Back contact battery, manufacturing method thereof and photovoltaic module

Abstract

The invention discloses a back contact battery, a manufacturing method thereof and a photovoltaic module, relates to the technical field of photovoltaic, and aims to improve the double-sided rate of the back contact battery and improve the conversion efficiency of the back contact battery. The back contact cell includes a semiconductor substrate, a doped semiconductor portion, and a spacer region. The doped semiconductor portion includes a first doped semiconductor portion and a second doped semiconductor portion. The first doped semiconductor part and the second doped semiconductor part are opposite in conduction type and are arranged on the first face of the semiconductor substrate at intervals in the first direction, and the first direction is parallel to the first face. The spacer region is a region, which is not correspondingly provided with the first doped semiconductor part and the second doped semiconductor part, in the first surface of the semiconductor substrate. Wherein the surfaces of the spacer regions are suede surfaces. In the first direction, the first doped semiconductor part and / or the second doped semiconductor part comprises a first doped region and a second doped region located on at least one side of the first doped region, and the doping forms of the first doped region and the second doped region are different.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic technology, and in particular to a back-contact battery, a manufacturing method thereof, and a photovoltaic module. Background Art

[0002] A back-contact battery refers to a solar cell in which the light-facing surface of the cell has no electrodes, and the positive and negative electrodes are both disposed on the backlight side of the cell, thereby reducing the shielding of the electrodes on the cell and increasing the short-circuit current of the cell and improving the energy conversion efficiency of the cell.

[0003] However, the conversion efficiency of existing back-contact batteries is relatively low. Summary of the Invention

[0004] The purpose of the present application is to provide a back-contact battery, a manufacturing method thereof, and a photovoltaic module, which are used to improve the bifaciality of the back-contact battery and improve the conversion efficiency of the back-contact battery.

[0005] To achieve the above object, in a first aspect, the present application provides a back-contact battery, which includes: a semiconductor substrate, a doped semiconductor portion, and a spacer region. The semiconductor substrate includes opposite first and second surfaces. The doped semiconductor portion includes a first doped semiconductor portion and a second doped semiconductor portion. The conduction types of the first doped semiconductor portion and the second doped semiconductor portion are opposite. The first doped semiconductor portion and the second doped semiconductor portion are spaced apart along a first direction on the first surface of the semiconductor substrate, and the first direction is parallel to the first surface. The spacer region is a region on the first surface of the semiconductor substrate where the first doped semiconductor portion and the second doped semiconductor portion are not correspondingly provided. Wherein, along the first direction, the first doped semiconductor portion and / or the second doped semiconductor portion includes a first doped region and a second doped region located on at least one side of the first doped region, and the doping forms of the first doped region and the second doped region are different.

[0006] In the back-contact battery provided by the present application, a first doped semiconductor portion and a second doped semiconductor portion with opposite conductivity types are arranged at intervals along a first direction on a first surface of a semiconductor substrate. Moreover, in the first surface of the semiconductor substrate, there is an interval region where the first doped semiconductor portion and the second doped semiconductor portion are not correspondingly arranged. The interval region can isolate at least partial regions of the first doped semiconductor portion and the second doped semiconductor portion with opposite conductivity types from each other, reducing the carrier recombination rate therebetween, which is beneficial to improving the conversion efficiency of the back-contact battery. In addition, the surface of the interval region can be a flat surface or a textured surface. When the passivation requirement for the interval region is relatively high, the surface of the interval region can be set as a flat surface, which is beneficial to improving the formation quality and film thickness of the surface passivation layer formed on the interval region, and improving the passivation effect of the surface passivation layer on the interval region. When the light trapping requirement for the interval region is relatively high, the surface of the interval region can be set as a textured surface, which is beneficial to increasing the surface roughness of the interval region, making the interval region have a good light trapping effect, and thus being beneficial to improving the bifaciality of the back-contact battery.

[0007] In addition, the first doped semiconductor portion and / or the second doped semiconductor portion includes a first doped region and a second doped region arranged along the first direction. Moreover, the doping forms of the first doped region and the second doped region are different. Different doping forms may refer to any doping-related characteristics such as doping materials (taking silicon materials as an example, such as single-crystalline silicon, polycrystalline silicon, amorphous silicon, microcrystalline silicon, etc.), doping concentrations, and doping element types being different. With such a setting, the doping forms corresponding to different regions along the first direction of the first doped semiconductor portion and / or the second doped semiconductor portion can be respectively set according to different actual requirements, so as to improve the applicability of the back-contact battery in different application scenarios, which is beneficial to improving the conversion efficiency of the back-contact battery.

[0008] As a possible implementation solution, in at least part of a single doped semiconductor portion, the first doped region includes a doped semiconductor layer provided on a partial region of the first surface. The second doped region includes a doped region provided within a partial region of the first surface.

[0009] At least part of a single doped semiconductor portion is divided into a first doped region including a doped semiconductor layer and a second doped region including a doped region. The presence of the doped semiconductor layer is beneficial to reducing the contact loss between the conductive electrode and the semiconductor substrate. In addition, because the doped semiconductor layer has a certain parasitic absorption, its presence will cause less light incident from the first surface side into the semiconductor substrate. Therefore, when the width of a single doped semiconductor portion along the first direction is fixed, the presence of the second doped region including the doped region can reduce the parasitic absorption of the single doped semiconductor portion, which is beneficial to improving the bifaciality of the back-contact battery, and thus improving the conversion efficiency of the back-contact battery.

[0010] As a possible implementation solution, the doping concentration of the first doped region is greater than that of the second doped region.

[0011] At least part of the single doped semiconductor part is divided into a first doped region with a higher doping concentration and a second doped region with a lower doping concentration. The presence of the first doped region can reduce the contact resistance between the conductive electrode and the first doped semiconductor part and / or the second doped semiconductor part, and reduce the carrier transport loss. In addition, compared with the first doped region, the presence of the second doped region with a lower doping concentration is beneficial to reducing the carrier recombination rate and improving the conversion efficiency of the back contact battery.

[0012] As a possible implementation solution, in at least part of the single doped semiconductor part, the surface of the local region of the first surface of the semiconductor substrate corresponding to the first doped region is a flat surface.

[0013] It can be understood that when the first doped region is a doped region arranged in the local region of the first surface of the semiconductor substrate, the surface of the local region of the first surface of the semiconductor substrate corresponding to the first doped region is the surface of the first doped region facing away from the semiconductor substrate. When the first doped region includes a doped semiconductor layer formed on the local region of the first surface of the semiconductor substrate, the surface undulation morphology of the doped semiconductor layer on the side facing away from the semiconductor substrate is substantially the same as the surface undulation morphology of the local region of the first surface of the semiconductor substrate corresponding to the first doped region. Therefore, when the surface of the local region of the first surface of the semiconductor substrate corresponding to the first doped region is a relatively flat plane, the surface of the first doped region facing away from the semiconductor substrate is also relatively flat, which is beneficial to improving the passivation effect of the surface passivation layer on the side of the first doped region facing away from the semiconductor substrate and reducing the carrier recombination rate. In addition, when the first doped region includes a doped semiconductor layer formed on the local region of the first surface, the surface of the local region of the first surface where the first doped region is formed is relatively flat, which is also beneficial to improving the formation quality of the doped semiconductor layer, improving the field passivation effect of the doped semiconductor layer, and further reducing the carrier recombination rate.

[0014] As a possible implementation solution, in at least part of the single doped semiconductor part, the surface of the local region of the first surface of the semiconductor substrate corresponding to the second doped region is a textured surface.

[0015] It can be understood that when the second doping region is a doping region arranged in a local area of the first surface of the semiconductor substrate, the surface of the local area of the first surface of the semiconductor substrate corresponding to the second doping region is the surface of the second doping region away from the semiconductor substrate. When the second doping region includes a doped semiconductor layer arranged on a local area of the first surface of the semiconductor substrate, the doped semiconductor layer formed by the deposition process has a surface undulation morphology on the side away from the semiconductor substrate that is roughly the same as the surface undulation morphology of the local area of the first surface of the semiconductor substrate corresponding to the second doping region. Therefore, whether the second doping region is a doping region or includes a doped semiconductor layer, the surface morphology of the local area of the first surface of the semiconductor substrate corresponding to the second doping region can roughly reflect the surface of the second doping region away from the semiconductor substrate. When the surface of the local area of the first surface of the semiconductor substrate corresponding to the second doping region is a relatively rough velvet surface, it is beneficial to improve the light trapping effect of the second doping region on the side away from the semiconductor substrate, further increase the double-sidedness of the back contact battery, and improve the conversion efficiency of the back contact battery.

[0016] As a possible implementation scheme, when the surface of the local area of the first surface of the semiconductor substrate corresponding to the second doping region is velvet, the velvet morphology of the local area of the first surface of the semiconductor substrate corresponding to the second doping region is different from the velvet morphology of the spacer. Such a configuration is conducive to making the surface of the second doping region away from the semiconductor substrate have a different light refraction effect from the surface of the spacer, thereby facilitating the change of the transmission path of the light on the first side of the back contact battery, so that more light is refracted into the semiconductor substrate at least by the surface of the second doping region away from the semiconductor substrate and the surface of the spacer under the interaction of the interaction, and is used by the semiconductor substrate, thereby increasing the double-sidedness of the back contact battery and improving the conversion efficiency of the back contact battery.

[0017] As a possible implementation scheme, in the surface of the first surface corresponding to a single first doped semiconductor portion and / or a single second doped semiconductor portion, a local surface with a first doped region and a local surface with a second doped region are staggered along the thickness direction of the semiconductor substrate.

[0018] As described above, in a single first-doped semiconductor portion and / or a single second-doped semiconductor portion, the first-doped region and the second-doped region have different doping forms. When, in the surface of the first side corresponding to the single first-doped semiconductor portion and / or the single second-doped semiconductor portion, the local surface provided with the first-doped region and the local surface provided with the second-doped region are staggered in the thickness direction of the semiconductor substrate, it is beneficial to prevent, after manufacturing one of the first-doped region and the second-doped region on the first side, the quality of the formation of the other of the first-doped region and the second-doped region from being affected due to the presence of residues on (or in) the surface of the first side corresponding to the other of the first-doped region and the second-doped region, or to prevent problems such as parasitic absorption and high carrier recombination rate, which is beneficial to improving the yield of the back-contact battery. In addition, when the local surface provided with the first-doped region and the local surface provided with the second-doped region are staggered in the thickness direction of the semiconductor substrate, there is also a sidewall surface between the local surface provided with the first-doped region and the local surface provided with the second-doped region on the first side. The presence of this sidewall surface can increase the passivation contact area between the semiconductor substrate and the surface passivation layer (or the first-doped semiconductor portion and / or the second-doped semiconductor portion), which is beneficial to improving the passivation effect and reducing the carrier recombination rate; at the same time, it is also beneficial to increasing the light absorption area on one side of the first side of the battery, which is beneficial to increasing the bifaciality of the back-contact battery and improving the conversion efficiency of the back-contact battery.

[0019] As a possible implementation solution, in the surface of the first side corresponding to the single first-doped semiconductor portion and / or the single second-doped semiconductor portion, the height difference between the local surface provided with the first-doped region and the local surface provided with the second-doped region in the thickness direction of the semiconductor substrate is greater than or equal to 10 nm and less than or equal to 10 μm.

[0020] When the height difference between the local surface provided with the first-doped region and the local surface provided with the second-doped region in the thickness direction of the semiconductor substrate is within the above range, it is beneficial to prevent residues from still remaining on (or in) the surface of the first side corresponding to the other of the first-doped region and the second-doped region due to the small height difference, which is beneficial to improving the yield of the back-contact battery. In addition, it can also prevent the light absorption depth at the portion of the semiconductor substrate corresponding to the one with the smaller setting height in the first-doped region and the second-doped region from being small due to the large height difference, which is beneficial to improving the light utilization rate of the semiconductor substrate; at the same time, it is also beneficial to realizing the thin-film production of the back-contact battery and reducing the manufacturing cost.

[0021] As a possible implementation, along the direction from the second surface to the first surface, in the first surface, the local surface provided with the second doping region is higher than the surface of the spacer region. With such a setting, the local surface provided with the second doping region and the surface of the spacer region are staggered along the thickness direction of the semiconductor substrate, so that there is a certain macroscopic undulation in the first surface within these two local surfaces, which is conducive to changing the transmission path of the light incident on one side of the first surface of the cell under the combined action of these two local surfaces, and is conducive to making more light refracted into the semiconductor substrate, further increasing the bifaciality of the back-contact cell.

