Solar cell, photovoltaic module and photovoltaic system

Abstract

The utility model is suitable for the photovoltaic technology field, and provides a solar cell, a photovoltaic assembly and a photovoltaic system, the solar cell comprises a silicon substrate, and the front surface or the back surface of the silicon substrate is provided with at least one group of repetitive units; each repetitive unit comprises a first doped layer and a second doped layer which are adjacent to each other or arranged at an interval, the polarity of the second doped layer is opposite to that of the first doped layer, and an electrically insulated spacer region is arranged between the first doped layer and the second doped layer; the repeating unit further comprises a stacking area and a grid line, a third doping layer is stacked on the first doping layer, the stacking area of the third doping layer and the first doping layer is the stacking area, the polarity of the third doping layer is the same as that of the second doping layer, and the third doping layer and the second doping layer are conductively communicated through the grid line. The third doped layer and the first doped layer are not conductively communicated through the grid line. When reverse voltage is applied to the two ends of the solar cell, composite leakage current with appropriate magnitude can be generated, and efficient transmission of current and effective control of heating are achieved.

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 is in a reverse-biased state, 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 significantly 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 includes 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 a first doping layer and a second doping layer which are adjacent or spaced apart. The second doping layer has a polarity opposite to that of the first doping layer, and an electrically insulating spacer is arranged between the first doping layer and the second doping layer;

[0006] The repeating unit further includes a stacked region and a grid line. A third doping layer is stacked on the first doping layer. The region where the third doping layer is stacked with the first doping layer is the stacked region. The third doping layer and the second doping layer have the same polarity. The third doping layer and the second doping layer are electrically connected through the grid line, and the third doping layer and the first doping layer are not electrically connected through the grid line.

[0007] Optionally, the first doping layer and the second doping layer are adjacent or spaced along a first direction, the stacked region is disposed between the adjacent first doping layer and the second doping layer, the stacked region is connected to the first doping layer, and the gate line extends along the first direction to connect the adjacent third doping layer and the second doping layer.

[0008] Optionally, the first doping layer and the second doping layer are alternately arranged along a first direction, a second direction is perpendicular to the first direction, the first doping layer extends a convex position along the first direction, and the adjacent second doping layer is provided with a concave position corresponding to the convex position. The third doping layer is disposed on the convex position, and the gate line extends along the second direction and is respectively disposed on the third doping layer and the second doping layer.

[0009] Optionally, the third doping layer extends in a direction opposite to the direction in which the convex position protrudes.

[0010] Optionally, the first direction and the second direction are perpendicular to each other. The first doping layer includes a first part and a second part that are spaced along the first direction and a second part that extends along the first direction. The second part is connected to one end of the first part;

[0011] The second doping layer includes a third part and a fourth part that are spaced along the first direction and a fourth part that extends along the first direction. The fourth part is connected to one end of the third part;

[0012] The first doping layer and the second doping layer are arranged opposite to each other, and the first part and the third part are adjacent or spaced along the first direction;

[0013] The stacked region is connected to the second part, and the gate line extends along the second direction and is disposed on the third doping layer and the second doping layer.

[0014] Optionally, the first direction and the second direction are perpendicular to each other. The first doping layer includes a first part, a fifth part that are spaced along the first direction, and a second part that extends along the first direction. The length of the fifth part along the second direction is less than the length of the first part along the second direction. The second part is connected to one end of the first part and the fifth part, and the first part and the fifth part are located on the same side of the second part;

[0015] The second doping layer includes a third part and a fourth part that are spaced along the first direction and a fourth part that extends along the first direction. The fourth part is connected to one end of the third part;

[0016] The first doping layer and the second doping layer are arranged opposite to each other, and the first part and the third part are adjacent or spaced along the first direction, and the fifth part faces the third part;

[0017] The stacked region is connected to the fifth part, and the gate line extends along the second direction and is disposed on the third doping layer and the second doping layer.

[0018] Optionally, multiple groups of repeating units are arranged side by side along the first direction.

[0019] Optionally, the second direction is perpendicular to the first direction, and multiple groups of repeating units are arranged side by side along the second direction.

[0020] Optionally, the stacked region is in a "cross" shape, and both ends of the "cross" are respectively connected to the first doping layer and the gate line.

