Solar cell, photovoltaic module and photovoltaic system
By providing alternate first doped layers and second doped layers in the solar cell of the photovoltaic module and forming a stacked region, the problem of heat spot effect of the photovoltaic module is solved, efficient current transmission and heat generation control are achieved, and high power output is maintained.
Patent Information
- Application Number
- CN202421894205.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-06
- Publication Date
- 2025-05-27
- Estimated Expiration
- 2034-08-06
AI Technical Summary
Existing photovoltaic modules have a high risk of heat spot during actual operation, resulting in safety problems such as power reduction and local temperature increase.
By providing at least one set of repeating units on the silicon substrate of the solar cell, the repeating units include alternately arranged first doped layers and second doped layers, the second doped layer having an opposite polarity to the first doped layer, and forming a laminated region to achieve conductive contact.
This design generates a composite leakage current of the appropriate size when the reverse voltage is applied to both ends of the solar cell, achieving efficient current transmission and effective control of heat generation, reducing the risk of heat spots, while maintaining the high power output of the component.
Smart Images
Figure CN222916531U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of photovoltaic, and particularly relates to a solar cell, a photovoltaic module and a photovoltaic system. Background Art
[0002] Photovoltaic modules composed of multiple cells are usually installed in open areas with sufficient sunlight. During long-term use, it is inevitable that they will be covered by obstacles such as birds, dust, and fallen leaves. These obstacles form shadows on the photovoltaic modules, and inappropriate row spacing in a large photovoltaic module array can also form shadows on each other. Due to the existence of local shadows, the current and voltage of some individual solar cells in the photovoltaic module change. Conventional solar cells have diode characteristics. The shaded cell has a reverse bias characteristic, which increases the product of the local current and voltage of the photovoltaic module, and its power consumption is extremely high, resulting in a phenomenon of local temperature rise on these photovoltaic modules. Defects in some individual cells in the photovoltaic module itself may also cause local heating during operation. This phenomenon is called the "hot spot effect". Therefore, existing photovoltaic modules with such cells have a relatively high hot spot risk during actual operation. After being encapsulated into a photovoltaic module, the hot spot effect may reduce the module power and bring safety problems of local temperature rise at the same time. In related technologies, the hot spot risk of photovoltaic modules is often avoided by setting bypass diodes, but this method will greatly reduce the module power. Therefore, it is urgent to reduce the "hot spot effect" through other technical means while maintaining the high-power output of the module. Summary of the Utility Model
[0003] The utility model provides a solar cell, a photovoltaic module and a photovoltaic system, aiming to solve the problem of how to reduce the "hot spot effect" while maintaining the high-power output of the module.
[0004] The utility model is realized as follows. A solar cell is characterized by including a silicon substrate, and at least one set of repeating units is arranged on the front or back surface of the silicon substrate;
[0005] The repeating unit includes alternately arranged first doping layers and second doping layers, and the second doping layer has a polarity opposite to that of the first doping layer;
[0006] The repeating unit further includes a stacked area, the second doping layer extends and stacks on the first doping layer, and the area where the second doping layer and the first doping layer are stacked is the stacked area.
[0007] Optionally, the first doping layers and the second doping layers are alternately arranged along a first direction, a spacer is arranged between adjacent first doping layers and second doping layers, a second direction is perpendicular to the first direction, and along the second direction, the stacked area and the second doping layer are arranged in sequence and connected to each other on one side of each first doping layer.
[0008] Optionally, the first doping layer and the second doping layer are alternately arranged along a first direction, a spacer is arranged between adjacent first doping layer and second doping layer, a second direction is perpendicular to the first direction, and adjacent first doping layer and second doping layer are connected through a stacked region arranged at one end of the second doping layer and / or the first doping layer.
[0009] Optionally, the first doping layer and the second doping layer are alternately arranged along a first direction, a spacer is arranged between adjacent first doping layer and second doping layer, a second direction is perpendicular to the first direction, the first doping layer extends a convex position along the first direction, the convex position extends to an adjacent second doping layer, and the stacked region is arranged at the convex position.
[0010] Optionally, the convex position of the first doping layer extends to a part or all of the region of the second doping layer along the first direction, and the stacked region is arranged at least at the convex position.
[0011] Optionally, the first direction and the second direction are perpendicular to each other, the first doping layer includes a first part arranged at intervals along the first direction and a second part extending along the first direction, and the second part is connected to one end of the first part;
[0012] The second doping layer includes a third part arranged at intervals along the first direction and a fourth part extending along the first direction, and the fourth part is connected to one end of the third part;
[0013] The first doping layer and the second doping layer are arranged opposite to each other, a spacer is arranged between the first doping layer and the second doping layer, and the first part and the third part are adjacent or arranged at intervals along the first direction;
[0014] Adjacent first doping layer and second doping layer along the first direction are connected through the stacked region, and / or adjacent first doping layer and second doping layer along the second direction are connected through the stacked region.
