Solar cell and preparation method thereof, conductive device and laser-assisted sintering equipment

Abstract

The present application relates to a solar cell and a preparation method thereof, a conductive device and a laser-assisted sintering device. The preparation method of the solar cell includes forming a grid line pattern on a battery body, wherein the grid line pattern includes N secondary grid lines arranged in parallel and spaced apart; applying a bias voltage to the N secondary grid lines, wherein the bias voltage on each secondary grid line is positively correlated with its conductive resistance; and performing a laser-assisted sintering process on the N secondary grid lines. In this way, the Joule heat generated by the local current flowing through each secondary grid line is conducive to the sintering of the secondary grid line, so that the N secondary grid lines can form good contact with the semiconductor layer of the battery body, thereby improving the conversion efficiency of the solar cell.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic technology, and in particular to solar cells and preparation methods thereof, conductive devices and laser-assisted sintering equipment. Background Art

[0002] The contact resistance between the surface electrode and the back electrode of a solar cell has a great influence on the conversion efficiency of the cell. The lower the metal-semiconductor contact resistance, the higher the conversion efficiency. At present, the main way to reduce the metal-semiconductor contact resistance is the Laser Enhanced Contact Optimization (LECO) process, also known as the laser-assisted sintering process, which uses high-intensity laser irradiation of photovoltaic cells to excite charge carriers and applies a deflection voltage to the photovoltaic cells to separate the carriers, forming a local current and inducing sintering to reduce the contact resistance between the metal and the semiconductor.

[0003] However, in the related art, when the LECO process is performed on solar cells, the problem of over-burning and under-burning of the gate lines is prone to occur, resulting in large differences in the contact effect between the gate lines and the semiconductor layer in different areas of the solar cell, which greatly limits the improvement of the conversion efficiency of the solar cell by the LECO process. Summary of the invention

[0004] Based on this, the present application provides a solar cell and a preparation method thereof, a conductive device and a laser-assisted sintering device, so that multiple secondary grid lines of the solar cell can form good contact with the semiconductor layer, thereby improving the conversion efficiency of the solar cell.

[0005] An embodiment of the first aspect of the present application provides a method for preparing a solar cell, comprising:

[0006] Forming a grid line pattern on the battery body, wherein the grid line pattern includes N auxiliary grid lines arranged in parallel and at intervals;

[0007] Applying a bias voltage to the N auxiliary grid lines, wherein the bias voltage on each auxiliary grid line is positively correlated with its conductive resistance;

[0008] The N secondary grid lines are subjected to laser-assisted sintering.

[0009] The method for preparing a solar cell provided in an embodiment of the present application applies a bias voltage to N auxiliary grid lines, and makes the bias voltage on each auxiliary grid line positively correlated with its conductive resistance, and performs laser-assisted sintering on the N auxiliary grid lines. That is, a corresponding bias voltage is applied to each auxiliary grid line according to its conductive resistance, so that the Joule heat generated by the local current flowing through each auxiliary grid line is beneficial to the sintering of the auxiliary grid line, so that the N auxiliary grid lines can form good contact with the semiconductor layer of the battery body, thereby improving the conversion efficiency of the solar cell.

[0010] In one embodiment, the step of applying a bias voltage to the N auxiliary gate lines comprises:

[0011] The N auxiliary grid lines are equally divided into M grid line groups along a first direction, and the conductive resistances of all the auxiliary grid lines in each grid line group fall within the same first preset range; the difference between the average conductive resistances of two adjacent grid line groups falls within a second preset range; wherein the average conductive resistance of the grid line group is the average value of the conductive resistances of all the auxiliary grid lines in the grid line group; the first direction is perpendicular to the thickness direction of the battery body, and the first direction is perpendicular to the extension direction of the auxiliary grid lines;

[0012] A bias voltage is applied to the M gate line groups, and the bias voltage on each gate line group is positively correlated with the average conductive resistance of the gate line group.

[0013] In one embodiment, the step of applying a bias voltage to the N auxiliary gate lines comprises:

[0014] The N auxiliary grid lines are equally divided into M grid line groups along the first direction, the line widths of all the auxiliary grid lines in each grid line group fall within the same third preset range; the difference in average line widths of two adjacent grid line groups falls within a fourth preset range; the average line width of the grid line group is the average value of the line widths of all the auxiliary grid lines in the grid line group; the first direction is perpendicular to the thickness direction of the battery body, and the first direction is perpendicular to the extension direction of the auxiliary grid lines;

[0015] A bias voltage is applied to M gate line groups, wherein the bias voltage on each gate line group is positively correlated with an average conductive resistance of the gate line group and negatively correlated with an average line width of the gate line group; and the average conductive resistance of the gate line group is an average value of the conductive resistances of all the auxiliary gate lines in the gate line group.

[0016] In one embodiment, the step of performing laser-assisted sintering on the N secondary grid lines comprises:

[0017] The N auxiliary grid lines are irradiated with laser to sinter the N auxiliary grid lines.

[0018] In one embodiment, the power of the laser is between 9W and 15W.

