CN117976770A - Photovoltaic cell preparation method, photovoltaic cell and photovoltaic module - Google Patents
Photovoltaic cell preparation method, photovoltaic cell and photovoltaic module Download PDFInfo
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Classifications
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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
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Abstract
The invention discloses a preparation method of a photovoltaic cell, the photovoltaic cell and a photovoltaic module, wherein the preparation method comprises the following steps: providing a phosphorus-diffused silicon substrate, and cutting a first surface of the silicon substrate along a direction perpendicular to the thickness of the silicon substrate to obtain a cut silicon substrate; etching the first surface of the cut silicon substrate to obtain an etched silicon substrate; the outer surface of the etched silicon substrate is a selective emitter; passivating one side of the selective emitter far away from the first surface and the cutting surface to obtain a silicon substrate with a passivation layer; after the phosphorus diffusion process for preparing the photovoltaic cell, the photovoltaic cell is cut into half pieces, and then etching and passivation are carried out, so that the edge cutting damage of the photovoltaic cell can be reduced, the surface recombination of a cutting surface is reduced, the efficiency is increased, and the influence on the productivity by slicing before texturing is small.
Description
Technical Field
The invention relates to the technical field of photovoltaics, in particular to a preparation method of a photovoltaic cell, the photovoltaic cell and a photovoltaic module.
Background
With the increasing demand for energy from global economic activities, solar energy has become an inexhaustible renewable energy source for human beings, and has sufficient cleanliness, absolute safety, and relative universality and maintenance-free properties. Therefore, photovoltaic module technology for generating electricity using solar energy has been rapidly developed.
In the production process of the photovoltaic module, the module end product needs to be subjected to subsequent production after the photovoltaic cell is cut into half pieces, but the cut surface and the surrounding surface of the photovoltaic cell are molten silicon when the photovoltaic cell is actually cut, the cut surface can cause larger damage to the cut edge of the photovoltaic cell, the recombination is increased, and the efficiency is greatly reduced.
Disclosure of Invention
In view of the above, the invention provides a preparation method of a photovoltaic cell, the photovoltaic cell and a photovoltaic module, which can reduce cutting damage of the edge of the photovoltaic cell, reduce surface recombination of a cutting surface and increase efficiency.
In a first aspect, the present application provides a method for preparing a photovoltaic cell, comprising:
Providing a phosphorus-diffused silicon substrate, wherein the phosphorus-diffused silicon substrate is provided with a first surface;
Cutting the first surface of the silicon substrate along the direction perpendicular to the thickness of the silicon substrate to obtain the cut silicon substrate;
Etching the first surface of the cut silicon substrate to obtain an etched silicon substrate; the outer surface of the etched silicon substrate is a selective emitter;
and passivating the side, far away from the first surface, of the selective emitter and the cutting surface to obtain the silicon substrate with the passivation layer.
Optionally, the method for cutting the silicon substrate includes: laser cutting, abrasive cutting, and diamond cutting.
Alternatively, when the cutting method of the silicon substrate is laser cutting, the laser running direction is along a thickness direction perpendicular to the silicon substrate.
Optionally, when the cutting method of the silicon substrate is laser cutting, the laser power range of the laser cutting is 15-20W; the laser frequency range of the laser cutting is 100-150kHz; the laser cutting laser operation speed range is 400-500mm/s.
Optionally, the etching the first surface of the cut silicon substrate includes:
Etching the first surface of the cut silicon substrate by using a chain type cleaning machine; the chain type cleaning machine comprises a conveyor belt, and the cut silicon substrate is placed on the conveyor belt for etching; the first surface of the silicon substrate faces to one side of the conveyor belt direction, and the cutting surface of the silicon substrate faces to the moving direction of the conveyor belt.
Optionally, the providing a silicon substrate after phosphorus diffusion further includes:
Acquiring the silicon substrate;
performing boron diffusion on the first surface of the silicon substrate to obtain the silicon substrate with the selective emitter;
The silicon substrate after boron diffusion is provided with a second surface which is opposite to the first surface, and a tunneling oxide layer is formed on the second surface of the silicon substrate;
depositing an amorphous silicon layer on one side of the tunneling oxide layer far away from the silicon substrate;
and performing phosphorus diffusion on one side of the amorphous silicon layer far away from the tunneling oxide layer to form a doped conductive layer.
Optionally, passivating a side of the selective emitter away from the first surface to obtain the silicon substrate with the passivation layer, and then further including:
the passivated silicon substrate is provided with a second surface corresponding to the first surface; coating the first surface and the second surface of the silicon substrate with the passivation layer to obtain the silicon substrate with a first antireflection layer and a second antireflection layer;
a first electrode is formed on the anti-reflective layer of the first face and a second electrode is formed on the anti-reflective layer of the second face.
In a second aspect, the present application also provides a photovoltaic cell comprising a photovoltaic cell prepared by the method of preparing a photovoltaic cell according to any one of the preceding claims; the photovoltaic cell comprises a silicon substrate, wherein the silicon substrate is provided with a cutting surface, and a passivation layer and a first anti-reflection layer are sequentially laminated on the cutting surface along the direction away from the silicon substrate.
Optionally, the length of the passivation layer on the cut surface along the thickness direction of the silicon substrate is smaller than the thickness of the photovoltaic cell along the thickness direction of the silicon substrate; the length of the first anti-reflection layer on the cutting surface along the thickness direction of the silicon substrate is smaller than the thickness of the photovoltaic cell along the thickness direction of the silicon substrate.
In a third aspect, the application further provides a photovoltaic module, which comprises a laminated piece and a frame wrapping the periphery of the laminated piece, wherein the laminated piece comprises a front plate, a first packaging adhesive film, a photovoltaic cell, a second packaging adhesive film and a back plate which are sequentially arranged, and the photovoltaic cell comprises the photovoltaic cell.
Compared with the prior art, the preparation method of the photovoltaic cell, the photovoltaic cell and the photovoltaic module provided by the invention have the following beneficial effects:
The invention provides a preparation method of a photovoltaic cell, the photovoltaic cell and a photovoltaic module, wherein the preparation method comprises the following steps: providing a phosphorus-diffused silicon substrate, and cutting a first surface of the silicon substrate along a direction perpendicular to the thickness of the silicon substrate to obtain a cut silicon substrate; etching the first surface of the cut silicon substrate to obtain an etched silicon substrate; the outer surface of the etched silicon substrate is a selective emitter; passivating one side of the selective emitter far away from the first surface and the cutting surface to obtain a silicon substrate with a passivation layer; after the phosphorus diffusion process for preparing the photovoltaic cell, the photovoltaic cell is cut into half pieces, and then etching and passivation are carried out, so that the edge cutting damage of the photovoltaic cell can be reduced, the surface recombination of a cutting surface is reduced, the efficiency is increased, and the influence on the productivity by slicing before texturing is small.
