Solar cell laser grooving structure and solar cell

Abstract

The utility model provides a solar cell laser grooving structure and a solar cell, the solar cell laser grooving structure comprises a plurality of laser grooving lines arranged at intervals along a first direction, at least part of the laser grooving lines comprises a plurality of laser grooving sub-line segments, and the laser grooving sub-line segments are arranged at intervals along the first direction. The multiple laser grooving sub-line segments are arranged at intervals in the second direction, the lengths of at least part of the laser grooving sub-line segments in the second direction are different, and the second direction intersects with the first direction. Therefore, while the contact efficiency is ensured, the back damage and recombination are reduced, the aperture ratio is reduced, the damage to the passivation layer is reduced, and the conversion efficiency of the cell is improved.

Description

Technical Field

[0001] The present application relates to the field of solar cells, and in particular to a solar cell laser groove structure and a solar cell. Background Art

[0002] Photovoltaic solar silicon wafers are the core part of solar power generation systems. The function of photovoltaic solar silicon wafers is to convert solar energy into electrical energy, which is sent to batteries for storage or directly used to drive loads. The conversion efficiency of photovoltaic solar silicon wafers directly determines the photoelectric conversion efficiency of the entire solar power generation system. In the preparation process of PERC cells (emitter and back passivation cells), the most critical links are the growth of the back passivation layer and the slotting laser. Passivation with the passivation layer can better reduce the back surface recombination rate of the silicon wafer, so that the minority carrier lifetime of the silicon wafer is maximized. The passivation layer prepared by the current passivation process is not conductive, so it is necessary to laser slot the passivation layer to draw out the current and achieve contact between the silicon wafer substrate and the back aluminum paste. For PERC cells, improving efficiency is the top priority. The current laser slotting pattern has serious back recombination and large damage to the back laser slotting, which will reduce the conversion efficiency of the cell to a certain extent.

[0003] Therefore, the current laser grooving patterns still need to be further improved. Utility Model Content

[0004] The utility model aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] In one aspect of the utility model, a solar cell laser slotting structure is proposed, comprising: a plurality of laser slotting lines arranged at intervals along a first direction, wherein at least some of the laser slotting lines include a plurality of laser slotting sub-line segments, the plurality of laser slotting sub-line segments are arranged at intervals in a second direction, at least some of the laser slotting sub-line segments have different lengths in the second direction, and the second direction intersects with the first direction. Thus, while ensuring contact efficiency, back damage and recombination are reduced, the opening rate is reduced, damage to the passivation layer is reduced, and the conversion efficiency of the battery is improved.

[0006] According to some embodiments of the present invention, each of the laser slotting lines includes a plurality of laser slotting sub-line segments.

[0007] According to some embodiments of the present invention, the laser grooved line includes a plurality of laser grooved areas arranged in sequence along the second direction, the laser grooved sub-line segments in the same laser grooved area have the same length along the second direction, and the laser grooved sub-line segments in different laser grooved areas have different lengths along the second direction.

[0008] According to some embodiments of the present invention, the laser grooved line includes a first laser grooved sub-line segment and a second laser grooved sub-line segment, the length of the first laser grooved sub-line segment in the second direction is less than the length of the second laser grooved sub-line segment in the second direction, and the first laser grooved sub-line segment and the second laser grooved sub-line segment are irregularly arranged in the second direction.

[0009] According to some embodiments of the present invention, the laser grooved line includes a first laser grooved sub-line segment and a second laser grooved sub-line segment, the length of the first laser grooved sub-line segment in the second direction is smaller than the length of the second laser grooved sub-line segment in the second direction, and the first laser grooved sub-line segment and the second laser grooved sub-line segment are arranged in sequence in the second direction.

[0010] According to some embodiments of the present invention, the laser grooved line includes a plurality of laser grooved areas arranged in sequence along the second direction, each of the laser grooved areas includes the first laser grooved sub-line segment and the second laser grooved sub-line segment, a first gap is formed between the first laser grooved sub-line segment and the second laser grooved sub-line segment, and a second gap is formed at one end of the second laser grooved sub-line segment away from the first gap.

