-bismuth alloy coating of 1 μm (the tin-lead-bismuth alloy contained 43wt% of Sn, 43wt% of Pd, and 14wt% of Bi).
Comparative example 8 provides a method for preparing a back fine grid structure of an IBC battery, comprising the following steps:
s1, printing a layer of SP7881-X aluminum paste with the height of 10 mu m and the width of 40 mu m manufactured by Hunan Lide electronic paste Co., ltd in the back P area of an IBC battery through screen printing, and drying at the temperature peak value of 210 ℃ for 20S under the condition of the belt speed of 12000 mm/min;
s2, printing a layer of AX101 silver paste with the height of 10 mu m and the width of 40 mu m produced by the photoelectric technology (Jiangsu) limited company on the back surface N area of the IBC battery prepared in the step S1 through screen printing, and drying for 30S at the temperature peak value of 200 ℃ under the condition of the belt speed of 12000 mm/min;
and S3, sintering the IBC battery piece dried in the step S1 and the step S2 for 45 seconds at the peak temperature of 750 ℃ under the condition of the belt speed of 12000mm/min, so as to obtain the back fine grid structure of the IBC battery.
The example 5 and comparative example 8 above used the same type of IBC battery cells, the same number and the same spacing of thin grid lines.
The thickness of the conductive paste of the back P region and the N region of the IBC battery in the above example 5 is 3.5 μm, the thickness of the conductive paste of the back P region and the N region of the IBC battery in the comparative example 8 is 10 μm, and the wet weight (the mass of the SP7881-X aluminum paste printed on the battery sheet and the mass of the AX101 silver paste) of the battery sheet corresponding to the back fine gate structure in the example 5 is only 35% of the wet weight of the battery sheet corresponding to the back fine gate structure in the comparative example 8, thereby greatly reducing the silver consumption of the back fine gate structure of the IBC battery.
Meanwhile, the same back main grid structure of the IBC battery is adopted on the basis of the back fine grid structures of the IBC batteries prepared in the embodiment 5 and the comparative example 8, and the corresponding IBC battery for testing is obtained respectively.
The electrical properties of the back side fine grid structures of the IBC batteries prepared in example 5 and comparative example 8 were represented by testing the electrical properties of the IBC batteries for the corresponding test in example 5 and comparative example 8, and the IBC batteries for the corresponding test in example 5 and comparative example 8 used the same test conditions.
ΔNcell, ΔFF, and ΔIsc for example 5 were 0.15%, 0.41%, and 0.099A, respectively, and ΔRc for example 5 was-0.233 mohm and ΔRgl was-0.276 ohm, respectively, relative to comparative example 8. The back fine grid structure of the IBC battery has the advantages that compared with the back fine grid structure of the IBC battery of pure slurry, the electrical property of the back fine grid structure of the IBC battery is greatly improved, the contact resistance and the line resistance of the crystalline silicon solar battery are reduced, and the filling factor, the short-circuit current and the photoelectric conversion efficiency of the crystalline silicon solar battery are improved.
While the present invention has been described with reference to the above embodiments, it is apparent to those skilled in the art from this disclosure that various changes and modifications can be made without departing from the spirit of the invention.
Claims (11)
1. The preparation method of the thin gate structure of the crystalline silicon solar cell is characterized by comprising the following steps of:
paving a layer of conductive paste with the thickness not exceeding 5 mu m on the surface of the crystalline silicon solar cell, drying, and sintering at 500-850 ℃ to form a plurality of conductive paste thin grid lines; the consumption of the conductive paste can eliminate the passivation layer and complete ohmic contact between the fine grid and the emitter;
the thin metal wires are parallelly paved on the height direction of the conductive paste thin grid wires in a laser auxiliary welding mode, and a thin grid structure of the crystalline silicon solar cell is obtained; the implementation position of the laser beam of the laser auxiliary welding is on the crystalline silicon solar cell within 100 mu m from the thin metal wire; the maximum length of the cross section of the thin metal wire is not more than 200 mu m.
2. The method for fabricating a thin gate structure of a crystalline silicon solar cell according to claim 1, wherein the laser beam for laser-assisted soldering is performed on a crystalline silicon solar cell sheet 10-50 μm away from the thin metal wire.
3. The method for preparing the thin-gate structure of the crystalline silicon solar cell according to claim 1, wherein the manner of laying a layer of conductive paste on the surface of the crystalline silicon solar cell is any one of screen printing, laser transfer printing, spray coating, dip coating or extrusion.
4. The method for manufacturing a thin gate structure of a crystalline silicon solar cell according to claim 1, wherein the cross-sectional shape of the thin metal wire is selected from any one of a circle, an ellipse, a rectangle, a trapezoid, and a triangle.
5. The method for manufacturing a fine gate structure of a crystalline silicon solar cell according to claim 1 or 4, wherein the fine metal wire is selected from any one of a fine copper wire, a fine tin-clad copper wire, a fine tin alloy-clad copper wire, a fine silver alloy-clad copper wire, a fine aluminum wire, a fine silver-clad aluminum wire, a fine silver alloy-clad aluminum wire, a fine tin-clad aluminum wire, and a fine tin alloy-clad aluminum wire.