Of course, it is not necessary for any one product embodying the invention to achieve all of the technical effects described above at the same time.
Other features of the present invention and its advantages will become apparent from the following detailed description of exemplary embodiments of the invention, which proceeds with reference to the accompanying drawings.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.
FIG. 1 is a schematic illustration of ideal and actual case interfaces for dicing photovoltaic cells;
Fig. 2 is a flowchart of a method for manufacturing a photovoltaic cell according to an embodiment of the present invention;
fig. 3 is a flow chart of the preparation of photovoltaic cells of the experimental set of this invention;
FIG. 4 is a schematic diagram of a chain washer etching silicon substrate in accordance with the present invention;
fig. 5 is a flow chart of the preparation of a photovoltaic cell of the control group of the present invention;
FIG. 6 is a PL (photoluminescence) imaging result of a photovoltaic cell of the experimental group of the invention;
FIG. 7 is the PL imaging results of a control group of photovoltaic cells in the present invention;
FIG. 8 is a flow chart of an alternative implementation of a silicon substrate after phosphorus diffusion, provided by an embodiment of the present invention;
FIG. 9 is a flow chart of generating first and second anti-reflection layers first and second electrodes on a surface of a silicon substrate having a passivation layer, according to an embodiment of the present invention;
Fig. 10 is a schematic structural view of a photovoltaic cell according to an embodiment of the present invention;
FIG. 11 is an enlarged view of a portion of FIG. 10 at A;
Fig. 12 is a schematic structural diagram of a photovoltaic module according to an embodiment of the present invention.
Detailed Description
Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise.
The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate.
In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of exemplary embodiments may have different values.
It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.
The existing photovoltaic cell cutting technology generally comprises the steps of cutting a whole cell into two half cells after the whole cell is produced, and then producing a photovoltaic module; the cutting and welding integrated machine is adopted to complete the cutting and series welding process, the whole piece is put into equipment during cutting, and a camera in the equipment can automatically grasp the position of a grid line to judge the starting point of cutting for cutting; the front structure of the battery piece is damaged when the front of the battery piece is cut by the component end, a plurality of micro cracks are generated, the tunneling oxidation structure on the back of the battery piece falls off, and a large amount of dust is adsorbed on the back of the battery piece; when the back of the battery piece is cut by the assembly end, a large number of defects exist on the diffusion surface, and when the surface recombination rate of the edge surface of the battery is high, the front surface is seriously compounded, and after the cutting is finished, the area of the edge of the battery within a certain range is influenced.
Referring to fig. 1, fig. 1 is a schematic diagram of an ideal and actual interface for cutting a photovoltaic cell, wherein when the photovoltaic cell is cut, a smooth section is generated in an ideal condition, and the efficiency is not reduced; however, when the photovoltaic cell is actually cut, the silicon melting on the cut surface and the surrounding surface is caused, the cut edge of the photovoltaic cell is greatly damaged by the cut surface, the recombination is increased, and the efficiency is greatly reduced.
Referring to fig. 2, fig. 2 is a flowchart of a method for manufacturing a photovoltaic cell according to an embodiment of the present invention; the present embodiment provides a method for manufacturing a photovoltaic cell 100, including:
step S1: providing a phosphorus-diffused silicon substrate 00, wherein the phosphorus-diffused silicon substrate 00 is provided with a first surface 01;
Specifically, as shown in fig. 2 and 3, fig. 3 is a flowchart of a preparation process of a photovoltaic cell of an experimental group in the present invention, the silicon substrate 00 includes a first surface 01 and a second surface 02 that are disposed opposite to each other, in this embodiment, the first surface 01 may be a front surface (a surface facing the sun, i.e. a light receiving surface), and the second surface 02 may be a back surface (a surface facing away from the sun, i.e. a backlight surface); in this embodiment, the phosphorus diffusion on the second surface 02 of the silicon substrate 00 may be performed by using a tubular phosphorus diffusion device to perform phosphorus diffusion on the back amorphous silicon surface of the silicon substrate 00 by using phosphorus trioxide to form a doped polysilicon layer; the process temperature of phosphorus diffusion can be 800 ℃, the back resistance after phosphorus diffusion can be 50ohm/squ, the thickness of the phosphosilicate glass can be 40mm, the doping concentration of phosphorus in polysilicon can be 3E20cm -3, and the junction depth can be 150mm.
It should be noted that, the silicon substrate 00 may be an N-type silicon substrate, the silicon substrate 00 may be a crystalline silicon substrate, for example, one of a polysilicon substrate, a monocrystalline silicon substrate, a microcrystalline silicon substrate, or a silicon carbide substrate, and the specific type of the silicon substrate 00 is not limited in the embodiments of the present application.
Step S2: cutting the first surface 01 of the silicon substrate 00 along the direction perpendicular to the thickness of the silicon substrate 00 to obtain a cut silicon substrate 00;
Specifically, the size of the silicon substrate 00 is directly related to the power output of the photovoltaic cell and the size of the photovoltaic module, the size of the silicon substrate 00 is generally represented by the side length or diagonal line length, and the common sizes of the whole silicon substrate 00 are 156mm×156mm, 156.75mm×156.75mm, 125mm×125mm and the like, so that in order to reduce the manufacturing cost and the flexibility of installation, the whole silicon substrate 00 is often cut into half pieces for subsequent production, the phosphorus-expanded silicon substrate 00 is cut, and only the size of production equipment of the subsequent process is required to be modified to be matched with the size of half-piece battery pieces, the size of the production equipment of the whole production line is not required to be modified, and the production equipment is simplified; cutting the first surface 01 of the silicon substrate 00 along the direction perpendicular to the thickness of the silicon substrate 00, it can be appreciated that the first surface 01 of the silicon substrate 00 may be the front surface (light receiving surface) of the silicon substrate 00, and the second surface 02 of the silicon substrate 00 may be the back surface (backlight surface) of the silicon substrate 00, and the direction perpendicular to the thickness of the silicon substrate 00 refers to the direction along which the first surface 01 of the silicon substrate 00 points to the second surface 02, i.e. the direction along which the front surface of the silicon substrate 00 points to the back surface; the cutting method of the silicon substrate 00 may include: laser cutting, abrasive cutting and diamond cutting; the abrasive cutting is to cut a silicon wafer by a certain abrasive in a high-speed rotation mode, has excellent lubricity, can accelerate the cutting speed, and simultaneously reduces the surface damage of the cut photovoltaic cell; the diamond cutting is to cut the silicon chip by a cutting blade made of diamond, and has the characteristics of high efficiency, low cost, high precision, narrow kerf, low surface damage and low chip rate, and the cutting surface is smooth, the service life is long, no lubricant is needed during cutting, and the use is environment-friendly; the laser cutting irradiates the silicon substrate 00 mainly through a focused laser beam, then moves the silicon substrate 00 or a laser head, and the silicon substrate 00 can be cut and diced by the laser along the moving direction because the material of the silicon substrate 00 is removed due to gasification, and the high-quality and high-efficiency cutting can be realized by cutting on the silicon substrate 00 through a high-energy laser beam, and the laser cutting can obtain better cutting quality because the laser spot is small, the energy density is high and the cutting speed is high; harmful substances are not generated in the laser cutting process, and the laser cutting machine is environment-friendly; the laser cutting speed is very fast, a large amount of cutting work can be completed in a short time, and the production efficiency is improved.
