Solar cell, preparation method and cell module

Abstract

The invention relates to a solar cell, a preparation method and a cell module. The solar cell comprises a substrate which comprises a light receiving surface and a backlight surface which are opposite to each other; the first surface is provided with a first type of doping layer region and a second type of doping layer region which are arranged in a staggered manner; the first surface is a light receiving surface or a backlight surface; the second surface is provided with a first type of doped layer region and / or a second type of doped layer region; the second surface is the surface except the first surface in the light receiving surface and the backlight surface; the first polarity structure is arranged in the direction, deviating from the substrate, of the first type doping layer region; and the second polarity structure is arranged in the direction, deviating from the substrate, of the second type doping layer region. By adopting the solar cell, the photoelectric conversion efficiency of the solar cell can be improved.

Description

Technical Field

[0001] The present application relates to the field of solar energy technology, and in particular to a solar cell, a preparation method and a solar cell assembly. Background Art

[0002] With the development of new green energy technologies, photovoltaic power generation technology has gradually matured. Under this circumstance, the requirements for power generation efficiency are becoming higher and higher.

[0003] Taking solar cells as an example, when improving the photoelectric conversion efficiency of solar cells, related technologies often optimize from multiple dimensions such as battery materials, battery structure, battery surface and battery environmental factors to improve the photoelectric conversion efficiency to varying degrees.

[0004] However, the related technology still has the problem of low battery conversion efficiency. Summary of the invention

[0005] Based on this, it is necessary to provide a solar cell, a preparation method and a cell assembly to address the above technical problems, so as to improve the photoelectric conversion efficiency of the solar cell.

[0006] In a first aspect, the present application provides a solar cell, the solar cell comprising:

[0007] A substrate, the substrate comprising a light-receiving surface and a backlight surface opposite to each other;

[0008] The first surface is provided with first-type doped layer regions and second-type doped layer regions arranged in a staggered manner; the first surface is a light-receiving surface or a backlight surface;

[0009] The second surface is provided with a first type doping layer region and / or a second type doping layer region; the second surface is a surface other than the first surface among the light receiving surface and the backlight surface;

[0010] A first polarity structure is arranged in a direction of the first type doping layer region away from the substrate;

[0011] The second polarity structure is arranged in the direction of the second type doping layer region away from the substrate.

[0012] In one embodiment, the polarity structure on the first surface and the polarity structure of the same type on the second surface are connected in series via a main grid or a welding ribbon.

[0013] In one embodiment, a first type doping layer region is provided on the second surface; the polarity structure on the first surface is connected in series with the same type of polarity structure on the second surface through a main grid or a welding strip, including:

[0014] The first polarity structure on the first surface and the first polarity structure on the second surface are connected in series through a main grid or a welding strip.

[0015] In one embodiment, a second type of doped layer region is provided on the second surface; the polarity structure on the first surface and the polarity structure of the same type on the second surface are connected in series through a main grid or a welding strip, including:

[0016] The second polarity structure on the first surface and the second polarity structure on the second surface are connected in series through a main grid or a welding strip.

[0017] In one embodiment, the second surface is provided with a first type doped layer region and a second type doped layer region; the polarity structure on the first surface is connected in series with the polarity structure of the same type on the second surface through a main grid or a welding strip, including:

[0018] The first polarity structure on the first surface and the first polarity structure on the second surface are connected in series via a main grid or a welding strip;

[0019] The second polarity structure on the first surface and the second polarity structure on the second surface are connected in series through a main grid or a welding strip.

[0020] In one embodiment, the area of ​​the first surface is not less than the total area of ​​the doped layer region on the first surface, and / or the area of ​​the second surface is not less than the total area of ​​the doped layer region on the second surface;

[0021] The orthographic projections of the first polarity structures on the substrate are all located within the orthographic projection range of the first type doping layer region, and the orthographic projection surfaces of the second polarity structures on the substrate are all located within the orthographic projection range of the second type doping layer region.

[0022] In one embodiment, a passivation layer is disposed between the doped layer region on the first surface and the first surface, and a transparent conductive layer and an anti-reflection layer are disposed on a side of the doped layer region on the first surface away from the first surface.

[0023] In one embodiment, a passivation layer is disposed between the doped layer region on the second surface and the second surface, and a transparent conductive layer and an anti-reflection layer are disposed on a side of the doped layer region on the second surface away from the second surface.

[0024] In one embodiment, each polar structure includes a gate line; the material of the gate line includes metal paste or alloy paste.

[0025] In one embodiment, one of the first polarity structure and the second polarity structure has the same polarity as the substrate, and the other polarity structure has a different polarity from the substrate;

[0026] The first polarity structure or the second polarity structure is wrapped with an insulating layer.