[0022] As a possible implementation, along the direction from the second surface to the first surface, the local surface provided with the second doped semiconductor portion in the first surface is higher than the surface of the spacer region. With such a setting, it is conducive to preventing, after manufacturing the second doped semiconductor portion on the first surface, due to the residues of the second doped semiconductor portion still existing on (or within) the surface of the spacer region, it is easy for the second doped semiconductor portion and the first doped semiconductor layer to leak electricity through the residues, resulting in problems such as a high carrier recombination rate, and is conducive to improving the yield and conversion efficiency of the back-contact cell. In addition, the local surface provided with the second doped semiconductor portion in the first surface and the surface of the spacer region are staggeredly arranged, which is also conducive to making more light incident on the first surface refracted into the semiconductor substrate under the cooperation of these two local surfaces (for example, the light can be reflected by the surface of the spacer region to the side wall between the local surface provided with the second doped semiconductor portion and the surface of the spacer region in the first surface, and refracted into the semiconductor substrate through this side wall), and being utilized by the semiconductor substrate, increasing the bifaciality of the back-contact cell.

[0023] As a possible implementation, along the direction from the second surface to the first surface, the local surface provided with the first doped semiconductor portion in the first surface and the local surface provided with the second doped semiconductor portion are staggeredly arranged along the thickness direction of the semiconductor substrate. With such a setting, it is conducive to preventing, after manufacturing one of the first doped semiconductor portion and the second doped semiconductor portion on the first surface, due to the residues still existing on (or within) the surface corresponding to the other of the first doped semiconductor portion and the second doped semiconductor portion in the first surface, affecting the formation quality of the other of the first doped semiconductor portion and the second doped semiconductor portion, and easily causing problems such as leakage, and is conducive to improving the yield and conversion efficiency of the back-contact cell.

[0024] As a possible implementation, in a single first doped semiconductor portion and / or a single second doped semiconductor portion, the first doping region and the second doping region are electrically conductive.

[0025] In a single first-doped semiconductor portion and / or a single second-doped semiconductor portion, the conduction types of the first-doped region and the second-doped region are the same. When the first-doped region and the second-doped region with the same conduction type are electrically connected, the carriers collected by one of the first-doped region and the second-doped region can be directly transmitted to the other through the interface between the two, and are led out through the conductive electrode in electrical contact with the other, without being transmitted to the other through the semiconductor substrate with relatively poor conductive characteristics (because the first-doped region and the second-doped region are formed on one side of the first surface of the semiconductor substrate and the doping concentration of the corresponding doping element is greater than that of the corresponding doping element in the semiconductor substrate), reducing the transmission loss and facilitating the improvement of the conversion efficiency of the back-contact battery.

[0026] As a possible implementation, when the local surface with the first-doped region and the local surface with the second-doped region are arranged staggeredly in the thickness direction of the semiconductor substrate on the surface corresponding to the single first-doped semiconductor portion and / or the single second-doped semiconductor portion on the first surface, the surface corresponding to the first-doped semiconductor portion and / or the second-doped semiconductor portion on the first surface has a stepped structure. Moreover, one of the first-doped region and the second-doped region also extends to cover the side wall of the stepped structure and is electrically connected to the other. With such an arrangement, one of the first-doped region and the second-doped region also extends to cover the side wall of the stepped structure, which not only facilitates increasing the formation range of the first-doped semiconductor portion and / or the second-doped semiconductor portion on one side of the first surface, thereby increasing the field passivation effect of the first-doped semiconductor portion and / or the second-doped semiconductor portion, but also facilitates timely leading out of the carriers collected by the one that is not directly in electrical contact with the conductive electrode in the first-doped region and the second-doped region, reducing the carrier recombination rate and facilitating the improvement of the conversion efficiency of the back-contact battery.

[0027] As a possible implementation, when the second-doped region includes a doped region arranged in a local area of the first surface and the second-doped region also extends into the side wall of the stepped structure, along the thickness direction of the semiconductor substrate, the docking height of the second-doped region and the first-doped region is greater than or equal to one-fifth of the thickness of the first-doped region and less than or equal to two-thirds of the thickness of the first-doped region.

[0028] The docking height of the second-doped region and the first-doped region within the above range is beneficial to preventing the carriers collected by the one that is not directly in electrical contact with the conductive electrode in the two from being difficult to be led out in time due to the small electrical connection area between the first-doped region and the second-doped region caused by the small docking height, further reducing the carrier recombination rate. In addition, it can also prevent problems such as too large a light absorption depth of the semiconductor substrate, relatively high parasitic absorption of at least one of the first-doped region and the second-doped region, and relatively high doping difficulty due to the too large docking height, which is beneficial to improving the light utilization rate of the back-contact battery and reducing the manufacturing difficulty.

[0029] As a possible implementation, in a single first-doped semiconductor portion and / or a single second-doped semiconductor portion, the first-doped region is disposed in the middle, and the second-doped regions are disposed on both sides of the first-doped region. With such an arrangement, in the single first-doped semiconductor portion and / or the single second-doped semiconductor portion, the distribution of the first-doped region and the second-doped regions on the first surface is relatively regular, which is conducive to the electrical contact between the first-doped region with the corresponding doping form and the conductive electrode, and will not cause the second-doped regions with different doping forms to be in electrical contact with the conductive electrode, improving the yield of the back-contact battery and facilitating the reduction of the manufacturing difficulty of the back-contact battery.

[0030] In a second aspect, the present application provides a method for manufacturing a back-contact battery. The method for manufacturing the back-contact battery includes: First, providing a semiconductor substrate. The semiconductor substrate includes opposite first and second surfaces. Next, forming a first-doped semiconductor portion in a partial region of the first surface. Next, forming a second-doped semiconductor portion in a partial region of the first surface. The first-doped semiconductor portion and the second-doped semiconductor portion have opposite conductivity types, and the first-doped semiconductor portion and the second-doped semiconductor portion are spaced apart along a first direction parallel to the first surface. Along the first direction, the first-doped semiconductor portion and / or the second-doped semiconductor portion includes a first-doped region and second-doped regions located on at least one side of the first-doped region, and the doping forms of the first-doped region and the second-doped regions are different. In the first surface of the semiconductor substrate, the region where the first-doped semiconductor portion and the second-doped semiconductor portion are not provided is an interval region. Next, performing a texturing treatment on the surface of the interval region to form a textured surface.

[0031] As a possible implementation, forming the first-doped semiconductor portion and / or the second-doped semiconductor portion in a partial region of the first surface includes: forming second-doped regions in partial regions of the first surface corresponding to the same first-doped semiconductor portion or the same second-doped semiconductor portion. Next, forming the first-doped region at least on the remaining regions of the first surface corresponding to the same first-doped semiconductor portion or the same second-doped semiconductor portion.

[0032] As a possible implementation, forming the first-doped semiconductor portion and / or the second-doped semiconductor portion in a partial region of the first surface includes: forming an intrinsic semiconductor layer on the region of the first surface that does not correspond to the second-doped regions included in one of the first-doped semiconductor portion and the second-doped semiconductor portion. Next, performing a doping treatment on the intrinsic semiconductor layer and the portion of the first surface exposed outside the intrinsic semiconductor layer, so that the intrinsic semiconductor layer forms the first-doped region, and forming second-doped regions in the regions of the first surface exposed outside the first-doped region. Next, selectively removing the portions of the first-doped region located in the interval region and on the portion of the first surface corresponding to the other of the first-doped semiconductor portion and the second-doped semiconductor portion.

[0033] As a possible implementation, after providing a semiconductor substrate and before forming a second doped region, the manufacturing method of the back contact battery further includes: performing texturing treatment on at least a partial surface of the first face corresponding to the second doped region to form a textured surface.

[0034] For the beneficial effects of the second aspect and its various implementation manners in this application, reference can be made to the analysis of the beneficial effects in the first aspect and its various implementation manners, which will not be elaborated here.

[0035] In a third aspect, this application provides a photovoltaic module, which includes: a battery string and a packaging layer. The battery string is formed by electrically connecting a plurality of back contact batteries provided as in the first aspect and its various implementation manners; the packaging layer covers the surface of the battery string.

[0036] For the beneficial effects of the third aspect and its various implementation manners in this application, reference can be made to the analysis of the beneficial effects in the first aspect and its various implementation manners, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings described herein are used to provide a further understanding of this application and constitute a part of this application. The schematic embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation to this application. In the drawings:

[0038] Figure 1 is a longitudinal sectional schematic view of the first structure of the back contact battery provided in an embodiment of this application Figure 1 ;

[0039] Figure 2 is a longitudinal sectional schematic view of the first structure of the back contact battery provided in an embodiment of this application Figure 2 ;

[0040] Figure 3 is a longitudinal sectional schematic view of the first structure of the back contact battery provided in an embodiment of this application Figure 3 ;

[0041] Figure 4 is a longitudinal sectional schematic view of the first structure of the back contact battery provided in an embodiment of this application Figure 4 ;

[0042] Figure 5 is a longitudinal sectional schematic view of the first structure of the back contact battery provided in an embodiment of this application Figure 5 ;

[0043] Figure 6 is a longitudinal sectional schematic view of the first structure of the back contact battery provided in an embodiment of this application Figure 6 ;

[0044] Figure 7Longitudinal sectional schematic of the first structure of the back-contact battery provided by the embodiments of the present application Figure 7 ;

[0045] Figure 8 Longitudinal sectional schematic of the first structure of the back-contact battery provided by the embodiments of the present application Figure 8 ;

[0046] Figure 9 Longitudinal sectional schematic of the first structure of the back-contact battery provided by the embodiments of the present application Figure 9 ;

[0047] Figure 10 Longitudinal sectional schematic of the first structure of the back-contact battery provided by the embodiments of the present application Figure 10 ;

[0048] Figure 11 Longitudinal sectional schematic of the first structure of the back-contact battery provided by the embodiments of the present application Figure 10 One;

[0049] Figure 12 Longitudinal sectional schematic of the first structure of the back-contact battery provided by the embodiments of the present application Figure 10 Two;

[0050] Figure 13 Longitudinal sectional schematic of the first structure of the back-contact battery provided by the embodiments of the present application Figure 10 Three;

[0051] Figure 14 Longitudinal sectional schematic of the first structure of the back-contact battery provided by the embodiments of the present application Figure 10 Four;

[0052] Figure 15 Structural schematic of the back-contact battery provided by the embodiments of the present application during the manufacturing process Figure 1 ;

[0053] Figure 16 Structural schematic of the back-contact battery provided by the embodiments of the present application during the manufacturing process Figure 2 ;

[0054] Figure 17 Structural schematic of the back-contact battery provided by the embodiments of the present application during the manufacturing process Figure 3 ;

[0055] Figure 18 Structural schematic of the back-contact battery provided by the embodiments of the present application during the manufacturing process Figure 4 ;

[0056] Figure 19 Structural schematic of the back-contact battery provided by the embodiments of the present application during the manufacturing processFigure 5 ;

[0057] Figure 20 Structural schematic of the back-contact battery provided by the embodiment of the present application during manufacturing Figure 6 ;

[0058] Figure 21 Structural schematic of the back-contact battery provided by the embodiment of the present application during manufacturing Figure 7 ;

[0059] Figure 22 Structural schematic of the back-contact battery provided by the embodiment of the present application during manufacturing Figure 8 ;

[0060] Figure 23 Structural schematic of the back-contact battery provided by the embodiment of the present application during manufacturing Figure 9 ;

[0061] Figure 24 Structural schematic of the back-contact battery provided by the embodiment of the present application during manufacturing Figure 10 ;

[0062] Figure 25 Structural schematic of the back-contact battery provided by the embodiment of the present application during manufacturing Figure 10 One;

[0063] Figure 26 Structural schematic of the back-contact battery provided by the embodiment of the present application during manufacturing Figure 10 Two;

[0064] Figure 27 Structural schematic of the back-contact battery provided by the embodiment of the present application during manufacturing Figure 10 Three;

[0065] Figure 28 Structural schematic of the back-contact battery provided by the embodiment of the present application during manufacturing Figure 10 Four;

[0066] Figure 29 Structural schematic of the back-contact battery provided by the embodiment of the present application during manufacturing Figure 10 Five;

[0067] Figure 30 Structural schematic of the back-contact battery provided by the embodiment of the present application during manufacturing Figure 10 Six;

[0068] Figure 31 Structural schematic of the back-contact battery provided by the embodiment of the present application during manufacturing Figure 10 Seven;

[0069] Figure 32 Structural schematic of the back-contact battery provided by the embodiment of the present application during the manufacturing process Figure 10 VIII.

