Method for manufacturing a solar cell

Abstract

The application relates to the technical field of solar cells, in particular to a manufacturing method of a solar cell. In the embodiment of the application, a target irradiation process is configured in a laser-assisted sintering process, so that the moving direction of the laser in the target irradiation process and the longitudinal extension direction of the first electrode intersect with each other. As a result, a larger range of non-electrode area can be covered, more carriers can be excited, the contact performance of the formed first electrode and the substrate can be improved more significantly, the precision requirement of the laser control can be reduced, the process window can be expanded, and the manufacturing efficiency can be improved. Therefore, by configuring the aforementioned target irradiation process, the contact performance of the first electrode and the substrate can be improved to a greater extent, the conversion efficiency of the solar cell can be improved, and the manufacturing process is facilitated and the manufacturing efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar cells, and particularly relates to a manufacturing method of a solar cell. BACKGROUND

[0002] A solar cell is a device for converting light energy into electric energy. The solar cell utilizes the photovoltaic principle to generate carriers, and then uses electrodes to lead out the carriers, thereby facilitating the effective utilization of electric energy. However, the conversion efficiency of the current solar cell needs to be further improved. SUMMARY

[0003] Therefore, it is necessary to provide a manufacturing method of a solar cell, which at least facilitates the improvement of the conversion efficiency of the solar cell.

[0004] The embodiment of the present application provides a manufacturing method of a solar cell, which comprises the following steps:

[0005] providing a solar cell substrate;

[0006] forming a first initial electrode on the solar cell substrate through a metallization heat treatment process;

[0007] controlling the laser to move and irradiate on the solar cell substrate to perform laser-assisted sintering treatment on the first initial electrode to form a first electrode, so as to obtain a solar cell;

[0008] wherein the execution times of the continuous movement and irradiation of the laser on the solar cell substrate is at least once.

[0009] all the continuous movement and irradiation processes have a target irradiation process, in the target irradiation process, the moving direction of the laser on the solar cell substrate and the longitudinal extension direction of the first electrode intersect with each other, and the moving direction of the laser on the solar cell substrate and the longitudinal extension direction of the first electrode are both perpendicular to the thickness direction of the solar cell substrate.

[0010] In one of the embodiments, the execution times of the continuous movement and irradiation of the laser on the solar cell substrate is multiple times.

[0011] wherein the moving direction of the laser in the first continuous movement and irradiation process is parallel to the longitudinal extension direction of the first electrode; or

[0012] the first continuous movement and irradiation process is the target irradiation process.

[0013] In one of the embodiments, the number of times of performing the continuous movement irradiation of the laser on the solar cell substrate is at least three; all the continuous movement irradiations except the first continuous movement irradiation are target irradiations; and the movement directions of the laser on the solar cell substrate in all the target irradiations form a movement direction set.

[0014] In the movement direction set, there are multiple movement directions with the same direction or multiple movement directions with opposite directions.

[0015] In the movement direction set, there are multiple movement directions intersecting with each other.

[0016] In one of the embodiments, the reverse bias of the laser in the first continuous movement irradiation is greater than that in any of the continuous movement irradiations except the first continuous movement irradiation; and / or

[0017] In one of the embodiments, the power of the laser in the first continuous movement irradiation is greater than that in any of the continuous movement irradiations except the first continuous movement irradiation; and / or

[0018] In one of the embodiments, the laser used in the continuous movement irradiation except the first continuous movement irradiation is red laser.

[0019] In one of the embodiments, the irradiation area formed by each continuous movement irradiation is the same area.

[0020] In one of the embodiments, there are different irradiation areas in the irradiation areas formed by all the continuous movement irradiations.

[0021] In one of the embodiments, there is a first target area in all the irradiation areas.

[0022] The first target area is determined based on the position of the first initial electrode.

[0023] In one of the embodiments, there is a second target area in all the irradiation areas.

[0024] The second target area is determined based on the corresponding area of the side surface of the solar cell substrate where the first initial electrode is located; the corresponding area includes at least one of the sintering poor area of the first initial electrode and the edge area of the solar cell substrate.

[0025] In one of the embodiments, the order of all the irradiation areas formed by the execution order of all the continuous movement irradiations is a preset order.

[0026] In the preset order, the sorting sequence number corresponding to the second target area is the middle sequence number; or

[0027] The ranking serial number corresponding to the second target region is the first serial number; or

[0028] The ranking serial number corresponding to the second target region is the last serial number.

[0029] In one embodiment, the angle between the moving direction of the laser in the target irradiation process and the longitudinal extension direction of the first electrode is 45° to 135°; and / or

[0030] The reverse bias of the laser is 10V to 30V, the power of the laser is 10W to 100W, and the scanning speed of the laser is 20000mm / s to 200000mm / s; and / or

[0031] The same irradiation region formed by the same continuous moving irradiation process is arranged continuously or discontinuously; and / or

[0032] The number of times of controlling the laser to perform the continuous moving irradiation on the solar cell substrate is twice.

[0033] In one embodiment, the laser is controlled to perform moving irradiation on the solar cell substrate to perform laser-assisted sintering treatment on the first initial electrode to form the first electrode, thereby obtaining a solar cell, including:

[0034] Providing a laser; the laser is located on one side of the thickness direction of the solar cell substrate and is arranged opposite to the central region of the solar cell substrate;

[0035] Controlling the laser to rotate so that the moving irradiation region of the laser emitted by the laser can cover at least part of the solar cell substrate to perform laser-assisted sintering treatment on the first initial electrode to form the first electrode.

[0036] In the method for manufacturing the solar cell, after the first initial electrode is formed by the metallization heat treatment process, the first initial electrode is subjected to laser-assisted sintering treatment to form the first electrode, thereby obtaining the solar cell. In this process, the target irradiation process is configured in the laser-assisted sintering treatment process, so that the moving direction of the laser in the target irradiation process and the longitudinal extension direction of the first electrode intersect with each other. In this way, on the one hand, part of the irradiation area formed by the laser in the target irradiation process covers the electrode area of the solar cell, which can improve the contact performance of the first electrode and the substrate. On the other hand, another part of the irradiation area formed by the laser in the target irradiation process covers the non-electrode area of the solar cell, which can excite carriers by means of the non-electrode area. When a certain reverse bias is applied, these excited charge carriers will move directionally, generating a local current. This local current can further increase the temperature of the sintering area, promote the mutual fusion and co-expansion of the first initial electrode and the substrate, and thus further improve the contact performance of the first electrode and the substrate. Compared with the way that the moving direction of the laser is parallel to the longitudinal extension direction of the first electrode, and the laser acts on the first initial electrode or the area near the first initial electrode, the laser in the target irradiation process not only can form a larger range covering the non-electrode area, thereby exciting more carriers and making the contact performance of the first electrode and the substrate improved more significantly, but also can reduce the precision requirement of controlling the laser, expand the process window and improve the manufacturing efficiency. Therefore, by configuring the target irradiation process, the contact performance of the first electrode and the substrate can be improved to a greater extent, the conversion efficiency of the solar cell can be improved, and the processing and manufacturing can be facilitated and the manufacturing efficiency can be improved.

