WO2018157825A1

WO2018157825A1 - P-type perc double-sided solar cell, assembly thereof and system thereof

Info

Publication number: WO2018157825A1
Application number: PCT/CN2018/077592
Authority: WO
Inventors: 方结彬; 何达能; 陈刚
Original assignee: 广东爱旭科技股份有限公司; 浙江爱旭太阳能科技有限公司
Priority date: 2017-03-03
Filing date: 2018-02-28
Publication date: 2018-09-07
Also published as: CN106876497A; CN106876497B

Abstract

Provided is a P-type PERC double-sided solar cell, comprising back sliver electrodes (1), back aluminum gate lines (2), a back passivation layer (3), P-type silicon (4), an N-type emitter (5), a front silicon nitride film (6), and a front silver electrode (7) in sequence. The back sliver electrodes are vertically connected to the back aluminum gate lines; intervals between the back aluminum gate lines are not equal; a first laser grooving area is formed by performing laser grooving on the back passivation layer; the back aluminum gate lines are connected to the P-type silicon by means of the first laser grooving area; the first laser grooving area comprises multiple groups of first laser grooving units which are provided horizontally; each group of first laser grooving units comprises one or more first laser grooving bodies which are provided horizontally; the back aluminum gate lines are vertical to the first laser grooving bodies.

Description

P-type PERC double-sided solar cell and its components and systems

Technical field

The present invention relates to the field of solar cells, and more particularly to a P-type PERC double-sided solar cell, and a solar cell module using the P-type PERC double-sided solar cell, and a solar system using the P-type PERC double-sided solar cell.

Background technique

A crystalline silicon solar cell is a device that effectively absorbs solar radiation energy and converts light energy into electrical energy by using a photovoltaic effect. When the sun shines on the semiconductor PN junction, a new hole-electron pair is formed, and the electric field at the PN junction Under the action, the holes flow from the N zone to the P zone, and the electrons flow from the P zone to the N zone, and a current is formed after the circuit is turned on.

Conventional crystalline silicon solar cells basically use only front passivation technology, depositing a layer of silicon nitride on the front side of the silicon wafer by PECVD to reduce the recombination rate of the minority on the front surface, which can greatly increase the open circuit voltage and short circuit of the crystalline silicon battery. Current, thereby increasing the photoelectric conversion efficiency of the crystalline silicon solar cell. However, since the back side of the silicon wafer is not passivated, the improvement in photoelectric conversion efficiency is still limited.

Prior art double-sided solar cell structure: the substrate adopts an N-type silicon wafer. When the solar photon illuminates the back surface of the battery, the carriers generated in the N-type silicon wafer pass through the silicon wafer having a thickness of about 200 μm, due to the N-type. The silicon wafer has a low lifetime and low carrier recombination rate, and some carriers can reach the front pn junction; the front side of the solar cell is the main light-receiving surface, and its conversion efficiency accounts for a high proportion of the entire battery conversion efficiency; The effect is to greatly improve the conversion efficiency of the battery. However, the price of N-type silicon wafer is high, and the process of N-type double-sided battery is complicated; therefore, how to develop high-efficiency and low-cost double-sided solar cells has become a hot spot for enterprises and researchers.

On the other hand, with the increasing requirements for the photoelectric conversion efficiency of crystalline silicon cells, the industry has been studying the PERC back passivation solar cell technology. The mainstream manufacturers in the industry mainly develop single-sided PERC solar cells. The present invention combines PERC high-efficiency batteries and double-sided batteries to develop a PERC double-sided solar cell with higher integrated photoelectric conversion efficiency.

For the PERC double-sided solar cell, the photoelectric conversion efficiency is high, and the solar energy is absorbed on both sides, and the power generation amount is higher, which has greater use value in practical applications. Therefore, the present invention aims to propose a P-type PERC double-sided solar cell with simple process, low cost, easy promotion, and high photoelectric conversion efficiency.

Summary of the invention

The technical problem to be solved by the present invention is to provide a P-type PERC double-sided solar cell with simple structure, low cost, easy promotion, and high photoelectric conversion efficiency.

The technical problem to be solved by the present invention is also to provide a P-type PERC double-sided solar cell module, which has a simple structure, low cost, easy promotion, and high photoelectric conversion efficiency.

The technical problem to be solved by the present invention is also to provide a P-type PERC double-sided solar energy system with simple structure, low cost, easy promotion, and high photoelectric conversion efficiency.