[0021] Optionally, the solar cell further includes:

[0022] A first passivation layer disposed between the first doping layer and the silicon substrate; and / or

[0023] A second passivation layer disposed between the second doping layer and the silicon substrate; and / or

[0024] A third passivation layer disposed between the third doping layer and the first doping layer, and the third doping layer is indirectly conductively contacted with the first doping layer through the third passivation layer.

[0025] Optionally, the first doping layer and the third doping layer are indirectly conductively contacted through the third passivation layer to form the stacked region, and the ratio range of the total area of the stacked region to the area of the front or back surface of the silicon substrate is 1E-8 to 0.03.

[0026] Optionally, the first doping layer and the second doping layer form a conductive channel in the stacked region, and the first doping layer and the third doping 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 ranges from greater than or equal to 0.1 mA / cm 2 , and less than or equal to 5 mA / cm 2 .

[0027] Optionally, the first doping layer and the third doping layer form a conductive channel in the stacked region, and the first doping layer and the second doping 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 ranges from greater than 1.5 mA / cm 2 , and less than or equal to 5 mA / cm 2 .

[0028] The present utility model further provides a photovoltaic module, including the above-mentioned solar cell.

[0029] The present utility model also provides a photovoltaic system, including the above-mentioned photovoltaic module.

[0030] The beneficial effects achieved by the present utility model are as follows: By optimizing the structural design of the solar cell, especially by forming a stacked region with the first doping layer and the third doping layer, when a reverse voltage is applied across the two ends of the solar cell, a composite leakage current with an appropriate magnitude can be generated, realizing 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 hot spot risk, and enhancing the reliability, power generation capacity, and service life of the solar cell. Description of the Drawings

[0031] Figure 1 It is the first cross-sectional structure schematic diagram of the stacked region of the solar cell provided by the present utility model;

[0032] Figure 2 It is the second cross-sectional structure schematic diagram of the stacked region of the solar cell provided by the present utility model;

[0033] Figure 3 It is the third cross-sectional structure schematic diagram of the stacked region of the solar cell provided by the present utility model;

[0034] Figure 4 It is the fourth cross-sectional structure schematic diagram of the stacked region of the solar cell provided by the present utility model;

[0035] Figure 5 It is the fifth cross-sectional structure schematic diagram of the stacked region of the solar cell provided by the present utility model;

[0036] Figure 6 It is the sixth cross-sectional structure schematic diagram of the stacked region of the solar cell provided by the present utility model;

[0037] Figure 7 It is the seventh cross-sectional structure schematic diagram of the stacked region of the solar cell provided by the present utility model;

[0038] Figure 8 It is the eighth cross-sectional structure schematic diagram of the stacked region of the solar cell provided by the present utility model;

[0039] Figure 9 It is the first arrangement schematic diagram of the doping layers of the solar cell provided by the present utility model;

[0040] Figure 10 It is the second arrangement schematic diagram of the doping layers of the solar cell provided by the present utility model;

[0041] Figure 11 It is the third arrangement schematic diagram of the doping layers of the solar cell provided by the present utility model.

[0042] Description of Reference Numerals of the Drawings

[0043] 100. Solar cell; 110. Silicon substrate; 120. First doping layer; 121. First part; 122. Second part; 123. Fifth part; 130. Second doping layer; 131. Third part; 132. Fourth part; 140. First passivation layer; 150. Second passivation layer; 160. Stacked region; 170. Third doping layer; 180. Third passivation layer; 190. Grid line. Detailed Embodiment

[0044] In order to make the objectives, technical solutions and advantages of the present utility model clearer and more 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, in which 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.

[0045] 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, and 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.

[0046] 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 indicating 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 described features. In the description of the present utility model, "a plurality of" means two or more, unless otherwise specifically defined.

[0047] In the description of the present utility model, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected" and "connected" 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 communication with each other; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside 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.

[0048] 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 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 first feature has a higher horizontal height than the second feature. The first feature being "below", "under" and "beneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0049] 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 arrangements 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. Such repetition is for the purpose of simplification and clarity, and in itself does not indicate the relationship between the various embodiments and / or arrangements discussed. In addition, the present utility model provides examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use of other materials.

