CN118507598A - Solar cell, manufacturing method thereof and photovoltaic module - Google Patents

Abstract

The invention relates to a solar cell, a manufacturing method thereof and a photovoltaic module. The manufacturing method of the solar cell comprises the following steps: providing a battery body, wherein patterned metal paste is formed on the surface of the first side and the surface of the second side of the battery body, an isolation groove extending to the substrate of the battery body is further formed on the surface of the first side of the battery body, and transition electrode paste insulated and isolated from the side wall of the isolation groove is formed at the bottom of the isolation groove; pre-sintering the battery body to form a first pre-cured electrode and a second electrode from metal paste on the surface of the first side and the surface of the second side of the battery body respectively, and forming a transition electrode from transition electrode paste; a reverse bias voltage is applied to the battery body through the first pre-cure electrode and the transition electrode, and a laser scan is performed on a surface of the first side of the battery body. The solar cell and the manufacturing method thereof and the photovoltaic module can reduce the surface recombination loss of the solar cell and have higher efficiency.

Description

Solar cell and manufacturing method thereof, photovoltaic module

Technical Field

The present invention relates to the technical field of solar cells, and in particular to a solar cell and a manufacturing method thereof, and a photovoltaic module.

Background Art

Laser-assisted sintering technology, also known as laser-enhanced contact optimization (LECO) technology, is an advanced laser sintering technology used to improve the contact between metal electrodes and silicon wafers in solar cells. In the laser-assisted sintering process of the related technology, a laser is used to scan the front side of the cell to generate very high charge carrier injection locally. Under a certain bias voltage, local high current density and instantaneous high temperature are simultaneously generated at the interface of the front and back electrodes, thereby inducing mutual diffusion of metal and silicon and forming ohmic contact. However, in the current laser-assisted sintering technology, when the interface contact point of the front electrode reaches the optimal size, the interface contact point of the back electrode is often over-sintered, resulting in large recombination losses on the back of the solar cell, affecting the efficiency of the solar cell.

Summary of the invention

Based on this, it is necessary to provide a solar cell and a method for manufacturing the same, as well as a photovoltaic module that can reduce the surface recombination loss of the solar cell and has higher efficiency.

A first aspect of an embodiment of the present application provides a method for manufacturing a solar cell, comprising:

A battery body is provided, wherein a surface of a first side and a surface of a second side of the battery body are both formed with patterned metal paste, an isolation groove extending to a base of the battery body is further provided on the surface of the first side of the battery body, a transition electrode paste insulated and isolated from a side wall of the isolation groove is formed at the bottom of the isolation groove, and the first side and the second side are arranged opposite to each other;

Pre-sintering the battery body so that the metal pastes on the surface of the first side and the surface of the second side of the battery body form a first pre-cured electrode and a second electrode respectively, and the transition electrode paste forms a transition electrode;

A reverse bias voltage is applied to the battery body through the first pre-cured electrode and the transition electrode, and a laser is scanned on the surface of the first side of the battery body to laser-induce sintering of the first pre-cured electrode into a first electrode.

In one embodiment, the step of providing a battery body specifically includes:

Provide a substrate having a first side surface on which a first doped conductive layer and a first passivation layer are sequentially stacked, and a second side surface on which a passivation contact layer and a second passivation layer are sequentially stacked, wherein the doping type of the first doped conductive layer is opposite to that of the substrate;

An isolation groove is formed on the first passivation layer, and the substrate is exposed from the isolation groove;

A transition electrode paste is formed on a portion of the substrate exposed from the isolation groove, and metal pastes are formed on surfaces of the first passivation layer and the second passivation layer facing away from the substrate.

In one embodiment, the step of forming a metal paste on the first passivation layer and the step of forming a transition electrode paste on the portion of the substrate exposed from the isolation trench are performed in the same process.

In one embodiment, the width of the isolation groove is 0.5 mm-1 mm, and the distance between the transition electrode slurry and the groove wall of the isolation groove is greater than 50 μm.

In one embodiment, the metal paste disposed on the surface of the first side of the battery body includes a plurality of metal patterns spaced apart along a first direction, and the isolation groove extends along the first direction and is located between two ends of the battery body in a second direction;

The first direction and the second direction are perpendicular to the thickness direction of the substrate.

In one embodiment, in the step of pre-sintering the battery body, the first peak temperature T1 of sintering the surface of the first side of the battery body satisfies: 700℃≤T1≤750℃, and the second peak temperature T2 of sintering the surface of the second side of the battery body satisfies: 650℃≤T2≤700℃.

In one embodiment, in the step of pre-sintering the battery body, the first peak temperature T1 for sintering the surface of the first side of the battery body satisfies: 600°C ≤ T1 < 700°C, and the duration of the first peak temperature is 2s-30s, and the second peak temperature T2 for sintering the surface of the second side of the battery body satisfies: 550°C ≤ T2 < 650°C, and the duration of the second peak temperature is 5s-10s; the cooling time range is 2s-5s.

In one embodiment, at least one of the metal paste on the surface of the first side and the metal paste on the surface of the second side comprises: silver powder, aluminum powder, glass powder, additives and an organic carrier, and based on the total weight of the metal paste as 100%, the weight percentage of the aluminum powder is 0%-0.5%; the weight percentage of the glass powder is 3%-5%;

The weight percentage of lead in glass powder is 30%-40%.

In one embodiment, the step of applying a reverse bias voltage to the battery body through the first pre-curing electrode and the transition electrode comprises:

The probe of the first external electrode of the external power source is pressed against the first pre-curing electrode, and the probe of the second external electrode of the external power source is pressed against the transition electrode. The polarities of the first external electrode and the second external electrode are opposite.

In one embodiment, the number of the isolation grooves is at least one, and all of them extend along the first direction. When the number of the isolation grooves is at least two, the isolation grooves are arranged at intervals along the second direction, and the isolation grooves divide the surface of the first side of the battery body into at least two sub-areas along the second direction;

The step of laser-induced sintering the first pre-cured electrode into the first electrode specifically includes:

Laser induced sintering is performed on the first pre-cured electrodes in each sub-region in sequence along the second direction.

In one embodiment, the step of laser induced sintering the first pre-cured electrode in any sub-region comprises:

The first pre-cured electrode in the sub-region and the transition electrode adjacent to the sub-region are electrically connected to the first external electrode and the second external electrode of the external power supply respectively, and the sub-region is laser scanned, the polarities of the first external electrode and the second external electrode are opposite, and the first direction, the second direction and the thickness direction of the battery body are perpendicular to each other.