[0019] The second aspect of the present application provides a solar cell, which is prepared by the preparation method described in any of the above embodiments, so as to improve the conversion efficiency of the solar cell.

[0020] The third aspect of the present application provides a conductive device, which is applied to a solar cell, including:

[0021] Mounting parts;

[0022] A probe assembly, comprising a plurality of probes arranged at intervals along a first preset direction and penetrating the mounting member, the probes being used to be electrically connected to the secondary grid lines of the solar cell;

[0023] A plurality of conductive modules are arranged at intervals on the mounting member; the plurality of conductive modules are connected to the plurality of probes in a one-to-one correspondence, and the conductive modules are used to control the bias voltage loaded to the corresponding probes.

[0024] The conductive device provided in the embodiment of the present application is provided with a mounting piece, a probe assembly and a plurality of conductive modules, so that the probe assembly includes a plurality of probes arranged at intervals along a first preset direction and penetrated on the mounting piece, and the plurality of conductive modules are connected to the plurality of probes in a one-to-one correspondence. In this way, when the solar cell is subjected to laser-assisted sintering, the first preset direction can be perpendicular to the thickness direction of the solar cell, and the first preset direction can be perpendicular to the extension direction of the secondary grid line, that is, the first preset direction is parallel to the first direction or the first preset direction coincides with the first direction. In this way, it is convenient to electrically connect the plurality of probes to the plurality of secondary grid lines of the solar cell. According to the conductive resistance of the secondary grid line, the bias voltage loaded to the corresponding probe is controlled by the conductive module, so that the bias voltage on each secondary grid line is positively correlated with its conductive resistance, so that the Joule heat generated by the local current flowing through each secondary grid line is beneficial to the sintering of the secondary grid line, and further, the plurality of secondary grid lines on the solar cell can form good contact with the semiconductor layer of the solar cell, thereby improving the conversion efficiency of the solar cell.

[0025] In one embodiment, the conductive module includes a conductive member and a voltage control module, the conductive member is connected to the corresponding probe; the voltage control module is electrically connected to the conductive member, and the voltage control module is used to control the bias voltage loaded to the corresponding probe.

[0026] In one embodiment, the conductive member includes a conductive block, the conductive block is disposed in the mounting member, a mounting hole is provided on the conductive block, and the probe is passed through the mounting hole;

[0027] The voltage control module includes a voltage controller, which is arranged on a mounting member and connected to the conductive block.

[0028] In one embodiment, the probe includes a conductive connector and a contact member, wherein the conductive connector is passed through the mounting member, and the contact member extends along a first preset direction and is connected to one end of the conductive connector; the contact member is used to contact the secondary grid line or the main grid line of the solar cell.

[0029] In one embodiment, the plurality of probes are arranged in rows along a first preset direction, and arranged in columns along a second preset direction intersecting the first preset direction; and two adjacent abutment members along the second preset direction are staggered along the first preset direction.

[0030] In one embodiment, the dimension of the abutment member along the first preset direction is L;

[0031] Of the two abutting members that are adjacent along the second preset direction and staggered along the first preset direction, the distance between the geometric center of one and the geometric center of the other in the first preset direction is S; 1 / 2L≤S<L.

[0032] In one embodiment, the plurality of probes are arranged at intervals along a first preset direction, and a distance between two adjacent abutment members is smaller than the first preset distance.

[0033] In one embodiment, the first preset distance is 0.2 mm-2 mm.

[0034] In one embodiment, the dimension of the abutment member along the first preset direction is L, 10 mm ≤ L ≤ 26.25 mm.

[0035] In one embodiment, the conductive connecting member includes a plurality of conductive rods, which are distributed in parallel and spaced apart and penetrate the mounting member, and the plurality of conductive rods are connected to the abutting member.

[0036] The embodiment of the fourth aspect of the present application provides a laser-assisted sintering device for performing laser-assisted sintering processing on a solar cell, comprising:

[0037] The conductive device described in any of the above embodiments;

[0038] A conductive support device is used to support the solar cell; and the conductive support device is also used to be electrically connected to the solar cell.

[0039] The laser assisted sintering equipment provided by the embodiment of the present application includes the conductive device and the conductive support device in any of the above embodiments, the conductive device includes a mounting part, a probe assembly and a plurality of conductive modules, the probe assembly includes a plurality of probes arranged at intervals along a first preset direction and penetrated on the mounting part, and the plurality of conductive modules are connected to the plurality of probes one by one. In this way, when the solar cell is subjected to laser assisted sintering, the conductive support device carries the solar cell and is electrically connected to the solar cell, and the plurality of probes are electrically connected to the plurality of secondary grid lines of the solar cell, so as to apply a bias voltage to the solar cell, and the conductive module can control the bias voltage loaded to the corresponding probe according to the conductive resistance of the secondary grid line, so that the bias voltage on each secondary grid line is positively correlated with its conductive resistance, so that the Joule heat generated by the local current flowing through each secondary grid line is conducive to the sintering of the secondary grid line, and then the plurality of secondary grid lines on the solar cell can form good contact with the semiconductor layer of the solar cell, thereby improving the conversion efficiency of the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The present invention is a flow chart of a method for preparing a solar cell provided in one embodiment of the present application.