In order to solve the above technical problem, the present invention provides a P-type PERC double-sided solar cell, which in turn comprises a back silver electrode, a back aluminum gate line, a back passivation layer, a P-type silicon, an N-type emitter, a front silicon nitride film. And a positive silver electrode, the back silver electrode is perpendicularly connected to the back aluminum gate line, and the spacing between the back aluminum gate lines is not equal;

The back aluminum grid line may also be curved, curved, wavy, or the like.

Forming, by laser grooving, a first laser grooving region on the back passivation layer, wherein the back aluminum gate line is connected to the P-type silicon through the first laser grooving region;

The first laser grooving zone comprises a plurality of sets of first laser grooving units arranged in a horizontal direction, and each set of first laser grooving units comprises one or more first laser grooving bodies arranged in a horizontal direction, the back The aluminum grid line is perpendicular to the first laser slotted body.

As a preferred mode of the above solution, the back aluminum grid line is provided with a grid line spine, and the grid line spine is connected with the back aluminum grid line;

The number of the gate line spines is 1-20, and the width of the grid line spines is 30-500 microns.

As a preferred mode of the above solution, the gate line spine is perpendicularly connected to the back aluminum grid line;

a third laser grooving zone is disposed under the ridge of the grid line, the third laser grooving zone comprises a plurality of sets of third laser grooving units, and each set of the third laser grooving unit comprises one or more vertical a third laser slotted body disposed in a direction, the third laser slotted body being perpendicular to the gate line spine, wherein the gate line spine is connected to the P-type silicon through the third laser slotted body.

As a preferred mode of the above solution, the pattern of the gate line spine is a continuous straight line or a broken line composed of a plurality of line segments;

The gridline spine is made of silver paste having a width of 30-60 microns; or the gridline spine is made of aluminum paste having a width of 50-500 microns.

As a preferred embodiment of the above solution, an aluminum grid outer frame is disposed around the back aluminum grid line, and the aluminum grid outer frame is connected to the back aluminum gate line and the back silver electrode.

As a preferred mode of the above solution, a second laser grooving zone is disposed under the aluminum grid outer frame, and the second laser grooving zone includes a second laser grooving unit disposed vertically or horizontally, each group The second laser grooving unit includes one or more second laser grooving bodies disposed vertically or horizontally, the aluminum grid outer frame being perpendicular to the second laser grooving body.

In a preferred embodiment of the above aspect, the first laser grooving units are disposed in parallel; in each of the first laser grooving units, the first laser grooving body is juxtaposed, and the first laser grooving The bodies are on the same level or staggered up and down;

The spacing between the first laser grooving units is 0.5-50 mm;

In each of the first laser grooving units, the spacing between the first laser grooving bodies is 0.5-50 mm;

The first laser grooving body has a length of 50-5000 microns and a width of 10-500 microns.

As a preferred embodiment of the above solution, the number of back aluminum gate lines is 30-500, the width of the back aluminum gate lines is 30-500 microns, and the width of the back aluminum gate lines is smaller than the first laser. The length of the slotted body.

Correspondingly, the present invention also discloses a PERC solar cell module comprising a PERC solar cell and a packaging material, and the PERC solar cell is any of the P-type PERC double-sided solar cells described above.

Correspondingly, the present invention also discloses a PERC solar energy system comprising a PERC solar cell, which is any of the P-type PERC double-sided solar cells described above.

The implementation of the present invention has the following beneficial effects:

In the invention, after the back passivation layer is formed on the back surface of the silicon wafer, the first laser grooved region is formed by laser grooving on the back passivation layer, and then the aluminum paste is printed in the vertical direction along the laser scribing direction, so that the aluminum paste is opened. The trench region is connected to the P-type silicon to obtain a back aluminum gate line. The PERC double-sided solar cell can prepare a battery grid structure on the front and back sides of the silicon wafer, and adopts a method different from the conventional printing aluminum paste. Since the width of the aluminum grid is much smaller than the length of the first laser grooved area, the aluminum can be omitted. The precise alignment of the slurry and the first laser grooving zone simplifies the laser process and the printing process, reduces the difficulty of debugging the printing equipment, and is easy to industrialize large production. In addition, the first laser grooved area outside the aluminum paste coverage area can increase the absorption of sunlight by the back surface of the battery and improve the photoelectric conversion efficiency of the battery. The spacing between the back aluminum grid lines is not equal, and the pitch distribution between the aluminum grid lines can be adjusted according to actual process conditions, thereby improving photoelectric conversion efficiency.