[0037] Additional aspects and advantages of the embodiments will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following and / or can be learned by practice of the embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0038] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the embodiments. The accompanying drawings are merely schematic and are not intended to be limiting of the application. Rather, for the purpose of explanation, the drawings provide principles of the application. The application is described and explained with additional specificity and detail through the use of the included drawings in which:

[0039] Figure 1 A flowchart of a method for manufacturing a solar cell according to some embodiments of the application;

[0040] Figure 2 A sectional view of a solar cell substrate according to some embodiments of the application;

[0041] Figure 3For Figure 2 A schematic diagram of a structure of a solar cell substrate on which a metal paste is printed;

[0042] Figure 4 For Figure 2 A schematic diagram of a structure of a solar cell substrate on which a first initial electrode is formed;

[0043] Figure 5 For Figure 2 A schematic diagram of a structure of a solar cell substrate on which a first electrode is formed;

[0044] Figure 6 A schematic diagram of a solar cell substrate on which a laser is irradiated in some embodiments of the present application;

[0045] Figure 7 A schematic diagram of a moving irradiation path provided in some embodiments of the present application;

[0046] Figure 8 A schematic diagram of a solar cell substrate on which a laser is irradiated in some embodiments of the present application;

[0047] Figure 9 A schematic diagram of an irradiation region in some embodiments of the present application;

[0048] Figure 10 A schematic diagram of an irradiation region in some embodiments of the present application;

[0049] Figure 11 A schematic diagram of an irradiation region on a solar cell substrate provided in some embodiments of the present application;

[0050] Figure 12 A schematic diagram of a moving irradiation path provided in some embodiments of the present application;

[0051] Figure 13 A schematic diagram of a moving irradiation path provided in some embodiments of the present application;

[0052] Figure 14 A schematic diagram of a moving irradiation path provided in some embodiments of the present application;

[0053] Figure 15 A schematic diagram of a first target region on a solar cell substrate provided in some embodiments of the present application;

[0054] Figure 16 A schematic diagram of a second target region on a solar cell substrate provided in some embodiments of the present application;

[0055] Figure 17 A schematic diagram of a moving irradiation path provided in some embodiments of the present application;

[0056] Figure 18 A flowchart of step S130 in the method for manufacturing a solar cell provided for some embodiments of the present application is shown in FIG. 13.

[0057] Figure 19 A sectional structure diagram of a solar cell provided for some embodiments of the present application is shown in FIG. 14.

[0058] Explanation of reference signs:

[0059] A solar cell 100;

[0060] A solar cell substrate 110, a substrate 111, a first surface m1, a second surface m2, a doped layer 112, a first passivation layer 113, a tunneling layer 114, a doped conductive layer 115, a second passivation layer 116, a first electrode E1, a second electrode E2;

[0061] A metal paste e0, a first initial electrode e1;

[0062] A laser Q, a laser L, a moving irradiation path P, an irradiation area W, a first target area Z1, a second target area Z2;

[0063] A moving direction M, a first angle ɵ, a first direction F1, a second direction F2, a third direction F3;

[0064] Steps S110, S120, S130, S131, S132. DETAILED DESCRIPTION

[0065] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of ways other than those described herein without departing from the spirit of the present application. It is therefore intended that the present application not be limited to the embodiments disclosed herein for purposes of craftsmanship.

[0066] In the description of the present application, it should be understood that if there are terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0067] In addition, if there are terms such as "first", "second", these terms are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can be explicitly or implicitly included at least one of the features. In the description of the present application, if the term "a plurality of" appears, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0068] In the present application, unless otherwise explicitly specified and limited, if there are terms such as "mounting", "connecting", "connecting", "fixing" and the like, these terms should be broadly understood. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. It should be noted that in the following description and the appended claims, one feature is "electrically connected" to another feature, which includes not only the direct contact between one feature and another feature to form an electric energy transmission or current transmission channel, but also the intermediate feature between one feature and another feature. The one feature, the other feature and the intermediate feature therebetween form an electric energy transmission channel or a current transmission channel to achieve electric energy transmission or transmission. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0069] In the present application, unless otherwise explicitly specified and limited, if there are terms such as "first" and "second" and the like, the meaning can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be the first feature directly above or obliquely above the second feature, or only indicates that the first feature is higher than the second feature in horizontal height. The first feature "below", "below" and "below" the second feature can be the first feature directly below or obliquely below the second feature, or only indicates that the first feature is lower than the second feature in horizontal height.

[0070] It should be noted that if an element is referred to as "fixed to" or "disposed on" another element, it can be directly on another element or there can be a middle element. If an element is considered to be "connected" to another element, it can be directly connected to another element or there can be a middle element. If present, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in the present application are only for illustrative purposes and do not represent the only implementation.

[0071] Figure 1A flowchart of a method for manufacturing a solar cell is shown. For ease of illustration, only the content related to the embodiments of the present application is shown.

[0072] Please refer to Figure 1 The embodiments of the present application provide a method for manufacturing a solar cell, comprising the following steps.

[0073] In step S110, a solar cell substrate is provided.

[0074] In step S120, a first initial electrode is formed on the solar cell substrate by a metallization heat treatment process.

[0075] In step S130, the laser is controlled to move and irradiate on the solar cell substrate to perform laser-assisted sintering treatment on the first initial electrode to form a first electrode, thereby obtaining a solar cell. The number of times of performing continuous movement and irradiation of the laser on the solar cell substrate is at least once. There is a target irradiation process in all continuous movement and irradiation processes. In the target irradiation process, the moving direction of the laser on the solar cell substrate and the longitudinal extension direction of the first electrode intersect with each other, and both the moving direction of the laser on the solar cell substrate and the longitudinal extension direction of the first electrode are perpendicular to the thickness direction of the solar cell substrate.

[0076] In step S110, please refer to Figure 2 , Figure 2 A cross-sectional structure diagram of a solar cell substrate 110 is shown. The solar cell substrate 110 comprises a substrate 111 and a layer structure arranged on the substrate 111. For example, in the embodiments of the present application, the first direction F1 is the thickness direction of the substrate 111, and the second direction F2 and the third direction F3 can be the length direction and the width direction of the substrate 111, respectively. The first direction F1, the second direction F2 and the third direction F3 are perpendicular to each other. It should be noted that the size of the substrate 111 along the length direction can be greater than or equal to the size along the width direction, which is not limited here. Figure 2

[0077] ​Specifically, the substrate 111 has a doping element, which is of N type or P type. The substrate 111 has a first surface m1 and a second surface m2 oppositely arranged. The first surface m1 and the second surface m2 are oppositely arranged along a first direction F1. Both the first surface m1 and the second surface m2 can be used to receive incident light. In the embodiments of the present application, the first surface m1 of the substrate 111 is a light-receiving surface, and the second surface m2 of the substrate 111 is a back light surface. It can be understood that the light-receiving surface and the back light surface are relative. The light-receiving surface is specifically a surface on which the substrate 111 is mainly irradiated by sunlight in a solar cell or in a photovoltaic module. With the development of solar cell technology, the back light surface will also receive the energy of sunlight, mainly from the reflected light or scattered light in the surrounding environment.