[0050] By optimizing the structural design of the solar cell, particularly by forming a stacked region with the first doping layer and the third 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, ensuring that the conversion efficiency of the solar cell is basically not lost while reducing the risk of hot spots, and enhancing the reliability, power generation capacity and service life of the solar cell.

[0051] Example 1

[0052] As Figures 1 to 11 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;

[0053] The repeating unit includes a first doping layer 120 and a second doping layer 130 that are adjacent or spaced apart, the second doping layer 130 has a polarity opposite to that of the first doping layer 120, and an electrically insulating spacer is disposed between the first doping layer 120 and the second doping layer 130;

[0054] The repeating unit further includes a stacked region 160 and a gate line 190. A third doped layer 170 is stacked on the first doped layer 120. The region where the third doped layer 170 is stacked with the first doped layer 120 is the stacked region 160. The third doped layer 170 and the second doped layer 130 have the same polarity. The third doped layer 170 and the second doped layer 130 are conductively connected through the gate line 190. The third doped layer 170 and the first doped layer 120 are not conductively connected through the gate line 190.

[0055] 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.

[0056] One or more groups of repeating units are arranged on the front or back of the silicon substrate 110. The first doped layer 120 and the second doped layer 130 are alternately arranged within the repeating unit. The first doped layer 120, the silicon substrate 110, and the second doped layer 130 form a pn junction structure to realize the process of photogenerated carrier separation and collection of the solar cell 100. In particular, the third doped layer 170 is stacked on the first doped layer 120, and the second doped layer 130 contacts the third doped layer 170 to realize the conductive connection between the first doped layer 120 and the third doped layer 170.

[0057] It can be understood that the conductive connection between the first doped layer 120 and the third doped layer 170 can be direct contact conduction or tunneling conduction through a passivation layer, which is not limited here.

[0058] The gate line 190 connects the third doped layer 170 and the second doped layer 130. Through the conduction of the gate line 190, the conductive connection between the first doped layer 120 and the second doped layer 130 is realized.

[0059] When the solar cell 100 generates electricity normally, the first doped layer 120, the second doped layer 130, and the stacked region 160 also perform 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 doped layer 120 and the third doped layer 170 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 heat risk of the hot spot effect.

[0060] Secondly, by deliberately 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 (i.e., it can reduce the heat generation caused by defects), can reduce or even cancel the control requirements for the defects of the silicon substrate 110, and improve the manufacturing capacity of the solar cell 100 while reducing the hot spot risk caused by the defects of the silicon substrate 110.

[0061] That is to say, by adopting the technical solution of the present application, in the present 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, and at the same time, the defect control requirements of the solar cell 100 can be reduced or even cancelled, and the manufacturing and production capacity of the solar cell 100 can be improved.

[0062] In addition, for a battery string composed of multiple solar cells 100, compared with the traditional method of anti-parallel bypass diodes at both ends of the battery string, under the structural design of the solar cell 100 of the present 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, which is not specifically limited herein.

[0063] It should be specifically 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 the thickness of another part of the first doping layer 120. The same situation applies to the thickness of the second doping layer 130 and the third doping layer 170 as that of the first doping layer 120, which will not be elaborated herein, and the present application does not limit this.

[0064] 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 a single crystal state, a polycrystalline state, an amorphous state or a microcrystalline state. For example, silicon can be at least one of single-crystalline silicon, polycrystalline silicon, amorphous silicon or microcrystalline silicon.

[0065] 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).

[0066] 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 migration, so that there is less recombination of carriers generated by the silicon substrate 110 and the first doping layer 120, and the number and mobility of carriers are increased.

[0067] Specifically, in the embodiments of the present application, the second doping layer 130 and the third doping layer 170 have opposite polarities to the first doping layer 120. The first doping layer 120 can be an N-type doping layer, and the second doping layer 130 and the third doping layer 170 can be P-type doping layers. Of course, it can also be that the first doping layer 120 is a P-type doping layer, and the second doping layer 130 and the third doping layer 170 are N-type doping layers.

