CN222126545U - Solar cell and photovoltaic module - Google Patents

Abstract

The present application relates to a solar cell and a photovoltaic module, which is beneficial to improving the photoelectric conversion efficiency and assembly yield of the photovoltaic module. The solar cell includes a power generation unit, a first electrode and a second electrode, the power generation unit has a light-facing surface and a backlight surface arranged opposite to each other, and a first side surface and a second side surface connecting the light-facing surface and the backlight surface, the first electrode is arranged on the light-facing surface and extends to the first side surface, and the second electrode is arranged on the backlight surface and extends to the second side surface.

Description

Solar cell and photovoltaic module

Technical Field

The application relates to the field of photovoltaics, in particular to a solar cell and a photovoltaic module.

Background

With the increasing situation of energy shortage, the development and utilization of renewable energy are urgent. Among the renewable energy sources, solar energy has the outstanding advantages of no exhaustion risk, safety, reliability, no noise, no pollution emission, no limitation of resource distribution regions in application and the like.

Photovoltaic power generation is a technology that uses the photovoltaic effect of a semiconductor interface to directly convert light energy into electrical energy. The photovoltaic module is a core unit of solar power generation and is formed by packaging a plurality of solar cells.

In the related art, a plurality of solar cells are commonly connected together using a solder ribbon. But the shielding of the solder strip affects the photoelectric conversion efficiency. And as the thickness of the silicon wafer is thinned, the welding of the welding strip and the solar cell is more difficult, the problems of cold joint, welding spot deviation and the like are more easy to occur, and the assembly yield is not easy to improve.

Disclosure of utility model

Based on the above problems, the application provides a solar cell and a photovoltaic module, which are beneficial to improving the photoelectric conversion efficiency and the assembly yield of the photovoltaic module.

An embodiment of a first aspect of the present application provides a solar cell, including a power generating unit, a first electrode and a second electrode, where the power generating unit has a light-facing surface and a light-backing surface that are disposed opposite to each other, and a first side surface and a second side surface that connect the light-facing surface and the light-backing surface, the first electrode is disposed on the light-facing surface and extends to the first side surface, and the second electrode is disposed on the light-backing surface and extends to the second side surface.

In some embodiments, the first electrode includes a first sub-electrode located on the light-facing surface and a second sub-electrode located on the first side surface, the second electrode includes a third sub-electrode located on the backlight surface and a fourth sub-electrode located on the second side surface, the first sub-electrode and the fourth sub-electrode have a first gap therebetween, and the second sub-electrode and the third sub-electrode have a second gap therebetween.

In some embodiments, the solar cell further comprises a first insulating layer filled in the first gap and a second insulating layer filled in the second gap.

In some embodiments, the solar cell is a P-type solar cell or an N-type solar cell.

In some embodiments, the power generation unit includes a substrate, and a doped conductive layer, a first passivation layer and a first dielectric layer sequentially stacked on one side of the substrate near the light-facing surface, where the first electrode is electrically connected to the doped conductive layer;

The power generation unit further comprises a passivation contact layer and a second passivation layer which are sequentially stacked on one side of the substrate close to the backlight surface, and the second electrode is electrically connected with the passivation contact layer.

In some embodiments, the doped conductive layer, the first passivation layer, and the first dielectric layer each extend to at least a partial region of the first side.

In some embodiments, the passivation contact layer and the second passivation layer each extend to at least a partial region of the second side.

In some embodiments, a surface of the substrate adjacent to the light-facing surface is further provided with a textured structure, and the textured structure further extends to at least a partial region of the first side surface.

An embodiment of the second aspect of the application proposes a photovoltaic module comprising at least one cell string comprising at least two solar cells as described in the first aspect.

In some embodiments, the cell string further comprises a conductive connection disposed between the first side and the second side of two adjacent solar cells, the conductive connection configured to connect a first electrode on the first side and a second electrode on the second side to electrically connect two adjacent solar cells.

The solar cell of the present application also has two types of electrodes on the first side and the second side. The two electrodes on the side face are in butt joint, so that the serial connection between the two adjacent solar cells can be realized without using a welding belt. Therefore, the problems of shadow welding, welding spot deviation and the like cannot occur, and the photoelectric conversion efficiency of the solar cell is improved, and the assembly efficiency and the assembly yield of the solar cell are improved.

