CN114937705A - Solar cell, production method and production system thereof, and photovoltaic module - Google Patents
Solar cell, production method and production system thereof, and photovoltaic module Download PDFInfo
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- CN114937705A CN114937705A CN202210448598.5A CN202210448598A CN114937705A CN 114937705 A CN114937705 A CN 114937705A CN 202210448598 A CN202210448598 A CN 202210448598A CN 114937705 A CN114937705 A CN 114937705A
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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
- H01L31/0216—Coatings
- H01L31/02161—Coatings for devices characterised by at least one potential jump barrier or surface barrier
- H01L31/02167—Coatings for devices characterised by at least one potential jump barrier or surface barrier for solar cells
- H01L31/02168—Coatings for devices characterised by at least one potential jump barrier or surface barrier for solar cells the coatings being antireflective or having enhancing optical properties for the solar cells
-
- 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
-
- 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 at least one potential-jump barrier or surface barrier
-
- 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 System
-
- 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
- H01L31/186—Particular post-treatment for the devices, e.g. annealing, impurity gettering, short-circuit elimination, recrystallisation
- H01L31/1868—Passivation
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- 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
Abstract
The invention provides a solar cell, a production method and a production system thereof, and a photovoltaic module, and relates to the technical field of photovoltaics. The solar cell includes: a silicon substrate; at least one first doping area is arranged in a local area of a light-facing surface of the silicon substrate; the doping type of each first doping region is the same as that of the silicon substrate, and the doping concentration of each first doping region is greater than that of the silicon substrate; sequentially stacking a chemical passivation film and a field passivation antireflection film on the silicon substrate and the light-facing side of the first doping region; at least one front grid line electrode located on the light-facing side of the silicon substrate; the at least one front gate line electrode and the at least one first doping region are in contact with each other. The solar cell has the advantages of less auger recombination, good process matching performance, good photoelectric conversion efficiency and capability of reducing the production cost.
Description
Technical Field
The invention relates to the technical field of photovoltaics, in particular to a solar cell, a production method and a production system thereof, and a photovoltaic module.
Background
The solar cell has a wide application prospect due to the potential of high photoelectric conversion efficiency.
However, the conventional solar cell still has some difficulties in improving the photoelectric conversion efficiency. At present, some problems can be solved appropriately mainly by changing the partial structure. However, the photoelectric conversion efficiency of the conventional solar cell has a large space for improvement.
Disclosure of Invention
The invention provides a solar cell, a production method and a production system thereof, and a photovoltaic module, and aims to solve the problem of low photoelectric conversion efficiency caused by poor process matching of the conventional solar cell.
In a first aspect of the present invention, there is provided a solar cell comprising:
a silicon substrate;
at least one first doping area is arranged in a local area of a light-facing surface of the silicon substrate; the doping type of each first doping area is the same as that of the silicon substrate, and the doping concentration of each first doping area is greater than that of the silicon substrate;
sequentially stacking a chemical passivation film and a field passivation antireflection film which are distributed on the silicon substrate and the light-facing side of the first doping region;
at least one front grid line electrode positioned on the light-facing side of the silicon substrate; at least one of the front gate line electrodes and at least one of the first doped regions are in contact with each other.
In the invention, the chemical passivation film arranged towards the light side can play a good role in chemical passivation, and the field passivation antireflection film can play a good role in field passivation and antireflection, so that the surface passivation capability of amorphous silicon can be basically achieved. And the chemical passivation film and the field passivation antireflection film have weak or almost no absorption to short wave and visible light of incident light, so that the loss of short circuit current of the solar cell can be reduced. Meanwhile, the first doping regions are only distributed on the local light-facing surface region of the silicon substrate, and Auger recombination basically does not exist at the positions without the first doping regions, so that the Auger recombination brought by the first doping regions is relatively less, the process matching performance is better, and the losses of short-circuit current and open-circuit voltage caused by Auger recombination can be reduced. Meanwhile, the first doping area on the light-facing side of the silicon substrate, the chemical passivation film and the field passivation antireflection film do not need to use amorphous silicon coating equipment and transparent conductive oxide coating equipment, so that the cost of production equipment and the space occupied by the production equipment can be greatly reduced, for example, half of the cost of the production equipment and half of the space occupied by the production equipment are substantially reduced. In addition, the light facing surface of the silicon substrate does not need to be provided with a transparent conductive oxide film, so that the production cost can be reduced.
Optionally, the highest doping concentration of each first doping region is: 2X 10 19 /cm 3 -5×10 20 /cm 3 。
Optionally, the depth of each first doping region is 0.1-0.5 um; the depth direction of the first doping region is parallel to the laminating direction of the chemical passivation film and the field passivation antireflection film.
Optionally, the chemical passivation film includes: a silicon oxide film or an aluminum oxide film; and/or the field passivation antireflection film comprises a silicon nitride film.
Optionally, the refractive index of the field passivation antireflection film is 1.9-2.2.
Optionally, the solar cell further includes: and the antireflection film is positioned on the light-facing side of the field passivation antireflection film.
Optionally, the material of the antireflection film is selected from silicon oxynitride.
Optionally, the solar cell further includes: the intrinsic amorphous silicon film, the doped amorphous silicon film, the transparent conductive oxide film and the back electrode are sequentially distributed on the backlight side of the silicon substrate in a stacking mode, wherein the doped amorphous silicon film is different from the doping type of the silicon substrate;
the back electrode is an entire electrode layer covering the transparent conductive oxide film, and the thickness of the transparent conductive oxide film is 5-80 nm; the thickness direction of the transparent conductive oxide film is parallel to the laminating direction of the chemical passivation film and the field passivation antireflection film.
Optionally, the thickness of the whole electrode layer is 1-10 um.
Optionally, the back electrode is a nickel-copper-silver laminated electrode.
Optionally, in the nickel-copper-silver laminated electrode: the mass ratio of the nickel element, the copper element and the silver element is as follows: (0.5-2.5): (5-9): (0.5-2.5).
Optionally, the front grid line electrode is a nickel-copper-silver laminated grid line electrode
Optionally, in the nickel-copper-silver laminated gate line electrode: the mass ratio of the nickel element, the copper element and the silver element is as follows: (0.5-2.5): (5-9): (0.5-2.5).
Optionally, each front gate line electrode and each first doping region are in one-to-one correspondence and are in contact with each other.
Optionally, a size of a projection of each front gate line electrode on the first doping region corresponding to the position in the first direction is equal to a size of the first doping region corresponding to the position in the first direction, and a size of a projection of each front gate line electrode on the first doping region corresponding to the position in the second direction is 15-50um smaller than a size of the first doping region corresponding to the position in the second direction; the first direction and the second direction are both parallel to a light facing surface of the silicon substrate and are vertical to each other;
and/or the height of each front grid line electrode is 5-20 um; the direction of the height is parallel to the laminating direction of the chemical passivation film and the field passivation antireflection film;
and/or the size of each front grating electrode in the second direction is 15-50 um.
Optionally, in the case that the chemical passivation film is a silicon oxide film, the thickness of the chemical passivation film is 0.5-5 nm;
under the condition that the chemical passivation film is an aluminum oxide film, the thickness of the chemical passivation film is 2-10 nm; the thickness direction is parallel to the laminating direction of the chemical passivation film and the field passivation antireflection film.
Optionally, the silicon substrate is an N-type silicon substrate, the first doping region is a phosphorus-doped region, and the doped amorphous silicon film is a boron-doped amorphous silicon film.
In a second aspect of the present invention, there is provided a photovoltaic module comprising: comprising a plurality of solar cells as described in any of the above.
In a third aspect of the present invention, there is provided a method for producing a solar cell, comprising:
forming at least one first doping area in a local area of a light-facing surface of the silicon substrate; the doping type of each first doping region is the same as that of the silicon substrate, and the doping concentration of each first doping region is greater than that of the silicon substrate;
sequentially forming a chemical passivation film and a field passivation antireflection film which are distributed in a stacked mode on the light-facing side of the silicon substrate; forming at least one front grid line electrode on the light-facing side of the silicon substrate; the position of at least one front grid line electrode and at least one first doping area are mutually contacted.
Optionally, the forming at least one first doping region in a local region of a light-facing surface of the silicon substrate includes:
forming an ultrathin silicon oxide film on the light facing surface of the silicon substrate through ultraviolet ozone oxidation;
infiltrating the silicon substrate light-facing surface formed with the ultrathin silicon oxide film with a liquid-phase phosphorus source to ensure that the surface of the ultrathin silicon oxide film is provided with the liquid-phase phosphorus source;
solidifying the liquid-phase phosphorus source on the surface of the ultrathin silicon oxide film to form a solid-state phosphorus source;
carrying out heat treatment on the solid phosphorus source on the surface of the ultrathin silicon oxide film, so that the solid phosphorus source and the ultrathin silicon oxide film form a silicon phosphide complex;
and irradiating a local area of the silicon phosphide complex by using laser, so that phosphorus atoms in the silicon phosphide complex of the local area irradiated by the laser are diffused to the light-facing side of the silicon substrate, and at least one first doping area is formed in the local area of the light-facing side of the silicon substrate.