[0027] In a second aspect, the present application also provides a method for preparing a solar cell, the method comprising:

[0028] Providing a substrate, the substrate comprising a light-receiving surface and a backlight surface opposite to each other;

[0029] Forming staggered first-type doped layer regions and second-type doped layer regions on a first surface of the substrate; the first surface is a light-receiving surface or a backlight surface;

[0030] forming a first type doped layer region and / or a second type doped layer region on a second surface of the substrate; the second surface is a surface other than the first surface among the light receiving surface and the backlight surface;

[0031] A first polarity structure is generated in the direction of the first type doped layer region away from the substrate, and a second polarity structure is generated in the direction of the second type doped layer region away from the substrate.

[0032] In one embodiment, each polarity structure comprises a gate line; and the method further comprises:

[0033] A grid line is made on the surface of each polar structure; the making method includes at least one of screen printing, laser transfer and electroplating.

[0034] In a third aspect, the present application further provides a battery assembly, which includes the solar cell in any embodiment of the first aspect, or includes a solar cell prepared according to the preparation method in any embodiment of the second aspect.

[0035] The solar cell, preparation method and cell assembly described above, the solar cell comprises: a substrate, the substrate comprises a light-receiving surface and a backlight surface opposite to each other; the first surface is provided with a staggered arrangement of first-type doping layer regions and second-type doping layer regions; the first surface is the light-receiving surface or the backlight surface; the second surface is provided with a first-type doping layer region and / or a second-type doping layer region; the second surface is the surface other than the first surface between the light-receiving surface and the backlight surface; the first polarity structure is provided in the direction of the first-type doping layer region away from the substrate; the second polarity structure is provided in the direction of the second-type doping layer region away from the substrate. In the solar cell, the first-type doping layer region and the second-type doping layer region are provided on the first surface at the same time, and the first polarity structure is provided in the direction of the first-type doping layer region away from the substrate, and the second polarity structure is provided in the direction of the second-type doping layer region away from the substrate, so that the first surface of the substrate is provided with the first polarity structure and the second polarity structure at the same time, the two types of polarity structures interact with each other to form a PN junction, and at least one of the two types of polarity structures forms a PN junction by connecting with the substrate to ensure that the basic structure of the solar cell is a two-electrode structure. On this basis, a first type of doped layer region or a second type of doped layer region is provided on the second surface of the substrate, which means that a first polarity structure or a second polarity structure is provided on the second surface. Then, when the polarity structure on the second surface is different from the polarity of the substrate, the polarity structure can be connected to the substrate to form a PN junction. When the polarity structure on the second surface is the same as the polarity of the substrate, the polarity structure is connected to a polarity structure of a different polarity type on the first surface to form a PN junction. In this way, the solar cell is upgraded to a three-electrode cell structure, which shortens the distance of the carrier collection path while increasing the number of carrier transmission paths, improving the carrier convergence speed, and improving the cell's fill factor and photoelectric conversion efficiency. Further, a first type of doped layer region and a second type of doped layer region are provided on the second surface of the substrate. At this time, the working principle of the second surface is the same as that of the first surface. The electrode structure of the solar cell is upgraded to a four-electrode cell structure, further improving the cell's photoelectric conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0037] FIG1 is a schematic structural diagram of a solar cell in one embodiment;

[0038] FIG2 is a schematic structural diagram of a solar cell in another embodiment;

[0039] FIG3 is a schematic structural diagram of a solar cell in another embodiment;

[0040] FIG4 is a schematic structural diagram of a solar cell in another embodiment;

[0041] FIG. 5 is a schematic diagram of a process for preparing a solar cell in one embodiment.

[0042] Description of reference numerals:

[0043] 1: substrate;

[0044] 2: The first type of doped layer region;

[0045] 3: The second type of doped layer region;

[0046] 4: First polarity structure;

[0047] 5: Second polarity structure;

[0048] 6: Main grid;

[0049] 7: Insulation layer. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by technicians in the technical field of the present application; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and any variations thereof in the specification and claims of the present application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions. In the description of the embodiments of the present application, the technical terms "first", "second", "third", "fourth", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0052] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0053] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "connection" should be understood in a broad sense, for example, it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0054] With the rapid development of new energy technologies, all walks of life are gradually reducing their dependence on traditional fossil energy and increasing the use of new green energy. In this context, photovoltaic power generation technology is gradually becoming mature, its application is becoming more and more extensive, and the requirements for power generation efficiency are becoming higher and higher.

[0055] Taking solar cells as an example, in the related technologies, when improving the photoelectric conversion efficiency of solar cells, optimization is often performed from multiple dimensions such as battery materials, battery structure, battery surface, and battery environmental factors to improve the photoelectric conversion efficiency to varying degrees. However, the problem of low battery conversion efficiency still exists in the related technologies.