[0015] Optionally, multiple groups of repeating units are arranged side by side along the first direction.
[0016] Optionally, multiple groups of repeating units are arranged side by side along the second direction.
[0017] Optionally, the stacked region is in a cross shape, and the protruding parts of the stacked region are respectively connected to the first doping layer and the second doping layer.
[0018] Optionally, the solar cell further includes:
[0019] A first passivation layer, the first passivation layer is arranged between the first doping layer and the silicon substrate; and / or
[0020] A second passivation layer is disposed between the second doped layer and the silicon substrate, and the second doped layer is indirectly conductively contacted with the first doped layer through the second passivation layer.
[0021] Optionally, the first doped layer and the second doped layer are indirectly conductively contacted through the first passivation layer and / or the second passivation layer to form the stacked region, and the ratio of the total area of the stacked region to the area of the front or back surface of the silicon substrate ranges from 1E-8 to 0.03.
[0022] Optionally, the first doped layer and the second doped layer form a conductive channel in the stacked region, and the first doped layer and the second doped layer release current through the conductive channel. Among them, under a reverse bias voltage of -12V or less than -12V, the current density of the solar cell ranges from greater than or equal to 0.1 mA / cm 2 , and less than or equal to 5 mA / cm 2 .
[0023] Optionally, the first doped layer and the second doped layer form a conductive channel in the stacked region, and the first doped layer and the second doped layer release current through the conductive channel. Among them, under a reverse bias voltage of -12V or less than -12V, the current density of the solar cell ranges from greater than 1.5 mA / cm 2 , and less than or equal to 5 mA / cm 2 .
[0024] The present invention also provides a photovoltaic module, including the above-mentioned solar cell.
[0025] The present invention also provides a photovoltaic system, including the above-mentioned photovoltaic module.
[0026] The beneficial effects achieved by the present invention are as follows: By optimizing the structural design of the solar cell, especially by forming a stacked region with a first doped layer and a second doped layer, when a reverse voltage is applied across the solar cell, a suitable composite leakage current can be generated, realizing efficient current transmission and effective control of heat generation. While ensuring that the conversion efficiency of the solar cell is basically not lost, the risk of hot spots is reduced, and the reliability, power generation capacity, and service life of the solar cell are improved. Description of the Drawings
[0027] Figure 1 is a first cross-sectional structural view of the stacked region of the solar cell provided by the present invention;
[0028] Figure 2 is a second cross-sectional structural view of the stacked region of the solar cell provided by the present invention;
[0029] Figure 3 It is the third schematic cross-sectional structure diagram of the stacked region of the solar cell provided by the present utility model;
[0030] Figure 4 It is the fourth schematic cross-sectional structure diagram of the stacked region of the solar cell provided by the present utility model;
[0031] Figure 5 It is the first schematic layout diagram of the doping layer of the solar cell provided by the present utility model;
[0032] Figure 6 It is the second schematic layout diagram of the doping layer of the solar cell provided by the present utility model;
[0033] Figure 7 It is the third schematic layout diagram of the doping layer of the solar cell provided by the present utility model;
[0034] Figure 8 It is the fourth schematic layout diagram of the doping layer of the solar cell provided by the present utility model;
[0035] Figure 9 It is the fifth schematic layout diagram of the doping layer of the solar cell provided by the present utility model;
[0036] Figure 10 It is the sixth schematic layout diagram of the doping layer of the solar cell provided by the present utility model;
[0037] Figure 11 It is the seventh schematic layout diagram of the doping layer of the solar cell provided by the present utility model;
[0038] Figure 12 It is the eighth schematic layout diagram of the doping layer of the solar cell provided by the present utility model;
[0039] Figure 13 It is the ninth schematic layout diagram of the doping layer of the solar cell provided by the present utility model.
[0040] Explanation of reference numerals:
[0041] 100, solar cell; 110, silicon substrate; 120, first doping layer; 121, first part; 122, second part; 130, second doping layer; 131, third part; 132, fourth part; 140, first passivation layer; 150, second passivation layer; 160, stacked region. Detailed implementation manners
[0042] In order to make the objectives, technical solutions and advantages of the present utility model more clear and understandable, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals indicate the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present utility model, and should not be construed as a limitation to the present utility model. In addition, it should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.
[0043] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.
[0044] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present utility model, the meaning of "a plurality" is two or more unless otherwise specifically defined.
[0045] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, an electrical connection, or a connection that can communicate with each other; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.
[0046] In the present utility model, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include direct contact between the first and second features, or may include the first and second features not being in direct contact but being in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath" and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the horizontal height of the first feature is less than that of the second feature.