6. A front side fine grid structure of a crystalline silicon solar cell, characterized in that the method for manufacturing the fine grid structure of the crystalline silicon solar cell is adopted according to any one of claims 1 to 5.
7. The crystalline silicon solar cell front side fine grid structure according to claim 6, comprising front side conductive paste fine grid lines and front side fine metal lines connected to the height direction of the front side conductive paste fine grid lines, wherein the width of the front side conductive paste fine grid lines is not more than 30 μm, the height of the front side conductive paste fine grid lines is not more than 5 μm, and the maximum length of the cross section of the front side fine metal lines is not more than 30 μm.
8. The crystalline silicon solar cell front side fine grid structure according to claim 7, wherein the width of the front side conductive paste fine grid line is 15-30 μm, the height of the front side conductive paste fine grid line is 2.5-3.5 μm, and the maximum length of the cross section of the front side fine metal line is 15-30 μm.
9. A back side fine grid structure of a crystalline silicon solar cell, characterized in that the method for manufacturing the fine grid structure of the crystalline silicon solar cell is adopted.
10. The crystalline silicon solar cell back side fine grid structure according to claim 9, comprising a back side conductive paste fine grid line and a back side fine metal line connected to the back side conductive paste fine grid line in the height direction, wherein the width of the back side conductive paste fine grid line is not more than 200 μm, the height of the back side conductive paste fine grid line is not more than 5 μm, and the maximum length of the cross section of the back side fine metal line is not more than 200 μm.
11. The crystalline silicon solar cell back side fine grid structure according to claim 10, wherein the width of the back side conductive paste fine grid line is 20-180 μm, the height of the back side conductive paste fine grid line is 2.5-3.5 μm, and the maximum length of the cross section of the back side fine metal line is 20-180 μm.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5084107A (en) * | 1989-06-05 | 1992-01-28 | Mitsubishi Denki Kabushiki Kaisha | Solar cell and solar cell array with adhered electrode |
| JP2004134656A (en) * | 2002-10-11 | 2004-04-30 | Sharp Corp | Solar cell fabricating method and solar cell fabricated thereby |
| CN102214729A (en) * | 2010-04-09 | 2011-10-12 | 陕西众森电能科技有限公司 | Front electrode structure of solar battery and manufacturing method of front electrode structure |
| CN102683437A (en) * | 2011-03-18 | 2012-09-19 | 陕西众森电能科技有限公司 | Solar cell electrode structure and solar cell series connection method |
| CN204204882U (en) * | 2014-09-28 | 2015-03-11 | 苏州中来光伏新材股份有限公司 | Without main grid high efficiency back contact solar cell assembly |
| CN205564768U (en) * | 2016-04-28 | 2016-09-07 | 泰州乐叶光伏科技有限公司 | Front -face electrode structure of solar battery |
| CN110212039A (en) * | 2019-05-30 | 2019-09-06 | 江苏欧达丰新能源科技发展有限公司 | The method that laser sintered tinsel prepares the thin gate line electrode of photovoltaic cell |
| CN113140647A (en) * | 2021-05-20 | 2021-07-20 | 成都晔凡科技有限公司 | Heterojunction solar cell, photovoltaic module and manufacturing method |
-
2023
- 2023-12-15 CN CN202311722633.9A patent/CN117410387B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5084107A (en) * | 1989-06-05 | 1992-01-28 | Mitsubishi Denki Kabushiki Kaisha | Solar cell and solar cell array with adhered electrode |
| JP2004134656A (en) * | 2002-10-11 | 2004-04-30 | Sharp Corp | Solar cell fabricating method and solar cell fabricated thereby |
| CN102214729A (en) * | 2010-04-09 | 2011-10-12 | 陕西众森电能科技有限公司 | Front electrode structure of solar battery and manufacturing method of front electrode structure |
| CN102683437A (en) * | 2011-03-18 | 2012-09-19 | 陕西众森电能科技有限公司 | Solar cell electrode structure and solar cell series connection method |
| CN204204882U (en) * | 2014-09-28 | 2015-03-11 | 苏州中来光伏新材股份有限公司 | Without main grid high efficiency back contact solar cell assembly |
| CN205564768U (en) * | 2016-04-28 | 2016-09-07 | 泰州乐叶光伏科技有限公司 | Front -face electrode structure of solar battery |
| CN110212039A (en) * | 2019-05-30 | 2019-09-06 | 江苏欧达丰新能源科技发展有限公司 | The method that laser sintered tinsel prepares the thin gate line electrode of photovoltaic cell |
| CN113140647A (en) * | 2021-05-20 | 2021-07-20 | 成都晔凡科技有限公司 | Heterojunction solar cell, photovoltaic module and manufacturing method |
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Denomination of invention: A Fine Grid Structure and Preparation Method for Crystal Silicon Solar Cells Granted publication date: 20240209 Pledgee: Bank of Nanjing Limited by Share Ltd. Wuxi branch Pledgor: Jinglan photoelectric technology (Jiangsu) Co.,Ltd. Registration number: Y2024980014217 |
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