[0070] Reference numerals: 11 is a semiconductor substrate, 12 is a first doped semiconductor portion, 13 is a second doped semiconductor portion, 14 is a spacer, 15 is a first doping region, 16 is a second doping region, 17 is an intrinsic semiconductor layer, 18 is an inner diffusion region, and 19 is an interface passivation layer. Detailed implementation manners

[0071] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present application. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present application.

[0072] Various structural schematic diagrams according to embodiments of the present application are shown in the accompanying drawings. These figures are not drawn to scale, and in order to express more clearly, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary. In practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0073] In the context of the present application, when a layer / component is referred to as being "on" another layer / component, the layer / component may be directly on the other layer / component, or there may be an intermediate layer / component between them. Additionally, if a layer / component is "on" another layer / component in one orientation, then when the orientation is reversed, the layer / component may be "under" the other layer / component. In order to make the technical problems, technical solutions, and beneficial effects to be solved by the present application more clearly understood, the present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely used to explain the present application and are not used to limit the present application.

[0074] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined. "Several" means one or more unless otherwise specifically defined.

[0075] In the description of the present application, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0076] A solar cell is a device that can convert the light energy of the sun into electrical energy. Specifically, when the solar cell is in a working state, sunlight shines on the semiconductor p-n junction of the solar cell, forming new hole-electron pairs. Under the action of the built-in electric field in the p-n junction, the photo-generated holes flow to the p region, and the photo-generated electrons flow to the n region. After connecting the circuit, an electric current can be generated.

[0077] Among them, a solar cell in which both the positive electrode and the negative electrode are on the back surface of the battery is a back-contact battery. Compared with a double-sided contact solar cell, the front surface of this back-contact battery has no metal electrode blockage, so that the light-receiving surface side of the back-contact battery has a higher light utilization rate. Therefore, the back-contact battery has a higher short-circuit current and a higher photoelectric conversion efficiency, which is one of the technical directions for realizing high-efficiency crystalline silicon batteries at present. However, the working performance of the existing back-contact batteries is not good.

[0078] To solve the above technical problems, in a first aspect, an embodiment of the present application provides a back-contact battery. As Figures 1 to 3 shown, the back-contact battery includes: a semiconductor substrate 11, a doped semiconductor portion, and a spacer region 14. The doped semiconductor portion includes a first doped semiconductor portion 12 and a second doped semiconductor portion 13. The conductivity types of the first doped semiconductor portion 12 and the second doped semiconductor portion 13 are opposite. The semiconductor substrate 11 includes opposite first and second surfaces. The first doped semiconductor portion 12 and the second doped semiconductor portion 13 are arranged at intervals in the first direction on the first surface of the semiconductor substrate 11, and the first direction is parallel to the first surface. The spacer region 14 is a region on the first surface of the semiconductor substrate 11 where the first doped semiconductor portion 12 and the second doped semiconductor portion 13 are not correspondingly provided. Among them, along the first direction, the first doped semiconductor portion 12 and / or the second doped semiconductor portion 13 includes a first doped region 15 and a second doped region 16 located on at least one side of the first doped region 15, and the doping forms of the first doped region 15 and the second doped region 16 are different.

[0079] As Figures 1 to 3As shown, in the back contact battery provided in the embodiment of the present application, a first doped semiconductor portion 12 and a second doped semiconductor portion 13 with opposite conduction types are arranged at intervals along a first direction on a first surface of a semiconductor substrate 11. Moreover, in the first surface of the semiconductor substrate 11, there is a spacer region 14 where the first doped semiconductor portion 12 and the second doped semiconductor portion 13 are not correspondingly arranged. The spacer region 14 can isolate at least partial regions of the first doped semiconductor portion 12 and the second doped semiconductor portion 13 with opposite conduction types, reducing the carrier recombination rate therebetween, which is beneficial to improving the conversion efficiency of the back contact battery. The surface of the spacer region 14 can be a planar surface or a textured surface. When the passivation requirement for the spacer region 14 is relatively high, the surface of the spacer region 14 can be set as a planar surface, which is beneficial to improving the formation quality and film thickness of the surface passivation layer formed on the spacer region 14 and enhancing the passivation effect of the surface passivation layer on the spacer region 14. When the light trapping requirement for the spacer region 14 is relatively high, the surface of the spacer region 14 can be set as a textured surface, which can increase the surface roughness of the spacer region 14, facilitating the spacer region 14 to have a good light trapping effect and being beneficial to improving the bifaciality of the back contact battery. In addition, the doped semiconductor portion is used to shunt and collect the photo-generated carriers generated in the semiconductor substrate 11 when the back contact battery is in a working state. In the doped semiconductor portion, the first doped semiconductor portion 12 and / or the second doped semiconductor portion 13 includes a first doped region 15 and a second doped region 16 arranged along the first direction. Moreover, the doping forms of the first doped region 15 and the second doped region 16 are different. Different doping forms can refer to any doping-related characteristics such as doping materials (taking silicon materials as an example, such as single-crystalline silicon, polycrystalline silicon, amorphous silicon, microcrystalline silicon, etc.), doping concentrations, and doping element types being different. With such a setting, the doping forms corresponding to different regions along the first direction of the first doped semiconductor portion 12 and / or the second doped semiconductor portion 13 can be respectively set according to different actual requirements, so as to improve the applicability of the back contact battery in different application scenarios and be beneficial to improving the conversion efficiency of the back contact battery.

[0080] For the semiconductor substrate, the semiconductor substrate is the main light absorption layer of the back contact battery, which is used to absorb light and generate photo-generated carriers. The embodiment of the present application does not make specific limitations on the material and conduction type of the semiconductor substrate. Exemplarily, the above semiconductor substrate can be a silicon substrate; alternatively, the above semiconductor substrate can also be a substrate of any semiconductor material such as a germanium-silicon substrate, a germanium substrate, or a gallium arsenide substrate. Secondly, the above semiconductor substrate can be an N-type semiconductor substrate, a P-type semiconductor substrate, or an intrinsic semiconductor substrate. In addition, the above semiconductor substrate includes opposite first and second surfaces. The first surface of the semiconductor substrate corresponds to the back surface of the back contact battery, and the second surface of the semiconductor substrate corresponds to the front surface of the back contact battery.

[0081] In terms of surface topography, the second surface of the semiconductor substrate can be a flat surface or a textured surface. When the second surface of the semiconductor substrate is a textured surface, it is beneficial to make the second surface have a high light trapping effect and improve the light utilization rate of the back contact battery. The embodiments of the present application do not specifically limit the types, sizes, and distributions of the textured surface structures of the second surface, which can be set according to actual needs.

[0082] In the first surface of the semiconductor substrate, the region where the first doped semiconductor portion and the second doped semiconductor portion are not provided is the spacer region. Optionally, as Figures 1 to 3 shown, the surface of the spacer region 14 can be a textured surface to improve the bifaciality of the back contact battery. The embodiments of the present application do not specifically limit the types, sizes, and distributions of the textured surface structures of the spacer region 14, which can be set according to actual needs. For example: The textured surface structure on the surface of the spacer region 14 can be a pyramid structure, a hole structure, a quasi-pyramid structure with a rounded top, or a V-groove structure, etc.

[0083] As for the topography of the local surface of the first surface of the semiconductor substrate corresponding to the first doped semiconductor portion and the second doped semiconductor portion, it can be set according to actual needs. In the first surface of the semiconductor substrate, the surface corresponding to at least part of a single first doped semiconductor portion can be a flat surface or a textured surface. In the first surface of the semiconductor substrate, the surface corresponding to at least part of a single second doped semiconductor portion can be a flat surface or a textured surface.

[0084] It can be understood that in the actual application process, as Figures 1 to 3 shown, there may be at least part of the first doped semiconductor portion 12 and / or at least part of the second doped semiconductor portion 13 disposed in a local area of the first surface of the semiconductor substrate 11. At this time, the topography of the local surface of the first surface corresponding to at least part of the first doped semiconductor portion 12 and / or at least part of the second doped semiconductor portion 13 is the same as the topography of the surface of at least part of the first doped semiconductor portion 12 and / or at least part of the second doped semiconductor portion 13 facing away from the semiconductor substrate 11.

[0085] As Figures 1 to 3As shown, at least a part of the first doped semiconductor portion 12 and / or at least a part of the second doped semiconductor portion 13 may be disposed on a partial region of the first surface of the semiconductor substrate 11. At this time, on the side surface of at least a part of the first doped semiconductor portion 12 and / or at least a part of the second doped semiconductor portion 13 formed on the partial region of the first surface and facing away from the semiconductor substrate 11, it often has a substantially same undulating morphology as the undulation of the partial surface covered by at least a part of the first doped semiconductor portion 12 and / or at least a part of the second doped semiconductor portion 13 in the first surface. Therefore, the surface morphology of the partial region of the first surface covered by at least a part of the first doped semiconductor portion 12 and / or at least a part of the second doped semiconductor portion 13 is substantially the same as the side surface of at least a part of the first doped semiconductor portion 12 and / or at least a part of the second doped semiconductor portion 13 facing away from the semiconductor substrate 11.

[0086] It can be seen that in the first surface of the semiconductor substrate, the morphology of the partial surface corresponding to the first doped semiconductor portion and the second doped semiconductor portion can be determined according to the structures of the first doped semiconductor portion and the second doped semiconductor portion, and the doping forms of the first doped region and the second doped region included in the first doped semiconductor portion and / or the second doped semiconductor portion. No specific limitation is made here.

[0087] Exemplarily, as Figures 1 to 3 shown, in at least a part of a single doped semiconductor portion, the surface of the partial region of the first surface of the semiconductor substrate 11 corresponding to the first doped region 15 can be a flat surface.

[0088] It can be understood that when the first doped region is a doped region disposed in a partial region of the first surface of the semiconductor substrate, the surface of the partial region of the first surface of the semiconductor substrate corresponding to the first doped region is the surface of the first doped region facing away from the semiconductor substrate. And when the first doped region includes a doped semiconductor layer disposed on a partial region of the first surface of the semiconductor substrate, for the doped semiconductor layer formed by a deposition process, the undulating morphology of the side surface facing away from the semiconductor substrate is substantially the same as the undulating morphology of the surface of the partial region of the first surface of the semiconductor substrate corresponding to the first doped region. Therefore, as Figures 1 to 3 shown, when the surface of the partial region of the first surface of the semiconductor substrate 11 corresponding to the first doped region 15 is a relatively flat plane, the surface of the first doped region 15 facing away from the semiconductor substrate 11 is also relatively flat, which is beneficial to improving the passivation effect of the surface passivation layer on the side of the first doped region 15 facing away from the semiconductor substrate 11 and reducing the carrier recombination rate. In addition, when the first doped region 15 includes a doped semiconductor layer formed on a partial region of the first surface, the surface of the partial region of the first surface where the first doped region 15 is formed is relatively flat, which is also beneficial to improving the formation quality of the doped semiconductor layer, improving the field passivation effect of the doped semiconductor layer, and further reducing the carrier recombination rate.

[0089] Exemplarily, as Figure 8 shown, in at least a part of a single doped semiconductor portion, the surface of a local region of the first surface of the semiconductor substrate 11 corresponding to the second doped region 16 can be a matte surface.

[0090] It can be understood that when the second doped region is a doped region provided in a local region of the first surface of the semiconductor substrate, the surface of the local region of the first surface of the semiconductor substrate corresponding to the second doped region is the surface of the second doped region facing away from the semiconductor substrate. And when the second doped region includes a doped semiconductor layer provided on a local region of the first surface of the semiconductor substrate, for the doped semiconductor layer formed by a deposition process, the surface undulation morphology on the side facing away from the semiconductor substrate is substantially the same as the surface undulation morphology of the local region of the first surface of the semiconductor substrate corresponding to the second doped region. Therefore, whether the second doped region is a doped region or includes a doped semiconductor layer, the surface morphology of the local region of the first surface of the semiconductor substrate corresponding to the second doped region can substantially reflect the surface of the second doped region facing away from the semiconductor substrate. As Figure 8 shown, when the surface of the local region of the first surface of the semiconductor substrate corresponding to the second doped region is a relatively rough matte surface, it is beneficial to improve the light trapping effect on the side of the second doped region facing away from the semiconductor substrate, further increase the bifaciality of the back contact cell, and improve the conversion efficiency of the back contact cell.