[0056] Based on this, the embodiments of the present application provide a solar cell, a preparation method and a battery assembly, by setting a first type of doped layer region and a second type of doped layer region on one surface of the solar cell substrate, setting at least one type of doped layer region on the other surface opposite to the surface, and generating a first polarity structure in the first type of doped layer region in the direction away from the substrate, and generating a second polarity structure in the second type of doped layer region in the direction away from the substrate, thereby increasing the number of electrodes of the battery, thereby shortening the distance of the carrier collection path, increasing the number of carrier transmission paths, achieving efficient carrier convergence, and improving the fill factor and photoelectric conversion efficiency of the battery.

[0057] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0058] In an exemplary embodiment, a solar cell is provided, see FIG1 , the solar cell comprising: a substrate 1, the substrate 1 comprising a relative light-receiving surface and a backlight surface; the first surface is provided with first-type doping layer regions 2 and second-type doping layer regions 3 arranged in an alternating manner; the first surface is the light-receiving surface or the backlight surface; the second surface is provided with first-type doping layer regions 2 and / or second-type doping layer regions 3; the second surface is the surface of the light-receiving surface and the backlight surface other than the first surface; a first polarity structure 4 is provided in the direction of the first-type doping layer region 2 away from the substrate 1; and a second polarity structure 5 is provided in the direction of the second-type doping layer region 3 away from the substrate 1.

[0059] In practical applications, the material of the substrate 1 may be amorphous, microcrystalline, polycrystalline, monocrystalline silicon or compound semiconductor, etc. The doping type of the substrate 1 of the solar cell, the first type doping layer region 2, and the second type doping layer region 3 may be N-type doping or P-type doping. On the basis that the first type doping layer region 2 and the second type doping layer region 3 are of opposite types, this embodiment does not limit this.

[0060] The light-receiving surface of the substrate 1 is the surface in direct contact with sunlight, and is used to receive sunlight and convert sunlight into electrons. The backlight surface is the other surface opposite to the light-receiving surface, and can be used to collect electrons.

[0061] It should be noted that the light-receiving surface can also collect electrons, but considering the influence of factors such as reflection and refraction on the light-receiving surface, its ability to collect electrons will be different from that of the backlight surface. Therefore, the backlight surface is usually used to collect electrons. In order to briefly and clearly explain the technical solution provided in the embodiment of the present application, the solar cell structure is explained below by taking the first surface as the backlight surface and the second surface as the light-receiving surface as an example.

[0062] Different types of doping layer regions are arranged on different surfaces of the substrate 1. The polarity type of the doping layer region may be the same as or different from the polarity type of the substrate 1. In this embodiment, the first type of doping layer region 2 and the second type of doping layer region 3 are used to represent them. Next, a first polarity structure 4 is arranged in the direction of the first type of doping layer region 2 away from the substrate 1, and a second polarity structure 5 is arranged in the direction of the second type of doping layer region 3 away from the substrate 1. Since the first type of doping layer region 2 and the second type of doping layer region 3 are of different types, the polarity types of the first polarity structure 4 arranged in the first type of doping layer region and the second polarity structure 5 arranged in the second type of doping layer region are naturally different.

[0063] In this way, the polar structure on the doping layer area with a polarity type different from that of the substrate 1 forms a PN junction by establishing an electric field with the substrate 1. The PN junction separates the electron-hole pairs generated by light, and under the action of the electric field, a potential difference is generated through the two ends of the PN junction to provide electric energy for the load, thereby realizing photovoltaic power generation; the polar structure on the doping layer area with a polarity type different from that of the substrate 1 also establishes an electric field with another type of doping layer area to form a PN junction. The PN junction separates the electron-hole pairs generated by light, and under the action of the electric field, a potential difference is generated through the two ends of the PN junction to provide electric energy for the load, thereby realizing photovoltaic power generation.

[0064] In order to further improve the speed of collecting electrons in the solar cell, two types of doped layer regions are set on the first surface (light-receiving surface or backlight surface) of the substrate 1, which means that a first polarity structure 4 and a second polarity structure 5 are simultaneously set on the first surface. Then, one type of polarity structure on the first surface forms a PN junction with the substrate 1, and a PN junction is formed between the two types of polarity structures on the first surface.

[0065] Furthermore, the first type of doped layer region 2 and / or the second type of doped layer region 3 are arranged on the second surface of the substrate 1, which means that at least one type of polar structure is arranged on the second surface, and the polar structure on the second surface can form a PN junction with the substrate 1, or can form a PN junction with another type of polar structure on the first surface. In summary, the solar cell in the embodiment of the present application is at least a three-electrode cell structure.