In addition, in the printing process, due to the large viscosity of the aluminum paste, the line width of the screen is relatively narrow, and occasionally an aluminum gate is broken. The aluminum gate breakage causes a black break in the image of the EL test. At the same time, the aluminum gate grid will affect the photoelectric conversion efficiency of the battery. Therefore, the present invention adds a gate line spine at the back aluminum gate line and an aluminum grid outer frame around the back aluminum gate line, the gate line spine is connected to the back aluminum gate line, and the aluminum grid outer frame is The back aluminum grid line and the back silver electrode are connected to provide a plurality of paths for the flow of electrons, preventing the influence of the aluminum gate grid on the photoelectric conversion efficiency of the battery, and avoiding the grid breakage of the EL test of the battery.

A second laser grooving zone may be disposed under the aluminum grid frame, and a third laser grooving zone is disposed below the gridline spine, which may not require the slurry and the second laser grooving zone, and the third laser grooving The precise alignment of the zone simplifies the laser process and printing process, reducing the difficulty of debugging the printing equipment. In addition, the second laser grooving zone and the third laser grooving zone outside the slurry coverage area can increase the absorption of sunlight by the back surface of the battery, and improve the photoelectric conversion efficiency of the battery.

Therefore, the invention has the advantages of simple structure, simple process, low cost, easy promotion, and high photoelectric conversion efficiency.

DRAWINGS

Figure 1 is a cross-sectional view showing a P-type PERC double-sided solar cell of the present invention;

2 is a schematic view showing a first embodiment of a back structure of a P-type PERC double-sided solar cell according to the present invention;

Figure 3 is a schematic view of an embodiment of the first laser grooving zone shown in Figure 1;

4 is a schematic view of another embodiment of the first laser grooving zone shown in FIG. 1.

5 is a schematic view showing a second embodiment of a back structure of a P-type PERC double-sided solar cell according to the present invention;

Figure 6 is a schematic view of the second laser grooved area shown in Figure 5;

Figure 7 is a schematic illustration of the third laser grooving zone of Figure 5.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings.

The existing single-sided solar cell has an all-aluminum back electric field on the back surface of the battery covering the entire back surface of the silicon wafer. The function of the all-aluminum back electric field is to increase the open circuit voltage Voc and the short-circuit current Jsc, forcing the minority carriers away from the surface. The minority carrier recombination rate is reduced, thereby improving battery efficiency as a whole. However, since the all-aluminum back electric field is opaque, the back side of the solar cell having an all-aluminum back electric field cannot absorb light energy, and only the front side can absorb light energy, and the integrated photoelectric conversion efficiency of the battery is difficult to be greatly improved.

In view of the above technical problems, with reference to FIG. 1 and FIG. 2, the present invention provides a P-type PERC double-sided solar cell, which in turn comprises a back silver electrode 1, a back aluminum gate line 2, a back passivation layer 3, a P-type silicon 4, N. The emitter 5, the front silicon nitride film 6, and the positive silver electrode 7, the back silver electrode 1 is vertically connected to the back aluminum gate line 2, and the pitch between the back aluminum gate lines 2 is not equal. The spacing between the back aluminum gate lines 2 is not equal, which simplifies the laser process and the printing process, reduces the difficulty of debugging the printing equipment, and improves the yield.

A first laser grooving region 8 is formed by laser grooving of the back passivation layer 3, and the back aluminum gate line 2 is connected to the P-type silicon 4 through the first laser grooving region 8. The positive silver electrode 7 includes a positive silver electrode main gate 7A and a positive silver electrode sub-gate 7B. The back passivation layer 3 includes an aluminum oxide layer 31 and a silicon nitride layer 32.

The invention improves the existing single-sided PERC solar cell, no longer has an all-aluminum back electric field, but turns it into a plurality of back aluminum grid lines 2, which are opened on the back passivation layer 3 by laser grooving technology. The first laser grooved area 8 is printed on the parallel first first laser grooved regions 8 so as to be in local contact with the P-type silicon 4, and the densely arranged rear aluminum gate lines 2 are arranged in parallel. It can not only improve the open circuit voltage Voc and the short circuit current Jsc, reduce the minority carrier recombination rate, and improve the photoelectric conversion efficiency of the battery. It can replace the all-aluminum back electric field of the existing single-sided battery structure, and the back aluminum grid line 2 The back surface of the silicon wafer is not completely covered, and sunlight can be projected from the back aluminum gate line 2 into the silicon wafer, thereby realizing absorption of light energy on the back surface of the silicon wafer and greatly improving the photoelectric conversion efficiency of the battery.