[0041] Figure 2 This is a schematic diagram of the structure of a conductive device provided in one embodiment of the present application.

[0042] Figure 3 This is a schematic structural diagram of a conductive device provided in one embodiment of the present application from another viewing angle.

[0043] Figure 4 A schematic diagram of the distribution of multiple abutment members in a conductive device provided in an embodiment of the present application.

[0044] Figure 5 Another schematic diagram of the distribution of multiple abutment members in a conductive device provided in an embodiment of the present application.

[0045] Figure 6 This is a schematic diagram of the partial structure of a laser-assisted sintering device provided in one embodiment of the present application.

[0046] Description of reference numerals:

[0047] 10. Conductive device; 11. Mounting piece; 12. Probe assembly; 121. Probe; 1211. Conductive connector; 1211a. Conductive rod; 1212. Abutment piece; 13. Conductive module; 20. Conductive support device; 30. Solar cell; 31. Main grid line; 32. Sub grid line; X, first preset direction; Y, second preset direction. DETAILED DESCRIPTION

[0048] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application 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 application. However, the present application 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 application, so the present application is not limited by the specific embodiments disclosed below.

[0049] In the description of the present application, it should be understood that if 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", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0050] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0051] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated 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 this application can be understood according to the specific circumstances.

[0052] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the 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. The first feature being "below", "below" and "below" the 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.

[0053] It should be noted that if 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. If 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. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0054] The contact resistance between the surface electrode and the back electrode of a solar cell has a great influence on the conversion efficiency of the cell. The lower the metal-semiconductor contact resistance, the higher the conversion efficiency. At present, the main way to reduce the metal-semiconductor contact resistance is the Laser Enhanced Contact Optimization (LECO) process, also known as the laser-assisted sintering process, which uses high-intensity laser irradiation of photovoltaic cells to excite charge carriers and applies a deflection voltage to the photovoltaic cells to separate the carriers, forming a local current and inducing sintering to reduce the contact resistance between the metal and the semiconductor.

[0055] However, in the related art, when the LECO process is performed on solar cells, the problem of over-burning and under-burning of the gate lines is prone to occur, resulting in large differences in the contact effect between the gate lines and the semiconductor layer in different areas of the solar cell, which greatly limits the improvement of the conversion efficiency of the solar cell by the LECO process.

[0056] Based on the above technical problems, the present application provides a solar cell and its preparation method, a conductive device and laser-assisted sintering equipment, so that multiple secondary grid lines of the solar cell can form good contact with the semiconductor layer, thereby improving the conversion efficiency of the solar cell.

[0057] See also Figure 1 In a first aspect, an embodiment of the present application provides a method for preparing a solar cell, comprising:

[0058] S10, forming a grid line pattern on the battery body, the grid line pattern comprising N auxiliary grid lines arranged in parallel and at intervals;

[0059] S20, applying a bias voltage to the N auxiliary gate lines, wherein the bias voltage on each auxiliary gate line is positively correlated with its conductive resistance;

[0060] Specifically, the conductive resistance of the secondary grid line can be obtained through multiple experiments.

[0061] S30, performing laser-assisted sintering processing on the N secondary grid lines.

[0062] The method for preparing a solar cell provided in an embodiment of the present application applies a bias voltage to N auxiliary grid lines, and makes the bias voltage on each auxiliary grid line positively correlated with its conductive resistance, and performs laser-assisted sintering on the N auxiliary grid lines. That is, a corresponding bias voltage is applied to each auxiliary grid line according to its conductive resistance, so that the Joule heat generated by the local current flowing through each auxiliary grid line is beneficial to the sintering of the auxiliary grid line, so that the N auxiliary grid lines can form good contact with the semiconductor layer of the battery body, thereby improving the conversion efficiency of the solar cell.

[0063] It is understandable that the solar cell may be a TOPCon cell (Tunneling Layer Passivation Contact Cell). Of course, the solar cell is not limited to being a TOPCon cell, but may also be a BC cell (Back Contact).

[0064] Taking the TOPCon cell as an example, the cell body of the solar cell includes a substrate, a tunneling layer, a doped polysilicon layer, a first functional layer, an emitter and a second functional layer. The tunneling layer is arranged on the first side of the substrate. The doped polysilicon layer is arranged on the tunneling layer, and the first functional layer is arranged on the doped polysilicon layer. The emitter is arranged on the second side of the substrate. The second functional layer is arranged on the emitter. The first functional layer and the second functional layer may be, but are not limited to, a passivation layer, an anti-reflection layer, etc. The material of the passivation layer may be, but are not limited to, one or more of the aluminum oxide film layer. The material of the anti-reflection layer may be, but are not limited to, one or more of the silicon nitride film layer. A gate line slurry is arranged on the first functional layer and the second functional layer to form a gate line pattern on the cell body. By adopting the above-mentioned preparation method, a plurality of auxiliary gate lines pass through the first functional layer to form good contact with the doped polysilicon layer, and a plurality of auxiliary gate lines pass through the second functional layer to form good contact with the emitter, thereby improving the conversion efficiency of the TOPCon cell.