[0091] The embodiments of the present application do not specifically limit the type, distribution, and size of the matte surface structure of the local region of the first surface of the semiconductor substrate corresponding to the second doped region, and can be set according to actual needs.

[0092] In addition, in the case where the surface of the local region of the first surface of the semiconductor substrate corresponding to the second doped region is a matte surface and the surface of the spacer region is also a matte surface, the matte surface morphology of the local region of the first surface of the semiconductor substrate corresponding to the second doped region can be the same as or different from the matte surface morphology of the spacer region.

[0093] There may be a height difference between the semiconductor substrates corresponding to the second doped region and the spacer region. By combining matte surface structures at different height positions, the change of the light transmission path is realized, combined light trapping is achieved, and a more optimized light trapping effect is obtained.

[0094] It should be noted that, as Figure 8As shown, when the surface texture of the local area of the first surface of the semiconductor substrate 11 corresponding to the second doping region 16 is different from the surface texture of the spacer region 14, it is beneficial to make the surface on the side of the second doping region 16 away from the semiconductor substrate 11 have a different light refraction effect from the surface of the spacer region 14. Furthermore, it is beneficial to change the transmission path of light on the side of the first surface of the back-contact cell, so that more light is refracted into the semiconductor substrate 11 at least under the interaction between the surface on the side of the second doping region 16 away from the semiconductor substrate 11 and the surface of the spacer region 14, and is utilized by the semiconductor substrate 11, increasing the bifaciality of the back-contact cell and improving the conversion efficiency of the back-contact cell.

[0095] The surface texture of the local area of the first surface of the semiconductor substrate corresponding to the second doping region and the surface texture of the spacer region can be different, which can mean that at least one of the information such as the type, distribution, and size of the surface texture structure of the local area of the first surface of the semiconductor substrate corresponding to the second doping region is different from at least one of the information such as the type, distribution, and size of the surface texture structure of the spacer region.

[0096] For example: when the surface texture structures of both the local area of the first surface of the semiconductor substrate corresponding to the second doping region and the spacer region are pyramid-shaped surface texture structures, it can be that the distribution density, apex angle of the pyramid structure, bottom side length of the pyramid structure, bottom diagonal length of the pyramid structure, or height of the pyramid structure of the surface texture structure of the local area of the first surface of the semiconductor substrate corresponding to the second doping region is different from that of the surface texture structure of the spacer region.

[0097] Exemplarily, when the surface texture structures of both the local area of the first surface of the semiconductor substrate corresponding to the second doping region and the spacer region are pyramid-shaped surface texture structures, it can be that the distribution density of the surface texture structure of the local area of the first surface of the semiconductor substrate corresponding to the second doping region is greater than that of the surface texture structure of the spacer region which is pyramid-shaped. With such a setting, it is beneficial to improve the light trapping effect on the surface of the local area of the first surface of the semiconductor substrate corresponding to the second doping region. And the surface of the spacer region has a smaller number of surface texture structures distributed, which is beneficial to improve the coating of the surface passivation layer on the spacer region, improve the passivation effect of the surface passivation layer on the spacer region, and reduce the carrier recombination rate. In addition, when the surface of the spacer region is lower than the surface of the second doping region on the first surface, the surface of the spacer region can also cooperate with the side surface located between the spacer region and the second doping region to change the transmission path of light. While increasing the bifaciality, it can reduce the requirement for the number of surface texture structures provided on the surface of the spacer region, reduce the time for texturing the spacer region, and is beneficial to make the part of the semiconductor substrate corresponding to the spacer region have a larger light absorption depth.

[0098] Exemplarily, when the surface texture structures of the local area of the first surface of the semiconductor substrate corresponding to the second doping region and the spacer region are both pyramid-shaped surface texture structures, it can also be that the apex angle of the surface texture structure of the local area of the first surface of the semiconductor substrate corresponding to the second doping region is smaller than the apex angle of the surface texture structure of the spacer region which is a pyramid-shaped surface texture structure. The application principle of the beneficial effects in this case can refer to the application principle of the beneficial effects that the distribution density of the surface texture structure of the local area of the first surface of the semiconductor substrate corresponding to the second doping region is greater than the distribution density of the surface texture structure of the spacer region which is a pyramid-shaped surface texture structure, and will not be elaborated here.

[0099] Of course, when the surface of the local area of the first surface of the semiconductor substrate corresponding to the second doping region is a surface texture, the surface texture morphologies of the local area of the first surface of the semiconductor substrate corresponding to the second doping region and the spacer region can also be substantially the same. At this time, the texturing operations of the surface texture of the local area of the first surface of the semiconductor substrate corresponding to the second doping region and the spacer region can be achieved in the same operation step and through the same manufacturing process, simplifying the manufacturing process of the back contact battery and improving the manufacturing efficiency of the back contact battery.

[0100] In terms of the surface setting height, as Figure 4 shown, along the direction from the second surface to the first surface, the local surface of the first surface where the first doped semiconductor portion 12 is provided can be staggeredly arranged in the thickness direction of the semiconductor substrate 11 with the local surface where the second doped semiconductor portion 13 is provided. Such an arrangement is beneficial to prevent, after manufacturing one of the first doped semiconductor portion 12 and the second doped semiconductor portion 13 on the first surface, the quality of the formation of the other of the first doped semiconductor portion 12 and the second doped semiconductor portion 13 from being affected due to the presence of residues on (or in) the surface corresponding to the other of the first doped semiconductor portion 12 and the second doped semiconductor portion 13 on the first surface. Moreover, the conduction types of the first doped semiconductor portion 12 and the second doped semiconductor portion 13 are opposite, so the presence of residues is also likely to cause problems such as leakage, which is beneficial to improving the yield and conversion efficiency of the back contact battery.

[0101] When the local surface of the first surface where the first doped semiconductor portion is provided is staggeredly arranged in the thickness direction of the semiconductor substrate with the local surface where the second doped semiconductor portion is provided, it can be determined according to actual needs whether the local surface of the first surface where the first doped semiconductor portion is provided is higher or the local surface where the second doped semiconductor portion is provided is higher along the direction from the second surface to the first surface.

[0102] As Figure 4As shown, it can be in the direction from the second surface to the first surface, and the local surface of the first doping semiconductor part 12 provided in the first surface is higher than the local surface of the second doping semiconductor part 13 provided. At this time, in the actual manufacturing process, the manufacturing sequence of the first doping semiconductor part 12 can be located before the manufacturing sequence of the second doping semiconductor part 13 to achieve a higher local surface of the first doping semiconductor part 12 provided in the first surface.

[0103] Alternatively, it can also be in the direction from the second surface to the first surface, and the local surface of the second doping semiconductor part provided in the first surface is higher than the local surface of the first doping semiconductor part. At this time, in the actual manufacturing process, the manufacturing sequence of the second doping semiconductor part can be located before the manufacturing sequence of the first doping semiconductor part to achieve a higher local surface of the second doping semiconductor part provided in the first surface.

[0104] When the local surface of the first doping semiconductor part provided in the first surface is staggeredly arranged with the local surface of the second doping semiconductor part along the thickness direction of the semiconductor substrate, the height difference between these two local surfaces along the thickness direction of the semiconductor substrate can be set according to the structures and doping forms of the first doping semiconductor part and the second doping semiconductor part, as well as actual requirements, and no specific limitation is made here.

[0105] Of course, as Figure 1 shown, in the direction from the second surface to the first surface, the local surface of the first doping semiconductor part 12 provided in the first surface can also be flush with the local surface of the second doping semiconductor part 13.

[0106] Exemplarily, as Figure 4As shown, along the direction from the second surface to the first surface, the local surface of the second doped semiconductor portion 13 provided in the first surface can be higher than the surface of the spacer region 14. Such a setting helps prevent problems such as high carrier recombination rate due to leakage current occurring between the second doped semiconductor portion 13 and the first doped semiconductor layer through the residues still present on (or within) the surface of the spacer region 14 after the second doped semiconductor portion 13 is fabricated on the first surface, which is beneficial to improving the yield and conversion efficiency of the back contact battery. Additionally, the local surface of the second doped semiconductor portion 13 provided in the first surface and the surface of the spacer region 14 are staggeredly arranged, which also helps to refract more incident light on the first surface into the semiconductor substrate 11 under the cooperation of these two local surfaces (for example, the light can be reflected by the surface of the spacer region 14 to the side wall between the local surface of the second doped semiconductor portion 13 provided in the first surface and the surface of the spacer region 14, and then refracted into the semiconductor substrate 11 through this side wall), and be utilized by the semiconductor substrate 11, increasing the bifaciality of the back contact battery. At this time, in the first surface, the height difference between the local surface of the second doped semiconductor portion 13 provided and the surface of the spacer region 14 in the thickness direction of the semiconductor substrate 11 can be set according to the structure and doping form of the second doped semiconductor portion 13 and actual requirements, and no specific limitation is made here.

[0107] Alternatively, along the direction from the second surface to the first surface, the local surface of the second doped semiconductor portion provided in the first surface can also be flush with the surface of the spacer region. It should be noted that when the surface of the spacer region is a textured surface, the local surface of the second doped semiconductor portion provided in the first surface being flush with the surface of the spacer region means that the local surface of the second doped semiconductor portion provided in the first surface is flush with the top of the textured structure in the spacer region (i.e., the side of the textured structure facing away from the semiconductor substrate).

[0108] Exemplarily, as Figures 1 to 4 shown, in the surface of the first surface corresponding to a single first doped semiconductor portion 12 and / or a single second doped semiconductor portion 13, the local surface provided with the first doped region 15 and the local surface provided with the second doped region 16 can be staggeredly arranged in the thickness direction of the semiconductor substrate 11.

[0109] For example: as Figure 1 、 Figure 3 and Figure 4 shown, in the case where the first doped semiconductor portion 12 includes the first doped region 15 and the second doped region 16, in the surface of the first surface corresponding to a single first doped semiconductor portion 12, the local surface provided with the first doped region 15 and the local surface provided with the second doped region 16 can be staggeredly arranged in the thickness direction of the semiconductor substrate 11.

[0110] For example: as Figure 2 andFigure 3 As shown, when the second doped semiconductor portion 13 includes a first doped region 15 and a second doped region 16, in the surface of the first side corresponding to a single second doped semiconductor portion 13, the partial surface provided with the first doped region 15 and the partial surface provided with the second doped region 16 may be staggeredly arranged along the thickness direction of the semiconductor substrate 11.

[0111] As described above, in a single first doped semiconductor portion and / or a single second doped semiconductor portion, the first doped region and the second doped region have different doping forms. As Figures 1 to 4 shown, when in the surface of the first side corresponding to a single first doped semiconductor portion 12 and / or a single second doped semiconductor portion 13, the partial surface provided with the first doped region 15 and the partial surface provided with the second doped region 16 are staggeredly arranged along the thickness direction of the semiconductor substrate 11, it is beneficial to prevent, after manufacturing one of the first doped region 15 and the second doped region 16 with the same conduction type on the first side, the quality of formation of the other of the first doped region 15 and the second doped region 16 from being affected due to the presence of residues on (or in) the surface corresponding to the other of the first doped region 15 and the second doped region 16 in the first side, or problems such as parasitic absorption and high carrier recombination rate, which is beneficial to improving the yield of the back contact battery. In addition, when the partial surface provided with the first doped region 15 and the partial surface provided with the second doped region 16 are staggeredly arranged along the thickness direction of the semiconductor substrate 11, there is also a sidewall surface between the partial surface provided with the first doped region 15 and the partial surface provided with the second doped region 16 on the first side. The presence of this sidewall surface can increase the passivation contact area between the semiconductor substrate 11 and the surface passivation layer (or the first doped semiconductor portion 12 and / or the second doped semiconductor portion 13), which is beneficial to improving the passivation effect and reducing the carrier recombination rate; at the same time, it is also beneficial to increase the light absorption area on one side of the first side of the battery, which is beneficial to increasing the bifaciality of the back contact battery and improving the conversion efficiency of the back contact battery.