[0047] The following disclosure provides many different embodiments or examples for implementing different structures of the present utility model. To simplify the disclosure of the present utility model, components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present utility model. In addition, the present utility model may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplification and clarity, and in itself does not indicate the relationship between various embodiments and / or settings discussed. In addition, the present utility model provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.
[0048] By optimizing the structural design of the solar cell, especially by forming a stacked region through the first doping layer and the second doping layer, when a reverse voltage is applied across the two ends of the solar cell, a suitable recombination leakage current can be generated, achieving efficient current transmission and effective control of heat generation, ensuring that the conversion efficiency of the solar cell is basically not lost while reducing the risk of hot spots, and improving the reliability, power generation capacity and service life of the solar cell.
[0049] Embodiment 1
[0050] As Figures 1 to 13 shown, this embodiment provides a solar cell 100, including a silicon substrate 110, and at least one set of repeating units is disposed on the front or back surface of the silicon substrate 110;
[0051] The repeating unit includes a first doping layer 120 and a second doping layer 130 which are adjacent or spaced apart, and the second doping layer 130 has a polarity opposite to that of the first doping layer 120;
[0052] The repeating unit further includes a stacked region 160. The second doping layer 130 extends and overlaps on the first doping layer 120, and the region where the second doping layer 130 overlaps with the first doping layer 120 is the stacked region 160.
[0053] For the solar cell 100 provided in this application, the "front" and "back" of the silicon substrate 110 are relative. That is, the "front" refers to the side facing the sunlight along the vertical direction, and the "back" refers to the side facing away from the sunlight along the vertical direction.
[0054] One or more sets of repeating units are provided on the front or back of the silicon substrate 110. In the repeating unit, the first doping layer 120 and the second doping layer 130 are alternately arranged. The first doping layer 120, the silicon substrate 110, and the second doping layer 130 form a pn junction structure to realize the separation and collection process of photo-generated carriers of the solar cell 100. In particular, the second doping layer 130 extends and overlaps on the first doping layer 120, and the second doping layer 130 contacts the first doping layer 120 to realize the conductive connection between the first doping layer 120 and the second doping layer 130.
[0055] It can be understood that the conductive connection between the first doping layer 120 and the second doping layer 130 can be direct contact conduction or tunneling conduction through a passivation layer, which is not limited here.
[0056] When the solar cell 100 generates electricity normally, the stacked region 160 of the first doping layer 120 and the second doping layer 130 also performs photoelectric conversion to generate electricity, thereby improving the power generation efficiency of the solar cell 100. At the module end, when the solar cell 100 is shaded, other solar cells 100 connected in series with it provide reverse current for the shaded solar cell 100. A suitable recombination leakage current can be generated between the first doping layer 120 and the second doping layer 130 of the solar cell 100, reducing the voltage across the shaded solar cell 100 (the voltage is less than the sum of the voltages of other solar cells 100 connected in series with this solar cell 100 and not shaded). The heating power of the solar cell 100 will be reduced, thereby reducing the high thermal risk of the hot spot effect.
[0057] Secondly, by specifically introducing a conductive contact structure in the solar cell 100, it has a protective effect on the hot spot effect caused by the defects of the silicon substrate 110 itself (that is, it can reduce the heat generated by the defects), and can reduce or even cancel the control requirements for the defects of the silicon substrate 110, while reducing the hot spot risk caused by the defects of the silicon substrate 110, it improves the manufacturing capacity of the solar cell 100.
[0058] That is to say, by adopting the technical solution of this application, in this application, by reasonably designing the area of the conductive contact structure and its position in the solar cell 100, the relationship between the photoelectric conversion efficiency of the solar cell 100 and the control of the hot spot risk can be balanced. The hot spot risk can be reduced while ensuring that the conversion efficiency of the solar cell 100 has no significant loss. At the same time, the defect control requirements of the solar cell 100 can be reduced or even canceled, and the manufacturing and production capacity of the solar cell 100 can be improved.
[0059] In addition, for a battery string composed of multiple solar cells 100, compared with the conventional method of anti-parallel connecting bypass diodes at both ends of the battery string, under the structural design of the solar cell 100 in this application, it is equivalent that each solar cell 100 has a bypass circuit. Therefore, in some embodiments, in a photovoltaic module, the use of bypass diodes can be reduced or omitted, thereby reducing costs. In some embodiments, in a photovoltaic module, bypass diodes can also be provided, and specific details are not limited herein.