Alternatively, when the cutting method of the silicon substrate 00 is laser cutting, the laser running direction is along the thickness direction perpendicular to the silicon substrate 00; it can be appreciated that after the silicon substrate 00 is cut, etching, passivation, coating, sintering and other processes are further required to be performed to prepare a photovoltaic cell, and the photovoltaic cell comprises the silicon substrate 00, a first electrode 70 and a second electrode 80 positioned on the surface of the silicon substrate 00; the first electrode 70 and/or the second electrode 80 may be a main grid line for converging current and providing sufficient tension, and a thin grid line intersecting the main grid line for collecting current generated by the photovoltaic cell 100, which may increase light absorption rate and output current, thereby improving conversion efficiency of the photovoltaic cell; the laser running direction is along a thickness direction perpendicular to the silicon substrate 00, that is, when the cutting method of the silicon substrate 00 is laser cutting, the laser running direction may be an extending direction of the thin gate line.
Alternatively, when the cutting method of the silicon substrate 00 is laser cutting, the laser power of the laser cutting is in the range of 15-20W; the laser frequency range of the laser cutting is 100-150kHz; the laser cutting operation speed range is 400-500mm/s.
Specifically, when the cutting method of the silicon substrate 00 is laser cutting, if the laser power of the laser cutting is less than 15W, the laser power is too small, which easily results in a small cutting degree, and the cut silicon substrate 00 is difficult to break off; if the laser power of the laser cutting is more than 20W, the laser power is too high, so that the silicon substrate 00 is easy to be seriously fused, the cuts are fused together, and the silicon substrate 00 is difficult to break off; therefore, the laser power range of laser cutting is designed to be 15-20W, so that the cutting degree can be ensured, the cut silicon substrate 00 can be broken off, the silicon melting phenomenon of the silicon substrate 00 can be avoided, and the situation that the cut is re-melted and cannot be broken off together is avoided; specifically, the laser power of the laser cutting may be 15W, 16W, 17W, 18W, 19W, or 20W.
When the cutting method of the silicon substrate 00 is laser cutting, if the laser frequency of the laser cutting is less than 100kHz, the laser frequency is too small to break the cut silicon substrate 00 off; if the laser frequency of the laser cutting is larger than 150kHz, the laser frequency is too large, and the damage to the silicon substrate 00 is easily excessive; therefore, the laser frequency range of laser cutting is designed to be 100-150kHz, so that the damage to the track 00 caused by overlarge laser frequency can be avoided, and the cut silicon substrate 00 can be broken off; in particular, the laser cutting may have a laser frequency of 100kHz, 110kHz, 120kHz, 130kHz, 140 or 150kHz.
When the cutting method of the silicon substrate 00 is laser cutting, if the laser operation speed of the laser cutting is greater than 500mm/s, the laser operation is too fast to break the cut silicon substrate 00 off; if the laser cutting laser running speed is less than 400mm/s, the laser running speed is too slow, and the damage to the silicon substrate 00 is easy to be too large; therefore, the laser running speed range of laser cutting is designed to be 400-500mm/s, so that the overlarge damage to the silicon substrate 00 caused by overlarge laser frequency can be avoided, and the cut silicon substrate 00 can be ensured to be broken off; in particular, the laser cutting may be performed at a laser operating speed of 400mm/s, 420mm/s, 440mm/s, 460mm/s, 480mm/s or 500mm/s.
Step S3: etching the first surface 01 of the cut silicon substrate 00 to obtain an etched silicon substrate 00; wherein the outer surface of the etched silicon substrate 00 is a selective emitter 10;
Specifically, the first face 01 of the cut silicon substrate 00 is etched, the process can primarily repair the edge and the cutting damage of the surface of the silicon substrate 00, and the phosphosilicate glass layer on the surface of the silicon substrate 00 can also be removed; specifically, the mixed solution of hydrofluoric acid (HF)/nitric acid (HNO 3) may be used for acid etching and polishing, or the solution of potassium hydroxide (KOH) may be used for alkali etching and polishing, and the first surface 01 of the etched silicon substrate 00 may be the selective emitter 10;
The selective emitter 10 on the outer surface of the first surface 01 of the silicon substrate 00 is to heavily dope the contact part of the metal gate line (electrode) and the silicon substrate 00 and lightly dope the contact part between the electrodes, so that the structure can reduce the recombination of diffusion layers, thereby improving the short-wave response of light, reducing the contact resistance between the front metal electrode and silicon, and improving the short-circuit current, the open-circuit voltage and the filling factor, thereby improving the conversion efficiency.
It should be noted that, when the silicon substrate 00 is an N-type silicon substrate, the emitter may be a P-type emitter, and the P-type emitter may be a boron-doped diffusion layer or a gallium-doped diffusion layer; the boron-doped diffusion layer and the gallium-doped diffusion layer are both emitters formed by using corresponding doping sources to diffuse doping source atoms to a certain depth on the front surface through a diffusion process; illustratively, when preparing the boron doped diffusion layer, the doping source may be liquid boron tribromide or boron trichloride; forming a selective emitter 10 by diffusing boron atoms through a boron source; because of the relatively high concentration of boron on the surface of the silicon substrate 00, a borosilicate glass layer (BSG) is typically formed, which has a metal gettering effect and can affect the normal operation of the solar cell, requiring subsequent removal.
Optionally, referring to fig. 4, fig. 4 is a schematic structural diagram of a chain washer for etching a silicon substrate according to the present invention, etching a first surface 01 of a cut silicon substrate 00, including:
Etching the first surface 01 of the cut silicon substrate 00 by using a chain type cleaning machine 1; the chain type cleaning machine 1 comprises a conveyor belt 2, and a cut silicon substrate 00 is placed on the conveyor belt 2 for etching; the first surface 01 of the silicon substrate 00 faces the side of the conveyor belt 2, and the cut surface 03 of the silicon substrate 00 faces the conveyor belt moving direction X.