In one embodiment, in the step of applying a reverse bias voltage to the battery body through the first pre-curing electrode and the transition electrode, and performing laser scanning on the surface of the first side of the battery body:

The wavelength range of the laser is 532nm-1064nm, the power range of the laser scanning is 60W-100W, and the reverse bias voltage is 10V-20V.

In one embodiment, the step of laser-induced sintering the first pre-cured electrode into the first electrode further includes:

The cell body is cut along the extending direction of the isolation groove to form at least two solar cells.

A second aspect of an embodiment of the present application provides a solar cell, which is manufactured using any of the above-mentioned methods for manufacturing a solar cell.

A third aspect of the embodiments of the present application provides a solar cell, comprising: a solar cell body, wherein a first electrode and a second electrode are respectively provided on a surface of a first side and a surface of a second side of the solar cell body;

The surface of the first side of the solar cell body is also provided with an isolation groove extending to the base of the solar cell body, and a transition electrode insulated and isolated from the side wall of the isolation groove is formed at the bottom of the isolation groove.

In one embodiment, the solar cell body further comprises a first doped conductive layer and a first passivation layer sequentially disposed on a first side of the substrate, and a passivation contact layer and a second passivation layer sequentially disposed on a second side of the substrate, wherein the first doped conductive layer and the passivation contact layer have opposite doping types;

The first electrode is disposed on the first passivation layer and is in ohmic contact with the first doped conductive layer, and the second electrode is disposed on the second passivation layer and is in ohmic contact with the passivation contact layer;

The isolation groove is opened on the surface of the first passivation layer away from the substrate.

In one embodiment, the first electrode includes a plurality of first electrode patterns arranged at intervals along a first direction;

The isolation trench extends along the first direction and is located between two ends of the substrate in the second direction; or

The isolation groove extends along the second direction and is located between two ends of the substrate in the first direction;

The first direction and the second direction are perpendicular to the thickness direction of the substrate.

In one embodiment, the number of the isolation groove is at least one;

The number of the isolation grooves is at least two, and when all of the isolation grooves extend along the first direction, the isolation grooves are arranged at intervals along the second direction;

The number of the isolation grooves is at least two, and when all of the isolation grooves extend along the second direction, the isolation grooves are arranged at intervals along the first direction.

In one embodiment, the first electrode includes a plurality of first electrode patterns arranged at intervals along a first direction;

The isolation groove extends along the first direction and is located at the end of the substrate in the second direction; or the isolation groove extends along the second direction and is located at the end of the substrate in the first direction;

The first direction and the second direction are perpendicular to the thickness direction of the substrate.

A third aspect of an embodiment of the present application provides a photovoltaic assembly, comprising at least one battery string, wherein the battery string comprises at least two of the above-mentioned solar cells.

The above-mentioned solar cell and its manufacturing method, photovoltaic module have the following beneficial effects:

Since patterned metal paste is formed on the surface of the first side and the surface of the second side of the battery body, during the pre-sintering process of the battery body, the metal paste on the surface of the first side and the surface of the second side of the battery body sequentially forms a first pre-cured electrode and a second electrode.

Since the surface of the first side of the battery body is provided with an isolation groove extending to the substrate of the battery body, the substrate can be exposed to the outside from the isolation groove, and a transition electrode slurry is formed at the bottom of the isolation groove to be insulated and isolated from the side wall of the isolation groove. Since the patterned metal slurry is formed on the surface of the first side of the battery body, after pre-sintering, the formed first pre-cured electrode will also be insulated and isolated from the transition electrode.

A reverse bias voltage is applied to the battery body through the first pre-cured electrode and the transition electrode, and the surface of the first side of the battery body is laser scanned to laser-induce sintering the first pre-cured electrode into the first electrode. In this process, only the first pre-cured electrode on the surface of the first side of the battery body is laser-induced sintered to form the first electrode, and the surface of the second side of the battery body is not laser-processed, that is, the second electrode can be formed only by pre-sintering the metal paste on the surface of the second side, avoiding over-sintering of the electrode on the surface of the second side of the solar cell, thereby reducing the composite loss of the surface of the second side and improving the efficiency of the solar cell.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the structure of a solar cell provided in an embodiment of the present application;

FIG2 is a schematic diagram of a top view of a solar cell provided in an embodiment of the present application;

FIG3 is a partial enlarged view of point A in FIG2 ;

FIG4 is a schematic diagram of a process of manufacturing a solar cell provided in an embodiment of the present application;

FIG5 is a schematic diagram of a partial structure of a solar cell body in a method for manufacturing a solar cell provided in an embodiment of the present application.

Description of Figure Numbers:

100. Solar cells;

101. Battery body; 102. Metal slurry; 103. Transition electrode slurry; 104. Sub-region;

10. substrate; 20. first doped conductive layer; 30. first passivation layer; 31. passivation film layer; 32. anti-reflection film layer; 40. isolation groove; 50. first electrode; 51. first electrode pattern; 60. passivation contact layer; 61. tunneling oxide layer; 62. polysilicon doped conductive layer; 70. second passivation layer; 80. second electrode; 90. transition electrode;

F, first side; S, second side; Y, first direction; R, second direction.

DETAILED DESCRIPTION

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

In the laser-assisted sintering technology of the related technology, that is, during the laser-induced sintering process, under the same laser energy and bias voltage, when the interface contact point of the front electrode reaches the optimal size, the interface contact point of the back electrode will be over-sintered, causing composite loss on the back of the battery.

In the embodiment of the present application, in order to avoid excessive sintering of the second electrode on the second side during the laser induced sintering of the first electrode on the first side of the battery, a single-sided laser induced sintering treatment method is adopted. The first precured electrode and the second electrode are formed by pre-sintering, and then the first precured electrode is sintered to form the first electrode using the laser induced sintering process. The second electrode is not subjected to laser induced sintering, thereby avoiding over-sintering of the second electrode.

The solar cell and its manufacturing method, and the photovoltaic module of the embodiment of the present application are described below with reference to the accompanying drawings.

FIG1 is a schematic diagram of the structure of a solar cell provided in an embodiment of the present application, FIG2 is a schematic diagram of the top view of the structure of a solar cell provided in an embodiment of the present application, and FIG3 is a partial enlarged view of point A in FIG2 .

