WO2018157823A1 - P-type perc double-sided solar cell, assembly thereof, system thereof and preparation method therefor - Google Patents

Abstract

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; gate line spines (10) are provided on the back aluminum gate lines and are connected to the back aluminum gate lines; a first laser grooving area (8) 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 (81) which are provided horizontally; each group of first laser grooving units comprises one or more first laser grooving bodies (82) which are provided horizontally; the back aluminum gate lines are vertical to the first laser grooving bodies. The solar cell is simple in structure, low in costs, easy to generalize, and high in photoelectric conversion efficiency.

Description

P-type PERC double-sided solar cell and component, system and preparation method thereof 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 method for preparing the P-type PERC double-sided solar cell. The solar cell module using the P-type PERC double-sided solar cell adopts the above-mentioned P-type Solar system for PERC double-sided solar cells.

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 preparation method of a P-type PERC double-sided solar cell, which has the advantages of simple process, 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 grid line, 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 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 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.

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 the back aluminum grid lines is 30-500, and the number of the gate line spines is 30-500;

The width of the back aluminum grid line is 30-500 microns, and the width of the back aluminum grid line is smaller than the length of the first laser slotted body;

The width of the gate line spine is 30-500 microns, and the width of the grid line spine is smaller than the length of the third laser slotted body.

As a preferred mode of the above aspect, the pattern of the gridline spine is a continuous straight line or a dotted line composed of a plurality of line segments; the gridline spine is made of silver paste and has a width of 30-60 micrometers; or The gridline spine is made of aluminum paste and has a width of 50-500 microns.

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

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

(2) diffusing the silicon wafer to form an N-type emitter;

(3) removing the frontal phosphosilicate glass and the peripheral PN junction formed by the diffusion process;

(4) depositing a cupric oxide film on the back side of the silicon wafer;

(5) depositing a silicon nitride film on the back side of the silicon wafer;

(6) depositing a silicon nitride film on the front side of the silicon wafer;

(7) laser grooving the back surface of the silicon wafer to form a first laser grooving zone, the first laser grooving zone comprising a plurality of sets of first laser grooving units arranged horizontally, each set of first laser grooving units a first laser slotted body including one or more horizontally disposed;

(8) printing a back silver main gate electrode on the back side of the silicon wafer;

(9) printing aluminum paste along the vertical direction of the laser grooving on the back side of the silicon wafer to obtain a back aluminum grid line, the back aluminum grid line being perpendicular to the first laser grooving body;

(10) printing a gridline spine on the back side of the silicon wafer;

(11) printing a positive electrode paste on a front surface of the silicon wafer;

(12) sintering the silicon wafer at a high temperature to form a back silver electrode and a positive silver electrode;

(13) Anti-LID annealing of the silicon wafer.

As a preferred mode of the above solution, between steps (3) and (4), the method further includes:

Polish the back side of the wafer.

As a preferred mode of the above solution, the step (7) further includes:

Laser grooving the backside of the silicon wafer to form a third laser grooving zone, the third laser grooving zone comprising a plurality of sets of third laser grooving units, each set of third laser grooving units comprising one or more vertical a third laser slotted body disposed in a direction, the third laser slotted body being perpendicular to the gridline spine.

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.

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 the gate line spine is connected with the back aluminum gate line, which provides a path for the electron flow to prevent the aluminum gate broken gate from causing the photoelectric conversion efficiency of the battery. The effect of avoiding the breakage of the EL test of the battery.

A third laser grooving zone may be disposed below the gridline spine, or a third laser grooving zone may not be provided. When the third laser grooving zone is provided, the slurry and the third laser may not be needed. The precise alignment of the slotted area simplifies the laser process and printing process, reducing the difficulty of debugging the printing equipment. In addition, 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;

3 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;

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

5 is a schematic view showing an embodiment of a first laser grooving zone of a P-type PERC double-sided solar cell according to the present invention;

Figure 6 is a schematic illustration of another embodiment of a first laser grooving zone of a P-type PERC double-sided solar cell of the present invention.

Figure 7 is a schematic illustration of a third laser grooving zone of a P-type PERC double-sided solar cell of the present invention.

detailed description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail 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 problem, in conjunction with FIG. 1, the present invention provides a P-type PERC double-sided solar cell, which in turn includes a back silver electrode 1, a back aluminum gate line 2, a back passivation layer 3, a P-type silicon 4, and an N-type 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 back aluminum grid line 2 is provided with a grid line spine 10, the grid line ridge The bone 10 is connected to the back aluminum grid line 2.

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. 2, 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 levels. The first laser grooving body 82 is disposed in a direction, and the back aluminum grid line 2 is perpendicular to the first laser grooving body 82. 5 and 6, the dotted frame shown in FIGS. 5 and 6 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. .

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 10 at the back aluminum gate line 2, and the grid line spine 10 is connected to the back aluminum gate line 2, providing a path for the flow of electrons to prevent the aluminum gate from being broken to the battery. The effect of photoelectric conversion efficiency, while avoiding the grid breakage of the EL test of the battery. 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.