[0112] When in the surface of the first side corresponding to a single first doped semiconductor portion and / or a single second doped semiconductor portion, the partial surface provided with the first doped region and the partial surface provided with the second doped region are staggeredly arranged along the thickness direction of the semiconductor substrate, it is possible to determine, according to actual requirements and the doping forms of the first doped region and the second doped region in the single first doped semiconductor portion and / or the single second doped semiconductor portion, whether the partial surface provided with the first doped region is higher or the partial surface provided with the second doped region is higher along the direction from the second side to the first side in the surface of the first side corresponding to the single first doped semiconductor portion and / or the single second doped semiconductor portion.

[0113] As Figures 1 to 4As shown, it may be that in the direction from the second surface to the first surface, in the surface of the first surface corresponding to the single first doped semiconductor portion 12 and / or the single second doped semiconductor portion 13, the local surface where the first doped region 15 is provided is higher than the local surface where the second doped region 16 is provided. At this time, in the actual manufacturing process, the manufacturing sequence of the first doped region 15 included in the single first doped semiconductor portion 12 and / or the single second doped semiconductor portion 13 may be placed before the manufacturing sequence of the second doped region 16, so as to achieve that the local surface of the first surface corresponding to the first doped region 15 is higher.

[0114] like Figure 5 As shown, it may also be that in the direction from the second surface to the first surface, in the surface of the first surface corresponding to the single first doped semiconductor portion 12 and / or the single second doped semiconductor portion 13, the local surface where the second doping region 16 is provided is higher than the local surface where the first doping region 15 is provided. In this case, in the actual manufacturing process, the manufacturing sequence of the single first doped semiconductor portion 12 and / or the single second doped semiconductor portion 13 including the second doping region 16 may be placed before the manufacturing sequence of the first doping region 15, so as to achieve that the local surface of the first surface corresponding to the second doping region 16 is higher.

[0115] As for the surface of the first surface corresponding to a single first doped semiconductor portion and / or a single second doped semiconductor portion, the height difference between the local surface where the first doped region is provided and the local surface where the second doped region is provided along the thickness direction of the semiconductor substrate can be set according to the surface morphology of the first doped region and the second doped region facing away from the semiconductor substrate, the doping form of the first doped region and the second doped region, and actual needs.

[0116] Optionally, in the surface of the first side corresponding to a single first-doped semiconductor portion and / or a single second-doped semiconductor portion, the height difference in the thickness direction of the semiconductor substrate between the local surface provided with the first-doped region and the local surface provided with the second-doped region may be greater than or equal to 10 nm and less than or equal to 10 μm. For example: in the surface of the first side corresponding to a single first-doped semiconductor portion and / or a single second-doped semiconductor portion, the height difference in the thickness direction of the semiconductor substrate between the local surface provided with the first-doped region and the local surface provided with the second-doped region may be 10 nm, 50 nm, 0.1 μm, 0.5 μm, 1 μm, 2 μm, 4 μm, 6 μm, 8 μm or 10 μm, etc. When the height difference in the thickness direction of the semiconductor substrate between the local surface provided with the first-doped region and the local surface provided with the second-doped region is within the above range, it is beneficial to prevent residues from remaining on (or in) the surface of the other one of the first-doped region and the second-doped region in the first side due to the small height difference, which is beneficial to improving the yield of the back-contact battery. In addition, it can also prevent the light absorption depth at the part of the semiconductor substrate corresponding to the one with a lower height among the first-doped region and the second-doped region from being small due to the large height difference, which is beneficial to improving the light utilization rate of the semiconductor substrate; at the same time, it is also beneficial to realize the thin-film production of the back-contact battery and reduce the manufacturing cost.

[0117] It should be noted that when the first-doped semiconductor portion includes a first-doped region and a second-doped region, and in the surface of the first side corresponding to a single first-doped semiconductor portion, the local surface provided with the first-doped region and the local surface provided with the second-doped region are staggeredly arranged in the thickness direction of the semiconductor substrate, the staggered arrangement of the local surface provided with the first-doped semiconductor portion and the local surface provided with the second-doped region in the first side along the direction from the second side to the first side as described above may mean: in the first side, the one with a lower height among the first-doped region and the second-doped region included in the corresponding first-doped semiconductor portion is higher than the surface of the part with a higher height in the surface of the second-doped semiconductor portion in the first side; it may also mean: in the first side, the one with a higher height among the first-doped region and the second-doped region included in the corresponding first-doped semiconductor portion is lower than the surface of the part with a lower height in the surface of the second-doped semiconductor portion in the first side.

[0118] When the second-doped semiconductor portion includes a first-doped region and a second-doped region, and in the surface of the first side corresponding to a single second-doped semiconductor portion, the local surface provided with the first-doped region and the local surface provided with the second-doped region are staggeredly arranged in the thickness direction of the semiconductor substrate, the meaning of the staggered arrangement of the local surface provided with the first-doped semiconductor portion and the local surface provided with the second-doped region in the first side along the direction from the second side to the first side as described above may refer to the corresponding meaning of the staggered arrangement when the first-doped semiconductor portion includes a first-doped region and a second-doped region as described above, and will not be elaborated here.

[0119] Secondly, when the second doped semiconductor portion includes a first doped region and a second doped region, and in the surface of the first side corresponding to a single second doped semiconductor portion, the local surface provided with the first doped region and the local surface provided with the second doped region are arranged staggeredly along the thickness direction of the semiconductor substrate, the local surface provided with the second doped semiconductor portion in the aforementioned first side being higher than the surface of the spacer region specifically means: the surface of the first side corresponding to the second doped semiconductor portion including the first doped region and the second doped region and having a lower height is higher than the surface of the spacer region.

[0120] Exemplarily, as Figure 4 and Figure 5 shown, along the direction from the second side to the first side, in the first side, the local surface provided with the second doped region 16 can be higher than the surface of the spacer region 14. With such a setting, the local surface provided with the second doped region 16 (which can belong to the first doped semiconductor portion 12 or the second doped semiconductor portion 13) and the surface of the spacer region 14 are arranged staggeredly along the thickness direction of the semiconductor substrate 11, so that there is a certain macroscopic-level undulation within these two local surfaces in the first side, which is beneficial to changing the transmission path of the light incident on one side of the first surface of the battery under the combined action of these two local surfaces, and is beneficial to making more light refracted into the semiconductor substrate 11, further increasing the bifaciality of the back contact battery.

[0121] As for the height difference between the local surface provided with the second doped region and the surface of the spacer region in the first side, it can be set according to the doping form of the second doped region, whether the second doped region belongs to the first doped semiconductor portion or the second doped semiconductor portion, the manufacturing sequence of the first doped semiconductor portion and the second doped semiconductor portion, and actual requirements, and no specific limitation is made here.

[0122] For the first doped semiconductor portion and the second doped semiconductor portion, in this application, the first doped semiconductor portion and the second doped semiconductor portion are used to shunt and collect the photo-generated carriers generated in the semiconductor substrate. One of the first doped semiconductor portion and the second doped semiconductor portion is used to collect electrons, and the other is used to collect holes. The present application embodiment does not make a specific limitation on the conduction type of the first doped semiconductor portion, as long as the conduction types of the first doped semiconductor portion and the second doped semiconductor portion are opposite. Exemplarily, the conduction type of the first doped semiconductor portion can be N-type, and at this time the conduction type of the second doped semiconductor portion is P-type; or, the conduction type of the first doped semiconductor portion can also be P-type, and at this time the conduction type of the second doped semiconductor portion is N-type.

[0123] As for the arrangement direction (i.e., the first direction) of the first doped semiconductor portion and the second doped semiconductor portion on the first surface, it can be any direction parallel to the first surface. Optionally, when the first surface of the semiconductor substrate is rectangular, the first direction can be parallel to the long side or the short side of the rectangle.

[0124] In terms of structure, in the first doped semiconductor portion and the second doped semiconductor portion, it can be that only at least part of a single first doped semiconductor portion includes a first doped region and a second doped region. It can also be that only at least part of a single second doped semiconductor portion includes a first doped region and a second doped region. It can further be that at least part of a single first doped semiconductor portion and at least part of a single second doped semiconductor portion both include a first doped region and a second doped region.

[0125] As for the doping forms of the first doped region and the second doped region in a single first doped semiconductor portion and / or a single second doped semiconductor portion, they can be set according to actual requirements.

[0126] Exemplarily, as Figure 4 and Figure 5 shown, in at least part of a single doped semiconductor portion, the first doped region 15 includes a doped semiconductor layer provided on a partial region of the first surface. The second doped region 16 includes a doped region provided within a partial region of the first surface.

[0127] It can be understood that the first doped semiconductor portion and the second doped semiconductor portion included in the doped semiconductor portion can be alternately and spacedly distributed on the first surface of the semiconductor substrate along the first direction. A single first doped semiconductor portion refers to the one located between two adjacent second doped semiconductor portions along the first direction, and / or the doped semiconductor portion located on the outermost side along the first direction is a first doped semiconductor portion. A single second doped semiconductor portion refers to the one located between two adjacent first doped semiconductor portions along the first direction, and / or the doped semiconductor portion located on the outermost side along the first direction is a second doped semiconductor portion.

[0128] As Figure 1 shown, in the case where the first doped semiconductor portion 12 includes a first doped region 15 and a second doped region 16, it can be that only part of a single first doped semiconductor portion 12 includes a first doped region 15 and a second doped region 16; it can also be that all single first doped semiconductor portions 12 include a first doped region 15 and a second doped region 16.

[0129] As Figure 2 shown, in the case where the second doped semiconductor portion 13 includes a first doped region 15 and a second doped region 16, it can be that only part of a single second doped semiconductor portion 13 includes a first doped region 15 and a second doped region 16; it can also be that all single second doped semiconductor portions 13 include a first doped region 15 and a second doped region 16.

[0130] As Figure 4 and Figure 5 shown, at least part of a single doped semiconductor portion can be at least divided into a first doped region 15 including a doped semiconductor layer and a second doped region 16 including a doped region. The presence of the doped semiconductor layer helps to reduce the contact loss between the conductive electrode and the semiconductor substrate 11. In addition, because the doped semiconductor layer has a certain parasitic absorption, its presence will cause less light incident from the first side into the semiconductor substrate 11. Therefore, when the width of at least part of the single doped semiconductor portion in the first direction is fixed, the presence of the second doped region 16 including the doped region can reduce the parasitic absorption of at least part of the single doped semiconductor portion, which is beneficial to improving the bifaciality of the back contact cell, and further improving the conversion efficiency of the back contact cell.

[0131] The material of the doped semiconductor layer can include any semiconductor material such as silicon, silicon germanium, germanium, or gallium arsenide. In terms of the arrangement form of substances, the crystal phase of the doped semiconductor layer can be amorphous, microcrystalline, nanocrystalline, single crystal, or polycrystalline, etc. Optionally, the doped semiconductor layer can include a doped crystalline silicon layer. Further, the doped semiconductor layer can include a doped polycrystalline silicon layer.

[0132] When both the first doped semiconductor portion and the second doped semiconductor portion include a first doped region and a second doped region, and the first doped regions in the first doped semiconductor portion and the second doped semiconductor portion both include a doped semiconductor layer, the materials of the doped semiconductor layer included in the first doped semiconductor portion and the doped semiconductor layer included in the second doped semiconductor portion can be the same or different.

[0133] When the first doped region includes a doped semiconductor layer, as Figure 4 and Figure 5 shown, the doped semiconductor layer can be directly disposed on a partial surface of the first side. Or, as Figure 6 shown, the first doped region 15 can further include an interface passivation layer 19 disposed between the semiconductor substrate 11 and the doped semiconductor layer. The interface passivation layer 19 can form a selective contact structure with the doped semiconductor layer. The selective contact structure has a high passivation effect and can achieve selective collection of carriers, reduce the carrier recombination rate, and is beneficial to improving the conversion efficiency of the back contact cell. The material and thickness of the interface passivation layer 19 can be set according to the material of the doped semiconductor layer and actual requirements, and will not be specifically limited here. For example: when the material of the doped semiconductor layer is doped polycrystalline silicon, the interface passivation layer is a tunneling passivation layer. Another example: when the material of the doped semiconductor layer includes at least one of doped amorphous silicon, doped microcrystalline silicon, and doped nanocrystalline silicon, the interface passivation layer is an intrinsic amorphous silicon layer, an intrinsic microcrystalline silicon layer, an intrinsic nanocrystalline silicon layer, or a mixed layer of the above three.