1, 2 and 3, a solar cell 100 provided in an embodiment of the present application includes a solar cell body, and a first electrode 50 and a second electrode 80 are respectively provided on the surface of a first side F and a surface of a second side S of the solar cell body. An isolation groove 40 extending to the substrate 10 of the solar cell body is further provided on the surface of the first side F of the solar cell body, and a transition electrode 90 insulated and isolated from the sidewall of the isolation groove 40 is formed at the bottom of the isolation groove 40.

The solar cell body also includes a first doped conductive layer 20 and a first passivation layer 30 stacked in sequence on a first side F of the substrate 10, and a passivation contact layer 60 and a second passivation layer 70 stacked in sequence on a second side S of the substrate 10. The doping types of the first doped conductive layer 20 and the passivation contact layer 60 are opposite, and the first side F and the second side S are arranged opposite to each other.

In addition, the first electrode 50 is disposed on the first passivation layer 30 and is in ohmic contact with the first doped conductive layer 20 , and the second electrode 80 is disposed on the second passivation layer 70 and is in ohmic contact with the passivation contact layer 60 .

The solar cell 100 in the embodiment of the present application may be a TOPCon cell, or may be configured as other types of cells as required.

When the solar cell 100 is a TOPCon cell, the solar cell 100 may include an N-type cell and a P-type cell, the substrate 10 of the N-type cell is doped with an N-type element, and the first doped conductive layer 20 is doped with a P-type element. The substrate 10 of the P-type cell is doped with a P-type element, and the first doped conductive layer 20 is doped with an N-type element. The first doped conductive layer 20 is used to form a PN junction with the substrate 10. In the embodiment of the present application, the substrate 10 is an N-type substrate as an example for explanation. At this time, the first doped conductive layer 20 may be P-type doped, for example, the first doped conductive layer 20 doped with boron element (also called P+ emitter).

The first passivation layer 30 may include a passivation film layer 31 and an anti-reflection film layer 32 sequentially stacked on the first doped conductive layer 20 .

The passivation film layer 31 may adopt a single-layer structure or a multi-layer structure, and the material may be at least one of aluminum oxide, silicon oxide, silicon nitride or silicon oxynitride.

The anti-reflection film layer 32 is located on the first side F of the substrate 10, that is, on the side of the solar cell 100 that receives incident light (called the front side or the light-receiving side), and has an anti-reflection effect on the front side of the solar cell 100. The anti-reflection film layer 32 can adopt a multi-layer structure. In the anti-reflection film layer 32 of the multi-layer structure, the material of each layer can be silicon oxide, silicon nitride or silicon oxynitride.

The passivation contact layer 60 includes a tunneling oxide layer 61 and a polysilicon doped conductive layer 62 sequentially stacked on the surface of the second side S of the substrate 10 . The tunneling oxide layer 61 is used to achieve interface passivation on the surface of the second side S of the substrate 10 , achieving a chemical passivation effect.

The second passivation layer 70 is stacked on the surface of the passivation contact layer 60 away from the substrate 10. The second passivation layer 70 can also adopt a single-layer or multi-layer structure. The material of the second passivation layer 70 can be silicon oxide, silicon nitride or silicon oxynitride. The reflectivity of the second side S surface of the solar cell 100 to sunlight can be reduced, and the absorption rate of sunlight can be increased. The second passivation layer 70 plays the role of passivation and anti-reflection at the same time.

In the embodiment of the present application, further referring to FIG. 2 and FIG. 3 , the isolation trench 40 is disposed on a surface of the first passivation layer 30 away from the substrate 10 , and the isolation trench 40 extends to the substrate 10 .

By providing the isolation groove 40 , the substrate 10 can be exposed to the outside through the isolation groove 40 . Since the transition electrode 90 does not contact the side groove wall of the isolation groove 40 , the transition electrode 90 is insulated and isolated from the first pre-cured electrode that will form the first electrode 50 .

In the process of forming the first electrode 50 and the second electrode 80, if the first electrode 50 is formed by laser induced sintering, a reverse bias voltage may be applied through the first pre-cured electrode and the transition electrode 90, and laser scanning may be performed to laser-induced sinter the first pre-cured electrode into the first electrode 50. In this process, only the first pre-cured electrode on the surface of the first side F is laser induced sintered to form the first electrode 50, and the second electrode 80 on the surface of the second side S is not laser processed, so as to avoid over-sintering of the second electrode 80 on the surface of the second side S of the solar cell 100, thereby reducing the recombination loss on the surface of the second side S and improving the efficiency of the solar cell 100.

It should be noted that in some other embodiments, after the laser induced sintering is completed, the solar cell is cut into two, three or even more quantities.

If cutting is required, the cutting can be performed along the direction of the isolation groove 40. Of course, the isolation groove 40 will be removed from the solar cell 100 after cutting.

Furthermore, the width of the isolation groove 40 is 0.5 mm-1 mm, and the distance between the transition electrode slurry (transition electrode 90 ) and the groove wall of the isolation groove 40 is greater than 50 μm.

Such arrangement ensures that there is a sufficient insulation distance between the transition electrode slurry and the isolation groove 40 , thereby ensuring that the metal slurry and the transition electrode can be insulated and isolated.

In addition, when the width of the isolation groove 40 is greater than 1 mm, the light absorption area on the surface of the solar cell 100 will be wasted, and when the width of the isolation groove 40 is less than 0.5 mm, it will not be able to make good contact with the probe of the external power supply. When the width of the isolation groove 40 is 0.5 mm-1 mm, it will not affect the efficiency of the solar cell 100, and can ensure good contact between the transition electrode 90 and the probe.

In the embodiment of the present application, referring to FIG. 2 and FIG. 3 , the first electrode 50 includes a plurality of first electrode patterns 51 arranged at intervals along the first direction Y, and the isolation groove 40 extends along the first direction Y and is located between two ends of the substrate 10 in the second direction R. The first direction Y and the second direction R are perpendicular to the thickness direction of the substrate 10 in pairs.

Further, the number of the isolation groove 40 is at least one, for example, only one can be provided as shown in FIG2 . Alternatively, the number of the isolation groove 40 can also be at least two, and when at least two isolation grooves 40 extend along the first direction Y, the isolation grooves 40 can be arranged along the second direction R at intervals.

In some other embodiments, the isolation trench 40 may extend along the second direction R and be located between two ends of the substrate 10 in the first direction Y.