Specifically, as shown in fig. 4, the cut silicon substrate 00 is etched by using a chain-slot integrated device, firstly, the first surface 01 of the silicon substrate 00 is corroded by using a chain cleaner 1, the silicon substrate 00 is required to be placed on a conveyor belt 2 of the chain cleaner 1, the silicon substrate 00 is partially immersed into a corrosive solution liquid level 3, the first surface 01 of the silicon substrate 00 is contacted with the upper surface of the conveyor belt 2, when the silicon substrate 00 has a cutting surface 03, the cutting surface 03 of the silicon substrate 00 faces a moving direction X of the conveyor belt, that is, a water flow direction Y of the corrosive solution is opposite to the moving direction X of the conveyor belt, during the moving process of the conveyor belt 2, the cutting surface 03 of the silicon substrate 00 faces the water flow of the corrosive solution, and the other parts of the cutting surface 03 of the silicon substrate 00 are contacted with the corrosive solution in preference to the other parts of the silicon substrate 00, so that surface substances of the cutting surface 03 are sufficiently cleaned;
wherein, the chain cleaning machine 1 generally contains Hydrogen Fluoride (HF) solution, the volume concentration range of the HF solution can be 20-40%, and the belt speed of the conveyor belt 2 can be 4m/min; if the volume concentration of the hydrogen fluoride solution is less than 20%, the phosphosilicate glass layer on the first surface 01 of the silicon substrate 00 cannot be removed; if the volume concentration of the hydrogen fluoride solution is more than 40%, the cost is wasted; therefore, the volume concentration range of the hydrogen fluoride solution is set to be 20% -40%, so that the problem that the phosphosilicate glass layer on the first surface 01 of the silicon substrate 00 cannot be removed can be avoided, and the problem of waste of cost is avoided; in particular, the hydrogen fluoride solution may have a volume concentration of 20%, 25%, 30%, 35%, or 40%.
After being cleaned by the chain type cleaning machine 1, the waste water is cleaned by a groove type cleaning machine, wherein chemical solution in the groove type cleaning machine comprises hydrofluoric acid (HF), hydrochloric acid (HCl), sodium hydroxide (NaOH) and hydrogen peroxide (H 2O2); in the tank cleaning machine, the silicon substrate 00 is vertically immersed in the chemical solution, the chemical solution can reduce the damage of the first surface 01 and the cutting surface 03 of the silicon substrate 00, and the damage of the cutting surface 03 can be cleaned and repaired by more than 50 percent.
Step S4: the cut silicon substrate 00 has a cut surface 03, and the side of the selective emitter 10 away from the first surface 01 and the cut surface 03 are passivated to obtain the silicon substrate 00 having the passivation layer 40.
Specifically, the side of the selective emitter 10 away from the first surface 01 and the cut surface 03 are passivated to obtain the silicon substrate 00 with the passivation layer 40, it is understood that the number of layers of the passivation layer 40 may be one or two, and the passivation layer 40 includes a front sub-passivation layer 401 and a side sub-passivation layer 402; in this embodiment, the side of the selective emitter 10 far from the first surface 01 may be passivated, and a front sub-passivation layer 401 is formed on the front surface of the silicon substrate 00; simultaneously, passivation is carried out on the cutting surface 03 of the silicon substrate 00, and a side sub-passivation layer 402 is formed on the cutting surface 03 of the silicon substrate 00; in this embodiment, the side of the selective emitter 10 far from the first surface 01 may be passivated preferentially, and a front sub-passivation layer 401 is formed on the front surface of the silicon substrate 00; after the front sub-passivation layer 401 is obtained, passivation is carried out on the cut surface 03 of the silicon substrate 00, and a side sub-passivation layer 402 is formed on the cut surface 03 of the silicon substrate 00; the passivation sequence of the first surface 01 and the cutting surface 03 of the silicon substrate 00 can be adjusted according to practical situations, and the passivation sequence of the first surface 01 and the cutting surface 03 of the silicon substrate 00 is not particularly limited in this embodiment; the length of the side sub-passivation layer 402 may be greater than 1.5 μm in the thickness direction of the silicon substrate 00.
Passivation is carried out on the first surface 01 and the cutting surface 03 of the silicon substrate 00, so that the cutting surface 01 and the area of the first surface 01 influenced by the cutting surface 03 can be further repaired on the basis of an etching process; specifically, the front sub-passivation layer 401 may be formed on the surface of the silicon substrate 00 by a thermal atomic deposition (ALD) method and simultaneously deposited on the first surface 01 of the silicon substrate 00, and the side sub-passivation layer 402 may be formed on the cut surface 03; the process parameters may include: the temperature can be 260 ℃, and the deposition thickness can be 4nm; the materials of the front sub-passivation layer 401 and the side sub-passivation layer 402 may include, but are not limited to, at least one of silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, etc., or any combination thereof; the front sub-passivation layer 401 and the side sub-passivation layer 402 can be used for fixing negative charges, eliminating parasitic capacitance effect, generating good passivation effect on the silicon substrate 00, and being beneficial to improving the conversion efficiency of the photovoltaic cell;
the thickness of the front sub-passivation layer 401 can be in the range of 10nm-120nm, if the thickness of the front sub-passivation layer 401 is smaller than 10nm, the front sub-passivation layer 401 is too low to repair damage to the cut silicon substrate 00; if the thickness of the front sub-passivation layer 401 is greater than 120nm, the front sub-passivation layer 401 is too high, so that the contact between the paste and the photovoltaic cell in the subsequent screen printing process is poor, and the cost is increased; therefore, the thickness range of the front sub-passivation layer 401 can be 10nm-120nm, so that the cut silicon substrate 00 can play a role in repairing damage, contact between the paste and the photovoltaic cell in the subsequent screen printing process can be ensured, and meanwhile, the cost is prevented from being increased; the thickness of the front sub-passivation layer 401 may be specifically 10nm, 20nm, 30nm, 42nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 120nm, or the like, but may be other values within the above range, and is not limited thereto.
In the method for manufacturing a photovoltaic cell provided in this embodiment, a silicon substrate 00 after phosphorus diffusion is provided, and a first surface 01 of the silicon substrate 00 is cut along a direction perpendicular to a thickness of the silicon substrate 00 to obtain a cut silicon substrate 00; etching the first surface 01 of the cut silicon substrate 00 to obtain an etched silicon substrate 00; passivating the side of the selective emitter 10 away from the first face 01 and the cut face 03 to obtain a silicon substrate 00 with a passivation layer 40; the steps of the present embodiment are related to each other, so that the steps cannot be divided, and the order of the steps cannot be adjusted.
The photovoltaic cell 100 can be TOPCon (Tunnel Oxide Passivated Contact, tunneling oxide passivation contact) cells, and TOPCon cells have high conversion efficiency, excellent interface passivation and carrier transport capability, and higher Voc (open circuit voltage); the photoinduced attenuation is low, the boron content in the phosphorus-doped N-type crystalline silicon is extremely low, and the influence of boron and oxygen on the silicon is weakened; the process equipment production line has high compatibility, and can be compatible with high-temperature preparation process production lines of PERC (back contact of a passivation emitter) and N-PERT (N-PASSIVATED EMITTER, rear Totally-diffused, full diffusion of the back surface of an N-type passivation emitter) double-sided batteries; the N-type TOPCon cell can be combined with SE (seletive-emitter, selective emitter), IBC (INTERDIGITATED BACK CONTACT, finger cross back contact), multi-main grid, half-sheet, lamination technology, and the cell efficiency and the component power are remarkably improved.