[0065] In one embodiment, in S20, applying a bias voltage to the N auxiliary gate lines specifically includes:

[0066] N secondary grid lines are equally divided into M grid line groups along a first direction, and the conductive resistances of all the secondary grid lines in each grid line group fall within the same first preset range; the difference in average conductive resistances of two adjacent grid line groups falls within a second preset range; wherein the average conductive resistance of the grid line group is the average value of the conductive resistances of all the secondary grid lines in the grid line group; the first direction is perpendicular to the thickness direction of the battery body, and the first direction is perpendicular to the extension direction of the secondary grid lines;

[0067] A bias voltage is applied to the M gate line groups, and the bias voltage on each gate line group is positively correlated with the average conductive resistance of the gate line group.

[0068] In the above process, N auxiliary grid lines are equally divided into M grid line groups along a first direction according to the conductive resistance of the auxiliary grid lines, the conductive resistance of all auxiliary grid lines in each grid line group falls within the same first preset range, and the difference in average conductive resistance of two adjacent grid line groups falls within a second preset range. By applying a bias voltage to the M grid line groups, the bias voltage on each grid line group is positively correlated with the average conductive resistance of the grid line group, so that the bias voltage loaded on each auxiliary grid line is positively correlated with the conductive resistance, so that the Joule heat generated by the local current flowing through each auxiliary grid line is beneficial to the sintering of the auxiliary grid line, so that the N auxiliary grid lines can form good contact with the semiconductor layer of the battery body, thereby improving the conversion efficiency of the solar cell. In addition, by dividing the N auxiliary grid lines into M grid line groups and applying bias voltage to the M grid line groups, the number of bias voltage parameters that need to be adjusted can be reduced, and the difficulty of bias voltage adjustment can be reduced. It can be convenient to achieve a positive correlation between the bias voltage and the conductive resistance on each auxiliary grid line, thereby making it convenient to achieve good contact between the N auxiliary grid lines and the semiconductor layer of the battery body, which is beneficial to improving the conversion efficiency of the solar cell.

[0069] In one embodiment, in S20, applying a bias voltage to the N auxiliary gate lines specifically includes:

[0070] N secondary grid lines are equally divided into M grid line groups along a first direction, and the line widths of all the secondary grid lines in each grid line group fall within the same third preset range; the difference in average line widths of two adjacent grid line groups falls within a fourth preset range; the average line width of a grid line group is the average value of the line widths of all the secondary grid lines in the grid line group; the first direction is perpendicular to the thickness direction of the battery body, and the first direction is perpendicular to the extension direction of the secondary grid lines;

[0071] A bias voltage is applied to M gate line groups, the bias voltage on each gate line group is positively correlated with the average conductive resistance of the gate line group and negatively correlated with the average line width of the gate line group; the average conductive resistance of the gate line group is the average conductive resistance of all auxiliary gate lines in the gate line group.

[0072] In the above process, N secondary grid lines are equally divided into M grid line groups along the first direction according to the line width of the secondary grid lines, the line widths of all secondary grid lines in each grid line group fall within the same third preset range, and the difference in average line widths of two adjacent grid line groups falls within a fourth preset range. By applying a bias voltage to the M grid line groups, the bias voltage on each grid line group is positively correlated with the average conductive resistance of the grid line group and negatively correlated with the average line width of the grid line group, so that the bias voltage loaded on each secondary grid line is positively correlated with the conductive resistance, so that the Joule heat generated by the local current flowing through each secondary grid line is beneficial to the sintering of the secondary grid line, so that the N secondary grid lines can form good contact with the semiconductor layer of the battery body, thereby improving the conversion efficiency of the solar cell. In addition, the line width of the auxiliary grid line is easy to measure. According to the line width of the auxiliary grid line, N auxiliary grid lines can be conveniently divided into M grid line groups. Applying bias voltage to the M grid line groups can reduce the number of bias voltage parameters that need to be adjusted, reduce the difficulty of bias voltage adjustment, and conveniently achieve a positive correlation between the bias voltage and the conductive resistance on each auxiliary grid line, thereby conveniently achieving good contact between the N auxiliary grid lines and the semiconductor layer of the battery body, which is beneficial to improving the conversion efficiency of the solar cell.

[0073] In one embodiment, in S30, laser-assisted sintering is performed on the N secondary gate lines, specifically including:

[0074] The N auxiliary grid lines are irradiated with laser to sinter the N auxiliary grid lines.

[0075] In the above process, laser is used to irradiate N auxiliary grid lines. The laser can heat the area where the auxiliary grid lines are located to excite charge carriers. Under the action of bias voltage, local current will be generated. The local current flows through the auxiliary grid lines to generate Joule heat, so that the auxiliary grid lines are sintered, so that the auxiliary grid lines form good contact with the semiconductor layer of the battery body of the solar cell, reducing the contact resistance, which is beneficial to improving the conversion efficiency of the solar cell.