As shown in FIGS. 3 and 4, the first laser grooving area 8 includes a plurality of sets of first laser grooving units 81 disposed in a horizontal direction, and each set of first laser grooving units 81 includes one or more horizontal direction settings. The first laser slotted body 82 is perpendicular to the first laser slotted body 82. The dashed frame shown in FIGS. 3 and 4 is the first laser grooving unit 81, and each set of the first laser grooving unit 81 includes one or more first laser grooving bodies 82 disposed in the horizontal direction.

It should be noted that the first laser grooving unit 81 has various embodiments, including:

(1) Each of the first laser grooving units 81 includes a first laser grooving body 82 disposed in a horizontal direction. At this time, the first laser grooving unit 81 is a continuous linear grooving area, as shown in FIG. Show. A plurality of first laser grooving units 81 are arranged in the vertical direction.

(2) Each group of the first laser grooving unit 81 includes a plurality of first laser grooving bodies 82 disposed in a horizontal direction. At this time, the first laser grooving unit 81 is a line segment type non-continuous linear grooving area, specifically As shown in Figure 3. The plurality of first laser grooving bodies 82 may be two, three, four or more, but are not limited thereto. The plurality of first laser grooving units 81 are arranged in the vertical direction.

When each set of the first laser grooving unit 81 includes a plurality of first laser grooving bodies 82 disposed in the horizontal direction, it is divided into the following cases:

A. The width, length and shape of the first laser slotted body 82 disposed in a plurality of horizontal directions are the same, and the size thereof is in the order of micrometers, and the length may be 50-5000 micrometers, but is not limited thereto; The first laser grooving body may be on the same horizontal plane, or may be staggered up and down (ie, not in the same horizontal plane), and the staggered distribution of the topography depends on production needs.

B. The width, length and shape of the first laser grooving body 82 disposed in a plurality of horizontal directions are the same, and the dimensions are in the order of millimeters, and the length may be 5-600 mm, but is not limited thereto; The first laser grooving body may be on the same horizontal plane, or may be staggered up and down (ie, not in the same horizontal plane), and the staggered distribution of the topography depends on production needs.

C. The width, length and/or shape of the first laser grooving body 82 disposed in a plurality of horizontal directions are different, and the combined design may be performed according to production needs. It should be noted that the first laser grooving bodies may be on the same horizontal plane, or may be staggered up and down (ie, not in the same horizontal plane), and the staggered distribution of the topography depends on production needs.

As a preferred embodiment of the present invention, the first laser grooving body is linear, which facilitates processing, simplifies the process, and reduces production costs. The first laser grooving body may also be provided in other shapes, such as a curved shape, an arc shape, a wave shape, etc., and embodiments thereof are not limited to the embodiment of the present invention. The back aluminum grid line may also be curved, curved, wavy, or the like.

The first laser grooving units are arranged in parallel. In each of the first laser grooving units, the first laser grooving bodies are arranged side by side, which simplifies the production process and is suitable for large-scale popularization and application.

The spacing between the first laser grooving units is 0.5-50 mm. In each of the first laser grooving units, the spacing between the first laser grooving bodies is 0.5-50 mm.

The first laser grooving body 82 has a length of 50-5000 microns and a width of 10-500 microns. Preferably, the first laser grooving body 82 has a length of 250-1200 microns and a width of 30-80 microns.

The length, width and spacing of the first laser grooving unit and the number and width of the aluminum grid are optimized on the basis of comprehensively considering the contact area of the aluminum grid and the P-type silicon, the opaque area of the aluminum grid, and the sufficient collection of electrons. The purpose is to reduce the shading area of the back aluminum grid as much as possible, while ensuring a good current output, thereby improving the overall photoelectric conversion efficiency of the battery.

The back aluminum gate lines have a number of 30-500, the back aluminum gate lines have a width of 30-500 microns, and the back aluminum grid lines have a width much smaller than the length of the first laser slotted body. Preferably, the number of the back aluminum grid lines is 80-220, and the width of the back aluminum grid lines is 50-300 microns.