At this time, the number of the isolation trench 40 may be one. Alternatively, when the number of the isolation trench 40 is at least two, if both isolation trenches 40 extend along the second direction R, the isolation trenches 40 are arranged along the first direction Y at intervals.

In some other embodiments, the isolation trench 40 may be located at a side end of the solar cell 100. For example, when the isolation trench 40 extends along the first direction Y, it may be located at an end of the substrate 10 in the second direction R. Alternatively, when the isolation trench 40 extends along the second direction S, it may be located at an end of the substrate 10 in the first direction Y.

In the embodiment of the present application, when the isolation trench 40 extends along the first direction Y, its extension length may be the same as the size of the substrate 10 along the first direction Y. When the isolation trench 40 extends along the second direction R, its extension length may be the same as the size of the substrate 10 along the second direction R.

FIG4 is a schematic diagram of a flow chart of a method for manufacturing a solar cell provided in an embodiment of the present application, and FIG5 is a schematic diagram of a partial structure of a solar cell body in the method for manufacturing a solar cell provided in an embodiment of the present application.

4 and 5 , a second aspect of an embodiment of the present application provides a method for manufacturing a solar cell. The method is used to manufacture the aforementioned solar cell 100. The method includes:

S10. Provide a battery body, wherein the surfaces of the first side and the second side of the battery body are both formed with patterned metal paste, the surface of the first side of the battery body is also provided with an isolation groove extending to the base of the battery body, and a transition electrode paste insulated and isolated from the side wall of the isolation groove is formed at the bottom of the isolation groove, and the first side and the second side are arranged opposite to each other.

S20, pre-sintering the battery body so that the metal pastes on the surface of the first side and the surface of the second side of the battery body form a first pre-cured electrode and a second electrode respectively, and the transition electrode paste forms a transition electrode.

S30, applying a reverse bias voltage to the battery body through the first pre-cured electrode and the transition electrode, and performing laser scanning on the surface of the first side of the battery body to laser-induced sintering of the first pre-cured electrode into a first electrode.

Since patterned metal paste 102 is formed on the surface of the first side F and the surface of the second side S of the battery body 101, during the pre-sintering process of the battery body 101, the metal paste 102 on the surface of the first side F and the surface of the second side S of the battery body 101 forms a first pre-cured electrode and a second electrode 80 respectively.

Since the surface of the first side F of the battery body 101 is provided with an isolation groove 40 extending to the substrate 10 of the battery body 101, the substrate 10 can be exposed to the outside from the isolation groove 40, and a transition electrode slurry 103 insulated and isolated from the side wall of the isolation groove 40 is formed at the bottom of the isolation groove 40. Here, the transition electrode slurry 103 does not contact the side groove wall of the isolation groove 40, and the patterned metal paste 102 is formed on the surface of the first side F of the battery body 101. Therefore, after pre-sintering, the formed first pre-cured electrode will also be insulated and isolated from the transition electrode 90.

A reverse bias voltage is applied to the battery body 101 through the first pre-cured electrode and the transition electrode 90, and the surface of the first side F of the battery body 101 is laser scanned to laser-induce sintering of the first pre-cured electrode into the first electrode 50. In this process, only the first pre-cured electrode on the surface of the first side F of the battery body 101 is laser-induced sintered to form the first electrode 50, and the surface of the second side S of the battery body 101 is not laser-processed, that is, the second electrode 80 can be formed only by pre-sintering the metal paste 102 on the surface of the second side S, thereby avoiding over-sintering of the electrode on the surface of the second side S of the solar cell 100, thereby reducing the recombination loss on the surface of the second side S and improving the efficiency of the solar cell 100.

In the embodiment of the present application, in step S10, the step of providing a battery body 101 specifically includes:

A substrate 10 is provided, wherein a first doped conductive layer 20 and a first passivation layer 30 are sequentially stacked on a surface of a first side F, and a passivation contact layer 60 and a second passivation layer 70 are sequentially stacked on a surface of a second side S. The doping type of the first doped conductive layer 20 is opposite to that of the substrate 10.

An isolation trench 40 is formed on the first passivation layer 30, and the substrate 10 is exposed from the isolation trench 40. For example, the first passivation layer 30 and a portion of the first doped conductive layer 20 are etched away to expose the substrate 10 to form the isolation trench 40.

A transition electrode paste 103 is formed on the portion of the substrate 10 exposed from the isolation trench 40 , and a metal paste 102 is formed on the surfaces of the first passivation layer 30 and the second passivation layer 70 facing away from the substrate 10 .

It should be noted that the transition electrode slurry 103 here needs to be a non-burn-through type to avoid affecting the surface of the substrate 10 during the pre-sintering process. The metal slurry 102 is a burn-through type slurry. In addition, the order of forming the transition electrode slurry 103 and forming the metal slurry 102 on the first passivation layer 30 and the second passivation layer 70 is not limited here, and can be selected according to actual needs.

In addition, in some embodiments, a first doped conductive layer 20 may be formed on the surface of the first side F of the substrate 10, a passivation contact layer 60 may be formed on the surface of the second side S of the substrate 10, a first passivation layer 30 may be formed on the surface of the first doped conductive layer 20 facing away from the substrate 10, and a second passivation layer 70 may be formed on the surface of the passivation contact layer 60 facing away from the substrate 10. The doping type of the first doped conductive layer 20 is opposite to that of the substrate 10, so that the two form a PN junction.

In addition, the isolation groove 40 may be formed by laser etching.

In the embodiment of the present application, the step of forming the metal paste 102 on the first passivation layer 30 and the step of forming the transition electrode paste 103 on the portion of the substrate 10 exposed from the isolation trench 40 are performed in the same process.

The first electrode 50 may include a main grid and a fine grid. In specific implementation, the metal paste 102 may be formed on the second passivation layer 70 first, and then the portion of the metal paste 102 formed on the first passivation layer 30 corresponding to the main grid of the first electrode 50 may be printed with the transition electrode paste 103 in the same process, and finally the portion of the metal paste 102 of the first passivation layer 30 corresponding to the fine grid of the first electrode 50 is formed. In this way, the transition electrode paste 103 can be formed at the same time as the metal paste 102 of the first passivation layer 30 is formed, which can save processes and reduce costs.

In addition, a metal paste 102 is formed on the second passivation layer 70, including first forming a portion of the metal paste 102 of the second passivation layer 70 corresponding to the main gate of the second electrode 80, and then forming a portion of the metal paste 102 of the second passivation layer 70 corresponding to the fine gate of the second electrode 80.