Optionally, after forming at least one first doping region in a local region of a light-facing surface of the silicon substrate, the method further includes:
and cleaning the silicon substrate with at least one first doping area to remove the residual solidified phosphorus source, the ultrathin silicon oxide film and the silicon phosphide complex on the light-facing side of the silicon substrate.
Optionally, the cleaning the silicon substrate with the at least one first doping region includes:
cleaning the light side of the silicon substrate by using hydrofluoric acid to remove the residual ultrathin silicon oxide film;
etching the light-facing side of the silicon substrate by adopting a first mixed solution to clean the light-facing side of the silicon substrate, and residual solidified phosphorus source and silicon phosphide complex; the first mixed solution includes: a mixed solution of hydrofluoric acid and nitric acid, and/or a mixed solution of hydrofluoric acid and ozone.
Optionally, in the process of etching the light-facing side of the silicon substrate by using the first mixed solution, the thickness of the etched silicon substrate on the light-facing side is 20-150 nm; the thickness direction is parallel to the lamination direction of the ultrathin silicon oxide film and the solidified phosphorus source.
Optionally, the thickness of the formed silicon phosphide complex is 10-100 nm; the thickness direction is parallel to the lamination direction of the ultrathin silicon oxide film and the solid-solidified phosphorus source.
Optionally, the liquid-phase phosphorus source comprises: an aqueous solution of phosphoric acid, and an organic solvent dissolved in the aqueous solution of phosphoric acid; the organic solvent is used for improving the wettability of the aqueous solution of phosphoric acid on the light facing surface of the silicon substrate with the ultrathin silicon oxide film; in the liquid-phase phosphorus source, the concentration of phosphoric acid is 0.1-5%.
Optionally, in the heat treatment process, the temperature rise rate of the silicon substrate towards the light side is 25 ℃/s-50 ℃/s, the heat treatment temperature is 700 and 950 ℃, and the heat treatment duration is 0.5-2 min.
Optionally, the sequentially forming a stacked chemical passivation film and a field passivation antireflection film includes:
tubular thermal oxidation is carried out to form a silicon oxide film, or an aluminum oxide film is deposited;
and depositing a silicon nitride film on the silicon oxide film or the aluminum oxide film.
Optionally, the method further includes: sequentially forming an intrinsic amorphous silicon film, a doped amorphous silicon film with a doping type different from that of the silicon substrate, a transparent conductive oxide film and a back electrode which are distributed in a stacked manner on the backlight side of the silicon substrate;
the forming of the front gate line electrode includes: slotting a chemical passivation film and a field passivation antireflection film to expose a first doping region, and electroplating on the exposed first doping region to form a nickel-copper-silver laminated grid line electrode;
and/or, the forming a back electrode comprises: and electroplating on the transparent conductive oxide film to form a whole layer of nickel-copper-silver laminated electrode.
Optionally, laser grooving is adopted; after laser grooving and before electroplating, the method further comprises: cleaning at least one of a chemical passivation film, a field passivation antireflection film and silicon oxide produced due to a thermal effect in a grooving process, which are remained in a laser grooving area, and etching part of a first doping area by adopting a second mixed solution so as to remove laser damage of the first doping area; the second mixed solution includes: a mixed solution of hydrofluoric acid and nitric acid, and/or a mixed solution of hydrofluoric acid and ozone.
Optionally, the thickness of the etched part of the first doping region is 20-80 nm; the depth direction is parallel to the laminating direction of the chemical passivation film and the field passivation antireflection film.
A fourth aspect of the present invention provides a production system of a solar cell, comprising:
a doping component for forming at least one first doping area in a local area of a light-facing surface of the silicon substrate; the doping type of each first doping region is the same as that of the silicon substrate, and the doping concentration of each first doping region is greater than that of the silicon substrate;
the front film processing component is used for sequentially forming a chemical passivation film and a field passivation antireflection film which are distributed in a stacked mode on the light-facing side of the silicon substrate;
a front grid line electrode setting component for forming at least one front grid line electrode on the light-facing side of the silicon substrate; at least one of the front gate line electrodes and at least one of the first doped regions are in contact with each other.
Optionally, the doping component includes: a chain apparatus, the chain apparatus comprising: the device comprises an ultraviolet ozone oxidation device, a liquid-phase phosphorus source tank body, an illumination drying device, a heat treatment device, a laser generation device and a transmission device positioned between adjacent devices, wherein the ultraviolet ozone oxidation device, the liquid-phase phosphorus source tank body, the illumination drying device, the heat treatment device and the laser generation device are sequentially distributed;
the ultraviolet ozone oxidation device is used for forming an ultrathin silicon oxide film on the light facing surface of the silicon substrate through ultraviolet ozone oxidation;
the liquid-phase phosphorus source tank body is used for infiltrating the silicon substrate light-facing surface formed with the ultrathin silicon oxide film with a liquid-phase phosphorus source so that the surface of the ultrathin silicon oxide film is provided with the liquid-phase phosphorus source;
the illumination drying device is used for solidifying the liquid-phase phosphorus source on the surface of the ultrathin silicon oxide film to form a solid phosphorus source;
the heat treatment device is used for carrying out heat treatment on the solidified phosphorus source on the surface of the ultrathin silicon oxide film so that the solidified phosphorus source and the ultrathin silicon oxide film form a silicon phosphide complex;
the laser generating device is used for irradiating the local area of the silicon phosphide complex by laser, so that phosphorus atoms in the silicon phosphide complex in the local area irradiated by the laser are diffused to the light-facing side of the silicon substrate, and at least one first doping area is formed in the local area of the light-facing surface of the silicon substrate.
Optionally, the illumination drying device comprises parallel arranged light tubes; and/or the heat treatment device comprises halogen tungsten lamps which are arranged in parallel.
Optionally, the production system of the solar cell further includes:
and the back structure setting component is used for sequentially forming an intrinsic amorphous silicon film, a doped amorphous silicon film with a doping type different from that of the silicon substrate, a transparent conductive oxide film and a back electrode which are distributed in a stacked mode on the backlight side of the silicon substrate.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the description of the embodiments of the present invention will be briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive labor.
FIG. 1 shows a schematic diagram of a solar cell in an embodiment of the invention;
fig. 2 shows a flow chart of steps of a method of producing a solar cell in an embodiment of the invention;
fig. 3 shows a schematic structural diagram of a silicon substrate in an embodiment of the invention;
FIG. 4 is a schematic view showing a partial structure of a first solar cell in the embodiment of the present invention;
FIG. 5 is a schematic view showing a partial structure of a second solar cell in the embodiment of the present invention;
fig. 6 is a partial schematic structural view showing a third solar cell in the embodiment of the present invention;
FIG. 7 is a partial schematic view showing a fourth solar cell in the embodiment of the present invention;
fig. 8 is a schematic view showing a partial structure of a fifth solar cell in the embodiment of the invention;
fig. 9 is a schematic view showing a partial structure of a sixth solar cell in the embodiment of the present invention;
fig. 10 is a schematic view showing a partial structure of a seventh solar cell in the embodiment of the present invention;
fig. 11 is a schematic view showing a partial structure of an eighth solar cell in the embodiment of the present invention;
fig. 12 is a partial schematic structural view of a ninth solar cell in the embodiment of the invention;
fig. 13 is a partial schematic structural view of a tenth solar cell in the embodiment of the present invention;
fig. 14 shows a schematic configuration of a chain apparatus in an embodiment of the present invention.
Description of the reference numerals:
1-silicon substrate, 11-first doping region, 2-chemical passivation film, 3-field passivation antireflection film, 4-front grid line electrode, 5-intrinsic amorphous silicon film, 6-doped amorphous silicon film, 7-transparent conductive oxide film, 8-back electrode, 91-solidified phosphorus source and 92-silicon phosphide complex.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without inventive step based on the embodiments of the present invention, are within the scope of protection of the present invention.
Fig. 1 shows a schematic structural diagram of a solar cell in an embodiment of the present invention. The solar cell includes: the silicon substrate 1, the light-facing side of the silicon substrate 1 is the side of the silicon substrate 1 mainly receiving light. The light-facing surface of the silicon substrate 1 is a surface of the silicon substrate 1 mainly receiving light. The solar cell includes at least one first doping region 11 formed in a local region of a light-facing surface of the silicon substrate 1, and the number of the first doping regions 11 is not particularly limited. The number of the first doping regions 11 of the local region of the light-facing surface of the silicon substrate 1 in the solar cell shown in fig. 1 is 2.
The area of the projection of all the first doping regions 11 on the light-facing surface of the silicon substrate 1 is smaller than the area of the light-facing surface of the silicon substrate 1. The projection area of all the first doping regions 11 on the silicon substrate 1 is smaller than the area of the light-facing surface of the silicon substrate 1, and is not particularly limited. That is, the first doping region 11 is locally distributed on the light-facing side of the silicon substrate 1 and does not entirely cover the light-facing side of the silicon substrate 1. The doping type of each first doping region 11 is the same as the doping type of the silicon substrate 1, and the doping concentration of each first doping region 11 is greater than the doping concentration of the silicon substrate 1. That is, the doping type of the first doping region 11 and the silicon substrate 1 are the same, and the first doping region 11 and the silicon substrate 1 form a high-low junction. The present invention does not specifically limit the type of the silicon substrate 1. For example, the silicon substrate 1 may be an N-type silicon substrate.