The width of the back aluminum grid line is much smaller than the length of the first laser slotted body. In the case where the aluminum grid is perpendicular to the first laser slotted body, the printing problem of the back aluminum grid line can be greatly facilitated. Without precise alignment, the aluminum grid can fall in the first laser grooving zone, which simplifies the laser process and printing process, reduces the difficulty of debugging the printing equipment, and is easy to industrialize and produce.

The invention forms the first laser grooving zone by laser grooving the back passivation layer, and then printing the aluminum paste in the vertical direction of the laser scribing direction, so that the aluminum paste is connected to the P-type silicon through the grooving zone to obtain the back aluminum. Grid line. The PERC double-sided solar cell can prepare a battery grid structure on the front and back sides of the silicon wafer, and adopts a method different from the conventional printing aluminum paste, so that precise alignment of the aluminum paste and the first laser grooved area is not required, and the process is simple. Easy to industrialize large production. The aluminum grid is parallel to the first laser slotted body, and the aluminum paste and the first laser slotted area need to be accurately aligned, which requires high precision and repeated production of the printing equipment, and the yield is difficult to control, and the defective products are more, resulting in The average photoelectric conversion efficiency decreases. With the present invention, the yield can be increased to 99.5%.

Referring to Figure 5, the present invention provides a second embodiment of a backside structure that adds an aluminum grid outer frame 9 and a gridline spine 10 to the first embodiment. This is because in the printing process, due to the large viscosity of the aluminum paste, the line width of the screen is narrow, and the aluminum grid is occasionally broken. The aluminum gate breakage causes a black break in the image of the EL test. At the same time, the aluminum gate grid will affect the photoelectric conversion efficiency of the battery.

Therefore, the present invention adds a gate line spine 10 at the back aluminum grid line 2, and an aluminum grid outer frame 9 is provided around the back aluminum grid line 2, the aluminum grid outer frame 9 and the back aluminum grid line 2, the back The silver electrodes 1 are connected, and the gate line spine 10 is connected with the back aluminum grid line 2, which provides multiple paths for the flow of electrons, prevents the influence of the aluminum gate grid on the photoelectric conversion efficiency of the battery, and avoids the battery. The EL test showed a broken gate. Preferably, the gate line spine 10 is perpendicularly connected to the back aluminum grid line 2. It should be noted that the gate line spine 10 and the back aluminum grid line 2 may also be connected at a certain oblique angle, for example, 15°, 30°, 45° 60°, but are not limited thereto. The pattern of the gridline spine 10 is a continuous straight line or a dashed line composed of a plurality of line segments, and the pattern of the gridline spine 10 shown in FIG. 5 is a continuous straight line.

Preferably, a second laser grooving zone 90 is disposed below the aluminum grid outer frame 9, and a third laser grooving zone 11 is disposed below the gridline vertebral 10.

When it is provided with the second laser grooving area 90, the second laser grooving area 90 includes a second laser grooving unit 91 disposed vertically or horizontally, and each set of the second laser grooving unit 91 includes one Or a plurality of second laser grooving bodies 92 disposed vertically or horizontally, the aluminum grid outer frame 9 being perpendicular to the second laser grooving body 92. Specifically, in conjunction with FIG. 6, the second laser grooving area 90 includes two second laser grooving units 91A disposed in a vertical direction and two second laser grooving units 91B disposed in a horizontal direction. The two laser grooving unit 91A includes a plurality of second laser grooving bodies 92 disposed in the horizontal direction, and the second laser grooving unit 91B disposed in the horizontal direction includes a plurality of second laser grooving bodies 92 disposed in the vertical direction.

When the second laser grooving zone 90 is provided, precise alignment of the aluminum paste and the second laser grooving zone is not required, which simplifies the laser process and the printing process, and reduces the difficulty in debugging the printing equipment. In addition, the second laser grooved area outside the aluminum paste coverage area can increase the absorption of sunlight by the back surface of the battery and improve the photoelectric conversion efficiency of the battery.

When the third laser grooving zone 11 is disposed below the gridline spine 10, as shown in FIG. 7, the third laser grooving zone 11 includes a plurality of sets of third laser grooving units 12, each of which is The three-laser grooving unit 12 includes one or more third laser grooving bodies 13 disposed in a vertical direction, the third laser grooving body 13 being perpendicular to the grid-line spine 10, and the grid-line vertebral 10 passing through The three laser slotted bodies 13 are connected to P-type silicon.