In the embodiment of the present application, the width of the isolation groove 40 is 0.5 μm-1 mm, and the distance between the transition electrode slurry 103 and the groove wall of the isolation groove 40 is greater than 50 μm.

Such configuration ensures that there is a sufficient insulation distance between the transition electrode slurry 103 and the isolation groove 40 , thereby ensuring that the metal slurry 102 and the transition electrode slurry 103 can be insulated and isolated.

In addition, when the width of the isolation groove 40 is greater than 1 mm, the light absorption area on the surface of the solar cell 100 will be wasted, and when the width of the isolation groove 40 is less than 0.5 mm, it will not be able to make good contact with the probe of the external power supply. When the width of the isolation groove 40 is 0.5 mm-1 mm, it will not affect the efficiency of the solar cell 100, and can ensure good contact between the transition electrode 90 and the probe.

In the embodiment of the present application, the metal paste 102 disposed on the surface of the first side F of the battery body 101 includes a plurality of metal patterns arranged at intervals along the first direction Y. The isolation groove 40 extends along the first direction Y and is located between the two ends of the battery body 101 in the second direction R.

With such arrangement, the final half-cutting stage can be performed along the direction of the isolation groove 40 , which can prevent the solar cell 100 from stress fracture during the half-cutting process.

Of course, the number of the isolation grooves 40 can be set as needed, for example, two isolation grooves 40 can be provided, and the two isolation grooves 40 can be arranged at intervals in the second direction R. For example, the two isolation grooves 40 can divide the battery body 101 into three equal parts.

In addition, the length of the isolation groove 40 may be the same as the dimension of the battery body 101 in the first direction Y, that is, the isolation groove 40 passes through two side surfaces of the battery body 101 in the first direction Y.

In addition, the isolation groove 40 may also be extended along the second direction R and located between two ends of the battery body 101 in the first direction Y.

At this time, the number of the isolation trench 40 may be one. Alternatively, when the number of the isolation trench 40 is at least two, if both isolation trenches 40 extend along the second direction R, the isolation trenches 40 are arranged along the first direction Y at intervals.

In some other embodiments, the isolation groove 40 may be located at the side end of the battery body 101. For example, when the isolation groove 40 extends along the first direction Y, it may be located at the end of the substrate 10 in the second direction R. Alternatively, when the isolation groove 40 extends along the second direction S, it may be located at the end of the substrate 10 in the first direction Y. In addition, other features of the isolation groove 40 have been described in detail in the aforementioned structure of the solar cell 100, and will not be repeated here.

In the embodiment of the present application, in step S20, in the step of pre-sintering the battery body 101, the first peak temperature T1 of sintering the surface of the first side F of the battery body 101 satisfies: 700℃≤T1≤750℃, and the second peak temperature T2 of sintering the surface of the second side S of the battery body 101 satisfies: 650℃≤T2≤700℃.

Here, the first peak temperature and the second peak temperature during pre-sintering are both about 50° C.-150° C. lower than those in the prior art, which can effectively prevent the second electrode 80 from being over-burned.

Furthermore, the first peak temperature T1 satisfies: 600°C ≤ T1 < 700°C, the duration of the first peak temperature is 2s-30s, the second peak temperature T2 for sintering the surface of the second side S of the battery body 101 satisfies: 550°C ≤ T2 < 650°C, the duration of the second peak temperature is 5-10s; the cooling time range is 2s-5s.

With such a configuration, during the pre-firing process of the metal paste 102, the cooling speed is fast after the peak temperature, which can control the overgrowth of some initial contact points and avoid over-firing. On the other hand, since the pre-firing is performed at a lower pre-firing temperature and a longer peak temperature holding time is used, the distribution of the initial contact points of the first pre-cured electrode and the first doped conductive layer 20 is more uniform, which can improve the process window and stability of the laser induced sintering of the first side F.

In addition, such a configuration also enables the solar cell 100 to simultaneously obtain a higher Voc value and a higher Isc value as well as a lower contact resistivity, thereby significantly improving the conversion efficiency of the solar cell.

In the embodiment of the present application, at least one of the metal paste 102 on the surface of the first side F and the metal paste on the surface of the second side S comprises: silver powder, aluminum powder, glass powder, additives and an organic carrier. With the total weight of the metal paste (referring to the metal paste on the surface of the first side F or the second side S) as 100%, the weight percentage of the aluminum powder is 0%-0.5%; the weight percentage of the glass powder is 3%-5%;

The weight percentage of lead in glass powder is 30%-40%.

It can be understood that, here, at least one of the metal slurry 102 on the surface of the first side F and the metal slurry on the surface of the second side S is set to the above ratio, which means that the metal slurry on the surface of the first side F can adopt the above ratio, or the metal slurry on the surface of the second side S can adopt the above ratio, or the metal slurry on the surface of the first side F and the metal slurry on the surface of the second side S can both adopt the above ratio.

Such arrangement makes the metal paste on the surface of the first side F and/or the metal paste on the surface of the first side F have low corrosivity, and can also avoid over-sintering of the first electrode 50 and/or the second electrode 80. In specific implementation, as mentioned above, the metal paste on the surface of the first side F may include a portion corresponding to the main grid of the first electrode 50 and a portion corresponding to the sub-grid of the first electrode 50, and preferably the portion corresponding to the sub-grid of the first electrode 50 adopts the metal paste of the above-mentioned proportion. Similarly, the metal paste on the surface of the second side S may include a portion corresponding to the main grid of the second electrode 80 and a portion corresponding to the sub-grid of the second electrode 80, and preferably the portion corresponding to the sub-grid of the second electrode 80 adopts the metal paste of the above-mentioned proportion.

In addition, the above adjustment can adjust the glass phase transition temperature and silver melting ability of the glass powder, improve the corrosion stability and uniformity of the metal slurry 102 on the passivation layer, and make the size and distribution of the initial contact points of the silver-silicon interface more uniform, which is beneficial to the uniform growth of the contact points during the subsequent laser induced sintering process, so that the contact resistance between the first electrode 50 and the first doped conductive layer 20 is smaller, the ohmic contact is better, and a lower metal contact composite can be obtained. At the same time, the acid resistance of the first electrode 50 is also improved, and the reliability risk of the solar cell in the subsequent use is reduced.

In the embodiment of the present application, in step S30, the step of applying a reverse bias voltage to the battery body 101 through the first pre-cured electrode and the transition electrode 90 includes:

The probe of the first external electrode of the external power source is pressed against the first pre-curing electrode, and the probe of the second external electrode of the external power source is pressed against the transition electrode 90 , and the polarities of the first external electrode and the second external electrode are opposite.