In order to embody the effect of the photovoltaic cell preparation method provided in this embodiment, effect comparison of the photovoltaic cell 100 of the experimental group and the photovoltaic cell 100 of the control group is also performed;
The comparison of the experimental group of photovoltaic cells 100 and the control group of photovoltaic cells 100 is as follows:
the experimental design is as follows: the process from the process of texturing to the process of phosphorus diffusion is a production line fixing process (namely, the preparation method sequentially comprises the steps of texturing, boron diffusion, back etching, tunneling oxidation and phosphorus diffusion), the test is carried out after phosphorus diffusion, and the silicon substrates 00 with similar minority carrier lifetime are selected to be divided into a control group and an experimental group.
Experimental group
Referring to fig. 3, fig. 3 is a flow chart of the preparation of photovoltaic cells of the experimental group according to the present invention, and the preparation steps of the test piece of the experimental group are as follows:
Step 1, slicing: cutting from the first surface 01 (namely the front surface or the boron diffusion surface) of the silicon substrate 00 along the direction of a selective emitter (namely the extending direction of a thin grid line) formed by boron diffusion by using a laser dicing machine, and then breaking into two halves;
Step 2, front etching: cleaning by using PSG+alkali polishing automatic equipment, wherein the equipment is chain type groove type integrated equipment, when the silicon substrate 00 is put into a chain type machine for best damage repairing effect, the cutting surface 03 of the silicon substrate 00 is placed towards the moving direction of the silicon substrate 00, and then cleaning is carried out by a groove type cleaning machine, and chemicals in the groove type cleaning machine comprise hydrofluoric acid (HF), hydrochloric acid (HCl), sodium hydroxide (NaOH) and hydrogen peroxide (H2O 2); the chemical substances can reduce the damage to the surface and the section of the silicon substrate 00;
Step 3, front passivation: then forming a passivation layer 40 (namely an alumina film structure) on the first surface 01 and the cutting surface 03 of the silicon substrate 00 through a passivation process, wherein the passivation layer 40 has excellent gap filling capability, and can further repair the damage of the first surface 01 and the cutting surface 03 caused by laser;
Step 4, double-sided film coating: finally, the silicon substrate 00 is coated, the coated film (namely the silicon nitride film structure) of the first surface 01 can repair the cutting damage of the section better, the coated film enters the screen printing and sintering process, the test piece of the experimental group can be obtained after being taken out, and the process needs to be carefully taken by using tweezers.
Step 5, preparing a photovoltaic module: arranging a plurality of photovoltaic cells 100 in sequence, sequentially connecting the photovoltaic cells 100 in series from head to tail through welding strips to form a cell string, and arranging the parallel cell strings in the same direction; sequentially stacking the front plate, the first packaging adhesive film, the photovoltaic cell, the second packaging adhesive film and the backboard together; applying pressure along the stacking direction, melting the first packaging adhesive film and the second packaging adhesive film under the vacuum high-temperature condition, adhering the battery strings, the front plate and the back plate together, and cooling and solidifying to obtain a photovoltaic module; the edge damage of the half photovoltaic cell 100 of the experimental group is repaired, and the half photovoltaic cell 100 is wrapped by a passivation layer and an antireflection layer (SiNx), so that the surface recombination of the edge of the half photovoltaic cell 100 is greatly reduced, and the efficiency of the manufactured photovoltaic module is almost equal to that of the whole photovoltaic cell.
Control group
Referring to fig. 5, fig. 5 is a flow chart of the preparation of a photovoltaic cell of a control group according to the present invention, and the control group test piece has the following steps:
the minority carrier lifetime test is completed from phosphorus expansion to sintering annealing to a production line fixing process (namely, the preparation method sequentially comprises front etching, front passivation, double-sided coating, screen printing and sintering), and then a laser dicing saw is used for cutting half pieces to obtain the photovoltaic cell 100 of the comparison group;
Then, arranging a plurality of photovoltaic cells 100 in sequence, wherein the photovoltaic cells 100 are sequentially connected in series from head to tail through welding strips to form a cell string, and the parallel cell strings are arranged in the same direction; sequentially stacking the front plate, the first packaging adhesive film, the photovoltaic cell, the second packaging adhesive film and the backboard together; applying pressure along the stacking direction, melting the first packaging adhesive film and the second packaging adhesive film under the vacuum high-temperature condition, adhering the battery strings, the front plate and the back plate together, and cooling and solidifying to obtain a photovoltaic module; the photovoltaic module is directly manufactured after the control group photovoltaic cell 100 is cut, the edges of the half photovoltaic cell 100 are exposed, so that the surface recombination of the edges of the half photovoltaic cell 100 is large, and the efficiency of the photovoltaic module is reduced by about 1% compared with that of the whole photovoltaic cell.
Test analysis
The half-sheets of the experimental group and the control group are correspondingly and tightly placed in photoluminescence imaging equipment (PL) for shooting test, and as shown in fig. 6 and 7, fig. 6 is a PL imaging result of the photovoltaic cell of the experimental group in the invention, and fig. 7 is a PL imaging result of the photovoltaic cell of the control group in the invention, wherein, gray bars on the right side of fig. 6 and 7 represent gray value ranges of the whole picture, and the darker color represents the smaller minority carrier lifetime; in the imaging result, the black part corresponds to the area with low minority carrier lifetime, the black strip area in the middle of the picture is the area with low minority carrier lifetime caused by the cutting damage of the photovoltaic cell, and as can be seen from the picture, the black strip width of the PL picture of the experimental group is smaller than that of the control group, because a part of cutting damage can be repaired in the procedure after the photovoltaic cell of the experimental group is phosphorus-expanded, the circling position in the control group is the influence of laser on the cutting surrounding area, the damage of the shallow surface layer is not found in the experimental group, and the shallow surface damage can be eliminated by the processes such as cleaning after phosphorus expansion.
The minority carrier lifetime tester is used for testing the experimental group and the control group, the minority carrier lifetime of the experimental group is reduced by 3% relative to the whole tablet, and the minority carrier lifetime of the control group is reduced by 20%.