Drawings

In order to more clearly illustrate the embodiments of the application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural view of a solar cell according to an embodiment of the present application;

FIG. 2 is a schematic cross-sectional view of the structure at E-E in FIG. 1;

FIG. 3 is a schematic view of a cross-sectional structure of the structure at E-E in FIG. 1;

fig. 4 is a schematic structural view of a power generation unit of a solar cell according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of a photovoltaic module according to an embodiment of the present application.

The reference numerals are as follows:

10 a-cell strings;

100-solar cell, 110-power generation unit, 110 a-light facing surface, 110 b-backlight surface, 110 c-first side surface, 110 d-second side surface, 120-first electrode, 121-first sub-electrode, 122-second sub-electrode, 130-second electrode, 131-third sub-electrode, 132-fourth sub-electrode;

111-substrate, 112-doped conductive layer, 113-first passivation layer, 114-first dielectric layer, 115-passivation contact layer, 116-second passivation layer;

140-first insulating layer, 150-second insulating layer, 200-conductive connection.

Detailed Description

In order that the above objects, features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the application, whereby the application is not limited to the specific embodiments disclosed below.

In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed, mechanically connected, electrically connected, directly connected, indirectly connected through an intervening medium, or in communication between two elements or in an interaction relationship between two elements, unless otherwise explicitly specified. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present application, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.

An embodiment of the first aspect of the present application proposes a solar cell 100. As shown in fig. 1 and 2, the solar cell 100 includes a power generating unit 110, a first electrode 120 and a second electrode 130, the power generating unit 110 has a light-facing surface 110a and a backlight surface 110b which are disposed opposite to each other, and a first side 110c and a second side 110d which connect the light-facing surface 110a and the backlight surface 110b, the first electrode 120 is disposed on the light-facing surface 110a and extends to the first side 110c, and the second electrode 130 is disposed on the backlight surface 110b and extends to the second side 110 d.

The solar cell 100 of the present application includes a power generation unit 110, a first electrode 120, and a second electrode 130. The power generation unit 110 refers to a structure in which a photovoltaic effect occurs to convert light energy into electric energy. When light is irradiated onto the power generation unit 110, electron-hole pairs are generated inside thereof. And, electrons flow into the n region and holes flow into the p region, thereby forming a potential difference at both sides of the power generation unit 110, and thus generating electric energy. As shown in fig. 1, the power generation unit 110 has a light-facing surface 110a and a backlight surface 110b disposed opposite to each other. As shown in fig. 2, the power generation unit 110 further has a first side 110c and a second side 110d that connect the light-facing surface 110a and the backlight surface 110b. It should be noted that fig. 2 illustrates that the first side 110c and the second side 110d are two opposite sides, but in practice, two sides may be two sides that are not opposite sides, which is not limited by the present application.

The first electrode 120 and the second electrode 130 serve to draw out current of both sides of the power generation unit 110 for connection with external components such as a control board. Alternatively, the first electrode 120 may be a positive electrode and the second electrode 130 may be a negative electrode.

In the related art, the first electrode 120 and the second electrode 130 are provided with solder strip connection points, and the solder strips pass through the solder strip connection points to connect two adjacent solar cells, so as to realize the serial connection of the solar cells. And the welding strip has a certain width, and the shielding of the welding strip can influence the photoelectric conversion efficiency. In addition, as the thickness of the power generation unit 110 is reduced, the difficulty of welding the welding strip is increased, and the situations of cold joint, welding spot offset and the like are more likely to occur, so that the assembly efficiency and the assembly yield are not improved.

Thus, the solar cell 100 of the present application improves the first electrode 120 and the second electrode 130. Specifically, the first electrode 120 is disposed on the light-facing surface 110a and extends to the first side 110c, and the second electrode 130 is disposed on the backlight surface 110b and extends to the second side 110 d. That is, the present application designs the side surfaces of the solar cell 100 to be polarized, and the first side surface 110c and the second side surface 110d are also provided with two electrodes of the solar cell 100. The two electrodes on the side face are butted, so that the adjacent two solar cells 100 can be connected in series without using a welding belt. In this way, the solder strip is not needed, the light is not blocked, and the problems of cold joint, solder joint offset and the like are not generated, so that the photoelectric conversion efficiency of the solar cell 100 is improved, and the assembly efficiency and the assembly yield of the solar cell 100 are improved.