Referring to fig. 1, the solar cell further includes: and a chemical passivation film 2 and a field passivation antireflection film 3 which are distributed on the light-facing side of the silicon substrate 1 are sequentially stacked. The chemical passivation film 2 functions to perform a good chemical passivation function. The field passivation antireflection film 3 functions to perform a good field passivation and antireflection function.
At least one front gate line electrode 4 located on the light-facing side of the silicon substrate 1, the at least one front gate line electrode 4 and the at least one first doping region 11 are in contact with each other. For example, only one front gate line electrode 4 and one first doping region 11 may contact each other, or each front gate line electrode 4 and each first doping region 11 corresponding to a position may contact each other, which may also be referred to as: each front gate line electrode 4 and each first doping region 11 corresponding to the position are in ohmic contact with each other. Under illumination, the front grid line electrode can collect photovoltaically-specific response current transmitted from the first doping region 11. This is not particularly limited in the embodiment of the present invention.
Specifically, the inventor finds that the front and back sides of the solar cell need to be provided with the amorphous silicon film and the transparent conductive oxide film, on one hand, the raw materials of the conductive oxide film are expensive, and on the other hand, the front and back sides of the solar cell need to be provided with the amorphous silicon coating equipment and the transparent conductive oxide coating equipment, which occupy large areas and have high cost. In order to reduce the cost, the existing solar cell adopts a part of polycrystalline silicon layer to replace amorphous silicon and transparent conductive oxide thin film on one surface, but the photoelectric conversion efficiency of the solar cell is reduced. The inventors found that the reason why the photoelectric conversion efficiency of the solar cell is reduced is mainly that: the absorption of the polycrystalline silicon layer on the short wave and the visible light of the incident light is strong, so that the loss of the short-circuit current of the solar cell is serious, the absorption of the polycrystalline silicon layer on the short wave and the visible light of the incident light is stronger along with the increase of the thickness of the polycrystalline silicon layer, in order to ensure a good passivation effect and the like, in the solar cell in the prior art, the thickness of the polycrystalline silicon layer needs to be set to be 60nm or more, so that the absorption of the polycrystalline silicon layer on the short wave and the visible light of the incident light is serious, and the loss of the short-circuit current of the solar cell is serious. For example, the loss of the short-circuit current of the solar cell caused by this is 500mA or more. In order to reduce the cost, the conventional solar cell also adopts a whole diffusion layer to replace amorphous silicon and a transparent conductive oxide thin film on one surface, but the photoelectric conversion efficiency of the solar cell is reduced. The inventors found that the main cause of the decrease in photoelectric conversion efficiency of the solar cell is: the diffusion layer of the whole diffusion layer can cause serious Auger recombination, so that the process matching is poor, and the short-circuit current and the open-circuit voltage of the solar cell are reduced. Meanwhile, the diffusion layer on the whole surface has longer diffusion forming time, and the production efficiency is reduced.
In the invention, the chemical passivation film 2 towards the light side can play a good role in chemical passivation, and the field passivation antireflection film 3 can play a good role in field passivation and antireflection, so that the surface passivation capability of amorphous silicon can be basically achieved. And the chemical passivation film 2 and the field passivation antireflection film 3 are weak or basically non-absorptive to short wave and visible light of incident light, so that the loss of short circuit current of the solar cell can be reduced. Meanwhile, the first doping regions 11 are not distributed on the light-facing surface of the silicon substrate 1 in the whole surface, but are locally distributed on the light-facing surface of the silicon substrate 1, and auger recombination basically does not exist at positions without the first doping regions 11, so auger recombination brought by the first doping regions is relatively less, and short-circuit current and open-circuit voltage loss caused by auger recombination can be reduced. Compared with the method for forming the diffusion layer on the whole surface, the method for forming the first doping region 11 only forms the first doping region 11 on the local region of the light-facing surface of the silicon substrate 1, the time for forming the first doping region 11 is relatively short, and the production efficiency can be improved. Meanwhile, in the invention, the first doping region 11, the chemical passivation film 2 and the field passivation antireflection film 3 on the light-facing side of the silicon substrate 1 do not need to use amorphous silicon coating equipment and transparent conductive oxide coating equipment, so that the cost of production equipment and the space occupied by the production equipment can be greatly reduced, for example, the cost of the production equipment and the space occupied by the production equipment are substantially reduced by half. In addition, the light facing surface of the silicon substrate 1 is not provided with a transparent conductive oxide film, so that the production cost can be reduced.
It should be noted that, in the embodiments of the present invention, the type of the solar cell is not particularly limited, and for example, the solar cell may be a heterojunction solar cell.
Optionally, the chemical passivation film 2 includes a silicon oxide film or an aluminum oxide film, and the chemical passivation film 2 absorbs short-wave and visible light of incident light weakly or substantially without absorption, so that the loss of short-circuit current of the solar cell can be reduced. And the chemical passivation film 2 has a good chemical passivation effect, for example, a good hydrogen passivation effect, and can basically achieve the surface passivation capability of amorphous silicon.
Optionally, the field passivation antireflection film 3 includes a silicon nitride film, and the field passivation antireflection film 3 has weak absorption or substantially no absorption of short wave and visible light of incident light, so as to reduce the loss of short circuit current of the solar cell. And the field passivation antireflection film 3 has a good field passivation antireflection effect and can basically achieve the surface passivation capability of amorphous silicon.
Optionally, the highest doping concentration of each first doping region 11 is 2 × 10 19 /cm 3 -5×10 20 /cm 3 . The highest doping concentration of the first doped region 11 is in this range, facilitating the separation of carriers.
Optionally, the depth of each first doping region 11 is 0.1-0.5um, and the direction of the depth is parallel to the stacking direction of the chemical passivation film 2 and the field passivation antireflection film 3. In fig. 1, a dotted line L1 indicates the stacking direction of the chemical passivation film 2 and the field passivation antireflection film 3. The first doping region 11 of the light facing surface of the silicon substrate 1 is flush with the light facing surface of the silicon substrate 1, and equivalently, the first doping region 11 is located within 0.1-0.5um from the light facing surface of the silicon substrate 1 to the inside of the silicon substrate 1, namely, the position of a high-low junction formed by the first doping region 11 and the silicon substrate 1 is 0.1-0.5um away from the light facing surface of the silicon substrate 1, and the high-low junction is in the height range, so that the formation and the separation of carriers are facilitated.
Optionally, the refractive index of the field passivation antireflection film 3 is 1.9 to 2.2, and the refractive index of the field passivation antireflection film 3 in this range has a better antireflection performance.
Optionally, the solar cell further comprises: and the antireflection film is positioned on the light-facing side of the field passivation antireflection film 3 so as to enhance the front antireflection effect.
Optionally, the material of the antireflection film is selected from silicon oxynitride, and the antireflection effect of the silicon oxynitride is better.
Optionally, the total thickness of the antireflection film and the field passivation antireflection film 3 is 60-90nm, and within the thickness range, the front surface field passivation and antireflection effects of the solar cell are better, and the cost is lower. The thickness is in a direction parallel to the lamination direction of the chemical passivation film 2 and the field passivation antireflection film 3. It should be noted that the thickness, height, and depth directions are all defined throughout this specification.
Optionally, in the case that the chemical passivation film 2 is a silicon oxide film, the thickness of the chemical passivation film 2 is 0.5-5nm, and within the thickness range, the silicon oxide film has better chemical passivation effect and lower cost.
Under the condition that the chemical passivation film 2 is an aluminum oxide film, the thickness of the chemical passivation film 2 is 2-10nm, and within the thickness range, the chemical passivation effect of the aluminum oxide film is better and the cost is lower.
Referring to fig. 1, the backlight side of the silicon substrate 1 and the light-facing side of the silicon substrate 1 are distributed oppositely. The solar cell further includes: an intrinsic amorphous silicon film 5, a doped amorphous silicon film 6 of a doping type different from that of the silicon substrate 1, a transparent conductive oxide thin film 7, and a back electrode 8 are sequentially stacked and distributed on the backlight side of the silicon substrate 1. For example, if the silicon substrate 1 is N-type, the doped amorphous silicon film 6 is P-type.
The back electrode 8 is an entire electrode layer covering the transparent conductive oxide film, and the thickness of the transparent conductive oxide film 7 is 5 to 80 nm. Compared with the prior art in which the thickness of the transparent conductive oxide film 7 is greater than 80nm, the invention has the advantage that the cost of the solar cell can be reduced to a greater extent by making the thickness of the transparent conductive oxide film 7 thinner. In addition, in the present invention, since the back electrode 8 is a full-area electrode layer, the back electrode 8 itself has a good lateral carrier collection capability, and thus the thickness of the transparent conductive oxide thin film 7 can be set low, the lateral conductivity due to the thinning and reduction of the transparent conductive oxide thin film 7 is compensated by the back electrode 8, and the solar cell still has a good lateral conductivity.
Optionally, the thickness of the entire electrode layer is 1 to 10um, and in this thickness range, the back electrode 8 can achieve good carrier derivation performance, and the cost is low.