[0068] In this embodiment, by optimizing the structural design of the solar cell 100, especially by forming the stacked region 160 through the first doping layer 120 and the third doping layer 170, when a reverse voltage is applied across the solar cell 100, a suitable recombination leakage current can be generated, realizing efficient current transmission and effective control of heat generation, ensuring that the conversion efficiency of the solar cell 100 is basically not lost while reducing the hot spot risk, and improving the reliability, power generation capacity, and service life of the solar cell 100.

[0069] Example 2

[0070] Based on Embodiment 1, the first doping layer 120 and the second doping layer 130 are adjacent or spaced along the first direction, the stacked region is arranged between the adjacent first doping layer 120 and the second doping layer 130, and the grid line 190 extends along the first direction and connects the adjacent third doping layer 170 and the second doping layer 130.

[0071] As Figure 9 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 arranged between the first doping layer 120 and the second doping layer 130. Specifically, the spacer region can be that the first doping layer 120 and the second doping layer 130 are electrically insulated, or a poor conductor can be arranged between them, which is not limited herein.

[0072] The stacked region is disposed between adjacent first doped layer 120 and second doped layer 130. Specifically, the first doped layer 120 extends towards the adjacent second doped layer 130, and does not extend to contact the second doped layer 130. A third doped layer 170 is disposed on the extended portion of the first doped layer 120, and the gate line 190 extends vertically to connect the third doped layer 170 and the adjacent second doped layer 130.

[0073] Alternatively, a third doped layer 170 is disposed on a part of the first doped layer 120, and the gate line 190 extends vertically to connect the third doped layer 170 and the adjacent second doped layer 130.

[0074] The shape of the stacked region 160 can have different forms. For example, the width of the stacked region 160 is greater than or less than the widths of the first doped layer 120 and the second doped layer 130, or the stacked region 160 is trapezoidal, triangular or other shapes, which are not limited herein.

[0075] Example 3

[0076] On the basis of the first embodiment, the first doped layer 120 and the second doped layer 130 are alternately disposed along a first direction, a second direction is perpendicular to the first direction, the first doped layer 120 extends a convex position along the first direction, and the adjacent second doped layer 130 is provided with a concave position corresponding to the convex position. The third doped layer 170 is disposed on the convex position, and the gate line 190 extends along the first direction and is respectively disposed on the first doped layer 120 and the second doped layer 130.

[0077] As Figure 10 shown, the vertical direction is the first direction, and the horizontal direction is the second direction. The first doped layer 120 and the second doped layer 130 are disposed at intervals along the vertical direction, and an interval region is disposed between the first doped layer 120 and the second doped layer 130. The interval 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 disposed between the two, which is not limited herein.

[0078] A part of the stacked region 160 extends into the second doped layer 130, that is, the convex position of the first doped layer 120 extends into the second doped layer 130. Since an interval region is disposed between the first doped layer 120 and the second doped layer 130, the first doped layer 120 and the second doped layer 130 cannot be in direct contact. Corresponding to the convex position of the first doped layer 120 extending into the second doped layer 130, the second doped layer 130 is provided with a concave position to avoid direct contact with the first doped layer 120. The third doped layer 170 is disposed on the convex position, and the gate line 190 is disposed along the horizontal direction to connect the third doped layer 170 and the second doped layer 130.

[0079] Example 4

[0080] Based on the first embodiment, the third doping layer 170 extends in the opposite direction to the direction in which the convex portion protrudes.

[0081] As Figure 10 shown, the third doping layer extends in the opposite direction to the direction in which the convex portion protrudes, increasing the area of the stacked region.

[0082] Example 5

[0083] Based on the first embodiment, the first direction and the second direction are perpendicular to each other. The first doping layer 120 includes a first part 1211 arranged at intervals along the first direction and a second part 122 extending along the first direction. The second part 122 is connected to one end of the first part 121.

[0084] The second doping layer 130 includes a third part 131 arranged at intervals along the first direction and a fourth part 132 extending along the first direction. The fourth part 132 is connected to one end of the third part 131.

[0085] 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 adjacent or spaced apart in the first direction.

[0086] The stacked region is connected to the second part, and the gate line 190 extends along the second direction and is disposed on the third doping layer 170 and the second doping layer 130.