In the solar cell 100, as shown in fig. 1, the first electrode 120 and the second electrode 130 may be in the form of electrode grids (main grid and thin grid). Or the first electrode 120 is in the form of an electrode grid line (main grid line and/or thin grid line), the second electrode 130 is in the form of a whole electrode, etc., which is not limited in the present application and can be flexibly arranged according to the type of the battery.

In some embodiments, as shown in fig. 2, the first electrode 120 includes a first sub-electrode 121 located on the light-facing surface 110a and a second sub-electrode 122 located on the first side 110c, the second electrode 130 includes a third sub-electrode 131 located on the backlight surface 110b and a fourth sub-electrode 132 located on the second side 110d, a first gap S1 is provided between the first sub-electrode 121 and the fourth sub-electrode 132, and a second gap S2 is provided between the second sub-electrode 122 and the third sub-electrode 131.

In the present embodiment, since the first electrode 120 also extends onto the first side 110c, the second electrode 130 also extends onto the second side 110 d. Accordingly, the first electrode 120 and the second electrode 130 are equally divided into two parts. Specifically, the first electrode 120 includes a first sub-electrode 121 located on the light-facing surface 110a and a second sub-electrode 122 located on the first side 110 c. The second electrode 130 includes a third sub-electrode 131 located on the backlight surface 110b and a fourth sub-electrode 132 located on the second side surface 110 d. Further, since the first side 110c connects the backlight 110b and the light-facing surface 110a. Therefore, a first gap S1 is provided between the first sub-electrode 121 and the fourth sub-electrode 132, and a second gap S2 is provided between the second sub-electrode 122 and the third sub-electrode 131. In this way, it is possible to avoid a short circuit between electrodes of different polarities, thereby contributing to an improvement in the safety of the solar cell 100.

In some embodiments, as shown in fig. 2 and 3, the solar cell 100 further includes a first insulating layer 140 filled in the first gap S1 and a second insulating layer 150 filled in the second gap S2. In this way, by providing the first insulating layer 140 and the second insulating layer 150, electrodes of different polarities can be insulated from each other, thereby contributing to further improvement in the safety of the solar cell 100. Alternatively, the material of the first insulating layer 140 and the second insulating layer 150 may be at least one of aluminum oxide, silicon nitride, or silicon oxynitride.

In some embodiments, the solar cell 100 is a P-type solar cell 100 or an N-type solar cell 100. The solar cell 100 in the embodiment of the application may be a P-type solar cell 100 or an N-type solar cell 100. The P-type solar cell 100 is a cell in which an n+/P structure is fabricated on a P-type silicon wafer (doped with 3-valent elements). The N-type solar cell 100 refers to a cell in which a p+/N structure is fabricated on an N-type silicon wafer (doped with 5-valent elements) using a boron diffusion process.

Alternatively, when the solar cell 100 is a P-type solar cell, it may be a PERC (Passivated Emitter Rear Cell) cell in particular. When the solar cell 100 is an N-type solar cell 100, it may be specifically one of TOPCon (Tunnel Oxide Passivated Contact) cells, HJT (junction WITH INTRINSIC THIN-film) cells, IBC (Interdigitated Back Contact) cells, and the like.

In a specific embodiment, as shown in fig. 4, the power generating unit 110 includes a substrate 111, and a doped conductive layer 112, a first passivation layer 113, and a first dielectric layer 114 sequentially stacked on a side of the substrate 111 near the light-facing surface 110a, where the first electrode 120 is electrically connected to the doped conductive layer 112. The power generation unit 110 further includes a passivation contact layer 115 and a second passivation layer 116 sequentially stacked on a side of the substrate 111 near the backlight surface 110b, and the second electrode 130 is electrically connected to the passivation contact layer 115.