In specific implementation, if the substrate 10 is an N-type substrate and the first doped conductive layer 20 is a P-type, it is necessary to set the first external electrode as a positive electrode and the second external electrode as a negative electrode to achieve the purpose of applying a reverse bias voltage to the battery body 101.

In the embodiment of the present application, as described above, referring to Figure 5, the number of isolation grooves 40 is at least one, and all extend along the first direction Y. When the number of isolation grooves 40 is at least two, at least two isolation grooves 40 are arranged at intervals along the second direction R, and the isolation grooves 40 separate the surface of the first side F of the battery body 101 into at least two sub-areas 104 along the second direction R.

In step S30, the step of laser-induced sintering the first pre-cured electrode into the first electrode 50 specifically includes:

Along the second direction R, laser induced sintering is performed on the first pre-cured electrodes in each sub-region 104 in sequence.

In a specific implementation, the step of laser-induced sintering of the first pre-cured electrode in any sub-region 104 includes:

The first pre-curing electrode in the sub-region 104 and the transition electrode 90 adjacent to the sub-region 104 are electrically connected to the first external electrode and the second external electrode of the external power supply respectively, and the sub-region 104 is laser scanned, and the polarities of the first external electrode and the second external electrode are opposite.

In this way, the first pre-cured electrode in each sub-region may be laser induced sintered.

Further, in the step of applying a reverse bias voltage to the battery body 101 through the first pre-curing electrode and the transition electrode 90, and performing laser scanning on the surface of the first side F of the battery body 101:

The wavelength range of the laser is 532nm-1064nm, the power range of the laser scanning is 60W-100W, and the reverse bias voltage is 10V-20V.

In some other embodiments, the bias voltage may also be 12V-18V (including the endpoint values), and the power range of the laser scanning may also be 70W-90W (including the endpoint values).

Furthermore, after the step of laser-induced sintering the first pre-cured electrode into the first electrode 50, the following steps are further included:

The battery body 101 is subjected to annealing treatment. During the annealing process, the temperature range is 100° C.-300° C., and the annealing time is 5 min-15 min.

In the embodiment of the present application, after the step of laser-induced sintering the first pre-cured electrode into the first electrode 50, the following steps are further included:

The cell body 101 is cut along the extending direction of the isolation groove 40 to form at least two solar cells 100 .

In this way, stress fracture can be prevented from occurring during the cutting process of the battery body 101. When there are multiple separation grooves 40, the separation grooves 40 can be set at the positions where cutting is to be performed, so as to cut the battery body 101 into the required number.

Of course, in the case where the separation groove 40 is formed at the end of the battery body 101, no cutting is required.

In the embodiment of the present application, since the first electrode 50 is formed using a laser induced electrode sintering process, and a low-corrosive silver paste is used on the surface of the first side F of the solar cell 100, and pre-sintering is performed at a temperature lower than the traditional sintering temperature, the first pre-cured electrode on the front side is then subjected to a laser induced sintering process, and a laser is used to scan the surface of the first side F to excite charge carriers, while bias voltages of different intensities are applied. A high-density local current is generated between the metal on the lower surface of the first pre-cured electrode and the first doped conductive layer 20, causing heat to be generated at the corresponding position, thereby inducing mutual diffusion and sintering of the metal and the substrate 10, thereby significantly reducing the contact resistance of the formed first electrode 50.

In addition, due to the single-sided laser induced sintering process, the contact performance of the first electrode 50 is guaranteed while the lowest electrode metal composite loss is obtained. The peak temperature is lowered during the pre-sintering process and the time for the silver-silicon interdiffusion to form contact is shortened during the laser induced sintering, thereby reducing the damage of the silver-aluminum nails to the first doped conductive layer 20 to reduce metal contact composite.

In the embodiment of the present application, because it is not restricted by the high energy of the laser, it is possible to obtain higher Voc and Isc values, while maintaining a low electrode contact resistance, thereby improving the sintering process window and stability of the thinner polysilicon doped conductive layer, making it more suitable for polysilicon doped conductive layers with a thickness of less than 100 nm.

The following is a method for manufacturing a solar cell according to an embodiment of the present application, which comprises the following steps:

Step B: forming a first doped conductive material layer on the surface of the first side F of the substrate 10 by a high-temperature boron diffusion process, removing the first doped conductive material layer and BSG on the side surface and the second side S of the substrate 10 by single-sided etching, and forming a first doped conductive layer 20 on the surface of the first side F of the substrate.

Step C: forming a tunneling oxide layer 61 and a polysilicon doped conductive layer 62 on the surface of the second side S of the substrate 10 by an LPCVD process, depositing an aluminum oxide film and a silicon nitride film on the first doped conductive layer 20 in sequence to form a first passivation layer 30, and depositing a silicon nitride film on the polysilicon doped conductive layer 62 as a second passivation layer 70, the thickness of the polysilicon doped conductive layer 62 is 50nm-100nm.

Step D: The first passivation layer 30 and the local area of the first doped conductive layer 20 are sequentially etched away in the middle position of the first passivation layer 30 along the second direction R by a laser etching process to form an isolation groove 40 with a width of less than 1 mm. Since the bottom of the isolation groove 40 extends to the substrate 10, the N-type substrate is exposed to the outside, and the isolation groove 40 can also be called an N-type isolation area. The N-type isolation area separates a plurality of sub-areas 104 in the first passivation layer 30, and a non-burn-through paste is printed at the bottom of the isolation groove 40 as a transition electrode paste 103. The transition electrode paste is spaced from the sidewall of the isolation groove 40 to achieve insulation isolation. Metal paste 102 is formed on the first passivation layer 30 at positions corresponding to each sub-area 104, and on the second passivation layer 70. The metal paste 102 on the first passivation layer 30 can be a low-corrosive paste, thereby forming a battery body 101. The metal paste on the first passivation layer 30 includes: silver powder, aluminum powder, glass powder, additives and organic carriers. Taking the total weight of the metal paste as 100%, the weight percentage of aluminum powder is 0%-0.5%; the weight percentage of glass powder is 3%-5%, and the weight percentage of lead in the glass powder is 30%-40%.