[0060] Specifically, it should be noted that the thickness of the first doping layer 120 can be uniform, that is, the overall thickness of the first doping layer 120 is consistent, or the thickness of the first doping layer 120 can be non-uniform, that is, the overall thickness of the first doping layer 120 is inconsistent, and the thickness of a part of the first doping layer 120 is greater than that of another part of the first doping layer 120. The situation of the thickness of the second doping layer 130 is the same as that of the first doping layer 120, and will not be elaborated herein. This application does not limit this.
[0061] In some embodiments, the material of the silicon substrate 110 can be an elemental semiconductor material. Specifically, the elemental semiconductor material is composed of a single element, for example, it can be silicon or germanium. Among them, the elemental semiconductor material can be in single crystal state, polycrystalline state, amorphous state or microcrystalline state. For example, silicon can be at least one of single crystal silicon, polycrystalline silicon, amorphous silicon or microcrystalline silicon.
[0062] In some embodiments, the silicon substrate 110 can be an N-type semiconductor substrate, a P-type semiconductor substrate or an intrinsic semiconductor substrate. The N-type semiconductor substrate is doped with an N-type doping element, and the N-type doping element can be any one of group V elements such as phosphorus (P), bismuth (Bi), antimony (Sb) or arsenic (As). The P-type semiconductor substrate is doped with a P-type element, and the P-type doping element can be any one of group III elements such as boron (B), aluminum (Al), gallium (Ga) or indium (In).
[0063] Preferably, in this embodiment, the silicon substrate 110 is a silicon substrate 110 made of single crystal silicon. The ordered crystal structure helps to reduce the scattering and recombination probability of carriers during the migration process, so that less recombination of carriers is generated between the silicon substrate 110 and the first doping layer 120, and the number and mobility of carriers are increased.
[0064] Specifically, in the embodiment of this application, the second doping layer 130 has the opposite polarity to the first doping layer 120. The first doping layer 120 can be an N-type doping layer, and the second doping layer 130 can be a P-type doping layer. Of course, it can also be that the first doping layer 120 is a P-type doping layer and the second doping layer 130 is an N-type doping layer.
[0065] In this embodiment, by optimizing the structural design of the solar cell, especially by forming a stacked region through the first doping layer and the second doping layer, when a reverse voltage is applied across the two ends of the solar cell, a composite leakage current of appropriate magnitude can be generated, achieving efficient current transmission and effective control of heat generation. While ensuring that the conversion efficiency of the solar cell is basically not lost, the hot spot risk is reduced, and the reliability, power generation capacity, and service life of the solar cell are improved.
[0066] Embodiment 2
[0067] Based on Embodiment 1, the first doping layer 120 and the second doping layer 130 are alternately arranged along the first direction, and a spacer region is provided between adjacent first doping layer 120 and second doping layer 130. The second direction is perpendicular to the first direction, and a stacked region 160 and a second doping layer 130 are sequentially connected along the second direction on one side of each first doping layer 120.
[0068] As Figure 5 shown, the vertical direction is the first direction, and the horizontal direction is the second direction. The first doping layer 120 and the second doping layer 130 are spaced along the vertical direction, and a spacer region is provided between the first doping layer 120 and the second doping layer 130. The spacer region can specifically be that the first doping layer 120 and the second doping layer 130 are electrically insulated, or a poor conductor can be provided between them, which is not limited herein.
[0069] Along the horizontal direction, a second doping layer 130 is further provided on one side of the first doping layer 120. The second doping layer 130 extends towards the first doping layer 120, and a part of the second doping layer 130 covers the first doping layer 120. The overlapping region of the first doping layer 120 and the second doping layer 130 is the stacked region 160, and the first doping layer 120 and the second doping layer 130 form a conductive contact in the stacked region 160. The shape of the stacked region 160 can have different forms. For example, the width of the stacked region 160 is greater than, equal to, or less than the widths of the first doping layer 120 and the second doping layer 130, or the stacked region 160 is trapezoidal, triangular, or other shapes, which is not limited herein.
[0070] Embodiment 3
[0071] Based on Embodiment 1, the first doping layer 120 and the second doping layer 130 are alternately arranged along the first direction, and a spacer region is provided between adjacent first doping layer 120 and second doping layer 130. The second direction is perpendicular to the first direction. At least one end of the stacked region 160 along the second direction is connected to the end of the first doping layer 120 along the second direction, and at least one end of the stacked region along the first direction is connected to the end of the second doping layer 130 along the first direction.
[0072] Specifically, the vertical direction is the first direction, and the horizontal direction is the second direction. The first doping layer 120 and the second doping layer 130 are arranged at intervals in the vertical direction, and a spacer region is provided between the first doping layer 120 and the second doping layer 130. The spacer region can specifically insulate the first doping layer 120 and the second doping layer 130 electrically, or a poor conductor can be provided between the two, which is not limited herein.