[0134] When both the first doped semiconductor portion and the second doped semiconductor portion include a first doped region and a second doped region, and the first doped regions in the first doped semiconductor portion and the second doped semiconductor portion both include a doped semiconductor layer, an interface passivation layer may be provided only between the doped semiconductor layer included in the first doped semiconductor portion and the semiconductor substrate; or an interface passivation layer may be provided only between the doped semiconductor layer included in the second doped semiconductor portion and the semiconductor substrate; or interface passivation layers may be provided between the doped semiconductor layers included in both the first doped semiconductor portion and the second doped semiconductor portion and the semiconductor substrate. In this case, the materials of these two interface passivation layers may be the same or different.

[0135] In addition, in some cases, such as Figure 7 As shown, in a single first doped semiconductor portion 12 and / or a single second doped semiconductor portion 13, the first doped region 15 may further include an inner diffusion region 18 provided in a partial region of the semiconductor substrate 11, and the doped semiconductor layer is located on the inner diffusion region 18. With such a setting, the presence of the inner diffusion region 18 can enhance the field passivation effect at the region where the doped semiconductor layer is provided on the first surface, which is beneficial to the collection of carriers.

[0136] In some cases, such as Figure 7 As shown, in the case where the first doped region 15 includes a doped semiconductor layer, in at least part of a single doped semiconductor portion, the surface of the partial region of the first surface of the semiconductor substrate 11 corresponding to the first doped region 15 may be flat, so as to be beneficial to improving the formation quality and film thickness of the doped semiconductor layer, enhancing the field passivation effect of the doped semiconductor layer, and improving the conversion efficiency of the back contact battery.

[0137] Alternatively, in the case where the first doped region includes a doped semiconductor layer, in at least part of a single doped semiconductor portion, the surface of the partial region of the first surface of the semiconductor substrate corresponding to the first doped region may also be a textured surface, so as to be beneficial to improving the bifaciality of the back contact battery while being beneficial to increasing the contact area between the first doped region and the conductive electrode, reducing the contact resistance therebetween, and improving the contact performance therebetween.

[0138] In some cases, such as Figure 7 As shown, in the case where the second doped region 16 includes a doped region, in at least part of a single doped semiconductor portion, the surface of the partial region of the first surface of the semiconductor substrate 11 corresponding to the second doped region 16 may be a textured surface, so as to be beneficial to improving the bifaciality of the back contact battery and enhancing the conversion efficiency of the back contact battery.

[0139] Alternatively, in the case where the second doped region includes a doped region, in at least part of a single doped semiconductor portion, the surface of the partial region of the first surface of the semiconductor substrate corresponding to the second doped region may also be flat, so as to be beneficial to improving the passivation effect of the surface passivation layer provided on this partial surface and reducing the carrier recombination rate.

[0140] In at least a part of a single doped semiconductor portion, when the first doped region includes a doped semiconductor layer disposed on a local region of a first surface, and the second doped region includes a doped region disposed within the local region of the first surface, the surface topography of the local region of the first surface of the semiconductor substrate corresponding to the first doped region and the second doped region can be set according to actual requirements, and no specific limitation is made here.

[0141] Exemplarily, the doping concentration of the first doped region can be greater than that of the second doped region. With such a setting, at least a part of the single doped semiconductor portion is at least divided into a first doped region with a higher doping concentration and a second doped region with a lower doping concentration. The presence of the first doped region can reduce the contact resistance between the conductive electrode and the first doped semiconductor portion and / or the second doped semiconductor portion, and reduce the carrier transport loss. In addition, compared with the first doped region, the presence of the second doped region with a lower doping concentration is beneficial to reducing the carrier recombination rate and improving the conversion efficiency of the back contact battery. As for the specific doping concentrations of the first doped region and the second doped region in a single first doped semiconductor portion and / or a single second doped semiconductor portion, they can be set according to actual requirements, and no specific limitation is made here.

[0142] It should be noted that in a single first doped semiconductor portion and / or a single second doped semiconductor portion, the difference in the doping forms of the first doped region and the second doped region can be only one of the doping forms such as the doping object, the doping concentration, or the doping element type. For example: in at least a part of a single first doped semiconductor portion and / or at least a part of a single second doped semiconductor portion, the first doped region includes a doped semiconductor layer, the second doped region includes a doped region, and the first doped region and the second doped region are the same in other doping forms such as the doping concentration and the doping element type. Or, the difference in the doping forms of the first doped region and the second doped region can also be: multiple doping forms such as the doping object, the doping concentration, and the doping element type are different. For example: in at least a part of a single first doped semiconductor portion and / or at least a part of a single second doped semiconductor portion, the first doped region includes a doped semiconductor layer, the second doped region includes a doped region, and the doping concentration of the doped semiconductor layer is greater than that of the doped region.

[0143] In terms of surface topography, exemplarily, such as Figure 7As shown, in a single first doped semiconductor portion 12 and / or a single second doped semiconductor portion 13, the surface of the first doped region 15 on the side facing away from the semiconductor substrate 11 can be a flat surface. With such a setting, it is beneficial to improve the passivation effect of the surface passivation layer on the side of the first doped region 15 facing away from the semiconductor substrate 11 and reduce the carrier recombination rate. Additionally, when the first doped region 15 includes a doped semiconductor layer formed on a partial region of the first surface, the surface topography of the first doped region 15 deposited on the semiconductor substrate 11 can often reflect the local surface topography of the first surface where the first doped region 15 is formed. Therefore, when the surface of the first doped region 15 on the side facing away from the semiconductor substrate 11 is a relatively flat surface, the local surface of the first surface where the first doped region 15 is formed is also relatively flat, which is beneficial to improving the formation quality of the doped semiconductor layer, enhancing the field passivation effect of the doped semiconductor layer, and further reducing the carrier recombination rate.

[0144] Exemplarily, as Figure 8 As shown, in a single first doped semiconductor portion 12 and / or a single second doped semiconductor portion 13, the surface of the second doped region 16 on the side facing away from the semiconductor substrate 11 is a matte surface. With such a setting, the surface of the second doped region 16 on the side facing away from the semiconductor substrate 11 is relatively rough, which is beneficial to improving the light trapping effect on the side of the second doped region 16 facing away from the semiconductor substrate 11, further increasing the bifaciality of the back contact cell, and improving the conversion efficiency of the back contact cell. Additionally, when the surface of the first surface corresponding to the second doped region 16 is higher than the surface of the spacer region 14, it is beneficial to change the transmission path of some of the light incident on the first surface side under the combined action of the matte surface of the second doped region 16 on the side facing away from the semiconductor substrate 11 and the matte surface of the spacer region 14, so that more light can be incident into the semiconductor substrate 11 from the first surface side of the cell and be utilized by the semiconductor substrate 11, thereby improving the conversion efficiency of the back contact cell.

[0145] As for the type, distribution, and size of the matte surface structure of the second doped region on the side facing away from the semiconductor substrate, they can be set according to actual requirements and are not specifically limited here.

[0146] Exemplarily, as Figure 8As shown in the figure, when the surface of the second doping region 16 on the side away from the semiconductor substrate 11 is a matte surface, the matte surface morphology of the second doping region 16 on the side away from the semiconductor substrate 11 and the matte surface morphology of the spacer region 14 can be different. With such a setting, it is beneficial to make the surface of the second doping region 16 on the side away from the semiconductor substrate 11 have a different light refraction effect from the surface of the spacer region 14, thereby facilitating the change of the light transmission path on the first surface side of the back-contact battery, so that more light is refracted into the semiconductor substrate 11 at least under the interaction between the surface of the second doping region 16 on the side away from the semiconductor substrate 11 and the surface of the spacer region 14, and is utilized by the semiconductor substrate 11, increasing the bifaciality of the back-contact battery and improving the conversion efficiency of the back-contact battery.

[0147] The fact that the matte surface morphology of the second doping region on the side away from the semiconductor substrate and the matte surface morphology of the spacer region can be different may mean that at least one of the types, distribution, and size of the matte surface structure of the second doping region on the side away from the semiconductor substrate is different from at least one of the types, distribution, and size of the matte surface structure of the spacer region. The specific situation of the different surface morphologies of the two can refer to the situation where the matte surface morphology of the local region of the first surface of the semiconductor substrate corresponding to the second doping region and the matte surface morphology of the spacer region are different as described above, and will not be elaborated here.

[0148] Of course, when the surface of the second doping region on the side away from the semiconductor substrate is a matte surface, the matte surface morphology of the second doping region on the side away from the semiconductor substrate and the matte surface morphology of the spacer region can also be substantially the same. At this time, the texturing operation of the matte surface of the second doping region on the side away from the semiconductor substrate (or the local surface formed with the second doping region on the first surface) and the matte surface of the spacer region can be realized in the same operation step and through the same manufacturing process, simplifying the manufacturing process of the back-contact battery and improving the manufacturing efficiency of the back-contact battery.

[0149] In addition, as Figure 7 shown, the surface of the second doping region 16 on the side away from the semiconductor substrate 11 can also be a flat surface. At this time, there is no need to texture the local surface of the first surface formed with the second doping region 16, which is beneficial to making the part of the semiconductor substrate 11 corresponding to the second doping region 16 have a larger light absorption depth and is beneficial to improving the light utilization rate of the semiconductor substrate 11.

[0150] It should be noted that when a tower base structure or a texture structure such as a matte surface structure is formed on the side of the first doped region and the second doped region included in a single first doped semiconductor portion and a single second doped semiconductor portion away from the semiconductor substrate, a texture structure such as a tower base structure or a matte surface structure with substantially the same morphology is also provided on the surface of the first face corresponding to the single first doped semiconductor portion and / or the single second doped semiconductor portion. At this time, in the surface of the first face corresponding to the single first doped semiconductor portion and / or the single second doped semiconductor portion, the height difference between the partial surface provided with the first doped region and the partial surface provided with the second doped region means: along the thickness direction of the semiconductor substrate, the top of the texture structure of the partial surface with a larger height corresponding to the first doped region and the second doped region on the first face, and the bottom of the texture structure of the partial surface with a smaller height corresponding to the first doped region and the second doped region on the first face.

[0151] In terms of electrical conduction, as Figure 7 and Figure 8 shown, in a single first doped semiconductor portion 12 and / or a single second doped semiconductor portion 13, the first doped region 15 and the second doped region 16 can be electrically conductive; or, as Figures 1 to 5 shown, the first doped region 15 and the second doped region 16 can also be arranged at intervals.

[0152] It should be noted that in a single first doped semiconductor portion and / or a single second doped semiconductor portion, the conduction types of the first doped region and the second doped region are the same. As Figure 7 and Figure 8 shown, when the first doped region 15 and the second doped region 16 with the same conduction type are electrically conductive, the carriers collected by one of the first doped region 15 and the second doped region 16 can be directly transmitted to the other through the interface between the two, and are led out through the conductive electrode in electrical contact with the other, without being transmitted to the other through the semiconductor substrate 11 with relatively poor conductive characteristics (because the first doped region 15 and the second doped region 16 are formed on one side of the first face of the semiconductor substrate 11 and the doping concentration of the corresponding doping elements is greater than the doping concentration of the corresponding doping elements in the semiconductor substrate 11), reducing the transmission loss and being beneficial to improving the conversion efficiency of the back contact battery.

[0153] As Figure 9 shown, when in a single first doped semiconductor portion 12 and / or a single second doped semiconductor portion 13, the first doped region 15 and the second doped region 16 are electrically conductive, and in the surface of the first face corresponding to the single first doped semiconductor portion 12 and / or the single second doped semiconductor portion 13, the partial surface provided with the first doped region 15 is flush with the partial surface provided with the second doped region 16, at least one of the first doped region 15 and the second doped region 16 can extend in a direction parallel to the first face and approaching each other to be electrically lapped with the other.

[0154] Alternatively, as shown in Figure 7 and Figure 8 , when in the surface of the first side corresponding to the single first doped semiconductor portion 12 and / or the single second doped semiconductor portion 13, the partial surface provided with the first doped region 15 and the partial surface provided with the second doped region 16 are staggeredly arranged along the thickness direction of the semiconductor substrate 11, at this time, the surface of the first side corresponding to the first doped semiconductor portion 12 and / or the second doped semiconductor portion 13 has a stepped structure. Moreover, one of the first doped region 15 and the second doped region 16 can also extend to cover the side wall of the stepped structure and be electrically connected to the other. With such an arrangement, one of the first doped region 15 and the second doped region 16 extends to cover the side wall of the stepped structure, which not only helps to increase the formation range of the first doped semiconductor portion 12 and / or the second doped semiconductor portion 13 on the first side, thereby increasing the field passivation effect of the first doped semiconductor portion 12 and / or the second doped semiconductor portion 13, but also helps to timely export the carriers collected by the one that is not directly in electrical contact with the conductive electrode in the first doped region 15 and the second doped region 16, reducing the carrier recombination rate and being beneficial to improving the conversion efficiency of the back contact battery.