[0066] Please continue to refer to Figure 1, which is a cross-sectional schematic diagram of a solar cell in which the second surface is the light-receiving surface, the first surface is the backlight surface, and the second surface is provided with a first-type doping layer region 2. In Figure 1, a PN junction is formed between the first polarity structure 4 on the second surface and the second polarity structure 5 on the first surface. Combined with the PN junction formed by the second polarity structure 5 on the first surface and the substrate 1, and the PN junction formed between the first polarity structure 4 and the second polarity structure 5 on the first surface, the solar cell is a three-electrode structure.

[0067] Next, based on setting the first polarity structure 4 and the second polarity structure 5 on the first surface, and taking the first polarity structure 4 set in the first type doping layer region 2 as having the same polarity as the substrate 1 as an example, the doping layer region set on the second surface is optimized to further improve the photoelectric conversion efficiency of the solar cell.

[0068] Please refer to Figure 2, which is a cross-sectional schematic diagram of a solar cell in which the second surface is the light-receiving surface, the first surface is the backlight surface, and the second surface is provided with a first type of doped layer region 2 and a second type of doped layer region 3. In Figure 2, a PN junction is formed between the second polarity structure 5 on the second surface and the substrate 1, and a PN junction is formed between the second polarity structure 5 on the second surface and the first polarity structure 4 in Figure 2. Combined with the PN junction formed by the second polarity structure 5 on the first surface and the substrate 1, and the PN junction formed between the first polarity structure 4 and the second polarity structure 5 on the first surface, the light-receiving surface and the backlight surface of the solar cell both have independent two-electrode systems. Such a solar cell with a four-electrode structure has a higher filling factor and conversion efficiency.

[0069] The solar cell in the embodiment of the present application is provided with a first type of doped layer region 2 and a second type of doped layer region 3 on the first surface, and a first polarity structure 4 is provided in the direction of the first type of doped layer region 2 away from the substrate 1, and a second polarity structure 5 is provided in the direction of the second type of doped layer region 3 away from the substrate 1. In this way, the first surface of the substrate 1 is provided with the first polarity structure 4 and the second polarity structure 5 at the same time, and the two types of polarity structures interact with each other to form a PN junction, and at least one of the two types of polarity structures forms a PN junction by connecting to the substrate 1 to ensure that the basic structure of the solar cell is a two-electrode structure. On this basis, the first type doping layer region 2 or the second type doping layer region 3 is arranged on the second surface of the substrate 1, which means that the first polarity structure 4 or the second polarity structure 5 is arranged on the second surface. Then, when the polarity structure on the second surface is different from the polarity of the substrate 1, the polarity structure can be connected to the substrate 1 to form a PN junction. When the polarity structure on the second surface is the same as the polarity of the substrate 1, the polarity structure is connected to the polarity structure of different polarity types on the first surface to form a PN junction. In this way, the solar cell is upgraded to a three-electrode cell structure, which shortens the distance of the carrier collection path while increasing the number of carrier transmission paths, improving the carrier convergence speed, and improving the cell's fill factor and photoelectric conversion efficiency. Further, the first type doping layer region 2 and the second type doping layer region 3 are arranged on the second surface of the substrate 1. At this time, the working principle of the second surface is the same as that of the first surface. The electrode structure of the solar cell is upgraded to a four-electrode cell structure, further improving the cell's photoelectric conversion efficiency.

[0070] In the field of solar cells, the types of electrons collected on the same polarity structure are the same. Therefore, when a solar cell includes multiple polarity structures, the electrons of the same polarity structure can be gathered together to be provided to the load for use.

[0071] In an exemplary embodiment, the polarity structure on the first surface and the polarity structure of the same type on the second surface are connected in series via a main grid 6 or a welding ribbon.

[0072] The main grid 6 and the welding strip are both connecting materials for conducting current carriers.

[0073] The main grid 6 is used to collect the electrons excited by sunlight on the cell sheet of the solar cell and guide them out, and can be located on the light-receiving surface of the cell sheet. The main grid 6 can be made of metal with good conductivity, such as silver, aluminum, etc., or a conductive layer can be set separately. There is no restriction on the material, thickness, and width of the main grid 6. The main grid 6 connection method has the advantages of low cost and simple manufacturing process.

[0074] The welding strip is used to connect the metal sheets on the battery cell. It can be made of metal materials such as copper and aluminum and can be located on the backlight side of the battery. The electrodes connected by the welding strip have the advantages of high reliability, high connection strength and long service life.

[0075] In terms of the selection of connection methods, the same type of polarity structures can be connected in series using a main grid 6 or a welding strip. Different series connection methods can also be used for different types of polarity structures. For example, the first polarity structure 4 and the first polarity structure 4 can be connected in series using a main grid 6, and the second polarity structure 5 and the second polarity structure 5 can be connected in series using a welding strip.