[0073] As Figure 6 shown, the ends of at least one side of the first doping layer 120 and the second doping layer 130 are flush, and the flush ends of the adjacent first doping layer 120 and the second doping layer 130 are respectively connected to the stacking region 160.
[0074] As Figure 7 shown, the ends of at least one side of the first doping layer 120 and the second doping layer 130 are not flush. Specifically, one side end may not be flush, or the ends of both sides may not be flush. The ends of the adjacent first doping layer 120 and the second doping layer 130 are concave-convex. The end of the first doping layer 120 or the second doping layer 130 located in the concave part is connected to the stacking region 160, and the side of the second doping layer 130 or the first doping layer 120 located in the convex part is connected to the stacking region 160.
[0075] As Figure 8 shown, the ends of both sides of the first doping layer 120 and the second doping layer 130 are not flush, and the ends of the multiple first doping layers 120 are flush, and the ends of the multiple second doping layers 130 are flush. The ends of the adjacent first doping layer 120 and the second doping layer 130 are concave-convex. The end of the first doping layer 120 or the second doping layer 130 located in the concave part is connected to the stacking region 160, and the stacking region 160 is respectively connected to the sides of the second doping layer 130 or the first doping layer 120 located in the convex parts on the adjacent two sides.
[0076] The shape of the stacking region 160 can be set according to the actual production situation, which is not limited herein.
[0077] Embodiment 4
[0078] On the basis of the first embodiment, the first doping layer 120 and the second doping layer 130 are adjacent or arranged at intervals in the first direction. The second direction is perpendicular to the first direction. The first doping layer 120 extends a convex position in the first direction, and the convex position extends to the adjacent second doping layer 130. The stacking region 160 is arranged at the convex position.
[0079] Specifically, as Figure 9As shown, the vertical direction is the first direction and the horizontal direction is the second direction. The first doping layer 120 and the second doping layer 130 are arranged at intervals in the vertical direction, and a spacer region is provided between the first doping layer 120 and the second doping layer 130. Specifically, the spacer region can be such that the first doping layer 120 and the second doping layer 130 are electrically insulated, or a poor conductor can be provided between the two, which is not limited herein.
[0080] The stacked region 160 is provided between adjacent first doping layer 120 and second doping layer 130, and is respectively connected to the side edges of the first doping layer 120 and the second doping layer 130.
[0081] Embodiment 5
[0082] On the basis of Embodiment 4, the convex portion of the first doping layer 120 extends into part or all of the region of the second doping layer 130 along the first direction, and the stacked region 160 is at least provided at the convex portion.
[0083] As Figure 10 shown, specifically, the stacked region 160 partially extends into the second doping layer 130, that is, the convex portion of the first doping layer 120 extends into the second doping layer 130. Alternatively, the stacked region 160 partially extends into the first doping layer 120, that is, the second doped layer extends along the stacked region 160 onto the first doping layer 120. It is also possible that the stacked region 160 extends into the first doping layer 120 and the second doping layer 130 respectively.
[0084] As Figure 11 shown, in particular, the stacked region 160 can penetrate all or part of the first doping layer 120 and the second doping layer 130 in the vertical direction.
[0085] Embodiment 6
[0086] On the basis of Embodiment 1, the first direction and the second direction are perpendicular to each other. The first doping layer 120 includes a first part 121 arranged at intervals in the first direction and a second part 122 extending in the first direction. The second part 122 is connected to one end of the first part 121;
[0087] The second doping layer 130 includes a third part 131 arranged at intervals in the first direction and a fourth part 132 extending in the first direction. The fourth part 132 is connected to one end of the third part 131;
[0088] The first doping layer 120 and the second doping layer 130 are arranged opposite to each other, and the first part 121 and the third part 131 are arranged at intervals in the first direction;
[0089] The first doped layer 120 and the second doped layer 130 adjacent in the first direction are connected by the stacking region 160, and / or the first doped layer 120 and the second doped layer 130 adjacent in the second direction are connected by the stacking region 160.
[0090] Specifically, the vertical direction is the first direction, and the horizontal direction is the second direction. The first part 121 of the first doped layer 120 and the third part 131 of the second doped layer 130 are alternately or spaced apart in the vertical direction, and there is a spacer region between the adjacent first part 121 and the third part 131. The second part 122 of the first doped layer 120 and the fourth part 132 of the second doped layer 130 extend in the vertical direction and are respectively connected to the ends of the first part 121 and the third part 131. The first doped layer 120 and the second doped layer 130 are arranged opposite to each other, the second part 122 and the fourth part 132 are respectively arranged on opposite sides, and there is a spacer region between the adjacent first part 121 and the fourth part 132, and there is a spacer region between the adjacent second part 122 and the third part 131. The spacer region can specifically be that the first doped layer 120 and the second doped layer 130 are electrically insulated, or a poor conductor can be provided between them, which is not limited herein.