As can be seen from the foregoing embodiments, the preparation method of the photovoltaic cell provided in this embodiment at least achieves the following beneficial effects:
The embodiment provides a method for preparing a photovoltaic cell, which comprises the following steps: providing a phosphorus-diffused silicon substrate 00, and cutting a first surface 01 of the silicon substrate 00 along a direction perpendicular to the thickness of the silicon substrate 00 to obtain a cut silicon substrate 00; etching the first surface 01 of the cut silicon substrate 00 to obtain an etched silicon substrate 00; the outer surface of the etched silicon substrate 00 is a selective emitter 10; passivating the side of the selective emitter 10 away from the first face 01 and the cut face 03 to obtain a silicon substrate 00 with a passivation layer 40; after the phosphorus diffusion process for preparing the photovoltaic cell, the photovoltaic cell 100 is cut into half pieces, and then etching and passivation are carried out, so that edge cutting damage of the photovoltaic cell 100 can be reduced, surface recombination of a cutting surface is reduced, efficiency is improved, and the influence on productivity is small compared with slicing before texturing.
In some alternative embodiments, referring to fig. 8, fig. 8 is a flowchart of an alternative implementation of obtaining a silicon substrate after phosphorus diffusion according to an embodiment of the present invention; step S1: providing a phosphorus diffused silicon substrate 00, further comprising:
Step S101: obtaining a silicon substrate 00;
Specifically, in this embodiment, the mixed aqueous solution of KOH and hydrogen peroxide may be first used to pre-clean the silicon substrate 00 to remove metal and organic pollutants on the surface, and then the silicon substrate 00 may be subjected to a texturing process to form a textured structure 90 (e.g. a pyramid structure), where the texturing process may be chemical etching, laser etching, mechanical method, plasma etching, and the like, and is not limited herein; illustratively, the surface of the silicon substrate 00 may be textured with NaOH solution, and the pyramidal textured structure 90 may be prepared due to the anisotropy of the NaOH solution; it can be appreciated that the texturing process makes the surface of the silicon substrate 00 have a textured structure 90, which generates a light trapping effect, and increases the amount of light absorbed by the photovoltaic cell 100, thereby improving the conversion efficiency of the photovoltaic cell 100.
Step S102: performing boron diffusion on the first surface 01 of the silicon substrate 00 to obtain the silicon substrate 00 with the selective emitter 10;
Specifically, a tubular boron diffusion device is adopted on the first surface 01 of the silicon substrate 00, boron diffusion is carried out on the front pyramid by utilizing boron tribromide to form the selective emitter 10, the process temperature of the boron diffusion can be 1000 ℃, the sheet resistance after the boron diffusion is 100ohm/squ, the doping concentration of boron in the silicon substrate 00 is 2E19cm -3, and the junction depth is 0.8 micron.
Step S103: the boron-diffused silicon substrate 00 has a second surface 02 arranged opposite to the first surface 01, and a tunneling oxide layer 20 is formed on the second surface 02 of the silicon substrate 00;
Specifically, a tunneling oxide layer 20 is formed on the second surface 02 of the silicon substrate 00 by high-temperature oxidation, where the tunneling oxide layer 20 may be a silicon dioxide (SiO 2) layer, and the process parameters include: the flow rate of oxygen (O 2) ranges from 30000sccm to 38000sccm, the temperature ranges from 580 ℃ to 620 ℃, and the thickness of the tunnel oxide layer 20 may range from 1nm to 2nm.
Step S104: depositing an amorphous silicon layer on the side of the tunneling oxide layer 20 away from the silicon substrate 00;
Specifically, an amorphous silicon layer is formed by thermal decomposition on the side of the tunnel oxide layer 20 away from the silicon substrate 00, and the process parameters include: the flow rate of silicon tetrahydride (SiH 4, also called silane) ranges from 1300sccm to 1700sccm, the temperature ranges from 590 ℃ to 610 ℃, and the thickness of the amorphous silicon layer can range from 30nm to 150nm.
Step S105: phosphorus diffusion is performed on the side of the amorphous silicon layer away from the tunnel oxide layer 20 to form the doped conductive layer 30.
Specifically, a tubular phosphorus diffusion device is used to perform phosphorus diffusion on the side, far away from the tunneling oxide layer 20, of the amorphous silicon layer to form a doped conductive layer 30, and the technological parameters include: the flow range of nitrogen (N 2) can be 500sccm-2000sccm, the flow range of oxygen (O 2) can be 600sccm-3000sccm, the temperature range can be 800-920 ℃, the phosphorus-diffused sheet resistance can be 50ohm/squ, the doping concentration of phosphorus in the amorphous silicon layer can be 3E20cm -3, and the junction depth can be 150mm.
In some alternative embodiments, referring to fig. 9, fig. 9 is a flowchart of generating a first antireflection layer and a second antireflection layer on a surface of a silicon substrate having a passivation layer, and step S4: passivating the side of the selective emitter 10 remote from the first face 01 results in a silicon substrate 00 with a passivation layer 40, which further comprises:
Step S401: the passivated silicon substrate 00 has a second face 02 corresponding to the first face 01; coating the first surface 01 and the second surface 02 of the silicon substrate 00 with the passivation layer 40 to obtain the silicon substrate 00 with the first anti-reflection layer 50 and the second anti-reflection layer 60;
Specifically, a first anti-reflection layer 50 is formed on the positive first surface 01 and a second anti-reflection layer 60 is formed on the second surface 02 by a plasma chemical vapor deposition (PECVD) method; the technological parameters include: the volume ratio of ammonia gas (NH 3) to silicon tetrahydroide (SiH 4, also known as silane) is 4:1-10:1, the temperature range can be 480-550 ℃ and the pressure can be 210Pa; the first and second anti-reflection layers 50 and 60 may function to reduce reflection of incident light; the first and second anti-reflection layers 50 and 60 may be a silicon oxide layer, an aluminum oxide layer, a silicon nitride layer, or a silicon nitride layer; wherein the first anti-reflection layer 50 includes a front sub-anti-reflection layer 501 and a side sub-anti-reflection layer 502; the front sub-passivation layer 501 is located on the side of the front sub-passivation layer 401 away from the silicon substrate 00, and the side sub-passivation layer 502 is located on the side of the side sub-passivation layer 402 away from the silicon substrate 00; the first surface 01 and the cutting surface 03 of the silicon substrate 00 are coated with a film, and the areas of the cutting surface 01 and the first surface 01 affected by the cutting surface 03 can be further repaired on the basis of an etching process and a passivation process.
Step S402: the first electrode 70 is formed on the first anti-reflection layer 50 of the first face 01, and the second electrode 80 is formed on the second anti-reflection layer 60 of the second face 02.
Specifically, a screen printer is adopted to print metal paste on a first face 01 and a second face 02 respectively to obtain grid lines, the grid lines comprise main grid lines and fine grid lines, the main grid lines are used for converging current and providing enough tension, the fine grid lines are used for collecting current generated by a photovoltaic cell 100, and the printing sequence of the first face 01 and the second face 02 is that the fine grid lines are printed firstly and then the main grid is printed; the silicon substrate 00 is fed into a sintering furnace to be sintered at a temperature ranging from 750 to 880 ℃ so that the gate lines penetrate through the plurality of film layers, the first electrode 70 is formed on the first anti-reflection layer 50 of the first face 01, and the second electrode 80 is formed on the second anti-reflection layer 60 of the second face 02.