A third laser grooving zone 11 may be provided below the gridline spine 10, see the first embodiment of the backside structure shown in FIG. The third laser grooving zone 11 may also be omitted below the gridline spine 10, see the second embodiment of the backside structure shown in FIG.

The pattern of the gridline spine is a continuous straight line or a plurality of line segments. The gridline spine 10 shown in FIGS. 2 and 3 is a continuous straight line, and the gridline spine 10 shown in FIG. A dotted line composed of multiple line segments.

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.

Preferably, the number of the gate line spines 10 is 30-500, 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 gridline spine 10 is made of silver paste, its width is 30-60 microns; when the gridline spine 10 is made of aluminum paste, its width is 50-500 microns.

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. The 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 5. 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 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 repeatability 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%.

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. The laser is grooved on the back side of the silicon wafer to form a first laser grooving area. The first laser grooving area includes a plurality of sets of first laser grooving units disposed in a horizontal direction, and each set of the first laser grooving unit includes a first laser slotted body disposed in one or more horizontal directions;

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, the back aluminum grid line being perpendicular to the first laser grooving body;

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.

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.

A third laser grooving zone may be disposed under the ridge of the grid line, or a third laser grooving zone may not be provided. When the third laser slotted area can be disposed under the ridge of the grid line, the step (7) further includes:

Laser grooving the backside of the silicon wafer to form a third laser grooving zone, the third laser grooving zone comprising a plurality of sets of third laser grooving units, each set of third laser grooving units comprising one or more vertical a third laser slotted body disposed in a direction, the third laser slotted body being perpendicular to the gridline spine.

It should be noted that the specific parameter setting of the first laser grooved area, the third laser grooved area, the back aluminum grid line, and the grid line spine in the preparation method is the same as that described above, and details are not described herein again.

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.

The invention is further illustrated by the following specific examples.

Example 1

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

(2) diffusing the silicon wafer to form an N-type emitter;

(3) removing the frontal phosphosilicate glass and the peripheral PN junction formed by the diffusion process;

(4) depositing a cupric oxide film on the back side of the silicon wafer;

(5) depositing a silicon nitride film on the back side of the silicon wafer;

(6) depositing a silicon nitride film on the front side of the silicon wafer;

(7) laser grooving the back surface of the silicon wafer to form a first laser grooving zone, the first laser grooving zone comprising a plurality of sets of first laser grooving units arranged horizontally, each set of first laser grooving units a first laser grooving body comprising one or more horizontally disposed, the first laser grooving body having a length of 1000 microns and a width of 40 microns;

(8) printing a back silver main gate electrode on the back side of the silicon wafer;

(9) 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, the back aluminum grid line being perpendicular to the first laser grooving body, and the number of back aluminum grid lines 150 strips, the back aluminum grid line has a width of 150 microns;

(10) printing a gridline spine on the back side of the silicon wafer, the gate line spine is selected from silver paste, the number of the gate line spine is 140, and the width is 60 micrometers;

(11) printing a positive electrode paste on a front surface of the silicon wafer;

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

(13) Anti-LID annealing of the silicon wafer.

Example 2

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

(2) diffusing the silicon wafer to form an N-type emitter;

(3) removing the frontal phosphorous silicon glass and the peripheral PN junction formed by the diffusion process, and polishing the back surface of the silicon wafer;

(4) depositing a cupric oxide film on the back side of the silicon wafer;

(5) depositing a silicon nitride film on the back side of the silicon wafer;

(6) depositing a silicon nitride film on the front side of the silicon wafer;

(7) laser grooving the back surface of the silicon wafer to form a first laser grooving zone and a third laser grooving zone, the first laser grooving zone comprising a plurality of sets of first laser grooving units arranged in a horizontal direction, each The first laser grooving unit comprises one or more first laser grooving bodies arranged in a horizontal direction, the first laser grooving body having a length of 500 microns and a width of 50 microns;

The third laser grooving area includes a plurality of sets of third laser grooving units, each set of third laser grooving units includes one or more third laser slotted bodies disposed in a vertical direction, and the third laser blasting unit The length of the trough is 500 microns and the width is 50 microns;

(8) printing a back silver main gate electrode on the back side of the silicon wafer;

(9) 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, the back aluminum grid line being perpendicular to the first laser grooving body, and the number of back aluminum grid lines 200 strips, the width of the back aluminum grid line is 200 microns;

(10) printing a gridline spine on the back side of the silicon wafer, the gate line spine is selected from silver paste, the number of the gate line spine is 190, and the width is 50 micrometers;

(11) printing a positive electrode paste on a front surface of the silicon wafer;

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

(13) Anti-LID annealing of the silicon wafer.