[0076] In one embodiment, the power of the laser is between 9W and 15W. Specifically, the power of the laser can be 9W, 10W, 11W, 12W, 13W, 14W, 15W or any value between 9W and 15W without any special limitation.

[0077] In a second aspect, an embodiment of the present application provides a solar cell, which is prepared by the preparation method described in any of the above embodiments, so as to improve the conversion efficiency of the solar cell.

[0078] Thirdly, see Figures 2 to 4The embodiment of the present application provides a conductive device 10, which is applied to a solar cell 30, including a mounting member 11, a probe assembly 12 and a plurality of conductive modules 13; the probe assembly 12 includes a plurality of probes 121 arranged at intervals along a first preset direction X and passing through the mounting member 11, and the probes 121 are used to be electrically connected to the secondary grid lines 32 of the solar cell 30; the plurality of conductive modules 13 are arranged at intervals on the mounting member 11; the plurality of conductive modules 13 are connected to the plurality of probes 121 in a one-to-one correspondence, and the conductive modules 13 are used to control the bias voltage loaded to the corresponding probes 121.

[0079] The conductive device 10 provided in the embodiment of the present application is provided with a mounting member 11, a probe assembly 12 and a plurality of conductive modules 13, so that the probe assembly 12 includes a plurality of probes 121 arranged at intervals along a first preset direction X and penetrated on the mounting member 11, and the plurality of conductive modules 13 are connected to the plurality of probes 121 in a one-to-one correspondence. In this way, when the solar cell 30 is subjected to laser-assisted sintering treatment, the first preset direction X can be made perpendicular to the thickness direction of the solar cell 30, and the first preset direction X can be made perpendicular to the extension direction of the secondary grid line 32, that is, the first preset direction X can be parallel to the first direction or the first preset direction X can coincide with the first direction. In this way, the plurality of probes 12 The probes 121 are arranged along the N secondary grid lines 32 on the solar cell 30 in a spaced-apart direction, so that the multiple probes 121 can be conveniently electrically connected to the N secondary grid lines 32 of the solar cell 30. According to the conductive resistance of the secondary grid lines 32, the bias voltage loaded to the corresponding probes 121 is controlled by the conductive module 13, so that the bias voltage on each secondary grid line 32 is positively correlated with its conductive resistance, so that the Joule heat generated by the local current flowing through each secondary grid line 32 is conducive to the sintering of the secondary grid line 32, and then the N secondary grid lines 32 on the solar cell 30 can form good contact with the semiconductor layer of the solar cell 30, so as to improve the conversion efficiency of the solar cell 30.

[0080] It should be noted that the probe 121 is used to electrically connect to the auxiliary grid line 32 of the solar cell 30. It can be understood that the probe 121 can be directly electrically connected to the auxiliary grid line 32 of the solar cell 30, for example, the probe 121 is directly in contact and electrically connected to the auxiliary grid line 32 of the solar cell 30; the probe 121 can also be indirectly electrically connected to the auxiliary grid line 32 of the solar cell 30, for example, the probe 121 is directly in contact and electrically connected to the main grid line 31 overlapped with the auxiliary grid line 32, thereby being indirectly electrically connected to the auxiliary grid line 32.

[0081] In one embodiment, the conductive module 13 includes a conductive member (not shown in the figure) and a voltage control module (not shown in the figure), the conductive member is connected to the corresponding probe 121; the voltage control module is electrically connected to the conductive member, and the voltage control module is used to control the bias voltage loaded to the corresponding probe 121.

[0082] In this way, by providing the conductive member and the voltage control module, the connection between the conductive module 13 and the probe 121 can be facilitated, and the conductive module 13 can control the bias voltage loaded to the corresponding probe 121 conveniently.

[0083] In one embodiment, the conductive part includes a conductive block (not shown in the figure), which is arranged in the mounting part 11, and a mounting hole is provided on the conductive block, and the probe 121 is passed through the mounting hole; the voltage control module includes a voltage controller (not shown in the figure), which is arranged on the mounting part 11 and connected to the conductive block.

[0084] In this way, by setting a conductive block and a voltage controller, the conductive block is set in the mounting member 11, and a mounting hole for the probe 121 to pass through is set on the conductive block. The probe 121 can be conveniently installed on the mounting member 11, and the bias voltage loaded on the probe 121 can be conveniently controlled by the voltage controller.

[0085] See also Figure 2 and Figure 3 In one embodiment, the probe 121 includes a conductive connector 1211 and a contact member 1212. The conductive connector 1211 is passed through the mounting member 11. The contact member 1212 extends along the first preset direction X and is connected to one end of the conductive connector 1211. The contact member 1212 is used to contact the secondary grid line 32 or the main grid line 31 of the solar cell 30.