The inventor finds that: in the prior art, the electrodes of the solar cell all adopt silver paste electrodes, on one hand, the cost of raw materials of the silver paste electrodes, particularly low-temperature silver paste, is high, on the other hand, the silver particles are less in contact due to the shape of the silver particles in the silver paste electrodes, and the silver paste contains organic components which can also influence the contact between the silver particles, so that the resistivity of the silver paste electrodes is high. Optionally, in the present invention, the front gate line electrode 4 is a nickel-copper-silver laminated gate line electrode, and/or the back electrode 8 is a nickel-copper-silver laminated gate line electrode. The contact between the electrode materials in the nickel-copper-silver laminated grid line electrode and the nickel-copper-silver laminated electrode is tight, so that the resistivity of the nickel-copper-silver laminated grid line electrode and the resistivity of the nickel-copper-silver laminated electrode are both low, the electrical performance of the solar cell can be improved, and the nickel-copper-silver laminated grid line electrode and the nickel-copper-silver laminated electrode have low silver content and low cost. Meanwhile, the nickel-copper-silver laminated gate line electrode and the nickel-copper-silver laminated electrode can be prepared by electroplating, and the purity of the formed nickel-copper-silver laminated gate line electrode and the formed nickel-copper-silver laminated electrode is high, so that the resistivity of the nickel-copper-silver laminated gate line electrode and the resistivity of the nickel-copper-silver laminated electrode are low, the electrical property of the solar cell can be improved, and the cost is low. Meanwhile, in the case that the back electrode 8 is a nickel-copper-silver laminated electrode, since the back electrode has a relatively low resistivity, the thickness of the transparent conductive oxide film 7 can be further reduced appropriately, and it can be ensured that the electrical properties of the solar cell are not affected, and the reduction in the thickness of the transparent conductive oxide film 7 can reduce the cost.
Optionally, in the nickel-copper-silver laminated gate line electrode and the nickel-copper-silver laminated electrode: the mass ratio of the nickel element, the copper element and the silver element is as follows: (0.5-2.5): (5-9): (0.5-2.5), the mass proportion of the noble metal silver in the nickel-copper-silver laminated grid line electrode and the nickel-copper-silver laminated electrode is lower, and the proportion is only 5% -25%, so that the cost of the nickel-copper-silver laminated grid line electrode and the nickel-copper-silver laminated electrode is relatively lower. For example, in the nickel-copper-silver laminated gate line electrode and the nickel-copper-silver laminated electrode: the mass ratio of the nickel element, the copper element and the silver element can be as follows: 1:8:1.
Optionally, each front grid line electrode 4 and each first doping region 11 are in one-to-one correspondence in position and are in contact with each other, and then each first doping region 11 is completely used for transmitting and collecting carriers, so that the photoelectric conversion efficiency of the solar cell can be improved.
Optionally, a projection of each front gate line electrode 4 on the first doping region 11 corresponding to the position in the first direction is equal to a size of the first doping region 11 corresponding to the position in the first direction, and a projection of each front gate line electrode 4 on the first doping region 11 corresponding to the position in the second direction is 15-50um smaller than a size of the first doping region 11 corresponding to the position in the second direction. The first direction and the second direction are both parallel to the light-facing surface of the silicon substrate and are perpendicular to each other. That is, the projection of each front gate line electrode 4 on the corresponding first doping region 11 completely falls into the corresponding first doping region. Meanwhile, in the surface parallel to the light-facing surface of the silicon substrate 1, in two mutually perpendicular opposite directions, the size of the front gate line electrode 4 and the size of the first doping region 11 corresponding to the position in the first direction are equal, and in the second direction, the size of the first doping region 11 is 15-50um larger than that of the front gate line electrode 4 corresponding to the position, which is beneficial to the collection and the derivation of carriers. The first direction may be parallel to a direction extending inward into the page, as indicated by L2 in fig. 1 as the second direction. In the following description, the first direction and the second direction are defined as the same. That is, each front grid line electrode 4 is in complete electrical contact with the corresponding first doped region, which is beneficial to improving the electrical performance of the solar cell. As shown in FIG. 1, i.e., 15 um. ltoreq. d1+ d 2. ltoreq.50 um.
And/or, the height of each front grid line electrode 4 is 5-20um, and in the height range, the collection and the derivation of carriers are facilitated. For example, the front gate line electrode 4 is a nickel-copper-silver laminated gate line electrode, and the height thereof is 10 um.
Optionally, the size d3 of each front gate line electrode 4 in the second direction is 15-50um, and in this size range, the collection and the derivation of carriers are facilitated. For example, the front gate line electrode 4 is a nickel-copper-silver laminated gate line electrode, and a dimension d3 in the second direction is 25 um.
Optionally, the silicon substrate 1 is an N-type silicon substrate, the resistivity of the silicon substrate 1 is 0.3 to 7ohm. cm (ohm-cm), and the thickness of the silicon substrate 1 is 50 to 150 um. The material of the intrinsic amorphous silicon film 5 on the backlight side of the silicon substrate 1 may be hydrogenated amorphous silicon, and a small amount of oxygen element or carbon element may be doped in the intrinsic amorphous silicon film 5. In the intrinsic amorphous silicon film 5: the hydrogen atom content is 10-30%, and the oxygen element or carbon element content is 0-5%. The thickness of the intrinsic amorphous silicon film 5 is between 5-15 nm. The doped amorphous silicon film 6 may be a boron-doped amorphous silicon film. In the doped amorphous silicon film 6: may contain a part of microcrystalline silicon, the percentage of boron element is between 0.1 and 5%, and the thickness of the doped amorphous silicon film 6 is between 10 and 40 nm.
The invention also provides a photovoltaic module comprising a plurality of any one of the aforementioned solar cells. The photovoltaic module has the same or similar beneficial effects as the solar cell, and the details are not repeated herein in order to avoid repetition.
Fig. 2 shows a flow chart of steps of a method of producing a solar cell in an embodiment of the invention. The invention also provides a production method of the solar cell. Referring to fig. 2, the method includes the steps of:
step S1, forming at least one first doping area in a local area of the light-facing surface of the silicon substrate; the doping type of each first doping region is the same as that of the silicon substrate, and the doping concentration of each first doping region is greater than that of the silicon substrate.
Fig. 3 shows a schematic structural diagram of a silicon substrate in an embodiment of the present invention. Referring to fig. 3, before the above step S1, the silicon substrate 1 may be subjected to texturing cleaning. The method specifically comprises the following steps: removing a damaged layer on the surface of the silicon substrate 1 by alkali polishing, pre-cleaning, alkali texturing, RCA cleaning, HF rinsing, water washing and drying. The thickness of the silicon substrate 1 removed by alkali polishing is 10-40um, the pyramid size of alkali texturing is about 2-5um, and the reflectivity is about 10% -13%.
The at least one first doping region 11 may be formed in a local region of the light-facing surface of the silicon substrate 1 by tubular phosphorus diffusion or other methods.
And step S2, sequentially forming a chemical passivation film and a field passivation antireflection film which are distributed in a stacked mode on the light-facing side of the silicon substrate.
The chemical passivation film 2 and the field passivation antireflection film 3 can be formed by deposition, sputtering, or the like. The formation method of both is not particularly limited.
Step S3, forming at least one front grid line electrode on the light-facing side of the silicon substrate; at least one front grid line electrode and at least one first doping area are contacted with each other;
for example, the front gate line electrode may be formed by electroplating, screen printing, laser transfer printing, or the like.
The production method of the solar cell has the same or similar beneficial effects as the solar cell, and the two can be mutually referred.
Optionally, the step S1 may include: forming an ultrathin silicon oxide film on a light facing surface of a silicon substrate; infiltrating the silicon substrate light-facing surface with the ultra-thin silicon oxide film formed by using a liquid-phase phosphorus source, so that the surface of the ultra-thin silicon oxide film is provided with the liquid-phase phosphorus source; solidifying the liquid-phase phosphorus source on the surface of the ultrathin silicon oxide film to form a solid phosphorus source; carrying out heat treatment on the solid phosphorus source on the surface of the ultrathin silicon oxide film, so that the solid phosphorus source and the ultrathin silicon oxide film form a silicon phosphide complex; and irradiating a local area of the silicon phosphide complex on the surface of the ultrathin silicon oxide film by using laser, so that phosphorus atoms in the silicon phosphide complex of the local area irradiated by the laser are diffused to the light-facing side of the silicon substrate, and at least one first doping area is formed in the local area of the light-facing surface of the silicon substrate.
Fig. 4 is a schematic partial structure diagram of a first solar cell in an embodiment of the present invention. Fig. 5 is a partial structural view of a second solar cell in the embodiment of the present invention. Fig. 6 shows a partial structural schematic diagram of a third solar cell in the embodiment of the present invention.
Specifically, referring to fig. 4, a chain type device may be used to transport the silicon substrate, the silicon substrate 1 is transported to an ultraviolet ozone oxidation device, ultra-thin silicon dioxide is formed on a light-facing surface of the silicon substrate 1 through ultraviolet ozone oxidation, and then a liquid-phase phosphorus source infiltrates the light-facing surface of the silicon substrate 1 on which the ultra-thin silicon oxide film is formed, so that the surface of the ultra-thin silicon oxide film has the liquid-phase phosphorus source, for example, the silicon substrate 1 on which the ultra-thin silicon oxide film is formed may be immersed in a phosphorus source tank, and the rest surfaces of the silicon substrate 1 on which the ultra-thin silicon oxide film is not formed may not infiltrate the liquid-phase phosphorus source basically, but the surface on which the ultra-thin silicon oxide film is formed may infiltrate the liquid-phase phosphorus source. The liquid phase phosphorus source on the surface of the ultra-thin silicon oxide film is solidified to form a solidified phosphorus source 91. The ultra-thin silicon oxide film is used to improve the wettability of the aqueous solution of phosphoric acid on the light-facing surface of the silicon substrate 1.