Referring to fig. 10, fig. 10 is a schematic structural diagram of a photovoltaic cell provided in an embodiment of the present invention, and based on the same inventive concept, the embodiment further provides a photovoltaic cell 100, including a photovoltaic cell 100 prepared by the method for preparing a photovoltaic cell 100 in any one of the above embodiments; the photovoltaic cell 100 includes a silicon substrate 00, the silicon substrate 00 having a cut surface 03, the cut surface 03 being sequentially laminated with a passivation layer 40 and a first anti-reflection layer 50 in a direction away from the silicon substrate 00.
Specifically, photovoltaic cell 100 includes a silicon substrate 00; the silicon substrate 00 comprises a first surface 01 and a second surface 02 which are oppositely arranged, and the first surface 01 of the silicon substrate 00 is sequentially provided with a front sub-antireflection layer 501, a front sub-passivation layer 401 and a selective emitter 10 along the thickness direction of the silicon substrate 00; the tunneling oxide layer 20, the doped conductive layer 30 and the second anti-reflection layer 60 are sequentially arranged on the second surface 02 of the silicon substrate 00 along the thickness direction of the silicon substrate 00;
The silicon substrate 00 further comprises a cut surface 03; along the direction perpendicular to the thickness of the silicon substrate 00, the cutting surface 03 of the silicon substrate 00 is sequentially provided with a side sub-passivation layer 402 and a side sub-antireflection layer 502; the front sub-passivation layer 401 may be connected to the side sub-passivation layer 402 to form the passivation layer 40, and the front sub-antireflection layer 501 may be connected to the side sub-antireflection layer 502 to form the first antireflection layer 50.
The photovoltaic cell 100 in this embodiment includes a silicon substrate 00, the silicon substrate 00 has a cutting surface 03, the cutting surface 03 is sequentially laminated with a passivation layer 40 and a first anti-reflection layer 50 along a direction away from the silicon substrate 00, the photovoltaic cell 100 is cut into half pieces after a phosphorus diffusion procedure for preparing the photovoltaic cell 100, and then etching, passivation and coating are performed, so that the cutting surface 03 has the passivation layer 40 and the first anti-reflection layer 50, the etching and passivation process can reduce edge cutting damage of the photovoltaic cell 100, reduce surface recombination of the cutting surface, increase efficiency, and have less influence on productivity compared with a slice before making a wool.
In some alternative embodiments, referring to fig. 11, fig. 11 is an enlarged view of a portion of fig. 10 at a; the length of passivation layer 40 on cut surface 03 in the thickness direction of silicon substrate 00 is smaller than the thickness of photovoltaic cell 100 in the thickness direction of silicon substrate 00; the length of the first anti-reflection layer 50 on the cut surface 03 in the thickness direction of the silicon substrate 00 is smaller than the thickness of the photovoltaic cell 100 in the thickness direction of the silicon substrate 00.
Specifically, the length of passivation layer 40 along the thickness direction of silicon substrate 00 on cut surface 03 is smaller than the thickness of photovoltaic cell 100 along the thickness direction of silicon substrate 00, and it is understood that side sub-passivation layer 402 is formed by deposition on cut surface 03 of silicon substrate 00, and the length of side sub-passivation layer 402 along the thickness direction of silicon substrate 00 is smaller than the thickness of photovoltaic cell 100 along the thickness direction of silicon substrate 00; that is, on the cut surface 03 of the silicon substrate 00, the side sub-passivation layer 402 is not in contact with the film structure of the second surface 02 of the silicon substrate 00, avoiding the risk of causing short circuits;
the length of the first anti-reflection layer 50 along the thickness direction of the silicon substrate 00 on the cut surface 03 is smaller than the thickness of the photovoltaic cell 100 along the thickness direction of the silicon substrate 00, it can be understood that the side sub-anti-reflection layer 502 is formed by coating the cut surface 03 of the silicon substrate 00, and the length of the side sub-anti-reflection layer 502 along the thickness direction of the silicon substrate 00 is smaller than the thickness of the photovoltaic cell 100 along the thickness direction of the silicon substrate 00; that is, on the cut surface 03 of the silicon substrate 00, the side sub-antireflection layer 502 is not in contact with the film structure of the second surface 02 of the silicon substrate 00, avoiding the risk of causing a short circuit.
Referring to fig. 12, fig. 12 is a schematic structural diagram of a photovoltaic module according to an embodiment of the present invention, and based on the same inventive concept, this embodiment further provides a photovoltaic module 000, which includes a laminate 200 and a frame 300 wrapping around the laminate 200, wherein the laminate 200 includes a front plate 400, a first packaging adhesive film 500, a photovoltaic cell 100, a second packaging adhesive film 600, and a back plate 700, which are sequentially arranged, and the photovoltaic cell 100 includes the photovoltaic cell 100 in the foregoing embodiment.
Specifically, the present embodiment further provides a photovoltaic module 000, which includes a laminate 200 and a frame 300 wrapped around the laminate 200, where the frame 300 is used for carrying and accommodating the laminate 200, the frame 300 may be made of a composite material, the frame 300 may be a cavity-type frame or an S-type frame, the structure of the frame 300 may be set according to actual situations, and this embodiment is not limited specifically;
laminate 200 includes front sheet 400, first encapsulant film 500, photovoltaic cell 100, second encapsulant film 600, and backsheet 700 arranged in that order, photovoltaic cell 100 including photovoltaic cell 100 in the above embodiments;
The front plate 400 may be made of glass, has high light transmittance, the light transmittance can reach more than 92%, low-iron tempered embossed glass is generally adopted, the thickness range can be 2.7-3.2mm, the thickness of the front plate 400 can be 2.7mm, 3mm, 3.1mm or 3.2mm, the thickness of the front plate 400 can be set according to practical conditions, and the embodiment is not particularly limited to the above; the light transmittance can reach more than 91% within the wavelength range of 380-1100 nm of the spectral response of the solar cell, and the solar cell has higher reflectivity for infrared light with the wavelength of 1200 nm; the front plate 400 may be conventional planar glass, and the shape of the front plate 400 is not limited in this embodiment, and may be square, circular or other shapes, as long as the purpose of this embodiment can be achieved; of course, the front plate 400 may also be a glass with a special shape, such as a curved glass, and in this embodiment, the curved angle corresponding to the curved glass is not limited any more, and may be set according to the actual situation, and may be 5 degrees, 10 degrees, 15 degrees, 20 degrees, or other degrees;
The first packaging adhesive film 500 and/or the second packaging adhesive film 600 may be an ethylene-vinyl acetate copolymer packaging adhesive film, a polyethylene octene co-elastomer packaging adhesive film, a polyvinyl butyral packaging adhesive film, an EP packaging adhesive film, or an EPE packaging adhesive film; the first packaging adhesive film 500 and/or the second packaging adhesive film 600 are used for packaging and protecting the photovoltaic cell 100, preventing the external environment from influencing the performance of the photovoltaic cell 100, bonding the front plate 400, the photovoltaic cell 100 and the back plate 700 together, and have certain bonding strength, high light transmittance, reasonable crosslinking degree, excellent ultraviolet aging resistance, excellent humidity and heat aging resistance, extremely low shrinkage, long-term strong bonding performance on various back plates and glass, and high volume resistivity; the thickness of the first and/or second encapsulation films 500 and 600 may range from 0.3 to 0.5mm;
the back plate 700 can be made of glass materials, TPT (polyvinyl fluoride composite film) or TPE (thermoplastic elastomer), and the back plate 700 is used for protecting internal packaging materials and batteries from mechanical damage and corrosion of external environment, has good insulating property, determines the service life of the assembly to a great extent, and has excellent weather resistance, low water vapor permeability, good electrical insulation and certain bonding strength; the thickness of the back plate 700 may range from 0.2 to 3.2mm, and the thickness of the back plate 700 may be 0.2mm, 1mm, 2mm, 3mm, or 3.2mm.