Step E: drying, and pre-sintering the battery body 101 at a relatively low temperature in a sintering furnace, wherein the first peak temperature T1 of the surface of the first side F of the battery body 101 satisfies: 700° C. ≤ T1 ≤ 750° C., and the second peak temperature T2 of the surface of the second side S of the battery body 101 satisfies: 650° C. ≤ T2 ≤ 700° C. After pre-sintering, the metal paste on the first side F of the battery body 101 is sintered into a first pre-cured electrode, and the metal paste on the second side S of the battery body 101 is sintered into a second electrode 80.

Step F, laser induced sintering is sequentially performed on the surface of the first side F of the battery body 101, that is, the sub-regions 104 on both sides of the isolation groove 40 along the direction perpendicular to the isolation groove 40 (the second direction R). Specifically, the probe (positive electrode) of the first external electrode of the external power supply is pressed against the first pre-cured electrode in one of the sub-regions 104, and the probe (negative electrode) of the second external electrode of the external power supply is pressed against the transition electrode 90 in the isolation groove 40 adjacent to the sub-region, and a bias voltage of 10V-20V (including the endpoint value) is applied to the battery body. The surface of the first side F of the battery body 101 is laser scanned, and the first pre-cured electrode is laser sintered into the first electrode 50. The wavelength range of the laser is 532nm-1064nm, and the power range of the laser scanning is 60W-100W (including the endpoint value).

After the laser induced sintering process is performed on the sub-region 104 , the same laser induced sintering process is continued to be performed on the sub-regions adjacent to the sub-region 104 until the first pre-cured electrodes in all the sub-regions 104 form the first electrodes 50 .

Step G: subjecting the battery body 101 to a low-temperature thermal annealing treatment for a certain period of time, wherein the annealing process temperature range is 100° C.-300° C.; the annealing process time range is 5 min-15 min. The low-temperature annealing process can further improve the passivation performance.

In some other embodiments, in step F, the bias voltage applied to the battery body may also be 12V-18V (including the endpoint values), and the power range of the laser scanning may also be 70W-90W (including the endpoint values).

The manufacturing method of the solar cell of the comparative example comprises:

Step H: forming a first doped conductive material layer on the surface of the first side of the substrate by a high-temperature boron diffusion process, removing the first doped conductive material layer and BSG on the side and back of the substrate by single-sided etching, and forming a first doped conductive layer on the surface of the first side of the substrate.

Step I: forming a tunnel oxide layer and a polysilicon doped conductive layer on the surface of the second side of the substrate by an LPCVD process, depositing an aluminum oxide film and a silicon nitride film on the first doped conductive layer in sequence to form a first passivation layer, and depositing a silicon nitride film on the polysilicon doped conductive layer as a second passivation layer.

Step J: Print metal paste on the surfaces of the first passivation layer and the second passivation layer facing away from the substrate respectively, dry them, and then perform pre-sintering treatment. The peak temperature T1 for sintering the first side of the substrate satisfies: 700℃≤T1≤750℃, and the peak temperature T2 for sintering the second side of the substrate satisfies: 650℃≤T2≤700℃. The metal pastes of the first passivation layer and the second passivation layer are respectively sintered into pre-cured electrodes.

Step K: Press the probe (positive electrode) of the first external electrode of the external power supply against the precured electrode on the first passivation layer, press the probe (negative electrode) of the second external electrode of the external power supply against the precured electrode on the second passivation layer, and apply a bias voltage of 10V-20V (including the endpoint value) to the battery body. Perform laser scanning on the surface of the first passivation layer, and sinter the precured electrodes on the first passivation layer and the second passivation layer into the final state of the electrode, wherein the laser wavelength is 532nm-1064nm, and the laser power range for processing the front electrode is 60W-100W (including the endpoint value).

Step L: performing low temperature thermal annealing.

The solar cells manufactured through step B to step G are recorded as the first group of solar cells, and the solar cells manufactured through comparative example step H to step L are recorded as the second group of solar cells. The first group of solar cells and the second group of solar cells are subjected to battery performance tests, and the test results are recorded in Table 1.

Among them, Eta is the conversion efficiency; Jsc is the short-circuit current density; Voc is the open-circuit voltage; FF is the fill factor.

Table 1

It can be seen from the experimental results in Table 1 that, compared with the second group of solar cells in the comparative example, the first group of solar cells prepared by the method of the embodiment of the present application has a cell conversion efficiency increased by 0.23%, a short-circuit current density increased by 0.09, a cell open-circuit voltage increased by 0.0034 V, and a fill factor increased by about 0.16%. It can be seen that the efficiency of the first group of solar cells prepared by the method of this embodiment is higher.

The third aspect of the embodiment of the present application further provides a photovoltaic module, comprising at least one battery string, wherein the battery string comprises at least two aforementioned solar cells 100. The solar cells 100 can be connected together by serial welding.

A fourth aspect of the embodiments of the present application further provides a photovoltaic system, comprising the above-mentioned photovoltaic component.

Photovoltaic systems can be used in photovoltaic power stations, such as ground power stations, rooftop power stations, water power stations, etc., and can also be used in equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it is understandable that the application scenarios of photovoltaic systems are not limited to this, that is to say, photovoltaic systems can be used in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array may be an array combination of multiple photovoltaic components. For example, multiple photovoltaic components can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter and is converted into the alternating current required by the mains power grid, and then connected to the mains network to realize solar power supply.

The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims (20)

1. A method of manufacturing a solar cell, comprising:

Providing a battery body, wherein patterned metal paste is formed on the surface of a first side and the surface of a second side of the battery body, an isolation groove extending to the substrate of the battery body is further formed on the surface of the first side of the battery body, transition electrode paste insulated and isolated from the side wall of the isolation groove is formed at the bottom of the isolation groove, and the first side and the second side are oppositely arranged;

Pre-sintering the battery body to form a first pre-cured electrode and a second electrode from the metal paste on the surface of the first side and the surface of the second side of the battery body, and forming a transition electrode from the transition electrode paste;

And applying a reverse bias voltage to the battery body through the first pre-cured electrode and the transition electrode, and carrying out laser scanning on the surface of the first side of the battery body so as to enable the first pre-cured electrode to be sintered into a first electrode by laser induction.

2. The method of claim 1, wherein the step of providing a cell body comprises:

providing a substrate, wherein a first doped conductive layer, a first passivation layer and a passivation contact layer are sequentially laminated on the surface of a first side, and a second passivation layer are sequentially laminated on the surface of a second side, and the doping type of the first doped conductive layer is opposite to that of the substrate;

forming the isolation groove on the first passivation layer, and exposing the substrate from the isolation groove;

and forming the transition electrode slurry on the part of the substrate exposed from the isolation groove, and forming the metal slurry on the surfaces of the first passivation layer and the second passivation layer, which are away from the substrate, respectively.