[0091] As Figure 12 shown, the stacking region 160 can be provided between the adjacent first part 121 and the third part 131 to achieve the conductive connection between the first part 121 and the third part 131.
[0092] As Figure 13 shown, the stacking region 160 can also be provided between the adjacent first part 121 and the fourth part 132 to achieve the conductive connection between the first part 121 and the third part 131. The stacking region 160 can also be provided between the adjacent second part 122 and the third part 131 to achieve the conductive connection between the first part 121 and the third part 131.
[0093] It can be understood that the setting positions of the above stacking regions 160 can exist simultaneously or independently. This is not limited herein.
[0094] Embodiment 7
[0095] Based on Embodiments 2 to 6, multiple sets of repeating units are arranged side by side in the first direction.
[0096] Multiple sets of repeating units are arranged side by side in the first direction to form an array. Each repeating unit includes an alternating structure of multiple first doped layers 120 and second doped layers 130 to ensure the uniformity and efficiency of the entire array.
[0097] Embodiment 8
[0098] Based on Embodiments 2 to 7, multiple sets of repeating units are arranged side by side in the second direction.
[0099] Multiple sets of repeating units are arranged side by side in the second direction to form an array. Each repeating unit contains an alternating structure of multiple first doping layers 120 and second doping layers 130, ensuring the uniformity and efficiency of the entire array.
[0100] Embodiment 9
[0101] As Figure 5 、 12 and shown in 13, on the basis of the first embodiment, the stacked region 160 is in a "cross" shape, and the protruding parts of the stacked region 160 are respectively connected to the first doping layer 120 and the second doping layer 130.
[0102] The stacked region 160 is presented in a "cross" shape, where the vertical and horizontal protruding parts are respectively connected to the first doping layer 120 and the second doping layer 130. This design makes the stacked region 160 relatively narrow, but the area of the stacked region 160 itself is large. The design of the cross-shaped stacked region 160 makes the stacked region 160 relatively narrow, which means that the probability of interface recombination is reduced. Interface recombination usually leads to the loss of photo-generated carriers and reduces the battery efficiency. At the same time, the large area of the cross-shaped stacked region 160 itself can provide sufficient reverse leakage current, which is crucial for achieving efficient current conduction and maintaining the working performance of the battery.
[0103] Embodiment 10
[0104] On the basis of the first embodiment, the solar cell 100 further includes:
[0105] A first passivation layer 140, which is disposed between the first doping layer 120 and the silicon substrate 110; and / or
[0106] A second passivation layer 150, which is disposed between the second doping layer 130 and the silicon substrate 110, and the second doping layer 130 is in indirect conductive contact with the first doping layer 120 through the second passivation layer 150.
[0107] The first doping layer 120 and the second doping layer 130 form a conductive contact in the following manner:
[0108] As Figure 1 shown, the first doping layer 120 and the second doping layer 130 cover the front or back of the silicon substrate 110, and the first doping layer 120 and the second doping layer 130 are alternately arranged. The second doping layer 130 extends towards the adjacent first doping layer 120 and partially covers the first doping layer 120, and the first doping layer 120 and the second doping layer 130 form a direct conductive contact.
[0109] As Figure 2As shown, the first doping layer 120 and the second doping layer 130 cover the front or back surface of the silicon substrate 110. The first doping layer 120 and the second doping layer 130 are arranged alternately, and a first passivation layer 140 is provided between the first doping layer 120 and the silicon substrate 110. The second doping layer 130 extends towards the adjacent first doping layer 120 and partially covers the first doping layer 120. The first doping layer 120 and the second doping layer 130 form a direct conductive contact.
[0110] As Figure 3 shown, the first doping layer 120 and the second doping layer 130 cover the front or back surface of the silicon substrate 110. The first doping layer 120 and the second doping layer 130 are arranged alternately, and a second passivation layer 150 is provided between the second doping layer 130 and the silicon substrate 110. The second doping layer 130 extends towards the adjacent first doping layer 120 and partially covers the first doping layer 120. The second passivation layer 150 extends along the extending direction of the second doping layer 130 and is disposed between the first doping layer 120 and the second doping layer 130. The first doping layer 120 forms an indirect conductive contact with the second doping layer 130 through the second passivation layer 150.
[0111] As Figure 4 shown, the first doping layer 120 and the second doping layer 130 cover the front or back surface of the silicon substrate 110. The first doping layer 120 and the second doping layer 130 are arranged alternately, a first passivation layer 140 is provided between the first doping layer 120 and the silicon substrate 110, and a second passivation layer 150 is provided between the second doping layer 130 and the silicon substrate 110. The second doping layer 130 extends towards the adjacent first doping layer 120 and partially covers the first doping layer 120. The second passivation layer 150 extends along the extending direction of the second doping layer 130 and is disposed between the first doping layer 120 and the second doping layer 130. The first doping layer 120 forms an indirect conductive contact with the second doping layer 130 through the second passivation layer 150.