[0011] According to some embodiments of the present invention, the length of the first laser-grooved sub-segment along the second direction is a mm, the length of the first gap along the second direction is b mm, the length of the second laser-grooved sub-segment along the second direction is c mm, the length of the second gap along the second direction is d mm, and satisfies: (a+c) / (a+b+c+d)<a / (a+b).

[0012] According to some embodiments of the present invention, 0.2 mm ≤ a ≤ 0.6 mm, 0.8 mm ≤ b ≤ 3.0 mm, 0.4 mm ≤ c ≤ 1.2 mm, and 0.8 mm ≤ d ≤ 3.0 mm.

[0013] According to some embodiments of the present invention, the laser grooved line further includes: a third laser grooved sub-line segment and a fourth laser grooved sub-line segment, the length of the third laser grooved sub-line segment in the second direction is smaller than the length of the first laser grooved sub-line segment in the second direction, and the length of the fourth laser grooved sub-line segment in the second direction is smaller than the length of the second laser grooved sub-line segment in the second direction.

[0014] In another aspect of the present invention, a solar cell is provided, comprising the aforementioned solar cell laser groove structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0016] Figure 1 The laser groove structure of a solar cell according to an embodiment of the utility model is shown.

[0017] Figure 2 The laser groove structure of a solar cell in the related art is shown.

[0018] Figure 3 Shows Figure 1 Schematic diagram of the structure of a laser slotted line in the middle dashed area.

[0019] Figure 4 The laser groove structure of a solar cell according to another embodiment of the present invention is shown.

[0020] Figure 5 Shows Figure 4 Schematic diagram of the structure of a laser slotted line in the middle dashed area.

[0021] Reference numerals:

[0022] 1: solar cell laser groove structure; 11: laser groove line; 111: laser groove sub-segment; 1111: first laser groove sub-segment; 1112: second laser groove sub-segment; 1115: third laser groove sub-segment; 1116: fourth laser groove sub-segment; 1113: first gap; 1114: second gap; A: hollow area. DETAILED DESCRIPTION

[0023] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. If no specific techniques or conditions are specified in the embodiments, the techniques or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be obtained commercially.

[0024] In one aspect of the present invention, a solar cell laser grooving structure 1 is provided, referring to Figure 1 The solar cell laser slotting structure 1 comprises: a plurality of laser slotting lines 11 arranged at intervals along a first direction, wherein at least some of the laser slotting lines 11 comprise a plurality of laser slotting sub-line segments 111, the plurality of laser slotting sub-line segments 111 are arranged at intervals in a second direction, at least some of the laser slotting sub-line segments 111 have different lengths in the second direction, and the second direction intersects the first direction. Specifically, referring to Figure 1The solar cell laser slotting structure 1 includes a uniformly distributed hollow area A and a laser slotting area. A plurality of laser slotting lines 11 are arranged at intervals along the length direction or width direction of the solar cell, and a plurality of laser slotting lines 11 are arranged in parallel. At least some of the laser slotting lines 11 include a plurality of laser slotting sub-line segments 111 arranged at intervals. The laser slotting sub-line segments 111 extend along a second direction, and the second direction is perpendicular to the first direction. At least some of the laser slotting sub-line segments 111 have different lengths. Thus, while ensuring the contact efficiency, the back damage and recombination are reduced, the opening rate is reduced, the damage to the passivation layer is reduced, and the conversion efficiency of the battery is improved.

[0025] The principle by which the utility model can achieve the above beneficial effects is described in detail below:

[0026] There are two main types of laser slotting structures 1 for solar cells in the related art: the first type is that a plurality of laser slotting lines 11 are arranged parallel and spaced apart along a first direction, and each laser slotting line 11 is in the shape of a straight line (refer to Figure 2 ); the second is that multiple laser grooved lines 11 are arranged in parallel and at intervals along the first direction, and each laser grooved line 11 is composed of line segments of the same length. The grooved areas of the laser grooved lines 11 of these two shapes are large, and the back damage and recombination are increased, which will greatly reduce the voltage and affect the conversion efficiency of the PERC cell. The solar cell laser grooved structure 1 proposed by the utility model, at least part of the laser grooved lines 11 are composed of laser grooved sub-segments 111 of different lengths. The longer laser grooved sub-segments 111 can improve the current collection capacity and ensure the contact efficiency of the PERC cell. The shorter laser grooved sub-segments 111 can reduce the grooved area, reduce back damage and recombination, and increase the opening rate of the PERC cell, thereby comprehensively improving the conversion efficiency of the PERC cell.