[0076] In an embodiment of the present application, a method of connecting the same type of polar structures on different surfaces in series is provided, which supports the efficient convergence of carriers collected on the same polar structure, increases the number of carrier collection paths, and speeds up the carrier collection speed.

[0077] Next, in the case where different types of doping layer regions are arranged on the second surface, the connection method of the polar structure is further described.

[0078] In an exemplary embodiment, a first type of doped layer region 2 is provided on the second surface; the polarity structure on the first surface is connected in series with the same type of polarity structure on the second surface through a main grid 6 or a welding strip, including: the first polarity structure 4 on the first surface is connected in series with the first polarity structure 4 on the second surface through a main grid 6 or a welding strip.

[0079] Please continue to refer to FIG. 1 . The second surface in FIG. 1 is provided with a first type doped layer region 2, and a first polarity structure 4 is provided in the direction of the first type doped layer region 2 away from the substrate 1. At the same time, the first surface is provided with staggered first polarity structures 4 and second polarity structures 5. Then, on the basis that the first surface and the second surface are both provided with the first polarity structure 4, the first polarity structure 4 on the first surface is connected in series with the first polarity structure 4 on the second surface through the main grid 6, and the first polarity structure 4 on the first surface is connected in series with the first polarity structure 4 on the second surface through the welding strip, so as to transfer the carriers collected on the first polarity structure 4 on the first surface to the first polarity structure 4 on the second surface, thereby improving the speed of collecting carriers by the first polarity structure 4 on the second surface, and thus improving the photoelectric conversion efficiency of the solar cell.

[0080] In an exemplary embodiment, the second surface is provided with a second type doped layer region 3; the polarity structure on the first surface and the polarity structure of the same type on the second surface are connected in series through a main grid 6 or a welding strip, including:

[0081] The second polarity structure 5 on the first surface is connected in series with the second polarity structure 5 on the second surface via a main grid 6 or a welding strip.

[0082] The second surface is provided with a second type of doped layer region 3, and the second type of doped layer region 3 is provided with a second polarity structure 5 in a direction away from the substrate 1. At the same time, the first surface is provided with a staggered arrangement of the first polarity structure 4 and the second polarity structure 5. Then, on the basis that the second polarity structure 5 is provided on both the first surface and the second surface, the second polarity structure 5 on the first surface is connected in series with the second polarity structure 5 on the second surface through the main grid 6, and the second polarity structure 5 on the first surface is connected in series with the second polarity structure 5 on the second surface through the welding strip, so as to transfer the carriers collected on the second polarity structure 5 on the first surface to the second polarity structure 5 on the second surface, thereby improving the speed of the first polarity structure 4 on the second surface collecting the carriers, and then improving the photoelectric conversion efficiency of the solar cell.

[0083] In an exemplary embodiment, the second surface is provided with a first type doped layer region 2 and a second type doped layer region 3; the polarity structure on the first surface and the polarity structure of the same type on the second surface are connected in series through a main grid 6 or a welding strip, including:

[0084] The first polarity structures 4 on the first surface are connected in series with the first polarity structures 4 on the first surface through the main grid 6 or the welding strip; the second polarity structures 5 on the first surface are connected in series with the second polarity structures 5 on the second surface through the main grid 6 or the welding strip.

[0085] Please continue to refer to FIG. 2. The second surface in FIG. 2 is provided with a first type doping layer region 2 and a second type doping layer region 3. The first type doping layer region 2 is provided with a first polarity structure 4 in a direction away from the substrate 1, and the second type doping layer region 3 is provided with a second polarity structure 5 in a direction away from the substrate 1. At the same time, the first surface is provided with staggered first polarity structures 4 and second polarity structures 5. Then, on the basis that both the first surface and the second surface are provided with the first polarity structure 4 and the second polarity structure 5, the first polarity structure 4 on the first surface is connected in series with the first polarity structure 4 on the second surface through a main grid 6 or a welding strip, so as to improve the speed of the first polarity structure 4 on the second surface collecting carriers; the second polarity structure 5 on the first surface is connected in series with the second polarity structure 5 on the second surface through a welding strip, so as to improve the speed of the second polarity structure 5 on the second surface collecting carriers, thereby improving the photoelectric conversion efficiency of the solar cell.

[0086] From the above embodiments, it can be seen that a doped layer region is provided on the surface of the substrate 1, so as to arrange electrodes on the surface of the substrate 1 to realize photoelectric conversion of the battery. The manner of providing the doped layer region on the substrate 1 is further described below.

[0087] In an exemplary embodiment, the area of ​​the first surface is not less than the total area of ​​the doped layer region on the first surface, and / or the area of ​​the second surface is not less than the total area of ​​the doped layer region on the second surface; wherein the orthographic projections of the first polarity structure 4 on the substrate 1 are all located within the orthographic projection range of the first type doped layer region 2, and the orthographic projections of the second polarity structure 5 on the substrate 1 are all located within the orthographic projection range of the second type doped layer region 3.