[0112] Embodiment 11
[0113] Based on Embodiment Ten, the first doping layer 120 and the second doping layer 130 form a stacked region 160 through an indirect conductive contact via the first passivation layer 140 and / or the second passivation layer 150. The ratio range of the total area of the stacked region 160 to the area of the front or back surface of the silicon substrate 110 is 1E - 8 to 0.03.
[0114] The first doping layer 120 and the second doping layer 130 are in direct electrical contact to form a stacked region 160, and the ratio of the total area of the stacked region 160 to the area of the front or back surface ranges from 1E-8 to 0.03. The first doping layer 120 and the second doping layer 130 are in indirect electrical contact through the first passivation layer 140 to form a stacked region 160, and the ratio of the total area of the stacked region 160 to the area of the front or back surface ranges from 1E-8 to 0.03. The first doping layer 120 and the second doping layer 130 are in indirect electrical contact through the second passivation layer 150 to form a stacked region 160, and the ratio of the total area of the stacked region 160 to the area of the front or back surface ranges from 1E-8 to 0.03.
[0115] Thus, setting the area ratio of the above-mentioned stacked region 160 within this reasonable range can avoid the reverse bias voltage being too high due to the too small total area ratio of the conductive stacked region 160, and can also avoid the area ratio of the conductive stacked region 160 being too large and seriously affecting the efficiency of the solar cell 100. That is, the efficiency of the solar cell 100 can be ensured while reducing the reverse conduction threshold. A reasonable contact area distribution can ensure uniform current distribution inside the solar cell 100, avoid local overheating and current concentration, and further improve the performance and stability of the battery.
[0116] Specifically, in such an embodiment, the ratio of the area of the stacked region 160 to the area of the front or back surface can be 1E-8, 0.01, 0.02, 0.03 or any other value between 1E-8 and 0.03, and specific values are not limited here.
[0117] Embodiment 12
[0118] On the basis of Embodiment 1, the first doping layer 120 and the second doping layer 130 form a conductive channel in the stacked region 160, and the first doping layer 120 and the second doping layer 130 release current through the conductive channel. Among them, under a reverse bias voltage of -12V or less than -12V, the current density range of the solar cell 100 is greater than or equal to 0.1 mA / cm 2 , and less than or equal to 5 mA / cm 2 .
[0119] The first doping layer 120 and the second doping layer 130 form a conductive channel in the stacked region 160, and the first doping layer 120 and the second doping layer 130 release current through the conductive channel. Among them, under a reverse bias voltage of -12V or less than -12V, the current density range of the solar cell 100 is 0.1 - 5 mA / cm 2 . The reverse bias voltage of -12V or less than -12V is the standard test voltage. Within this current density range, the internal reaction of the solar cell 100 is complete, and it has a high energy density and power density.
[0120] Embodiment 13
[0121] Based on Embodiment Twelve, the first doping layer 120 and the second doping layer 130 form a conductive channel in the stacked region 160, and the first doping layer 120 and the second doping layer 130 release current through the conductive channel. Among them, under a reverse bias voltage of -12V or less than -12V, the range of the current density of the solar cell 100 is greater than 1.5 mA / cm 2 and less than or equal to 5 mA / cm 2 .
[0122] The first doping layer 120 and the second doping layer 130 form a conductive channel in the stacked region 160, and the first doping layer 120 and the second doping layer 130 release current through the conductive channel. Among them, under a reverse bias voltage of -12V or less than -12V, the range of the current density of the solar cell 100 is greater than 1.5 mA / cm 2 less than or equal to 5 mA / cm 2 . The reverse bias voltage of -12V or less than -12V is the standard test voltage. Within this current density range, the internal reaction of the solar cell 100 is complete, and it has a high energy density and power density.
[0123] Specifically, the current density is defined as the current measured under a reverse bias voltage of -12V or less than -12V divided by the projected area of the front or back of the solar cell 100.
[0124] Embodiment 14
[0125] This embodiment provides a photovoltaic module, including the solar cell 100 of the above embodiment.
[0126] Generally, multiple solar cells 100 in a photovoltaic module can be connected in series in sequence to form a battery string, and each battery string can be connected in series, parallel, or in a series-parallel combination to achieve the converging output of current. For example, the connection between each solar cell 100 can be achieved by welding a solder strip, and the connection between each battery string can be achieved by a bus bar.
[0127] The beneficial effects of the photovoltaic module of this embodiment are the same as those of the above solar cell 100, and will not be elaborated here.