[0027] As an example, a laser slotting line 11 may have laser slotting sub-line segments 111 of the same length in some areas, and laser slotting sub-line segments 111 of different lengths in another area. Specifically, those skilled in the art may design it according to actual needs.

[0028] As an example, some areas on the back of the PERC cell have laser-grooved sub-segments 111 of different lengths, and another area has laser-grooved sub-segments 111 of the same length. Specifically, those skilled in the art can design it according to actual needs.

[0029] According to some embodiments of the present invention, reference Figure 1Each of the laser slotting lines 11 includes a plurality of laser slotting sub-segments 111. Specifically, the lengths of the plurality of laser slotting sub-segments 111 are different. The arrangement of the laser slotting sub-segments 111 with different lengths is not particularly limited and can be arranged regularly or irregularly. Thus, the slotting area is reduced, the back damage and recombination are reduced, the opening rate of the PERC cell is increased, and the conversion efficiency of the PERC cell is comprehensively improved.

[0030] According to some embodiments of the utility model, the laser slotting line 11 includes a plurality of laser slotting areas arranged in sequence along the second direction, the laser slotting sub-line segments 111 in the same laser slotting area have the same length along the second direction, and the laser slotting sub-line segments 111 in different laser slotting areas have different lengths along the second direction. In other words, in different areas of the laser slotting line 11, the shapes of the laser slotting sub-line segments 111 are different, the lengths of the laser slotting sub-line segments 111 in some areas are the same, and the lengths of the laser slotting sub-line segments 111 in other areas are different, which can be designed according to actual conditions. In this way, the slotting area is reduced, the back damage and recombination are reduced, the opening rate of the PERC cell is increased, and the conversion efficiency of the PERC cell is comprehensively improved.

[0031] According to some embodiments of the present invention, the laser slotting line 11 includes a first laser slotting sub-segment 1111 and a second laser slotting sub-segment 1112, the length of the first laser slotting sub-segment 1111 in the second direction is less than the length of the second laser slotting sub-segment 1112 in the second direction, and the first laser slotting sub-segment 1111 and the second laser slotting sub-segment 1112 are arranged irregularly in the second direction. Specifically, on a laser slotting line 11, the first laser slotting sub-segment 1111 and the second laser slotting sub-segment 1112 can be arranged irregularly, for example, the first laser slotting sub-segment 1111, the second laser slotting sub-segment 1112, the first laser slotting sub-segment 1111, the first laser slotting sub-segment 1111, the first laser slotting sub-segment 1111, the second laser slotting sub-segment 1112, etc. As a result, the slot area is reduced, the back damage and recombination are reduced, the opening rate of the PERC cell is increased, and the conversion efficiency of the PERC cell is comprehensively improved.

[0032] According to some embodiments of the present invention, the laser slotting line 11 includes a first laser slotting sub-segment 1111 and a second laser slotting sub-segment 1112, the length of the first laser slotting sub-segment 1111 in the second direction is less than the length of the second laser slotting sub-segment 1112 in the second direction, and the first laser slotting sub-segment 1111 and the second laser slotting sub-segment 1112 are arranged in sequence in the second direction. Specifically, refer to Figure 1 Each laser slotting line 11 is composed of laser slotting sub-line segments 111 of different lengths. On a laser slotting line 11, the first laser slotting sub-line segment 1111 and the second laser slotting sub-line segment 1112 are arranged regularly. For example, the arrangement can be the first laser slotting sub-line segment 1111, the second laser slotting sub-line segment 1112, the first laser slotting sub-line segment 1111, the second laser slotting sub-line segment 1112, etc. In this way, the slotting area is reduced, the back damage and recombination are reduced, the opening rate of the PERC cell is increased, and the conversion efficiency of the PERC cell is comprehensively improved.