[0088] The orthographic projections of the first polarity structure 4 on the substrate 1 are all located within the orthographic projection range of the first type doped layer region 2, and the orthographic projections of the second polarity structure 5 on the substrate 1 are all located within the orthographic projection range of the second type doped layer region 3. For the first surface, the sum of the areas of one or more types of doped layer regions on the first surface is less than or equal to the total area of ​​the first surface.

[0089] For the second surface, the sum of the areas of one or more types of doped layer regions disposed on the second surface is less than or equal to the total area of ​​the second surface, that is, the doped layer regions disposed on the second surface may not cover the entire second surface.

[0090] The example diagrams of the battery structure shown in Figures 1 and 2 above are illustrated by taking the example that the area of ​​the first surface is equal to the total area of ​​the doped layer region on the first surface, and the area of ​​the second surface is equal to the total area of ​​the doped layer region on the second surface. In another scenario, please refer to Figures 3 and 4, which are schematic diagrams of the battery structure in which the area of ​​the first surface is not less than the total area of ​​the doped layer region on the first surface, and / or the area of ​​the second surface is not less than the doped layer region on the second surface.

[0091] It should be noted that, when the area of ​​the first surface is not less than the total area of ​​the doped layer region on the first surface, an insulating layer can be wrapped on the surface of the doped layer region on the first surface to prevent oxidation or leakage; when the area of ​​the second surface is not less than the total area of ​​the doped layer region on the second surface, an insulating layer can be wrapped on the surface of the doped layer region on the second surface to prevent oxidation or leakage.

[0092] Please refer to Figures 3 and 4. Figure 3 is a schematic diagram of the battery structure corresponding to the second surface being the light-receiving surface, the first surface being the backlight surface, and the second surface being provided with a first type of doped layer region 2. In Figure 3, the area of ​​the first surface is larger than the total area of ​​the doped layer region on the first surface, and the area of ​​the second surface is equal to the doped layer region on the second surface. Figure 4 is a schematic diagram of the battery structure corresponding to the second surface being the light-receiving surface, the first surface being the backlight surface, and the second surface being provided with a first type of doped layer region 2. In Figure 4, the area of ​​the first surface is not less than the total area of ​​the doped layer region on the first surface, and the area of ​​the second surface is not less than the doped layer region on the second surface.

[0093] It should be noted that Figures 3 and 4 are schematic diagrams of the doping layer region and the surface area of ​​the substrate 1. In practical applications, the type of doping layer region set on the substrate 1 and the above-mentioned area setting rules can also be combined in other ways, for example, the area of ​​the first surface is equal to the total area of ​​the doping layer region on the first surface, the area of ​​the second surface is not less than the doping layer region on the second surface, the area of ​​the first surface is not less than the total area of ​​the doping layer region on the first surface, the area of ​​the second surface is equal to the doping layer region on the second surface, and so on.

[0094] In an exemplary embodiment, a passivation layer is disposed between the doped layer region on the first surface and the first surface, and a transparent conductive layer and an anti-reflection layer are disposed on a side of the doped layer region on the first surface away from the first surface.

[0095] It should be noted that the passivation layer can also be arranged on the side of the doped layer region on the first surface away from the first surface. In one embodiment, a transparent conductive layer, an anti-reflection layer and a passivation layer are arranged on the side of the doped layer region on the first surface away from the first surface.

[0096] In an exemplary embodiment, a passivation layer is disposed between the doped layer region on the second surface and the second surface, and a transparent conductive layer and an anti-reflection layer are disposed on a side of the doped layer region on the second surface away from the second surface.

[0097] It should be noted that the passivation layer can also be disposed on the side of the doped layer region on the second surface away from the second surface. In one embodiment, a transparent conductive layer, an anti-reflection layer and a passivation layer are disposed on the side of the doped layer region on the second surface away from the second surface.

[0098] In the embodiment of the present application, the orthographic projection of the first polarity structure on the substrate is entirely located within the orthographic projection range of the first type of doped layer region, and the orthographic projection surface of the second polarity structure on the substrate is entirely located within the orthographic projection range of the second type of doped layer region, thereby achieving maximum contact between the polarity structure and the doped layer region, thereby expanding the transmission path width of the carriers to the polarity structure and improving the carrier transmission speed.

[0099] In the field of solar cells, the grid line is the main channel for carrier transmission in solar cells and is a key structural element of the polar structure in solar cells. The position, width, shape and material of the grid line are all key factors affecting the conversion efficiency of solar cells.

[0100] In an exemplary embodiment, each polarity structure includes a gate line; the material of the gate line includes metal paste or alloy paste.