[0078] The first surface m1 side of the substrate 111 can be sequentially provided with a doping layer 112 and a first passivation layer 113, and the second surface m2 side of the substrate 111 can be sequentially provided with a tunnel layer 114, a doped conductive layer 115 and a second passivation layer 116, so as to form a solar cell substrate 110. The solar cell substrate 110 can constitute at least part of a TOPCon (Tunnel Oxide Passivating Contacts) cell. The layer structure provided on the substrate 111 can be improved according to actual use requirements. Of course, in other embodiments, the first surface m1 and the second surface m2 of the substrate 111 can be provided with different layers or structures according to specific use requirements. For example, the solar cell substrate 110 can also be used to constitute at least part of a BC (Back Contact) cell. That is, the required solar cell substrate 110 can be made according to actual use requirements, and can be used to constitute different types of solar cells, which are not specifically limited herein.

[0079] In step S120, the metallization heat treatment process can be a printing process and a sintering process. The printing process refers to a process of printing a metal paste on a corresponding region of the solar cell substrate. The printing process includes at least one of a screen printing process, a gravure printing process, a relief printing process, a flexographic printing process, a laser transfer printing process, an inkjet printing process and a 3D printing process. The sintering process refers to a process of making at least part of the metal paste penetrate the corresponding layer structure on the solar cell substrate through a heat treatment process.

[0080] Specifically, for example, Figure 3 , Figure 3 is shown Figure 2 The structure diagram schematically showing that the solar cell substrate 110 is printed with the metal paste e0, the metal paste e0 is printed on the side surface of the first passivation layer 113 away from the doping layer 112. The region of the printed metal paste e0 can be determined according to actual use requirements, which is not specifically limited herein. In combination with reference to Figure 4, Figure 4 It shows Figure 2 The schematic diagram shows a structure on a solar cell substrate 110 with a first initial electrode e1 formed thereon. The aforementioned metal paste e0 is sintered until at least a portion of the metal paste e0 burns through to a portion of the thickness of the first passivation layer 113, forming the first initial electrode e1. At this point, at least a portion of the first initial electrode e1 has not yet made contact with the doped layer 112. Alternatively, at least a portion of the metal paste e0 can penetrate the first passivation layer 113 and make electrical contact with the doped layer 112, forming the first initial electrode e1. In this case, at least a portion of the first initial electrode e1 makes contact with the doped layer 112. During this process, the metal paste e0 can be sintered in a sintering furnace.

[0081] In step S130, laser irradiation on the solar cell substrate forms a light spot. The shape of the light spot includes, but is not limited to, rectangular, circular, or elliptical shapes. During the movement of the laser, at least a majority of the area where the first initial electrode is located is covered by the area irradiated by the formed light spot. Thus, through laser-assisted sintering, the first initial electrode can be formed by laser-assisted sintering. (Refer to reference...) Figure 5 , Figure 5 It shows Figure 2 The schematic diagram shows a structure on a solar cell substrate 110 with a first electrode E1 formed thereon. Through laser-assisted sintering, the first initial electrode e1 is formed into the first electrode E1, which forms an ohmic contact with the doped layer 112. During this process, the laser can destroy a portion of the first passivation layer 113 located in the electrode region, causing localized melting and diffusion of the first initial electrode e1. This allows it to directly contact the doped layer 112, forming a micro-alloy junction, thereby reducing contact resistance and improving electron transport efficiency. The electrode region is the area where the first electrode E1 is located; the non-electrode region is the area where the first electrode E1 is not located.

[0082] A laser can be emitted by a laser device, and the laser can be configured as a line laser. During the movement of the laser beam, the irradiated area formed by this linear beam can be roughly considered as a line. (Refer to reference...) Figure 6 , Figure 6 This paper shows a schematic diagram of laser L irradiating a solar cell substrate 110 in some embodiments of this application. Figure 6 The corresponding electrodes are not shown. The laser L emitted by laser Q can be roughly regarded as a continuous line beam, in conjunction with the reference. Figure 7 , Figure 7 This paper shows a schematic diagram of a moving illumination path P provided in some embodiments of this application. Figure 7The arrow in the figure shows the moving irradiation path P of the laser L, and the laser Q can be controlled to move along the moving irradiation path P. The number of the emitted laser L can be determined according to the specific use requirement, i.e. the formed moving irradiation path P is Figure 7 The number of the moving irradiation path P in the figure is not specifically limited. Correspondingly, a plurality of lasers Q arranged side by side can be configured to emit a plurality of lasers L arranged side by side, and of course, one laser Q can also emit a plurality of lasers L, which is not specifically limited herein. It can be understood that the more intensive the formed moving irradiation path P is, the more areas on the solar cell substrate 111 are irradiated.

[0083] Of course, in some other embodiments, the laser L is irradiated on the solar cell substrate 110 in combination with the description of the above-mentioned Figure 8 , Figure 8 The figure shows the schematic diagram of the laser L irradiated on the solar cell substrate 110 in some other embodiments of the present application. The emitted laser L forms a light spot with a certain length and in a linear shape on the solar cell substrate 110 (which can be regarded as a long strip-shaped light spot), and moves along the extension direction of the light spot. The formed irradiation area can also be regarded as a line. The required laser can be selected according to the specific use requirement, which is not specifically limited herein.

[0084] The laser moves continuously for irradiation, i.e. the laser moves for irradiation on the solar cell substrate in one direction, and the moving process of the laser for irradiation on the solar cell substrate can be regarded as continuous. One continuous moving irradiation process is that the laser moves for irradiation on the solar cell substrate in one direction once. Since the laser is emitted by the laser Q, the continuous moving irradiation process can be regarded as controlling the laser Q to move for irradiation on the solar cell substrate in one direction. In this process, the laser Q can continuously emit light or intermittently emit light. In the case that the laser Q continuously emits light, for example, the laser L forms a continuous irradiation area W in the continuous moving irradiation process. In the case that the laser Q intermittently emits light, for example, the laser L forms a discontinuous irradiation area W in the continuous moving irradiation process. The discontinuous irradiation area W can be regarded as an intermittent irradiation area W. The continuous moving irradiation process of the laser can be set according to the actual use requirement, which is not specifically limited herein. Figure 9 Figure 10 The irradiation area formed in the continuous moving irradiation process has a starting end and a terminal end. The starting end and the terminal end of the irradiation area can be set according to the use requirement, and the required irradiation area can be obtained by controlling the light emission process and the moving process of the laser Q. In combination with the description of the above-mentioned

[0085] The irradiation area formed in the continuous moving irradiation process has a starting end and a terminal end. The starting end and the terminal end of the irradiation area can be set according to the use requirement, and the required irradiation area can be obtained by controlling the light emission process and the moving process of the laser Q. In combination with the description of the above-mentioned Figure 11 , Figure 11 ​A schematic diagram of the irradiation region W on the solar cell substrate 110 is shown in some embodiments of the present application. In order to show the irradiation region W, the related electrodes are not shown. The starting end of the irradiation region W is one side edge of the solar cell substrate 110, and the ending end of the irradiation region W is the other side edge of the solar cell substrate 110. In Figure 11 In the illustrated case, the irradiation region W is a continuous irradiation region. It can be understood that the width of each irradiation region W can be controlled by controlling the width of the light spot, and the distance between two adjacent irradiation regions W can be controlled by controlling the distance between the corresponding two lasers (i.e., the distance between two adjacent light spots). Of course, in some other embodiments, the starting end and / or the ending end of the irradiation region W can not be the corresponding edge of the solar cell substrate 110, and can be set according to the specific use, which is not specifically limited herein.