The embodiment also provides a photovoltaic module 000, which comprises the photovoltaic cell 100 in the embodiment, after the phosphorus diffusion process of the photovoltaic cell 100 is performed, the photovoltaic cell 100 is cut into half pieces, and then etching and passivation are performed, wherein the etching and passivation process can reduce edge cutting damage of the photovoltaic cell 100, reduce surface recombination of a cutting surface, increase efficiency, and have smaller influence on productivity compared with the pre-texturing slicing.
According to the embodiment, the preparation method of the photovoltaic cell, the photovoltaic cell and the photovoltaic module provided by the invention have the following beneficial effects:
The invention provides a preparation method of a photovoltaic cell, the photovoltaic cell and a photovoltaic module, wherein the preparation method comprises the following steps: providing a phosphorus-diffused silicon substrate, and cutting a first surface of the silicon substrate along a direction perpendicular to the thickness of the silicon substrate to obtain a cut silicon substrate; etching the first surface of the cut silicon substrate to obtain an etched silicon substrate; the outer surface of the etched silicon substrate is a selective emitter; passivating one side of the selective emitter far away from the first surface and the cutting surface to obtain a silicon substrate with a passivation layer; after the phosphorus diffusion process for preparing the photovoltaic cell, the photovoltaic cell is cut into half pieces, and then etching and passivation are carried out, so that the edge cutting damage of the photovoltaic cell can be reduced, the surface recombination of a cutting surface is reduced, the efficiency is increased, and the influence on the productivity by slicing before texturing is small.
While certain specific embodiments of the invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.
Claims (10)
1. A method of manufacturing a photovoltaic cell, comprising:
Providing a phosphorus-diffused silicon substrate, wherein the phosphorus-diffused silicon substrate is provided with a first surface;
Cutting the first surface of the silicon substrate along the direction perpendicular to the thickness of the silicon substrate to obtain the cut silicon substrate;
Etching the first surface of the cut silicon substrate to obtain an etched silicon substrate; the outer surface of the etched silicon substrate is a selective emitter;
and passivating the side, far away from the first surface, of the selective emitter and the cutting surface to obtain the silicon substrate with the passivation layer.
2. The method of manufacturing a photovoltaic cell according to claim 1, wherein the method of cutting the silicon substrate comprises: laser cutting, abrasive cutting, and diamond cutting.
3. The method of manufacturing a photovoltaic cell according to claim 2, wherein when the method of cutting the silicon substrate is laser cutting, the laser running direction is along a direction perpendicular to the thickness of the silicon substrate.
4. The method of manufacturing a photovoltaic cell according to claim 2, wherein when the method of cutting the silicon substrate is laser cutting, the laser power of the laser cutting is in the range of 15-20W; the laser frequency range of the laser cutting is 100-150kHz; the laser cutting laser operation speed range is 400-500mm/s.
5. The method of manufacturing a photovoltaic cell according to claim 1, wherein etching the first side of the cut silicon substrate comprises:
Etching the first surface of the cut silicon substrate by using a chain type cleaning machine; the chain type cleaning machine comprises a conveyor belt, and the cut silicon substrate is placed on the conveyor belt for etching; the first surface of the silicon substrate faces to one side of the conveyor belt direction, and the cutting surface of the silicon substrate faces to the moving direction of the conveyor belt.
6. The method of claim 1, wherein providing the phosphorus diffused silicon substrate further comprises:
Acquiring the silicon substrate;
performing boron diffusion on the first surface of the silicon substrate to obtain the silicon substrate with the selective emitter;
The silicon substrate after boron diffusion is provided with a second surface which is opposite to the first surface, and a tunneling oxide layer is formed on the second surface of the silicon substrate;
depositing an amorphous silicon layer on one side of the tunneling oxide layer far away from the silicon substrate;
and performing phosphorus diffusion on one side of the amorphous silicon layer far away from the tunneling oxide layer to form a doped conductive layer.
7. The method of claim 1, wherein passivating the side of the selective emitter remote from the first side results in the silicon substrate having a passivation layer, and further comprising:
the passivated silicon substrate is provided with a second surface corresponding to the first surface; coating the first surface and the second surface of the silicon substrate with the passivation layer to obtain the silicon substrate with a first antireflection layer and a second antireflection layer;
a first electrode is formed on the anti-reflective layer of the first face and a second electrode is formed on the anti-reflective layer of the second face.
8. A photovoltaic cell comprising a photovoltaic cell prepared by the method of any one of claims 1 to 7; the photovoltaic cell comprises a silicon substrate, wherein the silicon substrate is provided with a cutting surface, and a passivation layer and a first anti-reflection layer are sequentially laminated on the cutting surface along the direction away from the silicon substrate.
9. The photovoltaic cell of claim 8, wherein a length of the passivation layer on the cut surface in the thickness direction of the silicon substrate is less than a thickness of the photovoltaic cell in the thickness direction of the silicon substrate; the length of the first anti-reflection layer on the cutting surface along the thickness direction of the silicon substrate is smaller than the thickness of the photovoltaic cell along the thickness direction of the silicon substrate.
10. A photovoltaic module, characterized by including laminate and cladding in the frame around the laminate, the laminate includes front bezel, first encapsulation glued membrane, photovoltaic cell, second encapsulation glued membrane and backplate that arrange in proper order, photovoltaic cell includes the photovoltaic cell of claim 8 or 9.
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