[0086] In this way, by setting the conductive connecting member 1211 and the abutment member 1212, the conductive connecting member 1211 is passed through the mounting member 11, and the probe 121 can be conveniently passed through the mounting member 11; the abutment member 1212 extends along the first preset direction X and is connected to one end of the conductive connecting member 1211, and the abutment member 1212 is used to abut against the auxiliary grid line 32 or the main grid line 31 of the solar cell 30, so that the electrical connection between the probe 121 and the auxiliary grid line 32 can be facilitated so as to apply a bias voltage to the auxiliary grid line 32.

[0087] It can be understood that the abutment 1212 is used to abut against the auxiliary grid line 32 or the main grid line 31 of the solar cell 30, that is, the abutment 1212 can directly abut against the auxiliary grid line 32 of the solar cell 30, and the probe 121 is directly electrically connected to the auxiliary grid line 32 of the solar cell 30; the abutment 1212 can also abut against the main grid line 31 of the solar cell 30, and the abutment 1212 is electrically connected to the auxiliary grid line 32 through the main grid line 31, that is, the probe 121 can be electrically connected to the auxiliary grid line 32 through the main grid line 31.

[0088] See also Figure 4In one embodiment, a plurality of probes 121 are arranged in rows along a first preset direction X, and arranged in columns along a second preset direction Y intersecting the first preset direction X; two adjacent abutment members 1212 along the second preset direction Y are arranged in an alternating manner along the first preset direction X.

[0089] When the solar cell 30 is subjected to laser assisted sintering, the N auxiliary grid lines 32 on the solar cell 30 can be equally divided into M grid line groups according to the conductive resistance or line width of the auxiliary grid lines 32, so that the first preset direction X is parallel to the direction in which the N auxiliary grid lines 32 are arranged at intervals, and the second preset direction Y is parallel to the extension direction of the auxiliary grid lines 32. In this way, the plurality of probes 121 can be arranged in rows along the direction in which the N auxiliary grid lines 32 on the solar cell 30 are arranged at intervals, and in columns along the extension direction of the N auxiliary grid lines 32 on the solar cell 30, and the plurality of probes 121 correspond to the M grid line groups one by one; and since two adjacent abutment members 1212 along the second preset direction Y are arranged along the first preset direction X, The staggered arrangement allows the contact member 1212 of each probe 121 to abut against all the auxiliary grid lines 32 in a grid line group, that is, each probe 121 can be electrically connected to all the auxiliary grid lines 32 in a grid line group, and the bias voltage loaded to the corresponding probe 121 is controlled by the conductive module 13 to be positively correlated with the average conductive resistance of the grid line group, so that the bias voltage loaded on each auxiliary grid line 32 is positively correlated with its conductive resistance, so that the Joule heat generated by the local current flowing through each auxiliary grid line 32 is conducive to the sintering of the auxiliary grid line 32, and then the N auxiliary grid lines 32 are all in good contact with the semiconductor layer of the solar cell 30, thereby improving the conversion efficiency of the solar cell 30. In addition, when the solar cell 30 is a solar cell 30 without a main grid, it can be ensured that the N auxiliary grid lines 32 on the solar cell 30 without a main grid are all in good contact with the semiconductor layer of the solar cell 30, avoiding the problem of stripe EL poor appearance of the solar cell 30 without a main grid.

[0090] See also Figure 4 In one embodiment, the dimension of the abutment member 1212 along the first preset direction X is L; among two abutment members 1212 adjacent to each other along the second preset direction Y and staggered along the first preset direction X, the distance between the geometric center of one and the geometric center of the other in the first preset direction X is S; 1 / 2L≤S<L.

[0091] In this way, it can be ensured that the abutment piece 1212 of each probe 121 abuts against all the auxiliary grid lines 32 in a grid line group, and each probe 121 can be electrically connected to all the auxiliary grid lines 32 in a grid line group, so that the N auxiliary grid lines 32 on the solar cell 30 can form good contact with the semiconductor layer of the solar cell 30, thereby improving the conversion efficiency of the solar cell 30. In addition, the problem of striped EL poor occurrence in the solar cell 30 without a main grid can be avoided.

[0092] In one embodiment, the abutment member 1212 is constructed as a rod-shaped structure, and the cross-section of the abutment member 1212 is rectangular, triangular or circular.

[0093] See also Figure 5 In one embodiment, the plurality of probes 121 are arranged at intervals along the first preset direction X, and the distance between two adjacent abutting members 1212 is smaller than the first preset distance.

[0094] In this way, the first preset spacing can correspond to the spacing between two adjacent secondary grid lines 32, that is, the spacing between two adjacent abutting members 1212 is smaller than the spacing between two adjacent secondary grid lines 32, so that the abutting member 1212 of each probe 121 can be guaranteed to abut against all the secondary grid lines 32 in a grid line group, and each probe 121 can be electrically connected to all the secondary grid lines 32 in a grid line group, so that the N secondary grid lines 32 on the solar cell 30 can form good contact with the semiconductor layer of the solar cell 30, thereby improving the conversion efficiency of the solar cell 30. In addition, the problem of poor stripe EL in the solar cell 30 without a main grid can be avoided.