A third laser grooving zone 11 is disposed below the gridline spine 10, which eliminates the need for precise alignment of the slurry and the third laser grooving zone 11, simplifies the laser process and the printing process, and reduces the debugging of the printing apparatus. Difficulty. In addition, the third laser grooving zone 11 outside the slurry coverage area can increase the absorption of sunlight by the back surface of the battery and improve the photoelectric conversion efficiency of the battery.

It should be noted that the second laser grooved area 90 may not be disposed under the aluminum grid outer frame 9, and the third laser grooved area 11 may not be disposed below the grid line spine 10.

Preferably, the number of the gate line spines 10 is 1-20, the width of the grid line spine 10 is 30-500 microns, and the width of the grid line spine 10 is smaller than the third laser opening. The length of the trough body 13 can greatly facilitate the printing problem of the grid line spine 10 in the case where the grid line spine 10 is perpendicular to the third laser slotted body 13. Without precise alignment, the gridline spine 10 can fall within the third laser grooving zone 11, simplifying the laser process and printing process, reducing the difficulty of debugging the printing equipment, and facilitating industrial production.

The grid line spine 10 can be made of either silver paste or aluminum paste. When the gate line spine 10 is made of silver paste, its width is 30-60 microns; when the grid line spine 10 is made of aluminum paste, its width is 50-500 microns.

Further, the back passivation layer 3 includes an aluminum oxide layer 31 and a silicon nitride layer 32, the aluminum oxide layer 31 is connected to the P-type silicon 4, and the silicon nitride layer 32 is connected to the aluminum oxide layer 31;

The silicon nitride layer 32 has a thickness of 20-500 nm;

The aluminum oxide layer 31 has a thickness of 2 to 50 nm.

Preferably, the silicon nitride layer 32 has a thickness of 100-200 nm;

The aluminum oxide layer 31 has a thickness of 5 to 30 nm.

Correspondingly, the present invention also discloses a method for preparing a P-type PERC double-sided solar cell, comprising:

S101, forming a pile on the front and back sides of the silicon wafer, the silicon wafer being P-type silicon;

S102, diffusing the silicon wafer to form an N-type emitter;

S103, removing the frontal phosphorous silicon glass and the peripheral PN junction formed by the diffusion process;

S104, depositing an aluminum oxide film on the back side of the silicon wafer;

S105, depositing a silicon nitride film on the back side of the silicon wafer;

S106, depositing a silicon nitride film on the front side of the silicon wafer;

S107, laser grooving the back side of the silicon wafer;

S108, printing a back silver main gate electrode on the back side of the silicon wafer;

S109, printing aluminum paste along the vertical direction of the laser grooving on the back surface of the silicon wafer to obtain a back aluminum grid line, and printing aluminum paste along the circumference of the back aluminum grid line to obtain an aluminum grid outer frame;

S110, printing a gridline spine on the back of the silicon wafer;

S111, printing a positive electrode slurry on a front surface of the silicon wafer;

S112. The silicon wafer is sintered at a high temperature to form a back silver electrode and a positive silver electrode.

S113, performing anti-LID annealing on the silicon wafer.

It should be noted that the order of S106 and S104, S105 can be interchanged, and S106 can be before S104 and S105. In S109, the back aluminum grid line and the aluminum grid frame can be separated in two steps.

Between S103 and S104, the method further comprises: polishing the back surface of the silicon wafer. The present invention may be provided with a backside polishing step or no backside polishing step.

The grid line spine is made of silver paste or aluminum paste. When the grid line spine is made of silver paste, S109 and S110 are separated into two steps; when the grid line spine is made of aluminum paste, S109 and S110 Merge into one step.

It should be noted that the specific parameter setting of the laser grooving and the back aluminum grid line, the grid line ridge, and the aluminum grid frame in the preparation method are the same as those described above, and will not be described herein.

Correspondingly, the present invention also discloses a PERC solar cell module comprising a PERC solar cell and a packaging material, and the PERC solar cell is any of the P-type PERC double-sided solar cells described above. Specifically, as an embodiment of the PERC solar cell module, the high-permeability tempered glass, the ethylene-vinyl acetate copolymer EVA, the PERC solar cell, the ethylene-vinyl acetate copolymer EVA, and the highly permeable tempered glass are sequentially connected from top to bottom. composition.