[0101] In the embodiment of the present application, metal paste, such as copper paste, silver paste, etc., or alloy paste, such as silver-platinum paste, etc., can be used to make the secondary grid. Such a grid line production process is suitable for the existing battery manufacturing process to facilitate the mass production of solar cells and save production costs.

[0102] In an exemplary embodiment, one of the first polarity structure 4 and the second polarity structure 5 has the same polarity as the substrate 1 , and the other polarity structure has a different polarity from the substrate 1 ; the first polarity structure 4 or the second polarity structure 5 is wrapped with an insulating layer 7 .

[0103] Furthermore, it should be noted that the doping region where the polar structure wrapped by the insulating layer 7 is located is wrapped by the insulating layer 7 to prevent oxidation or leakage.

[0104] Please refer to FIG. 1 to FIG. 4 , the second polarity structure 5 on the doped layer region on the first surface is wrapped with an insulating layer 7 , and the corresponding doped region on the second polarity structure 5 is wrapped with the insulating layer 7 .

[0105] As can be seen from FIG. 1 to FIG. 4 , the side of the substrate 1 can be wrapped with an insulating layer 7 of the same material as the polar structure, and of course different insulating materials can also be used, which is not limited.

[0106] It is emphasized again that Figures 1 to 4 are schematic diagrams of the electrode structure of a solar cell, not hierarchical schematic diagrams of a solar cell. In actual scenarios, in addition to the doped layer region, the light-receiving surface and the backlight surface of the substrate 1 are also provided with an anti-reflection layer, a transparent conductive layer, or a passivation layer, etc.

[0107] The above is a description of the embodiments related to the solar cell structure. Based on this, the present application also provides an embodiment of a method for preparing the solar cell.

[0108] In an exemplary embodiment, as shown in FIG5 , the present application further provides a method for preparing a solar cell, the method comprising:

[0109] S501, providing a substrate, wherein the substrate includes a light-receiving surface and a backlight surface opposite to each other.

[0110] S502, forming first-type doping layer regions and second-type doping layer regions arranged alternately on a first surface of the substrate; the first surface is a light-receiving surface or a backlight surface.

[0111] S503, forming a first type doping layer region and / or a second type doping layer region on a second surface of the substrate; the second surface is a surface of the light-receiving surface and the backlight surface other than the first surface.

[0112] S504, generating a first polarity structure in a direction of the first type doping layer region away from the substrate, and generating a second polarity structure in a direction of the second type doping layer region away from the substrate.

[0113] In the embodiments of the present application, the structure of the solar cell prepared according to the preparation method can refer to the above embodiments. The material of the substrate can be amorphous, microcrystalline, polycrystalline, single crystal silicon or compound semiconductor, etc. The doping type of the substrate of the solar cell, the first type doping layer region, and the second type doping layer region can be N-type doping or P-type doping.

[0114] A first type of doped layer region and a second type of doped layer region are formed on the first surface of the substrate in an alternating manner. The doping types of the first type of doped layer region and the second type of doped layer region are opposite. A first polarity structure is formed in the first type of doped layer region in a direction away from the substrate, and a second polarity structure is formed in the second type of doped layer region in a direction away from the substrate. The polarities of the first polarity mechanism and the second polarity structure are opposite, and the polarity of the first polarity mechanism or the second polarity structure is the same as the polarity of the substrate, so that the first surface has a dual-electrode structure.

[0115] On this basis, a first type of doped layer region can be formed on the second surface of the substrate, and a first polarity structure can be formed on the first type of doped layer region to upgrade the battery structure to a three-electrode system structure; a second type of doped layer region can be formed on the second surface of the substrate, and a second polarity structure can be formed on the second type of doped layer region to upgrade the battery structure to a three-electrode system structure; a first type of doped layer region and a second type of doped layer region can be formed on the second surface of the substrate, and a first polarity structure can be formed on the first type of doped layer region, and a second polarity structure can be formed on the second type of doped layer region to upgrade the battery structure to a four-electrode system structure.

[0116] In the embodiment of the present application, two types of doped layer regions are first formed on the first surface of the substrate to form a first polarity structure and a second polarity structure, thereby ensuring that the solar cell has dual electrodes on a single side, and the first type of doped layer region and / or the second type of doped layer region are further formed on the second surface of the substrate to form a first polarity structure and / or a second polarity structure, thereby upgrading the structure of the solar cell to a three-electrode or four-electrode system structure and improving the photoelectric conversion efficiency of the cell.

[0117] In an exemplary embodiment, each polarity structure includes a gate line; the method further includes:

[0118] A grid line is made on the surface of each polar structure; the making method includes at least one of screen printing, laser transfer and electroplating.

[0119] The gate lines and partitions arranged on the light-receiving surface or the backlight surface of the substrate may be the same or different.