[0033] According to some embodiments of the present invention, reference Figure 3 , the laser slotting line 11 includes a plurality of laser slotting areas arranged in sequence along the second direction, each of the laser slotting areas includes the first laser slotting sub-line segment 1111 and the second laser slotting sub-line segment 1112, a first gap 1113 is formed between the first laser slotting sub-line segment 1111 and the second laser slotting sub-line segment 1112, and a second gap 1114 is formed at one end of the second laser slotting sub-line segment 1112 away from the first gap 1113. Specifically, the arrangement of the laser slotting sub-line segments 111 on each laser slotting line 11 is: the first laser slotting sub-line segment 1111, the second laser slotting sub-line segment 1112, the first laser slotting sub-line, the second laser slotting sub-line segment 1112, etc. Therefore, the regular arrangement of the first laser slotting sub-line segment 1111 and the second laser slotting sub-line segment 1112 can further simplify the light-input slotting process and reduce costs while improving conversion efficiency.

[0034] According to some embodiments of the present invention, reference Figure 3 , the length of the first laser grooved sub-segment 1111 along the second direction is a mm, the length of the first gap 1113 along the second direction is b mm, the length of the second laser grooved sub-segment 1112 along the second direction is c mm, the length of the second gap 1114 along the second direction is d mm, and it satisfies: (a+c) / (a+b+c+d)<a / (a+b). Thus, the shorter first laser grooved sub-segment 111 and the longer second laser grooved sub-segment 1112 are arranged at intervals, which can reduce the groove area, reduce back damage and recombination, and improve the opening rate of the PERC cell while ensuring the current collection ability of the solar cell, thereby comprehensively improving the open circuit voltage and short circuit current of the PERC cell, and thereby improving the conversion efficiency of the PERC cell. If the laser grooved line only includes shorter laser grooved sub-segments, the fill factor of the PERC cell will be reduced.

[0035] According to some embodiments of the present invention, 0.2mm≤a≤0.6mm, 0.8mm≤b≤3.0mm, 0.4mm≤c≤1.2mm, 0.8mm≤d≤3.0mm. Therefore, compared with the laser slotted structure having only laser slotted sub-segments 111 of the same length, the laser slotted sub-segments 111 of different lengths can reduce the slotted area, reduce back damage and recombination, increase the opening rate of the PERC cell, and thus comprehensively improve the conversion efficiency of the PERC cell.

[0036] As an example, a may be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm or 0.6 mm, etc., or may be a range consisting of any of the above values.

[0037] As an example, b can be 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm or 3.0 mm, etc., or can be a range consisting of any of the above values.

[0038] As an example, c may be 0.4 mm, 0.6 mm, 0.8 mm, 1.0 mm or 1.2 mm, etc., or may be a range consisting of any of the above values.

[0039] As an example, d may be 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm or 3.0 mm, etc., or may be a range consisting of any of the above values.

[0040] According to some embodiments of the present invention, the length of the first gap 1113 in the second direction is the same as the length of the second gap 1114 in the second direction.

[0041] According to some embodiments of the present invention, reference Figure 4 and Figure 5The laser grooved line 11 further includes: a third laser grooved sub-segment 1115 and a fourth laser grooved sub-segment 1116, wherein the length of the third laser grooved sub-segment 1115 in the second direction is less than the length of the first laser grooved sub-segment 1111 in the second direction, and the length of the fourth laser grooved sub-segment 1116 in the second direction is less than the length of the second laser grooved sub-segment 1112 in the second direction. Specifically, the laser slotting line 11 includes a plurality of laser slotting regions arranged in sequence along the second direction, each of the laser slotting regions includes the first laser slotting sub-segment 1111, the second laser slotting sub-segment 1112, the third laser slotting sub-segment 1115 and the fourth laser slotting sub-segment 1116, wherein the length of the first laser slotting sub-segment 1111 in the second direction is a mm, the length of the second laser slotting sub-segment 1112 in the second direction is c mm, the length of the third laser slotting sub-segment 1115 in the second direction is e mm, the length of the fourth laser slotting sub-segment 1116 in the second direction is f mm, and the conditions a>e, c>f are satisfied. Thus, by slotting the passivation layer in the above manner, the slotting area can be further reduced, the back damage and recombination can be reduced, the opening rate of the PERC cell can be increased, and the open circuit voltage and short circuit current of the PERC cell can be comprehensively increased, and the conversion efficiency of the PERC cell can be increased.