[0087] Specifically, the vertical direction is the first direction and the horizontal direction is the second direction. The first part 121 of the first doping layer 120 and the third part 131 of the second doping layer 130 are alternately or spaced apart along the vertical direction, and there is a spacer region between the adjacent first part 121 and third part 131. The second part 122 of the first doping layer 120 and the fourth part 132 of the second doping layer 130 extend along the vertical direction and are respectively connected to the ends of the first part 121 and the third part 131. The first doping layer 120 and the second doping layer 130 are arranged opposite to each other, the second part 122 and the fourth part 132 are respectively disposed on opposite sides, there is a spacer region between the adjacent first part 121 and fourth part 132, and there is a spacer region between the adjacent second part 122 and third part 131. The spacer region may specifically be that the first doping layer 120 and the second doping layer 130 are electrically insulated, or a poor conductor is provided between them, which is not limited herein.

[0088] As Figure 11 shown, the stacked region is disposed on the side of the second part 122 close to the third part 131. Specifically, the first doping layer 120 extends a part on the side of the second part 122 close to the third part 131, and the third doping layer 170 is provided on the extended part to form the stacked region. The gate line 190 extends horizontally and connects the third doping layer 170 and the adjacent second doping layer 130.

[0089] Example 6

[0090] Based on Embodiment 1, the first direction and the second direction are perpendicular to each other. The first doping layer 120 includes a first portion 121 and a fifth portion 123 that are spaced apart along the first direction, and a second portion 122 that extends along the first direction. The length of the fifth portion 123 along the second direction is less than the length of the first portion 121 along the second direction. The second portion 122 is connected to one end of the first portion 121 and the fifth portion 123, and the first portion 121 and the fifth portion 123 are located on the same side of the second portion 122.

[0091] The second doping layer 130 includes a third portion 131 that is spaced apart along the first direction and a fourth portion 132 that extends along the first direction. The fourth portion 132 is connected to one end of the third portion 131.

[0092] The first doping layer 120 and the second doping layer 130 are arranged opposite to each other, and the first portion 121 and the third portion 123 are adjacent or spaced apart in the first direction, and the fifth portion 123 faces the third portion 131.

[0093] The stacked region is connected to the fifth portion. The gate line 190 extends along the second direction and is disposed on the third doping layer 170 and the second doping layer 130.

[0094] As Figure 11 shown, the stacked region 160 is connected to the fifth portion 123. Specifically, the first doping layer 120 extends a part on the side of the second portion 122 close to the third portion 131, and a third doping layer 170 is disposed on a part of the extended portion to form the stacked region, and the part without the third doping layer 170 is the fifth portion 123, and the fifth portion 123 is connected to the second portion 122. The gate line 190 extends horizontally and connects the third doping layer 170 and the adjacent second doping layer 130.

[0095] Example 7

[0096] Based on Embodiments 2 to 6, multiple groups of repeating units are arranged side by side in the first direction.

[0097] Multiple groups 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 doping layers 120 and second doping layers 130, ensuring the uniformity and efficiency of the entire array.

[0098] Example 8

[0099] Based on Embodiments 2 to 7, multiple groups of repeating units are arranged side by side in the second direction.

[0100] Multiple sets of repeating units are arranged side by side along 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.

[0101] Example 9

[0102] As Figure 5 shown, based on 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 gate line 190.

[0103] 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 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.

[0104] Example 10

[0105] Based on the first embodiment, the solar cell 100 further includes:

[0106] A first passivation layer 140, which is disposed between the first doping layer 120 and the silicon substrate 110; and / or

[0107] A second passivation layer 150, which is disposed between the second doping layer 130 and the silicon substrate 110; and / or

[0108] A third passivation layer 180, which is disposed between the third doping layer 170 and the first doping layer 120, and the third doping layer 170 is in indirect conductive contact with the first doping layer 120 through the third passivation layer 180.

[0109] The first doping layer 120, the second doping layer 130, and the third doping layer 170 form conductive contacts in the following manner:

[0110] As Figure 1 shown, the first doping layer 120 and the second doping layer 130 cover the front or back surface of the silicon substrate 110, and the first doping layer 120 and the second doping layer 130 are alternately arranged. The third doping layer 170 partially covers the first doping layer 120, and the first doping layer 120 and the third doping layer 170 form a direct conductive contact.