Optionally, the liquid phase phosphorus source comprises: an aqueous solution of phosphoric acid, and an organic solvent dissolved in the aqueous solution of phosphoric acid for improving wettability of the aqueous solution of phosphoric acid on a light-facing surface of the silicon substrate 1 on which the ultra-thin silicon oxide film is formed, and specific components of the organic solvent are not particularly limited. In the liquid phase phosphorus source, the concentration of phosphoric acid is 0.1-5%. For example, the concentration of phosphoric acid is 0.1%, 1.2%, 2.5%, 5%. The phosphorus source of the above composition is easily infiltrated into the light-facing surface of the silicon substrate 1 on which the ultra-thin silicon oxide film is formed.
Referring to fig. 5, a solid-stated phosphorus source 91 is heat treated, and the solid-stated phosphorus source 91 and ultra-thin silicon oxide film form a silicon phosphide (SiP) composite 92.
Optionally, in the process of performing the heat treatment on the solidified phosphorus source 91, the temperature rising rate of the silicon substrate 1 to the light side is 25 ℃/s-50 ℃/s, the heat treatment temperature is 700-. For example, in the heat treatment of the solid phosphorus source 91, the temperature rise rate of the silicon substrate 1 to the light side is 40 ℃/s, the heat treatment temperature is 800 ℃, and the heat treatment duration is 1 min. It should be noted that, during the heat treatment of the solid phosphorus source 91, carbon-containing components possibly existing in the solid phosphorus source 91 and the silicon phosphide (SiP) composite 92 on the light side of the silicon substrate 1 can be burned in a thermal environment, so as to prevent the carbon-containing components from affecting the performance of the solar cell. Meanwhile, the heat treatment in the step is compared with the heating in the conventional tubular phosphorus diffusion: the conventional tubular phosphorus diffusion is usually carried out by heating the whole surface for at least about half an hour, and the heat treatment of the step only needs 0.5-2min, so that the time is obviously shortened, the production efficiency can be improved, the heating time is obviously shortened, the thermal stress influence on the silicon substrate is small, and the occurrence of warping of the silicon substrate is reduced.
Optionally, the thickness of the formed silicon phosphide complex 92 is 10-100nm, the direction of the thickness is parallel to the stacking direction of the ultrathin silicon oxide film and the solidified phosphorus source 91, and the thickness of the formed silicon phosphide complex 92 is within the range, so that the size and concentration of the formed first doping region can be ensured to be proper, and material waste is avoided.
Referring to fig. 6, a local area of the silicon phosphide complex 92 is irradiated with laser light, so that phosphorus atoms in the silicon phosphide complex 92 of the local area irradiated with the laser light are diffused to the light-facing side of the silicon substrate 1 to form at least one first doping region 11 on the light-facing side of the silicon substrate 1.
Specifically, the laser may be applied to the process of irradiating the local region of the silicon phosphide composite 92, and the nanosecond green laser with the wavelength of 532nm irradiates the local region of the silicon phosphide composite 92, so that the phosphorus atoms in the silicon phosphide composite 92 diffuse into the partial region of the silicon substrate 1 on the light side under the action of the laser. It should be noted that the shape of the local region corresponds to the pattern of the front gate line electrode.
Meanwhile, compared with the conventional tubular phosphorus diffusion, the phosphorus doping for forming the local area in the step: on one hand, the conventional tubular phosphorus diffusion is generally full-surface diffusion and needs about half an hour at least, while the phosphorus doping of the local area is formed, the time within 10 minutes is basically needed, and the time is obviously shortened; on the other hand, in the step of forming the phosphorus doping of the local area, the laser irradiation is only directed at the local area of the silicon substrate, and the total heating time is obviously shortened, so that the influence of thermal stress on the silicon substrate is obviously reduced, and the occurrence of warping of the silicon substrate is reduced.
Fig. 7 shows a partial structural schematic diagram of a fourth solar cell in the embodiment of the present invention. Referring to fig. 7, optionally, after forming two first doping regions 11, the method further includes: and cleaning the silicon substrate with at least one first doping region 11 to remove the residual solid phosphorus source 91, silicon phosphide complex 92 and ultrathin silicon oxide film on the light side of the silicon substrate 1.
Optionally, the cleaning the silicon substrate 1 includes: and cleaning the light side of the silicon substrate 1 by adopting hydrofluoric acid (HF), and etching the residual solidified phosphorus source and silicon phosphide complex on the light side of the silicon substrate 1 by adopting a first mixed solution. The first mixed solution herein includes: a mixed solution of hydrofluoric acid and nitric acid, and/or a mixed solution of hydrofluoric acid and ozone. In the process of etching the light-facing side of the silicon substrate 1 by using the first mixed solution, part of the area of the light-facing side of the silicon substrate 1 is properly etched, so that the pyramids on the surface of the silicon substrate 1 are rounded, and the pyramids on the surface of the silicon substrate 1 do not need to be rounded separately, thereby reducing the process steps.
More carefully, after the light-facing side of the silicon substrate is etched by the first mixed solution, the steps of RCA cleaning, hydrofluoric acid cleaning, water washing and drying can be sequentially carried out.
Optionally, in the process of etching the light-facing side of the silicon substrate 1 by using the first mixed solution, the thickness of the light-facing side of the etched silicon substrate 1 is 20-150nm, and the thickness direction is parallel to the stacking direction of the ultrathin silicon oxide film and the solidified phosphorus source. The thickness of the light-facing side of the silicon substrate 1 etched away here includes: residual solid-stated phosphorus source 91, residual silicon phosphide complex 92, possible residual ultra-thin silicon oxide film, and silicon substrate. The thickness of the etched silicon substrate 1 facing the light side is within the range, so that not only can the residual solid-state phosphorus source 91, the residual silicon phosphide complex 92 and the possible residual ultrathin silicon oxide film be thoroughly cleaned, but also the pyramid rounding degree of the silicon substrate 1 facing the light side is more suitable.
Optionally, the step S2 may include: a silicon oxide film is formed on the light-side of the silicon substrate 1 by tubular thermal oxidation, or an aluminum oxide film is deposited, e.g., by ALD (Atomic layer Deposition), and a silicon nitride film is deposited on the silicon oxide film or the aluminum oxide film, e.g., by PECVD (Plasma Enhanced Chemical Vapor Deposition). The process is simple and mature.
Fig. 8 is a partial structural view of a fifth solar cell in the embodiment of the present invention. As shown in fig. 8, a chemical passivation film 2, which may be an aluminum oxide film, is deposited on the light-facing side of the silicon substrate 1. Fig. 9 is a partial schematic structural view of a sixth solar cell in the embodiment of the present invention. As shown with reference to fig. 9, a field-passivated antireflection film 3 is formed on the chemical passivation film 2.
Fig. 10 is a partial schematic structural view of a seventh solar cell in the embodiment of the present invention. Optionally, referring to fig. 10, the step S3 may include: and (3) grooving the chemical passivation film 2 and the field passivation antireflection film 3 to expose the first doping region 11.
Optionally, the grooving method may be laser grooving, and the laser grooving speed is high. The laser grooving can use picosecond ultraviolet laser or picosecond green laser to irradiate a local area of the light-facing side of the silicon substrate 1 so as to remove the field passivation antireflection film 3 and the chemical passivation film 2 in the local area on the light-facing side of the silicon substrate 1.
Fig. 11 is a schematic view showing a partial structure of an eighth solar cell in the embodiment of the present invention. Optionally, after the laser grooving and before the electroplating of the front gate line electrode, the method may further include: and cleaning at least one of a chemical passivation film, a field passivation antireflection film and silicon oxide produced due to thermal effect in the grooving process, wherein the chemical passivation film and the field passivation antireflection film are remained in the laser grooving region, and etching part of the first doping region by adopting a second mixed solution so as to remove laser damage of the first doping region 11. The second mixed solution includes: a mixed solution of hydrofluoric acid and nitric acid, and/or a mixed solution of hydrofluoric acid and ozone.
For example, at least one of a small amount of chemical passivation film, field passivation antireflection film and silicon oxide produced by thermal effect in the grooving process can be removed from the local grooving area of picosecond laser by using HF solution, and then HF/HNO can be used 3 Or HF/O 3 The mixed solution etches a local heat treatment area of picosecond laser, and laser damage of the area is removed. And then RCA cleaning, HF cleaning, water washing and drying are carried out.
Optionally, the thickness of the etched first doping region 11 is 20-80nm, the depth direction is parallel to the stacking direction of the chemical passivation film 2 and the field passivation antireflection film 3, and the thickness of the etched first doping region 11 is within the range, so that laser damage can be completely removed, and material waste can be reduced.