[0155] Or, it can also be that both the first doped region and the second doped region in the single first doped semiconductor portion and / or the single second doped semiconductor portion extend to cover the side wall of the stepped structure and are electrically connected to each other at the side wall of the stepped structure.

[0156] When in the single first doped semiconductor portion and / or the single second doped semiconductor portion, one of the first doped region and the second doped region can also extend to cover the side wall of the stepped structure and be electrically connected to the other, the electrical connection manner and the size of the electrical connection area between the two can be set according to the set height of the first doped region and the second doped region along the thickness direction of the semiconductor substrate, the doping forms of the first doped region and the second doped region, and the actual requirements, and no specific limitation is made here.

[0157] Exemplarily, as shown in Figure 10 and Figure 11 , when the first doped region 15 includes a doped semiconductor layer and the second doped region 16 includes a doped region, as shown in Figure 10As shown, when among the surfaces corresponding to the single first doped semiconductor part 12 and / or the single second doped semiconductor part 13 on the first face, the local surface where the first doped region 15 is provided is lower than the local surface where the second doped region 16 is provided, it may be that the doped region included in the second doped region 16 extends into the sidewall of the stepped structure along the direction from the first face to the second face and is at least electrically connected to the doped semiconductor layer included in the first doped region 15 (when the first doped region 15 further includes an interface passivation layer 19 and / or an inner diffusion region 18, the doped region included in the second doped region 16 may also be electrically connected to the interface passivation layer 19 and / or the inner diffusion region 18 included in the first doped region 15). Or, as Figure 11 shown, it may be that the doped semiconductor layer included in the first doped region 15 extends onto the sidewall of the stepped structure along the direction from the second face to the first face and is electrically connected to the doped region included in the second doped region 16; at this time, it may be that the doped semiconductor layer included in the first doped region 15 is directly in electrical contact with the doped region included in the second doped region 16; or when the first doped region 15 further includes an interface passivation layer 19 and / or an inner diffusion region 18, it is that the doped semiconductor layer included in the first doped region 15 is also electrically connected to the doped region included in the second doped region 16 through the interface passivation layer 19 and / or the inner diffusion region 18 included in the first doped region 15.

[0158] In the case where the first doped region includes a doped semiconductor layer and the second doped region includes a doped region, as Figure 12 and Figure 13 shown, when among the surfaces corresponding to the single first doped semiconductor part 12 and / or the single second doped semiconductor part 13 on the first face, the local surface where the first doped region 15 is provided is higher than the local surface where the second doped region 16 is provided, as Figure 12 shown, it may be that the doped region included in the second doped region 16 extends into the sidewall of the stepped structure along the direction from the second face to the first face and is at least electrically connected to the doped semiconductor layer included in the first doped region 15 (when the first doped region 15 further includes an interface passivation layer 19 and / or an inner diffusion region 18, the doped region included in the second doped region 16 may also be electrically connected to the interface passivation layer 19 and / or the inner diffusion region 18 included in the first doped region 15). Or, as Figure 13 shown, it may be that the doped semiconductor layer included in the first doped region 15 extends onto the sidewall of the stepped structure along the direction from the first face to the second face and is electrically connected to the doped region included in the second doped region 16; at this time, it may be that the doped semiconductor layer included in the first doped region 15 can be directly in electrical contact with the doped region included in the second doped region 16.

[0159] Exemplarily, as Figure 10As shown, when the second doping region 16 includes a doping region disposed in a partial region of the first surface and the second doping region 16 further extends into the sidewall of the stepped structure, in the thickness direction of the semiconductor substrate 11, the height at which the second doping region 16 abuts against the first doping region 15 can be greater than or equal to one-fifth of the thickness of the first doping region 15 and less than or equal to two-thirds of the thickness of the first doping region 15. When the height at which the second doping region 16 abuts against the first doping region 15 is within the above range, it is beneficial to prevent the area of electrical connection between the first doping region 15 and the second doping region 16 from being small due to the small abutting height, which may cause the carriers collected by one of the two regions that are not directly electrically connected to the conductive electrode to be difficult to be exported in time, further reducing the carrier recombination rate. In addition, it can also prevent problems such as the light absorption depth of the semiconductor substrate 11 being too small, the parasitic absorption of at least one of the first doping region 15 and the second doping region 16 being high, and the doping difficulty being high due to the excessive abutting height, which is beneficial to improving the light utilization rate of the back contact battery and reducing the manufacturing difficulty.

[0160] Of course, when the second doping region includes a doping region disposed in a partial region of the first surface and the second doping region further extends into the sidewall of the stepped structure, in the thickness direction of the semiconductor substrate, the height at which the second doping region abuts against the first doping region can also be set to other appropriate values, as long as it can be applied to the back contact battery provided in the embodiments of the present application.

[0161] In terms of the setting position, in a single first doped semiconductor portion and / or a single second doped semiconductor portion, the second doping region can be disposed only on one side of the first doping region along the first direction. Alternatively, the second doping region can also be disposed on both sides of the first doping region along the second direction; at this time, the first doping region can be disposed in the middle, and the second doping regions are disposed on both sides of the first doping region (that is, along the first direction, the widths of the second doping regions on both sides of the first doping region along the first direction are substantially the same); it is also possible that there is a certain difference in the widths of the second doping regions on both sides of the first doping region along the first direction.

[0162] When, along the first direction, the widths of the second doping regions on both sides of the first doping region along the first direction are substantially the same, in a single first doped semiconductor portion and / or a single second doped semiconductor portion, the distributions of the first doping region and the second doping region on the first surface are relatively regular, which is beneficial for the first doping region with a corresponding doping form to be electrically connected to the conductive electrode, and will not cause the second doping region with a different doping form to be electrically connected to the conductive electrode, improving the yield of the back contact battery and being beneficial to reducing the manufacturing difficulty of the back contact battery. At the same time, the carriers collected by these two second doping regions can be timely conducted to the first doping region, reducing the transmission loss.

[0163] It should be noted that when only one of the first doped semiconductor portion and the second doped semiconductor portion includes the first doped region and the second doped region, the one of the first doped semiconductor portion and the second doped semiconductor portion that does not include the first doped region and the second doped region may also include a doped region provided in a partial region of the first surface of the semiconductor substrate, or may include a doped semiconductor layer provided on the partial region of the first surface.

[0164] When the one of the first doped semiconductor portion and the second doped semiconductor portion that does not include the first doped region and the second doped region includes a doped semiconductor layer provided on the partial region of the first surface, the setting principle of the material of the doped semiconductor layer may refer to the setting principle of the doped semiconductor layer material included in the first doped region in the foregoing text, and will not be elaborated here.

[0165] In addition, when the one of the first doped semiconductor portion and the second doped semiconductor portion that does not include the first doped region and the second doped region includes a doped semiconductor layer provided on the partial region of the first surface, as Figure 13 shown, the doped semiconductor layer may be directly provided on the first surface; or, as Figure 14 shown, the one of the first doped semiconductor portion 12 and the second doped semiconductor portion 13 that does not include the first doped region 15 and the second doped region 16 may further include an interface passivation layer 19 provided between the semiconductor substrate 11 and the doped semiconductor layer. The setting principle of the material of the interface passivation layer 19 may refer to the setting principle of the material of the interface passivation layer 19 included in the first doped region 15 in the foregoing text, and will not be elaborated here.

[0166] In addition, when one of the first doped semiconductor portion and the second doped semiconductor portion does not include the first doped region and the second doped region, the partial surface of the first surface corresponding to the one of the first doped semiconductor portion and the second doped semiconductor portion that does not include the first doped region and the second doped region may be a flat surface or a textured surface. The topography of the partial surface may be set according to the structure and actual requirements of the one of the first doped semiconductor portion and the second doped semiconductor portion that does not include the first doped region and the second doped region, and will not be specifically limited here.

[0167] For example: as Figure 13 shown, when the one of the first doped semiconductor portion 12 and the second doped semiconductor portion 13 that does not include the first doped region 15 and the second doped region 16 includes a doped semiconductor layer provided on the partial region of the first surface, the partial surface of the first surface corresponding to the one of the first doped semiconductor portion 12 and the second doped semiconductor portion 13 that does not include the first doped region 15 and the second doped region 16 may be a flat surface to improve the formation quality and film thickness of the doped semiconductor layer, enhance the field passivation effect of the doped semiconductor layer, and improve the conversion efficiency of the back contact battery.

[0168] Second aspect, embodiments of the present application provide a method for manufacturing a back-contact battery. The manufacturing process will be described below according to Figures 14 to 32 the cross-sectional views of the operations shown. Specifically, the method for manufacturing a back-contact battery includes: First, provide a semiconductor substrate. The semiconductor substrate includes opposite first and second surfaces. Next, as Figures 15 to 21 shown, or as Figures 25 to 29 shown, form a first doped semiconductor portion 12 in a partial region of the first surface. Next, as Figures 22 to 23 shown, or as Figures 30 to 31 shown, form a second doped semiconductor portion 13 in a partial region of the first surface. The first doped semiconductor portion 12 and the second doped semiconductor portion 13 have opposite conductivity types, and the first doped semiconductor portion 12 and the second doped semiconductor portion 13 are spaced apart along a first direction, the first direction being parallel to the first surface. Along the first direction, the first doped semiconductor portion 12 and / or the second doped semiconductor portion 13 includes a first doped region 15 and a second doped region 16 located on at least one side of the first doped region 15, and the doping forms of the first doped region 15 and the second doped region 16 are different. In the first surface of the semiconductor substrate 11, the region where the first doped semiconductor portion 12 and the second doped semiconductor portion 13 are not provided is an interval region 14. Next, as Figure 24 and Figure 32 shown, perform a texturing treatment on the surface of the interval region 14 to form a textured surface.

[0169] The structure, materials, etc. of the back-contact battery formed by the manufacturing method provided in the second aspect of the embodiments of the present application can be the same as those of the back-contact battery provided in the first aspect. The beneficial effects of the second aspect and its various implementation manners in the embodiments of the present application can refer to the analysis of the beneficial effects in the first aspect and its various implementation manners, and will not be elaborated here.

[0170] In the actual manufacturing process, the embodiments of the present application do not specifically limit the manufacturing sequence of the first doped semiconductor portion and the second doped semiconductor portion. The first doped semiconductor portion can be formed first in a partial region of the first surface, and then the second doped semiconductor portion can be formed in the partial region of the first surface where the first doped semiconductor portion is not formed. Alternatively, the second doped semiconductor portion can be formed first in a partial region of the first surface, and then the first doped semiconductor portion can be formed in the partial region of the first surface where the second doped semiconductor portion is not formed.

[0171] In addition, the embodiments of the present application do not specifically limit the manufacturing sequence of the first doped region and the second doped region in a single first doped semiconductor portion and / or a single second doped semiconductor portion. The first doped region can be formed first, and then the second doped region can be formed. Or the second doped region can be formed first, and then the first doped region can be formed.

[0172] The manufacturing processes of the first doped semiconductor portion and / or the second doped semiconductor portion will be described in the following two cases according to the different manufacturing sequences of the first doped region and the second doped region in the single first doped semiconductor portion and / or the single second doped semiconductor portion:

[0173] First, by way of example, forming the first doped semiconductor portion and / or the second doped semiconductor portion in a partial region of the first surface may include steps: As Figures 16 to 18 shown, a second doped region 16 is formed in a partial region of the first surface corresponding to the single first doped semiconductor portion 12 or the single second doped semiconductor portion 13. Next, as Figures 19 to 21 shown, the first doped region 15 is formed at least on the remaining regions of the first surface corresponding to the single first doped semiconductor portion 12 or the single second doped semiconductor portion 13.

[0174] In the actual manufacturing process, processes such as spraying can be used to perform doping treatment only on a partial region of the second doped region included in the single first doped semiconductor portion or the single second doped semiconductor portion on the first surface to form the second doped region. Or, as Figure 15 and Figure 17 shown, processes such as diffusion or ion implantation can also be used to perform doping treatment on the surfaces of all exposed regions of the first surface of the semiconductor substrate 11; then, as Figure 18 shown, processes such as deposition and etching are used to form a mask layer; and under the protection of the mask layer, processes such as wet etching or laser etching are used to pattern the second doped region 16 so as to form the second doped region 16 only in a partial region of the first surface corresponding to the single first doped semiconductor portion 12 or the single second doped semiconductor portion 13.