[0086] The number of times of performing the continuous movement irradiation is at least one, i.e., the number of times of the continuous movement irradiation can be one, two or other numbers. There is a target irradiation process in all the continuous movement irradiation processes, i.e., in the case of one continuous movement irradiation process, the continuous movement irradiation process is the target irradiation process, and in the case of multiple continuous movement irradiation processes, at least one of the continuous movement irradiation processes is the target irradiation process. For the target irradiation process, the laser is moved on the solar cell substrate 110 along the movement direction M, and the movement direction M and the longitudinal extension direction of the first electrode E1 intersect with each other, i.e., the movement direction M and the longitudinal extension direction of the first electrode E1 form a first angle ɵ. Figure 7 For example, the longitudinal extension direction of the first electrode E1 is the third direction F3 shown in the diagram, the thickness direction of the solar cell substrate 110 is the first direction F1 shown in the diagram, the movement direction M of the laser on the solar cell substrate 110 and the third direction F3 intersect with each other, i.e., the movement direction M and the third direction F3 form a first angle ɵ. Figure 7 In the diagram, the movement direction M and the third direction F3 are perpendicular to each other, and the movement direction M and the second direction F2 are parallel to each other, i.e., the first angle ɵ is 90°. Of course, the first angle ɵ can also be other angles, which are not specifically limited herein.

[0087] Thus, in the above-mentioned case, the first electrode is formed by performing the laser-assisted sintering process on the first initial electrode after the first initial electrode is formed by the metallization heat treatment process, and the solar cell is obtained. In this process, the target irradiation process is configured in the laser-assisted sintering process, so that the moving direction of the laser in the target irradiation process and the longitudinal extension direction of the first electrode intersect with each other. In this way, on the one hand, part of the irradiation area formed by the laser in the target irradiation process covers the electrode area of the solar cell, which can improve the contact performance of the first electrode and the substrate; on the other hand, another part of the irradiation area formed by the laser in the target irradiation process covers the non-electrode area of the solar cell, which can excite carriers by means of the non-electrode area. When a certain reverse bias is applied, these excited charge carriers will move directionally, generating a local current. This local current can further increase the temperature of the sintering area, promote the mutual fusion and co-expansion of the first initial electrode and the substrate, and thus further improve the contact performance of the first electrode and the substrate.

[0088] In related embodiments, the laser-assisted sintering is usually performed in a manner that the moving direction of the laser is parallel to the longitudinal extension direction of the first electrode, and the laser acts on the first initial electrode or the region near the first initial electrode. However, this manner can only perform laser-assisted sintering on the electrode area, which limits the improvement space of the contact performance. At the same time, since the first initial electrode or the region near the first initial electrode needs to be aligned, the alignment accuracy of the laser needs to be controlled, which makes the process of laser-assisted sintering difficult to control and the process efficiency too low.

[0089] It can be understood that, compared with the related embodiments described above, in the target irradiation process described above, not only can a larger range covering the non-electrode area be formed, thereby exciting more carriers and making the contact performance of the first electrode and the substrate improve more significantly, but also the accuracy requirement of the laser can be reduced, the process window can be expanded, and the manufacturing efficiency can be improved.

[0090] Therefore, by configuring the target irradiation process described above, not only can the contact performance of the first electrode and the substrate be improved to a greater extent, the conversion efficiency of the solar cell can be improved, but also the processing and manufacturing can be facilitated, and the manufacturing efficiency can be improved.

[0091] In some embodiments, the laser performs the continuous moving irradiation on the solar cell substrate for multiple times. In the first continuous moving irradiation process, the moving direction of the laser is parallel to the longitudinal extension direction of the first electrode; or the first continuous moving irradiation process is the target irradiation process.

[0092] For the case that the first continuous moving irradiation process is not the target irradiation process, the laser performs the continuous moving irradiation on the solar cell substrate for multiple times. In the first continuous moving irradiation process, the moving direction of the laser is parallel to the longitudinal extension direction of the first electrode; or the first continuous moving irradiation process is the target irradiation process.Figure 12 For example, the moving direction M of the laser is parallel to the longitudinal extension direction of the first electrode E1, i.e., the moving direction M is parallel to the third direction F3. Figure 12 The extension direction of the moving irradiation path P in the first continuous moving irradiation process is parallel to the extension direction of the first electrode E1. Figure 7 The extension direction of the moving irradiation path P in the first continuous moving irradiation process is parallel to the extension direction of the first electrode E1.

[0093] Of course, in other embodiments, the first continuous moving irradiation process can also be that the laser moves and irradiates on a non-first initial electrode region of the solar cell substrate to generate carriers and preliminarily promote the further inter-diffusion and co-expansion of the first initial electrode and the substrate.

[0094] For the case that the first continuous moving irradiation process is the target irradiation process, the target irradiation process can be used to preliminarily process the first initial electrode and the non-first initial electrode region, and then the subsequent continuous moving irradiation process is controlled to complete the required laser-assisted sintering process.

[0095] In the above-mentioned first continuous moving irradiation process, different preliminary processing processes can be combined to obtain different contact forms of the first initial electrode and the substrate. According to different contact forms, different subsequent continuous moving irradiation processes can be configured to achieve different process processes and different contact performances to meet different use requirements.

[0096] For example, in the case that the number of times of the continuous moving irradiation is twice, the first continuous moving irradiation process can be as shown in the case of Figure 12 The last continuous moving irradiation process is the target irradiation process, the reverse bias of the laser used in the last continuous moving irradiation process is less than the reverse bias of the laser used in the first continuous moving irradiation process, and the power of the laser used in the last continuous moving irradiation process is less than the power of the laser used in the first continuous moving irradiation process. The first continuous moving irradiation process can make the first initial electrode form a preliminary contact with the aforementioned doped layer without producing metal composite, and the last continuous moving irradiation process can make the first initial electrode form an ohmic contact with the doped layer, and the carriers generated in the non-electrode region can help the first initial electrode and the doped layer to further inter-diffuse and co-expand, thereby improving the contact performance.

[0097] Thus, the subsequent continuous movement irradiation process can be flexibly configured according to the specific process of the first continuous movement irradiation process, the process control window is expanded through the control of the related parameters of the laser in different continuous movement irradiation processes, and the controllability is higher. Not only can the required solar cell be obtained according to the use requirement, but also the manufacturing is further facilitated.

[0098] In some embodiments, the number of times of performing the continuous movement irradiation of the laser on the solar cell substrate is at least three. All the continuous movement irradiation processes, except for the first continuous movement irradiation process, are target irradiation processes. The moving directions of the laser on the solar cell substrate in all the target irradiation processes form a moving direction set. In the moving direction set, there are multiple moving directions with the same direction or multiple moving directions with opposite directions; or in the moving direction set, there are multiple moving directions intersecting with each other.

[0099] The moving direction set for the target irradiation process refers to a set of multiple moving directions. Each target irradiation process corresponds to a moving direction, and the number of target irradiation processes is the same as the number of moving directions in the moving direction set.