In this embodiment, the solar cell 100 is TOPCon cells. The substrate 111 is an N-type semiconductor. At this time, the doped conductive layer 112 is doped with a P-type element, and may be, for example, a boron-doped conductive layer 112 (also referred to as a p+ -type emitter). Thus, the doped conductive layer 112 may form a PN junction with the substrate 111, so that the photovoltaic effect of the solar cell 100 may occur.

The first passivation layer 113 and the first dielectric layer 114 are sequentially stacked on the doped conductive layer 112, and the first passivation layer 113 plays a surface passivation role in the solar cell 100. Alternatively, the first passivation layer 113 may have a single-layer structure or a multi-layer structure, and the material of the first passivation layer 113 may be at least one of aluminum oxide, silicon nitride, or silicon oxynitride. In addition, the first passivation layer 113 may be formed by chemical deposition.

The first dielectric layer 114 may have an anti-reflection effect on the light-facing surface 110a of the solar cell 100. Alternatively, the first dielectric layer 114 may have a single-layer or multi-layer structure. In the first dielectric layer 114 of the multilayer structure, the material of each layer may be silicon oxide, silicon nitride or silicon oxynitride.

The passivation contact layer 115 and the second passivation layer 116 are sequentially stacked on the substrate 111 at a side close to the backlight surface 110 b. The passivation contact layer 115 may reduce recombination of carriers on the surface of the substrate 111, thereby increasing an open circuit voltage of the solar cell 100 and improving photoelectric conversion efficiency of the solar cell 100. The second passivation layer 116 plays a surface passivation role in the solar cell 100.

The passivation contact layer 115 may include a tunneling oxide layer (not shown) and a polysilicon doped conductive layer (not shown) sequentially stacked on a side of the substrate 111 near the backlight surface 110 b. Alternatively, the material of the tunneling oxide layer may be a dielectric material, for example, at least one of silicon oxide, magnesium fluoride, silicon oxide, amorphous silicon, polysilicon, silicon carbide, silicon nitride, silicon oxynitride, aluminum oxide, or titanium oxide. The second passivation layer 116 may have a single-layer or multi-layer structure, and the material of the second passivation film layer 116 may be silicon oxide, silicon nitride, silicon oxynitride, or the like.

The first electrode 120 is electrically connected to the doped conductive layer 112, and the second electrode 130 is electrically connected to the passivation contact layer 115, thereby forming the positive and negative electrodes of the solar cell 100.

Optionally, a second dielectric layer may be disposed on a side surface of the second passivation layer 116 facing away from the passivation contact layer 115. In this way, the reflectance of the backlight of the solar cell 100 against sunlight can be reduced, and the absorptivity of the back of the solar cell 100 against sunlight can be improved.

In fig. 4, in order to show that the first electrode 120 is electrically connected to the doped conductive layer 112, and not to form a barrier to other structures in the drawing, a dashed box is used to indicate a relationship that the first electrode 120 is electrically connected to the doped conductive layer 112.

In some embodiments, as shown in fig. 4, doped conductive layer 112, first passivation layer 113, and first dielectric layer 114 all extend to at least a partial region of first side 110 c. In this embodiment, the doped conductive layer 112, the first passivation layer 113 and the first dielectric layer 114 all extend to at least a partial region of the first side 110 c. In this way, on the one hand, recombination and light reflection at the interface where the first side 110c is located can be reduced, and the efficiency of the solar cell 100 can be improved. On the other hand, a superior passivation effect on the first side 110c of the solar cell 100 can also be achieved.

In some embodiments, as shown in fig. 4, both passivation contact layer 115 and second passivation layer 116 extend to at least a partial region of second side 110 d. In this embodiment, the passivation contact layer 115 and the second passivation layer 116 each extend to at least a partial region of the second side 110 d. In this way, on the one hand, recombination at the interface where the second side 110d is located can be reduced, improving the efficiency of the solar cell 100. On the other hand, a superior passivation effect on the second side 110d of the solar cell 100 can also be achieved.