[0175] Next, as Figure 19 shown, a deposition process can be used to form an intrinsic semiconductor layer 17 for manufacturing the first doped region 15 on the first surface. Then, as Figure 20 shown, processes such as diffusion or ion implantation can be used to perform doping treatment on the intrinsic semiconductor layer to form the first doped region 15. Then, as Figure 21 shown, under the protection of the mask layer, processes such as wet etching or laser etching are used to pattern the first doped region 15 so as to form the first doped region 15 only on a partial region of the first surface corresponding to the single first doped semiconductor portion 12 or the single second doped semiconductor portion 13.

[0176] If the manufactured back-contact battery further includes an interface passivation layer, as Figure 19As shown, an interface passivation layer 19 needs to be formed on the first surface before forming the intrinsic semiconductor layer 17. The interface passivation layer 19 can be disposed only on a partial region of the first surface corresponding to a single first doped semiconductor portion 12 or a single second doped semiconductor portion 13. Alternatively, it can also be disposed on the entire first surface. In this case, the patterning process of the interface passivation layer 19 can be achieved together by using the mask structure and etchant applied during the patterning of the first doped region 15.

[0177] In addition, in the first case, after providing the semiconductor substrate and before forming the second doped region, as Figure 16 shown, at least the partial surface of the first surface corresponding to the second doped region can be textured to form a textured surface, so as to improve the bifacial ratio of the back contact cell.

[0178] Second, exemplarily, forming the first doped semiconductor portion and / or the second doped semiconductor portion in a partial region of the first surface may include the steps: as Figure 25 and Figure 26 shown, an intrinsic semiconductor layer 17 is formed on a region of the first surface that does not correspond to the second doped region 16 included in either the first doped semiconductor portion 12 or the second doped semiconductor portion 13. Next, as Figure 28 shown, doping treatment is performed on the intrinsic semiconductor layer and the portion of the first surface exposed outside the intrinsic semiconductor layer, so that the intrinsic semiconductor layer forms a first doped region 15, and a second doped region 16 is formed in the region of the first surface exposed outside the first doped region 15. Next, as Figure 29 shown, the portions of the first doped region 15 located in the spacer region 14 and on the first surface corresponding to the other of the first doped semiconductor portion 12 and the second doped semiconductor portion 13 are selectively removed.

[0179] In the second case, the intrinsic semiconductor layer for manufacturing the first doped region is formed first. Then, through the doping process, the doping treatments of the first doped region and the second doped region are achieved together. In the actual manufacturing process, a deposition process can be used to form an integral intrinsic semiconductor layer disposed on the first surface. Then, under the protection of the mask layer, the intrinsic semiconductor layer is patterned to expose the surface of the region in the first surface corresponding to the second doped region of the same conductivity type. Then, processes such as diffusion or ion implantation are used to perform doping treatment on the intrinsic semiconductor layer and the portion of the first surface exposed outside the intrinsic semiconductor layer, and the first doped region and the second doped region can be formed simultaneously. Next, as Figure 29 shown, under the protection of the mask layer, processes such as wet etching or laser etching are used to selectively remove the portions of the first doped region 15 located in the spacer region 14 and on the first surface corresponding to the other of the first doped semiconductor portion 12 and the second doped semiconductor portion 13.

[0180] If the manufactured back-contact battery further includes an interface passivation layer, as Figure 25 shown, it is necessary to form the interface passivation layer 19 on the first surface before forming the intrinsic semiconductor layer 17. The interface passivation layer 19 can be disposed only on a partial area of the first surface corresponding to a single first doped semiconductor portion 12 or a single second doped semiconductor portion 13. Alternatively, it can also be disposed on the entire first surface. In this case, the patterning process of the interface passivation layer 19 can be achieved together by using the mask structure and etchant applied during the patterning of the first doped region 15.

[0181] In addition, in the second case, after forming the intrinsic semiconductor layer on the region of the first surface that does not correspond to the second doped region included in one of the first doped semiconductor portion and the second doped semiconductor portion, and before performing doping treatment on the intrinsic semiconductor layer and the portion of the first surface exposed outside the intrinsic semiconductor layer, as Figure 27 shown, it is possible to at least perform texturing treatment on the local surface of the first surface corresponding to the second doped region to form a textured surface, so as to improve the bifaciality of the back-contact battery.

[0182] When in the manufactured back-contact battery, one of the first doped semiconductor portion and the second doped semiconductor portion does not include the first doped region and the second doped region, the manufacturing process of the first doped semiconductor portion or the second doped semiconductor portion that does not include the first doped region and the second doped region can be determined according to its own structure, and no specific limitation is made here.

[0183] Exemplarily, after forming one of the first doped semiconductor portion and the second doped semiconductor portion that includes the first doped region and the second doped region, as Figure 22 and Figure 23 shown, or, as Figure 30 and Figure 31 shown, processes such as deposition and doping are used to form a doped semiconductor layer disposed entirely on the first surface. Then, under the protection of the corresponding mask layer, the portions of the doped semiconductor layer covering the spacer region 14, the first doped region 15, and the second doped region 16 are selectively removed.

[0184] It should be noted that if the back-contact battery further includes an interface passivation layer between one of the first doped semiconductor portion and the second doped semiconductor portion that does not include the first doped region and the second doped region, and the semiconductor substrate, it is also necessary to form the interface passivation layer before forming the doped semiconductor layer.

[0185] In addition, the manufacturing sequence of one of the first doped semiconductor portion and the second doped semiconductor portion that does not include one of the first doped region and the second doped region may also be located before the manufacturing sequence of one of the first doped semiconductor portion and the second doped semiconductor portion that includes the first doped region and the second doped region. In this case, the manufacturing process of one of the first doped semiconductor portion and the second doped semiconductor portion that does not include one of the first doped region and the second doped region may also refer to the foregoing, and will not be elaborated herein.

[0186] In a third aspect, an embodiment of the present application provides a photovoltaic module, which includes: a battery string and a packaging layer. The battery string is formed by electrically connecting a plurality of back contact batteries provided as in the first aspect and its various implementation manners; the packaging layer covers the surface of the battery string.

[0187] For the beneficial effects of the third aspect and its various implementation manners in the embodiments of the present application, reference may be made to the analysis of the beneficial effects in the first aspect and its various implementation manners, and will not be elaborated herein.

[0188] In the above description, technical details such as the layout and etching of each layer are not described in detail. However, those skilled in the art should understand that various technical means can be used to form layers, regions, etc. with the required shapes. In addition, in order to form the same structure, those skilled in the art can also design methods that are not exactly the same as the methods described above. In addition, although the above embodiments are described separately, this does not mean that the measures in each embodiment cannot be used in combination advantageously.

[0189] The above describes the embodiments of the present application. However, these embodiments are only for more clearly explaining, rather than limiting the scope of the present application. The scope of the present application is defined by the appended claims and their equivalents. Without departing from the scope of the present application, those skilled in the art can make various substitutions and modifications, and these substitutions and modifications should all fall within the scope of the present application.

Claims

1. A back-contact battery, characterized in that, Comprising: A semiconductor substrate, a doped semiconductor portion, and a spacer; the semiconductor substrate includes opposite first and second surfaces; The doped semiconductor portion includes a first doped semiconductor portion and a second doped semiconductor portion; the first doped semiconductor portion and the second doped semiconductor portion have opposite conduction types; the first doped semiconductor portion and the second doped semiconductor portion are spaced apart along a first direction on the first surface of the semiconductor substrate, and the first direction is parallel to the first surface; The spacer is an area on the first surface of the semiconductor substrate where the first doped semiconductor portion and the second doped semiconductor portion are not correspondingly provided; Wherein, the surface of the spacer is a matte surface; Along the first direction, the first doped semiconductor portion and / or the second doped semiconductor portion includes a first doped region and a second doped region located on at least one side of the first doped region, and the doping forms of the first doped region and the second doped region are different.

2. The back contact battery according to claim 1, characterized in that, In at least part of a single doped semiconductor portion, the first doped region includes a doped semiconductor layer provided on a partial region of the first surface; the second doped region includes a doped region provided within a partial region of the first surface; And / or, the doping concentration of the first doped region is greater than the doping concentration of the second doped region.

3. The back contact battery according to claim 1, characterized in that, In at least part of a single doped semiconductor portion, the surface of the partial region of the first surface of the semiconductor substrate corresponding to the first doped region is a plane.

4. The back contact battery according to claim 1, characterized in that, The surface of the partial region of the first surface of the semiconductor substrate corresponding to the second doped region is a matte surface, and the matte surface morphology of the partial region of the first surface of the semiconductor substrate corresponding to the second doped region is different from the matte surface morphology of the spacer.

5. The back-contact battery according to claim 1, characterized in that, In the surface of the first surface corresponding to a single first doped semiconductor portion and / or a single second doped semiconductor portion, the partial surface provided with the first doped region and the partial surface provided with the second doped region are staggered along the thickness direction of the semiconductor substrate.

6. The back-contact battery according to claim 5, characterized in that, In the surface of the first surface corresponding to a single first doped semiconductor portion and / or a single second doped semiconductor portion, the height difference between the partial surface provided with the first doped region and the partial surface provided with the second doped region along the thickness direction of the semiconductor substrate is greater than or equal to 10 nm and less than or equal to 10 μm.

7. The back-contact battery according to claim 1, wherein In a single first doped semiconductor portion and / or a single second doped semiconductor portion, the first doped region is provided in the middle, and the second doped regions are provided on both sides of the first doped region.

8. The back-contact battery according to any one of claims 1 to 7, characterized in that, Along the direction from the second surface to the first surface, in the first surface, the partial surface provided with the second doped region is higher than the surface of the spacer; And / or, along the direction from the second surface to the first surface, the partial surface of the first surface provided with the second doped semiconductor portion is higher than the surface of the spacer; And / or, along the direction from the second surface to the first surface, the partial surface of the first surface provided with the first doped semiconductor portion and the partial surface of the first surface provided with the second doped semiconductor portion are staggered along the thickness direction of the semiconductor substrate.

9. The back-contact battery according to any one of claims 1 to 7, characterized in that In a single one of the first doped semiconductor portions and / or a single one of the second doped semiconductor portions, the first doped region and the second doped region are electrically connected.

10. The back-contact battery according to claim 9, wherein, In a surface of the first side corresponding to a single one of the first doped semiconductor portions and / or a single one of the second doped semiconductor portions, when a local surface provided with the first doped region and a local surface provided with the second doped region are arranged to be offset in the thickness direction of the semiconductor substrate, the surface of the first side corresponding to the first doped semiconductor portion and / or the second doped semiconductor portion has a stepped structure; one of the first doped region and the second doped region further extends to cover a sidewall of the stepped structure and is electrically connected to the other.

11. The back contact battery according to claim 10, characterized in that, In a case where the second doped region includes a doped region provided in a local region of the first side and the second doped region further extends into a sidewall of the stepped structure, in the thickness direction of the semiconductor substrate, a height at which the second doped region is docked with the first doped region is greater than or equal to one-fifth of the thickness of the first doped region and less than or equal to two-thirds of the thickness of the first doped region.

12. A manufacturing method of a back contact battery, characterized in that, Comprising: providing a semiconductor substrate; the semiconductor substrate includes opposite first and second sides; forming a first doped semiconductor portion in a local region of the first side; forming a second doped semiconductor portion in a local region of the first side; the first doped semiconductor portion and the second doped semiconductor portion have opposite conductivity types, and the first doped semiconductor portion and the second doped semiconductor portion are arranged at intervals in a first direction, the first direction being parallel to the first side; in the first direction, the first doped semiconductor portion and / or the second doped semiconductor portion includes a first doped region and a second doped region located on at least one side of the first doped region, the doping forms of the first doped region and the second doped region are different; in the first side of the semiconductor substrate, a region where the first doped semiconductor portion and the second doped semiconductor portion are not provided is an interval region; texturing the surface of the interval region to form a textured surface.

13. A photovoltaic module, characterized in that, Comprising: a battery string, the battery string being formed by electrically connecting a plurality of back-contact batteries according to any one of claims 1 to 11; and a packaging layer, the packaging layer covering the surface of the battery string.

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