[0111] AsFigure 2 As shown, a first doping layer 120 and a second doping layer 130 cover the front or back surface of a silicon substrate 110. The first doping layer 120 and the second doping layer 130 are alternately arranged, and a first passivation layer 140 is provided between the first doping layer 120 and the silicon substrate 110. A third doping layer 170 partially covers the first doping layer 120, and a direct conductive contact is formed between the first doping layer 120 and the third doping layer 170.

[0112] As Figure 3 As shown, a first doping layer 120 and a second doping layer 130 cover the front or back surface of a silicon substrate 110. The first doping layer 120 and the second doping layer 130 are alternately arranged, and a second passivation layer 150 is provided between the second doping layer 130 and the silicon substrate 110. A third doping layer 170 partially covers the first doping layer 120, and a direct conductive contact is formed between the first doping layer 120 and the third doping layer 170.

[0113] As Figure 4 As shown, a first doping layer 120 and a second doping layer 130 cover the front or back surface of a silicon substrate 110. The first doping layer 120 and the second doping layer 130 are alternately arranged, 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. A third doping layer 170 partially covers the first doping layer 120, and a direct conductive contact is formed between the first doping layer 120 and the third doping layer 170.

[0114] As Figure 5 As shown, a first doping layer 120 and a second doping layer 130 cover the front or back surface of a silicon substrate 110. The first doping layer 120 and the second doping layer 130 are alternately arranged. A third doping layer 170 partially covers the first doping layer 120, a third passivation layer 180 is provided between the third doping layer 170 and the first doping layer 120, and an indirect conductive contact is formed between the first doping layer 120 and the third doping layer 170.

[0115] As Figure 6 As shown, a first doping layer 120 and a second doping layer 130 cover the front or back surface of a silicon substrate 110. The first doping layer 120 and the second doping layer 130 are alternately arranged, and a first passivation layer 140 is provided between the first doping layer 120 and the silicon substrate 110. A third doping layer 170 partially covers the first doping layer 120, a third passivation layer 180 is provided between the third doping layer 170 and the first doping layer 120, and an indirect conductive contact is formed between the first doping layer 120 and the third doping layer 170.

[0116] As Figure 7As 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 second passivation layer 150 is provided between the second doping layer 130 and the silicon substrate 110. The third doping layer 170 partially covers the first doping layer 120. A third passivation layer 180 is provided between the third doping layer 170 and the first doping layer 120. The first doping layer 120 and the third doping layer 170 form an indirect conductive contact.

[0117] As Figure 8 As 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. A second passivation layer 150 is provided between the second doping layer 130 and the silicon substrate 110. The third doping layer 170 partially covers the first doping layer 120. A third passivation layer 180 is provided between the third doping layer 170 and the first doping layer 120. The first doping layer 120 and the third doping layer 170 form an indirect conductive contact.

[0118] Example 11

[0119] Based on Embodiment 1, the first doping layer 120 and the third doping layer 170 form a stacked region 160 through an indirect conductive contact via the third passivation layer 180. 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.

[0120] The first doping layer 120 and the third doping layer 170 form a stacked region 160 through a direct conductive contact. The ratio range of the total area of the stacked region 160 to the area of the front or back surface is 1E-8 to 0.03. The first doping layer 120 and the third doping layer 170 form a stacked region 160 through an indirect conductive contact via the third passivation layer 180. The ratio range of the total area of the stacked region 160 to the area of the front or back surface is 1E-8 to 0.03. The first doping layer 120 and the second doping layer 130 form a stacked region 160 through an indirect conductive contact via 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 is 1E-8 to 0.03.

[0121] 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 to say, while ensuring the reduction of the reverse conduction threshold, the efficiency of the solar cell 100 can be guaranteed. 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.

[0122] 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 arbitrary value between 1E-8 and 0.03, and specific values are not limited here.

[0123] Example 12

[0124] Based on Embodiment 1, the first doping layer 120 and the third doping layer 170 form a conductive channel in the stacked region 160, and the first doping layer 120 and the third doping layer 170 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 .

[0125] The first doping layer 120 and the third doping layer 170 form a conductive channel in the stacked region 160, and the first doping layer 120 and the third doping layer 170 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.