In some embodiments, as shown in fig. 4, a surface of the substrate 111 near the light-facing surface 110a is further provided with a texture 1111, and the texture 1111 further extends to at least a partial area of the first side 110 c. In this embodiment, the substrate 111 is further provided with a suede structure 1111, so that reflection and refraction of light can be reduced, which is beneficial to further improving the light utilization rate and photoelectric conversion efficiency of the solar cell 100.

Embodiments of the second aspect of the present application provide a photovoltaic module 10. As shown in fig. 5, the photovoltaic module 10 includes at least one cell string 10a, and the cell string 10a includes at least two solar cells 100 according to the first aspect.

The photovoltaic module 10 of the present application uses the solar cell 100 according to the first aspect. When the tandem connection of the adjacent two solar cells 100 is performed, a solder ribbon may not be required. In this way, the light is not blocked, and the problems of cold joint, welding spot deviation and the like are not caused, so that the photoelectric conversion efficiency of the solar cell 100 is improved, and the assembly efficiency and the assembly yield of the solar cell 100 are improved.

In some embodiments, as shown in fig. 5, the cell string 10a further includes a conductive connection 200 disposed between the first side 110c and the second side 110d of the adjacent two solar cells 100, the conductive connection 200 being configured to connect the first electrode 120 on the first side 110c and the second electrode 130 on the second side 110d to electrically connect the adjacent two solar cells 100. In this embodiment, the first side 110c and the second side 110d of two adjacent solar cells 100 refer to that, in the two adjacent solar cells 100, the first side 110c of the first solar cell 100 and the second side 110d of the second solar cell 100 are in butt joint. The present embodiment realizes the serial connection of two adjacent solar cells 100 through the conductive connection portion 200, rather than the solder strip manner in the related art, which is beneficial to improving the process convenience. Meanwhile, the conductive connection part 200 is positioned on the side surface, so that the light can not be blocked, and the performance of the photovoltaic module 10 can be improved.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the claims. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims (10)

1. The solar cell is characterized by comprising a power generation unit, a first electrode and a second electrode, wherein the power generation unit is provided with a light-facing surface, a backlight surface, a first side surface and a second side surface, the light-facing surface and the backlight surface are oppositely arranged, the first side surface and the second side surface are connected, the first electrode is arranged on the light-facing surface and extends to the first side surface, and the second electrode is arranged on the backlight surface and extends to the second side surface.

2. The solar cell of claim 1, wherein the first electrode comprises a first sub-electrode located on the light-facing surface and a second sub-electrode located on the first side surface, the second electrode comprises a third sub-electrode located on the backlight surface and a fourth sub-electrode located on the second side surface, the first sub-electrode and the fourth sub-electrode have a first gap therebetween, and the second sub-electrode and the third sub-electrode have a second gap therebetween.

3. The solar cell of claim 2, further comprising a first insulating layer filled in the first gap and a second insulating layer filled in the second gap.

4. The solar cell of claim 1, wherein the solar cell is a P-type solar cell or an N-type solar cell.

5. The solar cell according to claim 1, wherein the power generation unit comprises a substrate, and a doped conductive layer, a first passivation layer and a first dielectric layer which are sequentially stacked on one side of the substrate close to the light-facing surface, and the first electrode is electrically connected with the doped conductive layer;

The power generation unit further comprises a passivation contact layer and a second passivation layer which are sequentially stacked on one side of the substrate close to the backlight surface, and the second electrode is electrically connected with the passivation contact layer.

6. The solar cell of claim 5, wherein the doped conductive layer, the first passivation layer, and the first dielectric layer each extend to at least a partial region of the first side.

7. The solar cell of claim 5, wherein the passivation contact layer and the second passivation layer each extend to at least a partial region of the second side.

8. The solar cell according to any one of claims 5-7, wherein a side surface of the substrate adjacent to the light-facing surface is further provided with a textured structure, the textured structure further extending to at least a partial area of the first side surface.

9. A photovoltaic module comprising at least one cell string comprising at least two solar cells according to any one of claims 1-8.

10. The photovoltaic module of claim 9, wherein the string of cells further comprises a conductive connection disposed between the first and second sides of two adjacent solar cells, the conductive connection configured to connect a first electrode on the first side and a second electrode on the second side to electrically connect two adjacent solar cells.