Fig. 12 is a partial schematic structural view of a ninth solar cell in the embodiment of the present invention. After etching a part of the first doped region damaged by the laser and cleaning, an intrinsic amorphous silicon film 5 and a doped amorphous silicon film 6 with a doping type different from that of the silicon substrate are sequentially formed on the backlight side of the silicon substrate 1 in a stacked manner, and the intrinsic amorphous silicon film 5 and the doped amorphous silicon film 6 with a doping type different from that of the silicon substrate may be formed by Plasma Enhanced Chemical Vapor Deposition (PECVD), hot-wire CVD, or the like.
Fig. 13 is a partial schematic structural view of a tenth solar cell in the embodiment of the present invention. As shown in fig. 13, a transparent conductive oxide thin film 7 is deposited on the doped amorphous silicon film 6. The transparent conductive oxide thin film (TCO)7 may be obtained by using PVD (Physical Vapor Deposition) or RPD Deposition. And a back electrode 8 is formed on the transparent conductive oxide film 7. The back electrode 8 may be formed by plating, screen printing, laser transfer, or the like.
Alternatively, referring to fig. 1, a nickel-copper-silver (nicg) stacked gate line electrode is formed on the exposed first doping region 11 by electroplating. A back electrode of the nickel-copper-silver laminated electrode is formed on the transparent conductive oxide film 7 by plating. The contact between the electrode materials in the nickel-copper-silver laminated grid line electrode and the nickel-copper-silver laminated electrode is tight, so that the resistivity of the nickel-copper-silver laminated grid line electrode and the resistivity of the nickel-copper-silver laminated electrode are both low, the electrical performance of the solar cell can be improved, and the cost is low. Meanwhile, in the case that the back electrode 8 is a nickel-copper-silver laminated electrode, since the back electrode has a relatively low resistivity, the thickness of the transparent conductive oxide film can be further reduced appropriately, and it can be ensured that the electrical properties of the solar cell are not affected, and the thickness of the transparent conductive oxide film is reduced to reduce the cost.
The present invention also provides a production system of a solar cell, comprising:
a doping component for forming at least one first doping area in a local area of a light-facing surface of the silicon substrate; the doping type of each first doping area is the same as that of the silicon substrate, and the doping concentration of each first doping area is greater than that of the silicon substrate;
the front film processing component is used for sequentially forming a chemical passivation film and a field passivation antireflection film which are distributed in a stacked mode on the light-facing side of the silicon substrate; a front grid line electrode setting component for forming at least one front grid line electrode on the light-facing side of the silicon substrate; at least one front grid line electrode and at least one first doping area are mutually contacted, and the method can also be called as follows: at least one of the front gate line electrodes and at least one of the first doped regions are in ohmic contact with each other.
Optionally, the production system of the solar cell may further include: and the back structure setting component is used for sequentially forming an intrinsic amorphous silicon film, a doped amorphous silicon film with a doping type different from that of the silicon substrate, a transparent conductive oxide film and a back electrode which are distributed in a stacked mode on the backlight side of the silicon substrate.
Optionally, the doping component includes: fig. 14 shows a schematic structural view of a chain type apparatus 200 according to an embodiment of the present invention. Referring to fig. 14, the chain apparatus 200 includes: the device comprises an ultraviolet ozone oxidation device 201, a liquid-phase phosphorus source tank 202, an illumination drying device 203, a heat treatment device 204, a laser generation device 205 and a transmission device positioned between adjacent devices, wherein the ultraviolet ozone oxidation device, the liquid-phase phosphorus source tank 202, the illumination drying device 203, the heat treatment device 204 and the laser generation device 205 are sequentially distributed.
And the ultraviolet ozone oxidation device 201 is used for forming an ultrathin silicon oxide film on the light facing surface of the silicon substrate through ultraviolet ozone oxidation.
And the liquid-phase phosphorus source tank 202 is used for infiltrating the silicon substrate light-facing surface formed with the ultrathin silicon oxide film with the liquid-phase phosphorus source so that the surface of the ultrathin silicon oxide film has the liquid-phase phosphorus source.
And the illumination drying device 203 is used for solidifying the liquid-phase phosphorus source on the surface of the ultrathin silicon oxide film to form a solid-state phosphorus source.
And the heat treatment device 204 is used for carrying out heat treatment on the solid phosphorus source on the surface of the ultrathin silicon oxide film, so that the solid phosphorus source and the ultrathin silicon oxide film form a silicon phosphide complex.
And the laser generating device 205 is used for irradiating a local area of the silicon phosphide complex with laser, so that phosphorus atoms in the silicon phosphide complex of the local area irradiated with the laser are diffused to the light-facing side of the silicon substrate to form at least one first doping area in the local area of the light-facing surface of the silicon substrate.
The transmission device is used for transmitting the silicon substrate processed by the former device to the adjacent latter device. The transport device may also be used as an operation console of a certain device, which is not particularly limited in the embodiments of the present invention. The transmission device can be a roller, a crawler belt and the like, and can be contacted with a local area of the silicon substrate in the process of transmitting the silicon substrate so as to reduce the pollution of metal on the transmission device to the silicon substrate. The chain apparatus 200 enables efficient, mass-produced formation of the first doped region.
Optionally, in the solar cell production system, the illumination drying device 203 includes parallel-arranged light tubes. Specifically, when the silicon substrate is conveyed to the position right below the parallel arranged lamps, the silicon substrate stops conveying for about 1-3 seconds, during the period, the parallel arranged lamps are started, the silicon substrate is rapidly heated and dried, the surface temperature of the silicon substrate is rapidly raised to 60-150 ℃ from the room temperature, and the liquid-phase phosphorus source on the surface of the silicon substrate is solidified.
Optionally, the thermal treatment device 204 comprises parallel arranged tungsten halogen lamps. And when the silicon substrate is conveyed to the position right below the tungsten halogen lamps arranged in parallel, the silicon substrate stops conveying, and during the period of stopping conveying, the tungsten halogen lamps arranged in parallel are started to carry out heat treatment on the solidified phosphorus source on the surface of the ultrathin silicon oxide film, so that the solidified phosphorus source and the ultrathin silicon oxide film form a silicon phosphide complex.
The invention is further illustrated by the following specific examples:
examples
The process steps for producing the solar cell can be carried out according to the following process flow: silicon substrate texturing and cleaning → liquid-phase phosphorus source coating → heat treatment → laser local doping → backwashing → chemical passivation film growth → field passivation antireflection film deposition → cleaning → doped amorphous silicon film, doped amorphous silicon film deposition → TCO deposition → electroplating electrode.
Specifically, referring to fig. 3, the silicon substrate 1 is subjected to texturing and cleaning, and then, referring to fig. 4, the silicon substrate 1 is conveyed by using a chain type device, the silicon substrate 1 is conveyed to an ultraviolet ozone oxidation device 201, and ultra-thin silicon dioxide is formed on a light facing surface of the silicon substrate 1 through ultraviolet ozone oxidation. The silicon substrate 1 is then transported to a liquid-phase phosphorus source tank 202, and an aqueous solution of phosphoric acid and an organic solvent dissolved in the aqueous solution of phosphoric acid are contained in the liquid-phase phosphorus source tank 202. In the liquid-phase phosphorus source tank 202, only the surface on which the ultra-thin silicon oxide film is formed is soaked with the liquid-phase phosphorus source. Then, the silicon substrate 1 is transported to a light drying device 203, and the liquid-phase phosphorus source on the surface of the ultrathin silicon oxide film is cured to form a solidified phosphorus source 91. Next, referring to fig. 5, the silicon substrate 1 is transported to the heat treatment apparatus 204, and the solidified phosphorus source 91 on the surface of the ultra-thin silicon oxide film is heat-treated, so that the solidified phosphorus source 91 and the ultra-thin silicon oxide film form a silicon phosphide complex 92. Next, referring to fig. 6, the silicon substrate 1 is transported to a laser generating apparatus 205, and a local area of the silicon phosphide complex 92 is irradiated with laser light, so that phosphorus atoms in the silicon phosphide complex 92 of the local area irradiated with the laser light are diffused to the light-facing side of the silicon substrate 1 to form at least one first doping region 11 in the local area of the light-facing surface of the silicon substrate 1. Next, referring to fig. 7, the silicon substrate formed with the at least one first doping region 11 is cleaned to remove the solid phosphorus source 91, the silicon phosphide complex 92 and the ultra-thin silicon oxide film remaining on the light-side of the silicon substrate 1. Next, referring to fig. 8, an alumina chemical passivation film 2 is formed on the silicon substrate 1 by the ALD method toward the light side, and then, referring to fig. 9, a field passivation antireflection film 3 is formed on the chemical passivation film 2 by the PECVD method. Referring next to fig. 10, the chemical passivation film 2 and the field passivation antireflection film 3 are laser grooved so that the first doping region 11 is exposed. Referring to fig. 11, at least one of a chemical passivation film, a field passivation anti-reflective film and silicon oxide produced by a thermal effect in the grooving process, which are remained in the laser grooving region, is cleaned, and a portion of the first doping region is etched by using a second mixed solution to remove laser damage of the first doping region 11. In the cleaning process, the backlight side of the silicon substrate 1 may also be cleaned. Next, referring to fig. 12, an intrinsic amorphous silicon film 5 and a doped amorphous silicon film 6 having a different doping type from that of the silicon substrate are formed in a stacked manner in this order on the backlight side of the silicon substrate 1. Next, referring to fig. 13, a transparent conductive oxide thin film 7 is deposited on the doped amorphous silicon film 6. Finally, referring to fig. 1, a nickel-copper-silver laminated gate line electrode is formed on the exposed first doped region 11 by electroplating, and a back electrode 8 of the nickel-copper-silver laminated electrode is formed on the transparent conductive oxide film 7 by electroplating.