[0095] In one embodiment, the first preset spacing is 0.2 mm-2 mm. Specifically, the first preset spacing can be 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm or any value between 0.2 mm and 2 mm, without limitation.

[0096] In one embodiment, a dimension of the abutting member 1212 along the first predetermined direction X is L, and 10 mm≤L≤26.25 mm.

[0097] Specifically, the spacing between adjacent secondary grid lines 32 is usually 0.2 mm to 2 mm, and the number of fine grids is from dozens to hundreds. In this embodiment, by making the dimension L of the abutment member 1212 along the first preset direction X be 10 mm to 26.25 mm, one abutment member 1212 can abut against several or even dozens of secondary grid lines 32, so that the number of abutment members 1212 and conductive connectors 1211 can be reduced, thereby reducing the cost of the conductive device 10.

[0098] In a specific example, L may be 10 mm to 15 mm, 15 mm to 20 mm, or 20 mm to 26.25 mm.

[0099] In a specific example, L can be 10 mm, 12 mm, 14 mm, 16 mm, 18 mm, 20 mm, 22 mm, 24 mm or 26 mm.

[0100] In one embodiment, the distance K between two adjacent abutting members 1212 along the second preset direction Y is 1.2 mm to 20 mm.

[0101] In a specific example, K may be 1.2 mm to 5 mm, 5 mm to 10 mm, 10 mm to 15 mm, or 15 mm to 20 mm.

[0102] In a specific example, K can be 1.2mm, 2mm, 4mm, 5mm, 7mm, 9mm, 10mm, 12mm, 14mm, 15mm, 17mm, 19mm, or 20mm.

[0103] See also Figure 3 In one embodiment, the conductive connecting member 1211 includes a plurality of conductive rods 1211 a , which are distributed in parallel and spaced apart and penetrate the mounting member 11 , and the plurality of conductive rods 1211 a are connected to the abutting member 1212 .

[0104] Thus, when the abutment member 1212 abuts against the auxiliary grid line 32 or the main grid line 31, the plurality of conductive rods 1211a can apply downward pressure to the abutment member 121213 from a plurality of positions to prevent the abutment member 1212 from tilting during the abutment process, so that the abutment member 1212 is in full contact with the top surface of the auxiliary grid line 32 or the main grid line 31, so that the N auxiliary grid lines 32 on the solar cell 30 can all form good contact with the semiconductor layer of the solar cell 30, thereby improving the conversion efficiency of the solar cell 30. In addition, the problem of poor stripe EL in the solar cell 30 without a main grid can be avoided.

[0105] See also Figure 3 In a specific example, a plurality of conductive rods 1211 are distributed at intervals along a first preset direction X.

[0106] See also Figure 6 In the fourth aspect, an embodiment of the present application provides a laser-assisted sintering device for laser-assisted sintering processing of a solar cell 30. The laser-assisted sintering device includes a conductive device 10 and a conductive support device 20 in any of the above embodiments. The conductive support device 20 is used to support the solar cell 30; and the conductive support device 20 is also used to be electrically connected to the solar cell 30.

[0107] It is understandable that the laser-assisted sintering equipment further includes a laser source, which is disposed above the conductive support device 20 , and is used to irradiate the secondary grid lines 32 of the solar cell 30 .

[0108] The laser-assisted sintering equipment provided in the embodiment of the present application includes the conductive device 10 and the conductive support device 20 in any of the above embodiments, the conductive device 10 includes a mounting part 11, a probe assembly 12 and a plurality of conductive modules 13, the probe assembly 12 includes a plurality of probes 121 arranged at intervals along a first preset direction X and penetrated on the mounting part 11, and the plurality of conductive modules 13 are connected one-to-one with the plurality of probes 121. In this way, when the solar cell 30 is subjected to laser-assisted sintering treatment, the conductive support device 20 carries the solar cell 30 and is electrically connected to the solar cell 30, and multiple probes 121 are electrically connected to the N auxiliary grid lines 32 of the solar cell 30 so as to apply a bias voltage to the solar cell 30. According to the conductive resistance of the auxiliary grid line 32, the conductive module 13 can control the bias voltage loaded to the corresponding probe 121, so that the bias voltage on each auxiliary grid line 32 is positively correlated with its conductive resistance, so that the Joule heat generated by the local current flowing through each auxiliary grid line 32 is beneficial to the sintering of the auxiliary grid line 32, and then the N auxiliary grid lines 32 on the solar cell 30 can form good contact with the semiconductor layer of the solar cell 30, thereby improving the conversion efficiency of the solar cell 30.

[0109] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above 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.

[0110] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A method for preparing a solar cell, characterized in that: include: Forming a grid line pattern on the battery body, wherein the grid line pattern includes N auxiliary grid lines arranged in parallel and at intervals; Directly applying a bias voltage to the N auxiliary grid lines, wherein the bias voltage on each of the auxiliary grid lines is positively correlated with its conductive resistance; The N secondary grid lines are subjected to laser-assisted sintering.