[0042] In another aspect of the present invention, a solar cell is provided, comprising the aforementioned solar cell laser groove structure 1. Thus, the conversion efficiency of the solar cell can be improved.

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0044] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0045] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0047] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0048] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A solar cell laser grooving structure, characterized in that: include: A plurality of laser grooved lines are arranged at intervals along a first direction, wherein at least some of the laser grooved lines include a plurality of laser grooved sub-line segments, the plurality of laser grooved sub-line segments are arranged at intervals in a second direction, at least some of the laser grooved sub-line segments have different lengths in the second direction, and the second direction intersects with the first direction.

2. The solar cell laser groove structure according to claim 1, characterized in that: Each of the laser-grooved lines includes a plurality of laser-grooved sub-line segments.

3. The solar cell laser groove structure according to claim 2, characterized in that: The laser grooved line includes a plurality of laser grooved areas arranged in sequence along the second direction. The laser grooved sub-line segments in the same laser grooved area have the same length along the second direction, and the laser grooved sub-line segments in different laser grooved areas have different lengths along the second direction.

4. The solar cell laser groove structure according to claim 2, characterized in that: The laser grooved line includes a first laser grooved sub-line segment and a second laser grooved sub-line segment, the length of the first laser grooved sub-line segment in the second direction is less than the length of the second laser grooved sub-line segment in the second direction, and the first laser grooved sub-line segment and the second laser grooved sub-line segment are irregularly arranged in the second direction.

5. The solar cell laser groove structure according to claim 2, characterized in that: The laser grooved line includes a first laser grooved sub-line segment and a second laser grooved sub-line segment, the length of the first laser grooved sub-line segment in the second direction is less than the length of the second laser grooved sub-line segment in the second direction, and the first laser grooved sub-line segment and the second laser grooved sub-line segment are arranged in sequence in the second direction.

6. The solar cell laser groove structure according to claim 5, characterized in that: The laser grooved line includes a plurality of laser grooved areas arranged in sequence along the second direction, each of the laser grooved areas includes the first laser grooved sub-line segment and the second laser grooved sub-line segment, a first gap is formed between the first laser grooved sub-line segment and the second laser grooved sub-line segment, and a second gap is formed at one end of the second laser grooved sub-line segment away from the first gap.

7. The solar cell laser groove structure according to claim 6, characterized in that: The length of the first laser-grooved sub-segment along the second direction is a mm, the length of the first gap along the second direction is b mm, the length of the second laser-grooved sub-segment along the second direction is c mm, the length of the second gap along the second direction is d mm, and satisfies: (a+c) / (a+b+c+d)<a / (a+b).

8. The solar cell laser groove structure according to claim 7, characterized in that: 0.2mm≤a≤0.6mm, 0.8mm≤b≤3.0mm, 0.4mm≤c≤1.2mm, 0.8mm≤d≤3.0mm.

9. The solar cell laser groove structure according to claim 5, characterized in that: The laser grooved line further includes: a third laser grooved sub-line segment and a fourth laser grooved sub-line segment, wherein the length of the third laser grooved sub-line segment in the second direction is less than the length of the first laser grooved sub-line segment in the second direction, and the length of the fourth laser grooved sub-line segment in the second direction is less than the length of the second laser grooved sub-line segment in the second direction.

10. A solar cell, characterized in that: A solar cell laser grooved structure comprising any one of claims 1-9.

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