It should be noted that, in the above solar cell, the photovoltaic module, and the method for producing a solar cell, the three may be referred to each other, and the same or similar beneficial effects may be achieved.
Table 1 shows a table of measurement results of the experimental group and the control group of the examples of the present invention
| Item | Resistivity ohm | Efficiency of | Other indicators |
| |
1.81×10 -6 | 25.34％ | Voc＝734mV,Jsc＝41.1mA/cm2，FF＝84.0％ |
| |
1.81×10 -6 | 25.43％ | Voc＝735mV,Jsc＝41.1mA/cm2，FF＝84.2％ |
| |
1.81×10 -6 | 25.34％ | Voc＝735mV,Jsc＝41.0mA/cm2，FF＝84.1％ |
| Control group | 5.75×10 -6 | 25.35％ | Voc＝746mV,Jsc＝39.9mA/cm2，FF＝85.0％ |
Referring to the solar cell shown in fig. 1, the silicon substrate 1 is doped with phosphorus, and the doping concentration of the silicon substrate 1 is 2 × 10 15 /cm 3 The doped region 11 is doped with phosphorus, and the highest doping concentration of the doped region 11 is 2 × 10 20 /cm 3 The depth of the doped region 11 is 0.3um, and the chemical passivation film 2 is silicon oxide (SiO) with a thickness of 3nm 2 ) The film, the field passivation antireflection film 3, is silicon nitride (SiN) with a thickness of 76nm x : H) the film, the refracting index of field passivation antireflection coating 3 is 2.13, and positive grid line electrode 4 is the nickel copper silver stromatolite grid line electrode that thickness is 9um, and in the positive grid line electrode 4 nickel element, copper element, silver element three's mass ratio be: 1:8:1. In fig. 1, d3 is 20um, and d1+ d2 is 20 um. The thickness of the transparent conductive oxide film 7 is 80nm, the back electrode 8 is a nickel-copper-silver laminated electrode with the thickness of 9um, and the mass ratio of nickel element, copper element and silver element in the back electrode 8 is as follows: 1:8:1.
Referring to the solar cell shown in fig. 1, the silicon substrate 1 is doped with phosphorus, and the doping concentration of the silicon substrate 1 is 2 × 10 15 /cm 3 The doped region 11 is doped with phosphorus, and the highest doping concentration of the doped region 11 is 5 × 10 20 /cm 3 The depth of the doped region 11 is 0.3um, and the chemical passivation film 2 is silicon oxide (SiO) with a thickness of 5nm 2 ) The film, the field passivation antireflection film 3, is silicon nitride (SiN) with a thickness of 77nm x : H) the film, the refracting index of field passivation antireflection coating 3 is 2.13, and positive grid line electrode 4 is the nickel copper silver stromatolite grid line electrode that thickness is 9um, and in the positive grid line electrode 4 nickel element, copper element, silver element three's mass ratio be: 1:8:1. In fig. 1, d3 is 20um, and d1+ d2 is 20 um. The thickness of transparent conductive oxide film 7 is 80nm, and back electrode 8 is the nickel-copper-silver stromatolite electrode that thickness is 9um, and the mass ratio of nickel element, copper element, silver element three in back electrode 8 is: 1:8:1.
Referring to the solar cell shown in fig. 1, the silicon substrate 1 is doped with phosphorus, and the doping concentration of the silicon substrate 1 is 2 × 10 15 /cm 3 The doped region 11 is doped with phosphorus, and the highest doping concentration of the doped region 11 is 4 × 10 20 /cm 3 The depth of the doped region 11 is 0.3um, and the chemical passivation film 2 is silicon oxide (SiO) with a thickness of 5nm 2 ) The film, the field passivation antireflection film 3, is silicon nitride (SiN) with a thickness of 78nm x : H) the refracting index of membrane, field passivation antireflection coating 3 is 2.11, and positive grid line electrode 4 is the nickel copper silver stromatolite grid line electrode that thickness is 9um, and in positive grid line electrode 4 nickel element, copper element, silver element three's mass ratio be: 1:8:1. In fig. 1, d3 is 20um, and d1+ d2 is 20 um. The thickness of the transparent conductive oxide film 7 is 80nm, the back electrode 8 is a nickel-copper-silver laminated electrode with the thickness of 9um, and the mass ratio of nickel element, copper element and silver element in the back electrode 8 is as follows: 1:8:1.
Control group
The solar cell of the control group is a conventional HJT solar cell, i.e. the structure thereof is: the silicon substrate, the intrinsic amorphous silicon film, the doped amorphous silicon film, the transparent conductive oxide film and the back grid line electrode which are sequentially stacked on the backlight surface of the silicon substrate, and the intrinsic amorphous silicon film, the doped amorphous silicon film, the transparent conductive oxide film and the front grid line electrode which are sequentially stacked on the light-facing surface of the silicon substrate and are different from the doping type of the silicon substrate. The front grid line electrode and the back grid line electrode are made of low-temperature silver paste.
Table 1 shows the results of measuring and averaging the data related to 100 solar cells shown in the experimental group 1, measuring and averaging the data related to 100 solar cells shown in the experimental group 2, measuring and averaging the data related to 100 solar cells shown in the experimental group 3, and comparing the measured data with the conventional HJT solar cells shown in the group, according to the IEC (International Electro technical Commission) standard.
More specifically, the resistivities in table 1 are: according to the IEC standard, the resistivity of the front grid line electrodes 4 of the 100 solar cells shown in the experimental group 1 is measured respectively, and the average value is taken to obtain the result; respectively measuring the resistivity of the front grid line electrodes 4 of the 100 solar cells shown in the experimental group 2 according to the IEC standard, and averaging to obtain results; respectively measuring the resistivity of the front grid line electrodes 4 of the 100 solar cells shown in the experimental group 3 according to the IEC standard, and averaging to obtain results; and the resistivity of the front grid line electrode as measured according to IEC standard, as compared to the conventional HJT solar cell shown in the control group.
More specifically, the efficiencies in table 1 are: according to the IEC standard, the photoelectric conversion efficiencies of 100 solar cells shown in the experimental group 1 are respectively measured, and the average value is taken to obtain the result; according to the IEC standard, the photoelectric conversion efficiencies of 100 solar cells shown in the experimental group 2 are respectively measured, and the average value is obtained to obtain the result; according to the IEC standard, the photoelectric conversion efficiencies of 100 solar cells shown in the experimental group 3 are respectively measured, and the average value is taken to obtain the result; and conventional HJT solar cells as shown in the control group, disclosing photoelectric conversion efficiencies measured according to IEC standards.
More specifically, Voc in table 1 is: according to the IEC standard, the open-circuit voltages of 100 solar cells shown in the experimental group 1 are respectively measured, and the average value is taken to obtain the result; according to the IEC standard, the open-circuit voltages of 100 solar cells shown in the experimental group 2 are respectively measured, and the average value is taken to obtain the result; according to the IEC standard, the open-circuit voltages of 100 solar cells shown in the experimental group 3 are respectively measured, and the average value is taken to obtain the result; and open circuit voltage as measured according to IEC standard, for conventional HJT solar cells as shown in the control group.
More specifically, Jsc in table 1 is: according to the IEC standard, the short-circuit currents of 100 solar cells shown in the experimental group 1 are respectively measured, and the average value is obtained to obtain the result; according to the IEC standard, measuring the short-circuit current of 100 solar cells shown in the experimental group 2 respectively, and averaging to obtain a result; according to the IEC standard, the short-circuit currents of 100 solar cells shown in the experimental group 3 are respectively measured, and the average value is obtained to obtain a result; and a conventional HJT solar cell as shown in the control group, disclosing short circuit current measured according to IEC standard.
More specifically, FF in table 1 is: according to the IEC standard, the fill factors of 100 solar cells shown in the experimental group 1 are respectively measured, and the average value is taken to obtain the result; according to the IEC standard, the fill factors of 100 solar cells shown in the experimental group 2 are respectively measured, and the average value is taken to obtain the result; according to the IEC standard, the fill factors of 100 solar cells shown in the experimental group 3 are respectively measured, and the average value is taken to obtain the result; and a conventional HJT solar cell as shown in the control group, disclosing a fill factor measured according to IEC standards.
As can be seen from the above table, the resistivity of the front grid line electrode of the experimental group provided by the present invention is significantly lower than that of the front grid line electrode of the conventional HJT solar cell shown in the control group. The specific reasons are that: the front grid line electrodes 4 of the experimental group provided by the invention are all nickel-copper-silver laminated grid line electrodes, and the contact among electrode materials in the front grid line electrodes 4 is tight, so that the resistivity of the nickel-copper-silver laminated grid line electrodes is lower. The resistivity of the front grid line electrode 4 of the experimental group provided by the invention is lower, and the nickel-copper-silver laminated grid line electrode contains less silver, the mass ratio is only about 10%, and the cost is lower.