Correspondingly, the present invention also discloses a PERC solar energy system comprising a PERC solar cell, which is any of the P-type PERC double-sided solar cells described above. As a preferred embodiment of the PERC solar system, a PERC solar cell, a battery pack, a charge and discharge controller inverter, an AC power distribution cabinet, and a solar tracking control system are included. The PERC solar system may be provided with a battery pack, a charge and discharge controller inverter, or a battery pack or a charge and discharge controller inverter, and those skilled in the art may set according to actual needs.

It should be noted that in the PERC solar cell module and the PERC solar system, components other than the P-type PERC double-sided solar cell may be designed with reference to the prior art.

It should be noted that the above embodiments are only intended to illustrate the technical solutions of the present invention and are not intended to limit the scope of the present invention, although the present invention will be described in detail with reference to the preferred embodiments, The technical solutions of the present invention may be modified or equivalently substituted without departing from the spirit and scope of the technical solutions of the present invention.

Claims

A P-type PERC double-sided solar cell, comprising, in order, a back silver electrode, a back aluminum gate line, a back passivation layer, a P-type silicon, an N-type emitter, a front silicon nitride film, and a positive silver electrode, The back silver electrode is perpendicularly connected to the back aluminum gate line, and the spacing between the back aluminum gate lines is not equal;

Forming, by laser grooving, a first laser grooving region on the back passivation layer, wherein the back aluminum gate line is connected to the P-type silicon through the first laser grooving region;

The first laser grooving zone comprises a plurality of sets of first laser grooving units arranged in a horizontal direction, and each set of first laser grooving units comprises one or more first laser grooving bodies arranged in a horizontal direction, the back The aluminum grid line is perpendicular to the first laser slotted body.
The P-type PERC double-sided solar cell according to claim 1 , wherein the back aluminum grid line is provided with a grid line spine, and the grid line spine is connected to the back aluminum grid line;

The number of the gate line spines is 1-20, and the width of the grid line spines is 30-500 microns.
The P-type PERC double-sided solar cell according to claim 2, wherein the gate line spine is vertically connected to the back aluminum gate line;

a third laser grooving zone is disposed under the ridge of the grid line, the third laser grooving zone comprises a plurality of sets of third laser grooving units, and each set of the third laser grooving unit comprises one or more vertical a third laser slotted body disposed in a direction, the third laser slotted body being perpendicular to the gate line spine, wherein the gate line spine is connected to the P-type silicon through the third laser slotted body.
The P-type PERC double-sided solar cell according to claim 2, wherein the pattern of the gate line spine is a continuous straight line or a broken line composed of a plurality of line segments;

The gridline spine is made of silver paste having a width of 30-60 microns; or the gridline spine is made of aluminum paste having a width of 50-500 microns.
The P-type PERC double-sided solar cell according to claim 1, wherein an aluminum grid outer frame is arranged around the back aluminum grid line, and the aluminum grid outer frame is connected to the back aluminum gate line and the back silver electrode. .
The P-type PERC double-sided solar cell according to claim 5, wherein a second laser grooving zone is disposed under the aluminum grid outer frame, and the second laser grooving zone comprises a vertical or horizontal direction setting. a second laser grooving unit, each set of second laser grooving units comprising one or more second laser grooving bodies arranged vertically or horizontally, the aluminum grid outer frame being perpendicular to the second laser grooving body .
The P-type PERC double-sided solar cell according to claim 1, wherein the first laser grooving units are arranged in parallel; and in each of the first laser grooving units, the first laser grooving body For juxtaposition, the first laser grooving bodies are on the same horizontal plane or are staggered up and down;

The spacing between the first laser grooving units is 0.5-50 mm;

In each of the first laser grooving units, the spacing between the first laser grooving bodies is 0.5-50 mm;

The first laser grooving body has a length of 50-5000 microns and a width of 10-500 microns.
The P-type PERC double-sided solar cell according to claim 1, wherein the number of the back aluminum gate lines is 30-500, and the width of the back aluminum gate lines is 30-500 microns, the back The width of the aluminum grid line is less than the length of the first laser slotted body.
A PERC solar cell module comprising a PERC solar cell and a packaging material, wherein the PERC solar cell is the P-type PERC double-sided solar cell according to any one of claims 1-8.
A PERC solar energy system comprising a PERC solar cell, characterized in that the PERC solar cell is the P-type PERC double-sided solar cell according to any one of claims 1-8.