3. The method of claim 2, wherein the step of forming the metal paste on the first passivation layer and the step of forming the transition electrode paste on the portion of the substrate exposed from the isolation trench are performed in the same process.

4. The method for manufacturing a solar cell according to claim 1, wherein the width of the isolation groove is: 0.5mm-1mm, and the distance between the transition electrode slurry and the wall of the isolation groove is more than 50 mu m.

5. The method of claim 1, wherein the metal paste disposed on the surface of the first side of the cell body includes a plurality of metal patterns spaced apart along a first direction, and the isolation groove extends along the first direction and is located between two ends of the cell body in a second direction;

the first direction and the second direction are perpendicular to the thickness direction of the substrate.

6. The method according to claim 1, wherein in the step of pre-sintering the battery body, a first peak temperature T1 at which the surface of the first side of the battery body is sintered is set to be: the second peak temperature T2 of sintering the surface of the second side of the battery body at 700 ℃ to 750 ℃ is as follows: t2 at 650℃ the temperature is less than or equal to 700 ℃.

7. The method according to claim 1, wherein in the step of pre-sintering the battery body, a first peak temperature T1 at which the surface of the first side of the battery body is sintered is set to be: the temperature T1 is more than or equal to 600 ℃ and less than 700 ℃, the duration of the first peak temperature is 2s-30s, and the second peak temperature T2 for sintering the surface of the second side of the battery body meets the following conditions: the temperature of T2 is more than or equal to 550 ℃ and less than 650 ℃, and the duration of the second peak temperature is 5s-10s; the cooling time range is 2s-5s.

8. The method according to claim 1, wherein at least one of the metal paste on the surface of the first side and the metal paste on the surface of the second side comprises: silver powder, aluminum powder, glass powder, additives and an organic carrier, wherein the weight percentage of the aluminum powder is 0% -0.5% based on the total weight of the metal slurry being 100%; the weight percentage of the glass powder is 3% -5%;

the weight percentage of lead in the glass powder is 30% -40%.

9. The method of manufacturing a solar cell according to claim 1, wherein the step of applying a reverse bias voltage to the cell body through the first pre-cured electrode and the transition electrode comprises:

and pressing a probe of a first external electrode of an external power supply against the first pre-cured electrode, pressing a probe of a second external electrode of the external power supply against the transition electrode, wherein the polarities of the first external electrode and the second external electrode are opposite.

10. The method of manufacturing a solar cell according to claim 1, wherein the number of the isolation grooves is at least one, and each of the isolation grooves extends along a first direction; when the number of the isolation grooves is at least two, the isolation grooves are arranged at intervals along a second direction, and the isolation grooves divide the surface of the first side of the battery body into at least two sub-areas along the second direction;

the step of laser-induced sintering the first pre-cured electrode into a first electrode specifically comprises the following steps:

and sequentially carrying out laser-induced sintering on the first pre-solidified electrode in each sub-region along the second direction.

11. The method of claim 10, wherein the step of laser-induced sintering the first pre-cured electrode in any one of the sub-regions comprises:

And electrically connecting the first pre-cured electrode in the subarea and the transition electrode adjacent to the subarea with a first external electrode and a second external electrode of an external power supply respectively, and carrying out laser scanning on the subarea, wherein the polarities of the first external electrode and the second external electrode are opposite, and the first direction, the second direction and the thickness direction of the battery body are perpendicular to each other.

12. The method of any one of claims 1 to 11, wherein the step of applying a reverse bias voltage to the cell body through the first pre-cured electrode and the transition electrode and laser scanning the surface of the first side of the cell body comprises:

the wavelength range of the laser is 532nm-1064nm, the power range of the laser scanning is 60W-100W, and the reverse bias voltage is 10V-20V.

13. The method of any one of claims 1-11, wherein the step of laser-induced sintering the first pre-cured electrode to a first electrode is followed by:

The cell main body is cut along the extending direction of the isolation groove to form at least two solar cells.

14. A solar cell is characterized in that, a solar cell manufactured by the manufacturing method of any one of claims 1 to 13.

15. A solar cell, comprising: the solar cell comprises a solar cell body, wherein a first electrode and a second electrode are respectively arranged on the surface of a first side and the surface of a second side of the solar cell body;

The surface of the first side of the solar cell body is also provided with an isolation groove extending to the substrate of the solar cell body, and a transition electrode insulated and isolated from the side wall of the isolation groove is formed at the bottom of the isolation groove.

16. The solar cell of claim 15, wherein the solar cell body further comprises a first doped conductive layer and a first passivation layer disposed in sequence on a first side of the substrate, and a passivation contact layer and a second passivation layer disposed in sequence on a second side of the substrate, the doping types of the first doped conductive layer and the passivation contact layer being opposite;

The first electrode is arranged on the first passivation layer and in ohmic contact with the first doped conductive layer, and the second electrode is arranged on the second passivation layer and in ohmic contact with the passivation contact layer;

The isolation groove is formed in the surface, away from the substrate, of the first passivation layer.

17. The solar cell of claim 16, wherein the first electrode comprises a plurality of first electrode patterns spaced apart along a first direction;

the isolation groove extends along the first direction and is positioned between two ends of the substrate in the second direction; or alternatively

The isolation groove extends along the second direction and is positioned between two ends of the substrate in the first direction;

the first direction and the second direction are perpendicular to the thickness direction of the substrate.

18. The solar cell of claim 17, wherein the number of isolation trenches is at least one;

when the number of the isolation grooves is at least two and the isolation grooves extend along the first direction, the isolation grooves are arranged at intervals along the second direction;

When the number of the isolation grooves is at least two and the isolation grooves extend along the second direction, the isolation grooves are arranged at intervals along the first direction.

19. The solar cell of claim 16, wherein the first electrode comprises a plurality of first electrode patterns spaced apart along a first direction;

The isolation groove extends along a first direction and is positioned at the end part of the substrate in a second direction; or the isolation groove extends along the second direction and is positioned at the end part of the substrate in the first direction;

the first direction and the second direction are perpendicular to the thickness direction of the substrate.

20. A photovoltaic module comprising at least one cell string comprising at least two solar cells according to any one of claims 14-19.