As can be seen from the above table, the experimental group provided by the present invention has the characteristics of photoelectric conversion efficiency, open-circuit voltage, short-circuit current,The filling factor is basically equal to the photoelectric conversion efficiency, open-circuit voltage, short-circuit current and filling factor of the conventional HJT solar cell. The reasons are roughly that: in a first aspect, the silicon oxide film and SiN film have the thicknesses described above x : the H film can play a good role in chemical passivation, such as hydrogen passivation, field passivation and antireflection, can basically achieve the surface passivation capability of amorphous silicon, and the silicon oxide film and the SiN film with the thicknesses x : the H film absorbs short wave and visible light of incident light weakly or basically without absorption, so that the loss of short circuit current of the solar cell can be reduced; in a second aspect, the first doping regions 11 are locally distributed on the light-facing surface of the silicon substrate 1, auger recombination basically does not exist at positions without the first doping regions 11, auger recombination brought by the first doping regions is relatively less, process matching performance is good, and losses of short-circuit current and open-circuit voltage caused by auger recombination can be reduced; in the third aspect, the back electrode 8 is a full-surface electrode layer, and the back electrode 8 itself has a good lateral carrier collecting ability, so that the lateral conductivity due to the thinning reduction of the transparent conductive oxide thin film 7 can be compensated by the back electrode 8.
It should be noted that for simplicity of description, the method embodiments are described as a series of acts, but those skilled in the art should understand that the embodiments are not limited by the described order of acts, as some steps can be performed in other orders or simultaneously according to the embodiments. Further, those of skill in the art will recognize that the embodiments described in this specification are presently preferred embodiments and that no single embodiment of the present disclosure is necessarily required for all such variations and modifications.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which is stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal (such as a mobile phone, a computer, a server, an air conditioner, or a network device) to execute the method according to the embodiments of the present invention.
While the present invention has been described with reference to the particular illustrative embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but is intended to cover various modifications, equivalent arrangements, and equivalents thereof, which may be made by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (16)
1. A solar cell, comprising:
a silicon substrate;
the local area of the light-facing surface of the silicon substrate is provided with at least one first doping area; the doping type of each first doping region is the same as that of the silicon substrate, and the doping concentration of each first doping region is greater than that of the silicon substrate;
sequentially stacking a chemical passivation film and a field passivation antireflection film which are distributed on the silicon substrate and the light-facing side of the first doping region;
at least one front grid line electrode positioned on the light-facing side of the silicon substrate; at least one of the front gate line electrodes and at least one of the first doped regions are in contact with each other.
2. The solar cell of claim 1, wherein each of the first doped regions has a depth of 0.1-0.5 um; the depth direction of the first doping area is parallel to the laminating direction of the chemical passivation film and the field passivation antireflection film.
3. The solar cell according to claim 1, wherein the chemical passivation film comprises: a silicon oxide film or an aluminum oxide film; and/or the field passivation antireflection film comprises a silicon nitride film.
4. The solar cell of claim 3, further comprising: and the antireflection film is positioned on the light-facing side of the field passivation antireflection film.
5. The solar cell of any of claims 1-4, further comprising: the intrinsic amorphous silicon film, the doped amorphous silicon film, the transparent conductive oxide film and the back electrode are sequentially distributed on the backlight side of the silicon substrate in a stacking mode, wherein the doped amorphous silicon film is different from the doping type of the silicon substrate;
the back electrode is an entire electrode layer covering the transparent conductive oxide film, and the thickness of the transparent conductive oxide film is 5-80 nm; the thickness direction of the transparent conductive oxide film is parallel to the laminating direction of the chemical passivation film and the field passivation antireflection film.
6. The solar cell of claim 5, wherein the full-face electrode layer has a thickness of 1-10 um.
7. The solar cell according to any one of claims 1 to 4, wherein the front grid line electrode is a nickel-copper-silver laminated grid line electrode.
8. The solar cell of claim 7, wherein in the nickel-copper-silver laminated gate line electrode: the mass ratio of the nickel element, the copper element and the silver element is as follows: (0.5-2.5): (5-9): (0.5-2.5).
9. The solar cell according to any one of claims 1 to 4,
and each front grid line electrode corresponds to each first doping area in position one by one and is mutually contacted.
10. The solar cell of claim 9, wherein the projection of each front grid line electrode on the first doping region corresponding to the position in the first direction has a size equal to the size of the first doping region corresponding to the position in the first direction, and the projection of each front grid line electrode on the first doping region corresponding to the position in the second direction has a size 15-50um smaller than the size of the first doping region corresponding to the position in the second direction; the first direction and the second direction are both parallel to a light facing surface of the silicon substrate and are vertical to each other;
and/or, the height of each front grid line electrode is 5-20 um; the direction of the height is parallel to the laminating direction of the chemical passivation film and the field passivation antireflection film;
and/or the size of each front grating electrode in the second direction is 15-50 um.
11. The solar cell according to claim 3, wherein in the case where the chemical passivation film is a silicon oxide film, the chemical passivation film has a thickness of 0.5 to 5 nm;
under the condition that the chemical passivation film is an aluminum oxide film, the thickness of the chemical passivation film is 2-10 nm; the thickness direction is parallel to the laminating direction of the chemical passivation film and the field passivation antireflection film.
12. A photovoltaic module, comprising: comprising a plurality of solar cells as claimed in any of the claims 1-11.
13. A method for producing a solar cell, comprising:
forming at least one first doping area in a local area of a light-facing surface of the silicon substrate; the doping type of each first doping region is the same as that of the silicon substrate, and the doping concentration of each first doping region is greater than that of the silicon substrate;
sequentially forming a chemical passivation film and a field passivation antireflection film which are distributed in a stacked mode on the light-facing side of the silicon substrate;
forming at least one front grid line electrode on the light-facing side of the silicon substrate; at least one of the front gate line electrodes and at least one of the first doped regions are in contact with each other.
14. The method for manufacturing a solar cell according to claim 13, wherein the forming at least one first doping region in a local region of a light-facing surface of the silicon substrate comprises:
forming an ultrathin silicon oxide film on the light facing surface of the silicon substrate through ultraviolet ozone oxidation;
infiltrating the silicon substrate light-facing surface formed with the ultrathin silicon oxide film with a liquid-phase phosphorus source to ensure that the surface of the ultrathin silicon oxide film is provided with the liquid-phase phosphorus source;
solidifying the liquid-phase phosphorus source on the surface of the ultrathin silicon oxide film to form a solid phosphorus source;
carrying out heat treatment on the solid phosphorus source on the surface of the ultrathin silicon oxide film, so that the solid phosphorus source and the ultrathin silicon oxide film form a silicon phosphide complex;
and irradiating a local area of the silicon phosphide complex by using laser, so that phosphorus atoms in the silicon phosphide complex of the local area irradiated by the laser are diffused to the light-facing side of the silicon substrate, and at least one first doping area is formed in the local area of the light-facing side of the silicon substrate.
15. A production system for a solar cell, comprising:
a doping component for forming at least one first doping area in a local area of a light-facing surface of the silicon substrate; the doping type of each first doping region is the same as that of the silicon substrate, and the doping concentration of each first doping region is greater than that of the silicon substrate;
the front film processing component is used for sequentially forming a chemical passivation film and a field passivation antireflection film which are distributed in a stacked mode on the light-facing side of the silicon substrate;
a front grid line electrode setting component for forming at least one front grid line electrode on the light-facing side of the silicon substrate; at least one of the front gate line electrodes and at least one of the first doped regions are in contact with each other.
16. The solar cell production system of claim 15, wherein the doping component comprises: a chain apparatus, the chain apparatus comprising: the device comprises an ultraviolet ozone oxidation device, a liquid-phase phosphorus source tank body, an illumination drying device, a heat treatment device, a laser generation device and a transmission device positioned between adjacent devices, wherein the ultraviolet ozone oxidation device, the liquid-phase phosphorus source tank body, the illumination drying device, the heat treatment device and the laser generation device are sequentially distributed;
the ultraviolet ozone oxidation device is used for forming an ultrathin silicon oxide film on the light facing surface of the silicon substrate through ultraviolet ozone oxidation;
the liquid-phase phosphorus source tank body is used for infiltrating the silicon substrate light-facing surface formed with the ultrathin silicon oxide film with a liquid-phase phosphorus source so that the surface of the ultrathin silicon oxide film is provided with the liquid-phase phosphorus source;
the illumination drying device is used for solidifying the liquid-phase phosphorus source on the surface of the ultrathin silicon oxide film to form a solid phosphorus source;
the heat treatment device is used for carrying out heat treatment on the solid phosphorus source on the surface of the ultrathin silicon oxide film, so that the solid phosphorus source and the ultrathin silicon oxide film form a silicon phosphide complex;
the laser generating device is used for irradiating the local area of the silicon phosphide complex by laser, so that phosphorus atoms in the silicon phosphide complex in the local area irradiated by the laser are diffused to the light-facing side of the silicon substrate, and at least one doped area is formed in the local area of the light-facing surface of the silicon substrate.
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| CN116525723A (en) * | 2023-06-28 | 2023-08-01 | 广东利元亨智能装备股份有限公司 | Manufacturing method of heterojunction battery and battery thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN116525723A (en) * | 2023-06-28 | 2023-08-01 | 广东利元亨智能装备股份有限公司 | Manufacturing method of heterojunction battery and battery thereof |
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