Example 3

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

(2) diffusing the silicon wafer to form an N-type emitter;

(3) removing the frontal phosphosilicate glass and the peripheral PN junction formed by the diffusion process;

(4) depositing a cupric oxide film on the back side of the silicon wafer;

(5) depositing a silicon nitride film on the back side of the silicon wafer;

(6) depositing a silicon nitride film on the front side of the silicon wafer;

(7) laser grooving the back surface of the silicon wafer to form a first laser grooving zone, the first laser grooving zone comprising a plurality of sets of first laser grooving units arranged horizontally, each set of first laser grooving units a first laser grooving body comprising one or more horizontally disposed, the first laser grooving body having a length of 300 microns and a width of 30 microns;

(8) printing a back silver main gate electrode on the back side of the silicon wafer;

(9) printing aluminum paste along the vertical direction of the laser grooving on the back side of the silicon wafer to obtain a back aluminum grid line, and printing the grid line spine along the vertical direction of the back aluminum grid line, the grid line spine Aluminum paste is used, the back aluminum grid line is perpendicular to the first laser slotted body, the number of back aluminum grid lines is 250, the width of the back aluminum grid line is 250 microns, the number of spine lines is 240, and the width is 100. Micron

(10) printing a positive electrode paste on a front surface of the silicon wafer;

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

(12) Anti-LID annealing of the silicon wafer.

Example 4

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

(2) diffusing the silicon wafer to form an N-type emitter;

(3) removing the frontal phosphorous silicon glass and the peripheral PN junction formed by the diffusion process, and polishing the back surface of the silicon wafer;

(4) depositing a cupric oxide film on the back side of the silicon wafer;

(5) depositing a silicon nitride film on the back side of the silicon wafer;

(6) depositing a silicon nitride film on the front side of the silicon wafer;

(7) laser grooving the back surface of the silicon wafer to form a first laser grooving zone and a third laser grooving zone, the first laser grooving zone comprising a plurality of sets of first laser grooving units arranged in a horizontal direction, each The first laser grooving unit comprises one or more first laser grooving bodies arranged in a horizontal direction, the first laser grooving body having a length of 1200 microns and a width of 200 microns;

The third laser grooving area includes a plurality of sets of third laser grooving units, each set of third laser grooving units includes one or more third laser slotted bodies disposed in a vertical direction, and the third laser blasting unit The length of the trough is 1200 microns and the width is 200 microns;

(8) printing a back silver main gate electrode on the back side of the silicon wafer;

(9) printing aluminum paste along the vertical direction of the laser grooving on the back side of the silicon wafer to obtain a back aluminum grid line, and printing the grid line spine along the vertical direction of the back aluminum grid line, the grid line spine Aluminum paste is used, the back aluminum grid line is perpendicular to the first laser slotted body, the number of back aluminum grid lines is 300, the width of the back aluminum grid line is 300 microns, the number of spine lines is 280, and the width is 200. Micron

(10) printing a positive electrode paste on a front surface of the silicon wafer;

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

(12) Anti-LID annealing of the silicon wafer.

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 (10)

1. 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 vertically connected to the back aluminum grid line, and 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;

   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.
2. The P-type PERC double-sided solar cell according to claim 1, 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.
3. 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.
4. The P-type PERC double-sided solar cell according to claim 1, wherein the number of the back aluminum grid lines is 30-500, and the number of the gate line spines is 30-500;

   The width of the back aluminum grid line is 30-500 microns, and the width of the back aluminum grid line is smaller than the length of the first laser slotted body;

   The width of the gate line spine is 30-500 microns, and the width of the grid line spine is smaller than the length of the third laser slotted body.
5. The P-type PERC double-sided solar cell according to claim 4, 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.
6. A method for preparing a P-type PERC double-sided solar cell according to any one of claims 1 to 5, comprising:

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

   (2) diffusing the silicon wafer to form an N-type emitter;

   (3) removing the frontal phosphosilicate glass and the peripheral PN junction formed by the diffusion process;

   (4) depositing a cupric oxide film on the back side of the silicon wafer;

   (5) depositing a silicon nitride film on the back side of the silicon wafer;

   (6) depositing a silicon nitride film on the front side of the silicon wafer;

   (7) laser grooving the back surface of the silicon wafer to form a first laser grooving zone, the first laser grooving zone comprising a plurality of sets of first laser grooving units arranged horizontally, each set of first laser grooving units a first laser slotted body including one or more horizontally disposed;

   (8) printing a back silver main gate electrode on the back side of the silicon wafer;

   (9) printing aluminum paste along the vertical direction of the laser grooving on the back side of the silicon wafer to obtain a back aluminum grid line, the back aluminum grid line being perpendicular to the first laser grooving body;

   (10) printing a gridline spine on the back side of the silicon wafer;

   (11) printing a positive electrode paste on a front surface of the silicon wafer;

   (12) sintering the silicon wafer at a high temperature to form a back silver electrode and a positive silver electrode;

   (13) Anti-LID annealing of the silicon wafer.
7. The method of claim 6, wherein the step (3) and (4) further comprises:

   Polish the back side of the wafer.
8. The method of claim 7, wherein the step (7) further comprises:

   Laser grooving the backside of the silicon wafer to form a third laser grooving zone, the third laser grooving zone comprising a plurality of sets of third laser grooving units, each set of third laser grooving units comprising one or more vertical a third laser slotted body disposed in a direction, the third laser slotted body being perpendicular to the gridline spine.
9. 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 1-5.
10. 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 1-5.

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