[0100] For example, there are multiple target irradiation processes with the same moving direction of the laser, and the moving direction of the laser in the multiple target irradiation processes is the same. For example, there are multiple target irradiation processes with opposite moving directions of the laser, and the moving direction of the laser in the multiple target irradiation processes is opposite. In the case that the multiple target irradiation processes are adjacent target irradiation processes, the laser can be roughly regarded as reciprocating in the corresponding direction. Of course, the moving direction set can also include multiple moving directions with the same direction and multiple moving directions with opposite directions. For example, in combination with reference to Figure 13 , Figure 13 FIG. 6 shows a schematic diagram of a movement irradiation path P provided by some embodiments of the present application, Figure 7 the moving direction M shown in FIG. 5 and Figure 13 the moving direction M shown in FIG. 6 are opposite. For another example, in combination with reference to Figure 14 , Figure 14 FIG. 7 shows a schematic diagram of a movement irradiation path P provided by some embodiments of the present application, Figure 7 the moving direction M shown in FIG. 5 and Figure 14 the moving direction M shown in FIG. 6 intersect with each other.

[0101] Thus, in the case of multiple moving directions with the same direction or multiple moving directions with opposite directions, the movement process of the laser is facilitated. Further, in the case of opposite moving directions corresponding to two adjacent target irradiation processes, the sintering efficiency can be further improved. In the case of multiple moving directions intersecting with each other, the solar cell substrate can be irradiated more comprehensively, and the contact performance can be further improved.

[0102] In some embodiments, the reverse bias of the laser in the first continuous moving irradiation process is greater than that in any of the continuous moving irradiation processes other than the first continuous moving irradiation process.

[0103] Since a greater reverse bias can enhance the transport capacity of carriers, it is helpful for the inter-diffusion between the first initial electrode and the doped layer to form a good ohmic contact. Therefore, the electric field strength can be enhanced by the first continuous moving irradiation process to promote the accelerated motion of carriers between the first initial electrode and the solar cell substrate. This not only helps to more effectively break the potential barrier at the interface to promote the inter-diffusion between metal atoms and silicon atoms, thereby forming a better ohmic contact, but also helps to promote the nucleation and growth of metal grains to form larger-sized grains, thereby improving the conductivity of the electrode. In combination with the lower reverse bias in the subsequent continuous moving irradiation process, not only can the ohmic contact preliminarily formed be finely adjusted to further optimize the flatness and stability of the contact interface, but also the further growth of metal grains can be controlled to improve the surface roughness and unevenness of the first electrode caused by excessively large metal grains. Thus, by setting different reverse biases, the process can be flexibly adjusted according to different manufacturing stages and material properties of the solar cell.

[0104] It can be understood that for different types and thicknesses of the first initial electrode, the reverse bias of the laser can be flexibly adjusted as needed. For example, for some metal electrode materials with a higher melting point, a higher initial reverse bias can be used to promote sintering. For example, for a relatively fragile substrate, a lower subsequent reverse bias can reduce damage to the substrate. Thus, the process flexibility and adaptability can be improved.

[0105] The first initial electrode forms a certain metal composite with the aforementioned doped layer, and in combination with the reduced reverse bias in the subsequent continuous moving irradiation process, the contact between the first initial electrode and the doped layer can be further more accurately controlled to form the required first electrode. In this way, the contact performance of the first electrode can be facilitated and improved.

[0106] In some embodiments, the power of the laser in the first continuous moving irradiation process is greater than that in any of the continuous moving irradiation processes other than the first continuous moving irradiation process.

[0107] Since greater laser power can provide higher energy input in a shorter time, accelerating the solidification of the first initial electrode and promoting inter-diffusion between the first initial electrode and the doped layer, the first initial electrode and the aforementioned doped layer can form a certain metal composite through the first continuous moving irradiation process, which can more quickly remove the organic matter and volatile matter in the first initial electrode, improve the situation of generating bubbles and defects in the subsequent continuous moving irradiation process, and, in combination with the lower laser power in the subsequent continuous moving irradiation process, control the grain growth of the first initial electrode, making it more uniform and fine, further optimizing the contact interface, reducing interface defects and recombination centers, and improving the conductivity and stability of the formed first electrode. In this way, the first initial electrode can be more finely adjusted and optimized.

[0108] It can be understood that for different types and thicknesses of the first initial electrode, the power of the laser can be flexibly adjusted as needed. For example, for a thicker first initial electrode, the power of the laser in the first continuous moving irradiation process can be higher to improve the sintering sufficiency. For example, for a first initial electrode sensitive to temperature, the power of the laser in the subsequent continuous moving irradiation process can be reduced to improve the situation of overheating damage. In this way, the process window and the adaptability of the process can be expanded.

[0109] In some embodiments, the laser used in all continuous moving irradiation processes except the first continuous moving irradiation process is configured as a red laser. For example, the laser used in the first continuous moving irradiation process can be a green laser, an ultraviolet laser or other lasers, which not only have higher energy, but also are easy to obtain and have lower cost.

[0110] Since the energy of the red laser is relatively low compared with some high-energy lasers, using the red laser in the subsequent continuous moving irradiation process can improve the situation of causing excessive damage to the formed structure or damaging the solar cell substrate.

[0111] The above-mentioned embodiments of controlling the reverse bias of the laser and the power of the laser, and the embodiment of configuring the type of laser can be used simultaneously, and the performance of the solar cell produced by the cooperation of each continuous moving irradiation process can be improved.

[0112] In some embodiments, the irradiation area formed by each continuous moving irradiation process is the same area.

[0113] In this way, not only is it convenient to control the continuous moving irradiation process of the laser, but it is also beneficial to configure the required continuous moving irradiation process according to the area, and then produce the required first electrode.

[0114] In some embodiments, there are different irradiation regions in all irradiation regions formed by the continuous movement irradiation processes.

[0115] In this way, different continuous movement irradiation processes can be correspondingly configured according to the different states of the regions in the process of manufacturing the first electrode, which is conducive to further improving the performance of the solar cell as a whole.

[0116] Figure 15 A schematic diagram of a first target region z1 on a solar cell substrate 110 provided by some embodiments of the present application is shown; only the content related to the embodiments of the present application is shown for ease of illustration. For ease of showing the first target region z1, the related electrodes are not shown.

[0117] In some embodiments, please refer to Figure 15 , there is a first target region Z1 in all irradiation regions. The first target region Z1 is determined based on the position of the first initial electrode. That is, the first target region Z1 at least includes at least part of the region where the first initial electrode is located.

[0118] Specifically, the first target region Z1 can be formed by the aforementioned first continuous movement irradiation process as a non-target irradiation process. For example, in the case where Figure 15 the first target region Z1 includes the region where the first initial electrode is located and the region near the region where the first initial electrode is located, the first target region Z1 substantially corresponds to the first initial electrode one by one, and at this time, the first target region Z1 includes all the regions where the first initial electrode is located.

[0119] In this way, the first target region is determined by the position of the first initial electrode, which can more specifically laser-assisted sintering of the first initial electrode, which is conducive to improving the contact performance of the formed first electrode and the doped layer.

[0120] Figure 16 A schematic diagram of the relationship between the solar cell substrate 110 and the second target region Z2 provided by some embodiments of the present application is shown; only the content related to the embodiments of the present application is shown for ease of illustration. For ease of showing the second target region, the related electrodes are not shown.

[0121] In some embodiments, please refer to Figure 16 , there is a second target region Z2 in all irradiation regions. The second target region Z2 is determined based on the corresponding region of the side surface of the solar cell substrate 110 where the first electrode is located. The corresponding region includes at least one of the sintering poor region of the first initial electrode and the edge region of the solar cell substrate. For example, Figure 16 the second target region Z2 is the edge region of the solar cell substrate 110 is shown.