2. The method for preparing a solar cell according to claim 1, characterized in that: The step of applying a bias voltage to the N auxiliary gate lines comprises: The N auxiliary grid lines are equally divided into M grid line groups along a first direction, and the conductive resistances of all the auxiliary grid lines in each grid line group fall within the same first preset range; the difference between the average conductive resistances of two adjacent grid line groups falls within a second preset range; wherein the average conductive resistance of the grid line group is the average value of the conductive resistances of all the auxiliary grid lines in the grid line group; the first direction is perpendicular to the thickness direction of the battery body, and the first direction is perpendicular to the extension direction of the auxiliary grid lines; A bias voltage is applied to the M gate line groups, and the bias voltage on each gate line group is positively correlated with the average conductive resistance of the gate line group.

3. The method for preparing a solar cell according to claim 1, characterized in that: The step of applying a bias voltage to the N auxiliary gate lines comprises: The N auxiliary grid lines are equally divided into M grid line groups along the first direction, the line widths of all the auxiliary grid lines in each grid line group fall within the same third preset range; the difference in average line widths of two adjacent grid line groups falls within a fourth preset range; the average line width of the grid line group is the average value of the line widths of all the auxiliary grid lines in the grid line group; the first direction is perpendicular to the thickness direction of the battery body, and the first direction is perpendicular to the extension direction of the auxiliary grid lines; A bias voltage is applied to M gate line groups, wherein the bias voltage on each gate line group is positively correlated with an average conductive resistance of the gate line group and negatively correlated with an average line width of the gate line group; and the average conductive resistance of the gate line group is an average value of the conductive resistances of all the auxiliary gate lines in the gate line group.

4. The method for preparing a solar cell according to claim 1, characterized in that: The step of performing laser-assisted sintering on the N auxiliary grid lines comprises: The N auxiliary grid lines are irradiated with laser to sinter the N auxiliary grid lines.

5. The method for preparing a solar cell according to claim 4, characterized in that: The power of the laser is between 9W and 15W.

6. A solar cell, characterized in that: It is prepared by the preparation method according to any one of claims 1 to 5.

7. A conductive device used in the method for preparing a solar cell according to any one of claims 1 to 5, applied to a solar cell, characterized in that: include: Mounting parts; A probe assembly, comprising a plurality of probes arranged at intervals along a first preset direction and penetrating the mounting member, the probes being used to be directly electrically connected to the secondary grid lines of the solar cell; A plurality of conductive modules are arranged on the mounting member at intervals; The plurality of conductive modules are connected to the plurality of probes in a one-to-one correspondence, and the conductive modules are used to control the bias voltage loaded to the corresponding probes.

8. The conductive device according to claim 7, characterized in that: The conductive module includes a conductive member and a voltage control module, wherein the conductive member is connected to the corresponding probe; the voltage control module is electrically connected to the conductive member, and the voltage control module is used to control the bias voltage loaded to the corresponding probe.

9. The conductive device according to claim 8, characterized in that: The conductive member comprises a conductive block, the conductive block is arranged in the mounting member, a mounting hole is provided on the conductive block, and the probe is passed through the mounting hole; The voltage control module includes a voltage controller, which is arranged on a mounting member and connected to the conductive block.

10. The conductive device according to claim 7, characterized in that: The probe comprises a conductive connector and an abutment member, wherein the conductive connector is passed through the mounting member, and the abutment member extends along a first preset direction and is connected to one end of the conductive connector; the abutment member is used to abut against the secondary grid line of the solar cell.

11. The conductive device according to claim 10, characterized in that The plurality of probes are arranged in rows along a first preset direction, and in columns along a second preset direction intersecting the first preset direction; and two adjacent abutment members along the second preset direction are staggered along the first preset direction.

12. The conductive device according to claim 11, characterized in that The dimension of the abutment member along the first preset direction is L; Of the two abutting members that are adjacent along the second preset direction and staggered along the first preset direction, the distance between the geometric center of one and the geometric center of the other in the first preset direction is S; 1 / 2L≤S<L.

13. The conductive device according to claim 10, characterized in that The plurality of probes are arranged at intervals along a first preset direction, and a distance between two adjacent abutment members is smaller than the first preset distance.

14. The conductive device according to claim 13, characterized in that The first preset spacing is 0.2 mm-2 mm.

15. The conductive device according to any one of claims 10 to 14, characterized in that: The dimension of the abutment member along the first preset direction is L, 10 mm ≤ L ≤ 26.25 mm.

16. The conductive device according to claim 10, characterized in that The conductive connecting member comprises a plurality of conductive rods, which are distributed in parallel and spaced apart and penetrate the mounting member, and the plurality of conductive rods are connected to the abutting member.

17. A laser-assisted sintering device for performing laser-assisted sintering on solar cells, characterized in that: include: The conductive device according to any one of claims 7 to 16; A conductive support device, used for supporting the solar cell; Furthermore, the conductive support device is also used to be electrically connected to the solar cell.

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