[0120] In the battery preparation process, metal grid lines are made according to metal slurry or alloy slurry, and are printed on the surface of the polar structure by screen printing, laser transfer, or electroplating, so that the polar structure can collect carriers more efficiently and increase the carrier transmission speed.

[0121] In an exemplary embodiment, a battery assembly is provided, which includes the solar cell in the aforementioned embodiment, or includes a solar cell prepared according to the preparation method in the aforementioned embodiment. The specific structure and principle of the solar cell, and the specific steps of the preparation method can refer to the aforementioned embodiment, and this embodiment will not be repeated here.

[0122] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0123] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0124] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0125] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A solar cell, characterized in that: The solar cell comprises: A substrate, the substrate comprising a light-receiving surface and a backlight surface opposite to each other; The first surface is provided with first-type doped layer regions and second-type doped layer regions arranged in a staggered manner; the first surface is the light-receiving surface or the backlight surface; The second surface is provided with a first type doping layer region and / or a second type doping layer region; the second surface is a surface of the light-receiving surface and the backlight surface other than the first surface; A first polarity structure is arranged in a direction of the first type doping layer region away from the substrate; The second polarity structure is arranged in a direction where the second type doping layer region is away from the substrate.

2. The solar cell according to claim 1, characterized in that The polar structure on the first surface and the polar structure of the same type on the second surface are connected in series through a main grid or a welding strip.

3. The solar cell according to claim 2, characterized in that: The second surface is provided with the first type doping layer region; The polar structure on the first surface and the polar structure of the same type on the second surface are connected in series through a main grid or a welding strip, including: The first polarity structure on the first surface and the first polarity structure on the second surface are connected in series through a main grid or a welding strip.

4. The solar cell according to claim 2, characterized in that: The second surface is provided with the second type doping layer region; the polarity structure on the first surface is connected in series with the polarity structure of the same type on the second surface through a main grid or a welding strip, including: The second polarity structure on the first surface and the second polarity structure on the second surface are connected in series through a main grid or a welding strip.

5. The solar cell according to claim 2, characterized in that: The second surface is provided with the first type doping layer region and the second type doping layer region; The polar structure on the first surface and the polar structure of the same type on the second surface are connected in series through a main grid or a welding strip, including: The first polarity structure on the first surface and the first polarity structure on the second surface are connected in series via a main grid or a welding strip; The second polarity structure on the first surface and the second polarity structure on the second surface are connected in series through a main grid or a welding strip.

6. The solar cell according to any one of claims 1 to 5, characterized in that: The area of ​​the first surface is not less than the total area of ​​the doped layer region on the first surface, and / or the area of ​​the second surface is not less than the total area of ​​the doped layer region on the second surface; The orthographic projections of the first polarity structures on the substrate are all located within the orthographic projection range of the first type doping layer region, and the orthographic projection surfaces of the second polarity structures on the substrate are all located within the orthographic projection range of the second type doping layer region.

7. The solar cell according to any one of claims 1 to 5, characterized in that: A passivation layer is disposed between the doped layer region on the first surface and the first surface, and a transparent conductive layer and an anti-reflection layer are disposed on a side of the doped layer region on the first surface away from the first surface.

8. The solar cell according to any one of claims 1 to 5, characterized in that: A passivation layer is arranged between the doped layer region on the second surface and the second surface, and a transparent conductive layer and an anti-reflection layer are arranged on a side of the doped layer region on the second surface away from the second surface.

9. The solar cell according to any one of claims 1 to 5, characterized in that: Each polar structure includes a grid line; the material of the grid line includes metal paste or alloy paste.

10. The solar cell according to any one of claims 1 to 5, characterized in that: One of the first polarity structure and the second polarity structure has the same polarity as the substrate, and the other polarity structure has a different polarity from the substrate; The first polarity structure or the second polarity structure is wrapped with an insulating layer.

11. A method for preparing a solar cell, characterized in that: The method comprises: Providing a substrate, the substrate comprising a light-receiving surface and a backlight surface opposite to each other; Forming staggered first-type doped layer regions and second-type doped layer regions on the first surface of the substrate; the first surface is the light-receiving surface or the backlight surface; forming a first type doped layer region and / or a second type doped layer region on a second surface of the substrate; the second surface is a surface of the light-receiving surface and the backlight surface other than the first surface; A first polarity structure is generated in the direction of the first type doping layer region away from the substrate, and a second polarity structure is generated in the direction of the second type doping layer region away from the substrate.

12. The method according to claim 11, characterized in that Each polarity structure includes a grid line; the method further includes: A grid line is made on the surface of each polar structure; the making method includes at least one of screen printing, laser transfer and electroplating.

13. A battery assembly, characterized in that: The battery assembly includes the solar cell according to any one of claims 1 to 10, or includes a solar cell prepared by the preparation method according to claim 11 or 12.

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