[0128] Embodiment 15
[0129] This embodiment provides a photovoltaic system, including the photovoltaic module of the above embodiment.
[0130] The beneficial effects of the photovoltaic system of this embodiment are the same as those of the above solar cell 100, and will not be elaborated here.
[0131] The above are only the preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.
Claims
1. A solar cell, characterized in that: The invention comprises a silicon substrate, wherein at least one set of repeating units is arranged on the front side or the back side of the silicon substrate; The repeating unit comprises a first doping layer and a second doping layer which are alternately arranged, wherein the second doping layer has a polarity opposite to that of the first doping layer; The repeating unit further includes a stacking region, the second doping layer extends and is stacked on the first doping layer, and a region where the second doping layer and the first doping layer are stacked is the stacking region.
2. The solar cell according to claim 1, characterized in that The first doping layers and the second doping layers are alternately arranged along a first direction, a spacing area is arranged between adjacent first doping layers and second doping layers, a second direction is perpendicular to the first direction, and the stacked area and the second doping layers connected in sequence are arranged on one side of each first doping layer along the second direction.
3. The solar cell according to claim 1, characterized in that The first doping layers and the second doping layers are alternately arranged along a first direction, a spacing area is arranged between adjacent first doping layers and second doping layers, a second direction is perpendicular to the first direction, and adjacent first doping layers and second doping layers are connected by the stacking area arranged at one end of the second doping layer and / or the first doping layer.
4. The solar cell according to claim 1, characterized in that The first doping layers and the second doping layers are alternately arranged along a first direction, an interval area is arranged between adjacent first doping layers and second doping layers, a second direction is perpendicular to the first direction, the first doping layer extends a convex position along the first direction, the convex position extends to an adjacent second doping layer, and the stacking area is arranged at the convex position.
5. The solar cell according to claim 4, characterized in that: The protrusion of the first doping layer extends to a part or all of the area along the first direction in the second doping layer, and the stacking region is at least arranged at the protrusion.
6. The solar cell according to claim 1, characterized in that: The first direction and the second direction are perpendicular to each other, the first doping layer comprises a first portion spaced apart along the first direction and a second portion extending along the first direction, the second portion being connected to one end of the first portion; The second doping layer includes a third portion spaced apart along the first direction and a fourth portion extending along the first direction, wherein the fourth portion is connected to one end of the third portion; The first doping layer and the second doping layer are arranged opposite to each other, a spacing region is arranged between the first doping layer and the second doping layer, and the first portion and the third portion are arranged adjacently or spaced apart along a first direction; The first doped layer and the second doped layer adjacent to each other along a first direction are connected via the stacked region, and / or the first doped layer and the second doped layer adjacent to each other along a second direction are connected via the stacked region.
7. The solar cell according to any one of claims 2 to 6, characterized in that: A plurality of groups of repeating units are arranged in parallel along the first direction.
8. The solar cell according to any one of claims 2 to 6, characterized in that: A plurality of groups of repeating units are arranged in parallel along the second direction.
9. The solar cell according to claim 1, characterized in that: The stacking region is in a "cross" shape, and the protruding parts of the stacking region are respectively connected to the first doping layer and the second doping layer.
10. The solar cell according to claim 1, characterized in that: The solar cell also includes: a first passivation layer, the first passivation layer being disposed between the first doped layer and the silicon substrate; and\or A second passivation layer is disposed between the second doped layer and the silicon substrate, and the second doped layer is indirectly conductively contacted with the first doped layer through the second passivation layer.
11. The solar cell according to claim 10, characterized in that The first doped layer and the second doped layer are indirectly conductively contacted via the first passivation layer and / or the second passivation layer to form the stacked region, and the ratio of the total area of the stacked region to the area of the front or back side of the silicon substrate is in the range of 1E-8 to 0.
03.
12. The solar cell according to claim 1, characterized in that: The first doped layer and the second doped layer form a conductive channel in the stacked region, and the first doped layer and the second doped layer release current through the conductive channel, wherein under a reverse bias voltage of -12V or less than -12V, the current density of the solar cell is greater than or equal to 0.1mA / cm 2 , and less than or equal to 5mA / cm 2 .
13. The solar cell according to claim 12, characterized in that: The first doped layer and the second doped layer form a conductive channel in the stacked region, and the first doped layer and the second doped layer release current through the conductive channel, wherein under a reverse bias voltage of -12V or less than -12V, the current density of the solar cell is in the range of greater than 1.5mA / cm 2 , and less than or equal to 5mA / cm 2 .
14. A photovoltaic module, characterized in that: A solar cell comprising the solar cell according to any one of claims 1 to 13.
15. A photovoltaic system, characterized in that: The photovoltaic module according to claim 14 is included.