[0122] In the process of forming the first electrode, there can be a situation that some areas of the first initial electrode are sintered poorly. At this time, the second target area can be set based on the poorly sintered areas of the first initial electrode, and then the defect areas of the first initial electrode can be laser-assisted sintered in a targeted manner to improve the sintering yield of the first initial electrode.

[0123] In the process of printing the first initial electrode by the screen printing process, there can be a situation that too much paste is printed in the edge area of the solar cell substrate, and then the sintering effect of the edge area will be different from that of the middle area, so it is difficult to control the sintering process. At this time, the second target area can be set based on the edge area of the solar cell substrate, and then the area with poor sintering effect can be laser-assisted sintered in a targeted manner to improve the sintering effect of the edge area of the solar cell substrate.

[0124] In some embodiments, the order of all the irradiation areas formed by the execution order of all the continuous movement irradiation processes is a preset order. In this case, the sorting sequence number corresponding to the second target area is a middle sequence number; or the sorting sequence number corresponding to the second target area is a first sequence number; or the sorting sequence number corresponding to the second target area is a last sequence number.

[0125] That is, the sorting sequence number of the irradiation area formed by the first continuous movement irradiation process is one, the sorting sequence number of the irradiation area formed by the second continuous movement irradiation process is two, and so on. In the case where the sorting sequence number corresponding to the second target area is a middle sequence number, the number of continuous movement irradiation processes is at least three, and the irradiation area formed by any continuous movement irradiation process except the first continuous movement irradiation process and the last continuous movement irradiation process includes the second target area. In the case where the sorting sequence number corresponding to the second target area is a first sequence number, the irradiation area formed by the first continuous movement irradiation process includes the second target area. In the case where the sorting sequence number corresponding to the second target area is a last sequence number, the irradiation area formed by the last continuous movement irradiation process includes the second target area.

[0126] For example, after the first initial electrode is formed by the metallization heat treatment process, the second target area can be determined according to the detection result, and the sintering effect of the second target area can be improved by the first continuous movement irradiation process. For another example, after any continuous movement irradiation process, the second target area can be determined according to the detection result, and the sintering effect of the second target area can be improved by performing the continuous movement irradiation process again. For another example, after all the continuous movement irradiation processes are performed, the second target area can be determined according to the detection result, and the sintering effect of the second target area can be improved by laser-assisted sintering. The sintering effect of the second target area can be improved according to the specific use case and the specific configured process, which is not limited here.

[0127] In some embodiments, please continue to refer to Figure 7 , Figure 13 and Figure 14 , the moving direction M of the laser in the target irradiation process and the longitudinal extension direction of the first electrode E1 form an angle of 45° to 135°. That is, the moving direction M of the laser in the target irradiation process and the longitudinal extension direction of the first electrode E1 form a first angle θ, and the first angle θ is 45° to 135°.

[0128] For example, the first angle θ can be 45°, 55°, 65°, 80°, 90°, 100°, 110°, 120° or 135°. For example, Figure 7 and Figure 13 schematically show the case where the first angle θ is 90°. For example, Figure 14 schematically show the case where the first angle θ is 135°. It can be understood that the first angle θ formed by the moving direction opposite to the moving direction M in Figure 14 and the longitudinal extension direction of the first electrode E1 is 45°. In actual implementation, the first angle θ can be any angle in the range.

[0129] It can be understood that based on the case schematically shown in Figure 7 and Figure 13 , the moving direction M of the laser in the two consecutive moving irradiation processes is opposite, that is, it can be understood as corresponding to the multiple moving directions in the moving direction set schematically shown in some embodiments.

[0130] In this way, the required first angle can be flexibly set according to the actual use. In the case where the first angle θ is 45° to 135°, the processing effect can be improved by combining the shape of the solar cell substrate while performing laser-assisted sintering.

[0131] In some embodiments, the reverse bias of the laser is 10V to 30V, the power of the laser is 10W to 100W, and the scanning speed of the laser is 20000mm / s to 200000mm / s.

[0132] Exemplarily, the reverse bias of the laser can be 10V, 12V, 15V, 16V, 17V, 19V, 21V, 25V or 30V, the power of the laser can be 10W, 13W, 16W, 18W, 20W, 25W, 30W, 40W, 50W, 70W, 80W, 90W or 100W, and the scanning speed of the laser can be 20000mm / s, 30000mm / s, 50000mm / s, 80000mm / s, 110000mm / s, 150000mm / s, 180000mm / s or 200000mm / s. In actual implementation, the reverse bias of the laser, the power of the laser and the scanning speed of the laser can be any angle in the range.

[0133] In this way, controlling the reverse bias of the laser not only helps to reduce the recombination probability of the carriers, but also reduces the risk of damaging the solar cell substrate. Controlling the power of the laser not only helps to heat the first initial electrode for a short time, but also reduces the risk of overburning the first initial electrode, thereby reducing the risk of damaging the solar cell substrate. Controlling the scanning speed of the laser can reduce the risk of damaging the solar cell substrate due to excessive heat effect while maintaining a certain efficiency. In this way, by flexibly setting the reverse bias of the laser, the power of the laser and the scanning speed of the laser in different continuous moving irradiation processes, the use requirements of different continuous moving irradiation processes can be met through the cooperation of the three.

[0134] In some embodiments, please continue to refer to 9 and Figure 10 The same irradiation area W formed in the same continuous moving irradiation process is continuously or discontinuously extended.

[0135] Specifically, the laser in the continuous moving irradiation process can be configured as a plurality of lasers, each laser moves and irradiates on the solar cell substrate to form an irradiation area, and the irradiation area formed in the same continuous moving irradiation process is composed of the irradiation areas formed by all the lasers.

[0136] It should be noted that a plurality of light emitting devices can be integrated in the same laser to emit laser, or a plurality of lasers can emit laser respectively. Among them, the plurality of lasers can be arranged side by side, or arranged according to the required light emitting pattern, which is not limited here. In order to facilitate the illustration of the corresponding continuous moving irradiation process, the above-mentioned Figure 7 , Figures 12 to 14 is only schematically shown for one continuous moving irradiation process, and in order to facilitate understanding, the first electrode E1 is schematically shown, and the Figure 17It can also be understood in the same way. In the same continuous movement irradiation process, each laser can be emitted simultaneously or not simultaneously. Whether each laser is emitted simultaneously or not, the emission of the corresponding laser can be controlled according to the required irradiation area. For example, in the case of intermittent extension of the irradiation area, the laser corresponding to the irradiation area can be intermittently emitted. For different continuous movement irradiation processes, the emission process of the corresponding laser can be configured according to the pattern formed by the required irradiation area in different processes and the different movement irradiation sequences. The pattern formed by the required irradiation area in different processes can be pre-set in the control program, or can be set according to the detection result as described in some of the above embodiments, which is not specifically limited here. It can be understood that the first target area and the second target area described above can also be configured in this way.