[0126] Example 13

[0127] Based on Embodiment 12, the first doping layer 120 and the third doping layer 170 form a conductive channel in the stacked region 160, and the first doping layer 120 and the third doping layer 170 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 1.5 mA / cm 2 and less than or equal to 5 mA / cm 2 .

[0128] The first doping layer 120 and the third doping layer 170 form a conductive channel in the stacked region 160. The first doping layer 120 and the third doping layer 170 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.

[0129] 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 surface of the solar cell 100.

[0130] Example 14

[0131] This embodiment provides a photovoltaic module, including the solar cell 100 of the above embodiment.

[0132] Generally, multiple solar cells 100 in a photovoltaic module can be connected in series in sequence to form a battery string. Each battery string can be connected in series, in parallel, or in a series-parallel combination to achieve the current converging output. For example, the connection between each solar cell 100 can be achieved by welding solder tapes, and the connection between each battery string can be achieved by a bus bar.

[0133] The beneficial effects of the photovoltaic module of this embodiment are equivalent to those of the above solar cell 100, and will not be elaborated here.

[0134] Example 15

[0135] This embodiment provides a photovoltaic system, including the photovoltaic module of the above embodiment.

[0136] The beneficial effects of the photovoltaic system of this embodiment are equivalent to those of the above solar cell 100, and will not be elaborated here.

[0137] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

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 adjacent or spaced apart, the second doping layer has a polarity opposite to that of the first doping layer, and an electrically insulating spacer is provided between the first doping layer and the second doping layer; The repeating unit also includes a stacking area and a gate line. A third doping layer is stacked on the first doping layer. The area where the third doping layer and the first doping layer are stacked is the stacking area. The third doping layer and the second doping layer have the same polarity. The third doping layer and the second doping layer are conductively connected through the gate line, and the third doping layer and the first doping layer are not conductively connected through the gate line.

2. The solar cell according to claim 1, characterized in that The first doping layer and the second doping layer are adjacent or spaced apart along a first direction, the stacking region is arranged between adjacent first doping layers and second doping layers, and the gate line extends along the first direction to connect the adjacent third doping layer and the second doping layer.

3. The solar cell according to claim 1, characterized in that The first doping layer and the second doping layer are alternately arranged along a first direction, the second direction is perpendicular to the first direction, the first doping layer extends a convex position along the first direction, the adjacent second doping layer is provided with a concave position corresponding to the convex position, the third doping layer is arranged on the convex position, and the gate line extends along the second direction and is respectively arranged on the third doping layer and the second doping layer.

4. The solar cell according to claim 3, characterized in that The third doping layer extends in the opposite direction to the direction in which the protrusion is raised.

5. 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, and the first portion and the third portion are arranged adjacent to or spaced apart in a first direction; The stacked region is connected to the second portion, and the gate line extends along the second direction and is disposed on the third doping layer and the second doping layer.

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 doped layer includes a first portion and a fifth portion spaced apart along the first direction, and a second portion extending along the first direction, the length of the fifth portion along the second direction is less than the length of the first portion along the second direction, the second portion is connected to one end of the first portion and the fifth portion, and the first portion and the fifth portion are located on the same side of the second 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, and the first portion and the third portion are adjacent to or spaced apart in a first direction, and the fifth portion is opposite to the third portion; The stacked region is connected to the fifth portion, and the gate line extends along the second direction and is disposed on the third doping layer and the second doping layer.

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: The second direction is perpendicular to the first direction, and 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 stacked region is in a "cross" shape, and two ends of the "cross" are respectively connected to the first doped layer and the gate line.

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, the second passivation layer being disposed between the second doped layer and the silicon substrate; and\or A third passivation layer is disposed between the third doped layer and the first doped layer, and the third doped layer is indirectly conductively contacted with the first doped layer through the third passivation layer.

11. The solar cell according to claim 10, characterized in that The first doped layer and the third doped layer are in indirect conductive contact through the third passivation layer to form the stacked region, and the ratio of the total area of ​​the stacked region to the area of ​​the front side or the 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 third doped layer form a conductive channel in the stacked region, and the first doped layer and the third 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 third doped layer form a conductive channel in the stacked region, and the first doped layer and the third 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: Comprising the photovoltaic module described in claim 14.

Images