[0137] For example, Figure 14 and Figure 17 For example, Figure 17 shows a schematic diagram of the movement irradiation path P provided by some embodiments of the present application, Figure 14 the movement direction M shown in Figure 17 the movement direction M shown in Figure 14 In the case shown in Figure 14 compared with Figure 17 In the case shown in

[0138] In this way, by continuously or intermittently extending the irradiation area, not only can the needs of different continuous movement irradiation processes be flexibly met, but also the cost of laser can be saved and the work efficiency can be improved.

[0139] In some embodiments, the number of times of performing the continuous movement irradiation of the laser on the solar cell substrate is twice.

[0140] In this way, the sintering effect can be improved while reducing the use cost and improving the work efficiency.

[0141] Of course, in other embodiments, the number of times of performing the continuous movement irradiation of the laser on the solar cell substrate can also be three, four or other times, which is not specifically limited here.

[0142] Figure 18A flowchart of step S130 in the method for manufacturing a solar cell according to some embodiments of the present application is shown. For the purpose of illustration, only the content related to the embodiments of the present application is shown.

[0143] In some embodiments, referring to Figure 18 , step S130 comprises the following steps:

[0144] Step S131, providing a laser. The laser is located on one side of the thickness direction of the solar cell substrate, and is arranged opposite to the central region of the solar cell substrate.

[0145] Step S132, controlling the rotation of the laser, so that the moving irradiation area of the laser emitted by the laser can cover at least part of the solar cell substrate, to perform laser-assisted sintering treatment on the first initial electrode, to form the first electrode.

[0146] For example, referring to FIGS. Figure 6 and Figure 8 , the laser Q is located above the solar cell substrate 110 and opposite to the center of the solar cell substrate 110.

[0147] In this way, by controlling the laser in a rotating manner, the error of the irradiation area formed by the continuous moving irradiation process can be reduced, thereby facilitating the improvement of the accuracy of the laser-assisted sintering, and thus facilitating the improvement of the sintering effect.

[0148] The solar cell manufactured by the method for manufacturing a solar cell according to the embodiments of the present application will be described exemplarily below in combination with the above-mentioned embodiments and related comparative examples.

[0149] For example, referring to the structure of the solar cell 100 shown in Figure 19 , the solar cell 100 comprises a solar cell substrate 111, a first electrode E1 and a second electrode E2. The solar cell substrate 111 comprises a substrate 111, a doped layer 112, a first passivation layer 113, a tunneling layer 114, a doped conductive layer 115 and a second passivation layer 116. The doped layer 112, the first passivation layer 113 and the first electrode E1 are sequentially arranged on the first surface m1 side of the substrate 111, and the first electrode E1 and the doped layer 112 are in ohmic contact. The tunneling layer 114, the doped conductive layer 115, the second passivation layer 116 and the second electrode E2 are sequentially arranged on the second surface m2 side of the substrate 111, and the second electrode E2 and the doped conductive layer 115 are in ohmic contact. The substrate 111 is an N-type substrate with a thickness of 0.15 nm. The doped layer 112 is boron-doped monocrystalline silicon with a thickness of 1000 nm. The first passivation layer 113 is SiO2 with a thickness of 80 nm. The tunneling layer 114 is SiO2 with a thickness of 100 nm. The doped conductive layer 115 is boron-doped polycrystalline silicon with a thickness of 200 nm. The second passivation layer 116 is SiO2 with a thickness of 80 nm. The first electrode E1 is aluminum with a thickness of 200 nm. The second electrode E2 is silver with a thickness of 200 nm. x O y N z , thickness of 80 nm; the material of the tunneling layer 114 is Six O y , the material of the doped conductive layer 115 is phosphorus-doped polysilicon, and the thickness is 100 nm; the material of the second passivation layer 116 is Si x N y , the material of the first electrode E1 is Ag, the width is 20 pm, and the number is 150; the material of the second electrode E2 is Ag, the width is 40 pm, and the number is 200.

[0150] In Example 1, after the formation of the first initial electrode in the metallization heat treatment process, the number of times of performing continuous movement irradiation of the laser on the solar cell substrate 110 is controlled to be twice. In the first continuous movement irradiation process, the movement direction M of the laser is arranged to be 90° with the longitudinal extension direction of the first electrode E1, the reverse bias of the laser is 10 V, the power of the laser is 100 W, and the scanning speed of the laser is 20000 mm / s. In the second continuous movement irradiation process, the movement direction M of the laser is arranged to be 90° with the longitudinal extension direction of the first electrode E1, the reverse bias of the laser is 30 V, the power of the laser is 10 W, and the scanning speed of the laser is 200000 mm / s.

[0151] In Example 2, after the formation of the first initial electrode in the metallization heat treatment process, the number of times of performing continuous movement irradiation of the laser on the solar cell substrate 110 is controlled to be twice. In the first continuous movement irradiation process, the movement direction M of the laser is arranged to be 45° with the longitudinal extension direction of the first electrode E1, the reverse bias of the laser is 15 V, the power of the laser is 50 W, and the scanning speed of the laser is 100000 mm / s. In the second continuous movement irradiation process, the movement direction M of the laser is arranged to be 45° with the longitudinal extension direction of the first electrode E1, the reverse bias of the laser is 15 V, the power of the laser is 50 W, and the scanning speed of the laser is 100000 mm / s.

[0152] In Example 3, after the formation of the first initial electrode in the metallization heat treatment process, the number of times of performing continuous movement irradiation of the laser on the solar cell substrate 110 is controlled to be twice. In the first continuous movement irradiation process, the movement direction of the laser is arranged to be 90° with the longitudinal extension direction of the first electrode, the reverse bias of the laser is 30 V, the power of the laser is 10 W, and the scanning speed of the laser is 200000 mm / s. In the second continuous movement irradiation process, the movement direction of the laser is arranged to be 45° with the longitudinal extension direction of the first electrode, the reverse bias of the laser is 15 V, the power of the laser is 10 W, and the scanning speed of the laser is 50000 mm / s.

[0153] In Example 4, after the first initial electrode is formed by the metallization heat treatment process, the laser is controlled to perform the continuous moving irradiation on the solar cell substrate 110 once. The moving direction M of the laser during the continuous moving irradiation is arranged to be 90° to the longitudinal extension direction of the first electrode E1, the reverse bias voltage of the laser is 15V, the power of the laser is 15W, and the scanning speed of the laser is 50000mm / s.

[0154] In Example 5, after the first initial electrode is formed by the metallization heat treatment process, the laser is controlled to perform the continuous moving irradiation on the solar cell substrate 110 twice. The moving direction M of the laser during the first continuous moving irradiation is parallel to the longitudinal extension direction of the first electrode E1, the reverse bias voltage of the laser is 15V, the power of the laser is 15W, and the scanning speed of the laser is 100000mm / s. The moving direction M of the laser during the second continuous moving irradiation is arranged to be 90° to the longitudinal extension direction of the first electrode E1, the reverse bias voltage of the laser is 15V, the power of the laser is 15W, and the scanning speed of the laser is 100000mm / s.

[0155] In Comparative Example 1, after the first initial electrode is formed by the metallization heat treatment process, the laser is controlled to perform the continuous moving irradiation on the solar cell substrate 110 once. The moving direction M of the laser during the continuous moving irradiation is parallel to the longitudinal extension direction of the first electrode E1, the reverse bias voltage of the laser is 15V, the power of the laser is 15W, and the scanning speed of the laser is 100000mm / s. The irradiation region formed by the continuous moving irradiation is arranged based on the first initial electrode region.

[0156] In Comparative Example 2, after the first initial electrode is formed by the metallization heat treatment process, the laser is controlled to perform the continuous moving irradiation on the solar cell substrate 110 twice. The moving direction M of the laser during the first continuous moving irradiation is parallel to the longitudinal extension direction of the first electrode E1, the reverse bias voltage of the laser is 15V, the power of the laser is 15W, and the scanning speed of the laser is 100000mm / s. The moving direction M of the laser during the second continuous moving irradiation is parallel to the longitudinal extension direction of the first electrode E1, the reverse bias voltage of the laser is 15V, the power of the laser is 15W, and the scanning speed of the laser is 100000mm / s. The irradiation region formed by the twice continuous moving irradiation is arranged based on the first initial electrode region.

[0157] The solar cells produced in the above examples and comparative examples are tested for power under the conditions of AM1.5G simulated sunlight and 25 degrees Celsius using a digital source meter device, and the test results are shown in Table 1.

[0158] Table 1

[0159]

[0160] From Table 1, it can be seen that, compared with Comparative Example 1, Example 4 is also irradiated once by laser, the moving direction M of the laser is perpendicular to the longitudinal extension direction of the first electrode E1, and the conversion efficiency of the solar cell in Example 4 is improved by 0.04%. Compared with Comparative Example 1, Examples 1, 2, 3 and 5 are all irradiated twice by laser, and at least once the moving direction M of the laser is not parallel to the longitudinal extension direction of the first electrode E1, so that the conversion efficiency of the solar cell is improved by more than 0.06%. Compared with Comparative Example 2, Examples 1, 2, 3 and 5 are all irradiated twice by laser, and at least once the moving direction M of the laser is not parallel to the longitudinal extension direction of the first electrode E1, so that the conversion efficiency of the solar cell is improved by more than 0.04%. Among them, compared with Comparative Example 2, the laser in Example 4 is irradiated only once, and the conversion efficiency of the solar cell provided in Example 4 is improved by 0.02%. Therefore, the conversion efficiency of the solar cell provided in the embodiments of the present application is improved.

[0161] Based on the same inventive concept, the embodiments of the present application provide a solar cell, which is obtained by the manufacturing method of the solar cell in any of the above embodiments.

[0162] It should be noted that the solar cell can be a TOPCon cell, a BC cell or other types of cells, which are not specifically limited here. Among them, the solar cell can be provided with a main grid electrode, or can not be provided with a main grid electrode, which is not specifically limited here. In the above-mentioned Figure 7 、 Figure 12 、 Figure 13 、 Figure 14 and Figure 17 , the case of being provided with a main grid electrode (not indicated) is illustrated.

[0163] The manufacturing method of the above-mentioned solar cell has the advantages, and the solar cell also has the same advantages, which will not be repeated here.

[0164] The technical features of the above-mentioned embodiments can be combined arbitrarily, and in order to make the description simple, all possible combinations of the technical features in the above-mentioned embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0165] The above embodiments only express several implementation ways of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation to the patent scope of the application. It should be pointed out that for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, which all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A method of fabricating a solar cell, characterized by, The method comprises: providing a solar cell substrate; forming a first initial electrode on the solar cell substrate through a metallization heat treatment process; controlling a laser to perform continuous moving irradiation on the solar cell substrate to perform laser-assisted sintering treatment on the first initial electrode to form a first electrode, thereby obtaining the solar cell; wherein the number of times of performing the continuous moving irradiation of the laser on the solar cell substrate is multiple; the continuous moving irradiation is that the laser moves and irradiates the solar cell substrate in one direction, and in a set of the moving directions of the laser on the solar cell substrate, there are multiple moving directions intersecting with each other; there is a target irradiation process in all the continuous moving irradiation processes, in which the moving direction of the laser on the solar cell substrate and the longitudinal extension direction of the first electrode intersect with each other, and both the moving direction of the laser on the solar cell substrate and the longitudinal extension direction of the first electrode are perpendicular to the thickness direction of the solar cell substrate.

2. The method of producing a solar cell according to claim 1, wherein the moving direction of the laser in the first continuous moving irradiation process is parallel to the longitudinal extension direction of the first electrode; or the first continuous moving irradiation process is the target irradiation process.

3. The method of producing a solar cell according to claim 2, wherein the number of times of performing the continuous moving irradiation of the laser on the solar cell substrate is at least three; all the continuous moving irradiation processes except the first continuous moving irradiation process are the target irradiation processes; and the moving directions of the laser on the solar cell substrate in all the target irradiation processes form a moving direction set; wherein in the moving direction set, there are multiple moving directions with the same direction or multiple moving directions with opposite directions; or in the moving direction set, there are multiple moving directions intersecting with each other.

4. The method of producing a solar cell according to claim 2, wherein the reverse bias of the laser in the first continuous moving irradiation process is greater than that in any continuous moving irradiation process except the first continuous moving irradiation process in all the continuous moving irradiation processes; and / or the power of the laser in the first continuous moving irradiation process is greater than that in any continuous moving irradiation process except the first continuous moving irradiation process in all the continuous moving irradiation processes; and / or in the continuous moving irradiation process except the first continuous moving irradiation process in all the continuous moving irradiation processes, the laser used is configured as a red laser.

5. The method of producing a solar cell according to claim 2, wherein the irradiation area formed by each continuous moving irradiation process is the same area.

6. The method of producing a solar cell according to claim 2, wherein there are different irradiation areas in the irradiation areas formed by all the continuous moving irradiation processes.

7. The method of producing a solar cell according to claim 6, wherein there is a second target area in all the irradiation areas; the second target area is determined based on a corresponding area of one side surface of the solar cell substrate on which the first initial electrode is located; the corresponding area includes at least one of a sintering poor area of the first initial electrode and an edge area of the solar cell substrate.

8. The method of producing a solar cell according to claim 7, wherein the order of all the irradiation areas formed by the execution order of all the continuous moving irradiation processes is a preset order; The sorting sequence number corresponding to the second target region is a middle sequence number; or The sorting sequence number corresponding to the second target region is a first sequence number; or The sorting sequence number corresponding to the second target region is a last sequence number.

9. The method of producing a solar cell according to any one of claims 1 to 8, wherein The angle between the moving direction of the laser in the target irradiation process and the longitudinal extension direction of the first electrode is 45° to 135°; and / or The reverse bias of the laser is 10V to 30V, the power of the laser is 10W to 100W, and the scanning speed of the laser is 20000mm / s to 200000mm / s; and / or The same irradiation region formed by the same continuous moving irradiation process is continuously or discontinuously arranged; and / or The number of times of controlling the laser to perform continuous moving irradiation on the solar cell substrate is twice.

10. The method of producing a solar cell according to any one of claims 1 to 8, wherein The control of the laser to perform moving irradiation on the solar cell substrate to perform laser-assisted sintering treatment on the first initial electrode to form a first electrode to obtain the solar cell comprises: providing a laser; the laser is located on one side of the thickness direction of the solar cell substrate, and is arranged opposite to the central region of the solar cell substrate; controlling the laser to rotate, so that the moving irradiation region of the laser emitted by the laser can cover at least part of the solar cell substrate, so as to perform laser-assisted sintering treatment on the first initial electrode to form the first electrode.

Images